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Sample records for dynamic ct scanning

  1. Dynamic CT scan in cerebral infarction

    International Nuclear Information System (INIS)

    Kobayashi, Shigeki; Oka, Nobuo; Mitsuhashi, Hiromitsu

    1984-01-01

    Forty-two dynamic CT studies were performed on 27 patients with cerebral infarction (11 to 75 years of age), and perfusion patterns of low density areas on plain CT were evaluated. The initial studies were performed 1.5 hours to 60 days after acute onset. The following results were obtained. 1) The perfusion pattern in the low density area on plain CT varies among patients at any periods after onset, ranging from absent perfusion pattern to hyperfusion pattern. No consisitent perfusion pattern was obtained at any given time after onset. 2) Repeat dynamic CT revealed that the perfusion pattern in the low density area changed with time variously. 3) The perfusion pattern or change of perfusion pattern did not correlate with outcome of the patient. 4) At an acute stage, when no abnormal findings were obtained on plain CT, dynamic CT revealed abnormal perfusion pattern, enabling early diagnosis of cerebral infarction and estimation of blood perfusion in the infarcted area. In determining the treatment for the cerebral infarction at an acute stage, it is important to know the condition of the blood perfusion in the infarcted area. For the patients in whom recanalization has already taken place, mannitol or steroid might be effective, providing protection against severe brain edema and hemorrhagic infarction. On the other hand, if recanalization has not taken place, revascularization therapy might be worth trying within 6 hours since the onset. It has been said that ischemic brain damage may not be reversed by the revascularization after 6 hours. Dynamic CT is safe, less invasive, convenient and very useful for early diagnosis of the cerebral infarction and determination of the treatment at the acute stage. (J.P.N.)

  2. 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

  3. 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)

  4. 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, ...

  5. 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)

  6. 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)

  7. A case of severe acute pancreatitis with near total pancreatic necrosis diagnosed by dynamic CT scanning

    International Nuclear Information System (INIS)

    Takeda, Kazunori; Kakugawa, Yoichiro; Amikura, Katsumi; Miyagawa, Kikuo; Matsuno, Seiki; Sato, Toshio

    1987-01-01

    A 42 year-old woman with severe acute pancreatitis had drainage of the pancreatic bed, cholecystostomy and jejunostomy on admission, but symptoms were not improved. Fourteen days after admission, clinical sepsis and septisemia were recognized. Dynamic CT scanning of the pancreas showed near total pancreatic necrosis. Symptoms were improved after necrosectomy of the pancreas and debridement of the peripancreatic necrotic tissue were performed. Our experience suggests the usefulness of dynamic CT scanning for detection of pancreatic necrosis in severe acute pancreatitis. (author)

  8. Semiquantifying regional cerebral blood flow by dynamic CT scanning

    International Nuclear Information System (INIS)

    Takeuchi, Totaro; Kasahara, Eishi; Takahashi, Eriko; Kojima, Seiichi; Ogawa, Haruhiko; Suzuki, Keiko; Miyamae, Tatsuya; Yamazaki, Setsuo.

    1990-01-01

    The study was undertaken to evaluate the semi-quantitative significance of the absolute value obtained by calculating the regional cerebral blood flow index (rCBFI) from dynamic CT in comparison with SPECT. rCBFI was calculated from mean transit time (MTT) and blood capacity index (BCI) obtained by rapidly infusing 50 ml of Omnipurk into the elbow vein by the use of Hitachi's W-600. [rCBFI=BCI/MTT unit/sec (U/S)] measurment of the rCBF by SPECT was made according to the semi-quantitative method by Matsuda et al. by the use of SHIMADZU's improved type HEADTOME SET-050 with rapid infusion of 123 I-IMP in 3.5 m Ci from the elbow vein. Patients in whom no abnormality was observed in the cardiopulmonary function were enrolled as subjects. The rCBFI in each intracranial site was calculated from dynamic CT in 10 normal adults (aged 35-60, averaging 46.7) as subjects and compared with the rCBF obtained from SPECT in the same cases and same site. Comparative investigation was made similarly between rCBFI and rCBF regarding 10 patients with tracranial diseases (age 29-65, averaging 51.2). The mean rCBFIs in the normal adults obtained from dynamic CT were 1.15±0.18 U/S in the frontal lobar cortex, 1.28±0.19 U/S in the temporal lobar cortex, 1.43±0.1 U/S in the occipital lobar cortex, 1.27±0.2 U/S in the basal ganglia region and 0.43±0.1 U/S in the white matter. On the other hand, the mean rCBFs by SPECT were 47.36±3.93 ml/100 g/min, 55.19±2.22 ml/100 g/min, 61.92±5.42 ml/100 g/min, 54.38±3.51 ml/100 g/min and 38.68±6.18 ml/100 g/min, respectively. Positive correlation was observed between rCBFIs and rCBFs of 10 normal adults and 10 patients with intracranial disease, totalling 20 cases (r=0.79, P<0.005). The rCBFI by dynamic CT has a correlation with the rCBF by SPECT, suggesting the possibility of its evaluation as an absolute value, though semi-quantitatively. (author)

  9. 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 ...

  10. 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.

  11. 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.)

  12. 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.

  13. 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 ...

  14. 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 ...

  15. Improved image quality and radiation dose reduction in liver dynamic CT scan with the protocol change

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Yu Jin; Cho, Pyong Kon [Radiological Science, Catholic University of Daegu, Daegu (Korea, Republic of)

    2015-06-15

    The purpose is reducing radiation dose while maintaining of image quality in liver dynamic CT(LDCT) scan, by protocols generally used and the tube voltage set at a low level protocol compared to the radiation dose and image quality. The target is body mass index, 18.5-24 patients out of 40 patients who underwent the ACT(abdominal CT). Group A(tube voltage : 120 kVp, SAFIRE strength 1) of 20 people among 40 people, to apply the general abdominal CT scan protocol, group B(tube voltage : 100 kVp, apply SAFIRE strength 0-5) was 20 people, set a lower tube voltage. Image quality evaluation was setting a region of interest(ROI) in the liver parenchyma, aorta, superior mesenteric artery (SMA), celiac trunk, visceral fat of arterial phase. In the ROI were compared by measuring the noise, signal to noise ratio(SNR), contrast to noise ratio(CNR), CT number. In addition, qualitative assessments to evaluate two people in the rich professional experience in Radiology by 0-3 points. We compared the total radiation dose, dose length product(DLP) and effective dose, volume computed tomography dose index(CTDIvol). The higher SAFIRE in the tube voltage 100 kVp, noise is reduced, CT number was increased. Thus, SNR and CNR was increased higher the SAFIRE step. Compared with the tube voltage 120 kVp, noise, SNR, CNR was most similar in SAFIRE strength 2 and 3. Qualitative assessment SAFIRE strength 2 is the most common SAFIRE strength 2 the most common qualitative assessment, if the tube voltage of 100 kVp when the quality of the images better evaluated was SAFIRE strength 1. Dose was reduced from 21.69%, in 100 kVp than 120 kVp. In the case of a relatively high BMI is not LDCT scan, When it is shipped from the factory tube voltage is set higher, unnecessary radiation exposure when considering the reality that is concerned, when according to the results of this study, set a lower tube voltage and adjust the SAFIRE strength to 1 or 2, the radiation without compromising image quality

  16. Dynamic CT brain scanning in the haemodynamic evaluation of cerebral arterial occlusive disease

    International Nuclear Information System (INIS)

    Davis, S.M.; Melbourne Univ.; Tress, B.M.; Hopper, J.L.; Rossiter, S.C.; Kaye, A.H.

    1987-01-01

    Dynamic cerebral CT scanning (DCT) was used to quantitatively analyse the haemodynamic effects of extracranial and intracranial arterial occlusive lesions in 17 patients with TIA's or minor cerebral infarcts. Using DCT and gamma variate curve fitting, mean transit times were determined for the terminal internal carotid arteries, middle cerebral arteries and middle cerebral-supplied Sylvian cortex at the level of the Circle of Willis. Six patients were studied sequentially, four before and after transcranial bypass surgery. No arterial or tissue delays were found in patients without haemodynamic arterial lesions or cortical infarcts. Seven of nine patients with haemodynamic, extracranial carotid lesions showed ipsilateral delays in arterial or tissue transit times. Tissue delays usually correlated with CT or clinical evidence of infarction. Improved haemodynamics in patients re-studied correlated with the effects of surgery or clinical recovery. DCT has several important limitations but has the potential to provide additional haemodynamic information about the cerebral circulation in selected patients with cerebral arterial occlusive disease. (orig.)

  17. 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)

  18. A clinical study of major stroke cases of a low-perfusion pattern on a dynamic CT scan

    International Nuclear Information System (INIS)

    Shimada, Tsutomu; Kaneko, Mitsuo; Tanaka, Keisei; Sugiura, Masashi

    1986-01-01

    Preoperative dynamic CT scans have been done for the past 4 years in order to estimate the degree of ischemia in the region responsible. The hemodynamic patterns on the dynamic CT scans were consequently classified into three particular types: Type 1: The collateral flow was preserved considerably, and the peak value of the time-density curve exceeded 50 % of the opposite healthy side. Type 2: The residual flow was moderate, and the peak value was approximately from one-third to one-half of the normal side. Type 3: The residual flow was minimal, and the time-density curve was almost flat or the peak value did not reach even approximately one-third of the opposite side. In general, major stroke cases with a Type 1 pattern on the dynamic CT scan showed a considerably good recovery if the revascularization was completed within 6 hours after the attack. However, cases of the Type 3 pattern often developed into a massive cerebral infarction associated with a marked mid-line shift, and sometimes they were fulminent even after acute revascularization. In this paper, clinical results of 11 major stroke cases with the Type 2 pattern on dynamic CT scans were evaluated. All of them showed hemiplegia, with or without aphasia, just after the onset of the stroke, and dynamic CT scans were performed within 24 hours. The site of the occluded vessel was in the internal carotid artery (ICA) in 4 cases and in the middle cerebral artery (MCA) in 6; severe stenosis in ICA and MCA was found in only one case. The functional recovery was rather poor. Only one was capable of self-care at home; four others required partial care at home, and the other six were bed-ridden. In the 4 surgical cases of acute revascularization, the clinical symptoms did not improve, and the functional recovery was almost equivalent to the natural course. (J.P.N.)

  19. 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)

  20. Partial scan artifact reduction (PSAR) for the assessment of cardiac perfusion in dynamic phase-correlated CT.

    Science.gov (United States)

    Stenner, Philip; Schmidt, Bernhard; Bruder, Herbert; Allmendinger, Thomas; Haberland, Ulrike; Flohr, Thomas; Kachelriess, Marc

    2009-12-01

    Cardiac CT achieves its high temporal resolution by lowering the scan range from 2pi to pi plus fan angle (partial scan). This, however, introduces CT-value variations, depending on the angular position of the pi range. These partial scan artifacts are of the order of a few HU and prevent the quantitative evaluation of perfusion measurements. The authors present the new algorithm partial scan artifact reduction (PSAR) that corrects a dynamic phase-correlated scan without a priori information. In general, a full scan does not suffer from partial scan artifacts since all projections in [0, 2pi] contribute to the data. To maintain the optimum temporal resolution and the phase correlation, PSAR creates an artificial full scan pn(AF) by projectionwise averaging a set of neighboring partial scans pn(P) from the same perfusion examination (typically N approximately 30 phase-correlated partial scans distributed over 20 s and n = 1, ..., N). Corresponding to the angular range of each partial scan, the authors extract virtual partial scans pn(V) from the artificial full scan pn(AF). A standard reconstruction yields the corresponding images fn(P), fn(AF), and fn(V). Subtracting the virtual partial scan image fn(V) from the artificial full scan image fn(AF) yields an artifact image that can be used to correct the original partial scan image: fn(C) = fn(P) - fn(V) + fn(AF), where fn(C) is the corrected image. The authors evaluated the effects of scattered radiation on the partial scan artifacts using simulated and measured water phantoms and found a strong correlation. The PSAR algorithm has been validated with a simulated semianthropomorphic heart phantom and with measurements of a dynamic biological perfusion phantom. For the stationary phantoms, real full scans have been performed to provide theoretical reference values. The improvement in the root mean square errors between the full and the partial scans with respect to the errors between the full and the corrected scans is

  1. Partial scan artifact reduction (PSAR) for the assessment of cardiac perfusion in dynamic phase-correlated CT

    Energy Technology Data Exchange (ETDEWEB)

    Stenner, Philip; Schmidt, Bernhard; Bruder, Herbert; Allmendinger, Thomas; Haberland, Ulrike; Flohr, Thomas; Kachelriess, Marc [Institute of Medical Physics, Henkestrasse 91, 91052 Erlangen (Germany); Siemens AG, Healthcare Sector, Siemensstrasse 1, 91301 Forchheim (Germany); Institute of Medical Physics, Henkestrasse. 91, 91052 Erlangen (Germany)

    2009-12-15

    Purpose: Cardiac CT achieves its high temporal resolution by lowering the scan range from 2{pi} to {pi} plus fan angle (partial scan). This, however, introduces CT-value variations, depending on the angular position of the {pi} range. These partial scan artifacts are of the order of a few HU and prevent the quantitative evaluation of perfusion measurements. The authors present the new algorithm partial scan artifact reduction (PSAR) that corrects a dynamic phase-correlated scan without a priori information. Methods: In general, a full scan does not suffer from partial scan artifacts since all projections in [0, 2{pi}] contribute to the data. To maintain the optimum temporal resolution and the phase correlation, PSAR creates an artificial full scan p{sub n}{sup AF} by projectionwise averaging a set of neighboring partial scans p{sub n}{sup P} from the same perfusion examination (typically N{approx_equal}30 phase-correlated partial scans distributed over 20 s and n=1,...,N). Corresponding to the angular range of each partial scan, the authors extract virtual partial scans p{sub n}{sup V} from the artificial full scan p{sub n}{sup AF}. A standard reconstruction yields the corresponding images f{sub n}{sup P}, f{sub n}{sup AF}, and f{sub n}{sup V}. Subtracting the virtual partial scan image f{sub n}{sup V} from the artificial full scan image f{sub n}{sup AF} yields an artifact image that can be used to correct the original partial scan image: f{sub n}{sup C}=f{sub n}{sup P}-f{sub n}{sup V}+f{sub n}{sup AF}, where f{sub n}{sup C} is the corrected image. Results: The authors evaluated the effects of scattered radiation on the partial scan artifacts using simulated and measured water phantoms and found a strong correlation. The PSAR algorithm has been validated with a simulated semianthropomorphic heart phantom and with measurements of a dynamic biological perfusion phantom. For the stationary phantoms, real full scans have been performed to provide theoretical reference

  2. Partial scan artifact reduction (PSAR) for the assessment of cardiac perfusion in dynamic phase-correlated CT

    International Nuclear Information System (INIS)

    Stenner, Philip; Schmidt, Bernhard; Bruder, Herbert; Allmendinger, Thomas; Haberland, Ulrike; Flohr, Thomas; Kachelriess, Marc

    2009-01-01

    Purpose: Cardiac CT achieves its high temporal resolution by lowering the scan range from 2π to π plus fan angle (partial scan). This, however, introduces CT-value variations, depending on the angular position of the π range. These partial scan artifacts are of the order of a few HU and prevent the quantitative evaluation of perfusion measurements. The authors present the new algorithm partial scan artifact reduction (PSAR) that corrects a dynamic phase-correlated scan without a priori information. Methods: In general, a full scan does not suffer from partial scan artifacts since all projections in [0, 2π] contribute to the data. To maintain the optimum temporal resolution and the phase correlation, PSAR creates an artificial full scan p n AF by projectionwise averaging a set of neighboring partial scans p n P from the same perfusion examination (typically N≅30 phase-correlated partial scans distributed over 20 s and n=1,...,N). Corresponding to the angular range of each partial scan, the authors extract virtual partial scans p n V from the artificial full scan p n AF . A standard reconstruction yields the corresponding images f n P , f n AF , and f n V . Subtracting the virtual partial scan image f n V from the artificial full scan image f n AF yields an artifact image that can be used to correct the original partial scan image: f n C =f n P -f n V +f n AF , where f n C is the corrected image. Results: The authors evaluated the effects of scattered radiation on the partial scan artifacts using simulated and measured water phantoms and found a strong correlation. The PSAR algorithm has been validated with a simulated semianthropomorphic heart phantom and with measurements of a dynamic biological perfusion phantom. For the stationary phantoms, real full scans have been performed to provide theoretical reference values. The improvement in the root mean square errors between the full and the partial scans with respect to the errors between the full and the

  3. 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)

  4. Quantitative accuracy of denoising techniques applied to dynamic 82Rb myocardial blood flow PET/CT scans

    DEFF Research Database (Denmark)

    Harms, Hans; Tolbod, Lars Poulsen; Bouchelouche, Kirsten

    with suspected ischemic heart disease underwent a dynamic 7 minute 82Rb scan under resting and adenosine induced hyperaemic conditions after injection of 1100 MBq of 82Rb on a GE Discovery 690 PET/CT. Dynamic images were filtered using HighlY constrained backPRojection (HYPR) and a Hotelling filter of which...... the latter was evaluated using a range of 4 to 7 included factors and for both 2D and 3D filtering. Data were analyzed using Cardiac VUer and obtained MBF values were compared with those obtained when no denoising of the dynamic data was performed. Results: Both HYPR and Hotelling denoising could...

  5. Serial dynamic CT scan in patients with acute basal ganglia infarctions

    International Nuclear Information System (INIS)

    Node, Yoji; Nakazawa, Shozo; Tsuji, Yukihide.

    1987-01-01

    Dynamic computed tomography (CT) was performed on 15 patients (37 to 93 years of age) with acute basal ganglia infarctions, and the perfusion patterns of the infarcted regions on CT were evaluated. The initial dynamic CT was performed within 12 hours after onset, while the serial studies of the dynamic CT were performed on the 3rd and 7th days. The left-over-right ratio in the peak value in the basal ganglia in 15 normal subjects was 1.01 ± 0.03 (mean ± SD), so there were no differences in the peak values of the bilateral basal ganglia. We also examined the left-over-right ratio in the peak value and in the rapid-washout ratio in the basal ganglia in the 15 normal subjects. There was no difference in the peak values of the bilateral basal ganglia. The mean rapid-washout ratio was 0.62 ± 0.11 (mean ± SD). The prognoses of these patients three months after onset were as follows: 8 showed a good recovery, 5 had a moderate disability, and 2 had a severe disability. The perfusions on admission were as follows. 10 were hypoperfusions, 3 were hypo + late perfusions, one was a normoperfusion, and one was a late perfusion. There was a tendency for the rapid-washout ratio decrease more in the hypo + late perfusion group than in the other groups. Twelve patients showed an iso-density, while 3 showed a low density, on admission. The ''low-density'' group showed a decrease in the A/N ratio of the peak value. We performed serial dynamic CT in 11 cases. The group with severe disabilities (2 cases) showed a hypo + late perfusion in the initial CT, one case kept a hypo + late perfusion, and another case changed to a hypoperfusion; also, there was a tendency for there to be a poor improvement in the A/N ratio of the peak value in these two ''severe-disability'' patients. (J.P.N.)

  6. 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.)

  7. 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)

  8. The evaluation of slow injection dynamic CT scan for the vascular invasion of cancer of biliary system and pancreas

    International Nuclear Information System (INIS)

    Kikuchi, Toshiyuki

    1985-01-01

    Dynamic CT body scans were performed under an injection rate of 3 ml/sec with a total amount of 100 ml angiografin by rapid table shift, upon 64 cancer patients, 21 patients with cancer of the bile duct, 21 with pancreatic cancer, 14 with cancer of the gallbladder and 8 with cancer of ampulla of papilla vater. In this study, the detectability of these cancers and the accuracy of their vascular invasion were compared between the above mentioned CT scan (slow injection D. CT) and angiography by our criteria. The detectability of the main tumors was 33.3 % by plain CT but 85.7 % by slow injection D. CT. The criteria of the vascular invasion by slow injection D. CT were classified to four types; separated type, contact type, contact invasive type and involved type. By this criteria, the diagnostic overall accuracy of the arterial invasion was 96.8 % in SMA, 98.4 % in celiac axis, 92.1 % in CH and 46.1 % in proper and bilateral hepatic arteries. The larger the arterial caliber was, the higher the diagnostic accuracy was in slow injection D. CT. On the other hand, the angiographic diagnostic accuracy of the arterial invasion was 79 % in SMA, 88.7 % in celiac axis, 90.3 % in CH and 98.4 % in proper and bilateral hepatic arteries. So, the smaller the arterial caliber was, the higher the diagnostic accuracy was in angiography. The overall accuracy of the portal venous invasion was 90.6 % by means of slow injection D. CT and 88.7 % by means of angiography. 33 of 64 cases were with portal venous invasion, and 15 of 33 cases were resectable by reconstraction of the portal vein. 4 of 15 were contact type, 10 of 15 were contact invasive type, 1 of 15 was involved type. 10 of 11 contact invasive type were resectable, and only 1 of 18 involved type was resectable, so it was safe to say the case of contact invasive type was resectable, and the case of involved type was unresectable. (author)

  9. Estimation of radiation dose to patients from 18 FDG whole body PET/CT investigations using dynamic PET scan protocol

    Directory of Open Access Journals (Sweden)

    Aruna Kaushik

    2015-01-01

    Full Text Available Background & objectives: There is a growing concern over the radiation exposure of patients from undergoing 18FDG PET/CT (18F-fluorodeoxyglucose positron emission tomography/computed tomography whole body investigations. The aim of the present study was to study the kinetics of 18FDG distributions and estimate the radiation dose received by patients undergoing 18FDG whole body PET/CT investigations. Methods: Dynamic PET scans in different regions of the body were performed in 49 patients so as to measure percentage uptake of 18FDG in brain, liver, spleen, adrenals, kidneys and stomach. The residence time in these organs was calculated and radiation dose was estimated using OLINDA software. The radiation dose from the CT component was computed using the software CT-Expo and measured using computed tomography dose index (CTDI phantom and ionization chamber. As per the clinical protocol, the patients were refrained from eating and drinking for a minimum period of 4 h prior to the study. Results: The estimated residence time in males was 0.196 h (brain, 0.09 h (liver, 0.007 h (spleen, 0.0006 h (adrenals, 0.013 h (kidneys and 0.005 h (stomach whereas it was 0.189 h (brain, 0.11 h (liver, 0.01 h (spleen, 0.0007 h (adrenals, 0.02 h (kidneys and 0.004 h (stomach in females. The effective dose was found to be 0.020 mSv/MBq in males and 0.025 mSv/MBq in females from internally administered 18FDG and 6.8 mSv in males and 7.9 mSv in females from the CT component. For an administered activity of 370 MBq of 18FDG, the effective dose from PET/CT investigations was estimated to be 14.2 mSv in males and 17.2 mSv in females. Interpretation & conclusions: The present results did not demonstrate significant difference in the kinetics of 18FDG distribution in male and female patients. The estimated PET/CT doses were found to be higher than many other conventional diagnostic radiology examinations suggesting that all efforts should be made to clinically justify and

  10. Estimation of radiation dose to patients from (18) FDG whole body PET/CT investigations using dynamic PET scan protocol.

    Science.gov (United States)

    Kaushik, Aruna; Jaimini, Abhinav; Tripathi, Madhavi; D'Souza, Maria; Sharma, Rajnish; Mondal, Anupam; Mishra, Anil K; Dwarakanath, Bilikere S

    2015-12-01

    There is a growing concern over the radiation exposure of patients from undergoing 18FDG PET/CT (18F-fluorodeoxyglucose positron emission tomography/computed tomography) whole body investigations. The aim of the present study was to study the kinetics of 18FDG distributions and estimate the radiation dose received by patients undergoing 18FDG whole body PET/CT investigations. Dynamic PET scans in different regions of the body were performed in 49 patients so as to measure percentage uptake of 18FDG in brain, liver, spleen, adrenals, kidneys and stomach. The residence time in these organs was calculated and radiation dose was estimated using OLINDA software. The radiation dose from the CT component was computed using the software CT-Expo and measured using computed tomography dose index (CTDI) phantom and ionization chamber. As per the clinical protocol, the patients were refrained from eating and drinking for a minimum period of 4 h prior to the study. The estimated residence time in males was 0.196 h (brain), 0.09 h (liver), 0.007 h (spleen), 0.0006 h (adrenals), 0.013 h (kidneys) and 0.005 h (stomach) whereas it was 0.189 h (brain), 0.11 h (liver), 0.01 h (spleen), 0.0007 h (adrenals), 0.02 h (kidneys) and 0.004 h (stomach) in females. The effective dose was found to be 0.020 mSv/MBq in males and 0.025 mSv/MBq in females from internally administered 18FDG and 6.8 mSv in males and 7.9 mSv in females from the CT component. For an administered activity of 370 MBq of 18FDG, the effective dose from PET/CT investigations was estimated to be 14.2 mSv in males and 17.2 mSv in females. The present results did not demonstrate significant difference in the kinetics of 18FDG distribution in male and female patients. The estimated PET/CT doses were found to be higher than many other conventional diagnostic radiology examinations suggesting that all efforts should be made to clinically justify and carefully weigh the risk-benefit ratios prior to every 18FDG whole body PET/CT

  11. Parietal pleural invasion/adhesion of subpleural lung cancer: Quantitative 4-dimensional CT analysis using dynamic-ventilatory scanning

    Energy Technology Data Exchange (ETDEWEB)

    Sakuma, Kotaro, E-mail: ksakuma@ohara-hp.or.jp [Department of Radiology, Ohara General Hospital, 6-11 Omachi, Fukushima City, Fukushima 960-8611 (Japan); Department of Radiology and Nuclear Medicine, Fukushima Medical University, 1 Hikariga-oka, Fukushima City, Fukushima 960-1295 (Japan); Yamashiro, Tsuneo, E-mail: clatsune@yahoo.co.jp [Department of Radiology, University of the Ryukyus, 207 Uehara, Nishihara, Okinawa 903-0215 (Japan); Moriya, Hiroshi, E-mail: hrshmoriya@gmail.com [Department of Radiology, Ohara General Hospital, 6-11 Omachi, Fukushima City, Fukushima 960-8611 (Japan); Murayama, Sadayuki, E-mail: sadayuki@med.u-ryukyu.ac.jp [Department of Radiology, University of the Ryukyus, 207 Uehara, Nishihara, Okinawa 903-0215 (Japan); Ito, Hiroshi, E-mail: h-ito@fmu.ac.jp [Department of Radiology and Nuclear Medicine, Fukushima Medical University, 1 Hikariga-oka, Fukushima City, Fukushima 960-1295 (Japan)

    2017-02-15

    Highlights: • 4DCT can be used for assessment of pleural invasion/adhesion by lung cancer. • Quantitative 4DCT indices of lung cancer and adjacent structures are described. • An automatic analysis of pleural invasion/adhesion would be developed in the future. - Abstract: Purpose: Using 4-dimensional dynamic-ventilatory scanning by a 320-row computed tomography (CT) scanner, we performed a quantitative assessment of parietal pleural invasion and adhesion by peripheral (subpleural) lung cancers. Methods: Sixteen patients with subpleural lung cancer underwent dynamic-ventilation CT during free breathing. Neither parietal pleural invasion nor adhesion was subsequently confirmed by surgery in 10 patients, whereas the other 6 patients were judged to have parietal pleural invasion or adhesion. Using research software, we tracked the movements of the cancer and of an adjacent structure such as the rib or aorta, and converted the data to 3-dimensional loci. The following quantitative indices were compared by the Mann-Whitney test: cross-correlation coefficient between time curves for the distances moved from the inspiratory frame by the cancer and the adjacent structure, the ratio of the total movement distances (cancer/adjacent structure), and the cosine similarities between the inspiratory and expiratory vectors (from the cancer to the adjacent structure) and between vectors of the cancer and of the adjacent structure (from inspiratory to expiratory frames). Results: Generally, the movements of the loci of the lung cancer and the adjacent structure were similar in patients with parietal pleural invasion/adhesion, while they were independent in patients without. There were significant differences in all the parameters between the two patient groups (cross-correlation coefficient and the movement distance ratio, P < 0.01; cosine similarities, P < 0.05). Conclusion: These observations suggest that quantitative indices by dynamic-ventilation CT can be utilized as a

  12. 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.

  13. 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)

  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. CT scans in studies of the dynamics of liposynthesis and lipolysis of the human liver

    International Nuclear Information System (INIS)

    Huebener, K.H.; Schmitt, W.G.H.

    1981-01-01

    Following an analysis of the most important metabolic disturbances and other diseases associated ith fatty degeneration of the liver, it is shown, basing on a previous study, by means of examples, that subtle diagnosis of changes of the fatty content of the liver can be achieved via CT density measurement. Lipolysis in alcoholic fatty liver is quantified during abstention from alcohol, and a lipolysis factor of 1% fatty decomposition per day is determined from the measurements. Observations in pancreatitis with liver lipid storage during the course of the disease, point to an enzymatic weakness in lipid metabolism. Case histories show fatty degeneration associated with an enhanced cortisone serum level (in adrenal adenoma and cortisone therapy) and in poorly stabilized diabetes mellitus. It is concluded from the studies that determination of the relative fatty content by CT densitometry should be conducted as a routine procedure and that pathological lipid content should stimulate subtle diagnosis of the pancreas and the adrenals. In addition, examinations repeated during the course of the disease with assessment of changes in fatty content, will be useful for assessing the value of the therapy employed. (orig.) [de

  16. CT scans in studies of the dynamics of liposynthesis and lipolysis of the human liver

    Energy Technology Data Exchange (ETDEWEB)

    Huebener, K H; Schmitt, W G.H.

    1981-06-01

    Following an analysis of the most important metabolic disturbances and other diseases associated with fatty degeneration of the liver, it is shown, basing on a previous study, by means of examples, that subtle diagnosis of changes of the fatty content of the liver can be achieved via CT density measurement. Lipolysis in alcoholic fatty liver is quantified during abstention from alcohol, and a lipolysis factor of 1% fatty decomposition per day is determined from the measurements. Observations in pancreatitis with liver lipid storage during the course of the disease, point to an enzymatic weakness in lipid metabolism. Case histories show fatty degeneration associated with an enhanced cortisone serum level (in adrenal adenoma and cortisone therapy) and in poorly stabilized diabetes mellitus. It is concluded from the studies that determination of the relative fatty content by CT densitometry should be conducted as a routine procedure and that pathological lipid content should stimulate subtle diagnosis of the pancreas and the adrenals. In addition, examinations repeated during the course of the disease with assessment of changes in fatty content, will be useful for assessing the value of the therapy employed.

  17. Temporal dynamics for soil aggregates determined using X-ray CT scanning

    DEFF Research Database (Denmark)

    Garbout, Amin; Munkholm, Lars Juhl; Hansen, Søren Baarsgaard

    2013-01-01

    Soil structure plays a key role in the ability of soil to fulfil essential soil functions and services in relation to e.g. root growth, gas and water transport and organic matter turnover. However, soils are not a very easy object to study as they are highly complex and opaque to the human eye...... aggregate properties such as volume, surface area and sphericity based on 3D images. We tested the methods on aggregates from different treatments and quantified changes over time. A total of 32 collections of aggregates, enclosed in mesocosms, were incubated in soil to follow the structural changes over....... Traditionally, they have been studied using invasive or destructive techniques. The advantage of using X-ray computed tomography (CT) in soil morphology is that it enables non-destructive quantification of soil structure in three dimensions (3D). The prime objective of the present study was to characterize soil...

  18. 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.

  19. The brain stem function in patients with brain bladder; Clinical evaluation using dynamic CT scan and auditory brainstem response

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Toshihiro (Yokohama City Univ. (Japan). Faculty of Medicine)

    1990-11-01

    A syndrome of detrusor-sphincter dyssynergia (DSD) is occasionally found in patients with brain bladder. To evaluate the brain stem function in cases of brain bladder, urodynamic study, dynamic CT scan of the brain stem (DCT) and auditory brainstem response (ABR) were performed. The region of interest of DCT aimed at the posterolateral portion of the pons. The results were analysed in contrast with the presense of DSD in urodynamic study. DCT studies were performed in 13 cases with various brain diseases and 5 control cases without neurological diseases. Abnormal patterns of the time-density curve consisted of low peak value, prolongation of filling time and low rapid washout ratio (low clearance ratio) of the contrast medium. Four of 6 cases with DSD showed at least one of the abnormal patterns of the time-density curve bilaterally. In 7 cases without DSD none showed bilateral abnormality of the curve and in 2 of 7 cases only unilateral abnormality was found. ABR was performed in 8 patients with brain diseases. The interpeak latency of the wave I-V (I-V IPL) was considered to be prolonged in 2 cases with DSD compared to that of 4 without DSD. In 2 cases with DSD who had normal DCT findings, measurement of the I-V IPL was impossible due to abnormal pattern of the ABR wave. Above mentioned results suggests the presence of functional disturbance at the posterolateral portion of the pons in cases of brain bladder with DSD. (author).

  20. Clinical application of gated CT and dynamic CT

    Energy Technology Data Exchange (ETDEWEB)

    Ishikawa, T; Oyama, Y; Ashida, H; Uji, T [Saint Marianna Univ., Kawasaki, Kanagawa (Japan). School of Medicine

    1980-03-01

    Gated CT and dynamic CT were outlined. Experiences of portal hypertension accompanied by venous mass in posterior mediastinum and the usefulness of dynamic CT for this disease were described. Gated CT of the heart could visualize intracardiac structures and morphological abnormalities by improving technique of post-data-aquisition correlation. Changes with time in CT images of normal kidneys were discussed on patients whose unilateral or bilateral kidneys were thought to be normal and who had received dynamic scan. Dynamic scan could visualize well blood circulation and mechanism of urine excretion in the kidney, which suggests a possibility of CT to detect not only morphological abnormalities but also functional disturbance of the kidney. The effectiveness of conventional CT study might be promoted in dynamic CT of the head.

  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. 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

  3. Evaluation of a short dynamic 18F-fluoride PET/CT scanning method to assess bone metabolic activity in spinal orthopedics.

    Science.gov (United States)

    Peters, Marloes J M; Wierts, Roel; Jutten, Elisabeth M C; Halders, Servé G E A; Willems, Paul C P H; Brans, Boudewijn

    2015-11-01

    A complication after spinal fusion surgery is pseudarthrosis, but its radiological diagnosis is of limited value. (18)F-fluoride PET with its ability to assess bone metabolism activity could be of value. The goal of this study was to assess the clinical feasibility of calculating the static standardized uptake value (SUV) from a short dynamic scan without the use of blood sampling, thereby obtaining all dynamic and static parameters in a scan of only 30 min. This approach was tested on a retrospective patient population with persisting pain after spinal fusion surgery. In 16 patients, SUVs (SUV max, SUV mean) and kinetic parameters (K 1, k 2, k 3, v b, K i,NLR, K 1/k 2, k 3/(k 2 + k 3), K i,patlak) were derived from static and dynamic PET/CT scans of operated and control regions of the spine, after intravenous administration of 156-214 MBq (18)F-fluoride. Parameter differences between control and operated regions, as well as between pseudarthrosis and fused segments were evaluated. SUVmean at 30 and 60 min was calculated from kinetic parameters obtained from the dynamic data set (SUV mean,2TCM). Agreement between measured and calculated SUVs was evaluated through Bland-Altman plots. Overall, statistically significant differences between control and operated regions were observed for SUV max, SUV mean, K i,NLR, K i,patlak, K 1/k 2 and k 3/(k 2 + k 3). Diagnostic CT showed pseudarthrosis in 6/16 patients, while in 10/16 patients, segments were fused. Of all parameters, only those regarding the incorporation of bone [K i,NLR, K i,patlak, k 3/(k 2 + k 3)] differed statistically significant in the intervertebral disc space between the pseudarthrosis and fused patients group. The mean values of the patient-specific blood clearance rate [Formula: see text] differed statistically significant between the pseudarthrosis and the fusion group, with a p value of 0.011. This may correspond with the lack of statistical significance of the SUV values between pseudarthrosis and

  4. Transient Dynamics Simulation of Airflow in a CT-Scanned Human Airway Tree: More or Fewer Terminal Bronchi?

    Directory of Open Access Journals (Sweden)

    Shouliang Qi

    2017-01-01

    Full Text Available Using computational fluid dynamics (CFD method, the feasibility of simulating transient airflow in a CT-based airway tree with more than 100 outlets for a whole respiratory period is studied, and the influence of truncations of terminal bronchi on CFD characteristics is investigated. After an airway model with 122 outlets is extracted from CT images, the transient airflow is simulated. Spatial and temporal variations of flow velocity, wall pressure, and wall shear stress are presented; the flow pattern and lobar distribution of air are gotten as well. All results are compared with those of a truncated model with 22 outlets. It is found that the flow pattern shows lobar heterogeneity that the near-wall air in the trachea is inhaled into the upper lobe while the center flow enters the other lobes, and the lobar distribution of air is significantly correlated with the outlet area ratio. The truncation decreases airflow to right and left upper lobes and increases the deviation of airflow distributions between inspiration and expiration. Simulating the transient airflow in an airway tree model with 122 bronchi using CFD is feasible. The model with more terminal bronchi decreases the difference between the lobar distributions at inspiration and at expiration.

  5. Dynamic CT in the abdominal organ, 1

    International Nuclear Information System (INIS)

    Fukuda, Kunihiko

    1980-01-01

    By utilizing a 4.5-second CT (computed tomography) scanner which allows sequential scans the changes of the iodine concentration in abdominal organs can be observed as dynamics reflected in CT number. The abdominal dynamic CT was performed as following method. After performing the preliminary scan 50ml of 60% meglumine iothalamate was rapidly injected intravenously by hands. The sequential scanning was initiated when a half dose of contrast medium was injected. In completion of the 4 sequential scans under arrested respiration the conventional post contrast scanning was performed. The analysis of 112 cases dynamically studied by CT came to the following conclusion. CT number of the abdominal aorta was greatest on the 1st or 2nd scan of the sequential scans (7.5 - 20.5 seconds after initiation of injection). Following this peak formation, CT number of the abdominal aorta declined rapidly due to both prompt diffusion of contrast medium into the extravascular space and dilution by the intravascular fluid. Iodine concentration of the abdominal aorta during the peak period was calculated as 11.3 mg/ml by the present method, being theoretically sufficient for delineation of the vessels smaller than medium size. In the patients with impaired renal function, several characteristic patterns were noted on the dynamics of contrast medium within the abdominal organs. The abdominal dynamic CT was felt to be promissing for evaluation of the renal function. (author)

  6. Evaluation strategies in CT scanning

    DEFF Research Database (Denmark)

    In this talk, dimensional measurement results using different measuring strategies applied in different inspection software packages for volume and surface data analysis are presented. The influence of the strategy on the dimensional measurement is determined by calculating the measurement...... uncertainty. This investigation includes measurements of two industrial items, an aluminum pipe connector and a plastic toggle, a hearing aid component. These are measured using a commercial CT scanner. Traceability is transferred using tactile and optical coordinate measuring machines, which are used...

  7. 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.

  8. 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

  9. 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)

  10. 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%)

  11. 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)

  12. 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.)

  13. 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)

  14. Clinical values of CT and dynamic CT in brain infarction

    International Nuclear Information System (INIS)

    Lim, Soo Il; Jang, Do; Seo, Eun Joo; Sohn, Myung Hee; Choi, Ki Chul

    1985-01-01

    With the advent of faster scan time and new computer program, a scanning technique called 'dynamic computed tomography' has become possible. Dynamic computed tomography consisted of performing multiple rapid sequence scans after injection of contrast material. The authors have evaluated the clinical usefulness of computed tomography and dynamic computed tomography of 93 patients with brain infarction and/or ischemia during the period of 17 months from April 1983 to August 1984 in Department of Radiology, Chonbuk National University Hospital. The results were as follows; 1. The age distribution ranged from 18 years to 78 years. Among them the most common age group was between 50 years and 59 years (40.9%). 2. The sites of brain infarction were cerebral lobes (63 cases,68), basal ganglia (15 cases, 16.1%) and multiple sites (6 cases, 6.4%). The common affected site was middle cerebral artery territories. 3. The contrast enhancement of acute infarction was noted in 14 cases (17.5%) which occurred commonly between 3 days and 2 weeks from ictus. 4. The patterns of time-density curve in brain infarction and/or ischemia were as follow: a. Depression of slow wash-in phase was 20 cases (59%). b. Lower peak concentration was 17 cases (50%). c. Lower and delayed peak concentration was 7 cases (21%). d. No definite peak concentration was 6 cases (18%). First three patterns of time-density curve were thought as relatively characteristic curve of brain infarction and/or ischemia. 5. Two cases that showed negative findings on precontrast CT scan appeared to be positive findings as hypodensity on postcontrast CT scan and were confirmed as brain infarction by dynamic CT. 6. The diagnostic entity of dynamic CT scan were as follows; a. large artery thrombotic infarction were 23 cases (58%). b. lacnar infarction were 6 cases (15%). c. ischemia were 5 cases (13%). d. normal were 5 cases (13%). In six cases of lacunar infarction which was double hypodensity on pre-and postcontrast CT

  15. Clinical values of CT and dynamic CT in brain infarction

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Soo Il; Jang, Do; Seo, Eun Joo; Sohn, Myung Hee; Choi, Ki Chul [Chonbuk National University College of Medicine, Jeonju (Korea, Republic of)

    1985-04-15

    With the advent of faster scan time and new computer program, a scanning technique called 'dynamic computed tomography' has become possible. Dynamic computed tomography consisted of performing multiple rapid sequence scans after injection of contrast material. The authors have evaluated the clinical usefulness of computed tomography and dynamic computed tomography of 93 patients with brain infarction and/or ischemia during the period of 17 months from April 1983 to August 1984 in Department of Radiology, Chonbuk National University Hospital. The results were as follows; 1. The age distribution ranged from 18 years to 78 years. Among them the most common age group was between 50 years and 59 years (40.9%). 2. The sites of brain infarction were cerebral lobes (63 cases,68), basal ganglia (15 cases, 16.1%) and multiple sites (6 cases, 6.4%). The common affected site was middle cerebral artery territories. 3. The contrast enhancement of acute infarction was noted in 14 cases (17.5%) which occurred commonly between 3 days and 2 weeks from ictus. 4. The patterns of time-density curve in brain infarction and/or ischemia were as follow: a. Depression of slow wash-in phase was 20 cases (59%). b. Lower peak concentration was 17 cases (50%). c. Lower and delayed peak concentration was 7 cases (21%). d. No definite peak concentration was 6 cases (18%). First three patterns of time-density curve were thought as relatively characteristic curve of brain infarction and/or ischemia. 5. Two cases that showed negative findings on precontrast CT scan appeared to be positive findings as hypodensity on postcontrast CT scan and were confirmed as brain infarction by dynamic CT. 6. The diagnostic entity of dynamic CT scan were as follows; a. large artery thrombotic infarction were 23 cases (58%). b. lacnar infarction were 6 cases (15%). c. ischemia were 5 cases (13%). d. normal were 5 cases (13%). In six cases of lacunar infarction which was double hypodensity on pre

  16. 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.)

  17. 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.

  18. 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)

  19. 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

  20. 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)

  1. 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)

  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. Dynamic Flaps Electronic Scan Antenna

    National Research Council Canada - National Science Library

    Gonzalez, Daniel

    2000-01-01

    A dynamic FLAPS(TM) electronic scan antenna was the focus of this research. The novelty S of this SBIR resides in the use of plasma as the main component of this dynamic X-Band phased S array antenna...

  4. Dynamic CT of hepatocellular carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Fujita, Nobuyuki; Shirato, Hiroki; Shinohara, Masahiro; Miyasaka, Kazuo; Morita, Yutaka; Irie, Goro

    1983-03-01

    We performed dynamic CT in 30 cases of hepatocellular carcinoma, and concluded as below. Detecting the stain in the early phase of the dynamic series, it is possible to make a diagnosis of hepatocellular carcinoma. The dynamic CT is effective in a case of small hepatocellular carcinoma in which it is difficult to gain an accurate diagnosis in the routine CT study. The dynamic CT is also effective in the differential diagnosis of hepatic lesions, as other hepatic lesions such as hemangioma and metastatic liver cancer show different patterns compared with hepatocellular carcinoma.

  5. Dynamic CT of hepatocellular carcinoma

    International Nuclear Information System (INIS)

    Fujita, Nobuyuki; Shirato, Hiroki; Shinohara, Masahiro; Miyasaka, Kazuo; Morita, Yutaka; Irie, Goro

    1983-01-01

    We performed dynamic CT in 30 cases of hepatocellular carcinoma, and concluded as below. 1 Decting the stain in the early phase of the dynamic series, it is possible to make a diagnosis of hepatocellular carcinoma. 2 The dinamic CT is effective in a case of small hepatocellular carcinoma in which it is difficult to gain an accurate diagnosis in the routine CT study. 3 The dynamic CT is also effective in the differential diagnosis of hepatic lesions, as other hepatic lesions such as hemangioma and metastatic liver cancer show different patterns compared with hepatocellular carcinoma. (author)

  6. 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

  7. 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

  8. 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 ...

  9. 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.

  10. 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.

  11. 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)

  12. 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

  13. Dynamic CT myocardial perfusion imaging

    International Nuclear Information System (INIS)

    Caruso, Damiano; Eid, Marwen; Schoepf, U. Joseph; Jin, Kwang Nam; Varga-Szemes, Akos; Tesche, Christian; Mangold, Stefanie

    2016-01-01

    Highlights: • CT myocardial perfusion provides functional assessment of the myocardium. • CCTA is limited in determining the hemodynamic significance of coronary stenosis. • CT-MPI can accurately detect hemodynamically significant coronary artery stenosis. - Abstract: Non-invasive cardiac imaging has rapidly evolved during the last decade due to advancements in CT based technologies. Coronary CT angiography has been shown to reliably assess coronary anatomy and detect high risk coronary artery disease. However, this technique is limited to anatomical assessment, thus non-invasive techniques for functional assessment of the heart are necessary. CT myocardial perfusion is a new CT based technique that provides functional assessment of the myocardium and allows for a comprehensive assessment of coronary artery disease with a single modality when combined with CTA. This review aims to discuss dynamic CT myocardial perfusion as a new technique in the assessment of CAD.

  14. Dynamic CT myocardial perfusion imaging

    Energy Technology Data Exchange (ETDEWEB)

    Caruso, Damiano [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Radiological Sciences, Oncological and Pathological Sciences, University of Rome “Sapienza”, Latina (Italy); Eid, Marwen [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Schoepf, U. Joseph, E-mail: schoepf@musc.edu [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Division of Cardiology, Department of Medicine, Medical University of South Carolina, Charleston, SC (United States); Jin, Kwang Nam [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Radiology, Seoul Metropolitan Government-Seoul National University Boramae Medical Center, Seoul (Korea, Republic of); Varga-Szemes, Akos [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Tesche, Christian [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Cardiology and Intensive Care Medicine, Heart Center Munich-Bogenhausen, Munich (Germany); Mangold, Stefanie [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Diagnostic and Interventional Radiology, University Hospital of Tuebingen, Tuebingen (Germany); and others

    2016-10-15

    Highlights: • CT myocardial perfusion provides functional assessment of the myocardium. • CCTA is limited in determining the hemodynamic significance of coronary stenosis. • CT-MPI can accurately detect hemodynamically significant coronary artery stenosis. - Abstract: Non-invasive cardiac imaging has rapidly evolved during the last decade due to advancements in CT based technologies. Coronary CT angiography has been shown to reliably assess coronary anatomy and detect high risk coronary artery disease. However, this technique is limited to anatomical assessment, thus non-invasive techniques for functional assessment of the heart are necessary. CT myocardial perfusion is a new CT based technique that provides functional assessment of the myocardium and allows for a comprehensive assessment of coronary artery disease with a single modality when combined with CTA. This review aims to discuss dynamic CT myocardial perfusion as a new technique in the assessment of CAD.

  15. 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...

  16. 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.

  17. 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.)

  18. Dynamic computed tomography scanning of benign bone lesions: Preliminary results

    International Nuclear Information System (INIS)

    Levine, E.; Neff, J.R.

    1983-01-01

    The majority of benign bone lesions can be evaluated adequately using conventional radiologic techniques. However, it is not always possible to differentiate reliably between different types of benign bone lesions on the basis of plain film appearances alone. Dynamic computed tomography (CT) scanning provides a means for further characterizing such lesions by assessing their degree of vascularity. Thus, it may help in distinguishing an osteoid osteoma, which has a hypervascular nidus, from a Brodie's abscess, which is avascular. Dynamic CT scanning may also help in the differentiation between a fluid-containing simple bone cyst, which is avascular, and other solid or semi-solid benign bone lesions which slow varying degrees of vascularity. However, because of the additional irradiation involved, dynamic CT scanning should be reserved for evaluation of selected patients with benign bone lesions in whom the plain film findings are not definitive and in whom the CT findings may have a significant influence on management. (orig.)

  19. 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.

  20. 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

  1. 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)

  2. Computed Tomography (CT) Scans and Cancer

    Science.gov (United States)

    ... Reporting & Auditing Grant Transfer Grant Closeout Contracts & Small Business Training Cancer Training at NCI (Intramural) Resources for ... companies (and Medicare) do not currently reimburse the costs of this procedure. Also, because CT ... the effectiveness of low-dose helical CT for lung cancer ...

  3. 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.

  4. 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)

  5. 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)

  6. Diagnostic value of dynamic CT in early cerebral infarct

    International Nuclear Information System (INIS)

    Huang, K.-M.; Shih, T.T.F.

    1989-01-01

    The authors have tried to demonstrate early cerebral infarct by dynamic CT scanning without any CT change. They also have tried to find a correlation between the clinical outcome and the hemodynamic change of the damaged brain tissue supplied by the occluded vessels. (author) 14 refs.; 3 figs

  7. Photon CT scanning of advanced ceramic materials

    International Nuclear Information System (INIS)

    Sawicka, B.D.; Ellingson, W.A.

    1987-02-01

    Advanced ceramic materials are being developed for high temperature applications in advanced heat engines and high temperature heat recovery systems. Small size flaws (10 - 200 μm) and small nonuniformities in density distributions (0.1 -2%) present as long-range density gradients, are critical in most ceramics and their detection is of crucial importance. Computed tomographic (CT) imaging provides a means of obtaining a precise two-dimensional density map of a cross section through an object from which accurate information about small flaws and small density gradients can be obtained. With the use of high energy photon sources high contrast CT images can be obtained for both low and high density ceramics. In the present paper we illustrate the applicability of the photon CT technique to the examination of advanced ceramics. CT images of sintered alumina tiles are presented from which data on high-density inclusions, cracks and density gradients have been extracted

  8. CT scan findings in cerebral paragonimiasis

    International Nuclear Information System (INIS)

    Udaka, Fukashi; Okuda, Bungo; Okada, Masako; Okae, Shunji; Kameyama, Masakuni

    1982-01-01

    Computed tomography was performed on 5 patients with chronic cerebral paragonimiasis. CT showed solitary or multiple, amorphous, round, or oval calcifications, and ventricular enlargement in all 5 cases. A large low-density area is also found in 4 of the 5 cases. These CT findings are compatible with previously reported findings of simple X-ray films of the skull, pneumoencephalography, and pathological studies. (author)

  9. 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.)

  10. 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)

  11. 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

  12. 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.

  13. 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

  14. 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

  15. CT scan findings of fungal pneumonia

    International Nuclear Information System (INIS)

    Heckmann, M.; Uder, M.; Bautz, W.; Heinrich, M.

    2008-01-01

    The importance of fungal infection of the lung in immunocompromised patients has increased substantially during the last decades. Numerically the most patients are those with neutropenia, e.g. patients with malignancies or solid organ and stem cell transplantation, chemotherapy, corticosteroid use and HIV infection. Although fungal infections can occur in immunocompetent patients, their frequency in this population is rare. The clinical symptoms such as fever accompanied with non-productive cough are unspecific. In some patients progression to hypoxemia and dyspnea may occur rapidly. In spite of improved antifungal therapy morbidity and mortality of these infections are still high. Therefore an early and non-invasive diagnosis is very important. That is why CT and even better High-Resolution-CT (HR-CT) is a very important modality in examining immunocompromised patients with a probability of fungal infection. CT is everywhere available and, as a non-invasive method, able to give the relevant diagnose efficiently. This paper should give an overview about the radiologic findings and possible differential diagnosis of diverse pulmonary fungal infections in CT. Pneumonias caused by Aspergillus, Cryptococcus, Candida, Histoplasma, Mucor and Geotrichum capitatum are illustrated. (orig.)

  16. Varifocal mirror display of organ surfaces from CT scans

    International Nuclear Information System (INIS)

    Pizer, S.M.; Fuchs, H.; Bloomberg, S.H.; Li Ching Tsai; Heinz, E.R.

    1982-01-01

    A means will be presented of constructing a powerful varifocal mirror 3D display system with limited cost based on an ordinary color video digital display system. The importance of dynamic interactive control of the display of these images will be discussed; in particular, the design and usefulness of a method allowing real-time user-controlled motion of the 3D object being displayed will be discussed. Also, an effective method will be described of presenting images made of surfaces by the straightforward, automatic calculation of 3D edge strength, the ordering of the resulting voxels by edge strength, and the 3D grey-scale display of the top voxels on this ordered list. The application of these ideas to the 3D display of the intimal wall of the region of bifurcation of the carotid artery from 12-24 CT scans of the neck will be discussed

  17. 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.

  18. 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.).

  19. Diagnostic value of the coronary CT scan

    International Nuclear Information System (INIS)

    Kiuchi, Sousuke

    1982-01-01

    Using high-resolution computed tomography, coronary scanning has been made to investigate the radiographical details of the middle and inner ear organs. Twenty patients with chronic otitis media, secondary cholesteatoma, sensorineural hearing loss, facial spasm, and suspected meningitis, were evaluated. In 26 of 40 ears in this series, the coronary scans sharply outlined almost all of the bony structures, and showed also the eardrum as a clearly defined soft tissue, but no abnormal radiographical findings were recognized. In the remaining ears with chronic otitis media, the scans were valuable in demonstration of mucosal thickening, granulation tissue, and destruction of the auditory ossicles. (author)

  20. 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...

  1. 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.)

  2. 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.)

  3. 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

  4. Dynamic CT of the renal parenchyma

    International Nuclear Information System (INIS)

    Ohyama, Yukio; Imanishi, Yoshimasa; Ishikawa, Tohru; Fujii, Masamichi; Uji, Teruyuki

    1985-01-01

    Normal renal dynamic CT findings of 57 cases were analysed in termes of sequential change of renal parenchymal CT image. Cortex, outer medulla and inner medulla were delineated and their sequential CT image was well correlated with the anatomicophysiological character of the kidney. Dynamic CT of 32 abnormal cases showed abnormal sequential CT findings explaining the mechanism of the abnormalities. Especially, delayed enhancement of renal cortex was noted in 17 of 19 kidneys with arterial obstruction and delayed enhancement of renal medulla in 22 of 25 cases with renal dysfunction. Compaired with excretory urography in 11 cases with renal dysfunction, advantage of dynamic CT were noted. (author)

  5. 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.)

  6. 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.).

  7. 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.

  8. Value of CT scan in synovial diseases

    International Nuclear Information System (INIS)

    Tamisier, J.N.; Regent, D.; Thomas, P.; Pere, P.; Gaucher, A.; Capesius, P.

    1986-01-01

    The authors have developed a technique of CT arthroscan which, by the use of a gas or opaque contrast medium, is able to demonstrate the synovial structures of the knee, the shoulder and the hip. Among the essential indications, they include the demonstration of neoplasia of the synovium and the evaluation of the pannus in rheumatoid arthritis. Their secondary indications include the demonstration of fluid effusions in the hip, the precise evaluation of hyperostotic lesions in the same joint, the detection of ossification phenomena in the capsule of the inter-apophyseal joints in ankylosing spondylitis and, in some cases, following negative or doubtful arthrography for the detection of synovial plica. They also recall the usefulness or the arthroscan in the diagnosis of lesions of the labrum glenoidale [fr

  9. Value of CT scan in synovial diseases

    Energy Technology Data Exchange (ETDEWEB)

    Tamisier, J.N.; Regent, D.; Thomas, P.; Pere, P.; Gaucher, A.; Capesius, P.

    1986-02-01

    The authors have developed a technique of CT arthroscan which, by the use of a gas or opaque contrast medium, is able to demonstrate the synovial structures of the knee, the shoulder and the hip. Among the essential indications, they include the demonstration of neoplasia of the synovium and the evaluation of the pannus in rheumatoid arthritis. Their secondary indications include the demonstration of fluid effusions in the hip, the precise evaluation of hyperostotic lesions in the same joint, the detection of ossification phenomena in the capsule of the inter-apophyseal joints in ankylosing spondylitis and, in some cases, following negative or doubtful arthrography for the detection of synovial plica. They also recall the usefulness or the arthroscan in the diagnosis of lesions of the labrum glenoidale.

  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. 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)

  13. 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.

  14. 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)

  15. CT scan imaging in cervical infections

    International Nuclear Information System (INIS)

    Marsot-Dupuch, K.; Janklewicz, Ph.; Chabolle, F.

    1988-01-01

    Infections of face and neck represent serious and potentially life threatening conditions that are sometimes difficult to differentiate from neoplasic tumours, especially in subacute clinical forms. Conventional radiographic techniques offer interest for cervical masses, except Ultra-Sonographic examen, in sites regarding vascular axes, but carries little value for evaluating their spread the into different cervical spaces. On the other hand, C.T. is valuable to precise the location and the extent and to determine its inflammatory nature by studying the fats and the aponeurosis around it. It helps in the analysis of associated adjacent signs: soft tissue swelling, extensive obliteration of adjacent fats, swelling of cervical aponeurosis, thickening of adjacent muscles. These findings are documented by the study of fourteen patients, admitted in St-Antopine hospital. All abcesses, except one, were easy to diagnose because of their low central attenuation. False negative cases are possible and noted by other authors. So, in absence of response to appropriate therapy, surgery is necessary to eliminate a misdiagnosed abcess. Furthermore, it's sometimes possible to suspect an etiology (foreign body, tuberculosis) [fr

  16. 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

  17. 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.

  18. 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)

  19. 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

  20. 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

  1. 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)

  2. 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.

  3. 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...

  4. 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.)

  5. 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.)

  6. 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.

  7. 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)

  8. 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).

  9. 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

  10. 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)

  11. 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.)

  12. 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).

  13. 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)

  14. 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)

  15. 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)

  16. Solitary Pulmonary Nodule on Helical Dynamic CT Scans: Analysis of the Enhancement Patterns Using a Computer-Aided Diagnosis (CAD) System

    International Nuclear Information System (INIS)

    Choi, Eun Jung; Jin, Gong Yong; Han, Young Min; Lee, Young Sun; Kweon, Keun Sang

    2008-01-01

    We wanted to investigate the usefulness of a computer-aided diagnosis (CAD) system in assisting radiologists to diagnosis malignant solitary pulmonary nodules (SPNs), as compared with diagnosing SPNs with using direct personal drawing. Forty patients with SPNs were analyzed. After the pre-contrast scan was performed, an additional ten series of post-contrast images were obtained at 20-second intervals. Two investigators measured the attenuation values of the SPNs: a radiologist who drew the regions of interest (ROIs), and a technician who used a CAD system. The Bland and Altman plots were used to compare the net enhancement between a CAD system and direct personal drawing. The diagnostic characteristics of the malignant SPNs were calculated by considering the CAD and direct personal drawing and with using Fisher's exact test. On the Bland and Altman plot, the net enhancement difference between the CAD system and direct personal drawing was not significant (within ± 2 standard deriation). The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of diagnosing malignant SPNs using CAD was 92%, 85%, 75%, 96% and 88%, respectively. The sensitivity, specificity, PPV, NPV and accuracy of diagnosing malignant SPNs using direct drawing was 92%, 89%, 79%, 92% and 88%, respectively. The CAD system was a useful tool for diagnosing malignant SPNs

  17. 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)

  18. 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 ...

  19. 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...

  20. 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.)

  1. 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.

  2. 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

  3. 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)

  4. Dynamic CT in dissecting aortic aneurysm

    International Nuclear Information System (INIS)

    Fujita, Nobuyuki; Matsuoka, Yosuke; Mizuo, Hideyo; Shirato, Hiroki; Irie, Goro

    1985-01-01

    especially about the branching of major vessels Eight cases of aortic dissection were analysed to evaluate detectability of the branching of major vessels from a ture or false lumen, by dynamic CT. Although recognition of the branching is easy when the direct continuity to a dissected lumen is demonstrated, but without visualization of direct continuity or with no information about dissected lumens, it is sometimes difficult or leads us to misdiagnosis. The diagnostic accuracy is 100% when direct continuity to a dissected lumen is demonstrated, or dynamic CT revealed branching pattern distinctly. Dynamic CT is useful for a diagnosis of dissecting aneurysm and branching pattern of major vessels. (author)

  5. 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.)

  6. 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.

  7. 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.

  8. 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.

  9. 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

  10. 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

  11. Leigh's subacute necrotizing encephalomyelopathy: Possible diagnosis by CT scan

    International Nuclear Information System (INIS)

    Chi, J.G.; Yoo, H.W.; Chang, K.H.; Kim, C.W.; Moon, H.R.; Ko, K.W.

    1981-01-01

    A 28-month-old Korean girl developed a rapidly progressive disease, characterized by disturbance of consciousness, tremor, nystagmus, ophthalmoplegia, irregular deep respiration and vomiting. The patient succumbed 2 weeks after the onset of the illness. CT scan disclosed bilaterally symmetrical, low density lesions in the white matter and lateral basal ganglia. Distinctive histopathological findings at postmortem included spongiotic necrosis of the neuropil, marked capillary vascularity, persistence of relatively normal neurons in severely damaged zones, and comparatively little astrocytosis. The bilaterally symmetrical distribution of these changes in the putamen and periaqueductal gray matter of the midbrain were compatible with Leigh's disease. (orig.)

  12. Treatment of alzheimer disease with CT scans - a case report

    Energy Technology Data Exchange (ETDEWEB)

    Cuttler, J.M. [Cuttler & Associates Inc., Vaughan, Ontario (Canada); Moore, E.R. [Dow Chemical Co., Midland, MI (United States); Hosfeld, V.D. [MidMichigan Health, Midland, MI (United States); Nadolski, D.L. [Midland Internal Medicine Associates PC, Midland, MI (United States)

    2016-03-15

    Alzheimer disease (AD) primarily affects older adults. This neurodegenerative disorder is the most common cause of dementia and is a leading source of their morbidity and mortality. U.S. patient care costs are about 200 billion dollars and will more than double by 2040. This case report describes the remarkable improvement of an advanced AD patient in hospice, who received five CT scans of the brain, about 40 mGy each, over a period of three months. The mechanism appears to be radiation-induced up-regulation of the patient's adaptive protection systems against AD, which partially restored cognition, memory, speech, movement, and appetite. (author)

  13. Treatment of alzheimer disease with CT scans - a case report

    International Nuclear Information System (INIS)

    Cuttler, J.M.; Moore, E.R.; Hosfeld, V.D.; Nadolski, D.L.

    2016-01-01

    Alzheimer disease (AD) primarily affects older adults. This neurodegenerative disorder is the most common cause of dementia and is a leading source of their morbidity and mortality. U.S. patient care costs are about 200 billion dollars and will more than double by 2040. This case report describes the remarkable improvement of an advanced AD patient in hospice, who received five CT scans of the brain, about 40 mGy each, over a period of three months. The mechanism appears to be radiation-induced up-regulation of the patient's adaptive protection systems against AD, which partially restored cognition, memory, speech, movement, and appetite. (author)

  14. Primary laryngeal tuberculosis mimicking laryngeal carcinoma: CT scan features

    International Nuclear Information System (INIS)

    El Kettani, N Ech-Cherif; El Hassani, MR; Chakir, N; Jiddane, M

    2010-01-01

    Laryngeal tuberculosis is a rare disease. It is almost always associated with pulmonary tuberculosis. It occurs generally in adults without BCG vaccination or in cases of the acquired immune deficiency syndrome. On laryngoscopy and imaging, it often simulates laryngeal carcinoma, and confirmation is always histological. We report the case of a 36-year-old man who presented to our hospital with dysphonia and dysphagia. Laryngoscopy revealed a lesion of the left vocal cord and the ventricular strip. CT scan found focal, regular thickening of the left vocal cord, associated with irregular thickening of the posterior laryngeal wall. A biopsy confirmed the diagnosis of tuberculosis

  15. Diagnosis of anemia on CT scans of the thorax

    International Nuclear Information System (INIS)

    Corcoran, H.L.; Cook, D.E.; Proto, A.V.

    1986-01-01

    Visualization of the interventricular septum on nonenhanced CT scans of the thorax of patients with anemia has been illustrated in the literature and explained in terms of a density differential between the cardiac musculature and the blood of anemic patients (blood with a low hemoglobin level). There are no data on the frequency of visualization of the walls of the cardiac chambers, the aorta and its branches, the superior and inferior venae cavae, the brachiocephalic veins, the azygos arch, and so forth. Experience with 50 patients is reported in terms of the foregoing. Findings are correlated with the severity of the anemia, thereby indicating how commonly one may encounter such an appearance

  16. 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)

  17. 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)

  18. 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

  19. 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

  20. Light scattering in optical CT scanning of Presage dosimeters

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Y; Adamovics, J; Cheeseborough, J C; Chao, K S; Wuu, C S, E-mail: yx2010@columbia.ed

    2010-11-01

    The intensity of the scattered light from the Presage dosimeters was measured using a Thorlabs PM100D optical power meter (Thorlabs Inc, Newton, NJ) with an optical sensor of 1 mm diameter sensitive area. Five Presage dosimeters were made as cylinders of 15.2 cm, 10 cm, 4 cm diameters and irradiated with 6 MV photons using a Varian Clinac 2100EX. Each dosimeter was put into the scanning tank of an OCTOPUS' optical CT scanner (MGS Research Inc, Madison, CT) filled with a refractive index matching liquid. A laser diode was positioned at one side of the water tank to generate a stationary laser beam of 0.8 mm width. On the other side of the tank, an in-house manufactured positioning system was used to move the optical sensor in the direction perpendicular to the outgoing laser beam from the dosimeters at an increment of 1 mm. The amount of scattered photons was found to be more than 1% of the primary light signal within 2 mm from the laser beam but decreases sharply with increasing off-axis distance. The intensity of the scattered light increases with increasing light attenuations and/or absorptions in the dosimeters. The scattered light at the same off-axis distance was weaker for dosimeters of larger diameters and for larger detector-to-dosimeter distances. Methods for minimizing the effect of the light scattering in different types of optical CT scanners are discussed.

  1. 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.

  2. Dynamic CT for Parathyroid Adenoma Detection: How Does Radiation Dose Compare With Nuclear Medicine?

    Science.gov (United States)

    Czarnecki, Caroline A; Einsiedel, Paul F; Phal, Pramit M; Miller, Julie A; Lichtenstein, Meir; Stella, Damien L

    2018-05-01

    Dynamic CT is increasingly used for preoperative localization of parathyroid adenomas, but concerns remain about the radiation effective dose of CT compared with that of 99m Tc-sestamibi scintigraphy. The purpose of this study was to compare the radiation dose delivered by three-phase dynamic CT with that delivered by 99m Tc-sestamibi SPECT/CT performed in accordance with our current protocols and to assess the possible reduction in effective dose achieved by decreasing the scan length (i.e., z-axis) of two phases of the dynamic CT protocol. The effective dose of a 99m Tc-sestamibi nuclear medicine parathyroid study performed with and without coregistration CT was calculated and compared with the effective dose of our current three-phase dynamic CT protocol as well as a proposed protocol involving CT with reduced scan length. The median effective dose for a 99m Tc-sestamibi nuclear medicine study was 5.6 mSv. This increased to 12.4 mSv with the addition of coregistration CT, which is higher than the median effective dose of 9.3 mSv associated with the dynamic CT protocol. Reducing the scan length of two phases in the dynamic CT protocol could reduce the median effective dose to 6.1 mSv, which would be similar to that of the dose from the 99m Tc-sestamibi study alone. Dynamic CT used for the detection of parathyroid adenoma can deliver a lower radiation dose than 99m Tc-sestamibi SPECT/CT. It may be possible to reduce the dose further by decreasing the scan length of two of the phases, although whether this has an impact on accuracy of the localization needs further investigation.

  3. 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.)

  4. 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.)

  5. Diagnosis of small hepatocellular carcinoma by incremental dynamic CT

    International Nuclear Information System (INIS)

    Uchida, Masafumi; Kumabe, Tsutomu; Edamitsu, Osamu

    1993-01-01

    Thirty cases of pathologically confirmed small hepatocellular carcinoma were examined by Incremental Dynamic CT (ICT). ICT scanned the whole liver with single-breath-hold technique; therefore, effective early contrast enhancement could be obtained for diagnosis. Among the 30 tumors, 26 were detected. The detection rate was 87%. A high detection rate was obtained in tumors more than 20 mm in diameter. Twenty-two of 26 tumors could be diagnosed correctly. ICT examination was useful for detection of small hepatocellular carcinoma. (author)

  6. 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)

  7. 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

  8. Exploring miniature insect brains using micro-CT scanning techniques

    Science.gov (United States)

    Smith, Dylan B.; Bernhardt, Galina; Raine, Nigel E.; Abel, Richard L.; Sykes, Dan; Ahmed, Farah; Pedroso, Inti; Gill, Richard J.

    2016-01-01

    The capacity to explore soft tissue structures in detail is important in understanding animal physiology and how this determines features such as movement, behaviour and the impact of trauma on regular function. Here we use advances in micro-computed tomography (micro-CT) technology to explore the brain of an important insect pollinator and model organism, the bumblebee (Bombus terrestris). Here we present a method for accurate imaging and exploration of insect brains that keeps brain tissue free from trauma and in its natural stereo-geometry, and showcase our 3D reconstructions and analyses of 19 individual brains at high resolution. Development of this protocol allows relatively rapid and cost effective brain reconstructions, making it an accessible methodology to the wider scientific community. The protocol describes the necessary steps for sample preparation, tissue staining, micro-CT scanning and 3D reconstruction, followed by a method for image analysis using the freeware SPIERS. These image analysis methods describe how to virtually extract key composite structures from the insect brain, and we demonstrate the application and precision of this method by calculating structural volumes and investigating the allometric relationships between bumblebee brain structures. PMID:26908205

  9. 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.

  10. Intrapartum FHR monitoring and neonatal CT brain scan

    International Nuclear Information System (INIS)

    Takahashi, Yoshiki; Ukita, Masahiko; Nakada, Eizo

    1982-01-01

    The effect of fetal distress on the neonatal brain was investigated by neonatal CT brain scan, FHR monitoring and mode of delivery. This study involved 11 cases of full term vertex delivery in which FHR was recorded by fetal direct ECG during the second stage labor. All infants weighed 2,500 g or more. FHR monitoring was evaluated by Hon's classification. Neonatal brain edema was evaluated by cranial CT histgraphic analysis (Nakada's method). 1) Subdural hemorrhage was noted in 6 of 7 infants delivered by vacuum extraction or fundal pressure (Kristeller's method). 2) Intracranial hemorrhage was demonstrated in all of 3 infants with 5-min. Apgar score 7 or less. 3) Two cases with prolonged bradycardia and no variability had intraventricular or intracerebral hemorrhage which resulted in severe central nervous system damage. 4) The degree of neonatal brain edema correlated with 5-min. Apgar score. 5) One case with prolonged bradycardia and no variability resulted in severe neonatal brain edema. Four cases with variable deceleration and increased variability resulted in mild neonatal brain edema. Two cases with late deceleration and decreased variability resulted in no neonatal brain edema. (author)

  11. 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

  12. 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)

  13. 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)

  14. 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.

  15. 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

  16. Static and dynamic 3 dimensional studies of water in soil using computed tomographic scanning

    International Nuclear Information System (INIS)

    Crestana, S.; Mascarenhas, S.; Pozzi-Mucelli, R.S.

    1984-03-01

    Previous work of Petrovic, Siebert and Rieke demonstrated the possibility of using X-ray transmission computed tomography (CT) scanning for soil bulk density analysis in soil. We show in the present work that CT can also be used for the measurement of water content in soil. In our case we also show that CT can be applied to measure and follow dynamically the motion of water in soil in 3-dimensions. Further, more inhomogeneities of water content and motion in soil can be observed with this technique. Using a third generation CT scanner several different techniques can be applied such as differential, real time and spatial distribution scanning modes. A linear dependence was demonstrated for the Hounsfield Units (HU) used in CT and water content. The use of CT for water content and motion in soil in 3-dimensions opens new possibilities in this area of investigations. (author)

  17. 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.

  18. 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)

  19. 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.

  20. Protocol optimization in chest CT scans of child

    Energy Technology Data Exchange (ETDEWEB)

    Abrao L, L. T.; Amaral de O, F.; Prata M, A. [Biomedical Engineering Center, Centro Federal de Educacao Tecnologica de Minas Gerais, 30421-169, Belo Horizonte, Minas Gerais (Brazil); Bustos F, M., E-mail: luanaabrao@gmail.com [Universidad Federal de Minas Gerais, Department of Nuclear Engineering, Av. Pres. Antonio Carlos 6627, Pampulha, 31270-901 Belo Horizonte, Minas Gerais (Brazil)

    2017-10-15

    The dissemination of Computed Tomography (CT), a radiodiagnostic technique, has significant increase in the patient dose. In the last years, this technique has shown a high growth due to clinical cases of medical emergencies, neoplasm and pediatric traumas. Dose measurement is important to correlate with the deleterious effects of radiation on the organism and radiation future effects is related with stochastic risks due to tissue radiosensitivity, allied to the life expectancy of the child. In this work, a cylindrical phantom, representing an adult chest made of polymethylmethacrylate (PMMA), was used and a new born chest phantom with a shape oblong was developed based on the dimensions of a typical newborn. In a Ge CT scanner, Discovery model, with 64 channels, the central slice of the phantoms were irradiated successively in order to obtain dose measurements using an ionizing pencil camera. Based in the measurements, dose index was calculated (CTDI{sub vol}). The radiological service chest protocol using a voltage of 120 kV was used for scanning 10 cm of the central area of the adult and newborn phantom, in helical mode. An acquisition of images was performed using this radiological service chest protocol to compare with the protocol optimized. In the newborn phantom was also used protocols optimized using a voltage of 120 and 80 kV. The voltage of 80 kV has the lowest dose index for the pediatric object phantom. This work allowed the comparison between absorbed dose variations by the pediatric phantom changing the X-ray tube supply voltage. This dose variation has shown how important is specific protocols for children. (Author)

  1. Protocol optimization in chest CT scans of child

    International Nuclear Information System (INIS)

    Abrao L, L. T.; Amaral de O, F.; Prata M, A.; Bustos F, M.

    2017-10-01

    The dissemination of Computed Tomography (CT), a radiodiagnostic technique, has significant increase in the patient dose. In the last years, this technique has shown a high growth due to clinical cases of medical emergencies, neoplasm and pediatric traumas. Dose measurement is important to correlate with the deleterious effects of radiation on the organism and radiation future effects is related with stochastic risks due to tissue radiosensitivity, allied to the life expectancy of the child. In this work, a cylindrical phantom, representing an adult chest made of polymethylmethacrylate (PMMA), was used and a new born chest phantom with a shape oblong was developed based on the dimensions of a typical newborn. In a Ge CT scanner, Discovery model, with 64 channels, the central slice of the phantoms were irradiated successively in order to obtain dose measurements using an ionizing pencil camera. Based in the measurements, dose index was calculated (CTDI vol ). The radiological service chest protocol using a voltage of 120 kV was used for scanning 10 cm of the central area of the adult and newborn phantom, in helical mode. An acquisition of images was performed using this radiological service chest protocol to compare with the protocol optimized. In the newborn phantom was also used protocols optimized using a voltage of 120 and 80 kV. The voltage of 80 kV has the lowest dose index for the pediatric object phantom. This work allowed the comparison between absorbed dose variations by the pediatric phantom changing the X-ray tube supply voltage. This dose variation has shown how important is specific protocols for children. (Author)

  2. 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)

  3. The presence and progression of emphysema in COPD as determined by CT scanning and biomarker expression

    DEFF Research Database (Denmark)

    Coxson, Harvey O; Dirksen, Asger; Edwards, Lisa D

    2013-01-01

    Emphysema is a key contributor to airflow limitation in chronic obstructive pulmonary disease (COPD) and can be quantified using CT scanning. We investigated the change in CT lung density in a longitudinal, international cohort of patients with COPD. We also explored the potential relation between...... emphysema and patient characteristics, and investigated if certain circulating biomarkers were associated with decline in CT lung density....

  4. 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

  5. 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 ...

  6. 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)

  7. 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)

  8. Knowledge Representation Of CT Scans Of The Head

    Science.gov (United States)

    Ackerman, Laurens V.; Burke, M. W.; Rada, Roy

    1984-06-01

    We have been investigating diagnostic knowledge models which assist in the automatic classification of medical images by combining information extracted from each image with knowledge specific to that class of images. In a more general sense we are trying to integrate verbal and pictorial descriptions of disease via representations of knowledge, study automatic hypothesis generation as related to clinical medicine, evolve new mathematical image measures while integrating them into the total diagnostic process, and investigate ways to augment the knowledge of the physician. Specifically, we have constructed an artificial intelligence knowledge model using the technique of a production system blending pictorial and verbal knowledge about the respective CT scan and patient history. It is an attempt to tie together different sources of knowledge representation, picture feature extraction and hypothesis generation. Our knowledge reasoning and representation system (KRRS) works with data at the conscious reasoning level of the practicing physician while at the visual perceptional level we are building another production system, the picture parameter extractor (PPE). This paper describes KRRS and its relationship to PPE.

  9. 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....

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. An application of dynamic CT for diagnosis of abnormal external ocular muscle movement

    International Nuclear Information System (INIS)

    Tomita, Kazumi; Ogura, Yuuko; Takeshita, Gen; Koga, Sukehiko; Katada, Kazuhiro; Anno, Hirofumi.

    1993-01-01

    To evaluate the movements of retrobulbar structures radiologically, we have developed a new technique called 'external ocular muscle movement CT' (EOM CT), in which dynamic CT scanning is performed while the patient performs controlled eye movements. This new technique was applied in one volunteer and 72 patients with external ophthalmoplegia due to orbital mass lesion, hyperthyroid ophthalmopathy, blowout fracture, and other retrobulbar lesions. EOM CT permits the assessment of extraocular muscle contraction in cases of blowout fracture, the evaluation of muscular contraction in hypertrophy of the extraocular muscles, and the diagnosis of adhesions between the extraocular muscles and intraorbital masses. Radiation dose to the lens from EOM CT was measured using a phantom and TLD, and was compared with that of conventional CT scanning with a 5 mm slice thickness. The dose to the lens from EOM CT was three times higher than that for conventional CT in axial scanning, but in the coronal section of the retrobulbar region, the dose to the lens from EOM CT decreases to one twelfth of that of conventional CT. EOM CT promises to be a powerful modality for functional evaluation of the extraocular muscles and other retrobulbar structures. (author)

  15. 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.

  16. 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

  17. Spinal CT scan, 2. Lumbar and sacral spines

    Energy Technology Data Exchange (ETDEWEB)

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

    1982-08-01

    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.

  18. RADIODIAGNOSIS OF PLEURAL LESIONS WITH USG AND CT SCAN

    Directory of Open Access Journals (Sweden)

    Bheemashanker

    2017-09-01

    Full Text Available BACKGROUND Ultrasound is easy available, less expensive study. It differentiates pleural effusion, consolidation and masses. CT scores in diagnosing early pleural lesions and helps in localising lesions differentiating benign and malignant. The aim of the study is to- 1. Assess the value of ultrasonography and computed tomography in evaluation of pleural lesions. 2. Determine the sensitivity and specificity of ultrasound and CT in pleural lesions. MATERIALS AND METHODS The present study was aimed at assessing the value of ultrasonography and CT in evaluating the pleural lesions. In our study, during the period of 12 months, 100 patients with pleural effusions were evaluated. The most common cause was transudate. Exudates consist of malignant and non-malignant causes. RESULTS The study group was defined into two groups- Malignant and non-malignant group based on pleural effusion of transudate and exudate types. CT and ultrasound has success rate of 100% and 85% respectively to identify neoplastic and non-neoplastic disease. Diagnostic accuracy of CT and ultrasound are comparable while CT scores over ultrasound in failed cases. CT has 100% sensitivity and 100% specificity in pleural lesions. CT has more therapeutic value compared to ultrasound. CONCLUSION The role of ultrasound and CT are complimentary, give high yield of positive results for pleural mass differentiation; useful for guided procedures like pleural biopsy and pleural drainage. Combined study not only useful for localisation of lesion, but also gives information about the extent of disease and characterising the tissue density by analysis of attenuation coefficient.

  19. 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

  20. 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)

  1. Dynamic CT findings of eosinophilic hepatic abscess and its clinical course

    International Nuclear Information System (INIS)

    Cho, Dae Hyoun; Chang, Jae Chun; Seong, Ki Ho

    1996-01-01

    To evaluate dynamic CT features and its clinical courses of eosinophilic hepatic abscess. Two-phase dynamic CT findings and the clinical courses of 13 pathologically proven cases of eosinophilic abscess were reviewed. All patients showed peripheral eosinophilia, and diagnoses were confirmed by ultrasound-guided biopsy(n=9) or operation(n=4). In two of the four patients who underwent segmental hepatectomy, worms of the species fasciola hepatica were detected. Follow-up CT scans after treatment with antibiotics or praziquantel were available in seven and eitht patients, respectively. All hepatic lesions were found in a subcapsular location or in contact with Glisson's capsule around the bile duct Arterial-dominant phase CT(n=11) demonstrated clusters of ill-defined low density masses without rim enhancement. Late-phase CT(n=13) more clearly depicted clustering lesions with enhancing rims and diminyution of the low-density area. Follow-up CT scans after treatment with antibiotics(n=7) showed no change in the lesions in three patients and slight shrinkage of the main mass with additional new lesions in four. On CT scans of nine patients performad after praziquantel therapy, hepatic masses were seen in all patients to be very slightly smaller after improvement of peripheral hypereosinophilia. Two-phase dynamic CT features appear to be helpful for the diagnosis of eosinophilic hepatic abscess in patients with peripheral eosinophilia. Parasitic infestation by Fasciola hepatica for example, is the presumed cause of such abscesses, though further studies are required

  2. 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

  3. 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.

  4. Direct sagittal CT scanning in the diagnosis of pituitary fossa tumours and posterior fossa pathology

    International Nuclear Information System (INIS)

    Podlas, H.

    1981-01-01

    Two independent methods are presented for multidirectional CT scanning of the brain using the Philips Tomoscan 300. The advantages in scanning pituitary fossa tumours and pathology of the posterior fossa are discussed. No additional software or modifications are required. Direct sagittal scanning is particularly advantageous for accurate assessment of the size of pituitary tumours and intrasellar lesions requiring surgical intervention or radiation therapy. (Auth.)

  5. 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.

  6. 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

  7. 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.

  8. Diagnostic value of CT scanning in neuromuscular diseases

    International Nuclear Information System (INIS)

    Bulcke, J.A.L.; Leuven Univ.; Herpels, V.

    1983-01-01

    The diagnosis of myopathies has become easier since the CT technique is available. In this article the possibilities of CT for diagnostic procedures of neuromuscular diseases are pointed out. Density measurements increase differentiation of atrophy or hypertrophy of muscles as well as other pathological changes. (orig.)

  9. CT scanning may adversely influence choice of surgery in paediatric ...

    African Journals Online (AJOL)

    Kurt

    with a thyroid mass. Computed tomography (CT) revealed a lesion, missed by ultrasonography, which reversed the decision to perform con- servative thyroid surgery. The lesion proved to be non-neoplastic. CT may be a useful adjunct when ultrasound demonstrates a solitary lesion and conservative surgery is considered,.

  10. 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.

  11. [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.

  12. 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.

  13. 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)

  14. 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

  15. 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.

  16. 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.

  17. Automated movement correction for dynamic PET/CT images: evaluation with phantom and patient data.

    Science.gov (United States)

    Ye, Hu; Wong, Koon-Pong; Wardak, Mirwais; Dahlbom, Magnus; Kepe, Vladimir; Barrio, Jorge R; Nelson, Linda D; Small, Gary W; Huang, Sung-Cheng

    2014-01-01

    Head movement during a dynamic brain PET/CT imaging results in mismatch between CT and dynamic PET images. It can cause artifacts in CT-based attenuation corrected PET images, thus affecting both the qualitative and quantitative aspects of the dynamic PET images and the derived parametric images. In this study, we developed an automated retrospective image-based movement correction (MC) procedure. The MC method first registered the CT image to each dynamic PET frames, then re-reconstructed the PET frames with CT-based attenuation correction, and finally re-aligned all the PET frames to the same position. We evaluated the MC method's performance on the Hoffman phantom and dynamic FDDNP and FDG PET/CT images of patients with neurodegenerative disease or with poor compliance. Dynamic FDDNP PET/CT images (65 min) were obtained from 12 patients and dynamic FDG PET/CT images (60 min) were obtained from 6 patients. Logan analysis with cerebellum as the reference region was used to generate regional distribution volume ratio (DVR) for FDDNP scan before and after MC. For FDG studies, the image derived input function was used to generate parametric image of FDG uptake constant (Ki) before and after MC. Phantom study showed high accuracy of registration between PET and CT and improved PET images after MC. In patient study, head movement was observed in all subjects, especially in late PET frames with an average displacement of 6.92 mm. The z-direction translation (average maximum = 5.32 mm) and x-axis rotation (average maximum = 5.19 degrees) occurred most frequently. Image artifacts were significantly diminished after MC. There were significant differences (Pdynamic brain FDDNP and FDG PET/CT scans could improve the qualitative and quantitative aspects of images of both tracers.

  18. 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.)

  19. Comparison between angiography and CT scan in the urologic field

    Energy Technology Data Exchange (ETDEWEB)

    Fujioka, Toshio; Takao, Masaya; Odajima, Kunio; Nakamura, Hiroshi

    1988-02-01

    Seventy-five consecutive patients with urological diseases were examined preoperatively by means of computerized tomography and renal angiography. Classification of the diseases were 53 renal diseases which included renal cell carcinoma, sarcoma, cyst, renal bleeding, arteriovenous fistula, trauma, hydronephrosis and tuberculosis, 11 vesical diseases which included bladder tumor and endometriosis, 9 adrenal diseases which included primary aldosteronism, Cushing syndrome, pheochromocytoma, and metastatic tumor, and 1 case of intra-abdominal testes. For renal diseases, both angiography and CT were useful imaging tools. For vesical diseases, CT was a more useful imaging method but, for adrenal diseases, angiography was superior to CT. CT offers certain advantages over conventional techniques but, in the near future, it may be replaced by MRI. On the contrary, angiography will remain popular for a long time, because angiography is the only way to show which vessels feed organs.

  20. 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...

  1. Variations of patient dose in CT scan of skull using a female phantom

    International Nuclear Information System (INIS)

    Estanislau, Bruno A.; Mourao, Arnaldo P.

    2013-01-01

    This paper presents a comparison between the doses deposited in organs in CT scans of the skull when using different protocols in operating the TC unit. The protocols differ in the currents and voltages of the X-ray tube

  2. 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)

  3. 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.

  4. 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

  5. Motion estimation and compensation in dynamic spiral CT reconstruction

    International Nuclear Information System (INIS)

    Kimdon, J.; Grangeat, P.; Koenig, A.; Bonnet, St.

    2004-01-01

    Respiratory and cardiac motion causes blurring in dynamic X-ray Computed Tomography (CT). Fast scans reduce this problem, but they require a higher radiation dose per time period to maintain the signal to noise ratio of the resulting images, thereby magnifying the health risk to the patient. As an alternative to increased radiation, our team has already developed a cone-beam reconstruction algorithm based on a dynamic particle model that estimates, predicts, and compensates for respiratory motion in circular X-ray CT. The current paper presents an extension of this method to spiral CT, applicable to modern multi-slice scanners that take advantage of the speed and dose benefits of helical trajectories. We adapted all three main areas of the algorithm: backprojection, prediction, and compensation/accumulation. In backprojection, we changed the longitudinal re-binning technique, filter direction, and the method of enforcing the data sufficiency requirements. For prediction, we had to be careful of objects appearing and disappearing as the scanner bed advanced. For compensation/accumulation, we controlled the reconstruction time and combined images to cover a greater longitudinal extent for each phase in the respiratory or cardiac cycle. Tests with moving numerical phantoms demonstrate that the algorithm successfully improves the temporal resolution of the images without increasing the dose or reducing the signal-to-noise ratio. (authors)

  6. 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)

  7. 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...

  8. 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.

  9. Quantitative myocardial perfusion from static cardiac and dynamic arterial CT

    Science.gov (United States)

    Bindschadler, Michael; Branch, Kelley R.; Alessio, Adam M.

    2018-05-01

    Quantitative myocardial blood flow (MBF) estimation by dynamic contrast enhanced cardiac computed tomography (CT) requires multi-frame acquisition of contrast transit through the blood pool and myocardium to inform the arterial input and tissue response functions. Both the input and the tissue response functions for the entire myocardium are sampled with each acquisition. However, the long breath holds and frequent sampling can result in significant motion artifacts and relatively high radiation dose. To address these limitations, we propose and evaluate a new static cardiac and dynamic arterial (SCDA) quantitative MBF approach where (1) the input function is well sampled using either prediction from pre-scan timing bolus data or measured from dynamic thin slice ‘bolus tracking’ acquisitions, and (2) the whole-heart tissue response data is limited to one contrast enhanced CT acquisition. A perfusion model uses the dynamic arterial input function to generate a family of possible myocardial contrast enhancement curves corresponding to a range of MBF values. Combined with the timing of the single whole-heart acquisition, these curves generate a lookup table relating myocardial contrast enhancement to quantitative MBF. We tested the SCDA approach in 28 patients that underwent a full dynamic CT protocol both at rest and vasodilator stress conditions. Using measured input function plus single (enhanced CT only) or plus double (enhanced and contrast free baseline CT’s) myocardial acquisitions yielded MBF estimates with root mean square (RMS) error of 1.2 ml/min/g and 0.35 ml/min/g, and radiation dose reductions of 90% and 83%, respectively. The prediction of the input function based on timing bolus data and the static acquisition had an RMS error compared to the measured input function of 26.0% which led to MBF estimation errors greater than threefold higher than using the measured input function. SCDA presents a new, simplified approach for quantitative

  10. 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.)

  11. 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

  12. Brain CT scan in acute carbon monoxide poisoning

    International Nuclear Information System (INIS)

    We, En-Huei

    1986-01-01

    The brain CT findings in 19 patients with acute carbon monoxide poisoning was analysed and the emphasis was placed on the relationship between CT findings and prognosis. Five had a normal manifestation in CT ; eight had the findings of ovoid or patchy low density area in globus pallidus, bilateral or unlateral, during the second day to fifth week after poisoning, and the low density areas were decreasing and blurring in edge in follow up and at last disappeared during 3 - 14 weeks in three cases of them ; nine showed the appearance of diffuse low density of white matter and of globus pallidus in some of them ; two had an appearance of brain atrophy. The pathology of CT findings mentioned above may be brain edema, necrosis, malacia and degeneration in gray matter and globus pallidus. The result suggested the cases with normal CT manifestation, cerebral edema and decreasing and disappearing low density area had a good prognosis, in contrary, the cases with persistant low density in globus pallidus had a poorer prognosis. (author)

  13. 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

  14. 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.

  15. 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

  16. Multi-institutional collaborating study on CT scan of schizophrenia

    International Nuclear Information System (INIS)

    Takahashi, Ryo; Sato, Tokijiro; Okuma, Teruo

    1984-01-01

    More abnormal CT findings were observed in nuclear schizophrenic patients (55%) than in the matchable controls with a statistically significant difference. According to the site of the brain, these were marked in the whole ventricle (especially the third ventricle) and in the cortex including the longitudinal fissure, frontal lobe, temporal lobe, and sylvian fissure (especially of the left hemisphere). There was no correlation between the cerebral ventricular enlargement and the patient's age, the duration of illness or drug dosage, suggesting that the enlargement may exist from the onset of the disease. Aging or taking drug(s) were also not responsible for the cortical atrophy. CT findings were associated mainly with negative symptoms. In particular, the association between abnormalities of the left hemisphere and psychiatric symptoms was marked. Direct measurements of CT images revealed significantly higher incidences only in the third ventricular enlargement in schizophrenic patients. These results suggest the possibility that subtypes of schizophrenia can be classified. (Namekawa, K.)

  17. 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

  18. What are the potential advantages and disadvantages of volumetric CT scanning?

    Science.gov (United States)

    Voros, Szilard

    2009-01-01

    After the introduction and dissemination of 64-slice multislice computed tomography systems, cardiovascular CT has arrived at a crossroad, and different philosophies lead down different paths of technologic development. Increased number of detector rows in the z-axis led to the introduction of dynamic, volumetric scanning of the heart and allows for whole-organ imaging. Dynamic, volumetric "whole-organ" scanning significantly reduces image acquisition time; "single-beat whole-heart imaging" results in improved image quality and reduced radiation exposure and reduced contrast dose. It eliminates helical and pitch artifacts and allows for simultaneous imaging of the base and apex of the heart. Beyond coronary arterial luminal imaging, such innovations open up the opportunity for myocardial perfusion and viability imaging and coronary arterial plaque imaging. Dual-source technology with 2 x-ray tubes placed at 90-degree angles provides heart rate-independent temporal resolution and has the potential for tissue characterization on the basis of different attenuation values at different energy levels. Refined detector technology allows for improved low-contrast resolution and may be beneficial for more detailed evaluation of coronary arterial plaque composition. The clinical benefit of each of these technologies will have to be evaluated in carefully designed clinical trials and in everyday clinical practice. Such combined experience will probably show the relative benefit of each of these philosophies in different patient populations and in different clinical scenarios.

  19. 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

  20. 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...

  1. Improved dynamic CT angiography visualization by flow territory masking

    Directory of Open Access Journals (Sweden)

    Søren Christensen

    2015-01-01

    Full Text Available Backgound and Purpose: Computerized tomography (CT perfusion (or CTP source images from CT scanners with small detector widths can be used to create a dynamic CT angiogram (CTA similar to digital subtraction angiography (DSA. Because CTP studies use a single intravenous injection, all arterial territories enhance simultaneously, and individual arterial territories [i.e., anterior cerebral artery (ACA, middle cerebral artery (MCA, and posterior cerebral artery (PCA] cannot be delineated. This limits the ability to assess collateral flow patterns on dynamic CTAs. The aim of this study was to devise and test a postprocessing method to selectively color-label the major arterial territories on dynamic CTA. Materials and Methods: We identified 22 acute-stroke patients who underwent CTP on a 320-slice CT scanner within 6 h from symptom onset. For each case, two investigators independently generated an arterial territory map from CTP bolus arrival maps using a semiautomated method. The volumes of the arterial territories were calculated for each map and the average relative difference between these volumes was calculated for each case as a measure of interrater agreement. Arterial territory maps were superimposed on the dynamic CTA to create a vessel-selective dynamic CTA with color-coding of the main arterial territories. Two experts rated the arterial territory maps and the color-coded CTAs for consistency with expected arterial territories on a 3-point scale (excellent, moderate, poor. Results: Arterial territory maps were generated for all 22 patients. The median difference in arterial territory volumes between investigators was 2.2% [interquartile range (IQR 0.6-8.5%]. Based on expert review, the arterial territory maps and the vessel-selective dynamic CTAs showed excellent consistency with the expected arterial territories in 18 of 22 patients, moderate consistency in 2 patients, and poor consistency in another 2 patients. Conclusion: Using a

  2. 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.

  3. Exact cone beam CT with a spiral scan

    International Nuclear Information System (INIS)

    Tam, K.C.; Samarasekera, S.; Sauer, F.

    1998-01-01

    A method is developed which makes it possible to scan and reconstruct an object with cone beam x-rays in a spiral scan path with area detectors much shorter than the length of the object. The method is mathematically exact. If only a region of interest of the object is to be imaged, a top circle scan at the top level of the region of interest and a bottom circle scan at the bottom level of the region of interest are added. The height of the detector is required to cover only the distance between adjacent turns in the spiral projected at the detector. To reconstruct the object, the Radon transform for each plane intersecting the object is computed from the totality of the cone beam data. This is achieved by suitably combining the cone beam data taken at different source positions on the scan path; the angular range of the cone beam data required at each source position can be determined easily with a mask which is the spiral scan path projected on the detector from the current source position. The spiral scan algorithm has been successfully validated with simulated cone beam data. (author)

  4. 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

  5. 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.

  6. 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.

  7. 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)

  8. 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)

  9. 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)

  10. 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)

  11. 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,

  12. Usefulness of multi-plane dynamic subtraction CT (MPDS-CT) for intracranial high density lesions

    Energy Technology Data Exchange (ETDEWEB)

    Takagi, Ryo; Kumazaki, Tatsuo [Nippon Medical School, Tokyo (Japan)

    1996-02-01

    We present a new CT technique using the high speed CT scanner in detection and evaluation of temporal and spatial contrast enhancement of intracranial high density lesions. A multi-plane dynamic subtraction CT (MPDS-CT) was performed in 21 patients with intracranial high density lesions. These lesions consisted of 10 brain tumors, 7 intracerebral hemorrhages and 4 vascular malformations (2 untreated, 2 post-embolization). Baseline study was first performed, and 5 sequential planes of covering total high density lesions were selected. After obtaining the 5 sequential CT images as mask images, three series of multi-plane dynamic CT were performed for the same 5 planes with an intravenous bolus injection of contrast medium. MPDS-CT images were reconstructed by subtracting dynamic CT images from the mask ones. MPDS-CT were compared with conventional contrast-enhanced CT. MPDS-CT images showed the definite contrast enhancement of high density brain tumors and vascular malformations which were not clearly identified on conventional contrast-enhanced CT images because of calcified or hemorrhagic lesions and embolic materials, enabling us to eliminate enhanced abnormalities with non-enhanced areas such as unusual intracerebral hemorrhages. MPDS-CT will provide us further accurate and objective information and will be greatly helpful for interpreting pathophysiologic condition. (author).

  13. 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...

  14. 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

  15. 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.)

  16. 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.)

  17. 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

  18. 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

  19. 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...

  20. 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)

  1. Evaluation of pituitary adenomas by multidirectional multislice dynamic CT

    International Nuclear Information System (INIS)

    Abe, T.; Izumiyama, H.; Fujisawa, I.

    2002-01-01

    Purpose: Multidetector-row CT is a new technology with a short scanning time. Multislice dynamic CT (MSDCT) in various directions can be obtained using the multidetector-row CT with multiplanar reformatting (MPR) technique. Material and Methods: We evaluated the initial results of sagittal and coronal MSDCT images reconstructed by MPR (MSDCT-MPR) in 3 pituitary adenoma patients with a pacemaker. Results: In a patient with microadenoma, the maximum contrast between the normal anterior pituitary gland and the adenoma occurred approximately 50 s after the start of the contrast medium injection. A microadenoma was depicted as a less enhanced area relative to normal pituitary tissue. The macroadenomas were depicted as a less enhanced mass with cavernous sinus invasion in 1 patient and as a non-uniformly enhanced mass in another patient. Bone destruction and incomplete opening of the sellar floor during previous surgery were clearly detected in 2 patients with macroadenomas. These pituitary adenomas were removed via the transnasal route based on information from the MSDCT-MPR images only. The findings were verified surgically. Conclusion: The MSDCT-MPR provided the information needed for surgery with good image quality in the 3 patients with pacemakers. MSDCT-MPR appears to be a useful technique for patients with a pituitary adenoma in whom MR imaging is not available. This is the first report, to our knowledge, of the MSDCT-MPR technique being used to demonstrate pituitary disorders

  2. Evaluation of pituitary adenomas by multidirectional multislice dynamic CT

    Energy Technology Data Exchange (ETDEWEB)

    Abe, T.; Izumiyama, H. [Showa Univ. School of Medicine, Tokyo (Japan). Dept. of Neurosurgery; Fujisawa, I. [Kishiwada City Hospital, Kishiwada (Japan). Dept. of Radiology

    2002-11-01

    Purpose: Multidetector-row CT is a new technology with a short scanning time. Multislice dynamic CT (MSDCT) in various directions can be obtained using the multidetector-row CT with multiplanar reformatting (MPR) technique. Material and Methods: We evaluated the initial results of sagittal and coronal MSDCT images reconstructed by MPR (MSDCT-MPR) in 3 pituitary adenoma patients with a pacemaker. Results: In a patient with microadenoma, the maximum contrast between the normal anterior pituitary gland and the adenoma occurred approximately 50 s after the start of the contrast medium injection. A microadenoma was depicted as a less enhanced area relative to normal pituitary tissue. The macroadenomas were depicted as a less enhanced mass with cavernous sinus invasion in 1 patient and as a non-uniformly enhanced mass in another patient. Bone destruction and incomplete opening of the sellar floor during previous surgery were clearly detected in 2 patients with macroadenomas. These pituitary adenomas were removed via the transnasal route based on information from the MSDCT-MPR images only. The findings were verified surgically. Conclusion: The MSDCT-MPR provided the information needed for surgery with good image quality in the 3 patients with pacemakers. MSDCT-MPR appears to be a useful technique for patients with a pituitary adenoma in whom MR imaging is not available. This is the first report, to our knowledge, of the MSDCT-MPR technique being used to demonstrate pituitary disorders.

  3. Dose reduction using prospective electrocardiograph-triggered axial coronary scan on the 64-slice spiral CT

    International Nuclear Information System (INIS)

    Wang Yanyan; Wu Guogeng; Zhou Cheng; Gao Jianhua; Jiao Sheng; Cao Huizhi

    2008-01-01

    Objective: To compare radiation dose and image quality between prospective electrocardiograph (ECG)-triggered axial scan and retrospective ECG-gated helical scan in coronary 64-slice CT angiography (CTA). Methods: Seventy-seven consecutive patients [group A. Average body mass index (BMI): 24.6, heart rate 0.05). Conclusion: Prospective ECG-triggered axial scan in 64-slice coronary CTA can significantly reduce radiation exposure and the image quality can fulfill clinical diagnostic needs. (authors)

  4. CT scan findings and EEG in systemic lupus erythematodes patients with neuro-psychiatric disorders

    Energy Technology Data Exchange (ETDEWEB)

    Kan, Rumiko; Hagiwara, Mariko; Katayose, Keiko; Yashima, Yuko; Kumashiro, Hisashi

    1988-06-01

    In 14 patients with systemic lupus erythematodes presenting with neuro-psychiatric disorders, CT scans were compared with encephalographic (EEG) findings. CT findings were markedly abnormal in 6, slight with a sulcal enlargement in 3, and normal in 5. In the group of markedly abnormal CT findings, focal abnormal low density areas were detected in 2, severe generalized cerebral atrophy in one, and severe atrophy of the right hemisphere in one. EEG findings included focal paroxysmal abnormality of high voltage slow burst at the left frontal dominance and positive spike on the right hemisphere. Epileptic seizure and depressed sensorium seemed to be related to CT abnormality. In 3 patients with epileptic seizures, their symptoms were closely related to CT abnormality. Parkinsonisms and depressed sensorium were also related to CT abnormality. (Namekawa, K).

  5. CT scan findings and EEG in systemic lupus erythematodes patients with neuro-psychiatric disorders

    International Nuclear Information System (INIS)

    Kan, Rumiko; Hagiwara, Mariko; Katayose, Keiko; Yashima, Yuko; Kumashiro, Hisashi

    1988-01-01

    In 14 patients with systemic lupus erythematodes presenting with neuro-psychiatric disorders, CT scans were compared with encephalographic (EEG) findings. CT findings were markedly abnormal in 6, slight with a sulcal enlargement in 3, and normal in 5. In the group of markedly abnormal CT findings, focal abnormal low density areas were detected in 2, severe generalized cerebral atrophy in one, and severe atrophy of the right hemisphere in one. EEG findings included focal paroxysmal abnormality of high voltage slow burst at the left frontal dominance and positive spike on the right hemisphere. Epileptic seizure and depressed sensorium seemed to be related to CT abnormality. In 3 patients with epileptic seizures, their symptoms were closely related to CT abnormality. Parkinsonisms and depressed sensorium were also related to CT abnormality. (Namekawa, K)

  6. Optical CT imaging of solid radiochromic dosimeters in mismatched refractive index solutions using a scanning laser and large area detector.

    Science.gov (United States)

    Dekker, Kurtis H; Battista, Jerry J; Jordan, Kevin J

    2016-08-01

    The practical use of the PRESAGE® solid plastic dosimeter is limited by the inconvenience of immersing it in high-viscosity oils to achieve refractive index matching for optical computed tomography (CT) scanning. The oils are slow to mix and difficult to clean from surfaces, and the dosimeter rotation can generate dynamic Schlieren inhomogeneity patterns in the reference liquid, limiting the rotational and overall scan speed. Therefore, it would be beneficial if lower-viscosity, water-based solutions with slightly unmatched refractive index could be used instead. The purpose of this work is to demonstrate the feasibility of allowing mismatched conditions when using a scanning laser system with a large acceptance angle detector. A fiducial-based ray path measurement technique is combined with an iterative CT reconstruction algorithm to reconstruct images. A water based surrounding liquid with a low viscosity was selected for imaging PRESAGE® solid dosimeters. Liquid selection was optimized to achieve as high a refractive index as possible while avoiding rotation-induced Schlieren effects. This led to a refractive index mismatch of 6% between liquid and dosimeters. Optical CT scans were performed with a fan-beam scanning-laser optical CT system with a large area detector to capture most of the refracted rays. A fiducial marker placed on the wall of a cylindrical sample occludes a given light ray twice. With knowledge of the rotation angle and the radius of the cylindrical object, the actual internal path of each ray through the dosimeter can be calculated. Scans were performed with 1024 projections of 512 data samples each, and rays were rebinned to form 512 parallel-beam projections. Reconstructions were performed on a 512 × 512 grid using 100 iterations of the SIRT iterative CT algorithm. Proof of concept was demonstrated with a uniformly attenuating solution phantom. PRESAGE® dosimeters (11 cm diameter) were irradiated with Cobalt-60 irradiator to achieve

  7. CT scanning of the breast in problem cases

    Energy Technology Data Exchange (ETDEWEB)

    John, V.; Ewen, K. (Essen Univ. (Gesamthochschule) (Germany, F.R.). Radiologisches Zentrum; Zentralstelle fuer Sicherheitstechnik, Duesseldorf (Germany, F.R.))

    1989-09-01

    This is a report of the experience with 200 patients who during 1981 to 1984 underwent breast scanning on a conventional body scanner. Pre- and post-contrast scans of the breast were obtained. A postcontrast enhancement of 50 HU and more turned out to be specific for malignant lesions. Radiation dose to the breast was in the same range as with high filtration xeromammography and high resolution film-screen mammography with additional grid. Breast scanning is recommended in cases in which mammography alone is of limited value, including dense fibrocystic breasts in women at high risk, follow-up in breast cancer patients after breast conserving therapy, in patients with silastic implants and in the follow-up of breasts with huge scars due to multiple biopsies. (orig.).

  8. 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

  9. 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)

  10. Some practical aspects of dual-energy CT scanning

    International Nuclear Information System (INIS)

    Dunscombe, P.B.; Katz, D.E.; Stacey, A.J.

    1984-01-01

    Using the dual-energy scanning method developed by Brooks (1977), and making slow x-ray scans at 100 kVp, 35 mA and 140 kVp, 20 mA, measurements were made of electron density and effective atomic number in the lumbar spines of 36 patients aged from 22 to 87 years, and not known to be suffering from conditions which result in osteoporosis or osteomalacia. The authors discuss in detail the sources of experimental error which contributed to the large measured spread of normal values of electron density and effective atomic number. (U.K.)

  11. Some practical aspects of dual-energy CT scanning

    Energy Technology Data Exchange (ETDEWEB)

    Dunscombe, P.B.; Katz, D.E.; Stacey, A.J. (Charing Cross Group of Hospitals, London (UK))

    1984-01-01

    Using the dual-energy scanning method developed by Brooks (1977), and making slow x-ray scans at 100 kVp, 35 mA and 140 kVp, 20 mA, measurements were made of electron density and effective atomic number in the lumbar spines of 36 patients aged from 22 to 87 years, and not known to be suffering from conditions which result in osteoporosis or osteomalacia. The authors discuss in detail the sources of experimental error which contributed to the large measured spread of normal values of electron density and effective atomic number.

  12. 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

  13. 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.

  14. 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.

  15. 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.

  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. 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)

  18. Trends in CT scan rates in children and pregnant women: teaching, private, public and nonprofit facilities

    International Nuclear Information System (INIS)

    Hoshiko, Sumi; Smith, Daniel; Fan, Cathyn; Jones, Carrie R.; McNeel, Sandra V.; Cohen, Ronald A.

    2014-01-01

    Radiation exposure from medical sources now equals or exceeds that from natural background sources, largely attributable to a 20-fold increase in CT use since 1980. Increasing exposure to children and fetuses is of most concern due to their heightened susceptibility. More recently, CT use may be leveling or decreasing, but it is unclear whether this change is widespread or varies by type of institution. We sought to characterize trends in CT utilization in California hospitals and emergency departments among children and pregnant women, looking at different types of facilities, such as teaching, private, public and nonprofit institutions. We examined frequency of CT examinations by year from 229 facilities reporting CT usage in routinely collected California statewide data for 2005-2012. We modeled trends overall and by facility type. CT scans for pediatric and pregnant patient visits in the emergency department increased initially, then started to decline after 2008. Among hospital admissions, rates declined or leveled after 2005. In the emergency department, CT rates varied between types of facilities, with teaching hospitals reducing use sooner and more sharply than other types of facilities. CT utilization in California among children and pregnant women has begun to level or decline. Still, population exposure remains at historically high levels, warranting consideration of potential public health implications. Further examination of reasons for trends among hospital types, particularly how teaching hospitals have reduced rates of CT utilization, may help identify strategies for CT reduction without compromising patient care. (orig.)

  19. Trends in CT scan rates in children and pregnant women: teaching, private, public and nonprofit facilities

    Energy Technology Data Exchange (ETDEWEB)

    Hoshiko, Sumi; Smith, Daniel; Fan, Cathyn; Jones, Carrie R.; McNeel, Sandra V. [Environmental Health Investigations Branch, California Department of Public Health, Richmond, CA (United States); Cohen, Ronald A. [Children' s Hospital and Research Center Oakland, Department of Radiology, Oakland, CA (United States)

    2014-05-15

    Radiation exposure from medical sources now equals or exceeds that from natural background sources, largely attributable to a 20-fold increase in CT use since 1980. Increasing exposure to children and fetuses is of most concern due to their heightened susceptibility. More recently, CT use may be leveling or decreasing, but it is unclear whether this change is widespread or varies by type of institution. We sought to characterize trends in CT utilization in California hospitals and emergency departments among children and pregnant women, looking at different types of facilities, such as teaching, private, public and nonprofit institutions. We examined frequency of CT examinations by year from 229 facilities reporting CT usage in routinely collected California statewide data for 2005-2012. We modeled trends overall and by facility type. CT scans for pediatric and pregnant patient visits in the emergency department increased initially, then started to decline after 2008. Among hospital admissions, rates declined or leveled after 2005. In the emergency department, CT rates varied between types of facilities, with teaching hospitals reducing use sooner and more sharply than other types of facilities. CT utilization in California among children and pregnant women has begun to level or decline. Still, population exposure remains at historically high levels, warranting consideration of potential public health implications. Further examination of reasons for trends among hospital types, particularly how teaching hospitals have reduced rates of CT utilization, may help identify strategies for CT reduction without compromising patient care. (orig.)

  20. 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.

  1. 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)

  2. 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)

  3. 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

  4. 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.

  5. Ring-shaped lesions in the CT scan

    International Nuclear Information System (INIS)

    Kazner, E.; Steinhoff, H.; Wende, S.; Mauersberger, W.

    1978-01-01

    Computerised tomography has really opened new dimensions for the diagnosis of various intracranial space-occupying lesions. However, during the last years we had to learn how difficult it can be to evaluate a certain CT finding correctly. Especially the group of ring-type lesions still pose some unsolved problems even if clinical information available in the individual case is considered. The ring blush is a nonspecific finding which occurs in primary and metastatic neoplasms, abscess, infarction, certain stages of intracerebral hematomas and even after neurosurgical operations. The ring blush is caused partly by breakdown of the blood brain barrier, partly by hypervascular pathologic tissue or by both factors. (orig.) [de

  6. 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

  7. Characteristic of muscle involvement evaluated by CT scans in early stages of progressive muscular dystrophy

    International Nuclear Information System (INIS)

    Arai, Yumi

    1993-01-01

    Muscle CT scans were performed in order to compare the characteristic distribution of progressive muscle involvement in the early stages of Duchenne type (DMD) and Fukuyama type muscular dystrophy (FCMD). Muscle images at the levels of the 3rd lumbar vertebra, thigh and calf were assessed by visual inspection, and mean CT numbers calculated for individual muscles were statistically analysed. On visual inspection, intramuscular low density areas and muscular atrophy were observed in the muscles of older patients with either disease. These changes were, however, more extensive at thigh level in DMD, and at calf level in FCMD. Nevertheless, the mean CT numbers of muscles in which only slight changes were grossly visible on CT scans displayed progressive decreases with increasing age. Moreover, a significant negative relationship was recognizable between age and mean CT number in almost all muscles examined. Comparison of the slopes of the regression lines revealed that the so-called selective pattern of muscle involvement characteristic of the symptomatic stage had already partially manifested in the preclinical or early stages of both diseases. In FCMD, the rates of decrease in CT numbers were extremely rapid for calf muscles as compared with those in DMD, indicating that this is one reason for FCMD patients never becoming ambulatory. However, for almost all of the other muscles, the CT numbers in FCMD decreased in parallel with the corresponding CT numbers in DMD; thus, these diseases displayed a similarity in the pattern of muscle involvement, despite their different pathogenetic mechanisms and inheritance patterns. (author)

  8. 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.

  9. 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.

  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. 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

  12. X-ray CT Scanning Reveals Long-Term Copper Pollution Effects on Functional Soil Structure

    DEFF Research Database (Denmark)

    Naveed, Muhammad; Møldrup, Per; Homstrup, Martin

    Soil structure plays the main role in the ability of the soil to fulfill essential soil functions such as the root growth, rate of water infiltration and retention, transport of gaseous and chemicals/pollutants through the soil. Soil structure is a dynamic soil property and affected by various...... factors such as soil type, land use, and soil contamination. In this study, we quantified the soil structure using X-ray CT scanning and revealed the effect of a long history of Copper (Cu) pollution on it. A fallow field at Hygum Denmark provides this opportunity as it had a long history of Copper...... sulphate contamination in a gradient with Cu content varies from 21 mg kg-1 to 3837 mg kg-1. Total 20 intact soil columns (diameter of 10 cm and height of 8 cm) were sampled at five locations along the Cu-gradient from a depth of 5 to 15 cm below surface level. The soil columns were scanned at a voxel...

  13. Reversal of flow in the inferior vena cava and hepatic veins on dynamic CT

    International Nuclear Information System (INIS)

    Lelij, H. van der; Mallens, W.M.C.

    1988-01-01

    A tricuspid insufficiency may not be clinically evident and may remain unknown to the clinician. The phenomenon of a reversal of inferior vena caval blood flow and hepatic veins is known to occur in tricuspid regurgitation from right ventricular angiography and duplex scanning. Demonstration of such a reversal flow on a dynamic CT scan, as in our case, has, to our knowledge, not as yet been reported

  14. Standardised tumour, node and metastasis reporting of oncology CT scans

    International Nuclear Information System (INIS)

    Gormly, K. L. M.

    2009-01-01

    Full text: The oncology CT report is a vital piece of communication between the radiologist and the treating clinician and often determines patient management. The use of a standardised report that follows the tumour, node and metastasis (TNM) structure makes it easier for the radiologist to include all of the necessary information in an easy-to-read format. Presenting the results under the headings of primary tumour, lymph nodes, metastases, and other findings follows a similar pattern to that used by pathologists and also follows the thought process of the treating clinician. Standardised templates for TNM-based oncology CT reports were introduced into public and private institutions. An audit of 199 reports demonstrated a significant increase in the presence of measurements and conclusions in the template reports. While there was a non-significant increase in the use of correct Response Evaluation Criteria In Solid Tumours terminology for template reports, there was an improved attempt to describe the disease response. Saving measurements as a summary series on PACS also assists follow-up reporting

  15. 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)

  16. 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

  17. 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)

  18. 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)

  19. 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)

  20. 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.

  1. Body composition in chemotherapy: the promising role of CT scans.

    Science.gov (United States)

    Prado, Carla M M

    2013-09-01

    Reducing cancer-treatment toxicity was a largely ignored research agenda, which is now emerging as an active area of investigation. Studies of human body composition using computerized tomography scans have provided proof-of-concept that variability in drug disposition and toxicity profiles may be partially explained by different features in body composition. Collectively, studies suggest that skeletal muscle depletion (regardless of body weight) is an independent predictor of severe toxicity, affecting cancer treatment and its outcomes. Although precise mechanisms are unknown, pharmacokinetic parameters such as variations in volume of distribution and increased drug exposure may explain such findings. Computerized tomography scans are readily available in clinical databases of diagnostic images and provide feasible, reliable, and highly differentiated measurements of body composition. These images should be used to optimize screening and management of patients in order to prevent severe toxicity, and to improve the efficacy and cost-efficiency of chemotherapy treatments.

  2. 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

  3. 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

  4. 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)

  5. 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.)

  6. 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)

  7. 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.''

  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. 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)

  10. Quality assurance of CT scanning for industrial applications

    DEFF Research Database (Denmark)

    Angel, Jais Andreas Breusch

    components, representing tissue types such as lean meat, fat, and bone. Establishment of traceable volume measurements for the phantoms is performed using the gravimetric method (also called water displacement). The stability has been documented for the two phantoms. For the meat processing industry...... to 1348 mL, compared to average uncertainties below 10 mL using the gravimetric method. DMRI and DTU Compute have previously developed advanced image analysis software (PigClassWeb) which performs virtual dissections in pig carcasses. A DOE was carried out to document the performance of Pig...... assurance of CT for industrial measurements both in the manufacturing and in the meat processing industries. Various methods and reference objects have been developed in this project to establish metrological traceability of measurements. Moreover investigations as well as international comparisons...

  11. 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.)

  12. Case of pycnodysostosis. Observation of skull by CT scan

    Energy Technology Data Exchange (ETDEWEB)

    Anegawa, Shigetaka; Bekki, Yoshiaki; Furukawa, Yasuhiro; Yokota, Seishi; Torigoe, Ryuichiro

    1987-07-01

    A 13-year-old boy was presented to the Department of Neurosurgery, Saiseikai Fukuoka General Hospital for further examinations concerning abnormal findings in the skull radiogram taken when he struck his head. His physical features showed some characteristics the same as those of pycnodysostosis as follows - proportionate dwarfism, prominent forehead, short spoon-shaped fingers, bilateral exophthalmos. A skull radiogram revealed widely open cranial sutures with no healing of the fracture and craniotomy which was performed for an acute epidural hematoma 6 years ago. Furthermore, the mandible was hypoplastic with a virtural loss of mandibular angle. CT of the soft tissues showed somewhat dilated cortical sulci and ventricles without any structural abnormalities in the brain. CT of bone algorythum revealed specific characteristics of this disease. The paranasal sinuses were quite hypoplastic. Especially in the maxillary sinuses, frontal sinussus and mastoid air cells, none of developments of sinuses were noted, even though the middle and internal ear seemed to be normal. Moreover, the ethomoid and sphenoid sinuses were noted, although their developments were poor. The appearance of skull base was normal, including the inlets and outlets of cranial nerves or vessels and synchondroses. However, the density of the skull base, especially in the diploe, was higher than normal in Hansfield number. Furthermore, detailed measurements of skull base demonstrated that the skull base itself was also dwarfish. In our study, the development of sinuses in bones with intramembranous ossification are worse than that with endochondral ossification. Furthermore, sutures or synchondroses in the skull base were well-developed than those of the convex. So, it is considered that pycnodysostosis must be the neighboring entity of diseases such as achondroplastic dwarfism or cleidocranial dysplasia. (J.P.N.).

  13. 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

  14. 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

  15. Focused abdominal CT scan for acute appendicitis in children: can it help in need

    International Nuclear Information System (INIS)

    Akhtar, W.; Ali, S.; Arshad, M.; Nadeem, M.

    2011-01-01

    Objective: To evaluate the focused abdominal CT scan [FACT] in clinically equivocal cases of acute appendicitis in paediatric population. Methods: A cross-sectional study was conducted at the Radiology Department of Aga Khan Hospital, from August 2007 to November 2008. A total of 84 patients (42 males and 42 females) with clinically equivocal signs and symptoms of acute appendicitis referred to radiology department for CT evaluation were studied. CT findings were compared with histopathology and clinical follow-up. Results: The sensitivity of focused CT for acute appendicitis was 91%; specificity was 69% and accuracy of 76% while PPV and NPV were 58%, 94% respectively. Conclusion: Focused unenhanced CT is a quick, accurate and non invasive modality for the assessment of clinically equivocal cases of acute appendicitis for ruling out patients and reducing negative appendectomies. (author)

  16. 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

  17. 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...

  18. 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.

  19. 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

  20. Dynamic CT findings of eosinophilic hepatic abscess and its clinical course

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Dae Hyoun; Chang, Jae Chun; Seong, Ki Ho [Yeungnam Univ. School of Medicine, Taegu (Korea, Republic of)

    1996-01-01

    To evaluate dynamic CT features and its clinical courses of eosinophilic hepatic abscess. Two-phase dynamic CT findings and the clinical courses of 13 pathologically proven cases of eosinophilic abscess were reviewed. All patients showed peripheral eosinophilia, and diagnoses were confirmed by ultrasound-guided biopsy(n=9) or operation(n=4). In two of the four patients who underwent segmental hepatectomy, worms of the species fasciola hepatica were detected. Follow-up CT scans after treatment with antibiotics or praziquantel were available in seven and eitht patients, respectively. All hepatic lesions were found in a subcapsular location or in contact with Glisson's capsule around the bile duct Arterial-dominant phase CT(n=11) demonstrated clusters of ill-defined low density masses without rim enhancement. Late-phase CT(n=13) more clearly depicted clustering lesions with enhancing rims and diminyution of the low-density area. Follow-up CT scans after treatment with antibiotics(n=7) showed no change in the lesions in three patients and slight shrinkage of the main mass with additional new lesions in four. On CT scans of nine patients performad after praziquantel therapy, hepatic masses were seen in all patients to be very slightly smaller after improvement of peripheral hypereosinophilia. Two-phase dynamic CT features appear to be helpful for the diagnosis of eosinophilic hepatic abscess in patients with peripheral eosinophilia. Parasitic infestation by Fasciola hepatica for example, is the presumed cause of such abscesses, though further studies are required.

  1. 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

  2. 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.

  3. 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.

  4. Radiologic evaluation of orbital index among Ghanaians using CT scan.

    Science.gov (United States)

    Botwe, Benard Ohene; Sule, Derick Seyram; Ismael, Abdul Mumin

    2017-07-11

    Orbital index (OI) expresses the proportion of the orbital height to the orbital width and varies with race, regions within the same race and periods in evolution. This index is useful in forensic medicine, anthropology and surgery. However, the average OI among Ghanaian adults was unknown. The aim of this study was to determine the orbital index of adult Ghanaians and classify them under one of the three predetermined groups. The study design was a retrospective cross-sectional. A systematic random sampling method was used for selecting 350 adult Ghanaian head computed tomography images available from 1 January to 31 December 2015 at KBTH Hospital. The orbital height and orbital width of each orbit were measured on a 3D CT skull. Data was analysed using Microsoft Excel and Statistical Package for Social Sciences version 20. The study had more females than men (167, 47.71%, vs 183, 52.29%). The observed orbital index of Ghanaians in the study was 81.22 ± 4.22. The mean orbital index was 80.52 ± 4.66 in males and 82.15 ± 3.83 in females with their difference being statistically significant (p value forensic medicine for skull classification and also for better surgical approach in neurosurgery as well as cosmetic surgery.

  5. 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

  6. CT scan findings of fungal pneumonia; Diagnose der Pilzpneumonie in der Thorax-CT

    Energy Technology Data Exchange (ETDEWEB)

    Heckmann, M.; Uder, M.; Bautz, W.; Heinrich, M. [Erlangen-Nuernberg Univ., Erlangen (Germany). Inst. fuer Diagnostische Radiologie

    2008-07-01

    The importance of fungal infection of the lung in immunocompromised patients has increased substantially during the last decades. Numerically the most patients are those with neutropenia, e.g. patients with malignancies or solid organ and stem cell transplantation, chemotherapy, corticosteroid use and HIV infection. Although fungal infections can occur in immunocompetent patients, their frequency in this population is rare. The clinical symptoms such as fever accompanied with non-productive cough are unspecific. In some patients progression to hypoxemia and dyspnea may occur rapidly. In spite of improved antifungal therapy morbidity and mortality of these infections are still high. Therefore an early and non-invasive diagnosis is very important. That is why CT and even better High-Resolution-CT (HR-CT) is a very important modality in examining immunocompromised patients with a probability of fungal infection. CT is everywhere available and, as a non-invasive method, able to give the relevant diagnose efficiently. This paper should give an overview about the radiologic findings and possible differential diagnosis of diverse pulmonary fungal infections in CT. Pneumonias caused by Aspergillus, Cryptococcus, Candida, Histoplasma, Mucor and Geotrichum capitatum are illustrated. (orig.)

  7. 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

  8. 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.

  9. 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

  10. 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.)

  11. 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

  12. 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.

  13. 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

  14. 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.

  15. 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

  16. Age estimation by 3D CT-scans of the Borremose Woman, a Danish bog body

    DEFF Research Database (Denmark)

    Villa, Chiara; Møller Rasmussen, Maria; Lynnerup, Niels

    2011-01-01

    Non-invasive estimation of age at death has been carried out by using 3D CT scanning of a bog body discovered in 1948 in a peat bog in Borremose (Denmark). The bog body has been dated to the 8th century BC, in the last part of the Bronze Age. The skeletal structures useful for age estimation have...

  17. Preliminary report on a new mode of CT-scanning of the thorax

    NARCIS (Netherlands)

    Veiga-Pires, J.A.; Kaiser, M.C.

    1980-01-01

    The A.A. advocate a “longitudino-axial” mode of CT-scanning in examinations of the thorax and suggest it as the standard mode in children and adults of small stature. The full development of the method is at present limited by the design of both hardware and software of the current generations of

  18. Indications for direct multidirectional or multiplanar electronic reconstructions in CT-scanning of the head

    International Nuclear Information System (INIS)

    Kaiser, M.C.; Veiga-Pires, J.A.; Gooskens, R.; Troost, J.

    1982-01-01

    The authors set out to indicate the optimal applications at minimum radiation penalty of both direct multidirectional and multiplanar electronic reconstruction modes in CT-scanning of the head by means of two illustrative case reports of midline congenital tumours. (orig.)

  19. 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)

  20. 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

  1. 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.

  2. 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.

  3. 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.)

  4. Selection of colon cancer patients for neoadjuvant chemotherapy by preoperative CT scan

    DEFF Research Database (Denmark)

    Nørgaard, Anne; Dam, Claus; Jakobsen, Anders

    2014-01-01

    invasion (ETI), nodal stage (N-stage), extramural venous invasion (EVI) and the distance from tumor to nearest retroperitoneal fascia (DRF) were retrospectively assessed on the CT scan and compared blindly with the results of the pathological examination, including evaluation of the criteria for adjuvant...

  5. Virtual animation of victim-specific 3D models obtained from CT scans for forensic reconstructions

    DEFF Research Database (Denmark)

    Villa, C; Olsen, K B; Hansen, S H

    2017-01-01

    Post-mortem CT scanning (PMCT) has been introduced at several forensic medical institutions many years ago and has proved to be a useful tool. 3D models of bones, skin, internal organs and bullet paths can rapidly be generated using post-processing software. These 3D models reflect the individual...

  6. 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.

  7. Diffuse cystic peritoneal lymphangiomatosis. Long-term clinical, ultrasonographic and CT scan study in one case

    International Nuclear Information System (INIS)

    Berry, M.; Paillot, B.; Monneins, F.; Delafolie, A.; Guyet-Rousset, P.

    1987-01-01

    An adult male with episodic manifestations of abdominal lymphangiomatosis has been followed up over a 5 year period. This prolonged surveillance of clinical features combined with ultrasound and CT scan imaging has no doubt contributed to improved knowledge of diagnostic and physiopathologic factors of these rare lesions. The particular behavior of the case reported evokes discussion on the conventional surgical treatment of lymphangioma [fr

  8. The profile of CT scan findings in acute head trauma in Orotta ...

    African Journals Online (AJOL)

    The use of investigation modalities are influenced by socioeconomic and cost effectiveness of the tests. Objective and methods: The purpose of the present five months observational study was to describe the profile of cranial computed tomography (CT) scan findings of 110 cases of acute head trauma in Orotta Hospital.

  9. Automatic prostate localization on cone-beam CT scans for high precision image-guided radiotherapy

    NARCIS (Netherlands)

    Smitsmans, Monique H. P.; de Bois, Josien; Sonke, Jan-Jakob; Betgen, Anja; Zijp, Lambert J.; Jaffray, David A.; Lebesque, Joos V.; van Herk, Marcel

    2005-01-01

    PURPOSE: Previously, we developed an automatic three-dimensional gray-value registration (GR) method for fast prostate localization that could be used during online or offline image-guided radiotherapy. The method was tested on conventional computed tomography (CT) scans. In this study, the

  10. Peritoneal Super Scan on 18F - FDG PET-CT in a Patient of Burkitt's Lymphoma.

    Science.gov (United States)

    Roy, Shambo Guha; Parida, Girish Kumar; Tripathy, Sarthak; Singhal, Abhinav; Shamim, Shamim Ahmed; Tripathi, Madhavi

    2017-01-01

    Peritoneal lymphomatosis is seen less frequently, but when seen, it is mostly associated with aggressive variants of malignancies. FDG uptake has been reported in peritoneal lymphomatosis both in DLBCL and Burkitt's lymphoma. We report a case of Burkitt's lymphoma with involvement of entire peritoneum, which looks like a "peritoneal super scan" on FDG PET-CT.

  11. 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

  12. 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.

  13. Dissecting aneurysm of the cervical internal carotid artery. Cervical CT scan findings and treatment - case report

    Energy Technology Data Exchange (ETDEWEB)

    Itoh, Yoshihiro; Itoyama, Youichi; Fukumura, Akinobu; Matsukado, Yasuhiko; Kodama, Takafumi

    1987-06-01

    On lifting a heavy case, a 51-year-old male experienced a sudden onset of headache with giddiness and clouded vision. A week later, vertigo and right hand numbness were added to his symptoms. The next day anisocoria (right > left) and dilation of the left retinal veins were noted. Cranial computed tomography (CT) scan appeared normal and there were no other remarkable neurological findings. The patient was treated conservatively for cerebral infarction, however, the headache worsened and diplopia occurred. Neurological examination on admission revealed nothing unusual except for left Horner's syndrome. Physical examination showed a palpable sausage-like painless tumor on the left side of the neck. Angiography showed a narrowing of the internal carotid artery in the cervical region with a small dissecting aneurysm at the C3 level. Cervical CT scan at the upper C3 level showed a low density lunar defect in the high density section of the enlarged left internal carotid artery. The patient was operated on by superficial temporal artery-middle cerebral artery anastomosis to increase the intracranial blood flow. Postoperatively the symptoms were quickly relieved. Angiography 1 month later showed less narrowing of the carotid artery, though the dissecting aneurysm still remained. Postoperative cervical CT scan showed the left internal carotid artery to be of normal size. The patient returned to his work in normal condition 2 months later. It is emphasized that cervical CT scan may be useful in the diagnosis of this unusual type of cervical dissecting aneurysm.

  14. 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.

  15. Dissecting aneurysm of the cervical internal carotid artery. Cervical CT scan findings and treatment - case report

    Energy Technology Data Exchange (ETDEWEB)

    Itoh, Yoshihiro; Itoyama, Youichi; Fukumura, Akinobu; Matsukado, Yasuhiko; Kodama, Takafumi

    1987-06-01

    On lifting a heavy case, a 51-year-old male experienced a sudden onset of headache with giddiness and clouded vision. A week later, vertigo and right hand numbness were added to his symptoms. The next day anisocoria (right > left) and dilation of the left retinal veins were noted. Cranial computed tomography (CT) scan appeared normal and there were no other remarkable neurological findings. The patient was treated conservatively for cerebral infarction, however, the headache worsened and diplopia occurred. Neurological examination on admission revealed nothing unusual except for left Horner's syndrome. Physical examination showed a palpable sausage-like painless tumor on the left side of the neck. Angiography showed a narrowing of the internal carotid artery in the cervical region with a small dissecting aneurysm at the C3 level. Cervical CT scan at the upper C3 level showed a low density lunar defect in the high density section of the enlarged left internal carotid artery. The patient was operated on by superficial temporal artery-middle cerebral artery anastomosis to increase the intracranial blood flow. Postoperatively the symptoms were quickly relieved. Angiography 1 month later showed less narrowing of the carotid artery, though the dissecting aneurysm still remained. Postoperative cervical CT scan showed the left internal carotid artery to be of normal size. The patient returned to his work in normal condition 2 months later. It is emphasized that cervical CT scan may be useful in the diagnosis of this unusual type of cervical dissecting aneurysm.

  16. Virtual teeth: a 3D method for editing and visualizing small structures in CT scans

    DEFF Research Database (Denmark)

    Bro-Nielsen, Morten; Larsen, Per; Kreiborg, Sven

    1996-01-01

    The paper presents an interactive method for segmentation and visualization of small structures in CT scans. A combination of isosurface generation, spatial region growing and interactive graphics tools are used to extract small structures interactively. A practical example of segmentation of the...

  17. 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)

  18. 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)

  19. 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)

  20. 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.

  1. Transient disappearance of cerebral infarcts on CT scan, the so-called fogging effect

    International Nuclear Information System (INIS)

    Bech Skriver, E.; Skyhoej Olsen, T.; Bispebjerg Hospital, Copenhagen

    1981-01-01

    The fogging effect, whereby initially hypodense infarcts become isodense during the second and third week after the onset of stroke, was investigated in a prospective and consecutive series comprising 50 cases with completed stroke. CT scans were performed approximately 3 days, 10 days and 6 months after stroke. The fogging effect was found in 54% of cases. The hypodense areas reappeared on all scans at 6 months. Cerebral infarcts therefore may be overlooked or grossly underestimated if the scan is performed during the second and third week after stroke. (orig.)

  2. Automatic extraction of forward stroke volume using dynamic PET/CT

    DEFF Research Database (Denmark)

    Harms, Hans; Tolbod, Lars Poulsen; Hansson, Nils Henrik Stubkjær

    2015-01-01

    Background The aim of this study was to develop and validate an automated method for extracting forward stroke volume (FSV) using indicator dilution theory directly from dynamic positron emission tomography (PET) studies for two different tracers and scanners. Methods 35 subjects underwent...... a dynamic 11 C-acetate PET scan on a Siemens Biograph TruePoint-64 PET/CT (scanner I). In addition, 10 subjects underwent both dynamic 15 O-water PET and 11 C-acetate PET scans on a GE Discovery-ST PET/CT (scanner II). The left ventricular (LV)-aortic time-activity curve (TAC) was extracted automatically...... from PET data using cluster analysis. The first-pass peak was isolated by automatic extrapolation of the downslope of the TAC. FSV was calculated as the injected dose divided by the product of heart rate and the area under the curve of the first-pass peak. Gold standard FSV was measured using phase...

  3. 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.)

  4. 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.)

  5. Investigating the role of SPECT/CT in dynamic sentinel lymph node biopsy for penile cancers

    Energy Technology Data Exchange (ETDEWEB)

    Saad, Ziauddin Zia; Bomanji, Jamshed [University College Hospitals London, Department of Nuclear Medicine, London (United Kingdom); UCLH NHS Foundation Trust, Institute of Nuclear Medicine, 5th Floor, London (United Kingdom); Omorphos, Savvas; Malone, Peter; Nigam, Raj; Muneer, Asif [University College Hospitals London, Department of Urology, London (United Kingdom); Michopoulou, Sofia; Gacinovic, Svetislav [University College Hospitals London, Department of Nuclear Medicine, London (United Kingdom)

    2017-07-15

    Currently, most centres use 2-D planar lymphoscintigraphy when performing dynamic sentinel lymph node biopsy in penile cancer patients with clinically impalpable inguinal nodes. This study aimed to investigate the role of SPECT/CT following 2-D planar lymphoscintigraphy (dynamic and static) in the detection and localization of sentinel lymph nodes in the groin. A qualitative (visual) review was performed on planar followed by SPECT/CT lymphoscintigraphy in 115 consecutive patients (age 28-86 years) who underwent injection of {sup 99m}Tc-nanocolloid followed by immediate acquisition of dynamic (20 min) and early static scans (5 min) initially and further delayed static (5 min) images at 120 min followed by SPECT/CT imaging. The lymph nodes detected in each groin on planar lymphoscintigraphy and SPECT/CT were compared. A total of 440 and 467 nodes were identified on planar scintigraphy and SPECT/CT, respectively. Overall, SPECT/CT confirmed the findings of planar imaging in 28/115 cases (24%). In the remaining 87 cases (76%), gross discrepancies were observed between planar and SPECT/CT images. SPECT/CT identified 17 instances of skin contamination (16 patients, 13%) and 36 instances of in-transit lymphatic tract activity (24 patients, 20%) that had been interpreted as tracer-avid lymph nodes on planar imaging. In addition, SPECT/CT identified 53 tracer-avid nodes in 48 patients (42%) that were not visualized on planar imaging and led to reclassification of the drainage basins (pelvic/inguinal) of 27 tracer-avid nodes. The addition of SPECT/CT improved the rate of detection of true tracer-avid lymph nodes and delineated their precise (3-D) anatomic localization in drainage basins. (orig.)

  6. 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)

  7. 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.

  8. 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

  9. Variation compensation and analysis on diaphragm curvature analysis for emphysema quantification on whole lung CT scans

    Science.gov (United States)

    Keller, Brad M.; Reeves, Anthony P.; Barr, R. Graham; Yankelevitz, David F.; Henschke, Claudia I.

    2010-03-01

    CT scans allow for the quantitative evaluation of the anatomical bases of emphysema. Recently, a non-density based geometric measurement of lung diagphragm curvature has been proposed as a method for the quantification of emphysema from CT. This work analyzes variability of diaphragm curvature and evaluates the effectiveness of a compensation methodology for the reduction of this variability as compared to emphysema index. Using a dataset of 43 scan-pairs with less than a 100 day time-interval between scans, we find that the diaphragm curvature had a trend towards lower overall variability over emphysema index (95% CI:-9.7 to + 14.7 vs. -15.8 to +12.0), and that the variation of both measures was reduced after compensation. We conclude that the variation of the new measure can be considered comparable to the established measure and the compensation can reduce the apparent variation of quantitative measures successfully.

  10. Doses from pediatric CT examinations in Norway: are pediatric scan protocols developed and in daily use?

    International Nuclear Information System (INIS)

    Friberg, Eva G.

    2008-01-01

    Doses to pediatric patients from CT examinations are known to be unnecessarily high if scan protocols developed for adult patients are adopted. This overexposure is most often not recognized by the operating radiographer, due to the digital behavior of the imaging system. Use of optimized size-specific pediatric scan protocols is therefore essential to keep the doses at an appropriate level. The aim of this study was to investigate the doses to pediatric patients from CT examinations and to evaluate the level of optimization of the scan protocols. Patient data, applied scan parameters together with the dose parameters volume computed tomography dose index (CTD vol ) and dose length product (DLP) for examinations of the head, chest and abdomen were collected by means of a questionnaire from five university hospitals. The effective dose was estimated from the total DLP by use of region-specific conversion coefficients (E DLP ). Totally 136, 108 and 82 questionnaires were received for examinations of the head, chest and abdomen, respectively. Large variations in patient doses between the hospitals were observed, addressing the need for optimization of the scan protocols in general. Most of the hospitals applied successive lower mAs with decreasing patient age for all scan areas, while the use of lower tube voltage for small patients and a higher tube voltage for large patients were more rarely. This indicates the presence, to a certain level, of size specific scan protocols at some Norwegian hospitals. Focus on developing size-specific scan protocols for pediatric patients are important to reduce the doses and risks associated with pediatric CT examinations. (author)

  11. 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)

  12. 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...

  13. {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.)

  14. 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

  15. 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

  16. Serial CT scans and MRI scans of Tay-Sachs disease

    International Nuclear Information System (INIS)

    Shimoizumi, Hideo; Miyao, Masutomo; Ichihashi, Koh; Sawa, Rituko; Yamamoto, Yoshifumi; Tanaka, Osamu; Yanagisawa, Masayoshi; Kamoshita, Shigehiko.

    1986-01-01

    Serial X-ray CT and MRI were performed on 2 cases of Tay-Sachs disease. Case 1 : a 3-year-10-month-old girl. Her developmental milestones were normal until the age of 6 months. At the age of 10 months, hypotonia and unduly sensitiveness to sounds were noticed. She had cherry red spots in both fundi, and the serum hexosaminidase A activity was low. Significant clinical features during the next 3 years included regression of developmental milestones to the level of one month, and myoclonic and generalised seizures. After 3 years she showed megalencephaly, unstable body temperature, and respiratory disorders. Case 2 : a 2-year-6-month-old boy. His developmental milestones were normal until the age of 5 months. Then he manifested hyperreaction to noises and further developments ceased. He started to deteriorate from the age of 1 year and 2 months, and had no head control at the age of 1 year and 6 months. Cherry red spots were detected and the serum hexsosaminidase A activity was low, too. X-ray CT at the early stage of cases 1 and 2 showed mild cerebral atrophy and high density areas in bilateral thalami and basal ganglia. At the late stage of Case 1, high density areas appeared in occipital and frontal white matters. MRI in both patients were strikingly similar. In their grey matters, linear light areas were demonstrated on IR images. Their white matters showed extensive dark (long T 1 ) areas on IR images, and extensive light (long T 2 ) areas on SE images. Bilateral thalami and basal ganglia were light on IR images and dark on SE images. The findings of MRI in our patients seemed to correlate well with pathological and biochemical changes in their brains. (author)

  17. Comparison of demons deformable registration-based methods for texture analysis of serial thoracic CT scans

    Science.gov (United States)

    Cunliffe, Alexandra R.; Al-Hallaq, Hania A.; Fei, Xianhan M.; Tuohy, Rachel E.; Armato, Samuel G.

    2013-02-01

    To determine how 19 image texture features may be altered by three image registration methods, "normal" baseline and follow-up computed tomography (CT) scans from 27 patients were analyzed. Nineteen texture feature values were calculated in over 1,000 32x32-pixel regions of interest (ROIs) randomly placed in each baseline scan. All three methods used demons registration to map baseline scan ROIs to anatomically matched locations in the corresponding transformed follow-up scan. For the first method, the follow-up scan transformation was subsampled to achieve a voxel size identical to that of the baseline scan. For the second method, the follow-up scan was transformed through affine registration to achieve global alignment with the baseline scan. For the third method, the follow-up scan was directly deformed to the baseline scan using demons deformable registration. Feature values in matched ROIs were compared using Bland- Altman 95% limits of agreement. For each feature, the range spanned by the 95% limits was normalized to the mean feature value to obtain the normalized range of agreement, nRoA. Wilcoxon signed-rank tests were used to compare nRoA values across features for the three methods. Significance for individual tests was adjusted using the Bonferroni method. nRoA was significantly smaller for affine-registered scans than for the resampled scans (p=0.003), indicating lower feature value variability between baseline and follow-up scan ROIs using this method. For both of these methods, however, nRoA was significantly higher than when feature values were calculated directly on demons-deformed followup scans (p<0.001). Across features and methods, nRoA values remained below 26%.

  18. Automatic detection of axillary lymphadenopathy on CT scans of untreated chronic lymphocytic leukemia patients

    Science.gov (United States)

    Liu, Jiamin; Hua, Jeremy; Chellappa, Vivek; Petrick, Nicholas; Sahiner, Berkman; Farooqui, Mohammed; Marti, Gerald; Wiestner, Adrian; Summers, Ronald M.

    2012-03-01

    Patients with chronic lymphocytic leukemia (CLL) have an increased frequency of axillary lymphadenopathy. Pretreatment CT scans can be used to upstage patients at the time of presentation and post-treatment CT scans can reduce the number of complete responses. In the current clinical workflow, the detection and diagnosis of lymph nodes is usually performed manually by examining all slices of CT images, which can be time consuming and highly dependent on the observer's experience. A system for automatic lymph node detection and measurement is desired. We propose a computer aided detection (CAD) system for axillary lymph nodes on CT scans in CLL patients. The lung is first automatically segmented and the patient's body in lung region is extracted to set the search region for lymph nodes. Multi-scale Hessian based blob detection is then applied to detect potential lymph nodes within the search region. Next, the detected potential candidates are segmented by fast level set method. Finally, features are calculated from the segmented candidates and support vector machine (SVM) classification is utilized for false positive reduction. Two blobness features, Frangi's and Li's, are tested and their free-response receiver operating characteristic (FROC) curves are generated to assess system performance. We applied our detection system to 12 patients with 168 axillary lymph nodes measuring greater than 10 mm. All lymph nodes are manually labeled as ground truth. The system achieved sensitivities of 81% and 85% at 2 false positives per patient for Frangi's and Li's blobness, respectively.

  19. 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)

  20. 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)

  1. 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)

  2. 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%.

  3. 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%.

  4. 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.

  5. 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)

  6. 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)

  7. 18F-Fluorodeoxyglucose Positron Emission Tomography/CT Scanning in Diagnosing Vascular Prosthetic Graft Infection

    Science.gov (United States)

    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. 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) scanning has been suggested as an alternative for the diagnosis and assessment of infectious processes. Hybrid 18F-FDG PET/CT has established the role of 18F-FDG PET for the assessment of suspected VPGI, providing accurate anatomic localization of the site of infection. However, there are no clear guidelines for the interpretation of the uptake patterns of 18F-FDG as clinical tool for VPGI. Based on the available literature it is suggested that a linear, diffuse, and homogeneous uptake should not be regarded as an infection whereas focal or heterogeneous uptake with a projection over the vessel on CT is highly suggestive of infection. Nevertheless, 18F-FDG PET and 18F-FDG PET/CT can play an important role in the detection of VPGI and monitoring response to treatment. However an accurate uptake and pattern recognition is warranted and cut-off uptake values and patterns need to be standardized before considering the technique to be the new standard. PMID:25210712

  8. 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).

  9. 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).

  10. 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

  11. 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

  12. Computed tomography automatic exposure control techniques in 18F-FDG oncology PET-CT scanning.

    Science.gov (United States)

    Iball, Gareth R; Tout, Deborah

    2014-04-01

    Computed tomography (CT) automatic exposure control (AEC) systems are now used in all modern PET-CT scanners. A collaborative study was undertaken to compare AEC techniques of the three major PET-CT manufacturers for fluorine-18 fluorodeoxyglucose half-body oncology imaging. An audit of 70 patients was performed for half-body CT scans taken on a GE Discovery 690, Philips Gemini TF and Siemens Biograph mCT (all 64-slice CT). Patient demographic and dose information was recorded and image noise was calculated as the SD of Hounsfield units in the liver. A direct comparison of the AEC systems was made by scanning a Rando phantom on all three systems for a range of AEC settings. The variation in dose and image quality with patient weight was significantly different for all three systems, with the GE system showing the largest variation in dose with weight and Philips the least. Image noise varied with patient weight in Philips and Siemens systems but was constant for all weights in GE. The z-axis mA profiles from the Rando phantom demonstrate that these differences are caused by the nature of the tube current modulation techniques applied. The mA profiles varied considerably according to the AEC settings used. CT AEC techniques from the three manufacturers yield significantly different tube current modulation patterns and hence deliver different doses and levels of image quality across a range of patient weights. Users should be aware of how their system works and of steps that could be taken to optimize imaging protocols.

  13. 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)

  14. Evaluation in the use of bismuth shielding on cervical spine CT scan using a male phantom

    International Nuclear Information System (INIS)

    Aleme, C.; Mourao, A. P.; Lyra, M. A.

    2014-08-01

    The cervical spine is the region of the column that articulates the head and chest. The tests of computed tomography (CT) performed in this region have as main objectives to diagnose fractures, dislocations and tumors. In CT scans the cervical spine volume is limited by the foramen Magnum and the first thoracic vertebra. In this region is the thyroid that is directly irradiated by X-ray beam during cervical scan. Based on this information, it was studied the dose variation deposited in thyroid and in nearby organs, such as: lenses, spinal cord in the foramen Magnum region and breasts, with and without the use of bismuth protector. In this study was used a male anthropomorphic phantom and thermoluminescent s dosimeters (TLD-100) were required to register the individual doses in the organs of interest. CT scans were performed on a GE Bright Speed scanner of 32 channels. With the data obtained, it was found the organ dose variation. The largest recorded dose was in the thyroid. Comparing two scans it was possible to note that the use of the bismuth protector promoted a 26% reduction in the thyroid dose and an increase in the lens dose. (Author)

  15. Evaluation in the use of bismuth shielding on cervical spine CT scan using a male phantom

    Energy Technology Data Exchange (ETDEWEB)

    Aleme, C.; Mourao, A. P. [Centro Federal de Educacion Tecnologica de Minas Gerais, Biomedical Engineering Center, Belo Horizonte - MG (Brazil); Lyra, M. A., E-mail: carolinaaleme@gmail.com [Universidad Federal de Minas Gerais, Department of Nuclear Engineering, Av. Pdte. Antonio Carlos 6627, Pampulha, 31270-91 Belo Horizonte - MG (Brazil)

    2014-08-15

    The cervical spine is the region of the column that articulates the head and chest. The tests of computed tomography (CT) performed in this region have as main objectives to diagnose fractures, dislocations and tumors. In CT scans the cervical spine volume is limited by the foramen Magnum and the first thoracic vertebra. In this region is the thyroid that is directly irradiated by X-ray beam during cervical scan. Based on this information, it was studied the dose variation deposited in thyroid and in nearby organs, such as: lenses, spinal cord in the foramen Magnum region and breasts, with and without the use of bismuth protector. In this study was used a male anthropomorphic phantom and thermoluminescent s dosimeters (TLD-100) were required to register the individual doses in the organs of interest. CT scans were performed on a GE Bright Speed scanner of 32 channels. With the data obtained, it was found the organ dose variation. The largest recorded dose was in the thyroid. Comparing two scans it was possible to note that the use of the bismuth protector promoted a 26% reduction in the thyroid dose and an increase in the lens dose. (Author)

  16. 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)

  17. 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)

  18. 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.)

  19. 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

  20. 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.

  1. 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.)

  2. A study for the correlation of hemorrhagic cerebral infarction with the hemodynamics measured by dynamic CT

    International Nuclear Information System (INIS)

    Shibagaki, Yasuro

    1989-01-01

    In 15 cases of cerebral infarction (9 embolisms, 6 thromboses), dynamic CT scans were repeatedly undertaken during 4 week period of stroke. The ratio of peak height to mean transit time (PH/MTT), which was calculated from density time curve, was used as an index of cerebral blood flow. Hemorrhagic infarction was defined as a high density area with CT value over 50 within low density area. The PH/MTT was significantly increased after the appearance of hemorrhagic infarction. Nine of 10 areas, in which hemorrhagic infarctions were not recognized after recoverry of PH/MTT to over 0.5, did not show hemorrhagic infarctions during 4 week period of stroke. The areas in which hemorrhagic infarctions appeared during 4 week period of stroke had mdore prolonged period of low PH/MTT values than the areas in which hemorrhagic infarctions were not recognized. In conclusion dynamic CT is useful for predicting hemorrhagic infarction. (author)

  3. 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

  4. Patellar subluxation syndrome. Observation of the patellofemoral joint using CT-scan

    Energy Technology Data Exchange (ETDEWEB)

    Yagi, Tomonori; Sasaki, Tetsuto; Susuda, Koichi; Moji, Junichi (Hokkaido Univ., Sapporo (Japan). School of Medicine)

    1983-10-01

    Clinical symptoms of patellar subluxation syndrome associated with pain were investigated for 24 knees of 20 patients, and the state of patella dislocation was observed by CT-scan. The patients had high incidence of an apprehension sign, showing their fear of patellar luxation. Many of them complained of patello-femoral joint pain due to chondromalacia patellae. In order to derive patellar subluxation, the method of CT-Q-contraction was carried out at the extended position of the patellar joint. In patients with patellar subluxation syndrome, the rate of shift in the diseased side was significantly higher than that of the other side, suggesting decreased muscular strength of the musculus vastus of the diseased side. Improvement of the symptoms was seen in all except one of 12 knees operated by the combined method of Green's method with Blauth's more than 6 months before. Availability of this operation was verified by the CT-Q-contraction.

  5. Evaluation of CT-scanning of the temporal bone in the diagnosis of ear diseases

    International Nuclear Information System (INIS)

    Murata, Kiyotaka; Isono, Michio; Nishimae, Tadahide; Tamaki, Katsuhiko; Hosoi, Hiroshi; Ohta, Fumihiko

    1983-01-01

    CT-scanning of 96 temporal bones was carried out to reveal the extension of cholesteatoma, periossicular drainage, fracture lines, enlarged internal acoustic meatus and anomalies of labyrinthine capsules and ossicles. The clinical aspects of CT-scanning of the temporal bone (CTTB) were as follows: 1) Inner ear anomalies were observed in 17 temporal bones of unilateral deafness, high tone loss from unknown origin and fluctuant hearing loss. CTTB may explain the pathology of deafness from unknown origin. 2) Inner ear anomalies may be classified into more detailed groups than before. 3) The extension of cholesteatoma, localization and size of labyrinthine fistula can be estimated prior to surgery. 4) Cholesteatoma in a mastoidectomy cavity may be detected. 5) The malleus and incus may be visualized, although the stapes can hardly be found. 6) Fracture lines of a temporal bone, destruction of the internal acoustic meatus may be clearly detected. (author)

  6. The study on fatty infiltration of the liver with the use of CT scan

    International Nuclear Information System (INIS)

    Yamawaki, Tadaharu; Hirofuji, Hideo; Yatomi, Akira; Kawabe, Masami; Sugie, Hajime

    1981-01-01

    On the basis of experience thus far, it is said that the diagnosis of fatty liver is comparatively difficult. It has been reported that the diagnosis of fatty liver can be done by its decreased attenuation number on CT scan among diffuse liver diseases. We investigated 80 cases of which attenuation number revealed below 35 Hn (Hounsfield units). Analysis of correlations between eight variables (T. Cholesterol, β-lipoprotein, Triglyceride, HDL Cholesterol, Cholinesterase, Obsity index, BSP and the degree of fatty infiltration of the liver specimen) and mean attenuation number of the liver were investigated and highly significant correlation was found only between the degree of fatty infiltration of the liver and the mean attenuation number of the liver (r = -0.746, p < 0.01). Therefore, it is concluded that CT scan is an epochmaking morphological examination of fatty liver. (author)

  7. 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.)

  8. 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.)

  9. 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.)

  10. 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.

  11. 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.

  12. Neurolymphomatosis detected by 18F-FDG PET/CT scan - a case report

    International Nuclear Information System (INIS)

    Czepczynski, R.; Guzikowska-Ruszkowska, I.; Sowinski, J.

    2008-01-01

    Lymphoma involvement of the peripheral nerves is a rare clinical presentation of non-Hodgkin lymphoma. We report the case of a 59-year-old woman with the defect of peripheral motor neuron admitted for PET/CT scan. The scan disclosed increased 18 F-FDG activity along the brachial and lumbar plexuses together with very intense 18 F-FDG uptake in the cervical lymph node masses. The diagnosis, based on the subsequent histopathologic lymph node examination, was diffuse large B-cell lymphoma. (authors)

  13. Automatic extraction of forward stroke volume using dynamic PET/CT

    DEFF Research Database (Denmark)

    Harms, Hans; Tolbod, Lars Poulsen; Hansson, Nils Henrik

    Background: Dynamic PET can be used to extract forward stroke volume (FSV) by the indicator dilution principle. The technique employed can be automated and is in theory independent on the tracer used and may therefore be added to any dynamic cardiac PET protocol. The aim of this study...... was to validate automated methods for extracting FSV directly from dynamic PET studies for two different tracers and to examine potential scanner hardware bias. Methods: 21 subjects underwent a dynamic 27 min 11C-acetate PET scan on a Siemens Biograph TruePoint 64 PET/CT scanner (scanner I). In addition, 8...... subjects underwent a dynamic 6 min 15O-water PET scan followed by a 27 min 11C-acetate PET scan on a GE Discovery ST PET/CT scanner (scanner II). The LV-aortic time-activity curve (TAC) was extracted automatically from dynamic PET data using cluster analysis. The first-pass peak was isolated by automatic...

  14. 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.

  15. Optical CT imaging of solid radiochromic dosimeters in mismatched refractive index solutions using a scanning laser and large area detector

    Energy Technology Data Exchange (ETDEWEB)

    Dekker, Kurtis H., E-mail: kdekker2@uwo.ca [Department of Medical Biophysics, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, Ontario N6A 5C1 (Canada); Battista, Jerry J.; Jordan, Kevin J. [Departments of Medical Biophysics and Oncology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, Ontario N6A 5C1, Canada and Department of Physics and Engineering, London Regional Cancer Program, London Health Sciences Centre, 790 Commissioners Road East, London, Ontario N6A 4L6 (Canada)

    2016-08-15

    Purpose: The practical use of the PRESAGE® solid plastic dosimeter is limited by the inconvenience of immersing it in high-viscosity oils to achieve refractive index matching for optical computed tomography (CT) scanning. The oils are slow to mix and difficult to clean from surfaces, and the dosimeter rotation can generate dynamic Schlieren inhomogeneity patterns in the reference liquid, limiting the rotational and overall scan speed. Therefore, it would be beneficial if lower-viscosity, water-based solutions with slightly unmatched refractive index could be used instead. The purpose of this work is to demonstrate the feasibility of allowing mismatched conditions when using a scanning laser system with a large acceptance angle detector. A fiducial-based ray path measurement technique is combined with an iterative CT reconstruction algorithm to reconstruct images. Methods: A water based surrounding liquid with a low viscosity was selected for imaging PRESAGE® solid dosimeters. Liquid selection was optimized to achieve as high a refractive index as possible while avoiding rotation-induced Schlieren effects. This led to a refractive index mismatch of 6% between liquid and dosimeters. Optical CT scans were performed with a fan-beam scanning-laser optical CT system with a large area detector to capture most of the refracted rays. A fiducial marker placed on the wall of a cylindrical sample occludes a given light ray twice. With knowledge of the rotation angle and the radius of the cylindrical object, the actual internal path of each ray through the dosimeter can be calculated. Scans were performed with 1024 projections of 512 data samples each, and rays were rebinned to form 512 parallel-beam projections. Reconstructions were performed on a 512 × 512 grid using 100 iterations of the SIRT iterative CT algorithm. Proof of concept was demonstrated with a uniformly attenuating solution phantom. PRESAGE® dosimeters (11 cm diameter) were irradiated with Cobalt-60

  16. Automatic prostate localization on cone-beam CT scans for high precision image-guided radiotherapy

    International Nuclear Information System (INIS)

    Smitsmans, Monique H.P.; Bois, Josien de; Sonke, Jan-Jakob; Betgen, Anja; Zijp, Lambert J.; Jaffray, David A.; Lebesque, Joos V.; Herk, Marcel van

    2005-01-01

    Purpose: Previously, we developed an automatic three-dimensional gray-value registration (GR) method for fast prostate localization that could be used during online or offline image-guided radiotherapy. The method was tested on conventional computed tomography (CT) scans. In this study, the performance of the algorithm to localize the prostate on cone-beam CT (CBCT) scans acquired on the treatment machine was evaluated. Methods and Materials: Five to 17 CBCT scans of 32 prostate cancer patients (332 scans in total) were used. For 18 patients (190 CBCT scans), the CBCT scans were acquired with a collimated field of view (FOV) (craniocaudal). This procedure improved the image quality considerably. The prostate (i.e., prostate plus seminal vesicles) in each CBCT scan was registered to the prostate in the planning CT scan by automatic 3D gray-value registration (normal GR) starting from a registration on the bony anatomy. When these failed, registrations were repeated with a fixed rotation point locked at the prostate apex (fixed apex GR). Registrations were visually assessed in 3D by one observer with the help of an expansion (by 3.6 mm) of the delineated prostate contours of the planning CT scan. The percentage of successfully registered cases was determined from the combined normal and fixed apex GR assessment results. The error in gray-value registration for both registration methods was determined from the position of one clearly defined calcification in the prostate gland (9 patients, 71 successful registrations). Results: The percentage of successfully registered CBCT scans that were acquired with a collimated FOV was about 10% higher than for CBCT scans that were acquired with an uncollimated FOV. For CBCT scans that were acquired with a collimated FOV, the percentage of successfully registered cases improved from 65%, when only normal GR was applied, to 83% when the results of normal and fixed apex GR were combined. Gray-value registration mainly failed (or

  17. 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.

  18. 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.

  19. Renal Tumor Cryoablation Planning. The Efficiency of Simulation on Reconstructed 3D CT Scan

    Directory of Open Access Journals (Sweden)

    Ciprian Valerian LUCAN

    2010-12-01

    Full Text Available Introduction & Objective: Nephron-sparing surgical techniques risks are related to tumor relationships with adjacent anatomic structures. Complexity of the renal anatomy drives the interest to develop tools for 3D reconstruction and surgery simulation. The aim of the article was to assess the simulation on reconstructed 3D CT scan used for planning the cryoablation. Material & Method: A prospective randomized study was performed between Jan. 2007 and July 2009 on 27 patients who underwent retroperitoneoscopic T1a renal tumors cryoablation (RC. All patients were assessed preoperatively by CT scan, also used for 3D volume rendering. In the Gr.A, the patients underwent surgery planning by simulation on 3D CT scan. In the Gr.B., patients underwent standard RC. The two groups were compared in terms of surgical time, bleeding, postoperative drainage, analgesics requirement, hospital stay, time to socio-professional reintegration. Results: Fourteen patients underwent preoperative cryoablation planning (Gr.A and 13 patients underwent standard CR (Gr.B. All parameters analyzed were shorter in the Gr.A. On multivariate logistic regression, only shortens of the surgical time (138.79±5.51 min. in Gr.A. vs. 140.92±5.54 min in Gr.B. and bleeding (164.29±60.22 mL in Gr.A. vs. 215.38±100.80 mL in Gr.B. achieved statistical significance (p<0.05. The number of cryoneedles assessed by simulation had a 92.52% accuracy when compared with those effectively used. Conclusions: Simulation of the cryoablation using reconstructed 3D CT scan improves the surgical results. The application used for simulation was able to accurately assess the number of cryoneedles required for tumor ablation, their direction and approach.

  20. Atlantoaxial Ankylosis Detected on Neck CT Scans in a Patient with Ankylosing Spondylitis: A Case Report

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jeong Ah; Lee, Seung Hun; Joo, Kyung Bin [Dept. of Radiology, Seoul Hospital, Hanyang University College of Medicine, Seoul (Korea, Republic of); Ryu, Jeong Ah [Dept. of Radiology, Guri Hospital, Hanyang University College of Medicine, Guri (Korea, Republic of); Kim, Tae Hwan [Dept. of Rheynmatology, Seoul Hospital, Hanyang University College of Medicine, Seoul (Korea, Republic of)

    2011-07-15

    Ankylosing spondylitis is a chronic inflammatory disorder of unknown cause that principally affects the axial skeleton. The cervical spine is also vulnerable to this disease process and the characteristic feature of cervical involvement is atlantoaxial subluxation. However, only a few cases of atlantoaxial ankylosis have been reported to date. We report a case of atlantoaxial ankylosis in a patient with ankylosing spondylitis with radiologic findings incidentally detected on neck CT scans.

  1. Atlantoaxial Ankylosis Detected on Neck CT Scans in a Patient with Ankylosing Spondylitis: A Case Report

    International Nuclear Information System (INIS)

    Lee, Jeong Ah; Lee, Seung Hun; Joo, Kyung Bin; Ryu, Jeong Ah; Kim, Tae Hwan

    2011-01-01

    Ankylosing spondylitis is a chronic inflammatory disorder of unknown cause that principally affects the axial skeleton. The cervical spine is also vulnerable to this disease process and the characteristic feature of cervical involvement is atlantoaxial subluxation. However, only a few cases of atlantoaxial ankylosis have been reported to date. We report a case of atlantoaxial ankylosis in a patient with ankylosing spondylitis with radiologic findings incidentally detected on neck CT scans.

  2. Diagnosis of hearing impairment by high resolution CT scanning of inner ear anomalies

    International Nuclear Information System (INIS)

    Murata, Kiyotaka; Isono, Michio; Ohta, Fumihiko

    1988-01-01

    High resolution CT scanning of the temporal bone in our clinic has provided a more detailed radiological classification of inner ear anomalies than before. The statistical analysis of inner ear malformations based on the theory of quantification II has produced discriminant equations for the measurable diagnosis of hearing impairment and development of the inner ear. This analysis may make it possible to diagnose total and partial deafness on ipsi- and contralateral sides. (author)

  3. A case of retrocaval ureter diagnosed by CT scan combined with a ureteral catheter

    International Nuclear Information System (INIS)

    Matsumoto, Atsushi; Iio, Shozo; Toyama, Takashi; Mochizuki, Teruichi

    1986-01-01

    The patient was a 45-year-old male who was admitted for right flank pain, nausea and vomitting. IVP revealed right hydronephrosis and hydroureter with medial distortion at the level of the 3rd lumbar spine. The diagnosis of retrocaval ureter was made with CT scan combined with a ureteral catheter. End to end anastomosis after resection of the retrocaval segment was performed. IVP 21 days after the operation showed that the right hydroureteronephrosis had moderately improved. (author)

  4. 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.

  5. 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.

  6. Classification of pulmonary emphysema from chest CT scans using integral geometry descriptors

    Science.gov (United States)

    van Rikxoort, E. M.; Goldin, J. G.; Galperin-Aizenberg, M.; Brown, M. S.

    2011-03-01

    To gain insight into the underlying pathways of emphysema and monitor the effect of treatment, methods to quantify and phenotype the different types of emphysema from chest CT scans are of crucial importance. Current standard measures rely on density thresholds for individual voxels, which is influenced by inspiration level and does not take into account the spatial relationship between voxels. Measures based on texture analysis do take the interrelation between voxels into account and therefore might be useful for distinguishing different types of emphysema. In this study, we propose to use Minkowski functionals combined with rotation invariant Gaussian features to distinguish between healthy and emphysematous tissue and classify three different types of emphysema. Minkowski functionals characterize binary images in terms of geometry and topology. In 3D, four Minkowski functionals are defined. By varying the threshold and size of neighborhood around a voxel, a set of Minkowski functionals can be defined for each voxel. Ten chest CT scans with 1810 annotated regions were used to train the method. A set of 108 features was calculated for each training sample from which 10 features were selected to be most informative. A linear discriminant classifier was trained to classify each voxel in the lungs into a subtype of emphysema or normal lung. The method was applied to an independent test set of 30 chest CT scans with varying amounts and types of emphysema with 4347 annotated regions of interest. The method is shown to perform well, with an overall accuracy of 95%.

  7. 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)

  8. Differentiation between eclampsia and cerebrovascular disorders by brain CT scan in pregnant patients with convulsive seizures

    International Nuclear Information System (INIS)

    Eguchi, Katsuto; Lin, Yaw-Tyng; Noda, Kiyofumi; Saeki, Kazuhiko; Yonezawa, Masaru; Sekiba, Kaoru; Ochiai, Youji

    1987-01-01

    Six pregnant women with convulsions between 25 to 40 weeks of gestation were experienced. Among them, 4 patients were diagnosed as having intracranial hemorrhage and two as simple eclampsia. With the aid of brain CT scan, one case of arteriovenous malformation was detected and treated surgically with good prognosis for both the mother and the fetus. Two patients were diagnosed to have cerebral hemorrhage with subsequent penetration into the lateral ventricles and were treated conservatively. Their fetuses were delivered alive by cesarean section, but the mothers expired. The other patient with cerebral hemorrhage was treated surgically, and both the mother and the fetus survived. One of the simple eclampsia patients was noted to have a growth retarded fetus at 32 weeks of pregnancy with subsequent intra-uterine death, but the mother recovered after conservative treatment. Another patient at 40 weeks of pregnancy was also treated conservatively and both the fetus and the mother survived. Brain CT scan findings differed between these two eclampsia patients; local brain edema for the second patient and generalized brain edema for the first patient. Thus more active application of brain CT scan is recommended in managing pregnant patients with convulsions. (author)

  9. 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)

  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. The effects of misinterpretation of an artefact on multidetector row CT scans in children

    Energy Technology Data Exchange (ETDEWEB)

    Du Plessis, Anne-Marie; Theron, Salomine; Andronikou, Savvas [University of Stellenbosch, Radiology Department, Tygerberg Hospital, Cape Town (South Africa)

    2009-02-15

    Artefacts reflect problems with radiographic technique rather than true pathology. These may be misinterpreted as pathology with serious consequences. An artefact caused such problems in one paediatric imaging department. To determine the incidence, and consequences of misinterpretation, of a CT artefact in a paediatric imaging department. A retrospective review of images and reports of paediatric CT scans over a set period with a known artefact was performed. Reports were correlated with reviewers' evaluation of the presence of artefact and reviewed for correct identification of artefact, misinterpretation as pathology, and action taken as a result. A total of 74 CT scans had been performed over the study period and an artefact detected by reviewers on 32 (43%). Six (18.75%) of these were misinterpreted as pathology, of which three (9.4%) were reported as tuberculous granulomas, two (6.2%) as haemorrhages and one (3.1%) as an unknown hyperdensity. Two patients (6.2%) had subsequent MRI studies performed, and treatment for tuberculosis was continued in one patient (3.1%). No initial report identified the artefact. One-fifth of the scans with the artefact were misinterpreted as pathology and half of these misinterpretations led to further action. Artefacts result in false diagnoses and unnecessary investigations; vigilance is needed. (orig.)

  12. 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)

  13. The diagnostic value of CT scan and selective venous sampling in Cushing's syndrome

    International Nuclear Information System (INIS)

    Negoro, Makoto; Kuwayama, Akio; Yamamoto, Naoto; Nakane, Toshichi; Yokoe, Toshio; Kageyama, Naoki; Ichihara, Kaoru; Ishiguchi, Tsuneo; Sakuma, Sadayuki

    1986-01-01

    We studied 24 patients with Cushing's syndrome in order to find the best way to confirm the pituitary adenoma preoperatively. At first, the sellar content was studied by means of a high-resolution CT scan in each patient. Second, by selective catheterization in the bilateral internal jugular vein and the inferior petrosal sinus, venous samples (c) were obtained for ACTH assay. Simultaneously, peripheral blood sampling (P) was made at the anterior cubital vein for the same purpose, and the C/P ratio was carefully calculated in each patient. If the C/P ratio exceeded 2, it was highly suggestive of the presence of pituitary adenoma. Even by an advanced high-resolution CT scan with a thickness of 2 mm, pituitary adenomas were detected in only 32 % of the patients studied. The result of image diagnosis in Cushing disease was discouraging. As for the chemical diagnosis, the results were as follows. At the early stage of this study, the catheterization was terminated in the jugular veins of nine patients. Among these, in five patients the presence of pituitary adenoma was predicted correctly in the preoperative stage. Later, by means of inferior petrosal sinus samplings, pituitary microadenomas were detected in ten patients among the twelve. Selective venous sampling for ACTH in the inferior petrosal sinus or jugular vein proved to be useful for the differential diagnosis of Cushing's syndrome when other diagnostic measures such as CT scan were inconclusive. (author)

  14. Pedicle measurement of the thoracolumbar spine: a cadaveric, radiographic, and CT scan study in Filipinos

    International Nuclear Information System (INIS)

    Molano, A.M.V.; Sison, A.B.; Fong, H.C.; Lim, N.T.; Sabile, K.

    1994-01-01

    With the popular usage of spinal pedicular screw fixation, it is essential to have a knowledge of the morphometry of the pedicles of the spine of particular populations. This study compared the direct pedicle measurements of ten cadavers in an institution, with their respective radiographic and computerized tomographic (CT) scan values, and also compared the effective pedicle diameter (EPD) with the conventional outer pedicle diameter (OPD) measurements. A compilation of pedicle values was also made in X-ray and CT scan plates of a Filipino population. A statistical analysis made on the 2,760 pedicle measurements taken from cadaveric T6-L5 vertebrae showed that direct measurements were significantly different from X-ray and CT scan values. The mean values of the EPD differed from those of the OPD, but not statistically significant. Comparison with previous foreign studies revealed significant differences in these pedicle dimensions. Pedicle measurements in a living Filipino population were found to be significantly different statistically between sexes. Accurate measurement of the pedicle diameters and lengths are indeed critical for the success of a spinal stabilization procedure using pedicular screws. (author). 8 refs.; 5 figs.; 1 tab

  15. Differentiation between eclampsia and cerebrovascular disorders by brain CT scan in pregnant patients with convulsive seizures

    Energy Technology Data Exchange (ETDEWEB)

    Eguchi, Katsuto; Lin, Yaw-Tyng; Noda, Kiyofumi; Saeki, Kazuhiko; Yonezawa, Masaru; Sekiba, Kaoru; Ochiai, Youji

    1987-06-01

    Six pregnant women with convulsions between 25 to 40 weeks of gestation were experienced. Among them, 4 patients were diagnosed as having intracranial hemorrhage and two as simple eclampsia. With the aid of brain CT scan, one case of arteriovenous malformation was detected and treated surgically with good prognosis for both the mother and the fetus. Two patients were diagnosed to have cerebral hemorrhage with subsequent penetration into the lateral ventricles and were treated conservatively. Their fetuses were delivered alive by cesarean section, but the mothers expired. The other patient with cerebral hemorrhage was treated surgically, and both the mother and the fetus survived. One of the simple eclampsia patients was noted to have a growth retarded fetus at 32 weeks of pregnancy with subsequent intra-uterine death, but the mother recovered after conservative treatment. Another patient at 40 weeks of pregnancy was also treated conservatively and both the fetus and the mother survived. Brain CT scan findings differed between these two eclampsia patients; local brain edema for the second patient and generalized brain edema for the first patient. Thus more active application of brain CT scan is recommended in managing pregnant patients with convulsions.

  16. TIPS bilateral noise reduction in 4D CT perfusion scans produces high-quality cerebral blood flow maps

    NARCIS (Netherlands)

    A. Mendrik (Adrienne); E.J.P.A. Vonken; B.T.J. van Ginneken (Berbke); J.R. Riordan (John ); H.W.A.M. de Jong (Hugo); T. van Seeters (Tom); E.J. Smit (Ewoud); M.A. Viergever (Max); M. Prokop (Mathias)

    2011-01-01

    textabstractCerebral computed tomography perfusion (CTP) scans are acquired to detect areas of abnormal perfusion in patients with cerebrovascular diseases. These 4D CTP scans consist of multiple sequential 3D CT scans over time. Therefore, to reduce radiation exposure to the patient, the amount of

  17. 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

  18. 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.

  19. 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

  20. 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

  1. Radiation dosimetry assessment of routine CT scanning protocols used in Western Australia

    International Nuclear Information System (INIS)

    Moorin, Rachael E; Forsyth, Rene; Gibson, David J; Fox, Richard

    2013-01-01

    Technical data on local CT practice in Western Australia were collected for five major CT providers using a self-completed questionnaire. The CTDIvol DLP and effective dose for each protocol were obtained and providers were ranked according to radiation burden for each clinical scenario. The mean, median, 75th percentile and standard deviation were calculated for both effective dose and DLP for each scenario and these values were compared with published data. CT utilisation data were used to estimate the attributable radiation dose to the WA population and the potential change in population annual effective dose according to the protocol used was estimated. We found that wide variations in technique and radiation dose exist across providers for similar examinations, producing a higher radiation burden than reported internationally. As expected, the CT protocol used dramatically affects the radiation dose received, and this has a significant effect on annual population dose. This study highlights the need for recognition and understanding of both the degree of variation in radiation dose across providers and the relatively high radiation burden afforded by protocols in use in Western Australia so that necessary dialogue can be launched for practitioner consensus on appropriate diagnostic reference levels in CT scanning. (paper)

  2. 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

  3. 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

  4. 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.)

  5. A method for the reconstruction of four-dimensional synchronized CT scans acquired during free breathing

    International Nuclear Information System (INIS)

    Low, Daniel A.; Nystrom, Michelle; Kalinin, Eugene; Parikh, Parag; Dempsey, James F.; Bradley, Jeffrey D.; Mutic, Sasa; Wahab, Sasha H.; Islam, Tareque; Christensen, Gary; Politte, David G.; Whiting, Bruce R.

    2003-01-01

    Breathing motion is a significant source of error in radiotherapy treatment planning for the thorax and upper abdomen. Accounting for breathing motion has a profound effect on the size of conformal radiation portals employed in these sites. Breathing motion also causes artifacts and distortions in treatment planning computed tomography (CT) scans acquired during free breathing and also causes a breakdown of the assumption of the superposition of radiation portals in intensity-modulated radiation therapy, possibly leading to significant dose delivery errors. Proposed voluntary and involuntary breath-hold techniques have the potential for reducing or eliminating the effects of breathing motion, however, they are limited in practice, by the fact that many lung cancer patients cannot tolerate holding their breath. We present an alternative solution to accounting for breathing motion in radiotherapy treatment planning, where multislice CT scans are collected simultaneously with digital spirometry over many free breathing cycles to create a four-dimensional (4-D) image set, where tidal lung volume is the additional dimension. An analysis of this 4-D data leads to methods for digital-spirometry, based elimination or accounting of breathing motion artifacts in radiotherapy treatment planning for free breathing patients. The 4-D image set is generated by sorting free-breathing multislice CT scans according to user-defined tidal-volume bins. A multislice CT scanner is operated in the cine mode, acquiring 15 scans per couch position, while the patient undergoes simultaneous digital-spirometry measurements. The spirometry is used to retrospectively sort the CT scans by their correlated tidal lung volume within the patient's normal breathing cycle. This method has been prototyped using data from three lung cancer patients. The actual tidal lung volumes agreed with the specified bin volumes within standard deviations ranging between 22 and 33 cm 3 . An analysis of sagittal and

  6. Repeat CT-scan assessment of lymph node motion in locally advanced cervical cancer patients

    Energy Technology Data Exchange (ETDEWEB)

    Bondar, Luiza; Velema, Laura; Mens, Jan Willem; Heijmen, Ben; Hoogeman, Mischa [Erasmus Medical Center Cancer Institute, Department of Radiation Oncology, 3008 AE, Rotterdam (Netherlands); Zwijnenburg, Ellen [Radboud University Medical Center, Department of Radiation Oncology, Nijmegen (Netherlands)

    2014-12-15

    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 < 0.001). The motion of the nodal-vessels was large, nonrigid, patient-specific, and only moderately synchronous with the bony anatomy. This study highlights the need for caution when reducing the CTV-to-PTV (PTV planning target volume) margin of the nodal CTV for highly conformal radiation techniques. (orig.) [German] Bei Zervixkarzinompatientinnen wird davon ausgegangen, dass das nodale klinische Zielvolumen (CTV, definiert anhand der grossen Blutgefaesse des Beckens und vergroesserter Lymphknoten) sich synchron mit

  7. 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.

  8. The role of spiral CT in patients with intermediate probability V/Q scans: can spiral CT replace pulmonary angiography?

    International Nuclear Information System (INIS)

    Vu, T.; Glenn, D.; Lovett, I.; Moses, J.; Wadhwa, S.S.; Nour, R.

    2000-01-01

    Full text: Spiral CT (SCT) has been advocated as a replacement for pulmonary angiography (PA)in patients with intermediate probability (IP) ventilation-perfusion lung scans (V/Q). More generally it has been proposed as a replacement for V/Q to detect Pulmonary Embolism. This study investigates the accuracy of SCT in the IP patient group 31 patients with IP scans (Modified PIOPED criteria) who were not at high risk of contrast nephrotoxicity were enrolled to have both SCT and PA within the 24 hours following their V/Q. Patients were classified as IP due to a single segmental mismatch (n=7) or a matched V/Q abnormality corresponding to CXR opacity (n=21), or both (n=3). PA is the gold standard for the detection of PE. SCT was read by an experienced radiologist blinded to the PA results. SCT was performed according to standard protocol. All SCT were technically satisfactory for interpretation. Pulmonary embolism was present in 9/31 patients (29%). Of the patients with PE detected by PA, SCT was positive in 4 (44% sensitivity). Of the 22 patients who did not have PE, SCT was negative in 21 and positive in one (96% specificity). In conclusion SCT has limited sensitivity for the detection of PE in patients with IP lung scans. SCT may not be an adequate replacement for PA. Copyright (2000) The Australian and New Zealand Society of Nuclear Medicine Inc

  9. Cardiac MR imaging: Comparison with echocardiography and dynamic CT

    International Nuclear Information System (INIS)

    Colletti, P.M.; Norris, S.; Raval, J.; Boswell, W.; Lee, K.; Ralls, P.; Haywood, J.; Halls, J.

    1986-01-01

    The authors compared gated cardiac MR imaging with two-dimensional and Doppler echocardiography and dynamic CT. Gated cardiac MR imaging (VISTA unit, 0.5 T) was performed in 55 patients with a variety of conditions. Accuracy of diagnosis was compared. CT showed arterial, valvular, and pericardial calcifications not seen on MR imaging. Many lesions were seen as well on CT as on MR imaging. Two-dimensional echocardiography was superior in demonstrating wall motion and valvular disease. MR imaging was superior in demonstrating myocardial structures

  10. Pulmonary nodule registration in serial CT scans based on rib anatomy and nodule template matching

    International Nuclear Information System (INIS)

    Shi Jiazheng; Sahiner, Berkman; Chan, H.-P.; Hadjiiski, Lubomir; Zhou, C.; Cascade, Philip N.; Bogot, Naama; Kazerooni, Ella A.; Wu, Y.-T.; Wei, J.

    2007-01-01

    An automated method is being developed in order to identify corresponding nodules in serial thoracic CT scans for interval change analysis. The method uses the rib centerlines as the reference for initial nodule registration. A spatially adaptive rib segmentation method first locates the regions where the ribs join the spine, which define the starting locations for rib tracking. Each rib is tracked and locally segmented by expectation-maximization. The ribs are automatically labeled, and the centerlines are estimated using skeletonization. For a given nodule in the source scan, the closest three ribs are identified. A three-dimensional (3D) rigid affine transformation guided by simplex optimization aligns the centerlines of each of the three rib pairs in the source and target CT volumes. Automatically defined control points along the centerlines of the three ribs in the source scan and the registered ribs in the target scan are used to guide an initial registration using a second 3D rigid affine transformation. A search volume of interest (VOI) is then located in the target scan. Nodule candidate locations within the search VOI are identified as regions with high Hessian responses. The initial registration is refined by searching for the maximum cross-correlation between the nodule template from the source scan and the candidate locations. The method was evaluated on 48 CT scans from 20 patients. Experienced radiologists identified 101 pairs of corresponding nodules. Three metrics were used for performance evaluation. The first metric was the Euclidean distance between the nodule centers identified by the radiologist and the computer registration, the second metric was a volume overlap measure between the nodule VOIs identified by the radiologist and the computer registration, and the third metric was the hit rate, which measures the fraction of nodules whose centroid computed by the computer registration in the target scan falls within the VOI identified by the

  11. Clinical study on left atrial thrombi. Comparative study between echocardiography and CT scan

    Energy Technology Data Exchange (ETDEWEB)

    Shimada, E; Asano, H; Kurasawa, T; Mitsumoto, K; Yamane, Y [Tokyo Kosei-Nenkin Hospital (Japan)

    1981-09-01

    We studied left atrial thrombi (LAT) by both echocardiography and computed tomography (CT) and compared the features of the 2 methods. A total of 15 patients with mitral stenosis complicated by atrial fibrillation were selected as the subjects. LAT were noted on the M-mode echocardiograms in 2 patients including a questionably positive one, on the two-dimensional echocardiograms in 5, and on the CT scans in 6 of 15. The history of thromboembolism was rather frequent and was found in 7 of 15 patients. However, LAT was found in only 3 of these on the CT scans. A shaggy or fuzzy pattern on the M-mode echocardiogram cannot be regarded as representing thrombi, while a laminar pattern undoubtedly represented thrombi. Two-dimensional echocardiography has considerably contributed to the improved detection rate of LAT. For the characteristic properties of ultrasound beams, however, it was impossible to investigate the entire left atrium. The detection of the thrombi in the appendage was especially difficult. However, computed tomography, permitting transverse cross-sectional tomography, was capable of sectioning the heart even in the presence of air and bones. The measurement of CT values was suggestive of the properties of the substance or substances involved, and also allowed the presumption as to whether the thrombus has been fibrosed. Furthermore, it was possible to estimate more accurately as well as 3-dimensionally the location, shape and dimensions of the thrombi by the reconstruction of the heart according to the CT values. It was concluded that echocardiography and computed tomography are the mutual aid to further improvement in the detection rate of left atrial thrombi.

  12. A measurement-based generalized source model for Monte Carlo dose simulations of CT scans.

    Science.gov (United States)

    Ming, Xin; Feng, Yuanming; Liu, Ransheng; Yang, Chengwen; Zhou, Li; Zhai, Hezheng; Deng, Jun

    2017-03-07

    The goal of this study is to develop a generalized source model for accurate Monte Carlo dose simulations of CT scans based solely on the measurement data without a priori knowledge of scanner specifications. The proposed generalized source model consists of an extended circular source located at x-ray target level with its energy spectrum, source distribution and fluence distribution derived from a set of measurement data conveniently available in the clinic. Specifically, the central axis percent depth dose (PDD) curves measured in water and the cone output factors measured in air were used to derive the energy spectrum and the source distribution respectively with a Levenberg-Marquardt algorithm. The in-air film measurement of fan-beam dose profiles at fixed gantry was back-projected to generate the fluence distribution of the source model. A benchmarked Monte Carlo user code was used to simulate the dose distributions in water with the developed source model as beam input. The feasibility and accuracy of the proposed source model was tested on a GE LightSpeed and a Philips Brilliance Big Bore multi-detector CT (MDCT) scanners available in our clinic. In general, the Monte Carlo simulations of the PDDs in water and dose profiles along lateral and longitudinal directions agreed with the measurements within 4%/1 mm for both CT scanners. The absolute dose comparison using two CTDI phantoms (16 cm and 32 cm in diameters) indicated a better than 5% agreement between the Monte Carlo-simulated and the ion chamber-measured doses at a variety of locations for the two scanners. Overall, this study demonstrated that a generalized source model can be constructed based only on a set of measurement data and used for accurate Monte Carlo dose simulations of patients' CT scans, which would facilitate patient-specific CT organ dose estimation and cancer risk management in the diagnostic and therapeutic radiology.

  13. Quantitative CT scans of lung parenchymal pathology in premature infants ages 0-6 years.

    Science.gov (United States)

    Spielberg, David R; Walkup, Laura L; Stein, Jill M; Crotty, Eric J; Rattan, Mantosh S; Hossain, Md Monir; Brody, Alan S; Woods, Jason C

    2018-03-01

    Bronchopulmonary dysplasia (BPD) is a common, heterogeneous disease in premature infants. We hypothesized that quantitative CT techniques could assess lung parenchymal heterogeneity in BPD patients across a broad age range and demonstrate how pathologies change over time. A cross-sectional, retrospective study of children age 0-6 years with non-contrast chest CT scans was conducted. BPD subjects met NICHD/NHLBI diagnostic criteria for BPD and were excluded for congenital lung/airway abnormalities or other known/suspected pulmonary diagnoses; control subjects were not premature and had normal CT scan findings. Radiologic opacities, lucencies, and spatial heterogeneity were quantified via: 1) thresholding using CT-attenuation (HU); 2) manual segmentation; and 3) Ochiai reader-scoring system. Clinical outcomes included BPD severity by NICHD/NHLBI criteria, respiratory support at NICU discharge, wheezing, and respiratory exacerbations. Heterogeneity (standard deviation) of lung attenuation in BPD was significantly greater than in controls (difference 36.4 HU [26.1-46.7 HU], P < 0.001); the difference between the groups decreased 0.58 HU per month of age (0.08-1.07 HU per month, P = 0.02). BPD patients had greater amounts of opacities and lucencies than controls except with automated quantification of lucencies. Cross-sectionally, lucencies per Ochiai score and opacities per manual segmentation decreased with time. No approach measured a statistically significant relationship to BPD clinical severity. Opacities, lucencies, and overall heterogeneity of lungs via quantitative CT can distinguish BPD patients from healthy controls, and these abnormalities decrease with age across BPD patients. Defining BPD severity by clinical outcomes such as respiratory support at several time points (vs a single time point, per current guidelines) may be meaningful. © 2017 Wiley Periodicals, Inc.

  14. A measurement-based generalized source model for Monte Carlo dose simulations of CT scans

    Science.gov (United States)

    Ming, Xin; Feng, Yuanming; Liu, Ransheng; Yang, Chengwen; Zhou, Li; Zhai, Hezheng; Deng, Jun

    2017-03-01

    The goal of this study is to develop a generalized source model for accurate Monte Carlo dose simulations of CT scans based solely on the measurement data without a priori knowledge of scanner specifications. The proposed generalized source model consists of an extended circular source located at x-ray target level with its energy spectrum, source distribution and fluence distribution derived from a set of measurement data conveniently available in the clinic. Specifically, the central axis percent depth dose (PDD) curves measured in water and the cone output factors measured in air were used to derive the energy spectrum and the source distribution respectively with a Levenberg-Marquardt algorithm. The in-air film measurement of fan-beam dose profiles at fixed gantry was back-projected to generate the fluence distribution of the source model. A benchmarked Monte Carlo user code was used to simulate the dose distributions in water with the developed source model as beam input. The feasibility and accuracy of the proposed source model was tested on a GE LightSpeed and a Philips Brilliance Big Bore multi-detector CT (MDCT) scanners available in our clinic. In general, the Monte Carlo simulations of the PDDs in water and dose profiles along lateral and longitudinal directions agreed with the measurements within 4%/1 mm for both CT scanners. The absolute dose comparison using two CTDI phantoms (16 cm and 32 cm in diameters) indicated a better than 5% agreement between the Monte Carlo-simulated and the ion chamber-measured doses at a variety of locations for the two scanners. Overall, this study demonstrated that a generalized source model can be constructed based only on a set of measurement data and used for accurate Monte Carlo dose simulations of patients’ CT scans, which would facilitate patient-specific CT organ dose estimation and cancer risk management in the diagnostic and therapeutic radiology.

  15. 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.

  16. 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

  17. Open source deformable image registration system for treatment planning and recurrence CT scans. Validation in the head and neck region

    International Nuclear Information System (INIS)

    Zukauskaite, Ruta; Brink, Carsten; Hansen, Christian Roenn; Bertelsen, Anders; Johansen, Joergen; Eriksen, Jesper Grau; Grau, Cai

    2016-01-01

    Clinical application of deformable registration (DIR) of medical images remains limited due to sparse validation of DIR methods in specific situations, e. g. in case of cancer recurrences. In this study the accuracy of DIR for registration of planning CT (pCT) and recurrence CT (rCT) images of head and neck squamous cell carcinoma (HNSCC) patients was evaluated. Twenty patients treated with definitive IMRT for HNSCC in 2010-2012 were included. For each patient, a pCT and an rCT scan were used. Median interval between the scans was 8.5 months. One observer manually contoured eight anatomical regions-of-interest (ROI) twice on pCT and once on rCT. pCT and rCT images were deformably registered using the open source software elastix. Mean surface distance (MSD) and Dice similarity coefficient (DSC) between contours were used for validation of DIR. A measure for delineation uncertainty was estimated by assessing MSD from the re-delineations of the same ROI on pCT. DIR and manual contouring uncertainties were correlated with tissue volume and rigidity. MSD varied 1-3 mm for different ROIs for DIR and 1-1.5 mm for re-delineated ROIs performed on pCT. DSC for DIR varied between 0.58 and 0.79 for soft tissues and was 0.79 or higher for bony structures, and correlated with the volumes of ROIs (r = 0.5, p < 0.001) and tissue rigidity (r = 0.54, p < 0.001). DIR using elastix in HNSCC on planning and recurrence CT scans is feasible; an uncertainty of the method is close to the voxel size length of the planning CT images. (orig.) [de

  18. Open source deformable image registration system for treatment planning and recurrence CT scans : Validation in the head and neck region.

    Science.gov (United States)

    Zukauskaite, Ruta; Brink, Carsten; Hansen, Christian Rønn; Bertelsen, Anders; Johansen, Jørgen; Grau, Cai; Eriksen, Jesper Grau

    2016-08-01

    Clinical application of deformable registration (DIR) of medical images remains limited due to sparse validation of DIR methods in specific situations, e. g. in case of cancer recurrences. In this study the accuracy of DIR for registration of planning CT (pCT) and recurrence CT (rCT) images of head and neck squamous cell carcinoma (HNSCC) patients was evaluated. Twenty patients treated with definitive IMRT for HNSCC in 2010-2012 were included. For each patient, a pCT and an rCT scan were used. Median interval between the scans was 8.5 months. One observer manually contoured eight anatomical regions-of-interest (ROI) twice on pCT and once on rCT. pCT and rCT images were deformably registered using the open source software elastix. Mean surface distance (MSD) and Dice similarity coefficient (DSC) between contours were used for validation of DIR. A measure for delineation uncertainty was estimated by assessing MSD from the re-delineations of the same ROI on pCT. DIR and manual contouring uncertainties were correlated with tissue volume and rigidity. MSD varied 1-3 mm for different ROIs for DIR and 1-1.5 mm for re-delineated ROIs performed on pCT. DSC for DIR varied between 0.58 and 0.79 for soft tissues and was 0.79 or higher for bony structures, and correlated with the volumes of ROIs (r = 0.5, p elastix in HNSCC on planning and recurrence CT scans is feasible; an uncertainty of the method is close to the voxel size length of the planning CT images.

  19. Technique improvement of thoracoabdominal CT scan for patients with arm-raising disability

    International Nuclear Information System (INIS)

    Yuan Zhidong; Liu Yuanjian; Jiang Guoyin; Feng Fei; Wang Chenglin; Liu Pengcheng

    2010-01-01

    Objective: To explore a new scanning technique to reduce and avoid image artifacts of thoracoabdominal CT and improve image quality for patients who cannot raise their arms. Methods: Sixty-one patients with arm-raising disability between March 2004 and May 2009 were enrolled in the study. Thirty-one cases before June 2007 were scanned with their arms beside their body (control group), 30 cases after June 2007 were scanned with their arms shifting to different imaging planes of the spine (study group), and another 30 patients who can raising their arms were taken as routine group. The images artifacts were blindly evaluated by 5-points scale (severe, less severe, moderate, minimum and no artifact) by 2 experienced CT technologists and one radiologist and compared between the three groups (X 2 test). CT values and its noise of the liver with or without artifact of the three groups were measured and analyzed by one-way ANOVA test. Results: In the control group, 11 cases had severe, 15 cases had less severe, 5 cases had moderate. In the study group, 6 cases had moderate, 15 cases had minimum, 9 cases had no artifact. In the routine group, 8 cases minimum and 22 cases had no artifact. Image quality was significantly improved in the study group compared to the conventional group where X 2 =95.32 and P<0.01. CT value and the noise of the liver without artifact were (54.5 ± 3.0) HU and 10.7 ± 2.4 in the control group, (52.0 ± 3.5) HU and 10.7 ± 0.5 in the study group, (53.7 ± 3.1) HU and 9.9 ± 0.5 in the routine group, respectively. CT value and noise of the liver with artifact were (41.7 ± 8.4) HU and 17.9 ± 2.6 in control group, (53.1 ± 6.9) HU and 11.0 ± 0.7 in the study group, (54.1 ± 2.4) HU and 9.9 ± 0.5 in the routine group, respectively. The CT value and its noise variation with artifact were significantly higher in the control group than the study group and the control group, where F=36.352, 235.848, respectively and P<0.01. Conclusion: The image

  20. Case of minute hepatocellular carcinoma found by CT scan and diagnosed cytology under the ultrasonic aspiration transducer

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Waichi; Moriai, Norihiko; Komatsu, Kanji [Yuri Kumiai Sogo Hospital, Akita (Japan)

    1983-11-01

    CT scan detected a suspected minute hepatocellular carcinoma in a case of liver cirrhosis followed up for more than 10 years. A definite diagnosis was established by ultrasonic guided aspiration cytology. The cancer was resected using ultrasonic examination during operation.

  1. MRI and brain spect findings in patients with unilateral temporal lobe epilepsy and normal CT scan

    Directory of Open Access Journals (Sweden)

    P.G. Carrilho

    1994-06-01

    Full Text Available 26 patients with temporal lobe epilepsy clinically documented by several abnormal interictal surface EEGs with typical unitemporal epileptiform activity and a normal CT scan were studied. Interictal99mTC HMPAO brain SPECT and MRI were performed in all subjects. Abnormalities were shown in 61.5% of MRI (n=16 and 65.4% of SPECT (n=17. Hippocampal atrophy associated to a high signal on T2-weighted MRI slices suggesting mesial temporal sclerosis was the main finding (n=12; 75% of abnormal MRI. MRI correlated well to surface EEG in 50% (n=13. There was also a good correlation between MRI and SPECT in 30.7% (n=8. SPECT and EEG were in agreement in 57.7% (n=l5. MRI, SPECT and EEG were congruent in 26.9% (n=7. These results support the usefulness of interictal brain SPECT and MRI in detecting lateralized abnormalities in temporal lobe epilepsy. On the other hand, in two cases, interictal SPECT correlated poorly with surface EEG. This functional method should not be used isolately in the detection of temporal lobe foci. MRI is more useful than CT as a neuroimaging technique in temporal lobe epilepsy. It may detect small structural lesions and mesial temporal lobe sclerosis which are not easily seen with traditional CT scanning.

  2. 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 tempor