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Sample records for enhanced ct scan

  1. Evaluation of delayed contrast-enhanced CT scan in diagnosing hilar cholangiocarcinoma

    International Nuclear Information System (INIS)

    Li Jianding; Liang Chenyang; Zhang Hua; Zhang Yuezhen; Li Rui

    2001-01-01

    Objective: To assess the diagnostic value of delayed CT contrast enhancement patterns in hilar cholangiocarcinoma based on two-phased dynamic incremental CT scanning. Methods: Fifty-two patients with suspected hilar tumor and bile duct obstruction underwent spiral CT scan. The scan time for one revolution of the X-ray tube was 1 second. To elucidate the delay time for optimal imaging, all proved cholangiocarcinoma with delayed (6, 8, 10, 15, 20, 30 minutes) post-equilibrium-phase contrast-enhanced CT scans were acquired with unenhanced, dynamic contrast-enhanced, and delayed images. Degree of delayed enhancement was compared with that of surrounding liver parenchyma. Results: (1) 8-15 minutes after IV injection of contrast material was the delay time for optimal imaging. (2) Of 29 cholangiocarcinomas, the early CT showed hypo-attenuating (lower than that of liver parenchyma) in 23 tumors, iso-attenuating (equal to that of the liver) in 4 tumors, and hyper-attenuating (higher than that of liver) in 2 tumors. The delayed CT scan showed iso-attenuating in 8 tumors, hyper-attenuating in 21 tumors, and no hypo-attenuating. Most of delay imaging of hilar cholangiocarcinoma may appear hyper-attenuating (U = -4.3073, P 2 = 9.09, P < 0.01). Conclusion: When assessing hilar tumor, delayed CT contrast enhancement patterns based on two-phase dynamic incremental CT scans is useful in the detection and characterization of hilar cholangiocarcinoma

  2. The value of contrast-enhanced CT scan in prediction of development of contusional hemorrhage

    International Nuclear Information System (INIS)

    Yokoyama, Kazuhiro; Kyoi, Kikuo; Sakaki, Toshisuke; Kinugawa, Kazuhiko; Morimoto, Tetsuya

    1983-01-01

    It is often experienced that even if there are no significant findings on the initial plain CT scan in the patient with cerebral contusion, the patient has thereafter a serious clinical course and requires emergency operation for so-called contusional hemorrhage. In order to predict of the development of contusional hemorrhage we performed contrast-enhanced CT scan at the time of patient's arrival within 12 hours after injury, if there was cerebral contusion on the initial plain CT scan, and repeated plain CT scan 24 hours after the contrast-enhanced CT scan. If enhancement was demonstrated on the contrastenhanced CT scan, we predicted the development of contusional hemorrhage and if not demonstrated, we predicted no more development of contusional hemorrhage and then we studied the correlation between the prediction and the plain CT 24 hours after the contrast-enhanced CT scan. The results were as follows: 1) The prediction was correct in 13 cases out of 16 cases in which the development of contusional hemorrhage was observed. In 18 cases where no development of contusional hemorrhage was observed, the prediction was correct without exception. 2) Most of the cases in which enhancement was demonstrated were ones examined not before 3 hours after injury. 3) The extent of enhancement shown on contrastenhanced CT scan was well consistent with that of contusional hemorrhage on the plain CT scan 24 hours after the contrast-enhanced CT scan. From these results, the contrast-enhanced CT scan in acute stage of head injury was considered to by very useful in prediction of the development of contusional hemorrhage. (author)

  3. Contrast enhanced CT-scans are not comparable to non-enhanced scans in emphysema quantification

    International Nuclear Information System (INIS)

    Heussel, C.P.; Kappes, J.; Hantusch, R.; Hartlieb, S.; Weinheimer, O.; Kauczor, H.-U.; Eberhardt, R.

    2010-01-01

    Systemic, interventional and surgical treatments have gone new ways in treatment of emphysema. For longitudinal therapy monitoring and as end-points for clinical trials, quantification of the disease is necessary. Sensitive, easy to measure, as well as stable and reproducible parameters have to be characterized. One parameter that might affect emphysema quantification is IV contrast enhancement, which might also be indicated. Whether or not the contrast enhanced scan is also suited for emphysema quantification or an additional scan is necessary, a retrospective analysis of 12 adult patients undergoing clinically indicated both, a non-enhanced and enhanced thin section MSCT within a week (median 0 days, range 0-4 days) was done. The in-house YACTA software was used for automatic quantification of lung and emphysema volume, emphysema index, mean lung density, and 5th, 10th, 15th percentile. After IV contrast administration, the median CT derived lung volume decreased mild by 1.1%, while median emphysema volume decreased by relevant 11%. This results in a decrease of median emphysema index by 9%. The median lung density (15th percentile) increased after contrast application by 18 HU (9 HU). CT quantification delivers emphysema values that are clearly affected by IV contrast application. The detected changes after contrast application show the results of higher density in the lung parenchyma. Therefore the amount of quantified emphysema is reduced and the lung density increased after contrast enhancement. In longitudinal analyses, non-enhanced scans should be the reference, while enhanced scans cannot be used.

  4. Osmotic blood-brain barrier modification: clinical documentation by enhanced CT scanning and/or radionuclide brain scanning

    International Nuclear Information System (INIS)

    Neuwelt, E.A.; Specht, H.D.; Howieson, J.; Haines, J.E.; Bennett, M.J.; Hill, S.A.; Frenkel, E.P.

    1983-01-01

    Results of initial clinical trials of brain tumor chemotherapy after osmotic blood-brain barrier disruption are promising. In general, the procedure is well tolerated. The major complication has been seizures. In this report, data are presented which indicate that the etiology of these seizures is related to the use of contrast agent (meglumine iothalamate) to monitor barrier modification. A series of 19 patients underwent a total of 85 barrier modification procedures. Documentation of barrier disruption was monitored by contrast-enhanced computed tomographic (CT) scanning, radionuclide brain scanning, or a combination of both techniques. In 56 procedures (19 patients) monitored by enhanced CT, seizures occurred a total of 10 times in eight patients. Twenty-three barrier modification procedures (in nine of these 19 patients) documented by nuclear brain scans alone, however, resulted in only one focal motor seizure in each of two patients. In eight of the 19 patients who had seizures after barrier disruption and enhanced CT scan, four subsequently had repeat procedures monitored by radionuclide scan alone. In only one of these patients was further seizure activity noted; a single focal motor seizure was observed. Clearly, the radionuclide brain scan does not have the sensitivity and spatial resolution of enhanced CT, but at present it appears safer to monitor barrier modification by this method and to follow tumor growth between barrier modifications by enhanced CT. Four illustrative cases showing methods, problems, and promising results are presented

  5. Reducing radiation dose in liver enhanced CT scan by setting mAs according to plain scan noise

    International Nuclear Information System (INIS)

    Yang Shangwen; He Jian; Yang Xianfeng; Zhou Kefeng; Xin Xiaoyan; Hu Anning; Zhu Bin

    2013-01-01

    Objective: To investigate the feasibility of setting mAs in liver enhanced CT scan according to plain scan noise with fixed mA CT scanner, in order to reduce the radiation dose. Methods: One hundred continuous patients underwent liver enhanced CT scan (group A) prospectively. Two hundred and fifty mAs was used in plain and enhanced CT scans. Noises of plain and venous phase CT images were measured, and the image quality was evaluated. The equation between mAs of enhanced scan and noise of plain scan image was derived. Another 100 continuous patients underwent liver enhanced CT scan (group B). Enhanced scan mAs was calculated from noise on plain scan by using the equation above. Noises on venous phase images were measured and the image quality was measured. Based on body mass index (BMI), patients in groups A and B were divided into three subgroups respectively: BMI < 18.5 kg/m 2 , 18.5 kg/m 2 ≤ BMI < 25.0 kg/m 2 and BMI ≥ 25.0 kg/m 2 . Image quality score was compared with nonparametric rank sum test, CT dose index (CTDI) and effective dose (ED) were measured and compared between each subgroup with 2 independent samples t or t' test. Results: The equation between enhanced scan mAs (mAsX) and plain scan noise (SDp) was as follows: mAsX = mAs1 × [(0.989 × SDp + 1.06) /SDx] 2 , mAs1 = 250 mAs, SDx = 13. In patients with BMI < 18.5 kg/m 2 , ED of group A [(6.86 ± 0.38) mSv, n = 12] was significantly higher than group B [(2.66 ± 0.46) mSv, n = 10)] (t = 18.52, P < 0.01). In patients with 18.5 kg/m 2 ≤ BMI < 25.0 kg/m 2 , ED of group A [(7.08 ± 0.91) mSv, n = 66] was significantly higher than group B [(4.50 ± 1.41) mSv, n = 73] (t' = 10.57, P < 0.01). In patients with BMI ≥ 25.0 kg/m 2 , there was no significant difference between EDs of group A (7.54 ± 0.62 mSv, n = 22) and group B [(8.19 ± 3.16) mSv, n = 17] (t' = 0.89, P = 0.39). Image quality of 5 patients in group A and none in group B did not meet the diagnostic requirement

  6. Prevalence and characteristics of intravertebral enhancement on contrast-enhanced CT scans in cancer patients

    Energy Technology Data Exchange (ETDEWEB)

    Rasselet, Benjamin [Medical Imaging Department and Biostatistics Department, Montpellier University Hospital, 191 Avenue du Doyen Gaston Giraud, 34 295 Montpellier Cedex 5 (France); Larbi, Ahmed; Viala, Pierre [Medical Imaging Department, Nimes University Hospital, 4 rue du Professeur Robert Debré, 30029 Nîmes (France); Molinari, Nicolas [Biostatistics Department, Montpellier University Hospital, 191 Avenue du Doyen Gaston Giraud, 34 295 Montpellier Cedex 5 (France); Tetreau, Raphael [Medical Imaging Department, Montpellier Cancer Institute (ICM), 208 Avenue des Apothicaires, 34298 Montpellier Cedex 5 (France); Faruch-Bilfeld, Marie [Medical Imaging Department, Toulouse University Hospital, Place du Docteur Baylac, 31059 Toulouse Cedex 9 (France); Taourel, Patrice [Medical Imaging Department and Biostatistics Department, Montpellier University Hospital, 191 Avenue du Doyen Gaston Giraud, 34 295 Montpellier Cedex 5 (France); Cyteval, Catherine, E-mail: c-cyteval@chu-montpellier.fr [Medical Imaging Department and Biostatistics Department, Montpellier University Hospital, 191 Avenue du Doyen Gaston Giraud, 34 295 Montpellier Cedex 5 (France)

    2017-01-15

    Highlights: • 2.8% of collateral venous circulation seen on CT scan in a cancer population. • 37% of intravertebral enhancement in this population with collateral venous circulation. • 80.8% of intravertebral enhancements are located between C6 and. • 73% of intravertebral enhancements are located ipsilateral to the injection side. -  Abstract: Study design: This was a single center, retrospective observational study. Objective: to investigate—in a cancer population—the prevalence and hallmarks of intravertebral enhancement (IVE) detected on contrast-enhanced CT. Summary of background data: Intravertebral enhancements secondary to iodinated contrast stagnation have been described. Cancer patients have an increased risk of perivertebral venous thrombosis or stenosis secondary to several risk factors (cancer or drug induced hypercoagulability, deterioration of venous flow linked to catheter insertion, prolonged immobilization). In case of a high density lesion identified on CT, the diagnostic choice between metastasis and contrast media within bone marrow vessels may be an issue, especially as oncologic follow-up CT scans are usually performed with contrast medium injection. Methods: 2572 contrast-enhanced body CT scans performed in cancer patients over 3 months in the medical imaging department of a university hospital were retrospectively reviewed. IVE was sought when paravertebral venous collateral circulation was detected and bone metastasis ruled out and classified as linear or nodular. Their locations within vertebra, their relation to the injection side and the predominant collateral venous network side were evaluated. Results: Sixty-seven (2.8%) patients had a collateral paravertebral venous system and among them 21 had IVE (37%). There were 208 IVE locations involving 75 vertebrae. 199 IVE were linear-shaped (95.7%) and 9 nodular-shaped (4.3%). 80.8% were located between C6 and T4. 88.9% were localized in the vertebral body. 73.1% were located

  7. Prevalence and characteristics of intravertebral enhancement on contrast-enhanced CT scans in cancer patients

    International Nuclear Information System (INIS)

    Rasselet, Benjamin; Larbi, Ahmed; Viala, Pierre; Molinari, Nicolas; Tetreau, Raphael; Faruch-Bilfeld, Marie; Taourel, Patrice; Cyteval, Catherine

    2017-01-01

    Highlights: • 2.8% of collateral venous circulation seen on CT scan in a cancer population. • 37% of intravertebral enhancement in this population with collateral venous circulation. • 80.8% of intravertebral enhancements are located between C6 and. • 73% of intravertebral enhancements are located ipsilateral to the injection side. -  Abstract: Study design: This was a single center, retrospective observational study. Objective: to investigate—in a cancer population—the prevalence and hallmarks of intravertebral enhancement (IVE) detected on contrast-enhanced CT. Summary of background data: Intravertebral enhancements secondary to iodinated contrast stagnation have been described. Cancer patients have an increased risk of perivertebral venous thrombosis or stenosis secondary to several risk factors (cancer or drug induced hypercoagulability, deterioration of venous flow linked to catheter insertion, prolonged immobilization). In case of a high density lesion identified on CT, the diagnostic choice between metastasis and contrast media within bone marrow vessels may be an issue, especially as oncologic follow-up CT scans are usually performed with contrast medium injection. Methods: 2572 contrast-enhanced body CT scans performed in cancer patients over 3 months in the medical imaging department of a university hospital were retrospectively reviewed. IVE was sought when paravertebral venous collateral circulation was detected and bone metastasis ruled out and classified as linear or nodular. Their locations within vertebra, their relation to the injection side and the predominant collateral venous network side were evaluated. Results: Sixty-seven (2.8%) patients had a collateral paravertebral venous system and among them 21 had IVE (37%). There were 208 IVE locations involving 75 vertebrae. 199 IVE were linear-shaped (95.7%) and 9 nodular-shaped (4.3%). 80.8% were located between C6 and T4. 88.9% were localized in the vertebral body. 73.1% were located

  8. Value of contrast enhanced CT scanning in the non-trauma emergency room patient

    International Nuclear Information System (INIS)

    Wood, L.P.; Parisi, M.; Finch, I.J.

    1990-01-01

    To determine the value of performing contrast CT in addition to non-contrast CT in the evaluation of acute non-traumatic central nervous system disorders, we retrospectively reviewed 322 cases originating from the emergency room at our institution. The most common indication for scanning was seizure activity (34% of total), followed by headache (30%), focal neurological deficit (10%), and altered mental status (8%). 75% of the noncontrast scans were normal. The contrast enhanced scan revealed abnormalities not evident on the non-contrast scan in only three of these cases, and the information did not alter patient management. We conclude that in the acute setting, if a non-contrast CT is normal, a contrast study is usually unnecessary. Therefore, given the additional risks of contrast infusion, the contrast study, if needed, is generally best obtained at a later date, after more careful evaluation of the patient's history and medical records. If the non-contrast CT scan is abnormal, a contrast enhanced CT scan may be beneficial, but, again, is often not needed to direct acute patient management. (orig.)

  9. Differences in MRI findings in cases showing ring-enhancement on a CT scan

    International Nuclear Information System (INIS)

    Tokiwa, Kaichi; Hashimoto, Takashi; Miyasaka, Yoshio; Yada, Kenzoh; Kan, Shinichi; Takagi, Hiroshi.

    1990-01-01

    It is sometimes difficult to differentiate between a brain abscess and a tumor, for both show ring-enhancement on a CT scan. The present authors have studied the benefit of MRI for the differential diagnosis of these two lesions. The subjects of this study were 6 cases of brain abscess and 10 cases of brain tumor, all of them showing ring-enhancement on a CT scan. The MRI findings were compared with those of the CT scan taken at almost the same time, especially focussing on the difference in the ring-enhancement. In 5 out of the 6 cases of brain abscess, T 2 -weighted MRI demonstrated a comparatively thin and homogeneous low-intensity, round rim. In the cases of brain tumor, however, none of the cases demonstrated this typical low-intensity, round rim; rather, in them the rim was thick and irregular. The authors can conclude that those MRI findings can serve as important differential diagnostic findings between brain abscess and tumor; also, MRI may be used as a landmark for terminating the administration of antibiotics in cases of brain abscess. (author)

  10. Hybrid imaging with contrast enhanced CT scan: A nuclear physician's point of view

    International Nuclear Information System (INIS)

    Houzard, C.; Tychyj-Pinel, C.; Defez, D.; Valette, P.J.; Giammarile, F.; Houzard, C.; Valette, P.J.; Giammarile, F.

    2010-01-01

    The ongoing development of hybrid imaging, with physical association of CT scan and PET or SPECT scan, allows integrating morphological and functional information on a single exam. This important technological evolution changes diagnostic and therapeutic strategy in a major manner, essentially in oncology. The possibility to inject intravenously iodinated contrast media in order to enhance CT image contrast is still a controversial question in France. We present our experience in this domain by approaching technical problems and diagnostic advantages. (authors)

  11. Scanning and contrast enhancement protocols for multi-slice CT in evaluation of the upper abdomen

    International Nuclear Information System (INIS)

    Awai, Kazuo; Onishi, Hiromitsu; Takada, Koichi; Yamaguchi, Yasuo; Eguchi, Nobuko; Hiraishi, Kumiko; Hori, Shinichi

    2000-01-01

    The advent of multi-slice CT is one of the quantum leaps in computed tomography since the introduction of helical CT. Multi-slice CT can rapidly scan a large longitudinal (z-axis) volume with high longitudinal resolution and low image artifacts. The rapid volume coverage speed of multi-slice CT can increase the difficulty in optimizing the delay time between the beginning of contrast material injection and the acquisition of images and we need accurate knowledge about optimal temporal window for adequate contrast enhancement. High z-axis resolution of multi-slice can improve the quality of three-dimensional images and MPR images and we must select adequate slice thickness and slice intervals in each case. We discuss basic considerations for adequate contrast enhancement and scanning protocols by multi-slice CT scanner in the upper abdomen. (author)

  12. Intracranial ring enhancing lesions in dogs: a correlative CT scanning and neuropathologic study

    International Nuclear Information System (INIS)

    Wolf, Michael; Pedroia, Vince; Higgins, Robert J.; Koblik, Philip D.; Turrel, Jane M.; Owens, Jerry M.

    1995-01-01

    This retrospective analysis of 15 dogs with postcontrast ring enhancing brain lesions, each detected by a single Computed Tomography (CT) examination, searched for any association between their CT appearance and the pathologic diagnosis. In a subgroup of these dogs (n = 71) necropsied within 2 days of the last CT scan, we evaluated whether there was any anatomic correlation between the ring zone and the histopathologic features of the lesions. Our study consisted of eight dogs with primary brain tumors (3 meningiomas, 3 astrocytomas, 1 mixed glioma, 1 oligodendroglioma), 4 with metastatic brain tumors (2 fibrosarcomas, 1 mammary carcinoma, 1 melanoma) and 3 with non-neoplastic brain lesions (2 intraparenchymal hemorrhages, 1 pyogranulomatous meningoencephalitis). The overall size and shape of the contrast enhancing CT lesions, as well as the thickness, surface texture and degree of enhancement of the ring were subjectively evaluated. No association was found between the CT lesion characteristics and the pathologic diagnosis. In the sub-group of dogs euthanatized within 2 days of the CT examination, distinct histologic features which anatomically correlated with the zone of ring enhancement were found in 3 of 7 lesions. The findings of this study are consistent with those of ring-enhancing lesions in people, and indicates that CT ring enhancement is a nonspecific phenomenon which can occur in a variety of neoplastic and non-neoplastic lesions in the dog

  13. Feasibility of using intravenous contrast-enhanced computed tomography (CT) scans in lung cancer treatment planning

    International Nuclear Information System (INIS)

    Xiao Jianghong; Zhang Hong; Gong Youling; Fu Yuchuan; Tang Bin; Wang Shichao; Jiang Qingfeng; Li Ping

    2010-01-01

    Background and purpose: To investigate the feasibility of using intravenous contrast-enhanced computed tomography (CT) scans in 3-dimensional conformal radiotherapy (3D-CRT), stereotactic body radiation therapy (SBRT) and intensity-modulated radiotherapy (IMRT) treatment planning for lung cancers, respectively. Materials and methods: Twelve patients with bulky lung tumors and 14 patients with small lung tumors were retrospectively analyzed. Each patient took two sets of CT in the same position with active breathing control (ABC) technique before and after intravenous contrast agent (CA) injections. Bulky tumors were planned with 3D-CRT, while SBRT plans were generated for patients with small tumors based on CT scans with intravenous CA. In addition, IMRT plans were generated for patients with bulky tumors to continue on a planning study. All plans were copied and replaced on the scans without intravenous CA. The radiation doses calculated from the two sets of CTs were compared with regard to planning volumes (PTV), the organ at-risk (OAR) and the lungs using Wilcoxon's signed rank test. Results: In comparisons for 3D-CRT plans, CT scans with intravenous CA reduced the mean dose and the maximum dose of PTV with significant differences (p 95 ) for targets, respectively (p < 0.05). There was no statistical significance for lung parameters between two sets of scans in SBRT plans and IMRT plans. Conclusions: The enhanced CT scans can be used for both target delineation and treatment planning in 3D-CRT. The dose difference caused by intravenous CA is small. But for SBRT and IMRT, the minimum irradiation dose in targets may be estimated to be increased up to 2.71% while the maximum dose may be estimated to be decreased up to 1.36%. However, the difference in dose distribution in most cases were found to be clinical tolerable.

  14. CT scan of pituitary adenomas

    International Nuclear Information System (INIS)

    Sakoda, K.; Mukada, K.; Yonezawa, M.; Matsumura, S.; Yoshimoto, H.; Mori, S.; Uozumi, T.

    1981-01-01

    CT scan is an extremely useful, almost harmless means of diagnosing pituitary adenomas. Growth hormone (GH)-secreting adenomas tend to have higher absorption coefficent in plain CT than the nonfunctioning and prolactin (PRL)-secreting adenomas. The absorption coefficent on contrast-enhanced CT does not identify the specific type of adenoma. Ring-like enhancement was observed in five nonfunctioning and four PRL-secreting adenomas with suprasellar extension, while cystic components were observed in four nonfunctioning and four PRL-secreting adenomas. In three of ten cases of PRL-secreting microadenomas, the site corresponding to the adenoma was not enhanced, whereas the normal pituitary was. A correlation exists between the size of PRL-secreting adenoma and the serum PRL level, but not between the size of GH-secreting adenomas and the serum GH level. (orig.)

  15. Contrast bolus technique with rapid CT scanning

    International Nuclear Information System (INIS)

    Arnold, H.; Kuehne, D.; Rohr, W.; Heller, M.

    1981-01-01

    Twenty-three patients complying with the clinical criteria for brain death were studied by contrast-enhanced CT. In all but one, the great intracranial vessels escaped visualization; accordingly, angiography demonstrated cerebral circulatory arrest. In the remaining case, faint enhancement of the circle of Willis corresponded to angiographic demonstration of the proximal segments of cerebral arteris. Neither in normal brain nor in dead brain did slow CT scanning disclose any postcontrast increase in parenchymal attenuation. An improved technique is proposed to demonstrate the transit of the contrast bolus by rapid CT with image splitting. If cerebral blood flow is preserved, the grey and white matter will enhance significantly following administration of contrast medium. Vice versa, the absence of enhancement confirms brain death, even in instances in which the great cerebral vessels are obscured by hemorrhage or other extensive lesions. Two additional cases of brain death were evaluated by rapid CT scanning. As to brain death, the technique obviates the need for angiography or radionuclide angiography, usually applied in prospective organ donors, because its informative content is superior to that of either method. The CT technique described affords a reliable and safe diagnosis of brain death, and can be interpreted easily. (orig.)

  16. CT scanning in pediatric head trauma: correlation of clinical features with CT scan diagnosis

    International Nuclear Information System (INIS)

    Arkoncel, Mary Ann P.; Posadas, Ma. Belen A.

    1997-01-01

    A retrospective review was conducted on 205 cases of pediatric head trauma for which cranial computed tomography scans were done at the Makati Medical Center, to determine which clinical features might positively predict an abnormality on CT scan. The clinical findings of loss of consciousness, GCS < 12, vomiting headache, seizures, and focal abnormalities on Neurologic Examination were significantly associated with abnormal findings on CT scan. However, a significant discrepancy does exist as to how accurately clinical findings do in fact predict normal and abnormal CT scan findings. Such a discrepancy allows us to conclude that a more liberal use of CT Scanning in cases of pediatric head trauma must be stressed to insure proper diagnosis. This study shows that when a patient presents with the aforementioned positive signs and symptoms, or with a focal neurologic deficit, or in combination, a 60-100 % positive prediction of abnormal CT Scan can be made. However, prediction of normal CT Scan is only 0-40%. (Author)

  17. Evaluation of dynamic enhanced CT scanning in the differentiation of adrenal lipid-poor adenomas with metastases

    International Nuclear Information System (INIS)

    Fang Xiangming; Hu Chunhong; Hu Xiaoyun; Chen Hongwei; Wu Liyuan; Zou Xinnong; Qian Pingyan

    2006-01-01

    Objective: To evaluate dynamic enhanced CT in differentiating adrenal metastases from adrenal lipid-poor adenomas(ALPA). Methods: Both plain and dynamic enhanced CT scanning was performed in 9 metastases with 13 masses and 28 lipid-poor adenoma with 30 masses. The types of time-density curve according to peak time(PT) and relative washout percentage(Washr) besides shape, size, margin, internal structure, surrounding status and enhanced pattern of each lesion were measuerd and compared between the two groups of metastases and ALPA. Results: There is difference between metastases and ALPA in the aspects of shape, density, neighboring structure and the type of enhancement. The type of TDC of matastases was characterized by fast-washin and fast-washout, which was quite differed from the type of TDC of ALPA characterized by fast-washin and slow-washout. According to this, the sensitiveity and specificity for differentiating metastases from ALPA were 96.7%, 92.3%. Conclusion: The types of TDC of dynamic enhanced CT is of great value in differentiating metastases from ALPA. (authors)

  18. CT Scan

    Science.gov (United States)

    ... disease, lung nodules and liver masses Monitor the effectiveness of certain treatments, such as cancer treatment Detect ... scan done in a hospital or an outpatient facility. CT scans are painless and, with newer machines, ...

  19. Determination of entry site for acute type A aortic dissection by initial enhanced CT-scan

    International Nuclear Information System (INIS)

    Mase, Takenori; Narumiya, Chihiro; Aoyama, Takahiko; Nagata, Yoshihisa

    2002-01-01

    Acute type A aortic dissection presents a surgical emergency because conservative therapy is not effective in the majority of instances. Enhanced CT-scan of the chest is commonly available and is considered to be an optimal diagnostic method for this disease. The operative strategy is to resect the primary tear to close the entry site of the aortic dissection and replace it with a tubular Dacron graft. Therefore, the existence of the entry site is important in determining the operative procedure. Based on the numerical value of the enhanced CT-scan inspection, the present study seeks to preoperatively identify the location of the presumed entry site in aortic dissection. From May 1996 to June 1999, 21 consecutive patients (Marfan's syndrome excluded) with acute type A aortic dissection underwent surgical treatment. Nineteen patients were preoperatively examined by enhanced CT-scan: 11 men and 8 women, with a mean age of 61 years. CT-scan slices used for early diagnosis were of the ascending aorta, aortic arch, descending aorta, and thoracoabdominal aorta. The largest diameters of the whole and true lumen were measured from cross-sectional aortic images with a personal computer, and the areas of the whole and true lumen were obtained by the manual tracing method. The true ratio was calculated for the largest diameter and area of the whole lumen. The nineteen patients were divided into two groups according to the location of the entry site based on the operating views. Seven patients with the entry site in the ascending aorta were classified as group A, and twelve patients with the entry site further in the aortic arch and descending aorta were classified as group B. Comparisons were performed by non-parametric analysis. Moreover, a discriminant analysis was applied to evaluate the classification between the two groups. The ratio of the largest diameter of the true lumen in group A at the level of the ascending and descending aorta was significantly greater than that

  20. Determination of entry site for acute type A aortic dissection by initial enhanced CT-scan

    Energy Technology Data Exchange (ETDEWEB)

    Mase, Takenori; Narumiya, Chihiro; Aoyama, Takahiko; Nagata, Yoshihisa [Aichi Medical Univ., Nagakute (Japan). School of Medicine

    2002-01-01

    Acute type A aortic dissection presents a surgical emergency because conservative therapy is not effective in the majority of instances. Enhanced CT-scan of the chest is commonly available and is considered to be an optimal diagnostic method for this disease. The operative strategy is to resect the primary tear to close the entry site of the aortic dissection and replace it with a tubular Dacron graft. Therefore, the existence of the entry site is important in determining the operative procedure. Based on the numerical value of the enhanced CT-scan inspection, the present study seeks to preoperatively identify the location of the presumed entry site in aortic dissection. From May 1996 to June 1999, 21 consecutive patients (Marfan's syndrome excluded) with acute type A aortic dissection underwent surgical treatment. Nineteen patients were preoperatively examined by enhanced CT-scan: 11 men and 8 women, with a mean age of 61 years. CT-scan slices used for early diagnosis were of the ascending aorta, aortic arch, descending aorta, and thoracoabdominal aorta. The largest diameters of the whole and true lumen were measured from cross-sectional aortic images with a personal computer, and the areas of the whole and true lumen were obtained by the manual tracing method. The true ratio was calculated for the largest diameter and area of the whole lumen. The nineteen patients were divided into two groups according to the location of the entry site based on the operating views. Seven patients with the entry site in the ascending aorta were classified as group A, and twelve patients with the entry site further in the aortic arch and descending aorta were classified as group B. Comparisons were performed by non-parametric analysis. Moreover, a discriminant analysis was applied to evaluate the classification between the two groups. The ratio of the largest diameter of the true lumen in group A at the level of the ascending and descending aorta was significantly greater than

  1. Head CT scan

    Science.gov (United States)

    ... scan - orbits; CT scan - sinuses; Computed tomography - cranial; CAT scan - brain ... head size in children Changes in thinking or behavior Fainting Headache, when you have certain other signs ...

  2. Ocular volume measured by CT scans

    International Nuclear Information System (INIS)

    Hahn, F.J.; Wei-Kom Chu

    1984-01-01

    Newer CT scans have greatly enhanced oculometric research and made it possible to measure ocular dimensions. With these measurements, ocular volume can be more accurately estimated to understand its relationship with age and sex. One hundred CT orbit scans with presumed normal eyes were used for the data base. The mean values and normal variations of ocular volumes at various ages in both sexes are presented. Rapid growth of the eyeball was noted during the first 24 months of age. It reached its peak between the ages of 18 and 30 years of age, after which there was a reduction. Results may be of help in recognizing eye abnormalities such as microophthalmus and macrophthalmia. (orig.)

  3. Is contrast-enhanced CT indicated in acute head injury

    International Nuclear Information System (INIS)

    Mauser, H.W.; Nieuwenhuizen, O. van; Veiga-Pires, J.A.

    1984-01-01

    The authors discuss the value of intravenous contrast enhancement in CT scanning in acute head injury. In a series of seventy consecutive patients they conclude that no incremental information was obtained by performing contrast-enhanced CT scans in the acute phase of the head injury. (orig.)

  4. Enhanced dual-phase spiral CT features of polypoid ampullary carcinoma

    International Nuclear Information System (INIS)

    Zeng Mengsu; Yan Fuhua; Zhou Kangrong; Chen Huiming; Chen Gang; Chen Jin

    2001-01-01

    Objective: To understand CT features of polypoid ampullary carcinoma by enhanced dual-phase spiral CT. Methods: 15 cases of polypoid ampullary carcinoma (PAC) confirmed by surgical and pathological results were studied with thin slice enhanced dual-phase spiral CT (including arterial and portal phase scanning)with retrospective analysis, the scanning parameters were 5 mm thickness and 1.0 pitch for arterial phase scanning, and 5 mm thickness and 5 mm space for portal phase scanning. Results: All cases could display an enhanced mass as local filling defect at the site of the duodenal Vater's ampulla during arterial and portal phase scanning, the tumors ranged in size from 1 cm to 5 cm with mean of 2.3 cm, all were accompanied with dilated intrahepatic and common bile duct, enlarged gallbladder and dilated pancreatic duct, except one case which had marked atrophy of the pancreatic body and tail. Conclusion: The thin slices enhanced dual-phase spiral CT could not only accurately define the level of obstruction, but also demonstrate an enhanced mass as direct CT sign of the PAC, which is crucial for diagnosis of the PAC

  5. A contrast enhancement and scanning techniques for CT angiography of head and neck. One phase injection method for simultaneous imaging of vessels and tumor

    International Nuclear Information System (INIS)

    Morita, Yasuhiko; Indo, Hiroko; Noikura, Takenori

    1999-01-01

    We report on a method of CT-Angiography useful for examining lesion of the head and neck using three-dimensional images and measured CT value. This study focused on some of the important blood vessels in the head and neck. The aim of this method was to obtain high-contrast enhancement for both vessels and tumors at same time. A total amount of 100 ml nonionic contrast media (Omnipaque 240, 240 mg iodine per milliliter, Daiichi seiyaku, Tokyo, Japan) was injected intravenously with a flow of 1.5 ml/sec. Spiral scans, 24 rotations with 24 seconds, were started at a time when remaining amount of contrast media had become 30 to 20 ml. All CT scans were performed using double speed spiral scan technique with a slice thickness of 2 to 3 mm and table speeds from 3 to 5 mm/rotation. The patients populations consisted of 9 men and 6 women who ranged in age from 37 to 85 years. Sixteen CT-angiography were performed according to this method. Mean CT values of major blood vessels were measured in order to find out threshold at the level of submandibular gland in 13 examinations for 12 subjects. Important vessels like the common, internal, and the external artery, internal and external jugular vein were clearly visible in all subjects. Three dimensional images of these vessels could also be reconstructed for 15 of the subjects. Mean CT values were 211 Hounsfield units (HU) and 209 HU for the right and left internal carotid artery, respectively, and 204 HU and 206 HU for the right and left external carotid artery, respectively. Mean CT values for right and left internal jugular vein were 195 HU and 194 HU respectively. Measured CT values at each important blood vessels showed this method could yields acceptable enhancements. Good enhancement effect of tumor and blood vessels in the same scan seems to be mutually incompatible. One very important trade-off is the early enhancement effect at blood vessels versus the late enhancement effect at tumors. The other important trade

  6. Relationship between the natural history of chronic subdural hematoma and enhancement of the inner membrane on post-contrast CT scan

    International Nuclear Information System (INIS)

    Nakaguchi, Hiroshi; Yoshimasu, Norio; Tanishima, Takeo

    2003-01-01

    The purpose of this study was to determine the features and natural history of the inner membrane in CSDH (chronic subdural hematoma) patients using pre- and post-contrast CT scans. Twenty-four patients with CSDH (28 hematomas) who underwent pre- and post-contrast CT scanning prior to surgery ware studied. CSDH was classified according to the internal architecture as the homogeneous (HM) type, the laminar (LM) type, the separated (SP) type, and the trabecular (TR) type. For each type, the enhancement of the inner membrane, the outer membrane, and trabeculae was evaluated. Enhancement of the inner membrane develops as the stage of CSDH progresses. Although the inner membrane was not enhanced in the HM type, it was enhanced in almost all of the patients with the other types (p <0.0001). In 13% of patients with the LM type, 29% with the SP type, and 40% with the TR type, the inner membrane was moderately or markedly enhanced. The outer membrane was not thickened in any patient. In 88% of the patients who had contralateral hemiparesis on admission and 42% of those who did not have hemiparesis, the inner membrane was clearly enhanced (p=0.0166). This indicated that blood flow to the inner membrane from the pia matter induced hypoperfusion of the brain parenchyma beneath the hematoma in addition to the effect of direct compression. Contrast CT scanning may be useful for diagnosing the extent of enlargement of the inner membrane, predicting the risk of local brain damage, and evaluating the stage in the natural history of CSDH. (author)

  7. Relationship between the natural history of chronic subdural hematoma and enhancement of the inner membrane on post-contrast CT scan

    Energy Technology Data Exchange (ETDEWEB)

    Nakaguchi, Hiroshi; Yoshimasu, Norio [Teraoka Memorial Hospital, Shinichi, Hiroshima (Japan); Tanishima, Takeo [Tokyo Kosei Nenkin Hospital (Japan)

    2003-02-01

    The purpose of this study was to determine the features and natural history of the inner membrane in CSDH (chronic subdural hemotoma) patients using pre- and post-contrast CT scans. Twenty-four patients with CSDH (28 hematomas) who underwent pre- and post-contrast CT scanning prior to surgery ware studied. CSDH was classified according to the internal architecture as the homogeneous (HM) type, the laminar (LM) type, the separated (SP) type, and the trabecular (TR) type. For each type, the enhancement of the inner membrane, the outer membrane, and trabeculae was evaluated. Enhancement of the inner membrane develops as the stage of CSDH progresses. Although the inner membrane was not enhanced in the HM type, it was enhanced in almost all of the patients with the other types (p <0.0001). In 13% of patients with the LM type, 29% with the SP type, and 40% with the TR type, the inner membrane was moderately or markedly enhanced. The outer membrane was not thickened in any patient. In 88% of the patients who had contralateral hemiparesis on admission and 42% of those who did not have hemiparesis, the inner membrane was clearly enhanced (p=0.0166). This indicated that blood flow to the inner membrane from the pia matter induced hypoperfusion of the brain parenchyma beneath the hematoma in addition to the effect of direct compression. Contrast CT scanning may be useful for diagnosing the extent of enlargement of the inner membrane, predicting the risk of local brain damage, and evaluating the stage in the natural history of CSDH. (author)

  8. The sensitivity of computed tomography (CT) scans in detecting trauma: are CT scans reliable enough for courtroom testimony?

    Science.gov (United States)

    Molina, D Kimberley; Nichols, Joanna J; Dimaio, Vincent J M

    2007-09-01

    Rapid and accurate recognition of traumatic injuries is extremely important in emergency room and surgical settings. Emergency departments depend on computed tomography (CT) scans to provide rapid, accurate injury assessment. We conducted an analysis of all traumatic deaths autopsied at the Bexar County Medical Examiner's Office in which perimortem medical imaging (CT scan) was performed to assess the reliability of the CT scan in detecting trauma with sufficient accuracy for courtroom testimony. Cases were included in the study if an autopsy was conducted, a CT scan was performed within 24 hours before death, and there was no surgical intervention. Analysis was performed to assess the correlation between the autopsy and CT scan results. Sensitivity, specificity, positive predictive value, and negative predictive value were defined for the CT scan based on the autopsy results. The sensitivity of the CT scan ranged from 0% for cerebral lacerations, cervical vertebral body fractures, cardiac injury, and hollow viscus injury to 75% for liver injury. This study reveals that CT scans are an inadequate detection tool for forensic pathologists, where a definitive diagnosis is required, because they have a low level of accuracy in detecting traumatic injuries. CT scans may be adequate for clinicians in the emergency room setting, but are inadequate for courtroom testimony. If the evidence of trauma is based solely on CT scan reports, there is a high possibility of erroneous accusations, indictments, and convictions.

  9. CT scans in encephalitis

    International Nuclear Information System (INIS)

    Imanishi, Masami; Morimoto, Tetsuya; Iida, Noriyuki; Hisanaga, Manabu; Kinugawa, Kazuhiko

    1980-01-01

    Generally, CT scans reveal a decrease in the volume of the ventricular system, sylvian fissures and cortical sulci in the acute stage of encephalitis, and softening of the cerebral lobes with dilatation of the lateral ventricles and subarachnoidian dilated spaces in the chronic stage. We encountered three cases of encephalitis: mumps (case 1), herpes simplex (case 2), and syphilis (case 3). In case 1, brain edema was seen in the acute stage and brain atrophy in the chronic stage. In case 2, necrosis of the temporal pole, which is pathognomonic in herpes simplex encephalitis, was recognized. And in case 3, multiple lesions whose CT appearance was enhanced by contrast materials were found scattered over the whole brain. These lesions were diagnosed as inflammatory granuloma by histological examination. (author)

  10. Clinical features and CT scan findings of supratentorial ependymomas and ependymoblastomas

    International Nuclear Information System (INIS)

    Hanakita, Junya; Handa, Hajime

    1984-01-01

    The clinical courses and CT scan findings of 12 cases of supratentorial ependymoma and ependymoblastoma were reviewed. The age of the patient of ependymoma ranged from 3 years to 34 years, with an average age of 16 years. The follow-up time ranged from 2 months to 9 years and 10 months. All of the six patients are still alive. The age of the patients of ependymoblastoma ranged from 7 months to 34 years, with an average age of 17 years. During the follow-up period from 2 weeks to 6 years and 4 months, four patients died. Supratentorial ependymomas and ependymoblastomas show the following characteristic features of CT scans: 1. Calcification: The incidence of calcification was 50% in ependymoma-group, and 100% in ependymoblastoma-group. 2. Cyst formation, ring-enhancement: The cyst formation was noticed in both groups. In ependymoma-group a smooth ring-enhancement pattern and the strongly enhanced mural nodule-like contour were found, but in ependymoblastoma-group, the cyst wall was enhanced in irregular shape. 3. Perifocal edema and mass effect: Considerable mass effect was noticed in both groups. Perifocal edema was slight in many cases of ependymoma-group, but mostly prominent in ependymoblastoma-group. 4. CT scan findings of recurrent tumor: In ependymoma-group, recurrent tumor showed the same characteristics of CT scan as the initial ones. In ependymoblastoma-group, cystic portion decreased in size and irregular shaped solid portion increased in recurrence. (author)

  11. A case of Neuro-Behcet's disease with an interesting CT scan picture

    International Nuclear Information System (INIS)

    Sato, Jinichi; Kamitani, Hiroshi; Masuzawa, Hideaki; Matsui, Takayoshi; Mizobe, Masafumi.

    1981-01-01

    A Case of Neuro-Behcet's disease with an interesting CT scan picture was reported. A 31-year-old man with a known history of Behcet's disease was transferred to the Kantoh-Teishin Hospital upon suspicion of a brain tumor in the basal ganglia. Right hemiparesis and mild dysarthria of three weeks' duration and long-standing bilateral blindness were noted. Computerized tomography (CT) demonstrated an enhanced mass in the basal ganglia and surrounding irregular, low-density area in the white matter of the left frotoparietal lobe. The ventricles were shifted to the right. Left carotid angiography revealed a shift of the anterior cerebral artery to the right and a mild deformity of the Sylvian triangle. No tumor stain or abnormal vessels were seen. After high doses of prednisolone, his condition gradually improved. A CT scan two weeks later revealed a decrease in the low-density area and the mass effect, but an unchanged pathological contrast enhancement in the basal ganglia. The contrast enhancement lasted for two months. The CT scan of Neuro-Behcet's disease was discussed. (author)

  12. Topographic diagnosis of parathyroid tumor by CT scan

    International Nuclear Information System (INIS)

    Fukunaga, Masao; Harioka, Toshio; Morita, Rikuji

    1981-01-01

    In order to detect the hyperfunctioning parathyroid gland(s), CT scan over the neck was performed in patients with parathyroid disorders, including 10 primary hyperparathyroidism (6 bone type, 3 stone type and 1 chemical type), 8 chronic renal failure on hemodialysis with renal osteodystrophy and 2 multiple endocrine adenomatosis (MEA) type I. We used a whole-body scanner (CT/T, GE). The slice thickness was 5 mm. All patients were scanned from the sternal notch upward to the larynx, and were enhanced by the administration of 30% DIP Conray for 15 min. The results of the topographic diagnosis were compared with the surgical findings. Precise preoperative localization was accomplished in 9/10 adenomas in primary hyperparathyroidism, 27/32 hyperplasias in secondary hyperparathyroidism, and 2/4 hyperplasias in MEA type I. The smallest lesion weighed 0.2 g. It was shown that CT scan over the neck was a noninvasive and simple method to define the localization of hyperfunctionig parathyroid gland(s). (author)

  13. Effect of Work Improvement for Promotion of Outpatient Satisfaction on CT scan

    International Nuclear Information System (INIS)

    Han, Man Seok; Kim, Tae Hyung; Lee, Seung Youl; Lee, Myeong Goo; Jeon, Min Cheol; Cho, Jae Hwan

    2012-01-01

    Nowadays, most of the hospital serves 'one stop service' for CT scan. The patients could be taken the CT scan in the day they register for scan. On the contrary to the time convenience, patients are not satisfied with long waiting time and unkindness of staff. The objective of this study is to improve the patient's satisfaction for the CT scan, by analyzing inconvenience factors and improving the service qualities. From April 1 to August 30 in 2011, we investigated the satisfaction of patients who did examined abdomen CT scan with contrast media. We analyzed the 89 questionnaires before and after the service improvements from them. The worker's kindness, the environment of CT room and understanding about CT scan were answered by questionnaire and the waiting time of a day CT scan was drawn by medical information statistics. Also, the period before improvement was from April to June and the period after improvement was from July to September. And these questionnaire was analyzed through SPSS V. 15.0. In this study, kindness of staff, environment of CT room, intelligibility for CT scan and waiting time was explored and analyzed by SPSS V.15.0. The score of kindness was improved by 32%, satisfaction level of the environment was improved by 52.54%. The understanding level about CT scan was improved by 52.36% and the waiting time of a day CT was shortened by 21% through our service enhancement programs. Consequentially, it is considered that these efforts would contribute to increase the revenue of hospital.

  14. Effect of Work Improvement for Promotion of Outpatient Satisfaction on CT scan

    Energy Technology Data Exchange (ETDEWEB)

    Han, Man Seok; Kim, Tae Hyung [Dept. of Radiological Science, Kangwon National University, Chuncheon (Korea, Republic of); Lee, Seung Youl; Lee, Myeong Goo; Jeon, Min Cheol [Dept. of Radiology, Chungnam National University Hospital, Daejeon (Korea, Republic of); Cho, Jae Hwan [Dept. of Radiological Science, Gyeongsan University College, Daegu (Korea, Republic of)

    2012-03-15

    Nowadays, most of the hospital serves 'one stop service' for CT scan. The patients could be taken the CT scan in the day they register for scan. On the contrary to the time convenience, patients are not satisfied with long waiting time and unkindness of staff. The objective of this study is to improve the patient's satisfaction for the CT scan, by analyzing inconvenience factors and improving the service qualities. From April 1 to August 30 in 2011, we investigated the satisfaction of patients who did examined abdomen CT scan with contrast media. We analyzed the 89 questionnaires before and after the service improvements from them. The worker's kindness, the environment of CT room and understanding about CT scan were answered by questionnaire and the waiting time of a day CT scan was drawn by medical information statistics. Also, the period before improvement was from April to June and the period after improvement was from July to September. And these questionnaire was analyzed through SPSS V. 15.0. In this study, kindness of staff, environment of CT room, intelligibility for CT scan and waiting time was explored and analyzed by SPSS V.15.0. The score of kindness was improved by 32%, satisfaction level of the environment was improved by 52.54%. The understanding level about CT scan was improved by 52.36% and the waiting time of a day CT was shortened by 21% through our service enhancement programs. Consequentially, it is considered that these efforts would contribute to increase the revenue of hospital.

  15. CT scan of bacterial and aseptic meningitis

    International Nuclear Information System (INIS)

    Takemoto, Kazumasa; Saiwai, Shigeo; Tamaoka, Koichi

    1983-01-01

    CT scans of the patients with aseptic and bacterial meningitis were reviewed and compared to previous reports. In aseptic meningitis, no abnormal CT findings were observed. In bacterial meningitis, CT findings were ventricular dilatation, subdural fluid collection, parenchymal low density, intracerebral hematoma and meningeal enhancement after contrast injection. Three patients among 48 suffered from status epileptics during the course of the illness. All of 3 patients developed parenchymal inhomogeneous low density and progressive ventricular dilatation which did not improve after ventricular peritoneal shunt surgery. We believe that these changes are most likely due to hypoxic hypoxemia during epileptic seizure and meningitis itself seems to play a little role. (author)

  16. Serial CT scannings in herpes simplex encephalitis

    International Nuclear Information System (INIS)

    Fukushima, Masashi; Sawada, Tohru; Kuriyama, Yoshihiro; Kinugawa, Hidekazu; Yamaguchi, Takenori

    1981-01-01

    Two patients with serologically confirmed herpes simplex encephalitis were studied by serial CT scannings. Case 1, a 60-year-old woman, was admitted to National Cardiovascular Center because of headache, fever, and attacks of Jacksonian seizure. Case 2, a 54-year-old man, was admitted because of fever, consciousness disturbance and right hemipare sis. Pleocytosis (mainly lymphocytes) and elevation of protein content in cerebrospinal fluid were observed in both cases. Both patients presented ''das apallische Syndrom'' one month after admission. The diagnosis of herpes simplex encephalitis was confirmed by typical clinical courses and by greater than fourfold rises in serum antibody titer for herpes simplex virus as well as that in cerebrospinal fluid in case 1. Characteristic CT findings observed in these two cases were summarized as follows: Within a week after the onset, no obvious abnormalities could be detected on CT scans (Case 1). Two weeks after the onset, a large low-density area appeared in the left temporal lobe and in the contralateral insular cortex with midline shift toward the right side (Case 2). One month later, an ill-defined linear and ring-like high-density area (Case 1), or a well-defined high-density area (Case 2), that was enhanced after contrast administration, was observed in the large low-density area in the temporal lobe. These findings were considered as characteristic for hemorrhagic encephalitis. These high-density areas disappeared two months later, however, widespread and intensified low-density areas still remained. In both cases, the basal ganglia and thalamus were completely spared on CT scans. From these observations, it can be concluded that serial CT scannings are quite useful for diagnosis of herpes simplex encephalitis. (author)

  17. Application of low dose radiation and low concentration contrast media in enhanced CT scans in children with congenital heart disease.

    Science.gov (United States)

    Liu, Zhimin; Song, Lei; Yu, Tong; Gao, Jun; Zhang, Qifeng; Jiang, Ling; Liu, Yong; Peng, Yun

    2016-09-01

    The aim of this study was to explore the feasibility of using low dose radiation and low concentration contrast media in enhanced CT examinations in children with congenital heart disease. Ninety patients with congenital heart disease were randomly divided into three groups of 30 patients each who underwent contrast-enhanced cardiac scans on a Discovery CT750 HD scanner. Group A received 270 mg I/mL iodixanol, and group B received 320 mg I/mL iodixanol contrast media and was scanned with prospective ECG triggering mode. Group C received 320 mg I/mL iodixanol and was scanned with conventional retrospective ECG gating mode. The same weight-based contrast injection protocol was used for all three groups. Images were reconstructed using a 30% adaptive statistical iterative reconstruction (ASIR) algorithm and a 50% ASIR in groups A and B and a 30% ASIR in group C. The subjective and objective image quality evaluations, diagnostic accuracies, radiation doses and amounts of contrast media in the three groups were measured and compared. All images in the three groups met the diagnostic requirements, with the same diagnostic accuracy and image quality scores greater than 3 in a 4-point scoring system. However, ventricular enhancement and the objective noise, signal-to-noise ratio, contrast-to-noise ratio and subjective image quality scores in group C were better than those in groups A and B (all Pcontrast dose (14% lower than that of groups B and C). Enhanced CT scan images with low dose radiation and low concentration contrast media can meet the diagnostic requirements for examining children with congenital heart disease while reducing the potential risk of radiation damage and contrast-induced nephropathy. © 2016 John Wiley & Sons Ltd.

  18. Focal hepatic steatosis: ultrasound and CT scan features may mimick carcinoma of the liver

    International Nuclear Information System (INIS)

    Monnin, J.L.; Blanc, F.; Guiry, P.; Bruel, J.M.; Monnin, E.; Ciurana, A.J.

    1988-01-01

    Ultrasound and CT scan features of focal hepatic steatosis (FHS) may closely resemble those of primary or secondary malignant hepatic tumors. Three cases of FHS in chronic alcoholics are reported. In two cases, the area of steatosis was hyperechogenic upon ultrasonography. In all three patients, CT scan demonstrated a hypodense image, with poor enhancement following opacification and no mass effect. Diagnosis of FHS was ascertained upon hepatic biopsy under CT scan guidance in all three patients [fr

  19. Serial CT scannings in herpes simplex encephalitis

    Energy Technology Data Exchange (ETDEWEB)

    Fukushima, M.; Sawada, T.; Kuriyama, Y.; Kinugawa, H.; Yamaguchi, T. (National Cardivascular Center, Osaka (Japan))

    1981-10-01

    Two patients with serologically confirmed herpes simplex encephalitis were studied by serial CT scannings. Case 1, a 60-year-old woman, was admitted to National Cardiovascular Center because of headache, fever, and attacks of Jacksonian seizure. Case 2, a 54-year-old man, was admitted because of fever, consciousness disturbance and right hemiparesis. Pleocytosis (mainly lymphocytes) and elevation of protein content in cerebrospinal fluid were observed in both cases. Both patients presented ''das apallische Syndrom'' one month after admission. The diagnosis of herpes simplex encephalitis was confirmed by typical clinical courses and by greater than fourfold rises in serum antibody titer for herpes simplex virus as well as that in cerebrospinal fluid in case 1. Characteristic CT findings observed in these two cases were summarized as follows: Within a week after the onset, no obvious abnormalities could be detected on CT scans (Case 1). Two weeks after the onset, a large low-density area appeared in the left temporal lobe and in the contralateral insular cortex with midline shift toward the right side (Case 2). One month later, an ill-defined linear and ring-like high-density area (Case 1), or a well-defined high-density area (Case 2), that was enhanced after contrast administration, was observed in the large low-density area in the temporal lobe. These findings were considered as characteristic for hemorrhagic encephalitis. These high-density areas disappeared two months later, however, widespread and intensified low-density areas still remained. In both cases, the basal ganglia and thalamus were completely spared on CT scans. From these observations, it can be concluded that serial CT scannings are quite useful for diagnosis of herpes simplex encephalitis.

  20. CT scans of giant aneurysms in the vertebro-basilar artery

    International Nuclear Information System (INIS)

    Shishido, Toyofumi; Ohsugi, Tamotsu; Motozaki, Takahiko; Sakaki, Saburo; Matsuoka, Kenzo

    1980-01-01

    Clinical course and neurological and neuroradiological findings of giant aneurysms in the vertebro-basilar artery observed in two of our cases were discussed. The first case was a 66-year-old man. He complained of sensory disturbance over his left face and unstable gait for 2 years before admission. Neurological examinations on admission showed hypesthesia in the territory of the second branch of the left fifth cranial nerve, nystagmus, and a left cerebellar sign. No mental deterioration or pyramidal signs were noticed. Retrograde left brachial artery angiograms revealed a giant aneurysm with inferior pointing measuring 30 x 10 mm in diameter arising from the left superior cerebellar artery. Precontrast CT scans demonstrated a round, large, high-density area, cantaining a relatively low-density area within it, in the medioventral portion of the left cerebellum; a part of this high-density area was markedly enhanced in the postcontrast CT scan. No ventricular dilatations were noticed by CT scans. Direct surgery was abandoned due to the size and location of the aneurysm. No neurologically abnormal finding developed after discharge. The second case was a 61-year-old man. He complained of unstable gait for 2 years before admission. Neurological examinations on admission showed bilateral pyramidal sings (more pronounced on the left) and nystagmus. There were no cranial nerve palsy and no sensory disturbances. Precontrast CT scans showed a large, oval, high-density area in the medioventral portion of the right cerebellum, extending to the upper brainstem; a part of this high-density area was markedly enhanced in the postcontrast CT scans. Retrograde left brachial artery angiograms revealed that the fusiform aneurysm in the left vertebral, the basilar artery, and the dilated basilar artery ran 30 mm from the clivus, with a dorsal convex arch. (J.P.N.)

  1. Significance and problems of the dynamic CT scan for the diagnosis and treatment of cerebral infarctions

    International Nuclear Information System (INIS)

    Morita, Akio; Teraoka, Akira

    1985-01-01

    Dynamic CT scan is a very useful method for the diagnosis of cerebral infarctions and other ischemic disorders. We have used this method for 1) the ultra-early stage diagnosis of major infarctions, 2) the detection of the recanalization and the disruption of the blood-brain barrier, and 3) the detection of latent ischemic lesions. In this report we discussed the clinical cases and the usual use of this dynamic CT scan. We used a GE CT/T8800 scanner for dynamic CT scanning. Manual bolus-contrast-medium injection was done simultaneously with the first scanning, and 6 sequential scannings (scan time: 4.8 s; scan interval: 1.4 s) were done on the same slice level. Especially in major infarctions (e.g., MCA occlusion), OM 40 was the most preferred slice. In cases of ultra-early stage infarctions (i.e., no abnormal lesions in non-enhanced CT), we used this dynamic CT scan immediately after the non-enhanced CT; we could thus obtain information on the ischemic lesions and the ischemic degree. After that we repeated this examination on Days 3, 7, and 14 for the evaluation of the recanalization and blood-brain-barrier disruption. In the cases of TIA and impending or progressing strokes, dynamic CT scan could disclose latent ischemic lesions; in there instances, we treated the patients with intensive to prevent the prognosis from worsening. These benefits and also some problems were discussed. (author)

  2. Functional imaging in differentiating bronchial masses: an initial experience with a combination of (18)F-FDG PET-CT scan and (68)Ga DOTA-TOC PET-CT scan.

    Science.gov (United States)

    Kumar, Arvind; Jindal, Tarun; Dutta, Roman; Kumar, Rakesh

    2009-10-01

    To evaluate the role of combination of (18)F-FDG PET-CT scan and (68)Ga DOTA-TOC PET-CT scan in differentiating bronchial tumors observed in contrast enhanced computed tomography scan of chest. Prospective observational study. Place of study: All India Institute of Medical Sciences, New Delhi, India. 7 patients with bronchial mass detected in computed tomography scan of the chest were included in this study. All patients underwent (18)F-FDG PET-CT scan, (68)Ga DOTA-TOC PET-CT scan and fiberoptic bronchoscope guided biopsy followed by definitive surgical excision. The results of functional imaging studies were analyzed and the results are correlated with the final histopathology of the tumor. Histopathological examination of 7 bronchial masses revealed carcinoid tumors (2 typical, 1 atypical), inflammatory myofibroblastic tumor (1), mucoepidermoid carcinoma (1), hamartoma (1), and synovial cell sarcoma (1). The typical carcinoids had mild (18)F-FDG uptake and high (68)Ga DOTA-TOC uptake. Atypical carcinoid had moderate uptake of (18)F-FDG and high (68)Ga DOTA-TOC uptake. Inflammatory myofibroblastic tumor showed high uptake of (18)F-FDG and no uptake of (68)Ga DOTA-TOC. Mucoepidermoid carcinoma showed mild (18)F-FDG uptake and no (68)Ga DOTA-TOC uptake. Hamartoma showed no uptake on either scans. Synovial cell sarcoma showed moderate (18)F-FDG uptake and mild focal (68)Ga DOTA-TOC uptake. This initial experience with the combined use of (18)F-FDG and (68)Ga DOTA-TOC PET-CT scan reveals different uptake patterns in various bronchial tumors. Bronchoscopic biopsy will continue to be the gold standard; however, the interesting observations made in this study merits further evaluation of the utility of the combination of (18)F-FDG PET-CT scan and (68)Ga DOTA-TOC PET-CT scan in larger number of patients with bronchial masses.

  3. Spinal CT scan, 1

    International Nuclear Information System (INIS)

    Nakagawa, Hiroshi

    1982-01-01

    Methods of CT of the cervical and thoracic spines were explained, and normal CT pictures of them were described. Spinal CT was evaluated in comparison with other methods in various spinal diseases. Plain CT revealed stenosis due to spondylosis or ossification of posterior longitudinal ligament and hernia of intervertebral disc. CT took an important role in the diagnosis of spinal cord tumors with calcification and destruction of the bone. CT scan in combination with other methods was also useful for the diagnosis of spinal injuries, congenital anomalies and infections. (Ueda, J.)

  4. Spiral CT dual-phase scanning for hepatocellular carcinoma: comparison study on the peripheral enhancement and pathology

    International Nuclear Information System (INIS)

    Chen Wenxia; Min Pengqiu; Zhou Xiangping; Song Bin; Liu Yan; Shen Mingen; Li Zhenlin; Yang Min

    2002-01-01

    Objective: To compare the peripheral enhancement features of hepatocellular carcinoma (HCC) lesions in arterial and portal venous phases with histopathology, and to study the histopathologic bases of peripheral enhancement of the HCC lesions and how it affects the biologic behavior and prognosis. Methods: Forty-two histopathologically proven HCC patients were included. First, an unenhanced scanning covering the whole liver was done, and followed by arterial and portal venous phase scanning. The delay time was 20 sec and 60 sec after the injecting of contrast media. the slides of 5 μm thickness were stained with HE and the standard immunoperoxidase method using the polyclonal antibody of factor VIII-related antigen (F8RA). The pseudo capsule of the lesion, tumor invasion of the pseudo capsule, and the number of positive stained tumor vessels in the pseudo capsule were evaluated. Results: Among the 42 cases, in arterial phase, the pseudo capsule of the HCC lesions was demonstrated as hyper-or hypo-attenuation in 13 and 8 cases, respectively, and no marked pseudo capsule was perceived in 21 cases. In portal venous phase, hyper-attenuated pseudo capsule was shown in 27 cases, hypo-attenuated pseudo capsule in 2 cases, and no pseudo capsule in 13 cases. On CT scans, daughter foci were showed in 14 cases, in which 9 cases were single and 5 of 42 patients, and tumor cells invaded the pseudo capsule in 16 caes among these cases. F8RA immunohistochemical staining showed that the pseudo capsule contained rich positive staining neo-vascular structure in 15 of 25 cases, and the other 10 cases had thick pseudo capsule but few neo-vascular structure. HE staining showed no marked pseudo capsule in 17 cases, in which 8 cases exhibited no clear border between the tumor tissue and liver parenchyma. Conclusion: The peripheral enhancement features of HCC on spiral CT dural-phase scanning could reflect the histopathologic characteristics and predict the biologic behavior and prognosis

  5. Dual-time point scanning of integrated FDG PET/CT for the evaluation of mediastinal and hilar lymph nodes in non-small cell lung cancer diagnosed as operable by contrast-enhanced CT

    International Nuclear Information System (INIS)

    Kasai, Takami; Motoori, Ken; Horikoshi, Takuro; Uchiyama, Katsuhiro; Yasufuku, Kazuhiro; Takiguchi, Yuichi; Takahashi, Fumiaki; Kuniyasu, Yoshio; Ito, Hisao

    2010-01-01

    Purpose: To evaluate whether dual-time point scanning with integrated fluorine-18 fluorodeoxyglucose ( 18 F-FDG) positron emission tomography and computed tomography (PET/CT) is useful for evaluation of mediastinal and hilar lymph nodes in non-small cell lung cancer diagnosed as operable by contrast-enhanced CT. Materials and methods: PET/CT data and pathological findings of 560 nodal stations in 129 patients with pathologically proven non-small cell lung cancer diagnosed as operable by contrast-enhanced CT were reviewed retrospectively. Standardized uptake values (SUVs) on early scans (SUVe) 1 h, and on delayed scans (SUVd) 2 h after FDG injection of each nodal station were measured. Retention index (RI) (%) was calculated by subtracting SUVe from SUVd and dividing by SUVe. Logistic regression analysis was performed with seven kinds of models, consisting of (1) SUVe, (2) SUVd, (3) RI, (4) SUVe and SUVd, (5) SUVe and RI, (6) SUVd and RI, and (7) SUVe, SUVd and RI. The seven derived models were compared by receiver-operating characteristic (ROC) analysis. k-Fold cross-validation was performed with k values of 5 and 10. p < 0.05 was considered statistically significant. Results: Model (1) including the term of SUVe showed the largest area under the ROC curve among the seven models. The cut-off probability of metastasis of 3.5% with SUVe of 2.5 revealed a sensitivity of 78% and a specificity of 81% on ROC analysis, and approximately 60% and 80% on k-fold cross-validation. Conclusion: Single scanning of PET/CT is sufficiently useful for evaluating mediastinal and hilar nodes for metastasis.

  6. Low-dose non-enhanced CT versus full-dose contrast-enhanced CT in integrated PET/CT studies for the diagnosis of uterine cancer recurrence

    Energy Technology Data Exchange (ETDEWEB)

    Kitajima, Kazuhiro [Institute of Biomedical Research and Innovation, Department of PET Diagnosis, Kobe (Japan); Kobe University Graduate School of Medicine, Department of Radiology, Kobe (Japan); Suzuki, Kayo [Institute of Biomedical Research and Innovation, Department of PET Diagnosis, Kobe (Japan); Nakamoto, Yuji [Kyoto University Hospital, Department of Diagnostic Radiology, Kyoto (Japan); Onishi, Yumiko; Sakamoto, Setsu; Sugimura, Kazuro [Kobe University Graduate School of Medicine, Department of Radiology, Kobe (Japan); Senda, Michio [Institute of Biomedical Research and Innovation, Department of Molecular Imaging, Kobe (Japan); Kita, Masato [Kobe City Medical Center General Hospital, Department of Obstetrics and Gynecology, Kobe (Japan)

    2010-08-15

    To evaluate low-dose non-enhanced CT (ldCT) and full-dose contrast-enhanced CT (ceCT) in integrated {sup 18}F-fluorodeoxyglucose (FDG) PET/CT studies for restaging of uterine cancer. A group of 100 women who had undergone treatment for uterine cervical (n=55) or endometrial cancer (n=45) underwent a conventional PET/CT scans with ldCT, and then a ceCT scan. Two observers retrospectively reviewed and interpreted the PET/ldCT and PET/ceCT images in consensus using a three-point grading scale (negative, equivocal, or positive) per patient and per lesion. Final diagnoses were obtained by histopathological examination, or clinical follow-up for at least 6 months. Patient-based analysis showed that the sensitivity, specificity and accuracy of PET/ceCT were 90% (27/30), 97% (68/70) and 95% (95/100), respectively, whereas those of PET/ldCT were 83% (25/30), 94% (66/70) and 91% (91/100), respectively. Sensitivity, specificity and accuracy did not significantly differ between two methods (McNemar test, p=0.48, p=0.48, and p=0.13, respectively). There were 52 sites of lesion recurrence: 12 pelvic lymph node (LN), 11 local recurrence, 8 peritoneum, 7 abdominal LN, 5 lung, 3 supraclavicular LN, 3 liver, 2 mediastinal LN, and 1 muscle and bone. The grading results for the 52 sites of recurrence were: negative 5, equivocal 0 and positive 47 for PET/ceCT, and negative 5, equivocal 4 and positive 43 for PET/ldCT, respectively. Four equivocal regions by PET/ldCT (local recurrence, pelvic LN metastasis, liver metastasis and muscle metastasis) were correctly interpreted as positive by PET/ceCT. PET/ceCT is an accurate imaging modality for the assessment of uterine cancer recurrence. Its use reduces the frequency of equivocal interpretations. (orig.)

  7. Quantitative evaluation in enhancement of pancreas and adjacent vessels during spiral CT

    International Nuclear Information System (INIS)

    Kim, Hyoung Seuk; Shin, Kue Hee; Park, Cheol Min; Cha, Sang Hoon; Chung, Kyoo Byung

    1997-01-01

    To determine by quantitative evaluation of pancreatic and adjacent vascular enhancement during spiral CT, the ideal scan delay for examination of the pancreas. Dual(n=3D90) and triple(n=3D90) phase spiral CT scans of patients whose pancreas showed no pathologic condition were retrospectively evaluated. Dual-phase scans were performed at 43 seconds(early), and 5-6 minutes(delayed) after the injection of 120ml of contrast material at an injection rate of 3ml/sec;triple-phase scans were performed at 25 seconds(arterial),60-65 seconds (portal) and 5-6 minutes (delayed) after the injection of 120-140ml of contrast material at an injection rate of 2-4ml/sec, and ten patients also underwent precontrast scanning. CT attenuation values(HU) were measured in the head, body and tail of the pancreas, aorta, and main portal vein during each phase of all scans. Triple-phase protocol was used to measure the effect of different total volumes and injection rates on enhancement of the pancreas and adjacent vessels. There was no significant difference in the degree of enhancement of the pancreas head, body and tail during each phase(p>0.05). The pancreas was maximally enhanced on 43 second delayed scan(132±20HU)(p 0.05). The main portal vein showed maximum enhancement on 43-second delayed scan(207±44HU)(p<0.05). Different total volume of contrast material did not change the enhancement of the pancreas and adjacent vessels. At an injection rate of 2ml/sec, peak enhancement of the pancreas, aorta and portal vein was obtained on 60-65 second delayed scan, and at 4ml/sec, peak enhancement was obtained on 25 second delayed scan(p<0.05). Observing the usual protocols for abdominal spiral CT scanning, the pancreas was most effectively evaluated using a 43-second delayed scan. An increased injection rate resulted in earlier enhancement of the pancreas, aorta and portal vein

  8. Serial CT scans of cerebral hypoxia due to prolonged status epilepticus

    Energy Technology Data Exchange (ETDEWEB)

    Saiwai, Shigeo; Matsumura, Yasumasa; Tamaoka, Koichi; Fukuda, Teruo; Miyamoto, Takeshi [Kobe Central Municipal Hospital, Kobe (Japan)

    1983-04-01

    Serial computed tomography (CT) scans of 5 infants with status epilepticus were reviewed. Four out of the 5 infants fortunately had CT scans before status epilepticus because of a convulsion. There was a diffuse and mild low density in the hemisphere, with small ventricles and tight sulci (brain swelling) at 1 to 2 days after ictus. Thereafter, a diffuse low density became apparent except for the cerebellum, the brain stem, the thalamus, and the basal ganglia. Two to 4 weeks after ictus, a localized, mottled low density was demonstrated on the cerebral mantle and atrophic changes became progressively clear. In 3 cases, no abnormal enhancement was elicited on contrast CT scans performed between 5 to 16 days after status epilepticus. We discussed the possible pathophysiological aspects of the brain damage due to ''prolonged status epilepticus.''

  9. {sup 18}F-FDG PET/CT imaging versus dynamic contrast-enhanced CT for staging and prognosis of inflammatory breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Champion, Laurence; Edeline, Veronique; Giraudet, Anne-Laure; Wartski, Myriam [Service de Medecine Nucleaire, Saint-Cloud (France); Lerebours, Florence [Service d' Oncologie Medicale, Saint-Cloud (France); Cherel, Pascal [Institut Curie, Hopital Rene Huguenin, Service de Radiologie, Saint-Cloud (France); Bellet, Dominique [Service de Medecine Nucleaire, Saint-Cloud (France); Universite Paris Descartes, Pharmacologie Chimique et Genetique and Imagerie, Inserm U1022 CNRS UMR 8151, Faculte des sciences pharmaceutiques et biologiques, Paris (France); Alberini, Jean-Louis [Service de Medecine Nucleaire, Saint-Cloud (France); Universite Versailles Saint-Quentin, Faculte de medecine, Saint-Quentin-en-Yvelines (France)

    2013-08-15

    Inflammatory breast cancer (IBC) is the most aggressive type of breast cancer with a poor prognosis. Locoregional staging is based on dynamic contrast-enhanced (DCE) CT or MRI. The aim of this study was to compare the performances of FDG PET/CT and DCE CT in locoregional staging of IBC and to assess their respective prognostic values. The study group comprised 50 women (median age: 51 {+-} 11 years) followed in our institution for IBC who underwent FDG PET/CT and DCE CT scans (median interval 5 {+-} 9 days). CT enhancement parameters were net maximal enhancement, net early enhancement and perfusion. The PET/CT scans showed intense FDG uptake in all primary tumours. Concordance rate between PET/CT and DCE CT for breast tumour localization was 92 %. No significant correlation was found between SUVmax and CT enhancement parameters in primary tumours (p > 0.6). PET/CT and DCE CT results were poorly correlated for skin infiltration (kappa = 0.19). Ipsilateral foci of increased axillary FDG uptake were found in 47 patients (median SUV: 7.9 {+-} 5.4), whereas enlarged axillary lymph nodes were observed on DCE CT in 43 patients. Results for axillary node involvement were fairly well correlated (kappa = 0.55). Nineteen patients (38 %) were found to be metastatic on PET/CT scan with a significant shorter progression-free survival than patients without distant lesions (p = 0.01). In the primary tumour, no statistically significant difference was observed between high and moderate tumour FDG uptake on survival, using an SUVmax cut-off of 5 (p = 0.7 and 0.9), or between high and low tumour enhancement on DCE CT (p > 0.8). FDG PET/CT imaging provided additional information concerning locoregional involvement to that provided by DCE CT on and allowed detection of distant metastases in the same whole-body procedure. Tumour FDG uptake or CT enhancement parameters were not correlated and were not found to have any prognostic value. (orig.)

  10. Multiphase CT scanning and different intravenous contrast media concentrations in combined F-18-FDG PET/CT: Effect on quantitative and clinical assessment

    Energy Technology Data Exchange (ETDEWEB)

    Rebiere, Marilou, E-mail: Marilou.Rebiere@rwth-aachen.de [Department of Nuclear Medicine, University Hospital RWTH Aachen, Pauwelsstrasse 30, 52057 Aachen (Germany); Verburg, Frederik A., E-mail: fverburg@ukaachen.de [Department of Nuclear Medicine, University Hospital RWTH Aachen, Pauwelsstrasse 30, 52057 Aachen (Germany); Department of Nuclear Medicine, Maastricht University Medical Center, P. Debeylaan 25, 6202 AZ Maastricht (Netherlands); Palmowski, Moritz, E-mail: mpalmowski@ukaachen.de [Department of Nuclear Medicine, University Hospital RWTH Aachen, Pauwelsstrasse 30, 52057 Aachen (Germany); Department of Radiology, University Hospital RWTH Aachen, Pauwelsstrasse 30, 52057 Aachen (Germany); Department of Experimental Molecular Imaging, University Hospital RWTH Aachen, Pauwelsstrasse 30, 52057 Aachen (Germany); Krohn, Thomas, E-mail: tkrohn@ukaachen.de [Department of Nuclear Medicine, University Hospital RWTH Aachen, Pauwelsstrasse 30, 52057 Aachen (Germany); Pietsch, Hubertus, E-mail: hubertus.pietsch@bayer.com [Contrast Media Research, Bayer Pharma AG, Muellerstr. 178, 13353 Berlin (Germany); Kuhl, Christiane K., E-mail: ckuhl@ukaachen.de [Department of Radiology, University Hospital RWTH Aachen, Pauwelsstrasse 30, 52057 Aachen (Germany); Mottaghy, Felix M., E-mail: fmottaghy@ukaachen.de [Department of Nuclear Medicine, University Hospital RWTH Aachen, Pauwelsstrasse 30, 52057 Aachen (Germany); Department of Nuclear Medicine, Maastricht University Medical Center, P. Debeylaan 25, 6202 AZ Maastricht (Netherlands); Behrendt, Florian F., E-mail: fbehrendt@ukaachen.de [Department of Nuclear Medicine, University Hospital RWTH Aachen, Pauwelsstrasse 30, 52057 Aachen (Germany)

    2012-08-15

    Purpose: To evaluate the influence of multiphase CT scanning and different intravenous contrast media on contrast enhancement, attenuation correction and image quality in combined PET/CT. Material and methods: 140 patients were prospectively enrolled for F-18-FDG-PET/CT including a low-dose unenhanced, arterial and venous contrast enhanced CT. The first (second) 70 patients, received contrast medium with 370 (300) mg iodine/ml. The iodine delivery rate (1.3 mg/s) and total iodine load (44.4 g) were identical for both groups. Contrast enhancement and maximum and mean standardized FDG uptake values (SUVmax and SUVmean) were determined for the un-enhanced, arterial and venous PET/CT at multiple anatomic sites and PET reconstructions were visually evaluated. Results: Arterial contrast enhancement was significantly higher for the 300 mg/ml contrast medium compared to 370 mg I/ml at all anatomic sites. Venous enhancement was not different between the two contrast media. SUVmean and SUVmax were significantly higher for the contrast enhanced compared to the non-enhanced PET/CT at all anatomic sites (all P < 0.001). Tracer uptake was significantly higher in the arterial than in the venous PET/CT in the arteries using both contrast media (all P < 0.001). No differences in tracer uptake were found between the contrast media (all P > 0.05). Visual assessment revealed no relevant differences between the different PET reconstructions. Conclusions: There is no relevant qualitative influence on the PET scan from the use of different intravenous contrast media in its various phases in combined multiphase PET/CT. For quantitative analysis of tracer uptake it is required to use an identical PET/CT protocol.

  11. Enhancement pattern of small hepatic hemangioma: findings on multiphase spiral CT and dynamic MRI

    International Nuclear Information System (INIS)

    Choi, Byung In; Lee, Seung Koo; Kim, Myeong Jin; Chung, Jae Joon; Yoo, Hyung Sik; Lee, Jong Tae

    1999-01-01

    To compare the enhancement characteristics of small hemangiomas seen on multiphase spiral CT and dynamic MR imaging. Thirteen patients with 20 hepatic hemangiomas less than 25mm in diameter underwent both multiphase spiral CT and dynamic MR imaging. All lesions were assigned to one of three classified into 3 categories according to the enhancement pattern seen on multiphase spiral CT : typical delayed pooling, atypical early enhancement, or continuous low attenuation. The enhancement patterns seen on spiral CT and on dynamic MRI were correlated. On CT scans, ten lesions (50%) showed delayed pooling. Six (30%) showed early arterial enhancement and four (20%) showed continuous low attenuation. On delayed-phase MRI, all lesions showed delayed high signal intensity compared to adjacent liver parenchyma. Four of six lesions with early enhancement on CT showed peripheral globular enhancement on early arterial-phase MRI. On multiphase spiral CT scans, small hemangiomas can show variable atypical enhancement features. In this situation, contrast-enhanced dynamic MRI is helpful for the diagnosis of hemangiomas

  12. Early appearance of SARS on chest CT scan

    International Nuclear Information System (INIS)

    Cheng Xiaoguang; Feng Suchen; Xia Guoguang; Zhao Tao; Gu Xiang; Qu Hui

    2003-01-01

    Objective: To evaluate the early appearance of SARS on chest CT scan and its role in the early diagnosis. Methods: Forty cases of SARS in keeping with the criteria of the Ministry of Health had chest CT scans within 7 days of onset of symptoms, and CR chest X-ray films were available as well. These chest X-rays and CT images were retrospectively reviewed to determine if there were any abnormalities on the images. The lesions on the chest CT images were then further analyzed in terms of the number, location, size, and density. Results: Positive abnormalities on chest CT scans were revealed in all 40 SARS cases. Positive findings on CR chest films were showed in only 25 cases, equivocal in 6, and normal in 9 cases. The main abnormalities seen on CT and X-rays were pulmonary infiltrations varied markedly in severity. 70 % cases had 1 or 2 lesions on chest CT scan, 30 % cases had 3 or more lesions. The lesions seen on chest CT scan tended to be ground-glass opacification, sometimes with consolidation which was very faint and inhomogeneous, easily missed on chest X-rays. Typically the lesions were located in the periphery of the lung, or both central and peripheral lung, but very rare in a pure central location. They were commonly in the shape of patch or ball. Conclusions: Chest CT scan is much more sensitive in detecting the lesions of the lung in SARS. The early appearance of SARS on chest CT scan is characteristic but non-specific, indicating that chest CT scan plays a very important role in the early diagnosis and differential diagnosis of SARS

  13. Dual-time point scanning of integrated FDG PET/CT for the evaluation of mediastinal and hilar lymph nodes in non-small cell lung cancer diagnosed as operable by contrast-enhanced CT

    Energy Technology Data Exchange (ETDEWEB)

    Kasai, Takami, E-mail: takaby@hotmail.co [Department of Radiology, Chiba University Hospital, 1-8-1 Inohana, Chuo-ku, Chiba City, Chiba-ken 260-8677 (Japan); Motoori, Ken, E-mail: motoorik@faculty.chiba-u.j [Department of Radiology, Chiba University Hospital, 1-8-1 Inohana, Chuo-ku, Chiba City, Chiba-ken 260-8677 (Japan); Horikoshi, Takuro, E-mail: taku_steelfish@yahoo.co.j [Department of Radiology, Chiba University Hospital, 1-8-1 Inohana, Chuo-ku, Chiba City, Chiba-ken 260-8677 (Japan); Uchiyama, Katsuhiro, E-mail: ka-uchiyama@nifty.co [Diagnostic PET Imaging Center, Department of Radiology, Sannoh Medical Center, 166-2 Sannohcho, Inage-ku, Chiba City, Chiba-ken 263-0002 (Japan); Yasufuku, Kazuhiro, E-mail: kyasufuku@faculty.chiba-u.j [Department of Thoracic Surgery, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba City, Chiba-ken 260-8670 (Japan); Takiguchi, Yuichi, E-mail: takiguchi@faculty.chiba-u.j [Department of Respirology, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba City, Chiba-ken 260-8670 (Japan); Takahashi, Fumiaki, E-mail: takahashifu@pharm.kitasato-u.ac.j [Division of Biostatistics, Graduate School of Pharmaceutical Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641 (Japan); Kuniyasu, Yoshio, E-mail: kuniyasu@ace.ocn.ne.j [Diagnostic PET Imaging Center, Department of Radiology, Sannoh Medical Center, 166-2 Sannohcho, Inage-ku, Chiba City, Chiba-ken 263-0002 (Japan); Ito, Hisao, E-mail: hisao@faculty.chiba-u.j [Department of Radiology, Chiba University Hospital, 1-8-1 Inohana, Chuo-ku, Chiba City, Chiba-ken 260-8677 (Japan)

    2010-08-15

    Purpose: To evaluate whether dual-time point scanning with integrated fluorine-18 fluorodeoxyglucose ({sup 18}F-FDG) positron emission tomography and computed tomography (PET/CT) is useful for evaluation of mediastinal and hilar lymph nodes in non-small cell lung cancer diagnosed as operable by contrast-enhanced CT. Materials and methods: PET/CT data and pathological findings of 560 nodal stations in 129 patients with pathologically proven non-small cell lung cancer diagnosed as operable by contrast-enhanced CT were reviewed retrospectively. Standardized uptake values (SUVs) on early scans (SUVe) 1 h, and on delayed scans (SUVd) 2 h after FDG injection of each nodal station were measured. Retention index (RI) (%) was calculated by subtracting SUVe from SUVd and dividing by SUVe. Logistic regression analysis was performed with seven kinds of models, consisting of (1) SUVe, (2) SUVd, (3) RI, (4) SUVe and SUVd, (5) SUVe and RI, (6) SUVd and RI, and (7) SUVe, SUVd and RI. The seven derived models were compared by receiver-operating characteristic (ROC) analysis. k-Fold cross-validation was performed with k values of 5 and 10. p < 0.05 was considered statistically significant. Results: Model (1) including the term of SUVe showed the largest area under the ROC curve among the seven models. The cut-off probability of metastasis of 3.5% with SUVe of 2.5 revealed a sensitivity of 78% and a specificity of 81% on ROC analysis, and approximately 60% and 80% on k-fold cross-validation. Conclusion: Single scanning of PET/CT is sufficiently useful for evaluating mediastinal and hilar nodes for metastasis.

  14. Serial CT scans of cerebral hypoxia due to prolonged status epilepticus

    Energy Technology Data Exchange (ETDEWEB)

    Saiwai, Shigeo; Matsumura, Yasumasa; Tamaoka, Koichi; Fukuda, Teruo; Miyamoto, Takeshi (Kobe Central Municipal Hospital, Kobe (Japan))

    1983-04-01

    Serial computed tomography (CT) scans of 5 infants with status epilepticus were reviewed. Four out of the 5 infants fortunately had CT scans before status epilepticus because of a convulsion. There was a diffuse and mild low density in the hemisphere, with small ventricles and tight sulci (brain swelling) at 1 to 2 days after ictus. Thereafter, a diffuse low density became apparent except for the cerebellum, the brain stem, the thalamus, and the basal ganglia. Two to 4 weeks after ictus, a localized, mottled low density was demonstrated on the cerebral mantle and atrophic changes became progressively clear. In 3 cases, no abnormal enhancement was elicited on contrast CT scans performed between 5 to 16 days after status epilepticus. We discussed the possible pathophysiological aspects of the brain damage due to ''prolonged status epilepticus.''

  15. Serial CT scans of cerebral hypoxia due to prolonged status epilepticus

    International Nuclear Information System (INIS)

    Saiwai, Shigeo; Matsumura, Yasumasa; Tamaoka, Koichi; Fukuda, Teruo; Miyamoto, Takeshi

    1983-01-01

    Serial computed tomography (CT) scans of 5 infants with status epilepticus were reviewed. Four out of the 5 infants fortunately had CT scans before status epilepticus because of a convulsion. There was a diffuse and mild low density in the hemisphere, with small ventricles and tight sulci (brain swelling) at 1 to 2 days after ictus. Thereafter, a diffuse low density became apparent except for the cerebellum, the brain stem, the thalamus, and the basal ganglia. Two to 4 weeks after ictus, a localized, mottled low density was demonstrated on the cerebral mantle and atrophic changes became progressively clear. In 3 cases, no abnormal enhancement was elicited on contrast CT scans performed between 5 to 16 days after status epilepticus. We discussed the possible pathophysiological aspects of the brain damage due to ''prolonged status epilepticus.'' (author)

  16. Pediatric CT Scans

    Science.gov (United States)

    The Radiation Epidemiology Branch and collaborators have initiated a retrospective cohort study to evaluate the relationship between radiation exposure from CT scans conducted during childhood and adolescence and the subsequent development of cancer.

  17. Heart CT scan

    Science.gov (United States)

    ... make to decrease the risk of heart disease. Risks Risks of CT scans include: Being exposed to ... urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows ...

  18. Application of dual-energy scanning technique with dual-source CT in pulmonary mass lesions

    International Nuclear Information System (INIS)

    Jiang Jie; Xu Yiming; He Bo; Xie Xiaojie; Han Dan

    2012-01-01

    Objective: To explore the feasibility of DSCT dual-energy technique in pulmonary mass lesions. Methods: A total of 100 patients with pulmonary masses underwent conventional plain CT scan and dual-energy enhanced CT scan. The virtual non-contrast (VNC) images were obtained at post-processing workstation.The mean CT value,enhancement value,signal to noise ratio (SNR), image quality and radiation dose of pulmonary masses were compared between the two scan techniques using F or t test and the detectability of lesions was compared using Wilcoxon test. Results: There was no statistically significant difference among VNC (A) (32.89 ± 12.58) HU,VNC (S) (30.86 ± 9.60) HU and conventional plain images (35.89 ± 9.99) HU in mean CT value of mass (F =2.08, P>0.05). There was statistically significant difference among VNC (A) (3.29 ± 1.45), VNC (S) (3.93 ± 1.49) and conventional plain image (4.61 ± 1.50) in SNR (F =6.01, P<0.05), which of conventional plain scan was higher than that of VNC.The enhancement value of mass in conventional enhanced scan (60.74 ± 13.9) HU and distribution of iodine from VNC (A) (58.26 ± 31.99) HU was no statistically significant difference (t=0.48, P>0.05), but there was a significant difference between conventional enhanced scan (56.51 ± 17.94) HU and distribution of iodine from VNC (S) (52.65 ± 16.78) HU (t=4.45, P<0.05). There was no statistically significant difference among conventional plain scan (4.69 ± 0.06) and VNC (A) (4.60 ± 0.09), VNC (S) (4.61 ±0.11) in image quality at mediastinal window (F=3.014, P>0.05). The appearance, size, internal features of mass (such as necrosis, calcification and cavity) were showed the same in conventional plain scan, VNC (A) and VNC (S). Of 41 patients with hilar mass, 18 patients were found to have lobular and segmental perfusion decrease or defect. Perfusion defect area was found in 59 patients with peripheral lung mass. The radiation dose of dual-energy enhanced scan was lower than that of

  19. Alveolar architecture of clear cell renal carcinomas (≤5.0 cm) show high attenuation on dynamic CT scanning

    International Nuclear Information System (INIS)

    Fujimoto, Hiroyuki; Wakao, Fumihiko; Moriyama, Noriyuki; Tobisu, Kenichi; Kakizoe, Tadao; Sakamoto, Michiie

    1999-01-01

    To establish the correlation between tumor appearance on CT and tumor histology in renal cell carcinomas. The density and attenuation patterns of 96 renal cell carcinomas, each ≤5 cm in greatest diameter, were studied by non-enhanced CT and early and late after bolus injection of contrast medium using dynamic CT. The density and attenuation patterns and pathological maps of each tumor were individually correlated. High attenuated areas were present in 72 of the 96 tumors on early enhanced dynamic CT scanning. All 72 high attenuated areas were of the clear cell renal cell carcinoma and had alveolar architecture. The remaining 24 tumors that did not demonstrate high attenuated foci on early enhanced scanning included three clear cell, nine granular cell, six papillary, five chromophobe and one collecting duct type. With respect to tumor architecture, all clear cell tumors of alveolar architecture demonstrated high attenuation on early enhanced scanning. Clear cell renal cell carcinomas of alveolar architecture show high attenuation on early enhanced dynamic CT scanning. A larger number of patients are indispensable to obtaining clear results. However, these findings seem to be an important clue to the diagnosis of renal cell carcinomas as having an alveolar structure. (author)

  20. Automated Detection of Healthy and Diseased Aortae from Images Obtained by Contrast-Enhanced CT Scan

    Directory of Open Access Journals (Sweden)

    Michael Gayhart

    2013-01-01

    Full Text Available Purpose. We developed the next stage of our computer assisted diagnosis (CAD system to aid radiologists in evaluating CT images for aortic disease by removing innocuous images and highlighting signs of aortic disease. Materials and Methods. Segmented data of patient’s contrast-enhanced CT scan was analyzed for aortic dissection and penetrating aortic ulcer (PAU. Aortic dissection was detected by checking for an abnormal shape of the aorta using edge oriented methods. PAU was recognized through abnormally high intensities with interest point operators. Results. The aortic dissection detection process had a sensitivity of 0.8218 and a specificity of 0.9907. The PAU detection process scored a sensitivity of 0.7587 and a specificity of 0.9700. Conclusion. The aortic dissection detection process and the PAU detection process were successful in removing innocuous images, but additional methods are necessary for improving recognition of images with aortic disease.

  1. Usefulness of percentage enhancement washout value calculated on unenhanced, contrast-enhanced, and delayed enhanced CT in adrenal masses: adenoma versus metastasis

    International Nuclear Information System (INIS)

    Sohn, Kyung Myung; Lee, Sung Yong; Lee, Keun Ho

    2003-01-01

    To determine the usefulness of percentage enhancement washout value calculated on unenhanced, enhanced and delayed enhanced CT scans for the characterization of adrenal masses. Forty adrenal masses less than 5 cm in size were assessed using a protocol consisting of unenhanced CT, enhanced CT 60 seconds after intravenous administration of contrast material, and delayed enhanced CT at 10 minutes. The CT attenuation value of adrenal tumors was estimated on each scan, and percentage enhancement washout value was calculated as follows:[(attenuation value at enhanced CT-attenuation value at delayed CT)/ (attenuation value at enhanced CT-attenuation value at unenhanced CT)x100]. An adrenal mass was considered benign if its percentage enhancement washout value was at the threshold value, set to 60% and 50%, or higher. The accuracy of the procedure was determined by comparing its findings with the final clinical diagnosis. Twenty-nine massess were benign and 11 were malignant. The mean percentage enhancement washout value of the former was significantly higher than that of the latter (66.7% vs. 21.8%; p<0.01). All adenomas except one had a washout value of more than 50%. With a percentage washout threshold of 60%, 35 of 40 lesions were correctly characterized as benign or malignant [sensitivity 82.7% (24/29), specificity 100% (11/11), accuracy 87.5% (35/40)]; with a threshold of 50%, 39 of 40 lesions were correctly characterized [(sensitivity 96.5% (28/29), specificity 100% (11/11), accuracy 97.5% (39/40)]. Percentage enhancement washout values are useful for characterizing an adrenal mass as benign or malignant. For characterization, a threshold value of 50% was more accurate than one of 60%

  2. FDG-avid portal vein tumor thrombosis from hepatocellular carcinoma in contrast-enhanced FDG PET/CT

    Directory of Open Access Journals (Sweden)

    Canh Nguyen

    2015-01-01

    Full Text Available Objective(s: In this study, we aimed to describe the characteristics of portal vein tumor thrombosis (PVTT, complicating hepatocellular carcinoma (HCC in contrast-enhanced FDG PET/CT scan. Methods: In this retrospective study, 9 HCC patients with FDG-avid PVTT were diagnosed by contrast-enhanced fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT, which is a combination of dynamic liver CT scan, multiphase imaging, and whole-body PET scan. PET and CT DICOM images of patients were imported into the PET/CT imaging system for the re-analysis of contrast enhancement and FDG uptake in thrombus, the diameter of the involved portal vein, and characteristics of liver tumors and metastasis. Results: Two patients with previously untreated HCC and 7 cases with previously treated HCC had FDG-avid PVTT in contrast-enhanced FDG PET/CT scan. During the arterial phase of CT scan, portal vein thrombus showed contrast enhancement in 8 out of 9 patients (88.9%. PET scan showed an increased linear FDG uptake along the thrombosed portal vein in all patients. The mean greatest diameter of thrombosed portal veins was 1.8 ± 0.2 cm, which was significantly greater than that observed in normal portal veins (P<0.001. FDG uptake level in portal vein thrombus was significantly higher than that of blood pool in the reference normal portal vein (P=0.001. PVTT was caused by the direct extension of liver tumors. All patients had visible FDG-avid liver tumors in contrast-enhanced images. Five out of 9 patients (55.6% had no extrahepatic metastasis, 3 cases (33.3% had metastasis of regional lymph nodes, and 1 case (11.1% presented with distant metastasis. The median estimated survival time of patients was 5 months. Conclusion: The intraluminal filling defect consistent with thrombous within the portal vein, expansion of the involved portal vein, contrast enhancement, and linear increased FDG uptake of the thrombus extended from liver tumor are

  3. Diagnosis of gynecologic pelvic masses by CT scans

    International Nuclear Information System (INIS)

    Ito, Hisao; Kubo, Atsushi; Takagi, Yaeko; Kinoshita, Fumio; Maekawa, Akira.

    1981-01-01

    Two hundred eighty four patients with gynecologic pelvic masses were evaluated with CT scans. Of the patients, 196 had subsequent surgical determination of abnormalities and pathological proof of diagnosis was obtained. Only these 196 patients were included in this study. The CT scans could provide correct diagnosis in 113 of 114 (99%) patients with benign uterine tumor and in all (100%) patients with either serous cystadenoma or dermoid cyst. However, evaluation of mucinous cystadenoma (44%) and endometriosis cyst (37%) by CT scan has some limitations. It was difficult to differentiate mucinous cystadenoma from ovarian carcinoma, because both lesions had partial multiloculation and solid-like areas in the cyst. The CT findings of endometriosis cyst had similarity with serous cystadenoma, and 5 of 8 patients with this disease were diagnosed as serous cystadenoma. Ovarian fibroma and endometrial cancer were also not determined by CT scans. CT identified 87% of patients with ovarian cancer, while false positive rate of this disease was 38% (8/21). In 6 of 13 patients with both of leiomyoma and ovarian cyst, CT was able to demonstrate ovarian lesions that were overlooked by bimanual examinations. The role of CT scanning in our clinical practice is discussed. (author)

  4. Lecithin-coated gold nanoflowers (GNFs) for CT scan imaging applications and biochemical parameters; in vitro and in vivo studies.

    Science.gov (United States)

    Aziz, Farooq; Bano, Khizra; Siddique, Ahmad Hassan; Bajwa, Sadia Zafar; Nazir, Aalia; Munawar, Anam; Shaheen, Ayesha; Saeed, Madiha; Afzal, Muhammad; Iqbal, M Zubair; Wu, Aiguo; Khan, Waheed S

    2018-01-09

    We report a novel strategy for the fabrication of lecithin-coated gold nanoflowers (GNFs) via single-step design for CT imaging application. Field-emission electron microscope confirmed flowers like morphology of the as-synthesized nanostructures. Furthermore, these show absorption peak in near-infrared (NIR) region at λ max 690 nm Different concentrations of GNFs are tested as a contrast agent in CT scans at tube voltage 135 kV and tube current 350 mA. These results are compared with same amount of iodine at same CT scan parameters. The results of in vitro CT scan study show that GNFs have good contrast enhancement properties, whereas in vivo study of rabbits CT scan shows that GNFs enhance the CT image clearly at 135 kV as compared to that of iodine. Cytotoxicity was studied and blood profile show minor increase of white blood cells and haemoglobin, whereas decrease of red blood cells and platelets.

  5. Computed tomography of liver tumors, 2. Differential diagnosis between hepatocellular carcinoma and metastatic hepatic tumor by dynamic CT scanning

    Energy Technology Data Exchange (ETDEWEB)

    Naito, Akira; Fukuoka, Haruhito; Kashiwado, Kouzou; Ichiki, Toshio; Makidono, Yoko [Hiroshima Red Cross Hospital (Japan)

    1984-02-01

    Differential diagnosis between hepatocellular carcinoma and metastatic hepatic tumor was attempted using dynamic CT scanning. Homogeneous and patchy types were peculiar to hepatocellular carcinoma, and ring-like type to metastatic hepatic tumor. However, with no enhancement, hepatocellular carcinoma could not be denied. Hepatocellular carcinoma was characterized by the enhancement shown on the early stage of dynamic CT. Ring enhancement was not visualized on dynamic CT but visualized on conventional contrast enhanced CT in hepatocellular carcinomas; it was visualized on conventional contrast enhanced CT and on dynamic CT in metastatic hepatic tumors.

  6. CT scan of Parkinson's disease

    Energy Technology Data Exchange (ETDEWEB)

    Konishi, T; Noguchi, S; Nishitani, H [National Sanatorium of Utano, Kyoto (Japan); Kitano, H; Ikegami, Y

    1981-04-01

    In forty-eight patients with Parkinson's disease, we examined the ventricular size and the degree of cortical atrophy which were measured by the photos of CT scan and compared them with their clinical symptoms and side effects of anti-parkinsonian drugs. The ventricular size was expressed as the ventricular ratio which is the percentage of superimposed lateral ventricular area to the white and gray matter area at the slice number 2B of CT scan photos. The degree of the cortical atrophy was expressed as the sulcal numbers which were clearly visualized at the slice number 3B or 4A of CT scan photos. We used the CT scan photos of age-matched other patients which did not show definit central nervous system abnormalities. Our findings were as follows: (1) The ventricular enlargement was observed in the parkinsonian patients who showed dementia and/or Yahr's classification grades IV or V. (2) There was no correlation between the duration of this disease and the L--dopa treatments with the ventricular size and sulcal numbers. (3) The side effects of drugs such as visual hallucination were tended to be observed in the patients who showed the ventricular enlargement. (4) There was no definite correlation between the degree of cortical atrophy with clinical symptoms and side effects of various drugs. These findings suggested that the ventricular enlargement in Parkinson's disease was an important sign of dementia and the tendency of appearance of side effects of various drugs.

  7. CT scan of Parkinson's disease

    International Nuclear Information System (INIS)

    Konishi, Tetsuro; Noguchi, Sadako; Nishitani, Hiroshi; Kitano, Haruo; Ikegami, Yoshinori.

    1981-01-01

    In forty-eight patients with Parkinson's disease, we examined the ventricular size and the degree of cortical atrophy which were measured by the photos of CT scan and compared them with their clinical symptoms and side effects of anti-parkinsonian drugs. The ventricular size was expressed as the ventricular ratio which is the percentage of superimposed lateral ventricular area to the white and gray matter area at the slice number 2B of CT scan photos. The degree of the cortical atrophy was expressed as the sulcal numbers which were clearly visualized at the slice number 3B or 4A of CT scan photos. We used the CT scan photos of age-matched other patients which did not show definit central nervous system abnormalities. Our findings were as follows: (1) The ventricular enlargement was observed in the parkinsonian patients who showed dementia and/or Yahr's classification grades IV or V. (2) There was no correlation between the duration of this disease and the L--dopa treatments with the ventricular size and sulcal numbers. (3) The side effects of drugs such as visual hallucination were tended to be observed in the patients who showed the ventricular enlargement. (4) There was no definite correlation between the degree of cortical atrophy with clinical symptoms and side effects of various drugs. These findings suggested that the ventricular enlargement in Parkinson's disease was an important sign of dementia and the tendency of appearance of side effects of various drugs. (author)

  8. Preliminary study of the scan-delay-time during the combined examation of CT perfusion and CT angiography after contrast media administration in cerebral and cervical CT angiography

    International Nuclear Information System (INIS)

    Cai Wu; Gong Jianping; Zhu Jiangtao; Qiao Fang; Chen Guangqiang; Zhang Bo; Yi Bixing; Qian Minghui

    2010-01-01

    Objective: To discuss the feasibility of the time to peak of cerebral CT perfusion (CTP) in predicting the scan-delay-time after contrast media administration in cerebral and cervical CT angiography (CTA). Methods: Retrospective Analysis was performed in eighty patients who had been examined with cerebral and cervical CTA, they were divided randomly into two groups. Group A:40 patients were performed by the method of experience of 20 seconds as scan-delay-time. Group B:the other 40 patients were examined with the combination scanning technology of CTP-CTA. They were all measured with enhancement value of CT in the M1 segment of left middle cerebral artery, superior sagittal sinus , left common carotid artery adjacent to the fourth cervical vertebrace and internal jugular vein, and then calculate the difference between the arterys and the veins in the same layer. Statistical significance was determined with t test. Results: (1)The enhancement value of CT in the cerebral and cervical artery vessels and the resolving power between the arterys and the veins in the same layer of group B were higher than that in group A. (2) Group B whose cerebral and cervical artery vessels rescontructed from the raw CT data set showed clearly; There were an advance in 3 cases (7.5%), a delay in 5 cases (12.5%) in group A whose cerebral and cervical artery vessels rescontructed from the raw CT data set didn't show clearly.Conclusion It's a satisfactory method based on successful cerebral and cervical CTA study to take the time to peak in CT perfusion as the scan-delay-time during the combined examination of CTP and CTA with 64-detector spiral CT. (authors)

  9. Role of computed tomography (CT scan in staging of cervical carcinoma

    Directory of Open Access Journals (Sweden)

    T V Prasad

    2014-01-01

    Full Text Available Background & objectives: Staging of cervical carcinoma is done clinically using International Federation of Obstetrics and Gynecology (FIGO guidelines. It is based on physical examination findings and also includes results of biopsy, endoscopy and conventional radiological tests like chest radiograph, intravenous urography and barium enema. These conventional radiological investigations have largely been replaced by computed tomography (CT and magnetic resonance imaging (MRI at present. FIGO staging system does not consider CT and MRI mandatory; however, use of these modalities are encouraged. This prospective study was conducted to determine the role of CT in staging work up in women diagnosed with cervical carcinoma. Methods: Fifty three women diagnosed with cervical carcinoma were evaluated with contrast enhanced CT scan of abdomen and pelvis. CT scan images were especially evaluated to determine tumour size, invasion of parmetrium, pelvic walls, rectum, urinary bladder and ureters, pelvic or retroperitoneal lymphadenopathy and distant metastases. CT findings were associated with clinical findings and staging, including findings from cystoscopy and sigmoidoscopy. Results: There was a poor agreement between clinical and CT staging of cervical carcinoma. Primary tumour was demonstrated on CT in 36 (70% of 53 patients. CT underestimated the parametrial, vaginal and pelvic wall invasion when compared with physical examination. CT overestimated the urinary bladder and rectal invasion when compared with cysto-sigmoidoscopy, however, CT had 100 per cent negative predictive value (NPV to exclude bladder and rectal involvement. CT detection of lymph node enlargement and lung metastases influenced the management. Interpretation & conclusions: Our findings show that CT scan does not reliably correlate with clinical FIGO staging of cervical cancer. However, it can detect urinary obstruction as well as nodal or distant metastases and thus improves the

  10. Metal artifact reduction of CT scans to improve PET/CT

    NARCIS (Netherlands)

    Van Der Vos, Charlotte S.; Arens, Anne I.J.; Hamill, James J.; Hofmann, Christian; Panin, Vladimir Y.; Meeuwis, Antoi P.W.; Visser, Eric P.; De Geus-Oei, Lioe Fee

    2017-01-01

    In recent years, different metal artifact reduction methods have been developed for CT. These methods have only recently been introduced for PET/CT even though they could be beneficial for interpretation, segmentation, and quantification of the PET/CT images. In this study, phantom and patient scans

  11. Metal Artifact Reduction of CT Scans to Improve PET/CT

    NARCIS (Netherlands)

    Vos, C.S. van der; Arens, A.I.J.; Hamill, J.J.; Hofmann, C.; Panin, V.Y.; Meeuwis, A.P.W.; Visser, E.P.; Geus-Oei, L.F. de

    2017-01-01

    In recent years, different metal artifact reduction methods have been developed for CT. These methods have only recently been introduced for PET/CT even though they could be beneficial for interpretation, segmentation, and quantification of the PET/CT images. In this study, phantom and patient scans

  12. Correlation between image quality of CT scan and amount of intravenous contrast media

    International Nuclear Information System (INIS)

    Yoon, Dae Young; Choi, Dae Seob; Kim, Seung Hyup; Han, Joon Koo; Choi, Byung Ihn; Im, Jung Gi; Han, Moon Hee; Chang, Kee Hyun; Kim, Jong Hyo; Han, Man Chung

    1993-01-01

    A blind, comparative clinical study was performed prospectively to examine the correlation between image quality of CT scan in terms of contrast enhancement effect and amount of intravenous contrast media. A total of 357 patients were randomized into two groups. Ionic high-osmolality contrast media (68% meglumine ioglicate) was administered intravenously as 100 ml bolus in one group and as 50 ml bolus in the other group. Statistically significant differences of image quality were found in CT scans of the brain, head and neck, chest and abdomen (p 0.05). We suggest that amount of contrast media may be reduced in pelvis CT without significant degradation of image quality

  13. Multidetector row computed tomography of acute pancreatitis: Utility of single portal phase CT scan in short-term follow up

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Yongwonn [Department of Radiology, Konkuk University Medical Center, 4-12, Hwayang-dong, Gwangjin-gu, Seoul 143-729 (Korea, Republic of); Park, Hee Sun, E-mail: heesun.park@gmail.com [Department of Radiology, Konkuk University Medical Center, 4-12, Hwayang-dong, Gwangjin-gu, Seoul 143-729 (Korea, Republic of); Kim, Young Jun; Jung, Sung Il; Jeon, Hae Jeong [Department of Radiology, Konkuk University Medical Center, 4-12, Hwayang-dong, Gwangjin-gu, Seoul 143-729 (Korea, Republic of)

    2012-08-15

    Objective: The purpose of this study is to evaluate the question of whether nonenhanced CT or contrast enhanced portal phase CT can replace multiphasic pancreas protocol CT in short term monitoring in patients with acute pancreatitis. Materials and methods: This retrospective study was approved by the Institutional Review Board. From April 2006 to May 2010, a total of 52 patients having acute pancreatitis who underwent initial dual phase multidetector row CT (unenhanced, arterial, and portal phase) at admission and a short term (within 30 days) follow up dual phase CT (mean interval 10.3 days, range 3-28 days) were included. Two abdominal radiologists performed an independent review of three sets of follow up CT images (nonenhanced scan, single portal phase scan, and dual phase scan). Interpretation of each image set was done with at least 2-week interval. Radiologists evaluated severity of acute pancreatitis with regard to pancreatic inflammation, pancreatic necrosis, and extrapancreatic complication, based on the modified CT severity index. Scores of each image set were compared using a paired t-test and interobserver agreement was evaluated using intraclass correlation coefficient statistics. Results: Mean scores of sum of CT severity index on nonenhanced scan, portal phase scan, and dual phase scan were 5.7, 6.6, and 6.5 for radiologist 1, and 5.0, 5.6, and 5.8 for radiologist 2, respectively. In both radiologists, contrast enhanced scan (portal phase scan and dual phase scan) showed significantly higher severity score compared with that of unenhanced scan (P < 0.05), while portal phase and dual phase scan showed no significant difference each other. The trend was similar regarding pancreatic inflammation and extrapancreatic complications, in which contrast enhanced scans showed significantly higher score compared with those of unenhanced scan, while no significant difference was observed between portal phase scan and dual phase scan. In pancreatic necrosis

  14. Diagnostic value of axial CT scan

    International Nuclear Information System (INIS)

    Kiuchi, Sousuke

    1983-01-01

    Axial CT scan was used to investigate the radiological details of the temporal bone of 33 patients with chronic otitis media, secondary cholesteatoma, sensorineural hearing loss, Meniere disease, vertigo, facial spasm, and neoplasma. The axial scans showed anatomic details of the temporal bone, and at the same time clearly demonstrated the extent of the soft-tissue masses in the middle ears, as well as the destructions of the ossicles. Bone changes of the anterior walls of the epitympanum and external auditory meatus were more clearly demonstrated than by coronary CT scan. However, the axial scan had the disadvantages in demonstrating the stapes, crista transversa, and the mastoid portion of the facial canal. (author)

  15. CT scan for the diagnosis of maxillary sinus carcinoma

    International Nuclear Information System (INIS)

    Kimura, Yo; Kato, Isao; Aoyagi, Masaru; Kikuchi, Akira; Koike, Yoshio; Suzuki, Hachiro.

    1984-01-01

    A comparative study between the conventional radiological examination and the computed tomographical examination for the diagnosis of maxillary sinus carcinoma was done. CT scan has been more appreciated to detect the tumor invasion in the pterygopalatine fossa, orbit, posterior ethmoid sinus and skull base than the conventional examination. CT scan was most usefull for the determination of size and location of the tumor. The prognosis by the stage-grouping was significantly separated by the new classification with CT scan. Therefore, new TNM classification of maxillary sinus carcinoma with CT scan should be taken into account. (author)

  16. Body CT (CAT Scan)

    Science.gov (United States)

    ... a CT scan can be reformatted in multiple planes, and can even generate three-dimensional images. These ... other medical conditions and whether you have a history of heart disease, asthma, diabetes, kidney disease or ...

  17. Aortic valve calcification - a commonly observed but frequently ignored finding during CT scanning of the chest.

    Science.gov (United States)

    Raju, Prashanth; Sallomi, David; George, Bindu; Patel, Hitesh; Patel, Nikhil; Lloyd, Guy

    2012-06-01

    To describe the frequency and severity of Aortic valve calcification (AVC) in an unselected cohort of patients undergoing chest CT scanning and to assess the frequency with which AVC was being reported in the radiology reports. Consecutive CT scan images of the chest and the radiological reports (December 2009 to May 2010) were reviewed at the district general hospital (DGH). AVC on CT scan was visually graded on a scale ranging from 0 to IV (0 = no calcification, IV = severe calcification). Total of 416 (232 male; 184 female) CT chest scans [Contrast enhanced 302 (72%), unenhanced 114 (28%)] were reviewed. Mean age was 70.55 ± 11.48 years. AVC in CT scans was identified in 95 of the 416 patients (22.83%). AVC classification was as follows: Grade I: 60 (63.15%), Grade II: 22 (23.15%), Grade III: 9 (9.47%), Grade IV: 4 (4.21%). Only one CT report mentioned AVC. Only 31 of 95 AVC had Transthoracic echocardiogram (TTE). The interval time between CT scan and TTE was variable.   Aortic valve calcification in CT chest scans is a common finding and studies have shown that it is strongly related to the presence and severity of aortic valve disease. As CT scans are considered as a valuable additional screening tool for detection of aortic stenosis, AVC should always be commented upon in the radiology reports. Furthermore, patients with at least Grade III and IV AVC should be sent for TTE. © 2012 Blackwell Publishing Ltd.

  18. Multidetector computed tomography for the assessment of adnexal Mass: Is unenhenced CT scan necessary?

    International Nuclear Information System (INIS)

    Jung, Sung Il; Park, Hee Sun; Kim, Young Jun; Jeon, Hae Jeong

    2014-01-01

    To compare the diagnostic performance and radiation dose between contrast-enhanced CT (ECT) alone, and combined unenhanced and contrast-enhanced CT (UE + ECT) for the assessment of adnexal mass. This retrospective study was approved by the Institutional Review Board. A total of 146 consecutive patients (mean age, 41.1 years) who underwent preoperative unenhanced and contrast-enhanced multidetector CT of the pelvis and had adnexal masses found at surgery were included. Two readers independently evaluated the likelihood of adnexal malignancy on a 5-point scale on two different imaging datasets (ECT alone and UE + ECT). The area under the receiver operating characteristic curve (AUC) was used to evaluate diagnostic performance. Radiation dose to patients was calculated by the volume CT dose index (CTDIvol) and the dose length products (DLP) on each dataset. Of the total 178 adnexal masses, 133 masses were benign and 45 masses were malignant. For both readers, there is no significant difference of AUC values between ECT alone and UE + ECT for the detection of adnexal malignancy (reader 1, 0.93 vs. 0.95; reader 2, 0.92 vs. 0.91) (p > 0.05). The mean CTDIvol (12.6 ± 2.2 mGy) and DLP (641.2 ± 137.2 mGy) of ECT alone was significantly lower than the mean CTDIvol (21.5 ± 2.7 mGy) and DLP (923.6 ± 158.8 mGy) of UE + ECT (p < 0.0001). The use of unenhanced CT scan in addition to contrast-enhanced CT scan does not improve the detection of adnexal malignancy, but increases radiation exposure.

  19. Evaluation of normal brain CT scan in Korean

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Y. H.; Suh, J. H.; Park, C. Y. [Yonsei University College of Medicine, Seoul (Korea, Republic of)

    1981-06-15

    The safety of procedure combined with wealth of information have resulted in rapid acceptance of CT as a practical and reliable neurodignostic technique. To understand the alternation in tissue density and associated displacement and distortion caused by pathologic lesion in CT, it is necessary to have clear understanding of normal anatomical landmark. For the purpose of establishing normative criteria in Korean for comparative diagnosis, 500 normal CT scan without neurologic sign were studied. The brief results are follows; 1. Among many ventricular index measured for lateral ventricle, the bifrontal CVI is more sensitive and easily determined. Ventricular size increased with age, especially after 6th decade but no difference with sex. 2. Mean width of third ventricle is 5 mm ({+-} 0.3), more wider in male (male; 5.2 mm, female; 4.5 mm) and increased with age. 2. Mean width of fourth ventricle is 13 mm ({+-} 1.3), without difference in age and sex. The shape of ventricle is variable form of triangle. The position of ventricle relative to Twining's line can be determined, so ratio of distance from tuberculum sellae to center of fourth ventricle to Twining's line is between 0.46-0.52. 4. Suprasellar cistern is visible in 89.7% of scan and shape of cistern is found to be pentagonal (73.3%), hexagonal (23.0%) and tetragonal (3.7%). 5. Choroid plexus can be identified in 90% and asymmetrical in 4%. 45% of identified choroid plexus can be visible on scan without contrast enhancement, and more frequently visible in older age.

  20. Evaluation of normal brain CT scan in Koreans

    International Nuclear Information System (INIS)

    Lee, Y. H.; Suh, J. H.; Park, C. Y.

    1981-01-01

    The safety of procedure combined with wealth of information have resulted in rapid acceptance of CT as a practical and reliable neurodiagnostic technique. To understand the alternation in tissue density and associated displacement and distortion caused by pathologic lesion in CT, it is necessary to have clear understanding of normal anatomical landmark. For the purpose of establishing normartive criteria in Koreans for comparative diagnosis, 500 normal CT scan without neurologic sign were studied. The brief results are follows; 1. Among many ventricular index measured for lateral ventricle, the bifrontal CVI is more sensitive and easily determined. Ventricular size increased with age, especially after 6th decade but no difference with sex. 2. Mean width of third ventricle is 5mm( ± 0.3), more wider in male (male; 5.2mm, female; 4.5mm) and increased with age. 3. Mean width of fourth ventricle is 13mm( ± 1.3), without difference in age and sex. The shape of ventricle is variable form of triangle. The position of ventricle relative to Twining's line can be determined, so ratio of distance from tuberculum sellae to center of fourth ventricle to Twining's line is between 0.46-0.52. 4. Suprasellar cistern is visible in 89.7% of scan and shape of cistern is found to be pentagonal (73.3%), hexagonal (23.0%) and tetragonal (3.7%). 5. Choroid plexus can be identified in 90% and asymetrical in 4%. 45% of identified choroid plexus can be visible on scan without contrast enhancement, and more frequently visible in older age

  1. Evaluation of normal brain CT scan in Korean

    International Nuclear Information System (INIS)

    Lee, Y. H.; Suh, J. H.; Park, C. Y.

    1981-01-01

    The safety of procedure combined with wealth of information have resulted in rapid acceptance of CT as a practical and reliable neurodignostic technique. To understand the alternation in tissue density and associated displacement and distortion caused by pathologic lesion in CT, it is necessary to have clear understanding of normal anatomical landmark. For the purpose of establishing normative criteria in Korean for comparative diagnosis, 500 normal CT scan without neurologic sign were studied. The brief results are follows; 1. Among many ventricular index measured for lateral ventricle, the bifrontal CVI is more sensitive and easily determined. Ventricular size increased with age, especially after 6th decade but no difference with sex. 2. Mean width of third ventricle is 5 mm (± 0.3), more wider in male (male; 5.2 mm, female; 4.5 mm) and increased with age. 2. Mean width of fourth ventricle is 13 mm (± 1.3), without difference in age and sex. The shape of ventricle is variable form of triangle. The position of ventricle relative to Twining's line can be determined, so ratio of distance from tuberculum sellae to center of fourth ventricle to Twining's line is between 0.46-0.52. 4. Suprasellar cistern is visible in 89.7% of scan and shape of cistern is found to be pentagonal (73.3%), hexagonal (23.0%) and tetragonal (3.7%). 5. Choroid plexus can be identified in 90% and asymmetrical in 4%. 45% of identified choroid plexus can be visible on scan without contrast enhancement, and more frequently visible in older age

  2. Emergency medicine summary code for reporting CT scan results: implementation and survey results.

    Science.gov (United States)

    Lam, Joanne; Coughlin, Ryan; Buhl, Luce; Herbst, Meghan; Herbst, Timothy; Martillotti, Jared; Coughlin, Bret

    2018-06-01

    The purpose of the study was to assess the emergency department (ED) providers' interest and satisfaction with ED CT result reporting before and after the implementation of a standardized summary code for all CT scan reporting. A summary code was provided at the end of all CTs ordered through the ED from August to October of 2016. A retrospective review was completed on all studies performed during this period. A pre- and post-survey was given to both ED and radiology providers. A total of 3980 CT scans excluding CTAs were ordered with 2240 CTs dedicated to the head and neck, 1685 CTs dedicated to the torso, and 55 CTs dedicated to the extremities. Approximately 74% CT scans were contrast enhanced. Of the 3980 ED CT examination ordered, 69% had a summary code assigned to it. Fifteen percent of the coded CTs had a critical or diagnostic positive result. The introduction of an ED CT summary code did not show a definitive improvement in communication. However, the ED providers are in consensus that radiology reports are crucial their patients' management. There is slightly increased satisfaction with the providers with less than 5 years of experience with the ED CT codes compared to more seasoned providers. The implementation of a user-friendly summary code may allow better analysis of results, practice improvement, and quality measurements in the future.

  3. Organ dose evaluation for CT scans based on in-phantom measurements

    International Nuclear Information System (INIS)

    Liu Haikuan; Zhuo Weihai; Chen Bo; Yi Yanling; Li Dehong

    2009-01-01

    Objective: To explore the organ doses and their distributions in different projections of CT scans. Methods: The CT values were measured and the linear absorption coefficients were derived for the main organs of the anthropomorphic phantom to compare with the normal values of human beings. The radiophotoluminescent glass dosimeters were set into various tissues or organs of the phantom for mimic measurements of the organ doses undergoing the head, chest, abdomen and pelvis CT scans, respectively. Results: The tissue equivalence of the phantom used in this study was good. The brain had the largest organ dose undergoing the head CT scan. The organ doses in thyroid, breast, lung and oesophagus were relatively large in performing the chest CT scan, while the liver, stomach, colon and lung had relatively hrge organ doses in abdomen CT practice. The doses in bone surface and colon exceeded by 50 mGy in a single pelvis CT scan. Conclusions: The organ doses and their distributions largely vary with different projections of CT scans. The organ doses of colon, bone marrow,gonads and bladder are fairly large in performing pelvis CT scan, which should be paid attention in the practice. (authors)

  4. Peripancreatic vascular abnormalities complicating acute pancreatitis: contrast-enhanced helical CT findings

    International Nuclear Information System (INIS)

    Mortele, Koenraad J.; Mergo, Patricia J.; Taylor, Helena M.; Wiesner, Walter; Cantisani, Vito; Ernst, Michael D.; Kalantari, Babak N.; Ros, Pablo R.

    2004-01-01

    Objective: To determine the prevalence and morphologic helical computed tomography (CT) features of peripancreatic vascular abnormalities in patients with acute pancreatic inflammatory disease in correlation with the severity of the pancreatitis. Materials and methods: One hundred and fifty-nine contrast-enhanced helical CT scans of 100 consecutive patients with acute pancreatitis were retrospectively and independently reviewed by three observers. CT scans were scored using the CT severity index (CTSI): pancreatitis was graded as mild (0-2 points), moderate (3-6 points), and severe (7-10 points). Interobserver agreement for both the CT severity index and the presence of peripancreatic vascular abnormalities was calculated (K-statistic). Correlation between the prevalence of complications and the degree of pancreatitis was estimated using Fisher's exact test. Results: The severity of pancreatitis was graded as mild (n=59 scans), moderate (n=82 scans), and severe (n=18 scans). Venous abnormalities detected included splenic vein (SV) thrombosis (31 scans, 19 patients), superior mesenteric vein (SMV) thrombosis (20 scans, 14 patients), and portal vein (PV) thrombosis (17 scans, 13 patients). Arterial hemorrhage occurred in five patients (6 scans). In our series, no cases of arterial pseudoaneurysm formation were detected. The interobserver agreement range for scoring the degree of pancreatitis and the overall presence of major vascular abnormalities was 75.5-79.2 and 86.2-98.8%, respectively. The presence of the vascular abnormalities in correlation with the severity of pancreatitis was variable. Conclusion: Vascular abnormalities are relatively common CT findings in association with acute pancreatitis. The CT severity index is insufficiently accurate in predicting some of these complications since no statistically significant correlation between their prevalence and the severity of pancreatitis could be established

  5. Clinical and CT scan pictures of cerebral cysticercosis

    Energy Technology Data Exchange (ETDEWEB)

    Singounas, E.G.; Krassanakis, K.; Karvounis, P.C. (Evangelismos Hospital, Athens (Greece))

    1982-01-01

    The clinical presentations and CT scan pictures of four patients harbouring big cysticercus cysts are described. The value of CT scanning in detecting these cysts is emphasized, and also the fact that these cysts can behave as space-occyping lesions, which must be differentiated from other cystic formations.

  6. A Study for Reappearance According to the Scan Type, the CT Scanning by a Moving Phantom

    International Nuclear Information System (INIS)

    Choi, Jae Hyock; Jeong, Do Hyeong; Choi, Gye Suk; Jang, Yo Jong; Kim, Jae Weon; Lee, Hui Seok

    2007-01-01

    CT scan shows that significant tumor movement occurs in lesions located in the proximity of the heart, diaphragm, and lung hilus. There are differences concerning three kinds of type to get images following the Scan type called Axial, Helical, Cine (4D-CT) mode, when the scanning by CT. To know how each protocol describe accurately, this paper is going to give you reappearance using the moving phantom. To reconstruct the movement of superior-inferior and anterior-posterior, the manufactured moving phantom and the motor following breathing were used. To distinguish movement from captured images by CT scanning, a localizer adhered to the marker on the motor. The moving phantom fixed the movement of superior-inferior upon 1.3 cm /1 min. The motor following breathing fixed the movement of anterior-posterior upon 0.2 cm /1 min. After fixing each movement, CT scanning was taken by following the CT protocols. The movement of A localizer and volume-reappearance analyzed by RTP machine. Total volume of a marker was 88.2 cm 3 considering movement of superior-inferior. Total volume was 184.3 cm 3 . Total volume according to each CT scan protocol were 135 cm 3 by axial mode, 164.9 cm 3 by helical mode, 181.7 cm 3 by cine (4D-CT) mode. The most closely describable protocol about moving reappearance was cine mode, the marker attached localizer as well. CT scan should reappear concerning a exact organ-description and target, when the moving organ is being scanned by three kinds of CT protocols. The cine (4D-CT) mode has the advantage of the most highly reconstructible ability of the three protocols in reappearance of the marker using a moving phantom. The marker on the phantom has always regular motion but breathing patients don't move like a phantom. Breathing education and devices setting patients were needed so that images reconstruct breathing as exactly as possible. Users should also consider that an amount of radiation to patients is being bombed.

  7. Diagnosis of pituitary adenoma by dynamic CT scanning

    International Nuclear Information System (INIS)

    Tanabe, Sumiyoshi; Uede, Teiji; Daibo, Masahiko; Niwa, Jun; Hashi, Kazuo

    1988-01-01

    The advantage of high resolution CT in the diagnosis of pituitary microadenomas has been established, but the diagnosis becomes more difficult when the pituitary microadenoma is less than 5 mm in diameter. We have studied the usefulness of dynamic CT scans particularly for diagnosis of small microadenomas. The dynamic CT scans were performed for 61 normal pituitary glands and 68 pituitary adenomas (36 microadenomas, 32 macroadenomas) with a GECT/T 9800 scanner. Coronal sections of 1.5 mm thickness were taken at the plane just in front of the pituitary stalk of the pituitary gland. Following a bolus intra-venous injection of 40 - 60 ml of contrast media using an automatic injector, ten consecutive CT scans of 2 seconds scan time were obtained, beginning 2 seconds from the start of intravenous injection. The first seven scans were taken with an interval of 2.3 seconds, and the last three scans with an interval of 10 seconds. Then, time-density curves were obtained at the ROI which were set on the anterior pituitary gland, the vascular bed of the pituitary gland, the pituitary stalk and the area of the pituitary adenoma respectively. In a normal pituitary gland, the density increases gradually and makes an S shaped curve, then attains the maximum density value (92.3 CT number) approximately 60 seconds after the administration of contrast media. The pituitary vascular bed is located in midline on the upper surface of the pituitary gland, and shows a symmetrical square, triangular or rhomboid shape. In case of pituitary adenoma, the time-density curve makes a plateau curve and attains the maximum density value (60.1 CT number) approximately 60 seconds after the administration of contrast media. In microadenoma, the pituitary vascular bed is either deformed or compressed, showing an asymmetrical shape. (author)

  8. Pathophysiological study of experimental hydrocephalus with computed tomography (CT) scan

    International Nuclear Information System (INIS)

    Murata, Takaho

    1980-01-01

    In order to investigate the pathophysiological changes during a development of hydrocephalus, the observations employing computed tomography (CT) scans and monitorings of intracranial epidural pressure (EDP) were performed in a series of kaolin-induced canine hydrocephalus. According to ''volume index'' of ventricles which was calculated from printed-out CT numbers, great individual variations were recognized in the degree of a ventricular enlargement as well as the rate of EDP. They are thought to be due to the difference in types of hydrocephalus, which have been induced by a discrepancy in the site and degree of an obstruction caused by kaolin. Periventricular lucency (PVL) of various degrees were also detected on CT scans of experimental hydrocephalus. It was always marked in the superolateral angle of frontal horn of the lateral ventricles, and differed in degree from severe to mild. PVLs were distinct in the acute stage with high EDP, and gradually became indistinct and had a tendency to disappear thereafter along with decreased EDP. They immediately disappeared after shunting operation. The pathogenesis of PVL was investigated with histological examinations, as well as by using contrast enhancement, Metrizamide ventriculography, the analysis of linear density profiles, and the measurement of regional cerebral blood flow (rCBF). Consequently, PVLs in hydrocephalus are considered to represent an acute edema or a chronic CSF retention in the periventricular white matter caused by increase of water content. In other words, they are regarded as a sign of present or preceding intraventricular hypertension on CT scan, and may become a clinical indication for shunting operation. (author)

  9. Abnormal CT scan in a patient with Gilles de la Tourette syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Kjaer, M.; Boris, P.; Gadegaard Hansen, L.

    1986-07-01

    In a 28-year-old woman, who presented multiple muscular and vocal tics, typical of Gilles de la Tourette syndrome, CT scans revealed a large porencephalic cyst in the right hemisphere involving the right basal ganglia, as well as contrast enhancement in the region of the left basal ganglia.

  10. The value of contrast-enhanced 64-row CT in differentiating benign from malignant serous ovarian neoplasms

    International Nuclear Information System (INIS)

    Dong Tianfa; Wu Meixian; Zhang Jiayun; Song Ting

    2009-01-01

    Objective: To assess the diagnostic value of contrast-enhanced 64-row CT scanning in deciding benign or malignant serous ovarian tumors. Methods: Fifty-eight cases of serous ovarian tumors proved pathologically were reviewed, including 25 malignant tumors, 25 benign, 8 borderline tumors. All patients underwent 64-row CT scanning, including plain scanning and contrast-enhance scanning. The tumors' shape, density, blood supply and enhancement features were evaluated. Results: Twenty-five cases of benign serous cystic adenoma were mostly unicameral, and showed a moderate mural enhancement only in 4 cases (16%) due to chronic pelvic infection and the others (21/25, 84%) had no of slight enhancement. Malignant tumors were cystic-solid mass with unclear margin, irregular shape and septa. Twenty-two cases of serous cystadenocarcinoma out of 25 cases (88%) appeared obvious enhancement and other 3 cases no enhancement. And 7 cases out of 8 (87.5%) borderlined serous cystadenomas showed different enhancement patterns. Conclusion: Benign ovarian serous neoplasms were mostly unicameral and no strong mural enhancement, suggesting a lack of blood supply. While, there were obvious enhancement in the ovarian serous cystadenocarcinoma and borderline serous cystadenoma with malignant potential. The 64-row CT is helpful for differentiating the nature of the serous ovarian neoplasm. (authors)

  11. Optical-CT scanning of polymer gels

    Energy Technology Data Exchange (ETDEWEB)

    Oldham, M [Radiation Oncology Physics, Duke University Medical Center, Duke University, NC (United States)

    2004-01-01

    The application of optical-CT scanning to achieve accurate high-resolution 3D dosimetry is a subject of current interest. The purpose of this paper is to provide a brief overview of past research and achievements in optical-CT polymer gel dosimetry, and to review current issues and challenges. The origins of optical-CT imaging of light-scattering polymer gels are reviewed. Techniques to characterize and optimize optical-CT performance are presented. Particular attention is given to studies of artifacts in optical-CT imaging, an important area that has not been well studied to date. The technique of optical-CT simulation by Monte-Carlo modeling is introduced as a tool to explore such artifacts. New simulation studies are presented and compared with experimental data.

  12. Optical-CT scanning of polymer gels

    International Nuclear Information System (INIS)

    Oldham, M

    2004-01-01

    The application of optical-CT scanning to achieve accurate high-resolution 3D dosimetry is a subject of current interest. The purpose of this paper is to provide a brief overview of past research and achievements in optical-CT polymer gel dosimetry, and to review current issues and challenges. The origins of optical-CT imaging of light-scattering polymer gels are reviewed. Techniques to characterize and optimize optical-CT performance are presented. Particular attention is given to studies of artifacts in optical-CT imaging, an important area that has not been well studied to date. The technique of optical-CT simulation by Monte-Carlo modeling is introduced as a tool to explore such artifacts. New simulation studies are presented and compared with experimental data

  13. Cranial CT revisited: do we really need contrast enhancement?

    International Nuclear Information System (INIS)

    Demaerel, P.; Buelens, C.; Wilms, G.; Baert, A.L.

    1998-01-01

    The aim of this study was to define guidelines for intravenous contrast administration in cranial CT, as currently there are no recent guidelines based on a large series of patients. In 1900 consecutive patients (1480 adults and 420 children) pre- and post-contrast scan was analysed in order to assess the contribution of contrast enhancement to the diagnosis. The findings were grouped according to whether abnormalities were seen on the pre- and/or post-contrast scan, or whether no abnormalities were seen at all. Sensitivity, specificity, positive predictive value, negative predictive value and accurracy of a pre-contrast scan were used to determine validity. Intravenous contrast enhancement only contributes to the diagnosis if a suspicious abnormality is seen on the unenhanced scan or in the appropriate clinical setting (33.6 %). In the remaining patients (65.6 %) there is no diagnostic contribution, except for a small number of abnormalities (0.8 %). These are often anatomical variants and have no therapeutic impact. The number of contrast-enhanced cranial CT examinations can significantly be reduced by using four general guidelines for contrast administration resulting in considerable cost savings without affecting the quality of service to the patient. These guidelines are defined by the clinical findings/presentation or by the findings on the unenhanced scan. The number of contrast-related complications will be reduced, which may have medicolegal implications. These guidelines can be applied in any radiology department. (orig.) (orig.)

  14. Abnormal CT scan in a patient with Gilles de la Tourette syndrome

    International Nuclear Information System (INIS)

    Kjaer, M.; Boris, P.; Gadegaard Hansen, L.

    1986-01-01

    In a 28-year-old woman, who presented multiple muscular and vocal tics, typical of Gilles de la Tourette syndrome, CT scans revealed a large porencephalic cyst in the right hemisphere involving the right basal ganglia, as well as contrast enhancement in the region of the left basal ganglia. (orig.)

  15. Clinical study of retrocaval ureter diagnosed by CT scan

    International Nuclear Information System (INIS)

    Kiriyama, Isao; Hata, Ryosuke; Amemiya, Hiroshi

    1987-01-01

    Although retrocaval ureter is relatively uncommon congenital anomaly, surgical intervention is often necessary to alleviate the clinical signs and symptoms of the patients. Vena cavography has been indispensable imaging modality for the definitive diagnosis of this anomaly. Recently, however, CT scan in addition to excretory urography (IVP) and retrograde pyelography(RP) has been utilized in many reported cases in the diagnosis of retrocaval ureter. We have experienced 3 cases of retrocaval ureter consecutively. In this paper we report these 3 cases of retrocaval ureter, in which CT scan enabled us to confirm the definitive diagnosis. We also report another case of pelviureteric stenosis that was taken for retrocaval ureter by CT scan. Causes of the misdiagnosis is discussed. In conclusion CT scan is useful diagnostic modality in the diagnosis of retrocaval ureter and this lesser invasive technique might lessen the need for vena cavography. (author)

  16. Incidental apical disease at CT scanning

    International Nuclear Information System (INIS)

    McLoud, T.C.; Satoh, K.; Shepard, J.O.; Moore, E.H.; Kosiuk, J.P.

    1990-01-01

    Apical caps are commonly noted on standard radiographs. This paper determines how often abnormalities in the extreme apex of the lung could be identified on CT scans obtained for other reasons. A total of 158 consecutive CT scans were reviewed prospectively. Excluded were patients with obvious upper lobe pleural or parenchymal disease. Apical abnormalities were identified in 74 (46.8%) of the 158 cases. The prevalence increased with age (19% in the 8-39-year age group and 82% in patients older than 80 years). Opacities were unilateral in 44.5% and bilateral in 55.5%. The most common abnormality was linear opacities (95%)

  17. CT findings of pancreatic carcinoma. Evaluation with the combined method of early enhancement CT and high dose enhancement CT

    International Nuclear Information System (INIS)

    Itoh, Shigeki; Endo, Tokiko; Isomura, Takayuki; Ishigaki, Takeo; Ikeda, Mitsuru; Senda, Kouhei.

    1995-01-01

    Computed tomographic (CT) findings of pancreatic ductal adenocarcinoma were studied with the combined method of early enhancement CT and high dose enhancement CT in 72 carcinomas. Common Findings were change in pancreatic contour, abnormal attenuation in a tumor and dilatation of the main pancreatic duct. The incidence of abnormal attenuation and dilatation of the main pancreatic duct and bile duct was constant regardless of tumor size. The finding of hypoattenuation at early enhancement CT was most useful for demonstrating a carcinoma. However, this finding was negative in ten cases, five of which showed inhomogenous hyperattenuation at high dose enhancement CT. The detection of change in pancreatic contour and dilatation of the main pancreatic duct was most frequent at high dose enhancement CT. The finding of change in pancreatic contour and/or abnormal attenuation in a tumor could be detected in 47 cases at plain CT, 66 at early enhancement CT and 65 at high dose enhancement CT. Since the four cases in which neither finding was detected by any CT method showed dilatated main pancreatic duct, there was no case without abnormal CT findings. This combined CT method will be a reliable diagnostic technique in the imaging of pancreatic carcinoma. (author)

  18. Volumetric measurement of the maxillary sinus by coronal CT scan

    International Nuclear Information System (INIS)

    Ikeda, Atsuko

    1996-01-01

    The volume of the maxillary sinus was estimated by coronal CT scan. The purpose of this study was to compare the estimated volume of the normal maxillary sinus with that of the inflamed maxillary sinus. Patients were classified following evaluation by CT scan of the paranasal sinuses into 3 categories. Group A (n=12): Patients suffered from headache, facial pain and epistaxis, but CT scans of their nasal cavity and paranasal sinus were within normal limits without inflammatory change. Group B (n=69): Patients with bilateral chronic maxillary sinusitis, CT scans of whom showed inflammatory changes in both maxillary sinuses. All of the patients in this group underwent sinus surgery after coronal CT scans. Group C (n=14): Patients with unilateral chronic maxillary sinusitis, CT scans of whom showed inflammatory change in unilateral maxillary sinuses. CT scans of these patients were measured by Plannimeter to take the area of each image of the maxillary sinus. Consecutively imaged areas were summated by integral calculus to obtain an estimate of the sinus volume. The mean maxillary sinus volume in the affected sinuses was significantly smaller than those in the contralateral normal sinuses (p<0.05, Wilcoxon-test). The various volumes of the maxillary sinuses and the developmental cause were discussed. Comparison of groups A with B suggested three distinct patterns; the maxillary sinus volume has decreased due to inflammatory changes in the bone. The small sinuses have a tendency to develop chronic inflammatory change. The aeration in the maxillary sinus may be decreased when anatomic variations that may obstruct the ethmoid infundibulum exist. (K.H.)

  19. Volumetric measurement of the maxillary sinus by coronal CT scan

    Energy Technology Data Exchange (ETDEWEB)

    Ikeda, Atsuko [Tokyo Medical and Dental Univ. (Japan). School of Medicine

    1996-08-01

    The volume of the maxillary sinus was estimated by coronal CT scan. The purpose of this study was to compare the estimated volume of the normal maxillary sinus with that of the inflamed maxillary sinus. Patients were classified following evaluation by CT scan of the paranasal sinuses into 3 categories. Group A (n=12): Patients suffered from headache, facial pain and epistaxis, but CT scans of their nasal cavity and paranasal sinus were within normal limits without inflammatory change. Group B (n=69): Patients with bilateral chronic maxillary sinusitis, CT scans of whom showed inflammatory changes in both maxillary sinuses. All of the patients in this group underwent sinus surgery after coronal CT scans. Group C (n=14): Patients with unilateral chronic maxillary sinusitis, CT scans of whom showed inflammatory change in unilateral maxillary sinuses. CT scans of these patients were measured by Plannimeter to take the area of each image of the maxillary sinus. Consecutively imaged areas were summated by integral calculus to obtain an estimate of the sinus volume. The mean maxillary sinus volume in the affected sinuses was significantly smaller than those in the contralateral normal sinuses (p<0.05, Wilcoxon-test). The various volumes of the maxillary sinuses and the developmental cause were discussed. Comparison of groups A with B suggested three distinct patterns; the maxillary sinus volume has decreased due to inflammatory changes in the bone. The small sinuses have a tendency to develop chronic inflammatory change. The aeration in the maxillary sinus may be decreased when anatomic variations that may obstruct the ethmoid infundibulum exist. (K.H.)

  20. Non-enhanced CT versus contrast-enhanced CT in integrated PET/CT studies for nodal staging of rectal cancer

    International Nuclear Information System (INIS)

    Tateishi, Ukihide; Maeda, Tetsuo; Morimoto, Tsuyoshi; Miyake, Mototaka; Arai, Yasuaki; Kim, E.E.

    2007-01-01

    The purpose of the present study was to determine the diagnostic accuracy of non-enhanced CT and contrast-enhanced CT in integrated PET/CT studies for preoperative nodal staging of rectal cancer. Retrospective analysis was performed in 53 patients with pathologically proven rectal cancer who had been referred for preoperative staging. All patients underwent integrated PET/CT consisting of non-enhanced and contrast-enhanced CT followed by whole-body fluorine-18-fluorodeoxyglucose ([ 18 F]FDG) PET. Both non-enhanced and contrast-enhanced PET/CT images were evaluated separately by two observers in consensus. The reference standard was histopathologic results. For nodal staging of rectal cancer, we compared diagnostic accuracy on a per-patient basis between the two modalities. Nodal staging was correctly determined with non-enhanced studies in 37 patients (70%) and with contrast-enhanced studies in 42 patients (79%). On a per-patient basis, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of regional lymph node staging were 85%, 68%, 83%, 72%, and 79%, respectively, with contrast-enhanced studies, and 85%, 42%, 73%, 62%, and 70%, respectively, with non-enhanced studies. The difference in the accuracy of nodal staging between the two modalities was not significant (p = 0.063). Compared with non-enhanced studies, contrast-enhanced studies determined more correctly the status of pararectal lymph nodes (p 0.002), internal iliac lymph nodes (p = 0.004), and obturator lymph nodes (p < 0.0001). Contrast-enhanced PET/CT is superior to non-enhanced PET/CT for precise definition of regional nodal status in rectal cancer. (orig.)

  1. Patients with liver FNH and HCC patients with negative AFP: plain and dynamic enhanced MRI and CT findings

    Directory of Open Access Journals (Sweden)

    LI Mingtong

    2015-05-01

    Full Text Available ObjectiveTo investigate plain and dynamic enhanced magnetic resonance imaging (MRI and computed tomography (CT findings in patients with focal nodular hyperplasia (FNH of the liver and hepatocellular carcinoma (HCC patients with negative alpha-fetoprotein (AFP. MethodsA statistical analysis was performed on the clinical data of 124 cases of liver tumor admitted to Beijing Miyun County Hospital from April 2012 to April 2014. ResultsFifty-five of the 74 patients with FNH underwent CT examination, among whom 38 patients received three-phase dynamic enhanced scan and 16 received only plain scan; 62 cases had plain and enhanced MRI with the application of contrast agent Gd-BOPTA in 42 patients. Among the 50 HCC patients with negative AFP, CT examination was performed in 40 and 10 only had plain scan; 46 patients received plain and enhanced MRI with the use of contrast agent Gd-BOPTA in 30. Delayed scan after 1-2 h demonstrated low signal in 30 lesions of the 30 cases. ConclusionFor patients with liver FNH and AFP-negative HCC patients, their plain and dynamic enhanced MRI and CT scan have respective characteristics. A combination of multiple examination methods can significantly improve diagnostic yield of the two diseases.

  2. Immediate total-body CT scanning versus conventional imaging and selective CT scanning in patients with severe trauma (REACT-2): a randomised controlled trial.

    Science.gov (United States)

    Sierink, Joanne C; Treskes, Kaij; Edwards, Michael J R; Beuker, Benn J A; den Hartog, Dennis; Hohmann, Joachim; Dijkgraaf, Marcel G W; Luitse, Jan S K; Beenen, Ludo F M; Hollmann, Markus W; Goslings, J Carel

    2016-08-13

    Published work suggests a survival benefit for patients with trauma who undergo total-body CT scanning during the initial trauma assessment; however, level 1 evidence is absent. We aimed to assess the effect of total-body CT scanning compared with the standard work-up on in-hospital mortality in patients with trauma. We undertook an international, multicentre, randomised controlled trial at four hospitals in the Netherlands and one in Switzerland. Patients aged 18 years or older with trauma with compromised vital parameters, clinical suspicion of life-threatening injuries, or severe injury were randomly assigned (1:1) by ALEA randomisation to immediate total-body CT scanning or to a standard work-up with conventional imaging supplemented with selective CT scanning. Neither doctors nor patients were masked to treatment allocation. The primary endpoint was in-hospital mortality, analysed in the intention-to-treat population and in subgroups of patients with polytrauma and those with traumatic brain injury. The χ(2) test was used to assess differences in mortality. This trial is registered with ClinicalTrials.gov, number NCT01523626. Between April 22, 2011, and Jan 1, 2014, 5475 patients were assessed for eligibility, 1403 of whom were randomly assigned: 702 to immediate total-body CT scanning and 701 to the standard work-up. 541 patients in the immediate total-body CT scanning group and 542 in the standard work-up group were included in the primary analysis. In-hospital mortality did not differ between groups (total-body CT 86 [16%] of 541 vs standard work-up 85 [16%] of 542; p=0.92). In-hospital mortality also did not differ between groups in subgroup analyses in patients with polytrauma (total-body CT 81 [22%] of 362 vs standard work-up 82 [25%] of 331; p=0.46) and traumatic brain injury (68 [38%] of 178 vs 66 [44%] of 151; p=0.31). Three serious adverse events were reported in patients in the total-body CT group (1%), one in the standard work-up group (<1%), and

  3. Non-tumor enhancement at the surgical margin on CT after the removal of brain tumors

    International Nuclear Information System (INIS)

    Adachi, Michito; Hosoya, Takaaki; Yamaguchi, Kohichi; Yamada, Kiyotada

    1992-01-01

    Marginal enhancement is occasionally seen at the surgical margin on CT after the total removal of brain tumors. This enhancement disappears in due time, and therefore we call it non-tumor enhancement. It is often difficult, however, to differentiate non-tumor enhancement from tumor recurrence. In this study, we attempted to determine the characteristics of non-tumor enhancement. The subjects of the study consisted of 15 patients with astrocytoma and one with metastatic tumor in whom sequential CT scans had been performed after total removal of the tumor. Based on the observation of these sequential CT scans, the characteristics of non-tumor enhancement were presumed to be as follows: (1) In four cases, enhancement at the surgical margin persisted more than four months after surgery and then disappeared. Therefore, these cases were considered non-tumor enhancement. Prolonged duration of enhancement such as that in these cases is not necessarily due to recurrence. Marginal enhancement within 3 mm in thickness and with a well-demarcated border like that of a flax is likely to be non-tumor enhancement. (author)

  4. Immediate total-body CT scanning versus conventional imaging and selective CT scanning in patients with severe trauma (REACT-2): a randomised controlled trial

    NARCIS (Netherlands)

    Sierink, Joanne C.; Treskes, Kaij; Edwards, Michael J. R.; Beuker, Benn J. A.; den Hartog, Dennis; Hohmann, Joachim; Dijkgraaf, Marcel G. W.; Luitse, Jan S. K.; Beenen, Ludo F. M.; Hollmann, Markus W.; Goslings, J. Carel; Saltzherr, T. P.; Schep, N. W. L.; Streekstra, G. J.; van Lieshout, E. M. M.; Patka, P.; Klimek, M.; van Vugt, R.; Tromp, T. J. N.; Brink, M.; Harbers, J. S.; El Moumni, M.; Wendt, K. W.; Bingisser, R.; Ummenhofer, W.; Bless, N.

    2016-01-01

    Published work suggests a survival benefit for patients with trauma who undergo total-body CT scanning during the initial trauma assessment; however, level 1 evidence is absent. We aimed to assess the effect of total-body CT scanning compared with the standard work-up on in-hospital mortality in

  5. Dual scan CT image recovery from truncated projections

    Science.gov (United States)

    Sarkar, Shubhabrata; Wahi, Pankaj; Munshi, Prabhat

    2017-12-01

    There are computerized tomography (CT) scanners available commercially for imaging small objects and they are often categorized as mini-CT X-ray machines. One major limitation of these machines is their inability to scan large objects with good image quality because of the truncation of projection data. An algorithm is proposed in this work which enables such machines to scan large objects while maintaining the quality of the recovered image.

  6. Delayed intracerebral hemorrhage as demonstrated by CT scanning

    International Nuclear Information System (INIS)

    Brunetti, J.; Zingesser, L.; Dunn, J.; Rovit, R.L.; Saint Vincent's Hospital and Medical Center, New York

    1979-01-01

    Three patients are presented who developed delayed intracerebral hematomas after head injury. Two patients had essentially negative CT scans on admission and developed intracerebral hematomas within 24 h after injury. They required surgical treatment and had fatal outcomes. The third patient presented with an epidural hematoma on CT scan, developed an intracerebral hematoma 48 h after evacuation of the epidural hematoma, and did well with conservative management. (orig.) [de

  7. Role of CT scan in diagnosis of acute appendicitis

    International Nuclear Information System (INIS)

    Salem, O.A.; Khasawneh, M.

    2007-01-01

    To evaluate the diagnostic accuracy of the spiral-CT in patients with clinically suspected acute appendicitis. A total of 124 patients referred for CT scan with suspected appendicitis between January 2005 and October 2006 were assessed for the appendiceal size and the presence of signs of appendicitis. The findings were correlated with surgical histopathology. CT scan had a sensitivity of 95 percent and a specifity of 93 percent and an overall accuracy of 92 percent. The use of spiral CT in patients with equivocal clinical presentation suspected of having acute appendicitis can lead to significant improvement in the preoperative diagnosis. (author)

  8. SU-F-I-32: Organ Doses from Pediatric Head CT Scan

    Energy Technology Data Exchange (ETDEWEB)

    Liu, H; Liu, Q; Qiu, J; Zhuo, W [Institute of Radiation Medicine Fudan University, Shanghai (China); Majer, M; Knezevic, Z; Miljanic, S [Radiation Chemistry and Dosimetry Laboratory, Ruder Boskovic Institute, Zagreb (Croatia); Hrsak, H [Clinical Hospital Centre Zagreb, Zagreb (Croatia)

    2016-06-15

    Purpose: To evaluate the organ doses of pediatric patients who undergoing head CT scan using Monte Carlo (MC) simulation and compare it with measurements in anthropomorphic child phantom.. Methods: A ten years old children voxel phantom was developed from CT images, the voxel size of the phantom was 2mm*2mm*2mm. Organ doses from head CT scan were simulated using MCNPX software, 180 detectors were placed in the voxel phantom to tally the doses of the represented tissues or organs. When performing the simulation, 120 kVp and 88 mA were selected as the scan parameters. The scan range covered from the top of the head to the end of the chain, this protocol was used at CT simulator for radiotherapy. To validate the simulated results, organ doses were measured with radiophotoluminescence (RPL) detectors, placed in the 28 organs of the 10 years old CIRS ATOM phantom. Results: The organ doses results matched well between MC simulation and phantom measurements. The eyes dose was showed to be as expected the highest organ dose: 28.11 mGy by simulation and 27.34 mGy by measurement respectively. Doses for organs not included in the scan volume were much lower than those included in the scan volume, thymus doses were observed more than 10 mGy due the CT protocol for radiotherapy covered more body part than routine head CT scan. Conclusion: As the eyes are superficial organs, they may receive the highest radiation dose during the CT scan. Considering the relatively high radio sensitivity, using shielding material or organ based tube current modulation technique should be encouraged to reduce the eye radiation risks. Scan range was one of the most important factors that affects the organ doses during the CT scan. Use as short as reasonably possible scan range should be helpful to reduce the patient radiation dose. This work was supported by the National Natural Science Foundation of China(11475047)

  9. CT-scanning in otolaryngology, 2

    International Nuclear Information System (INIS)

    Kusakari, Jun; Endo, Satomi; Hara, Akira

    1982-01-01

    Combined computerized tomography-sialography was performed in 28 patients with parotid tumors. Sialography was performed in the usual fashion. After confirming the presence of the contrast material within the parotid gland by X-ray, 4 to 5 scannings were done at the width of 10 mm below Repid's base line. With this procedure, the parotid gland was clearly demonstrated and the location of the tumor was shown as a shadow defect. Although the nature of the tumor, especially whether it was malignant or benign was difficult to predict, the CT-findings regarding the size and location of the tumor were completely coincident with the operative findings in all the cases. Accurate appraisal of the relation between the tumor and the facial nerve was possible in all but two cases. The preoperative information obtained from CT-scanning is extremely useful in the case of parotid tumor surgery. (author)

  10. Importance of repeated CT scan in Fournier gangrene treatment: clinical case

    International Nuclear Information System (INIS)

    Ignatenco, Sergiu

    2011-01-01

    A patient of 53 years presented fever, swelling and erythema in the perineal region. After computed tomography (CT) was diagnosed Fournier gangrene. After aggressive surgical debridement postoperative evolution was unfavorable. Repeated CT scan trace spread of infection to new areas that led to new surgical debridement on time. Use of CT scan in the postoperative period allows assessment of the effectiveness of surgical debridement and spread of infection. This article presents CT scan images and the most important periods of intraoperative surgical intervention. (authors)

  11. Dual-energy CT in the evaluation of solitary pulmonary nodules by virtual non-enhanced images: initial experience

    International Nuclear Information System (INIS)

    Guo Xing; Ding Wei; Qin Huijuan

    2011-01-01

    Objective: To determine the accuracy and radiation dose of dual-energy computed tomography (CT) in evaluating solitary pulmonary nodules (SPNs) by virtual non-enhanced images. Methods: Sixty-one patients with SPNs including 39 malignant and 18 benign nodules proved by pathology underwent DECT scans. The CT values of SPNs on enhanced weighted average and virtual non-enhanced images were compared by using Liver VNC processing unit in terms of their diagnostic accuracy for distinguishing malignant and benign nodules with a 20 HU threshold. Diagnostic accuracy was compared. In 28 patients of all patients, image noise and quality score of the non-enhanced and virtual non-enhanced images were compared, and radiation doses of each patient were recorded. The paired t test was used to analyze the noise difference between the plain scan and virtual non-enhanced scan. The Mann-Whitney U test. was used to analyze statistically significant differences of the image quality score and radiation dose between the non-enhanced scan and virtual non-enhanced scan. Results: The sensitivity, specificity and accuracy for distinguishing benign and malignant nodules by using the virtual non-enhanced image of were 89.7% (35/39), 72.2% (13/18), 84.2% (48/57) respectively. The noise of common CT and virtual non- enhanced images were (8.49±1.94) HU and (10.14±2.18) HU, and there were statistically difference (t=9.45, P 0.05). The radiation doses of common CT and DECT were (3.72±0.48) mSv and (3.78±0.45) mSv, and there were no statistical difference (U= 350.50, P>0.05). Conclusion: DECT by using virtual non-enhanced images is useful tool to distinguish the benign and malignant SPN without additional radiation dose. (authors)

  12. Classication Methods for CT-Scanned Carcass Midsections

    DEFF Research Database (Denmark)

    Skytte, Jacob Lercke; Dahl, Anders Lindbjerg; Larsen, Rasmus

    2011-01-01

    Computed tomography (CT) has successfully been applied in medical environments for decades. In recent years CT has also made its entry to the industrial environments, including the slaughterhouses. In this paper we investigate classication methods for an online CT system, in order to assist...... in the segmentation of the outer fat layer in the mid- section of CT-scanned pig carcasses. Prior information about the carcass composition can potentially be applied for a fully automated solution, in order to optimize the slaughter line. The methods comprise Markov Random Field and contextual Bayesian classication...

  13. A simulation study on proton computed tomography (CT) stopping power accuracy using dual energy CT scans as benchmark

    DEFF Research Database (Denmark)

    Hansen, David Christoffer; Seco, Joao; Sørensen, Thomas Sangild

    2015-01-01

    Background. Accurate stopping power estimation is crucial for treatment planning in proton therapy, and the uncertainties in stopping power are currently the largest contributor to the employed dose margins. Dual energy x-ray computed tomography (CT) (clinically available) and proton CT (in...... development) have both been proposed as methods for obtaining patient stopping power maps. The purpose of this work was to assess the accuracy of proton CT using dual energy CT scans of phantoms to establish reference accuracy levels. Material and methods. A CT calibration phantom and an abdomen cross section...... phantom containing inserts were scanned with dual energy and single energy CT with a state-of-the-art dual energy CT scanner. Proton CT scans were simulated using Monte Carlo methods. The simulations followed the setup used in current prototype proton CT scanners and included realistic modeling...

  14. Algorithm-enabled partial-angular-scan configurations for dual-energy CT.

    Science.gov (United States)

    Chen, Buxin; Zhang, Zheng; Xia, Dan; Sidky, Emil Y; Pan, Xiaochuan

    2018-05-01

    We seek to investigate an optimization-based one-step method for image reconstruction that explicitly compensates for nonlinear spectral response (i.e., the beam-hardening effect) in dual-energy CT, to investigate the feasibility of the one-step method for enabling two dual-energy partial-angular-scan configurations, referred to as the short- and half-scan configurations, on standard CT scanners without involving additional hardware, and to investigate the potential of the short- and half-scan configurations in reducing imaging dose and scan time in a single-kVp-switch full-scan configuration in which two full rotations are made for collection of dual-energy data. We use the one-step method to reconstruct images directly from dual-energy data through solving a nonconvex optimization program that specifies the images to be reconstructed in dual-energy CT. Dual-energy full-scan data are generated from numerical phantoms and collected from physical phantoms with the standard single-kVp-switch full-scan configuration, whereas dual-energy short- and half-scan data are extracted from the corresponding full-scan data. Besides visual inspection and profile-plot comparison, the reconstructed images are analyzed also in quantitative studies based upon tasks of linear-attenuation-coefficient and material-concentration estimation and of material differentiation. Following the performance of a computer-simulation study to verify that the one-step method can reconstruct numerically accurately basis and monochromatic images of numerical phantoms, we reconstruct basis and monochromatic images by using the one-step method from real data of physical phantoms collected with the full-, short-, and half-scan configurations. Subjective inspection based upon visualization and profile-plot comparison reveals that monochromatic images, which are used often in practical applications, reconstructed from the full-, short-, and half-scan data are largely visually comparable except for some

  15. Spinal CT scan, 1. Cervical and thoracic spines

    Energy Technology Data Exchange (ETDEWEB)

    Nakagawa, Hiroshi (Aichi Medical Univ. (Japan))

    1982-01-01

    Methods of CT of the cervical and thoracic spines were explained, and normal CT pictures of them were described. Spinal CT was evaluated in comparison with other methods in various spinal diseases. Plain CT revealed stenosis due to spondylosis or ossification of posterior longitudinal ligament and hernia of intervertebral disc. CT took an important role in the diagnosis of spinal cord tumors with calcification and destruction of the bone. CT scan in combination with other methods was also useful for the diagnosis of spinal injuries, congenital anomalies and infections.

  16. CT-scanning of ancient Greenlandic Inuit temporal bones

    International Nuclear Information System (INIS)

    Homoe, P.; Videbaek, H.

    1992-01-01

    Additional morphological evidence of former infectious middle ear disease (IMED) was found by CT-scanning in 5 of 6 Greenlandic Inuit crania strongly suspected for former IMED due to earlier examination revealing either bilateral hypocellularity or asymmetry of the pneumatized area of the temporal bones. The CT-scans showed sclerosing and obliteration of the air cells and even destruction of the cellular septae, and a high degree of irregularity of the cells. Sclerosing of the surrounding bone tissue was also found. The findings in one cranium were dubious and could both be regarded as a congenital malformation or an infection in infanthood. CT-scan confirms and even adds to the results of conventional X-ray of temporal bones making hypotheses of paleopathology more reliable. The findings also support the environmental theory of pneumatization of the air cell system in the temporal bones. (13 refs., 10 figs.)

  17. CT-scanning of ancient Greenlandic Inuit temporal bones

    Energy Technology Data Exchange (ETDEWEB)

    Homoe, P [Copenhagen Univ. (Denmark). Lab. of Biological Anthropology and Dept. of Otolaryngology, Head and Neck Surgery; Lynnerup, N [Copenhagen Univ., Lab. of Biological Anthropology and Univ. Inst. of Ferensic Medicine, Copenhagen (Denmark); Videbaek, H [Hvidovre Univ. Hospital, Copenhagen (Denmark). Dept. of Radiology

    1992-01-01

    Additional morphological evidence of former infectious middle ear disease (IMED) was found by CT-scanning in 5 of 6 Greenlandic Inuit crania strongly suspected for former IMED due to earlier examination revealing either bilateral hypocellularity or asymmetry of the pneumatized area of the temporal bones. The CT-scans showed sclerosing and obliteration of the air cells and even destruction of the cellular septae, and a high degree of irregularity of the cells. Sclerosing of the surrounding bone tissue was also found. The findings in one cranium were dubious and could both be regarded as a congenital malformation or an infection in infanthood. CT-scan confirms and even adds to the results of conventional X-ray of temporal bones making hypotheses of paleopathology more reliable. The findings also support the environmental theory of pneumatization of the air cell system in the temporal bones. (13 refs., 10 figs.).

  18. Complications in CT-guided Procedures: Do We Really Need Postinterventional CT Control Scans?

    Energy Technology Data Exchange (ETDEWEB)

    Nattenmüller, Johanna, E-mail: johanna.nattenmueller@med.uni-heidelberg.de; Filsinger, Matthias, E-mail: Matthias_filsinger@web.de; Bryant, Mark, E-mail: mark.bryant@med.uni-heidelberg.de; Stiller, Wolfram, E-mail: Wolfram.Stiller@med.uni-heidelberg.de; Radeleff, Boris, E-mail: boris.radeleff@med.uni-heidelberg.de; Grenacher, Lars, E-mail: lars.grenacher@med.uni-heidelberg.de; Kauczor, Hans-Ullrich, E-mail: hu.kauczor@med.uni-heidelberg.de; Hosch, Waldemar, E-mail: waldemar.hosch@urz.uni-heidelberg.de [University Hospital Heidelberg, Department of Diagnostic and Interventional Radiology (Germany)

    2013-06-19

    PurposeThe aim of this study is twofold: to determine the complication rate in computed tomography (CT)-guided biopsies and drainages, and to evaluate the value of postinterventional CT control scans.MethodsRetrospective analysis of 1,067 CT-guided diagnostic biopsies (n = 476) and therapeutic drainages (n = 591) in thoracic (n = 37), abdominal (n = 866), and musculoskeletal (ms) (n = 164) locations. Severity of any complication was categorized as minor or major. To assess the need for postinterventional CT control scans, it was determined whether complications were detected clinically, on peri-procedural scans or on postinterventional scans only.ResultsThe complication rate was 2.5 % in all procedures (n = 27), 4.4 % in diagnostic punctures, and 1.0 % in drainages; 13.5 % in thoracic, 2.0 % in abdominal, and 3.0 % in musculoskeletal procedures. There was only 1 major complication (0.1 %). Pneumothorax (n = 14) was most frequent, followed by bleeding (n = 9), paresthesia (n = 2), material damage (n = 1), and bone fissure (n = 1). Postinterventional control acquisitions were performed in 65.7 % (701 of 1,067). Six complications were solely detectable in postinterventional control acquisitions (3 retroperitoneal bleeds, 3 pneumothoraces); all other complications were clinically detectable (n = 4) and/or visible in peri-interventional controls (n = 21).ConclusionComplications in CT-guided interventions are rare. Of these, thoracic interventions had the highest rate, while pneumothoraces and bleeding were most frequent. Most complications can be detected clinically or peri-interventionally. To reduce the radiation dose, postinterventional CT controls should not be performed routinely and should be restricted to complicated or retroperitoneal interventions only.

  19. Complications in CT-guided Procedures: Do We Really Need Postinterventional CT Control Scans?

    International Nuclear Information System (INIS)

    Nattenmüller, Johanna; Filsinger, Matthias; Bryant, Mark; Stiller, Wolfram; Radeleff, Boris; Grenacher, Lars; Kauczor, Hans-Ullrich; Hosch, Waldemar

    2014-01-01

    PurposeThe aim of this study is twofold: to determine the complication rate in computed tomography (CT)-guided biopsies and drainages, and to evaluate the value of postinterventional CT control scans.MethodsRetrospective analysis of 1,067 CT-guided diagnostic biopsies (n = 476) and therapeutic drainages (n = 591) in thoracic (n = 37), abdominal (n = 866), and musculoskeletal (ms) (n = 164) locations. Severity of any complication was categorized as minor or major. To assess the need for postinterventional CT control scans, it was determined whether complications were detected clinically, on peri-procedural scans or on postinterventional scans only.ResultsThe complication rate was 2.5 % in all procedures (n = 27), 4.4 % in diagnostic punctures, and 1.0 % in drainages; 13.5 % in thoracic, 2.0 % in abdominal, and 3.0 % in musculoskeletal procedures. There was only 1 major complication (0.1 %). Pneumothorax (n = 14) was most frequent, followed by bleeding (n = 9), paresthesia (n = 2), material damage (n = 1), and bone fissure (n = 1). Postinterventional control acquisitions were performed in 65.7 % (701 of 1,067). Six complications were solely detectable in postinterventional control acquisitions (3 retroperitoneal bleeds, 3 pneumothoraces); all other complications were clinically detectable (n = 4) and/or visible in peri-interventional controls (n = 21).ConclusionComplications in CT-guided interventions are rare. Of these, thoracic interventions had the highest rate, while pneumothoraces and bleeding were most frequent. Most complications can be detected clinically or peri-interventionally. To reduce the radiation dose, postinterventional CT controls should not be performed routinely and should be restricted to complicated or retroperitoneal interventions only

  20. Serial CT scans and Menkes' kinky hair disease

    International Nuclear Information System (INIS)

    Nakada, Eizo; Kameyama, Junji; Yoshimitsu, Hajime; Mori, Mikio; Tanaka, Mutsuo; Yoshimitsu, Kazunori.

    1988-01-01

    Menkes' kinky hair disease is a sex-linked recessive disorder of copper metabolism, characterized by progressive psychomotor deterioration, seizures, and peculiar hair structure. We examined serial CT scans of patients with this disease. A 2,210-g male infant was delivered after an uneventful gestation of 36 weeks. His one-minute Apgar score was 9. His uncle had died at 1 year of age. His first cousin was also diagnosed as having Menkes' kinky hair disease when our patient was 2 years old. Shortly after birth he had mild respiratory distress. At 5 days of age, he developed setting-sun signs. The first CT scan, at 10 days of age, revealed mild posterior fossa hemorrhages. At 3 months of age, myoclonic seizures began, and the CT scan revealed subdural effusion and mild brain atrophy. The seizures were controllable by using phenobarbital, valproic acid, and nitrazepam. He did not follow light or a fixate, but the fundi were normal. He was diffusely hypotonic. At 9 months of age, the seizures became uncontrollable. The CT scans at 15 and 31 months of age showed subdural hemorrhage and/or brain atrophy. At 15 months of age, the serum copper level was 42 μ g/dl, while the serum ceruloplasmin level was 3.2 mg/dl. He exhibited severe developmental failure. At 4 years of age, he died. (author)

  1. Scan Quality and Entrance Skin Dose in Thoracic CT: A Comparison between Bismuth Breast Shield and Posteriorly Centered Partial CT Scans

    International Nuclear Information System (INIS)

    Tappouni, Rafel; Mathers, Bradley

    2012-01-01

    Objectives. To compare the effectiveness of the bismuth breast shield and partial CT scan in reducing entrance skin dose and to evaluate the effect of the breast shield on image quality (IQ). Methods. Nanodots were placed on an adult anthropomorphic phantom. Standard chest CT, CT with shield, and partial CT were performed. Nanodot readings and effective doses were recorded. 50 patients with chest CTs obtained both with and without breast shields were reviewed. IQ was evaluated by two radiologists and by measuring Hounsfield units (HUs) and standard deviation (SD) of HU in anterior subcutaneous region. Results. Breast shield and the partial CT scans reduced radiation to the anterior chest by 38% and 16%, respectively. Partial CT increased dose to the posterior chest by 37% and effective dose by 8%. Change in IQ in shield CT was observed in the anterior chest wall. Significant change in IQ was observed in 5/50 cases. The shield caused an increase of 20 HU (P = 0.021) and a 1.86 reduction in SD of HU (P = 0.027) in the anterior compared to posterior subcutaneous regions. Summary. Bismuth breast shield is more effective than the partial CT in reducing entrance skin dose while maintaining image quality

  2. Adult head CT scans: the uncertainties of effective dose estimates

    International Nuclear Information System (INIS)

    Gregory, Kent J.; Bibbo, Giovanni; Pattison, John E.

    2008-01-01

    Full Text: CT scanning is a high dose imaging modality. Effective dose estimates from CT scans can provide important information to patients and medical professionals. For example, medical practitioners can use the dose to estimate the risk to the patient, and judge whether this risk is outweighed by the benefits of the CT examination, while radiographers can gauge the effect of different scanning protocols on the patient effective dose, and take this into consideration when establishing routine scan settings. Dose estimates also form an important part of epidemiological studies examining the health effects of medical radiation exposures on the wider population. Medical physicists have been devoting significant effort towards estimating patient radiation doses from diagnostic CT scans for some years. The question arises: How accurate are these effective dose estimates? The need for a greater understanding and improvement of the uncertainties in CT dose estimates is now gaining recognition as an important issue (BEIR VII 2006). This study is an attempt to analyse and quantify the uncertainty components relating to effective dose estimates from adult head CT examinations that are calculated with four commonly used methods. The dose estimation methods analysed are the Nagel method, the ImpaCT method, the Wellhoefer method and the Dose-Length Product (DLP) method. The analysis of the uncertainties was performed in accordance with the International Standards Organisation's Guide to the Expression of Uncertainty in Measurement as discussed in Gregory et al (Australas. Phys. Eng. Sci. Med., 28: 131-139, 2005). The uncertainty components vary, depending on the method used to derive the effective dose estimate. Uncertainty components in this study include the statistical and other errors from Monte Carlo simulations, uncertainties in the CT settings and positions of patients in the CT gantry, calibration errors from pencil ionization chambers, the variations in the organ

  3. Transient gyriform brightness on non-contrast enhanced computed tomography (CT) brain scan of seven infants

    International Nuclear Information System (INIS)

    Close, P.J.; Carty, H.M.

    1991-01-01

    Spontaneous gyriform brightness seen on CT scan is an unusual finding unless associated with arteriovenous malformations (AVM). There are sporadic case reports in the literature of its occurrence in association with herpex simplex virus encephalitis (HSVE), purulent meningitis, following chemotherapy for leukaemia, in a child with chronic renal failure, and in a child with folic acid deficiency. We present a series of seven cases exhibiting this phenomenon, none of whom have AVMs, who have been scanned at this hospital in the first 2 1/2 years following the installation of a CT scanner. Four of the cases had congenital heart disease requiring corrective surgery or cardiac catheterisation. The other three had probable meningo-encephalitis. In all cases the gyriform brightness followed an ischaemic insult to the child's brain. We hypothesise that this phenomenon is an ischaemic response in the immature brain and that its occurrence is not so rare as the literature may suggest. (orig.)

  4. Automated image quality assessment for chest CT scans.

    Science.gov (United States)

    Reeves, Anthony P; Xie, Yiting; Liu, Shuang

    2018-02-01

    Medical image quality needs to be maintained at standards sufficient for effective clinical reading. Automated computer analytic methods may be applied to medical images for quality assessment. For chest CT scans in a lung cancer screening context, an automated quality assessment method is presented that characterizes image noise and image intensity calibration. This is achieved by image measurements in three automatically segmented homogeneous regions of the scan: external air, trachea lumen air, and descending aorta blood. Profiles of CT scanner behavior are also computed. The method has been evaluated on both phantom and real low-dose chest CT scans and results show that repeatable noise and calibration measures may be realized by automated computer algorithms. Noise and calibration profiles show relevant differences between different scanners and protocols. Automated image quality assessment may be useful for quality control for lung cancer screening and may enable performance improvements to automated computer analysis methods. © 2017 American Association of Physicists in Medicine.

  5. CT diagnosis of retroperitoneal gigantic liposarcoma

    International Nuclear Information System (INIS)

    Fang Wei; Zheng Zhaohua; Liao Zuyuan; Hu Yinsong

    2009-01-01

    Objective: To analyze CT manifestation of retroperitoneal gigantic liposaxcoma and to improve the image understanding. Methods: Five cases of retroperitoneal gigantic liposarcoma confirmed by surgery and pathology in our hospital were collected. Plain and enhanced CT scan were performed. Results: Of five cases, one was substantive, two was pseudocyst and two was mixed tumor. Several patterns of enhancement such as strip, floccule, irregular patchy or nodular enhancement were revealed inside the lesions on enhanced CT scan. And strip-form of high density enhancement was a typical type. Conclusion: CT examination could determine the tumor's location, size and density, together with the relationship to adjacent organizations CT scan is an important method in diagnosing retroperitoneal gigantic liposarcoma. (authors)

  6. Dual purpose QA tool developed for teletherapy unit and CT scan in SNDH

    International Nuclear Information System (INIS)

    Shilvant, D.V.; Tamane, C.J.; Pangam, S.B.; Raees, M.D.; Aynoor, S.K.; Pol, P.S.; Verghese, Aju; Ghorpade, C.J.

    2007-01-01

    To make a simple device used in Teletherapy unit and CT scan for depth data measurement. The accurate depth data is essential and very important factor for precise treatment in SAD isocentric setup calculation. In CT scan based treatment planning, the calculation obtained is from the depth given by the CT scan. The success of treatment depends on the same parameters in treatment unit matched with diagnostic CT scan data. To check the depth parameters in both CT scan and Teletherapy unit we have developed a single QA tool in our hospital. As this tool is precise, handy and easily accessible the results obtained from it assures the quality of Teletherapy unit as well as CT scan depth data. This small device resulted data helps a lot in calculations of complicated SAD setup in Telecobalt and also useful in recent new treatment modalities such as IMRT, micro MLC, etc

  7. CT diagnosis of mediastinal tuberculous lymphadenopathy in adults

    International Nuclear Information System (INIS)

    Liu Fugeng; Pan Jishu; Wu Guogeng; Chen Qihang; Yu Jingying; Zhou Cheng

    2001-01-01

    Objective: To evaluate the features of mediastinal tuberculous lymphadenopathy in adults on CT, especially on enhanced CT scan. Methods: Seventeen patients with adult mediastinal tuberculous lymphadenopathy proved by operation, biopsy, and (or) anti-tuberculous therapy were evaluated on chest film and CT scan, and 6 patients were performed with enhanced CT scan. Results: The chest film finding was intrathoracic mass and (or) hilar mass only in 6 patients, but CT detected 37 enlarged nodes in all patients. Most of the enlarged nodes were located in 2R and (or) 4R (59.4%). 30 nodes (81.1%) presented as low-density in the center of nodes, and there were marked enhancement at the periphery areas of the nodes after enhancement in all 6 patients (100.0%). Conclusion: CT scan, especially the enhanced CT scan, is the first method of choice to diagnose the mediastinal tuberculous lymphadenopathy in adults

  8. Impact of the planning CT scan time on the reflection of the lung tumor motion

    International Nuclear Information System (INIS)

    Kim, Su San; Choi, Eun Kyung; Yi, Byong Yong; Ha, Sung Whan

    2004-01-01

    To evaluate the reflection of tumor motion according to the planning CT scan time. A model of N-shape, which moved along the longitudinal axis during the ventilation caused by a mechanical ventilator, was produced. The model was scanned by planning CT, while setting the relative CT scan time (T; CT scan time/ventilatory period) to 0.33, 0.50, 0.67, 0.75, 1.00, 1.33 T, and 1.53 T. In addition, three patients with non-small cell lung cancer who received stereotactic radiosurgery in the Department of Radiation Oncology, Asan Medical Center from 03/19/2002 to 05/21/2002 were scanned. Slow (IQ Premier, Picker, scan time 2.0 seconds per slice) and fast CT scans (Light Speed, GE Medical System, with a scan time of 0.8 second per slice) were performed for each patient. The magnitude of reflected movement of the N-shaped model was evaluated by measuring the transverse length, which reflected the movement of the declined bar of the model at each slice. For patients' scans, all CT data sets were registered using a stereotactic body frame scale with the gross tumor volumes delineated in one CT image set. The volume and three-dimensional diameter of the gross tumor volume were measured and analyzed between the slow and fast CT scans. The reflection degree of longitudinal movement of the model increased in proportion to the relative CT scan times below 1.00 T, but remained constant above 1.00 T. Assuming the mean value of scanned transverse lengths with CT scan time 1.00 T to be 100%, CT scans with scan times of 0.33, 0.50, 0.67, and 0.75 T missed the tumor motion by 30, 27, 20, and 7.0% respectively. Slow (scan time 2.0 sec) and Fast (scan time 0.8 sec) CT scans of three patients with longitudinal movement of 3, 5, and 10 mm measured by fluoroscopy revealed the increases in the diameter along the longitudinal axis increased by 6.3, 17, and 23% in the slow CT scans. As the relative CT scan time increased, the reflection of the respiratory tumor movement on planning CT also

  9. A simulation study on proton computed tomography (CT) stopping power accuracy using dual energy CT scans as benchmark.

    Science.gov (United States)

    Hansen, David C; Seco, Joao; Sørensen, Thomas Sangild; Petersen, Jørgen Breede Baltzer; Wildberger, Joachim E; Verhaegen, Frank; Landry, Guillaume

    2015-01-01

    Accurate stopping power estimation is crucial for treatment planning in proton therapy, and the uncertainties in stopping power are currently the largest contributor to the employed dose margins. Dual energy x-ray computed tomography (CT) (clinically available) and proton CT (in development) have both been proposed as methods for obtaining patient stopping power maps. The purpose of this work was to assess the accuracy of proton CT using dual energy CT scans of phantoms to establish reference accuracy levels. A CT calibration phantom and an abdomen cross section phantom containing inserts were scanned with dual energy and single energy CT with a state-of-the-art dual energy CT scanner. Proton CT scans were simulated using Monte Carlo methods. The simulations followed the setup used in current prototype proton CT scanners and included realistic modeling of detectors and the corresponding noise characteristics. Stopping power maps were calculated for all three scans, and compared with the ground truth stopping power from the phantoms. Proton CT gave slightly better stopping power estimates than the dual energy CT method, with root mean square errors of 0.2% and 0.5% (for each phantom) compared to 0.5% and 0.9%. Single energy CT root mean square errors were 2.7% and 1.6%. Maximal errors for proton, dual energy and single energy CT were 0.51%, 1.7% and 7.4%, respectively. Better stopping power estimates could significantly reduce the range errors in proton therapy, but requires a large improvement in current methods which may be achievable with proton CT.

  10. Comparison of CT scanning and radionuclide imaging in liver disease

    International Nuclear Information System (INIS)

    Friedman, M.L.; Esposito, F.S.

    1980-01-01

    Early experience with body CT suggested its usefulness in many diagnostic problems; jaundice, renal and pancreatic masses, and in the evaluation of relatively inaccessible parts of the body, such as the retroperitineum, mediastinum, and pelvis. Investigation of hepatic disease by CT was not unexpectedly compared to radionuclide liver scanning, the major preexisting modality for imaging the liver. In the evaluation of the jaundiced patient, CT rapidly assumed a major role, providing more specific information about the liver than the RN liver scan, as well as demonstrating adjacent organs. CT differentiate obstructive from non-obstructive jaundice. With respect to mass lesions of the liver, the RN liver scan is more sensitive than CT but less specific. The abnormalities on an isotope image of the liver consist of normal variants in configuration, extrinsic compression by adjacent structures, cysts, hemangiomata, abscesses, and neoplasms. These suspected lesions may then be better delineated by the CT image, and a more precise diagnosis made. The physiologic information provided by the RN liver scan is an added facet which is helpful in the patient with diffuse hepatic disease. The CT image will be normal in many of these patients, however, hemochromatosis and fatty infiltration lend themselves especially to density evaluation by CT. The evaluation of lymphoma is more thorough with CT. Structures other than the liver, such as lymph nodes, are visualized. Gallium, however, provides additional isotopic information in patients with lymphoma, and in addition, is known to be useful in the investigation of a febrile patient with an abscess. Newer isotopic agents expand hepatic imaging in other directions, visualizing the biliary tree and evaluating the jaundiced patient

  11. Vascular anatomy of the liver and porta hepatis with dynamic CT scan

    International Nuclear Information System (INIS)

    Hiramatsu, Yoshihiro; Wada, Mitsuyoshi; Nakajima, Teiichi; Tonooka, Reiko; Matsumoto, Kunihiko

    1983-01-01

    Vascular anatomy of the liver and porta heaptis demonstrated by dynamic CT scan was studied Identification of the individual vessels was sometimes difficult due to slight differencies in respiratory depths among the scans. Limitation in the number of slices also made the evalution of the vascular anatomy difficult. Angiography was therefore utilized for comparison in identifying the vessels. Dynamic CT scan was proved to be usefull in demonstrating the anteroposterior relationship of the vessels and surrounding structures, which is difficult with convetional angiography without multiple projections. Three dimensional understanding of the vessels was then possible with dynamic CT scan and angiography. When combined with recently advancing digital subtraction angiography, dynamic CT scan might reduce the necessity for conventional angiography with Seldinger's technique. (author)

  12. Value of a step-up diagnosis plan: CRP and CT-scan to diagnose and manage postoperative complications after major abdominal surgery

    Directory of Open Access Journals (Sweden)

    Jennifer Straatman

    2014-12-01

    Full Text Available Postoperative complications frequently follow major abdominal surgery and are associated with increased morbidity and mortality. Early diagnosis and treatment of complications is associated with improved patient outcome. In this study we assessed the value of a step-up diagnosis plan by C-reactive protein and CT-scan (computed tomography-scan imaging for detection of postoperative complications following major abdominal surgery. An observational cohort study was conducted of 399 consecutive patients undergoing major abdominal surgery between January 2009 and January 2011. Indication for operation, type of surgery, postoperative morbidity, complications according to the Clavien-Dindo classification and mortality were recorded. Clinical parameters were recorded until 14 days postoperatively or until discharge. Regular C-reactive protein (CPR measurements in peripheral blood and on indication -enhanced CT-scans were performed. Eighty-three out of 399 (20.6 % patients developed a major complication in the postoperative course after a median of seven days (IQR 4-9 days. One hundred and thirty two patients received additional examination consisting of enhanced CT-scan imaging, and treatment by surgical reintervention or intensive care observation. CRP levels were significantly higher in patients with postoperative complications. On the second postoperative day CRP levels were on average 197.4 mg/L in the uncomplicated group, 220.9 mg/L in patients with a minor complication and 280.1 mg/L in patients with major complications (p < 0,001. CT-scan imaging showed a sensitivity of 91.7 % and specificity of 100 % in diagnosis of major complications. Based on clinical deterioration and the increase of CRP, an additional enhanced CT-scan offered clear discrimination between patients with major abdominal complications and uncomplicated patients. Adequate treatment could then be accomplished.

  13. Relationship between Hounsfield Unit in CT Scan and Gray Scale in CBCT

    Directory of Open Access Journals (Sweden)

    Tahmineh Razi

    2014-06-01

    Full Text Available Background and aims. Cone-beam computed tomography (CBCT is an imaging system which has many advantages over computed tomography (CT. In CT scan, Hounsfield Unit (HU is proportional to the degree of x-ray attenuation by the tissue. In CBCT, the degree of x-ray attenuation is shown by gray scale (voxel value. The aim of the present study was to investigate the relationship between gray scale in CBCT and Hounsfield Unit (HU in CT scan. Materials and methods. In this descriptive study, the head of a sheep was scanned with 3 CBCT and one medical CT scanner. Gray scales and HUs were detected on images. Reconstructed data were analyzed to investigate relationship between CBCT gray scales and HUs. Results. A strong correlation between gray scales of CBCT and HUs of CT scan was determined. Conclusion. Considering the fact that gray scale in CBCT is the criteria in measurement of bone density before implant treatments, it is recommended because of the lower dose and cost compared to CT scan.

  14. Addison's disease due to adrenal tuberculosis: Contrast-enhanced CT features and clinical duration correlation

    International Nuclear Information System (INIS)

    Guo Yingkun; Yang Zhigang; Li Yuan; Ma Ensen; Deng Yuping; Min Pengqiu; Yin Longlin; Hu Jian; Zhang Xiaochun; Chen Tianwu

    2007-01-01

    Purpose: To describe CT morphology of untreated adrenal tuberculosis during the different stages of the natural history of the disease and to evaluate the diagnostic implications of CT features. Materials and methods: We retrospectively evaluated CT features in 42 patients with documented adrenal tuberculosis for the location, size, morphology, and enhancement patterns shown on CT images. The clinical duration were correlated with the CT features. Results: Of the 42 patients with untreated adrenal tuberculosis, bilaterally enlarged adrenal glands were revealed in 38 cases (91%), unilaterally enlarged in 3 cases (7%), and normal size in 1 case (2%). Of the 41 cases (98%) with enlargement, mass-like enlargement was seen in 20 cases (49%) and enlargement with preserved contours in 21 cases (51%). Peripheral rim enhancement presented in 22 cases (52%) on contrast-enhanced CT. Non-enhanced CT scan revealed calcification in 21 cases (50%). As the duration of Addison's disease increased, the presence of calcification and contour preservation increased concomitantly (p < 0.001), whereas peripheral rim enhancement and mass-like enlargement decreased concomitantly on CT images (p < 0.001). Conclusion: CT may be helpful in diagnosing adrenal tuberculosis when clinically suspected, and CT features are correlated to the clinical duration of Addison's disease

  15. Wedge-shaped parenchymal enhancement peripheral to the hepatic hemangioma : two-phase spiral CT findings

    International Nuclear Information System (INIS)

    Kim, Kyoung Won; Kim, Tae Kyoung; Han, Joon Koo; Kim, Ah Young; Lee, Hyun Ju; Song, Chi Sung; Choi, Byung Ihn

    2000-01-01

    To determine the incidence of hepatic hemangiomas associated with wedge-shaped parenchymal enhancements adjacent to the tumors as seen on two-phase spiral CT images obtained during the hepatic arterial phase and to characterize the two-phase spiral CT findings of those hemangiomas. One hundred and eight consecutive hepatic hemangiomas in 63 patients who underwent two-phase spiral CT scanning during an 11-month period were included in this study. Two-phase spiral CT scans were obtained during the hepatic arterial phase (30-second delay) and portal venous phase (65-second delay) after injection of 120 mL of contrast material at a rate of 3 mL/sec. We evaluated the frequency with which wedge-shaped parenchymal enhancement was adjacent to the hemangiomas during the hepatic arterial phase and divided hemangiomas into two groups according to whether or not wedge-shaped parenchymal enhancement was noted (Group A and Group B). The presence of such enhancement in hemangiomas was correlated with tumor size and the grade of intratumoral enhancement. In 24 of 108 hemangiomas, wedge-shaped parenchymal enhancement adjacent to hepatic tumors was seen on two-phase CT images obtained during the hepatic arterial phase. Mean hemangioma size was 22mm in group A and 24mm in group B. There was no statistically significant relationship between lesion size and the presence of wedge-shaped parenchymal enhancement adjacent to a hemangioma. In 91.7% and 100% of tumors in Group A, and in 9.6% and 17.8% in Group B, hemangiomas showed more than 50% intratumoral enhancement during the arterial and portal venous phase, respectively. Wedge-shaped parenchymal enhancements peripheral to hepatic hemangiomas was more frequently found in tumors showing more than 50% intratumoral enhancement during these two phases (p less than 0.01). Wedge-shaped parenchymal enhancements is not uncommonly seen adjacent to hepatic hemangiomas on two-phase spiral CT images obtained during the hepatic arterial phase. A

  16. Prospective evaluation of fluorodeoxyglucose positron emission tomography/computed tomography scan (FDG-PET/CT) for axillary staging in breast cancer

    International Nuclear Information System (INIS)

    Yamaguchi, Masahide; Noguchi, Akinori; Tani, Naoki

    2008-01-01

    Seventy-two patients from 2005 October to 2007 February with operative breast cancer underwent fluorodeoxyglucose positron emission tomography/computed tomography scan (FDG-PET/CT) of chest and body, ultrasound scan (US) and enhanced computed tomography scan (CT) followed by sentinel lymph node biopsy (SLNB) and axillary lymph node dissection (ALND). The results of PET/CT were compared with histopathological diagnosis of SLNB and ALND. Sensitivity, specificity and accuracy of PET/CT for detection of axillary lymph node metastases were 61%, 96% and 88%, respectively. Seven false-negative and two false-positive of PET/CT results were found. In patients with false-negative of PET/CT results there are two skin-invasive breast cancer patients and axillary lymph node metastases were detected in three patients with US, in one with CT and in four with SLNB. In clinical method for diagnosis of axillary lymph node metastases SLNB should be recommended because sensitivity of PET/CT for early breast cancer patients were low and positive diagnosis of axillary lymph node metastases with PET needs more than 1 cm size of lesion. PET/CT is useful for not-early breast cancer patients. To decide the operation of axillary lymph node disection needs total diagnosis of US, CT, SLNB and clinical findings. (author)

  17. The Beatles, the Nobel Prize, and CT scanning of the chest.

    Science.gov (United States)

    Goodman, Lawrence R

    2010-01-01

    From its first test scan on a mouse, in 1967, to current medical practice, the CT scanner has become a core imaging tool in thoracic diagnosis. Initially financed by money from Beatles' record sales, the first patient scan was performed in 1971. Only 8 years later, a Nobel Prize in Physics and Medicine was awarded to Hounsfield and Cormack for their discovery. This article traces the history of CT scanner development and how each technical advance expanded chest diagnostic frontiers. Chest imaging now accounts for 30% of all CT scanning.

  18. The use of contrast-enhanced post Mortem CT in the detection of cardiovascular deaths.

    Directory of Open Access Journals (Sweden)

    Jonas Christoph Apitzsch

    Full Text Available OBJECTIVES: To evaluate the diagnostic value of contrast enhanced post mortem computed tomography (PMCT in comparison to non-enhanced post mortem CT in the detection of cardiovascular causes of death (COD. BACKGROUND: As autopsy rates decline, new methods to determine CODs are necessary. So contrast enhanced PMCT shall be evaluated in comparison to established non-enhanced PMCT in order to further improve the method. METHODS: In a prospective study, 20 corpses were examined using a 64-row multisclice CT (MSCT before and after intraarterial perfusion with a newly developed, barium-bearing contrast agent and ventilation of the lungs. The cause of death was determined in enhanced and unenhanced scans and a level of confidence (LOC was given by three experienced radiologists on a scale between 0 and 4. Results were compared to autopsy results as gold standard. Autopsy was performed blinded to PMCT-findings. RESULTS: The method allowed visualization of different types of cause of death. There was a significant improvement in LOC in enhanced scans compared to unenhanced scans as well as an improvement in the detection of COD. The cause of death could be determined in 19 out of 20 patients. CONCLUSIONS: PMCT is feasible and appears to be robust for diagnosing cardiovascular causes of death. When compared with unenhanced post-mortem CT intraarterial perfusion and pulmonary ventilation significantly improve visualization and diagnostic accuracy. These promising results warrant further studies.

  19. Acquiring 4D thoracic CT scans using a multislice helical method

    International Nuclear Information System (INIS)

    Keall, P J; Starkschall, G; Shukla, H; Forster, K M; Ortiz, V; Stevens, C W; Vedam, S S; George, R; Guerrero, T; Mohan, R

    2004-01-01

    Respiratory motion degrades anatomic position reproducibility during imaging, necessitates larger margins during radiotherapy planning and causes errors during radiation delivery. Computed tomography (CT) scans acquired synchronously with the respiratory signal can be used to reconstruct 4D CT scans, which can be employed for 4D treatment planning to explicitly account for respiratory motion. The aim of this research was to develop, test and clinically implement a method to acquire 4D thoracic CT scans using a multislice helical method. A commercial position-monitoring system used for respiratory-gated radiotherapy was interfaced with a third generation multislice scanner. 4D cardiac reconstruction methods were modified to allow 4D thoracic CT acquisition. The technique was tested on a phantom under different conditions: stationary, periodic motion and non-periodic motion. 4D CT was also implemented for a lung cancer patient with audio-visual breathing coaching. For all cases, 4D CT images were successfully acquired from eight discrete breathing phases, however, some limitations of the system in terms of respiration reproducibility and breathing period relative to scanner settings were evident. Lung mass for the 4D CT patient scan was reproducible to within 2.1% over the eight phases, though the lung volume changed by 20% between end inspiration and end expiration (870 cm 3 ). 4D CT can be used for 4D radiotherapy, respiration-gated radiotherapy, 'slow' CT acquisition and tumour motion studies

  20. The use of CT scan in the pre-operative staging of bronchogenic carcinoma

    International Nuclear Information System (INIS)

    Pada, C.C.

    1992-01-01

    Surgery remains the treatment of choice in patients with localized bronchogenic carcinoma. Pre-operative identification of inoperability spares the patient from unnecessary surgery. This prospective study was carried out to determine the correctness of judgement regarding a patient's operability or inoperability based on the pre-operative staging of CT scan; to find out the sensitivity, specificity and overall accuracy of the CT scan in estimating tumor description, nodal status and metastatic spread to the chest. Staging was done by 3 senior radiologists aware of the diagnosis. Both the surgical and histopathologic findings and staging were gathered and used as measurement of truth in arriving at the CT scan's accuracy. Overall accuracy rate of CT scan in determining operability or inoperability is 80%; tumor description accuracy of assessment is 87% and nodal status estimation has an accuracy of 60%. Sensitivity of CT scan is assessment of metastatic spread to the chest is 93%. There is no statistically significant difference in the judgement of operability or interpretability by CT scan compared to surgical and histopathologic results. The CT scan is recommended as a valuable tool in the pre-operative staging of patients with bronchogenic carcinoma who are candidates for surgery. (auth.). 21 refs.; 8 tabs

  1. Automatic three-dimensional rib centerline extraction from CT scans for enhanced visualization and anatomical context

    Science.gov (United States)

    Ramakrishnan, Sowmya; Alvino, Christopher; Grady, Leo; Kiraly, Atilla

    2011-03-01

    We present a complete automatic system to extract 3D centerlines of ribs from thoracic CT scans. Our rib centerline system determines the positional information for the rib cage consisting of extracted rib centerlines, spinal canal centerline, pairing and labeling of ribs. We show an application of this output to produce an enhanced visualization of the rib cage by the method of Kiraly et al., in which the ribs are digitally unfolded along their centerlines. The centerline extraction consists of three stages: (a) pre-trace processing for rib localization, (b) rib centerline tracing, and (c) post-trace processing to merge the rib traces. Then we classify ribs from non-ribs and determine anatomical rib labeling. Our novel centerline tracing technique uses the Random Walker algorithm to segment the structural boundary of the rib in successive 2D cross sections orthogonal to the longitudinal direction of the ribs. Then the rib centerline is progressively traced along the rib using a 3D Kalman filter. The rib centerline extraction framework was evaluated on 149 CT datasets with varying slice spacing, dose, and under a variety of reconstruction kernels. The results of the evaluation are presented. The extraction takes approximately 20 seconds on a modern radiology workstation and performs robustly even in the presence of partial volume effects or rib pathologies such as bone metastases or fractures, making the system suitable for assisting clinicians in expediting routine rib reading for oncology and trauma applications.

  2. Full-Body CT Scans - What You Need to Know

    Science.gov (United States)

    ... Procedures Medical Imaging Medical X-ray Imaging Full-Body CT Scans - What You Need to Know Share ... if you are thinking of having a whole-body screening: Whole-body CT screening has not been ...

  3. Evolution of traumatic intracerebral hematoma. Analysis of sequential CT scans since per-acute stage

    Energy Technology Data Exchange (ETDEWEB)

    Nagaseki, Yoshishige; Horikoshi, Satoru [Gunma Univ., Maebashi (Japan). School of Medicine; Tamura, Masaru

    1984-05-01

    To clarify the evolution of traumatic intracerebral hematoma (TICH), initial computerized tomography (CT) scans of 28 TICH cases performed within one hour after head trauma were studied along with their follow-up CT scans. They were classified into the following two groups; per-acute group included seven cases in which TICH was completed on the initial CT scans taken within one hour after head injury and acute group included 21 cases in which the initial CT scans revealed isodensity or high density spot and repeat CT scans disclosed TICH by 48 hours after injury. In the per-acute group, initial CT scans showed a homogeneous, well defined, and high density mass (1.5-6.5 cm in diameter). In sequential CT scans of the three cases, the hematoma did not increase but spontaneously disappeared. Other four cases died early after head trauma. Their initial CT scans revealed a large high density mass (3-6.5 cm in diameter) combined with other extracerebral hemorrhages. In the acute group, initial CT scans demonstrated isodensity or high density spot and sequential CT scans showed mottled appearance of salt and pepper appearance, and after a while showed fusion of small high density areas to become a massive high density area (contusional hematoma) by 48 hours after injury. In six cases of this group, the contusional hematoma was removed within 24 hours after injury and in one case at 3.5 days. In other 14 cases, the hematomas shrank or disappeared spontaneously. From these results, it was considered that evolution of TICH's were classified into the two groups; per-acute group resulting from rupture of vessels and acute group resulting from contusion.

  4. Cervical lymph node metastasis of oral squamous cell carcinomas. CT enhancement and histopathological evaluations

    Energy Technology Data Exchange (ETDEWEB)

    Etoh, Yohei; Kimura, Takuji; Sasaki, Akira; Kishimoto, Koji; Matsumura, Tomohiro; Kishi, Kanji [Okayama Univ. (Japan). Dental School

    2000-06-01

    A comparison of the results of histopathological and enhanced CT examinations were carried out for 88 patients with oral squamous cell carcinomas who underwent neck dissection. CT scanning (5-mm thick section) images obtained during bolus/drip injection of Iopamidol were routinely taken through the neck. Ninety-two of 1634 nodes were histologically diagnosed as metastatic. Low density areas surrounding enhancement rims were metastatic nodal central necrosis or keratinization. Enhanced areas in many metastatic nodes were considered to be lymphatic architecture, not metastatic masses especially in the avascular keratinization. Enhanced CT produced accurate information of lymph node size, location, shape, grouping and spread from nodes to adjacent structures. However, it was considered that not every metastatic lymph node should show enlargement and/or enhancement. Improved assessment of solid metastatic features of lymph nodes (shape, size, and involvement) may be achieved with the aid of thin-thickness CT. (author)

  5. Cervical lymph node metastasis of oral squamous cell carcinomas. CT enhancement and histopathological evaluations

    International Nuclear Information System (INIS)

    Etoh, Yohei; Kimura, Takuji; Sasaki, Akira; Kishimoto, Koji; Matsumura, Tomohiro; Kishi, Kanji

    2000-01-01

    A comparison of the results of histopathological and enhanced CT examinations were carried out for 88 patients with oral squamous cell carcinomas who underwent neck dissection. CT scanning (5-mm thick section) images obtained during bolus/drip injection of Iopamidol were routinely taken through the neck. Ninety-two of 1634 nodes were histologically diagnosed as metastatic. Low density areas surrounding enhancement rims were metastatic nodal central necrosis or keratinization. Enhanced areas in many metastatic nodes were considered to be lymphatic architecture, not metastatic masses especially in the avascular keratinization. Enhanced CT produced accurate information of lymph node size, location, shape, grouping and spread from nodes to adjacent structures. However, it was considered that not every metastatic lymph node should show enlargement and/or enhancement. Improved assessment of solid metastatic features of lymph nodes (shape, size, and involvement) may be achieved with the aid of thin-thickness CT. (author)

  6. Change in contrast enhancement of HCC on 1-month follow-up CT after local radiotherapy: An early predictor of final treatment response

    International Nuclear Information System (INIS)

    Kim, Eun Young; Choi, Dongil; Lim, Do Hoon; Lee, Won Jae; Yoo, Byung Chul; Paik, Seung Woon

    2009-01-01

    Background: The purpose of this study was to evaluate the change in contrast enhancement of HCC on 1-month follow-up CT after local radiotherapy (RT) as an early predictor of final treatment response. Materials: Fifty patients who underwent local RT for HCCs had both pre-RT and post-RT CT scans including 1-month follow-up CT. We assessed the final treatment response by using the change in maximal tumor size on 6-12-month follow-up CT scan after RT. We also evaluated the change in tumor enhancement between pre-RT and 1-month follow-up CT scans. Results: A final treatment response was achieved in 27 (54%) of 50 patients, who showed either a complete response (n = 11) or a partial response (n = 16). Compared with non-responsive patients (n = 23), responsive patients showed a significant decrease in tumor enhancement on 1-month follow-up CT after RT in both objective and subjective analyses (each P < 0.001). Conclusion: The change in contrast enhancement of HCC seen on the 1-month follow-up CT in patients after local RT may be used as an early predictor of final treatment response.

  7. Socio-economic variation in CT scanning in Northern England, 1990-2002

    Directory of Open Access Journals (Sweden)

    Pearce Mark S

    2012-01-01

    Full Text Available Abstract Background Socio-economic status is known to influence health throughout life. In childhood, studies have shown increased injury rates in more deprived settings. Socio-economic status may therefore be related to rates of certain medical procedures, such as computed tomography (CT scans. This study aimed to assess socio-economic variation among young people having CT scans in Northern England between 1990 and 2002 inclusive. Methods Electronic data were obtained from Radiology Information Systems of all nine National Health Service hospital Trusts in the region. CT scan data, including sex, date of scan, age at scan, number and type of scans were assessed in relation to quintiles of Townsend deprivation scores, obtained from linkage of postcodes with census data, using χ2 tests and Spearman rank correlations. Results During the study period, 39,676 scans were recorded on 21,089 patients, with 38,007 scans and 19,485 patients (11344 male and 8132 female linkable to Townsend scores. The overall distributions of both scans and patients by quintile of Townsend deprivation scores were significantly different to the distributions of Townsend scores from the census wards included in the study (p Conclusions Social inequalities exist in the numbers of young people undergoing CT scans with those from deprived areas more likely to do so. This may reflect the rates of injuries in these individuals and implies that certain groups within the population may receive higher radiation doses than others due to medical procedures.

  8. CT scan and histological findings in experimental cerebral infarctions in cats

    International Nuclear Information System (INIS)

    Morimoto, Tetsuya

    1981-01-01

    Experimental cerebral infarctions were made in sixty-five cats by the transorbital approach. CT scanning was done at various periods after right-middle cerebral artery occlusion, and all cases were studied histopathologically. Cerebral microcirculation was studied by the carbon perfusion method, and blood-brain barrier (BBB) dysfunction was studied by intravenous fluorescein administration. The iodine content of brain tissue was measured and this value was compared with the findings on CT scan. Experimental cerebral infarction was divided into four stages according to CT scan findings. These are the pre-edema stage, edema stage, edema diminishing stage, and cavity stage. The low density area (LDA) in the edema stage has a mass effect and a spongy appearance is seen histopathologically. LDA in the edema diminishing stage is localized to the extent of the macroscopic infarcted region, and macrophage (so called ''gitter cells'') and capillaries are seen. Fluorescein stain indicating the area of BBB dysfunction shows almost the same extent as the area of disturbed microcirculation indicated by impaired carbon filling. In the edema diminishing stage, there is good carbon filling in the infarcted region, and enlarged capillaries with carbon black inside are seen. The study of iodine content showed that the iodine level is very high in the infarcted region, and the level has good correlation with the number of capillaries. The mechanism of contrast enhancement in the cerebral infarction seems to be well linked to the capillaries with BBB dysfunction. This study indicates that the contrast medium leaks through the capillary wall. (author)

  9. The pictures of CT scan of gold pneumonitis

    International Nuclear Information System (INIS)

    Taguchi, Yoshio; Iwata, Takekuni; Kuroda, Yasumasa; Sadato, Norihiro; Tanemoto, Kiichiro; Adachi, Kazuhiko.

    1987-01-01

    We experienced two cases of gold pneumonitis and their interesting findings of CT scan. After the cessation of gold salt, both cases were treated with the corticosteroid, resulting in the disappearance of pulmonary manifestations and clearing of shadows on chest roentgenograms. The findings of CT scan on both cases were very interesting. They were the high density shadows along the bronchovascular bundles, the fluffy figures surroundings these shadows and band like shadows reached to the thoracic wall. We considered that each shadows were pathologically compatible with severe exudative changes of interstitial pneumonitis, shrinkage surroundings them and thickness of interlobular septum. (author)

  10. Automated lung volumetry from routine thoracic CT scans: how reliable is the result?

    Science.gov (United States)

    Haas, Matthias; Hamm, Bernd; Niehues, Stefan M

    2014-05-01

    Today, lung volumes can be easily calculated from chest computed tomography (CT) scans. Modern postprocessing workstations allow automated volume measurement of data sets acquired. However, there are challenges in the use of lung volume as an indicator of pulmonary disease when it is obtained from routine CT. Intra-individual variation and methodologic aspects have to be considered. Our goal was to assess the reliability of volumetric measurements in routine CT lung scans. Forty adult cancer patients whose lungs were unaffected by the disease underwent routine chest CT scans in 3-month intervals, resulting in a total number of 302 chest CT scans. Lung volume was calculated by automatic volumetry software. On average of 7.2 CT scans were successfully evaluable per patient (range 2-15). Intra-individual changes were assessed. In the set of patients investigated, lung volume was approximately normally distributed, with a mean of 5283 cm(3) (standard deviation = 947 cm(3), skewness = -0.34, and curtosis = 0.16). Between different scans in one and the same patient the median intra-individual standard deviation in lung volume was 853 cm(3) (16% of the mean lung volume). Automatic lung segmentation of routine chest CT scans allows a technically stable estimation of lung volume. However, substantial intra-individual variations have to be considered. A median intra-individual deviation of 16% in lung volume between different routine scans was found. Copyright © 2014 AUR. Published by Elsevier Inc. All rights reserved.

  11. Spontaneous spinal epidural hematoma diagnosed by CT scan

    International Nuclear Information System (INIS)

    Abumiya, Takeo; Isu, Toyohiko; Iwasaki, Yoshinobu; Akino, Minoru; Abe, Hiroshi

    1985-01-01

    A case of spinal epidural hematoma diagnosed by CT scan is reported. A 58-year-old man was admitted on June 18, 1984. He had had a sudden onset of severe low-back pain 7 days before admission and had developed paraparesis and numbness of the lower limbs 4 day before admission. Physical examination revealed weakness in the lower limbs, with the reflexes there decreased. The Babinski reflex and the Chaddock reflex were, however, present on both sides. Sensory disturbances were noted below L 2 . Urinary incontinence was present, too. Metrizamide myelography revealed an epidural mass which was located from the power part of T 11 to the upper part of L 2 . A CT scan revealed a biconvex, relatively high-density mass in the posterior spinal canal. On the day of admission, a laminectomy was performed from T 11 to L 1 , and the epidural hematoma was evacuated. The postoperative course was uneventful. Spinal epidural hematoma is uncommon. A CT scan can be used for an early diagnosis of this lesion. According to the review of the CT findings in 15 reported cases, including our case, CT reveals a smoothly marginated biconvex homogeneous density mass. The density of the hematoma decreases with the time. An acute type (within 3 days) is high-density, while a chronic type has a relatively high or isodensity. The acute type is easily differentiated from other epidural masses, such as a herniated disc, an epidural abscess, and an epidural tumor. On the other hand, the diagnosis of the chronic type is not always easy. (author)

  12. Serial CT scans and Menkes' kinky hair disease

    Energy Technology Data Exchange (ETDEWEB)

    Nakada, Eizo; Kameyama, Junji; Yoshimitsu, Hajime; Mori, Mikio; Tanaka, Mutsuo; Yoshimitsu, Kazunori.

    1988-02-01

    Menkes' kinky hair disease is a sex-linked recessive disorder of copper metabolism, characterized by progressive psychomotor deterioration, seizures, and peculiar hair structure. We examined serial CT scans of patients with this disease. A 2,210-g male infant was delivered after an uneventful gestation of 36 weeks. His one-minute Apgar score was 9. His uncle had died at 1 year of age. His first cousin was also diagnosed as having Menkes' kinky hair disease when our patient was 2 years old. Shortly after birth he had mild respiratory distress. At 5 days of age, he developed setting-sun signs. The first CT scan, at 10 days of age, revealed mild posterior fossa hemorrhages. At 3 months of age, myoclonic seizures began, and the CT scan revealed subdural effusion and mild brain atrophy. The seizures were controllable by using phenobarbital, valproic acid, and nitrazepam. He did not follow light or a fixate, but the fundi were normal. He was diffusely hypotonic. At 9 months of age, the seizures became uncontrollable. The CT scans at 15 and 31 months of age showed subdural hemorrhage and/or brain atrophy. At 15 months of age, the serum copper level was 42 ..mu.. g/dl, while the serum ceruloplasmin level was 3.2 mg/dl. He exhibited severe developmental failure. At 4 years of age, he died.

  13. CT Scanning in Identification of Sheep Cystic Echinococcosis.

    Science.gov (United States)

    Mao, Rui; Qi, Hongzhi; Pei, Lei; Hao, Jie; Dong, Jian; Jiang, Tao; Ainiwaer, Abudula; Shang, Ge; Xu, Lin; Shou, Xi; Zhang, Songan; Wu, Ge; Lu, Pengfei; Bao, Yongxing; Li, Haitao

    2017-01-01

    We aim to determine the efficiency of CT in identification of cystic echinococcosis in sheep. Fifty-three sheep with liver cysts confirmed by ultrasonography were subject to CT scan to evaluate the number, size, and type of the cysts in liver and lung, confirmed using necropsy. The correlation of numbers between liver cysts and lung cysts was calculated using Pearson analysis. Necropsy indicated a 98% consensus on size, location, number, and activity compared with CT scan. The viable cysts were 53.1% and 50.6% in the liver and lung, respectively. Among the cysts in liver, 35.5%, 9.5%, 5.7%, 10.2%, and 39.1% were Types CE1, CE2, CE3, CE4, and CE5, respectively. The cysts in the lungs, 17.4%, 26.9%, 12.1%, 11.6%, and 32.1%, were Types CE1, CE2, CE3, CE4, and CE5, respectively. A significant correlation was noticed between the number of cysts in liver and those in lung ( R = 0.770, P < 0.001). CT scan is a suitable tool in determining the size and type of cystic hydatid cysts in both liver and lung of sheep. A significant correlation was noticed between the numbers in liver and lung, indicating that lung infection was likely due to the expansion of liver cyst burden pressure.

  14. Lumbar spine joint synovial cysts of intraspinal development. CT scan imaging

    Energy Technology Data Exchange (ETDEWEB)

    Vallee, C.; Chevrot, A.; Benhamouda, M. and others

    CT scan imaging findings are described in 22 patients with lumbar spine joint synovial cysts, of intraspinal development, provoking sciatica or lumbosciatica from nerve compression in spinal canal. Diagnosis was suggested by a mass at the posterior joint level, of variable density, sometimes with peripheral calcification, presenting a vacuum appearance on occasions, and with enhanced image with contrast. Differential diagnosis is from excluded hernia and postoperative fibrosis. Posterior intra-articular arthrography can confirm diagnosis and allow treatment with prolonged action corticoid infiltrations.

  15. Post-operative abdominal CT scanning in extrahepatic biliary atresia

    Energy Technology Data Exchange (ETDEWEB)

    Day, D L; Mulcahy, P F; Letourneau, J G; Dehner, L P

    1989-07-01

    A retrospective review of the abdominal CT scans of 26 children with extrahepatic biliary atresia was performed, and the results were correlated with available surgical and pathologic data. Associated congenital anomalies or acquired abnormalities were identified in these patients. Congenital anomalies included polysplenia, venous anomalies and bowel stenosis. Acquired abnormalities developed secondary to cirrhosis, portal hypertension, intrahepatic biliary duct dilatation, and hepatic ischemia. Despite frequent episodes of ascending cholangitis in these children, no hepatic abscesses were identified by CT or by pathologic examination. In conclusion, abdominal CT scanning of children with extrahepatic biliary atresia can define congenital and acquired abnormalities and provide important anatomic data for the surgeons before liver transplantation. (orig.).

  16. Helical CT scan for emergent patients with cerebrovascular diseases

    International Nuclear Information System (INIS)

    Matsumoto, Masato; Sato, Naoki; Nakano, Masayuki; Watanabe, Youichi; Kodama, Namio

    1995-01-01

    We studied 44 emergent patients with cerebrovascular diseases (18 cases of subarachnoid hemorrhage, 15 of occlusive lesions, 7 of intracerebral hematoma and 4 of suspected subarachnoid hemorrhage) using helical CT scan. The helical CT scan was performed with contrast medium at a rate of 3 ml/sec with a delay of 20 sec, and was carried out before conventional angiography. The reconstruction time of 3D-CTA was within 10 min. We were able to obtain findings for the lesion on 3D-CTA before those on conventional angiography. The 3D-CTA yielded excellent images of the vascular structures and anatomical relationships of the aneurysm, its neck and parent artery, and surrounding arteries. However, it proved difficult to visualize vessels of less than 1 mm in diameter, especially the perforating arteries. In occlusive diseases, the degree of stenosis depended on the changes in CT number threshold: at present, evaluations of the lesions should be made by conventional angiography. 3D-CTA using helical CT scan can thus be applied for emergent patients with cerebrovascular diseases. Surgical simulation images of 3D-CTA were especially useful at the time of operation. (author)

  17. Helical CT scan for emergent patients with cerebrovascular diseases

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, Masato; Sato, Naoki; Nakano, Masayuki; Watanabe, Youichi; Kodama, Namio [Fukushima Medical Coll. (Japan)

    1995-08-01

    We studied 44 emergent patients with cerebrovascular diseases (18 cases of subarachnoid hemorrhage, 15 of occlusive lesions, 7 of intracerebral hematoma and 4 of suspected subarachnoid hemorrhage) using helical CT scan. The helical CT scan was performed with contrast medium at a rate of 3 ml/sec with a delay of 20 sec, and was carried out before conventional angiography. The reconstruction time of 3D-CTA was within 10 min. We were able to obtain findings for the lesion on 3D-CTA before those on conventional angiography. The 3D-CTA yielded excellent images of the vascular structures and anatomical relationships of the aneurysm, its neck and parent artery, and surrounding arteries. However, it proved difficult to visualize vessels of less than 1 mm in diameter, especially the perforating arteries. In occlusive diseases, the degree of stenosis depended on the changes in CT number threshold: at present, evaluations of the lesions should be made by conventional angiography. 3D-CTA using helical CT scan can thus be applied for emergent patients with cerebrovascular diseases. Surgical simulation images of 3D-CTA were especially useful at the time of operation. (author).

  18. Multi-detector row CT of the kidney: Optimizing scan delays for bolus tracking techniques of arterial, corticomedullary, and nephrographic phases

    Energy Technology Data Exchange (ETDEWEB)

    Goshima, Satoshi [Department of Radiology, Gifu University School of Medicine, 1-1 Yanagido, Gifu 501-1193 (Japan); Kanematsu, Masayuki [Department of Radiology, Gifu University School of Medicine, 1-1 Yanagido, Gifu 501-1193 (Japan); Department of Radiology Services, Gifu University School of Medicine, 1-1 Yanagido, Gifu 501-1193 (Japan); Nishibori, Hironori; Kondo, Hiroshi; Tsuge, Yusuke [Department of Radiology, Gifu University School of Medicine, 1-1 Yanagido, Gifu 501-1193 (Japan); Yokoyama, Ryujiro; Miyoshi, Toshiharu [Department of Radiology Services, Gifu University School of Medicine, 1-1 Yanagido, Gifu 501-1193 (Japan); Onozuka, Minoru [Department of Physiology and Neuroscience, Kanagawa Dental College, Yokosuka, Kanagawa (Japan); Shiratori, Yoshimune [Department of Medical Informatics, Gifu University School of Medicine, Gifu (Japan); Moriyama, Noriyuki [Department of Diagnostic Radiology, National Cancer Center Hospital, Tsukiji, Chuo-Ku, Tokyo (Japan); Bae, Kyongtae T. [Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO (United States)

    2007-09-15

    Purpose: To determine optimal scan delays for renal arterial-, corticomedullary-, and nephrographic-phase imaging with multi-detector row computed tomography (MDCT) of the kidney using a bolus-tracking technique. Methods and materials: One hundred and twenty-eight patients underwent three-phase CT scan of the kidney with eight-row MDCT after receiving 2 mL/kg of 300 mg I/mL contrast medium at 4 mL/s. Patients were prospectively randomized into three groups with different scan delays for the three scan phases (arterial, corticomedullary, and nephrographic) after bolus-tracking triggered at 50 HU of aortic contrast enhancement: group 1 (5, 20, 45 s); group 2 (10, 25, 50 s); and group 3 (15, 30, 55 s). Mean CT values (HU) of the abdominal aorta, renal artery, renal vein, renal cortex, and renal medulla were measured; increases in CT values pre- to post-contrast were assessed as contrast enhancement. Renal artery-to-vein and renal cortex-to-medulla contrast differences were also assessed. Qualitative analysis was also performed. Results: Mean renal artery enhancement was 240-288 HU at 5-15 s after the trigger and peaked at 10 s (P < .001). Mean renal cortical enhancement was 195-217 HU at 10-30 s and peaked at 25 s (P < .01). Contrast enhancement in the renal medulla increased gradually and reached mean 145 HU at 55 s. Cortex-to-medulla contrast difference was high (110-140 HU) at 5-30 s and decreased below 30 HU at 45 s after the trigger. Renal artery-to-vein contrast difference was high (121-125 HU) at 5-10 s. Qualitative results correlated well with quantitative results. Conclusion: For the injection protocol used in this study, optimal scan delays after the bolus-tracking trigger were 5-10 s for renal arterial, 15-25 s for corticomedullary, and 50-55 s for nephrographic phases.

  19. Patient dose estimation from CT scans at the Mexican National Neurology and Neurosurgery Institute

    International Nuclear Information System (INIS)

    Alva-Sánchez, Héctor; Reynoso-Mejía, Alberto; Casares-Cruz, Katiuzka; Taboada-Barajas, Jesús

    2014-01-01

    In the radiology department of the Mexican National Institute of Neurology and Neurosurgery, a dedicated institute in Mexico City, on average 19.3 computed tomography (CT) examinations are performed daily on hospitalized patients for neurological disease diagnosis, control scans and follow-up imaging. The purpose of this work was to estimate the effective dose received by hospitalized patients who underwent a diagnostic CT scan using typical effective dose values for all CT types and to obtain the estimated effective dose distributions received by surgical and non-surgical patients. Effective patient doses were estimated from values per study type reported in the applications guide provided by the scanner manufacturer. This retrospective study included all hospitalized patients who underwent a diagnostic CT scan between 1 January 2011 and 31 December 2012. A total of 8777 CT scans were performed in this two-year period. Simple brain scan was the CT type performed the most (74.3%) followed by contrasted brain scan (6.1%) and head angiotomography (5.7%). The average number of CT scans per patient was 2.83; the average effective dose per patient was 7.9 mSv; the mean estimated radiation dose was significantly higher for surgical (9.1 mSv) than non-surgical patients (6.0 mSv). Three percent of the patients had 10 or more brain CT scans and exceeded the organ radiation dose threshold set by the International Commission on Radiological Protection for deterministic effects of the eye-lens. Although radiation patient doses from CT scans were in general relatively low, 187 patients received a high effective dose (>20 mSv) and 3% might develop cataract from cumulative doses to the eye lens

  20. Patient dose estimation from CT scans at the Mexican National Neurology and Neurosurgery Institute

    Science.gov (United States)

    Alva-Sánchez, Héctor; Reynoso-Mejía, Alberto; Casares-Cruz, Katiuzka; Taboada-Barajas, Jesús

    2014-11-01

    In the radiology department of the Mexican National Institute of Neurology and Neurosurgery, a dedicated institute in Mexico City, on average 19.3 computed tomography (CT) examinations are performed daily on hospitalized patients for neurological disease diagnosis, control scans and follow-up imaging. The purpose of this work was to estimate the effective dose received by hospitalized patients who underwent a diagnostic CT scan using typical effective dose values for all CT types and to obtain the estimated effective dose distributions received by surgical and non-surgical patients. Effective patient doses were estimated from values per study type reported in the applications guide provided by the scanner manufacturer. This retrospective study included all hospitalized patients who underwent a diagnostic CT scan between 1 January 2011 and 31 December 2012. A total of 8777 CT scans were performed in this two-year period. Simple brain scan was the CT type performed the most (74.3%) followed by contrasted brain scan (6.1%) and head angiotomography (5.7%). The average number of CT scans per patient was 2.83; the average effective dose per patient was 7.9 mSv; the mean estimated radiation dose was significantly higher for surgical (9.1 mSv) than non-surgical patients (6.0 mSv). Three percent of the patients had 10 or more brain CT scans and exceeded the organ radiation dose threshold set by the International Commission on Radiological Protection for deterministic effects of the eye-lens. Although radiation patient doses from CT scans were in general relatively low, 187 patients received a high effective dose (>20 mSv) and 3% might develop cataract from cumulative doses to the eye lens.

  1. Patient dose estimation from CT scans at the Mexican National Neurology and Neurosurgery Institute

    Energy Technology Data Exchange (ETDEWEB)

    Alva-Sánchez, Héctor, E-mail: halva@ciencias.unam.mx [Unidad de Imagen Molecular PET/CT, Instituto Nacional de Neurología y Neurocirugía Manuel Velasco Suárez, Insurgentes Sur 3877 Col. La Fama, 14269, México D.F. (Mexico); Reynoso-Mejía, Alberto [Unidad de Imagen Molecular PET/CT, Instituto Nacional de Neurología y Neurocirugía Manuel Velasco Suárez, Insurgentes Sur 3877 Col. La Fama, 14269, México D.F., Mexico and Departamento de Neuroimagen, Instituto Nacional de (Mexico); Casares-Cruz, Katiuzka; Taboada-Barajas, Jesús [Departamento de Neuroimagen, Instituto Nacional de Neurología y Neurocirugía Manuel Velasco Suárez, Insurgentes Sur 3877 Col. La Fama, 14269, México D.F. (Mexico)

    2014-11-07

    In the radiology department of the Mexican National Institute of Neurology and Neurosurgery, a dedicated institute in Mexico City, on average 19.3 computed tomography (CT) examinations are performed daily on hospitalized patients for neurological disease diagnosis, control scans and follow-up imaging. The purpose of this work was to estimate the effective dose received by hospitalized patients who underwent a diagnostic CT scan using typical effective dose values for all CT types and to obtain the estimated effective dose distributions received by surgical and non-surgical patients. Effective patient doses were estimated from values per study type reported in the applications guide provided by the scanner manufacturer. This retrospective study included all hospitalized patients who underwent a diagnostic CT scan between 1 January 2011 and 31 December 2012. A total of 8777 CT scans were performed in this two-year period. Simple brain scan was the CT type performed the most (74.3%) followed by contrasted brain scan (6.1%) and head angiotomography (5.7%). The average number of CT scans per patient was 2.83; the average effective dose per patient was 7.9 mSv; the mean estimated radiation dose was significantly higher for surgical (9.1 mSv) than non-surgical patients (6.0 mSv). Three percent of the patients had 10 or more brain CT scans and exceeded the organ radiation dose threshold set by the International Commission on Radiological Protection for deterministic effects of the eye-lens. Although radiation patient doses from CT scans were in general relatively low, 187 patients received a high effective dose (>20 mSv) and 3% might develop cataract from cumulative doses to the eye lens.

  2. CT scan findings in focal epilepsy

    International Nuclear Information System (INIS)

    Kobayashi, Eiki; Mihara, Tadahiro; Yamamoto, Kunimitsu; Yamashita, Kenji; Asakura, Tetsuhiko

    1980-01-01

    In 80 cases of focal epilepsy, excluding such cases as late onset after the age of 30 and traumatic or expansive lesions, the epileptogenic foci have been studied by comparing the CT findings with the seizure types and the EEG findings. The results were as follows: (1) Abnormal CT findings were observed in 36% of the patients. (2) These findings were classified into 4 large groups: localized cerebral atrophy, localized low density, localized high density with contrast enhancement and diffuse cerebral atrophy. (3) The incidence of CT abnormality was higher in the cases with continuous and localized EEG abnormality than in the cases with other types of EEG abnormality. In 48% of the cases, the location of the abnormal CT findings coincided with their EEG foci. (4) In the cases of temporal lobe epilepsy without abnormal CT images, the print-out data compared with the bilateral promised temporal regions, before and after contrast enhancement. The EMI-No. of the medial temporal focus increased more than that of the contralateral side in 3 cases out of 4 after contrast-media injection. (5) Moreover, for the purpose of comparing the CT findings on general seizures with those in focal seizures, we have studied 80 cases of general seizures. In the cases of the general seizures, abnormal CT findings were observed in only 16%. These abnormal findings were diffuse in 5 cases, localized in 6 cases, and combined in 3 cases. (author)

  3. CT angiography. Abdominal CT using intravenous aortography for contrast enhancement

    Energy Technology Data Exchange (ETDEWEB)

    Nagai, J; Nakauma, Y; Egawa, J; Kawamura, M [Teikyo Univ., Tokyo (Japan). Faculty of Medicine

    1980-04-01

    To obtain imaging effects close to those of abdominal aortography and investigate a technique with little invasion to patients, intravenous aortography was applied to contrast enhancement (CE) in abdominal CT, and its usefulness was discussed. Intravenous aortography could clearly visualize lesions with rich neovascularity such as hepatocellular carcinoma and renal cell carcinoma. Differing from a drip infusion method, this method has complexities in its technique that contrast medium is injected at once, blood circulation time which is represented by the time between the injection and the time when the patients feel bitterness (10 - 12 seconds) must be measured before CE, and scanning begins 2 seconds before the patients feel bitterness. However, the invasion to patients due to this method is slight, and the capacity of this method to visualize neovascularity is superior to CE by a drip infusion method. Therefore, qualitative diagnosis by CT will be improved by using this method together with a drip infusion method.

  4. Colon distension and scan protocol for CT-colonography: An overview

    Energy Technology Data Exchange (ETDEWEB)

    Boellaard, Thierry N., E-mail: t.n.boellaard@amc.uva.nl [Department of Radiology, Academic Medical Center, University of Amsterdam, PB 22660, 1100 DD Amsterdam (Netherlands); Haan, Margriet C. de, E-mail: m.c.dehaan@amc.uva.nl [Department of Radiology, Academic Medical Center, University of Amsterdam, PB 22660, 1100 DD Amsterdam (Netherlands); Venema, Henk W., E-mail: h.w.venema@amc.uva.nl [Department of Radiology, Academic Medical Center, University of Amsterdam, PB 22660, 1100 DD Amsterdam (Netherlands); Department of Biomedical Engineering and Physics, Academic Medical Center, University of Amsterdam, PB 22660, 1100 DD Amsterdam (Netherlands); Stoker, Jaap, E-mail: j.stoker@amc.uva.nl [Department of Radiology, Academic Medical Center, University of Amsterdam, PB 22660, 1100 DD Amsterdam (Netherlands)

    2013-08-15

    This article reviews two important aspects of CT-colonography, namely colonic distension and scan parameters. Adequate distension should be obtained to visualize the complete colonic lumen and optimal scan parameters should be used to prevent unnecessary radiation burden. For optimal distension, automatic carbon dioxide insufflation should be performed, preferably via a thin, flexible catheter. Hyoscine butylbromide is – when available – the preferred spasmolytic agent because of the positive effect on insufflation and pain/burden and its low costs. Scans in two positions are required for adequate distension and high polyp sensitivity and decubitus position may be used as an alternative for patients unable to lie in prone position. The great intrinsic contrast between air or tagging and polyps allows the use of low radiation dose. Low-dose protocol without intravenous contrast should be used when extracolonic findings are deemed unimportant. In patients suspected for colorectal cancer, normal abdominal CT scan protocols and intravenous contrast should be used in supine position for the evaluation of extracolonic findings. Dose reduction can be obtained by lowering the tube current and/or voltage. Tube current modulation reduces the radiation dose (except in obese patients), and should be used when available. Iterative reconstructions is a promising dose reducing tool and dual-energy CT is currently evaluated for its applications in CT-colonography. This review also provides our institution's insufflation procedure and scan parameters.

  5. {sup 18}F-FDG PET/CT and contrast-enhanced CT findings of pulmonary cryptococcosis

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Si-yun, E-mail: wang_shuxia@outlook.com [Department of PET Center, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong (China); Chen, Gang, E-mail: cgggh@outlook.com [Department of Thoracic Surgery, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong (China); Luo, Dong-lan, E-mail: 695532870@qq.com [Department of Pathology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong (China); Shao, Dan, E-mail: shaodan501@outlook.com [Department of PET Center, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong (China); Liu, En-tao, E-mail: GDGH2015@gmail.com [Department of PET Center, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong (China); Sun, Taotao, E-mail: sunmoodsdaisy@bjmu.edu.cn [Department of PET Center, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong (China); Wang, Shu-Xia, E-mail: wsyggh@outlook.com [Department of PET Center, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong (China)

    2017-04-15

    Purpose: Pulmonary cryptococcosis is an uncommon cause of pulmonary nodules in non-AIDS patients. This study reports the {sup 18}F-fluorodeoxyglucose-positron emission tomography ({sup 18}F-FDG PET/CT) and contrast-enhanced CT (CE-CT) findings of 42 patients with pulmonary cryptococcosis. Materials and methods: A retrospective review of the {sup 18}F-FDG PET/CT and CE-CT findings of 42 patients with histologically proven pulmonary cryptococcosis was conducted. All patients underwent PET/CT and CE-CT in the same session. The CT diagnosis was based on the location, morphological features, and enhancement of lesions. The PET/CT findings were recorded, and clinical data and surgical and histopathological findings were collected. Results: The results of the PET scans revealed that 37 (88%) of 42 patients showed higher FDG uptake, and 5 (12%) patients demonstrated lower FDG uptake than the mediastinal blood pool. The maximum standardized uptake value (SUV) of pulmonary cryptococcosis ranged from 1.4 to 13.0 (average: 5.7 ± 3.3, median 4.9). A single nodular pattern was the most prevalent pattern observed and was found in 29 (69%) patients. This pattern was followed by scattered nodular (n = 4, 10%), clustered nodular (n = 3, 7%), mass-like (n = 3, 7%), and bronchopneumonic (n = 3, 7%) patterns. The most frequent pattern of immunocompetent patients was the single nodular pattern (29 of 33, 88%). Immunocompromised patients most frequently pattern exhibited mass-like (3 of 9, 33%) and bronchopneumonic (3 of 9, 33%) patterns. Conclusion: Pulmonary cryptococcosis most commonly appears as single nodules in immunocompetent patients. Mass-like and bronchopneumonic patterns were common in immunocompromised patients. In 88% of patients, lung lesions showed high FDG uptake, thus mimicking a possible malignant condition.

  6. Estimating local noise power spectrum from a few FBP-reconstructed CT scans

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Rongping, E-mail: rongping.zeng@fda.hhs.gov; Gavrielides, Marios A.; Petrick, Nicholas; Sahiner, Berkman; Li, Qin; Myers, Kyle J. [Division of Imaging, Diagnostics, and Software Reliability, Office of Science and Engineering Laboratories, CDRH, FDA, Silver Spring, Maryland 20993 (United States)

    2016-01-15

    Purpose: Traditional ways to estimate 2D CT noise power spectrum (NPS) involve an ensemble average of the power spectrums of many noisy scans. When only a few scans are available, regions of interest are often extracted from different locations to obtain sufficient samples to estimate the NPS. Using image samples from different locations ignores the nonstationarity of CT noise and thus cannot accurately characterize its local properties. The purpose of this work is to develop a method to estimate local NPS using only a few fan-beam CT scans. Methods: As a result of FBP reconstruction, the CT NPS has the same radial profile shape for all projection angles, with the magnitude varying with the noise level in the raw data measurement. This allows a 2D CT NPS to be factored into products of a 1D angular and a 1D radial function in polar coordinates. The polar separability of CT NPS greatly reduces the data requirement for estimating the NPS. The authors use this property and derive a radial NPS estimation method: in brief, the radial profile shape is estimated from a traditional NPS based on image samples extracted at multiple locations. The amplitudes are estimated by fitting the traditional local NPS to the estimated radial profile shape. The estimated radial profile shape and amplitudes are then combined to form a final estimate of the local NPS. We evaluate the accuracy of the radial NPS method and compared it to traditional NPS methods in terms of normalized mean squared error (NMSE) and signal detectability index. Results: For both simulated and real CT data sets, the local NPS estimated with no more than six scans using the radial NPS method was very close to the reference NPS, according to the metrics of NMSE and detectability index. Even with only two scans, the radial NPS method was able to achieve a fairly good accuracy. Compared to those estimated using traditional NPS methods, the accuracy improvement was substantial when a few scans were available

  7. Inclusion of brain in FDG PET/CT scanning techniques in cancer patients: Does it obviate the need for dedicated brain imaging?

    International Nuclear Information System (INIS)

    Purandare, Nilendu C.

    2011-01-01

    Metastases to the brain can affect about 10-20% cancer patients. Rising incidence of brain metastases in recent years is related to improved survival rates as a result of advances in cancer therapy and development of more sensitive diagnostic imaging techniques. In patients with extracranial malignancies detection of brain metastases is very important in deciding further diagnostic procedures, planning therapeutic strategies and also to ascertain prognosis. Computerized tomography (CT) and magnetic resonance imaging (MRI) are the modalities which have been traditionally used to assess metastatic disease to the central nervous system. It is generally accepted that MRI (contrast enhanced) is superior to CT scan (contrast enhanced) in the diagnosis of brain metastases. An inherently better soft tissue contrast resolution, stronger contrast enhancement, lack of bone artifacts and partial volume effects and direct multiplanar imaging enables MRI to pick up smaller sized as well as more number of metastases than a CT scan

  8. 'Lymphoid hypophysitis' : Its features on CT scan and the clinical course

    International Nuclear Information System (INIS)

    Kurisaka, Masahiro; Kamimura, Yoshihiko; Seike, Masato; Sada, Yasuo; Arimitsu, Tetsuo; Mori, Koreaki

    1986-01-01

    Lymphoid hypophysitis is a rare disease which was previously diagnosed mainly at autopsy. It has, however, been recently identified by biopsy in craniotomy and transsphenoidal operations for sellar and suprasellar masses confirmed by computed tomography (CT) scan. There is as yet no definite method of establishing the diagnosis by any of the presently available neuroradiological exams; it can only be arrived at following histological exams and immunological tests for autoimmune disease of the pituitary gland. Thus, it may be suspected if an intra- or suprasellar enhancing mass is found on CT in a pregnant woman or one with a normal delivery during the previous year. A hormone-replacement therapy is essential in the early stage to prevent the panhypopituitarism which often follows the lymphocytic inflammation of the pituitary gland. (author)

  9. CT-Urography

    International Nuclear Information System (INIS)

    Dalla Palma, Ludovico; Grotto, Maurizio; Morra, Aldo

    2005-01-01

    In this paper we present an overview of CT-Urography. With the advent of multislice CT scanners and the evolution of image processing methods this technique now affords optimal urographic images comparable to those obtained with conventional techniques. We describe the acquisition techniques and protocols used by the various authors. Effective radiation dose has conditioned the use of CT-Urography so that the tendency today is to reduce the number of scans by performing, after the non enhanced scan, a single contrast-enhanced scan comprising both the nephrographic and urographic phase. With the use of multislice CT the quality of the urogram improves with the number of slices. We illustrate a variety of processing techniques, multiplanar reconstruction (MPR), maximum (MIP) and average intensity projection (AIP) and volume rendering (VR) and present a series of upper urinary tract tumours testifying to the superiority of the AIP technique over MIP. We then review the results of comparative studies of CT-Urography with conventional urography in upper urinary tract diagnostics. Finally, we describe the advantages and limitations of CT-Urography [it

  10. Clinical Application of colored three-dimensional CT (3D-CT) for brain tumors using helical scanning CT (HES-CT)

    International Nuclear Information System (INIS)

    Ogura, Yuko; Katada, Kazuhiro; Fujisawa, Kazuhisa; Imai, Fumihiro; Kawase, Tsukasa; Kamei, Yoshifumi; Kanno, Tetsuo; Takeshita, Gen; Koga, Sukehiko

    1995-01-01

    We applied colored three-dimensional CT (colored 3D-CT) images to distinguish brain tumors from the surrounding vascular and bony structures using a work station system and helical scanning CT (HES-CT). CT scanners with a slip-ring system were employed (TCT-900S and X vigor). A slice thickness of 2 mm and bed speed of 2 mm/s were used. The volume of contrast medium injected was 60 to 70 ml. Four to 8 colors were used for the tissue segmentation on the workstation system (xtension) using the data transferred from HES-CT. Tissue segmentation succeeded on the colored 3D-CT images in all 13 cases. The relationship between the tumors and the surrounding structures were easily recognized. The technique was useful to simulate operative fields, because deep structures could be visualized by cutting and drilling the colored 3D-CT volumetric data. On the basis of our findings, we suggest that colored 3D-CT images should be used as a supplementary aid for preoperative simulation. (author)

  11. Synchronized control of spiral CT scan for security inspection device

    International Nuclear Information System (INIS)

    Wang Jue; Jiang Zenghui; Wang Fuquan

    2008-01-01

    In security inspection system of spiral CT, the synchronization between removing and rotating, and the scan synchronization between rotating and sampling influence quality of image reconstruction, so it is difficulty and important that how to realize synchronized scan. According to the controlling demand of multi-slice Spiral CT, the method to realize synchronized scan is given. a synchronized control system is designed, in which we use a industrial PC as the control computer, use magnetic grids as position detectors, use alternating current servo motor and roller motor as drivers respectively drive moving axis and rotating axis. This method can solve the problem of synchronized scan, and has a feasibility and value of use. (authors)

  12. FDG-PET/contrast-enhanced CT as a post-treatment tool in head and neck squamous cell carcinoma: comparison with FDG-PET/non-contrast-enhanced CT and contrast-enhanced CT

    Energy Technology Data Exchange (ETDEWEB)

    Suenaga, Yuko; Kitajima, Kazuhiro; Sugimura, Kazuro [Kobe University Graduate School of Medicine, Department of Radiology, Kobe (Japan); Ishihara, Takeaki; Sasaki, Ryohei [Kobe University Graduate, School of Medicine, Department of Radiology, Division of Radiation Oncology, Kobe (Japan); Otsuki, Naoki; Nibu, Ken-ichi [Kobe University Graduate, School of Medicine, Department of Otolaryngology-Head and Neck Surgery, Kobe (Japan); Minamikawa, Tsutomu [Kobe University Graduate School of Medicine, Department of Oral and Maxillofacial Surgery, Kobe (Japan); Kiyota, Naomi [Kobe University Hospital, Department of Medical Oncology and Hematology, Kobe (Japan)

    2016-04-15

    To evaluate the accuracy of PET/CT using {sup 18}F-fluorodeoxyglucose (FDG) with IV contrast for suspected recurrent head and neck squamous cell carcinoma (HNSCC). One hundred and seventy patients previously treated for HNSCC underwent PET/CT, consisting of non-contrast-enhanced and contrast-enhanced CT, to investigate suspected recurrence. Diagnostic performance of PET/contrast-enhanced CT (PET/ceCT), PET/non-contrast-enhanced CT (PET/ncCT) and contrast-enhanced CT (ceCT) for local or regional recurrence, distant metastasis, overall recurrence and second primary cancer was evaluated. The reference standard included histopathology, treatment change and imaging follow-up. The patient-based areas under the receiver operating characteristic curves (AUC) for ceCT, PET/ncCT and PET/ceCT were 0.82, 0.96 and 0.98 for local recurrence, 0.73, 0.86 and 0.86 for regional recurrence, 0.86, 0.91 and 0.92 for distant metastasis, 0.72, 0.86 and 0.87 for overall recurrence, and 0.86, 0.89 and 0.91 for a second primary cancer. Both PET/ceCT and PET/ncCT statistically showed larger AUC than ceCT for recurrence, and the difference between PET/ceCT and PET/ncCT for local recurrence reached a significant level (p = 0.039). The accuracy of PET/ceCT for diagnosing overall recurrence was high, irrespective of the time interval after the last treatment (83.3-94.1 %). FDG-PET/CT was a more accurate HNSCC restaging tool than ceCT. The added value of ceCT at FDG-PET/CT is minimal. (orig.)

  13. Low-tube-voltage selection for non-contrast-enhanced CT: Comparison of the radiation dose in pediatric and adult phantoms.

    Science.gov (United States)

    Shimonobo, Toshiaki; Funama, Yoshinori; Utsunomiya, Daisuke; Nakaura, Takeshi; Oda, Seitaro; Kiguchi, Masao; Masuda, Takanori; Sakabe, Daisuke; Yamashita, Yasuyuki; Awai, Kazuo

    2016-01-01

    We used pediatric and adult anthropomorphic phantoms to compare the radiation dose of low- and standard tube voltage chest and abdominal non-contrast-enhanced computed tomography (CT) scans. We also discuss the optimal low tube voltage for non-contrast-enhanced CT. Using a female adult- and three differently-sized pediatric anthropomorphic phantoms we acquired chest and abdominal non-contrast-enhanced scans on a 320-multidetector CT volume scanner. The tube voltage was set at 80-, 100-, and 120 kVp. The tube current was automatically assigned on the CT scanner in response to the set image noise level. On each phantom and at each tube voltage we measured the surface and center dose using high-sensitivity metal-oxide-semiconductor field-effect transistor detectors. The mean surface dose of chest and abdominal CT scans in 5-year olds was 4.4 and 5.3 mGy at 80 kVp, 4.5 and 5.4 mGy at 100 kV, and 4.0 and 5.0 mGy at 120 kVp, respectively. These values were similar in our 3-pediatric phantoms (p > 0.05). The mean surface dose in the adult phantom increased from 14.7 to 19.4 mGy for chest- and from 18.7 to 24.8 mGy for abdominal CT as the tube voltage decreased from 120 to 80 kVp (p voltage and the low tube voltage technique can be used for non-contrast-enhanced chest- and abdominal scanning. Copyright © 2015 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  14. Detailed Review of CT Scans Aids Assessment of the Airway in ...

    African Journals Online (AJOL)

    Two cases are presented that illustrate the importance of information gained from CT scans of the head and neck taken in patients presenting for maxillo-facial surgery. The first case involved a 25 year old with a massive tumour filling his mouth. Pre-operative assessment was done without reviewing the CT scans of his ...

  15. Radiation exposure distribution in patients undergoing CT brain scans

    International Nuclear Information System (INIS)

    Yang Zhanshan; Feng Dinghua; Chang Zichi; Li Shijun

    1989-12-01

    The distribution of surface exposures in patients undergoing single and multiple computerized tomographic brain scans with Hitachi CT-W500 was measured by LiF(Mg, Ti) thermoluminescent dosimetry. It was found that there was no significant difference in the sufrace exposures from different scanning slices. However, the exposure doses at different scanning angles around the head were different significantly. The reference point of the maximum surface exposure was at the temporal part of the head. the maximum surface exposure was at 1.65 x 10 -3 C·kg -1 while the average exposure was 1.55 x 10 -3 C·kg -1 . The ratio of the average dose resulting from nine scans to that from a single scan was 1.3, and the surface exposure contribution of scattered radiation was computed. At the same time the radiation doses to eyes, thyroid, chest and gonads of patiens at corresponding position were also measured and were compared with those from CT cranial scans in children and skull radiographic procedures respectively

  16. Evaluation of Image Quality in Low Tube-Voltage Chest CT Scan

    International Nuclear Information System (INIS)

    Kim, Hyun Ju; Cho, Jae Hwan; Park, Cheol Soo

    2010-01-01

    The patients who visited this department for pulmonary disease and need CT scans for Follow-up to observe change of CT value, evaluation of image quality and decrease of radiation dose as change of kVp. Subjects were the patients of 20 persons visited this department for pulmonary disease and Somatom Sensation 16(Semens, Enlarge, Germany) was used. Measurement of CT value as change of kVp was done by setting up ROI diameter of 1cm at the height of thyroid, aortic arch, right pulmonary artery in arterial phase image using 100 kVp, measuring 3 times, and recorded the average. CT value of phantom was measured by scanning phantoms which means contrast media diluted by normal saline by various ratio with tube voltage of 80 kVp, 100 kVp, 120 kVp, 140 kVp and recorded the average of 3 CT values of center of phantom image. In analysing radiation dose, CTDIVOL values of the latest arterial phase image of 120 kVp and as this research set that of 100 kVp were analyzed comparatively. 2 observers graded quality of chest images by 5 degrees (Unacceptable, Suboptimal, Adequate, Good, Excellent). CT value of chest image increased at 100 kVp by 14.06%∼27.26% in each ROI than 120 kVp. CT value of phantom increased as tube voltage lowered at various concentration of contrast media. CTDIVOL decreased at 100 kVp(5.00 mGy) by 36% than 120 kVp(7.80 mGy) in radiation dose analysis. here were 0 Unacceptable, 1 Suboptimal, 3 Adequate, 10 Good, 6 Excellent in totally 20 persons. Chest CT scanning with low kilo-voltage for patients who need CT scan repeatedly can bring images valuable for diagnose, and decrease radiation dose against patients

  17. CT study of pancreatic diseases with modified dynamic scanning

    International Nuclear Information System (INIS)

    Qian Minghui; Zhu Guangying

    1990-01-01

    Experience of 20 cases modified dynamic CT scanning is presented. With a slight increased X-ray tube burden, it is possible to investigate tumor blood supply and find small pancreatic insulinoma with this method. The capsular sign typical for chronic traumatic pancreatic hematoma on CT is presented

  18. Dental-CT: image quality and absorbed radiation dose of different scan protocols

    International Nuclear Information System (INIS)

    Schorn, C.; Alamo, L.; Funke, M.; Grabbe, E.; Visser, H.; Hermann, K.P.

    1999-01-01

    Purpose: To develop a scan protocol for dental-CT which guarantees good image quality at the lowest possible radiation dose. Methods: In an experimental investigation Dental-CT (HSA, GE, Milwaukee, USA) of the mandible of two human skeletons positioned in a water tank were performed in order to define the most advantageous scan protocol. Tube currents ranged from 40 to 200 mA and the scan technique was modified (axial mode or helical mode with pitches of 1 to 3 and corresponding increments of 0.4 to 1.0 mm). 39 patients underwent a dental-CT with decreased current (80 mA) in the helical scan mode (pitch 2, slice thickness 1 mm). Dose measurements were performed for two different scan protocols (A: axial, 130 mAs, B: helical, 80 mA, pitch 2). Results: The preliminary investigations of image quality showed only a minor effect of the applied current. For the helical scan mode, pitches of more than 2 impaired image quality. A low increment had no advantages. There were no disadvantages in clinical practice using protocol B with decreased tube current. Absorbed radiation dose of dental CT performed with protocol B was decreased to one third in comparison to protocol A. Conclusions: A scan protocol with a low tube current (e.g., 80 mA, for a rotation time of 1 s) and a helical scan mode (e.g., for a slice thickness of 1 mm with a pitch of 2 and an increment of 1 mm) is recommended for performing dental-CT. (orig.) [de

  19. Image quality of high-resolution CT with 16-channel multidetector-row CT. Comparison between helical scan and conventional step-shoot scan

    International Nuclear Information System (INIS)

    Sumikawa, Hiromitsu; Johkoh, Takeshi; Koyama, Mitsuhiro

    2005-01-01

    The aim of this study was to evaluate the image quality of high-resolution CT (HRCT) reconstructed from volumetric data with 16-channel multidetector-row CT (MDCT). Eleven autopsy lungs that were diagnosed histopathologically were scanned by 16-channel MDCT with the step-and-shoot scan mode and three helical scan modes. Each helical mode had each size of focal spot, pitch, and time of gantry rotation. HRCT images were reconstructed from the volumetric data with each helical mode and axial sequence data. Two observers evaluated the image quality and noted the most appropriate diagnosis for each imaging. Visualization of abnormal structures with one helical mode was equal to those with axial mode, whereas those with the other two helical modes were inferior to those with axial mode (Wilcoxon signed rank test; p<0.0001). There was no significant difference in diagnostic efficacy between modes. The image quality of HRCT with appropriate helical mode is equal to that with axial mode and diagnostic efficacy is equal among all modes. These results may indicate that sufficient HRCT images can be obtained by only one helical scan without the addition of conventional axial scans. (author)

  20. Developing optimized CT scan protocols: Phantom measurements of image quality

    International Nuclear Information System (INIS)

    Zarb, Francis; Rainford, Louise; McEntee, Mark F.

    2011-01-01

    Purpose: The increasing frequency of computerized tomography (CT) examinations is well documented, leading to concern about potential radiation risks for patients. However, the consequences of not performing the CT examination and missing injuries and disease are potentially serious, impacting upon correct patient management. The ALARA principle of dose optimization must be employed for all justified CT examinations. Dose indicators displayed on the CT console as either CT dose index (CTDI) and/or dose length product (DLP), are used to indicate dose and can quantify improvements achieved through optimization. Key scan parameters contributing to dose have been identified in previous literature and in previous work by our group. The aim of this study was to optimize the scan parameters of mA; kV and pitch, whilst maintaining image quality and reducing dose. This research was conducted using psychophysical image quality measurements on a CT quality assurance (QA) phantom establishing the impact of dose optimization on image quality parameters. Method: Current CT scan parameters for head (posterior fossa and cerebrum), abdomen and chest examinations were collected from 57% of CT suites available nationally in Malta (n = 4). Current scan protocols were used to image a Catphan 600 CT QA phantom whereby image quality was assessed. Each scan parameter: mA; kV and pitch were systematically reduced until the contrast resolution (CR), spatial resolution (SR) and noise were significantly lowered. The Catphan 600 images, produced by the range of protocols, were evaluated by 2 expert observers assessing CR, SR and noise. The protocol considered as the optimization threshold was just above the setting that resulted in a significant reduction in CR and noise but not affecting SR at the 95% confidence interval. Results: The limit of optimization threshold was determined for each CT suite. Employing optimized parameters, CTDI and DLP were both significantly reduced (p ≤ 0.001) by

  1. Attenuation changes of the normal and ischemic canine kidney. Dynamic CT scanning after intravenous contrast medium bolus

    Energy Technology Data Exchange (ETDEWEB)

    Jaschke, W.; Lipton, M.J.; Boyd, D.P.; Cann, C.; Strauss, L.; Sievers, R.S.

    The potential of CT scanning to explore total and regional renal blood flow was evaluated in a dog model with unilateral renal artery stenosis (n=7, reduction of renal blood flow: 32-75% of base line flow). Attenuation versus time curves were generated for the renal cortex and medulla, as well as for the aorta and renal vein. A fast CT scanner was used which allowed for up to 24 scans/minute at the same level (slice thickness: 10 mm). A total of 10 ml contrast medim was injected into a peripheral vein for each scan series taken. During baseline conditions, the curve of the renal cortex and medulla demonstrated 2 peaks. The first peak was mainly related to early vascular enhancement, whereas the second peak corresponded mainly to the appearance of contrast medium in the distal convolutes and collecting ducts. Ischemia of the kidney resulted in a reduction of the first peak and a flattening of the leading edge slope. Transport of contrast medium through the extravascular compartments of the kidney was delayed during ischemia. Relative renal blood flow was obtained from the CT data by dividing peak enhancement by rise-time as assessed from the cortical curve. All measurements were related to baseline flow and validated by flow measurements using radioactive labeled microspheres (n=5). Correlation was found to be r=0.97. (orig.).

  2. Castleman disease of the neck: CT and MR imaging findings

    International Nuclear Information System (INIS)

    Jiang, Xin-hua; Song, Hao-ming; Liu, Qing-yu; Cao, Yun; Li, Guo-hong; Zhang, Wei-dong

    2014-01-01

    Objective: To characterize the computed tomography (CT) and magnetic resonance imaging (MRI) findings of Castleman disease of the neck. Methods: The imaging findings of 21 patients with Castleman disease of the neck were reviewed retrospectively. Of the 21 patients, 16 underwent unenhanced and contrast-enhanced CT scans; 5 underwent unenhanced and contrast-enhanced MRI scans. Results: The unenhanced CT images showed isolated or multiple well-defined homogenous mild hypodensity lesions in fifteen cases, and a heterogeneous nodule with central areas of mild hypodensity in one case. Calcification was not observed in any of the patients. In five patients, MR T1-weighted images revealed well-defined, homogeneous isointense or mild hyperintense lesions to the muscle; T2-weighted images showed these as intermediate hyperintense. Sixteen cases showed intermediate to marked homogeneous enhancement on contrast-enhanced CT or MR T1-weighted images. Of the other five cases that underwent double-phase CT scans, four showed mild or intermediate heterogeneous enhancement at the arterial phase, and homogeneous intermediate or marked enhancement at the venous phase; the remaining case showed mild and intermediate ring-enhancement with a central non-enhanced area at the arterial and venous phases, respectively. Conclusion: Castleman disease of the neck can be characterized as solitary or multiple well-defined, mild hypodensity or homogeneous intense lesions on plain CT/MR scans, and demonstrates intermediate and marked enhancement on contrast-enhanced CT/MR scans. On double-phase CT scans, Castleman disease often demonstrates mild enhancement at the arterial phase, and gradually uniform enhancement at venous phase. Double-phase enhanced CT or MRI may help to differentiate Castleman disease from other diseases

  3. Castleman disease of the neck: CT and MR imaging findings

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Xin-hua [Department of Radiology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, Guangdong 510060 (China); Song, Hao-ming [Department of Cardiology, Shanghai Tongji Hospital, Shanghai 200065 (China); Liu, Qing-yu [Department of Radiology, The Second Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong 510120 (China); Cao, Yun [Department of Pathology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, Guangdong 510060 (China); Li, Guo-hong [Department of Radiology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, Guangdong 510060 (China); Zhang, Wei-dong, E-mail: dongw.z@163.com [Department of Radiology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, Guangdong 510060 (China)

    2014-11-15

    Objective: To characterize the computed tomography (CT) and magnetic resonance imaging (MRI) findings of Castleman disease of the neck. Methods: The imaging findings of 21 patients with Castleman disease of the neck were reviewed retrospectively. Of the 21 patients, 16 underwent unenhanced and contrast-enhanced CT scans; 5 underwent unenhanced and contrast-enhanced MRI scans. Results: The unenhanced CT images showed isolated or multiple well-defined homogenous mild hypodensity lesions in fifteen cases, and a heterogeneous nodule with central areas of mild hypodensity in one case. Calcification was not observed in any of the patients. In five patients, MR T1-weighted images revealed well-defined, homogeneous isointense or mild hyperintense lesions to the muscle; T2-weighted images showed these as intermediate hyperintense. Sixteen cases showed intermediate to marked homogeneous enhancement on contrast-enhanced CT or MR T1-weighted images. Of the other five cases that underwent double-phase CT scans, four showed mild or intermediate heterogeneous enhancement at the arterial phase, and homogeneous intermediate or marked enhancement at the venous phase; the remaining case showed mild and intermediate ring-enhancement with a central non-enhanced area at the arterial and venous phases, respectively. Conclusion: Castleman disease of the neck can be characterized as solitary or multiple well-defined, mild hypodensity or homogeneous intense lesions on plain CT/MR scans, and demonstrates intermediate and marked enhancement on contrast-enhanced CT/MR scans. On double-phase CT scans, Castleman disease often demonstrates mild enhancement at the arterial phase, and gradually uniform enhancement at venous phase. Double-phase enhanced CT or MRI may help to differentiate Castleman disease from other diseases.

  4. A consideration of a measuring point of ventricular dilatation on CT scanning

    International Nuclear Information System (INIS)

    Kuno, Koichi; Miyake, Kazuo

    1980-01-01

    Ventricular dilatation has been judged by pneumo-ventricurography, pneumo-encepharography and carotid angiography (CAG), though all these procedures are very uncomfortable for patients. On the other hand, the CT scan is very easy as a follow-up study of ventricular dilatation for a weak patient. We carried out the CT scan (Hitachi CT-H 250 Scanner, NaI detector) and CAG on 84 cases. The ventricular dilatation was judged by the degree of outstretch of the strio-thalamic vein on an AP view of the phrebogram, classified into 3 types. For all three types classified by the phrebogram, we studied various measuring points of the ventricle on the CT scan. The portions measured on the CT scan were: (1) the frontal cerebro-ventricular index (F-CVI), (2) the bicaudate cerebro-ventricular index (Bicaud-CVI), and (3) the maximum Monro's cerebro-ventricular index (M-CVI), the width of the frontal horn, and the thickness of the ventricular body. The following results were obtained: (1) In measuring the ventricular size on the CT scan, the most interrelated point with the ventricular dilatation is the M-CVI - the ratio of the largest width of the body through the Monro foramen to the width of the brain. In this case, however, the width of the frontal horn and of the body should also be considered. (2) Voltage and electric current changed the EMI-number, but did not alter the measuring value. In this case, the width and the level should be kept constant. (3) The group with the marked ventricular dilatation has a larger value of the CT scan than its value of GAG. (4) The normal value of the M-CVI is 24 +- 3%, moreover, the width of the frontal horn is less than 10 mm, and the thickness of the ventricular body is less than 17 mm. (author)

  5. Estimation of the total effective dose from low-dose CT scans and radiopharmaceutical administrations delivered to patients undergoing SPECT/CT explorations

    International Nuclear Information System (INIS)

    Montes, C.; Hernandez, J.; Gomez-Caminero, F.; Garcia, S.; Martin, C.; Rosero, A.; Tamayo, P.

    2013-01-01

    Hybrid imaging, such as single photon emission computed tomography (SPECT)/CT, is used in routine clinical practice, allowing coregistered images of the functional and structural information provided by the two imaging modalities. However, this multimodality imaging may mean that patients are exposed to a higher radiation dose than those receiving SPECT alone. The study aimed to determine the radiation exposure of patients who had undergone SPECT/CT examinations and to relate this to the Background Equivalent Radiation Time (BERT). 145 SPECT/CT studies were used to estimate the total effective dose to patients due to both radiopharmaceutical administrations and low-dose CT scans. The CT contribution was estimated by the Dose-Length Product method. Specific conversion coefficients were calculated for SPECT explorations. The radiation dose from low-dose CTs ranged between 0.6 mSv for head and neck CT and 2.6 mSv for whole body CT scan, representing a maximum of 1 year of background radiation exposure. These values represent a decrease of 80-85% with respect to the radiation dose from diagnostic CT. The radiation exposure from radiopharmaceutical administration varied from 2.1 mSv for stress myocardial perfusion SPECT to 26 mSv for gallium SPECT in patients with lymphoma. The BERT ranged from 1 to 11 years. The contribution of low-dose CT scans to the total radiation dose to patients undergoing SPECT/CT examinations is relatively low compared with the effective dose from radiopharmaceutical administration. When a CT scan is only acquired for anatomical localization and attenuation correction, low-dose CT scan is justified on the basis of its lower dose. (author)

  6. Detection of active intraabdominal hemorrhage after blunt trauma: value of delayed CT scanning

    Energy Technology Data Exchange (ETDEWEB)

    Sivit, C.J. [Department of Radiology, Rainbow Babies and Children' s Hospital of the University Hospitals of Cleveland and Case Western Reserve School of Medicine, 11100 Euclid Avenue, Cleveland, OH (United States)

    2000-02-01

    Active hemorrhage is a rare finding at CT following blunt abdominal trauma. The time interval between IV contrast administration and scanning the abdomen may impact on the ability to visualize active hemorrhage at CT. We report a case of active hemorrhage associated with splenic injury that was identified only at delayed CT scanning. (orig.)

  7. Detection of active intraabdominal hemorrhage after blunt trauma: value of delayed CT scanning

    International Nuclear Information System (INIS)

    Sivit, C.J.

    2000-01-01

    Active hemorrhage is a rare finding at CT following blunt abdominal trauma. The time interval between IV contrast administration and scanning the abdomen may impact on the ability to visualize active hemorrhage at CT. We report a case of active hemorrhage associated with splenic injury that was identified only at delayed CT scanning. (orig.)

  8. CT enhancement of acute cerebral infarction following long-term continuous contrast infusion

    International Nuclear Information System (INIS)

    Ito, Umeo; Seida, Mitsuru; Tomida, Shuichi; Inaba, Yutaka.

    1985-01-01

    In this experimental study, we employed a long-term (3 hours) continuous-drip infusion of the contrast medium (200 ml of meglumine amidtrizoate) rather than the conventional bolus injection. On admission, four-vessel angiography was performed on all 14 patients. Within 3 days after the onset of the disease, CT scan was carried out repeatedly just prior to contrast infusion, immediately after the end of the continuous-contrast infusion, and additionally, in 4 cases, 3 hours after the end of the contrast infusion. The Haunsfield number was calculated in 3 regions of interest (Radius 5) in the infarction. Positive enhancement was observed in 10 out of the 14 patients (71 %). Among them, 4 out of 5 patients in whom no vascular obstraction on angiography, but marked low-density areas with a mass effect on CT were observed, showed moderate to marked enhancement. In these 4 patients, a temporary cerebral ischemia due to vascular embolization was considered. From the other 4 patients in whom the additional CT scan was performed 3 hours after the end of the contrast infusion, a blood sample was obtained at each of the 3 CT scannings. The iodine concentrations of the blood samples were measured, and their Haunsfield numbers were calculated in the water phantom. The above two parameters were well correlated in a linear function. Among the 4 patients, Gado's tissue-blood ratio (the Haunsfield number of the CT lesion is divided by that of the blood sample) was more than 17.2 % immediately after, and more than 54.7 % 3 hours after, the contrast infusion. Thus, we could conclude that the break-down of the BBB which was demonstrated by a long-term high-blood-concentration level of the contrast medium is an earlier event in human cerebral infarction than is usually accepted. The findings are compatible with our results in animal experiments. (author)

  9. Accuracy of cancellous bone volume fraction measured by micro-CT scanning

    DEFF Research Database (Denmark)

    Ding, Ming; Odgaard, A; Hvid, I

    1999-01-01

    Volume fraction, the single most important parameter in describing trabecular microstructure, can easily be calculated from three-dimensional reconstructions of micro-CT images. This study sought to quantify the accuracy of this measurement. One hundred and sixty human cancellous bone specimens...... which covered a large range of volume fraction (9.8-39.8%) were produced. The specimens were micro-CT scanned, and the volume fraction based on Archimedes' principle was determined as a reference. After scanning, all micro-CT data were segmented using individual thresholds determined by the scanner...

  10. A case of the CT scanning of a suicidal hanging brain

    International Nuclear Information System (INIS)

    Kawamata, Masaharu; Murooka, Hiroshi; Tanabe, Yasuhiko.

    1988-01-01

    A CT scanning of a case of hanging brain is reported. A 63-year-old man, who had been maintained with Aspirin (30 mg every morning) for cerebral infarction, attempted suicide by hanging, but failed. Several hours later, he was admitted because of consciousness disturbance and so was examined by means of CT scanning. Plain CT scanning showed symmetrical multiple intracerebral hemorrhages. Hemorrhages were found in the subcortical region of the bilateral temporal lobes and in the subependymal region near the foramen of Monro or in the choroidal plexus. We speculated that these hemorrhages may be caused by the congestion of the intracranial venous system caused by squeezing both internal jugular veins by hanging. Past angiograms (1981) for cerebral infarction revealed neither AVM nor angioma. (author)

  11. A review of patient dose and optimisation methods in adult and paediatric CT scanning

    International Nuclear Information System (INIS)

    Dougeni, E.; Faulkner, K.; Panayiotakis, G.

    2012-01-01

    Highlights: ► CT scanning frequency has grown with the development of new clinical applications. ► Up to 32-fold dose variation was observed for similar type of procedures. ► Scanning parameters should be optimised for patient size and clinical indication. ► Cancer risks knowledge amongst physicians of certain specialties was poor. ► A significant number of non-indicated CT scans could be eliminated. - Abstract: An increasing number of publications and international reports on computed tomography (CT) have addressed important issues on optimised imaging practice and patient dose. This is partially due to recent technological developments as well as to the striking rise in the number of CT scans being requested. CT imaging has extended its role to newer applications, such as cardiac CT, CT colonography, angiography and urology. The proportion of paediatric patients undergoing CT scans has also increased. The published scientific literature was reviewed to collect information regarding effective dose levels during the most common CT examinations in adults and paediatrics. Large dose variations were observed (up to 32-fold) with some individual sites exceeding the recommended dose reference levels, indicating a large potential to reduce dose. Current estimates on radiation-related cancer risks are alarming. CT doses account for about 70% of collective dose in the UK and are amongst the highest in diagnostic radiology, however the majority of physicians underestimate the risk, demonstrating a decreased level of awareness. Exposure parameters are not always adjusted appropriately to the clinical question or to patient size, especially for children. Dose reduction techniques, such as tube-current modulation, low-tube voltage protocols, prospective echocardiography-triggered coronary angiography and iterative reconstruction algorithms can substantially decrease doses. An overview of optimisation studies is provided. The justification principle is discussed along

  12. Three-dimensional-CT imaging of colorectal disease with thin collimation helical CT scanning

    International Nuclear Information System (INIS)

    Ogura, Toshihiro; Koizumi, Koichi; Sakai, Tatsuya; Kai, Shunkichi; Takatsu, Kazuaki; Maruyama, Masakazu

    1998-01-01

    We have conducted research on three-dimensional (3D)-CT-colonoscopy with thin collimation helical CT scanning over the past three years. This has lately become a subject of special interest. 3D-CT-colonoscopy has three kinds of visualizing methods depending on the threshold setting of CT values. The first one is the virtual endoscopy method which is displayed in a similar fashion to colonoscopic images. The second one is the air image method using the air in the digestive tract as a contrast medium. The third one is the pseudo-tract method which has characteristics of both virtual endoscopy and the air image method and visualizes in a shape of the digestive tract. The image visualized by 3D-CT-colonoscopy is similar to that of conventional colonoscopy and barium enema study, which is obtained with minimal invasion to patients. Obvious advanced carcinomas were easily visualized, and even a small flat polyp measuring 5 mm in size, was able to be observed retrospectively. The characteristics of our method are that we can easily make an examination in a short time and with little dependence on expert technique. Also patients have little discomfort compared to that experienced during colonoscopy and barium enema study. Important features are as follows; long calculation time, insufficient air insufflation, fecal material in the patient''s bowel, whole abdominal scan, and spatial resolution. In the near future, a multislice CT scanner system will have ability to overcome these problems. Therefore, 3D-CT-colonoscopy might be applied in the future for first line examination as a mass screening for colorectal carcinoma. (author)

  13. Anatomy of right superior septal artery demonstrated on the coronary CT scan

    Energy Technology Data Exchange (ETDEWEB)

    Takeguchi, Takaya (Mitsui Memorial Hospital, Department of Diagnostic Radiology, Tokyo (Japan); Tokyo Medical and Dental University, Department of Diagnostic Radiology, Tokyo (Japan)); Ibukuro, Kenji; Fukuda, Hozumi; Tobe, Kimiko; Abe, Shoko (Mitsui Memorial Hospital, Department of Diagnostic Radiology, Tokyo (Japan)), Email: kj-ibkr@qd6.so-net.ne.jp

    2012-02-15

    Background. A coronary CT scan allows for non-invasive visualization of the anatomy of a coronary artery in three dimensions compared to the two dimensions afforded by conventional angiography. The septal artery, the main blood source of the interventricular septum, is usually derived from the left anterior descending artery; however, it is occasionally derived from the right coronary artery. Purpose. To analyze the prevalence, origin, diameter, and length of the right superior septal artery (RSSA) demonstrated on a coronary CT scan. Material and Methods. The right superior septal artery was retrospectively reviewed on the reconstructed axial scan images (0.5-mm thickness, 0.25-mm interval) in 1290 consecutive patients who underwent coronary CT scans. All patients were scanned on a 320-row CT scanner. The images were transferred to a workstation to trace the vessel to analyze the origin, diameter, and length. We also compared the length of the RSSA between patients with and without coronary artery stenosis. Results. The RSSA was identified in 51 (3.9%) of 1290 patients. The origin was the proximal portion of the right coronary artery (n = 40) or the right sinus of Valsalva (n 11). The artery co-existed with the conus artery in 15 (29%) of 51 patients. The length was 16-62 mm (mean 31.2 mm +- 10.5), and the diameter was 0.8-2.0 mm (mean 1.3 mm +- 0.2). Longer RSSAs tended to be demonstrated in the patients with coronary artery stenosis rather than with normal coronary arteries (P < 0.05). Conclusion. The right superior septal artery and its anatomical variant could be analyzed with a coronary CT scan. The ability to demonstrate this artery on the coronary CT scan was the same as with coronary angiography. The recognition of this vessel is useful for physicians managing with the diagnosis and treatment of the coronary artery disease

  14. X-CT imaging method for large objects using double offset scan mode

    International Nuclear Information System (INIS)

    Fu Jian; Lu Hongnian; Li Bing; Zhang Lei; Sun Jingjing

    2007-01-01

    In X-ray computed tomography (X-CT) inspection, rotate-only scanner is commonly used because this configuration offers the highest imaging speed and best utilization of X-ray dose. But it requires that the imaging region of the scanned object must fit within the X-ray beam. Another configuration, transverse-rotate scanner, has a bigger field of view, but it is much more time consuming. In this paper, a two-dimensional X-CT imaging method for large objects is proposed to overcome the existing disadvantages. The scan principle of this method has been described and the reconstruction algorithm has been deduced. The results of the computer simulation and the experiments show the validity of the new method. Analysis shows that the scan field of view of this method is 1.8 times larger than that of rotate-only X-CT. The scan speed of this method is also much quicker than transverse-rotate X-CT

  15. Computer graphic display of cardiac CT scans

    International Nuclear Information System (INIS)

    Palmer, R.; Carlsson, E.

    1982-01-01

    In order to improve spatial conception and quantitative assessment of the cardiac structures based on cardiac computed tomography, methods for computer graphic display were developed. Excised hearts and living dogs with myocardial infarctions were subjected to CT scanning. The data on the scanner tapes were processed to provide isodensity plots, linear section plots, time-weighted integrated isodensity plots as well as topographical density displays and three-dimensional spatial reconstructions of single and multi-layer scans. (orig.)

  16. Primary pulmonary low-grade angiosarcoma characterized by mismatch between {sup 18}F-FDG FET and dynamic contrast-enhanced CT

    Energy Technology Data Exchange (ETDEWEB)

    KIm, Eun Young; Lee, Ho Yun; Han, Joung Ho; Choi, Joon Young [Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2015-10-15

    We report a rare case of primary pulmonary low-grade angiosarcoma on dynamic contrast-enhanced CT and {sup 18}F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT imaging. A 38-year-old, asymptomatic woman was hospitalized because of an abnormality on chest radiography. A dynamic contrast-enhanced chest CT showed a 1.2 cm-sized irregular-margined nodule with strong and persistent enhancement in the right lower lobe. The lesion had low metabolic activity on an {sup 18}F-FDG PET/CT scan. The patient underwent a wedge resection for the lesion, and pathology revealed a primary pulmonary low-grade angiosarcoma.

  17. The value of spiral CT scan on fracture of ankle joint and tarsal bones

    International Nuclear Information System (INIS)

    Li Zhaoli; Liang Jingyin; Pan Zhifeng

    2009-01-01

    Objective: To study the value of spiral CT scan on the fracture of ankle joint and tarsal bones. Methods: 43 cases with the fracture of ankle joint and tarsal bones were collected and analyzed. All the cases were examined by plain film radiography and spiral CT thin slice scan. Multi-planar reformation (MPR), surface shaded display (SSD) and other techniques of image post-processing were performed in 35 cases of them. Results: Spiral CT scan could demonstrate more fractures than plain film radiography in 28 cases(65.1%). There are 15 cases (34.9%) which are normal in plain film radiography but abnormal in Spiral CT scan. Spiral CT could demonstrate the different length, width, direction and number of linear low density shadow. SSD and MPR were performed again in the cases with avulsion fracture and fragmental fracture to demonstrate the fracture direction and the shape, size and location of fragments more clearly. Conclusion: Spiral CT thin slice scan with image post-processing techniques can play an important role in fracture of ankle joint and tarsal bones. (authors)

  18. Side-by-side reading of PET and CT scans in oncology: Which patients might profit from integrated PET/CT?

    International Nuclear Information System (INIS)

    Reinartz, Patrick; Wieres, Franz-Josef; Schneider, Wolfram; Schur, Alexander; Buell, Ulrich

    2004-01-01

    Most early publications on integrated positron emission tomography/computed tomography (PET/CT) devices have reported the new scanner generation to be superior to conventional PET. However, few of these studies have analysed the situation where, in addition to PET, a current CT scan is available for side-by-side viewing. This fact is important, because combined PET/CT or a software-based fusion of the two modalities may improve diagnosis only in cases where side-by-side reading of PET and CT data does not lead to a definitive diagnosis. The aim of this study was to analyse which patients will profit from integrated PET/CT in terms of lesion characterization. A total of 328 consecutively admitted patients referred for PET in whom a current CT scan was available were included in the study. The localization of all pathological PET lesions, as well as possible infiltration of adjacent anatomical structures, was assessed. Of 467 pathological lesions, 94.0% were correctly assessed with respect to localization and infiltration by either conventional PET alone (51.6%) or combined reading of PET and the already existing CT scans (42.4%). Hence, in only 6.0% of all lesions, affecting 6.7% of all patients, could evaluation have profited from integrated PET/CT. We conclude that side-by-side viewing of PET and CT scans is essential, as in 42.4% of all cases, combined viewing was important for a correct diagnosis in our series. In up to 6.7% of patients, integrated PET/CT might have given additional information, so that in nearly 50% of patients some form of combined viewing of PET and CT data is needed for accurate lesion characterization. (orig.)

  19. Multimodality functional imaging of spontaneous canine tumors using 64Cu-ATSM and 18FDG PET/CT and dynamic contrast enhanced perfusion CT

    International Nuclear Information System (INIS)

    Hansen, Anders E.; Kristensen, Annemarie T.; Law, Ian; McEvoy, Fintan J.; Kjær, Andreas; Engelholm, Svend A.

    2012-01-01

    Purpose: To compare the distribution and uptake of the hypoxia tracer 64 Cu-diacetyl-bis(N 4 -methylthiosemicarbazone) ( 64 Cu-ATSM) PET/CT, FDG PET/CT and dynamic contrast enhanced perfusion CT (DCE-pCT) in spontaneous canine tumors. In addition 64 Cu-ATSM distribution over time was evaluated. Methods and materials: Nine spontaneous cancer-bearing dogs were prospectively enrolled. FDG (1 h pi.) and 64 Cu-ATSM (3 and 24 h pi.) PET/CT were performed over three consecutive days. DCE-pCT was performed on day 2. Tumor uptake of FDG and 64 Cu-ATSM was assessed semi-quantitatively and the distribution of FDG, 64 Cu-ATSM and CT perfusion parameters correlated. Results: 64 Cu-ATSM distribution on scans performed 24 h apart displayed moderate to strong correlation; however, temporal changes were observed. The spatial distribution pattern of 64 Cu-ATSM between scans was moderately to strongly positively correlated to FDG, whereas the correlation of CT perfusion parameters to FDG and to 64 Cu-ATSM yielded more varying results. Conclusions: 64 Cu-ATSM uptake was positively correlated to FDG. 64 Cu-ATSM was found to be relatively stable between PET scans performed at different time points, important temporal changes were however observed in hypo-perfused regions. These findings potentially indicate that prolonged uptake periods for 64 Cu-ATSM imaging may be needed. Although a moderate to strong correlation between 64 Cu-ATSM and FDG PET/CT is observed, the two tracers provide different biological information with an overlapping spatial distribution.

  20. A longitudinal study of neurocysticercosis through CT scan of the brain

    Directory of Open Access Journals (Sweden)

    Abhiram Chakraborty

    2011-09-01

    Full Text Available Objective: To find out the role of CT scan in the diagnosis of neurocysticercosis (NC and also to get an idea of the nature and extent of this disease in a definite geographical ethnic location. Methods: CT scan of the brain of altogether 4 762 persons residing in a congested area of central Kolkata, was performed between 2004 and 2010, in an imaging centre in central Kolkata (Calcutta, of whom 1 114 (23.39% suspected patients were investigated for NC, having complaints of convulsion (472, headache (272, right sided weakness (98, loss of consciousness (84, left sided weakness (61, abnormal behavior (48, slurring of speech (34, difficulty with keeping balance (33 and dementia (12. Results: NC was detected in 45, 1, 0, 2, 1, 0, 0, 1 and 0, respectively consisting 4.48% (50/1 114 of the suspected cases varying from as low as 2 (in 2006 to as high as 23 (in 2005 in different years indicating this parasitic infection is perennial. The age of patients varied from 6 to 59 years of whom 28 (56% were vegan. We were also able to detect 4 types of lesions viz. calcified lesions (14, small hypodense i.e. vesicle (12, bright central spot i.e. vesicular lesion with central spot (2 and ring enhancement (22. For 3 patients, further imaging investigation (MRI was needed to confirm the diagnosis. We calculated the specificity and sensitivity of CT scan of brain diagnosing NC which was found to be 64% and 100%, respectively. Conclusions: Although, the sample may not be the representatives of the whole community, the findings suggest that cysticercosis is a significant but under-recognized public health concern in Kolkata.

  1. Posterior Urethra Rupture: Contrast-Enhanced Computed Tomography Scan and Urethrocystography Demonstrations

    Directory of Open Access Journals (Sweden)

    Wojciech Marks

    2012-01-01

    Full Text Available In the follow-up study of patients with pelvic fractures, rupture of the posterior urethra is registered in 3–25% of cases (Koraitim et al., 1996. The diagnostic gold standard for the assessment of hemodynamically stable trauma patients is contrast-enhanced CT scan, especially helical CT. Nevertheless, simultaneous suprapubic cystography and ascending urethrograms (the so-called up-and-downogram are the investigation of choice in assessing the site, severity, and length of urethral injuries. (Carlin and Resnick, 1995 This paper discusses the evaluation and diagnosis of urethral injury in multiple-trauma patient.

  2. Progression of CT scan findings in Rett syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Hisaharu; Hirayama, Yoshito; Sakuragawa, Norio; Arima, Masataka (National Center of Neurology and Psychiatry, Kodaira, Tokyo (Japan))

    1989-07-01

    Progression of the lesions revealed by CT scan was observed in five girls with Rett syndrome. The most distinct and common finding was progressive dilatation of Sylvian fissures, frontal extracerebral space, interhemispheric fissure, and sulci mainly in frontal lobe. It may indicate progressive lesion in the frontal and the temporal lobes. In addition, dilatation of the anterior horns of the lateral ventricles and the third ventricle was noted in some cases. Brainstem and cerebellum were small at any age with some morphological development as the patients became elder. Neither malformations nor abnormalities in density were found in any case. It is concluded that the main lesion of Rett syndrome on CT scan is progressive and localized in the frontal and the temporal lobes. (author).

  3. Experiences of using a single post-contrast CT scan of the urinary tract after triphasic contrast injection

    Directory of Open Access Journals (Sweden)

    Phillip Carl Pretorius

    2011-12-01

    Full Text Available I was alerted to an article in Radiology Vol. 255 No. 2 (May 20101 by a colleague. The article, entitled ‘Kidney and urinary tract imaging: Triple-bolus multidetector CT urography as a one-stop shop – Protocol design, opacification, and image quality analysis’, clearly describes the technique, while the quotation below, from the article, summarises the findings: ‘We have shown that triple-bolus multidetector CT urography allowed visualization of renal parenchymal, excretory, and vascular contrast-enhancement phases in a single dose-efficient acquisition and provided sufficient opacification of the UUT, with simultaneous and adequate image quality of renal parenchyma and vascular anatomy.’ The main emphasis on this technique is to reduce the number of unnecessary CT scans when assessing the urinary tract. Our previous protocol for scanning the urinary tract for pathology included four phases: a pre-contrast, corticomedullary, nephrographic and delay excretory phase.

  4. CT scans in young people in Northern England: trends and patterns 1993-2002

    Energy Technology Data Exchange (ETDEWEB)

    Pearce, Mark S.; Salotti, Jane A.; Metcalf, Wenhua [Newcastle University, Sir James Spence Institute, Royal Victoria Infirmary, Institute of Health and Society, Newcastle upon Tyne (United Kingdom); McHugh, Kieran [Great Ormond Street Hospital for Children NHS Trust, London (United Kingdom); Kim, Kwang P. [Kyung Hee University, Department of Nuclear Engineering, Gyeongi-Do (Korea, Republic of); Craft, Alan W. [Newcastle University, Northern Institute of Cancer Research, Sir James Spence Institute, Royal Victoria Infirmary, Newcastle upon Tyne (United Kingdom); Parker, Louise [Dalhousie University and Cancer Care Nova Scotia, Departments of Medicine and Paediatrics, Population Cancer Research Program, Halifax, NS (Canada); Ron, Elaine [National Cancer Institute, Radiation Epidemiology Branch, Division of Cancer Epidemiology and Genetics, Bethesda, MD (United States)

    2011-07-15

    Although CT can be greatly beneficial, its relatively high radiation doses have caused public health concerns. To assess patterns in CT usage among patients aged less than 22 years in Northern England during the period 1993-2002. Electronic data were obtained from radiology information systems of all nine National Health Service trusts in the region. A total of 38,681 scans had been performed in 20,483 patients aged less than 22 years. The number of CT examinations rose, with the steepest increase between 1997 and 2000. The number of patients scanned per year increased less dramatically, with 2.24/1,000 population aged less than 22 years having one scan or more in 1993 compared to 3.54/1,000 in 2002. This reflects an increase in the median number of scans per patient, which rose from 1 in 1993 to 2 by 1999. More than 70% of CT examinations were of the head, with the number of head examinations varying with time and patient age. The frequency of CT scans in this population more than doubled during the study period. This is partly, but not wholly, explained by an increase in the number of scans per patient. (orig.)

  5. Image processing based detection of lung cancer on CT scan images

    Science.gov (United States)

    Abdillah, Bariqi; Bustamam, Alhadi; Sarwinda, Devvi

    2017-10-01

    In this paper, we implement and analyze the image processing method for detection of lung cancer. Image processing techniques are widely used in several medical problems for picture enhancement in the detection phase to support the early medical treatment. In this research we proposed a detection method of lung cancer based on image segmentation. Image segmentation is one of intermediate level in image processing. Marker control watershed and region growing approach are used to segment of CT scan image. Detection phases are followed by image enhancement using Gabor filter, image segmentation, and features extraction. From the experimental results, we found the effectiveness of our approach. The results show that the best approach for main features detection is watershed with masking method which has high accuracy and robust.

  6. Cushing's syndrome with an apparently normal CT scan

    International Nuclear Information System (INIS)

    Vlahos, L.; Strigaris, K.; Aliferopoulos, D.; Pontifex, G.

    1981-01-01

    A case of Cushing's syndrome is described in which the CT scan was considered as normal. The diagnosis was established with selective venography and blood sampling and was verified surgically. (orig.)

  7. The diagnostic value of PET/CT scanning in patients with cervical cancer

    DEFF Research Database (Denmark)

    Loft, Annika; Berthelsen, Anne Kiil; Roed, Henrik

    2007-01-01

    OBJECTIVE: To investigate the clinical value of PET/CT as a supplement to FIGO staging in patients with cervical cancer stage >or=1B. METHODS: This prospective study included 120 consecutive patients. After staging, a whole-body PET/CT scan was performed and these examinations were divided into two....../CT scanning for newly diagnosed cervical cancer FIGO stage >or=1B has a high sensitivity and specificity, and can be a valuable supplement to the FIGO staging procedure....

  8. Analysis the findings of chest radiograph and CT scan in 217 acute thoracic trauma

    International Nuclear Information System (INIS)

    Huang Shaoying

    2005-01-01

    Objective: To evaluate chest radiograph and CT scan in assessing acute thoracic trauma. Methods: Retrospectively analyzed the findings of chest radiograph and CT scan in 217 cases of acute thoracic trauma and positive rate of each modality was compared. Results: The positive rate of rib and clavicle fracture was higher in chest radiograph than these in CT scan. But the positive rate of chest wall hematoma, mediastinum and subcutaneous emphysema, pneumothorax, hydropneumothorax, damage of lung parenchyma and traumatic pulmonary atelectasis was higher in CT scan than those in chest radiograph. Conclusion: The application of the combined imaging modalities improves assessing of acute thoracic trauma, because the imaging manifestation of the lesion is various. (authors)

  9. Ultrafast CT scanning of an oak log for internal defects

    Science.gov (United States)

    Francis G. Wagner; Fred W. Taylor; Douglas S. Ladd; Charles W. McMillin; Fredrick L. Roder

    1989-01-01

    Detecting internal defects in sawlogs and veneer logs with computerized tomographic (CT) scanning is possible, but has been impractical due to the long scanning time required. This research investigated a new scanner able to acquire 34 cross-sectional log scans per second. This scanning rate translates to a linear log feed rate of 85 feet (25.91 m) per minute at one...

  10. Leptomeningeal angiomatosis of the left occipital surface detected by CT scan

    International Nuclear Information System (INIS)

    Niiro, Masaki; Mihara, Tadahiro; Maeda, Yoshiki; Awa, Hiroshi; Kadota, Koki; Asakura, Tetsuhiko

    1982-01-01

    A case of left occipital leptomeningeal angiomatosis was reported. The patient was a 12-year-old boy who had episodes of severe vascular type headache accompanied by transient right homonymous hemianopsia. CT scan showed localized superficial high density area in the left occipital pole. Remarkable enhancement of the lower and inner surface of the left occipital lobe was demonstrated. Angiography showed poor filling of the distal portion of the left posterior cerebral artery. Skull tomograms showed linear calcifications in the left occipital region. Brain scan showed increased RI uptake in the left occipital region. During operation, the surface of the left occipital lobe was covered by excessive, fine, vascular networks which extended over the arachnoid membrane. The abnormal vessels were cauterized by a CO 2 laser as throughly as possible. The occipital pole, felt gritty. Histologically, the abnormal vessels had spread into the subarachnoid space and were predominantly veins with thin and enlarged walls. The abnormal vessels followed the leptomeninges in the sulci of the cerebral cortex. Underneath the abnormal vessels, in the external layers of the cerebral cortex, calcium deposits were scattered and gliosis and degeneration of the ganglion cells were observed. The lesion was comparable with leptomeningeal angiomatosis. Though the pathological findings of the specimen, CT findings, and brain scan findings were extremely similar to those of Sturge-Weber disease, in this case, the typical clinical and roentgenographic findings of Sturge-Weber disease were all absent. (author)

  11. The impact of the PET/CT in comparison with the same day contrast enhanced CT in breast cancer management

    International Nuclear Information System (INIS)

    Piperkova, E.; Raphael, B.; Altinyay, M.; Castellon, I.; Libes, R.; Abdel-Dayem, H.

    2006-01-01

    Full text: The aim of this study is to evaluate the impact of 18F-fluorodeoxyglucose FDG positron emission tomography with fused computerized tomography (PET/CT) in comparison with the same day contrast enhanced CT (CE-CT) in the breast cancer (BC) management. 68 studies in 48 BC patients, 8 for initial and 60 for restaging disease, after surgery, radiation/chemotherapy, for radiation therapy planning or evaluating treatment response were included. All patients underwent whole body PET/CT for diagnostic purposes followed by CE-CT diagnostic scans of selected body regions. PET/CT was performed approximately 90 minutes following 10-15 mCi of 18F-FDG on a GE Discovery PET/CT system. CT part acquired with low dose X-ray for localization and attenuation correction. The CE-CT was performed according to departmental protocol. Out of a total of 235 lesions in 68 PET/CT and CE-CT studies, 189 were concordant between PET/CT and CE-CT. However, there were 46 discordant lesions, which were verified by either follow-up or biopsy. PET/CT correctly identified 25 (True Positive-TP). CE-CT identified 2 TP lesions missed by PET/CT (False negative): one liver metastasis with necrosis, which is a known non-avid FDG, the other was a missed abdominal metastatic node, which did not change staging or treatment. PET/CT incorrectly identified 2 lesions (False Positive) while CE-CT incorrectly identified 17 FP. For evaluating treatment response in 40 follow up studies PET/CT reported complete response in 15, partial response in 11, stable disease in 2, progression in 5, and free of disease following surgery - in 7. The CE-CT described progression of the disease in 1 PET/CT true negative study and no progression in 2 TP PET/CT studies. In this study, PET/CT played more important role than CECT scans alone and provided an impact on the management of BC patients

  12. [Non-operation management of 12 cases with brain abscess demonstrated by CT scan].

    Science.gov (United States)

    Long, J

    1990-12-01

    This paper reported 12 cases with brain abscess demonstrated by CT scan. Using antibiotic management without surgical intervention, in 10 cases the curative effects were satisfactory. The paper indicated that CT scan was very useful in prompt and correct diagnosis of brain abscess and with sequential CT scan medical therapy was feasible. It is significant in treatment of brain abscess especially for the patients who have a poor general condition, have the brain abscess located in important functional area or have multiple abscesses so that the operation is difficult for them.

  13. Meta-analysis: Serum creatinine changes following contrast enhanced CT imaging

    International Nuclear Information System (INIS)

    Kooiman, Judith; Pasha, Sharif M.; Zondag, Wendy; Sijpkens, Yvo W.J.; Molen, Aart J. van der; Huisman, Menno V.; Dekkers, Olaf M.

    2012-01-01

    Purpose: Contrast induced nephropathy (CIN) is defined as a decrease in renal function following administration of contrast media. The aim of this meta-analysis was to asses the overall risk of CIN, chronic loss of kidney function and the need for renal replacement therapy (RRT) after intravenous contrast enhanced CT-scan. Secondly, we aimed to identify subgroups at increased risk for CIN. Materials and methods: A literature search in Pubmed, Medline, Embase and Cochrane databases was performed. Data extraction was carried out independently by two reviewers. Meta-analysis and meta-regression were performed using an exact likelihood approach. Results: Forty studies evaluating the incidence of CIN after CT were included. The pooled incidence of CIN was 6.4% (95% CI 5.0–8.1). The risk of RRT after CIN was low, 0.06% (95% CI 0.01–0.4). The decline in renal function persisted in 1.1% of patients (95% CI 0.6–2.1%). Patients with chronic kidney disease (odds ratio 2.26, p < 0.001) or diabetes mellitus (odds ratio 3.10, p < 0.001) were at increased risk for the development of CIN. Conclusion: CIN occurred in 6% of patients after contrast enhanced CT. In 1% of all patients undergoing contrast enhanced CT the decline in renal function persisted

  14. Meta-analysis: Serum creatinine changes following contrast enhanced CT imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kooiman, Judith, E-mail: j.kooiman@lumc.nl [Department of Thrombosis and Haemostasis, LUMC, Leiden (Netherlands); Pasha, Sharif M., E-mail: s.m.pasha@lumc.nl [Department of Thrombosis and Haemostasis, LUMC, Leiden (Netherlands); Zondag, Wendy, E-mail: w.zondag@lumc.nl [Department of Thrombosis and Haemostasis, LUMC, Leiden (Netherlands); Sijpkens, Yvo W.J., E-mail: ysijpens@bronovo.nl [Department of Nephrology, Bronovo Hospital, The Hague (Netherlands); Molen, Aart J. van der, E-mail: molen@lumc.nl [Department of Radiology, LUMC, Leiden (Netherlands); Huisman, Menno V., E-mail: m.v.huisman@lumc.nl [Department of Thrombosis and Haemostasis, LUMC, Leiden (Netherlands); Dekkers, Olaf M., E-mail: o.m.dekkers@lumc.nl [Department of Clinical Epidemiology and Department of Endocrinology, LUMC, Leiden (Netherlands)

    2012-10-15

    Purpose: Contrast induced nephropathy (CIN) is defined as a decrease in renal function following administration of contrast media. The aim of this meta-analysis was to asses the overall risk of CIN, chronic loss of kidney function and the need for renal replacement therapy (RRT) after intravenous contrast enhanced CT-scan. Secondly, we aimed to identify subgroups at increased risk for CIN. Materials and methods: A literature search in Pubmed, Medline, Embase and Cochrane databases was performed. Data extraction was carried out independently by two reviewers. Meta-analysis and meta-regression were performed using an exact likelihood approach. Results: Forty studies evaluating the incidence of CIN after CT were included. The pooled incidence of CIN was 6.4% (95% CI 5.0–8.1). The risk of RRT after CIN was low, 0.06% (95% CI 0.01–0.4). The decline in renal function persisted in 1.1% of patients (95% CI 0.6–2.1%). Patients with chronic kidney disease (odds ratio 2.26, p < 0.001) or diabetes mellitus (odds ratio 3.10, p < 0.001) were at increased risk for the development of CIN. Conclusion: CIN occurred in 6% of patients after contrast enhanced CT. In 1% of all patients undergoing contrast enhanced CT the decline in renal function persisted.

  15. Estimation of absorbed dose of radiosensitive organs and effective sose in patients underwent abdominopelvic spiral CT scan using impact CT patient dosimetry

    Directory of Open Access Journals (Sweden)

    Ayoub Amirnia

    2017-05-01

    Full Text Available Background: Due to the presence of radiosensitive organs in the abdominopelvic region and increasing the number of requests for CT scan examinations, concerns about increasing radiation doses in patients has been greatly elevated. Therefore, the goal of this study was to determine the absorbed dose of radiosensitive organs and the effective dose in patients underwent abdominopelvic CT scan using ImPACT CT patient dosimetry Calculator (version 1.0.4, Imaging Performance Assessment on Computed Tomography, www.impactscan.org. Methods: This prospective cross-sectional study was conducted in Imam Reza Hospital from November to February 2015 February 2015 in the Imam Reza Hospital, in Urmia, Iran. The demographic and dosimetric information of 100 patients who underwent abdominopelvic CT scan in a 6-slice CT scanner were obtained through the data collection forms. The demographic data of the patients included age, weight, gender, and BMI. The dosimetric parameters included pitch value, CT dose volume index (CTDIvol, dose-length product (DLP, tube voltage, tube current, exposure time, collimation size, scan length, and scan time. To determine the absorbed dose of radiosensitive organs and also the effective dose in patients, ImPACT CT patient dosimetry calculator was used. Results: The results of this study demonstrated that the mean and standard deviation (SD of patients' effective dose in abdominopelvic CT scan was 4.927±0.164 mSv. The bladder in both genders had the greatest mean organ dose, which was 64.71±17.15 mGy for men and 77.56±18.48 mGy for women (P<0.001. Conclusion: The effective dose values of this examination are in the same range as previous studies, as well as International Commission on Radiological Protection (ICRP recommendations. However, the radiation dose from CT scan has the largest contribution to the medical imaging. According to the ALARA principle, it is recommended that the scan parameters, especially mAs, should be

  16. Diagnostic performance of Contrast-enhanced CT in Pyrrolizidine Alkaloids-induced Hepatic Sinusoidal Obstructive Syndrome

    Science.gov (United States)

    Kan, Xuefeng; Ye, Jin; Rong, Xinxin; Lu, Zhiwen; Li, Xin; Wang, Yong; Yang, Ling; Xu, Keshu; Song, Yuhu; Hou, Xiaohua

    2016-01-01

    Hepatic sinusoidal obstruction syndrome (HSOS) can be caused by pyrrolizidine alkaloids(PAs)-containing herbals. Since PAs exposure is obscure and clinical presentation of HSOS is unspecific, it is challenge to establish the diagnosis of PAs-induced HSOS. Gynura segetum is one of the most wide-use herbals containing PAs. The aim of our study is to describe the features of contrast-enhanced computed tomography (CT) in gynura segetum-induced HSOS, and then determine diagnostic performance of radiological signs. We retrospectively analyzed medical records and CT images of HSOS patients (71 cases) and the controls (222 cases) enrolled from January 1, 2008, to Oct 31, 2015. The common findings of contrast CT in PAs-induced HSOS included: ascites (100%), hepatomegaly (78.87%), gallbladder wall thickening (86.96%), pleural effusion (70.42%), hepatic vein narrowing (87.32%), patchy liver enhancement (92.96%), and heterogeneous hypoattenuation (100%); of these signs, patchy enhancement and heterogeneous hypoattenuation were valuable features. Then, the result of diagnostic performance demonstrated that contrast CT possessed better performance in diagnosing PAs-induced HSOS compared with various parameters of Seattle criteria. In conclusion, the patients with PAs-induced HSOS display distinct radiologic features at CT-scan, which reveals that contrast-enhanced CT provides an effective noninvasive method for diagnosing PAs-induced HSOS. PMID:27897243

  17. Eighteen cases of small breast cancer: a comparative study of mammography, CT scan and pathology

    International Nuclear Information System (INIS)

    Wu Yaopan; Lin Haogao; Cai Peiqiang; Ouyang Yi; Zhang Weizhang; Lu Bingui

    2003-01-01

    Objective: To improve the early diagnosis of breast cancer through a study of the mammography and CT findings of small breast cancer. Methods: The mammography and CT findings of 18 cases of small breast cancer (φ≤2.0 cm in diameter) were studied and compared with pathological results. Results: The diagnostic accuracy of CT and mammography was 83% and 61%, respectively. There was a statistical difference between both modalities (P<0.05), CT scan was superior to mammography. However, there was no difference between them when assessing the lesion arising in F-type breast. In detecting breast fine cluster of calcification, the sensitivity of mammography was better than CT scan. Conclusion: The patient suspected of small breast cancer should take mammography as the first evaluation. CT scan is reserved for the further investigation. The mammography combined with CT scan can improve the early diagnostic rate of breast cancer

  18. Analysis of cranial CT-scan findings in cerebral palsy

    Energy Technology Data Exchange (ETDEWEB)

    Wada, F.; Andoh, T.; Une, K.; Takamatsu, T. (Kitakyushu Municipal Sogo-Ryoiku Center (Japan))

    1981-06-01

    CT-scan findings of 87 cerebral palsied children were studied. They consist of 23 cases of spastic quadriplegia, 9 cases of diplegia, 12 cases of paraplegia, 24 cases of athetosis and mixed type, and 19 cases of hemiplegia. In the former four types, ventricular dilatation and cortical atrophy were measured and abnormal changes in cerebral substance and cerebellar atrophy were observed. Spastic quadriplegia showed most intense changes in every aspect of the abnormalities, while paraplegia had almost normal appearance. Athetosis and mixed type had moderate changes. Hemiplegia always showed asymmetrical view on CT-scan, dilatation of lateral ventricle or atrophy of hemisphere in contralateral side being observed.

  19. Analysis of cranial CT-scan findings in cerebral palsy

    International Nuclear Information System (INIS)

    Wada, Fumio; Andoh, Tadashi; Une, Koji; Takamatsu, Tsurukichi

    1981-01-01

    CT-scan findings of 87 cerebral palsied children were studied. They consist of 23 cases of spastic quadriplegia, 9 cases of diplegia, 12 cases of paraplegia, 24 cases of athetosis and mixed type, and 19 cases of hemiplegia. In the former four types, ventricular dilatation and cortical atrophy were measured and abnormal changes in cerebral substance and cerebellar atrophy were observed. Spastic quadriplegia showed most intense changes in every aspect of the abnormalities, while paraplegia had almost normal appearance. Athetosis and mixed type had moderate changes. Hemiplegia always showed asymmetrical view on CT-scan, dilatation of lateral ventricle or atrophy of hemisphere in contralateral side being observed. (author)

  20. Introduction of the Canadian CT Head Rule Reduces CT Scan Use ...

    African Journals Online (AJOL)

    amnesia or witnessed disorientation in a patient with a GCS score of 13–15 who has suffered a traumatic event, the evaluation of minor head injury using. Computerized Axial Tomography Scan of the Head. (CT-head) has remained controversial.(1,3). CT–head is expensive, time consuming, strenuous to human resource ...

  1. Preliminary study on the differentiation between parapelvic cyst and hydronephrosis with non-calculous using only pre-contrast dual-energy spectral CT scans

    Science.gov (United States)

    Han, Dong; Ma, Guangming; Wei, Lequn; Ren, Chenglong; Zhou, Jieli; Shen, Chen

    2017-01-01

    Objective: To investigate the value of using the quantitative parameters from only the pre-contrast dual-energy spectral CT imaging for distinguishing between parapelvic cyst and hydronephrosis with non-calculous (HNC). Methods: This retrospective study was approved by the institutional review board. 28 patients with parapelvic cyst and 24 patients with HNC who underwent standard pre-contrast and multiphase contrast-enhanced dual-energy spectral CT imaging were retrospectively identified. The parapelvic cyst and HNC were identified using the contrast-enhanced scans, and their CT number in the 70-keV monochromatic images, effective atomic number (Zeff), iodine concentration (IC) and water concentration in the pre-contrast images were measured. The slope of the spectral curve (λ) was calculated. The difference in the measurements between parapelvic cyst and HNC was statistically analyzed using SPSS® v. 19.0 (IBM Corp., New York, NY; formerly SPSS Inc., Chicago, IL) statistical software. Receiver-operating characteristic analysis was performed to assess the diagnostic performance. Results: The CT numbers in the 70-keV images, Zeff and IC values were statistically different between parapelvic cyst and HNC (all p  0.05). Conclusion: The quantitative parameters obtained in the pre-contrast dual-energy spectral CT imaging may be used to differentiate between parapelvic cyst and HNC. Advances in knowledge: The pre-contrast dual-energy spectral CT scans may be used to screen parapelvic cysts for patients who are asymptomatic, thereby avoiding contrast-enhanced CT or CT urography examination for these patients to reduce ionizing radiation dose and contrast dose. PMID:28281789

  2. Study on the brain CT scan of SLE patients

    Energy Technology Data Exchange (ETDEWEB)

    Nagaoka, S; Narita, M; Katoh, K; Matsunaga, K; Ishigatsubo, Y [Yokohama City Univ. (Japan). Faculty of Medicine

    1982-03-01

    Cranial CT scanning revealed abnormality in 12 of 25 patients with SLE (48%). Ventricular sulcal enlargement was found mostly in younger patients between 16 and 36 years, an average of 25 years. Abnormality in electroencephalogram, principally paroxysmal abnormality, was found in 8 of 13 cases (62%) of normal CT findings. Non-paroxysmal slow-wave abnormality was observed in 9 of 12 abnormal CT cases. Of 13 patients with CNS symptoms, 8 had abnormal CT findings, and 5 had only mental disorder with normal CT findings. In 12 patients without neuropsychiatric involvement, 4 (33%) had abnormal CT findings. The rate of abnormal CT findings was increased in the patients receiving a high dosage of a steroid agent. Five of 6 patients who showed ventricular sulcal enlargement had been given prednisolone in a dosage of 35 mg or more per day.

  3. Value of preoperative enhanced multi-slice spiral CT scan for judging TNM staging of gastric cancer as well as its relationship with tumor marker and proliferation molecule expression

    Directory of Open Access Journals (Sweden)

    Ai-Jun Wu

    2016-12-01

    Full Text Available Objective: To study the value of preoperative enhanced multi-slice spiral CT scan for judging TNM staging of gastric cancer as well as its relationship with tumor marker and proliferation molecule expression. Methods: A total of 135 patients with gastric cancer who received surgical resection in our hospital between May 2012 and October 2015 were selected as the research subjects, preoperative enhanced multi-slice spiral CT scan was conducted to judge TNM staging, and serum was collected to determine the content of tumor markers; tumor tissue was collected after operation to determine the content of cytokines and pro-proliferation molecules. Results: CEA, CA199, CA153, CA125 and CA724 content in serum as well as TGFβ1, TGFβ2, VEGF, FGF2, PTP1B, PIK3CD, Survivin, Ezrin and YAP content in gastric cancer tissue of patients with TNM II, III and IV stage gastric cancer were significantly higher than those of patients with TNM I stage; CEA, CA199, CA153, CA125 and CA724 content in serum as well as TGFβ1, TGFβ2, VEGF, FGF2, PTP1B, PIK3CD, Survivin, Ezrin and YAP content in gastric cancer tissue of patients with TNM III and IV stage gastric cancer were significantly higher than those of patients with TNM II stage; CEA, CA199, CA153, CA125 and CA724 content in serum as well as TGFβ1, TGFβ2, VEGF, FGF2, PTP1B, PIK3CD, Survivin, Ezrin and YAP content in gastric cancer tissue of patients with TNM IV stage gastric cancer were significantly higher than those of patients with TNM III stage. Conclusions: TNM staging of gastric cancer decided by preoperative enhanced multi-slice spiral CT scan has good consistency with the content of tumor markers in serum and proliferation molecules in tumor lesion.

  4. Diagnostic value of contrast-enhanced dynamic CT in predicting the malignancy of solitary pulmonary nodules

    International Nuclear Information System (INIS)

    Goo, Hyun Woo; Song, Koun Sik; Lee, Eun Hye; Kim, Ji Hoon; Lee, Jin Seong; Lim, Tae Hwan

    1997-01-01

    To determine whether the maximal enhancement time in dynamic CT is different between benign and malignant solitary pulmonary nodules (SPN)s, and to evaluate the value of densitometry on dynamic CT in predicting the malignancy of SPN. Fifty-six patients with SPN of less than 4cm in diameter as seen on chest radiograph and SPN without benign pattern of calcification or fat, as seen on pre-enhance-ment spiral CT scans were included in this study. SPN with small cavitation sufficient to measure CT density, were also included. Thirty-four SPNs were diagnosed pathologically or radiologically as 20 malignant nodules and 14 benign nodules. Dynamic CT was performed by two techniques after injection of 50ml of nonionic contrast media at the rate of 2ml/sec. In 28 patients, incremental dynamic CT was performed before and of 15 seconds, 1 minute, 2 minutes, 3 minutes, and 4 minutes after injection of contrast media during shallow respiration. In 28 patients, double spiral CT was performed 2 minutes and 3 minutes after injection of contrast media during single breath hold. CT readings were taken at the central portion of SPNs, with a circular region of interest. The degree and time of maximal enhancement were recorded. In dynamic CT the maximal enhancement time of SPNs was not significantly different between malignant (2.73±1.27 minute) and benign nodules (2.56±1.24 minute). The enhancement of malignant nodules was significantly greater (21.42±12.17 HU) than of benign nodules (5.15±5.25 HU) (p<.0001). In dynamic CT of SPNs, there is no difference in maximal enhancement time between benign and malignant nodules;enhancement of the latter is significantly greater than that of the former. Maximal enhancement greater than 15 HU can be a good predictor of malignancy of SPNs

  5. Utility of CT scan for the diagnosis of chest wall tuberculosis

    Energy Technology Data Exchange (ETDEWEB)

    Khalil, A.; Le Breton, C.; Tassart, M.; Korzec, J.; Bigot, J.M.; Carette, M.F. [Department of Radiology, Tenon Hospital, Paris (France)

    1999-10-01

    The objective of this study was to determine the utility of CT scan findings for the diagnosis of chest wall tuberculosis, excluding the spine. We reviewed 15 patients (13 Africans and 2 Indians) with chest wall tuberculosis, retrospectively. The radiologic examination consisted of a plain X-ray and a CT scan of the chest for each patient. The site of disease was the rib in 13 patients or the body of the sternum in 2 patients. One rib was involved in 11 patients, 2 contiguous ribs (one site) in 2 patients, and bilateral disease (two sites) was observed in the remaining patient. The 14 rib sites involved the posterior arc or costovertebral joint in 11 cases, the anterior arc in 2 cases, and the anterior and middle arc in 1 case. The CT scan findings were an abscess (n = 14) or a soft tissue mass (n = 2), osteolytic lesions (n = 13), periosteal reaction (n = 10), and sequestrum (n = 14). Bone sclerosis was observed only in 3 cases of rib involvement. The association of a soft tissue abscess, an osteolytic lesion, and sequestrum, especially in immigrants to France, suggests chest wall tuberculosis on CT scan. (orig.) With 5 figs., 2 tabs., 11 refs.

  6. CT scanning in stroke patients: meeting the challenge in the remote and rural district general hospital.

    Science.gov (United States)

    Todd, A W; Anderson, E M

    2009-05-01

    National audit data allow crude comparison between centres and indicate that most Scottish hospitals fail to meet current guidelines for CT scanning of the brain in stroke patients. This study identifies some of the reasons for delay in performing CT scans in a largely rural population. This audit study assesses the delays from onset of symptoms, time of admission and request received to CT scan in stroke patients for three different in-patient groups as well as those managed in the community. The reasons for delay in CT scanning varied between different patient groups but for one group of in-patients, changes in booking procedure and introduction of a second CT scanner increased the proportion scanned within 48 hours of request from 65% to 96%. Further developments including the introduction of Saturday and Sunday routine CT scanning, radiologist reporting from home and additional CT scanners placed in remote hospitals may be expected to improve these figures further. Target times of three hours from onset of symptoms to scan to allow thrombolysis may however be impossible to meet for all stroke patients in rural areas.

  7. Role of contrast-enhanced helical CT in the evaluation of acute thoracic aortic injuries after blunt chest trauma

    International Nuclear Information System (INIS)

    Scaglione, M.; Pinto, A.; Pinto, F.; Romano, L.; Ragozzino, A.; Grassi, R.

    2001-01-01

    The purpose of this retrospective study was to determine the value of contrast-enhanced helical CT for detecting and managing acute thoracic aortic injury (ATAI). Between June 1995 and February 2000, 1419 consecutive chest CT examinations were performed in the setting of major blunt trauma. The following CT findings were considered indicative of ATAI: intimal flap; pseudoaneurysm; contour irregularity; lumen abnormality; and extravasation of contrast material. On the basis of these direct findings no further diagnostic investigations were performed. Isolated mediastinal hematoma on CT scans was considered an indirect sign of ATAI: In these cases, thoracic aortography was performed even if CT indicated normal aorta. Seventy-seven patients had abnormal CT scans: Among the 23 patients with direct CT signs, acute thoracic aortic injuries was confirmed at thoracotomy in 21. Two false-positive cases were observed. The 54 remaining patients had isolated mediastinal hematoma without aortic injuries at CT and corresponding negative angiograms. The 1342 patients with negative CT scans were included in the 8-month follow-up program and did not show any adverse sequela based on clinical and radiographic criteria. Contrast-enhanced helical CT has a critical role in the exclusion of thoracic aortic injuries in patient with major blunt chest trauma and prevents unnecessary thoracic aortography. Direct CT signs of ATAI do not require further diagnostic investigations to confirm the diagnosis: Isolated aortic bands or contour vessel abnormalities should be first considered as possible artifacts or related to non-traumatic etiologies especially when mediastinal hematoma is absent. In cases of isolated mediastinal hematoma other possible sources of bleeding should be considered before directing patients to thoracic aortography. (orig.)

  8. Feasibility of F-18-FDG PET/CT scan in abdominopelvic regions

    International Nuclear Information System (INIS)

    Suga, Kazuyoshi

    2008-01-01

    F-18-2-Fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET)/CT scan, which simultaneously provides metabolic function and morphology on the same tomographic section, is being the key imaging modality for diagnosis and treatment strategy of makignancies in various organs. FDG PET/CT scanning of the whole body beneficially allows the assessment of primary tumor and regional lymph nodes, and distant metastases and co-existed benign/other malignant lesions, as ''one stop shopping'' fashion. This technique contributes to the selection of the optimal treatment in individual patients, and also can predict histopathologic response to treatment and postoperative/post chemo-radiation therapeutic prognosis. In this paper, we describe the fundamental knowledge required for accurate interpretation of FDG PET/CT scan, and review the utility of this technique for diagnosis and treatment strategy of makignancies in abdominal and pelvic regions. (author)

  9. Reconstruction of a time-averaged midposition CT scan for radiotherapy planning of lung cancer patients using deformable registration.

    Science.gov (United States)

    Wolthaus, J W H; Sonke, J J; van Herk, M; Damen, E M F

    2008-09-01

    lower lobe lung tumors move with amplitudes of up to 2 cm due to respiration. To reduce respiration imaging artifacts in planning CT scans, 4D imaging techniques are used. Currently, we use a single (midventilation) frame of the 4D data set for clinical delineation of structures and radiotherapy planning. A single frame, however, often contains artifacts due to breathing irregularities, and is noisier than a conventional CT scan since the exposure per frame is lower. Moreover, the tumor may be displaced from the mean tumor position due to hysteresis. The aim of this work is to develop a framework for the acquisition of a good quality scan representing all scanned anatomy in the mean position by averaging transformed (deformed) CT frames, i.e., canceling out motion. A nonrigid registration method is necessary since motion varies over the lung. 4D and inspiration breath-hold (BH) CT scans were acquired for 13 patients. An iterative multiscale motion estimation technique was applied to the 4D CT scan, similar to optical flow but using image phase (gray-value transitions from bright to dark and vice versa) instead. From the (4D) deformation vector field (DVF) derived, the local mean position in the respiratory cycle was computed and the 4D DVF was modified to deform all structures of the original 4D CT scan to this mean position. A 3D midposition (MidP) CT scan was then obtained by (arithmetic or median) averaging of the deformed 4D CT scan. Image registration accuracy, tumor shape deviation with respect to the BH CT scan, and noise were determined to evaluate the image fidelity of the MidP CT scan and the performance of the technique. Accuracy of the used deformable image registration method was comparable to established automated locally rigid registration and to manual landmark registration (average difference to both methods noise of individual 4D CT scan frames. We implemented an accurate method to estimate the motion of structures in a 4D CT scan. Subsequently, a

  10. Anatomy of right superior septal artery demonstrated on the coronary CT scan

    International Nuclear Information System (INIS)

    Takeguchi, Takaya; Ibukuro, Kenji; Fukuda, Hozumi; Tobe, Kimiko; Abe, Shoko

    2012-01-01

    Background. A coronary CT scan allows for non-invasive visualization of the anatomy of a coronary artery in three dimensions compared to the two dimensions afforded by conventional angiography. The septal artery, the main blood source of the interventricular septum, is usually derived from the left anterior descending artery; however, it is occasionally derived from the right coronary artery. Purpose. To analyze the prevalence, origin, diameter, and length of the right superior septal artery (RSSA) demonstrated on a coronary CT scan. Material and Methods. The right superior septal artery was retrospectively reviewed on the reconstructed axial scan images (0.5-mm thickness, 0.25-mm interval) in 1290 consecutive patients who underwent coronary CT scans. All patients were scanned on a 320-row CT scanner. The images were transferred to a workstation to trace the vessel to analyze the origin, diameter, and length. We also compared the length of the RSSA between patients with and without coronary artery stenosis. Results. The RSSA was identified in 51 (3.9%) of 1290 patients. The origin was the proximal portion of the right coronary artery (n = 40) or the right sinus of Valsalva (n 11). The artery co-existed with the conus artery in 15 (29%) of 51 patients. The length was 16-62 mm (mean 31.2 mm ± 10.5), and the diameter was 0.8-2.0 mm (mean 1.3 mm ± 0.2). Longer RSSAs tended to be demonstrated in the patients with coronary artery stenosis rather than with normal coronary arteries (P < 0.05). Conclusion. The right superior septal artery and its anatomical variant could be analyzed with a coronary CT scan. The ability to demonstrate this artery on the coronary CT scan was the same as with coronary angiography. The recognition of this vessel is useful for physicians managing with the diagnosis and treatment of the coronary artery disease

  11. Quantitative measurement of ventricular dilatation on CT scan

    International Nuclear Information System (INIS)

    Okita, Naoshi; Mochizuki, Hiroshi; Takase, Sadao

    1985-01-01

    Cerebral atrophy might be judged from the ventricular dilatation with some indices, calculated from various ventricular width. But, there is no general agreement on what index is the most reliable. In this paper, we attempted to establish the index, easy to measure and most reliable. Our method is as follow. 1) We carried out the CT scan (EMI 1010) on 89 neurologically intact patients. Scans were parallel to orbito-meatal line (OML), and were 10 mm in thickness. On CT scan films, various width, area of anterior horns and area of bodies of lateral ventricles were measured. Measurement about the anterior horns of lateral ventricles were carried out on image the most clearly showed the foramen of Monro. And measurements about the bodies of lateral ventricles were on image, 20 mm above the image of anterior horn. Correlations of various width and areas were calculated. Then we proposed new indices with high correlations (over 0.9) with ventricular area; Anterior horn CVI (Cerebro-Ventricular Index) and Body CVI. 2) Patients with myotonic dystrophy show cerebral atrophy. We carried out the CT scan (GECT/T 8800) on 17 myotonic dystrophy patients and 30 controls. Between the two groups, age and sex were almost matched. In the two groups, we calculated our new indices as well as various indices which have been reported; Huckman number, Bifrontal CVI, Bicaudal CVI, Anterior horn index, Hirajima's index, and Cella-media index. The data were analyzed statistically. The ventricular dilatation of myotonic dystrophy patients is more definite with Anterior horn CVI, Bicaudal CVI and Body CVI (p<0.01). These indices have higher correlations with the ventricular area (about 0.9). (J.P.N.)

  12. Non-hodgkin lymphoma containing low attenuation area at enhanced CT : correlation with histopathologic typing

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kyung Hoon; Kim, Hyung Jin; Ahn, In Oak; Chung, Sung Hoon [College of Medicine, Gyeongsang National University, Jinju (Korea, Republic of); Park, Ji Hyun [Masan Koryo General Hospital, Masan (Korea, Republic of)

    1994-12-15

    To evaluate the frequently of low attenuation area in enhanced CT scans of non-Hodgkin lymphoma(NHL) and to find out if there is any pertinent relationship between this and the histopathologic classification. The authors reviewed CT scans in the newly-diagnosed 53 patients with NHL. We defined the low attenuation area as the one with CT attenuation value lower than that of the muscle, surrounding lesion, or other lymph nodes after contrast enhancement. NHL with the low attenuation areas were correlated with the histopathologic findings according to the classification based on the Working Formulation and the frequency of the lesion was evaluated. Of the 53 patients, the low attenuation area was found in 13 patients (25%) at CT. The histopathologic classification could be made in 12 patients, among whom one patient was classified as low-grade, six as intermediate-grade, and five as high-grade. Concerning the specific cell typing, the diffuse large cell type was most common in intermediate-grade NHL seen in five patients and the large cell, immunoblastic type was most common in high-grade NHL seen in three patients. The authors concluded that the low attenuation area within lymphoma is not an infrequent finding at CT, and there was no statistically significant correlation between this finding and the prognostic grading of the Working Formulation.

  13. A case of pineal teratoma with intraventricular free fat on CT scan

    International Nuclear Information System (INIS)

    Uede, Teiji; Takaya, Satoru; Shinya, Toshiyuki; Tanabe, Sumiyoshi; Hashi, Kazuo; Sohma, Tsutomu.

    1986-01-01

    Detection of an intraventricular or intratumoral fat-fluid level on the plain craniograms has been known as a characteristic sign indicating the presence of intracranial teratomatous tumors. On CT scans, however, only thirteen cases have been previously reported to be found an intraventricular and/or subarachnoid free fat associated with spontaneous ruptures of these tumors. We reported a case of pineal teratoma with intraventricular free-fat seen on CT scans. A nine-year-old male with precocious puberty was admitted to our hospital complaining a moderate nonpulsatile headache. Neurological examinations were normal without signs of meningeal irritation. The serum and CSF titer of HCG were raised markedly. The laboratory data of the CSF were normal and there were no pathological cells in the CSF. The CT scans revealed a large heterogeneous mass containing multiple areas of negative density in the pineal region. There were negative density droplets in the bilateral frontal horn on the same CT scans indicating a presence of free fats. At surgery, an yellowish oily material was drained from the tumor, but there was no sign of meningitis over the cortical surface of the occipital lobe. An intraventricular free fat on CT scan have been reported in fourteen cases including ours following the first case described by Fawcitt in 1976. Although most of the cases presented headache, only two cases was diagnosed clinically as chemical meningitis. Pathological changes indicating granulomatous meningitis, however, were noted in five cases, all of them presenting seizure attacks. (author)

  14. Colon distension and scan protocol for CT-colonography: an overview

    NARCIS (Netherlands)

    Boellaard, Thierry N.; de Haan, Margriet C.; Venema, Henk W.; Stoker, Jaap

    2013-01-01

    This article reviews two important aspects of CT-colonography, namely colonic distension and scan parameters. Adequate distension should be obtained to visualize the complete colonic lumen and optimal scan parameters should be used to prevent unnecessary radiation burden. For optimal distension,

  15. Brain tumors and CT scan in infants and children, (1). The impact on pediatric neuroradiology

    Energy Technology Data Exchange (ETDEWEB)

    Ohi, S; Velasco, J M [Northwestern Univ., Chicago, IL (USA). Medical School

    1980-10-01

    The dramatic change in the neuroradiological procedures have been noted after CT scan was introduced in the last several years. Remarkable decreasing numbers of angiographic, pneumoencephalographic and other invasive neuroradiologic studies as well as nuclear brain scan were also found in the pediatric neuroradiology. The authors analyzed the total numbers of these studies performed in the last several years in pediatric neurological/neurosurgical practice in the light of the impact of CT scan especially in the diagnostic procedures and treatments of brain tumor in children. Although the number of these procedures decreased up to 49% in plain skull X-ray, 54% in cerebral angiography, 70% in pneumoencephalography/ventriculography and 79% in nuclear brain scan after CT scan was installed in our results, it is extremely important to renew understanding of those characteristics in each special procedures. Cerebral angiography as well as pneumoencephalography may give the surgeon more precise ideas of the anatomical relationship between the lesion and other normal structures, especially in the posterior fossa tumor in which CT scan occassionally demonstrates only a gross finding. A case with false negative result and another case with a complicated anatomical structure in CT scan were presented. The significance of cerebral angiography and other invasive studies in the diagnosis and follow up of brain tumor in CT scan were discussed.

  16. Optimization of individualized abdominal scan protocol with 64-slice CT scanner

    International Nuclear Information System (INIS)

    Hu Minxia; Zhao Xinming; Song Junfeng; Zhou Chunwu

    2012-01-01

    Objective: To explore an individualized abdominal scan protocol with a 64-slice CT scanner. Methods: From Sep. 2010 to Nov. 2010, one hundred consecutive patients, who underwent twice non-contrast-enhanced abdominal CT scans within 3 months, were enrolled in this study. For each patient, the tube current of 274 eff. mAs and 207 eff. mAs were applied respectively in the first and second abdominal scan. The imaging qualities of the two scans were evaluated retrospectively by 3 reviewers. All the individual variants,including height, weight, body mass index (BMI), the maximum transverse diameter, the anteroposterior diameter and the average maximum diameter of abdomen were recorded. A five-point scale was used for grading the image noise of eight organs, including abdominal aorta, portal vein, liver, spleen, gallbladder, pancreas, renal cortex and renal medulla. Diagnostic acceptability of CT images at three anatomic levels,including porta hepatis, pancreas and the upper pole of renal, was also evaluated by using a five-point scale. The noise value of abdominal aorta was defined as the standard deviation (SD) of CT values of aorta at the level of porta hepatis. Scatter diagram and Pearson correlation analysis were used for evaluating the linear relationship between the individual variants and the noise value of abdominal aorta, and multivariate linear regression analysis was used for evaluating the relevance between the individual variants and the noise value of aorta. Results: In this patients group, the average height was (164.6 ± 7.5) cm,the average weight was (64.3 ± 11.0) kg, the BMI was (23.7 ±3.3) kg/m 2 , the maximum transverse diameter of abdomen was (29.8 ± 2.3) cm, the anteroposterior diameter of abdomen was (23.1 ± 2.9) cm, and the average maximum diameter of abdomen was (26.5 ± 2.5) cm. Pearson correlation analysis showed significant positive linear correlation between the noise value of abdominal aorta (1 1.7 ± 3.0) and patients' weight (r=0

  17. Contrast material-enhanced CT of the abdomen

    International Nuclear Information System (INIS)

    Fishman, E.K.; Kuhlman, J.E.; Garrity, M.; Paris, D.A.

    1988-01-01

    A randomized double-blind comparison of a nonionic contrast agent (Omnipaque) and an ionic contrast agent (Hypaque) was performed to determine any difference between the two agents in the quality and performance of computed body tomography (CT). A total of 40 patient studies were performed on a state-of-the-art CT scanner with similar scanning techniques. The contrast agent was administered intravenously as a rapid infusion in all cases. The image quality of the abdominal CT scans was good to excellent in all cases. There was no difference between the ionic and nonionic agents in terms of study quality. The 20 patients who received nonionic contrast agents had no major or minor reactions. Five of the 20 patients receiving the ionic contrast agent had a total of ten adverse reactions, including nausea and vomiting, nasal congestion, sneezing, and urticaria. The authors conclude that nonionic contrast agents provide high-quality CT scans equal to those provided by ionic agents and also result in fewer reactions and less discomfort

  18. Comparison of absorbed dose of two protocols of tomographic scanning in PET/CT exams

    International Nuclear Information System (INIS)

    Paiva, F.G.

    2017-01-01

    Positron Emission Tomography (PET) associated with Computed Tomography (CT) allows the fusion of functional and anatomical images. When compared to other diagnostic techniques, PET-CT subjects patients to higher levels of radiation, because two modalities are used in a single exam. In this study, the doses absorbed in 19 patient organs from the tomographic scan were evaluated. Radiochromic films were correctly positioned in the Alderson anthropomorphic simulator, male version. For evaluation, two whole body scan protocols were compared. For evaluation, two whole body scan protocols were compared. An increase of up to 600% in the absorbed dose in the pituitary was observed when the protocols were compared, with the lowest observed increase of approximately 160% for the liver. It is concluded that the dose from CT in patients submitted to PET-CT scanning is higher in the protocol used for diagnosis. Considering the high cost of PET-CT exam, in many cases it is preferable that the CT examination is of diagnostic quality, and not only for anatomical mapping, an argument based on the Principle of Justification

  19. Mediastinal lymph node enlargement on CT scans in idiopathic pulmonary fibrosis

    International Nuclear Information System (INIS)

    Ahn, Joong Mo; Im, Jung Gi; Yu, Kyu In; Kim, Hyeong Seog; Kim, Dae Young; Yu, Pil Mun

    1992-01-01

    The increase in size of lymph node on CT scan is the single most important finding of lymphadenopathy. The purpose of this study was to evaluate the size of mediastinal lymph nodes in patients with idiopathic pulmonary fibrosis with no evidence of malignancy or current infection. CT scans of 70 patients (16 with conventional CT and 54 with high-resolution CT) were assessed for lymph node size and location. The duration of symptoms, and the extent and pattern of the parenchymal lung disease on CT scans were correlated with lymph node enlargement. In 54 of 70 patients, more than one lymph nodes were large than 1-1.5 cm. The prevalence of node enlargement increased significant with a longer duration of symptom (p=0.001), large extent of the disease (p=0.043), and with a greater proportion of honeycomb pattern (p=0.033). Right paratracheal, subcarinal, right tracheobronchial, and paraesophageal nodes were the most common sites of node enlargement. In conclusion, mediastinal lymph node enlargement is common in patients with idiopathic pulmonary fibrosis and is more frequently seen in patients with a longer duration of clinical symptoms, greater extent of the disease, and with a larger proportion of honeycomb pattern

  20. Mediastinal lymph node enlargement on CT scans in idiopathic pulmonary fibrosis

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Joong Mo; Im, Jung Gi; Yu, Kyu In; Kim, Hyeong Seog [Seoul National University College of Medicine, Seoul (Korea, Republic of); Kim, Dae Young [Chung Buk National University College of Medicine, Chungju (Korea, Republic of); Yu, Pil Mun [Dankuk University College of Medicine, Seoul (Korea, Republic of)

    1992-09-15

    The increase in size of lymph node on CT scan is the single most important finding of lymphadenopathy. The purpose of this study was to evaluate the size of mediastinal lymph nodes in patients with idiopathic pulmonary fibrosis with no evidence of malignancy or current infection. CT scans of 70 patients (16 with conventional CT and 54 with high-resolution CT) were assessed for lymph node size and location. The duration of symptoms, and the extent and pattern of the parenchymal lung disease on CT scans were correlated with lymph node enlargement. In 54 of 70 patients, more than one lymph nodes were large than 1-1.5 cm. The prevalence of node enlargement increased significant with a longer duration of symptom (p=0.001), large extent of the disease (p=0.043), and with a greater proportion of honeycomb pattern (p=0.033). Right paratracheal, subcarinal, right tracheobronchial, and paraesophageal nodes were the most common sites of node enlargement. In conclusion, mediastinal lymph node enlargement is common in patients with idiopathic pulmonary fibrosis and is more frequently seen in patients with a longer duration of clinical symptoms, greater extent of the disease, and with a larger proportion of honeycomb pattern.

  1. Increased inspiratory pressure for reduction of atelectasis in children anesthetized for CT scan

    International Nuclear Information System (INIS)

    Sargent, Michael A.; Jamieson, Douglas H.; McEachern, Anita M.; Blackstock, Derek

    2002-01-01

    Background: Atelectasis is more frequent and more severe in children anesthetized for CT scan than it is in children sedated for CT scan.Objective: To determine the effect of increased inspiratory pressure on atelectasis during chest CT in anesthetized children. Materials and methods: Atelectasis on chest CT was assessed by two observers in three groups of patients. Group A comprised 13 children (26 lungs) anesthetized at inspiratory pressures up to and including 25 cm H 2 O. Group B included 11 children anesthetized at inspiratory pressures ≥30 cm H 2 O. Group C included 8 children under deep sedation. Results: Atelectasis was significantly more severe in group A than in groups B and C. There was no significant difference between groups B and C. Conclusion: An inspiratory pressure of 30 cm H 2 O is recommended for children anesthetized for CT scan of the chest. (orig.)

  2. Technological features and clinical feasibility of megavoltage CT scanning

    International Nuclear Information System (INIS)

    Nakagawa, Keiichi; Aoki, Yukimasa; Akanuma, Atsuo; Sakata, Kouichi; Karasawa, Katsuyuki; Terahara, Atsurou; Onogi, Yuzou; Hasezawa, Kenji; Sasaki, Yasuhito

    1992-01-01

    Megavoltage CT scanning using 4-MV and 6-MV radiotherapy beams has been developed and applied to verify errors in patient positioning. A detector system composed of 120 pairs of cadmium tungstate scintillators with photodiodes is mounted to the treatment unit at a distance of 160 cm from the beam source. Image reconstruction is performed with a standard filtered back-projection algorithm. Scanning time and reconstruction time for a slice is approximately 35 s and 60 s respectively. Although spatial resolution is as large as 4 mm, it has sufficient image quality to be applied for treatment planning and verification. The delivered dose with 4 MV and 6 MV is about 1.4 cGy and 2.8 cGy respectively. When a megavoltage CT image is taken in treatment position, the positioning errors are easily detected by comparing it with diagnostic CT sections for treatment planning. Several clinical examples are presented. (orig.)

  3. A False Positive {sup 18}F-FDG PET/CT Scan Caused by Breast Silicone Injection

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Chao Jung; Lee, Bi Fang; Yao, Wei Jen; Wu, Pei Shan; Chen, Wen Chung; Peng, Shu Lin; Chiu, Nan Tsing [Cheng Kung University Medical College and Hospital, Tainan (Turkmenistan)

    2009-04-15

    We present here the case of a 40-year-old woman with a greater than 10 year prior history of bilateral breast silicone injection and saline bag implantation. Bilateral palpable breast nodules were observed, but the ultrasound scan was suboptimal and the magnetic resonance imaging showed no gadolinium enhanced tumor. The {sup 18}F-FDG PET/CT scan showed a hypermetabolic nodule in the left breast with a 30% increase of {sup 18}F-FDG uptake on the delayed imaging, and this mimicked breast cancer. She underwent a left partial mastectomy and the pathology demonstrated a siliconoma.

  4. CT of portal vein tumor thrombosis. Usefulness of dynamic CT

    Energy Technology Data Exchange (ETDEWEB)

    Takemoto, Kazumasa; Inoue, Yuichi; Tanaka, Masahiro; Nemoto, Yutaka; Nakamura, Kenji [Osaka City Univ. (Japan). Faculty of Medicine

    1983-08-01

    We evaluated CT findings of portal vein tumor thrombosis in 16 hepatomas by plain, contrast and dynamic CT. Plain and contrast CT findings were an enlargement of the portal vein (81%), intraluminal low density area (63%). Dynamic CT enhanced the diagnostic capability of the tumor thrombus as a relatively low density area because of the marked enhancement of the portal vein. In addition, dynamic CT newly demonstrated hyperdense peripheral ring (35%) and arterio portal shunt (35%). It is advisable to select the scan level to include the portal vein when dynamic CT is performed in the patient of hepatocellular carcinoma.

  5. Centre for Industrial Application of CT scanning (CIA-CT) – Four years of results 2009-2013

    DEFF Research Database (Denmark)

    De Chiffre, Leonardo; Andreasen, Jan Lasson; Christensen, Lars Bager

    activities: Centre of Excellence, Dissemination, Collaboration, Research, and Initiation of new activities. The consortium has consisted of nine partners, including three research institutions, two consultancy partners, two large companies, and two small / medium enterprises. The consortium has acted......The innovation consortium project, carried out September 2009 – August 2013, has aimed to help the participating companies and Danish industry with the introduction of CT scanning as measuring technology, carrying out research at international level. The project has operated through five main...... as a centre of excellence for industrial CT scanning, both nationally and internationally. A network with approx. 40 participants has been established, and a total of 22 students have been educated. Dissemination activities have encompassed: a web page www.cia-ct.mek.dtu.dk , 8 newsletters, 4 topical...

  6. Contrast enhancement CT by iopamidol

    International Nuclear Information System (INIS)

    Mori, Masaki; Makita, Nobue; Yanai, Kyoko

    1984-01-01

    In order to evaluate the contrast enhancement effect and safety of iopamidol (IOP) in CT examination, IOP was compared with angiographin (AG). In the liver and abdominal aorta, peak CT values were obtained earlier and were higher in the group with AG than in the group with IOP. However, CT values in the group with IOP decreased a little more slowly than those in the group with AG. There was no significant difference in the effect on contrast enhancement between the groups. Intravenous injection of IOP caused lower degree of burning sensation than that of AG, and some of the patients with IOP did not feel burning sensation at all. Changes in clinical laboratory values were slight before and after intravenous injection of IOP. These results suggest that IOP is satisfactory in terms of safety and effect on contrast enhancement in CT examination. (Namekawa, K.)

  7. A STUDY OF CORRELATION BETWEEN NASAL ENDOSCOPY AND CT SCAN IN CASES OF CHRONIC RHINOSINUSITIS

    Directory of Open Access Journals (Sweden)

    Arun Kumar

    2015-07-01

    Full Text Available BACKGROUND: The accurate diagnosis of Chronic Rhinosinusitis (CRS is still a challenge therefore, the American Academy of Otorhinolaryngology - Head and Neck Surgery (AAO - HNS 1 has met in a multidisciplinary encounter and formulated a consensus based on only clinical symptoms. The computed tomography (CT scan and the nasal endoscopy (NE were introduced to make an accurate diagnosis of CRS and verify the disease severity. AIM: The aim of this study is to make a correlation between nasal endoscopy and CT scan in cases of clinically diagnosed Chronic Rhinosinusitis patients. METHOD: A study was carried out on 90 patients at Jhalawar Medical College, Jhalawar (Raj. during Sept. 20 12 to Dec. 2014. Diagnostic Nasal Endoscopy and CT Scan PNS done in patients, suffering from Chronic Rhinosinusitis. As a classification instruments, Metson / Gliklich's classification was used to evaluate the tomographic diagnosis and the Stankiewicz / Chow' s classification to evaluate the endoscopic diagnosis of Chronic Rhinosinusitis. RESULTS: Our study showed high specificity of endoscopy in comparison to CT scan though CT scan results are more sensitive. CONCLUSION: Endoscopy can confirm a Chronic Rhinosi nusitis diagnosis, but cannot rule it out, and that CT should be performed in cases of suspected CRS even if mucopurulence is not noted on endoscopy. The CT scan and the nasal endoscopy making easier the treatment planning and the disease resolution.

  8. Reconstruction of a time-averaged midposition CT scan for radiotherapy planning of lung cancer patients using deformable registration

    International Nuclear Information System (INIS)

    Wolthaus, J. W. H.; Sonke, J.-J.; Herk, M. van; Damen, E. M. F.

    2008-01-01

    Purpose: lower lobe lung tumors move with amplitudes of up to 2 cm due to respiration. To reduce respiration imaging artifacts in planning CT scans, 4D imaging techniques are used. Currently, we use a single (midventilation) frame of the 4D data set for clinical delineation of structures and radiotherapy planning. A single frame, however, often contains artifacts due to breathing irregularities, and is noisier than a conventional CT scan since the exposure per frame is lower. Moreover, the tumor may be displaced from the mean tumor position due to hysteresis. The aim of this work is to develop a framework for the acquisition of a good quality scan representing all scanned anatomy in the mean position by averaging transformed (deformed) CT frames, i.e., canceling out motion. A nonrigid registration method is necessary since motion varies over the lung. Methods and Materials: 4D and inspiration breath-hold (BH) CT scans were acquired for 13 patients. An iterative multiscale motion estimation technique was applied to the 4D CT scan, similar to optical flow but using image phase (gray-value transitions from bright to dark and vice versa) instead. From the (4D) deformation vector field (DVF) derived, the local mean position in the respiratory cycle was computed and the 4D DVF was modified to deform all structures of the original 4D CT scan to this mean position. A 3D midposition (MidP) CT scan was then obtained by (arithmetic or median) averaging of the deformed 4D CT scan. Image registration accuracy, tumor shape deviation with respect to the BH CT scan, and noise were determined to evaluate the image fidelity of the MidP CT scan and the performance of the technique. Results: Accuracy of the used deformable image registration method was comparable to established automated locally rigid registration and to manual landmark registration (average difference to both methods <0.5 mm for all directions) for the tumor region. From visual assessment, the registration was good

  9. CT SCAN EVALUATION OF PULMONARY NODULE

    Directory of Open Access Journals (Sweden)

    A. Ravi Kumar

    2016-06-01

    Full Text Available BACKGROUND Lung carcinomas are quite commonly diagnosed. Thanks to the ever increasing smokers’ population. Majority of the city dwellers are at a higher risk of having this disease when compared to the village counterparts. The stigma through which the person and the family have to undergo before confirming the diagnosis is enormous. So the radiographic methods of diagnosing the malignancies have to improve. Before confirming the diagnosis, the radiologists, the treating physicians should be somewhat confident about the diagnosis so as to prepare the patients and their relatives for the most probable diagnosis before the confirmatory report. The confirmatory procedures include the PET scan and the Histopathology. Both are time consuming procedures and in an economy like ours, finding a PET scanning centre is rather difficult. So the most probable diagnosis has to be thought of using minimal resource. This study puts in a sincere effort to understand and evaluate the pulmonary nodule when identified by a CT scan. This paper is intended to help the practicing radiologists and also make life easy for a practicing physician to identify correctly the lesions and also help the patients to prevent further progression of the disease. METHODS The study was a cross-sectional study. The sample size of the study consisted of thirty patients. CT scan was done in thirty patients who were identified to have lung nodules either by other mode of radiological studies or first time identified in a CT scan itself. The study was conducted in Fathima Institute of Medical Sciences, Kadapa. The study was conducted from 2014 to 2015. RESULT Non-solid nodules were more in number when compared to the solid nodules. All the non-solid nodules were confirmed to be adenomas. Eighty percent of the nodules which were more than 8 mm in size were confirmed to be malignant. One hundred percent of the spiculated border on CT was confirmed to be malignant. In the present study

  10. Contrast enhancement technique in brain 3D-CTA studies. Optimizing the amount of contrast medium according to scan time based on TDC

    International Nuclear Information System (INIS)

    Terasawa, Kazuaki; Hatcho, Atsushi

    2008-01-01

    In three-dimensional CT angiography (3D-CTA), good reproducibility can be obtained by maintaining the maximum CT numbers (HU) at a specified level. However, the correlation between the scan time and the injection time showed that the maximum CT numbers increased and varied due to the additional contrast enhancement effect from recirculation of the injected contrast medium for longer injection times when the dose of iodinated contrast medium per unit time (mgI/s) was maintained at a specified level based on the time-density curve (TDC) of the phantom. The amount of contrast medium employed at our hospital has been optimized based on an iodinated contrast medium dose per unit time providing a contrast enhancement effect of 300 HU in the middle cerebral artery. Using this standard, a TDC phantom was employed to obtain an iodinated contrast medium dose per unit time, permitting equivalent maximum CT values (used as standard values) to be obtained by changing the injection time. A contrast-enhancement technique that accounts for the variation in the scan time was evaluated. Strong correlations were observed between the scan time and the injection time (R 2 =0.969) and between the injection time and the dose of iodinated contrast medium per unit body weight (R 2 =0.994). We conclude that adjusting the dose of iodinated contrast medium per unit body weight per unit time according to the scan time permits optimization of the contrast-enhancement technique. (author)

  11. CT manifestations of liver abscess

    International Nuclear Information System (INIS)

    Yan Jianfeng; Peng Yongjun

    2006-01-01

    Objective: To study CT findings of hepatic abscess. Methods: CT findings and clinical materials of 38 patients with liver abscess verified by aspiration were retrospectively viewed. All patients were examined by non-enhanced and contrast enhanced CT. Results: In 25 cases, inhomogeneous hypodense lesions with unclear demarcation were found on non-enhanced CT. On contrast enhanced CT scan, target or cluster enhancement was found Additionally, air was found within some lesions. In the rest 13 cases with early stage liver abscess, no typical sign was found on non-enhanced CT, while rosette sign and continued enhancement sign were demonstrated after the contrast agent was given. Conclusion: Various CT findings are found in different stages of liver abscess. The diagnosis and differential diagnosis should be based on CT manifestations and clinical history as well. (authors)

  12. Dose profile study in head CT scans using a male anthropomorphic phantom

    International Nuclear Information System (INIS)

    Gomez, Alvaro M.L.; Santana, Priscila do C.; Mourao, Arnaldo P.

    2017-01-01

    Computed tomography (CT) test is an efficient and non-invasive method to obtain data about internal structures of the human body. CT scans contribute with the highest absorbed doses in population due X-ray beam attenuation and it has raised concern in radiosensitive tissues. Techniques for the optimization of CT scanning protocols in diagnostic services have been developing with the objective of decreasing the absorbed dose in the patient, aiming image quality within acceptable parameters for diagnosis by noise control. Routine head scans were performed using GE CT scan of 64 channels programmed with automatic exposure control and voltages of 80, 100 and 120 kV attaching the noise index in approximately 0.5%, using the tool of smart mA. An anthropomorphic adult male phantom was used and radiochromic film strips were placed to measure the absorbed dose deposited in areas such as the lens, thyroid and pituitary for study of dose deposited in these important areas containing high radiosensitive tissues. Different head scans were performed using optimized values of mA.s for the different voltages. The absorbed dose measured by the film strips were in the range of the 0.58 and 44.36 mGy. The analysis of noise in the images is within the acceptable levels for diagnosis, and the optimized protocol happens with the voltage of 100 kV. The use of other voltage values can allow obtain better protocols for head scans. (author)

  13. Dose profile study in head CT scans using a male anthropomorphic phantom

    Energy Technology Data Exchange (ETDEWEB)

    Gomez, Alvaro M.L.; Santana, Priscila do C.; Mourao, Arnaldo P., E-mail: amlgphys@gmail.com, E-mail: pridili@gmail.com, E-mail: apratabhz@gmail.com.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte (Brazil). Departamento de Engenharia Nuclear; Centro Federal de Educação Tecnológica de Minas Gerais (CEFET-MG), Belo Horizonte, MG (Brazil)

    2017-11-01

    Computed tomography (CT) test is an efficient and non-invasive method to obtain data about internal structures of the human body. CT scans contribute with the highest absorbed doses in population due X-ray beam attenuation and it has raised concern in radiosensitive tissues. Techniques for the optimization of CT scanning protocols in diagnostic services have been developing with the objective of decreasing the absorbed dose in the patient, aiming image quality within acceptable parameters for diagnosis by noise control. Routine head scans were performed using GE CT scan of 64 channels programmed with automatic exposure control and voltages of 80, 100 and 120 kV attaching the noise index in approximately 0.5%, using the tool of smart mA. An anthropomorphic adult male phantom was used and radiochromic film strips were placed to measure the absorbed dose deposited in areas such as the lens, thyroid and pituitary for study of dose deposited in these important areas containing high radiosensitive tissues. Different head scans were performed using optimized values of mA.s for the different voltages. The absorbed dose measured by the film strips were in the range of the 0.58 and 44.36 mGy. The analysis of noise in the images is within the acceptable levels for diagnosis, and the optimized protocol happens with the voltage of 100 kV. The use of other voltage values can allow obtain better protocols for head scans. (author)

  14. Contrast enhanced CT of spinal cord angioma

    International Nuclear Information System (INIS)

    Nakamura, Takahiko; Ebitani, Tsutomu; Honma, Takao; Sofue, Muroto; Nakamura, Shigeru

    1982-01-01

    Contrast enhanced CT on 6 patients with spinal cord angioma showed enhancement in 2 of them. The conditions to produce contrast enhancement were the window width of 100 - 200, and the window level of 0 - 50. In spinal cord angioma, contrast enhanced CT is presently only an adjunct to angiography and myelography. Nevertheless, contrast enhanced CT is useful in the screening test for spinal cord angioma, in the patients who are nonindicated to angiography, and in the postoperative follow-up. (Ueda, J.)

  15. Percutaneous CT-guided lung biopsy: sequential versus spiral scanning. A randomized prospective study

    International Nuclear Information System (INIS)

    Ghaye, B.; Dondelinger, R.F.; Dewe, W.

    1999-01-01

    The aim of this study was to evaluate in a prospective and randomized study spiral versus sequential scanning in the guidance of percutaneous lung biopsy. Fifty thoracic lesions occurring in 48 patients were biopsied by a senior and a junior operator. Six different time segments of the procedure were measured. Scanning mode versus length of procedure, pathological results, irradiation and complications were evaluated. Total duration of the procedure and of the first sampling was significantly longer with spiral CT for the senior operator (p < 0.004). No significant time difference was observed for the junior operator. Diameter of the lesion, depth of location, position of the patient and needle entry site did not influence the results. The sensitivity was 90.9, specificity 100, positive predictive value 100 and negative predictive value 60 % for spiral CT, and 94.7, 100, 100 and 85.7 % for sequential CT, respectively. Eleven pneumothoraces and ten perinodular hemorrhages were seen with spiral CT and six and ten, respectively, with sequential CT. The mean dose of irradiation was 4027 mAs for spiral CT and 2358 mAs for conventional CT. Spiral CT does neither reduce procedure time nor the rate of complications. Pathological results do not differ compared with sequential CT, and total dose of irradiation is higher with spiral scanning. (orig.)

  16. Interactive lung segmentation in abnormal human and animal chest CT scans

    International Nuclear Information System (INIS)

    Kockelkorn, Thessa T. J. P.; Viergever, Max A.; Schaefer-Prokop, Cornelia M.; Bozovic, Gracijela; Muñoz-Barrutia, Arrate; Rikxoort, Eva M. van; Brown, Matthew S.; Jong, Pim A. de; Ginneken, Bram van

    2014-01-01

    Purpose: Many medical image analysis systems require segmentation of the structures of interest as a first step. For scans with gross pathology, automatic segmentation methods may fail. The authors’ aim is to develop a versatile, fast, and reliable interactive system to segment anatomical structures. In this study, this system was used for segmenting lungs in challenging thoracic computed tomography (CT) scans. Methods: In volumetric thoracic CT scans, the chest is segmented and divided into 3D volumes of interest (VOIs), containing voxels with similar densities. These VOIs are automatically labeled as either lung tissue or nonlung tissue. The automatic labeling results can be corrected using an interactive or a supervised interactive approach. When using the supervised interactive system, the user is shown the classification results per slice, whereupon he/she can adjust incorrect labels. The system is retrained continuously, taking the corrections and approvals of the user into account. In this way, the system learns to make a better distinction between lung tissue and nonlung tissue. When using the interactive framework without supervised learning, the user corrects all incorrectly labeled VOIs manually. Both interactive segmentation tools were tested on 32 volumetric CT scans of pigs, mice and humans, containing pulmonary abnormalities. Results: On average, supervised interactive lung segmentation took under 9 min of user interaction. Algorithm computing time was 2 min on average, but can easily be reduced. On average, 2.0% of all VOIs in a scan had to be relabeled. Lung segmentation using the interactive segmentation method took on average 13 min and involved relabeling 3.0% of all VOIs on average. The resulting segmentations correspond well to manual delineations of eight axial slices per scan, with an average Dice similarity coefficient of 0.933. Conclusions: The authors have developed two fast and reliable methods for interactive lung segmentation in

  17. Xe enhanced CT in the human newborn infant

    International Nuclear Information System (INIS)

    Fuse, Yozen; Nemoto, Yuko; Shimizu, Mitsumasa; Uga, Naoki; Tada, Hiroshi; Fujii, Toshi; Machida, Keiichi; Kikuchi, Hideo; Izumi, Shigemitsu.

    1990-01-01

    With a cranial computed tomography (CT) using stable xenon gas as a diffusible tracer, we measured regional cerebral blood flow (rCBF) in 6 newborn infants with a variety of neurological abnormalities. Gestational ages and birthweights were 35 to 43 weeks and 2436 to 3540 g, respectively. Four infants exhibited hypoxic-ischemic encephalopathy (HIE), one infant had subdural hemorrhage and the other one was the infant with hyponatremia. A baseline CT was done during denitrogenation by 100% oxygen breathing and then a mixture of 35% xenon and 65% oxygen was breathed for 6 minutes. Six scans were obtained during the inhalation period then the infant was returned to breathing 100% oxygen and additional 7 scans were taken. Four samples of arterial blood were collected every 2 minutes before and during inhalation of the xenon gas. A rCBF was calculated with the changes of Hounsfield units in brain tissue and arterial blood. Relatively high blood flows in the region of the basal nuclei as well as decreased flows in the occipital white matter were observed in the infants with HIE. In an infant with subdural hemorrhage, the blood flows were markedly reduced in the areas adjacent to the lesion, including the basal nuclei, and frontal white matter in the opposite hemisphere. Xenon-enhanced CT by inhaling low concentration of the xenon gas enables to measure rCBF in the human newborn infants without no obvious side effect. (author)

  18. CT scanning in patients with amputated legs

    International Nuclear Information System (INIS)

    Huebener, K.H.; Ahlemann, L.M.

    1981-01-01

    CT scanning after above-knee amputation and below-knee amputation helps to determine the calcium salt content of the examined bones, and to differentiate changes in the surrounding soft parts. By comaring the sides, it is quite easy to detect osteoporotic changes shortly after amputation which would otherwise remain undetected by X-ray film examination. It is equally easy to verify muscular changes, whereas characteristic changes in density allow to determine the share of vacant fat in muscular atrophy. Initial examinations proved the usefulness of CT diagnosis for early detection of dystrophic osseous and muscular changes and also show the possibilities of early therapy control of dystrophy treatment. (orig.) [de

  19. CT of hepatocellular carcinoma. Analysis of contrast-enhanced CT using CT arteriography

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, H; Tanaka, T; Hori, S; Tokunaga, K; Yoshioka, H [Osaka Univ. (Japan). Faculty of Medicine

    1981-02-01

    Although changes in the CT appearance resulting from contrast enhancement (CE) for hepatocellular carcinoma have been considered in association with vascularity of tumors, no detailed studies have yet been made. We analyzed changes in the CT appearance following CE by comparing with hepatic arteriogram and CT arteriogram (CTA) performed during intraarterial infusion of contrast medium. When tumors showing low density in the plain CT were enhanced by contrast, the results were variable, ranging from intensification of the low density to replacement by high density, and the results were classified into L/sub 0/ to L/sub 3/ according to vascularity of tumors. The results after CE could also be classified into I/sub 0/ to I/sub 3/ when tumors showed isodensity in the plain CT. There was a correlation between vascularity presumed from CE and vascularity by CTA. It may be concluded that tumor vascularity could be estimated by the findings of CE which might indicate a possibility of qualitative diagnosis of tumors.

  20. On the uncertainties in effective dose estimates of adult CT head scans

    International Nuclear Information System (INIS)

    Gregory, Kent J.; Bibbo, Giovanni; Pattison, John E.

    2008-01-01

    Estimates of the effective dose to adult patients from computed tomography (CT) head scanning can be calculated using a number of different methods. These estimates can be used for a variety of purposes, such as improving scanning protocols, comparing different CT imaging centers, and weighing the benefits of the scan against the risk of radiation-induced cancer. The question arises: What is the uncertainty in these effective dose estimates? This study calculates the uncertainty of effective dose estimates produced by three computer programs (CT-EXPO, CTDosimetry, and ImpactDose) and one method that makes use of dose-length product (DLP) values. Uncertainties were calculated in accordance with an internationally recognized uncertainty analysis guide. For each of the four methods, the smallest and largest overall uncertainties (stated at the 95% confidence interval) were: 20%-31% (CT-EXPO), 15%-28% (CTDosimetry), 20%-36% (ImpactDose), and 22%-32% (DLP), respectively. The overall uncertainties for each method vary due to differences in the uncertainties of factors used in each method. The smallest uncertainties apply when the CT dose index for the scanner has been measured using a calibrated pencil ionization chamber

  1. Contribution of brain imaging techniques: CT-scan and magnetic resonance imaging (MRI)

    International Nuclear Information System (INIS)

    Pasco-Papon, A.; Gourdier, A.L.; Papon, X.; Caron-Poitreau, C.

    1996-01-01

    In light of the current lack of consensus on the benefit of carotid artery surgery to treat asymptomatic carotid artery stenosis, the decision to operate on a patient depends on individual evaluation and characterization of risk factors on carotid artery stenosis greater than 70 %. The assessment of such risk factors is based especially on non-invasive brain imaging techniques.Computed tomography scanning (CT-scan) and magnetic resonance imaging (MRI) enable two types of stenosis to be differentiated, i.e. stenoses which are symptomatic and those that are radiologically proven versus those which are clinically and radiologically silent. CT-scan investigation (with and without injection of iodinated contrast media) still continues to be a common routine test in 1996 whenever a surgical revascularization procedure is planned. The presence of deep lacunar infarcts ipsilateral to the carotid artery stenosis generally evidence the reality of stenosis and thus are useful to the surgeon in establishing whether surgery is indicated. In the absence a consensus on indications for surgical management, the surgeon could use the CT-scan and MRI as medicolegal records which could be compared to a subsequent postoperative CT-scan in case of ischemic complications associated with the surgical procedure. Furthermore, recent cerebral ischemia as evidenced by filling with contrast material, will call for postponing treatment by a few weeks. Although conventional MRI is more contributive than brain CT-scan in terms of sensibility and specificity, its indications are narrower because of its limited availability and cost constraints. But, development of angio-MRI and functional imaging promise that its future is assured and even perhaps as the sole diagnostic method if its indications are expanded to include preoperative angiographic evaluation of atheromatous lesions of supra-aortic trunks. (authors). 37 refs

  2. Aphasia caused by intracerebral hemorrhage; CT-scan findings and prognosis

    Energy Technology Data Exchange (ETDEWEB)

    Furuya, Kazuhide; Segawa, Hiromu; Shiokawa, Yoshiaki; Hasegawa, Isao; Sano, Keiji (Fuji Brain Institute and Hospital, Shizuoka (Japan))

    1992-10-01

    It is generally accepted that cases of aphasia can be divided into several groups according to verbal fluency, auditory comprehension, and repetition abilities. Although many authors have studied aphasia and its location by means of a CT scan, the primary lesion on a CT scan with regard to the subtypes of aphasia still remains controversial. In this report we present our new CT classification for the syndromes of aphasia and the prognosis. Twenty-one patients with intracerebral hematoma (ICH) were followed up for more than 3 months after onset. ICH was classified according to the mode of the horizontal extension of the hematoma on a CT scan. Four lines were decided as follows: Line (a) is between the anterior horn of the lateral ventricle and the midpoint of the third ventricle; Line (b) is the vertical line to the saggital line which originates from the midpoint of the third ventricle; Line (c) is between the trigone of the lateral ventricle and the midpoint of the third ventricle. The CT classification consisted of 4 types: in Type A, ICH was located anterior to line (a); in Type B, ICH was located between line (a) and line (b); in Type C, ICH was located between line (b) and line (c); Type B+C, was a combination of Type B and Type C. Transcortical motor aphasia belonged to the Type A group. Transcortical sensory aphasia belonged to the Type B and Type B+C groups. Wernicke's and anomic aphasia belonged to the Type C group. Conduction and global aphasia belonged to the Type B+C group. Pure Broca's aphasia could not be observed in this series. Several relationships between the syndromes of aphasia and its CT findings were evident. On the other hand, the syndromes of aphasia and the degree of recovery were not correlated, except for global aphasia. (author).

  3. Aphasia caused by intracerebral hemorrhage; CT-scan findings and prognosis

    Energy Technology Data Exchange (ETDEWEB)

    Furuya, Kazuhide; Segawa, Hiromu; Shiokawa, Yoshiaki; Hasegawa, Isao; Sano, Keiji [Fuji Brain Institute and Hospital, Shizuoka (Japan)

    1992-10-01

    It is generally accepted that cases of aphasia can be divided into several groups according to verbal fluency, auditory comprehension, and repetition abilities. Although many authors have studied aphasia and its location by means of a CT scan, the primary lesion on a CT scan with regard to the subtypes of aphasia still remains controversial. In this report we present our new CT classification for the syndromes of aphasia and the prognosis. Twenty-one patients with intracerebral hematoma (ICH) were followed up for more than 3 months after onset. ICH was classified according to the mode of the horizontal extension of the hematoma on a CT scan. Four lines were decided as follows: Line (a) is between the anterior horn of the lateral ventricle and the midpoint of the third ventricle; Line (b) is the vertical line to the saggital line which originates from the midpoint of the third ventricle; Line (c) is between the trigone of the lateral ventricle and the midpoint of the third ventricle. The CT classification consisted of 4 types: in Type A, ICH was located anterior to line (a); in Type B, ICH was located between line (a) and line (b); in Type C, ICH was located between line (b) and line (c); Type B+C, was a combination of Type B and Type C. Transcortical motor aphasia belonged to the Type A group. Transcortical sensory aphasia belonged to the Type B and Type B+C groups. Wernicke's and anomic aphasia belonged to the Type C group. Conduction and global aphasia belonged to the Type B+C group. Pure Broca's aphasia could not be observed in this series. Several relationships between the syndromes of aphasia and its CT findings were evident. On the other hand, the syndromes of aphasia and the degree of recovery were not correlated, except for global aphasia. (author).

  4. Phase- and size-adjusted CT cut-off for differentiating neoplastic lesions from normal colon in contrast-enhanced CT colonography

    International Nuclear Information System (INIS)

    Luboldt, W.; Kroll, M.; Wetter, A.; Vogl, T.J.; Toussaint, T.L.; Hoepffner, N.; Holzer, K.; Kluge, A.

    2004-01-01

    A computed tomography (CT) cut-off for differentiating neoplastic lesions (polyps/carcinoma) from normal colon in contrast-enhanced CT colonography (CTC) relating to the contrast phase and lesion size is determined. CT values of 64 colonic lesions (27 polyps 0 . The slope m was determined by linear regression in the correlation (lesion ∝[xA + (1 - x)V]//H) and the Y-intercept y 0 by the minimal shift of the line needed to maximize the accuracy of separating the colonic wall from the lesions. The CT value of the lesions correlated best with the intermediate phase: 0.4A+ 0.6V(r=0.8 for polyps ≥10 mm, r=0.6 for carcinomas, r=0.4 for polyps <10 mm). The accuracy in the differentiation between lesions and normal colonic wall increased with the height implemented as divisor, reached 91% and was obtained by the dynamic cut-off described by the formula: cut-off(A,V,H) = 1.1[0.4A + 0.6V]/H + 69.8. The CT value of colonic polyps or carcinomas can be increased extrinsically by scanning in the phase in which 0.4A + 0.6V reaches its maximum. Differentiating lesions from normal colon based on CT values is possible in contrast-enhanced CTC and improves when the cut-off is adjusted (normalized) to the contrast phase and lesion size. (orig.)

  5. Helical CT finding of carotid-cavernous fistula: a sign of early enhancing superior ophthalmic vein

    International Nuclear Information System (INIS)

    Kim, Jae Hyung; Na, Dong Gyu; Byun, Hong Sik; Ryoo, Jae Wook

    2000-01-01

    The purpose of this study was to determine the diagnostic value of a sign of early enhancing superior ophthalmic vein (SOV), as seen on helical CT images in patients with carotid-cavernous fistula (CCF). This study involved 16 patients with CCF and 28 control patients. Axial CT images with scanning delays of 30 seconds following bolus injection of contrast material (90 mL, 3 mL/sec) were obtained, and this procedure was followed by coronal CT imaging. To determine the presence or absence of early enhancement or, dilatation of the SOV, bulging of the cavernous sinus, and enlargement of extraocular muscle, CT images were analysed by three observers in a blinded, random manner. Early enhancement of SOV was determined to be present where enhancement of the SOV was similar to or stronger than that of the ipsilateral posterior cerebral artery. A sign of early enhancing SOV was seen in 14 of the 16 patients with CCF but in no control patients (88% sensitivity and 100% specificity). The respective sensitivity and specificity of other CT features were 71% and 100% (dilatation of the SOV, as seen on axial images), 60% and 83% (dilatation of the SOV, as seen on coronal images), 71% and 89% (dilatation of the cavernous sinus), and 65% and 98% (enlargement of extraocular muscle). A sign of early enhancing SOV is a characteristic and specific CT finding of CCF, and is useful for the diagnosis of CCF. (author)

  6. Performance of integrated FDG-PET/contrast-enhanced CT in the staging and restaging of colorectal cancer: Comparison with PET and enhanced CT

    International Nuclear Information System (INIS)

    Dirisamer, Albert; Halpern, Benjamin S.; Floery, Daniel; Wolf, Florian; Beheshti, Mohsen; Mayerhoefer, Marius E.; Langsteger, Werner

    2010-01-01

    Objective: The purpose of this study was to assess the diagnostic value of PET/CT as a one step examination in patients with colorectal cancer. Therefore we proved whether diagnostic PET/CT adds information over PET or contrast-enhanced CT alone for staging or restaging of patients with colorectal cancer. Methods: Seventy-three patients (46 males and 27 females; age range: 50-81 years; mean age: 67 years) with known colorectal cancer underwent 18F-FDG-PET/CT for staging or restaging. Results: Of the 73 patients 26 patients underwent PET/CT for staging and 47 for restaging. 266 metastases could be detected in 60 patients. Contrast-enhanced PET/CT had a lesion-based sensitivity of 100%, contrast-enhanced CT of 91% and PET of 85%. PET/CT identified 2 lesions as false positive. PET/CT could also reach a patient-based sensitivity of 100%, which was superior to contrast-enhanced CT and PET. Conclusion: Our study clearly demonstrated the added value of contrast-enhanced PET/CT in staging and restaging patients with colorectal cancer over CT and PET alone.

  7. Evaluation of radiation dose and image quality of CT scan for whole-body pediatric PET/CT: A phantom study

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Ching-Ching, E-mail: cyang@tccn.edu.tw [Department of Medical Imaging and Radiological Sciences, Tzu-Chi College of Technology, 970, Hualien, Taiwan (China); Liu, Shu-Hsin [Department of Nuclear Medicine, Buddhist Tzu-Chi General Hospital, 970, Hualien, Taiwan and Department of Medical Imaging and Radiological Sciences, Tzu-Chi College of Technology, 970, Hualien, Taiwan (China); Mok, Greta S. P. [Biomedical Imaging Laboratory, Department of Electrical and Computer Engineering, Faculty of Science and Technology, University of Macau, Macau (China); Wu, Tung-Hsin [Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, 112, Taipei, Taiwan (China)

    2014-09-15

    Purpose: This study aimed to tailor the CT imaging protocols for pediatric patients undergoing whole-body PET/CT examinations with appropriate attention to radiation exposure while maintaining adequate image quality for anatomic delineation of PET findings and attenuation correction of PET emission data. Methods: The measurements were made by using three anthropomorphic phantoms representative of 1-, 5-, and 10-year-old children with tube voltages of 80, 100, and 120 kVp, tube currents of 10, 40, 80, and 120 mA, and exposure time of 0.5 s at 1.75:1 pitch. Radiation dose estimates were derived from the dose-length product and were used to calculate risk estimates for radiation-induced cancer. The influence of image noise on image contrast and attenuation map for CT scans were evaluated based on Pearson's correlation coefficient and covariance, respectively. Multiple linear regression methods were used to investigate the effects of patient age, tube voltage, and tube current on radiation-induced cancer risk and image noise for CT scans. Results: The effective dose obtained using three anthropomorphic phantoms and 12 combinations of kVp and mA ranged from 0.09 to 4.08 mSv. Based on our results, CT scans acquired with 80 kVp/60 mA, 80 kVp/80 mA, and 100 kVp/60 mA could be performed on 1-, 5-, and 10-year-old children, respectively, to minimize cancer risk due to CT scans while maintaining the accuracy of attenuation map and CT image contrast. The effective doses of the proposed protocols for 1-, 5- and 10-year-old children were 0.65, 0.86, and 1.065 mSv, respectively. Conclusions: Low-dose pediatric CT protocols were proposed to balance the tradeoff between radiation-induced cancer risk and image quality for patients ranging in age from 1 to 10 years old undergoing whole-body PET/CT examinations.

  8. Value of early follow-up CT in paediatric tuberculous meningitis

    International Nuclear Information System (INIS)

    Andronikou, Savvas; Wieselthaler, Nicky; Smith, Bruce; Douis, Hassan; Fieggen, A. Graham; Toorn, Ronald van; Wilmshurst, Jo

    2005-01-01

    The value of CT in the diagnosis of tuberculous meningitis (TBM) in children is well reported. Follow-up CT scanning for these patients is, however, not well described and, in particular, the value of early follow-up CT has not been addressed for children with TBM. To assess the value of early follow-up CT in children with TBM in identifying diagnostic, prognostic and therapeutically relevant features of TBM. A retrospective 4-year review of CT scans performed within 1 week and 1 month of initial CT in children with proven (CSF culture-positive) and probable TBM (CSF profile-positive but culture-negative) and comparison with initial CT for the diagnostic, prognostic and therapeutic CT features of TBM. The CT scans of 50 children were included (19 ''definite'' TBM; 31 ''probable'' TBM). Of these, 30 had CT scans performed within 1 week of the initial CT. On initial CT, 44 patients had basal enhancement. Only 24 patients had contrast medium-enhanced follow-up scans. Important findings include: 8 of 29 patients (who were not shunted) developed new hydrocephalus. New infarcts developed in 24 patients; 45% of those who did not have infarction initially developed new infarcts. Three of the six patients who did not show basal enhancement on initial scans developed this on the follow-up scans, while in seven patients with pre-existing basal enhancement this became more pronounced. Two patients developed hyperdensity in the cisterns on non-contrast medium scans. Eight patients developed a diagnostic triad of features. Three patients developed CT features of TBM where there was none on the initial scans. Early follow-up CT is useful in making a diagnosis of TBM by demonstrating features that were not present initially and by demonstrating more sensitive, obvious or additional features of TBM. In addition, follow-up CT is valuable as a prognostic indicator as it demonstrates additional infarcts which may have developed or become more visible since the initial study. Lastly

  9. Value of early follow-up CT in paediatric tuberculous meningitis

    Energy Technology Data Exchange (ETDEWEB)

    Andronikou, Savvas [University of Cape Town, Department of Radiology, Cape Town (South Africa); Wieselthaler, Nicky; Smith, Bruce; Douis, Hassan [Red Cross Children' s Hospital, Department of Paediatric Radiology, School of Child and Adolescent Health, Cape Town (South Africa); Fieggen, A. Graham; Toorn, Ronald van; Wilmshurst, Jo [Red Cross Children' s Hospital, Department of Paediatric Radiology, School of Child and Adolescent Health, Cape Town (South Africa); Red Cross Children' s Hospital, Department of Neurosciences, School of Child and Adolescent Health, Cape Town (South Africa)

    2005-11-01

    The value of CT in the diagnosis of tuberculous meningitis (TBM) in children is well reported. Follow-up CT scanning for these patients is, however, not well described and, in particular, the value of early follow-up CT has not been addressed for children with TBM. To assess the value of early follow-up CT in children with TBM in identifying diagnostic, prognostic and therapeutically relevant features of TBM. A retrospective 4-year review of CT scans performed within 1 week and 1 month of initial CT in children with proven (CSF culture-positive) and probable TBM (CSF profile-positive but culture-negative) and comparison with initial CT for the diagnostic, prognostic and therapeutic CT features of TBM. The CT scans of 50 children were included (19 ''definite'' TBM; 31 ''probable'' TBM). Of these, 30 had CT scans performed within 1 week of the initial CT. On initial CT, 44 patients had basal enhancement. Only 24 patients had contrast medium-enhanced follow-up scans. Important findings include: 8 of 29 patients (who were not shunted) developed new hydrocephalus. New infarcts developed in 24 patients; 45% of those who did not have infarction initially developed new infarcts. Three of the six patients who did not show basal enhancement on initial scans developed this on the follow-up scans, while in seven patients with pre-existing basal enhancement this became more pronounced. Two patients developed hyperdensity in the cisterns on non-contrast medium scans. Eight patients developed a diagnostic triad of features. Three patients developed CT features of TBM where there was none on the initial scans. Early follow-up CT is useful in making a diagnosis of TBM by demonstrating features that were not present initially and by demonstrating more sensitive, obvious or additional features of TBM. In addition, follow-up CT is valuable as a prognostic indicator as it demonstrates additional infarcts which may have developed or become more

  10. TU-F-BRF-03: Effect of Radiation Therapy Planning Scan Registration On the Dose in Lung Cancer Patient CT Scans

    International Nuclear Information System (INIS)

    Cunliffe, A; Contee, C; White, B; Justusson, J; Armato, S; Malik, R; Al-Hallaq, H

    2014-01-01

    Purpose: To characterize the effect of deformable registration of serial computed tomography (CT) scans on the radiation dose calculated from a treatment planning scan. Methods: Eighteen patients who received curative doses (≥60Gy, 2Gy/fraction) of photon radiation therapy for lung cancer treatment were retrospectively identified. For each patient, a diagnostic-quality pre-therapy (4–75 days) CT scan and a treatment planning scan with an associated dose map calculated in Pinnacle were collected. To establish baseline correspondence between scan pairs, a researcher manually identified anatomically corresponding landmark point pairs between the two scans. Pre-therapy scans were co-registered with planning scans (and associated dose maps) using the Plastimatch demons and Fraunhofer MEVIS deformable registration algorithms. Landmark points in each pretherapy scan were automatically mapped to the planning scan using the displacement vector field output from both registration algorithms. The absolute difference in planned dose (|ΔD|) between manually and automatically mapped landmark points was calculated. Using regression modeling, |ΔD| was modeled as a function of the distance between manually and automatically matched points (registration error, E), the dose standard deviation (SD-dose) in the eight-pixel neighborhood, and the registration algorithm used. Results: 52–92 landmark point pairs (median: 82) were identified in each patient's scans. Average |ΔD| across patients was 3.66Gy (range: 1.2–7.2Gy). |ΔD| was significantly reduced by 0.53Gy using Plastimatch demons compared with Fraunhofer MEVIS. |ΔD| increased significantly as a function of E (0.39Gy/mm) and SD-dose (2.23Gy/Gy). Conclusion: An average error of <4Gy in radiation dose was introduced when points were mapped between CT scan pairs using deformable registration. Dose differences following registration were significantly increased when the Fraunhofer MEVIS registration algorithm was used

  11. The use of the eyes protection for dose reduction in CT scans of skull

    International Nuclear Information System (INIS)

    Mourao, Arnaldo P.; Silva, Teogenes A.; Alonso, Thessa C.

    2013-01-01

    The technique for imaging the brain scans of the skull by computed tomography (CT) scanning is the volume bounded by the foramen magnum and the apex of the skull. The lenses are radiosensitive tissues and CT scans of the head deposited significant doses on them, since they are in the region of incidence of the primary beam of X-rays. Thus, the variation of the dose deposited in the crystalline skull CT scans for diagnostic imaging of the brain was investigated. Cranial scans were performed using the acquisition protocol routine with or without the use of bismuth to shield the eyes. To carry out the scans we used a male anthropomorphic phantom, Alderson Rando model and dosimeters (TLD-100) were used to record the doses. These TLDs were used to record specific doses internally to the phantom in specific organs (crystalline, pituitary, thyroid, spinal cord and breasts). The scans were performed on a GE machine, model 64 Discovery channels. The data obtained allowed to observe the variation of dose in organs. The highest dose was recorded in the lens (26,18 mGy), followed by spinal cord (17,79 mGy). Comparing the doses of the two scans it was significant variation in the crystal. Scan using bismuth shield generated smaller doses in the eyes and in the eyes occurred the higher dose reduction, about 37%. The results may contribute to spread a suitable procedure for the optimization of CT scans of the skull

  12. CT-scanning of ancient Greenlandic Inuit temporal bones

    DEFF Research Database (Denmark)

    Homøe, P; Lynnerup, N; Videbaek, H

    1992-01-01

    Additional morphological evidence of former infectious middle ear disease (IMED) was found by CT-scanning in 5 of 6 Greenlandic Inuit crania strongly suspected for former IMED due to earlier examination revealing either bilateral hypocellularity or asymmetry of the pneumatized area of the temporal...

  13. Contrast medium enhancement of soft tissues and brain in CT examinations of dogs

    International Nuclear Information System (INIS)

    Pavlicek, M.

    2000-11-01

    CT is an x-ray based method which shows less contrast for soft tissue as has been known from radiography. Therefore, it is necessary to use intravenously administered iodine contrast media to detect and localize tumors, fistulas or other pathologic lesions. Usually contrast medium is administered manually which yields random patterns of media distribution due to varying application pressure during varying administration time, therefore enhancement of parenchymous organs could not be used to the optimum extent. The use of an automatic injection pump guarantees the necessary constancy during the examination procedure to undoubtedly detect pathologic enhancement of organs in the CT-image as known from human medicine. The standards which are expected of the injection pump and the contrast media are: a good contrast enhancement, a good accumulation in the examined organs, an accumulation, which lasts long enough during the diagnostic phase, and a rapid excretion without side effects. Because of the short scan time of the modern CT-scanner, the best contrast enhancement can be administered by a short bolus injection, which can be applied by the automatic injection pump with a defined flow and a defined quantity of contrast media. This guarantees a good enhancement in the chosen region for the duration of the scan. The main aim of this study is to find a standardized flow and quantity of contrast media for defined regions and organs considering the speed of the scanner. In a subsequent step, the existing scan-protocols are then updated using the newly found information. This study showed, that CT examination of the head and brain in middle-sized dogs can be administered with a flow of 0.5 ml/s and a dose of 2 ml of contrast medium per kg weight. The contrast enhancement of the brain is caused by the enhancement of the vessels, the parenchym is free of contrast media - brain shows a low increase of density. Only if the blood-brain-barrier is destroyed, it is possible that

  14. Contrast medium enhancement of soft tissues and brain in CT examinations of dogs

    International Nuclear Information System (INIS)

    Pavlicek, M.

    2000-11-01

    CT is a x-ray based method which shows less contrast for soft tissue as has been known from radiography. Therefore, it is necessary to use intravenously administered iodine contrast media to detect and localize tumors, fistulas or other pathologic lesions. Usually contrast medium is administered manually which yields random patterns of media distribution due to varying application pressure during varying administration time, therefore enhancement of parenchymous organs could not be used to the optimum extent. The use of an automatic injection pump guarantees the necessary constancy during the examination procedure to undoubtedly detect pathologic enhancement of organs in the CT-image as known from human medicine. The standards which are expected of the injection pump and the contrast media are: a good contrast enhancement, a good accumulation in the examined organs, an accumulation, which lasts long enough during the diagnostic phase, and a rapid excretion without side effects. Because of the short scan time of the modern CT-scanner, the best contrast enhancement can be administered by a short bolus injection, which can be applied by the automatic injection pump with a defined flow and a defined quantity of contrast media. This guarantees a good enhancement in the chosen region for the duration of the scan. The main aim of this study is to find a standardized flow and quantity of contrast media for defined regions and organs considering the speed of the scanner. In a subsequent step, the existing scan-protocols are then updated using the newly found information. This study showed, that CT examination of the head and brain in middle-sized dogs can be administered with a flow of 0.5 ml/s and a dose of 2 ml of contrast medium per kg weight. The contrast enhancement of the brain is caused by the enhancement of the vessels, the parenchym is free of contrast media - brain shows a low increase of density. Only if the blood-brain-barrier is destroyed, it is possible that

  15. A new method of CT scanning for the diagnosis of mandibular fractures

    International Nuclear Information System (INIS)

    Tsukagoshi, Taku; Satoh, Kaneshige; Onizuka, Takuya

    1990-01-01

    The condylar neck of the mandible is one of the most common fracture sites in the facial skeleton. Such a fracture is routinely diagnosed by A-P, lateral oblique, and Towne projection roentgenography or orthopantomography. Despite the combination of these films, fracture of the neck of the mandible is still difficult to diagnose definitely. Therefore, a new CT scanning method was developed for diagnosing fractures of the neck of the condylar mandible. The CT axis is projected along the length of the mandible, extending from the condyle to the symphysis. This projection visualizes both the condyle and the mandibular symphysis in the same plane. The patient is placed in a supine position with the head fully extended. The base line, a line extending from the midpoint of the glenoid fossa to the menton, is determined with a lateral facial cephalogram. CT scanning with a 5 mm window is performed in parallel with and 2 cm anterior to and 2 cm posterior to the base line. When CT scanning was performed in a healthy volunteer, the condition of the condyle and the condylar neck of the mandible was clearly shown, and the view extended from the condyle to the symphysis. For automobile accident patients in whom fracture of the neck of the mandible was associated with fracture of the symphysis, two fractures were found in the same plane. A newly developed CT scanning technique is useful in the diagnosis of fractures of the condylar neck of the mandible and in the identification of fractures at other mandibular sites. It also allows scanning of patients in a supine position, which may aid in managing patients with multiple traumas. (N.K.)

  16. An evaluation of the regional cerebral blood flow (rCBF) measurement by xenon-enhanced dynamic CT with helical scanning technique and the functional imaging by multiplanar reconstruction (MPR). Fundamental study and clinical application

    International Nuclear Information System (INIS)

    Watanabe, Kenichi

    1997-01-01

    We evaluated the quantitative rCBF by xenon-enhanced dynamic CT with helical scanning technique on all brain regions, and also examined clinical usefulness of coronal and sagittal section images which are similar to SPECT images obtained by the functional multiplanar reconstitution (MPR) imaging of many successive flow maps. We used 14 clinical cases. The conventional xenon-enhanced CT was simple and ideal method to measure rCBF, however, it had disadvantages; it gives a few laminagraphical images or only the axial directional images, compared to SPECT or PET. There is a risk to overlook lesions out of the image or not to obtain the whole images of the lesion. Although the helical scanning technique has a methodological characteristics to use adjacent data for the image reconstitution, it is by no means inferior to the conventional method in the contrast resolution or the image resolution when the co-helical function and an appropriate reconstituted function were used. It has an advantage to scan all brain regions by only one cycle of scanning. Furthermore on making good use of the property that the helical scanning technique can give the successive data, we can observe rCBF by coronal and sagittal images when many flow maps were made up by reconstituted images of the narrow steps. This shows the clinical usefulness of this technique. One of the future problem to be solved is to decrease the exposure dose. (K.H.)

  17. Value of CT scanning in radiation therapy treatment planning: a prospective study

    International Nuclear Information System (INIS)

    Goitein, M.; Wittenberg, J.; Mendiondo, M.; Doucette, J.; Friedberg, C.; Ferrucci, J.; Gunderson, L.; Linggood, R.; Shipley, W.U.; Fineberg, H.V.

    1979-01-01

    We report the results of a prospective study in which we assessed the value of computed tomography (CT) scanning in planning radiation therapy for 77 patients. First, conventional studies were performed, treatment fields were designed and simulated and, where appropriate, computer generated treatment plans drawn up. Then a CT scan was performed to delineate the location of the tumor and adjacent uninvolved tissues. The treatment goals and plans were reevaluated and changed when necessary. Forty of the 77 patients (52%) had their treatment changed as a result of the CT scan. Of these, four (5%) had a change of treatment modality. Thirty-two patients (42%) had changes in the radiotherapy technique because of inadequate tumor coverage (in 24 patients (31%) part of the tumor was outside one or more of the fields and in the other 8 patients (10%) the tumor coverage was marginal). Field changes resulting only from considerations of normal tissue coverage were made for 4 of these patients (5%). In total, normal tissue coverage was affected in 36 patients (47%). When the significance of these changes was evaluated, CT scanning was judged to be of major value for 28 of the 77 patients (36%) and of minor value in a further 12 patients

  18. Micro computed tomography (CT) scanned anatomical gateway to insect pest bioinformatics

    Science.gov (United States)

    An international collaboration to establish an interactive Digital Video Library for a Systems Biology Approach to study the Asian citrus Psyllid and psyllid genomics/proteomics interactions is demonstrated. Advances in micro-CT, digital computed tomography (CT) scan uses X-rays to make detailed pic...

  19. Four cases with localized brain-stem lesion on CT scan following closed head injury

    International Nuclear Information System (INIS)

    Saeki, Naokatsu; Odaki, Masaru; Oka, Nobuo; Takase, Manabu; Ono, Junichi.

    1981-01-01

    Cases of primary brain-stem injury following closed head injury, verified by a CT scan, have been increasingly reported. However, most of them have other intracranial lesions in addition to the brain stem, resulting in a poor outcome. The CT scan of 200 cases with severe head injury-Araki's classification of types 3 and 4 - were analysed. Four cases out of them had localized brain-stem lesion without any other significant intracranial injury on a CT scan at the acute stage and had a better outcome than had previously been reported. In this analysis, these 4 cases were studied, and the CT findings, prognosis, and pathogenesis of the localized brain-stem injury were discussed. Follow-up CT of three cases, and taken one month or more later, showed diffuse cortical atrophy. This may indicate the presence of diffuse cerebral injury which could not be seen on CT scans at the acute stage. This atrophic change may also be related with the mechanism of posttraumatic conscious impairment and posttraumatic neurological deficits, such as mental symptoms and impairment of the higher cortical function. Shearing injury is a probable pathogenesis for this diffuse cortical injury. On the other hand, one case did not have any cortical atrophy on a follow-up CT scan. Therefore, this is a case with a localized primary brain-stem injury. Coup injury against the brain stem by a tentorial margin in a case with a small tentorial opening is a possible mechanism producing the localized brain-stem injury. (J.P.N.)

  20. Applications of contrast enhanced CT through external jugular access

    International Nuclear Information System (INIS)

    Xu Qiaolan; Zou Wenxing; Chen Meixia; Xie Hongbo

    2005-01-01

    Objective: A retrospective analysis and evaluation for the effects of contrast enhanced computed tomography through external jugular access. Methods: 1250 cases (male 692 and female 558) underwent CT contrast enhanced examination were retrospectively reviewed from May, 2002 to Oct, 2002. The patients aged from 12 to 86 years, averagely 49 years. Contrast agent (Ultravist) was given through an intravenous catheter placed in the cubital vein. Precise injection rates were ensured by a power injector (Medrad MCT310, USA). Excellent enhancement was achieved with this protocol in most of the patients, while external jugular access was established in 96 cases because it was unable to setup a cubital venous access. Results: Good enhancement were acquired when 96 cases of contrast agent injected through external jugular vein. And the external jugular access was setup successfully with a single puncture. Conclusion: It is a common occasion when patient undergoing contrast enhanced CT scan is in poor conditions: debility, cachexia, or with complication of chemotherapy or radiation therapy, which often results in invalidity of cabital venous access, and consequently, making bolus injection impossible. The external jugular vein is a large and central blood vessel, which is easy to setup an access. In our experience, an external jugular access should be recommended as a substitution if the cubital venous access is not available. (authors)

  1. Applications of contrast enhanced CT through external jugular access

    Energy Technology Data Exchange (ETDEWEB)

    Qiaolan, Xu; Wenxing, Zou; Meixia, Chen; Hongbo, Xie [The First Affiliated Hospital of Sun Yat-sen University, Guangzhou (China). Dept. of Radiology

    2005-09-15

    Objective: A retrospective analysis and evaluation for the effects of contrast enhanced computed tomography through external jugular access. Methods: 1250 cases (male 692 and female 558) underwent CT contrast enhanced examination were retrospectively reviewed from May, 2002 to Oct, 2002. The patients aged from 12 to 86 years, averagely 49 years. Contrast agent (Ultravist) was given through an intravenous catheter placed in the cubital vein. Precise injection rates were ensured by a power injector (Medrad MCT310, USA). Excellent enhancement was achieved with this protocol in most of the patients, while external jugular access was established in 96 cases because it was unable to setup a cubital venous access. Results: Good enhancement were acquired when 96 cases of contrast agent injected through external jugular vein. And the external jugular access was setup successfully with a single puncture. Conclusion: It is a common occasion when patient undergoing contrast enhanced CT scan is in poor conditions: debility, cachexia, or with complication of chemotherapy or radiation therapy, which often results in invalidity of cabital venous access, and consequently, making bolus injection impossible. The external jugular vein is a large and central blood vessel, which is easy to setup an access. In our experience, an external jugular access should be recommended as a substitution if the cubital venous access is not available. (authors)

  2. CT perfusion scanning of the brain in stroke and beyond

    International Nuclear Information System (INIS)

    Riedel, Christian

    2011-01-01

    CT perfusion scanning (CTP) allows for quantitative analysis of cerebral blood flow (CBF) and cerebral blood volume (CBV). Until recently, it was only possible to study brain perfusion parameters in a small stack of CT-slices close to the skull base. With the introduction of multidetector CT scanners with 64 and more detector rows it has become possible to assess perfusion of the entire brain. An optimal choice of scanning parameters like the new 'shuttle'-technique combined with a well adapted regimen for contrast administration is required to guarantee reliable perfusion measurements while still keeping the X-ray dose absorbed by the patient at a minimum. With these techniques, CTP is not only an important modality in the work-up of patients suffering from acute ischemic stroke but can also be valuable in other emergency situations such as in prolonged epileptic seizures or to monitor patients with subacute subarachnoid hemorrhage. (orig.)

  3. A comparison between intrastomal 3D ultrasonography, CT scanning and findings at surgery in patients with stomal complaints.

    Science.gov (United States)

    Näsvall, P; Wikner, F; Gunnarsson, U; Rutegård, J; Strigård, K

    2014-10-01

    Since there are no reliable investigative tools for imaging parastomal hernia, new techniques are needed. The aim of this study was to assess the validity of intrastomal three-dimensional ultrasonography (3D) as an alternative to CT scanning for the assessment of stomal complaints. Twenty patients with stomal complaints, indicating surgery, were examined preoperatively with a CT scan in the supine position and 3D intrastomal ultrasonography in the supine and erect positions. Comparison with findings at surgery, considered to be the true state, was made. Both imaging methods, 3D ultrasonography and CT scanning, showed high sensitivity (ultrasound 15/18, CT scan 15/18) and specificity (ultrasound 2/2, CT scan 1/2) when judged by a dedicated radiologist. Corresponding values for interpretation of CT scans in routine clinical practice was for sensitivity 17/18 and for specificity 1/2. 3D ultrasonography has a high validity and is a promising alternative to CT scanning in the supine position to distinguish a bulge from a parastomal hernia.

  4. Subperiosteal chondroma. Diagnostic value of CT scan imaging in two cases

    International Nuclear Information System (INIS)

    Lerais, J.M.; Auquier, F.; Baudrillard, J.C.; Durot, J.F.; Laugareil, P.; Wallays, C.; Lefort, G.; Daoud, S.; Gaillard, D.

    1988-01-01

    Results of CT scan exploration are reported in two cases of subperiosteal chondroma, one in a 4 year old child affecting the anterior tibial tuberosity the other in a 9 year old child involving the upper end of humerus. Data from CT scan imaging were undoubtedly superior to those of conventional radiography and appear to be characteristic of this benign cartilaginous tumor, greatly facilitating correlation between clinical, radiological and pathologic findings. The scanner should allow certain situations to be dedramatized and the surgical attitude adapted when the functional prognosis is involved [fr

  5. Diagnosis of tumors of the pituitary region by two-plane CT scans

    International Nuclear Information System (INIS)

    Murata, Minoru; Inoue, Hiroshi; Misumi, Shuzo; Shimizu, Tsuneo; Tamura, Masaru

    1981-01-01

    Thirty five cases of tumors in the pituitary region were analysed by two-plane CT (ordinary sections and reverse sections) in order to obtain a more accurate image of the tumor and thus establish an appropriate indication for the subnasal transsphenoidal approach. The tumors of pituitary region were classified into six groups (types I-VI) according to their degree of extension and direction of growth. Small tumors such as types I and II were detected more clearly by the reverse section than by the ordinary section. In cases of large tumors (types III-VI) relation of the tumor to the surrounding structures such as the sphenoid sinus, third ventricle, lateral ventricule, middle fossa and brain stem was accurately demonstrated by the reverse section. In the differential diagnosis of tumors in the pituitary regions, tumors showing mixed density or slightly high density and widening of the anteroposterior diameter of the sella in the precontrast reverse section and homogeneous enhancement by infusion were likely to be pituitary adenomas. One third of the pituitary adenomas showed ring-like high density in the post-contrast reverse section. Calcification was not seen in the pituitary adenomas by CT scans. All craniopharyngiomas belonged to types III-VI. Craniopharyngiomas showed high and/or low density, and various degrees of calcification in plain CT scans. Ring-like high density was seen in two thirds of the craniopharyngiomas. About one third of the craniopharyngiomas showed widening of the antero-posterior diameter of the sella. (J.P.N.)

  6. SU-F-I-31: Reproducibility of An Automatic Exposure Control Technique in the Low-Dose CT Scan of Cardiac PET/CT Exams

    Energy Technology Data Exchange (ETDEWEB)

    Park, M; Rosica, D; Agarwal, V; Di Carli, M; Dorbala, S [Brigham and Women’s Hospital and Harvard Medical School, Boston, MA (United States)

    2016-06-15

    Purpose: Two separate low-dose CT scans are usually performed for attenuation correction of rest and stress N-13 ammonia PET/CT myocardial perfusion imaging (PET/CT). We utilize an automatic exposure control (AEC) technique to reduce CT radiation dose while maintaining perfusion image quality. Our goal is to assess the reproducibility of displayed CT dose index (CTDI) on same-day repeat CT scans (CT1 and CT2). Methods: Retrospectively, we reviewed CT images of PET/CT studies performed on the same day. Low-dose CT utilized AEC technique based on tube current modulation called Smart-mA. The scan parameters were 64 × 0.625mm collimation, 5mm slice thickness, 0.984 pitch, 1-sec rotation time, 120 kVp, and noise index 50 with a range of 10–200 mA. The scan length matched with PET field of view (FOV) with the heart near the middle of axial FOV. We identified the reference slice number (RS) for an anatomical landmark (carina) and used it to estimate axial shift between two CTs. For patient size, we measured an effective diameter on the reference slice. The effect of patient positioning to CTDI was evaluated using the table height. We calculated the absolute percent difference of the CTDI (%diff) for estimation of the reproducibility. Results: The study included 168 adults with an average body-mass index of 31.72 ± 9.10 (kg/m{sup 2}) and effective diameter was 32.72 ± 4.60 cm. The average CTDI was 1.95 ± 1.40 mGy for CT1 and 1.97 ± 1.42mGy for CT2. The mean %diff was 7.8 ± 6.8%. Linear regression analysis showed a significant correlation between the table height and %diff CTDI. (r=0.82, p<0.001) Conclusion: We have shown for the first time in human subjects, using two same-day CT images, that the AEC technique in low-dose CT is reproducible within 10% and significantly depends on the patient centering.

  7. Interobserver variability in visual evaluation of thoracic CT scans and comparison with automatic computer measurements of CT lung density

    DEFF Research Database (Denmark)

    Winkler Wille, Mathilde Marie; Thomsen, Laura Hohwü; Dirksen, Asger

    2012-01-01

    lung density measurements, i.e. densitometry. Methods – In a pilot study 60 CT scans were selected from a sample of 3980 CT scans from The Danish Lung Cancer Screening Trial (DLCST). The amount of emphysema in these scans was scored independently by two observers, who were blinded regarding clinical...... information. The lung was segmented automatically by in-house developed computer software, and the percentage of pixels below -950 HU was used as a surrogate marker for emphysema. The observer variability, as well as the correlation with the lung density measurements, was analysed using Spearman’s rank...... in emphysema grading. However, the agreement with the CT lung density measurement was poor, indicating that the two types of evaluation represent different aspects of emphysema. Most likely, they should be seen as complementary rather than competitive evaluations. Future comparison with physiological tests...

  8. Assessment of pancreatic adenocarcinoma: use of low-dose whole pancreatic CT perfusion and individualized dual-energy CT scanning

    International Nuclear Information System (INIS)

    Li, Hai-ou; Guo, Jun; Li, Xiao; Qi, Yao-dong; Wang, Xi-ming; Xu, Zhuo-dong; Liu, Cheng; Chen, Jiu-hong

    2015-01-01

    The objective of this study was to investigate the value of low-dose whole pancreatic computed tomography (CT) perfusion integrated with individualized dual-energy CT (DECT) scanning in the diagnosis of pancreatic adenocarcinoma. Twenty patients with pancreatic adenocarcinoma underwent pancreatic CT perfusion as well as individualized dual-phase DECT pancreatic scans. Perfusion characteristics of non-tumourous pancreatic parenchyma and pancreatic adenocarcinoma were analysed. Weighted-average 120 kVp images and the optimal monoenergetic images in dual phase were reconstructed and the contrast noise ratio (CNR) of pancreas-to-tumour were compared. There were significant difference on blood flow as well as blood volume between pancreatic adenocarcinoma and the non-tumourous pancreatic parenchyma (P < 0.05), whereas no difference on permeability (P > 0.05). CNRs of pancreas-to-tumour in individualized pancreatic phase were significantly higher than those in venous phase (P < 0.05), and CNRs of optimal monoenergetic images were higher than those on weighted-average 120 kVp images (P < 0.05) in both phase. Total effective radiation dose of CT examination was around 9.32–13.75 mSv. Low-dose whole pancreatic CT perfusion can provide functional information, and the individualized pancreatic phase DECT scan is the optimal method for detecting pancreatic adenocarcinomas. The integration of the two techniques has great value in clinical application.

  9. 18F-FDG PET/CT Findings Following Repeated Intramuscular Injections of "Site Enhancement Oil" in the Upper Extremities

    DEFF Research Database (Denmark)

    Dejanović, Danijela; Loft, Annika

    2017-01-01

    We present the findings on F-FDG PET/CT in a 50-year-old man known to self-administer intramuscular injections with site enhancement oil in the upper extremities. PET images show diffuse pathological high FDG uptake in soft tissue of the upper arms and in scanned portions of the forearms. On the CT...

  10. MRI of patients with cerebral palsy and normal CT scan

    International Nuclear Information System (INIS)

    Bogaert, P. van; Szliwowski, H.B.

    1992-01-01

    Three children with clinical evidence of cerebral palsy (CP) and normal cerebral computed tomography (CT) scans were evaluated by magnetic resonance imaging (MRI) to identify CT-undetectable white matter lesions in the watershed zones of arterial territories. The two patients with spastic diplegia showed bilateral lesions either in the subcortical regions or in the occipital periventricular regions. The patient with congenital hemiplegia exhibited unilateral lesions in the periventricular region. We conclude that MRI is more informative than CT for the evaluation of patients with CP. (orig.)

  11. MRI of patients with cerebral palsy and normal CT scan

    Energy Technology Data Exchange (ETDEWEB)

    Bogaert, P. van; Szliwowski, H.B. (Hopital Erasme, Brussels (Belgium). Dept. of Neurology); Baleriaux, D.; Christophe, C. (Hopital Erasme, Brussels (Belgium). Dept. of Radiology (Neuroradiology))

    1992-02-01

    Three children with clinical evidence of cerebral palsy (CP) and normal cerebral computed tomography (CT) scans were evaluated by magnetic resonance imaging (MRI) to identify CT-undetectable white matter lesions in the watershed zones of arterial territories. The two patients with spastic diplegia showed bilateral lesions either in the subcortical regions or in the occipital periventricular regions. The patient with congenital hemiplegia exhibited unilateral lesions in the periventricular region. We conclude that MRI is more informative than CT for the evaluation of patients with CP. (orig.).

  12. Utility of bolus dynamic CT for the detection of hypervascular malignant hepatic tumors. Mainly referring to the comparison with delayed phase contrast-enhanced CT

    International Nuclear Information System (INIS)

    Matsuda, Hiromichi; Abe, Kimihiko; Freeny, P.C.

    1996-01-01

    In order to analyze the usefulness of dynamic contrast-enhanced CT, 84 patients who had hepatocellular carcinoma or suspected hypervascular metastases were studied with conventional incremental dynamic CT (CID-CT) or double helical CT (DH-CT). Delayed phase contrast-enhanced CT studies were consecutively performed in all patients. Thirty-six of 84 patients had malignant hepatic neoplasms; six had hepatocellular carcinoma and 30 had metastatic tumors. At first, the detectability of hepatic lesions was evaluated with bolus dynamic CT and delayed phase CT. Dynamic CT has detected more lesions than delayed CT. Some hepatic lesions described as isodensity were missed on CID-CT. Therefore, delayed phase CT cannot be eliminated when CID-CT is performed. Secondly, hepatic lesion detectability with CID-CT was compared with that of DH-CT. DH-CT did not miss the hepatic lesions picked up by delayed phase CT and was expected to provide excellent detectability of hypervascular hepatic neoplasms. In addition, first helical CT showed most hepatic lesions as areas of obvious hyperdensity, while CID-CT did not show their correct vascularities. So-called hypervascular hepatic tumors, however, were not always hypervascular and were demonstrated as areas of iso-hypodensity even on initial helical scanning. Second helical CT was useful to detect these so-called hypervascular, but actually hypovascular lesions. In conclusion, dynamic CT was helpful in detecting hypervascular hepatic malignant neoplasms, and DH-CT was more accurate than-CID-CT for the detection of hepatic lesions and the evaluation of vascular lesion. (author)

  13. Iodide and xenon enhancement of computed tomography (CT) in multiple sclerosis (MS)

    International Nuclear Information System (INIS)

    Radue, E.W.; Kendall, B.E.

    1978-01-01

    The characteristic findings on computed tomography (CT) in multiple sclerosis (MS) are discussed. In a series of 49 cases plain CT was normal in 21 (43%), cerebral atrophy alone was present in 17 (35%) and plaques were visible in 11 (23%). These were most often adjacent to the lateral ventricles (14 plaques) and in the parietal white matter (10 plaques). CT was performed after the intravenous administration of iodide in 16 of these cases. Two patients with low attenuation plaques were scanned with xenon enhancement; the plaques absorbed less xenon than the corresponding contralateral brain substance and additional, previously isodense plaques were revealed. In one case the white matter absorbed much less xenon than normal and its uptake relative to grey matter was reduced. (orig.) [de

  14. Influence of PET/CT-introduction on PET scanning frequency and indications. Results of a multicenter study

    International Nuclear Information System (INIS)

    Stergar, H.; Bockisch, A.; Eschmann, S.M.; Krause, B.J.; Roedel, R.; Tiling, R.; Weckesser, M.

    2007-01-01

    Aim: to evaluate the influence of the introduction of combined PET/CT scanners into clinical routine. This investigation addresses the quantitative changes between PET/CT and stand alone PET. Methods: the study included all examinations performed on stand alone PET- or PET/CT-scanners within 12 month prior to and after implementation of PET/CT. The final data analysis included five university hospitals and a total number of 15 497 exams. We distinguished exams on stand alone tomographs prior to and after installation of the combined device as well as PET/CT scans particularly with regard to disease entities. Various further parameters were investigated. Results: the overall number of PET scans (PET and PET/CT) rose by 146% while the number of scans performed on stand alone scanners declined by 22%. Only one site registered an increase in stand alone PET. The number of exams for staging in oncology increased by 196% while that of cardiac scans decreased by 35% and the number of scans in neurology rose by 47%. The use of scans for radiotherapy planning increased to 7% of all PET/CT studies. The increase of procedures for so-called classic PET oncology indications was moderate compared to the more common tumors. An even greater increase was observed in some rare entities. Conclusions: the introduction of PET/CT led to more than a doubling of overall PET procedures with a main focus on oncology. Some of the observed changes in scanning frequency may be caused by a rising availability of new radiotracers and advancements of competing imaging methods. Nevertheless the evident increase in the use of PET/CT for the most common tumour types demonstrates its expanding role in cancer staging. The combination of molecular and morphologic imaging has not only found its place but is still gaining greater importance with new developments in technology and radiochemistry. (orig.)

  15. Body surface area determined by whole-body CT scanning: need for new formulae?

    DEFF Research Database (Denmark)

    Villa, Chiara; Primeau, Charlotte; Hesse, Ulrik

    2017-01-01

    Calculation of the estimated body surface area (BSA) by body height and weight has been a challenge in the past centuries due to lack of a well-documented gold standard. More recently, available techniques such as 3D laser surface scanning and CT scanning may be expected to quantify the BSA...... Mimics software, and BSA values were automatically extracted from the program. They were compared with nine predictive equations from the literature. Remarkably, close correlations (r > 0·90) were found between BSA values from CT scans and those from the predictive formulae. A mean BSA of the 54 cadavers...... equations, with the CT scan determination as gold standard. It is concluded that DuBois and DuBois' equation can be safely used in normal-weight male subjects with high accuracy, but it seems likely that BSA is underestimated in underweight subjects and overestimated in overweight individuals. Creation...

  16. Experimental study of abdominal CT scanning exposal doses adjusted on the basis of pediatric abdominal perimeter

    International Nuclear Information System (INIS)

    Wei Wenzhou; Zhu Gongsheng; Zeng Lingyan; Yin Xianglin; Yang Fuwen; Liu Changsheng

    2006-01-01

    Objective: To optimize the abdominal helical CT scanning parameters in pediatric patients and to reduce its radiation hazards. Methods: 60 canines were evenly grouped into 4 groups on the basis of pediatric abdominal perimeter, scanned with 110,150,190 and 240 mAs, and their qualities of canine CT images were analyzed. 120 pediafric patients with clinic suspected abdominal diseases were divided into 4 groups on the basis of abdominal perimeter, scanned by optimal parameters and their image qualities were analyzed. Results: After CT exposure were reduced, the percentages of total A and B were 90.9 % and 92.0 % in experimental canines and in pediatric patients, respectively. Compared with conventional CT scanning, the exposure and single slice CT dose index weighted (CTDIw) were reduced to 45.8%-79.17%. Conclusion: By adjusted the pediatric helical CT parameters basedon the of pediatric abdominal perimeter, exposure of patient to the hazards of radiation is reduced. (authors)

  17. Gambaran CT Scan Toraks Sesuai dengan Jenis Sitologi/Histologi pada Pasien Kanker Paru yang Merokok

    Directory of Open Access Journals (Sweden)

    Rosa Tatun

    2016-03-01

    Full Text Available Kanker paru merupakan  penyebab kematian paling banyak akibat keganasan. Kanker paru memberikan gambaran CT scan yang berbeda sesuai dengan jenis sitologi/histologinya. Pemeriksaan CT scan  toraksdengan teknik high resolution computed tomography (HRCT dapat memperlihatkan kelainan kanker parusecara rinci. Penelitian dilakukan di Instalasi Radiologi RSU Persahabatan, Jakarta bekerja sama denganDepartemen Pulmonologi dan Respirasi RSU Persahabatan terhadap 100 sampel yang diperoleh pada bulanNovember 2014 hingga Maret 2015. Berdasarkan jenis sitologi/histologi kanker paru (adenokarsinoma dankarsinoma sel skuamosa/KSS tidak ditemukan  variabel yang bermakna secara statistik  (bentuk, letak, tepispikulasi, tepi lobulasi, nodul satelit. Variabel yang paling banyak ditemukan pada adenokarsinoma maupunKSS adalah bentuk massa, lokasi di sentral dan paru sebelah kanan. Gambaran kanker paru adenokarsinomadan KSS pada pasien merokok paling banyak berupa massa, lokasi di sentral dan lobus kanan paru. Kata kunci: kanker paru, merokok, CT scan toraks   Lung Cancer CT Scan Findings in Smoker Patients Basedon Cytology/Histology Abstract Lung cancer is the leading cause of most deaths due to malignancy. Lung cancer CT scan provides an overview according to the type of cytology / histology. Thorax CT scan with high resolution technique (HRCT may revealdetail lung cancer abnormalities. This study was conducted between Department of Radiology and Departmentof Pulmonology Respiratory, Persahabatan Hospital Jakarta based on 100 samples, November 2014 until March2015. Based on cytological/histological type (adenocarcinoma and squamous cell carcinoma/KSS, it was not found significant meaningfull variables (shape, location, spiculate edge, lobulate edge, satellite nodules. Most commonly variables found in adenocarcinomas and KSS were mass forming, central location, right lung location.Most of adenocarcinoma and SCC in smoked patients were mass forming, central

  18. Direct CT scanning of the lesser pelvis - frontal vs sagittal plane

    International Nuclear Information System (INIS)

    Khadzhigeorgiev, G.; Lichev, A.

    1994-01-01

    Whenever axial scanning alone is used, the anatomical patterns of the true pelvis and the organs contained in it, particularly in women, give rise to diagnostic difficulties during CT assessment of neoplasms originating from these organs. The high demands on precision characterization of the pathological changes in the pelvis minor organs necessitate the obtaining of reliable density and size measurement data, not merely from the axial plane, but from the frontal and sagittal ones as well. The deficient information afforded by secondary reconstruction of the pelvis mind images requires an mandatory evaluation of the potentialities of direct frontal and direct sagittal scanning of the pelvis minor using standard CT equipment. Information yielded by images from direct frontal and direct sagittal pelvis minor scanning as well as diagnostic problems where application of this type of scanning is indicated operational difficulties and their overcoming, are among the issues discussed. 8 figs., 7 refs

  19. Synthetic CT: Simulating low dose single and dual energy protocols from a dual energy scan

    International Nuclear Information System (INIS)

    Wang, Adam S.; Pelc, Norbert J.

    2011-01-01

    Purpose: The choice of CT protocol can greatly impact patient dose and image quality. Since acquiring multiple scans at different techniques on a given patient is undesirable, the ability to predict image quality changes starting from a high quality exam can be quite useful. While existing methods allow one to generate simulated images of lower exposure (mAs) from an acquired CT exam, the authors present and validate a new method called synthetic CT that can generate realistic images of a patient at arbitrary low dose protocols (kVp, mAs, and filtration) for both single and dual energy scans. Methods: The synthetic CT algorithm is derived by carefully ensuring that the expected signal and noise are accurate for the simulated protocol. The method relies on the observation that the material decomposition from a dual energy CT scan allows the transmission of an arbitrary spectrum to be predicted. It requires an initial dual energy scan of the patient to either synthesize raw projections of a single energy scan or synthesize the material decompositions of a dual energy scan. The initial dual energy scan contributes inherent noise to the synthesized projections that must be accounted for before adding more noise to simulate low dose protocols. Therefore, synthetic CT is subject to the constraint that the synthesized data have noise greater than the inherent noise. The authors experimentally validated the synthetic CT algorithm across a range of protocols using a dual energy scan of an acrylic phantom with solutions of different iodine concentrations. An initial 80/140 kVp dual energy scan of the phantom provided the material decomposition necessary to synthesize images at 100 kVp and at 120 kVp, across a range of mAs values. They compared these synthesized single energy scans of the phantom to actual scans at the same protocols. Furthermore, material decompositions of a 100/120 kVp dual energy scan are synthesized by adding correlated noise to the initial material

  20. An assessment of pulmonary emphysema in smokers using CT scan

    International Nuclear Information System (INIS)

    Satoh, Katashi; Kobayashi, Takuya; Misao, Takahiko

    1999-01-01

    We assessed the relationship between PE and smoking in 639 cases (411 males and 228 females with age ranged 21-86 years) who underwent CT scans during the period, from December 1997 to December 1998, under suspicion of respiratory disease on chest radiograph or some respiratory complaints. PE was diagnosed by the existence of low attenuation areas in CT scan and not by pulmonary function tests. CT was performed with 10 mm collimation in a standard algorithm. PE, regardless of the grade, was seen: in 189 out of 348 (54.3%) cases in male smokers and in only 2 out of 63 (3.2%) cases in male non-smokers; and in 5 out of 25 (20.0%) female smokers and in 4 out of 203 (2.0%) female non-smokers. PE was observed in more than half of male smokers. High incidence of PE was also observed in even younger generation, and its severity progresses with advancing age and increasing smoking index. (author)

  1. A New, Simple Method for Estimating Pleural Effusion Size on CT Scans

    Science.gov (United States)

    Moy, Matthew P.; Berko, Netanel S.; Godelman, Alla; Jain, Vineet R.; Haramati, Linda B.

    2013-01-01

    Background: There is no standardized system to grade pleural effusion size on CT scans. A validated, systematic grading system would improve communication of findings and may help determine the need for imaging guidance for thoracentesis. Methods: CT scans of 34 patients demonstrating a wide range of pleural effusion sizes were measured with a volume segmentation tool and reviewed for qualitative and simple quantitative features related to size. A classification rule was developed using the features that best predicted size and distinguished among small, moderate, and large effusions. Inter-reader agreement for effusion size was assessed on the CT scans for three groups of physicians (radiology residents, pulmonologists, and cardiothoracic radiologists) before and after implementation of the classification rule. Results: The CT imaging features found to best classify effusions as small, moderate, or large were anteroposterior (AP) quartile and maximum AP depth measured at the midclavicular line. According to the decision rule, first AP-quartile effusions are small, second AP-quartile effusions are moderate, and third or fourth AP-quartile effusions are large. In borderline cases, AP depth is measured with 3-cm and 10-cm thresholds for the upper limit of small and moderate, respectively. Use of the rule improved interobserver agreement from κ = 0.56 to 0.79 for all physicians, 0.59 to 0.73 for radiology residents, 0.54 to 0.76 for pulmonologists, and 0.74 to 0.85 for cardiothoracic radiologists. Conclusions: A simple, two-step decision rule for sizing pleural effusions on CT scans improves interobserver agreement from moderate to substantial levels. PMID:23632863

  2. Scanning technology with multi-slice helical CT in security inspection domain

    International Nuclear Information System (INIS)

    Wang Jue; Wang Fuquan; Jiang Zenghui

    2008-01-01

    The paper analyzes the technology conditions of security inspection in home and abroad, and expatiates technology of spiral CT and how to define CT value etc, with studying on the key technology of spiral CT scanning way (X-RAY, detector, technology of pulley etc) and mutual relation. By comparing the present products of security inspection, the conclusion was drawn that it is inevitable to develop the tendency of security inspection area with the checking and discerning the substance by using the technology of multi-layer spiral CT. (authors)

  3. Study of CT Scan Flooding System at High Temperature and Pressure

    Science.gov (United States)

    Chen, X. Y.

    2017-12-01

    CT scan flooding experiment can scan micro-pore in different flooding stages by the use of CT scan technology, without changing the external morphology and internal structure of the core, and observe the distribution characterization in pore medium of different flooding fluid under different pressure.thus,it can rebuilt the distribution images of oil-water distribution in different flooding stages. However,under extreme high pressure and temperature conditions,the CT scan system can not meet the requirements. Container of low density materials or thin shell can not resist high pressure,while high density materials or thick shell will cause attenuation and scattering of X-ray. The experiment uses a simple Ct scanning systems.X ray from a point light source passing trough a micro beryllium shell on High pressure stainless steal container,continuously irradiates the core holder that can continuously 360° rotate along the core axis. A rare earth intensifying screen behind the core holder emitting light when irradiated with X ray can show the core X ray section image. An optical camera record the core X ray images through a transparency high pressure glazing that placed on the High pressure stainless steal container.Thus,multiple core X ray section images can reconstruct the 3D core reconstruction after a series of data processing.The experiment shows that both the micro beryllium shell and rare earth intensifying screen can work in high temperature and high pressure environment in the stainless steal container. This way that X-ray passes through a thin layer of micro beryllium shell , not high pressure stainless steal shell,avoid the attenuation and scattering of X-ray from the container shell,while improving the high-pressure experiment requirements.

  4. Gyral high density on CT scan after head injury; [sup 123]I-IMP SPECT and MRI findings in three children

    Energy Technology Data Exchange (ETDEWEB)

    Abe, Takumi; Matsumoto, Kiyoshi (Showa Univ., Tokyo (Japan). School of Medicine); Sakamoto, Tetsuya; Aruga, Tohru

    1994-02-01

    The authors treated three children who had 'gyral high density' on plain CT scans after head injury with acute subdural hematoma. [sup 123]I-IMP SPECT (IMP) and MRI in the chronic stage were performed. All were males, about one year of age, with acute subdural hematoma. CT scan 48 hours after injury showed diffuse low density in the ipsilateral parenchyma with minimum midline shift, and IMP showed decreased activity in the same area. Plain CT scan 1 to 3 weeks after injury showed remarkably high density along the gyri in part of the same area. This area was markedly enhanced on CT with contrast medium and showed decreased blood flow on IMP. This high density area disappeared within 2 months after injury and the area concerned showed brain atrophy. In the chronic stage (after 6 months), only the high density area along the gyri seen in the CT scan showed MRI evidence of ishemia, but there was no definite evidence of hemorrhage. All three children had hemiplegia at the time of discharge. The gyral high density suggests ischemic brain, but the pathophysiological process might be different from that of so-called hemorrhagic infarction. Presumably, it is due to incomplete autoregulation, the incomplete blood-brain barrier and the sensitivity to stimulation of cerebral blood vessels in the brains of infants. The intensity and range of the gyral high density are considered to be important in estimating the future amount of atrophic change in the insulted brain and the resulting sequelae. (author).

  5. Detection of underlying malignancy in patients with paraneoplastic neurological syndromes: comparison of {sup 18}F-FDG PET/CT and contrast-enhanced CT

    Energy Technology Data Exchange (ETDEWEB)

    Schramm, N.; Schmid-Tannwald, C.; Meinel, F.G.; Reiser, M.F.; Rist, C. [Ludwig-Maximilians-University Hospital Munich, Institute for Clinical Radiology, Munich (Germany); Rominger, A. [Ludwig-Maximilians-University Hospital Munich, Department of Nuclear Medicine, Munich (Germany); Schmidt, C. [Ludwig-Maximilians-University Hospital Munich, Department of Neurology, Munich (Germany); Morelli, J.N. [Texas A and M Health Sciences Center, Department of Radiology, Temple, TX (United States)

    2013-07-15

    To determine the value of combined {sup 18}F-FDG PET/CT with diagnostic contrast-enhanced CT (CECT) in detecting primary malignancies and metastases in patients with paraneoplastic neurological syndromes (PNS) and to compare this with CECT alone. PET/CT scans from 66 patients with PNS were retrospectively evaluated. Two blinded readers initially reviewed the CECT portion of each PET/CT scan. In a second session 3 months later, the readers analysed the combined PET/CT scans. Findings on each study were assessed using a four-point-scale (1 normal/benign; 2 inconclusive, further diagnostic work-up may be necessary; 3 malignant; 4 inflammatory). Sensitivity and specificity for malignant findings were calculated for PET/CT and CECT. Interreader agreement was determined by calculating Cohen's kappa. Pooled data from clinical follow-up (including histopathology and follow-up imaging, median follow-up 20.0 months) served as the reference gold standard. Both readers classified 12 findings in ten patients (15 %) as malignant on the PET/CT scans (two patients had two primary tumours). One such imaging finding (suspected thymic cancer) was false-positive (i.e. benign histology). The most common tumours were bronchial carcinoma (n = 3), lymph node metastases of gynaecological tumours (n = 3) and tonsillar carcinoma (n = 2). Three of 12 findings (25 %) were not detected by CECT alone (cervical carcinoma, lymph node metastasis and tonsillar carcinoma). In a per-patient analysis, sensitivity and specificity for malignant findings were 100 % and 90 % for PET/CT and 78 % and 88 % for CECT. In 24 % (reader 1) and 21 % (reader 2) of the patients, the PET/CT findings were inconclusive. Of these findings, 57 % (reader 1) and 56 % (reader 2) were only diagnosed with PET (e.g. focal FDG uptake of the thyroid, gastrointestinal tract and ovaries). On follow-up, none of these findings corresponded to malignancy. Overall agreement between the two readers was excellent with a Cohen

  6. Diagnosis value of dual-phase contrast enhancement CT combined with virtual non-enhanced images by dual-energy CT in clear cell renal cell carcinoma

    International Nuclear Information System (INIS)

    Ma Zhoupeng; Zhou Jianjun; Liu Xueling; Wang Chun; Zhang Shunzhuang

    2012-01-01

    Objective: To explore the diagnostic value of dual-phase contrast enhancement CT combined with virtual non-enhanced images by dual-energy CT in clear cell renal cell carcinoma. Methods: Sixty patients who were suspected of clear cell renal cell carcinoma underwent non-enhanced CT and contrast enhancement CT of early interface-phase between cortex -medulla and parenchymal phase on a dual-energy CT. The true non-enhanced kidney CT (TNCT) was performed in a single-energy acquisition mode, but the dual-phase contrast enhancement CT were performed in a dual-energy mode of 80 kV and 140 kV respectively. The virtual non-enhanced CT (VNCT) images were derived from the data of early interface phase using liver virtual non-contrast software. The diagnose according to VNCT combined dual-phase contrast enhancement CT and dual-phase contrast enhancement CT only were made respectively and compared with χ 2 test. Between the true non-contrast CT and the virtual non-contrast CT, the image quality was compared with Wilcoxon test; The radiation dose of volume CT dose index (CTDIvol) and dose length product(DLP) in a single-phase and total examination, the mean CT HU values of the tumours were compared with t test. Results: The accuracy of VNCT combined dual-phase contrast enhancement CT was higher than that of dual-phase contrast enhancement CT only [93.3% (56/60) vs.78.3% (47/60); χ 2 =5.6, P<0.05]. The detective ability (score) of VNCT was near to that of TNCT and the difference was not obvious (Z=0.00, P>0.05). The radiation dose of volume CT dose index (CTDIvol) and dose length product (DLP) in a single phase and total examination of VNCT [(8.85 ± 1.28) mGy, (196.45 ±21.12) mGy·cm, (17.69±2.35) mGy, (392.90±42.25) mGy · cm] were lower than that of TNCT [(10.20 ± 1.44) mGy,(218.29 ± 29.60) mGy · cm, (30.61 ± 3.27) mGy and (654.86 ± 88.81) mGy ·cm], t=4.21, 3.58, 23.63, 16.12 respectively, P<0.05. The mean CT HU values of tumours on VNCT images was higher than that

  7. Dose profile study in head CT scans using radiochromic films

    International Nuclear Information System (INIS)

    Ladino G, A. M.; Prata M, A.

    2016-10-01

    Diagnostic images of computed tomography generate higher doses than other methods of diagnostic radiology using X-ray beam attenuation. Clinical applications of CT have been increased by technological advances, what leads to a wide variety of scanner in the Brazilian technological pool. It has been difficult to implement dose reduction strategies because of the lack of proper guidance on computed tomography examinations. However, CT scanners allow adjusting acquisition parameter according to the patients physical profile and diagnostic application for which the scan is intended. The knowledge of the dose distribution is important because changes in image acquisition parameters may provide dose reduction. In this study, it was used a cylindrical head phantom in PMMA with 5 openings, what allows dose measurement in 5 regions. In a GE CT scanner, Discovery model of 64 channels, the central slice of the head phantom was irradiated and the absorbed doses were measured using a pencil ionization chamber. Radiochromic film strips were placed in the peripheral and in the central region of the head phantom and was performed a scan of 10 cm in the phantom central region. The scan was performed using the head scanning protocol of the radiobiology service, with a voltage of 120 kV. After scanning, the radiochromic film strips were digitalized and their digital images were used to have the dose longitudinal profiles. The dose values recorded have variation in a range of 18.66 to 23.57 mGy. In the results it was compared the dose index values obtained by the pencil chamber measurement to the dose longitudinal profiles recorded by the film strips. (Author)

  8. Dose profile study in head CT scans using radiochromic films

    Energy Technology Data Exchange (ETDEWEB)

    Ladino G, A. M.; Prata M, A., E-mail: amlgphys@gmail.com [Universidade Federal de Minas Gerais, Departamento de Engenharia Nuclear, Av. Pte. Antonio Carlos 6627, 31270-901 Belo Horizonte, Minas Gerais (Brazil)

    2016-10-15

    Diagnostic images of computed tomography generate higher doses than other methods of diagnostic radiology using X-ray beam attenuation. Clinical applications of CT have been increased by technological advances, what leads to a wide variety of scanner in the Brazilian technological pool. It has been difficult to implement dose reduction strategies because of the lack of proper guidance on computed tomography examinations. However, CT scanners allow adjusting acquisition parameter according to the patients physical profile and diagnostic application for which the scan is intended. The knowledge of the dose distribution is important because changes in image acquisition parameters may provide dose reduction. In this study, it was used a cylindrical head phantom in PMMA with 5 openings, what allows dose measurement in 5 regions. In a GE CT scanner, Discovery model of 64 channels, the central slice of the head phantom was irradiated and the absorbed doses were measured using a pencil ionization chamber. Radiochromic film strips were placed in the peripheral and in the central region of the head phantom and was performed a scan of 10 cm in the phantom central region. The scan was performed using the head scanning protocol of the radiobiology service, with a voltage of 120 kV. After scanning, the radiochromic film strips were digitalized and their digital images were used to have the dose longitudinal profiles. The dose values recorded have variation in a range of 18.66 to 23.57 mGy. In the results it was compared the dose index values obtained by the pencil chamber measurement to the dose longitudinal profiles recorded by the film strips. (Author)

  9. CT Scan Features of Presumptive Haemorrhagic Stroke in a Dog with Cushing’s Disease

    Directory of Open Access Journals (Sweden)

    A. Liotta

    2014-01-01

    Full Text Available A 9-year-old, intact male, Brie’s shepherd dog, with a 10-day history of depression and tachypnoea developed signs of central neurological dysfunction. 16 Multislice Computed Tomography (CT pre- and postcontrast studies of the brain revealed a single intra-axial homogeneous well-circumscribed hyperattenuating (+/− 62 HU and noncontrast-enhancing area, 5 mm in diameter, in the caudal part of the mesencephalon. This finding was highly suggestive of a haemorrhagic event. A pituitary-dependent hyperadrenocorticism (PDH was identified and is considered likely to be the underlying cause. A repeat CT scan examination, 2 months later, showed almost complete resolution of the brain lesion. The present case describes a solitary 5 mm diameter lesion: the result of intracranial haemorrhage in a dog with presumed PDH.

  10. Predicting tumor hypoxia in non-small cell lung cancer by combining CT, FDG PET and dynamic contrast-enhanced CT.

    Science.gov (United States)

    Even, Aniek J G; Reymen, Bart; La Fontaine, Matthew D; Das, Marco; Jochems, Arthur; Mottaghy, Felix M; Belderbos, José S A; De Ruysscher, Dirk; Lambin, Philippe; van Elmpt, Wouter

    2017-11-01

    Most solid tumors contain inadequately oxygenated (i.e., hypoxic) regions, which tend to be more aggressive and treatment resistant. Hypoxia PET allows visualization of hypoxia and may enable treatment adaptation. However, hypoxia PET imaging is expensive, time-consuming and not widely available. We aimed to predict hypoxia levels in non-small cell lung cancer (NSCLC) using more easily available imaging modalities: FDG-PET/CT and dynamic contrast-enhanced CT (DCE-CT). For 34 NSCLC patients, included in two clinical trials, hypoxia HX4-PET/CT, planning FDG-PET/CT and DCE-CT scans were acquired before radiotherapy. Scans were non-rigidly registered to the planning CT. Tumor blood flow (BF) and blood volume (BV) were calculated by kinetic analysis of DCE-CT images. Within the gross tumor volume, independent clusters, i.e., supervoxels, were created based on FDG-PET/CT. For each supervoxel, tumor-to-background ratios (TBR) were calculated (median SUV/aorta SUV mean ) for HX4-PET/CT and supervoxel features (median, SD, entropy) for the other modalities. Two random forest models (cross-validated: 10 folds, five repeats) were trained to predict the hypoxia TBR; one based on CT, FDG, BF and BV, and one with only CT and FDG features. Patients were split in a training (trial NCT01024829) and independent test set (trial NCT01210378). For each patient, predicted, and observed hypoxic volumes (HV) (TBR > 1.2) were compared. Fifteen patients (3291 supervoxels) were used for training and 19 patients (1502 supervoxels) for testing. The model with all features (RMSE training: 0.19 ± 0.01, test: 0.27) outperformed the model with only CT and FDG-PET features (RMSE training: 0.20 ± 0.01, test: 0.29). All tumors of the test set were correctly classified as normoxic or hypoxic (HV > 1 cm 3 ) by the best performing model. We created a data-driven methodology to predict hypoxia levels and hypoxia spatial patterns using CT, FDG-PET and DCE-CT features in NSCLC. The

  11. Childhood CT scans linked to leukemia and brain cancer later in life

    Science.gov (United States)

    Children and young adults scanned multiple times by computed tomography (CT), a commonly used diagnostic tool, have a small increased risk of leukemia and brain tumors in the decade following their first scan.

  12. Ventricular Geometry From Non-contrast Non-ECG-gated CT Scans: An Imaging Marker of Cardiopulmonary Disease in Smokers.

    Science.gov (United States)

    Rahaghi, Farbod N; Vegas-Sanchez-Ferrero, Gonzalo; Minhas, Jasleen K; Come, Carolyn E; De La Bruere, Isaac; Wells, James M; González, Germán; Bhatt, Surya P; Fenster, Brett E; Diaz, Alejandro A; Kohli, Puja; Ross, James C; Lynch, David A; Dransfield, Mark T; Bowler, Russel P; Ledesma-Carbayo, Maria J; San José Estépar, Raúl; Washko, George R

    2017-05-01

    Imaging-based assessment of cardiovascular structure and function provides clinically relevant information in smokers. Non-cardiac-gated thoracic computed tomographic (CT) scanning is increasingly leveraged for clinical care and lung cancer screening. We sought to determine if more comprehensive measures of ventricular geometry could be obtained from CT using an atlas-based surface model of the heart. Subcohorts of 24 subjects with cardiac magnetic resonance imaging (MRI) and 262 subjects with echocardiography were identified from COPDGene, a longitudinal observational study of smokers. A surface model of the heart was manually initialized, and then automatically optimized to fit the epicardium for each CT. Estimates of right and left ventricular (RV and LV) volume and free-wall curvature were then calculated and compared to structural and functional metrics obtained from MRI and echocardiograms. CT measures of RV dimension and curvature correlated with similar measures obtained using MRI. RV and LV volume obtained from CT inversely correlated with echocardiogram-based estimates of RV systolic pressure using tricuspid regurgitation jet velocity and LV ejection fraction respectively. Patients with evidence of RV or LV dysfunction on echocardiogram had larger RV and LV dimensions on CT. Logistic regression models based on demographics and ventricular measures from CT had an area under the curve of >0.7 for the prediction of elevated right ventricular systolic pressure and ventricular failure. These data suggest that non-cardiac-gated, non-contrast-enhanced thoracic CT scanning may provide insight into cardiac structure and function in smokers. Copyright © 2017. Published by Elsevier Inc.

  13. Brain atrophy in Huntington's disease: A CT-scan study

    International Nuclear Information System (INIS)

    Starkstein, S.E.; Folstein, S.E.; Brandt, J.; McDonnell, A.; Folstein, M.

    1989-01-01

    CT-scan measurements of cortical and subcortical atrophy were carried out in 34 patients with Huntington's disease (HD). While a significant correlation was observed between parameters of subcortical atrophy (bicaudate ratio, bifrontal ratio and third ventricular ratio) and duration of the disease, there was no significant correlation between these parameters and age. On the other hand, measurements of cortical atrophy (frontal fissure ratio and cortical sulci ratio) correlated significantly with age but not with duration of the disease. When a group of 24 HD patients were compared on CT-scan measurements with a group of 24 age-matched normal controls, significant differences were obtained for all the variables examined, but the bicaudate ratio showed the highest sensitivity and specificity. Even mildly affected patients, with duration of motor symptoms less than 3 years had higher bicaudate ratios than age-matched controls. (orig.)

  14. Acute appendicitis: sensitivity, specificity and diagnostic accuracy of thin-section contrast-enhanced CT findings

    International Nuclear Information System (INIS)

    Lee, Ji Yon; Choi, Dong Il; Park, Hae Won; Lee, Young Rae; Kook, Shin Ho; Kwang, Hyon Joo; Kim, Seung Kwon; Chung, Eun Chul

    2002-01-01

    To assess the sensitivity, specificity, and diagnostic accuracy of individual contrast-enhanced helical CT findings of acute appendicitis. We retrospectively reviewed the appendiceal helical CT scans, obtained after intravenous contrast administration (abdomen; 7-mm collimation, abdominopelvic junction; 5-mm collimation), of 50 patients with surgically proven acute appendicitis and 112 with alternative diagnoses. The following parameters were analysed by three radiologists: enlarged appendix (>6 mm in diameter), appendiceal wall thickening, appendiceal wall enhancement, no identification of the appendix, appendicolith(s), (appendiceal) intraluminal air, abscess, lymphadenopathy, terminal ileal wall thickening, focal cecal apical thickening, focal colonic wall thickening, and segmental colonic wall thickening. The CT findings of acute appendicitis that statistically distinguished it from alternative diagnoses were an enlarged appendix (sensitivity; 92%, specificity; 93%, diagnostic accuracy; 93%), appendiceal wall thickening (for these three parameters: 68%, 96% and 88%, respectively), periappendiceal fat stranding (90%, 79%, 82%), appendiceal wall enhancement (72%, 86%, 82%), appendicolith (16%, 100%, 74%), and focal cecal apical thickening (14%, 100%, 74%) (for each, p<0305). On thin-section contrast-enhanced helical CT, an enlarged appendix and periappendiceal fat stranding were found in 90% or more patients with acute appendicitis. Appendiceal wall thickening and enhancement were alearly demonstrated and significant findings for diagnosis. Less common but specific findings include appendicolith, focal cecal apical thickening and intramural air, can also help us establish a diagnosis of acute appendicitis

  15. Adaptive statistical iterative reconstruction technology in the application of PET/CT whole body scans

    International Nuclear Information System (INIS)

    Xin Jun; Zhao Zhoushe; Li Hong; Lu Zhe; Wu Wenkai; Guo Qiyong

    2013-01-01

    Objective: To improve image quality of low dose CT in whole body PET/CT using adaptive statistical iterative reconstruction (ASiR) technology. Methods: Twice CT scans were performed with GE water model,scan parameters were: 120 kV, 120 and 300 mA respectively. In addition, 30 subjects treated with PET/CT were selected randomly, whole body PET/CT were performed after 18 F-FDG injection of 3.70 MBq/kg, Sharp IR+time of flight + VUE Point HD technology were used for 1.5 min/bed in PET; CT of spiral scan was performed under 120 kV using automatic exposure control technology (30-210 mA, noise index 25). Model and patients whole body CT images were reconstructed with conventional and 40% ASiR methods respectively, and the CT attenuation value and noise index were measured. Results: Research of model and clinical showed that standard deviation of ASiR method in model CT was 33.0% lower than the conventional CT reconstruction method (t =27.76, P<0.01), standard deviation of CT in normal tissues (brain, lung, mediastinum, liver and vertebral body) and lesions (brain, lung, mediastinum, liver and vertebral body) reduced by 21.08% (t =23.35, P<0.01) and 24.43% (t =16.15, P<0.01) respectively, especially for normal liver tissue and liver lesions, standard deviations of CT were reduced by 51.33% (t=34.21, P<0.0) and 49.54% (t=15.21, P<0.01) respectively. Conclusion: ASiR reconstruction method was significantly reduced the noise of low dose CT image and improved the quality of CT image in whole body PET/CT, which seems more suitable for quantitative analysis and clinical applications. (authors)

  16. Evaluation of diagnostic quality in musculoskeletal three-dimensional CT scans

    International Nuclear Information System (INIS)

    Vannier, M.W.; Hildebolt, C.F.; Gilula, L.A.; Sutherland, C.J.; Offutt, C.J.; Drebin, R.; Mantle, M.; Giordono, T.A.

    1988-01-01

    A major application of three-dimensional computed tomography (CT) is in the imaging of the skeleton. Three-dimensional CT has an important role in determining the presence and extent of congenital and acquired orthopedic abnormalities. The objective of this study was to compare the diagnostic sensitivity and specificity of three-dimensional CT, planar CT, and plain radiography in the detection and characterization of orthopedic abnormalities. Three-dimensional CT scan reconstructions were obtained by two methods, surface reconstruction and volumetric techniques. Seventy patients were imaged with CT, three-dimensional CT, and plain radiography. The consensus opinion of experts with access to all images plus clinical history, surgical findings, and follow-up findings were taken as truth. Expert radiologists read these cases in a blinded fashion. The results were compared using receiver operating characteristic (ROC) analysis. The diagnostic value of each three-dimensional reconstruction method and the parameters used to perform the reconstructions were evaluated

  17. CT diagnosis of occipital bone pacchionian depression

    International Nuclear Information System (INIS)

    Zhu Jianguo; Xu Xiaolin

    2004-01-01

    Objective: To improve the recognition of the CT findings of occipital bone pacchionian depression, in order to avoid misdiagnosis. Methods: occipital bone pacchionian depression underwent CT with plain scan and intravenous contrast enhancement in 11 cases, and then the CT findings were analyzed. Results: Occipital bone pacchionian depression situated beside the torcular herophilia in 11 cases. The depression or bone defect were found at occipital bone inner plate, they can reach diploe or outer plate and had no enhancement after contrast injection. Conclusions: CT scans play an important role in diagnosis and differential diagnosis of occipital bone pacchionian depression

  18. Malignant pleural mesothelioma with heterologous osteoblastic differentiation: case report of the characteristic CT and bone scan findings

    International Nuclear Information System (INIS)

    Cho, Young Jun; Kim, Joung Sook; Kim, Ji Young; Choi, Soo Jeon; Choi, Sang Bong

    2008-01-01

    Malignant pleural mesothelioma is an uncommon neoplasm which is accompanied extremely rarely by osteoblastic heterologous elements. The CT manifestations of this tumor have been reported in several references. And, to our knowledge, only one case report provides a description of the bone scan findings. Here, we report the case of a rapidly progressing malignant pleural mesothelioma with heterologous osteoblastic elements. A CT scan reveals diffuse irregular pleural thickening and very coarse nodular calcifications along the right pleura and major fissure. A bone scan revealed an area of extensive increased radioactivity consistent with the pleural calcifications on the CT scan in the right hemithorax. A follow-up CT scan performed 40 days later suggests the presence of rapidly progressing nodular coarse calcifications

  19. Malignant pleural mesothelioma with heterologous osteoblastic differentiation: case report of the characteristic CT and bone scan findings

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Young Jun; Kim, Joung Sook; Kim, Ji Young; Choi, Soo Jeon; Choi, Sang Bong [Sanggye Paik Hospital, Inje University College of Medicine, Seoul (Korea, Republic of)

    2008-06-15

    Malignant pleural mesothelioma is an uncommon neoplasm which is accompanied extremely rarely by osteoblastic heterologous elements. The CT manifestations of this tumor have been reported in several references. And, to our knowledge, only one case report provides a description of the bone scan findings. Here, we report the case of a rapidly progressing malignant pleural mesothelioma with heterologous osteoblastic elements. A CT scan reveals diffuse irregular pleural thickening and very coarse nodular calcifications along the right pleura and major fissure. A bone scan revealed an area of extensive increased radioactivity consistent with the pleural calcifications on the CT scan in the right hemithorax. A follow-up CT scan performed 40 days later suggests the presence of rapidly progressing nodular coarse calcifications.

  20. Choice ofoptimal phase for liver angiography and multi-phase scanning with multi-slice spiral CT

    International Nuclear Information System (INIS)

    Fang Hong; Song Yunlong; Bi Yongmin; Wang Dong; Shi Huiping; Zhang Wanshi; Zhu Hongxian; Yang Hua; Ji Xudong; Fan Hongxia

    2008-01-01

    Objective: To evaluate the efficacy of test bolus technique with multi-slice spiral CT (MSCT) for determining the optimal scan delay time in CT Hepatic artery (HA)-portal vein (PV) angiography and multi-phase scanning. Methods: MSCT liver angiography and multi-phase scanning were performed in 187 patients divided randomly into two groups. In group A (n=59), the scan delay time was set according to the subjective experiences of operators; in group B (n=128), the scan delay time was determined by test bolus technique. Abdominal aorta and superior mesenteric, vein were selected as target blood vessels, and 50 HU was set as enhancement threshold value. 20 ml contrast agent was injected intravenously and time-density curve of target blood vessels were obtained, then HA-PV scanning delay time were calculated respectively. The quality of CTA images obtained by using these 2 methods were compared and statistically analysed using Chi-square criterion. Results: For hepatic artery phase, the images of group A are: excellent in 34 (58%), good in 17 (29%), and poor in 8 (13%), while those of group B are excellent in 128(100%), good in 0(0%), and poor in 0(0%). For portal vein phase, the images of group A are: excellent in 23 (39%), good in 27 (46%), and poor in 9 (15%), while those of group B are excellent in 96 (75%), good in 28 (22%), and poor in 4 (3%) respectively. There was statistically significant difference between the ratios of image quality in group A and group B (χ 2 =14.97, 9.18, P< 0.05). Conclusion: Accurate scan delay time was best determined by using test bolus technique, which can improve the image quality of liver angiography and multi-phase scanning. (authors)

  1. Advantage of CT scan in muscular pathology. Personal cases and review of the literature

    International Nuclear Information System (INIS)

    Laroche, M.; Rousseau, H.; Mazieres, B.; Bonafe, A.; Joffre, F.; Arlet, J.

    1989-01-01

    The advantage of CT scans in muscular pathology is studied. The scan, in addition to the diagnosis of tumors and muscular abscesses, permits to differentiate primary myopathies from neurogenic atrophies: in the course of myopathies, the muscle volume is preserved and they appear as a hypodensity; in neurogenic atrophies, the muscle volume is reduced with preserved density. The CT scan permits to determine the extension of these lesions. In the course of polymyositis, certain forms of rheumatid arthritis, the scan discloses a trabecular and 'worm-eaten' aspect of the muscles. This is also observed after long-term steroid therapy and other endocrine diseases (hyperthyroidism, osteomalacia) indicating an infra-clinical myopathy. In vertebral osteoporosis with fractures and patients with chronic lumbalgia, very ofter, an atrophy of the spinal muscle is observed. Finally, in the course of acquired kyphosis of the adult patient (camptocormia), the CT scan suggest an isolated myopathy, with late manifestations, of the paravertebral muscles [fr

  2. Advantage of CT scan in muscular pathology. Personal cases and review of the literature

    Energy Technology Data Exchange (ETDEWEB)

    Laroche, M.; Rousseau, H.; Mazieres, B.; Bonafe, A.; Joffre, F.; Arlet, J.

    1989-05-01

    The advantage of CT scans in muscular pathology is studied. The scan, in addition to the diagnosis of tumors and muscular abscesses, permits to differentiate primary myopathies from neurogenic atrophies: in the course of myopathies, the muscle volume is preserved and they appear as a hypodensity; in neurogenic atrophies, the muscle volume is reduced with preserved density. The CT scan permits to determine the extension of these lesions. In the course of polymyositis, certain forms of rheumatid arthritis, the scan discloses a trabecular and 'worm-eaten' aspect of the muscles. This is also observed after long-term steroid therapy and other endocrine diseases (hyperthyroidism, osteomalacia) indicating an infra-clinical myopathy. In vertebral osteoporosis with fractures and patients with chronic lumbalgia, very ofter, an atrophy of the spinal muscle is observed. Finally, in the course of acquired kyphosis of the adult patient (camptocormia), the CT scan suggest an isolated myopathy, with late manifestations, of the paravertebral muscles.

  3. Short- and long-term effects of clinical audits on compliance with procedures in CT scanning

    International Nuclear Information System (INIS)

    Oliveri, Antonio; Howarth, Nigel; Gevenois, Pierre Alain; Tack, Denis

    2016-01-01

    To test the hypothesis that quality clinical audits improve compliance with the procedures in computed tomography (CT) scanning. This retrospective study was conducted in two hospitals, based on 6950 examinations and four procedures, focusing on the acquisition length in lumbar spine CT, the default tube current applied in abdominal un-enhanced CT, the tube potential selection for portal phase abdominal CT and the use of a specific ''paediatric brain CT'' procedure. The first clinical audit reported compliance with these procedures. After presenting the results to the stakeholders, a second audit was conducted to measure the impact of this information on compliance and was repeated the next year. Comparisons of proportions were performed using the Chi-square Pearson test. Depending on the procedure, the compliance rate ranged from 27 to 88 % during the first audit. After presentation of the audit results to the stakeholders, the compliance rate ranged from 68 to 93 % and was significantly improved for all procedures (P ranging from <0.001 to 0.031) in both hospitals and remained unchanged during the third audit (P ranging from 0.114 to 0.999). Quality improvement through repeated compliance audits with CT procedures durably improves this compliance. (orig.)

  4. Triphasic contrast enhanced CT simulation with bolus tracking for pancreas SBRT target delineation.

    Science.gov (United States)

    Godfrey, Devon J; Patel, Bhavik N; Adamson, Justus D; Subashi, Ergys; Salama, Joseph K; Palta, Manisha

    Bolus-tracked multiphasic contrast computed tomography (CT) is often used in diagnostic radiology to enhance the visibility of pancreas tumors, but is uncommon in radiation therapy pancreas CT simulation, and its impact on gross tumor volume (GTV) delineation is unknown. This study evaluates the lesion conspicuity and consistency of pancreas stereotactic body radiation therapy (SBRT) GTVs contoured in the different contrast phases of triphasic CT simulation scans. Triphasic, bolus-tracked planning CT simulation scans of 10 consecutive pancreas SBRT patients were acquired, yielding images of the pancreas during the late arterial (LA), portal venous (PV), and either the early arterial or delayed phase. GTVs were contoured on each phase by a gastrointestinal-specialized radiation oncologist and reviewed by a fellowship-trained abdominal radiologist who specializes in pancreatic imaging. The volumes of the registered GTVs, their overlap ratio, and the 3-dimensional margin expansions necessary for each GTV to fully encompass GTVs from the other phases were calculated. The contrast difference between tumor and normal pancreas was measured, and 2 radiation oncologists rank-ordered the phases according to their value for the lesion-contouring task. Tumor-to-pancreas enhancement was on average much larger for the LA and PV than the delayed phase or early arterial phases; the LA and PV phases were also consistently preferred by the radiation oncologists. Enhancement differences among the phases resulted in highly variable GTV volumes with no observed trends. Overlap ratios ranged from 18% to 75% across all 3 phases, improving to 43% to 91% when considering only the preferred LA and PV phases. GTV expansions necessary to encompass all GTVs ranged from 0.3 to 1.8 cm for all 3 phases, improving slightly to 0.1 to 1.4 cm when considering just the LA and PV phases. For pancreas SBRT, we recommend combining the GTVs from a multiphasic CT simulation with bolus-tracking, including

  5. Estimation of enhanced cancer risk with 18FDG PET/CT investigations

    International Nuclear Information System (INIS)

    Kaushik, Aruna; Mishra, Anil K.; Sharma, Rajnish; Mondal, Anupam; Dwarakanath, B.S.

    2014-01-01

    18 F-Fluorodeoxyglucose ( 18 FDG) Positron Emission Tomography/Computed Tomography (PET/CT) investigation involves internal administration of 18 FDG and use of CT X-rays for the purpose of obtaining functional and anatomical information of a patient. However, the radiation exposure from undergoing PET/CT investigation may enhance the risk of cancer incidence as per the Linear-No-Threshold (LNT) model. The objective of the present study was to quantify the risk of cancer incidence associated with radiation exposure from 18 FDG PET/CT investigations. The organ doses from internally administered 18 FDG were estimated using OLINDA/EXM Code by performing dynamic PET scans in different regions of the body in a total of forty-nine patients. Organ doses from the CT component were calculated using the software CT-Expo. The associated cancer risk was calculated in terms of life time risk of cancer incidence resulting from a specified dose of ionizing radiation and was expressed in terms of Lifetime Attributable Risk (LAR). LAR values and the organ doses estimated for males and females were used to estimate the lifetime risk of cancer incidence from whole body 18 FDG PET/CT scan. Since from 18 FDG whole body PET/CT investigations, various tissues of the body receive substantially different doses, the site specific risk of cancer incidence was estimated and summed to obtain the total risk. This was compared with the baseline lifetime risk of cancer incidence in Indian population. LAR of cancer incidence was observed to be relatively higher in females as compared to males. The risk estimates ranged from 0.36% to 0.49% for a 20 year old male and 0.58% to 0.79% for a 20 year old female and were observed to be higher in younger ages and decreased with age. 18 FDG whole body PET/CT investigation was observed to be associated with non-negligible radiation risk as compared to the risks associated with other diagnostic modalities. (author)

  6. Two methods for isolating the lung area of a CT scan for density information

    International Nuclear Information System (INIS)

    Hedlund, L.W.; Anderson, R.F.; Goulding, P.L.; Beck, J.W.; Effmann, E.L.; Putman, C.E.

    1982-01-01

    Extracting density information from irregularly shaped tissue areas of CT scans requires automated methods when many scans are involved. We describe two computer methods that automatically isolate the lung area of a CT scan. Each starts from a single, operator specified point in the lung. The first method follows the steep density gradient boundary between lung and adjacent tissues; this tracking method is useful for estimating the overall density and total area of lung in a scan because all pixels within the lung area are available for statistical sampling. The second method finds all contiguous pixels of lung that are within the CT number range of air to water and are not a part of strong density gradient edges; this method is useful for estimating density and area of the lung parenchyma. Structures within the lung area that are surrounded by strong density gradient edges, such as large blood vessels, airways and nodules, are excluded from the lung sample while lung areas with diffuse borders, such as an area of mild or moderate edema, are retained. Both methods were tested on scans from an animal model of pulmonary edema and were found to be effective in isolating normal and diseased lungs. These methods are also suitable for isolating other organ areas of CT scans that are bounded by density gradient edges

  7. Repeat CT-scan assessment of lymph node motion in locally advanced cervical cancer patients

    International Nuclear Information System (INIS)

    Bondar, Luiza; Velema, Laura; Mens, Jan Willem; Heijmen, Ben; Hoogeman, Mischa; Zwijnenburg, Ellen

    2014-01-01

    In cervical cancer patients the nodal clinical target volume (CTV, defined using the major pelvic blood vessels and enlarged lymph nodes) is assumed to move synchronously with the bony anatomy. The aim of this study was to verify this assumption by investigating the motion of the major pelvic blood vessels and enlarged lymph nodes visible in CT scans. For 13 patients treated in prone position, four variable bladder-filling CT scans per patient, acquired at planning and after 40 Gy, were selected from an available dataset of 9-10 CT scans. The bladder, rectum, and the nodal-vessels structure containing the iliac vessels and all visible enlarged nodes were delineated in each selected CT scan. Two online patient setup correction protocols were simulated. The first corrected bony anatomy translations and the second corrected translations and rotations. The efficacy of each correction was calculated as the overlap between the nodal-vessels structure in the reference and repeat CT scans. The motion magnitude between delineated structures was quantified using nonrigid registration. Translational corrections resulted in an average overlap of 58 ± 13% and in a range of motion between 9.9 and 27.3 mm. Translational and rotational corrections significantly improved the overlap (64 ± 13%, p value = 0.007) and moderately reduced the range of motion to 7.6-23.8 mm (p value = 0.03). Bladder filling changes significantly correlated with the nodal-vessels motion (p [de

  8. Examination of CT-AEC when the positioning changes after planning of CT scanning

    International Nuclear Information System (INIS)

    Esaki, Tooru; Yamazaki, Shoichi

    2009-01-01

    CT-automatic exposure control (AEC) controls tube current collecting information of the subject from positioning shooting. Because of this, we consider that CT-AEC does not get to operate properly if the body position of the test subject changes after the positioning shooting. However, we often experience in body positions of test subjects after the positioning shooting. In cases like this, we measured by using a phantom again to see how they affect the tube current value and standard deviation (SD) value comparing them to the normal scan where a body position does not change. As a result of the measurement, there was an impact on CT-AEC that optimization of tube current becomes insufficient if the body position of a test subject changes. As the image quality is deteriorated and radiation exposure increases because of this, taking positioning shooting again is required on the part of users and it's desirable on the part of manufacturers to develop CT-AEC that can be controlled with high accuracy. (author)

  9. Eye lens radiation exposure and repeated head CT scans: A problem to keep in mind

    International Nuclear Information System (INIS)

    Michel, Morgane; Jacob, Sophie; Roger, Gilles; Pelosse, Béatrice; Laurier, Dominique; Le Pointe, Hubert Ducou; Bernier, Marie-Odile

    2012-01-01

    Objectives: The deterministic character of radiation-induced cataract is being called into question, raising the possibility of a risk in patients, especially children, exposed to ionizing radiation in case of repeated head CT-scans. This study aims to estimate the eye lens doses of a pediatric population exposed to repeated head CTs and to assess the feasibility of an epidemiological study. Methods: Children treated for a cholesteatoma, who had had at least one CT-scan of the middle ear before their tenth birthday, were included. Radiation exposure has been assessed from medical records and telephone interviews. Results: Out of the 39 subjects contacted, 32 accepted to participate. A total of 76 CT-scans were retrieved from medical records. At the time of the interview (mean age: 16 years), the mean number of CT per child was 3. Cumulative mean effective and eye lens doses were 1.7 mSv and 168 mGy, respectively. Conclusion: A relatively high lens radiation dose was observed in children exposed to repeated CT-scans. Due to that exposure and despite the difficulties met when trying to reach patients’ families, a large scale epidemiological study should be performed in order to assess the risk of radiation-induced cataracts associated with repeated head CT.

  10. Study on CT scanning technique of inferior horn of lateral ventricle

    International Nuclear Information System (INIS)

    Kakoi, Iwao; Okubo, Mitsuo; Nakamura, Sumio; Yoshinaga, Toshihiko; Shimono, Tetsuo

    1984-01-01

    It is said that temporal lobe epilepsy (TLE), one of the incurable epilepsies, results from the lesions of various structrues located in the medial and deep portion of the temporal lobe such as the hippocampus and amygdaloid nucleus. Routine CT scanning techniques cannot adequately delineate these structures in the assessment of TLE. The anatomical relationship between these medial temporal structures and the inferior horn of lateral ventricle which is lateral to them and easily identified by CT lead us to believe that the sections through the longitudinal plane of the inferior horn may clearly delineate them. The present experimental study was undertaken to develop the CT scan technique of the inferior horn of lateral ventricle, which results in the clear delineation of the region of the hippocampus and amygdaloid nucleus. As a result, A total of the 3-4 reversed axial 5 mm-thick section centered at 2.5 cm cephalad to the roof of the external auditory canal at a reversed 25 0 angle to ABL are adequate to delineate the inferior horn and the medial temporal structures. This scan technique is considered to be useful in the assessment of TLE. (author)

  11. Short- and long-term effects of clinical audits on compliance with procedures in CT scanning.

    Science.gov (United States)

    Oliveri, Antonio; Howarth, Nigel; Gevenois, Pierre Alain; Tack, Denis

    2016-08-01

    To test the hypothesis that quality clinical audits improve compliance with the procedures in computed tomography (CT) scanning. This retrospective study was conducted in two hospitals, based on 6950 examinations and four procedures, focusing on the acquisition length in lumbar spine CT, the default tube current applied in abdominal un-enhanced CT, the tube potential selection for portal phase abdominal CT and the use of a specific "paediatric brain CT" procedure. The first clinical audit reported compliance with these procedures. After presenting the results to the stakeholders, a second audit was conducted to measure the impact of this information on compliance and was repeated the next year. Comparisons of proportions were performed using the Chi-square Pearson test. Depending on the procedure, the compliance rate ranged from 27 to 88 % during the first audit. After presentation of the audit results to the stakeholders, the compliance rate ranged from 68 to 93 % and was significantly improved for all procedures (P ranging from audit (P ranging from 0.114 to 0.999). Quality improvement through repeated compliance audits with CT procedures durably improves this compliance. • Compliance with CT procedures is operator-dependent and not perfect. • Compliance differs between procedures and hospitals, even within a unified department. • Compliance is improved through audits followed by communication to the stakeholders. • This improvement is sustainable over a one-year period.

  12. CT findings of tuberculous lymphadenifis in parotid gland

    International Nuclear Information System (INIS)

    Wang Changfu; Wang Binjie; Zhang Heping; Jin Haiying; Nie Peng; Chang Liang; Wei Haigang; Zou Ling

    2008-01-01

    Objective: To analyze the CT findings of tuberculous lymphadenitis in parotid gland, so as to improve the diagnostic accuracy of tuberculosis of parotid gland. Methods: Nine cases with tuberculous lymphadenitis in parotid gland confirmed by surgical pathology and acid-fast bacilli after preoperative spiral CT plain scan and two phases dynamic enhancement scan were retrospectively analyzed. Imaging findings of CT were reviewed and compared with surgical pathology. Results: Seven of the 9 cases of tuberculosis of the parotid gland occurred in the left side, and 2 in the right side, and superficial lobe involvement occurred in 8 cases and deep lobe in 1 case. The lesion was classified as tumour type (8 cases) and infiltration type (1 case). In turnout type, the number of lesion was from 1 to 4, and the size was from 2.7 to 5.3 cm in diameter. One case of infiltration type measured 3.4 cm in diameter. On CT plain scan, the lesions showed homogeneous slight high-density with regular edge in 5 cases and irregular low-density in 4 cases, and 2 of them with partly blurred edge. On CT enhanced scan, uniform moderate enhancement was seen in 3 cases, circular enhancement in 4 cases, inhomogeneous enhancement in 1 case, and lace-like enhancement in 1 case. Local infiltration occurred in 6 cases. Lymphadenovarix in the same side of lesion occurred in 2 cases. Conclusion: CT findings of tuberculous lymphadenitis in parotid gland present diversification, which correlate well with pathological changes. Understanding of characteristic CT findings of tuberculous lymphadenitis in parotid gland is helpful for differential diagnosis, but final diagnosis still depends on pathology and acid-fast bacilli. (authors)

  13. Intrathoracic kidney. Diagnostic value of CT scan imaging

    International Nuclear Information System (INIS)

    Baillet, A.M.; Escure, M.N.

    1988-01-01

    Two cases are reported of an ectopic right kidney that was partially intrathoracic in position. Diagnosis was simple from CT scan imaging appearances, the examination being performed to investigate an intrathoracic mass. Images showed a tissular mass within a fatty zone in sections without contrast and the typical appearance of the kidney on sections with contrast [fr

  14. Initial staging of Hodgkin's disease: role of contrast-enhanced 18F FDG PET/CT.

    Science.gov (United States)

    Chiaravalloti, Agostino; Danieli, Roberta; Caracciolo, Cristiana Ragano; Travascio, Laura; Cantonetti, Maria; Gallamini, Andrea; Guazzaroni, Manlio; Orlacchio, Antonio; Simonetti, Giovanni; Schillaci, Orazio

    2014-08-01

    The objective of this study was to compare the diagnostic accuracy of positron emission tomography/low-dose computed tomography (PET/ldCT) versus the same technique implemented by contrast-enhanced computed tomography (ceCT) in staging Hodgkin's disease (HD).Forty patients (18 men and 22 women, mean age 30 ± 9.6) with biopsy-proven HD underwent a PET/ldCT study for initial staging including an unenhanced low-dose computed tomography for attenuation correction with positron emission tomography acquisition and a ceCT, performed at the end of the PET/ldCT scan, in the same exam session. A detailed datasheet was generated for illness locations for separate imaging modality comparison and then merged in order to compare the separate imaging method results (PET/ldCT and ceCT) versus merged results positron emission tomography/contrast-enhanced computed tomography (PET/ceCT). The nodal and extranodal lesions detected by each technique were then compared with follow-up data that served as the reference standard.No significant differences were found at staging between PET/ldCT and PET/ceCT in our series. One hundred and eighty four stations of nodal involvement have been found with no differences in both modalities. Extranodal involvement was identified in 26 sites by PET/ldCT and in 28 by PET/ceCT. We did not find significant differences concerning the stage (Ann Arbor).Our study shows a good concordance and conjunction between PET/ldCT and ceCT in both nodal and extranodal sites in the initial staging of HD, suggesting that PET/ldCT could suffice in most of these patients.

  15. Study of CT head scans using different voltages: image quality evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Pacheco de Freitas C, I.; Prata M, A. [Centro Federal de Educacao Tecnologica de Minas Gerais, Centro de Engenharia Biomedica, Av. Amazonas 5253, 30421-169 Nova Suica, Belo Horizonte, Minas Gerais (Brazil); Alonso, T. C. [Centro de Desenvolvimento da Tecnologia Nuclear / CNEN, Av. Pte. Antonio Carlos 6627, 31270-901 Pampulha, Belo Horizonte, Minas Gerais (Brazil); Santana, P., E-mail: iarapfcorrea@gmail.com [Universidade Federal de Minas Gerais, Departamento de Anatomia e Imagem, Av. Prof. Alfredo Balena 190, 30130-100 Belo Horizonte, Minas Gerais (Brazil)

    2016-10-15

    Computed tomography (CT) was introduced to medical practice in 1972. It generates images recognized by high diagnostic potential. CT allows investigation of structures in the human body inaccessible by conventional image methods, replacing invasive methods in many cases. Noise is a kind of variation of brightness observed on CT images, and it is inherent to this method. The magnitude of the noise is determined by the standard deviation of CT numbers of a region of interest in a homogeneous material. The aim of this study is to analyze the noise in head CT images generated by different acquisition protocols using four voltage values. Five different scans were performed using a female Alderson phantom and their images were analyzed with the RadiAnt software. With the average HU values and standard deviation of each scan, the values of noise were calculated in some region of interest. The obtained noise values were compared and it was observed that the 140 kV voltage promotes the in the lower noise in the image, resulting in better image quality. The results also show that the parameters, such as voltage and current, can be adjusted so that the noise can be decreased. Thus, acquisition protocols may be adapted to produce images with diagnostic quality and lower doses in patient. (Author)

  16. Study of CT head scans using different voltages: image quality evaluation

    International Nuclear Information System (INIS)

    Pacheco de Freitas C, I.; Prata M, A.; Alonso, T. C.; Santana, P.

    2016-10-01

    Computed tomography (CT) was introduced to medical practice in 1972. It generates images recognized by high diagnostic potential. CT allows investigation of structures in the human body inaccessible by conventional image methods, replacing invasive methods in many cases. Noise is a kind of variation of brightness observed on CT images, and it is inherent to this method. The magnitude of the noise is determined by the standard deviation of CT numbers of a region of interest in a homogeneous material. The aim of this study is to analyze the noise in head CT images generated by different acquisition protocols using four voltage values. Five different scans were performed using a female Alderson phantom and their images were analyzed with the RadiAnt software. With the average HU values and standard deviation of each scan, the values of noise were calculated in some region of interest. The obtained noise values were compared and it was observed that the 140 kV voltage promotes the in the lower noise in the image, resulting in better image quality. The results also show that the parameters, such as voltage and current, can be adjusted so that the noise can be decreased. Thus, acquisition protocols may be adapted to produce images with diagnostic quality and lower doses in patient. (Author)

  17. The value of precontrast thoraco-abdominopelvic CT in polytrauma patients

    Energy Technology Data Exchange (ETDEWEB)

    Esposito, A.A., E-mail: rxandreaesposito@yahoo.it [Department of Radiology, Foundation IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Via Francesco Sforza 35, 20121 Milan (Italy); Zilocchi, M., E-mail: massimo.zilocchi@gmail.com [Department of Radiology, Foundation IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Via Francesco Sforza 35, 20121 Milan (Italy); Fasani, P., E-mail: fasapier65@gmail.com [Department of Radiology, Foundation IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Via Francesco Sforza 35, 20121 Milan (Italy); Giannitto, C., E-mail: caterina.giannitto@gmail.com [School of Radiology, University of Milan, Via A. di Rudinì 8, Milan (Italy); Maccagnoni, S., E-mail: maccagnnisara@libero.it [School of Radiology, University of Milan, Via A. di Rudinì 8, Milan (Italy); Maniglio, M., E-mail: marinamaniglio@gmail.com [School of Radiology, University of Milan, Via A. di Rudinì 8, Milan (Italy); Campoleoni, M., E-mail: campoleoni@policlinico.mi.it [Medical Phisic Unit, Foundation IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Via Francesco Sforza, 35, 20121 Milan (Italy); Brambilla, R., E-mail: roberto.brambilla@policlinico.mi.it [Medical Phisic Unit, Foundation IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Via Francesco Sforza, 35, 20121 Milan (Italy); Casiraghi, E., E-mail: casiraghi@di.unimi.it [Computer Science Department, University of Milan, Via Comelico 39, Milan (Italy); Biondetti, P.R., E-mail: pibionde@tin.it [Department of Radiology, Foundation IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Via Francesco Sforza 35, 20121 Milan (Italy)

    2015-06-15

    Highlights: • We evaluated the additional value of precontrast CT in polytrauma patient. • We evaluated the radiation dose CT in polytrauma patient. • Precontrast CT scan does not have an additional value in polytrauma patient. • Precontrast CT expose patient to an unjustified radiation dose. - Abstract: Purpose: To evaluate the utility and radiation dose of thoraco-abdominopelvic precontrast CT in polytrauma patients. Materials and methods: We examined retrospectively 125 patients who underwent a thoraco-abdominopelvic CT for trauma. Two radiologists, independently, evaluated precontrast CT acquisition and two other radiologists examined the contrast-enhanced scans. A further two radiologists assessed both the acquisitions. Mean value of sensitivity (SE), specificity (SP), positive predictive value (PPV) and negative predictive value (NPV) were calculated by each group of radiologists. For 104 patients, CTDIvol, DLP data and individual mean size were collected to calculate effective dose. Results: Mean values of SE, SP, PPV and NPV of findings of radiologists who assessed contrast-enhanced acquisitions were respectively: SE = 85%, SP = 98%, PPV = 86%, NPV = 88% versus: SE = 43%, SP = 95%, PPV = 69%, NPV = 88% of radiologists who examined non-contrast-enhanced scans. Mean values of radiologists who analyzed both acquisitions were: SE = 80%, SP = 97%, PPV = 80%, NPV = 88%. Neither the precontrast scans nor the precontrast and postcontrast scans together provided additional useful information compared to the single contrast-enhanced acquisition. Patients received a mean dose of 12 mSv for the precontrast CT. Conclusions: Precontrast CT acquisition did not provide significant information in trauma patients, exposing them to an unjustified radiation dose.

  18. The value of precontrast thoraco-abdominopelvic CT in polytrauma patients

    International Nuclear Information System (INIS)

    Esposito, A.A.; Zilocchi, M.; Fasani, P.; Giannitto, C.; Maccagnoni, S.; Maniglio, M.; Campoleoni, M.; Brambilla, R.; Casiraghi, E.; Biondetti, P.R.

    2015-01-01

    Highlights: • We evaluated the additional value of precontrast CT in polytrauma patient. • We evaluated the radiation dose CT in polytrauma patient. • Precontrast CT scan does not have an additional value in polytrauma patient. • Precontrast CT expose patient to an unjustified radiation dose. - Abstract: Purpose: To evaluate the utility and radiation dose of thoraco-abdominopelvic precontrast CT in polytrauma patients. Materials and methods: We examined retrospectively 125 patients who underwent a thoraco-abdominopelvic CT for trauma. Two radiologists, independently, evaluated precontrast CT acquisition and two other radiologists examined the contrast-enhanced scans. A further two radiologists assessed both the acquisitions. Mean value of sensitivity (SE), specificity (SP), positive predictive value (PPV) and negative predictive value (NPV) were calculated by each group of radiologists. For 104 patients, CTDIvol, DLP data and individual mean size were collected to calculate effective dose. Results: Mean values of SE, SP, PPV and NPV of findings of radiologists who assessed contrast-enhanced acquisitions were respectively: SE = 85%, SP = 98%, PPV = 86%, NPV = 88% versus: SE = 43%, SP = 95%, PPV = 69%, NPV = 88% of radiologists who examined non-contrast-enhanced scans. Mean values of radiologists who analyzed both acquisitions were: SE = 80%, SP = 97%, PPV = 80%, NPV = 88%. Neither the precontrast scans nor the precontrast and postcontrast scans together provided additional useful information compared to the single contrast-enhanced acquisition. Patients received a mean dose of 12 mSv for the precontrast CT. Conclusions: Precontrast CT acquisition did not provide significant information in trauma patients, exposing them to an unjustified radiation dose

  19. Detection of skeletal muscle metastasis: torso FDG PET-CT versus contrast-enhanced chest or abdomen CT.

    Science.gov (United States)

    So, Young; Yi, Jeong Geun; Song, Inyoung; Lee, Won Woo; Chung, Hyun Woo; Park, Jeong Hee; Moon, Sung Gyu

    2015-07-01

    Skeletal muscle metastasis (SMM) in cancer patients has not been sufficiently evaluated regarding prevalence and proper method of detection. To determine the prevalence of SMM and compare the diagnostic competencies for SMM of torso F-18 fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET-CT) and contrast-enhanced chest or abdomen CT. We investigated 18,225 PET-CT studies of 6359 cancer patients performed from 2005 to 2012. The PET-CT studies describing potential SMM were retrieved and the corresponding medical records were reviewed. The gold standard for SMM was histopathologically-proven SMM or imaging study-based disease progression. The detectability of SMM was compared between PET-CT and contrast-enhanced CT. Twenty-six patients had 84 SMM lesions, representing a SMM prevalence of 0.41%. Lung cancer was the most common SMM-associated malignancy (54%) and the gluteal/pelvic girdle muscle was the most frequently involved SMM site (37%). All 84 SMM lesions were visualized on PET-CT (100%). Of these PET-CT positive 84 SMM lesions, 51 lesions were in the CT field of view (FOV) (61%), whereas 33 lesions were out of the CT FOV (39%). Among these 51 lesions, 17 lesions showed rim-enhancing nodules/masses (33%), eight lesions showed homogeneously enhancing nodules (16%), three lesions showed heterogeneously enhancing nodules (6%), and 23 SMM lesions (45%) were non-diagnostic by CT. All 51 SMM lesions within CT FOV were detected on PET-CT (100%), whereas only 28 were visualized on CT (54.9%), resulting in a significant difference (P SMM was revealed by PET-CT. The prevalence of SMM was as low as 0.41% in the current large cohort of cancer patients. Torso PET-CT was a more competent modality than contrast-enhanced CT in the detection of SMM. © The Foundation Acta Radiologica 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  20. Virtual planning of dental implant placement using CT double scan-technique - own experience

    International Nuclear Information System (INIS)

    Wojciechowski, W.; Urbanik, A.; Kownacki, P.; Kownacki, S.

    2007-01-01

    The correctness of CT performed with the use of a double-scan technique is the basis for achieving proper quality of 3D reconstructions of the maxilla or mandible and subsequent virtual planning of dental implant placement. The aim of this study was the presentation of the methodology of computed tomography scanning and own experience with the use of the double-scan technique. The study group included 26 individuals who underwent MDCT with a double-scan technique using a MDCT scanner SOMATOM Sensation (Siemens, Germany). The parameters of the examination: slice-collimation 10 x 0.75 mm, slice-thickness 0.75 mm. The first CT scan in the procedure was the scan of the patient wearing a radiological prosthesis and occlusal index, which was followed by a separate scan of the radiological prosthesis. These two CT scans were copied and transferred to PC with Procera Software program (Nobel Biocare, Sweden) where dental implant placement was virtually planned. In all 26 patients, precise three-dimensional reconstructions of the anatomical structure were obtained. In 11 patients, on the basis of the virtual planning, the implant placement was performed, 5 patients were referred to preparatory procedures, that is, restoration of the alveolar process, otolaryngological treatment of the maxillary sinuses. The remaining 10 patients did not qualify to the procedure because of unfavorable anatomical ideation's. Correct computed tomography with double-scan technique enables virtual planning of dental implant placement, on the basis of which the real procedure of implantation can be performed. (author)

  1. CT scanning in Australia: a report by the National Health Technology Advisory Panel

    International Nuclear Information System (INIS)

    1988-06-01

    An overview of trends in the usage of CT scanning in Australia is given and the areas of benefit and uncertainty associated with this technology are outlined. Numbers and distribution of CT units, costs of CT services, clinical applications, safety aspects and the effects of new developments are discussed. 54 refs., 5 figs., 18 tabs

  2. Application of low-dose radiation protocols in survey CT scans

    International Nuclear Information System (INIS)

    Fu Qiang; Liu Ting; Lu Tao; Xu Ke; Zhang Lin

    2009-01-01

    Objective: To characterize the protocols with low-dose radiation in survey CT scans for localization. Methods: Eighty standard adult patients, head and body phantoms were recruited. Default protocols provided by operator's manual setting were that all the tube voltage for head, chest, abdomen and lumbar was 120 kV; the tube currents were 20,10,20 and 40 mA, respectively. Values of kV and mA in the low-dose experiments were optimized according to the device options. For chest and abdomen, the tube position were compared between default (0 degree) and 180 degree. Phantoms were scanned with above protocols, and the radiation doses were measured respectively. Paired t-test were used for comparisons of standard deviation in CT value, noise and exposure surface dose (ESD) between group with default protocols and group with optimized protocols. Results: The optimized protocols in low-dose CT survey scans were 80 kV, 10 mA for head, 80 kV, 10 mA for chest, 80 kV, 10 mA for abdomen and 100 kV, 10 mA for lumbar. The values of ESD for phantom scan in default and optimized protocols were 0.38 mGy/0.16 mGy in head, 0.30 mGy/0.20 mGy in chest, 0.74 mGy/0.30 mGy in abdomen and 0.81 mGy/0.44 mGy in lumbar, respectively. Compared with default protocols, the optimized protocols reduced the radiation doses 59%, 33%, 59% and 46% in head, chest, abdomen and lumbar. When tube position changed from 0 degree to 180 degree, the ESD were 0.24 mGy/0.20 mGy for chest; 0.37 mGy/0.30 mGy for abdomen, and the radiation doses were reduced 20% and 17%. Conclusion: A certain amount of image noise is increased in low-dose protocols, but image quality is still acceptable without problem in CT localization. The reduction of radiation dose and the radiation harm to patients are the superiority. (authors)

  3. Fibroelastic pseudotumor elastofibroma dorsi detected by 18F-FDG PET/CT scan and by postherapy radioiodine SPECT/CT.

    Science.gov (United States)

    Oporto, M; Cepa, F; Orta, N; Rubí, S; Navalón, H; Peña, C

    Radioiodine uptake in the thyroid tissue, metastasis of differentiated thyroid cancer (DTC), and in other tissues, depends on the expression of sodium-iodide symporter (NIS). Vascular permeability, effusions, inflammation, and other mechanisms may also play a role in the accumulation of radioactive iodine. A 63-year-old woman underwent radioiodine therapy, as well as a post-therapy whole-body scan, as she was suspected of having lung metastasis from thyroid carcinoma. The scan not only showed uptake at the lung metastasis but also a faint diffuse bilateral uptake in the posterior thorax. On SPECT/CT this uptake was located in a known Elastofibroma Dorsi (ED) previously diagnosed by contrast CT and viewed in a FDG PET/CT. The radioiodine uptake in ED, especially if typical, is not a diagnostic problem in SPECT/CT study, but can be misleading in a study limited to a few planar images, particularly if the uptake occurs asymmetrically, or ED is located in a unsuspected area. Copyright © 2017 Elsevier España, S.L.U. y SEMNIM. All rights reserved.

  4. Radiation protection for the eyes of the children experiencing an operation of artificial cochlear implant against CT scan

    International Nuclear Information System (INIS)

    Liu Changsheng; Zheng Xiaohua; Li Maojing; Wei Wenzhou; Pan Ewu; Tang Guangqiao; Zhang Duanlian

    2006-01-01

    Objective: To optimize the CT scanning parameters in pediatric temporal bone examination with artificial cochlear implant and reduce its radiation hazards. Methods: The temporal bones of 87 patients with suspected inner ear disease which include 31 experienced artificial cochlear implant were scanned by HRCT. Regarding adult scan parameters as a criteria, properly adjusted the scanning dose and scanning angle until the quality of CT images was beyond the diagnosis demands. Finally the exposed doses, single scanning CT dose index weighted (CTDI w ) and dose length product (DLP) were analysed. Results: Compared with adult temporal bone scanning, the exposure value and CTDI w were reduced to 66.67%-83.33%, DLP of temporal bone scanning in pediatrics was reduced to 66.67%-83.33%, moreover, the imaging quality of tridimensional reconstruction for inner ear and implant electrode was improved. Conclusion: The proper reduction of CT scan exposure on preoperative and postoperative children with cochlear implants and the proper adjustment of scan angle can significantly reduce the exposure dose to local temporal bone and effectually avoid the damage to lens of children. (authors)

  5. Optimization of input parameters of supra-threshold stochastic resonance image processing algorithm for the detection of abdomino-pelvic tumors on PET/CT scan

    International Nuclear Information System (INIS)

    Pandey, Anil Kumar; Saroha, Kartik; Patel, C.D.; Bal, C.S.; Kumar, Rakesh

    2016-01-01

    Administration of diuretics increases the urine output to clear radioactive urine from kidneys and bladder. Hence post-diuretic pelvic PET/CT scan enhances the probability of detection of abdomino-pelvic tumor. However, it causes discomfort in patients and has some side effects also. Application of supra threshold stochastic resonance (SSR) image processing algorithm on Pre-diuretic PET/CT scan may also increase the probability of detection of these tumors. Amount of noise and threshold are two variable parameters that effect the final image quality. This study was conducted to investigate the effect of these two variable parameters on the detection of abdomen-pelvic tumor

  6. [Automated detection and volumetric segmentation of the spleen in CT scans].

    Science.gov (United States)

    Hammon, M; Dankerl, P; Kramer, M; Seifert, S; Tsymbal, A; Costa, M J; Janka, R; Uder, M; Cavallaro, A

    2012-08-01

    To introduce automated detection and volumetric segmentation of the spleen in spiral CT scans with the THESEUS-MEDICO software. The consistency between automated volumetry (aV), estimated volume determination (eV) and manual volume segmentation (mV) was evaluated. Retrospective evaluation of the CAD system based on methods like "marginal space learning" and "boosting algorithms". 3 consecutive spiral CT scans (thoraco-abdominal; portal-venous contrast agent phase; 1 or 5 mm slice thickness) of 15 consecutive lymphoma patients were included. The eV: 30 cm³ + 0.58 (width × length × thickness of the spleen) and the mV as the reference standard were determined by an experienced radiologist. The aV could be performed in all CT scans within 15.2 (± 2.4) seconds. The average splenic volume measured by aV was 268.21 ± 114.67 cm³ compared to 281.58 ± 130.21 cm³ in mV and 268.93 ± 104.60 cm³ in eV. The correlation coefficient was 0.99 (coefficient of determination (R²) = 0.98) for aV and mV, 0.91 (R² = 0.83) for mV and eV and 0.91 (R² = 0.82) for aV and eV. There was an almost perfect correlation of the changes in splenic volume measured with the new aV and mV (0.92; R² = 0.84), mV and eV (0.95; R² = 0.91) and aV and eV (0.83; R² = 0.69) between two time points. The automated detection and volumetric segmentation software rapidly provides an accurate measurement of the splenic volume in CT scans. Knowledge about splenic volume and its change between two examinations provides valuable clinical information without effort for the radiologist. © Georg Thieme Verlag KG Stuttgart · New York.

  7. Automated detection and volumetric segmentation of the spleen in CT scans

    International Nuclear Information System (INIS)

    Hammon, M.; Dankerl, P.; Janka, R.; Uder, M.; Cavallaro, A.; Kramer, M.; Seifert, S.; Tsymbal, A.; Costa, M.J.

    2012-01-01

    To introduce automated detection and volumetric segmentation of the spleen in spiral CT scans with the THESEUS-MEDICO software. The consistency between automated volumetry (aV), estimated volume determination (eV) and manual volume segmentation (mV) was evaluated. Retrospective evaluation of the CAD system based on methods like ''marginal space learning'' and ''boosting algorithms''. 3 consecutive spiral CT scans (thoraco-abdominal; portal-venous contrast agent phase; 1 or 5 mm slice thickness) of 15 consecutive lymphoma patients were included. The eV: 30 cm 3 + 0.58 (width x length x thickness of the spleen) and the mV as the reference standard were determined by an experienced radiologist. The aV could be performed in all CT scans within 15.2 (± 2.4) seconds. The average splenic volume measured by aV was 268.21 ± 114.67 cm 3 compared to 281.58 ± 130.21 cm 3 in mV and 268.93 ± 104.60 cm 3 in eV. The correlation coefficient was 0.99 (coefficient of determination (R 2 ) = 0.98) for aV and mV, 0.91 (R 2 = 0.83) for mV and eV and 0.91 (R 2 = 0.82) for aV and eV. There was an almost perfect correlation of the changes in splenic volume measured with the new aV and mV (0.92; R 2 = 0.84), mV and eV (0.95; R 2 = 0.91) and aV and eV (0.83; R 2 = 0.69) between two time points. The automated detection and volumetric segmentation software rapidly provides an accurate measurement of the splenic volume in CT scans. Knowledge about splenic volume and its change between two examinations provides valuable clinical information without effort for the radiologist. (orig.)

  8. Patterns of uterine enhancement with helical CT

    Energy Technology Data Exchange (ETDEWEB)

    Kaur, H.; Loyer, E.M.; Charnsangavej, C. [Department of Diagnostic Radiology, Box 57, The University of Texas, M.D. Anderson Cancer Center, 1515 Holcombe Blvd. Houston, TX 77030 (United States); Minami, M. [Department of Radiology, Faculty of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-Ku, Tokyo 113 (Japan)

    1998-10-01

    Objective: The purpose of this study was to evaluate the enhancement characteristics of the normal uterine body and cervix using dynamic contrast-enhanced helical CT. Methods: Thirty-eight women scheduled for pelvic CT for non-gynecologic malignancies underwent dynamic contrast-enhanced helical CT of the pelvis. Data acquisition was during the arterial phase (30-45 s after the start of injection), the parenchymal phase (90-120 s after the start of injection), and delayed phase (3-9 min after the start of injection). The images were evaluated by four radiologists for the pattern of myometrial and cervical enhancement. Correlation was made with the age and menstrual status of the patients. Results: In the uterine body, three types of enhancement were observed. Type 1 enhancement, seen in 16 patients (42%), was characterized by the visualization of a subendometrial zone of enhancement, 30-120 s after the start of injection. Eight of these patients also showed an enhancing zone in the outer myometrium. Both zones were transitory, and in all cases, the uterus became homogeneous in the delayed phase. This pattern was seen predominantly in premenopausal women with a mean age of 34 years. Type 2 enhancement, seen in 17 cases (45%), was defined by the absence of subendometrial enhancement in the early phase. Enhancement was either diffuse from the outset or originated in the outer myometrium. This pattern was seen nearly equally in premenopausal and postmenopausal women with a mean age of 40 years. Type 3 enhancement was seen in five postmenopausal patients (13%) with a mean age of 53 years and was characterized by faint diffuse enhancement. In the cervix, a zonal pattern of enhancement defining inner and outer stroma was seen in 23 patients (61%). Fifteen patients were premenopausal and eight were postmenopausal. Conclusion: In this study, we have shown a transitory zonal distribution of the contrast in the myometrium and cervix using dynamic contrast-enhanced helical CT

  9. Patterns of uterine enhancement with helical CT

    International Nuclear Information System (INIS)

    Kaur, H.; Loyer, E.M.; Charnsangavej, C.; Minami, M.

    1998-01-01

    Objective: The purpose of this study was to evaluate the enhancement characteristics of the normal uterine body and cervix using dynamic contrast-enhanced helical CT. Methods: Thirty-eight women scheduled for pelvic CT for non-gynecologic malignancies underwent dynamic contrast-enhanced helical CT of the pelvis. Data acquisition was during the arterial phase (30-45 s after the start of injection), the parenchymal phase (90-120 s after the start of injection), and delayed phase (3-9 min after the start of injection). The images were evaluated by four radiologists for the pattern of myometrial and cervical enhancement. Correlation was made with the age and menstrual status of the patients. Results: In the uterine body, three types of enhancement were observed. Type 1 enhancement, seen in 16 patients (42%), was characterized by the visualization of a subendometrial zone of enhancement, 30-120 s after the start of injection. Eight of these patients also showed an enhancing zone in the outer myometrium. Both zones were transitory, and in all cases, the uterus became homogeneous in the delayed phase. This pattern was seen predominantly in premenopausal women with a mean age of 34 years. Type 2 enhancement, seen in 17 cases (45%), was defined by the absence of subendometrial enhancement in the early phase. Enhancement was either diffuse from the outset or originated in the outer myometrium. This pattern was seen nearly equally in premenopausal and postmenopausal women with a mean age of 40 years. Type 3 enhancement was seen in five postmenopausal patients (13%) with a mean age of 53 years and was characterized by faint diffuse enhancement. In the cervix, a zonal pattern of enhancement defining inner and outer stroma was seen in 23 patients (61%). Fifteen patients were premenopausal and eight were postmenopausal. Conclusion: In this study, we have shown a transitory zonal distribution of the contrast in the myometrium and cervix using dynamic contrast-enhanced helical CT

  10. Analysis of lenses absorbed dose in head CT scan with the use of bismuth shielding

    Energy Technology Data Exchange (ETDEWEB)

    Santos, F.S.; Santana, P.C., E-mail: fernanda.stephaniebh@yahoo.com.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte (Brazil); Mourão, A.P. [Centro de Educação Tecnológica de Minas Gerais (CEFET-MG), Belo Horizonte, MG (Brazil)

    2017-07-01

    Computed Tomography (CT) has become an important tool to diagnose cancer and to obtain additional information for different clinical questions. However, CT scan usually requires a higher radiation exposure than a conventional radiography examination. Head CT scans are used for diagnosis of traumatic head injuries, infections and other diseases with instability. Based on this information, it was studied the dose variation deposited in the lenses and in nearby organs, such as: pharynx, hypophysis and salivary gland with and without the use of bismuth shield. In this study a head CT scan was performed on anthropomorphic male phantom using a GE scanner. Dose measurements have been performed by using radiochromic film strips to register the individual doses in the organs of interest. The results show that the lenses had a reduction of 26% of the dose with the use of the bismuth shield. (author)

  11. Dose assessment of head CT examination by volume scanning with 320-area-detector

    International Nuclear Information System (INIS)

    Suzuki, Shoichi; Kobayashi, Masanao

    2009-01-01

    CT with the 320-area-detector (320-ADCT), first presented in 2007, still requires further basic studies, particularly in the field of dose assessment, as the CT has been widely spread in clinic due to its many advantages compared with the usual spiral CT. In this paper, the assessment in the title was thereby done in human phantom and a patient with suspicious acute cerebral infarction under different scanning modes (non-spiral, spiral and volume) for their comparison. Machines for 320-ADCT, and non-spiral and spiral CT were Toshiba Aquilion ONE, and Aquilion 64-MD, respectively. Scanning of the phantom and patient was individually conducted under similar conditions of tube voltage/ current, rotation time and length with the same field of view with defined nominal slice thicknesses. Alderson human body phantom in which 240 thermoluminescent dosimeters were indwelled, was used; doses were read by the thermoluminescence dosimeter (TLD) reader model 3000 (Kyokko Co.) after scanning; and effective doses were calculated with reference to ICRP publ. 102/103 equations for patient's head to be 4.2 (64-MDCT) and 6.6 (320-ADCT) mSv, which were respectively 6.4 and 5.4 mSv when estimated using the conversion coefficient and DLP (dose length product) in the texts. It was suggested that the exposure dose at the volume scanning by 320-ADCT can be reduced in the routine examination, and in the exact diagnosis, possibly increases. These doses can be reduced further by optimization of scanning conditions by additional basic investigations. (K.T.)

  12. Quantitative analysis of titanium-induced artifacts and correlated factors during micro-CT scanning.

    Science.gov (United States)

    Li, Jun Yuan; Pow, Edmond Ho Nang; Zheng, Li Wu; Ma, Li; Kwong, Dora Lai Wan; Cheung, Lim Kwong

    2014-04-01

    To investigate the impact of cover screw, resin embedment, and implant angulation on artifact of microcomputed tomography (micro-CT) scanning for implant. A total of twelve implants were randomly divided into 4 groups: (i) implant only; (ii) implant with cover screw; (iii) implant with resin embedment; and (iv) implants with cover screw and resin embedment. Implants angulation at 0°, 45°, and 90° were scanned by micro-CT. Images were assessed, and the ratio of artifact volume to total volume (AV/TV) was calculated. A multiple regression analysis in stepwise model was used to determine the significance of different factors. One-way ANOVA was performed to identify which combination of factors could minimize the artifact. In the regression analysis, implant angulation was identified as the best predictor for artifact among the factors (P  0.05). Non-embedded implants with the axis parallel to X-ray source of micro-CT produced minimal artifact. Implant angulation and resin embedment affected the artifact volume of micro-CT scanning for implant, while cover screw did not. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. Gynecological applications of helical CT using SmartPrep

    Energy Technology Data Exchange (ETDEWEB)

    Sakurada, Akira; Kakizaki, Dai; Abe, Kimihiko [Tokyo Medical Coll. (Japan)

    1999-11-01

    SmartPrep is software program for scanning a given region of interest (ROI) at optimal contrast density. An operator can arbitrarily define ROI and preset the CT value at which scanning should be started. After the injection of a contrast medium, system conducts continuous monitoring of the ROI and the operator starts helical scanning of the planned region when the present CT value has been reached. In comparison with conventional helical CT that requires a period of time from the beginning of contrast medium injection to the beginning of scanning, SmartPrep minimizes personal error and better depicts the artery-predominant phase under optimal conditions. In this study we examine the usefulness of contrast-enhanced helical CT using SmartPrep in the evaluation of gynecological disease. When the contrast medium was injected into the dorsal vein of the hand at a rate of 3 ml/sec, strong staining of pelvic arteries was observed in the CT images started at 17 to 23 sec after injection. The early-phase helical CT obtained under these conditions provided good depiction of lesions in cases of placenta accreta and invasive mole, as well as clear demonstration of tumor angiogenesis and evaluation of laterality in cases of cervical cancer. Comparison of the early and delayed phase also facilitated easier evaluation of lymph nodes than conventional comparison of simple and contrast-enhanced CT. The results thus suggest the usefulness of contrast-enhanced helical CT using SmartPrep in gynecology. (author)

  14. Implementation of dual energy CT scanning

    International Nuclear Information System (INIS)

    Marshall, W.; Hall, E.; Doost-Hoseini, A.; Alvarez, R.; Macovski, A.; Cassel, D.

    1984-01-01

    A prereconstruction method for dual energy (PREDECT) analysis of CT scans is described. In theory, this method can (a) eliminate beam hardening and produce an accuracy comparable with monoenergetic scans and (b) provide the effective atomic number and electron density of any voxel scanned. The implementation proves these statements and eliminates some of the objectionable noise. A phantom was constructed with a cylindrical sleeve-like compartment containing known amounts of high atomic number material simulating a removable skull. Conventional scans, with and without this beam hardener, were done of a water bath containing tubes of high electron and high atomic number material. Dual energy scans were then done for PREDECT. To increase the effective separation of the low and high energy beams by using more appropriate tube filtration, a beam filter changer was fabricated containing erbium, tungsten, aluminum, and steel. Erbium, tungsten, and steel were used at high energy and aluminum, steel, and erbium at low energy for data acquisition. The reconstructions were compared visually and numerically for noise levels with the original steel only filtration. A decrease was found in noise down to approximately one-half the prior level when erbium/aluminum or tungsten/aluminum replaced the steel/steel filter. Erbium and tungsten were equally effective. Steel/erbium and steel/aluminum also significantly reduced image noise. The noise in the photoelectric (P) and Compton (C) images is negatively correlated. At any pixel, if the noise is positive in the P image, it is most probably negative in the C. Using this fact, the noise was reduced by postreconstruction processing

  15. Investigation of ultra low-dose scans in the context of quantum-counting clinical CT

    Science.gov (United States)

    Weidinger, T.; Buzug, T. M.; Flohr, T.; Fung, G. S. K.; Kappler, S.; Stierstorfer, K.; Tsui, B. M. W.

    2012-03-01

    In clinical computed tomography (CT), images from patient examinations taken with conventional scanners exhibit noise characteristics governed by electronics noise, when scanning strongly attenuating obese patients or with an ultra-low X-ray dose. Unlike CT systems based on energy integrating detectors, a system with a quantum counting detector does not suffer from this drawback. Instead, the noise from the electronics mainly affects the spectral resolution of these detectors. Therefore, it does not contribute to the image noise in spectrally non-resolved CT images. This promises improved image quality due to image noise reduction in scans obtained from clinical CT examinations with lowest X-ray tube currents or obese patients. To quantify the benefits of quantum counting detectors in clinical CT we have carried out an extensive simulation study of the complete scanning and reconstruction process for both kinds of detectors. The simulation chain encompasses modeling of the X-ray source, beam attenuation in the patient, and calculation of the detector response. Moreover, in each case the subsequent image preprocessing and reconstruction is modeled as well. The simulation-based, theoretical evaluation is validated by experiments with a novel prototype quantum counting system and a Siemens Definition Flash scanner with a conventional energy integrating CT detector. We demonstrate and quantify the improvement from image noise reduction achievable with quantum counting techniques in CT examinations with ultra-low X-ray dose and strong attenuation.

  16. The use of CT-scanning at the medicolegal external postmortem examination and at the forensic autopsy

    DEFF Research Database (Denmark)

    Leth, Peter Mygind

    2006-01-01

    Introduction: Can CT-scanning of deceased at the medico legal external examination improve the selection of cases to autopsy? Is CT-scanning a substitute or a supplement to the traditional forensic autopsy? Material: In 2006 60 deceased individuals from Southern Denmark (counties of Fyn and Sønde...

  17. Effect of clinical information in brain CT scan interpretation : a blinded double crossover study

    International Nuclear Information System (INIS)

    Zhianpour, M.; Janghorbani, M.

    2004-01-01

    Errors and variations in interpretation can happen in clinical imaging. Few studies have examined the biased effect of clinical information on reporting of brain CT scans. In a blinded double crossover design, we studied whether three radiologists were biased by clinical information when making CT scan diagnosis of the brain. Three consultant radiologists in three rounds with at least a one month interval assessed 100 consecutive cases of brain CT scan. In the first round, clinical information was not available and 100 films without clinical information were given to radiologists. In the second round, the same 100 films were given and true clinical information was available. In the third round, the same 100 films were given and false clinical information was allocated. In 180 cases (60%) the evaluation resulted in the same diagnosis on all three occasions (95% confidence interval (CI): 54.5, 65.5), whereas 120(40%; 95% CI:34.5, 45.5) sets were evaluated differently. 48 cases (16%; 95% CI:11.9,20.1) had discordant evaluation with true and 33 (11%; 95% CI:7.5, 14.5) with false clinical information. Discordance without and with true and false clinical information was 39 (13%; 95% CI:9.2, 16.8). Correct clinical information improves the brain CT report, while the report became less accurate false clinical information was allocated. These results indicate that radiologists are biased by clinical information when reporting brian CT scans

  18. X-ray and CT findings of costal eosinophilic granuloma

    International Nuclear Information System (INIS)

    Tu Zhanhai; Lin Zhengyu; Chen Yiguang

    2010-01-01

    Objective: To study the X-ray and CT features of costal eosinophilic granuloma for a better understanding. Methods: Eight patients with costal eosinophilic granuloma proved by surgery or biopsy were analyzed retrospectively. All patients had X-ray plain film, 6 patients had CT examination, including a case of enhanced CT scan. Results: All 8 lesions were solitary. Six lesions were in the anterior rib and 2 in the posterior rib. On X-ray, all case showed single cavity and oval lesion with clear boundary. On CT images, 5 lesions demonstrated expansile destruction of bone with cortical bone thinning, and 3 were osteolystic destruction with soft tissue mass around. On the patient with enhanced CT scan, the lesions showed a moderate and uniform enhancement. Conclusion: The X-ray and CT findings of costal eosinophilic granuloma are characteristic. (authors)

  19. How to distinguish between bleeding and coagulated extradural hematomas on the plain CT scanning

    International Nuclear Information System (INIS)

    Petersen, O.F.; Espersen, J.O.

    1984-01-01

    Four types of extradural hematoma could be separated at examination of the plain CT scan in 54 extradural hematomas. Two major groups appear: the still bleeding hematoma showing either generally low attenuation values of ''holes'', and a coagulated homogenous type with generally high attenuation values. The attenuation values of the bleeding-liquid part of hematoma - were correlated to hemoglobin concentration in blood, to which clots were not related. Seven extradural hematomas grew and coagulated on repeated preoperative CT scans. In two cases intravenous contrast was given to the bleeding type of hematoma, and the contrast media appeared in ''holes'', but not in areas of high attenuation value. It is easy to distinguish between the different types of hematoma on the plain CT scan, and the separation by eye between the still bleeding and the coagulated extradural hematoma seems reliable. (orig.)

  20. Myocardial perfusion imaging and coronary calcium scoring with a two-slice SPECT/CT system: can the attenuation map be calculated from the calcium scoring CT scan?

    Energy Technology Data Exchange (ETDEWEB)

    Wenning, Christian; Rahbar, Kambiz; Schober, Otmar; Stegger, Lars [University of Muenster, Department of Nuclear Medicine, Muenster (Germany); Vrachimis, Alexis; Schaefers, Michael [University of Muenster, Department of Nuclear Medicine, Muenster (Germany); University of Muenster, European Institute for Molecular Imaging, Muenster (Germany)

    2013-07-15

    Coronary artery calcium scoring can complement myocardial perfusion imaging (MPI). The purpose of this study was to evaluate the feasibility and accuracy of using the CalciumScore-CT derived from a combined SPECT/CT device also for SPECT attenuation correction (AC). The study group comprised 99 patients who underwent both post-stress and rest MPI using a two-slice SPECT/CT system. For AC, one of the two scans was accompanied by a CalciumScore-CT scan (CalciumScore-CTAC) and the other by a conventional spiral CT (AttenCorr-CT) scan (AttenCorr-CTAC). In 48 patients the CalciumScore-CT scan was acquired with the post-stress scan and the AttenCorr-CT scan with the rest scan, and in 51 patients the order was reversed. The accuracy of the images based on AC was determined qualitatively by consensus reading with respect to the clinical diagnoses as well as quantitatively by comparing the perfusion summed stress scores (SSS) and the summed rest scores (SRS) between attenuation-corrected and uncorrected images. In comparison to the uncorrected images CalciumScore-CTAC led to regional inaccuracies in 14 of 51 of studies (27.5 %) versus 12 of 48 studies (25 %) with AttenCorr-CTAC for the stress studies and in 5 of 48 (10 %) versus 1 of 51 (2 %) for the rest studies, respectively. This led to intermediate and definite changes in the final diagnosis (ischaemia and/or scarring) in 12 % of the studies (12 of 99) and in 7 % of the studies (7 of 99) with CalciumScore-CTAC and in 9 % of the studies (9 of 99) and 4 % of the studies (4 of 99) with AttenCorr-CTAC. Differences in SSS and SRS with respect to the uncorrected images were greater for the CalciumScore-CTAC images than for the AttenCorr-CTAC images ({Delta}SSS 4.5 {+-} 5.6 and 2.1 {+-} 4.4, p = 0.023; {Delta}SRS 4.2 {+-} 4.9 and 1.6 {+-} 3.2, p = 0.004, respectively). Using the same CT scan for calcium scoring and SPECT AC is feasible. Image interpretation must, however, include uncorrected images since CT-based AC relatively

  1. Volumetric gain of the human pancreas after left partial pancreatic resection: A CT-scan based retrospective study.

    Science.gov (United States)

    Phillip, Veit; Zahel, Tina; Danninger, Assiye; Erkan, Mert; Dobritz, Martin; Steiner, Jörg M; Kleeff, Jörg; Schmid, Roland M; Algül, Hana

    2015-01-01

    Regeneration of the pancreas has been well characterized in animal models. However, there are conflicting data on the regenerative capacity of the human pancreas. The aim of the present study was to assess the regenerative capacity of the human pancreas. In a retrospective study, data from patients undergoing left partial pancreatic resection at a single center were eligible for inclusion (n = 185). Volumetry was performed based on 5 mm CT-scans acquired through a 256-slice CT-scanner using a semi-automated software. Data from 24 patients (15 males/9 females) were included. Mean ± SD age was 68 ± 11 years (range, 40-85 years). Median time between surgery and the 1st postoperative CT was 9 days (range, 0-27 days; IQR, 7-13), 55 days (range, 21-141 days; IQR, 34-105) until the 2nd CT, and 191 days (range, 62-1902; IQR, 156-347) until the 3rd CT. The pancreatic volumes differed significantly between the first and the second postoperative CT scans (median volume 25.6 mL and 30.6 mL, respectively; p = 0.008) and had significantly increased further by the 3rd CT scan (median volume 37.9 mL; p = 0.001 for comparison with 1st CT scan and p = 0.003 for comparison with 2nd CT scan). The human pancreas shows a measurable and considerable potential of volumetric gain after partial resection. Multidetector-CT based semi-automated volume analysis is a feasible method for follow-up of the volume of the remaining pancreatic parenchyma after partial pancreatectomy. Effects on exocrine and endocrine pancreatic function have to be evaluated in a prospective manner. Copyright © 2015 IAP and EPC. Published by Elsevier B.V. All rights reserved.

  2. Multi-organ segmentation from multi-phase abdominal CT via 4D graphs using enhancement, shape and location optimization.

    Science.gov (United States)

    Linguraru, Marius George; Pura, John A; Chowdhury, Ananda S; Summers, Ronald M

    2010-01-01

    The interpretation of medical images benefits from anatomical and physiological priors to optimize computer-aided diagnosis (CAD) applications. Diagnosis also relies on the comprehensive analysis of multiple organs and quantitative measures of soft tissue. An automated method optimized for medical image data is presented for the simultaneous segmentation of four abdominal organs from 4D CT data using graph cuts. Contrast-enhanced CT scans were obtained at two phases: non-contrast and portal venous. Intra-patient data were spatially normalized by non-linear registration. Then 4D erosion using population historic information of contrast-enhanced liver, spleen, and kidneys was applied to multi-phase data to initialize the 4D graph and adapt to patient specific data. CT enhancement information and constraints on shape, from Parzen windows, and location, from a probabilistic atlas, were input into a new formulation of a 4D graph. Comparative results demonstrate the effects of appearance and enhancement, and shape and location on organ segmentation.

  3. Feasibility of Single Scan for Simultaneous Evaluation of Regional Krypton and Iodine Concentrations with Dual-Energy CT: An Experimental Study.

    Science.gov (United States)

    Hong, Sae Rom; Chang, Suyon; Im, Dong Jin; Suh, Young Joo; Hong, Yoo Jin; Hur, Jin; Kim, Young Jin; Choi, Byoung Wook; Lee, Hye-Jeong

    2016-11-01

    Purpose To evaluate the feasibility of a simultaneous single scan of regional krypton and iodine concentrations by using dual-energy computed tomography (CT). Materials and Methods The study was approved by the institutional animal experimental committee. An airway obstruction model was first made in 10 beagle dogs, and a pulmonary arterial occlusion was induced in each animal after 1 week. For each model, three sessions of dual-energy CT (80% krypton ventilation [krypton CT], 80% krypton ventilation with iodine enhancement [mixed-contrast agent CT], and iodine enhancement [iodine CT]) were performed. Krypton maps were made from krypton and mixed-contrast agent CT, and iodine maps were made from iodine and mixed-contrast agent CT. Observers measured overlay Hounsfield units of the diseased and contralateral segments on each map. Values were compared by using the Wilcoxon signed-rank test. Results In krypton maps of airway obstruction, overlay Hounsfield units of diseased segments were significantly decreased compared with those of contralateral segments in both krypton and mixed-contrast agent CT (P = .005 for both). However, the values of mixed-contrast agent CT were significantly higher than those of krypton CT for both segments (P = .005 and .007, respectively). In iodine maps of pulmonary arterial occlusion, values were significantly lower in diseased segments than in contralateral segments for both iodine and mixed-contrast agent CT (P = .005 for both), without significant difference between iodine and mixed-contrast agent CT for both segments (P = .126 and .307, respectively). Conclusion Although some limitations may exist, it might be feasible to analyze regional krypton and iodine concentrations simultaneously by using dual-energy CT. © RSNA, 2016.

  4. Renal streaky artifact during contrast-enhanced abdominal and pelvic CT: Comparison of high versus low osmolality contrast media

    International Nuclear Information System (INIS)

    Kim, Dae Hong; Kim, Jong Chul; Lee, Chung Keun; Shin, Kyoung Suk

    1994-01-01

    Introduction of low osmolality contrast agent(LOCA) has allowed safer, more comfortable contrast-enhanced CT examination, but there has been significant increase in image degradation when evaluating the kidneys due to streaky artifact. The authors reviewed findings of contrast- enhanced abdominal and pelvic computed tomography(CT) to know the difference of renal streaky artifact between a high osmolality contrast agent (HOCA) and LOCA. This study included two hundred contrast-enhanced CT in 200 patients, 100 performed with HOCA(meglumine ioglicate, 150 ml) and 100 performed with LOCA (iopromide,150 ml). The severity of renal streaky artifact was compared between HOCA and LOCA groups. Of the scans performed with HOCA, 40 had no artifact, 52 had grade I artifact, 6 had grade II artifact, and 2 had grade III artifact. Of the scans preformed with LOCA, 23 had no artifact, 44 had grade I artifact, 29 had grade II artifact, and 4 had grade III artifact. There was significant difference in the degree of the streaky artifact depending upon the osmolality of the contrast media used(by χ 2 -test, P=.0001). The results of this study revealed a statistically significant increased incidence of artifacts and distortions of renal image with LOCA when compared with HOCA

  5. Does head CT scan pathology predict outcome after mild traumatic brain injury?

    Science.gov (United States)

    Lannsjö, M; Backheden, M; Johansson, U; Af Geijerstam, J L; Borg, J

    2013-01-01

    More evidence is needed to forward our understanding of the key determinants of poor outcome after mild traumatic brain injury (MTBI). A large, prospective, national cohort of patients was studied to analyse the effect of head CT scan pathology on the outcome. One-thousand two-hundred and sixty-two patients with MTBI (Glasgow Coma Scale score 15) at 39 emergency departments completed a study protocol including acute head CT scan examination and follow-up by the Rivermead Post Concussion Symptoms Questionnaire and the Glasgow Outcome Scale Extended (GOSE) at 3 months after MTBI. Binary logistic regression was used for the assessment of prediction ability. In 751 men (60%) and 511 women (40%), with a mean age of 30 years (median 21, range 6-94), we observed relevant or suspect relevant pathologic findings on acute CT scan in 52 patients (4%). Patients aged below 30 years reported better outcome both with respect to symptoms and GOSE as compared to patients in older age groups. Men reported better outcome than women as regards symptoms (OR 0.64, CI 0.49-0.85 for ≥3 symptoms) and global function (OR 0.60, CI 0.39-0.92 for GOSE 1-6). Pathology on acute CT scan examination had no effect on self-reported symptoms or global function at 3 months after MTBI. Female gender and older age predicted a less favourable outcome. The findings support the view that other factors than brain injury deserve attention to minimize long-term complaints after MTBI. © 2012 The Author(s) European Journal of Neurology © 2012 EFNS.

  6. Delayed contrast enhancement imaging of a murine model for ischemia reperfusion with carbon nanotube micro-CT.

    Directory of Open Access Journals (Sweden)

    Laurel M Burk

    Full Text Available We aim to demonstrate the application of free-breathing prospectively gated carbon nanotube (CNT micro-CT by evaluating a myocardial infarction model with a delayed contrast enhancement technique. Evaluation of murine cardiac models using micro-CT imaging has historically been limited by extreme imaging requirements. Newly-developed CNT-based x-ray sources offer precise temporal resolution, allowing elimination of physiological motion through prospective gating. Using free-breathing, cardiac-gated CNT micro-CT, a myocardial infarction model can be studied non-invasively and with high resolution. Myocardial infarction was induced in eight male C57BL/6 mice aged 8-12 weeks. The ischemia reperfusion model was achieved by surgically occluding the LAD artery for 30 minutes followed by 24 hours of reperfusion. Tail vein catheters were placed for contrast administration. Iohexol 300 mgI/mL was administered followed by images obtained in diastole. Iodinated lipid blood pool contrast agent was then administered, followed with images at systole and diastole. Respiratory and cardiac signals were monitored externally and used to gate the scans of free-breathing subjects. Seven control animals were scanned using the same imaging protocol. After imaging, the heart was harvested, cut into 1mm slices and stained with TTC. Post-processing analysis was performed using ITK-Snap and MATLAB. All animals demonstrated obvious delayed contrast enhancement in the left ventricular wall following the Iohexol injection. The blood pool contrast agent revealed significant changes in cardiac function quantified by 3-D volume ejection fractions. All subjects demonstrated areas of myocardial infarct in the LAD distribution on both TTC staining and micro-CT imaging. The CNT micro-CT system aids straightforward, free-breathing, prospectively-gated 3-D murine cardiac imaging. Delayed contrast enhancement allows identification of infarcted myocardium after a myocardial ischemic

  7. Standardized CT protocols and nomenclature: better, but not yet there

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Sarabjeet; Kalra, Mannudeep K. [Harvard Medical School, Department of Radiology, Massachusetts General Hospital, Boston, MA (United States)

    2014-10-15

    Radiation dose associated with CT is an important safety concern in patient care, especially in children. Technical advancements in multidetector-row CT scanner technology offer several advantages for clinical applications; these advancements have considerably increased CT utilization and enhanced the complexity of CT scanning protocols. Furthermore there are several scan manufacturers spearheading these technical advancements, leading to different commercial names causing confusion among the users, especially at imaging sites with scanners from different vendors. Several scientific studies and the National Council on Radiation Protection and Measurements (NCRP) have shown variation in CT radiation doses for same body region and similar scanning protocols. Therefore there is a need for standardization of scanning protocols and nomenclature of scan parameters. The following material reviews the status and challenges in standardization of CT scanning and nomenclature. (orig.)

  8. Aquilion ONE / ViSION Edition CT scanner realizing 3D dynamic observation with low-dose scanning

    International Nuclear Information System (INIS)

    Kazama, Masahiro; Saito, Yasuo

    2015-01-01

    Computed tomography (CT) scanners have been continuously advancing as essential diagnostic imaging equipment for the diagnosis and treatment of a variety of diseases, including the three major disease classes of cerebrovascular disease, cardiovascular disease, and cancer. Through the development of helical CT scanners and multislice CT scanners, Toshiba Medical Systems Corporation has developed the Aquilion ONE, a CT scanner with a scanning range of up to 160 mm per rotation that can obtain three-dimensional (3D) images of the brain, heart, and other organs in a single rotation. We have now developed the Aquilion ONE / ViSION Edition, a next-generation 320-row multislice CT scanner incorporating the latest technologies that achieves a shorter scanning time and significant reduction in dose compared with conventional products. This product with its low-dose scanning technology will contribute to the practical realization of new diagnosis and treatment modalities employing four-dimensional (4D) data based on 3D dynamic observations through continuous rotations. (author)

  9. Comparison of radiation dose estimates, image noise, and scan duration in pediatric body imaging for volumetric and helical modes on 320-detector CT and helical mode on 64-detector CT

    International Nuclear Information System (INIS)

    Johnston, Jennifer H.; Podberesky, Daniel J.; Larson, David B.; Alsip, Christopher; Yoshizumi, Terry T.; Angel, Erin; Barelli, Alessandra; Toncheva, Greta; Egelhoff, John C.; Anderson-Evans, Colin; Nguyen, Giao B.; Frush, Donald P.; Salisbury, Shelia R.

    2013-01-01

    Advanced multidetector CT systems facilitate volumetric image acquisition, which offers theoretic dose savings over helical acquisition with shorter scan times. Compare effective dose (ED), scan duration and image noise using 320- and 64-detector CT scanners in various acquisition modes for clinical chest, abdomen and pelvis protocols. ED and scan durations were determined for 64-detector helical, 160-detector helical and volume modes under chest, abdomen and pelvis protocols on 320-detector CT with adaptive collimation and 64-detector helical mode on 64-detector CT without adaptive collimation in a phantom representing a 5-year-old child. Noise was measured as standard deviation of Hounsfield units. Compared to 64-detector helical CT, all acquisition modes on 320-detector CT resulted in lower ED and scan durations. Dose savings were greater for chest (27-46%) than abdomen/pelvis (18-28%) and chest/abdomen/pelvis imaging (8-14%). Noise was similar across scanning modes, although some protocols on 320-detector CT produced slightly higher noise. Dose savings can be achieved for chest, abdomen/pelvis and chest/abdomen/pelvis examinations on 320-detector CT compared to helical acquisition on 64-detector CT, with shorter scan durations. Although noise differences between some modes reached statistical significance, this is of doubtful diagnostic significance and will be studied further in a clinical setting. (orig.)

  10. The use of 3D contrast-enhanced CT reconstructions to project images of vascular rings and coarctation of the aorta.

    Science.gov (United States)

    Di Sessa, Thomas G; Di Sessa, Peter; Gregory, Bill; Vranicar, Mark

    2009-01-01

    Aortic arch and pulmonary artery anomalies make up a group of vascular structures that have complex three-dimensional (3D) shapes. Tortuosity as well as hypoplasia or atresia of segments of the aortic arch or pulmonary artery makes the conventional two-dimensional (2D) imaging difficult. Nine patients with native coarctation or recoarctation and 4 patients with a vascular ring had a CT scan as a part of their clinical evaluation. There were 7 males. The mean age was 11.7 years. (range 19 days to 29 years) The mean weight was 22.7 kg (range 3.3-139.0 kg). The dicom data from contrast CT scans were converted by the Amira software package into a 3D image. The areas of interest were selected. The images were then projected in 3D on a standard video monitor and could be rotated 360 degrees in any dimension. Adequate CT scans and 3D reconstructions were obtained in 12 of 13 patients. There were 85-1,044 slices obtained in the adequate studies. We could not reconstruct a 3D image from a patient's CT scan that had only 22 slices. The anatomy defined by 3D was compared to 2D CT imaging and confirmed by cardiac catheterization or direct visualization in the operating room in the 12 patients with adequate 3D reconstructions. In 5 of 12 patients, 3D reconstructions provided valuable spatial information not observed in the conventional 2D scans. We believe that 3D reconstruction of contrast-enhanced CT scans of these complex structures provides additional valuable information that is helpful in the decision-making process.

  11. CT findings of renal abscess

    International Nuclear Information System (INIS)

    Lee, Myung Jun; Kim, Mi Young; Woo, Jung Ju; Kim, Ho Kyun; Kim, Won Hong; Jeon, Jeong Dong; Jeon, Woo Ki; Han, Chang Yul

    1996-01-01

    The purpose of this study is to determine characteristic CT findings in renal abscess. Twenty cases of renal abscess were retrospectively analyzed for CT findings relating to the shape and extent of the abscess, change of nephrogram, peripheral rim enhancement, wedge-shaped enhancement on delayed scans, enlargement of the kidney involved and associated findings. Seven patients had a renal abscess at the right kidney, nine at the lift kidney and two bilaterally. The abscesses were round in 18 cases and finger-like in two. Rim enhancement around renal abscess was seen in four cases (20%). Changes in the nephrogram around the abscess were seen in 12 cases (60%). In all six patients who had undergone delayed postcontrast scans, wedge-shaped enhancement was shown around the abscess (100%). In the observation of the extent of renal abscesses, 14 cases were within the kidney, six cases extended the beyond renal capsule, and two were loculated in the renal fascia itself. Renal enlargement was seen in nine cases (45%). These results suggest that CT findings such as delayed wedge-shaped enhancement, change of nephrogram, peripheral rim enhancement, renal enlargement, and associated findings are valuable for diagnosis, and that CT also gives information concerning the extent, evolution and complication of a renal abscess

  12. Automated volumetry of temporal horn of lateral ventricle for detection of Alzheimer's disease in CT scan

    Science.gov (United States)

    Takahashi, Noriyuki; Kinoshita, Toshibumi; Ohmura, Tomomi; Matsuyama, Eri; Toyoshima, Hideto

    2018-02-01

    The rapid increase in the incidence of Alzheimer's disease (AD) has become a critical issue in low and middle income countries. In general, MR imaging has become sufficiently suitable in clinical situations, while CT scan might be uncommonly used in the diagnosis of AD due to its low contrast between brain tissues. However, in those countries, CT scan, which is less costly and readily available, will be desired to become useful for the diagnosis of AD. For CT scan, the enlargement of the temporal horn of the lateral ventricle (THLV) is one of few findings for the diagnosis of AD. In this paper, we present an automated volumetry of THLV with segmentation based on Bayes' rule on CT images. In our method, first, all CT data sets are normalized into an atlas by using linear affine transformation and non-linear wrapping techniques. Next, a probability map of THLV is constructed in the normalized data. Then, THLV regions are extracted based on Bayes' rule. Finally, the volume of the THLV is evaluated. This scheme was applied to CT scans from 20 AD patients and 20 controls to evaluate the performance of the method for detecting AD. The estimated THLV volume was markedly increased in the AD group compared with the controls (P < .0001), and the area under the receiver operating characteristic curve (AUC) was 0.921. Therefore, this computerized method may have the potential to accurately detect AD on CT images.

  13. Contrast Dose and Radiation Dose Reduction in Abdominal Enhanced Computerized Tomography Scans with Single-phase Dual-energy Spectral Computerized Tomography Mode for Children with Solid Tumors.

    Science.gov (United States)

    Yu, Tong; Gao, Jun; Liu, Zhi-Min; Zhang, Qi-Feng; Liu, Yong; Jiang, Ling; Peng, Yun

    2017-04-05

    Contrast dose and radiation dose reduction in computerized tomography (CT) scan for adult has been explored successfully, but there have been few studies on the application of low-concentration contrast in pediatric abdominal CT examinations. This was a feasibility study on the use of dual-energy spectral imaging and adaptive statistical iterative reconstruction (ASiR) for the reduction of radiation dose and iodine contrast dose in pediatric abdominal CT patients with solid tumors. Forty-five patients with solid tumors who had initial CT (Group B) and follow-up CT (Group A) after chemotherapy were enrolled. The initial diagnostic CT scan (Group B) was performed using the standard two-phase enhanced CT with 320 mgI/ml concentration contrast, and the follow-up scan (Group A) was performed using a single-phase enhanced CT at 45 s after the beginning of the 270 mgI/ml contrast injection using spectral mode. Forty percent ASiR was used for the images in Group B and monochromatic images with energy levels ≥60 keV in Group A. In addition, filtered back-projection (FBP) reconstruction was used for monochromatic images hounsfield unit (HU). The abdominal organs of Groups A and B had similar degrees of absolute and relative enhancement (t = 0.36 and -1.716 for liver, -0.153 and -1.546 for pancreas, and 2.427 and 0.866 for renal cortex, all P> 0.05). Signal-to-noise ratio of the abdominal organs was significantly lower in Group A than in Group B (t = -8.11 for liver, -7.83 for pancreas, and -5.38 for renal cortex, all P 3, indicating clinically acceptable image quality. Single-phase, dual-energy spectral CT used for children with solid abdominal tumors can reduce contrast dose and radiation dose and can also maintain clinically acceptable image quality.

  14. Budd-Chiari syndrome: dynamic enhancement findings with multi-slice helical CT and CT angiography analysis

    International Nuclear Information System (INIS)

    Meng Xiaochun; Shan Hong; Zhu Kangshun; Xu Chuan; Zhang Jiansheng; Liu Lingyun; Ye Binbin

    2005-01-01

    Objective: To investigate the dynamic enhancement regulations of liver and their mechanism in Budd-Chiari syndrome (BCS) by using multi-slice CT and evaluate the value of CT angiography in the diagnosis of BCS. Methods: 28 cases with BCS confirmed by digital subtraction angiography (DSA) were retrospectively analyzed. All patients underwent dynamic enhancement examinations with multi-slice CT within 1 week before DSA. The relevant vessels were reconstructed respectively with MIP, VR and MPR. Compared with the results of DSA, we analyzed the dynamic enhancement regulations of liver in BCS, estimated the value of dynamic enhancement CT exams and CTA techniques in judging the obstruction level and showing collateral vessels. Results: Of all 28 cases, CT correctly showed the obstruction level in 26 cases, and 2 had incorrect results which proved to be membranous obstruction of the inferior vena cava superior to diaphragm. In 22 cases with hepatic vein obstructions, hepatic parenchyma displayed typical patchy enhancement in 19, atypical patchy enhancement in 3.8 cases among these showed benign nodules. Simultaneously, CT showed stenosis and rigidity of portal vein branches in 20, enlargement of hepatic artery in 14, hepatic collateral vessels in 20 out of 22 cases. In 6 cases with simple obstruction of inferior vena cava, hepatic changes were not found. Collateral circulations in or out of liver corresponded to the obstruction level. Conclusion: Dynamic enhancement examinations with multi-slice CT can correctly reflect the hepatic hemodynamic changes. Transverse images, combined with CTA, can explicitly display the obstruction level of vascular lesions and collateral circulations in BCS. (authors)

  15. The value of CT in genetic counseling in tuberous sclerosis

    International Nuclear Information System (INIS)

    Scotti, L.N.; Bartoletti, S.C.

    1980-01-01

    The families of two patients with known tuberous sclerosis were electively evaluated by computed tomography. The CT positive (and negative) examination proved to be valuable for the genetic counseling of family members without overt clinical manifestations of tuberous sclerosis. Two patients had evidence of smaller enhancing lesions (minimal demonstrable mass without hydrocephalus) following intravenous contrast enhancement. We, therefore, suggest the use of contrast enhanced scans in addition to the plain scans to identify what may represent occult neoplasms. Abdominal CT scans can prove useful in identifying the frequently associated renal hamartomas. (orig.) [de

  16. The CT diagnose of pleural metastasis tumour

    International Nuclear Information System (INIS)

    Chen Liqun; Han Kaibin; Pan Heng; Huang Xiaoru; Zhou Bingcao; Huang Yuehua

    2007-01-01

    Objective: To discuss the CT characteristic of pleural metastasis tumour,enhance the diagnostic level of pleural metastasis tumour. Methods: Review 30 cases which have been performed CT scan in our hospital during March 2002 to June 2003, which have been approved to pleural metastasis tumour by pathology and clinic. Make use of GE Hispeed.zx/i spiral CT,10mm thickness,10mm increment, l.5 pitch, some of them use 10mm or high resolution mode. All cases have been performed normal scan, 25 cases with contrast scan. Results: The CT representation of pleural metastasis tumour are encapsulated pleural effusion with irregular pleural thickening(56.6%), nodular pleural thickening(46.6%), pleural masses (13.3%), pneumothorax (3.3%), etc. Encapsulated pleural effusion and nodular pleural thickening are 76.6%, use contrast mode to scan pleural pathological changes enhance upon middle level, CT value increment > 20HU, there are 66.6% cases with other chest metastasis symptom, 73.3% primary lesion are pulmonary cancer, and 20% no primary lesion are found. Conclusion: Combine primary lesion history and other chest metastasis symptom, Spiral CT examination can differentiate most of pleural metastasis tumour, but it is difficult to differentiate the cases between with a little pleural effusion or light band pleural thickening and reactive alteration. (authors)

  17. Enhanced transbuccal salmon calcitonin (sCT) delivery: effect of chemical enhancers and electrical assistance on in vitro sCT buccal permeation.

    Science.gov (United States)

    Oh, Dong-Ho; Chun, Kyeung-Hwa; Jeon, Sang-Ok; Kang, Jeong-Won; Lee, Sangkil

    2011-10-01

    This study investigates the combined effect of absorption enhancers and electrical assistance on transbuccal salmon calcitonin (sCT) delivery, using fresh swine buccal tissue. We placed 200 IU (40 μg/mL) of each sCT formulation--containing various concentrations of ethanol, N-acetyl-L-cysteine (NAC), and sodium deoxyglycocholate (SDGC)--onto the donor part of a Franz diffusion cell. Then, 0.5 mA/cm(2) of fixed anodal current was applied alone or combined with chemical enhancers. The amount of permeated sCT was analyzed using an ELISA kit, and biophysical changes of the buccal mucosa were investigated using FT-IR spectroscopy, and hematoxylin-eosin staining methods were used to evaluate histological alteration of the buccal tissues. The flux (J(s)) of sCT increased with the addition of absorption enhancer groups, but it was significantly enhanced by the application of anodal iontophoresis (ITP). FT-IR study revealed that all groups caused an increase in lipid fluidity but only the groups containing SDGC showed statistically significant difference. Although the histological data of SDGC groups showed a possibility for tissue damage, the present enhancing methods appear to be safe. In conclusion, the combination of absorption enhancers and electrical assistance is a potential strategy for the enhancement of transbuccal sCT delivery. Copyright © 2011 Elsevier B.V. All rights reserved.

  18. Myocardial delayed-enhancement CT: initial experience in children and young adults

    Energy Technology Data Exchange (ETDEWEB)

    Goo, Hyun Woo [University of Ulsan College of Medicine, Department of Radiology and Research Institute of Radiology, Asan Medical Center, Seoul (Korea, Republic of)

    2017-10-15

    Clinical utility of myocardial delayed enhancement CT has not been reported in children and young adults. To describe initial experience of myocardial delayed enhancement CT regarding image quality, radiation dose and identification of myocardial lesions in children and young adults. Between August 2013 and November 2016, 29 consecutive children and young adults (median age 16 months) with suspected coronary artery or myocardial abnormality underwent arterial- and delayed-phase cardiac CT at our institution. We measured CT densities in normal myocardium, left ventricular cavity, and arterial and delayed hypo-enhancing and delayed hyperenhancing myocardial lesions. We then compared the extent of delayed hyperenhancing lesions with delayed-enhancement MRI or thallium single-photon emission CT. Normal myocardium and left ventricular cavity showed significantly higher CT numbers on arterial-phase CT than on delayed-phase CT (t-test, P<0.0001). Contrast-to-noise ratios of the arterial and delayed hypo-enhancing and delayed hyperenhancing lesions on CT were 26.7, 17.6 and 18.7, respectively. Delayed-phase CT findings were equivalent to those of delayed-enhancement MRI in all cases (7/7) and to those of thallium single-photon emission CT in 70% (7/10). Myocardial delayed-enhancement CT can be added to evaluate myocardial lesions in select children and young adults with suspected coronary artery or myocardial abnormality. (orig.)

  19. Myocardial delayed-enhancement CT: initial experience in children and young adults

    International Nuclear Information System (INIS)

    Goo, Hyun Woo

    2017-01-01

    Clinical utility of myocardial delayed enhancement CT has not been reported in children and young adults. To describe initial experience of myocardial delayed enhancement CT regarding image quality, radiation dose and identification of myocardial lesions in children and young adults. Between August 2013 and November 2016, 29 consecutive children and young adults (median age 16 months) with suspected coronary artery or myocardial abnormality underwent arterial- and delayed-phase cardiac CT at our institution. We measured CT densities in normal myocardium, left ventricular cavity, and arterial and delayed hypo-enhancing and delayed hyperenhancing myocardial lesions. We then compared the extent of delayed hyperenhancing lesions with delayed-enhancement MRI or thallium single-photon emission CT. Normal myocardium and left ventricular cavity showed significantly higher CT numbers on arterial-phase CT than on delayed-phase CT (t-test, P<0.0001). Contrast-to-noise ratios of the arterial and delayed hypo-enhancing and delayed hyperenhancing lesions on CT were 26.7, 17.6 and 18.7, respectively. Delayed-phase CT findings were equivalent to those of delayed-enhancement MRI in all cases (7/7) and to those of thallium single-photon emission CT in 70% (7/10). Myocardial delayed-enhancement CT can be added to evaluate myocardial lesions in select children and young adults with suspected coronary artery or myocardial abnormality. (orig.)

  20. A case of intracranial malignant lymphoma with pure akinesia and repeated regression on CT scans

    International Nuclear Information System (INIS)

    Suzuki, Takeo; Yamamoto, Mari; Saitoh, Mitsunori; Aoki, Akira; Imai, Hisamasa; Narabayashi, Hirotaro.

    1984-01-01

    In a case of primary reticulum cell sarcoma in the brain, histologically verified by biopsy, the tumor regressed twice on a CT scan without radiotherapy. The systemic freezing phenomenon was seen as a main clinical symptom. The patient, a 44 year-old male, first complained of decreased livido and festinating speech. He also showed frozen gait, micrographia, a decrease in spontaneity and urinary incontinence. Four months after onset he was hospitalized. Neurological findings on admission revealed freezing of gait, writing, and speech, but there was no weakness of muscles with normal tendon reflexes, and normal muscular tone. In the CT scan on admission, there were high density areas mainly in the head of the right caudate nucleus, the medial deep portion of the right frontal lobe, the right side of the hypothalamus, the anterior thalamus, the globus pallidus. There were also nodular-type enhanced effects in the same areas. Regression of the tumor was seen on the CT scans after administration of betamethasone. The tumor which had again incrased in size regressed spontaneously without the use of steroids after 3 months. Thereafter, the tumor gradually became larger and an open biopsy was perfomed. Histopathological findings showed a reticulum cell sarcoma. There were no findings of systemic malignant lymphoma. Such intracrainal malignant lymphomas showing repeated regression including spontaneous one are very rare in the literature. The freezing phenomenon in this case started with festinating speech and spread to writing and gait. L-DOPA had no effect. This systemic freezing phenomenon was considered to be the same as that in the cases of pure akinesia without rigidity and tremor reported by Narabayashi and Imai, which did not respond to L-DOPA at all. But on the other hand, L-Threo-3, 4-Dihydroxyphenylserine was effective to the frozen gait of this patient. (J.P.N.)

  1. Comparative study of CT scan findings and intellectual function between Parkinson's disease and vascular Parkinsonism

    International Nuclear Information System (INIS)

    Indo, Toshikatsu

    1986-01-01

    Comparative study of CT scan findings and intellectual function between 64 cases with Parkinson's disease and 25 cases with vascular Parkinsonism was carried out. The rate of abnormality of CT scan findings, either ventricular dilatation or widening of sulci, in vascular Parkinsonism was strikingly high compared with Parkinson's disease. Patients could be divided into three groups according to the degree of overall abnormalities of CT scan findings (group A: markedly abnormal, group B: mildly abnormal, group C: normal). Incidences of group A were 9.4 % in Parkinson's disease and 52 % in vascular Parkinsonism, whereas those of group C were 56 % in the former and 28 % in the latter. All patients of group A were over 65 years of age in Parkinson's disease, but one-third of patients in group A were under 59 years of age in vascular Parkinsonism. Moreover, in vascular Parkinsonism, the level of disability was directly proportional to the abnormality of CT scan findings. The rate of predementia and dementia classified by Hasegawa's intelligence scale was 12.5 % in Parkinson's disease and 48 % in vascular Parkinsonism. No difference was found between the mean values of intelligence scale and background factors in Parkinson's disease. On the other hand, the mean value was significantly low in proportion to the poverty of L-dopa effect in vascular Parkinsonism. From these results, the abnormality of CT scan findings and intellectual impairment were probably related to the cerebral pathological process in vascular Parkinsonism, but these relationship was absent in Parkinson's disease. (author)

  2. Comparative study of CT scan findings and intellectual function between Parkinson's disease and vascular Parkinsonism

    Energy Technology Data Exchange (ETDEWEB)

    Indo, Toshikatsu

    1986-01-01

    Comparative study of CT scan findings and intellectual function between 64 cases with Parkinson's disease and 25 cases with vascular Parkinsonism was carried out. The rate of abnormality of CT scan findings, either ventricular dilatation or widening of sulci, in vascular Parkinsonism was strikingly high compared with Parkinson's disease. Patients could be divided into three groups according to the degree of overall abnormalities of CT scan findings (group A: markedly abnormal, group B: mildly abnormal, group C: normal). Incidences of group A were 9.4 % in Parkinson's disease and 52 % in vascular Parkinsonism, whereas those of group C were 56 % in the former and 28 % in the latter. All patients of group A were over 65 years of age in Parkinson's disease, but one-third of patients in group A were under 59 years of age in vascular Parkinsonism. Moreover, in vascular Parkinsonism, the level of disability was directly proportional to the abnormality of CT scan findings. The rate of predementia and dementia classified by Hasegawa's intelligence scale was 12.5 % in Parkinson's disease and 48 % in vascular Parkinsonism. No difference was found between the mean values of intelligence scale and background factors in Parkinson's disease. On the other hand, the mean value was significantly low in proportion to the poverty of L-dopa effect in vascular Parkinsonism. From these results, the abnormality of CT scan findings and intellectual impairment were probably related to the cerebral pathological process in vascular Parkinsonism, but these relationship was absent in Parkinson's disease.

  3. CT diagnosis of invasive hydatidiform mole

    International Nuclear Information System (INIS)

    Lu Mingquan; Jiang Lina; Li Xianxing; Wang Peijun

    2000-01-01

    Objective: To investigate the CT features and the diagnostic value in invasive mole. Methods: Eleven cases (age, 30 to 53 years, mean 40 years) with invasive mole proved by operation and pathology were studied, including 3 cases during peri-menopausal period of eight months, ten months and twelve months respectively. All cases were scanned by CT and enhanced study was done. Results: All cases showed enlargement of uterus of varying degrees. On CT, the density of uterine cavity was similar to that of water, intermingled with spotty patchy and hazy circular isodense shadows. High density stripe-like bleeding foci were found in 3 cases. The outline of uterine cavity was locally disrupted in all case and the muscle layer was thickened in 3 cases. On enhanced CT scan, the lesions in the uterine cavity appeared markedly hyperdense, just like 'the crater' and the 'mole sign'. The muscle layers at the site of disruption showed inhomogeneous enhancement after contrast injection. Conclusion: The CT features of invasive mole are characteristic, with important diagnostic value, especially for those during peri-menopausal period

  4. Study of effect of different CT scanning protocols on HU variation and their impact on TPS calculations

    International Nuclear Information System (INIS)

    Mahur, Mamta; Sharma, Richa; Sasindaran, M.; Singh, Anshu; Gedam, Varsha; Negi, P.S.; Grover, R.K.

    2016-01-01

    Computer tomographic (CT) scans are used to correct for tissue inhomogeneties in radiotherapy treatment planning. In order to guarantee a precise treatment, it is important to obtain the relationship between CT Hounsfield units and relative electron densities, which is the basic input for radiotherapy planning systems which consider tissue heterogeneities. The purpose of this study is to investigate the influence of different CT scan parameters (kVp, mAs) on uniformity of CT numbers versus relative electron density (HURED) curves and their different dosimetric impact

  5. Clinical study of acute cerebral infarction with a midline shift on the CT scan

    Energy Technology Data Exchange (ETDEWEB)

    Takemae, T; Mizukami, M; Kin, H; Kawase, T; Araki, G [Mihara Memorial Hospital, Isezaki, Gunma (Japan)

    1978-12-01

    Twenty-one cases of acute cerebral infarction with a midline shift on the CT scan were studied with respect to the development of the midline shift, the angiographic findings, the clinical pictures and the outcome of these patients. The CT findings of hemorrhagic infarction were also studied. No cases showed a midline shift on a CT scan taken within 6 hours after the onset. A midline shift was, however, noted as early as 9 hours after the onset, and it reached its peak between the 2nd and 7th day of the onset. It gradually disappeared by the end of the third week. Hemorrhagic infarction was diagnosed in 6 patients by either spinal tap or autopsy. The CT findings of these hemorrhagic infarction were divided into two types, solid hemorrhages with an unequivocal high density within the low-density area, and small, scattered hemorrhagic of almost the same density as normal brain tissue within the low-density area. In 19 of 21 patients, an round-edged occlusion and/or embolus were observed on the initial angiograms. The recanalization of the occluded vessels was proved in 10 of 14 patients by subsequent angiographic studies. Twenty of 21 patients showed a sudden development of neurological symptoms, and 15 patients had a history of various kinds of heart disease, such as atrial fibrillation, valvular heart disease and myocardial infarction. The patients had atrial fibrillation on EKG on admission. These angiographic findings and clinical pictures strongly suggest that the infarction with a midline shift on the CT scan may be caused by a cerebral embolism of cardiac origin. Eight patients died of cerebral herniation between the 2nd and 6th day of the onset. Taking these poor outcomes into consideration, surgical as well as medical decompression of the brain would seem to be most important when the CT scan shows a midline shift.

  6. Dose profile variation with voltage in head CT scans using radiochromic films

    Science.gov (United States)

    Mourão, A. P.; Alonso, T. C.; DaSilva, T. A.

    2014-02-01

    The voltage source used in an X-ray tube is an important part of defining the generated beam spectrum energy profile. The X-ray spectrum energy defines the X-ray beam absorption as well as the characteristics of the energy deposition in an irradiated object. Although CT scanners allow one to choose between four different voltage values, most of them employ a voltage of 120 kV in their scanning protocols, regardless of the patient characteristics. Based on this fact, this work investigated the deposited dose in a polymethyl methacrylate (PMMA) cylindrical head phantom. The entire volume was irradiated twice. Two CT scanning protocols were used with two different voltage values: 100 and 120 kV. The phantom volume was irradiated, and radiochromic films were employed to record dose profiles. Measurements were conducted with a calibrated pencil ionization chamber, which was positioned in the center and in four peripheral bores of the head PMMA phantom, to calibrate the radiochromic films. The central slice was then irradiated. This procedure allowed us to find the conversion factors necessary to obtain dose values recorded in the films. The data obtained allowed us to observe the dose variation profile inside the phantom head as well as in the peripheral and central regions. The peripheral region showed higher dose values than those of the central region for scans using both voltage values: approximately 31% higher for scanning with 120 kV and 25% higher with 100 kV. Doses recorded with the highest voltage are significantly higher, approximately 50% higher in the peripheral region and 40% higher in the central region. A longitudinal variation could be observed, and the maximum dose was recorded at the peripheral region, at the midpoint of the longitudinal axis. The obtained results will most likely contribute to the dissemination of proper procedure as well as to optimize dosimetry and tests of quality control in CT because the choice of protocols with different voltage

  7. A coarse-to-fine approach for pericardial effusion localization and segmentation in chest CT scans

    Science.gov (United States)

    Liu, Jiamin; Chellamuthu, Karthik; Lu, Le; Bagheri, Mohammadhadi; Summers, Ronald M.

    2018-02-01

    Pericardial effusion on CT scans demonstrates very high shape and volume variability and very low contrast to adjacent structures. This inhibits traditional automated segmentation methods from achieving high accuracies. Deep neural networks have been widely used for image segmentation in CT scans. In this work, we present a two-stage method for pericardial effusion localization and segmentation. For the first step, we localize the pericardial area from the entire CT volume, providing a reliable bounding box for the more refined segmentation step. A coarse-scaled holistically-nested convolutional networks (HNN) model is trained on entire CT volume. The resulting HNN per-pixel probability maps are then threshold to produce a bounding box covering the pericardial area. For the second step, a fine-scaled HNN model is trained only on the bounding box region for effusion segmentation to reduce the background distraction. Quantitative evaluation is performed on a dataset of 25 CT scans of patient (1206 images) with pericardial effusion. The segmentation accuracy of our two-stage method, measured by Dice Similarity Coefficient (DSC), is 75.59+/-12.04%, which is significantly better than the segmentation accuracy (62.74+/-15.20%) of only using the coarse-scaled HNN model.

  8. CT of multiple sclerosis: reassessment of delayed scanning with high doses of contrast material

    International Nuclear Information System (INIS)

    Spiegel, S.M.; Vinuela, F.; Fox, A.J.; Pelz, D.M.

    1985-01-01

    A prospective study involving 87 patients was carried out to evaluate the necessity for a high dose of contrast material in addition to delayed computed tomographic (CT) scanning for optimal detection of the lesions of multiple sclerosis in the brain. In patients with either clinically definite multiple sclerosis or laboratory-supported definite multiple sclerosis, CT scans were obtained with a uniform protocol. Lesions consistent with multiple sclerosis were demonstrated on the second scan in 54 patients. In 36 of these 54 patients, the high-dose delayed scan added information. These results are quite similar to those of a previous study from this institution using different patients, in whom the second scan was obtained immediately after the bolus injection of contrast material containing 40 g of organically bound iodine. The lack of real difference in the results of the two studies indicate that the increased dose, not just the delay in scanning, is necessary for a proper study

  9. CT-Urography; Urografia CT

    Energy Technology Data Exchange (ETDEWEB)

    Dalla Palma, Ludovico; Grotto, Maurizio [Trieste Univ., Trieste (Italy). Dipartimento di scienze cliniche, morfologiche e tecnologiche, UCO di radiologia; Morra, Aldo [CRO, Aviano (Italy). Reparto di radiologia

    2005-09-15

    In this paper we present an overview of CT-Urography. With the advent of multislice CT scanners and the evolution of image processing methods this technique now affords optimal urographic images comparable to those obtained with conventional techniques. We describe the acquisition techniques and protocols used by the various authors. Effective radiation dose has conditioned the use of CT-Urography so that the tendency today is to reduce the number of scans by performing, after the non enhanced scan, a single contrast-enhanced scan comprising both the nephrographic and urographic phase. With the use of multislice CT the quality of the urogram improves with the number of slices. We illustrate a variety of processing techniques, multiplanar reconstruction (MPR), maximum (MIP) and average intensity projection (AIP) and volume rendering (VR) and present a series of upper urinary tract tumours testifying to the superiority of the AIP technique over MIP. We then review the results of comparative studies of CT-Urography with conventional urography in upper urinary tract diagnostics. Finally, we describe the advantages and limitations of CT-Urography. [Italian] Gli Autori presentano una panoramica sulla Urografia TC (Uro TC). L'avvento della TC multistrato e l'evoluzione delle tecniche di elaborazione consentono di ottenere dei quadri urografici ottimali comparativi con quelli convenzionali. Vengono ricordate le varie tecniche di acquisizione e i protocolli usati dai vari Autori. La dose effettiva di radiazioni ha rappresentato uno dei fattori condizionanti per cui oggi prevale l'orientamento di ridurre il numero di scansioni, considerando dopo la scansione senza mezzo di contrasto un'unica scansione contrasto grafica comprendente sia la fase nefrografica che quella urografica. Con l'uso della TC multistrato la qualita dell'urogramma migliora con l'aumento del numero degli strati. Vengono descritte le varie tecniche di elaborazione, la

  10. Assessment value of quantitative indexes of pancreatic CT perfusion scanning for malignant degree of pancreatic cancer

    Directory of Open Access Journals (Sweden)

    Jiang-Xia Lei

    2016-10-01

    Full Text Available Objective: To analyze the assessment value of the quantitative indexes of pancreatic CT perfusion scanning for malignant degree of pancreatic cancer. Methods: A total of 58 patients with space-occupying pancreatic lesions were divided into 20 patients with pancreatic cancer and 38 patients with benign pancreatic lesions after pancreatic CT perfusion. Patients with pancreatic cancer received palliative surgery, and the cancer tissue and para-carcinoma tissue specimens were collected during operation. The differences in pancreatic CT perfusion scanning parameter values and serum tumor marker levels were compared between patients with pancreatic cancer and patients with benign pancreatic lesions, mRNA expression levels of malignant molecules in pancreatic cancer tissue and para-carcinoma tissue were further determined, and the correlation between pancreatic CT perfusion scanning parameter values and malignant degree of pancreatic cancer was analyzed. Results: CT perfusion scanning BF, BV and Per values of patients with pancreatic cancer were lower than those of patients with benign pancreatic lesions; serum CA19-9, CEA, CA125 and CA242 levels were higher than those of patients with benign pancreatic lesions (P<0.05; mRNA expression levels of Bcl-2, Bcl-xL and survivin in pancreatic cancer tissue samples were higher than those in paracarcinoma tissue samples, and mRNA expression levels of P53 and Bax were lower than those in para-carcinoma tissue samples (P<0.05; CT perfusion scanning parameters BF, BV and Per values of patients with pancreatic cancer were negatively correlated with CA19-9, CEA, CA125 and CA242 levels in serum as well as mRNA expression levels of Bcl-2, Bcl-xL and survivin in pancreatic cancer tissue, and positively correlated with mRNA expression levels of P53 and Bax in pancreatic cancer tissue (P<0.05. Conclusions: Pancreatic CT perfusion scanning is a reliable way to judge the malignant degree of pancreatic cancer and plays a

  11. Community-Acquired Pneumonia Visualized on CT Scans but Not Chest Radiographs: Pathogens, Severity, and Clinical Outcomes.

    Science.gov (United States)

    Upchurch, Cameron P; Grijalva, Carlos G; Wunderink, Richard G; Williams, Derek J; Waterer, Grant W; Anderson, Evan J; Zhu, Yuwei; Hart, Eric M; Carroll, Frank; Bramley, Anna M; Jain, Seema; Edwards, Kathryn M; Self, Wesley H

    2018-03-01

    The clinical significance of pneumonia visualized on CT scan in the setting of a normal chest radiograph is uncertain. In a multicenter prospective surveillance study of adults hospitalized with community-acquired pneumonia (CAP), we compared the presenting clinical features, pathogens present, and outcomes of patients with pneumonia visualized on a CT scan but not on a concurrent chest radiograph (CT-only pneumonia) and those with pneumonia visualized on a chest radiograph. All patients underwent chest radiography; the decision to obtain CT imaging was determined by the treating clinicians. Chest radiographs and CT images were interpreted by study-dedicated thoracic radiologists blinded to the clinical data. The study population included 2,251 adults with CAP; 2,185 patients (97%) had pneumonia visualized on chest radiography, whereas 66 patients (3%) had pneumonia visualized on CT scan but not on concurrent chest radiography. Overall, these patients with CT-only pneumonia had a clinical profile similar to those with pneumonia visualized on chest radiography, including comorbidities, vital signs, hospital length of stay, prevalence of viral (30% vs 26%) and bacterial (12% vs 14%) pathogens, ICU admission (23% vs 21%), use of mechanical ventilation (6% vs 5%), septic shock (5% vs 4%), and inhospital mortality (0 vs 2%). Adults hospitalized with CAP who had radiological evidence of pneumonia on CT scan but not on concurrent chest radiograph had pathogens, disease severity, and outcomes similar to patients who had signs of pneumonia on chest radiography. These findings support using the same management principles for patients with CT-only pneumonia and those with pneumonia seen on chest radiography. Copyright © 2017 American College of Chest Physicians. All rights reserved.

  12. Dose reduction for CT in children with cystic fibrosis: is it feasible to reduce the number of images per scan?

    International Nuclear Information System (INIS)

    Jong, Pim A. de; Tiddens, Harm A.W.M.; Nakano, Yasutaka; Lequin, Maarten H.

    2006-01-01

    Reducing the dose for each CT scan is important for children with cystic fibrosis (CF). To determine whether the number of CT images and therefore the dose per CT scan could be reduced without any significant loss of information in children with CF. A cohort of children with CF was followed with biennial surveillance CT scans, obtained in inspiration after a voluntary breath-hold as 1-mm thick images at 10-mm intervals from lung apex to base. A random set of 20 baseline CT scans and 10 follow-up CT scans were blinded. Sets of every image (10-mm intervals), every second image (20-mm intervals), every third image (30-mm intervals) and a selection of three and five images were scored randomly using a published CT scoring system by one experienced observer. The 20 subjects were 10 years of age with a range of 3.7-17.6 years at baseline. Fewer CT images resulted in a significantly lower (less abnormal) CT score and the number of patients positive for abnormalities decreased subsequently. At intervals greater than 20 mm no significant change in CT score over 2 years could be detected, while the CT scores at 10-mm (P=0.02) and 20-mm (P=0.02) intervals worsened significantly. A reduction in the number of inspiratory CT images by increasing the interval between images to greater than 10 mm is not a valid option for radiation dose reduction in children with CF. (orig.)

  13. Angiogenesis in hepatocellular carcinoma: correlation of single-level dynamic spiral CT scans in arterial phase and expression of α-smooth muscle actin

    International Nuclear Information System (INIS)

    Liu Yan; Min Pengqiu; Chen Weixia; Zhang Lin

    2005-01-01

    Objective: To investigate the correlation between the single-level dynamic spiral CT scans (SDCT) of hepatocellular carcinoma (HCC) in arterial phase (AP) and the immunohistochemistry expression of α-smooth muscle actin (ASMA). Methods: 33 cases of suspected HCC undergoing spiral CT plain scan of the whole liver, the single-level dynamic scan of the target level of lesion in AP and finally the whole liver scan in portal-venous phase before operations and proved after were included into the study. After the SDCT, a time-density curve (T-DC) was drawn according to the density change of the region of interest (ROI) of the tumor parenchyma with some parameters calculated, and signs of enhancement evaluated. Slices of post-operation specimen underwent hemotoxylin-eosin (HE) and ASMA immunohistochemistry staining. Then the slices were evaluated with emphases on the ASMA-positive neovasculatures in the parenchyma and mesenchyma of carcinomas, and the average count in a low microscopic field (x 100) was recorded (5 low microscopic field were observed and then an average was calculated.). Finally the immunohistochemistry and histologic results were correlated with image findings. Results: According to the PV of the tumor parenchyma, T-DC was divided into type I, II and III in which the criteria were PV>80, 40 HU< PV< 80 HU and PV<40 HU respectively. In the 33 cases, type I, II and III of T-DC were 3, 17 and 13 cases with PV of 103.30, 57.65 and 33.55 HU respectively. In ASMA immunohistochemistry study, ASMA-positive neovasculatures were devided into type A with a thick wall and B with a thin wall. The mean count of neovasculatures of tumor parenchyma in type I, II and III of T-DC were 10, 4.59 and 1 respectively. Statistically, different types of T-DC were significantly correlated with the count of neovasculatures in the parenchyma of carcinomas (r=-0.567, P<0.01). Homogeneous and inhomogeneous enhancement of carcinomas during SDCT in AP were correlated with the

  14. Automated Agatston score computation in non-ECG gated CT scans using deep learning

    Science.gov (United States)

    Cano-Espinosa, Carlos; González, Germán.; Washko, George R.; Cazorla, Miguel; San José Estépar, Raúl

    2018-03-01

    Introduction: The Agatston score is a well-established metric of cardiovascular disease related to clinical outcomes. It is computed from CT scans by a) measuring the volume and intensity of the atherosclerotic plaques and b) aggregating such information in an index. Objective: To generate a convolutional neural network that inputs a non-contrast chest CT scan and outputs the Agatston score associated with it directly, without a prior segmentation of Coronary Artery Calcifications (CAC). Materials and methods: We use a database of 5973 non-contrast non-ECG gated chest CT scans where the Agatston score has been manually computed. The heart of each scan is cropped automatically using an object detector. The database is split in 4973 cases for training and 1000 for testing. We train a 3D deep convolutional neural network to regress the Agatston score directly from the extracted hearts. Results: The proposed method yields a Pearson correlation coefficient of r = 0.93; p <= 0.0001 against manual reference standard in the 1000 test cases. It further stratifies correctly 72.6% of the cases with respect to standard risk groups. This compares to more complex state-of-the-art methods based on prior segmentations of the CACs, which achieve r = 0.94 in ECG-gated pulmonary CT. Conclusions: A convolutional neural network can regress the Agatston score from the image of the heart directly, without a prior segmentation of the CACs. This is a new and simpler paradigm in the Agatston score computation that yields similar results to the state-of-the-art literature.

  15. Evaluation of variation of voltage (kV) absorbed dose in chest CT scans

    International Nuclear Information System (INIS)

    Mendonca, Bruna G.A.; Mourao, Arnaldo P.

    2013-01-01

    Computed tomography (CT) is one of the most important diagnostic techniques images today. The increasing utilization of CT implies a significant increase of population exposure to ionizing radiation. Optimization of practice aims to reduce doses to patients because the image quality is directly related to the diagnosis. You can decrease the amount of dose to the patient, and maintain the quality of the image. There are several parameters that can be manipulated in a CT scan and these parameters can be used to reduce the energy deposited in the patient. Based on this, we analyzed the variation of dose deposited in the lungs, breasts and thyroid, by varying the supply voltage of the tube. Scans of the thorax were performed following the protocol of routine chest with constant and variable current for the same applied voltage. Moreover, a female phantom was used and thermoluminescent dosimeters (TLD-100), model bat, were used to record the specific organ doses. Scans were performed on a GE CT scanner, model 64 Discovery channels. Higher doses were recorded for the voltage of 120 kV with 200 mAs in the lungs (22.46 mGy) and thyroid (32.22 mGy). For scans with automatic mAs, variable between 100 and 440, this same tension contributed to the higher doses. The best examination in terms of the dose that was used with automatic 80 kV mAs, whose lungs and thyroid received lower dose. For the best breast exam was 100 kV. Since the increase in the 80 kV to 100 kV no impact so much the dose deposited in the lungs, it can be concluded that lowering the applied voltage to 100 kV resulted in a reduction in the dose absorbed by the patient. These results can contribute to optimizing scans of the chest computed tomography

  16. Automatic calibration method of voxel size for cone-beam 3D-CT scanning system

    International Nuclear Information System (INIS)

    Yang Min; Wang Xiaolong; Wei Dongbo; Liu Yipeng; Meng Fanyong; Li Xingdong; Liu Wenli

    2014-01-01

    For a cone-beam three-dimensional computed tomography (3D-CT) scanning system, voxel size is an important indicator to guarantee the accuracy of data analysis and feature measurement based on 3D-CT images. Meanwhile, the voxel size changes with the movement of the rotary stage along X-ray direction. In order to realize the automatic calibration of the voxel size, a new and easily-implemented method is proposed. According to this method, several projections of a spherical phantom are captured at different imaging positions and the corresponding voxel size values are calculated by non-linear least-square fitting. Through these interpolation values, a linear equation is obtained that reflects the relationship between the voxel size and the rotary stage translation distance from its nominal zero position. Finally, the linear equation is imported into the calibration module of the 3D-CT scanning system. When the rotary stage is moving along X-ray direction, the accurate value of the voxel size is dynamically exported. The experimental results prove that this method meets the requirements of the actual CT scanning system, and has virtues of easy implementation and high accuracy. (authors)

  17. Comparative evaluation of coronal images of the middle ear visualized by CT scan and polytomography

    International Nuclear Information System (INIS)

    Sugiyama, Masao; Nakai, Yoshiaki; Cho, Kansei; Tanabe, Kyoji; Inoue, Yuichi; Onoyama, Yasuto

    1982-01-01

    We retrospectively analysed the coronal images of the middle ear obtained by multidirectional tomography (polytomography) and computed tomography (CT) in 40 patients. Although CT was capable of demonstrating water density in the middle ear more clearly than polytomography and of delineating a lesion extending even outside of the petrous bone, the diagnostic capability was not much different between the two tomographic techniques. On the other hand, coronal CT scan has a disadvantage in that it usually has to be performed during hyperextension of the neck or while patients are in an uncomfortable hanging head position. We think that CT scan should be utilized only in case with a lesion extending beyond the petrous bone and/or is not well visualized by polytomography. (author)

  18. The relationship between contrast enhancement on CT and cerebral vasospasm in patient with subarachnoid hemorrhage

    International Nuclear Information System (INIS)

    Tazawa, Toshiaki; Mizukami, Masahiro; Kawase, Takeshi; Usami, Takashi; Togashi, Osamu

    1982-01-01

    Sixty patients with a single rupture of an aneurysm were subjected to study. Contrast enhanced CT (CECT) was performed by intravenous infusion of 100 ml of 60% meglumine iothalamate in 10 minutes. Post-contrast CT scans were repeated serially just after infusion, 15 minutes and 30 minutes later. Prominent increase in density in the region of the circle of Willis and its branches 30 minutes after infusion was considered as remarkable enhancement. In 17 (46%) out of 37 patients who underwent CECT within day 3, the contrast enhancement was remarkable. Transient or permanent symptomatic vasospasm occurred in 13 (76.5%) out of these 17 patients and the remaining 4 patients who underwent the operation with successful removal of subarachnoid clot within day 3 did not develop symptomatic vasospasm. Eight (67%) out of 12 patients operated within day 3, in whom post-operative CT showed incomplete removal of subarachnoid clot, developed transient or permanent symptomatic vasospasm. In only one (5%) out of 20 patients without remarkable enhancement, transient symptomatic vasospasm occurred. The abnormal contrast enhancement in the region of the circle of Willis and its branches within day 3 was closely related to the subsequent occurrence of vasospasm. Contrast enhanced CT was performed in 41 patients after day 3. There was no patient with remarkable enhancement on CECT. There was no relationship between the findings on CECT after day 3 and the occurrence of vasospasm. CECT within day 3 allows prediction of that patient destined for vasospasm and early removal of subarachnoid clot within day 3 may minimize the future development of vasospasm.(J.P.N.)

  19. Evaluation of the image quality of chest CT scans: a phantom study

    Energy Technology Data Exchange (ETDEWEB)

    Martins N, P. I.; Prata M, A., E-mail: priscillainglid@gmail.com [Centro Federal de Educacao Tecnologica de Minas Gerais, Centro de Engenharia Biomedica, Av. Amazonas 5253, 30421-169 Nova Suica, Belo Horizonte, Minas Gerais (Brazil)

    2016-10-15

    Computed tomography (CT) is considered one of the most important methods of medical imaging employed nowadays, due to its non-invasiveness and the high quality of the images it is able to generate. However, the diagnostic radiation dose received by an individual over the year often exceeds the dose received on account of background radiation. Therefore, it is important to know and to control the dose distribution in the patient by varying the image acquisition parameters. The aim of this study is to evaluate the variation of the image quality of chest CT scans performed by two phantoms. In this paper, a cylindrical Polymethyl Methacrylate (PMMA) chest phantom was used and a second PMMA phantom has been developed with the same volume but an oblong shape, based on the actual dimensions of a male human thorax, in the axillary region. Ten-centimeter scans of the central area of each phantom were performed by a 16-channel Toshiba CT scanner, model Alexion. The scanning protocol employed was the radiology service protocol for chest scans. The noise survey was conducted within the image of the center slice, in five regions: one central and four peripheral areas close to the edge of the object (anterior, posterior, left and right). The recorded values showed that the oblong phantom, with a shape that is more similar to the actual human chest, has a considerably smaller noise, especially in the anterior, posterior and central regions. (Author)

  20. Evaluation of the image quality of chest CT scans: a phantom study

    International Nuclear Information System (INIS)

    Martins N, P. I.; Prata M, A.

    2016-10-01

    Computed tomography (CT) is considered one of the most important methods of medical imaging employed nowadays, due to its non-invasiveness and the high quality of the images it is able to generate. However, the diagnostic radiation dose received by an individual over the year often exceeds the dose received on account of background radiation. Therefore, it is important to know and to control the dose distribution in the patient by varying the image acquisition parameters. The aim of this study is to evaluate the variation of the image quality of chest CT scans performed by two phantoms. In this paper, a cylindrical Polymethyl Methacrylate (PMMA) chest phantom was used and a second PMMA phantom has been developed with the same volume but an oblong shape, based on the actual dimensions of a male human thorax, in the axillary region. Ten-centimeter scans of the central area of each phantom were performed by a 16-channel Toshiba CT scanner, model Alexion. The scanning protocol employed was the radiology service protocol for chest scans. The noise survey was conducted within the image of the center slice, in five regions: one central and four peripheral areas close to the edge of the object (anterior, posterior, left and right). The recorded values showed that the oblong phantom, with a shape that is more similar to the actual human chest, has a considerably smaller noise, especially in the anterior, posterior and central regions. (Author)

  1. Detection of lacunar infarction in brain CT-scans: No evidence of bias from accompanying patient information

    International Nuclear Information System (INIS)

    Bonke, B.; Knippenberg, F.C.E. van; Duivenvoorden, H.J.; Kappelle, L.J.

    1989-01-01

    Interobserver agreement in assessing brain CT-scans is, in general, high. The extent, however, to which such agreement is caused by bias through knowledge of other clinical details remains uncertain. The hypothesis that observers are somehow prejudiced before assessing ambiguous, CT-scans in this particular situation was tested. Sixteen neurologists and 16 radiologists volunteered to interpret two ambiguous brain CT-scans, with regard to the presence or absence of a lacunar infarct in the region of the internal capsule. The scans were accompanied by 'patient' information that was or was not suggestive of a stroke. These scans were camouflaged by a variety of other scans, to be assessed in the same way, to mask the purpose of the study. I was assumed that the observers, in their assessments of the scans, would somehow let their ratings of the likelihood of a lacunar infarction in or near the internal capsule be subject to the accompanying information. Results showed lower ratings produced by neurologists (i.e., less likelihood of an infarction) than by radiologists in the majority of all assessments, but no bias by the accompanying information. (orig.)

  2. Iohexol for contrast enhancement of bowel in pediatric abdominal CT

    International Nuclear Information System (INIS)

    Smevik, B.; Westvik, J.

    1990-01-01

    Abdominal CT scans from 160 examinations performed on pediatric patients using iohexol 2 percent as contrast medium for bowel enhancement were evaluated retrospectively. When diluted with a beverage of the child's choice, iohexol has a neutral taste and cannot be detected, and 139 out of 142 patients drank the full amount of dilute contrast offered to them. The enhancement of bowel in the area of interest was graded as good (58%), reasonable (23%), or poor (19%). The contrast medium was prepared from leftovers from our angiocardiography studies. We conclude that the use of water-soluble contrast medium in a low concentration is a safe and cost-effective way of facilitating ingesion of sufficient amounts of the medium in oncologic pediatric patients undergoing cytotoxic and/or radiation treatment. (orig.)

  3. Helical CT appearance of hypovascular small hepatocellular carcinoma with pathologic correlation

    International Nuclear Information System (INIS)

    Zheng Keguo; Xu Dasheng; Shen Jingxian

    2003-01-01

    Objective: To study the helical CT dual-phase enhancement manifestation of the hypodense small hepatocellular carcinoma, and to evaluate its correlation with the histopathology. Methods: The CT signs and its histopathologic changes were analyzed in 25 cases with 27 hypodense lesions in helical CT dual-phase enhancement. All the lesions were confirmed as small hepatocellular carcinoma by operation and histopathology. Results: (1) On unenhanced scan, 16 lesions were with obscure borders and 11 lesions were with well-delineated borders. On enhanced scan, only 7 lesions were with obscure borders and the other 20 lesions were with well-delineated borders, and their contours were slightly irregular. (2) On unenhanced scan, 18 lesions showed homogeneous hypodensity and 9 lesions showed heterogeneous hypodensity. On enhanced scan, only 6 lesions showed homogeneous hypodensity and the other 21 lesions showed heterogeneous hypodensity with multiple flecks of more hypodense areas. Conclusion: The helical CT dual-phase enhancement characteristic manifestations of hypodense small hepatocellular carcinoma were as follows: the border of the lesion was obscure on unenhanced scan, however the border of the lesion became well-delineated and slightly irregular, and there were multiple flecks of more hypodense areas in the lesions after enhancement. This might be an important character in distinguishing hypodense small hepatocellular carcinoma from other hypodense diseases in the liver

  4. Spinal CT scan, 2

    International Nuclear Information System (INIS)

    Nakagawa, Hiroshi

    1982-01-01

    Plain CT described fairly accurately the anatomy and lesions of the lumbar and sacral spines on their transverse sections. Since hernia of the intervertebral disc could be directly diagnosed by CT, indications of myelography could be restricted. Spinal-canal stenosis of the lumbar spine occurs because of various factors, and CT not only demonstrated the accurate size and morphology of bony canals, but also elucidated thickening of the joints and yellow ligament. CT was also useful for the diagnosis of tumors in the lumbar and sacral spines, visualizing the images of bone changes and soft tissues on the trasverse sections. But the diagnosis of intradural tumors required myelography and metrizamide CT. CT has become important for the diagnosis of spinal and spinal-cord diseases and for selection of the route of surgical arrival. (Chiba, N.)

  5. Computed tomography of hepatocellular carcinoma: Usefulness of dynamic CT

    Energy Technology Data Exchange (ETDEWEB)

    Takemoto, Kazumasa; Inoue, Yuichi; Matsuoka, Toshiyuki; Nakatsuka, Haruki; Oda, Junro [Osaka City Univ. (Japan). Faculty of Medicine

    1983-04-01

    Dynamic computed tomography (CT) scans in 65 hepatocellular carcinomas were analyzed and compared to plain and drip infusion contrast CT scans of those. Scans were obtained before, 10, 30, and 50 seconds after an intravenous bolus injection of 50ml 65% Angiografin. By this method, 49 hepatomas had moderate to marked enhancement at the arterial phase while the enhancement of normal liver parenchyma was only slight at the arterial phase and peaked at the portal phase. Compared to a drip infusion contrast CT, a dynamic CT had advantages to detect an isodense hepatoma in 4 and daughter tumors in 16 both of which were not appreciated by a plain and a drip infusion contrast CT. The tumor extension was also better delineated by a dynamic CT because a part of hepatoma had an isodense area. An arterio-portal shunt was visualized in one. Tumor thrombus in the portal vein was clearly demonstrated in 6 at the portal phase of a dynamic CT. Since a dynamic CT is convenient to perform without any special program or soft wear and gives us very useful information, we believe that it should be routinely employed as a part of a liver CT examination.

  6. Abdominal lymphadenopathy in tuberculosis and lymphoma: Differentiation with CT

    International Nuclear Information System (INIS)

    Shin, Yong Moon; Choi, Byung Ihn; Han, Joon Koo; Han, Man Chung; Song, Chi Sung; Yang, Seoung Oh

    1993-01-01

    Tuberculosis and lymphoma, these 2 dieases can present with lymphadenopathy in anywhere of the body. Therefore differentiation of tuberculosis from lymphoma is often difficult. CT scans of 17 patients with tuberculosis and 23 patients with lymphoma were retrospectively reviewed to evaluate the efficacy of CT scans in differentating adenopathy between tuberculosis and lymphoma. All the patients underwent abdominal CT scans with contrast enhancement before treatment. The size, internal architecture, distribution of lymph nodes, and associated findings on CT scans were analyzed. As compared with lymphoma, tuberculous lymphadenopathy showed 1) female preponderance (65%), 2) predilection for percolative lymph nodes (47%), 3) internal low attenuation in lymph nodes (82%), 4) cold abscess formation (24%). Characteristics of lymphoma on CT scans include 1) male preponderance (78%), 2) conglomeration of lymph nodes (39%), 3) homogeneous internal lymph node structure (83%). These results suggest that evaluation of the cahracteristics of lymphadenopathy on CT scans is helpful for differentiating between tuberculousis and lymphoma

  7. Gadolinium-DTPA and gadodiamide as an alternative contrast medium for CT

    International Nuclear Information System (INIS)

    Engelbrecht, V.; Koch, J.A.; Rassek, M.; Moedder, U.

    1996-01-01

    To evaluate the effect of intravenously applied gadolinium-based contrast medium in computed tomographic (CT) studies. Serial dilutions of iohexol 300, Gd-DTPA and gadodiamide were scanned with CT in a phantom study using water filled tubes. For quantification of X-ray attenuation, the mean Hounsfield units (HU) were calculated from the CT scans. Five patients with contraindications against iodine contrast agents were examined with abdominal or thoracic CT before and after application of 0.2 mmol/kg body weight of a gadolinium-based contrast agent. In these patients attenuation values were obtained in ROI from unenhanced and enhanced CT scans. The phantom study revealed a 38,4% enhancement for Gd-DTPA and a 35.7% enhancement for gadodiamide scaled on the reference measurements with iohexol 300. Thus, 130.2 ml Gd-DTPA or 140.1 ml gadodiamide are needed to achieve the same attenuation as an i.v. injection of 50 ml iohexol 300. Consequently the corresponding dose of 1 mmol/kg body weight would exceed the manufacturer's recommended dose. In four patients with complete thoracic or abdominal CT, i.v. applied gadolinium-based contrast medium (0.2 mmol/kg) yielded no visible advantage. In these patients parenchymal enhancement did not exceed 25%. Dynamic CT of a patient with focal liver lesion revealed an arterial enhancement peak of 75%. Sufficient parenchymal enhancement in CT studies cannot be achieved with the available gadolinium-based contrast mediums. They might be helpful if only short time vascular enhancement is required. (orig.) [de

  8. Measurement of mesothelioma on thoracic CT scans: A comparison of manual and computer-assisted techniques

    International Nuclear Information System (INIS)

    Armato, Samuel G. III; Oxnard, Geoffrey R.; MacMahon, Heber; Vogelzang, Nicholas J.; Kindler, Hedy L.; Kocherginsky, Masha; Starkey, Adam

    2004-01-01

    Our purpose in this study was to evaluate the variability of manual mesothelioma tumor thickness measurements in computed tomography (CT) scans and to assess the relative performance of six computerized measurement algorithms. The CT scans of 22 patients with malignant pleural mesothelioma were collected. In each scan, an initial observer identified up to three sites in each of three CT sections at which tumor thickness measurements were to be made. At each site, five observers manually measured tumor thickness through a computer interface. Three observers repeated these measurements during three separate sessions. Inter- and intra-observer variability in the manual measurement of tumor thickness was assessed. Six automated measurement algorithms were developed based on the geometric relationship between a specified measurement site and the automatically extracted lung regions. Computer-generated measurements were compared with manual measurements. The tumor thickness measurements of different observers were highly correlated (r≥0.99); however, the 95% limits of agreement for relative inter-observer difference spanned a range of 30%. Tumor thickness measurements generated by the computer algorithms also correlated highly with the average of observer measurements (r≥0.93). We have developed computerized techniques for the measurement of mesothelioma tumor thickness in CT scans. These techniques achieved varying levels of agreement with measurements made by human observers

  9. Contrast between hypervascularized liver lesions and hepatic parenchyma. Early dynamic PET versus contrast-enhanced CT

    International Nuclear Information System (INIS)

    Freesmeyer, M.; Winkens, T.; Schierz, J.-H.

    2014-01-01

    To detect hypervascularized liver lesions, early dynamic (ED) 18 F-FDG PET may be an alternative when contrast-enhanced (CE) imaging is infeasible. This retrospective pilot analysis compared contrast between such lesions and liver parenchyma, an important objective image quality variable, in ED PET versus CE CT. Twenty-eight hypervascularized liver lesions detected by CE CT [21 (75%) hepatocellular carcinomas; mean (range) diameter 4.9 ± 3.5 (1-14) cm] in 20 patients were scanned with ED PET. Using regions of interest, maximum and mean lesional and parenchymal signals at baseline, arterial and venous phases were calculated for ED PET and CE CT. Lesional/parenchymal signal ratio was significantly higher (P < 0.005) with ED PET versus CE CT at the arterial phase and similar between the methods at the venous phase. In liver imaging, ED PET generates greater lesional-parenchymal contrast during the arterial phase than does CE CT; these observations should be formally, prospectively evaluated. (author)

  10. Low-dose computed tomography scans with automatic exposure control for patients of different ages undergoing cardiac PET/CT and SPECT/CT.

    Science.gov (United States)

    Yang, Ching-Ching; Yang, Bang-Hung; Tu, Chun-Yuan; Wu, Tung-Hsin; Liu, Shu-Hsin

    2017-06-01

    This study aimed to evaluate the efficacy of automatic exposure control (AEC) in order to optimize low-dose computed tomography (CT) protocols for patients of different ages undergoing cardiac PET/CT and single-photon emission computed tomography/computed tomography (SPECT/CT). One PET/CT and one SPECT/CT were used to acquire CT images for four anthropomorphic phantoms representative of 1-year-old, 5-year-old and 10-year-old children and an adult. For the hybrid systems investigated in this study, the radiation dose and image quality of cardiac CT scans performed with AEC activated depend mainly on the selection of a predefined image quality index. Multiple linear regression methods were used to analyse image data from anthropomorphic phantom studies to investigate the effects of body size and predefined image quality index on CT radiation dose in cardiac PET/CT and SPECT/CT scans. The regression relationships have a coefficient of determination larger than 0.9, indicating a good fit to the data. According to the regression models, low-dose protocols using the AEC technique were optimized for patients of different ages. In comparison with the standard protocol with AEC activated for adult cardiac examinations used in our clinical routine practice, the optimized paediatric protocols in PET/CT allow 32.2, 63.7 and 79.2% CT dose reductions for anthropomorphic phantoms simulating 10-year-old, 5-year-old and 1-year-old children, respectively. The corresponding results for cardiac SPECT/CT are 8.4, 51.5 and 72.7%. AEC is a practical way to reduce CT radiation dose in cardiac PET/CT and SPECT/CT, but the AEC settings should be determined properly for optimal effect. Our results show that AEC does not eliminate the need for paediatric protocols and CT examinations using the AEC technique should be optimized for paediatric patients to reduce the radiation dose as low as reasonably achievable.

  11. A fully automated non-external marker 4D-CT sorting algorithm using a serial cine scanning protocol.

    Science.gov (United States)

    Carnes, Greg; Gaede, Stewart; Yu, Edward; Van Dyk, Jake; Battista, Jerry; Lee, Ting-Yim

    2009-04-07

    Current 4D-CT methods require external marker data to retrospectively sort image data and generate CT volumes. In this work we develop an automated 4D-CT sorting algorithm that performs without the aid of data collected from an external respiratory surrogate. The sorting algorithm requires an overlapping cine scan protocol. The overlapping protocol provides a spatial link between couch positions. Beginning with a starting scan position, images from the adjacent scan position (which spatial match the starting scan position) are selected by maximizing the normalized cross correlation (NCC) of the images at the overlapping slice position. The process was continued by 'daisy chaining' all couch positions using the selected images until an entire 3D volume was produced. The algorithm produced 16 phase volumes to complete a 4D-CT dataset. Additional 4D-CT datasets were also produced using external marker amplitude and phase angle sorting methods. The image quality of the volumes produced by the different methods was quantified by calculating the mean difference of the sorted overlapping slices from adjacent couch positions. The NCC sorted images showed a significant decrease in the mean difference (p < 0.01) for the five patients.

  12. Arterio-venous anastomoses in mice affect perfusion measurements with dynamic contrast enhanced CT

    International Nuclear Information System (INIS)

    Gabra, Peter; Lee, Ting-Yim; Shen, Gang; Xuan, Jim

    2010-01-01

    Accurate measurement of perfusion with dynamic contrast enhanced CT requires an arterial input curve (AIC) uncontaminated by venous sources. Arterio-venous anastomoses (AVAs) are sources of contamination if contrast is injected intravenously. We seek to identify AVAs in mice and associated errors in perfusion measurements. Six transgenic mice with spontaneous prostate tumor were scanned with a micro-CT scanner (GE Healthcare (GE)) using a high resolution anatomical and a lower resolution perfusion protocol. For the anatomical protocol, a CT scan was performed during injection of an iodinated contrast agent (Hypaque) into a tail vein. Images covering the thoracic, abdominal and pelvic regions at an isotropic resolution of 175 µm were reconstructed and rendered in 3D to show the arterial and venous tree (Advantage Window, GE). For the perfusion protocol, each mouse was continuously scanned for 40 s and the contrast agent (Hypaque) was injected via a tail vein 5 s into scanning. Tumor images were reconstructed every second. Tumor blood flow (BF) and volume (BV) maps were calculated with CT perfusion software (GE) using AIC measured either from abdominal aorta (AA) or tail (caudal) artery (TA). In all mice, there was an AVA from the bifurcation of the inferior vena cava to the tail artery shunting venous blood and portion of the contrast agent injected into the tail vein into the TA. Contrast arrival time at the TA preceded that at the AA by 3.3 ± 0.5 s (P < 0.05). Mean tumor BV and BF values calculated with AA versus TA were 10.0 ± 1.8 versus 4.8 ± 2.1 ml (100 g) −1 (P < 0.05) and 108.8 ± 26.5 versus 33.0 ± 8.5 ml min −1 100 g −1 (P < 0.05), respectively. AVA in the murine pelvic region can result in inaccurate and more variable measurements of pelvic organ/tissue perfusion when the tail artery is used as the AIC

  13. CT and MRI diagnosis of intracranial chondroma

    International Nuclear Information System (INIS)

    Liu Xuejun; Sui Qinglan

    2006-01-01

    Objective: To summarize and study the features of intracranial chondroma on CT and MRI imaging. Methods: CT and MRI findings of ten cases of intracranial chondroma proved by surgery and pathology from 1994. 1 to 2004.9 were retrospectively analyzed. Results: Among 10 cases, 4 cases were located at the skull base, 4 cases at convexity, 1 case at the region of falx cerebri, and 1 case within the brain parenchyma. CT scans showed obvious calcification and clear border of the tumors in 10 cases, mixed attenuation in 9 eases, and adjacent bone invasion in 5 cases. 4 cases of MRI scans showed hypointense signal on T 1 and T 2 -weighted images in calcified element of the tumor, intermediate to hypointense signal intensity on T 1 -weighted image, and hyperintense signal intensity on T 2 -weighted image in parenchyma of the tumor. 4 cases of CT scans showed slightly enhancement. Conclusion: Intracranial chondroma are often originated from synchondrosis of the skull base, convexity of brain and region of falx cerebri. Obvious calcification may be seen in most cases. Slightly enhancement and marked delayed contrast enhancement were characteristic. The accurate diagnosis still depends on pathology. (authors)

  14. F-18-Fluorodeoxyglucose Positron Emission Tomography/CT Scanning in Diagnosing Vascular Prosthetic Graft Infection

    NARCIS (Netherlands)

    Saleem, Ben R.; Pol, Robert A.; Slart, Riemer H. J. A.; Reijnen, Michel M. P. J.; Zeebregts, Clark J.

    2014-01-01

    Vascular prosthetic graft infection (VPGI) is a severe complication after vascular surgery. CT-scan is considered the diagnostic tool of choice in advanced VPGI. The incidence of a false-negative result using CT is relatively high, especially in the presence of low-grade infections.

  15. Computed tomographic (CT) scans in cerebral palsy (CP)

    International Nuclear Information System (INIS)

    Kolawole, T.M.; Patel, P.J.; Mahdi, A.H.

    1989-01-01

    The CT findings in 120 cerebral palsied children are analysed. The 72.5% positive findings are correlated with the clinical types, as well as the aetiological basis for the cerebral palsy. The spastic type, 83.3% of the total number of children, had the highest positive findings. The yield was increased in children with seizures (91.3%) and those in the postnatal group (90%), as well as those with birth trauma and neonatal asphyxia (94%). The findings were those of atrophy in 30.8%, hydrocephalus, in 10%, infarct in 11.6%, porencephaly in 8.3% and others. The atropic changes and their patterns are explained. Treatable lesions, such as tumour, hydrocephalus, subdural haematoma, porencephaly and hygroma were identified in 22.5% of cases. It is concluded that CT scan is definitely efficacious in the management of cerebral palsied children. (orig.)

  16. Is direct radiologist supervision of abdominal computed tomography (CT) scans necessary?

    Energy Technology Data Exchange (ETDEWEB)

    Goh, V. [Department of Clinical Radiology, Northwick Park and St Mark' s Hospitals, Harrow (United Kingdom); Paul Strickland Scanner Centre, Mount Vernon Hospital, Northwood (United Kingdom); Halligan, S. [Department of Clinical Radiology, Northwick Park and St Mark' s Hospitals, Harrow (United Kingdom)]. E-mail: s.halligan@imperial.ac.uk; Anderson, J.M. [Department of Clinical Radiology, Northwick Park and St Mark' s Hospitals, Harrow (United Kingdom); Hugill, J. [Department of Clinical Radiology, Northwick Park and St Mark' s Hospitals, Harrow (United Kingdom); Leonard, A. [Department of Clinical Radiology, Northwick Park and St Mark' s Hospitals, Harrow (United Kingdom)

    2005-07-01

    AIM: To determine the effect of direct radiological supervision of patients attending for abdominal CT by assessing the frequency of protocol alteration subsequent to radiologist review of the images obtained. MATERIALS AND METHODS: A prospective questionnaire-based observational study was performed of 187 consecutive patients undergoing abdominal CT. The CT protocol was determined by a radiologist in advance, with reference to the request form. Any subsequent change in the prescribed study that was contingent on radiologist review of the images obtained was documented on the questionnaire. Comparison was made with a second (control) group of 100 patients undergoing cranial CT. RESULTS: A protocol change was undertaken following radiologist review of the CT images of 17 (9%) of the group undergoing abdominal CT, compared with 14 (14%) of the group undergoing cranial CT. In the abdominal CT group, further scanning was performed for lesion characterization, to guide a subsequent interventional procedure, because of inadequate anatomical coverage or to evaluate an unexpected lung tumour. There was no significant difference in proportions between the two groups (p=0.23). CONCLUSION: When abdominal and cranial CT studies were compared, there was no significant difference in the proportion of studies requiring a change in the prescribed protocol following radiologist review of the images obtained. There was no evidence to suggest that abdominal CT was any less suited to protocol.

  17. The influence of upper limb position on the effect of a contrast agent in chest CT enhancement

    International Nuclear Information System (INIS)

    Feng, Shi-Ting; Wang, Meng; Gao, Zhenhua; Tan, Guosheng; Cai, Huasong; Hu, Xiaoshu; Yang, Jianyong; Li, Zi-Ping

    2013-01-01

    Purpose: To compare the influence of two different upper limb positions on contrast agent effects in chest CT enhancement. Materials and methods: In 142 patients undergoing contrast-enhanced CT chest scanning, an indwelling venous catheter was placed in the right hand and iodinated contrast agent was injected through a high-pressure single syringe pump. The patients were divided into three age groups (<40 years; 40–60 years; and >60 years) and randomly assigned to one of two upper limb position groups: (1) supine position, both upper limbs extended and raised above head in the same horizontal plane as the body; and (2) supine position, both upper limbs raised and crossed on the forehead, with the right arm on top. Differences in mean CT values on the two sides of the thoracic inlet along the right subclavian vein were used to evaluate the effects of the contrast agent. Results: Although contrast agent effects were not significantly different among the three age groups with either limb position, there was a significant difference between patients adopting the second limb positions (Chi-square value was 5.936, P < 0.05). An excellent or good contrast agent effect was observed in 63.08% of patients assuming the first limb position, as compared with 81.69% assuming the second position. Conclusion: For contrast-enhanced CT chest scans, use of the second limb position can reduce retention of the contrast agent in the right axillary vein and the right subclavian vein outside the thorax, increase contrast agent utilization, and decrease artifacts caused by high-density, local retention of the contrast agent

  18. Case of asymmetrical arthrogryposis. A clinical study and a preliminary report on the value of CT-scanning

    Energy Technology Data Exchange (ETDEWEB)

    Hageman, G.; Vette, J.K.; Willemse, J. (University Hospital, Utrecht (Netherlands))

    1983-01-01

    Following the introduction of the conception that arthrogryposis is a symptom and not a clinical entity, a case of the very rare asymmetric form of neurogenic arthrogryposis is presented. The asymmetry of congenital contractures and weakness is associated with hemihypotrophy. The value of muscular CT-scanning prior to muscle biopsy is demonstrated. Muscular CT-scanning shows the extension of adipose tissue, which has replaced damaged muscles and therby indicates the exact site for muscle biopsy. Since orthopaedic treatment in arthrogryposis can be unrewarding due to severe muscular degeneration, preoperative scanning may provide additional important information on muscular function and thus be of benefit for surgery. The advantage of muscular CT-scanning in other forms of arthrogryposis requires further determination. The differential diagnosis with Werdnig-Hoffmann disease is discussed.

  19. Bone scan and SPECT/CT findings in marble bone disease

    International Nuclear Information System (INIS)

    Kapoor, Jiten; Joshi, Prathamesh; Lele, Vikram

    2012-01-01

    Marble bone disease or osteopetrosis, is a rare inborn disorder characterized by the failure of osteoclasts to resorb bone. Overall incidence of the disease is estimated to be 1 case in 100,000-500,000 population. Whereas the radiographic features of the disease are well known, information on bone scan imaging is sparse in the literature. We present technitium 99m methylene diphosphonate ( 99m Tc MDP) bone scan features of osteopetrosis, along with single photon emission computed tomography-computed tomography(SPECT/CT) correlation in a young male.

  20. Bone scan and SPECT/CT findings in marble bone disease

    Energy Technology Data Exchange (ETDEWEB)

    Kapoor, Jiten; Joshi, Prathamesh; Lele, Vikram [Jaslok Hospital and Research Centre, Woril (India)

    2012-03-15

    Marble bone disease or osteopetrosis, is a rare inborn disorder characterized by the failure of osteoclasts to resorb bone. Overall incidence of the disease is estimated to be 1 case in 100,000-500,000 population. Whereas the radiographic features of the disease are well known, information on bone scan imaging is sparse in the literature. We present technitium 99m methylene diphosphonate ({sup 99m}Tc MDP) bone scan features of osteopetrosis, along with single photon emission computed tomography-computed tomography(SPECT/CT) correlation in a young male.

  1. Contrast-enhanced dedicated breast CT detection of invasive breast cancer preceding mammographic diagnosis

    Directory of Open Access Journals (Sweden)

    Nicolas D. Prionas, MD, PhD

    2015-01-01

    Full Text Available Dedicated breast computed tomography (bCT generates high-resolution, three-dimensional images of the pendent uncompressed breast. Intravenous iodinated contrast during bCT provides additional physiologic information. In this case, a 10.0-mm invasive ductal carcinoma was visualized using contrast-enhanced breast CT one year before mammographic detection. Mammography four months before bCT was negative. The bCT contrast enhancement pattern closely matched the dynamic contrast-enhanced MRI obtained after diagnosis. Lesion enhancement at contrast-enhanced breast CT matched previously published enhancement values of breast cancer. Contrast-enhanced dedicated bCT provided high-resolution tomographic images and physiologic contrast enhancement data that facilitated the detection of an early breast cancer.

  2. Neuro-Behcet's syndrome with contrast enhancement on brain computed tomography

    International Nuclear Information System (INIS)

    Yamada, Takeshi; Tobimatsu, Shozo; Itoyama, Yasuto; Goto, Ikuo; Kuroiwa, Yoshigoro

    1986-01-01

    Two cases of neuro-Behcet's syndrome (N-B) with contrast enhancement (enhancement) on brain computed tomography (CT) are reported. Case 1. A 34-year-old man, who had a history of recurrent aphthous stomatitis, developed a left inferior homonymous quadrantanopsia. CT scans showed a large lucent area with a ring-like enhancement (3 cm in diameter) lesion in the right parietooccipital region. When he developed a left hemiplegia, CT scans showed a irregular lucent area with heterogenous enhancement lesions in the right basal ganglia and midbrain. Case 2. A 38-year-old woman, who had a history of recurrent aphthous stomatitis and genital ulcer, developed mental confusion. CT scans showed a large lucent area with a homogenous marked round enhancement lesion in the left basal ganglia. When she developed generalized convulsion, CT scans showed a large lucent area with a heterogenous irregular enhancement lesion in the right occipital lobe. Enhancement lesions were observed in the area corresponded to their neurological symptoms during acute exacerbations and disappeared within three months. Our cases suggest that N-B with acute exacerbations could show transient enhancement on CT. (author)

  3. Radiation dose reduction at a price: the effectiveness of a thyroid shield during head CT scanning

    International Nuclear Information System (INIS)

    Fu Qiang; Lu Tao; Zhang Ling

    2008-01-01

    Objective: To assess radiation dose to the thyroid in patients undergoing head CT scanning and to evaluate dose reduction to the thyroid by load shielding. Methods: A post-morterm was scanned by different model and study was undertaken to evaluate the dose reduction by thyroid lead shields and assess their practicality in a clinical setting. (a)No thyroid shields and (b) thyroid shield. One thermoluminescent dosimeters (TLDs)were placed over the thyroid gland center, A thyroid lead shield (Pb eq 0.5mm)was placed around the neck of post-morterm. Scan parameter, CTDIw and DLP were recorded. Results: (a) 0.207mSv; (b) 0.085mSv. A mean effective radiation dose reduction of 58% was seen in the shielded versus the unshielded. Conclusion: Thyroid exposure to scattered radiation from head CT scanning only once is associated with a low but not negligible risk of cancer, but accumulatived doses to the thyroid are serious, highlighting the need for increased awareness of patient radiation protection. Thyroid lead shielding yields significant radiation protection, which should be used routinely during head CT scan. (authors)

  4. Optimal CT scanning parameters for commonly used tumor ablation applicators

    International Nuclear Information System (INIS)

    Eltorai, Adam E.M.; Baird, Grayson L.; Monu, Nicholas; Wolf, Farrah; Seidler, Michael; Collins, Scott; Kim, Jeomsoon; Dupuy, Damian E.

    2017-01-01

    Highlights: • This study aimed to determine optimal scanning parameters for commonly-used tumor ablation applicators. • The findings illustrate the overall interaction of the effects of kVp, ASiR, and reconstruction algorithm within and between probes, so that radiologists may easily reference optimal imaging performance. • Optimum combinations for each probe are provided. - Abstract: Purpose: CT-beam hardening artifact can make tumor margin visualization and its relationship to the ablation applicator tip challenging. To determine optimal scanning parameters for commonly-used applicators. Materials and methods: Applicators were placed in ex-vivo cow livers with implanted mock tumors, surrounded by bolus gel. Various CT scans were performed at 440 mA with 5 mm thickness changing kVp, scan time, ASiR, scan type, pitch, and reconstruction algorithm. Four radiologists blindly scored the images for image quality and artifact quantitatively. Results: A significant relationship between probe, kVp level, ASiR level, and reconstruction algorithm was observed concerning both image artifact and image quality (both p = <0.0001). Specifically, there are certain combinations of kVp, ASiR, and reconstruction algorithm that yield better images than other combinations. In particular, one probe performed equivalently or better than any competing probe considered here, regardless of kVp, ASiR, and reconstruction algorithm combination. Conclusion: The findings illustrate the overall interaction of the effects of kVp, ASiR, and reconstruction algorithm within and between probes, so that radiologists may easily reference optimal imaging performance for a certain combinations of kVp, ASiR, reconstruction algorithm and probes at their disposal. Optimum combinations for each probe are provided.

  5. Optimal CT scanning parameters for commonly used tumor ablation applicators

    Energy Technology Data Exchange (ETDEWEB)

    Eltorai, Adam E.M. [Warren Alpert Medical School of Brown University (United States); Baird, Grayson L. [Department of Diagnostic Imaging (United States); Warren Alpert Medical School of Brown University (United States); Lifespan Biostatistics Core (United States); Rhode Island Hospital (United States); Monu, Nicholas; Wolf, Farrah; Seidler, Michael [Department of Diagnostic Imaging (United States); Warren Alpert Medical School of Brown University (United States); Rhode Island Hospital (United States); Collins, Scott [Department of Diagnostic Imaging (United States); Rhode Island Hospital (United States); Kim, Jeomsoon [Department of Medical Physics (United States); Rhode Island Hospital (United States); Dupuy, Damian E., E-mail: ddupuy@comcast.net [Department of Diagnostic Imaging (United States); Warren Alpert Medical School of Brown University (United States); Rhode Island Hospital (United States)

    2017-04-15

    Highlights: • This study aimed to determine optimal scanning parameters for commonly-used tumor ablation applicators. • The findings illustrate the overall interaction of the effects of kVp, ASiR, and reconstruction algorithm within and between probes, so that radiologists may easily reference optimal imaging performance. • Optimum combinations for each probe are provided. - Abstract: Purpose: CT-beam hardening artifact can make tumor margin visualization and its relationship to the ablation applicator tip challenging. To determine optimal scanning parameters for commonly-used applicators. Materials and methods: Applicators were placed in ex-vivo cow livers with implanted mock tumors, surrounded by bolus gel. Various CT scans were performed at 440 mA with 5 mm thickness changing kVp, scan time, ASiR, scan type, pitch, and reconstruction algorithm. Four radiologists blindly scored the images for image quality and artifact quantitatively. Results: A significant relationship between probe, kVp level, ASiR level, and reconstruction algorithm was observed concerning both image artifact and image quality (both p = <0.0001). Specifically, there are certain combinations of kVp, ASiR, and reconstruction algorithm that yield better images than other combinations. In particular, one probe performed equivalently or better than any competing probe considered here, regardless of kVp, ASiR, and reconstruction algorithm combination. Conclusion: The findings illustrate the overall interaction of the effects of kVp, ASiR, and reconstruction algorithm within and between probes, so that radiologists may easily reference optimal imaging performance for a certain combinations of kVp, ASiR, reconstruction algorithm and probes at their disposal. Optimum combinations for each probe are provided.

  6. Nodule detection methods using autocorrelation features on 3D chest CT scans

    International Nuclear Information System (INIS)

    Hara, T.; Zhou, X.; Okura, S.; Fujita, H.; Kiryu, T.; Hoshi, H.

    2007-01-01

    Lung cancer screening using low dose X-ray CT scan has been an acceptable examination to detect cancers at early stage. We have been developing an automated detection scheme for lung nodules on CT scan by using second-order autocorrelation features and the initial performance for small nodules (< 10 mm) shows a high true-positive rate with less than four false-positive marks per case. In this study, an open database of lung images, LIDC (Lung Image Database Consortium), was employed to evaluate our detection scheme as an consistency test. The detection performance for solid and solitary nodules in LIDC, included in the first data set opened by the consortium, was 83% (10/12) true-positive rate with 3.3 false-positive marks per case. (orig.)

  7. Role of mediastinal and multi-organ CT scans in staging presumable surgical candidates with non-small-cell lung cancer

    Energy Technology Data Exchange (ETDEWEB)

    Osada, Hiroaki; Nakajima, Yasuo; Taira, Yasuhiko; Yokote, Kumio; Noguchi, Teruhiko

    1987-09-01

    In order to evaluate the role of CT scan and bone scan in staging patients with non-small-cell lung cancer presumably indicated for surgery, 70 consecutive patients who underwent thoracotomy were reviewed. Most of them received mediastinal and multi-organ (brain, liver and adrenal) CT scans and a bone scan. In the most recent 40 of the 70 patients, CT findings of the mediastinal lymph nodes were compared to the pathology following complete sampling. The overall accuracy of the mediastinal CT was 60.0 per cent (12 true positive and 12 true negative), but the negative predictable value was 12/(12 + 3) or 80.0 per cent, whereas 3 were false negatives though they showed an acceptable postoperative course. Sixteen out of 21 patients with one, or at the most, three enlarged nodes detected on CT also did well postoperatively and retrospectively, were considered not to have required mediastinoscopy. A group of patients showing no, or at the most, three enlarged mediastinal lymph nodes on CT may be considered as candidates for surgery even without mediastinoscopy. Multi-organ survey by means of CT was believed cost-ineffective and omittable. Bone scan however, retrospectively detected three true positives among 20 patients with a positive uptake, so that it cannot be omitted out of hand, though further examination of this point is required.

  8. Study Finds Small Increase in Cancer Risk after Childhood CT Scans

    Science.gov (United States)

    A study published in the June 6, 2012, issue of The Lancet shows that radiation exposure from computed tomography (CT) scans in childhood results in very small but increased risks of leukemia and brain tumors in the first decade after exposure.

  9. False Positive Uptake in Bilateral Gynecomastia on 68Ga-PSMA PET/CT Scan.

    Science.gov (United States)

    Sasikumar, Arun; Joy, Ajith; Nair, Bindu P; Pillai, M R A; Madhavan, Jayaprakash

    2017-09-01

    A 66-year-old man on hormonal therapy with prostate cancer was referred for Ga-PSMA PET/CT scan for biochemical recurrence. Ga-PSMA PET/CT scan detected moderate heterogeneous tracer concentration in bilateral breast parenchyma, in addition to the abnormal tracer concentration in enlarged prostate gland, right external iliac lymph node, and sclerotic lesion in L4 vertebra. On clinical examination, he was found to have bilateral gynecomastia. Abnormal concentration of Ga-PSMA in breast cancer is now well known, and in this context, it is important to know that tracer localization can occur in gynecomastia as well, as evidenced in this case.

  10. Brain tumors and CT scans in infants and children, (3)

    International Nuclear Information System (INIS)

    Oi, Shizuo

    1983-01-01

    In clinical pictures of brain tumors in infants and children, many features are not identical to those in adults, including characteristics of the tumors in age population, the locations of the tumors, the clinical symptoms and signs, and various factors affecting prognosis. We have, therefore, clinically and extensively analyzed brain tumors in infants and children. This study was also performed in order to analyze the characteristic CT findings of astrocytoma, the tumor most frequently occurring among infants and children. The subjects were 24 cases of astrocytoma and 2 cases of glioblastoma in infants and children under 16 years. The locations and characteristics of the tumors were as follows. Most of the tumors occurred in the 4th ventricle, had a characteristic low density, and could almost entirely be clearly distinguished from medulloblastomas, but not from ependymomas, on CT. The features of the supratentorial tumors were similar to those of the astrocytomas and glioblastomas mostly appearing in adults, as previously reported, in the relatively close correlation with the location and malignancy of the tumor. There was also a case of diffuse astrocytoma, a ''non-enhanced low-density solid tumor,'' which raised clinical problems. Among low-grade astrocytomas in infants and children, only a few show a high density on plain CT, many have, at least macroscopically, a strong contrast enhancement, and peritumoral edema is not observed on CT or, if observed, is observed only slightly. As individual features, homogenous enhancement pattern, a mixed density, a central low density, and a rare absence of enhancement are listed. (author)

  11. Combined endeavor of Neutrosophic Set and Chan-Vese model to extract accurate liver image from CT scan.

    Science.gov (United States)

    Siri, Sangeeta K; Latte, Mrityunjaya V

    2017-11-01

    Many different diseases can occur in the liver, including infections such as hepatitis, cirrhosis, cancer and over effect of medication or toxins. The foremost stage for computer-aided diagnosis of liver is the identification of liver region. Liver segmentation algorithms extract liver image from scan images which helps in virtual surgery simulation, speedup the diagnosis, accurate investigation and surgery planning. The existing liver segmentation algorithms try to extort exact liver image from abdominal Computed Tomography (CT) scan images. It is an open problem because of ambiguous boundaries, large variation in intensity distribution, variability of liver geometry from patient to patient and presence of noise. A novel approach is proposed to meet challenges in extracting the exact liver image from abdominal CT scan images. The proposed approach consists of three phases: (1) Pre-processing (2) CT scan image transformation to Neutrosophic Set (NS) and (3) Post-processing. In pre-processing, the noise is removed by median filter. The "new structure" is designed to transform a CT scan image into neutrosophic domain which is expressed using three membership subset: True subset (T), False subset (F) and Indeterminacy subset (I). This transform approximately extracts the liver image structure. In post processing phase, morphological operation is performed on indeterminacy subset (I) and apply Chan-Vese (C-V) model with detection of initial contour within liver without user intervention. This resulted in liver boundary identification with high accuracy. Experiments show that, the proposed method is effective, robust and comparable with existing algorithm for liver segmentation of CT scan images. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. CT and MR findings of ovarian fibroma

    Energy Technology Data Exchange (ETDEWEB)

    Kong, Soo Jin; Rho, Myung Ho; Kim, Byung Heon; Song, Yun Gyu; Lee, Soo Han; Choi, Pil Yeob; Sung, Young Soon; Kwon, Jae Soo; Lee, Sang Wook [Masan Samsung Hospital, Masan (Korea, Republic of)

    1997-08-01

    To evaluate the charateristic CT and MR findings of the primary ovarian fibromas. We retrospectively reviewed 11 cases which had undergone precontrast and postcontrast scanning, and two in which cases T1-weighted (WI) and postcontrast T1WI and T2WI images had been done. All cases were pathologically confirmed after surgical resection. These masses were analysed on the bases of clinical symptoms, age, size(longest diameter), laterality, margin, attenuation(unenhanced and enhanced), signal intensity(SI), calcification, and amount of the ascites. The patients' mean age was 46.6(range, 22-81)years, and the longest diameter was 14.8(range, 8-28)cm. All tumors were unilateral, and eight were located in the left ovary and five in the right ovary. In all cases, the tumor margin was well-defined;seven were lobulated, four were oval, one was round, and one was nodularly marginated. On CT scan, the masses showed mild to moderate heterogenous enhancement with irregular lower density portions. The amount of the ascites was marked in three cases(23%), mild in two(15%), and minimal in three cases. Calcification were seen in 3 of 11 CT cases(27%), and in one, this was extensive. On MR scans, signal intensity (SI) of the masses on T1WI was isoSI, relativetive to the uterine myometrium, and heterogeneously enhanced after infusion of contrast media. On T2WI, SI was slightly lower that of the uterine myometrium with internal high SI portions. The characteristic finding of ovarian fibroma is a unilateral, well-defined, oval or lobulated, solid mass with or without ascites and calcification. On CT scan, tumor has mild to moderate heterogeneous enhancement. On MR scan, SI of mass is isoSI on T1WI with heterogeneous enhancement, and low SI on T2WI due to fibrous component.

  13. Quantifying the impact of µCT-scanning of human fossil teeth on ESR age results.

    Science.gov (United States)

    Duval, Mathieu; Martín-Francés, Laura

    2017-05-01

    Fossil human teeth are nowadays systematically CT-scanned by palaeoanthropologists prior to any further analysis. It has been recently demonstrated that this noninvasive technique has, in most cases, virtually no influence on ancient DNA preservation. However, it may have nevertheless an impact on other techniques, like Electron Spin Resonance (ESR) dating, by artificially ageing the apparent age of the sample. To evaluate this impact, we µCT-scanned several modern enamel fragments following the standard analytical procedures employed by the Dental Anthropology Group at CENIEH, Spain, and then performed ESR dose reconstruction for each of them. The results of our experiment demonstrate that the systematic high-resolution µCT-scanning of fossil hominin remains introduces a nonnegligible X-ray dose into the tooth enamel, equivalent to 15-30 Gy depending on the parameters used. This dose may be multiplied by a factor of ∼8 if no metallic filter is used. However, this dose estimate cannot be universally extrapolated to any µCT-scan experiment but has instead to be specifically assessed for each device and set of parameters employed. The impact on the ESR age results is directly dependent on the magnitude of the geological dose measured in fossil enamel but could potentially lead to an age overestimation up to 40% in case of Late Pleistocene samples, if not taken into consideration. © 2017 Wiley Periodicals, Inc.

  14. A fully automatic end-to-end method for content-based image retrieval of CT scans with similar liver lesion annotations.

    Science.gov (United States)

    Spanier, A B; Caplan, N; Sosna, J; Acar, B; Joskowicz, L

    2018-01-01

    The goal of medical content-based image retrieval (M-CBIR) is to assist radiologists in the decision-making process by retrieving medical cases similar to a given image. One of the key interests of radiologists is lesions and their annotations, since the patient treatment depends on the lesion diagnosis. Therefore, a key feature of M-CBIR systems is the retrieval of scans with the most similar lesion annotations. To be of value, M-CBIR systems should be fully automatic to handle large case databases. We present a fully automatic end-to-end method for the retrieval of CT scans with similar liver lesion annotations. The input is a database of abdominal CT scans labeled with liver lesions, a query CT scan, and optionally one radiologist-specified lesion annotation of interest. The output is an ordered list of the database CT scans with the most similar liver lesion annotations. The method starts by automatically segmenting the liver in the scan. It then extracts a histogram-based features vector from the segmented region, learns the features' relative importance, and ranks the database scans according to the relative importance measure. The main advantages of our method are that it fully automates the end-to-end querying process, that it uses simple and efficient techniques that are scalable to large datasets, and that it produces quality retrieval results using an unannotated CT scan. Our experimental results on 9 CT queries on a dataset of 41 volumetric CT scans from the 2014 Image CLEF Liver Annotation Task yield an average retrieval accuracy (Normalized Discounted Cumulative Gain index) of 0.77 and 0.84 without/with annotation, respectively. Fully automatic end-to-end retrieval of similar cases based on image information alone, rather that on disease diagnosis, may help radiologists to better diagnose liver lesions.

  15. Evaluation of optimal scan duration and end time in cerebral CT perfusion study

    International Nuclear Information System (INIS)

    Hirata, Masaaki; Sugawara, Yoshifumi; Miki, Hitoshi; Mochizuki, Teruhito; Murase, Kenya

    2005-01-01

    The purpose of this study was to evaluate the optimal end time of scanning and the influence of varying the number of source images adopted for calculation of the parameter values in computerized tomography (CT) perfusion. Nineteen CT perfusion studies in 14 patients with cerebrovascular disease were retrospectively analyzed. CT perfusion scanning was performed using continuous scans of 1 sec/rotation x 60 sec with 5-mm-thick sections. To determine the appropriate end time of scanning, the time-density curves (TDCs) of the anterior cerebral artery (ACA), superior sagittal sinus (SSS), and basal ganglia were analyzed. The functional maps of cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT) were retrospectively generated from various numbers (30, 35, 40, 45, 50, 55, and 60) of source images. Defining the values calculated from the number of source images equal to the end time of the first pass as standard values, the percentage difference between the standard values and the values generated from various numbers of sources were evaluated. The TDCs of SSS showed the latest end time of the first pass (mean, 38.6±5.2 sec; range, 32 to 48 sec). Therefore, the values calculated from the number of source images equal to the end time of the first pass of SSS were defined as standard values. Increase and decrease of the number of source images for calculation resulted in increase of the percentage difference in every parameter value. The percentage differences ranged up to 49.6% for CBF, 48.0% for CBV, and 20.0% for MTT. Scanning until the end time of the first pass of SSS is necessary and sufficient for reliable measurement. Variable scan time based on the TDC of the SSS may be of better utility than use of fixed scan time. Further, the radiation dose could be minimized in many cases by reducing the scan time. (author)

  16. Diagnosis of pancreatic tumors by spiral angio CT

    International Nuclear Information System (INIS)

    Miura, Kohi; Nakao, Norio; Takayasu, Yukio; Okawa, Tomohisa

    1995-01-01

    Spiral angio were performed with injection of 30 ml of contrast material at a rate of 1 ml/sec with a scan delay of 6 sec through catheter into the celiac artery while the blood flow of the superior mesenteric artery (SMA) was occluded by the inflated balloon catheter. Spiral CT scans were obtained using Somatom Plus (Siemens). Parameter for spiral CT were 24-sec acquisition time, 5 mm collimation, 5 mm/sec table incrementation. Reconstructions were performed every 5 mm. Pancreatic cancers were characteristically depicted with spiral angio CT as hypodensity relative to normal enhanced pancreatic parenchyma. On dynamic angio CT studies performed in pancreatic cancers, the area of cancer and normal parenchyma had maximum level of enhancement at 10-15 sec after injection of contrast material via catheter into the celiac, and there was no difference in enhancement between tumor and normal parenchyma. On the other hand, the lesions of cancer were revealed as hypodensity with spiral angio CT. In case of chronic pancreatitis, the enhancement of the entire pancreas obtained with spiral angio CT was homogeneous. Insulinoma in the tail of pancreas was detected by spiral angio CT but was not detected by both selective angiography and conventional CT. Three-dimensional (3-D) rendering spiral angio CT data shows the extent of vascular involvement by pancreatic cancer and provides useful information for surgical planning. Spiral angio CT is the most useful procedure for diagnosis of pancreatic tumor. (author)

  17. CT manifestations of peritoneal carcinomatosis.

    Science.gov (United States)

    Walkey, M M; Friedman, A C; Sohotra, P; Radecki, P D

    1988-05-01

    Seventy-three abdominopelvic contrast-enhanced CT scans obtained in 60 patients with peritoneal tumor spread were reviewed retrospectively to determine the CT signs of peritoneal malignancy. Ascites was present in 54 studies (74%) and was the most common CT finding. Loculation of the fluid occurred in 25 (46%) of these. In nine (17%) of the 54, a new finding, absence of cul-de-sac fluid in the presence of generalized ascites, was noted. Parietal peritoneal thickening with contrast enhancement of the peritoneum, making the peritoneum visible as a thin line along the abdominal wall, was present in 45 (62%) of studies. This is believed to represent confluent peritoneal metastases. Small-bowel involvement was present in half of the cases (wall thickening and irregularity with or without obstruction). Tumor involvement of the omentum was visible as soft-tissue permeation of fat, enhancing nodules, and/or an omental cake. Of the 26 patients without a previously known malignancy, identification of the primary tumor in addition to peritoneal carcinomatosis was possible in 13 (50%). Appreciation of the spectrum of CT findings in peritoneal carcinomatosis is essential for accurate evaluation of scans in patients with abdominopelvic malignancies.

  18. 18F-FDG SPECT/CT in the diagnosis of differentiated thyroid carcinoma with elevated thyroglobulin and negative iodine-131 scans

    International Nuclear Information System (INIS)

    Ma, C.; Wu, Z.; Wang, H.; Wang, X.; Shao, M.; Zhao, L.; Jiawei, X.

    2015-01-01

    Aim of the present study was to investigate the usefulness of 18 F-FDG SPECT/CT in differentiated thyroid cancer (DTC) with elevated serum thyroglobulin (Tg) but negative iodine-131 scan. This retrospective review of patients with DTC recurrence who had 18 F-FDG SPECT/CT and 18 F-FDG PET/CT for elevated serum Tg but negative iodine-131 scan (March 2007-October 2012). After total thyroidectomy followed by radioiodine ablation, 86 consecutive patients with elevated Tg levels underwent 18 F-FDG SPECT/CT or 18 F-FDG PET/CT. Of these, 45 patients had 18 F-FDG SPECT/CT, the other 41 patients had 18 F-FDG PET/CT 3-4 weeks after thyroid hormone withdrawal. The results of 18 F-FDG PET/CT and SPECT/CT were correlated with patient follow-up information, which included the results from subsequent imaging modalities such as neck ultrasound, MRI and CT, Tg levels, and histologic examination of surgical specimens. The diagnostic accuracy of the two imaging modalities was evaluated. In 18 F-FDG SPECT/CT scans, 24 (24/45) patients had positive findings, 22 true positive in 24 patients, false positive in 2 patients, true-negative and false-negative in 6, 15 patients, respectively. The overall sensitivity, specificity, and accuracy of 18F-FDG SPECT/CT were 59.5%, 75% and 62.2%, respectively. Twenty six patients had positive findings on 18 F-FDG PET/CT scans, 23 true positive in 26 (26/41) patients, false positive in 3 patients, true-negative and false-negative in 9, 6 patients, respectively. The overall sensitivity, specificity, and accuracy of 18F-FDG PET/CT were 79.3%, 81.8% and 78.1%, respectively. Clinical management changed for 13 (29%) of 45 patients by 18 F-FDG SPECT/CT, 14 (34%) of 41 patients by 18F-FDG PET/CT including surgery, radiation therapy, or multi kinase inhibitor. Based on the retrospective analysis of 86 patients, 18F-FDG SPECT/CT has lower sensitivity in the diagnosis of DTC recurrence with elevated Tg and negative iodine-131scan to 18F-FDG PET/CT. The clinical

  19. The evaluation of CT and MRI in the diagnosis of pancreatic tuberculosis and peripancreatic tuberculous lymphadenopathy

    International Nuclear Information System (INIS)

    Yang Zenian; Wang Xiaoyan; Peng Zhenpeng; Lin Jianqin; Zhang Ting

    2008-01-01

    Objective: To study the manifestations and its pathologic basis of pancreatic tubeiculosis and peripancreatic tuberculous lymphadenopathy. And evaluate the diagnostic values of CT and MRI. Methods: Two cases of pancreatic tuberculosis and eleven cases of peripancreatic tuberculous lymphadenopathy were collected. All cases were conformed by pathology or clinic. Plain scan and enhanced scan with spiral CT were performed in all cases. Plain scan and enhanced scan with MRI were performed in two cases. The CT and MRI features of 13 cases were analyzed retrospectively. Results: Pancreatic tuberculosis showed that the lesion was located mainly at the head of the pancreas and displayed on CT as a low-density mass with marginal or honeycomb enhancement. Peripancreatic tuberculous lymphadenopathy was seen in 11 cases, of which ring-like enhancement was seen in seven cases, calcifications in two cases and mixed in two cases. Splenic involvement was found in five cases. Conclusion: Pancreatic tuberculosis and peripancreatic tuberculous lymphadenopathy have the main features of low-density mass With marginal or honeycomb enhancement and ting-like enhancement in petipancreatic lymphadenopathy. CT and MRI are feasible methods in diagnosis of pancreatic tuberculosis and peripancreatic tuberculous lymphadenopathy. (authors)

  20. Case of idiopathic portalhypertension. Comparison of pre- and post-operative CT scan findings of collateral circulation

    Energy Technology Data Exchange (ETDEWEB)

    Serizawa, K; Yajima, Y; Onodera, H; Hirata, T; Sugawara, H [Tohoku Univ., Sendai (Japan). School of Medicine

    1982-02-01

    A 40-year-old man was referred to our clinic for esophageal varices. Histological examination of the liver biopsy samples revealed no sign of liver cirrhosis. Celiac angiography and ultrasound showed no obstruction of portal vein. A diagnosis of idiopathic portalhypertension was established. Splenomegaly and collateral circulation from spleen to left retroperitoneum were shown on CT scan and confirmed by surgical operation. CT scan following operation showed no collateral circulation.

  1. Computer-assisted solid lung nodule 3D volumetry on CT : influence of scan mode and iterative reconstruction: a CT phantom study

    NARCIS (Netherlands)

    Coenen, Adriaan; Honda, Osamu; van der Jagt, Eric J.; Tomiyama, Noriyuki

    2013-01-01

    To evaluate the effect of high-resolution scan mode and iterative reconstruction on lung nodule 3D volumetry. Solid nodules with various sizes (5, 8, 10 and 12 mm) were placed inside a chest phantom. CT images were obtained with various tube currents, scan modes (conventional mode, high-resolution

  2. The value of brain scanning in cerebro-vascular disease by CT

    International Nuclear Information System (INIS)

    Huber, G.; Emde, H.

    1980-01-01

    Brain scanning by scintigraphy and CT studies of the brain are complementary methods. The precise demonstration of the anatomy and the pathology of the brain by CT is supplemented by brain scintigraphy due to the latter's value to assess the hemodynamic properties of a lesion and thus provide important clues to its site and sometimes even its histology. This is especially true in vascular brain disease thus either dispensing the need for an invasive procedure such as angiography or providing information for a specific approach. (orig.) 891 MG/orig. 892 MKO [de

  3. A vast increase in the use of CT scans for investigating occult hip fractures

    International Nuclear Information System (INIS)

    Jordan, Robert; Dickenson, Edward; Westacott, Daniel; Baraza, Njalalle; Srinivasan, Kuntrapka

    2013-01-01

    Background: Early diagnosis in neck of femur fractures has been shown to improve outcome. The National Institute for Clinical Excellence recommends if an occult hip fracture is suspected then an MRI should be performed and if not available within 24 h a CT should be considered. At our centre, emergency MRI is rarely available and so CT is commonly used. Objectives: Our study aims to analyse the trends in CT use over a five year period for the diagnosis of neck of femur fractures. Methods: Both the number of patients with a hip fracture and those undergoing a CT hip to diagnose an occult injury were identified across two district general hospitals between 2006–2007 and 2010–2011. The time from initial radiograph to CT and initial radiograph to operation were calculated. Results: In 2006–2007, of 547 hip fractures, 20 CT hips were performed and 6 reported as a fractured neck of femur (30%). In 2010–2011, of 499 hip fractures, 239 CT hips were performed and 65 fractures were recognised (27%). The mean time from radiograph until CT scan was 2.0 days in 2007 and 3.2 days in 2011, which was a statistically significant difference (p < 0.001). For those diagnosed using a CT scan the mean time from admission X-ray to surgery was 1.2 days in 2007 and 3.6 days in 2011. Conclusion: Clinicians are becoming increasingly reliant on CT for the diagnosis of hip fractures with our data suggesting further imaging is one factor that can delay time to diagnosis and theatre

  4. A vast increase in the use of CT scans for investigating occult hip fractures

    Energy Technology Data Exchange (ETDEWEB)

    Jordan, Robert, E-mail: Robert.jordan@doctors.org.uk; Dickenson, Edward, E-mail: edwarddickenson@doctors.org.uk; Westacott, Daniel, E-mail: dan_westacott@hotmail.com; Baraza, Njalalle, E-mail: njaleb@Doctors.Org.Uk; Srinivasan, Kuntrapka, E-mail: bijusri@Yahoo.Co.Uk

    2013-08-15

    Background: Early diagnosis in neck of femur fractures has been shown to improve outcome. The National Institute for Clinical Excellence recommends if an occult hip fracture is suspected then an MRI should be performed and if not available within 24 h a CT should be considered. At our centre, emergency MRI is rarely available and so CT is commonly used. Objectives: Our study aims to analyse the trends in CT use over a five year period for the diagnosis of neck of femur fractures. Methods: Both the number of patients with a hip fracture and those undergoing a CT hip to diagnose an occult injury were identified across two district general hospitals between 2006–2007 and 2010–2011. The time from initial radiograph to CT and initial radiograph to operation were calculated. Results: In 2006–2007, of 547 hip fractures, 20 CT hips were performed and 6 reported as a fractured neck of femur (30%). In 2010–2011, of 499 hip fractures, 239 CT hips were performed and 65 fractures were recognised (27%). The mean time from radiograph until CT scan was 2.0 days in 2007 and 3.2 days in 2011, which was a statistically significant difference (p < 0.001). For those diagnosed using a CT scan the mean time from admission X-ray to surgery was 1.2 days in 2007 and 3.6 days in 2011. Conclusion: Clinicians are becoming increasingly reliant on CT for the diagnosis of hip fractures with our data suggesting further imaging is one factor that can delay time to diagnosis and theatre.

  5. The added value of 68Ga-DOTA-TATE-PET to contrast-enhanced CT for primary site detection in CUP of neuroendocrine origin.

    Science.gov (United States)

    Kazmierczak, Philipp M; Rominger, Axel; Wenter, Vera; Spitzweg, Christine; Auernhammer, Christoph; Angele, Martin K; Rist, Carsten; Cyran, Clemens C

    2017-04-01

    To quantify the additional value of 68 Ga-DOTA-TATE PET/CT in comparison with contrast-enhanced CT alone for primary tumour detection in neuroendocrine cancer of unknown primary (CUP-NET). In total, 38 consecutive patients (27 men, 11 women; mean age 62 years) with histologically proven CUP-NET who underwent a contrast-enhanced 68 Ga-DOTA-TATE PET/CT scan for primary tumour detection and staging between 2010 and 2014 were included in this IRB-approved retrospective study. Two blinded readers independently analysed the contrast-enhanced CT and 68 Ga-DOTA-TATE PET datasets separately and noted from which modality they suspected a primary tumour. Consensus was reached if the results were divergent. Postoperative histopathology (24 patients) and follow-up 68 Ga-DOTA-TATE PET/CT imaging (14 patients) served as the reference standards and statistical measures of diagnostic accuracy were calculated accordingly. The majority of confirmed primary tumours were located in the abdomen (ileum in 19 patients, pancreas in 12, lung in 2, small pelvis in 1). High interobserver agreement was noted regarding the suspected primary tumour site (Cohen's k 0.90, p DOTA-TATE PET demonstrated a significantly higher sensitivity (94 % vs. 63 %, p = 0.005) and a significantly higher accuracy (87 % vs. 68 %, p = 0.003) than contrast-enhanced CT. Ga-DOTA-TATE PET/CT compared with contrast-enhanced CT alone provides an improvement in sensitivity of 50 % and an improvement in accuracy of 30 % in primary tumour detection in CUP-NET. • 68 Ga-DOTA-TATE PET augments the sensitivity of contrast-enhanced CT by 50 % • 68 Ga-DOTA-TATE PET augments the accuracy of contrast-enhanced CT by 30 % • Somatostatin receptor-targeted hybrid imaging optimizes primary tumour detection in CUP-NET.

  6. CT features of gastric heterotopic pancreas

    International Nuclear Information System (INIS)

    Wu Guangyao; Tian Zhixiong; Zhang Zaipeng; Huang Xiong

    2007-01-01

    Objective: To analyze CT findings correlated with pathologic findings in ectopic pancreas of the stomach. Methods: CT scans of 15 surgically proven eases of ectopic pancreas of the stomach were reviewed, and enhanced CT scan was performed in 11 cases. CT findings were correlated with the pathologic findings. Results: All cases had single lesion, and all lesions showed homogeneous density on plain scans without cystic or malignant changes. The size ranged from 1.3 to 3.1 cm, with mean diameter of (1.9±0.2) cm. The lesions were round or oval in shape with broad base against the gastric wall. Two showed central umbilication sign. Only 2 cases were correctly diagnosed prior to operation and the rest were misdiagnosed or diagnosed indistinctly. The locations were in the gastric antrum in 11 cases, in the body in 3, and in fundus in one; The ectopic pancreas located in the greater curvature in 10, and in the lesser curvature in 5. Homogeneous or inhomogeneous strong enhancement similar to the pancreas was seen in 8 cases and they consisted mainly of pancreatic acini with the same histologic features as the pancreas. Three cases showed poor enhancement and consisted mainly of ducts and hypertrophied muscle, pancreatic acini were a minor component. Conclusion: Ectopic pancreas of the stomach showed characteristic locations with the findings of submucosal diseases. Different enhancing patterns were correlated with their pathologic findings. (authors)

  7. Imaging of head and neck tumors -- methods: CT, spiral-CT, multislice-spiral-CT

    International Nuclear Information System (INIS)

    Baum, Ulrich; Greess, Holger; Lell, Michael; Noemayr, Anton; Lenz, Martin

    2000-01-01

    Spiral-CT is standard for imaging neck tumors. In correspondence with other groups we routinely use spiral-CT with thin slices (3 mm), a pitch of 1.3-1.5 and an overlapping reconstruction increment (2-3 mm). In patients with dental fillings a short additional spiral parallel to the corpus of the mandible reduces artifacts behind the dental arches and improves the diagnostic value of CT. For the assessment of the base of the skull, the orbital floor, the palate and paranasal sinuses an additional examination in the coronal plane is helpful. Secondary coronal reconstructions of axial scans are helpful in the evaluation of the crossing of the midline by small tumors of the tongue base or palate. For an optimal vascular or tissue contrast a sufficient volume of contrast medium and a start delay greater than 70-80 s are necessary. In our opinion the best results can be achieved with a volume of 150 ml, a flow of 2.5 ml/s and a start delay of 80 s. Dynamic enhanced CT is only necessary in some special cases. There is clear indication for dynamic enhanced CT where a glomus tumor is suspected. Additional functional CT imaging during i-phonation and/or Valsalva's maneuver are of great importance to prove vocal cords mobility. Therefore, imaging during i-phonation is an elemental part of every thorough examination of the hypopharynx and larynx region. Multislice-spiral-CT allows almost isotropic imaging of the head and neck region and improves the assessment of tumor spread and lymph node metastases in arbitrary oblique planes. Thin structures (the base of the skull, the orbital floor, the hard palate) as well as the floor of the mouth can be evaluated sufficiently with multiplanar reformations. Usually, additional coronal scanning is not necessary with multislice-spiral-CT. Multislice-spiral-CT is especially advantageous in defining the critical relationships of tumor and lymph node metastases and for functional imaging of the hypopharynx and larynx not only in the

  8. A clue for the diagnosis of lung cancer looking lobar consolidation with emphasis on thickness and enhancement pattern of bronchial wall on CT

    International Nuclear Information System (INIS)

    Yoo, Ho Seok; Kwon, Woo Cheol; Cha, Seung Whan; Kim, Sang Ha; Koh, Sang Baek; Kim, Myung Soon

    2007-01-01

    To differentiate between lung cancer and pneumonia for cases of lobar consolidation, with an emphasis on the thickness and enhancement pattern of the bronchial wall viewed by a CT. We retrospectively analyzed 17 patients with evidence of lobar consolidation, from a simple-chest radiographs, and divided them into groups by condition (lung cancer, n = 5; pneumonia, n 12). CT scans were performed on all patients and bronchial wall thickness, which is the cranio-caudal length of the bronchial wall thickness and the enhancement pattern, were measured and analyzed at the mediastinal window setting. The thickness of the bronchial wall in the lung cancer group (2.46 ± 0.37 mm) was significantly greater than the pneumonia group (1.73 ± 0.36 mm) (ρ = 0.002). Moreover, the bronchial wall thickness was greater than 2.0 mm for all patients in the cancer group. Further, if a diagnostic criterion was set to be larger than 2.0 mm, 100% sensitivity and 66.7% specificity would be achieved for the study subjects. The cranio-caudal length of the bronchial wall thickness in the cancer group was 37.5 ± 16.4 mm, which was significantly greater than the pneumonia group (16.3 ± 6.6 mm) (ρ = 0.001). We found no significant difference for the degree of contrast enhancement between the two groups. A CT scan measurement of the bronchial wall thickness greater than 2 mm in CT scans can be an indicator for diagnosing lung cancer in patients with lobar consolidation

  9. A case of linear nevus sebaceous syndrome showing abnormalities by head CT scan

    International Nuclear Information System (INIS)

    Matsuda, Yoshio; Kuraya, Kazue; Sumiyoshi, Minoru; Seki, Shuichiro; Murakami, Naoki

    1982-01-01

    A female baby weighing 2,702 g, who was delivered spontaneously after 37 weeks of gestation, showed linear nevus sebaceous syndrome with abnormalities on EEG and head CT scan. Immediately after birth, the baby showed abnormalities of the skin in the left half of the body, especially from the head to the face. At the same time, EEG showed a low voltage on the affected side, and head CT scan showed expansion of the lateral ventricle. Funduscopic findings showed retinochoroidal toxoplasmosis-like degeneration. This disease has been rarely reported. An early diagnosis is seemed to be important since the skin lesion per se was premalignant, and generalized abnormalities including those of the central nervous system occurred concurrently. (Chiba, N.)

  10. Sepsis patients' renal manifestation on contrast-enhanced CT

    International Nuclear Information System (INIS)

    Sasaguri, K.; Yamaguchi, K.; Nakazono, T.; Mizuguchi, M.; Irie, H.

    2016-01-01

    Aim: To evaluate renal volume and attenuation changes in patients with sepsis on contrast-enhanced computed tomography (CT) with respect to the severity of sepsis. Materials and methods: Forty-four patients with sepsis who underwent CT before and after the onset of sepsis were retrospectively analysed. Renal volume and CT attenuation value of the renal cortex on contrast-enhanced CT were measured for each patient and changes in renal volume and CT attenuation value from before to after the onset of sepsis were calculated. The changes were correlated with the severity of sepsis (Sepsis-related Organ Failure Assessment [SOFA] score). The time course of the renal volume and CT attenuation changes were also evaluated. Results: Renal volume increased by 17.6% and CT attenuation value decreased by 19% after the onset of sepsis with statistically significant differences (p<0.001 for both renal volume and CT attenuation changes). The renal volume and CT attenuation changes had significant correlations with the SOFA score (r=0.36, p=0.018 and −0.43, p=0.005, respectively). The time course of the renal volume and CT attenuation changes seemed to be gradual compared to that of the SOFA score and to lag behind the peak of the SOFA score. Conclusion: In patients with sepsis, the renal volume increases and the CT attenuation value decreases in proportion to the severity of sepsis. The changes may lag behind the peak of severity of sepsis and can be observed for a relatively long time after a patient's recovery from sepsis. - Highlights: • The renal volume increases and the renal enhancement on contrast-enhanced CT decreases in patients with sepsis. • The degrees of these changes are correlated with severity of sepsis. • These changes may lag behind the peak of severity of sepsis and last for a long time after a patient's recovery from sepsis.

  11. Fuzzy-neural network in the automatic detection and volumetry of the spleen on spiral CT scans

    International Nuclear Information System (INIS)

    Heitmann, K.R.; Mainz Univ.; Rueckert, S.; Heussel, C.P.; Thelen, M.; Kauczor, H.U.; Uthmann, T.

    2000-01-01

    Purpose: To assess spleen segmentation and volumetry in spiral CT scans with and without pathological changes of splenic tissue. Methods: The image analysis software HYBRIKON is based on region growing, self-organized neural nets, and fuzzy-anatomic rules. The neural nets were trained with spiral CT data from 10 patients, not used in the following evaluation on spiral CT scans from 19 patients. An experienced radiologist verified the results. The true positive and false positive areas were compared in terms to the areas marked by the radiologist. The results were compared with a standard thresholding method. Results: The neural nets achieved a higher accuracy than the thresholding method. Correlation coefficient of the fuzzy-neural nets: 0.99 (thresholding: 0.63). Mean true positive rate: 90% (thresholding: 75%), mean false positive rate: 5% (thresholding>100%). Pitfalls were caused by accessory spleens, extreme changes in the morphology (tumors, metastases, cysts), and parasplenic masses. Conclusions: Self-organizing neural nets combined with fuzzy rules are ready for use in the automatic detection and volumetry of the spleen in spiral CT scans. (orig.) [de

  12. CT and MRI analysis of central nervous system Rosai-Dorfman disease

    International Nuclear Information System (INIS)

    Zhang Jiatang; Lang Senyang; Pu Chuanqiang; Zhu Ruyuan; Wang Dianjun

    2008-01-01

    Objective: To study the CT and MRI imaging features of central nervous system Rosai-Dorfman disease and to enhance knowledge and differential diagnostic ability for central nervous system Rosai-Doffman disease. Methods: The CT and MRI imaging appearances in 4 cases of pathologically proven Rosai-Dorfman disease were retrospectively evaluated and the literature of central nervous system Rosai- Dorfman disease were reviewed. Results: Two cases had cranial CT scans, 4 cases had cranial MRI scans. On CT scans, cerebral edema was demonstrated in one case and the other case was normal. MRI scans showed the lesions were solitary in saddle area in 3 cases, and multiple in anterior cranial fossa in 1 case. The lesions exhibited iso- to hypointensity on both T 1 WI and T 2 WI images. Following intravenous injection of contrast medium, ring-like enhancement was seen in 2 cases and homogeneous enhancement in 1 case. Nodular enhancement was seen in the case of multiple lesions in the anterior cranial fossa. All lesions were dural-based. Conclusions: In patients with fever, headache, elevation of the erythrocyte sedimentation rate (ESR) and a polyclonal increase in γ-globulins, the possibility of central nervous system Rosai-Dorfman disease should be considered when single or multiple dural-based mass lesions, especially in sellar region, were identified by CT and MRI. (authors)

  13. Differential Aging Signals in Abdominal CT Scans.

    Science.gov (United States)

    Orlov, Nikita V; Makrogiannis, Sokratis; Ferrucci, Luigi; Goldberg, Ilya G

    2017-12-01

    Changes in the composition of body tissues are major aging phenotypes, but they have been difficult to study in depth. Here we describe age-related change in abdominal tissues observable in computed tomography (CT) scans. We used pattern recognition and machine learning to detect and quantify these changes in a model-agnostic fashion. CT scans of abdominal L4 sections were obtained from Baltimore Longitudinal Study of Aging (BLSA) participants. Age-related change in the constituent tissues were determined by training machine classifiers to differentiate age groups within male and female strata ("Younger" at 50-70 years old vs "Older" at 80-99 years old). The accuracy achieved by the classifiers in differentiating the age cohorts was used as a surrogate measure of the aging signal in the different tissues. The highest accuracy for discriminating age differences was 0.76 and 0.72 for males and females, respectively. The classification accuracy was 0.79 and 0.71 for adipose tissue, 0.70 and 0.68 for soft tissue, and 0.65 and 0.64 for bone. Using image data from a large sample of well-characterized pool of participants dispersed over a wide age range, we explored age-related differences in gross morphology and texture of abdominal tissues. This technology is advantageous for tracking effects of biological aging and predicting adverse outcomes when compared to the traditional use of specific molecular biomarkers. Application of pattern recognition and machine learning as a tool for analyzing medical images may provide much needed insight into tissue changes occurring with aging and, further, connect these changes with their metabolic and functional consequences. Published by Elsevier Inc.

  14. Dynamic helical CT mammography of breast cancer

    International Nuclear Information System (INIS)

    Yamamoto, Akira; Fukushima, Hitoshi; Okamura, Ryuji; Nakamura, Yoshiaki; Morimoto, Taisuke; Urata, Yoji; Mukaihara, Sumio; Hayakawa, Katsumi

    2006-01-01

    The purpose of this study was to determine whether dynamic helical computed tomography (CT)-mammography could assist in selecting the most appropriate surgical method in women with breast cancer. Preoperative contrast-enhanced helical CT scanning of the breast was performed on 133 female patients with suspicion of breast cancer at the same time as clinical, mammographic, and/or ultrasonographic examinations. The patients were scanned in the prone position with a specially designed CT-compatible device. A helical scan was made with rapid intravenous bolus injection (3 ml/s) of 100 ml of iodine contrast material. Three-dimensional maximum intensity projection (MIP) images were reconstructed, and CT findings were correlated with surgical and histopathological findings. Histopathological analysis revealed 84 malignant lesions and seven benign lesions. The sensitivity, specificity, and accuracy levels of the CT scanning were 94.6%, 58.6%, and 78.9%. Helical scanning alone revealed additional contralateral carcinomas in three of four patients and additional ipsilateral carcinomas in three of five patients. However, the technique gave false-positive readings in 24 patients. The preoperative CT-mammogram altered the surgical method in six patients. Dynamic helical CT-mammography in the prone position may be one of the choices of adjunct imaging in patients with suspected breast cancer scheduled for surgery. (author)

  15. Triage of Limited Versus Extensive Disease on 18F-FDG PET/CT Scan in Small Cell lung Cancer

    Directory of Open Access Journals (Sweden)

    Saima Riaz

    2017-06-01

    Full Text Available Objective(s: Small cell lung cancer (SCLC is an aggressive neuroendocrine carcinoma, which accounts for 10-15% of pulmonary cancers and exhibits early metastatic spread. This study aimed to determine the added value of 18F-FDG PET/CT imaging in tumor, node, and metastasis (TNM staging of SCLC, compared to the conventional computed tomography (CT scan and its potential role as a prognosticator.Methods: This retrospective review was conducted on 23 patients, who were histopathologically diagnosed to have SCLC and referred for undergoing 18F-FDG PET/CT scanning during October 2009-December 2015. The rate of agreement between the CT and 18F-FDG PET/CT findings for TNM staging was calculated using the Cohen’s kappa (κ. The median follow-up time was eight months, ranging 27-3 months. The overall and disease-free survival rates were calculated based on the extent of disease.Results: 19 cases were male and four female with the mean age of 58±9 years. The 18F-FDG PET/CT identified limited and extensive diseases in 2 (8.7% and 21 (91.3% patients, respectively. In addition, the results of the Cohen’s kappa demonstrated a strong (κ=0.82, fair (κ=0.24, and poor (κ=0.12 agreement between the PET/CT and CT findings for determining tumor, node, and metastasis stages, respectively. The 18F-FDG PET/CT scans upstaged disease in 47% of the cases with visceral and osseous metastasis. The disease-free survival rates for the limited and extensive diseases were 100% and 23% within the 12-month follow-up. In addition, 8 (35% patients expired during the follow-up period.Conclusion: Improved nodal and metastatic disease identification highlights the role of 18F-FDG PET/CT scanning in initial staging of SCLC with prognostic implications.

  16. 3D quantification of soil structure and functioning based on PET and CT scanning techniques

    DEFF Research Database (Denmark)

    Garbout, Amin

    This thesis explores the potential of PET and CT scanning techniques to quantify and visualize soil structure, root development, and soil/plant interactions. At the investigated scale, these non-invasive and nondestructive techniques have some obvious advantages compared with most other techniques....... The processed measurements show some expected and a few unexpected effects (or lack of effects) on different characteristics of soil structure. The combination of CT and PET scanning in an air plant soil controller system revealed some very interesting research possibilities. Interactions between soil structure...

  17. Immediate CT findings following embolization of cerebral aneurysms: suggestion of blood-brain barrier or vascular permeability change

    International Nuclear Information System (INIS)

    Baik, Seung Kug; Kim, Yong Sun; Lee, Hui Jung; Kim, Gab Chul; Park, Jaechan

    2008-01-01

    Although endovascular techniques are widely used for the treatment of cerebral aneurysms, the immediate postprocedural brain CT findings have not been reported. Therefore, in the present study we assessed the immediate postprocedural brain CT findings following the uneventful coil embolization of cerebral aneurysms. Included in the study were 59 patients with 61 cerebral aneurysms after uncomplicated coil embolization. Acute subarachnoid hemorrhage was present with 32 of the 61 aneurysms. All patients underwent a brain CT scan just before and within 2 h after the endovascular treatment. If the postprocedural CT scan revealed any new findings, a follow-up CT scan and/or MRI were performed within 24 h. The variables related to the abnormal CT findings were also evaluated. Among the 61 immediate brain CT scans, 26 (43%) showed abnormal findings, including cortical contrast enhancement (n=21, 34%), subarachnoid contrast enhancement (n=8, 13%), intraventricular contrast enhancement (n=5, 8%), and striatal contrast enhancement (n=2, 3%). Single or mixed CT findings were also seen. None of the 61 aneurysms was associated with new neurological symptoms after endovascular treatment, and all patients made an uneventful recovery. Abnormal findings were more likely to be found with lower body weight and with increased corrected amounts of contrast material and heparin (P<0.05). After uneventful endovascular treatment of cerebral aneurysms, the immediate brain CT findings can reveal various patterns of abnormal contrast enhancement. Recognizing the immediate brain CT findings is important, as they can mimic various diseases. (orig.)

  18. [Indications and instructions to patients for a positron emission tomography-PET scan. The importance of the hybridic PET/CT-computerised tomography scan and which specialty should be responsible for its function].

    Science.gov (United States)

    Grammaticos, Philip; Datseris, Ioannis; Gerali, Sofia; Papantoniou, Vassilios; Valsamaki, Pipitsa; Boundas, Dimitrios

    2007-01-01

    Indications and instructions to patients for performing a positron emission tomography - PET scan are mentioned. Although PET camera was developed in 1970 its clinical indications were established in about 1998. The hybridic PET/CT- computerized tomography scanner appeared in 2001 and its clinical indications are still under discussion. These discussions refer to both the use of PET/CT as an acquisition correction and anatomic localization device for PET images (AC/A) and to its use as a diagnostic CT scan (dCT). Most of the patients submitted for a PET scan have already done a dCT scan. This was the case in 286 out of the first 300 patients referred to "Evangelismos" hospital in Athens for a PET scan. These two scans can be matched electronically. Extra cost, space, personnel and radiation absorption dose especially in children, are additional factors to be considered in using the PET/CT scanner. The specialty of Nuclear Medicine is now based on the PET camera, its best part and main equipment for molecular imaging. It is very much easier and faster for a Nuclear Medicine physician who routinely reports tomographic PET and SPET images, to be familiar with the CT images than for a Radiologist to get to "know how" about the PET camera and the whole Nuclear Medicine Department. Nuclear Medicine is about open radiation sources, molecular imaging, specific radio-pharmacology, radiobiology, radiation protection etc, while on the other hand in some countries, Nuclear Physicians have already spent, as part of their official training, six months in a Radiology Department whose function is considered to be at least 25% about the CT scanner. We come to the conclusion that the PET/CT scanner should be under the responsibility of the Nuclear Medicine Department and the Radiologist should act as an advisor.

  19. Dose responses in a normoxic polymethacrylic acid gel dosimeter using optimal CT scanning parameters

    Energy Technology Data Exchange (ETDEWEB)

    Cho, K.H. [Department of Radiation Oncology, College of Medicine, Soonchunhyang University, Bucheon 420-767 (Korea, Republic of); Department of Medical Physics, Kyonggi University, Suwon 443-760 (Korea, Republic of); Cho, S.J. [Department of Radiation Oncology, College of Medicine, Eulji University, Seongnam 461-713 (Korea, Republic of); Lee, S. [Department of Radiation Oncology, College of Medicine, Korea University, Seoul 130-701 (Korea, Republic of); Lee, S.H. [Cheil General Hospital and Women' s Healthcare Center, Kwandong University College of Medicine, Seoul 100-380 (Korea, Republic of); Min, C.K.; Kim, Y.H.; Moon, S.K.; Kim, E.S.; Chang, A.R. [Department of Radiation Oncology, College of Medicine, Soonchunhyang University, Bucheon 420-767 (Korea, Republic of); Kwon, S.I., E-mail: sikwon@kyonggi.ac.kr [Department of Medical Physics, Kyonggi University, Suwon 443-760 (Korea, Republic of)

    2012-05-21

    The dosimetric characteristics of normoxic polymethacrylic acid gels are investigated using optimal CT scanning parameters and the possibility of their clinical application is also considered. The effects of CT scanning parameters (tube voltage, tube current, scan time, slick thickness, field of view, and reconstruction algorithm) are experimentally investigated to determine the optimal parameters for minimizing the amount of noise in images obtained using normoxic polymethacrylic acid gel. In addition, the dose sensitivity, dose response, accuracy, and reproducibility of the normoxic polymethacrylic acid gel are evaluated. CT images are obtained using a head phantom that is fabricated for clinical applications. In addition, IMRT treatment planning is performed using a Tomotherapy radiation treatment planning system. A program for analyzing the results is produced using Visual C. A comparison between the treatment planning and the CT images of irradiated gels is performed. The dose sensitivity is found to be 2.41{+-}0.04 HGy{sup -1}. The accuracies of dose evaluation at doses of 2 Gy and 4 Gy are 3.0% and 2.6%, respectively, and their reproducibilities are 2.0% and 2.1%, respectively. In the comparison of gel and Tomotherpay planning, the pass rate of the {gamma}-index, based on the reference values of a dose error of 3% and a DTA of 3 mm, is 93.7%.

  20. Dose responses in a normoxic polymethacrylic acid gel dosimeter using optimal CT scanning parameters

    Science.gov (United States)

    Cho, K. H.; Cho, S. J.; Lee, S.; Lee, S. H.; Min, C. K.; Kim, Y. H.; Moon, S. K.; Kim, E. S.; Chang, A. R.; Kwon, S. I.

    2012-05-01

    The dosimetric characteristics of normoxic polymethacrylic acid gels are investigated using optimal CT scanning parameters and the possibility of their clinical application is also considered. The effects of CT scanning parameters (tube voltage, tube current, scan time, slick thickness, field of view, and reconstruction algorithm) are experimentally investigated to determine the optimal parameters for minimizing the amount of noise in images obtained using normoxic polymethacrylic acid gel. In addition, the dose sensitivity, dose response, accuracy, and reproducibility of the normoxic polymethacrylic acid gel are evaluated. CT images are obtained using a head phantom that is fabricated for clinical applications. In addition, IMRT treatment planning is performed using a Tomotherapy radiation treatment planning system. A program for analyzing the results is produced using Visual C. A comparison between the treatment planning and the CT images of irradiated gels is performed. The dose sensitivity is found to be 2.41±0.04 HGy-1. The accuracies of dose evaluation at doses of 2 Gy and 4 Gy are 3.0% and 2.6%, respectively, and their reproducibilities are 2.0% and 2.1%, respectively. In the comparison of gel and Tomotherpay planning, the pass rate of the γ-index, based on the reference values of a dose error of 3% and a DTA of 3 mm, is 93.7%.

  1. Development of 1-year-old computational phantom and calculation of organ doses during CT scans using Monte Carlo simulation

    International Nuclear Information System (INIS)

    Pan, Yuxi; Qiu, Rui; Ge, Chaoyong; Xie, Wenzhang; Li, Junli; Gao, Linfeng; Zheng, Junzheng

    2014-01-01

    With the rapidly growing number of CT examinations, the consequential radiation risk has aroused more and more attention. The average dose in each organ during CT scans can only be obtained by using Monte Carlo simulation with computational phantoms. Since children tend to have higher radiation sensitivity than adults, the radiation dose of pediatric CT examinations requires special attention and needs to be assessed accurately. So far, studies on organ doses from CT exposures for pediatric patients are still limited. In this work, a 1-year-old computational phantom was constructed. The body contour was obtained from the CT images of a 1-year-old physical phantom and the internal organs were deformed from an existing Chinese reference adult phantom. To ensure the organ locations in the 1-year-old computational phantom were consistent with those of the physical phantom, the organ locations in 1-year-old computational phantom were manually adjusted one by one, and the organ masses were adjusted to the corresponding Chinese reference values. Moreover, a CT scanner model was developed using the Monte Carlo technique and the 1-year-old computational phantom was applied to estimate organ doses derived from simulated CT exposures. As a result, a database including doses to 36 organs and tissues from 47 single axial scans was built. It has been verified by calculation that doses of axial scans are close to those of helical scans; therefore, this database could be applied to helical scans as well. Organ doses were calculated using the database and compared with those obtained from the measurements made in the physical phantom for helical scans. The differences between simulation and measurement were less than 25% for all organs. The result shows that the 1-year-old phantom developed in this work can be used to calculate organ doses in CT exposures, and the dose database provides a method for the estimation of 1-year-old patient doses in a variety of CT examinations. (paper)

  2. CT findings in autoimmune pancreatitis: assessment using multiphase contrast-enhanced multisection CT

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, K., E-mail: Kojiro@med.nagoya-u.ac.j [Department of Radiology, Nagoya University Graduate School of Medicine, Nagoya (Japan); Itoh, S. [Department of Radiology, Nagoya Hirokoji Clinic, Nagoya (Japan); Nagasaka, T. [Departments of Medical Technology, Nagoya University School of Health Science, Nagoya (Japan); Ogawa, H.; Ota, T.; Naganawa, S. [Department of Radiology, Nagoya University Graduate School of Medicine, Nagoya (Japan)

    2010-09-15

    Aim: To assess the spectrum of findings using multiphase contrast-enhanced computed tomography (CT) in patients with autoimmune pancreatitis (AIP). Materials and methods: Fifty patients (four female and 46 male, mean age 65 years) were retrospectively identified from consecutive patients with abnormal CT findings of the pancreas and negative work-up for known causes. These patients had at least one finding supporting the diagnosis of AIP: serological abnormality, histopathological abnormality, or response to steroid. Two radiologists evaluated multiphase contrast-enhanced CT images in consensus. Results: The pancreas showed diffuse enlargement (n = 16; 32%), focal enlargement (n = 18; 36%), or no enlargement (n = 16; 32%). Forty-nine (98%) patients showed abnormal contrast enhancement in the affected pancreatic parenchyma, including hypoattenuation during the pancreatic phase (n = 45; 90%) and hyperattenuation during the delayed phase (n = 39; 87%). The following findings were also seen in the pancreas: a capsule-like rim (n = 24; 48%); no visualization of the main pancreatic duct lumen (n = 48; 96%); ductal enhancement (n = 26; 52%); upstream dilatation of the main pancreatic duct (n = 27; 54%); upstream atrophy of the pancreatic parenchyma (n = 27; 54%); calcification (n = 7; 14%); and cysts (n = 5; 10%). Forty-two (84%) patients showed one or more of the following extrapancreatic findings: biliary duct or gallbladder abnormality (n = 40; 80%); peripancreatic (n = 8; 16%) or para-aortic (n = 10; 20%) soft-tissue proliferation; and renal involvement (n = 15; 30%). Conclusion: Patients with AIP presented with a variety of CT findings in the pancreas and the extrapancreatic organs. The present study highlights pancreatic ductal enhancement in a subset of patients with AIP.

  3. A case of hemiballism presenting atypical, responsive lesion by CT scan

    International Nuclear Information System (INIS)

    Kawahata, Nobuya; Honda, Masao.

    1983-01-01

    Hemiballism of the right limbs developed after cerebral infarction in an 83-year-old female patient. On admission, examination revealed hemiballism of the right limbs, monologia, disorientation of thought and motor skills, irritability and the absence of DTR in the right upper limb. Without aggressive treatment, however, involuntary movement disappeared after 18 days, and she was discharged on her own power. CT scan demonstrated a low density area in the left fronto-parietal lobe. However, no obvious abnormality in bilateral subthalamic nuclei was observed. Although the contralateral subthalamic body of Luys is involved in most instances, lesions have been reported to exist in the cerebral cortex, thalamus, corpus striatum, internal capsule and brain stem in some cases. The prognosis for this disease has been generally considered to be fatal. However, this case demonstrated an atypical lesion in CT scan, and spontaneous recovery from hemiballism took place within three weeks. Previous reports on hemiballism were reviewed, and responsive lesions and the prognosis for this case were discussed. (author)

  4. Gliomatosis cerebri followed-up with sequential CT scans report of case and a brief review

    International Nuclear Information System (INIS)

    Shiino, Akihiko; Suda, Kinya; Matsuda, Masayuki; Handa, Jyoji; Hazama, Fumitada

    1984-01-01

    Gliomatosis cerebri is a rare condition in which the tumor cells grow infiltratively and diffusely into the central nervous system without destructing the normal architechtures of the brain to a significant degree. As no single diagnostic test is highly specific to this condition, its clinical diagnosis is often very difficult. In the present case of a 71-year-old man, we could follow the course of the disease by repeated CT scans performed in 2 and a half years, and found such sequential CT scans very useful for the diagnosis of this condition. To our knowledge, this is the first report of sequential CT studies in gliomatosis cerebri. This case is reported and the relevant literature on gliomatosis cerebri is briefly reviewed. (author)

  5. A case of diffuse hemispheric gyral high density on CT scan following acute subdural hematoma in children

    International Nuclear Information System (INIS)

    Kannuki, Seiji; Oi, Shizuo

    1986-01-01

    A case of diffuse hemispheric gyral high density area following acute subdural hematoma was reported. A 2 - 10/12 year-old male was admitted to our hospital in comatous state after head injury by fall. Neurological examination revealed deep coma with anisocoria (R < L), absence of light reflex and positive bilateral Babinski reflex. CT scan disclosed left acute subdural hematoma with remarkable midline shift and tentorial herniation sign. Emergency decompressive craniectomy was performed. Posttraumatic hydrocephalus appeared after 10 days. So, ventriculoperitoneal shunt was done. The patient became gradually improved, but was in appalic state. 23 days after craniectomy, suddenly diffuse hemispheric gyral high density appeared on plain CT scan. In spite of this change, no clinical change was found. This high density spontaneously disappeared 10 days after appearance. Cerebral infarction-like phenomenon on postoperative CT scan of acute subdural hematoma in infants was sometimes reported. This phenomenon was sometimes accompanied with hemorrhagic infarction-like high density on CT scan. Diffuse hemispheric gyral high density was probably a kind of those hemorrhagic infarction-like phenomenon. Possible mechanism of this peculiar high density is discussed on the basis of characteristics of child's cerebral artery and pathophysiology of cerebral infarction. (author)

  6. Cardiac CT angiography after coronary artery surgery in children using 64-slice CT scan

    International Nuclear Information System (INIS)

    Marini, Davide; Agnoletti, Gabriella; Brunelle, Francis; Sidi, Daniel; Bonnet, Damien; Ou, Phalla

    2009-01-01

    Objective: The purpose of this study was to compare the diagnostic accuracy of 64-slice CT with that of invasive angiography in the detection of graft and/or coronary angioplasty stenosis in children who had undergone coronary artery surgery. Population and methods: Fifteen consecutive children (8 male and 7 female; age 9.2 ± 6.1 years) underwent 64-slice CT because of chest pain or ECG changes mean 4.8 ± 3.7 years after surgical coronary artery surgery; 10 patients had coronary angioplasty using a patch from the saphenous vein, four had mammary artery bypass, and one had saphenous vein bypass. Six main segments of the coronary arteries and all the bypass graft considered as a single segment were analyzed and compared with invasive angiography used as the reference standard. Results: CT correctly identified the four children with coronary angioplasty and mammary graft lesions that were confirmed by conventional angiography: one patient had a significant stenosis (>50% stenosis) at the mammary bypass graft anastomosis site; three other had non-significant stenosis (<50% stenosis) including a mild lesion of the saphenous vein patch in two patients and a mild lesion at the anastomosis site of the mammary bypass in one. All segments identified as normal by CT in the other 11 children were also found to be normal by conventional angiography. Conclusion: In centers expert in this technique, 64-slice CT scanning is a promising, rapid, and useful diagnostic technique for evaluating both coronary angioplasty and bypass graft lesions in children who had undergone coronary artery surgery.

  7. CT diagnostic significance of tuboovarian abscess

    International Nuclear Information System (INIS)

    Du Tieqiao; Dong Jie; Xu Quanying; An Haiqin; Sang Chunyu

    2006-01-01

    Objective: To analyze computed tomographic (CT) imaging features of tuboovarian abscess as well as to discuss CT diagnostic significance. Methods: Ten patients with tuboovarian abscess were performed CT enhancing scans. Results: Ten patients manifested thick-walled, cystic-solid complex adnexal mass and indistinct margins on CT imaging. Internal thick septations and layered enhancement of the mass border on CT contrast images were common. Associated findings of CT included thickening of' the uterosacral ligaments in 9 of 10 patients, increased attenuation of the presacral and perirectal fat secondary to edema in 9 patients, serpiginous structure corresponding to a dilated, pus-filled fallopian tube in 6 patients and fluid-filled within uterine cavity in 4 patients. On CT scans, the inflammatory infiltration of adnexal abscesses involved pelvic structure included adhesion with borders of uterus in 9 patients, adhesion with rectal or sigmoid in 4 patients and pelvic wall or bowel loop in 3 patients. Two cases with peritoneal thicken showed ascites on CT images and right adnexal tuboovarian abscess in 2 patients were associated with appendicitis. Conclusion: CT can reveal pelvic adjacent organs involvement or adhesion and inflammatory infihration of pelvic floor soft-tissues or fascial planes except showing cystic solid complex mass of adnexal location so that indicating characteristics and the extent of the suspected pelvic inflammatory diseases. CT can be valuable in difficult cases of gynecologic infective diseases. (authors)

  8. CT manifestation of the carcinoma of ovary: diagnosis and differential diagnosis

    International Nuclear Information System (INIS)

    Liu Mingjuan; Guo Yan; Zhang Ling; Huang Zhaomin

    2007-01-01

    Objective: To study the CT manifestations of carcinoma of ovary and the CT findings that mimic the carcinoma of ovary. Methods: CT findings were retrospectively studied in 47 cases of pelvic masses including 42 cases of carcinoma of ovary and 5 misdiagnosed as carcinoma of ovary. Misdiagnosis was made in 8 of the 42 cases of carcinoma of ovary. Non-contrast and enhanced CT scan were performed in all cases. Results: Pelvic or abdominal-pelvic masses were demonstrated in 92.4% cases. The lesions were parenchymatous, cystic, or cystic-parenchymatous masses, in which the parenchyma and septum were remarkably enhanced after the contrast agent was given intravenously. No mass was found in 7.6% cases, in which the ascites and thickening of the omentum were noted on CT images. Ascites was shown in 57.2% cases. Calicification was manifested in 19.0% cases. Abscess or tuberculosis located in pelvis could have the similar CT findings with cystic carcinoma of ovary, while these infectious lesions presented with regular or smooth wall and septum, instead of mural nodule. Another characteristic sign of abscess or tuberculosis was air density identified within the cavity of the cysts. Chocolate cysts with recent hemorrhage or subserous leiomyoma uteri with cystic degeneration were cystic-parenchymatous mass during the non-contrast enhanced scan. No enhancement could be revealed in parenchyma of the former and slight enhancement could be identified in the parenchymatous component of the latter. Conclusion: Contrast enhanced CT scan can demonstrate the structure of the mass and the adjacent organs, and reveal the enhancement of the lesions, which plays a valuable role in diagnosis or differential diagnosis of carcinoma of ovary with atypical CT findings. (authors)

  9. CT findings of focal organizing pneumonia: correlation with pathologic findings

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yang Soo; Kim, Young Goo; Park, Un Sup [College of Medicine, Chungang University, Seoul (Korea, Republic of)

    1994-11-15

    To evaluate the CT findings of focal organizing pneumonia and to correlate them with pathologic findings to help differentiating from lung cancer. We evaluated radiologic and pathologic findings of five patients with solitary pulmonary nodule which were confirmed as focal organizing pneumonia pathologically. On CT scan, focal organizing pneumonia had irregular margin contacting the pleura in all five cases. The shape of the nodules were spherical to wedge or elliptical and the size from 3.5cm to 5.5cm(average 4.2 cm) in largest diameter. On postcontrast CT scan, all nodules showed enhancement and four cases showed central low density components. Two nodules contained air within the nodule. In four cases, pleural changes such as effusion and/or focal thickening were noted. No lymphadenopathy was found in all cases. Pathologically, the enhancing portion on CT showed findings of organizing pneumonia such as granulation tissue with fibroblast proliferation in alveolar space and interstitial thickening. The central low density areas on CT were due to ischemic necrosis, abscess and exudate, transudate and infiltration of foamy histiocyte. The possibility of focal organizing pneumonia should be considered when peripherally located solitary pulmonary nodule had enhancing component with no combined lymphadenopathy on CT scan.

  10. CT findings of focal organizing pneumonia: correlation with pathologic findings

    International Nuclear Information System (INIS)

    Kim, Yang Soo; Kim, Young Goo; Park, Un Sup

    1994-01-01

    To evaluate the CT findings of focal organizing pneumonia and to correlate them with pathologic findings to help differentiating from lung cancer. We evaluated radiologic and pathologic findings of five patients with solitary pulmonary nodule which were confirmed as focal organizing pneumonia pathologically. On CT scan, focal organizing pneumonia had irregular margin contacting the pleura in all five cases. The shape of the nodules were spherical to wedge or elliptical and the size from 3.5cm to 5.5cm(average 4.2 cm) in largest diameter. On postcontrast CT scan, all nodules showed enhancement and four cases showed central low density components. Two nodules contained air within the nodule. In four cases, pleural changes such as effusion and/or focal thickening were noted. No lymphadenopathy was found in all cases. Pathologically, the enhancing portion on CT showed findings of organizing pneumonia such as granulation tissue with fibroblast proliferation in alveolar space and interstitial thickening. The central low density areas on CT were due to ischemic necrosis, abscess and exudate, transudate and infiltration of foamy histiocyte. The possibility of focal organizing pneumonia should be considered when peripherally located solitary pulmonary nodule had enhancing component with no combined lymphadenopathy on CT scan

  11. CT head-scan dosimetry in an anthropomorphic phantom and associated measurement of ACR accreditation-phantom imaging metrics under clinically representative scan conditions

    Energy Technology Data Exchange (ETDEWEB)

    Brunner, Claudia C.; Stern, Stanley H.; Chakrabarti, Kish [U.S. Food and Drug Administration, 10903 New Hampshire Avenue, Silver Spring, Maryland 20993 (United States); Minniti, Ronaldo [National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899 (United States); Parry, Marie I. [Walter Reed National Military Medical Center, 8901 Rockville Pike, Bethesda, Maryland 20889 (United States); Skopec, Marlene [National Institutes of Health, 9000 Rockville Pike, Bethesda, Maryland 20892 (United States)

    2013-08-15

    Gy, respectively. The GE Discovery delivers about the same amount of dose (43.7 mGy) when run under similar operating and image-reconstruction conditions, i.e., without tube current modulation and ASIR. The image-metrics analysis likewise showed that the MTF, NPS, and CNR associated with the reconstructed images are mutually comparable when the three scanners are run with similar settings, and differences can be attributed to different edge-enhancement properties of the applied reconstruction filters. Moreover, when the GE scanner was operated with the facility's scanner settings for routine head exams, which apply 50% ASIR and use only approximately half of the 100%-FBP dose, the CNR of the images showed no significant change. Even though the CNR alone is not sufficient to characterize the image quality and justify any dose reduction claims, it can be useful as a constancy test metric.Conclusions: This work presents a straightforward method to connect direct measurements of CT dose with objective image metrics such as high-contrast resolution, noise, and CNR. It demonstrates that OSLD measurements in an anthropomorphic head phantom allow a realistic and locally precise estimation of magnitude and spatial distribution of dose in tissue delivered during a typical CT head scan. Additional objective analysis of the images of the ACR accreditation phantom can be used to relate the measured doses to high contrast resolution, noise, and CNR.

  12. CT diagnosis of rare histological variant of hepatocellular carcinoma

    International Nuclear Information System (INIS)

    Li Huaibo; Feng Zhipeng; Duan Shaoyin; Zhaugn Xiangrong

    2009-01-01

    Objective: To explore and understand the CT findings of 5 rare histological variants of hepatocellular carcinoma. Methods: CT findings of 31 cases of rare histological variants confirmed by surgery and pathology were analyzed retrospectively. Results: 13 cases were clear cell hepatocellular carcinoma. 3 cases of them showed patchy fat density in plain scans. Enhanced CT showed features of 'fast in fast out' which was similar to the common hepatocellular carcinoma. 4 cases belonged to sclerosis hepatocellular carcinoma. They appeared as heterogeneous, slowly enhancement on arterial phase images, and delay enhancement on portal venous phase and delay phase images. 9 cases belonged to mixed hepatocellular carcinoma. 5 cases of them showed inhomogeneous enhancement and 4 without enhancement during arterial phase, 3 cases showed delay enhancement and 4 without during portal venous and delay phase. 3 cases were fibrolamellar hepatocellular carcinoma. All showed obvious and fastly enhancement on arterial phase images, subsided slowly on the portal venous and delay phase images, showing features of 'fast in slow out', no enhancement was seen in the central scar. Shrinkage phenomenon on the surface of liver could be seen on the CT plain scans in sclerosis, mixed and fibrolamellar hepatocellular carcinoma. 2 cases were the type of dense hepatocellular carcinoma. The surrounding part in the 2 cases were slightly enhanced, while the most part of the center were not enhanced similar to necrosis. Conclusion: The CT findings of rate histological variant of hepatocellular carcinoma are characteristic. Analyzing the CT plain and enhancement finding is helpful to the diagnosis of these types of hepatocellular carcinoma. (authors)

  13. A study of the short- to long-phantom dose ratios for CT scanning without table translation

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xinhua; Zhang, Da; Liu, Bob, E-mail: bliu7@mgh.harvard.edu [Division of Diagnostic Imaging Physics, Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts 02114 and Webster Center for Advanced Research and Education in Radiation, Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts 02114 (United States); Yang, Jie [Pinnacle Health - Fox Chase Regional Cancer Center, Harrisburg, Pennsylvania 17109 (United States)

    2014-09-15

    Purpose: For CT scanning in the stationary-table modes, AAPM Task Group 111 proposed to measure the midpoint dose on the central and peripheral axes of sufficiently long phantoms. Currently, a long cylindrical phantom is usually not available in many clinical facilities. The use of a long phantom is also challenging because of the heavy weight. In order to shed light on assessing the midpoint dose in CT scanning without table movement, the authors present a study of the short- to long-phantom dose ratios, and perform a cross-comparison of CT dose ratios on different scanner models. Methods: The authors performed Geant4-based Monte Carlo simulations with a clinical CT scanner (Somatom Definition dual source CT, Siemens Healthcare), and modeled dosimetry measurements using a 0.6 cm{sup 3} Farmer type chamber and a 10-cm long pencil ion chamber. The short (15 cm) to long (90 cm) phantom dose ratios were computed for two PMMA diameters (16 and 32 cm), two phantom axes (the center and the periphery), and a range of beam apertures (3–25 cm). The results were compared with the published data of previous studies with other multiple detector CT (MDCT) scanners and cone beam CT (CBCT) scanners. Results: The short- to long-phantom dose ratios changed with beam apertures but were insensitive to beam qualities (80–140 kV, the head and body bowtie filters) and MDCT and CBCT scanner models. Conclusions: The short- to long-phantom dose ratios enable medical physicists to make dosimetry measurements using the standard CT dosimetry phantoms and a Farmer chamber or a 10 cm long pencil chamber, and to assess the midpoint dose in long phantoms. This method provides an effective approach for the dosimetry of CBCT scanning in the stationary-table modes, and is useful for perfusion and interventional CT.

  14. A study of the short- to long-phantom dose ratios for CT scanning without table translation

    International Nuclear Information System (INIS)

    Li, Xinhua; Zhang, Da; Liu, Bob; Yang, Jie

    2014-01-01

    Purpose: For CT scanning in the stationary-table modes, AAPM Task Group 111 proposed to measure the midpoint dose on the central and peripheral axes of sufficiently long phantoms. Currently, a long cylindrical phantom is usually not available in many clinical facilities. The use of a long phantom is also challenging because of the heavy weight. In order to shed light on assessing the midpoint dose in CT scanning without table movement, the authors present a study of the short- to long-phantom dose ratios, and perform a cross-comparison of CT dose ratios on different scanner models. Methods: The authors performed Geant4-based Monte Carlo simulations with a clinical CT scanner (Somatom Definition dual source CT, Siemens Healthcare), and modeled dosimetry measurements using a 0.6 cm 3 Farmer type chamber and a 10-cm long pencil ion chamber. The short (15 cm) to long (90 cm) phantom dose ratios were computed for two PMMA diameters (16 and 32 cm), two phantom axes (the center and the periphery), and a range of beam apertures (3–25 cm). The results were compared with the published data of previous studies with other multiple detector CT (MDCT) scanners and cone beam CT (CBCT) scanners. Results: The short- to long-phantom dose ratios changed with beam apertures but were insensitive to beam qualities (80–140 kV, the head and body bowtie filters) and MDCT and CBCT scanner models. Conclusions: The short- to long-phantom dose ratios enable medical physicists to make dosimetry measurements using the standard CT dosimetry phantoms and a Farmer chamber or a 10 cm long pencil chamber, and to assess the midpoint dose in long phantoms. This method provides an effective approach for the dosimetry of CBCT scanning in the stationary-table modes, and is useful for perfusion and interventional CT

  15. The diagnostic analysis using the CT scan, of cystic lesions in the cranial basis in pediatric cases

    International Nuclear Information System (INIS)

    Oshida, Kinya; Ishimori, Shoji; Okada, Ryoho.

    1978-01-01

    It is the purpose of this paper to evaluate the low-density lesions of those pediatric cases which were treated at this hospital in the six months beginning July, 1977, using a CT scan, EMI-1010 Type. Among 1500 consecutive cases diagnosed with the CT scan, 300 pediatric cases were included. We discuss particularly eight patients, two with arachnoidal cysts, two with cystic craniopharyngiomas, two with cystic cerebellar astrocytomas and two with Dandy-Walker syndromes, one of which was accompanied by corpus callosum agenesis. The distribution of ages was from 2 to 12 years. We calculated the matrix of each slice of these patients, CT scan in the cystic lesions, the area including the cystic lesion, ventricles and brain tissue, predominantly the white matter or interhemispheric cortex including white matter, without dye enhancement. The x-ray absorption values of the low-density lesions were definitely different according to the nature of the cystic contents. The mean values of x-ray absorption, the standard deviations, and the sample sizes of each area in the matrix were compared statistically with those of cystic lesions. The mean values of the arachnoidal cysts, the contents of which were almost like CSF, were 17 - 21; that of cystic craniopharyngiomas, the contents of which were a thick yellowic fluid with cholesterin crystals, were 23 - 28; those of cerebellar astrocytomas, with Froin positive fluid, were 22 - 24; the cystic lesions of the posterior fossa in the Dandy-Walker syndrome were 8 - 13. The difference in the x-ray absorption values (Hounsfield number) were compared statistically for analyzing the differential diagnosis of these low-density lesions by calculating the P-values. All of these lesions were verified by surgical explorations. (author)

  16. Evaluation of Dixon Sequence on Hybrid PET/MR Compared with Contrast-Enhanced PET/CT for PET-Positive Lesions

    International Nuclear Information System (INIS)

    Jeong, Ju Hye; Cho, Ihn Ho; Kong, Eun Jung; Chun, Kyung Ah

    2014-01-01

    Hybrid positron emission tomography and magnetic resonance (PET/MR) imaging performs a two-point Dixon MR sequence for attenuation correction. However, MR data in hybrid PET/MR should provide anatomic and morphologic information as well as an attenuation map. We evaluated the Dixon sequence of hybrid PET/MR for anatomic correlation of PET-positive lesions compared with contrast-enhanced PET/computed tomography (CT) in patients with oncologic diseases. Twelve patients underwent a single injection, dual imaging protocol. PET/CT was performed with an intravenous contrast agent (85±13 min after 18 F-FDG injection of 403± 45 MBq) and then (125±19 min after injection) PET/MR was performed. Attenuation correction and anatomic allocation of PET were performed using contrast-enhanced CT for PET/CT and Dixon MR sequence for hybrid PET/MR. The Dixon MR sequence and contrast-enhanced CT were compared for anatomic correlation of PET-positive lesions (scoring scale ranging from 0 to 3 for visual ratings). Additionally, standardized uptake values (SUVs) for the detected lesions were assessed for quantitative comparison. Both hybrid PET/MR and contrast-enhanced PET/CT identified 55 lesions with increased FDG uptake in ten patients. In total, 28 lymph nodes, 11 bone lesions, 3 dermal nodules, 3 pleural thickening lesions, 2 thyroid nodules, 1 pancreas, 1 liver, 1 ovary, 1 uterus, 1 breast, 1 soft tissue and 2 lung lesions were present. The best performance was observed for anatomic correlation of PET findings by the contrast-enhanced CT scans (contrast-enhanced CT, 2.64± 0.70; in-phase, 1.29±1.01; opposed-phase, 1.29±1.15; water-weighted, 1.71±1.07; fat weighted, 0.56±1.03). A significant difference was observed between the scores obtained from the contrast-enhanced CT and all four coregistered Dixon MR images. Quantitative evaluation revealed a high correlation between the SUVs measured with hybrid PET/MR (SUVmean, 2.63±1.62; SUVmax, 4.30±2.88) and contrast-enhanced PET/CT

  17. Evaluation of Dixon Sequence on Hybrid PET/MR Compared with Contrast-Enhanced PET/CT for PET-Positive Lesions

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Ju Hye; Cho, Ihn Ho; Kong, Eun Jung; Chun, Kyung Ah [Yeungnam Univ. Hospital, Daegu (Korea, Republic of)

    2014-03-15

    Hybrid positron emission tomography and magnetic resonance (PET/MR) imaging performs a two-point Dixon MR sequence for attenuation correction. However, MR data in hybrid PET/MR should provide anatomic and morphologic information as well as an attenuation map. We evaluated the Dixon sequence of hybrid PET/MR for anatomic correlation of PET-positive lesions compared with contrast-enhanced PET/computed tomography (CT) in patients with oncologic diseases. Twelve patients underwent a single injection, dual imaging protocol. PET/CT was performed with an intravenous contrast agent (85±13 min after {sup 18}F-FDG injection of 403± 45 MBq) and then (125±19 min after injection) PET/MR was performed. Attenuation correction and anatomic allocation of PET were performed using contrast-enhanced CT for PET/CT and Dixon MR sequence for hybrid PET/MR. The Dixon MR sequence and contrast-enhanced CT were compared for anatomic correlation of PET-positive lesions (scoring scale ranging from 0 to 3 for visual ratings). Additionally, standardized uptake values (SUVs) for the detected lesions were assessed for quantitative comparison. Both hybrid PET/MR and contrast-enhanced PET/CT identified 55 lesions with increased FDG uptake in ten patients. In total, 28 lymph nodes, 11 bone lesions, 3 dermal nodules, 3 pleural thickening lesions, 2 thyroid nodules, 1 pancreas, 1 liver, 1 ovary, 1 uterus, 1 breast, 1 soft tissue and 2 lung lesions were present. The best performance was observed for anatomic correlation of PET findings by the contrast-enhanced CT scans (contrast-enhanced CT, 2.64± 0.70; in-phase, 1.29±1.01; opposed-phase, 1.29±1.15; water-weighted, 1.71±1.07; fat weighted, 0.56±1.03). A significant difference was observed between the scores obtained from the contrast-enhanced CT and all four coregistered Dixon MR images. Quantitative evaluation revealed a high correlation between the SUVs measured with hybrid PET/MR (SUVmean, 2.63±1.62; SUVmax, 4.30±2.88) and contrast-enhanced

  18. Coronary artery visibility in free-breathing young children with congenital heart disease on cardiac 64-slice CT: dual-source ECG-triggered sequential scan vs. single-source non-ECG-synchronized spiral scan

    Energy Technology Data Exchange (ETDEWEB)

    Goo, Hyun Woo; Yang, Dong Hyun [University of Ulsan College of Medicine, Department of Radiology and Research Institute of Radiology, Asan Medical Center, Seoul (Korea, Republic of)

    2010-10-15

    The potential impact of dual-source ECG-triggered sequential CT scan on coronary artery visibility has not been evaluated in free-breathing young children. To compare coronary artery visibility in free-breathing young children with congenital heart disease on cardiac 64-slice CT between dual-source ECG-triggered sequential (DSET) scan and single-source non-ECG-synchronized spiral (SSNE) scan. In 93 young children, 108 cardiac 64-slice CT examinations were performed during free-breathing. Visibility of coronary arteries and side branches was compared between SSNE and DSET scans. Heart rates and trigger delays for DSET scan were recorded. Effective dose of each scan technique was calculated. Visual grades were significantly higher (P < 0.001 or =0.011) on DSET scan than on SSNE scan except for the distal left anterior descending artery. Coronary arteries were traceable in 79.3% on DSET scan and 54.3% on SSNE scan in the overlapped scan range (P < 0.0001), and 97.1% and 71.9% for the origins and proximal segments (P < 0.0001). Visibility of side branches was improved on DSET scan by a factor of 2.0. Heart rates and trigger delays for DSET scan were 131 {+-} 24 beats per min and 199 {+-} 44 ms, respectively. Effective doses of DSET and SSNE scans were 0.36 {+-} 0.12 mSv and 0.99 {+-} 0.23 mSv, respectively. DSET scan improves visibility of coronary arteries on cardiac 64-slice CT in free-breathing young children with congenital heart disease, compared with SSNE scan. (orig.)

  19. CT imaging before transcatheter aortic valve implantation (TAVI) using variable helical pitch scanning and its diagnostic performance for coronary artery disease

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, Shunsuke; Yamada, Yoshitake; Hashimoto, Masahiro; Okamura, Teppei; Jinzaki, Masahiro [Keio University School of Medicine, Department of Diagnostic Radiology, Shinanomachi, Shinjuku-ku, Tokyo (Japan); Yamada, Minoru [Keio University School of Medicine, Research Park, Tokyo (Japan); Yashima, Fumiaki; Hayashida, Kentaro; Fukuda, Keiichi [Keio University School of Medicine, Department of Cardiology, Tokyo (Japan)

    2017-05-15

    To evaluate the effectiveness of CT before TAVI using variable helical pitch (VHP) scanning and its diagnostic performance for coronary artery disease (CAD). Sixty patients (84.4 ± 4.6 years) scheduled for TAVI underwent CT using VHP scanning with the contrast material (CM) volume calculated as scanning time x weight [kg] x 0.06 mL. Retrospective electrocardiography (ECG)-gated scanning was utilized to examine the thorax, and non-ECG-gated scanning of the abdomen immediately followed. We analyzed CT attenuation values of the coronary arteries, aorta, iliac and femoral arteries. The coronary CT angiography images were evaluated for the presence of stenosis (≥50 %); invasive coronary angiography served as a reference standard. The average attenuations of all of the arteries were greater than 400 HU. We could evaluate the peripheral access vessels and dimensions of the ascending aorta, aortic root, and aortic annulus in all patients. The average volume of CM was 38.7 ± 8.5 mL. On per-patient and vessel analysis, CT showed 91.7 % and 89.5 % sensitivity, and 91.3 % and 97.4 % negative predictive value (NPV). CT using VHP scanning with an average CM volume of 38.7 mL is useful before TAVI and had a high sensitivity and NPV in excluding obstructive CAD. (orig.)

  20. Comparison of 18F-FDG PET to CT scan in the detection of recurrent colorectal carcinoma - an ROC analysis

    International Nuclear Information System (INIS)

    Scott, A.M.; Akhurst, T.; Berlangieri, S.U.; Fitt, G.; Schelleman, T.; Jones, R.; Hannah, A.; Tochon-Danguy, H.

    2000-01-01

    Full text: This study examined 43 scans performed in 40 patients from a group of 93 prospectively enrolled in a trial examining the utility of 18 F-FDG PET in patients with potentially resectable recurrent colorectal cancer. All patients had PET and CT scans prior to surgery, where a total of 84 anatomical regions were biopsied, and 364 regions examined by the surgeons. All PET and CT scans were viewed blinded to clinical and imaging data. The scans were interpreted according to a five-point confidence scale to enable an ROC analysis to be performed. An assessment of the impact of PET over CT in patients was also made. Of the 43 cases PET and CT were concordant in 24 (56%). There were 16 cases where PET added additional diagnostic information to the benefit of the patient (37%), and three (7%) where PET alone would have lead to a potentially negative outcome. The majority of cases where PET performed better were in cases with extrahepatic disease. CT was more sensitive in the detection of pulmonary nodules, although the specificity of CT was less than PET. In conclusion, 18 F-FDG PET performed significantly better than CT both in terms of a regional analysis as well as a patient by patient basis. Copyright (2000) The Australian and New Zealand Society of Nuclear Medicine Inc

  1. Feasibility of power contrast injections and bolus triggering during CT scans in oncologic patients with totally implantable venous access ports of the forearm

    International Nuclear Information System (INIS)

    Goltz, Jan Peter; Machann, Wolfram; Noack, Claudia; Hahn, Dietbert; Kickuth, Ralph

    2011-01-01

    Background: Conventional totally implantable venous access ports (TIVAPs) are not approved for power contrast injections but often remain the only venous access site in oncologic patients. Therefore, these devices can play an important role if patients with a TIVAP are scheduled for a contrast-enhanced computed tomography (ceCT) as vascular access may become more difficult during the course of chemotherapy. Purpose: To evaluate the feasibility and safety of power injections in conventional TIVAPs in the forearm and to analyze the feasibility of bolus triggering during CT scans. Material and Methods: In this retrospective study we analyzed 177 power injections in 141 patients with TIVAPs in the forearm. Between October 2008 and March 2010 all patients underwent power injections (1.5 mL/s, 150 psi) via the TIVAP for ceCT because conventional vascular access via a peripheral vein had failed. Adequate functioning and catheter's tip location after injection were evaluated. Peak injection pressure and attenuation levels of aorta, liver and spleen were analyzed and compared with results of 50 patients who were injected via classical peripheral cannulas (3 mL/s, 300 psi). Feasibility of automatic scan initiation was evaluated. In vitro the port was stressed with 5 mL/s (300 psi). Results: One TIVAP showed tip dislocation with catheter rupture. Three (2.1%) devices were explanted owing to assumed infection within 4 weeks after the injection. Mean injection pressure was 121.9 ±24.1 psi. Triggering with automatic scan initiation succeeded in 13/44 (29.6%) scans. Injection via classical cannulas resulted in significantly higher enhancement (p < 0.05). In vitro the port system tolerated flow rates of up to 5 mL/s, injection pressures of up to 338 psi. Conclusion: Power injection is a safe alternative for patients with TIVAPs in the forearm if classic vascular access ultimately fails. Triggering was successful in one-third of the attempts. Image quality in the arterial phase

  2. Relative location prediction in CT scan images using convolutional neural networks.

    Science.gov (United States)

    Guo, Jiajia; Du, Hongwei; Zhu, Jianyue; Yan, Ting; Qiu, Bensheng

    2018-07-01

    Relative location prediction in computed tomography (CT) scan images is a challenging problem. Many traditional machine learning methods have been applied in attempts to alleviate this problem. However, the accuracy and speed of these methods cannot meet the requirement of medical scenario. In this paper, we propose a regression model based on one-dimensional convolutional neural networks (CNN) to determine the relative location of a CT scan image both quickly and precisely. In contrast to other common CNN models that use a two-dimensional image as an input, the input of this CNN model is a feature vector extracted by a shape context algorithm with spatial correlation. Normalization via z-score is first applied as a pre-processing step. Then, in order to prevent overfitting and improve model's performance, 20% of the elements of the feature vectors are randomly set to zero. This CNN model consists primarily of three one-dimensional convolutional layers, three dropout layers and two fully-connected layers with appropriate loss functions. A public dataset is employed to validate the performance of the proposed model using a 5-fold cross validation. Experimental results demonstrate an excellent performance of the proposed model when compared with contemporary techniques, achieving a median absolute error of 1.04 cm and mean absolute error of 1.69 cm. The time taken for each relative location prediction is approximately 2 ms. Results indicate that the proposed CNN method can contribute to a quick and accurate relative location prediction in CT scan images, which can improve efficiency of the medical picture archiving and communication system in the future. Copyright © 2018 Elsevier B.V. All rights reserved.

  3. Normal CT anatomy of the spine

    International Nuclear Information System (INIS)

    Quiroga, O.; Matozzi, F.; Beranger, M.; Nazarian, S.; Salamon, G.; Gambarelli, J.

    1982-01-01

    To analyse the anatomo-radiological correlation of the spine and spinal cord, 22 formalized, frozen anatomical specimens corresponding to different regions of the spinal column (8 cervical, 5 dorsal, and 9 lumbar) were studied by CT scans on axial, sagittal and coronal planes and by contact radiography after they were cut into anatomical slices in order to clarify the normal CT anatomy of the spinal column. The results obtained from CT patient scans, performed exclusively on the axial plane, were compared with those obtained from the anatomical specimens (both CT and contrast radiography). High resolution CT programs were used, enabling us to obtain better individualization of the normal structures contained in the spinal column. Direct sagittal and coronal sections were performed on the specimens in order to get further anatomo-radiological information. Enhanced CT studies of the specimens were also available because of the air already present in the subarachnoid spaces. Excellent visualization was obtained of bone structures, soft tissue and the spinal cord. High CT resolution of the spine appeares to be an excellent neuroradiological procedure to study the spine and spinal cord. A metrizamide CT scan is, however, necessary when a normal unenhanced CT scan is insufficient for diagnosis and when the spinal cord is not clearly visible, as often happens at the cervical level. Clinical findings are certainly very useful to ascertain the exact CT level and to limit the radiation exposure. (orig.)

  4. Analysis of the acetabulum by CT scan in Japanese with osteoarthritis of the hip

    International Nuclear Information System (INIS)

    Ishibashi, Masanori

    1997-01-01

    The morphology of the acetabulum was analyzed by CT scan in 66 Japanese patients with osteoarthritis of the hip mainly following congenital dislocation or dysplasia. The CT scan data was analyzed to standardize the pelvic inclination in all directions. In these patients, the acetabular floor had thickened and the acetabulum was located in the anterolateral portion. The bilateral difference in the acetabular anteversion angle was not different between patients and normal individuals, but the acetabular sector angle in patients was smaller than in the normal subjects. As the stage of osteoarthritis of the hip advanced, the thickness of the acetabular floor in the center and posterior portions and the anterior sector angle increased, and the lateralization of the acetabulum advanced, but the anteversion angle decreased. A bone-forming change is characteristic of the anterior acetabulum and acetabular fossa in the center and posterior portions in Japanese patients with osteoarthritis of the hip. In comparison with data obtained by standard radiography, these changes detected by CT scan corresponded to an increase of the width of a tear drop, the lateralization of the femoral head and the lack of the support of the femoral head from the acetabulum. (author)

  5. Analysis of the acetabulum by CT scan in Japanese with osteoarthritis of the hip

    Energy Technology Data Exchange (ETDEWEB)

    Ishibashi, Masanori [Keio Univ., Tokyo (Japan). School of Medicine

    1997-11-01

    The morphology of the acetabulum was analyzed by CT scan in 66 Japanese patients with osteoarthritis of the hip mainly following congenital dislocation or dysplasia. The CT scan data was analyzed to standardize the pelvic inclination in all directions. In these patients, the acetabular floor had thickened and the acetabulum was located in the anterolateral portion. The bilateral difference in the acetabular anteversion angle was not different between patients and normal individuals, but the acetabular sector angle in patients was smaller than in the normal subjects. As the stage of osteoarthritis of the hip advanced, the thickness of the acetabular floor in the center and posterior portions and the anterior sector angle increased, and the lateralization of the acetabulum advanced, but the anteversion angle decreased. A bone-forming change is characteristic of the anterior acetabulum and acetabular fossa in the center and posterior portions in Japanese patients with osteoarthritis of the hip. In comparison with data obtained by standard radiography, these changes detected by CT scan corresponded to an increase of the width of a tear drop, the lateralization of the femoral head and the lack of the support of the femoral head from the acetabulum. (author)

  6. Analysis of thyroid absorbed dose in cervical CT scan with the use of bismuth shielding

    International Nuclear Information System (INIS)

    Santos, Fernanda S.; Gómez, Álvaro M.L.; Mourão, Arnaldo P.; Santana, Priscila C.

    2017-01-01

    The Computed Tomography (CT) has become an important tool to diagnose cancer and to obtain additional information for different clinical questions. Today, it is a very fast, painless and noninvasive test that can be performed high quality images. However, CT scan usually requires a higher radiation exposure dose than a conventional radiography examination. The aim of this study is to determine the dose variation deposited in thyroid and in nearby radiosensitive organs, such as: lenses, pharynx, hypophysis, salivary gland and spinal cord with and without the use of bismuth shielded. A cervical CT scan was performed on anthropomorphic male phantom model Alderson Rando, from the occipital to the first thoracic vertebra, using a GE scanner, Discovery model with 64 channels. Dose measurements have been performed by using radiochromic film strips to register the individual doses in the organs of interest. After the phantom cervical CT scan the radiochromic film strips were processed for obtaining digital images. Digital images were worked to obtain the dose variation profiles for each film. With the data obtained, it was found the organ dose variation. The results show that the thyroid received the highest dose, 40.9 mGy, in the phantom, according to the incidence of the primary X-ray beam. (author)

  7. Analysis of thyroid absorbed dose in cervical CT scan with the use of bismuth shielding

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Fernanda S.; Gómez, Álvaro M.L.; Mourão, Arnaldo P., E-mail: fernanda.stephaniebh@yahoo.com.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear; Santana, Priscila C. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Anatomia e Imagem

    2017-07-01

    The Computed Tomography (CT) has become an important tool to diagnose cancer and to obtain additional information for different clinical questions. Today, it is a very fast, painless and noninvasive test that can be performed high quality images. However, CT scan usually requires a higher radiation exposure dose than a conventional radiography examination. The aim of this study is to determine the dose variation deposited in thyroid and in nearby radiosensitive organs, such as: lenses, pharynx, hypophysis, salivary gland and spinal cord with and without the use of bismuth shielded. A cervical CT scan was performed on anthropomorphic male phantom model Alderson Rando, from the occipital to the first thoracic vertebra, using a GE scanner, Discovery model with 64 channels. Dose measurements have been performed by using radiochromic film strips to register the individual doses in the organs of interest. After the phantom cervical CT scan the radiochromic film strips were processed for obtaining digital images. Digital images were worked to obtain the dose variation profiles for each film. With the data obtained, it was found the organ dose variation. The results show that the thyroid received the highest dose, 40.9 mGy, in the phantom, according to the incidence of the primary X-ray beam. (author)

  8. Differentiating intraparenchymal hemorrhage from contrast extravasation on post-procedural noncontrast CT scan in acute ischemic stroke patients undergoing endovascular treatment

    Energy Technology Data Exchange (ETDEWEB)

    Payabvash, Seyedmehdi [Zeenat Qureshi Stroke Institute, Minneapolis, MN (United States); University of Minnesota, Department of Radiology, Minneapolis, MN (United States); Qureshi, Mushtaq H.; Khan, Shayaan M.; Khan, Mahnoor; Majidi, Shahram; Pawar, Swaroop; Qureshi, Adnan I. [Zeenat Qureshi Stroke Institute, Minneapolis, MN (United States)

    2014-09-15

    This study aimed to identify the imaging characteristics that can help differentiate intraparenchymal hemorrhage from benign contrast extravasation on post-procedural noncontrast CT scan in acute ischemic stroke patients after endovascular treatment. We reviewed the clinical and imaging records of all acute ischemic stroke patients who underwent endovascular treatment in two hospitals over a 3.5-year period. The immediate post-procedural CT scan was evaluated for the presence of hyperdense lesion(s). The average attenuation of the lesion(s) was measured. Intraparenchymal hemorrhage was defined as a persistent hyperdensity visualized on follow-up CT scan, 24 h or greater after the procedure. Of the 135 patients studied, 74 (55 %) patients had hyperdense lesion(s) on immediate post-procedural CT scan. Follow-up scans confirmed the diagnosis of intraparenchymal hemorrhage in 20 of these 74 patients. A receiver operating characteristic analysis showed that the average attenuation of the most hyperdense lesion can differentiate intraparenchymal hemorrhage from contrast extravasation with an area under the curve of 0.78 (p = 0.001). An average attenuation of <50 Hounsfield units (HU) in the most visually hyperattenuating hyperdense lesion had 100 % specificity and 56 % sensitivity for identification of contrast extravasations. Petechial hyperdensity was seen in 46/54 (85 %) patients with contrast extravasation versus 9/20 (45 %) patients with intraparenchymal hemorrhage on the immediate post-procedural CT scan (p < 0.001). An average attenuation <50 HU of the most hyperattenuating hyperdense parenchymal lesion on immediate post-procedural CT scan was very specific for differentiating contrast extravasation from intraparenchymal hemorrhage in acute ischemic stroke patients after endovascular treatment. (orig.)

  9. Differentiating intraparenchymal hemorrhage from contrast extravasation on post-procedural noncontrast CT scan in acute ischemic stroke patients undergoing endovascular treatment

    International Nuclear Information System (INIS)

    Payabvash, Seyedmehdi; Qureshi, Mushtaq H.; Khan, Shayaan M.; Khan, Mahnoor; Majidi, Shahram; Pawar, Swaroop; Qureshi, Adnan I.

    2014-01-01

    This study aimed to identify the imaging characteristics that can help differentiate intraparenchymal hemorrhage from benign contrast extravasation on post-procedural noncontrast CT scan in acute ischemic stroke patients after endovascular treatment. We reviewed the clinical and imaging records of all acute ischemic stroke patients who underwent endovascular treatment in two hospitals over a 3.5-year period. The immediate post-procedural CT scan was evaluated for the presence of hyperdense lesion(s). The average attenuation of the lesion(s) was measured. Intraparenchymal hemorrhage was defined as a persistent hyperdensity visualized on follow-up CT scan, 24 h or greater after the procedure. Of the 135 patients studied, 74 (55 %) patients had hyperdense lesion(s) on immediate post-procedural CT scan. Follow-up scans confirmed the diagnosis of intraparenchymal hemorrhage in 20 of these 74 patients. A receiver operating characteristic analysis showed that the average attenuation of the most hyperdense lesion can differentiate intraparenchymal hemorrhage from contrast extravasation with an area under the curve of 0.78 (p = 0.001). An average attenuation of <50 Hounsfield units (HU) in the most visually hyperattenuating hyperdense lesion had 100 % specificity and 56 % sensitivity for identification of contrast extravasations. Petechial hyperdensity was seen in 46/54 (85 %) patients with contrast extravasation versus 9/20 (45 %) patients with intraparenchymal hemorrhage on the immediate post-procedural CT scan (p < 0.001). An average attenuation <50 HU of the most hyperattenuating hyperdense parenchymal lesion on immediate post-procedural CT scan was very specific for differentiating contrast extravasation from intraparenchymal hemorrhage in acute ischemic stroke patients after endovascular treatment. (orig.)

  10. Chest CT scans are frequently abnormal in asymptomatic patients with newly diagnosed acute myeloid leukemia.

    Science.gov (United States)

    Vallipuram, Janaki; Dhalla, Sidika; Bell, Chaim M; Dresser, Linda; Han, Heekyung; Husain, Shahid; Minden, Mark D; Paul, Narinder S; So, Miranda; Steinberg, Marilyn; Vallipuram, Mayuran; Wong, Gary; Morris, Andrew M

    2017-04-01

    Chest computed tomography (CT) findings of nodules, ground glass opacities, and consolidations are often interpreted as representing invasive fungal infection in individuals with febrile neutropenia. We assessed whether these CT findings were present in asymptomatic individuals with acute myeloid leukemia (AML) at low risk of invasive fungal disease. A retrospective study of consecutive asymptomatic adult patients with newly diagnosed AML over a 2-year period was performed at a tertiary care oncology center. Radiology reports of baseline chest CTs were reviewed. Of 145 CT scans, the majority (88%) had pulmonary abnormalities. Many (70%) had one or both of unspecified opacities (52%) and nodules (49%). Ground glass opacities (18%) and consolidations (12%) occurred less frequently. Radiologists suggested pneumonia as a possible diagnosis in 32% (n = 47) of scans. Chest CT may result in over-diagnosis of invasive fungal disease in individuals with febrile neutropenia if interpreted without correlation to the patients' clinical status.

  11. Dynamic contrast-enhanced CT appearances of the intraductal papillary neoplasms of the bile duct

    International Nuclear Information System (INIS)

    Song Fengxiang; Zhou Jianjun; Zeng Mengsu; Zhou Kangrong; Ding Yuqin; He Deming; Shi Yuxin; Zhou Jun

    2013-01-01

    Objective: To analyze the dynamic contrast-enhanced CT appearances of intraductal papillary neoplasms of the bile duct and improve its diagnostic accuracy. Methods: Sixteen patients with intraductal papillary neoplasms of the bile duct confirmed histopathologically after surgical operation underwent dynamic contrast-enhanced multi-detector row CT scans. All imaging data were reviewed and analyzed retrospectively in correlation with surgical and pathological findings. CT values of 38 well-visualized lesions in 12 of the 16 patients at the pre-contrast phase, arterial phase and venous phase were measured. Four of the 12 patients with 17 lesions had benign tumors, and 8 of the 12 patients with 21 lesions had malignant tumors. Comparisons of CT values at the three phases between the two groups were carried out using independent sample t test. The bile CT values were measured in these 12 cases, 40 normal volunteers, and 40 subjects with bile duct stones, and the Wilcoxon signed-rank test was applied to compare the bile CT values between tumor group and the normal group and between tumor group and the bile duct stone group. The diameters of the bile ducts proximal to and distal to tumors were also measured, and Fisher exact method was carried to analyze the data. Results: Lesions located at the left lobe in 8 out of the 16 patients, the right lobe in 1 case, both the left and right lobes in 1 case, the hepatic hilum in 1 case, the common bile duct in 3 cases, and both the right lobe and the common bile duct in 2 cases. Eleven lesions appeared as papillary masses, 3 as flat masses, 1 as mixed papillary and flat masses. In one case, tumor mass could not be definitely visualized, and only dilated bile ducts and stones were demonstrated. The mean CT values of the benign tumors were (25.8 ± 8.0), (37.7 ± 10.3) and (51.7 ± 17.1) HU respectively at pre-contrast phase, arterial phase, and venous phase, and the malignant tumors were (38.4 ± 10.2), (56.6 ± 18.0) and (68.4

  12. 3D dosimetry by optical-CT scanning

    Science.gov (United States)

    Oldham, Mark

    2006-12-01

    The need for an accurate, practical, low-cost 3D dosimetry system is becoming ever more critical as modern dose delivery techniques increase in complexity and sophistication. A recent report from the Radiological Physics Center (RPC) (1), revealed that 38% of institutions failed the head-and-neck IMRT phantom credentialing test at the first attempt. This was despite generous passing criteria (within 7% dose-difference or 4mm distance-to-agreement) evaluated at a half-dozen points and a single axial plane. The question that arises from this disturbing finding is - what percentage of institutions would have failed if a comprehensive 3D measurement had been feasible, rather than measurements restricted to the central film-plane and TLD points? This question can only be adequately answered by a comprehensive 3D-dosimetry system, which presents a compelling argument for its development as a clinically viable low cost dosimetry solution. Optical-CT dosimetry is perhaps the closest system to providing such a comprehensive solution. In this article, we review the origins and recent developments of optical-CT dosimetry systems. The principle focus is on first generation systems known to have highest accuracy but longer scan times.

  13. The effect of iodine uptake on radiation dose absorbed by patient tissues in contrast enhanced CT imaging. Implications for CT dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Perisinakis, Kostas; Damilakis, John [University of Crete, Department of Medical Physics, Medical School, Heraklion, Crete (Greece); University Hospital of Heraklion, Department of Medical Physics, Heraklion, Crete (Greece); Tzedakis, Antonis; Papadakis, Antonios E. [University Hospital of Heraklion, Department of Medical Physics, Heraklion, Crete (Greece); Spanakis, Kostas [University Hospital of Heraklion, Department of Radiology, Heraklion, Crete (Greece); Hatzidakis, Adam [University Hospital of Heraklion, Department of Radiology, Heraklion, Crete (Greece); University of Crete, Department of Radiology, Medical School, Heraklion, Crete (Greece)

    2018-01-15

    To investigate the effect of iodine uptake on tissue/organ absorbed doses from CT exposure and its implications in CT dosimetry. The contrast-induced CT number increase of several radiosensitive tissues was retrospectively determined in 120 CT examinations involving both non-enhanced and contrast-enhanced CT imaging. CT images of a phantom containing aqueous solutions of varying iodine concentration were obtained. Plots of the CT number increase against iodine concentration were produced. The clinically occurring iodine tissue uptake was quantified by attributing recorded CT number increase to a certain concentration of aqueous iodine solution. Clinically occurring iodine uptake was represented in mathematical anthropomorphic phantoms. Standard 120 kV CT exposures were simulated using Monte Carlo methods and resulting organ doses were derived for non-enhanced and iodine contrast-enhanced CT imaging. The mean iodine uptake range during contrast-enhanced CT imaging was found to be 0.02-0.46% w/w for the investigated tissues, while the maximum value recorded was 0.82% w/w. For the same CT exposure, iodinated tissues were found to receive higher radiation dose than non-iodinated tissues, with dose increase exceeding 100% for tissues with high iodine uptake. Administration of iodinated contrast medium considerably increases radiation dose to tissues from CT exposure. (orig.)

  14. Repeated CT scans in trauma transfers: An analysis of indications, radiation dose exposure, and costs

    International Nuclear Information System (INIS)

    Hinzpeter, Ricarda; Sprengel, Kai; Wanner, Guido A.; Mildenberger, Peter; Alkadhi, Hatem

    2017-01-01

    Highlights: • Repetition of CT in trauma patients occurs relatively often. • Repetition of CT is mainly caused by inadequate image data transfer. • Potentially preventable CT examinations add radiation dose to patients. • Repeated CT is associated with excess costs to the health care system. - Abstract: Objectives: To identify the number of CT scans repeated in acute trauma patients receiving imaging before being referred to a trauma center, to define indications, and to assess radiation doses and costs of repeated CT. Methods: This retrospective study included all adult trauma patients transferred from other hospitals to a Level-I trauma center during 2014. Indications for repeated CT scans were categorized into: inadequate CT image data transfer, poor image quality, repetition of head CT after head injury together with completion to whole-body CT (WBCT), and follow-up of injury known from previous CT. Radiation doses from repeated CT were determined; costs were calculated using a nation-wide fee schedule. Results: Within one year, 85/298 (28.5%) trauma patients were transferred from another hospital because of severe head injury (n = 45,53%) and major body trauma (n = 23;27%) not manageable in the referring hospital, repatriation from a foreign country (n = 14;16.5%), and no ICU-capacity (n = 3;3.5%). Of these 85 patients, 74 (87%) had repeated CT in our center because of inadequate CT data transfer (n = 29;39%), repetition of head CT with completion to WBCT (n = 24;32.5%), and follow-up of known injury (n = 21;28.5%). None occurred because of poor image quality. Cumulative dose length product (DLP) and annual costs of potential preventable, repeated CT (inadequate data transfer) was 631mSv (81′304mGy*cm) and 35′233€, respectively. Conclusion: A considerable number of transferred trauma patients undergo potentially preventable, repeated CT, adding radiation dose to patients and costs to the health care system.

  15. Repeated CT scans in trauma transfers: An analysis of indications, radiation dose exposure, and costs

    Energy Technology Data Exchange (ETDEWEB)

    Hinzpeter, Ricarda, E-mail: Ricarda.Hinzpeter@usz.ch [Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Raemistr. 100, Zurich CH-8091 (Switzerland); Sprengel, Kai, E-mail: Kai.Sprengel@usz.ch [Division of Trauma Surgery, Department of Surgery, University Hospital Zurich, University of Zurich, Raemistr. 100, CH-8091 Zurich (Switzerland); Wanner, Guido A., E-mail: Guido.Wanner@sbk-vs.de [Division of Trauma Surgery, Department of Surgery, University Hospital Zurich, University of Zurich, Raemistr. 100, CH-8091 Zurich (Switzerland); Department of General Surgery, Schwarzwald-Baar Klinikum, University of Freiburg, Klinikstr. 11, D-78052 Villingen-Schwenningen (Germany); Mildenberger, Peter, E-mail: peter.mildenberger@unimedizin-mainz.de [Department of Diagnostic and Interventional Radiology, University Hospital of Mainz, Langenbeckstr. 1, D-55131 Mainz (Germany); Alkadhi, Hatem, E-mail: hatem.alkadhi@usz.ch [Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Raemistr. 100, Zurich CH-8091 (Switzerland)

    2017-03-15

    Highlights: • Repetition of CT in trauma patients occurs relatively often. • Repetition of CT is mainly caused by inadequate image data transfer. • Potentially preventable CT examinations add radiation dose to patients. • Repeated CT is associated with excess costs to the health care system. - Abstract: Objectives: To identify the number of CT scans repeated in acute trauma patients receiving imaging before being referred to a trauma center, to define indications, and to assess radiation doses and costs of repeated CT. Methods: This retrospective study included all adult trauma patients transferred from other hospitals to a Level-I trauma center during 2014. Indications for repeated CT scans were categorized into: inadequate CT image data transfer, poor image quality, repetition of head CT after head injury together with completion to whole-body CT (WBCT), and follow-up of injury known from previous CT. Radiation doses from repeated CT were determined; costs were calculated using a nation-wide fee schedule. Results: Within one year, 85/298 (28.5%) trauma patients were transferred from another hospital because of severe head injury (n = 45,53%) and major body trauma (n = 23;27%) not manageable in the referring hospital, repatriation from a foreign country (n = 14;16.5%), and no ICU-capacity (n = 3;3.5%). Of these 85 patients, 74 (87%) had repeated CT in our center because of inadequate CT data transfer (n = 29;39%), repetition of head CT with completion to WBCT (n = 24;32.5%), and follow-up of known injury (n = 21;28.5%). None occurred because of poor image quality. Cumulative dose length product (DLP) and annual costs of potential preventable, repeated CT (inadequate data transfer) was 631mSv (81′304mGy*cm) and 35′233€, respectively. Conclusion: A considerable number of transferred trauma patients undergo potentially preventable, repeated CT, adding radiation dose to patients and costs to the health care system.

  16. A clinical study of acute cerebral infarction with a midline shift on the CT scan

    International Nuclear Information System (INIS)

    Takemae, Toshiki; Mizukami, Masahiro; Kin, Hiroshi; Kawase, Takeshi; Araki, Goro

    1978-01-01

    Twenty-one cases of acute cerebral infarction with a midline shift on the CT scan were studied with respect to the development of the midline shift, the angiographic findings, the clinical pictures and the outcome of these patients. The CT findings of hemorrhagic infarction were also studied. No cases showed a midline shift on a CT scan taken within 6 hours after the onset. A midline shift was, however, noted as early as 9 hours after the onset, and it reached its peak between the 2nd and 7th day of the onset. It gradually disappeared by the end of the third week. Hemorrhagic infarction was diagnosed in 6 patients by either spinal tap or autopsy. The CT findings of these hemorrhagic infarction were divided into two types, solid hemorrhages with an unequivocal high density within the low-density area, and small, scattered hemorrhagic of almost the same density as normal brain tissue within the low-density area. In 19 of 21 patients, an round-edged occlusion and/or embolus were observed on the initial angiograms. The recanalization of the occluded vessels was proved in 10 of 14 patients by subsequent angiographic studies. Twenty of 21 patients showed a sudden development of neurological symptoms, and 15 patients had a history of various kinds of heart disease, such as atrial fibrillation, valvular heart disease and myocardial infarction. The patients had atrial fibrillation on EKG on admission. These angiographic findings and clinical pictures strongly suggest that the infarction with a midline shift on the CT scan may be caused by a cerebral embolism of cardiac origin. Eight patients died of cerebral herniation between the 2nd and 6th day of the onset. Taking these poor outcomes into consideration, surgical as well as medical decompression of the brain would seem to be most important when the CT scan shows a midline shift. (author)

  17. Case of multiple hepatic abscesses detected by CT scan in the patient with acute lymphoblastic leukemia

    Energy Technology Data Exchange (ETDEWEB)

    Saburi, Yoshio; Shuto, Ryusuke; Mizutani, Ryoko; Hosokawa, Takafumi; Itoga, Takashi (Medical Coll. of Oita (Japan))

    1983-12-01

    A 34 year old man admitted to a hospital on 21 Feb. 1983 was diagnosed acute lymphoblastic leukemia. A hematological complete remission was achieved by combination therapy of vincristine, prednisolone and L-asparaginase. However, he had been complaining of high fever and right hypochondralgia since early in Apr. 1983, and it was revealed that elevation of right diaphragm on chest X-ray. Therefore, he was also given several antibiotics (CPZ, TOB, LMOX, PIPC, LCM, AMK, MINO and GM) for complication of probable liver abscess. Remittent fever persisted in spite of as mentioned above various antibiotics. The multiple hepatic abscesses were found by CT scan of the mid-abdomen as the low density lesions, but bacterial cultures detected no pathogens. His complaining of remittent fever and right hypochondralgia were improved by treatment with Miconazole during about one month, and decreasing in size and number of multiple hepatic abscesses were found by CT scan. Though we could not determine clearly, but suspected that multiple hepatic abscesses were due to fungus infection, by reason of therapeutic result. Regarding the complication of hepatic abscesses with leukemia, 5 cases have been reported in Japan, and one case out of 5 cases were detected by CT scan. We thought that CT scans were useful procedures for early diagnosis of hepatic abscesses. Recently, the patient has continued complete remission hematologically.

  18. CT findings of medulloblastoma

    International Nuclear Information System (INIS)

    Tsuchida, Tadashi; Fukuda, Mitsunori; Takeda, Norio; Tanaka, Ryuichi; Ito, Jusuke.

    1982-01-01

    Computed tomography (CT) of ten patients with medulloblastomas was evaluated. Six of them showed solid, nearly homogeneous lesions and a definite enhancement after the infusion of the contrast medium. However, 4 cases showed heterogenous mass lesions composed of areas of a low density and an iso- or slightly high density which was attenuated by contrast enhancement. Histological examinations revealed differentiated medulloblastomas in two of them, but the other two cases were typical medulloblastomas. It should be remembered that medulloblastomas can reveal heterogenous cerebellar midline mass lesions in CT scans. (author)

  19. Comparison of CT scan and colour flow doppler ultrasound in detecting venous tumour thrombous in renal cell carcinoma

    International Nuclear Information System (INIS)

    Khan, A.R.; Anwar, K.

    2008-01-01

    Renal cell carcinoma has marked tendency to spread into renal vein, inferior vena cava and right side of heart. Extension of tumour thrombus into these veins will alter the surgical approach. We have compared the CT scan with Colour flow Doppler ultrasound in detecting venous tumour thrombus in renal vein and inferior vena cava. This cross-sectional study included 30 adult patients presenting with renal tumour. Patients of either gender were included in the study. Non probability convenience sampling was used. All patients underwent colour flow Doppler ultrasound and CT scan with contrast to asses the renal vein and inferior vena cava. The results were confirmed by intra operative findings and histopathology. The data was analyzed using SPSS version 12. Out of 30 patients, 20 (66%) were males and 10 (34%) female. The tumour was predominantly on the right side (60%), as was renal venous tumour thrombus (44%). Inferior vena cava was involved in 4 cases predominantly due to right sided tumours. The sensitivity of Doppler ultrasound in detecting renal venous tumour thrombus (88% on right and 100% on left side) was higher than CT scan (63% on right and 60% on left side). Doppler ultrasound was also superior to CT scan in detecting vena caval thrombus. The overall sensitivity of Doppler sonography was higher than CT scan in detecting tumour extension into renal veins and inferior vena cava. Therefore, it can be used as a complementary tool in equivocal cases. (author)

  20. Reduction of Cone-Beam CT scan time without compromising the accuracy of the image registration in IGRT

    DEFF Research Database (Denmark)

    Westberg, Jonas; Jensen, Henrik R; Bertelsen, Anders

    2010-01-01

    In modern radiotherapy accelerators are equipped with 3D cone-beam CT (CBCT) which is used to verify patient position before treatment. The verification is based on an image registration between the CBCT acquired just before treatment and the CT scan made for the treatment planning. The purpose...... of this study is to minimise the scan time of the CBCT without compromising the accuracy of the image registration in IGRT....