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Sample records for ct initial experience

  1. Initial experience with AcQsim CT simulator

    International Nuclear Information System (INIS)

    Michalski, Jeff M.; Gerber, Russell; Bosch, Walter R.; Harms, William; Matthews, John W.; Purdy, James A.; Perez, Carlos A.

    1995-01-01

    Purpose: We recently replaced our university developed CT simulator prototype with a commercial grade spiral CT simulator (Picker AcQsim) that is networked with three independent virtual simulation workstations and our 3D radiation therapy planning (3D-RTP) system multiple workstations. This presentation will report our initial experience with this CT simulation device and define criteria for optimum clinical use as well as describe some potential drawbacks of the current system. Methods and Materials: Over a 10 month period, 210 patients underwent CT simulation using the AcQsim. An additional 127 patients had a volumetric CT scan done on the device with their CT data and target and normal tissue contours ultimately transferred to our 3D-RTP system. We currently perform the initial patient localization and immobilization in the CT simulation suite by using CT topograms and a fiducial laser marking system. Immobilization devices, required for all patients undergoing CT simulation, are constructed and registered to a device that defines the treatment table coordinates. Orthogonal anterior and lateral CT topograms document patient alignment and the position of a reference coordinate center. The volumetric CT scan with appropriate CT contrast materials administered is obtained while the patient is in the immobilization device. On average, more than 100 CT slices are obtained per study. Contours defining tumor, target, and normal tissues are drawn on a slice by slice basis. Isocenter definition can be automatically defined within the target volume and marked on the patient and immobilization device before leaving the initial CT simulation session. Virtual simulation is then performed on the patient data set with the assistance of predefined target volumes and normal tissue contours displayed on rapidly computed digital reconstructed radiographs (DRRs) in a manner similar to a conventional fluoroscopic radiotherapy simulator. Lastly, a verification simulation is

  2. Cardiac 82rubidium PET/CT: initial European experience

    International Nuclear Information System (INIS)

    Groves, Ashley M.; Dickson, John C.; Kayani, Irfan; Endozo, Raymondo; Blanchard, Patty; Shastry, Manu; Prvulovich, Elizabeth; Waddington, Wendy A.; Ben-Haim, Simona; Bomanji, Jamshed B.; Ell, Peter J.; Speechly-Dick, Marie-Elsya; McEwan, Jean R.

    2007-01-01

    Myocardial perfusion with PET/CT has advantages over conventional SPECT. We describe our initial European experience using 82 Rubidium-PET/CT, as part of a clinical myocardial perfusion service. We studied the first 100 patients (64 male; 36 female, mean age = 60: SD +/-12.5y, mean body mass index = 30: SD +/-6.9kg/m 2 ) who underwent 82 Rubidium cardiac PET/CT in our institution. Thirty patients had recently undergone coronary angiography. Patients underwent imaging during adenosine infusion and at rest. Images were acquired over 5 minutes using a GE-PET/CT instrument. Image quality was described as good, adequate or inadequate. Images were reported patient-by-patient by a minimum of five nuclear medicine physicians. A segment-by-segment analysis (17-segment model) was also performed. Image quality was good in 77%, adequate 23% and inadequate 0%. There was no statistical difference in image quality between obese and non-obese patients (Fisher's exact test, p = 0.2864). 59% had normal perfusion studies, 29% had inducible ischaemia, 12% had myocardial infarction (11% with super added ischaemia). There was reduced 82 Rubidium uptake in 132/1700 segments during stress. There was reduced 82 Rubidium uptake at rest in 42/1700 segments. The 82 Rubidium PET/CT findings were consistent with the angiographic findings in 28/30 cases. We show that, even from initial use of 82 Rubidium, it is possible to perform myocardial perfusion studies quickly with good image quality, even in the obese. The PET findings correlated well in the third of the cases where angiography was available. As such, 82 Rubidium cardiac PET/CT is likely to be an exciting addition to the European nuclear physician/ cardiologist's radionuclide imaging arsenal. (orig.)

  3. Multi-detector CT knee arthrography - initial experience

    International Nuclear Information System (INIS)

    Thomson, J.M.Z.; Fallon, M.; Breidahl, W.H.

    2002-01-01

    Full text: Traditional plain film arthrography can achieve reasonable accuracy and is an accepted method of investigation of patients with knee pain and possible meniscal tear. Multi-detector CT can potentially provide a more detailed and accurate examination due to its high-resolution crosssectional and multi-planar capabilities. The aim of this study was to assess the accuracy of our technique. All patients who underwent a multi-detector CT knee arthrogram in an initial 8 month period were identified. Initially the referring clinician was contacted. If the patient was referred to an orthopaedic surgeon the outcome of orthopaedic review was recorded using clinical, arthroscopic and / or MRI follow-up of the patient population. One hundred and twelve patients had a Multi-detector CT knee arthrogram performed within and 8 month period. Follow-up information was received in 69.7% of patients. Of these 68.9% had orthopaedic assessment - of which 69.2% underwent a knee arthroscopy.There was total agreement of findings in 67%, agreement of meniscal findings in 67% and chondral findings in 100%. Overall, orthopaedic opinion agreed with CT findings in 76.9%. At this stage, all meniscal tears not described in the initial CT arthrogram report have in retrospect been visible. Multi-detector CT knee arthrography is an accurate and elegant technique for investigation of knee pain, providing information in a format familiar to those reporting knee MRI. There is an initial learning curve. The technique is particularly useful in chondral assessment. It is accurate for meniscal pathology, although caution and recognition of potential pitfalls is required. Copyright (2002) Blackwell Science Pty Ltd

  4. Myocardial delayed-enhancement CT: initial experience in children and young adults

    Energy Technology Data Exchange (ETDEWEB)

    Goo, Hyun Woo [University of Ulsan College of Medicine, Department of Radiology and Research Institute of Radiology, Asan Medical Center, Seoul (Korea, Republic of)

    2017-10-15

    Clinical utility of myocardial delayed enhancement CT has not been reported in children and young adults. To describe initial experience of myocardial delayed enhancement CT regarding image quality, radiation dose and identification of myocardial lesions in children and young adults. Between August 2013 and November 2016, 29 consecutive children and young adults (median age 16 months) with suspected coronary artery or myocardial abnormality underwent arterial- and delayed-phase cardiac CT at our institution. We measured CT densities in normal myocardium, left ventricular cavity, and arterial and delayed hypo-enhancing and delayed hyperenhancing myocardial lesions. We then compared the extent of delayed hyperenhancing lesions with delayed-enhancement MRI or thallium single-photon emission CT. Normal myocardium and left ventricular cavity showed significantly higher CT numbers on arterial-phase CT than on delayed-phase CT (t-test, P<0.0001). Contrast-to-noise ratios of the arterial and delayed hypo-enhancing and delayed hyperenhancing lesions on CT were 26.7, 17.6 and 18.7, respectively. Delayed-phase CT findings were equivalent to those of delayed-enhancement MRI in all cases (7/7) and to those of thallium single-photon emission CT in 70% (7/10). Myocardial delayed-enhancement CT can be added to evaluate myocardial lesions in select children and young adults with suspected coronary artery or myocardial abnormality. (orig.)

  5. Myocardial delayed-enhancement CT: initial experience in children and young adults

    International Nuclear Information System (INIS)

    Goo, Hyun Woo

    2017-01-01

    Clinical utility of myocardial delayed enhancement CT has not been reported in children and young adults. To describe initial experience of myocardial delayed enhancement CT regarding image quality, radiation dose and identification of myocardial lesions in children and young adults. Between August 2013 and November 2016, 29 consecutive children and young adults (median age 16 months) with suspected coronary artery or myocardial abnormality underwent arterial- and delayed-phase cardiac CT at our institution. We measured CT densities in normal myocardium, left ventricular cavity, and arterial and delayed hypo-enhancing and delayed hyperenhancing myocardial lesions. We then compared the extent of delayed hyperenhancing lesions with delayed-enhancement MRI or thallium single-photon emission CT. Normal myocardium and left ventricular cavity showed significantly higher CT numbers on arterial-phase CT than on delayed-phase CT (t-test, P<0.0001). Contrast-to-noise ratios of the arterial and delayed hypo-enhancing and delayed hyperenhancing lesions on CT were 26.7, 17.6 and 18.7, respectively. Delayed-phase CT findings were equivalent to those of delayed-enhancement MRI in all cases (7/7) and to those of thallium single-photon emission CT in 70% (7/10). Myocardial delayed-enhancement CT can be added to evaluate myocardial lesions in select children and young adults with suspected coronary artery or myocardial abnormality. (orig.)

  6. CT-guided spinal injection: initial experience with Sprotte tip needles

    Energy Technology Data Exchange (ETDEWEB)

    Pua, Uei [Tan Tock Seng Hospital, Department of Diagnostic Radiology, Singapore (Singapore)

    2010-09-15

    The purpose of this paper is to describe our initial experience and to illustrate the potential benefits of using small caliber (25 and 27 G), noncutting pencil point needles (Sprotte) with single puncture coaxial technique in CT-guided spinal intervention (CTSI). From January 2009 to June 2009, Sprotte needles with single puncture coaxial technique were used in a total of ten patients for selective nerve root block (SNRB), facet joint block, and pars block under CT fluoroscopy (total of 16 target structures). All procedures were performed without conscious sedation, and visual analog scale (VAS) scores were recorded to determine pain related to needle placement. Total CT fluoroscopy time and out-of-plane needle deviation were obtained. Final needle position was documented by contrast injection for SNRBs and image capture for joint space cannulation. Sixteen out of the 16 structures were successfully targeted. No increase in VAS scores associated with needle placement was recorded, after infiltration of local anesthesia. Optimal peri-neurograms were obtained in all cases of SNRB, despite the side-hole opening in the Sprotte needles. Mean CT fluoroscopy time was 2 s (range 2-8 s per structure), and there was no case of out-of-plane needle deviation that required adjustment of the CT gantry. The use of small caliber Sprotte needles in CTSI is technically feasible and represents a potential refinement to current techniques in the management of chronic spinal pain. (orig.)

  7. CT guided percutaneous needle biopsy of the chest: initial experience

    African Journals Online (AJOL)

    The objective of this article is to report our first experience of CT guided percutaneous thoracic biopsy and to demonstrate the accuracy and safety of this procedure. This was a retrospective study of 28 CT-Guided Percutaneous Needle Biopsies of the Chest performed on 24 patients between November 2014 and April 2015.

  8. Initial experience with FDG-PET/CT in the evaluation of breast cancer

    International Nuclear Information System (INIS)

    Tatsumi, Mitsuaki; Cohade, Christian; Mourtzikos, Karen A.; Wahl, Richard L.; Fishman, Elliot K.

    2006-01-01

    We retrospectively reviewed FDG-PET/CT images in patients with breast cancer to determine whether PET/CT improved the level of diagnostic confidence as compared with PET and to compare PET/CT and CT findings at the location of suspected malignancies. The study included 75 patients with known breast cancer. The initial PET/CT study for each patient was retrospectively reviewed to determine whether improved diagnostic confidence (IDC) regarding lesion localization and characterization was observed with PET/CT as compared with PET alone. PET/CT and CT findings were compared regarding lesion characterization and staging in 69 of the 75 patients, and in the case of discordant findings, comparison with histological or informative follow-up results was also performed. Fifty of the 75 patients exhibited increased FDG uptake in a total of 95 regions. In the comparison of PET/CT and PET, PET/CT resulted in IDC in 30 (60%) of these 50 patients and in 52 (55%) of the 95 regions. In the comparison between PET/CT and CT in 69 patients, PET/CT demonstrated a significantly better accuracy than CT (P<0.05). PET/CT showed definitely positive findings in 60 regions with malignancies, among which CT exhibited positive findings in 43 (72%). PET/CT and CT accurately staged 59 (86%) and 53 (77%) of the 69 patients, respectively. (orig.)

  9. Initial experience of Fag-PET/CT guided Imr of head-and-neck carcinoma

    International Nuclear Information System (INIS)

    Wang Dian; Schultz, Christopher J.; Jursinic, Paul A.; Bialkowski, Mirek; Zhu, X. Ronald; Brown, W. Douglas; Rand, Scott D.; Michel, Michelle A.; Campbell, Bruce H.; Wong, Stuart; Li, X. Allen; Wilson, J. Frank

    2006-01-01

    Purpose: The purpose of this study is to evaluate the impact of 18 F-fluorodeoxyglucose positron emission tomography (Fag-PET) fused with planning computed tomography (CT) on tumor localization, which guided intensity-modulated radiotherapy (Imr) of patients with head-and-neck carcinoma. Methods and Materials: From October 2002 through April 2005, we performed Fag-PET/CT guided Imr for 28 patients with head-and-neck carcinoma. Patients were immobilized with face masks that were attached with five fiducial markers. Fag-PET and planning CT scans were performed on the same flattop table in one session and were then fused. Target volumes and critical organs were contoured, and Imr plans were generated based on the fused images. Results: All 28 patients had abnormal increased uptake in Fag-PET/CT scans. PET/CT resulted in CT-based staging changes in 16 of 28 (57%) patients. PET/CT fusions were successfully performed and were found to be accurate with the use of the two commercial planning systems. Volume analysis revealed that the PET/CT-based gross target volumes (GTVs) were significantly different from those contoured from the CT scans alone in 14 of 16 patients. In addition, 16 of 28 patients who were followed for more than 6 months did not have any evidence of locoregional recurrence in the median time of 17 months. Conclusion: Fused images were found to be useful to delineate GTV required in IMRT planning. PET/CT should be considered for both initial staging and treatment planning in patients with head-and-neck carcinoma

  10. CT-guided conformal cryoablation for peripheral NSCLC: Initial experience

    International Nuclear Information System (INIS)

    Zhang, Xiao; Tian, Jinlin; Zhao, Lei; Wu, Bin; Kacher, Daniel S.; Ma, Xuyang; Liu, Shurong; Ren, Chao; Xiao, Yue-Yong

    2012-01-01

    Purpose: To study the feasibility of CT-guided and monitored percutaneous conformal cryoablation of Non-Small Cell Lung Cancer for patients who are not suitable for surgical resection. Materials and method: CT-guided percutaneous conformal cryoablation was performed on 46 patients with peripheral Non-Small Cell Lung Cancer. Patients with tumor sizes less than 3 cm in diameter were treated with double-needle clamping cryoablation, while the patients with 3–5 cm tumor sizes were treated with multiple-needle conformal cryoablation. CT was used to monitor the extent of cryoablation during the procedures. At month 1, 3, 6, 12, and 24 post-procedure, enhanced CT scans and/or PET-CT scans were performed to evaluate the impact of the therapy. Results: The average tumor CT values were 32 ± 10 HU and −21 ± 8 HU before and after cryoablation, respectively. The largest diameters of the lesions at month 1, 3, 6, 12, and 24 post-procedure were 2.63 ± 0.56 cm, 1.93 ± 0.51 cm, 1.55 ± 0.39 cm, 1.43 ± 0.40 cm, and 1.38 ± 0.38 cm, respectively, in patients with tumor diameter less than 3 cm, and 3.63 ± 0.39 cm, 2.98 ± 0.31 cm, 2.62 ± 0.32 cm, 2.54 ± 0.34 cm, and 2.56 ± 0.37 cm respectively in patients with the tumor diameters between 3 and 5 cm. At the 24th month, there were 36 cases of complete response (83.7%), 7 cases of partial response (16.3%), and no cases of stable disease or progressive disease. 3 patients died due to multiple metastases. Conclusion: CT-guided percutaneous conformal cryoablation is a safe, effective, and minimally invasive therapeutic method for peripheral lung cancer.

  11. Imaging CT findings in cases of subdural hematoma after cardiovascular surgery. Initial signs of SDH

    Energy Technology Data Exchange (ETDEWEB)

    Maruyama, Michiyuki; Kuriyama, Yoshihiro; Sawada, Tohru; Ogawa, Makoto; Kaneko, Takaji; Sakamoto, Akira; Kawazoe, Kouhei; Fujita, Tsuyoshi; Omae, Teruo

    1987-12-01

    A characteristic initial sign of CT findings, as seen in cases of subdural hematoma (SDH) after cardiovascular surgery, was reported. Central-nervous-system (CNS) complications after cardiovascular surgery have been thought to be due mainly to the ischemic brain damage caused by both reduced cerebral perfusion pressure and microembolism during extracorporeal circulation. However, we observed 8 cases of SDH in 39 patients suffering from major CNS complications after cardiovascular surgery. In view of these experiences, SDH was thought to be one of the most significant factors causing CNS complications after cardiovascular surgery. In the sequential CT scans of 8 cases of SDH, four exhibited a typical, small, spotty high-density area in the early period of SDH. The clinical courses of these four patients were relatively acute or subacute, and the initial small high-density area progressed to definite SDH findings in that region in the follow-up CT. These initial findings of CT scans were regarded as ''initial signs of SDH-ISS-''. Although there have been many reports concerning the sequential CT changes in SDH, there has been no report describing the above-mentioned finding. It was emphasized that ''ISS'' is of great importance in the early management for SDH.

  12. Low-dose CT colonography in children: initial experience, technical feasibility and utility

    International Nuclear Information System (INIS)

    Anupindi, Sudha; Perumpillichira, James; Zalis, Michael E.; Jaramillo, Diego; Israel, Esther J.

    2005-01-01

    CT colonography (CTC) is utilized as a diagnostic tool in the detection of colon polyps and early colorectal cancer in adults. Large studies in the literature, although focused on adult populations, have shown CTC to be a safe, accurate, non-invasive technique. We evaluated the technical feasibility of CTC in children using a low-dose technique. From November 2001 to April 2004 we evaluated eight patients (3-17 years) with non-contrast CTC. Seven of the patients had CTC, followed by standard colonoscopy (SC) the same day; in one patient, CTC followed a failed SC. CTC results were compared to results of SC. The estimated effective dose from each CTC was calculated and compared to that of standard barium enema. CTC results were consistent with those of SC. Sensitivity for polyps 5-10 mm was 100%, and sensitivity for polyps 10 mm and larger was 66.7%. The estimated mean effective dose was 2.17 mSv for CTC, compared to the 5-6 mSv for a standard air-contrast barium enema in a small child. Our initial experience shows CTC in children is well-tolerated, safe, and useful. The procedure can be performed successfully with a low radiation dose, and preliminary results compare well with SC. (orig.)

  13. 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.

  14. Four-Dimensional CT of the Diaphragm in Children: Initial Experience

    Science.gov (United States)

    2018-01-01

    Objective To evaluate the technical feasibility of four-dimensional (4D) CT for the functional evaluation of the pediatric diaphragm. Materials and Methods In 22 consecutive children (median age 3.5 months, age range 3 days–3 years), 4D CT was performed to assess diaphragm motion. Diaphragm abnormalities were qualitatively evaluated and diaphragm motion was quantitatively measured on 4D CT. Lung density changes between peak inspiration and expiration were measured in the basal lung parenchyma. The diaphragm motions and lung density changes measured on 4D CT were compared between various diaphragm conditions. In 11 of the 22 children, chest sonography was available for comparison. Results Four-dimensional CT demonstrated normal diaphragm (n = 8), paralysis (n = 10), eventration (n = 3), and diffusely decreased motion (n = 1). Chest sonography demonstrated normal diaphragm (n = 2), paralysis (n = 6), eventration (n = 2), and right pleural effusion (n = 1). The sonographic findings were concordant with the 4D CT findings in 90.9% (10/11) of the patients. In diaphragm paralysis, the affected diaphragm motion was significantly decreased compared with the contralateral normal diaphragm motion (−1.1 ± 2.2 mm vs. 7.6 ± 3.8 mm, p = 0.005). The normal diaphragms showed significantly greater motion than the paralyzed diaphragms (4.5 ± 2.1 mm vs. −1.1 ± 2.2 mm, p Hounsfield units [HU] vs. 180 ± 71 HU, p = 0.03), while no significant differences were found between the normal diaphragms and the paralyzed diaphragms (136 ± 66 HU vs. 89 ± 73 HU, p = 0.1) or between the normal diaphragms and the contralateral normal diaphragms in paralysis (136 ± 66 HU vs. 180 ± 71 HU, p = 0.1). Conclusion The functional evaluation of the pediatric diaphragm is feasible with 4D CT in select children. PMID:29354007

  15. Dual-source CT cardiac imaging: initial experience

    International Nuclear Information System (INIS)

    Johnson, Thorsten R.C.; Nikolaou, Konstantin; Wintersperger, Bernd J.; Rist, Carsten; Buhmann, Sonja; Reiser, Maximilian F.; Becker, Christoph R.; Leber, Alexander W.; Ziegler, Franz von; Knez, Andreas

    2006-01-01

    The relation of heart rate and image quality in the depiction of coronary arteries, heart valves and myocardium was assessed on a dual-source computed tomography system (DSCT). Coronary CT angiography was performed on a DSCT (Somatom Definition, Siemens) with high concentration contrast media (Iopromide, Ultravist 370, Schering) in 24 patients with heart rates between 44 and 92 beats per minute. Images were reconstructed over the whole cardiac cycle in 10% steps. Two readers independently assessed the image quality with regard to the diagnostic evaluation of right and left coronary artery, heart valves and left ventricular myocardium for the assessment of vessel wall changes, coronary stenoses, valve morphology and function and ventricular function on a three point grading scale. The image quality ratings at the optimal reconstruction interval were 1.24±0.42 for the right and 1.09±0.27 for the left coronary artery. A reconstruction of diagnostic systolic and diastolic images is possible for a wide range of heart rates, allowing also a functional evaluation of valves and myocardium. Dual-source CT offers very robust diagnostic image quality in a wide range of heart rates. The high temporal resolution now also makes a functional evaluation of the heart valves and myocardium possible. (orig.)

  16. Initial investigation into lower-cost CT for resource limited regions of the world

    Science.gov (United States)

    Dobbins, James T., III; Wells, Jered R.; Segars, W. Paul; Li, Christina M.; Kigongo, Christopher J. N.

    2010-04-01

    This paper describes an initial investigation into means for producing lower-cost CT scanners for resource limited regions of the world. In regions such as sub-Saharan Africa, intermediate level medical facilities serving millions have no CT machines, and lack the imaging resources necessary to determine whether certain patients would benefit from being transferred to a hospital in a larger city for further diagnostic workup or treatment. Low-cost CT scanners would potentially be of immense help to the healthcare system in such regions. Such scanners would not produce state-of-theart image quality, but rather would be intended primarily for triaging purposes to determine the patients who would benefit from transfer to larger hospitals. The lower-cost scanner investigated here consists of a fixed digital radiography system and a rotating patient stage. This paper describes initial experiments to determine if such a configuration is feasible. Experiments were conducted using (1) x-ray image acquisition, a physical anthropomorphic chest phantom, and a flat-panel detector system, and (2) a computer-simulated XCAT chest phantom. Both the physical phantom and simulated phantom produced excellent image quality reconstructions when the phantom was perfectly aligned during acquisition, but artifacts were noted when the phantom was displaced to simulate patient motion. An algorithm was developed to correct for motion of the phantom and demonstrated success in correcting for 5-mm motion during 360-degree acquisition of images. These experiments demonstrated feasibility for this approach, but additional work is required to determine the exact limitations produced by patient motion.

  17. Initial thoracic involvement in lymphoma. CT assessment

    International Nuclear Information System (INIS)

    Bustos, A.; Corredoira, J.; Ferreiros, J.; Cabeza, B.; Jorquera, M.; Pedrosa, I.; Martinez, R.; Fernandez, C.

    2002-01-01

    To analyze the initial thoracic involvement by CT in a consecutive series of patients with lymphoma. A retrospective analysis was made of thoracic CT studies made at the time of diagnosis of 259 patients with lymphoma. Mediastinal pulmonary, pleural, pericardial and chest wall involvement was assessed by CT. Of 259 patients (129 men y 130 women), 56 had Hodgkin's disease (HD) and 203 had non-Hodgkin lymphoma (NHL). Forty-two percent (42.5%, 110/259) of the patients had chest involvement on CT: 33 of 56 patients with HD (58.9%) and 77 of 203 patients with NHL (37.9%). All the patients with thoracic HD) and 71.4% of patients with thoracic NHL, had mediastinal lymph node involvement. of the patients with thoracic involvement 12.1% (4/33) of the patient with HD and 23.3% (18/77) of the patients with NHL had pulmonary involvement. Thoracic involvement on CT was more frequent in HD. Mediastinal lymph node involvement was the most common finding fundamentally in HD. Pulmonary disease always occurred in the presence of mediastinal lymph node involvement in HD but could occur as an isolated finding in NHL. (Author) 24 refs

  18. Initial clinical experience with spiral CT angiography in the abdomen

    International Nuclear Information System (INIS)

    Gaa, J.; Stehling, M.K.; Costello, P.

    1993-01-01

    The latest developments in modern CT instruments, offering scanning times of a second, opened up new possibilities in CT imaging in combination with the spiral technique. The data set normally taken with single-breath-hold technique is free of respiratory artefacts and thus is a good basis for accurate 3D image reconstruction. Spiral CTA allows a non-invasive 3D imaging of various blood vessels. Patients with abdominal aortic aneurysms of aorto-iliac bypass can be examined as outpatients within 15 minutes. (orig.) [de

  19. Experiments on CT plasma merging in the CTCC-1

    International Nuclear Information System (INIS)

    Watanabe, K.; Ikegami, K.; Nishikawa, M.; Ozaki, A.; Satomi, N.; Uyama, T.

    1982-01-01

    A compact toroid (CT) plasma merging experiment has been tried preliminarily in the CTCC-1 experiment as a method for further-heating of CT, on producing two CT plasmas in the flux conserver successively. Two CT plasmas were observed really to merge with each other in the flux conserver. In the merging process, it is found that the field reconnection of surface magnetic field lines of CT is completed until 30 μs after the second CT injection, but magnetic field lines around the center of CT merge slowly, taking about 100 μs. Experimental results indicate that merging of CT results in doubled addition of toroidal fluxes and no-addition of poloidal fluxes

  20. Novel characteristics of CtIP at damage-induced foci following the initiation of DNA end resection

    International Nuclear Information System (INIS)

    Fujisawa, Hiroshi; Fujimori, Akira; Okayasu, Ryuichi; Uesaka, Mitsuru; Yajima, Hirohiko

    2015-01-01

    Highlights: • CtIP becomes hyperphosphorylated and forms foci following cell irradiation. • CtIP accumulates in foci subsequent to the peak of hyperphosphorylation. • CtIP is maintained in a hypophosphorylated state at later times. • CtIP is continuously recruited to DNA double strand breaks downstream of resection. • CtIP presumably have a distinct role following the initiation of resection. - Abstract: Homologous recombination (HR) is a major repair pathway for DNA double strand breaks (DSBs), and end resection, which generates a 3′-single strand DNA tail at the DSB, is an early step in the process. Resection is initiated by the Mre11 nuclease together with CtIP. Here, we describe novel characteristics of CtIP at DSBs. At early times following exposure of human cells to ionizing radiation, CtIP localized to the DSB, became hyperphosphorylated and formed foci in an ATM-dependent manner. At later times, when the initiation of resection had occurred, CtIP foci persist but CtIP is maintained in a hypophosphorylated state, which is dependent on ATM and ATR. Exposure to cycloheximide revealed that CtIP turns over at DSB sites downstream of resection. Our findings provide strong evidence that CtIP is continuously recruited to DSBs downstream of both the initiation and extension step of resection, strongly suggesting that CtIP has functions in addition to promoting the initiation of resection during HR

  1. CT-guided biopsy of thoracic lesions with a novel wire-based needle guide device - initial experiences

    Energy Technology Data Exchange (ETDEWEB)

    Kroepil, Patric; Bilk, Philip; Quentin, Michael; Miese, Falk R; Lanzman, Rotem S; Scherer, Axel (Dept. of Radiology, Medical Faculty, Univ. Duesseldorf, Duesseldorf (Germany)), email: Patric.Kroepil@med.uni-duesseldorf.de

    2011-10-15

    Background Biopsies guided by computed tomography (CT) play an important role in clinical practice. A short duration, minimal radiation dose and complication rate are of particular interest. Purpose To evaluate the potential of a novel self-manufactured wire-based needle guide device for CT-guided thoracic biopsies with respect to radiation dose, intervention time and complication rate. Material and Methods Forty patients that underwent CT-guided biopsies of thoracic lesions were included in this study and assigned to two groups. Patients in group A (n = 20, mean age 69 +- 8.4 years) underwent biopsies with a novel wire-based needle guide device, while patients in group B (n = 20, mean age 68.4 +- 10.1 years) were biopsied without a needle guide device. The novel self-manufactured needle guide device consists of an iron/zinc wire modelled to a ring with a flexible arm and an eye at the end of the arm to stabilize the biopsy needle in the optimal position during intervention. Predefined parameters (radiation dose, number of acquired CT-slices, duration of intervention, complications) were compared between both groups. Results Mean radiation dose (CTDIvol 192 mGy versus 541 mGy; P = 0.001) and the number of acquired slices during intervention (n = 49 +- 33 vs. n = 126 +- 78; P = 0.001) were significantly lower in group A compared with group B. Intervention time in group A (13.1 min) was significantly lower than in group B (18.5 min, P < 0.01). A pneumothorax as peri-interventional complication was observed less frequent after device assisted biopsies (n = 4 vs. n = 8, n.s.). Conclusion The novel wire-based needle guide device is a promising tool to facilitate CT-guided thoracic biopsies reducing radiation dose, intervention time, and related complications. Further studies are mandatory to confirm these initial results

  2. CT-guided biopsy of thoracic lesions with a novel wire-based needle guide device - initial experiences

    International Nuclear Information System (INIS)

    Kroepil, Patric; Bilk, Philip; Quentin, Michael; Miese, Falk R; Lanzman, Rotem S; Scherer, Axel

    2011-01-01

    Background Biopsies guided by computed tomography (CT) play an important role in clinical practice. A short duration, minimal radiation dose and complication rate are of particular interest. Purpose To evaluate the potential of a novel self-manufactured wire-based needle guide device for CT-guided thoracic biopsies with respect to radiation dose, intervention time and complication rate. Material and Methods Forty patients that underwent CT-guided biopsies of thoracic lesions were included in this study and assigned to two groups. Patients in group A (n = 20, mean age 69 ± 8.4 years) underwent biopsies with a novel wire-based needle guide device, while patients in group B (n = 20, mean age 68.4 ± 10.1 years) were biopsied without a needle guide device. The novel self-manufactured needle guide device consists of an iron/zinc wire modelled to a ring with a flexible arm and an eye at the end of the arm to stabilize the biopsy needle in the optimal position during intervention. Predefined parameters (radiation dose, number of acquired CT-slices, duration of intervention, complications) were compared between both groups. Results Mean radiation dose (CTDIvol 192 mGy versus 541 mGy; P = 0.001) and the number of acquired slices during intervention (n = 49 ± 33 vs. n = 126 ± 78; P = 0.001) were significantly lower in group A compared with group B. Intervention time in group A (13.1 min) was significantly lower than in group B (18.5 min, P < 0.01). A pneumothorax as peri-interventional complication was observed less frequent after device assisted biopsies (n = 4 vs. n = 8, n.s.). Conclusion The novel wire-based needle guide device is a promising tool to facilitate CT-guided thoracic biopsies reducing radiation dose, intervention time, and related complications. Further studies are mandatory to confirm these initial results

  3. Translation of field-reversed configurations in the FRX C/T experiment

    Energy Technology Data Exchange (ETDEWEB)

    Rej, D.J.; Armstrong, W.T.; Chrien, R.E.; Klingner, P.L.; Linford, R.K.; McKenna, K.F.; Milroy, R.D.; Sherwood, E.G.; Siemon, R.E.; Tuszewski, M.

    1984-01-01

    One of the unique features inherent to compact toroids is the potential ability to translate the plasma along its geometric axis. CT translation has proven useful in reactor design studies, and has been the focus of several experimental investigations. In this paper, we report on the initial results from translation experiments performed with the field-reversed configuration (FRC) plasmas generated in the FRX-C/T device.

  4. Translation of field-reversed configurations in the FRX C/T experiment

    International Nuclear Information System (INIS)

    Rej, D.J.; Armstrong, W.T.; Chrien, R.E.

    1984-01-01

    One of the unique features inherent to compact toroids is the potential ability to translate the plasma along its geometric axis. CT translation has proven useful in reactor design studies, and has been the focus of several experimental investigations. In this paper, we report on the initial results from translation experiments performed with the field-reversed configuration (FRC) plasmas generated in the FRX-C/T device

  5. PET/MRI and PET/CT in advanced gynaecological tumours: initial experience and comparison

    Energy Technology Data Exchange (ETDEWEB)

    Queiroz, Marcelo A.; Schulthess, Gustav von; Veit-Haibach, Patrick [University Hospital Zurich, Department Medical Radiology, Nuclear Medicine, Zurich (Switzerland); University Hospital Zurich, Department Medical Radiology, Diagnostic and Interventional Radiology, Zurich (Switzerland); University of Zurich, Zurich (Switzerland); Kubik-Huch, Rahel A.; Freiwald-Chilla, Bianka [Kantonsspital Baden AG, Department of Radiology, Baden (Switzerland); Hauser, Nik [Kantonsspital Baden AG, Department of Gynaecology, Baden (Switzerland); Froehlich, Johannes M. [Guerbet AG, Zurich (Switzerland)

    2015-08-15

    To compare the diagnostic accuracy of PET/MRI and PET/CT for staging and re-staging advanced gynaecological cancer patients as well as identify the potential benefits of each method in such a population. Twenty-six patients with suspicious or proven advanced gynaecological cancer (12 ovarian, seven cervical, one vulvar and four endometrial tumours, one uterine metastasis, and one primary peritoneal cancer) underwent whole-body imaging with a sequential trimodality PET/CT/MR system. Images were analysed regarding primary tumour detection and delineation, loco-regional lymph node staging, and abdominal/extra-abdominal distant metastasis detection (last only by PET/CT). Eighteen (69.2 %) patients underwent PET/MRI for primary staging and eight patients (30.8 %) for re-staging their gynaecological malignancies. For primary tumour delineation, PET/MRI accuracy was statistically superior to PET/CT (p < 0.001). Among the different types of cancer, PET/MRI presented better tumour delineation mainly for cervical (6/7) and endometrial (2/3) cancers. PET/MRI for local evaluation as well as PET/CT for extra-abdominal metastases had therapeutic consequences in three and one patients, respectively. PET/CT detected 12 extra-abdominal distant metastases in 26 patients. PET/MRI is superior to PET/CT for primary tumour delineation. No differences were found in detection of regional lymph node involvement and abdominal metastases detection. (orig.)

  6. Evaluation of abdominal CT in the initial treatment of abdominal trauma

    International Nuclear Information System (INIS)

    Watanabe, Shinsuke; Ishii, Takashi; Kuwata, Katsuya; Yoneyama, Chihiro; Kitamura, Kazuya; Sasaki, Yoshifumi; Kamachi, Masahiro; Nishiguchi, Hiroyasu.

    1986-01-01

    During the last four years 102 patients with abdominal trauma were examined by CT for preoperative evaluation in our hospital. In 35 patients (34 %), the CT scans revealed no abnormal findings. They were all managed conservatively except for one case of perforated small bowel. In 67 patients (66 %) CT revealed evidences of substantial abdominal or retroperitoneal trauma. In 30 of them CT findings were confirmed by surgery. Hepatic injury is usually easily recognized by CT. CT is also useful for the detection of renal or splenic injuries. The majority of those parenchymatous organ injuries were successfully managed with conservative therapy, despite apparent traumatic lesions revealed by CT. Repeat CT scans is proved to be very useful to follow the changes of these traumatic lesions. In conclusion, application of abdominal CT is extremely useful for the initial decision making in treatment of patients with abdominal trauma and for the follow-up observation of injured lesions. (author)

  7. The similar hexheimer reaction during initial treatment of pulmonary tuberculosis: CT appearances

    International Nuclear Information System (INIS)

    Lu Yan; Zhou Xinhua; Xie Ruming; Xu Jinping

    2009-01-01

    Objective: To investigate CT features of similar Hexheimer's reaction during initial treatment of active pulmonary tuberculosis. Methods: The similar Hexheimer's reaction in 44 patients diagnosed by clinic and follow-up CT scans were retrospectively reviewed by three radiologists. Results: During initial treatment of active pulmonary tuberculosis, development of radiographic progression were observed in 57 foci, including 28 pulmonary lesions increased at the site of their original lesion or new opacities elsewhere, ipsilateral or contralateral to the original lesion or both, 10 lesions related to the pleura (pleural effusion, pleural tuberculoma), 15 lymphadenectasis, 3 thymus reactions, and 1 cardiac pericardium thickening, respectively. These reactions appeared from the 20 days to 3.5 months, then with continuation of the initial chemotherapy for 1.0-3.0 months, the radiographic response was excellent with the areas of progression and the original lesions demonstrating resolution or improvement. Conclusion: The CT appearances of similar Hexheimer's reaction during initial treatment of active tuberculosis are specific to a certainty. (authors)

  8. Association of initial CT findings with quality-of-life outcomes for traumatic brain injury in children

    Energy Technology Data Exchange (ETDEWEB)

    Swanson, Jonathan O. [Seattle Children' s Hospital and University of Washington, Department of Radiology, Seattle, WA (United States); Vavilala, Monica S.; Wang, Jin; Rivara, Frederick P. [Harborview Medical Center, University of Washington, Department of Pediatrics, Seattle, WA (United States); Pruthi, Sumit [Monroe Carell Jr. Children' s Hospital at Vanderbilt University, Department of Radiology, Nashville, TN (United States); Fink, James [University of Washington, Department of Radiology, Seattle, WA (United States); Jaffe, Kenneth M. [University of Washington, Department of Rehabilitation Medicine, Seattle, WA (United States); Durbin, Dennis [University of Pennsylvania, Department of Pediatrics, Center for Injury Research and Prevention, The Children' s Hospital of Philadelphia, Philadelphia, PA (United States); Koepsell, Thomas [University of Washington, Department of Epidemiology, Seattle, WA (United States); Temkin, Nancy [University of Washington, Biostatistics, Seattle, WA (United States)

    2012-08-15

    Traumatic brain injury (TBI) is a leading cause of acquired disability in children and adolescents. To demonstrate the association between specific findings on initial noncontrast head CT and long-term outcomes in children who have suffered TBI. This was an IRB-approved prospective study of children ages 2-17 years treated in emergency departments for TBI and who underwent a head CT as part of the initial work-up (n = 347). The change in quality of life at 12 months after injury was measured by the PedsQL scale. Children with TBI who had intracranial injuries identified on the initial head CT had a significantly lower quality-of-life scores compared to children with TBI whose initial head CTs were normal. In multivariate analysis, children whose initial head CT scans demonstrated intraventricular hemorrhage, parenchymal injury, midline shift {>=}5 mm, hemorrhagic shear injury, abnormal cisterns or subdural hematomas {>=}3 mm had lower quality of life scores 1 year after injury than children whose initial CTs did not have these same injuries. Associations exist between findings from the initial noncontrast head CT and quality of life score 12 months after injury in children with TBI. (orig.)

  9. Performance of FDG PET/CT at initial diagnosis in a rare lymphoma: nodular lymphocyte-predominant Hodgkin lymphoma

    Energy Technology Data Exchange (ETDEWEB)

    Grellier, Jean Francois; Weinmann, Pierre [AP-HP- Hopital Europeen Georges Pompidou, Service de medecine nucleaire, Paris (France); Vercellino, Laetitia; Merlet, Pascal; Toubert, Marie-Elisabeth; Berenger, Nathalie [AP-HP- Hopital Saint-Louis, Service de medecine nucleaire, Paris (France); Leblanc, Thierry [Hopital Saint-Louis, Service d' immuno-hematologie, Paris (France); Thieblemont, Catherine [Universite Paris Diderot, Sorbonne Paris Cite - INSERM UMR-S1165, AP-HP- Hopital Saint-Louis, Service d' hemato-Oncologie, Paris (France); Briere, Josette [AP-HP- Hopital Saint-Louis, Service de pathologie, Paris (France); Brice, Pauline [AP-HP- Hopital Saint-Louis, Service d' hemato-Oncologie, Paris (France)

    2014-11-15

    Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) is a rare Hodgkin lymphoma distinguished from classical Hodgkin lymphoma (cHL) by the nature of the neoplastic cells which express B-cell markers. We wanted to determine the diagnostic performance of FDG PET/CT in initial assessment and its therapeutic impact on staging. We retrospectively studied a population of 35 patients with NLPHL (8 previously treated for NLHPL, 27 untreated). All patients underwent an initial staging by pretherapeutic FDG PET/CT. The impact on initial stage or relapse stage was assessed by an independent physician. In a per-patient analysis, the sensitivity of the pretherapeutic FDG PET/CT was 100 %. In a per-site analysis, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of pretherapeutic FDG PET/CT were 100 %, 99 %, 97 %, 100 % and 99 %, respectively. Pretherapeutic FDG PET/CT led to a change in the initial stage/relapse stage in 12 of the 35 patients (34 %). In contrast to previous results established without FDG PET/CT, 20 % of patient had osteomedullary lesions. Pretherapeutic FDG PET/CT has excellent performance for initial staging or relapse staging of NLPHL. (orig.)

  10. Computerized tomography(CT) in patients with head injuries, assessment of outcome based upon initial clinical findings and initial CT scans

    International Nuclear Information System (INIS)

    Espersen, J.O.; Petersen, O.F.

    1982-01-01

    In this study, which comprises 144 consecutive head injuries, the initial clinical assessment and the findings of the initial CT scan are relatd to the outcome. The mortality is related to the patient's level of consiousness and pupillary light reflex on admission. The disability rate (= number of disabled/number of survivors) was independent of the level of consiousness but closely related to pupillary light reaction. Diminished and obliterated basal cisterns were bad prognostic signs, with a mortality rate of 66% in the latter group. Both disability and mortality increase with the number of different lesion types. (Author)

  11. Evaluation of bone metastases with 18 F- Sodium fluoride PET/CT; initial experience

    International Nuclear Information System (INIS)

    Sanchez C, N.; Serna M, J.A.; Quiroz C, O.; Quinzanos, F.; Valenzuela, J.; Ramirez A, J.L.

    2007-01-01

    The study of NaF-18 PET/CT is the modality with bigger sensitivity and specificity for the bony metastases detection. This additional value of the NaF-18 PET/CT can have a beneficent impact in the clinical handling of the patients with prostate cancer with high risk. (Author)

  12. PET/CT-guided interventional procedures: rationale, justification, initial study, and research plan

    Energy Technology Data Exchange (ETDEWEB)

    Wong, K.; Rahill, J.; Cleary, K. [Computer Aided Interventions and Medical Robotics (CAIMR), Imaging Science and Information Systems (ISIS) Center, Georgetown Univ. Medical Center, Washington, DC (United States); Petrillo, S.; Earl-Graef, D. [Dept. of Radiology, Georgetown Univ. Hospital, MedStar Health, Washington, DC (United States); Banovac, F.; Levy, E. [Computer Aided Interventions and Medical Robotics (CAIMR), Imaging Science and Information Systems (ISIS) Center, Georgetown Univ. Medical Center, Washington, DC (United States); Dept. of Radiology, Georgetown Univ. Hospital, MedStar Health, Washington, DC (United States); Shekhar, R. [Dept. of Radiology, Univ. of Maryland Medical Center, Baltimore, MD (United States)

    2007-06-15

    Positron-emission tomography (PET) and PET/CT (computed tomography) are becoming increasingly important for diagnosis and treatment of cancer. Clinically relevant changes can sometimes be seen on PET that are not seen on other imaging modalities. However, PET is not suitable for guiding biopsy as the images are not obtained in real-time. Therefore, our research group has begun developing a concept for PET/CT-guided interventional procedures. This paper presents the rationale for this concept, outlines our research plan, and includes an initial study to evaluate the relative sensitivity of CT and PET/CT in detecting suspicious lesions. (orig.)

  13. Initial staging of Hodgkin's disease: role of contrast-enhanced 18F FDG PET/CT.

    Science.gov (United States)

    Chiaravalloti, Agostino; Danieli, Roberta; Caracciolo, Cristiana Ragano; Travascio, Laura; Cantonetti, Maria; Gallamini, Andrea; Guazzaroni, Manlio; Orlacchio, Antonio; Simonetti, Giovanni; Schillaci, Orazio

    2014-08-01

    The objective of this study was to compare the diagnostic accuracy of positron emission tomography/low-dose computed tomography (PET/ldCT) versus the same technique implemented by contrast-enhanced computed tomography (ceCT) in staging Hodgkin's disease (HD).Forty patients (18 men and 22 women, mean age 30 ± 9.6) with biopsy-proven HD underwent a PET/ldCT study for initial staging including an unenhanced low-dose computed tomography for attenuation correction with positron emission tomography acquisition and a ceCT, performed at the end of the PET/ldCT scan, in the same exam session. A detailed datasheet was generated for illness locations for separate imaging modality comparison and then merged in order to compare the separate imaging method results (PET/ldCT and ceCT) versus merged results positron emission tomography/contrast-enhanced computed tomography (PET/ceCT). The nodal and extranodal lesions detected by each technique were then compared with follow-up data that served as the reference standard.No significant differences were found at staging between PET/ldCT and PET/ceCT in our series. One hundred and eighty four stations of nodal involvement have been found with no differences in both modalities. Extranodal involvement was identified in 26 sites by PET/ldCT and in 28 by PET/ceCT. We did not find significant differences concerning the stage (Ann Arbor).Our study shows a good concordance and conjunction between PET/ldCT and ceCT in both nodal and extranodal sites in the initial staging of HD, suggesting that PET/ldCT could suffice in most of these patients.

  14. Initial experience with megavoltage (MV) CT guidance for daily prostate alignments

    International Nuclear Information System (INIS)

    Langen, Katja M.; Zhang Yashan; Andrews, Rhonda D.; Hurley, Monica E.; Meeks, Sanford L.; Poole, Darrell O.; Willoughby, Twyla R.; Kupelian, Patrick A.

    2005-01-01

    Purpose: The on-board megavoltage (MV) computed tomography (CT) capabilities of a TomoTherapy Hi*ART unit were used to obtain daily MVCT images of prostate cancer patients. For patient alignment the daily MVCT image needs to be registered with the planning CT image to calculate couch shifts. Three manual techniques of registering the MVCT images with the planning kilovoltage (kV) CT images were evaluated. The techniques are based on visual alignment of (1) fiducial prostate markers (2) CT anatomy, and (3) kVCT contours. Methods and Materials: One hundred and twelve alignments from 3 patients were available for analysis. The radiation therapists visually registered the MVCT images with the planning kVCT images based on fiducial markers for actual patient alignment. Retrospectively, the therapists registered each image set using anatomy and contour-based techniques. In addition to the therapists, a physician retrospectively registered each image set based on each of the three techniques. For each MVCT to kVCT image pair a reference alignment was computed from the center-of-mass (COM) of the three fiducial markers. All registration results were compared with these reference alignments. The physician's image registrations were compared with the radiation therapists' registrations to assess the user variability of the different techniques. Results: The marker-based registration results agree best with the reference alignments, while the contour-based registrations show the least degree of agreement. Using anatomy and contour-based registrations, the radiation therapist's alignments differed by ≥ 3 mm from the reference alignments in 24%, 33%, and 3% and 55%, 48%, and 21% of all registrations in the anterior-posterior, superior-inferior, and lateral directions, respectively. The respective values for the marker-based alignments were 3%, 6%, and 3%. The physician's registrations showed the same general trend. The marker-based registrations showed the least amount of

  15. [Virtual bronchoscopy in the child using multi-slice CT: initial clinical experiences].

    Science.gov (United States)

    Kirchner, J; Laufer, U; Jendreck, M; Kickuth, R; Schilling, E M; Liermann, D

    2000-01-01

    Virtual bronchoscopy of the pediatric patient has been reported to be more difficult because of artifacts due to breathing or motion. We demonstrate the benefit of the accelerated examination based on multislice spiral CT (MSCT) in the pediatric patient which has not been reported so far. MSCT (tube voltage 120 kV, tube current 110 mA, 4 x 1 mm Slice thickness, 500 ms rotation time, Pitch 6) was performed on a CT scanner of the latest generation (Volume Zoom, Siemens Corp. Forchheim, Germany). In totally we examined 11 patients (median age 48 months, range 2-122 months) suspected of having tracheoesophageal fistula (n = 2), tracheobronchial narrowing (n = 8) due to intrinsic or extrinsic factors or injury of the bronchial system (n = 1). In all patients we obtained sufficient data for 3D reconstruction avoiding general anesthesia. 6/11 examinations were described to be without pathological finding. A definite diagnosis was obtained in 10 patients. Virtual bronchoscopy could avoid other invasive diagnostic examination in 8/11 patients (73%). Helical CT provides 3D-reconstruction and virtual bronchoscopy in the newborn as well as the infant. It avoids additional diagnostic bronchoscopy in a high percentage of all cases.

  16. Coronary CT angiography-derived fractional flow reserve correlated with invasive fractional flow reserve measurements - initial experience with a novel physician-driven algorithm

    International Nuclear Information System (INIS)

    Baumann, Stefan; Wang, Rui; Schoepf, U.J.; Steinberg, Daniel H.; Spearman, James V.; Bayer, Richard R.; Hamm, Christian W.; Renker, Matthias

    2015-01-01

    The present study aimed to determine the feasibility of a novel fractional flow reserve (FFR) algorithm based on coronary CT angiography (cCTA) that permits point-of-care assessment, without data transfer to core laboratories, for the evaluation of potentially ischemia-causing stenoses. To obtain CT-based FFR, anatomical coronary information and ventricular mass extracted from cCTA datasets were integrated with haemodynamic parameters. CT-based FFR was assessed for 36 coronary artery stenoses in 28 patients in a blinded fashion and compared to catheter-based FFR. Haemodynamically relevant stenoses were defined by an invasive FFR ≤0.80. Time was measured for the processing of each cCTA dataset and CT-based FFR computation. Assessment of cCTA image quality was performed using a 5-point scale. Mean total time for CT-based FFR determination was 51.9 ± 9.0 min. Per-vessel analysis for the identification of lesion-specific myocardial ischemia demonstrated good correlation (Pearson's product-moment r = 0.74, p < 0.0001) between the prototype CT-based FFR algorithm and invasive FFR. Subjective image quality analysis resulted in a median score of 4 (interquartile ranges, 3-4). Our initial data suggest that the CT-based FFR method for the detection of haemodynamically significant stenoses evaluated in the selected population correlates well with invasive FFR and renders time-efficient point-of-care assessment possible. (orig.)

  17. Adenosine-stress dynamic real-time myocardial perfusion CT and adenosine-stress first-pass dual-energy myocardial perfusion CT for the assessment of acute chest pain: Initial results

    Energy Technology Data Exchange (ETDEWEB)

    Weininger, Markus [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); Schoepf, U. Joseph, E-mail: schoepf@musc.edu [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); Department of Medicine, Division of Cardiology, Medical University of South Carolina, Charleston, SC (United States); Ramachandra, Ashok [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); Fink, Christian [Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University (Germany); Rowe, Garrett W.; Costello, Philip [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); Henzler, Thomas [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University (Germany)

    2012-12-15

    Purpose: Recent innovations in CT enable the evolution from mere morphologic imaging to dynamic and functional testing. We describe our initial experience performing myocardial stress perfusion CT in a clinical population with acute chest pain. Methods and materials: Myocardial stress perfusion CT was performed on twenty consecutive patients (15 men, 5 women; mean age 65 ± 8 years) who presented with acute chest pain and were clinically referred for stress/rest SPECT and cardiac MRI. Prior to CT each patient was randomly assigned either to Group A or to Group B in a consecutive order (10 patients per group). Group A underwent adenosine-stress dynamic real-time myocardial perfusion CT using a novel “shuttle” mode on a 2nd generation dual-source CT. Group B underwent adenosine-stress first-pass dual-energy myocardial perfusion CT using the same CT scanner in dual-energy mode. Two experienced observers visually analyzed all CT perfusion studies. CT findings were compared with MRI and SPECT. Results: In Group A 149/170 myocardial segments (88%) could be evaluated. Real-time perfusion CT (versus SPECT) had 86% (84%) sensitivity, 98% (92%) specificity, 94% (88%) positive predictive value, and 96% (92%) negative predictive value in comparison with perfusion MRI for the detection of myocardial perfusion defects. In Group B all myocardial segments were available for analysis. Compared with MRI, dual-energy myocardial perfusion CT (versus SPECT) had 93% (94%) sensitivity, 99% (98%) specificity, 92% (88%) positive predictive value, and 96% (94%) negative predictive value for detecting hypoperfused myocardial segments. Conclusion: Our results suggest the clinical feasibility of myocardial perfusion CT imaging in patients with acute chest pain. Compared to MRI and SPECT both, dynamic real-time perfusion CT and first-pass dual-energy perfusion CT showed good agreement for the detection of myocardial perfusion defects.

  18. Adenosine-stress dynamic real-time myocardial perfusion CT and adenosine-stress first-pass dual-energy myocardial perfusion CT for the assessment of acute chest pain: Initial results

    International Nuclear Information System (INIS)

    Weininger, Markus; Schoepf, U. Joseph; Ramachandra, Ashok; Fink, Christian; Rowe, Garrett W.; Costello, Philip; Henzler, Thomas

    2012-01-01

    Purpose: Recent innovations in CT enable the evolution from mere morphologic imaging to dynamic and functional testing. We describe our initial experience performing myocardial stress perfusion CT in a clinical population with acute chest pain. Methods and materials: Myocardial stress perfusion CT was performed on twenty consecutive patients (15 men, 5 women; mean age 65 ± 8 years) who presented with acute chest pain and were clinically referred for stress/rest SPECT and cardiac MRI. Prior to CT each patient was randomly assigned either to Group A or to Group B in a consecutive order (10 patients per group). Group A underwent adenosine-stress dynamic real-time myocardial perfusion CT using a novel “shuttle” mode on a 2nd generation dual-source CT. Group B underwent adenosine-stress first-pass dual-energy myocardial perfusion CT using the same CT scanner in dual-energy mode. Two experienced observers visually analyzed all CT perfusion studies. CT findings were compared with MRI and SPECT. Results: In Group A 149/170 myocardial segments (88%) could be evaluated. Real-time perfusion CT (versus SPECT) had 86% (84%) sensitivity, 98% (92%) specificity, 94% (88%) positive predictive value, and 96% (92%) negative predictive value in comparison with perfusion MRI for the detection of myocardial perfusion defects. In Group B all myocardial segments were available for analysis. Compared with MRI, dual-energy myocardial perfusion CT (versus SPECT) had 93% (94%) sensitivity, 99% (98%) specificity, 92% (88%) positive predictive value, and 96% (94%) negative predictive value for detecting hypoperfused myocardial segments. Conclusion: Our results suggest the clinical feasibility of myocardial perfusion CT imaging in patients with acute chest pain. Compared to MRI and SPECT both, dynamic real-time perfusion CT and first-pass dual-energy perfusion CT showed good agreement for the detection of myocardial perfusion defects.

  19. Role of carbon-11 choline PET/CT in the management of uterine carcinoma. Initial experience

    International Nuclear Information System (INIS)

    Sofue, Keitaro; Sawada, Morio; Arai, Yasuaki; Tateishi, Ukihide; Inoue, Tomio; Maeda, Tetsuo; Sugimura, Kazuro; Terauchi, Takashi; Kano, Daisuke

    2009-01-01

    The present study was conducted to clarify the role of carbon-11 choline ( 11 C-choline) positron emission tomography (PET)/computed tomography (CT) in the management of uterine carcinoma. Twenty-two patients who underwent 11 C-choline PET/CT and pelvic MRI were evaluated retrospectively. The images were reviewed by a board-certified radiologist and a nuclear medicine specialist who were unaware of any clinical information, and a consensus was reached. Diagnostic accuracy of PET/CT was evaluated for staging. The reference standard consisted of histological examination (n=17) and follow-up conventional CT (n=5). In five patients with cervical carcinoma, 11 C-choline PET/CT was performed before and after treatment that consisted of cisplatin infusion and subsequent radiotherapy. Standardized uptake value (SUV) was compared with unidimensional and volumetric measurements that were made on magnetic resonance images (MRI) before and after treatment. Based on PET/CT interpretations, the reviewers correctly classified tumor (T) stage in 8 patients (47%), nodes (N) stage in 21 patients (96%), metastasis (M) stage in 20 patients (91%), and tumor, nodes and metastasis (TNM) stage in 15 patients (88%). Tumor size, volume, and SUV decreased after treatment in five patients with cervical carcinoma. Using the Pearson correlation test, a significant correlation was found between the reduction rate of SUV and reduction rate of tumor volume. 11 C-choline PET/CT is an accurate means for the management of patients with uterine carcinoma. The combination of 11 C-choline PET/CT and MRI increases the accuracy of staging in patients with uterine carcinoma. (author)

  20. Imaging of blunt pancreatic trauma: The value of initial and sequential CT examinations

    International Nuclear Information System (INIS)

    Szmigielski, W.; Darweesh, A.; Kassem, H.; Alhilli, S.

    2008-01-01

    The purpose of the study was to assess the value of initial, repeated and sequential computed tomography (CT) in patients with blunt pancreatic trauma, and then define and correlate CT findings with endoscopic retrograde cholangiopancreatography (ERCP) or magnetic resonance cholangiopancreatography (MRCP), ultrasound (US), both laboratory and surgical findings. This retrospective study covers an eight-year period from 1999 to 2007. The material includes 21 patients (17 males and 4 females) with confirmed pancreatic injury. CT was performed on admission in all cases and in 15 cases follow-up CT was performed from 24 hrs to 14 days later. US was performed in 9 cases, ERCP in 8 cases and MRCP in one case. Serum amylase level was obtained at the admission in all cases. The CT at admission was positive in 17 patients (81.0%); the diagnosis was missed in 4 patients (19.0%), all performed on single row spiral CT. In all these four cases repeated CT was positive. ERCP showed rupture of the main pancreatic duct in 7 cases, one was inconclusive. One MRCP was positive. The serum amylase was elevated in 14 cases (66.7%) Specific CT features in initial and repeated examinations together were: organ fracture - 33.3%, swelling - 38.1%, haematoma/ contusion - 38.1%, fluid between splenic vein and pancreas - 19.0%. Non-specific features were: thickening of anterior-renal fascia- 23.8%, fluid in lesser sac - 28.6%, extra peritoneal fluid - 42.9%, associated splenic injury -14.3% and intraperitoneal fluid - 38.1%. On retrospective analysis, two out of four false negative CT results could have been avoided. No correlation between the CT features and the outcome of surgical and conservative management could be found in this study. A proper technique and accurate reading of images are mandatory for the diagnosis of pancreatic injury. When CT performed on admission is negative and there is abdominal pain and an elevated serum amylase, CT examination should be repeated within 24-48 hours

  1. Multicenter Comparison of Contrast-Enhanced FDG PET/CT and 64-Slice Multi-Detector-Row CT for Initial Staging and Response Evaluation at the End of Treatment in Patients With Lymphoma.

    Science.gov (United States)

    Gómez León, Nieves; Delgado-Bolton, Roberto C; Del Campo Del Val, Lourdes; Cabezas, Beatriz; Arranz, Reyes; García, Marta; Cannata, Jimena; González Ortega, Saturnino; Pérez Sáez, Mª Ángeles; López-Botet, Begoña; Rodríguez-Vigil, Beatriz; Mateo, Marta; Colletti, Patrick M; Rubello, Domenico; Carreras, José L

    2017-08-01

    To compare staging correctness between contrast-enhanced FDG PET/ceCT and 64-slice multi-detector-row CT (ceCT64) for initial staging and response evaluation at the end of treatment (EOT) in patients with Hodgkin lymphoma, diffuse large B cell lymphoma (DLBCL), and follicular lymphoma. This prospective study compared initial staging and response evaluation at EOT. One hundred eighty-one patients were randomly assigned to either ceCT64 or FDG PET/ceCT. A nuclear medicine physician and a radiologist read FDG PET/ceCT scans independently and achieved post hoc consensus, whereas another independent radiologist interpreted ceCT64 separately. The reference standard included all clinical information, all tests, and follow-up. Ethics committees of the participating centers approved the study, and all participants provided written consent. Ninety-one patients were randomized to ceCT64 and 90 to FDG PET/ceCT; 72 had Hodgkin lymphoma, 72 had DLBCL, and 37 had follicular lymphoma. There was excellent correlation between the reference standard and initial staging for both FDG PET/ceCT (κ = 0.96) and ceCT64 (κ = 0.84), although evaluation of the response at EOT was excellent only for FDG PET/ceCT (κ = 0.91). Our study demonstrated satisfactory agreement between FDG PET/ceCT (κ = 0.96) and ceCT64 (κ = 0.84) in initial staging compared with the reference standard (P = 0.16). Response evaluation at EOT with FDG PET/ceCT (κ = 0.91) was superior compared with ceCT64 (κ = 0.307) (P < 0.001).

  2. Automated lung module detection at low-dose CT: preliminary experience

    International Nuclear Information System (INIS)

    Goo, Jin-Mo; Lee, Jeong-Won; Lee, Hyun-Ju; Kim, Seung-Wan; Kim, Jong-Hyo; Im, Jung-Gi

    2003-01-01

    To determine the usefulness of a computer-aided diagnosis (CAD) system for the automated detection of lung nodules at low-dose CT. A CAD system developed for detecting lung nodules was used to process the data provided by 50 consecutive low-dose CT scans. The results of an initial report, a second look review by two chest radiologists, and those obtained by the CAD system were compared, and by reviewing all of these, a gold standard was established. By applying the gold standard, a total of 52 nodules were identified (26 with a diameter ≤ 5 mm; 26 with a diameter > 5 mm). Compared to an initial report, four additional nodules were detected by the CAD system. Three of these, identified only at CAD, formed part of the data used to derive the gold standard. For the detection of nodules > 5 mm in diameter, sensitivity was 77% for the initial report, for the second look review, and 88% for the second look review,and 65% for the CAD system. There were 8.0 ± 5.2 false-positive CAD results per CT study. These preliminary results indicate that a CAD system may improve the detection of pulmonary nodules at low-dose CT

  3. Initial observations of electronic medical record usage during CT and MRI interpretation: Frequency of use and impact on workflow.

    Science.gov (United States)

    Lin, Abraham; Harris, Mitchell; Zalis, Michael

    2010-07-01

    Electronic medical record (EMR) systems permit integration of contextual nonimaging EMR data into examination interpretation; however, the extra effort required to search and review these nonradiologic data are not well characterized. We assessed the gross frequency and pattern of EMR usage in the interpretation of diagnostic CT and MRI examinations. We defined nonradiologic EMR data as laboratory data, nonimaging specialty report, clinical note, and administrative data not available on PACS. For abdominal, neuroradiologic, and musculoskeletal CT and MRI, we prospectively recorded the time required for image analysis (including prior imaging studies and their reports), nonradiologic EMR use, and initial report drafting by fellows and staff in randomized sessions. We assessed EMR use as a fraction of work activity and according to technique, subspecialty, inpatient status, and radiologist experience. We observed 372 CT and MRI interpretations by 33 radiologists. For CT, radiologists used the EMR in 34% of abdominal, 57% of neuroradiologic, and 38% of musculoskeletal interpretations. For MRI, EMR was used in 73% of abdominal, 56% of neuroradiologic, and 33% of musculoskeletal interpretations. For CT, EMR usage comprised 18%, 14%, and 18% of diagnostic effort (image analysis plus EMR use) for abdominal, neuroradiologic, and musculoskeletal interpretations, respectively; for MRI, EMR usage comprised 21%, 16%, and 15% of diagnostic effort for abdominal, neuroradiologic, and musculoskeletal interpretations, respectively. Frequency of EMR use was significantly greater for neuroradiology CT and abdominal MRI (p < 0.05, Fisher's test). EMR usage was not consistently related to inpatient status for CT or radiologist experience. For CT and MRI interpretation, EMR usage is frequent and comprises a significant fraction of diagnostic effort.

  4. Serial high resolution CT in non-specific interstitial pneumonia: prognostic value of the initial pattern

    Energy Technology Data Exchange (ETDEWEB)

    Screaton, N.J. [Department of Radiology, Addenbrooke' s Hospital, Cambridge (United Kingdom)]. E-mail: nicholas.screaton@papworth.nhs.uk; Hiorns, M.P. [Department of Radiology, Great Ormond Street Hospital, London (United Kingdom); Lee, K.S. [Samsung Medical Centre, Seoul (Korea); Franquet, T. [Hospital de Saint Pau, Universidad Autonoma de Barcelona, Barcelona (Spain); Johkoh, T. [Department of Medical Physics and Radiology, Osaka University Graduate School of Medicine, Osaka (Japan); Fujimoto, K. [Department of Radiology, Kurume University School of Medicine, Kurume (Japan); Ichikado, K. [First Department of Internal Medicine, Kumamoto University School of Medicine, Kumamoto (Japan); Colby, T.V. [Department of Laboratory Medicine/Pathology, Mayo Clinic Scottsdale, AZ (United States); Mueller, N.L. [Department of Radiology, Vancouver General Hospital, Vancouver (Canada)

    2005-01-01

    AIM: To assess the relationship between initial CT pattern and serial changes in CT findings and pulmonary function tests (PFTs) in patients with non-specific interstitial pneumonia (NSIP). MATERIALS AND METHODS: Serial high resolution (HR) CTs and PFTs were retrospectively analyzed in 38 cases of histologically proven NSIP, including 4 with cellular NSIP, 13 with mixed cellular and fibrotic NSIP, and 21 with fibrotic NSIP. The presence and extent of various CT findings were assessed. A fibrosis index (defined as the ratio of the extent of a reticular/honeycomb pattern to the overall extent of abnormal parenchyma) was derived. RESULTS: The predominant CT pattern was reticular/honeycomb in 27 (84%) cases and ground-glass/consolidation in 6 (16%) cases. Between scans, mean disease extent reduced by 5.2%. Disease extent reduced by >10% in 13 (34%) and increased by >10% in 6 (16%) patients. Histopathological subtype of NSIP did not correlate with individual CT pattern, predominant pattern, fibrosis index or serial change in disease extent on CT or PFTs. Response on follow-up CT was associated with fibrosis index, predominant pattern and extent of consolidation on initial CT. CONCLUSION: In NSIP disease, progression on CT correlates with the predominant CT pattern, fibrosis index, and extent of consolidation but not with histopathological subtype. An inflammatory (ground-glass/consolidation) predominant pattern is associated with better outcome in terms of disease extent on HRCT.

  5. FDG PET/CT in initial staging and early response to chemotherapy assessment of paediatric rhabdomyosarcomas

    International Nuclear Information System (INIS)

    Eugene, T.; Ansquer, C.; Oudoux, A.; Carlier, T.; Kraeber-Bodere, T.; Bodet-Milin, C.; Corradini, N.; Thomas, C.; Dupas, B.

    2010-01-01

    Purpose: The objective of this study was to retrospectively evaluate the impact of positron emission tomography/computed tomography (PET/CT) using fluorine-18-fluorodeoxyglucose (FDG), in comparison with conventional imaging modalities (CIM), for initial staging and early therapy assessment in paediatric rhabdomyosarcoma. Patients and methods: Prior to treatment, 18 patients (age range, 9 months to 18 years) with histologically proven rhabdomyosarcoma underwent FDG PET/CT in addition to CIM (magnetic resonance imaging of primary site, whole body CT and bone scintigraphy). After three courses of chemotherapy, 12 patients underwent FDG PET/CT in addition to CIM. RECIST criteria and visual analysis of FDG uptake were used for assessment of response. The standard of reference was determined by an interdisciplinary tumor board based on imaging material, histopathology and follow-up data (median = 5 years). Results: PET/CT sensitivity was superior to CIM's concerning lymph node involvement (100% versus 83%, respectively) and metastases detection (100% versus 50%, respectively). PET/CT results changed therapeutic management in 11% of cases. After three courses of chemotherapy, the rate of complete response was 66% with PET/CT versus 8% with CIM. Five percent of patients relapsed during follow-up (median = 5 years). Conclusion: This study confirms that PET/CT depicts important additional information in initial staging of paediatric rhabdomyosarcomas and suggests a superior prognostic value of PET/CT in early response to chemotherapy assessment. (authors)

  6. CT-TRX1, a triggered-reconnection compact toroid experiment

    International Nuclear Information System (INIS)

    Hoffman, A.L.

    1980-05-01

    A new compact toroid experiment, CT-TRX1, based on the field reversed theta pinch is under construction. The unique feature of this experiment is the incorporation of several quasi-steady and pulsed magnets to carefully control the reconnection process. The motivation for this emphasis is to duplicate and extend the results reported by Kurtmullaev, et al., where delayed reconnection produced efficient axial shock heating and resulted in large diameter compact toroids which exhibited complete MHD stability for the 100 μsec decay time of their pulsed magnets. CT-TRX1 incorporates moderate E/sub theta/ radial shock heating, along with the triggered reconnection capability, to investigate the full range of conditions between the USSR experiments and the radial shock heated experiments at LASL, where m = 2 rotational instabilities occur. An additional feature of CT-TRX1 is the incorporation of a compound magnet which will provide long magnetic field decay times. The requirements for both high field quasi-steady outer magnets, and several high voltage, individually triggered pulsed inner magnets, present unique engineering design problems which are discussed

  7. How to choose PET-CT or CT in the diagnosis and staging of lung cancer. Practical experience in China

    International Nuclear Information System (INIS)

    Jiang, T.; Tao, X.; Liu, H.; Liu, S.; Zheng, X.

    2010-01-01

    How to use CT and PET-CT rationally to raise diagnosis, staging and prognostic assessment of lung cancer to a higher level at the best cost-effect ratio is a subject that Chinese clinicians and radiologists should face conscientiously. We review the rational application of CT and PET-CT in four aspects of lung cancer, including screening and detection, morphologic evaluation, haemodynamic or metabolic feature evaluation, and follow-up, staging and prognostic evaluation. As PET-CT is only available in class III-A hospitals today, CT is the most popular equipment in China. PET-CT is more valuable only in cases where CT presentation of lung cancer is atypical or difficult to determine, or in cases where the diagnosis of lung cancer has been initially confirmed, for which clinical staging and decision concerning on therapeutic regimens are needed. We also recommend the current strategies of CT and PET-CT managing of SPN in China. (orig.)

  8. Coronary artery imaging with 64-slice spiral CT in atrial fibrillation patients: initial experience

    International Nuclear Information System (INIS)

    Zhou Xuhui; Yan Chaogui; Xie Hongbo; Li Xiangmin; Li Ziping; Meng Quanfei; Chen Xing

    2008-01-01

    Objective: To discuss the clinical value of coronary artery imaging using 64-slice spiral CT in patient with atrial fibrillation. Methods: The images of 31 patients with atrial fibrillation who underwent contrast-enhanced CT coronary angiography were evaluated. The presence of stenosis on each segment of coronary arteries was recorded and their degree of stenosis was measured using the vessel analysis software. Ten patients additionally underwent conventional coronary angiography. The results of conventional coronary angiography were compared with CT coronary angiography of the 10 patients. Results: Image reconstruction was based on absolute timing. The image quality of 364 coronary vessel segments on the images from 31 patients was evaluated and defined as excellent, fine, moderate or poor. The image quality was excellent, fine, moderate and poor in 85, 41, 5, and 8 vessel segments respectively in patient group with heart rate between 47 beat per minent (bpm) and 69 bpm; and in 63, 16, 13, and 15 vessel segments respectively in patent group with heart rate between 70 bpm and 79 bpm;and in 46, 25, 23, and 24 vessel segments in patient group with heart rate between 80 bpm and 105 bpm. There was significant difference among the three patient groups (H=22.08, P<0.01). Comparison was carried out between CT angiographic findings and conventional angiographic findings of the 125 segments of the coronary arteries in the 10 patients who underwent conventional coronary angiography. The sensitivity and specificity of CT angiography for diagnosing vessel with significant coronary stenosis (≥50% narrowing) was 85.0% (17/20) and 95.2% (100/105), respectively. Positive predictive value was 77.3% (17/22), and negative predictive value was 97.1% (100/103). Coronary CTA underestimated the lesions of 3 vessel segments and overestimated the lesions of 5 vessel segments. Conclusion: Coronary artery imaging with 64-slice row CT had clinical value for patients with atrial fibrillation

  9. CT colonography: effect of experience and training on reader performance

    International Nuclear Information System (INIS)

    Taylor, Stuart A.; Burling, David; Morley, Simon; Bartram, Clive I.; Halligan, Steve; Bassett, Paul; Atkin, Wendy

    2004-01-01

    The purpose of this paper was to investigate the effect of radiologist experience and increasing exposure to CT colonography on reader performance. Three radiologists of differing general experience (consultant, research fellow, trainee) independently analysed 100 CT colonographic datasets. Readers had no prior experience of CT colonography and received feedback and training after the first 50 cases from an independent experienced radiologist. Diagnostic performance and reporting times were compared for the first and second 50 datasets and compared with the results of a radiologist experienced in CT colonography. Before training only the consultant reader achieved statistical equivalence with the reference standard for detection of larger polyps. After training, detection rates ranged between 25 and 58% for larger polyps. Only the trainee significantly improved after training (P=0.007), with performance of other readers unchanged or even worse. Reporting times following training were reduced significantly for the consultant and fellow (P<0.001 and P=0.03, respectively), but increased for the trainee (P<0.001). In comparison to the consultant reader, the odds of detection of larger polyps was 0.36 (CI 0.16, 0.82) for the fellow and 0.36 (CI 0.14, 0.91) for the trainee. There is considerable variation in the ability to report CT colonography. Prior experience in gastrointestinal radiology is a distinct advantage. Competence cannot be assumed even after directed training via a database of 50 cases. (orig.)

  10. High-pitch dual-source CT angiography of the whole aorta without ECG synchronisation: Initial experience

    International Nuclear Information System (INIS)

    Beeres, Martin; Schell, Boris; Mastragelopoulos, Aristidis; Kerl, Josef Matthias; Gruber-Rouh, Tatjana; Lee, Clara; Siebenhandl, Petra; Bodelle, Boris; Zangos, Stephan; Vogl, Thomas J.; Jacobi, Volkmar; Bauer, Ralf W.; Herrmann, Eva

    2012-01-01

    To investigate the feasibility, image quality and radiation dose for high-pitch dual-source CT angiography (CTA) of the whole aorta without ECG synchronisation. Each group of 40 patients underwent CTA either on a 16-slice (group 1) or dual-source CT device with conventional single-source (group 2) or high-pitch mode with a pitch of 3.0 (group 3). The presence of motion or stair-step artefacts of the thoracic aorta was independently assessed by two readers. Subjective and objective scoring of motion and artefacts were significantly reduced in the high-pitch examination protocol (p < 0.05). The imaging length was not significantly different, but the imaging time was significantly (p < 0.001) shorter in the high-pitch group (12.2 vs. 7.4 vs. 1.7 s for groups 1, 2 and 3). The ascending aorta and the coronary ostia were reliably evaluable in all patients of group 3 without motion artefacts as well. High-pitch dual-source CT angiography of the whole aorta is feasible in unselected patients. As a significant advantage over regular pitch protocols, motion-free imaging of the aorta is possible without ECG synchronisation. Thus, this CT mode bears potential to become a standard CT protocol before trans-catheter aortic valve implantation (TAVI). (orig.)

  11. Preliminary results on the role of PET/CT in initial staging, restaging, and management of lung cancer

    Energy Technology Data Exchange (ETDEWEB)

    Malamitsi, J. [Department of PET/CT, Diagnostic and Therapeutic Center of Athens, Hygeia, Athens (Greece): Department of Medical Physics, Medical School, University of Athens (Greece)]. E-mail: j.malamitsi@yahoo.gr; Valotassiou, B. [Department of PET/CT, Diagnostic and Therapeutic Center of Athens, Hygeia, Athens (Greece); Iliadis, K. [Thoracic Surgical Department, Diagnostic and Therapeutic Center of Athens, Hygeia, Athens (Greece); Kosmidis, P. [2nd Medical Oncology Department, Diagnostic and Therapeutic Center of Athens, Hygeia, Athens (Greece); Laspas, F. [Department of PET/CT, Diagnostic and Therapeutic Center of Athens, Hygeia, Athens (Greece); Vasilaki, M. [Oncologist, Diagnostic and Therapeutic Center of Athens, Hygeia, Athens (Greece); Pipini, E. [Thoracic Medicine Clinic, Diagnostic and Therapeutic Center of Athens, Hygeia, Athens (Greece); Petounis, A. [1st Internal Medicine and Oncology Department, Diagnostic and Therapeutic Center of Athens, Hygeia, Athens (Greece); Gogou, L. [Department of PET/CT, Diagnostic and Therapeutic Center of Athens, Hygeia, Athens (Greece); Pagou, M. [Department of PET/CT, Diagnostic and Therapeutic Center of Athens, Hygeia, Athens (Greece); Dalianis, K. [Department of PET/CT, Diagnostic and Therapeutic Center of Athens, Hygeia, Athens (Greece); Efthimiadou, R. [Department of PET/CT, Diagnostic and Therapeutic Center of Athens, Hygeia, Athens (Greece); Andreou, J. [Department of PET/CT, Diagnostic and Therapeutic Center of Athens, Hygeia, Athens (Greece)

    2006-12-20

    Aim: To determine true-positive and true-negative rates of PET/CT studies in the staging of lung cancer as compared with conventional imaging (CT and bone scan and occasionally MRI) and the impact of PET/CT on the treatment strategy in patients with lung cancer. Materials and method: Twenty patients (21 studies) with known or suspected lung cancer (14 patients with non-small-cell lung cancer (NSCLC), three patients with small-cell lung cancer (SCLC), three patients with solitary pulmonary nodule underwent initial staging (seven studies) or restaging (14 studies) with combined FDG PET and CT scans on a PET/CT tomograph. PET/CT images were evaluated separately by two nuclear medicine physicians and two radiologists specialized on PET, CT, and MRI. Histology results and a more than 6 months follow-up served as the reference standards. Results: Accurate diagnosis was achieved on 16 studies. Site-by-site analysis gave the following results: 16 true-positive sites (seven on histology, nine on >6 months follow-up), six true-negative sites (two on histology, four on >6 months follow-up). On PET/CT, six patients were correctly down-staged, three patients were correctly upstaged and seven patients were diagnosed correctly as being on the same stage (2/7 with increase of extent of disease, 5/7 with the same extent of disease). One patient was falsely upstaged and three patients were falsely down-staged. On the basis of PET/CT results, change of management was induced in six patients, while in 14 patients there was no change induced. In five cases PET/CT was partially accurate: on site-by-site analysis, four sites proved true positive (on histology), one site false positive (on histology), and four sites false negative (one on histology, three on >6 months follow-up). Conclusion: In our early experience, PET/CT contributed significantly to correct staging and management of patients with lung cancer.

  12. Preliminary results on the role of PET/CT in initial staging, restaging, and management of lung cancer

    International Nuclear Information System (INIS)

    Malamitsi, J.; Valotassiou, B.; Iliadis, K.; Kosmidis, P.; Laspas, F.; Vasilaki, M.; Pipini, E.; Petounis, A.; Gogou, L.; Pagou, M.; Dalianis, K.; Efthimiadou, R.; Andreou, J.

    2006-01-01

    Aim: To determine true-positive and true-negative rates of PET/CT studies in the staging of lung cancer as compared with conventional imaging (CT and bone scan and occasionally MRI) and the impact of PET/CT on the treatment strategy in patients with lung cancer. Materials and method: Twenty patients (21 studies) with known or suspected lung cancer (14 patients with non-small-cell lung cancer (NSCLC), three patients with small-cell lung cancer (SCLC), three patients with solitary pulmonary nodule underwent initial staging (seven studies) or restaging (14 studies) with combined FDG PET and CT scans on a PET/CT tomograph. PET/CT images were evaluated separately by two nuclear medicine physicians and two radiologists specialized on PET, CT, and MRI. Histology results and a more than 6 months follow-up served as the reference standards. Results: Accurate diagnosis was achieved on 16 studies. Site-by-site analysis gave the following results: 16 true-positive sites (seven on histology, nine on >6 months follow-up), six true-negative sites (two on histology, four on >6 months follow-up). On PET/CT, six patients were correctly down-staged, three patients were correctly upstaged and seven patients were diagnosed correctly as being on the same stage (2/7 with increase of extent of disease, 5/7 with the same extent of disease). One patient was falsely upstaged and three patients were falsely down-staged. On the basis of PET/CT results, change of management was induced in six patients, while in 14 patients there was no change induced. In five cases PET/CT was partially accurate: on site-by-site analysis, four sites proved true positive (on histology), one site false positive (on histology), and four sites false negative (one on histology, three on >6 months follow-up). Conclusion: In our early experience, PET/CT contributed significantly to correct staging and management of patients with lung cancer

  13. 18F-FDG PET/CT in breast cancer: Evidence-based recommendations in initial staging.

    Science.gov (United States)

    Caresia Aroztegui, Ana Paula; García Vicente, Ana María; Alvarez Ruiz, Soledad; Delgado Bolton, Roberto Carlos; Orcajo Rincon, Javier; Garcia Garzon, Jose Ramon; de Arcocha Torres, Maria; Garcia-Velloso, Maria Jose

    2017-10-01

    Current guidelines do not systematically recommend 18F-FDG PET/CT for breast cancer staging; and the recommendations and level of evidence supporting its use in different groups of patients vary among guidelines. This review summarizes the evidence about the role of 18F-FDG PET/CT in breast cancer staging and the therapeutic and prognostic impact accumulated in the last decade. Other related aspects, such as the association of metabolic information with biology and prognosis are considered and evidence-based recommendations for the use of 18F-FDG PET/CT in breast cancer staging are offered. We systematically searched MEDLINE for articles reporting studies with at least 30 patients related to clinical questions following the Problem/Population, Intervention, Comparison, and Outcome framework. We critically reviewed the selected articles and elaborated evidence tables structuring the summarized information into methodology, results, and limitations. The level of evidence and the grades of recommendation for the use of 18F-FDG PET/CT in different contexts are summarized. Level III evidence supports the use of 18F-FDG PET/CT for initial staging in patients with recently diagnosed breast cancer; the diagnostic and therapeutic impact of the 18F-FDG PET/CT findings is sufficient for a weak recommendation in this population. In patients with locally advanced breast cancer, level II evidence supports the use of 18F-FDG PET/CT for initial staging; the diagnostic and therapeutic impact of the 18F-FDG PET/CT findings is sufficient for a strong recommendation in this population. In patients with recently diagnosed breast cancer, the metabolic information from baseline 18F-FDG PET/CT is associated with tumor biology and has prognostic implications, supported by level II evidence. In conclusion, 18F-FDG PET/CT is not recommended for staging all patients with early breast cancer, although evidence of improved regional and systemic staging supports its use in locally advanced

  14. Implementing radiographic CT head reporting: The experiences of students and managers

    International Nuclear Information System (INIS)

    Clarke, Ruth; Allen, David; Arnold, Paul; Snaith, Beverley

    2014-01-01

    Introduction: In the face of growing demand in radiology, skill mix initiatives have sought to improve and expand service provision. Within the UK radiographer reporting is now widespread, although the growth in computerised tomography (CT) head reporting has not been as rapid as anticipated. The literature in this area is limited, but case studies have highlighted the successful implementation of this training through new radiographer roles in practice. Method: A cross-sectional survey was developed to elicit information from radiographers and managers on their experiences before, during and after post-graduate training in CT head reporting. Results: Seventy one responses were received comprising 48 past students (n = 48/111; 43.2%) and 23 service managers (n = 23/67; 34.3%). Key factors for the development were personal continual professional development for students and departmental need for managers. Challenges during training included a lack of study time due to staff shortages and access to radiologist mentors. Only 48.8% of students responding have gone on to use the new skills in practice cited reasons include staff shortages, resistance from radiologists and increase in radiological staffing. Conclusions: This qualitative study has demonstrated that those trusts who have implemented CT head reporting have evidenced perceptible benefits for both the department and individuals. Those radiographers who are successfully reporting have shown themselves to be highly motivated and persistent in their development

  15. Unenhanced multidetector CT (CT KUB) in the initial imaging of suspected acute renal colic: evaluating a new service

    International Nuclear Information System (INIS)

    Chowdhury, F.U.; Kotwal, S.; Raghunathan, G.; Wah, T.M.; Joyce, A.; Irving, H.C.

    2007-01-01

    Aim: To evaluate a new imaging pathway for the investigation of patients presenting with suspected acute renal colic. Materials and methods: A retrospective review of 500 consecutive cases of suspected acute renal colic was undertaken to evaluate the initial results of a new imaging pathway introduced at our institution, which completely replaced the intravenous urogram (IVU) with unenhanced multidetector CT (CT KUB). Results: The positive rate for urolithiasis was 44% (221/500), the negative rate 46% (229/500) and the rate of other significant findings was 12% (59/500). Female patients had a low positive rate compared with male patients (27.5 versus 57.5%; p < 0.001). Urological intervention was required in 28% (61/221) and these patients had a larger average stone size (6.6 versus 3.7 mm; p < 0.001) and the stone was located more proximally. Out-of-hours imaging was performed in 37% (186/500), and these patients had a higher positive rate (52 versus 40%; p < 0.001). Other findings included a wide range of acute non-urological conditions. Conclusion: The feasibility of replacing the acute IVU with CT KUB in the initial assessment of suspected acute renal colic was demonstrated in the present study. The technique enables rapid diagnosis of urolithiasis, stratification of patients likely to proceed to urological intervention, and prompt diagnosis of a variety of other acute pathological conditions

  16. Intra-arterial CT-angiography for cerebral arteriovenous malformation--initial experiences for treatment planning of radiosurgery

    International Nuclear Information System (INIS)

    Kunieda, Etsuo; Kawaguchi, Osamu; Onozuka, Satoshi; Momoshima, Suketaka; Takeda, Atsuya; Shigematsu, Naoyuki; Hashimoto, Subaru; Ohira, Takayuki; Kubo, Atsushi

    2002-01-01

    Purpose: To clarify the feasibility and effectiveness of intra-arterial CT angiography (IACTA) for treatment planning of arteriovenous malformation radiosurgery. Methods and Materials: A CT scanner installed in an angiographic examination room was used. Helical IACTA was performed in 22 patients during continuous intra-arterial infusion of contrast medium via the internal carotid or vertebral artery, and dynamic IACTA was performed in 20 of these patients with reconstruction at 0.2-s intervals. The dynamic IACTA was repeated for each 3- or 5-mm increment to encompass the nidus. Subtractions were performed in postembolization cases. A retrospective review of IACTA was performed to assess the effectiveness of dynamic scans. Results: No complications related to the angiographic procedure or CT imaging were detected. High contrast enhancement was obtained for both helical and dynamic IACTA. In 18 of the 20 cases (90%), draining veins were separated from the nidus by using the enhancement patterns, and in 13 cases (65%), feeding arteries were separated. Conclusion: Dynamic IACTA added important information for target-volume determinations. Conventional CT and MRI could be omitted from the protocol, and the period that patients wore the frame was substantially shortened. We conclude that IACTA is a practical and useful method for radiosurgical treatment planning of arteriovenous malformations

  17. The analysis of initial cranial CT of early hematoma enlargement in spontaneous intracerebral hemorrhage

    OpenAIRE

    BEI Yu-zhang; CHEN Ben-yang; QI Hao-bo; ZHOU Zheng-ping; LI Yu-bo

    2012-01-01

    Objective To investigate the predictive effect of initial cranial CT on early hematoma enlargement in spontaneous intracerebral hemorrhage. Methods Three hundred patients with spontaneous intracerebral hemorrhage within 6 hours after onset were studied. Chi-square test and logistic regression analysis were used to detect the related factors which may indicate hematoma enlargement. Results Sixty-one (20.33% ) patients presented hematoma enlargement on cranial CT. Single factor and multivariate...

  18. Percutaneous Cryoablation of Small Hepatocellular Carcinoma with US Guidance and CT Monitoring: Initial Experience

    International Nuclear Information System (INIS)

    Orlacchio, Antonio; Bazzocchi, Gabriele; Pastorelli, Daniela; Bolacchi, Francesca; Angelico, Mario; Almerighi, Cristiana; Masala, Salvatore; Simonetti, Giovanni

    2008-01-01

    The purpose of this study was to retrospectively determine the safety and effectiveness of percutaneous cryoablation, monitored with computed tomography (CT) and ultrasonographic (US) guidance, for the treatment of hepatocellular carcinoma (HCC). Four patients with small HCCs underwent one percutaneous cryoablation treatment session monitored with CT and US guidance. All patients underwent pretreatment blood chemistry testing and imaging evaluation. We treated lesions with simultaneous insertion of multiple 17-G cryoprobes (two or three) and defined technical success when the extension of a visible iceball was beyond 5 mm from the tumor margin. Intralesional enhancement or tumoral size increase was defined as local progression compared with that on images obtained immediately after ablation. We evaluated complications and follow-up (at 1, 3, and 6 months). All patients survived without short- or long-term complications. Cryoablation was technically successful in all patients at the end of the procedure. During follow-up two patients developed disease recurrence. One patient developed local tumor progression on the margin of the lesion; the other, a new HCC. In the case of local tumor progression a new elevation of α-fetoprotein (αFP) levels occurred at first follow-up control. In the other case levels of αFP remained stable during the first 3 months after the procedure, then demonstrated a progressive increase in αFP levels beginning at the fourth month, without tumor evidence during CT control at 3 months. We conclude that percutaneous cryotherapy with US guidance and CT monitoring is a feasible, safe, and effective for treatment of HCC. If local ablative procedures of hepatic lesions are to be performed, percutaneous cryoablation, not laparotomic, should be discussed as an alternative therapeutic measure. Longer follow-up should provide proof of the effectiveness of this technique

  19. Nondestructive test for assembly relationship of initiating explosive device

    International Nuclear Information System (INIS)

    Wang Xiangang; Zhang Chaozong; Guo Zhiping

    2009-01-01

    A 3D computed tomography (CT) method to inspect assembly relationship of initiating explosive device and to nondestructively evaluate assembly relationship by building geometric model from CT images was described. The experiment result proves that this method accurately inspects assembly relationship of initiating explosive device. (authors)

  20. Initial Experience in Colombia in Patients with PET/CT-FDG Studies of the Central Nervous System

    International Nuclear Information System (INIS)

    Ucros, Gonzalo; Bernal, Patricia; Bermudez Sonia

    2009-01-01

    To describe the experience of patients who underwent a brain PET-CT during sixteen consecutive months. Method: 41 studies were made using flourodeoxiglucose (FDG) and registered with computed tomography. Results: These studies correspond to 5% of all PET studies performed at our institution. The age of patients ranged from 11 to 74 years. The main indications were: search for an epileptic focus (34%), cognitive disorder (32%), tumor evaluation (22%) and others (12%). Conclusion: The main applications of the brain PETCT FDG in our patients were: evaluation of untreatable epileptic patients thinking of undergoing surgery, evaluation of patients with cognitive disorders like Alzheimer's and other related dementias and finally, evaluation of patients with residual or primary brain tumors. It is among these patients in which this diagnostic modality has better diagnostic utility with abnormal findings, useful for their management.

  1. PET CT imaging: the Philippine experience

    International Nuclear Information System (INIS)

    Santiago, Jonas Y.

    2011-01-01

    Currently, the most discussed fusion imaging is PET CT. Fusion technology has tremendous potential in diagnostic imaging to detect numerous conditions such as tumors, Alzheimer's disease, dementia and neural disorders. The fusion of PET with CT helps in the localization of molecular abnormalities, thereby increasing diagnostic accuracy and differentiating benign or artefact lesions from malignant diseases. It uses a radiotracer called fluro deoxyglucose that gives a clear distinction between pathological and physiological uptake. Interest in this technology is increasing and additional clinical validation are likely to induce more health care providers to invest in combined scanners. It is hope that in time, a better appreciation of its advantages over conventional and traditional imaging modalities will be realized. The first PET CT facility in the country was established at the St. Luke's Medical Center in Quezon City in 2008 and has since then provided a state-of-the art imaging modality to its patients here and those from other countries. The paper will present the experiences so far gained from its operation, including the measures and steps currently taken by the facility to ensure optimum workers and patient safety. Plans and programs to further enhance the awareness of the Filipino public on this advanced imaging modality for an improved health care delivery system may also be discussed briefly. (author)

  2. Interstitial lung disease in anti-synthetase syndrome: Initial and follow-up CT findings

    Energy Technology Data Exchange (ETDEWEB)

    Debray, Marie-Pierre, E-mail: marie-pierre.debray@bch.aphp.fr [AP-HP, Bichat-Claude Bernard Hospital, Department of Radiology, 46, rue Henri Huchard, 75877 Paris Cedex 18 (France); Borie, Raphael, E-mail: raphael.borie@bch.aphp.fr [AP-HP, Bichat-Claude Bernard Hospital, Department of Pneumology A and Centre de Compétence Maladies Pulmonaires rares, DHU Fire 46, rue Henri Huchard, 75877 Paris Cedex 18 (France); Inserm, U1152, Paris (France); Revel, Marie-Pierre, E-mail: marie-pierre.revel@htd.aphp.fr [AP-HP, Cochin Hospital, Department of Radiology, 27, Rue du Fg Saint Jacques, 75679 Paris Cedex 14 (France); Naccache, Jean-Marc, E-mail: jean-marc.naccache@tnn.aphp.fr [AP-HP, Avicenne Hospital, Department of Pneumology and Centre de Compétence Maladies Pulmonaires rares, Bobigny (France); AP-HP, Tenon Hospital, Department of Pneumology and Centre de Compétence Maladies Pulmonaires rares, 4, rue de la Chine, 75020 Paris (France); Khalil, Antoine, E-mail: antoine.khalil@tnn.aphp.fr [AP-HP, Tenon Hospital, Department of Radiology, 4, rue de la Chine, 75020 Paris (France); Toper, Cécile, E-mail: cecile.toper@gmail.com [AP-HP, Tenon Hospital, Department of Pneumology and Centre de Compétence Maladies Pulmonaires rares, 4, rue de la Chine, 75020 Paris (France); Israel-Biet, Dominique, E-mail: dominique.israel-biet@egp.aphp.fr [Université Paris Descartes and AP-HP, Department of Pneumology, Georges Pompidou European Hospital, 20, rue Leblanc, 75015 Paris (France); and others

    2015-03-15

    Purpose: To describe the initial and follow-up CT features of interstitial lung disease associated with anti-synthetase syndrome (AS-ILD). Materials and methods: Two independent thoracic radiologists retrospectively analysed thin-section CT images obtained at diagnosis of AS-ILD in 33 patients (17 positive for anti-Jo1, 13 for anti-PL12, and three for anti-PL7 antibodies). They evaluated the pattern, distribution and extent of the CT abnormalities. They also evaluated the change in findings during follow-up (median 27 months; range 13–167 months) in 26 patients. Results: At diagnosis, ground-glass opacities (100%), reticulations (87%) and traction bronchiectasis (76%) were the most common CT findings. Consolidations were present in 45% of patients. A non-specific interstitial pneumonia (NSIP), organizing pneumonia (OP) or mixed NSIP-OP CT pattern were observed in 15 out of 33 (45%), seven out of 33 (21%) and eight out of 33 (24%) patients, respectively, whereas the CT pattern was indeterminate in three patients. During follow-up, consolidations decreased or disappeared in 11 out of 12 patients (92%), among which seven within the first 6 months, but honeycombing progressed or appeared in ten out of 26 patients (38%) and overall disease extent increased in nine out of 26 patients (35%). Conclusion: CT features at diagnosis of AS-ILD mainly suggest NSIP and OP, isolated or in combination. Consolidations decrease or disappear in most cases but the disease may progress to fibrosis in more than one third of patients.

  3. A benchmark on computational simulation of a CT fracture experiment

    International Nuclear Information System (INIS)

    Franco, C.; Brochard, J.; Ignaccolo, S.; Eripret, C.

    1992-01-01

    For a better understanding of the fracture behavior of cracked welds in piping, FRAMATOME, EDF and CEA have launched an important analytical research program. This program is mainly based on the analysis of the effects of the geometrical parameters (the crack size and the welded joint dimensions) and the yield strength ratio on the fracture behavior of several cracked configurations. Two approaches have been selected for the fracture analyses: on one hand, the global approach based on the concept of crack driving force J and on the other hand, a local approach of ductile fracture. In this approach the crack initiation and growth are modelized by the nucleation, growth and coalescence of cavities in front of the crack tip. The model selected in this study estimates only the growth of the cavities using the RICE and TRACEY relationship. The present study deals with a benchmark on computational simulation of CT fracture experiments using three computer codes : ALIBABA developed by EDF the CEA's code CASTEM 2000 and the FRAMATOME's code SYSTUS. The paper is split into three parts. At first, the authors present the experimental procedure for high temperature toughness testing of two CT specimens taken from a welded pipe, characteristic of pressurized water reactor primary piping. Secondly, considerations are outlined about the Finite Element analysis and the application procedure. A detailed description is given on boundary and loading conditions, on the mesh characteristics, on the numerical scheme involved and on the void growth computation. Finally, the comparisons between numerical and experimental results are presented up to the crack initiation, the tearing process being not taken into account in the present study. The variations of J and of the local variables used to estimate the damage around the crack tip (triaxiality and hydrostatic stresses, plastic deformations, void growth ...) are computed as a function of the increasing load

  4. CT and MRI evaluation of orbital tumors: our experience

    International Nuclear Information System (INIS)

    Cabrini, Marcelo; Docampo, Jorge; Martinez, Manuel; Bruno, Claudio; Morales, Carlos

    2007-01-01

    Purpose: To show our experience in the evaluation of orbital masses on computed tomography (CT) and magnetic resonance imaging (MRI). To describe their most important findings and epidemiological features found on literature review, related to their differential diagnosis. Materials and methods: During a 48-months period of time, 26 patients (13 male, 13 female; age range, 3 to 75 years) with orbital tumors were evaluated. Seventeen patients underwent MR scans, 8 underwent CT scans, and one underwent both imaging methods. It was employed 0,5 and 1 Tesla MR scanners, and axial-helical CT scanners. Results: Benign lesions were found on 7 patients (cavernous hemangioma [n=2], meningioma [n=1], epidermoid cyst [n=1], dermoid cyst [n=1], lipoma [n=1], orbital vein deformity [n=1]). It was found lesions with undetermined behavior (optical nerve glioma [n=2]), and malignant ones were found on 17 patients (metastatic lesions [n=5], non- Hodgkin's lymphoma [n=3], hemangiopericytoma [n=2], retinoblastoma [n=2], rhabdomyosarcoma [n=2], melanoma [n=1], and lacrimal adenocarcinoma [n=1]). Conclusion: In our experience, 65.4% was malignant tumors (orbital metastasis was the most common; 19.2%). More than one-quarter was benign tumor, where cavernous hemangioma was the most frequent. (author) [es

  5. Experience with contrast-enhanced CT in delayed traumatic intracerebral hematoma

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, Shiro; Nakazawa, Shozo; Yokota, Hiroyuki; Isayama, Kazuo; Yajima, Kouzo; Otsuka, Toshibumi [Nippon Medical School, Tokyo

    1984-02-01

    During the four-and-a-half-year period from April, 1976, to September, 1980, out of 257 patients with severe head injuries graded 8 or less by the Glasgow Coma Scale in the Department of Neurosurgery and Critical Care Medicine of the Nippon Medical School, Tokyo, Japan, 33 cases showed the development of delayed traumatic intracerebral hematoma (DTICH) upon the serial computerized tomography (CT). Contrast-enhanced CT was performed in 20 cases of the 33 patients demonstrating DTICH. Among these, 8 cases (40%) indicated the development of DTICH in the lesions of cerebral contusion (a salt-and-pepper appearance in the initial plain CT) which showed a remarkable enhancement, sustaining the extravasation of the contrast medium into the contused brain tissue. The authors discuss the pathogenesis of DTICH and suggest that vasoparalysis in the cerebral contusion might be a factor in the development of DTICH in patients with servere head injuries.

  6. Enhanced temporal resolution at cardiac CT with a novel CT image reconstruction algorithm: Initial patient experience

    Energy Technology Data Exchange (ETDEWEB)

    Apfaltrer, Paul, E-mail: paul.apfaltrer@medma.uni-heidelberg.de [Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, PO Box 250322, 169 Ashley Avenue, Charleston, SC 29425 (United States); Institute of Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, D-68167 Mannheim (Germany); Schoendube, Harald, E-mail: harald.schoendube@siemens.com [Siemens Healthcare, CT Division, Forchheim Siemens, Siemensstr. 1, 91301 Forchheim (Germany); Schoepf, U. Joseph, E-mail: schoepf@musc.edu [Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, PO Box 250322, 169 Ashley Avenue, Charleston, SC 29425 (United States); Allmendinger, Thomas, E-mail: thomas.allmendinger@siemens.com [Siemens Healthcare, CT Division, Forchheim Siemens, Siemensstr. 1, 91301 Forchheim (Germany); Tricarico, Francesco, E-mail: francescotricarico82@gmail.com [Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, PO Box 250322, 169 Ashley Avenue, Charleston, SC 29425 (United States); Department of Bioimaging and Radiological Sciences, Catholic University of the Sacred Heart, “A. Gemelli” Hospital, Largo A. Gemelli 8, Rome (Italy); Schindler, Andreas, E-mail: andreas.schindler@campus.lmu.de [Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, PO Box 250322, 169 Ashley Avenue, Charleston, SC 29425 (United States); Vogt, Sebastian, E-mail: sebastian.vogt@siemens.com [Siemens Healthcare, CT Division, Forchheim Siemens, Siemensstr. 1, 91301 Forchheim (Germany); Sunnegårdh, Johan, E-mail: johan.sunnegardh@siemens.com [Siemens Healthcare, CT Division, Forchheim Siemens, Siemensstr. 1, 91301 Forchheim (Germany); and others

    2013-02-15

    Objective: To evaluate the effect of a temporal resolution improvement method (TRIM) for cardiac CT on diagnostic image quality for coronary artery assessment. Materials and methods: The TRIM-algorithm employs an iterative approach to reconstruct images from less than 180° of projections and uses a histogram constraint to prevent the occurrence of limited-angle artifacts. This algorithm was applied in 11 obese patients (7 men, 67.2 ± 9.8 years) who had undergone second generation dual-source cardiac CT with 120 kV, 175–426 mAs, and 500 ms gantry rotation. All data were reconstructed with a temporal resolution of 250 ms using traditional filtered-back projection (FBP) and of 200 ms using the TRIM-algorithm. Contrast attenuation and contrast-to-noise-ratio (CNR) were measured in the ascending aorta. The presence and severity of coronary motion artifacts was rated on a 4-point Likert scale. Results: All scans were considered of diagnostic quality. Mean BMI was 36 ± 3.6 kg/m{sup 2}. Average heart rate was 60 ± 9 bpm. Mean effective dose was 13.5 ± 4.6 mSv. When comparing FBP- and TRIM reconstructed series, the attenuation within the ascending aorta (392 ± 70.7 vs. 396.8 ± 70.1 HU, p > 0.05) and CNR (13.2 ± 3.2 vs. 11.7 ± 3.1, p > 0.05) were not significantly different. A total of 110 coronary segments were evaluated. All studies were deemed diagnostic; however, there was a significant (p < 0.05) difference in the severity score distribution of coronary motion artifacts between FBP (median = 2.5) and TRIM (median = 2.0) reconstructions. Conclusion: The algorithm evaluated here delivers diagnostic imaging quality of the coronary arteries despite 500 ms gantry rotation. Possible applications include improvement of cardiac imaging on slower gantry rotation systems or mitigation of the trade-off between temporal resolution and CNR in obese patients.

  7. Fluoroscopic and CT enteroclysis in children: initial experience, technical feasibility, and utility

    International Nuclear Information System (INIS)

    Brown, Shanaree; Applegate, Kimberly E.; Sandrasegaran, Kumar; Jennings, S.G.; Garrett, Joshua; Maglinte, Dean T.; Skantharajah, Arunan

    2008-01-01

    Partial small-bowel obstruction can be difficult to diagnose on clinical examination. These obstructions might not be detected on routine abdominal/pelvic CT. To evaluate the feasibility, safety, and techniques of fluoroscopic enteroclysis (FE) and CT enteroclysis (CTE), and to review their indications and findings in children. We retrospectively reviewed all enteroclysis studies in children younger than 18 years performed between January 2002 and March 2007. We correlated the results with other abdominal imaging and surgical and pathological findings. The review revealed 112 FE and 74 CTE studies performed in 175 children (mean age 14 years, range 3-18 years). FE and CTE studies were performed most commonly for evaluation of known Crohn disease (FE 38%, CTE 29%) and abdominal pain (FE 26%, CTE 26%). One FE study was terminated because of patient anxiety, and one CTE study was terminated because of patient discomfort. No complications of FE or CTE were reported. The findings were normal in 54% of the FE studies and 46% of the CTE studies. The most common small bowel diagnoses were Crohn disease (FE 34%, CTE 28%) and partial small bowel obstruction (FE 3%, CTE 10%). Two FE studies (2%) and 14 CTE studies (19%) showed abnormalities outside the small bowel. In 54 patients with inflammatory bowel disease, 11 FE studies and 25 CTE studies showed additional bowel abnormalities. Overall, 14 and 21 patients had surgery as a result of the findings of FE and CTE, respectively. FE and CTE are safe, feasible, and accurate in depicting small-bowel pathology in children. These techniques can be particularly useful in children with Crohn disease involving the small bowel. (orig.)

  8. Collateral ventilation to congenital hyperlucent lung lesions assessed on xenon-enhanced dynamic dual-energy CT: an initial experience.

    Science.gov (United States)

    Goo, Hyun Woo; Yang, Dong Hyun; Kim, Namkug; Park, Seung Il; Kim, Dong Kwan; Kim, Ellen Ai-Rhan

    2011-01-01

    We wanted to evaluate the resistance to collateral ventilation in congenital hyperlucent lung lesions and to correlate that with the anatomic findings on xenon-enhanced dynamic dual-energy CT. Xenon-enhanced dynamic dual-energy CT was successfully and safely performed in eight children (median age: 5.5 years, 4 boys and 4 girls) with congenital hyperlucent lung lesions. Functional assessment of the lung lesions on the xenon map was done, including performing a time-xenon value curve analysis and assessing the amplitude of xenon enhancement (A) value, the rate of xenon enhancement (K) value and the time of arrival value. Based on the A value, the lung lesions were categorized into high or low (A value > 10 Hounsfield unit [HU]) resistance to collateral ventilation. In addition, the morphologic CT findings of the lung lesions, including cyst, mucocele and an accessory or incomplete fissure, were assessed on the weighted-average CT images. The xenon-enhanced CT radiation dose was estimated. Five of the eight lung lesions were categorized into the high resistance group and three lesions were categorized into the low resistance group. The A and K values in the normal lung were higher than those in the low resistance group. The time of arrival values were delayed in the low resistance group. Cysts were identified in five lesions, mucocele in four, accessory fissure in three and incomplete fissure in two. Either cyst or an accessory fissure was seen in four of the five lesions showing high resistance to collateral ventilation. The xenon-enhanced CT radiation dose was 2.3 ± 0.6 mSv. Xenon-enhanced dynamic dual-energy CT can help visualize and quantitate various degrees of collateral ventilation to congenital hyperlucent lung lesions in addition to assessing the anatomic details of the lung.

  9. Primary Hepatosplenic B-cell Lymphoma: Initial Diagnosis and Assessment of Therapeutic Response with F-18 FDG PET/CT

    International Nuclear Information System (INIS)

    Kang, Sung Min; Lee, Hong Je; Seo, Ji Hyoung; Lee, Sang Woo; Ahn, Byeong Cheol; Lee, Jae Tae

    2008-01-01

    A 52-year-old woman with a history of general weakness, fatigue, weight loss, elevated serum levels of liver transaminase enzyme for three months underwent an F-18 FDG PET/CT to evaluate a cause of the hepatosplenomegaly found on abdominal ultrasonography. Initial PET/CT revealed markedly enlarged liver and spleen with intense FDG uptake. Otherwise, there were no areas of abnormal FDG uptake in whole body image. Histological evaluation by a hepatic needle biopsy demonstrated diffuse large B cell type lymphoma and final diagnosis for this patient was hepatosplenic B-cell lymphoma. She received five cycles of CHOP chemotherapy, and second PET/CT was followed after then. Follow-up PET-CT revealed normal sized liver with disappearance of abnormal FDG uptake. Hepatosplenic B-cell lymphoma is relatively rare and mostly presents as single or multiple nodules. Diffuse type hepatosplenic lymphoma is extremely rare and poorly recognized entity. The diagnosis is very difficult and complicated by the presence of misleading symptoms.4 In this rare hepatosplenic B-cell lymphoma case, F-18 FDG PET/CT provided a initial diagnostic clue of hepatosplenic lymphoma and an accurate chemotherapy response

  10. Primary Hepatosplenic B-cell Lymphoma: Initial Diagnosis and Assessment of Therapeutic Response with F-18 FDG PET/CT

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Sung Min; Lee, Hong Je; Seo, Ji Hyoung; Lee, Sang Woo; Ahn, Byeong Cheol; Lee, Jae Tae [Kyungpook National University Hospital, Daegu (Korea, Republic of)

    2008-08-15

    A 52-year-old woman with a history of general weakness, fatigue, weight loss, elevated serum levels of liver transaminase enzyme for three months underwent an F-18 FDG PET/CT to evaluate a cause of the hepatosplenomegaly found on abdominal ultrasonography. Initial PET/CT revealed markedly enlarged liver and spleen with intense FDG uptake. Otherwise, there were no areas of abnormal FDG uptake in whole body image. Histological evaluation by a hepatic needle biopsy demonstrated diffuse large B cell type lymphoma and final diagnosis for this patient was hepatosplenic B-cell lymphoma. She received five cycles of CHOP chemotherapy, and second PET/CT was followed after then. Follow-up PET-CT revealed normal sized liver with disappearance of abnormal FDG uptake. Hepatosplenic B-cell lymphoma is relatively rare and mostly presents as single or multiple nodules. Diffuse type hepatosplenic lymphoma is extremely rare and poorly recognized entity. The diagnosis is very difficult and complicated by the presence of misleading symptoms.4 In this rare hepatosplenic B-cell lymphoma case, F-18 FDG PET/CT provided a initial diagnostic clue of hepatosplenic lymphoma and an accurate chemotherapy response.

  11. Additional value of integrated PET/CT over PET alone in the initial staging and follow up of head and neck malignancy

    International Nuclear Information System (INIS)

    Ishikita, Tomohiro; Oriuchi, Noboru; Higuchi, Tetsuya

    2010-01-01

    Clinical application of fluorodeoxyglucose (FDG)-positron emission tomography (PET) in head and neck cancer includes identification of metastases, unknown primary head and neck malignancy, or second primary carcinoma, and also recurrent tumor after treatment. In this study, the additional value of PET/CT fusion images over PET images alone was evaluated in patients with initial staging and follow up of head and neck malignancy. Forty patients with suspected primary head and neck malignancy and 129 patients with suspected relapse after treatment of head and neck malignancy were included. FDG-PET/CT study was performed after the intravenous administration of FDG (5 MBq/kg). Target of evaluation was set at primary tumor, cervical lymph node, and whole body. PET images and PET with CT fusion images were compared. Sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) were calculated. Results of PET and PET/CT were compared with postoperative histopathological examination, and case by case comparison of PET and PET/CT results for each region was performed. The additional value of CT images over PET only images was assessed. Statistical differences in sensitivity and specificity were evaluated. In the comparative evaluation of 507 targets by PET alone and PET/CT, 401 targets showed agreement of the results. Of the 106 discordant targets, 103 showed a positive result on PET alone and negative result on PET/CT. These results showed a significant difference (p<0.01). Sensitivity of PET/CT was slightly higher than that of PET without statistical significance, while specificity of PET/CT was significantly higher than that of PET alone (Initial Staging: 90.5% vs. 62.2%, p<0.01; Follow up: 97.2% vs. 74.4%, p<0.01). In Fisher's direct probability test, a significant difference was noted in the sensitivity (Initial staging: 91.3% vs. 87.0%, p<0.01; Follow up: 93.9% vs. 91.4%, p<0.01). Combined PET/CT showed improved diagnostic

  12. Experience with contrast-enhanced CT in delayed traumatic intracerebral hematoma

    International Nuclear Information System (INIS)

    Kobayashi, Shiro; Nakazawa, Shozo; Yokota, Hiroyuki; Isayama, Kazuo; Yajima, Kouzo; Otsuka, Toshibumi

    1984-01-01

    During the four-and-a-half-year period from April, 1976, to September, 1980, out of 257 patients with severe head injuries graded 8 or less by the Glasgow Coma Scale in the Department of Neurosurgery and Critical Care Medicine of the Nippon Medical School, Tokyo, Japan, 33 cases showed the development of delayed traumatic intracerebral hematoma (DTICH) upon the serial computerized tomography (CT). Contrast-enhanced CT was performed in 20 cases of the 33 patients demonstrating DTICH. Among these, 8 cases (40%) indicated the development of DTICH in the lesions of cerebral contusion (a salt-and-pepper appearance in the initial plain CT) which showed a remarkable enhancement, sustaining the extravasation of the contrast medium into the contused brain tissue. The authors discuss the pathogenesis of DTICH and suggest that vasoparalysis in the cerebral contusion might be a factor in the development of DTICH in patients with servere head injuries. (author)

  13. The role of CT-guided percutaneous drainage of loculated air collections: an institutional experience.

    Science.gov (United States)

    Patel, Bhavik N; Morgan, Madeline; Tyler, Douglas; Paulson, Erik; Jaffe, Tracy A

    2015-10-01

    The purpose of this study is to describe our experience with the role of CT-guided percutaneous drainage of loculated intra-abdominal collections consisting entirely of gas. An IRB-approved retrospective study analyzing patients with air-only intra-abdominal collections over an 8-year period was undertaken. Seven patients referred for percutaneous drainage were included. Size of collections, subsequent development of fluid, and microbiological yield were determined. Clinical outcome was also analyzed. Out of 2835 patients referred for percutaneous drainage between 2004 and 2012, seven patients (5M, 2F; average age 63, range 54-85) met criteria for inclusion with CT showing air-only collections. Percutaneous drain placement (five 8 Fr, one 10 Fr, and one 12 Fr) using Seldinger technique was performed. Four patients (57%) had recently undergone surgery (2 Whipple, 1 colectomy, 1 hepatic resection) while two (29%) had a remote surgery (1 abdominoperineal resection, 1 sigmoidectomy). Despite the lack of detectable fluid on the original CT, 6 patients (86%) had air and fluid aspirated at drainage, 5 (83%) of the aspirates developed positive microbacterial cultures. Four patients (57%) presented with fever at the time of the initial scan, all of whom had positive cultures from aspirated fluid. Four patients (57%) had leukocytosis, all of whom had positive cultures from aspirated fluid. Although relatively rare in occurrence, patients with air-only intra-abdominal collections with signs of infection should be considered for percutaneous management similar to that of conventional infected fluid collections. Although fluid is not visible on CT, these collections can produce fluid that contains organisms.

  14. Clinical usefulness of 18F–FDG PET/CT for initial staging and assessment of treatment efficacy in patients with lymph node tuberculosis

    International Nuclear Information System (INIS)

    Lefebvre, Nicolas; Argemi, Xavier; Meyer, Nicolas; Mootien, Joy; Douiri, Nawal; Sferrazza-Mandala, Stefania; Schramm, Frédéric; Weingertner, Noëlle; Christmann, Daniel; Hansmann, Yves; Imperiale, Alessio

    2017-01-01

    Introduction: Few studies have evaluated the promising role of 18 F–fluoro-2-deoxy-D-glucose positron emission tomography (PET) and PET/computed tomography FDG PET/CT in evaluating and monitoring treatment response in patients with lymph node tuberculosis (LNTB). The aim of this clinical investigation was to assess the clinical usefulness of FDG PET/CT for initial tuberculosis staging and to determine the prognostic value of the decrease of 18 F–FDG uptake during antibiotic treatment in LNTB patients. Methods: We retrospectively reviewed 18 cases of LNTB admitted at a single center from 2004 to 2014. Medical records of patients who underwent two FDG PET/CT (>6 months interval), at initial staging and at the end of therapy were reviewed to determine the impact of FDG PET/CT on initial management of LNTB and response to therapy. Statistical analysis was performed using linear mixed-effects model. Results: Thirteen cases of disseminated LNTB and five cases of localized LNTB were included in the study. Initial FDG PET/CT allowed guided biopsy for initial diagnosis in 5 patients and identified unknown extra-LN TB sites in 9 patients. Visual analysis follow-up of FDG PET/CT showed a complete metabolic response in 9/18 patients (all of whom were cured), a partial response in 7/18 (5 of whom were cured) and no response in 2/18 (all of whom were not cured). The semi-quantitative evaluation of 18F–FDG intensity decrease based on the maximum standardized uptake value (SUVmax), compared to targeted estimated decrease allowed to predict correctly a complete response to treatment in 14/18 cases. Conclusion: FDG PET/CT allows an accurate pre-therapeutic mapping of LNTB and helps for early TB confirmation. The SUVmax follow up is a potential tool for monitoring the treatment response.

  15. Assessment of regional lung functional impairment with co-registered respiratory-gated ventilation/perfusion SPET-CT images: initial experiences

    International Nuclear Information System (INIS)

    Suga, Kazuyoshi; Yasuhiko, Kawakami; Zaki, Mohammed; Yamashita, Tomio; Seto, Aska; Matsumoto, Tsuneo; Matsunaga, Naofumi

    2004-01-01

    In this study, respiratory-gated ventilation and perfusion single-photon emission tomography (SPET) were used to define regional functional impairment and to obtain reliable co-registration with computed tomography (CT) images in various lung diseases. Using a triple-headed SPET unit and a physiological synchroniser, gated perfusion SPET was performed in a total of 78 patients with different pulmonary diseases, including metastatic nodules (n=15); in 34 of these patients, it was performed in combination with gated technetium-99m Technegas SPET. Projection data were acquired using 60 stops over 120 for each detector. Gated end-inspiration and ungated images were reconstructed from 1/8 data centered at peak inspiration for each regular respiratory cycle and full respiratory cycle data, respectively. Gated images were registered with tidal inspiration CT images using automated three-dimensional (3D) registration software. Registration mismatch was assessed by measuring 3D distance of the centroid of the nine selected round perfusion-defective nodules. Gated SPET images were completed within 29 min, and increased the number of visible ventilation and perfusion defects by 9.7% and 17.2%, respectively, as compared with ungated images; furthermore, lesion-to-normal lung contrast was significantly higher on gated SPET images. In the nine round perfusion-defective nodules, gated images yielded a significantly better SPET-CT match compared with ungated images (4.9±3.1 mm vs 19.0±9.1 mm, P<0.001). The co-registered SPET-CT images allowed accurate perception of the location and extent of each ventilation/perfusion defect on the underlying CT anatomy, and characterised the pathophysiology of the various diseases. By reducing respiratory motion effects and enhancing perfusion/ventilation defect clarity, gated SPET can provide reliable co-registered images with CT images to accurately characterise regional functional impairment in various lung diseases. (orig.)

  16. 18F-DOPA PET and enhanced CT imaging for congenital hyperinsulinism: initial UK experience from a technologist's perspective.

    Science.gov (United States)

    Meintjes, Marguerite; Endozo, Raymond; Dickson, John; Erlandsson, Kjel; Hussain, Khalid; Townsend, Caroline; Menezes, Leon; Bomanji, Jamshed

    2013-06-01

    Congenital hyperinsulinism (CHI) is the most common cause of persistent hypoglycaemia in infants and children. Histologically, there are two subgroups, diffuse and focal. The aim of this study was to evaluate the accuracy of (18)F-fluoro-L-dihydroxyphenylalanine ((18)F-DOPA) PET/computed tomography (CT) and contrast-enhanced CT in distinguishing between focal and diffuse lesions in infants with CHI who are unresponsive to medical therapy. In addition, this paper describes the detailed protocol used for imaging and analysis of (18)F-DOPA PET/CT images in our clinical practice. Twenty-two (18)F-DOPA PET/CT and contrast-enhanced CT imaging studies were carried out on 18 consecutive patients (nine boys and nine girls) with CHI (median age, 2 years and 1 month; range, 1-84 months) who had positive dominant ABCC8 mutation genetic results or negative ABCC8/t results but did not respond to first-line medical therapy with high-dose diazoxide. (18)F-DOPA was produced by the cyclotron unit of Woolfson Molecular Imaging Centre, Manchester, and transported to our centre in central London after synthesis and implementation of quality control measures. (18)F-DOPA was administered intravenously at a dose of 4 MBq/kg, and iodine contrast medium was injected intravenously at a dose of 1.5 ml/kg. Single bed position PET/CT images of the pancreas were acquired under light sedation with oral chloral hydrate. Four PET dynamic data acquisition scans were taken 20, 40, 50 and 60 min after injection for a duration of 10 min each. The results were assessed by visual interpretation and quantitative measurements of standardized uptake values (SUVs) in the head, body, and tail of the pancreas. Of the 18 patients, 13 showed diffuse and five showed focal (18)F-DOPA PET pancreatic uptake. Three regions of interest were drawn over the head, body and tail of the pancreas to calculate the SUV(max). Using the formula - highest SUV(max)/next highest SUV(max) - a ratio was calculated. Five patients had

  17. Initial clinical experience with a sac-anchoring endoprosthesis for aortic aneurysm repair.

    Science.gov (United States)

    Donayre, Carlos E; Zarins, Christopher K; Krievins, Dainis K; Holden, Andrew; Hill, Andrew; Calderas, Carlos; Velez, Jaime; White, Rodney A

    2011-03-01

    All current aortic endografts depend on proximal and distal fixation to prevent migration. However, migration and rupture can occur, particularly in patients with aortic necks that are short or angulated, or both. We present our initial clinical experience with a new sac-anchoring endoprosthesis designed to anchor and seal the device within the aneurysm sac. The initial worldwide experience using a new endoprosthesis for the treatment of aortic aneurysms (Nellix Endovascular, Palo Alto, Calif) was reviewed. The endoprosthesis consists of dual balloon-expandable endoframes surrounded by polymer-filled endobags designed to obliterate the aneurysm sac and maintain endograft position. Clinical results and follow-up contrast computed tomography (CT) scans at 30 days and 6 and 12 months were reviewed. The endograft was successfully deployed in 21 patients with infrarenal aortic aneurysms measuring 5.7 ± 0.7 cm (range, 4.3-7.4 cm). Two patients with common iliac aneurysms were treated with sac-anchoring extenders that maintained patency of the internal iliac artery. Infusion of 71 ± 37 mL of polymer (range, 19-158 mL) into the aortic endobags resulted in complete aneurysm exclusion in all patients. Mean implant time was 76 ± 35 minutes, with 33 ± 17 minutes of fluoroscopy time and 180 ± 81 mL of contrast; estimated blood loss was 174 ± 116 mL. One patient died during the postoperative period (30-day mortality, 4.8%), and one died at 10 months from non-device-related causes. During a mean follow-up of 8.7 ± 3.1 months and a median of 6.3 months, there were no late aneurysm- or device-related adverse events and no secondary procedures. CT imaging studies at 6 months and 1 year revealed no increase in aneurysm size, no device migration, and no new endoleaks. One patient had a limited proximal type I endoleak at 30 days that resolved at 60 days and remained sealed. One patient has an ongoing distal type I endoleak near the iliac bifurcation, with no change in aneurysm

  18. Initial Results of Using Daily CT Localization to Correct Portal Error in Prostate Cancer

    International Nuclear Information System (INIS)

    Lattanzi, Joseph; McNeely, Shawn; Barnes, Scott; Das, Indra; Schultheiss, Timothy E; Hanks, Gerald E.

    1997-01-01

    Purpose: To evaluate the use of daily CT simulation in prostate cancer to correct errors in portal placement and organ motion. Improved localization with this technique should allow the reduction of target margins and facilitate dose escalation in high risk patients while minimizing the risk of normal tissue morbidity. Methods and Materials : Five patients underwent standard CT simulation with the alpha cradle cast, IV contrast, and urethrogram. All were initially treated to 46 Gy in a four field conformal technique which included the prostate, seminal vesicles and pelvic lymph nodes (GTV 1 ). The prostate or prostate and seminal vesicles (GTV 2 ) then received 56 Gy with a 1.0 cm margin to the PTV. At 50 Gy a second CT simulation was performed with IV contrast, urethrogram and the alpha cradle secured to a rigid sliding board. The prostate was contoured, a new isocenter generated, and surface markers placed. Prostate only treatment portals for the final conedown (GTV 3 ) were created with 0.25 cm isodose margins to the PTV. The final six fractions in 2 patients with favorable disease and eight fractions in 3 patients with unfavorable disease were delivered using the daily CT technique. On each treatment day the patient was placed in his cast on the sliding board and a CT scan performed. The daily isocenter was calculated in the A/P and lateral dimension and compared to the 50 Gy CT simulation isocenter. Couch and surface marker shifts were calculated to produce perfect portal alignment. To maintain positioning, the patient was transferred to a gurney while on the sliding board in his cast, transported to the treatment room and then transferred to the treatment couch. The patient was then treated to the corrected isocenter. Portal films and real time images were obtained for each portal. Results: Utilizing CT-CT image registration (fusion) of the daily and 50 Gy baseline CT scans the isocenter changes were quantified to reflect the contribution of positional

  19. Combined CT Angiography and CT Venography in Thromboembolic disease: clinical impact

    International Nuclear Information System (INIS)

    Bouzas, R.; Migueles, Y.; Gomez, S.; Mallo, R.; Garcia-Tejedor, J. L.; Diaz Vega, M. J.

    2002-01-01

    Combined CT Venography and Pulmonary Angiography was described in 1998 as a tool for diagnostic Thromboembolic Disease. The purpose is to relate our own experience with this technique in a population with suspected pulmonary embolism. 46 consecutive patients with suspected pulmonary embolism underwent combined CT Venography after Pulmonary CT Angiography to depict Deep Venous Thrombosis (DVT). CT Venography where obtained with a 3 minutes delay from injection, without additional intravenous contrast, from upper abdomen to fibular head. A prospective study from emergency reports where used. The reports where aimed by nine different radiologist at diary emergency room (images where not retrospective review). We report if a pulmonary embolus or deep venous thrombus or another alternative diagnostic where done. An endo luminal thrombus in any pulmonary arteries was assessed as a positive study for PE. A Thrombus in the leg veins or in an abdominal vein without diminished size of vein was assessed as an acute DVT. In those patients with a CT negative to Thromboembolic Disease was the clinician who decide if more proves where needed. Those patients without evidence in CT of Thromboembolic Disease where asked for symptoms related to the episode in a 3 months period after initial CT. Patients free of symptoms for 3 months without anticoagulation therapy where considered true negative for CT. CT shows Thromboembolic Disease in 23 of 46 patients. 21PE, 14 DVT 2 of 14 patients with DVT don't show PE, CT excluded thromboembolic disease in 23 patients and in 15 of those patients an alternative diagnostic was shown. In 22 of those 23 patients CT excluded correctly Thromboembolic Disease. One patient result in a false negative CT, Pulmonary Angiography of that patient shows us a subsegmentary embolus. (Author) 9 refs

  20. Our experience in using the whole body computed tomography unit (GE CT/T)

    International Nuclear Information System (INIS)

    Murakawa, Yasuhiro; Morimoto, Mitsuo; Ishigaki, Naoya; Zaitsu, Hiroaki; Kawabata, Kohji

    1983-01-01

    Since our hospital installed the CT unit of the head and neck (SCT-100N) in April, 1979, we reported our experience in using this equipment in 1980 and 1982. After that, since the whole body CT unit (GE CT/T) was installed in our hospital in April, 1982, the total number of CT examination have reached approximately three thousand five handred till this August. Consequently, this CT image seemed to be superior in image quality to that obtained by other CT equipment. The most important characteristic of this equipment is that the retrospective and prospective reviews of the target image and the coronal and sagittal recontruction from contiguous transverse axial scans are possible. We show in this report two experimental CT photograms obtained by the reviews of the target image in using of microchart phantom and CT photograms of uterus myoma, metastatic thyroid and liver cancers and further, of contiguous transverse axial scans of cerebral embolism and the coronal recontruction. The important problems for the future of this equipment are those of absorbed X-ray dose of the patients and the scan time. (author)

  1. Five Years of Cyclotron Radioisotope Production Experiences at the First PET-CT in Venezuela

    International Nuclear Information System (INIS)

    Colmenter, L.; Coelho, D.; Esteves, L. M.; Ruiz, N.; Morales, L.; Lugo, I.; Sajo-Bohus, L.; Liendo, J. A.; Greaves, E. D.; Barros, H.; Castillo, J.

    2007-01-01

    Five years operation of a compact cyclotron installed at PET-CT facility in Caracas, Venezuela is given. Production rate of 18 F labeled FDG, operation and radiation monitoring experience are included. We conclude that 18 FDG CT-PET is the most effective technique for patient diagnosis

  2. Initial thoracic involvement in lymphoma. CT assessment; Afectacion toracica inicial en el linfom. Valoracion con TC

    Energy Technology Data Exchange (ETDEWEB)

    Bustos, A.; Corredoira, J.; Ferreiros, J.; Cabeza, B.; Jorquera, M.; Pedrosa, I.; Martinez, R.; Fernandez, C. [Hospital Clinico San Carlos. Madrid (Spain)

    2002-07-01

    To analyze the initial thoracic involvement by CT in a consecutive series of patients with lymphoma. A retrospective analysis was made of thoracic CT studies made at the time of diagnosis of 259 patients with lymphoma. Mediastinal pulmonary, pleural, pericardial and chest wall involvement was assessed by CT. Of 259 patients (129 men y 130 women), 56 had Hodgkin's disease (HD) and 203 had non-Hodgkin lymphoma (NHL). Forty-two percent (42.5%, 110/259) of the patients had chest involvement on CT: 33 of 56 patients with HD (58.9%) and 77 of 203 patients with NHL (37.9%). All the patients with thoracic HD and 71.4% of patients with thoracic NHL, had mediastinal lymph node involvement. of the patients with thoracic involvement 12.1% (4/33) of the patient with HD and 23.3% (18/77) of the patients with NHL had pulmonary involvement. Thoracic involvement on CT was more frequent in HD. Mediastinal lymph node involvement was the most common finding fundamentally in HD. Pulmonary disease always occurred in the presence of mediastinal lymph node involvement in HD but could occur as an isolated finding in NHL. (Author) 24 refs.

  3. Collateral Ventilation to Congenital Hyperlucent Lung Lesions Assessed on Xenon-Enhanced Dynamic Dual-Energy CT: an Initial Experience

    OpenAIRE

    Goo, Hyun Woo; Yang, Dong Hyun; Kim, Namkug; Park, Seung Il; Kim, Dong Kwan; Kim, Ellen Ai-Rhan

    2011-01-01

    Objective We wanted to evaluate the resistance to collateral ventilation in congenital hyperlucent lung lesions and to correlate that with the anatomic findings on xenon-enhanced dynamic dual-energy CT. Materials and Methods Xenon-enhanced dynamic dual-energy CT was successfully and safely performed in eight children (median age: 5.5 years, 4 boys and 4 girls) with congenital hyperlucent lung lesions. Functional assessment of the lung lesions on the xenon map was done, including performing a ...

  4. Percutaneous CT-guided interventional procedures in musculoskeletal system (our experience)

    Energy Technology Data Exchange (ETDEWEB)

    Thanos, Loukas E-mail: loutharad@yahoo.com; Mylona, Sophia; Kalioras, Vasilios; Pomoni, Maria; Batakis, Nikolaos

    2004-06-01

    Percutaneous interventional procedures include a broad spectrum of minimal invasive techniques, which are a useful diagnostic and therapeutic tool. In this study we present our experience in CT-guided percutaneous musculoskeletal biopsies, drainages of musculoskeletal abscesses, facet and sacroiliac joint injection and radiofrequency thermal ablation of painful metastases or osteoid osteomas.

  5. Clinical experience of quantex coordinate software for CT guided stereotactic surgery

    International Nuclear Information System (INIS)

    Yabashi, Toshitake; Ichikawa, Hideo; Yasuda, Eisuke; Tsuruta, Hatsuo; Ishikawa, Yoshihisa; Kimura, Tokuji; Kanamori, Isao

    1991-01-01

    Recently, Quantex Coordinate Software was newly developed for CT-guided stereotactic surgery. We have the opportunity of using this software in 6 cases with intracerebral hematoma for evacuation and 2 cases with brain tumor for needle biopsy by using CT-guided stereotactic surgery. The followings are the features with a little clinical experience. One of the biggest features is that this software can simulate the best expected route of the puncture needle from burr hole to target point before inserting. Also compared with CT 9000 series Software, it has many new functions for more advanced hardware as well as advance standard software. Two cases of intracerebral hematoma for evacuation and 1 case of a brain tumor for a biopsy were carried out using this software mainly as a simulation. In all cases, this software proved to be very useful. (author)

  6. 18F-FDG PET/CT for initial staging in breast cancer patients. Is there a relevant impact on treatment planning compared to conventional staging modalities?

    International Nuclear Information System (INIS)

    Krammer, J.; Schnitzer, A.; Kaiser, C.G.; Buesing, K.A.; Schoenberg, S.O.; Wasser, K.; Sperk, E.; Brade, J.; Wasgindt, S.; Suetterlin, M.; Sutton, E.J.

    2015-01-01

    To evaluate the impact of whole-body 18 F-FDG PET/CT on initial staging of breast cancer in comparison to conventional staging modalities. This study included 102 breast cancer patients, 101 patients were eligible for evaluation. Preoperative whole-body staging with PET/CT was performed in patients with clinical stage ≥ T2 tumours or positive local lymph nodes (n = 91). Postoperative PET/CT was performed in patients without these criteria but positive sentinel lymph node biopsy (n = 10). All patients underwent PET/CT and a conventional staging algorithm, which included bone scan, chest X-ray and abdominal ultrasound. PET/CT findings were compared to conventional staging and the impact on therapeutic management was evaluated. PET/CT led to an upgrade of the N or M stage in overall 19 patients (19 %) and newly identified manifestation of breast cancer in two patients (2 %). PET/CT findings caused a change in treatment of 11 patients (11 %). This is within the range of recent studies, all applying conventional inclusion criteria based on the initial T and N status. PET/CT has a relevant impact on initial staging and treatment of breast cancer when compared to conventional modalities. Further studies should assess inclusion criteria beyond the conventional T and N status, e.g. tumour grading and receptor status. (orig.)

  7. MR imaging-guided percutaneous cryotherapy for lung tumors: initial experience.

    Science.gov (United States)

    Liu, Shangang; Ren, Ruimei; Liu, Ming; Lv, Yubo; Li, Bin; Li, Chengli

    2014-09-01

    To evaluate prospectively the initial clinical experience of magnetic resonance (MR) imaging-guided percutaneous cryotherapy of lung tumors. MR imaging-guided percutaneous cryotherapy was performed in 21 patients with biopsy-proven lung tumors (12 men, 9 women; age range, 39-79 y). Follow-up consisted of contrast-enhanced chest computed tomography (CT) scan performed at 3-month intervals to assess tumor control; CT scanning was carried out for 12 months or until death. Cryotherapy procedures were successfully completed in all 21 patients. Pneumothorax occurred in 7 (33.3%) of 21 patients. Chest tube placement was required in one (4.8%) case. Hemoptysis was exhibited by 11 (52.4%) patients, and pleural effusion occurred in 6 (28.6%) patients. Other complications were observed in 14 (66.7%) patients. The mean follow-up period was 10.5 months (range, 9-12 mo) in patients who died. At month 12 of follow-up, 7 (33.3%) patients had a complete response to therapy, and 10 (47.6%) patients showed a partial response. In addition, two patients had stable disease, and two patients developed progressive disease; one patient developed a tumor in the liver, and the other developed a tumor in the brain. The 1-year local control rate was 81%, and 1-year survival rate was 90.5%. MR imaging-guided percutaneous cryotherapy appears feasible, effective, and minimally invasive for lung tumors. Copyright © 2014 SIR. Published by Elsevier Inc. All rights reserved.

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

    International Nuclear Information System (INIS)

    Guo Xing; Ding Wei; Qin Huijuan

    2011-01-01

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

  9. First experiences with multidetector CT in traumatized children

    International Nuclear Information System (INIS)

    Hoermann, Marcus; Scharitzer, Martina; Philipp, M.; Metz, Viktor M.; Lomoschitz, F.

    2003-01-01

    Introduction: The aim of this study was to describe and discuss first experiences with multidetector CT (MDCT) in the assessment of traumatized children. Material and methods: Since the implementation of a MDCT scanner in April 2002, 85 children (31 girls, 54 boys with a mean age of 9.2 years) consecutively underwent MDCT (Siemens, Erlangen, Germany) with different protocols depending on age, weight, trauma mechanism and clinical presentation. In all patients in whom pathology was suspected, multiplanar reformations (MPR) in coronal and or sagittal orientation was performed. Examinations were evaluated by two radiologists retrospectively and in consensus. Results: In 55 (65%) children, a MDCT solely of the head was performed, in 46 there was no pathology found. In six (7%), head and facial bones were scanned. Head and abdomen was examined in two (2%), in two (2%) the abdomen only and in one (1%) the pelvis solely. Scans of the spine were obtained in seven (8%) children. A thorax and abdomen examination only was obtained in one (1%) child each. In 11 (13%) children, a polytrauma protocol was performed. In all patients, the time of examination did not exceed 17 min, including setup time. All children survived at the writing of this report. Conclusion: MDCT was promising in the management of traumatized children and seems to shorten the necessary time to reach diagnosis and to initiate life-saving treatment

  10. First experiences with multidetector CT in traumatized children

    Energy Technology Data Exchange (ETDEWEB)

    Hoermann, Marcus E-mail: marcus.hoermann@univie.ac.at; Scharitzer, Martina; Philipp, M.; Metz, Viktor M.; Lomoschitz, F

    2003-10-01

    Introduction: The aim of this study was to describe and discuss first experiences with multidetector CT (MDCT) in the assessment of traumatized children. Material and methods: Since the implementation of a MDCT scanner in April 2002, 85 children (31 girls, 54 boys with a mean age of 9.2 years) consecutively underwent MDCT (Siemens, Erlangen, Germany) with different protocols depending on age, weight, trauma mechanism and clinical presentation. In all patients in whom pathology was suspected, multiplanar reformations (MPR) in coronal and or sagittal orientation was performed. Examinations were evaluated by two radiologists retrospectively and in consensus. Results: In 55 (65%) children, a MDCT solely of the head was performed, in 46 there was no pathology found. In six (7%), head and facial bones were scanned. Head and abdomen was examined in two (2%), in two (2%) the abdomen only and in one (1%) the pelvis solely. Scans of the spine were obtained in seven (8%) children. A thorax and abdomen examination only was obtained in one (1%) child each. In 11 (13%) children, a polytrauma protocol was performed. In all patients, the time of examination did not exceed 17 min, including setup time. All children survived at the writing of this report. Conclusion: MDCT was promising in the management of traumatized children and seems to shorten the necessary time to reach diagnosis and to initiate life-saving treatment.

  11. Analogue experiment of the crustal deformation by X-ray CT; X sen CT wo mochiita chikaku no henkei no analogue jikken

    Energy Technology Data Exchange (ETDEWEB)

    Nakajima, Y.; Shi, B; Murakami, Y. [Geological Survey of Japan, Tsukuba (Japan)

    1997-05-27

    This paper reports a predictive result on a deformation experiment on sand beds using an X-ray computerized tomography (CT) equipment. The X-ray CT is a method to perform the following processes: X-rays are irradiated on a sample; decayed intensity data are measured along ray paths of the permeated X-rays; the data are inverted by using the Fourier transform; and spatial distribution of the coefficient of X-ray absorption inside the sample is acquired as a gray scale image. The deformation experiment was carried by putting sand into an acrylic container to a depth of 2 cm and manually pressing a plate in the horizontal direction. Sand blocks make a relative motion along a specific plane when they are deformed, but it was not possible to recognize faults clearly by naked eyes. Upon completion of the deformation, the experimental device was placed on the CT equipment to acquire images of the two-dimensional cross section. The higher the X-ray absorption coefficient, the brighter the picture elements. It can be seen that three inversed faults have been imaged clearly. Therefore, this equipment was verified usable as an effective observation equipment for an analogue deformation experiment. 4 refs., 2 figs.

  12. EXPERIENCES WITH IDEA PROMOTING INITIATIVES

    DEFF Research Database (Denmark)

    Gish, Liv

    2011-01-01

    In new product development a central activity is to provide new ideas. Over the last decades experiences with stimulating employee creativity and establishing idea promoting initiatives have been made in industrial practice. Such initiatives are often labeled Idea Management – a research field...... with a growing interest. In this paper I examine three different idea promoting initiatives carried out in Grundfos, a leading pump manufacturer. In the analysis I address what understandings of idea work are inscribed in the initiatives and what role these initiatives play in the organization with respect...... understandings of idea work are inscribed in the idea promoting initiatives as they to some degree have to fit with the understandings embedded in practice in order to work....

  13. CT Imaging for Evaluation of Calcium Crystal Deposition in the Knee: Initial Experience from The Multicenter Osteoarthritis (MOST) Study

    Science.gov (United States)

    Misra, Devyani; Guermazi, Ali; Sieren, Jered P.; Lynch, John; Torner, James; Neogi, Tuhina; Felson, David T.

    2014-01-01

    Objective Role of intra-articular calcium crystals in osteoarthritis (OA) is unclear. Imaging modalities used to date for its evaluation have limitations in their ability to fully characterize intra-articular crystal deposition. Since Computed Tomography (CT) imaging provides excellent visualization of bones and calcified tissue, in this pilot project we evaluated the utility of CT scan in describing intra-articular calcium crystal deposition in the knees. Method We included 12 subjects with and 4 subjects without radiographic chondrocalcinosis in the most recent visit from the Multicenter Osteoarthritis (MOST) study, which is a longitudinal cohort of community-dwelling older adults with or at risk for knee OA. All subjects underwent CT scans of bilateral knees. Each knee was divided into 25 subregions and each subregion was read for presence of calcium crystals by a musculoskeletal radiologist. To assess reliability, readings were repeated 4 weeks later. Results CT images permitted visualization of 25 subregions with calcification within and around the tibio-femoral and patello-femoral joints in all 24 knees with radiographic chondrocalcinosis. Intra-articular calcification was seen universally including meniscal cartilage (most common site involved in 21/24 knees), hyaline cartilage, cruciate ligaments, medial collateral ligament and joint capsule. Readings showed good agreement for specific tissues involved with calcium deposition (kappa: 0.70, 95% CI 0.62–0.80). Conclusion We found CT scan to be a useful and reliable tool for describing calcium crystal deposition in the knee and therefore potentially for studying role of calcium crystals in OA. We also confirmed that “chondrocalcinosis” is a misnomer because calcification is present ubiquitously. PMID:25451303

  14. The repeat CT-findings of the contusional hematoma

    International Nuclear Information System (INIS)

    Tsubokawa, Takashi; Yamada, Jitsuhiro; Tomizawa, Noritami; Takeuchi, Totaro; Shinozaki, Hideo

    1980-01-01

    Twenty-seven cases of traumatic intracerebral hematoma were treated from 1977 to 1979. The intracerebral hematomas are classified into three groups: central type, hematoma within contusional area and contusional hematoma, according to the CT findings and the clinical course. Fourteen of these cases are diagnosed as contusional hematoma which show a normal CT scan, subarachnoidal hemorrhage, subdural hematoma and epidural hematoma without any kind of intracerebral high density in the initial CT scan performed within 6 hours after injury. Ten of the cases were found during conservative treatment; in 2 cases, hematomas were revealed within 24 hours; in 2 more cases within 48 hours, and in 6 cases, within 3 - 5 days following injury. In the other 4 cases, hematoma occurred 1 - 2 days following the emergency evacuation of a subdural hematoma and decompressive craniectomy. Based on the clinical experience outlined above, it is our current practice in diagnosing patients with contusional hematoma to perform repeat CT scanning within 5 - 6 days after injury whenever isodensity or subarachnoidal hemorrhage with a shift in the midline structure is observed in an initial CT scan within 6 hours or whenever an evacuation of the subdural hematoma with decompressive craniectomy is performed. (author)

  15. Impact of initial FDG-PET/CT and serum-free light chain on transformation of conventionally defined solitary plasmacytoma to multiple myeloma.

    Science.gov (United States)

    Fouquet, Guillemette; Guidez, Stéphanie; Herbaux, Charles; Van de Wyngaert, Zoé; Bonnet, Sarah; Beauvais, David; Demarquette, Hélène; Adib, Salim; Hivert, Bénédicte; Wemeau, Mathieu; Berthon, Céline; Terriou, Louis; Coiteux, Valérie; Macro, Margaret; Decaux, Olivier; Facon, Thierry; Huglo, Damien; Leleu, Xavier

    2014-06-15

    Solitary plasmacytoma (SP) is a localized proliferation of monoclonal plasma cells in either bone or soft tissue, without evidence of multiple myeloma (MM), and whose prognosis is marked by a high risk of transformation to MM. We studied the impact of FDG-PET/CT (2[18F]fluoro-2-deoxy-D-glucose positron emission tomography-computed tomography) on the risk of transformation of SP to overt MM among other markers in a series of 43 patients diagnosed with SP. Median age was 57.5 years; 48% of patients had an abnormal involved serum-free light chain (sFLC) value, and 64% had an abnormal sFLC ratio at diagnosis. Thirty-three percent had two or more hypermetabolic lesions on initial PET/CT, and 20% had two or more focal lesions on initial MRI. With a median follow-up of 50 months, 14 patients transformed to MM with a median time (TTMM) of 71 months. The risk factors that significantly shortened TTMM at diagnosis were two or more hypermetabolic lesions on PET/CT, abnormal sFLC ratio and involved sFLC, and to a lesser extent at completion of treatment, absence of normalized involved sFLC and PET/CT or MRI. In a multivariate analysis, abnormal initial involved sFLC [OR = 10; 95% confidence interval (CI), 1-87; P = 0.008] and PET/CT (OR = 5; 95% CI, 0-9; P = 0.032) independently shortened TTMM. An abnormal involved sFLC value and the presence of at least two hypermetabolic lesions on PET/CT at diagnosis of SP were the two predictors of early evolution to myeloma in our series. This data analysis will need confirmation in a larger study, and the study of these two risk factors may lead to a different management of patients with SP in the future. . ©2014 American Association for Cancer Research.

  16. PET/CT versus bone marrow biopsy in the initial evaluation of bone marrow infiltration in various pediatric malignancies.

    Science.gov (United States)

    Zapata, Claudia P; Cuglievan, Branko; Zapata, Catalina M; Olavarrieta, Raquel; Raskin, Scott; Desai, Kavita; De Angulo, Guillermo

    2018-02-01

    Accurate staging is essential in the prognosis and management of pediatric malignancies. Current protocols require screening for marrow infiltration with bone marrow biopsy (BMB) as the gold standard. Positron emission tomography-computed tomography (PET-CT) is commonly used to complete the staging process and can also be used to evaluate marrow infiltration. To compare PET-CT and BMB in the initial evaluation of bone marrow infiltration in pediatric cancers. We retrospectively reviewed new cases of EWS, rhabdomyosarcoma, neuroblastoma, and lymphoma diagnosed between January 2009 and October 2014. Each case had undergone both PET-CT and BMB within 4 weeks without treatment in the interval between screening modalities. We reviewed 69 cases. Bone marrow infiltration was demonstrated in 34 cases by PET-CT and in 18 cases by BMB. The sensitivity and negative predictive value of PET-CT were both 100%. Interestingly, the cases in which infiltration was not detected on BMB had an abnormal marrow signal on PET-CT focal or distant to iliac crest. PET-CT has a high sensitivity when assessing marrow infiltration in pediatric malignancies. Advances in radiologic modalities may obviate the use of invasive, painful, and costly procedures like BMB. Furthermore, biopsy results are limited by insufficient tissue or the degree of marrow infiltration (diffuse vs. focal disease). PET-CT can improve the precision of biopsy when used as a guiding tool. This study proposes the use of PET-CT as first-line screening for bone marrow infiltration to improve the accuracy of staging in new diagnoses. © 2017 Wiley Periodicals, Inc.

  17. Initial conditions of radiative shock experiments

    International Nuclear Information System (INIS)

    Kuranz, C. C.; Drake, R. P.; Krauland, C. M.; Marion, D. C.; Grosskopf, M. J.; Rutter, E.; Torralva, B.; Holloway, J. P.; Bingham, D.; Goh, J.; Boehly, T. R.; Sorce, A. T.

    2013-01-01

    We performed experiments at the Omega Laser Facility to characterize the initial, laser-driven state of a radiative shock experiment. These experiments aimed to measure the shock breakout time from a thin, laser-irradiated Be disk. The data are then used to inform a range of valid model parameters, such as electron flux limiter and polytropic γ, used when simulating radiative shock experiments using radiation hydrodynamics codes. The characterization experiment and the radiative shock experiment use a laser irradiance of ∼7 × 10 14 W cm −2 to launch a shock in the Be disk. A velocity interferometer and a streaked optical pyrometer were used to infer the amount of time for the shock to move through the Be disk. The experimental results were compared with simulation results from the Hyades code, which can be used to model the initial conditions of a radiative shock system using the CRASH code

  18. Perfusion CT in childhood stroke—Initial observations and review of the literature

    Energy Technology Data Exchange (ETDEWEB)

    Zebedin, D., E-mail: doris.zebedin@medunigraz.at [Division of Pediatric Radiology, Department of Radiology, University Hospital LKH Graz (Austria); Sorantin, E.; Riccabona, M. [Division of Pediatric Radiology, Department of Radiology, University Hospital LKH Graz (Austria)

    2013-07-15

    Introduction: To report the preliminary results of contrast-enhanced perfusion multi-detector CT for diagnoses of perfusion disturbances in children with clinical suspicion of stroke. Patients and methods: Within the last two years emergency perfusion CT was performed in ten children (age: 8–17 years, male:female = 3:7) for assessment of suspected childhood stroke. These intracranial perfusion CT, intracranial CT-digital subtraction angiography (CT-DSA) and extracranial CT-angiography (CTA) studies were retrospectively reviewed and compared with MRI, follow-up CT, catheter angiography and final clinical diagnosis. The total dose length product (DLP) for the entire examination was recorded. The image quality of perfusion CT-maps, CT-DSA and CTA were evaluated with a subjective three-point scale ranging from very good to non-diagnostic image quality rating perfusion disturbance, intracranial peripheral vessel depiction, and motion- or streak artifacts. Results: In nine of ten children perfusion CT showed no false positive or false negative results. In one of ten children suffering from migraine focal hypo-perfusion was read as perfusion impairment potentially indicating early stroke, but MRI and MRA follow-up were negative. Overall, perfusion-CT with CT-DSA was rated very good in 80% of cases for the detection of perfusion disturbances and vessel anatomy. Conclusions: In comparison to standard CT, contrast-enhanced perfusion CT improves CTs’ diagnostic capability in the emergency examination of children with a strong suspicion of ischemic cerebral infarction.

  19. 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.

  20. Blind CT image quality assessment via deep learning strategy: initial study

    Science.gov (United States)

    Li, Sui; He, Ji; Wang, Yongbo; Liao, Yuting; Zeng, Dong; Bian, Zhaoying; Ma, Jianhua

    2018-03-01

    Computed Tomography (CT) is one of the most important medical imaging modality. CT images can be used to assist in the detection and diagnosis of lesions and to facilitate follow-up treatment. However, CT images are vulnerable to noise. Actually, there are two major source intrinsically causing the CT data noise, i.e., the X-ray photo statistics and the electronic noise background. Therefore, it is necessary to doing image quality assessment (IQA) in CT imaging before diagnosis and treatment. Most of existing CT images IQA methods are based on human observer study. However, these methods are impractical in clinical for their complex and time-consuming. In this paper, we presented a blind CT image quality assessment via deep learning strategy. A database of 1500 CT images is constructed, containing 300 high-quality images and 1200 corresponding noisy images. Specifically, the high-quality images were used to simulate the corresponding noisy images at four different doses. Then, the images are scored by the experienced radiologists by the following attributes: image noise, artifacts, edge and structure, overall image quality, and tumor size and boundary estimation with five-point scale. We trained a network for learning the non-liner map from CT images to subjective evaluation scores. Then, we load the pre-trained model to yield predicted score from the test image. To demonstrate the performance of the deep learning network in IQA, correlation coefficients: Pearson Linear Correlation Coefficient (PLCC) and Spearman Rank Order Correlation Coefficient (SROCC) are utilized. And the experimental result demonstrate that the presented deep learning based IQA strategy can be used in the CT image quality assessment.

  1. Using multidetector-row CT in neonates with complex congenital heart disease to replace diagnostic cardiac catheterization for anatomical investigation: initial experiences in technical and clinical feasibility

    International Nuclear Information System (INIS)

    Lee, Tain; Tsai, I.C.; Chen, Min-Chi; Fu, Yun-Ching; Jan, Sheng-Lin; Wang, Chung-Chi; Chang, Yen

    2006-01-01

    Echocardiography is the first-line modality for the investigation of neonatal congenital heart disease. Diagnostic cardiac catheterization, which has a small but recognized risk, is usually performed if echocardiography fails to provide a confident evaluation of the lesions. To verify the technical and clinical feasibilities of replacing diagnostic cardiac catheterization with multidetector-row CT (MDCT) in neonatal complex congenital heart disease. Over a 1-year period we prospectively enrolled all neonates with complex congenital heart disease referred for diagnostic cardiac catheterization after initial assessment by echocardiography. MDCT was performed using a 40-detector-row CT scanner with dual syringe injection. A multidisciplinary congenital heart disease team evaluated the MDCT images and decided if further diagnostic cardiac catheterization was necessary. The accuracy of MDCT in detecting separate cardiovascular anomalies and bolus geometry of contrast enhancement were calculated. A total of 14 neonates were included in the study. No further diagnostic cardiac catheterization was needed in any neonate. The accuracy of MDCT in diagnosing separate cardiovascular anomalies was 98% (53/54) with only one atrial septal defect missed in a patient with coarctation syndrome. The average cardiovascular enhancement in evaluated chambers was 471 HU. No obvious beam-hardening artefact was observed. The technical and clinical feasibility of MDCT in complex congenital heart disease in neonates is confirmed. After initial assessment with echocardiography, MDCT could probably replace diagnostic cardiac catheterization for further anatomical clarification in neonates. (orig.)

  2. Combined electrocardiography- and respiratory-triggered CT of the lung to reduce respiratory misregistration artifacts between imagining slabs in free-breathing children: Initial experience

    International Nuclear Information System (INIS)

    Goo, Hyun Woo; Allmendinger, Thomas

    2017-01-01

    Cardiac and respiratory motion artifacts degrade the image quality of lung CT in free-breathing children. The aim of this study was to evaluate the effect of combined electrocardiography (ECG) and respiratory triggering on respiratory misregistration artifacts on lung CT in free-breathing children. In total, 15 children (median age 19 months, range 6 months–8 years; 7 boys), who underwent free-breathing ECG-triggered lung CT with and without respiratory-triggering were included. A pressure-sensing belt of a respiratory gating system was used to obtain the respiratory signal. The degree of respiratory misregistration artifacts between imaging slabs was graded on a 4-point scale (1, excellent image quality) on coronal and sagittal images and compared between ECG-triggered lung CT studies with and without respiratory triggering. A p value < 0.05 was considered significant. Lung CT with combined ECG and respiratory triggering showed significantly less respiratory misregistration artifacts than lung CT with ECG triggering only (1.1 ± 0.4 vs. 2.2 ± 1.0, p = 0.003). Additional respiratory-triggering reduces respiratory misregistration artifacts on ECG-triggered lung CT in free-breathing children

  3. Combined electrocardiography- and respiratory-triggered CT of the lung to reduce respiratory misregistration artifacts between imagining slabs in free-breathing children: Initial experience

    Energy Technology Data Exchange (ETDEWEB)

    Goo, Hyun Woo [Dept. of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul (Korea, Republic of); Allmendinger, Thomas [Siemens Healthcare, GmbH, Computed Tomography Division, Forchheim (Germany)

    2017-09-15

    Cardiac and respiratory motion artifacts degrade the image quality of lung CT in free-breathing children. The aim of this study was to evaluate the effect of combined electrocardiography (ECG) and respiratory triggering on respiratory misregistration artifacts on lung CT in free-breathing children. In total, 15 children (median age 19 months, range 6 months–8 years; 7 boys), who underwent free-breathing ECG-triggered lung CT with and without respiratory-triggering were included. A pressure-sensing belt of a respiratory gating system was used to obtain the respiratory signal. The degree of respiratory misregistration artifacts between imaging slabs was graded on a 4-point scale (1, excellent image quality) on coronal and sagittal images and compared between ECG-triggered lung CT studies with and without respiratory triggering. A p value < 0.05 was considered significant. Lung CT with combined ECG and respiratory triggering showed significantly less respiratory misregistration artifacts than lung CT with ECG triggering only (1.1 ± 0.4 vs. 2.2 ± 1.0, p = 0.003). Additional respiratory-triggering reduces respiratory misregistration artifacts on ECG-triggered lung CT in free-breathing children.

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

    International Nuclear Information System (INIS)

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

    2005-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-11-01

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

  6. Initial clinical experience with the heartstring

    International Nuclear Information System (INIS)

    Kazui, Toshinobu; Doi, Hirosato; Suzuki, Masato; Okamoto, Takashi; Koshima, Ryuji; Sugiki, Kenji; Ohno, Takemi

    2006-01-01

    The Heartstring is one of the devices that enable proximal anastomosis without clamping the aorta. We have applied the device not only to low-risk patients with normal aortas but also to high-risk patients with diseased aortas. The purpose of this study was to investigate the initial outcomes of using this device. The Heartstring was used on 87 patients between January and December 2004. The patients comprised 62 men and 25 women 48-86 years old (mean 68.4±8.4 years). The ascending aorta was evaluated by computed tomography (CT) scanning before surgery. If a patient's aorta was severely calcified, epiaortic echocardiography was performed. The aortas were ranked into four grades, and the preoperative patient's status were evaluated by the EuroSCORE. Angiography was performed on the third postoperative day. CT scanning revealed that 74 patients had no calcification in the ascending aorta, 10 patients had scattered calcification, and 3 patients had plate-like calcification. The EuroSCORE was 6.86±1.03. We performed 93 proximal anastomoses and 149 distal anastomoses. The average distal anastomosis was 1.6±0.6 sites per graft. Of the distal anastomoses, 74.2% were to the circumflex artery territory. Postoperative coronary angiography revealed that all grafts were patent. The Heartstring facilitates safe proximal anastomosis, even in high-risk patients. Their short-term outcome was good. The device assists in bypassing circumflex artery territory. Long-term follow-up is necessary. (author)

  7. CT-guided thin needles percutaneous cryoablation (PCA) in patients with primary and secondary lung tumors: A preliminary experience

    Energy Technology Data Exchange (ETDEWEB)

    Pusceddu, Claudio, E-mail: clapusceddu@gmail.com [Division of Interventional Radiology, Department of Oncological Radiology, Businco Hospital, Regional Referral Center for Oncologic Diseases, Cagliari, Zip code 09100 (Italy); Sotgia, Barbara, E-mail: barbara.sotgia@gmail.com [Department of Oncological Radiology, Businco Hospital, Regional Referral Center for Oncological Diseases, Cagliari, Zip code 09100 (Italy); Fele, Rosa Maria, E-mail: rosellafele@tiscali.it [Department of Oncological Radiology, Businco Hospital, Regional Referral Center for Oncological Diseases, Cagliari, Zip code 09100 (Italy); Melis, Luca, E-mail: doclucamelis@tiscali.it [Department of Oncological Radiology, Businco Hospital, Regional Referral Center for Oncological Diseases, Cagliari, Zip code 09100 (Italy)

    2013-05-15

    Purpose: To report the data of our initial experience with CT-guided thin cryoprobes for percutaneous cryoablation (PCA) in patients with primary and secondary pulmonary tumors. Material and methods: CT-guided thin needles PCA was performed on 34 lung masses (11 NSCLC = 32%; 23 secondary lung malignancies = 68%) in 32 consecutive patients (24 men and 8 women; mean age 67 ± 10 years) not suitable for surgical resection. Lung masses were treated using two types of cryoprobes: IceRod and IceSeed able to obtain different size of iceball. The number of probes used ranged from 1 to 5 depending on the size of the tumor. After insertion of the cryoprobes into the lesion, the PCA were performed with two 2 (91%) or 3 (9%) cycles each of 12 min of freezing followed by a 4 min active thawing phase and a 4 min passive thawing phase for each one for all treatments. Results: All cryoablation sessions were successfully completed. All primary and metastatic lung tumors were ablated. No procedure-related deaths occurred. Morbidity consisted of 21% (7 of 34) pneumothorax and 3% (1 of 34) cases asymptomatic small pulmonary hemorrhage, respectively, all of CTCAE grade 1 (Common Terminology Criteria for Adverse Events). Low density of entire lesion, central necrosis and solid mass appearance were identify in 21 (62%), 7 (21%) and 6 (17%) of cryoablated tumors, respectively. No lymphadenopathy developed in the region of treated lesions. Technical success (complete lack of enhancement) was achieved in 82%, 97% and 91% of treated lesions at 1-, 3- and 6-months CT follow-up scan, respectively (p < .000). Comparing the tumor longest diameter between the baseline and at 6 month CT images, technical success was revealed in 92% cases (p < .000). Conclusion: Our preliminary experience suggests that PCA is a feasible treatment option. Well-designed clinical trials with a larger patient population are necessary to further investigate the long-term results and prognostic factors.

  8. Evaluation of bone metastases with {sup 18} F- Sodium fluoride PET/CT; initial experience; Evaluacion de metastasis oseas con {sup 18} F-Fluoruro de sodio PET/CT; experiencia inicial

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez C, N.; Serna M, J.A.; Quiroz C, O.; Quinzanos, F.; Valenzuela, J.; Ramirez A, J.L. [Hospital Angeles del Pedregal, Mexico D.F. (Mexico)

    2007-07-01

    The study of NaF-18 PET/CT is the modality with bigger sensitivity and specificity for the bony metastases detection. This additional value of the NaF-18 PET/CT can have a beneficent impact in the clinical handling of the patients with prostate cancer with high risk. (Author)

  9. Volume doubling time and growth rate of renal cell carcinoma determined by helical CT: a single-institution experience

    International Nuclear Information System (INIS)

    Lee, Ji Young; Kim, Chan Kyo; Choi, Dongil; Park, Byung Kwan

    2008-01-01

    The purpose of this study was to retrospectively evaluate the volume doubling time (VDT) and growth rate of renal cell carcinomas (RCC) on a serial computed tomography (CT) scan. Thirty pathologically proven RCCs were reviewed with helical CT. Each tumor underwent at least two CT scans. Tumor volume was determined using an area measuring tool and the summation-of-areas technique. Growth rate was evaluated in terms of diameter and volume changes. VDT and volume growth rate were compared in relation to several factors (initial diameter, initial volume, diameter growth rate, volume growth rate, tumor grade, tumor subtype, sex or age). Mean VDT of RCCs was 505 days. Mean diameter and volume growth rate were 0.59 cm/year and 19.1 cm 3 /year, respectively. For volume and diameter growth rate, tumors ≤4 cm showed lower rates than those >4 cm (P 0.05). Volume growth rate was moderately to strongly positively correlated with initial diameter, initial volume and diameter growth rate (P < 0.05). In conclusion, small RCCs grew at a slow rate both diametrically and volumetrically. More accurate assessment of tumor growth rate and VDT may be helpful to understand the natural history of RCC. (orig.)

  10. Diagnosing and quantification of acute alcohol intoxication. Comparison of dual-energy CT with biochemical analysis. Initial experience

    International Nuclear Information System (INIS)

    Korkusuz, H.; Abbas Raschidi, B.; Keese, D.; Kromen, W.; Bauer, R.W.; Vogl, T.J.; Namgaladze, D.

    2012-01-01

    Purpose: To quantify the correlation between fat content of an acute alcohol intoxication and the difference of computer tomography attenuation value in dual-energy CT in comparison to biochemical triglyceride analysis and to evaluate qualitatively the value of DECT in the diagnosis of fatty liver caused by ethanol-dosage in rats. Materials and Methods: DECT at 140 kV and 80 kV was performed on 20 rats before and two days after the administration of 3 ml of 50 % ethanol. The CT attenuation value in the livers at 140 kV, 80 kV and the differences between them in Hounsfield units (ΔH) were collected. Parts of the liver (100 mg) were measured in biochemical triglyceride analysis as the reference standard. A blood sample was also taken to measure specific liver enzymes. Results: Linear correlation between biochemical triglyceride analysis and CT density of ΔH was found (r = 0.949). 140 kV attenuation data were between 44 HU and 61.3 HU, 80 kV attenuation data were between 58.4 HU and 64.7 HU, and ΔH data were between 3.4 HU and 14.4 HU (p ≤ 0.037). The biochemical triglyceride analysis data were between 7.1 mg/g and 41.1 mg/g. The hepatic enzymes serum aspartate (ASAT) aminotransferase and alanine aminotransferase (ALAT) were elevated in all rats. ASAT correlated directly with ΔHU (r = -0.86). Conclusion: DECT provides a non-invasive method to determine and evaluate hepatic fat content after acute alcohol intoxication. It provides the possibility to detect and quantify the hepatic fat content of liver graft. (orig.)

  11. The utility of first-pass perfusion CT in hyperacute ischemic stroke: early experience

    International Nuclear Information System (INIS)

    Lee, Tae Jin; Lee, Myeong Sub; Kim, Myung Soon; Hong, In Soo; Lee, Young Han; Lee, Ji Yong; Whang, Kum

    2003-01-01

    To evaluate the findings of first-pass perfusion CT in hyperacute stroke patients and to determine the relationship between a perfusion map and final infarct outcome. Thirty-five patients admitted with ischemic stroke within six hours of the onset of symptoms underwent conventional cerebral CT immediately followed by first-pass perfusion CT. Nineteen underwent follow-up CT or MRI, and three types of dynamic perfusion map-cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) - were evaluated by two radiologists. In these 19 patients, initial perfusion maps correlated with final infarct size, determined during follow-up studies. In all 35 patients, major large vessel perfusion abnormalities [middle cerebral artery - MCA MCA and anterior cerebral artery - ACA (n=2); posterior cerebral artery - PCA (n=8)] were detected. On first-pass perfusion maps depicting CBF and MTT, all lesions were detected, and CBF and delayed MTT values were recorded. CBV maps showed variable findings. In all 19 patients who were followed up, the final infarct size of perfusion abnormalities was less than that depicted on CBF and MTT maps, and similar to or much greater than that seen on CBV maps. First-pass perfusion CT scanning is a practical, rapid and advanced imaging technique. In hyperacute stroke patients, it provides important and reliable hemodynamic information as to which brain tissue is salvageable by thrombolytic therapy, and predicts outcome of such treatment

  12. Optimizing CT angiography in patients with Fontan physiology: single-center experience of dual-site power injection

    International Nuclear Information System (INIS)

    Sandler, K.L.; Markham, L.W.; Mah, M.L.; Byrum, E.P.; Williams, J.R.

    2014-01-01

    Aim: To identify adult patients with single-ventricle congenital heart disease and Fontan procedure palliation who have been misdiagnosed with or incompletely evaluated for pulmonary embolism. Additionally, this study was designed to demonstrate that simultaneous, dual-injection of contrast medium into an upper and lower extremity vein is superior to single-injection protocols for CT angiography (CTA) of the chest in this population. Materials and methods: Patients included in the study were retrospectively selected from the Adult Congenital Heart Disease (ACHD) database. Search criteria included history of Fontan palliation and available chest CT examination. Patients were evaluated for (1) type of congenital heart disease and prior operations;(2) indication for initial CT evaluation;(3) route of contrast medium administration for the initial CT examination and resulting diagnosis;(4) whether or not anticoagulation therapy was initiated; and (5) final diagnosis and treatment plan. Results: The query of the ACHD database resulted in 28 individuals or patients with Fontan palliation (superior and inferior venae cavae anastomosed to the pulmonary arteries). Of these, 19 patients with Fontan physiology underwent CTA of the pulmonary circulation, and 17 had suboptimal imaging studies. Unfortunately, seven of these 17 patients (41%) were started on anticoagulation therapy due to a diagnosis of pulmonary embolism that was later excluded. Conclusion: Patients with single-ventricle/Fontan physiology are at risk of thromboembolic disease. Therefore, studies evaluating their complex anatomy must be performed with the optimal imaging protocol to ensure diagnostic accuracy, which is best achieved with dual-injection of an upper and lower extremity central vein. - Highlights: • The adult congenital heart disease population is growing. • Many of these patients have single ventricle/Fontan physiology. • Patients with Fontan physiology are at increased risk for

  13. Initial clinical experience with dual-layer detector spectral CT in patients with acute intracerebral haemorrhage: A single-centre pilot study.

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    Soo Buem Cho

    Full Text Available The purpose of this study was to investigate the clinical feasibility of spectral analyses using dual-layer detector spectral computed tomography (CT in acute intracerebral haemorrhage (ICH.We retrospectively reviewed patients with acute ICH who underwent CT angiography on a dual-layer detector spectral CT scanner. A spectral data analysis was performed to detect contrast enhancement in or adjacent to acute ICH by using spectral image reconstructions including monoenergetic (MonoE, virtual noncontrast (VNC, and iodine overlay fusion images. We also acquired a spectral plot to assess material differentiation within lesions.Among the 30 patients, the most common cause of acute ICH was chronic hypertension (18/30, 60% followed by trauma (5/30, 16.7%, brain tumour (3/30, 10%, Moyamoya disease (2/30, 6.7%, and haemorrhagic diathesis from anticoagulation therapy (2/30, 6.7%. Of 30 patients, 13 showed suboptimal iodine suppression in the subcalvarial spaces on VNC images compared with true noncontrast images. The CT angiographic spot sign within the acute ICH was detected in four patients (4/30, 13.3%. All three tumours were metastatic and included lung cancer (n = 2 and hepatocellular carcinoma (n = 1 which showed conspicuous delineation of an enhancing tumour portion in the spectral analysis. Spectral analyses allowed the discrimination of acute haemorrhage and iodine with enhanced lesion visualization on the MonoE images obtained at lower keVs (less than 70 keV and spectral plot.Even though the image quality of VNC is perceived to be inferior, it is feasible to evaluate acute ICH in clinical settings using dual-layer detector spectral CT. The MonoE images taken at lower keVs were useful for depicting contrast enhancing lesion, and spectral plot might be helpful for material differentiation in patients with acute ICH.

  14. Initial clinical experience with dual-layer detector spectral CT in patients with acute intracerebral haemorrhage: A single-centre pilot study.

    Science.gov (United States)

    Cho, Soo Buem; Baek, Hye Jin; Ryu, Kyeong Hwa; Moon, Jin Il; Choi, Bo Hwa; Park, Sung Eun; Bae, Kyungsoo; Jeon, Kyung Nyeo; Kim, Dong Wook

    2017-01-01

    The purpose of this study was to investigate the clinical feasibility of spectral analyses using dual-layer detector spectral computed tomography (CT) in acute intracerebral haemorrhage (ICH). We retrospectively reviewed patients with acute ICH who underwent CT angiography on a dual-layer detector spectral CT scanner. A spectral data analysis was performed to detect contrast enhancement in or adjacent to acute ICH by using spectral image reconstructions including monoenergetic (MonoE), virtual noncontrast (VNC), and iodine overlay fusion images. We also acquired a spectral plot to assess material differentiation within lesions. Among the 30 patients, the most common cause of acute ICH was chronic hypertension (18/30, 60%) followed by trauma (5/30, 16.7%), brain tumour (3/30, 10%), Moyamoya disease (2/30, 6.7%), and haemorrhagic diathesis from anticoagulation therapy (2/30, 6.7%). Of 30 patients, 13 showed suboptimal iodine suppression in the subcalvarial spaces on VNC images compared with true noncontrast images. The CT angiographic spot sign within the acute ICH was detected in four patients (4/30, 13.3%). All three tumours were metastatic and included lung cancer (n = 2) and hepatocellular carcinoma (n = 1) which showed conspicuous delineation of an enhancing tumour portion in the spectral analysis. Spectral analyses allowed the discrimination of acute haemorrhage and iodine with enhanced lesion visualization on the MonoE images obtained at lower keVs (less than 70 keV) and spectral plot. Even though the image quality of VNC is perceived to be inferior, it is feasible to evaluate acute ICH in clinical settings using dual-layer detector spectral CT. The MonoE images taken at lower keVs were useful for depicting contrast enhancing lesion, and spectral plot might be helpful for material differentiation in patients with acute ICH.

  15. Dual-contrast agent photon-counting computed tomography of the heart: initial experience.

    Science.gov (United States)

    Symons, Rolf; Cork, Tyler E; Lakshmanan, Manu N; Evers, Robert; Davies-Venn, Cynthia; Rice, Kelly A; Thomas, Marvin L; Liu, Chia-Ying; Kappler, Steffen; Ulzheimer, Stefan; Sandfort, Veit; Bluemke, David A; Pourmorteza, Amir

    2017-08-01

    To determine the feasibility of dual-contrast agent imaging of the heart using photon-counting detector (PCD) computed tomography (CT) to simultaneously assess both first-pass and late enhancement of the myocardium. An occlusion-reperfusion canine model of myocardial infarction was used. Gadolinium-based contrast was injected 10 min prior to PCD CT. Iodinated contrast was infused immediately prior to PCD CT, thus capturing late gadolinium enhancement as well as first-pass iodine enhancement. Gadolinium and iodine maps were calculated using a linear material decomposition technique and compared to single-energy (conventional) images. PCD images were compared to in vivo and ex vivo magnetic resonance imaging (MRI) and histology. For infarct versus remote myocardium, contrast-to-noise ratio (CNR) was maximal on late enhancement gadolinium maps (CNR 9.0 ± 0.8, 6.6 ± 0.7, and 0.4 ± 0.4, p contrast agent cardiac imaging is feasible with photon-counting detector CT. These initial proof-of-concept results may provide incentives to develop new k-edge contrast agents, to investigate possible interactions between multiple simultaneously administered contrast agents, and to ultimately bring them to clinical practice.

  16. Dual energy virtual CT colonoscopy with dual source computed tomography. Initial experience

    International Nuclear Information System (INIS)

    Karcaaltincaba, M.; Karaosmanoglu, D.; Akata, D.; Sentuerk, S.; Oezmen, M.; Alibek, S.

    2009-01-01

    Purpose: To describe the technique of DE MDCT colonoscopy and to assess its feasibility. Materials and Methods: 8 patients were scanned with DSCT with a DE scan protocol and dose modulation software. Analysis was performed using dedicated DE software. Prone non-contrast images and DE supine images after contrast injection were obtained. Results: DE colonoscopic images were successfully obtained in 7 patients, but the FOV did not cover all colonic segments in 1 patient, thus resulting in a technical success rate was 87.5%. Streak artifacts were present in the pelvic region in 2 patients. Virtual unenhanced images and iodine map images were obtained for all patients. In 1 patient a polypoid non-enhancing structure was noted on the iodine map, and conventional colonoscopy revealed impacted stool. Enhancing rectal cancer in 1 patient was correctly shown on the iodine map. Iodine maps helped to differentiate stool fragments/retained fluid by the absence of enhancement when compared to prone CT images. The major advantage of DE colonoscopy was the lack of misregistration. Conclusion: DE MDCT colonoscopy is technically feasible and may obviate the need for unenhanced prone images. It may be possible to perform noncathartic DECT colonoscopy. The major limitation is the limited FOV of tube B. The dose should be optimized to reduce streak artifacts in the pelvic region. (orig.)

  17. [Virtual CT-pneumocystoscopy: indications, advantages and limitations. Our experience].

    Science.gov (United States)

    Regine, Giovanni; Atzori, Maurizio; Buffa, Vitaliano; Miele, Vittorio; Ialongo, Pasquale; Adami, Loredana

    2003-09-01

    The use of CT volume-rendering techniques allows the evaluation of visceral organs without the need for endoscopy. Conventional endoscopic evaluation of the bladder is limited by the invasiveness of the technique and the difficulty exploring the entire bladder. Virtual evaluation of the bladder by three-dimensional CT reconstruction offers potential advantages and can be used in place of endoscopy. This study investigates the sensitivity of virtual CT in assessing lesion of the bladder wall to compare it with that of conventional endoscopy, and outlines the indications, advantages and disadvantages of virtual CT-pneumocystography. Between September 2001 and May 2002, 21 patients with haematuria and positive cystoscopic findings were studied. After an initial assessment by ultrasound, the patients underwent pelvic CT as a single volumetric scan after preliminary air distension of the bladder by means of 12 F Foley catheter. The images were processed on an independent workstation (Advantage 3.0 GE) running dedicated software for endoluminal navigation. The lesions detected by endoscopy were classified as sessile or pedunculated, and according to size (more or less than 5 mm). Finally, the results obtained at virtual cystoscopy were evaluated by two radiologists blinded to the conventional cystoscopy results. Thirty lesions (24 pedunculated, 6 sessile) were detected at conventional cystoscopy in 16 patients (multiple polyposis in 3 cases). Virtual cystoscopy identified 23 lesions (19 pedunculated and 4 sessile). The undetected lesions were pedunculated <5 mm (5 cases) and sessile (2 cases). One correctly identified pedunculated lesion was associated with a bladder stone. Good quality virtual images were obtained in all of the patients. In only one patient with multiple polyposis the quality of the virtual endoscopic evaluation was limited by the patient's intolerance to bladder distension, although identification of the lesions was not compromised. The overall

  18. Initial experience in hybrid PET-MRI for evaluation of refractory focal onset epilepsy.

    Science.gov (United States)

    Shin, Hae W; Jewells, Valerie; Sheikh, Arif; Zhang, Jingwen; Zhu, Hongtu; An, Hongyu; Gao, Wei; Shen, Dinggang; Hadar, Eldad; Lin, Weili

    2015-09-01

    We aim to evaluate the utility/improved accuracy of hybrid PET/MR compared to current practice separate 3T MRI and PET-CT imaging for localization of seizure foci. In a pilot study, twenty-nine patients undergoing epilepsy surgery evaluation were imaged using PET/MR. This subject group had 29 previous clinical 3T MRI as well as 12 PET-CT studies. Prior clinical PET and MR images were read sequentially while the hybrid PET/MR was concurrently read. The median interval between hybrid PET/MR and prior imaging studies was 5 months (range 1-77 months). In 24 patients, there was no change in the read between the clinical exams and hybrid PET/MR while new anatomical or functional lesions were identified by hybrid PET/MR in 5 patients without significant clinical change. Four new anatomical MR lesions were seen with concordant PET findings. The remaining patient revealed a new abnormal PET lesion without an MR abnormality. All new PET/MR lesions were clinically significant with concordant EEG and/or SPECT results as potential epileptic foci. Our initial hybrid PET-MRI experience increased diagnostic yields for detection of potential epileptic lesions. This may be due to the unique advantage of improved co-registration and simultaneous review of both structural and functional data. Copyright © 2015 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

  19. Initial Experience of Using Dual-Energy CT with an Iodine Overlay Image for Hand Psoriatic Arthritis: Comparison Study with Contrast-enhanced MR Imaging.

    Science.gov (United States)

    Fukuda, Takeshi; Umezawa, Yoshinori; Tojo, Shinjiro; Yonenaga, Takenori; Asahina, Akihiko; Nakagawa, Hidemi; Fukuda, Kunihiko

    2017-07-01

    Purpose To determine the feasibility of dual-energy (DE) computed tomography (CT) with an iodine overlay image (IOI) for evaluation of psoriatic arthritis in the hand. Materials and Methods Approval from the institutional ethics committee and written informed consent from all patients were obtained. This prospective study included 16 patients who had psoriasis with finger joint symptoms from January 2015 to January 2016. Contrast material-enhanced (CE) DE CT and 1.5-T CE magnetic resonance (MR) imaging were performed within 1 month of each other. DE CT was performed with a tube voltage of 80 kV and 140 kV with use of a 0.4-mm tin filter. Images acquired with both modalities were evaluated by two radiologists independently by using a semiquantitative scoring system. Interreader agreement was calculated for each modality: Weighted κ values were calculated for synovitis, flexor tenosynovitis, and extensor peritendonitis, and κ values were calculated for periarticular inflammation. With consensus scores and CE MR images as the reference, the sensitivity and specificity of IOI DE CT for inflammatory lesions were calculated. Statistical analysis of discordant readings was performed by using the McNemar test. Results Interreader agreement for inflammatory lesions was excellent or good (weighted κ = 0.83 and κ = 0.75 in IOI DE CT; weighted κ = 0.81 and κ = 0.87 in CE MR imaging). The sensitivity and specificity of IOI DE CT were 0.78 and 0.87, respectively. Total agreement was 86.3%; however, there were significantly more lesions detected with IOI DE CT than with CE MR imaging alone (134 vs 20 lesions in 1120 evaluated items; P the abnormalities detected with IOI DE CT alone were located in distal interphalangeal joints. Conclusion IOI DE CT is a new imaging modality that may be useful for evaluating psoriatic arthritis in the hand, particularly in the detection of inflammatory lesions in small joints, and may be more useful than CE MR imaging, within the limitation

  20. Initial experience with lung-MRI at 3.0 T: Comparison with CT and clinical data in the evaluation of interstitial lung disease activity

    International Nuclear Information System (INIS)

    Lutterbey, G.; Grohe, C.; Gieseke, J.; Falkenhausen, M. von; Morakkabati, N.; Wattjes, M.P.; Manka, R.; Trog, D.; Schild, H.H.

    2007-01-01

    Objectives: We evaluated the feasibility of highfield lung-MRI at 3.0 T. A comparison with Computed Tomography (CT) and clinical data regarding the assessment of inflammatory activity in patients with diffuse lung disease was performed. Material and methods: Prospective evaluation of 21 patients (15 males, 6 females, 43-80 y) with diffuse lung diseases who underwent clinical work-up inclusive laboratory tests, lung-function tests and transbronchial biopsy. After routine helical CT (additional 12 HRCT) a lung-MRI (3.0 Intera, Philips Medical Systems, Best, The Netherlands) using a T2-weighted, cardiac and respiratory triggered Fast-Spinecho-Sequence (TE/TR = 80/1500-2500 ms, 22 transverse slices, 7/2 mm slice-thickness/-gap) was performed. A pneumologist classified the cases into two groups: A = temporary acute interstitial disease or chronic interstitial lung disease with acute episode or superimposed infection/B = burned out interstitial lung disease without activity. Two blinded CT-radiologists graded the cases in active/inactive disease on the basis of nine morphological criteria each. A third radiologist rated the MRI-cases as active/inactive, depending on the signal-intensities of lung tissues. Results: The pneumologist classified 14 patients into group A and 7 patients into group B. Using CT, 6 cases were classified as active, 15 cases as inactive disease. With MRI 12 cases were classified as active and 9 cases as inactive. In the complete group of 21 patients MRI decisions and CT decisions respectively were false positive/false negative/correct in 2/4/15 respectively 0/8/13 cases. Correct diagnoses were obtained in 72% (MRI) respectively 62% (CT). In the subgroup of 12 cases including HRCT, MRI respectively CT were false positive/false negative/correct in 2/1/9 respectively 0/5/7 cases. Correct diagnoses were obtained in 75% (MRI) respectively 58% (CT). Conclusion: Highfield MRI of the lung is feasible and performed slightly better compared to CT in the

  1. Initial experience with lung-MRI at 3.0 T: Comparison with CT and clinical data in the evaluation of interstitial lung disease activity

    Energy Technology Data Exchange (ETDEWEB)

    Lutterbey, G. [Department of Radiology, University of Bonn, Sigmund-Freud-Strasse 25, D-53105 Bonn (Germany)]. E-mail: goetz.lutterbey@ukb.uni-bonn.de; Grohe, C. [Department of Internal Medicine, University of Bonn (Germany); Gieseke, J. [PHILIPS Medical Systems, Best (Netherlands); Falkenhausen, M. von [Department of Radiology, University of Bonn, Sigmund-Freud-Strasse 25, D-53105 Bonn (Germany); Morakkabati, N. [Department of Radiology, University of Bonn, Sigmund-Freud-Strasse 25, D-53105 Bonn (Germany); Wattjes, M.P. [Department of Radiology, University of Bonn, Sigmund-Freud-Strasse 25, D-53105 Bonn (Germany); Manka, R. [Department of Internal Medicine, University of Bonn (Germany); Trog, D. [Department of Radiology, University of Bonn, Sigmund-Freud-Strasse 25, D-53105 Bonn (Germany); Schild, H.H. [Department of Radiology, University of Bonn, Sigmund-Freud-Strasse 25, D-53105 Bonn (Germany)

    2007-02-15

    Objectives: We evaluated the feasibility of highfield lung-MRI at 3.0 T. A comparison with Computed Tomography (CT) and clinical data regarding the assessment of inflammatory activity in patients with diffuse lung disease was performed. Material and methods: Prospective evaluation of 21 patients (15 males, 6 females, 43-80 y) with diffuse lung diseases who underwent clinical work-up inclusive laboratory tests, lung-function tests and transbronchial biopsy. After routine helical CT (additional 12 HRCT) a lung-MRI (3.0 Intera, Philips Medical Systems, Best, The Netherlands) using a T2-weighted, cardiac and respiratory triggered Fast-Spinecho-Sequence (TE/TR = 80/1500-2500 ms, 22 transverse slices, 7/2 mm slice-thickness/-gap) was performed. A pneumologist classified the cases into two groups: A = temporary acute interstitial disease or chronic interstitial lung disease with acute episode or superimposed infection/B = burned out interstitial lung disease without activity. Two blinded CT-radiologists graded the cases in active/inactive disease on the basis of nine morphological criteria each. A third radiologist rated the MRI-cases as active/inactive, depending on the signal-intensities of lung tissues. Results: The pneumologist classified 14 patients into group A and 7 patients into group B. Using CT, 6 cases were classified as active, 15 cases as inactive disease. With MRI 12 cases were classified as active and 9 cases as inactive. In the complete group of 21 patients MRI decisions and CT decisions respectively were false positive/false negative/correct in 2/4/15 respectively 0/8/13 cases. Correct diagnoses were obtained in 72% (MRI) respectively 62% (CT). In the subgroup of 12 cases including HRCT, MRI respectively CT were false positive/false negative/correct in 2/1/9 respectively 0/5/7 cases. Correct diagnoses were obtained in 75% (MRI) respectively 58% (CT). Conclusion: Highfield MRI of the lung is feasible and performed slightly better compared to CT in the

  2. Krypton ventilation imaging using dual-energy CT in chronic obstructive pulmonary disease patients: initial experience.

    Science.gov (United States)

    Hachulla, Anne-Lise; Pontana, François; Wemeau-Stervinou, Lidwine; Khung, Suonita; Faivre, Jean-Baptiste; Wallaert, Benoit; Cazaubon, Jean-François; Duhamel, Alain; Perez, Thierry; Devos, Patrick; Remy, Jacques; Remy-Jardin, Martine

    2012-04-01

    To evaluate the tolerance and level of enhancement achievable after inhalation of stable krypton. This study was approved by the institutional review board and the local ethics committee. Written informed consent was obtained from all subjects. The study was planned as a Fleming two-stage design, enabling one to assess the effectiveness of a newer treatment or technique on a small number of patients. At the end of each stage, the results are computed, and the trial can be stopped if the effectiveness is less than a minimum success rate or greater than an expected success rate. After informed consent was obtained, a total of 32 patients (ie, two successive series of 16 patients each) with severe emphysema underwent a dual-source, dual-energy chest computed tomographic (CT) examination after inhalation of a mixture of stable krypton (80%) and oxygen (20%), with reconstruction of diagnostic and ventilation images. For each patient, two regions of interest were selected on a diagnostic image, one in a region of severe emphysema (presumed to be poorly ventilated or not ventilated) and a second one in a region devoid of structural abnormalities (presumed to be normally ventilated), with measurements of attenuation values on the corresponding ventilation image. All examinations were successfully performed, without adverse effects. Differences in attenuation between normal lung and emphysematous areas were found in 28 patients (88%; 95% confidence interval: 71%, 96.5%). The maximal level of attenuation within normal lung was 18.5 HU. Krypton attenuation difference between normal and emphysematous lung was significant, with a median value of 51.8% (P krypton and its excellent clinical tolerance makes this gas eligible for ventilation CT examinations. © RSNA, 2012.

  3. MDCT of acute pancreatitis: Intraindividual comparison of single-phase versus dual-phase MDCT for initial assessment of acute pancreatitis using different CT scoring systems

    Energy Technology Data Exchange (ETDEWEB)

    Avanesov, Maxim, E-mail: m.avanesov@uke.de [Department of Diagnostic and Interventional Radiology and Nuclear Medicine, University Medical Center Hamburg-Eppendorf, Hamburg (Germany); Weinrich, Julius M.; Kraus, Thomas [Department of Diagnostic and Interventional Radiology and Nuclear Medicine, University Medical Center Hamburg-Eppendorf, Hamburg (Germany); Derlin, Thorsten [Department of Nuclear Medicine, Hannover Medical School (Germany); Adam, Gerhard; Yamamura, Jin [Department of Diagnostic and Interventional Radiology and Nuclear Medicine, University Medical Center Hamburg-Eppendorf, Hamburg (Germany); Karul, Murat [Department of Diagnostic and Interventional Radiology, Marienkrankenhaus Hamburg (Germany)

    2016-11-15

    Objectives: The purpose of the retrospective study was to evaluate the additional value of dual-phase multidetector computed tomography (MDCT) protocols over a single-phase protocol on initial MDCT in patients with acute pancreatitis using three CT-based pancreatitis severity scores with regard to radiation dose. Methods: In this retrospective, IRB approved study MDCT was performed in 102 consecutive patients (73 males; 55years, IQR48–64) with acute pancreatitis. Inclusion criteria were CT findings of interstitial edematous pancreatitis (IP) or necrotizing pancreatitis (NP) and a contrast-enhanced dual-phase (arterial phase and portal-venous phase) abdominal CT performed at ≥72 h after onset of symptoms. The severity of pancreatic and extrapancreatic changes was independently assessed by 2 observers using 3 validated CT-based scoring systems (CTSI, mCTSI, EPIC). All scores were applied to arterial phase and portal venous phase scans and compared to score results of portal venous phase scans, assessed ≥14 days after initial evaluation. For effective dose estimation, volume CT dose index (CTDIvol) and dose length product (DLP) were recorded in all examinations. Results: In neither of the CT severity scores a significant difference was observed after application of a dual-phase protocol compared with a single-phase protocol (IP: CTSI: 2.7 vs. 2.5, p = 0.25; mCTSI: 4.0 vs. 4.0, p = 0.10; EPIC: 2.0 vs. 2.0, p = 0.41; NP: CTSI: 8.0 vs. 7.0, p = 0.64; mCTSI: 8.0 vs. 8.0, p = 0.10; EPIC: 3.0 vs. 3.0, p = 0.06). The application of a single-phase CT protocol was associated with a median effective dose reduction of 36% (mean dose reduction 31%) compared to a dual-phase CT scan. Conclusions: An initial dual-phase abdominal CT after ≥72 h after onset of symptoms of acute pancreatitis was not superior to a single-phase protocol for evaluation of the severity of pancreatic and extrapancreatic changes. However, the effective radiation dose may be reduced by 36% using a

  4. Stanford type A aortic dissection with closed false lumen: Analysis of prognostic factors at initial CT or MRI

    Energy Technology Data Exchange (ETDEWEB)

    Matsuoka, Yohjiro; Sakamoto, Ichiro; Ogawa, Yohji; Sueyoshi, Eijun; Hayashi, Kuniaki; Takagi, Masatake [Nagasaki Univ. (Japan). School of Medicine; Narimatsu, Motoharu

    1997-08-01

    Nineteen patients with Stanford type A acute aortic dissection with closed false lumen were reviewed. In the follow-up examinations, ulcerlike projection (ULP) in the ascending aorta (AA) or aortic arch (AR) was identified in 8 of 19 patients. In 5 of these 8 patients, acute cardiac tamponade occurred and 3 of them died. In the other 11 patients, there was no mortality, and only one patient underwent elective surgery. The appearance of ULP in the AA/AR is considered an indication for urgent surgery because it is regarded as a precursor of lethal complications such as cardiac tamponade. The purpose of this study was to investigate predictors of the appearance of ULP in the AA/AR with early imagings (CT or MRI) before the appearance of ULP. The patients were divided into two groups: patients with ULP in the AA/AR (8 patients) and others (11 patients). Initial CT or MRI findings of the thoracic aorta were retrospectively statistically analyzed in each group. Three predictive factors were statistically significant for the appearance of ULP in the AA/AR (diameter of the AA{>=}5 cm, thickness of the false lumen of the AA{>=}1 cm, thickness of the false lumen of the AA{>=} that of the descending aorta). Close attention should be paid, if any of these 3 factors is observed at initial CT or MRI. (author)

  5. Stanford type A aortic dissection with closed false lumen: Analysis of prognostic factors at initial CT or MRI

    International Nuclear Information System (INIS)

    Matsuoka, Yohjiro; Sakamoto, Ichiro; Ogawa, Yohji; Sueyoshi, Eijun; Hayashi, Kuniaki; Takagi, Masatake; Narimatsu, Motoharu.

    1997-01-01

    Nineteen patients with Stanford type A acute aortic dissection with closed false lumen were reviewed. In the follow-up examinations, ulcerlike projection (ULP) in the ascending aorta (AA) or aortic arch (AR) was identified in 8 of 19 patients. In 5 of these 8 patients, acute cardiac tamponade occurred and 3 of them died. In the other 11 patients, there was no mortality, and only one patient underwent elective surgery. The appearance of ULP in the AA/AR is considered an indication for urgent surgery because it is regarded as a precursor of lethal complications such as cardiac tamponade. The purpose of this study was to investigate predictors of the appearance of ULP in the AA/AR with early imagings (CT or MRI) before the appearance of ULP. The patients were divided into two groups: patients with ULP in the AA/AR (8 patients) and others (11 patients). Initial CT or MRI findings of the thoracic aorta were retrospectively statistically analyzed in each group. Three predictive factors were statistically significant for the appearance of ULP in the AA/AR (diameter of the AA≥5 cm, thickness of the false lumen of the AA≥1 cm, thickness of the false lumen of the AA≥ that of the descending aorta). Close attention should be paid, if any of these 3 factors is observed at initial CT or MRI. (author)

  6. Impact of institutional volume and experience with CT interpretation on sizing of transcatheter aortic valves: A multicenter retrospective study

    International Nuclear Information System (INIS)

    Verma, Divya Ratan; Pershad, Yash; Pershad, Ashish; Fang, Kenith; Gellert, George; Morris, Michael F.

    2016-01-01

    Background: Computed tomography (CT) has become the standard imaging modality for pre-procedural aortic annular sizing prior to transcatheter aortic valve replacement (TAVR). We hypothesized that the accuracy of CT derived annular measurements would be greater at sites with higher TAVR procedural volume. Methods: Within a large integrated health system, TAVR was performed at low ( 75 cases). 181 patients underwent TAVR with a Sapien XT transcatheter heart valve (THV). Two blinded experienced readers independently remeasured the annulus on CT and compared their measurements to site reported measurements. Hypothetical THV sizes were chosen based on measurements from site CT reports and independent readers’ measurements, and compared to the implanted THV size. Results: Correlation between site reported measurements and independent readers measurements of mean annulus size varied between low-volume (r = 0.31, p = 0.18), intermediate-volume (r = 0.34, p = 0.01), and high-volume sites (r = 0.96, p < 0.01). On multivariate analysis, interpretation of ≥20 CT scans (OR 0.29; 95% CI 0.03–0.81; p 0.02) and high-volume site (OR 0.16; 95% CI 0.10–0.82; p 0.02) were associated with reduced mismatch between the site predicted THV size and independent readers predicted THV size. Mismatch between site predicted THV size and implanted THV size was associated with a worse 30-day composite of mortality, dialysis-dependent renal failure, cerebrovascular accident, new permanent pacemaker, and hospital readmission (55.3 vs. 38.7%; p = 0.05). Conclusions: Accuracy of CT aortic annular sizing is improved with higher individual experience and site TAVR volume. These findings should be confirmed in larger, prospective studies. - Highlights: • Accuracy of CT aortic annular sizing is improved with higher individual experience and site TAVR volume. • CT readers with experience interpreting ≥20 pre-TAVR CT scans had significantly improved accuracy in identifying the annulus.

  7. Automatic spectral imaging protocol selection and iterative reconstruction in abdominal CT with reduced contrast agent dose: initial experience.

    Science.gov (United States)

    Lv, Peijie; Liu, Jie; Chai, Yaru; Yan, Xiaopeng; Gao, Jianbo; Dong, Junqiang

    2017-01-01

    To evaluate the feasibility, image quality, and radiation dose of automatic spectral imaging protocol selection (ASIS) and adaptive statistical iterative reconstruction (ASIR) with reduced contrast agent dose in abdominal multiphase CT. One hundred and sixty patients were randomly divided into two scan protocols (n = 80 each; protocol A, 120 kVp/450 mgI/kg, filtered back projection algorithm (FBP); protocol B, spectral CT imaging with ASIS and 40 to 70 keV monochromatic images generated per 300 mgI/kg, ASIR algorithm. Quantitative parameters (image noise and contrast-to-noise ratios [CNRs]) and qualitative visual parameters (image noise, small structures, organ enhancement, and overall image quality) were compared. Monochromatic images at 50 keV and 60 keV provided similar or lower image noise, but higher contrast and overall image quality as compared with 120-kVp images. Despite the higher image noise, 40-keV images showed similar overall image quality compared to 120-kVp images. Radiation dose did not differ between the two protocols, while contrast agent dose in protocol B was reduced by 33 %. Application of ASIR and ASIS to monochromatic imaging from 40 to 60 keV allowed contrast agent dose reduction with adequate image quality and without increasing radiation dose compared to 120 kVp with FBP. • Automatic spectral imaging protocol selection provides appropriate scan protocols. • Abdominal CT is feasible using spectral imaging and 300 mgI/kg contrast agent. • 50-keV monochromatic images with 50 % ASIR provide optimal image quality.

  8. Advances in CT imaging for urolithiasis

    Directory of Open Access Journals (Sweden)

    Yasir Andrabi

    2015-01-01

    Full Text Available Urolithiasis is a common disease with increasing prevalence worldwide and a lifetime-estimated recurrence risk of over 50%. Imaging plays a critical role in the initial diagnosis, follow-up and urological management of urinary tract stone disease. Unenhanced helical computed tomography (CT is highly sensitive (>95% and specific (>96% in the diagnosis of urolithiasis and is the imaging investigation of choice for the initial assessment of patients with suspected urolithiasis. The emergence of multi-detector CT (MDCT and technological innovations in CT such as dual-energy CT (DECT has widened the scope of MDCT in the stone disease management from initial diagnosis to encompass treatment planning and monitoring of treatment success. DECT has been shown to enhance pre-treatment characterization of stone composition in comparison with conventional MDCT and is being increasingly used. Although CT-related radiation dose exposure remains a valid concern, the use of low-dose MDCT protocols and integration of newer iterative reconstruction algorithms into routine CT practice has resulted in a substantial decrease in ionizing radiation exposure. In this review article, our intent is to discuss the role of MDCT in the diagnosis and post-treatment evaluation of urolithiasis and review the impact of emerging CT technologies such as dual energy in clinical practice.

  9. Return to Experience and Initial Wage Level

    DEFF Research Database (Denmark)

    Sørensen, Kenneth Lykke; Vejlin, Rune Majlund

    This paper estimates the relationship between initial wage and return to experience. We use a Mincer-like wage model to nonparametrically estimate this relationship allowing for an unobservable individual permanent effect in wages and unobservable individual return to experience. The relationship...

  10. CT-Guided Percutaneous Drainage of Infected Collections Due to Gastric Leak After Sleeve Gastrectomy for Morbid Obesity: Initial Experience

    International Nuclear Information System (INIS)

    Kelogrigoris, M.; Sotiropoulou, E.; Stathopoulos, K.; Georgiadou, V.; Philippousis, P.; Thanos, L.

    2011-01-01

    This study was designed to evaluate the efficacy and safety of computed tomography (CT)-guided drainage in treating infected collections due to gastric leak after laparoscopic sleeve gastrectomy for morbid obesity. From January 2007 to June 2009, 21 patients (9 men and 12 women; mean age, 39.2 (range, 26–52) years) with infected collections due to gastric leak after laparoscopic sleeve gastrectomy for morbid obesity underwent image-guided percutaneous drainage. All procedures were performed using CT guidance and 8- to 12-Fr pigtail drainage catheters. Immediate technical success was achieved in all 21 infected collections. In 18 of 21 collections, we obtained progressive shrinkage of the collection with consequent clinical success (success rate 86%). In three cases, the abdominal fluid collection was not resolved, and the patients were reoperated. Among the 18 patients who avoided surgery, 2 needed replacement of the catheter due to obstruction. No major complications occurred during the procedure. The results of our study support that CT-guided percutaneous drainage is an effective and safe method to treat infected abdominal fluid collections due to gastric leak in patients who had previously underwent laparoscopic sleeve gastrectomy for morbid obesity. It may be considered both as a preparatory step for surgery and a valuable alternative to open surgery. Failure of the procedure does not, however, preclude a subsequent surgical operation.

  11. Return to experience and initial wage level

    DEFF Research Database (Denmark)

    Sørensen, K.L.; Vejlin, R.

    2014-01-01

    This paper estimates the relationship between initial wage and return to experience. We use a Mincer-like wage model to non-parametrically estimate this relationship allowing for an unobservable individual permanent effect in wages and unobservable individual return to experience. The relationshi...

  12. Evaluation of dual energy spectral CT in differentiating metastatic from non-metastatic lymph nodes in rectal cancer: Initial experience

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Huanhuan [Department of Radiology, Ruijin Hospital Affiliated to Shanghai Jiaotong University, School of Medicine, Shanghai 200025 (China); Department of Radiology, Xinhua Hospital affiliated to Shanghai Jiaotong University School of Medicine (China); Yan, Fuhua; Pan, Zilai; Lin, Xiaozhu; Luo, Xianfu; Shi, Cen [Department of Radiology, Ruijin Hospital Affiliated to Shanghai Jiaotong University, School of Medicine, Shanghai 200025 (China); Chen, Xiaoyan [Department of Pathology, Ruijin Hospital Affiliated to Shanghai Jiaotong University, School of Medicine, Shanghai 200025 (China); Wang, Baisong [Department of Biomedical Statistics, Shanghai Jiaotong University, School of Medicine, Shanghai 200025 (China); Zhang, Huan, E-mail: huanzhangy@126.com [Department of Radiology, Ruijin Hospital Affiliated to Shanghai Jiaotong University, School of Medicine, Shanghai 200025 (China)

    2015-02-15

    Highlights: • Colorectal cancer is the third most prevalent cancer and the status of the regional lymph nodes in rectal cancer is considered to be one of the most powerful prognostic factor in the absence of distant metastatic disease. Detecting LNs metastasis is still a challenging problem due to the presence of microscopic metastasis or inflammatory swelling of LNs. • We investigated the value of dual energy spectral CT in differentiating metastatic from non-metastatic lymph nodes in rectal cancer. Our study demonstrated that the quantitative normalized iodine concentration (nIC) could be useful for differentiating metastatic and non-metastatic lymph nodes. The combination of nIC in portal venous phase and conventional size criterion could improve the diagnostic accuracy, sensitivity, specificity, positive predictive value and negative predictive value of rectal cancer. - Abstract: Objectives: To investigate the value of dual energy spectral CT (DEsCT) imaging in differentiating metastatic from non-metastatic lymph nodes in rectal cancer. Methods: Fifty-five patients with rectal cancer underwent the arterial phase (AP) and portal venous phase (PP) contrast-enhanced DEsCT imaging. The virtual monochromatic images and iodine-based material decomposition images derived from DEsCT imaging were interpreted for lymph nodes (LNs) measurement. The short axis diameter and the normalized iodine concentration (nIC) of metastatic and non-metastatic LNs were measured. The two-sample t test was used to compare the short axis diameters and nIC values of metastatic and non-metastatic LNs. ROC analysis was performed to assess the diagnostic performance. Results: One hundred and fifty two LNs including 92 non-metastatic LNs and 60 metastatic LNs were matched using the radiological-pathological correlation. The mean short axis diameter of metastatic LNs was significantly larger than that of the non-metastatic LNs (7.28 ± 2.28 mm vs. 4.90 ± 1.64 mm, P < 0.001). The mean n

  13. Impact of institutional volume and experience with CT interpretation on sizing of transcatheter aortic valves: A multicenter retrospective study

    Energy Technology Data Exchange (ETDEWEB)

    Verma, Divya Ratan [Cardiovascular Institute, Banner University Medical Center, Phoenix, AZ (United States); Division of Interventional Cardiology, Banner University Medical Center, Phoenix, AZ (United States); Pershad, Yash [Department of Radiology, Banner University Medical Center, Phoenix, AZ (United States); Pershad, Ashish [Cardiovascular Institute, Banner University Medical Center, Phoenix, AZ (United States); Division of Interventional Cardiology, Banner University Medical Center, Phoenix, AZ (United States); Fang, Kenith [Cardiovascular Institute, Banner University Medical Center, Phoenix, AZ (United States); Division of Cardiothoracic Surgery, Banner University Medical Center, Phoenix, AZ (United States); Gellert, George [Cardiovascular Institute, Banner University Medical Center, Phoenix, AZ (United States); Department of Anesthesiology, Banner University Medical Center, Phoenix, AZ (United States); Morris, Michael F., E-mail: mfmorris@mail.arizona.edu [Cardiovascular Institute, Banner University Medical Center, Phoenix, AZ (United States); Department of Radiology, Banner University Medical Center, Phoenix, AZ (United States)

    2016-12-15

    Background: Computed tomography (CT) has become the standard imaging modality for pre-procedural aortic annular sizing prior to transcatheter aortic valve replacement (TAVR). We hypothesized that the accuracy of CT derived annular measurements would be greater at sites with higher TAVR procedural volume. Methods: Within a large integrated health system, TAVR was performed at low (<40 cases), intermediate (40–75 cases), and high-volume sites (>75 cases). 181 patients underwent TAVR with a Sapien XT transcatheter heart valve (THV). Two blinded experienced readers independently remeasured the annulus on CT and compared their measurements to site reported measurements. Hypothetical THV sizes were chosen based on measurements from site CT reports and independent readers’ measurements, and compared to the implanted THV size. Results: Correlation between site reported measurements and independent readers measurements of mean annulus size varied between low-volume (r = 0.31, p = 0.18), intermediate-volume (r = 0.34, p = 0.01), and high-volume sites (r = 0.96, p < 0.01). On multivariate analysis, interpretation of ≥20 CT scans (OR 0.29; 95% CI 0.03–0.81; p 0.02) and high-volume site (OR 0.16; 95% CI 0.10–0.82; p 0.02) were associated with reduced mismatch between the site predicted THV size and independent readers predicted THV size. Mismatch between site predicted THV size and implanted THV size was associated with a worse 30-day composite of mortality, dialysis-dependent renal failure, cerebrovascular accident, new permanent pacemaker, and hospital readmission (55.3 vs. 38.7%; p = 0.05). Conclusions: Accuracy of CT aortic annular sizing is improved with higher individual experience and site TAVR volume. These findings should be confirmed in larger, prospective studies. - Highlights: • Accuracy of CT aortic annular sizing is improved with higher individual experience and site TAVR volume. • CT readers with experience interpreting ≥20 pre-TAVR CT scans had

  14. Complications of CT guided lumbar sympathicolysis: own experience and review of literature

    International Nuclear Information System (INIS)

    Ernst, S.; Heindel, W.; Fischbach, R.; Langen, H.J.; Krahe, T.; Gawenda, M.; Neubauer, S.

    1998-01-01

    Aim: To review the complications of CT guided lumbar sympathicolysis (CTLS) on the basis of our own experience and the available literature. Methods: 241 CTLS were performed by a standard technique according to Haaga's method. Clinical follow-up revealed 4 serious complications; these were analysed and compared with published cases. Results: Amongst our patients there were three fibrotic ureter stenoses and one retroperitoneal abscess. Analysis of the serious complications described in the literature indicates that introduction of CT guided lumbar sympathicolysis has reduced the severity and frequency of complications as compared with surgical and 'blind' procedures. With CTLS, no deaths due to the procedure have been reported in the literature. The results indicate that damage to the ureters can be caused by substances used for the neurolysis. (orig./MG) [de

  15. Initial state radiation experiment at MAMI

    Energy Technology Data Exchange (ETDEWEB)

    Mihovilovič, M.; Merkel, H. [Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, Johann-Joachim-Becher-Weg 45, 55128 Mainz (Germany); Collaboration: A1-Collaboration

    2013-11-07

    In an attempt to contribute further insight into the discrepancy between the Lamb shift and elastic scattering determinations of the proton charge radius, a new experiment at MAMI is underway, aimed at measuring proton form-factors at very low momentum transfers by using a new technique based on initial state radiation. This paper reports on first findings of the pilot measurement performed in 2010, whose main goal was to check the feasibility of the proposed experiment and to recognize and overcome potential obstacles before running the full experiment in 2013.

  16. Could new reconstruction CT techniques challenge MRI for the detection of brain metastases in the context of initial lung cancer staging?

    Energy Technology Data Exchange (ETDEWEB)

    Millon, Domitille; Byl, David; Coche, Emmanuel E. [Universite Catholique de Louvain, Department of Radiology and Medical Imaging, Cliniques Universitaires Saint Luc, Brussels (Belgium); Collard, Philippe [Universite Catholique de Louvain, Department of Pneumology, Cliniques Universitaires Saint Luc, Brussels (Belgium); Cambier, Samantha E.; Maanen, Aline G. van [Universite Catholique de Louvain, Statistic Unit, King Albert II Cancer Institute, Brussels (Belgium); Vlassenbroek, Alain [Philips Healthcare, Brussels (Belgium)

    2018-02-15

    To evaluate the diagnostic performance of brain CT images reconstructed with a model-based iterative algorithm performed at usual and reduced dose. 115 patients with histologically proven lung cancer were prospectively included over 15 months. Patients underwent two CT acquisitions at the initial staging, performed on a 256-slice MDCT, at standard (CTDIvol: 41.4 mGy) and half dose (CTDIvol: 20.7 mGy). Both image datasets were reconstructed with filtered back projection (FBP) and iterative model-based reconstruction (IMR) algorithms. Brain MRI was considered as the reference. Two blinded independent readers analysed the images. Ninety-three patients underwent all examinations. At the standard dose, eight patients presented 17 and 15 lesions on IMR and FBP CT images, respectively. At half-dose, seven patients presented 15 and 13 lesions on IMR and FBP CT images, respectively. The test could not highlight any significant difference between the standard dose IMR and the half-dose FBP techniques (p-value = 0.12). MRI showed 46 metastases on 11 patients. Specificity, negative and positive predictive values were calculated (98.9-100 %, 93.6-94.6 %, 75-100 %, respectively, for all CT techniques). No significant difference could be demonstrated between the two CT reconstruction techniques. (orig.)

  17. How does arm positioning of polytraumatized patients in the initial computed tomography (CT) affect image quality and diagnostic accuracy?

    International Nuclear Information System (INIS)

    Kahn, Johannes; Grupp, Ulrich; Maurer, Martin

    2014-01-01

    Purpose: To evaluate the influence of different arm positions on abdominal image quality during initial whole-body CT (WBCT) in polytraumatized patients and to assess the risk of missing potentially life-threatening injuries due to arm artifacts. Materials and methods: Between July 2011 and February 2013, WBCT scans of 203 patients with arms in the abdominal area during initial WBCT were analyzed. Six different arms-down positions were defined: patients with both (group A)/one arm(s) (group B) down alongside the torso, patients with both (group C)/one arm(s) (group D) crossed in front of the upper abdomen, patients with both (group E)/one arm(s) (group F) crossed in front of the pelvic area. A group of 203 patients with elevated arms beside the head served as a control group. Two observers jointly evaluated image quality of different organ regions using a 4-point scale system. Follow-up examinations (CT scans and/or ultrasound) were analyzed to identify findings missed during initial WBCT due to reduced image quality. Results: Image quality for most of the organ regions analyzed was found to be significantly different among all groups (p < 0.05). Image quality was most severely degraded in group A, followed by groups E and C. Positioning with one arm up resulted in significantly better image quality than both arms down (p < 0.05). Overall, arms-up positioning showed significantly better image quality than arms-down positions (p < 0.05). In one case, liver hemorrhage missed in the initial WBCT because of arm artifacts, was revealed by follow-up CT. Conclusion: In WBCT arms-down positioning significantly degrades abdominal image quality and artifacts might even conceal potentially life-threatening injuries. If the patient's status does not allow elevation of both arms, image quality can benefit from raising at least one arm. Otherwise, arms should be placed in front of the upper abdomen instead of alongside the torso

  18. Initial clinical results for breath-hold CT-based processing of respiratory-gated PET acquisitions

    International Nuclear Information System (INIS)

    Fin, Loic; Daouk, Joel; Morvan, Julie; Esper, Isabelle El; Saidi, Lazhar; Meyer, Marc-Etienne; Bailly, Pascal

    2008-01-01

    Respiratory motion causes uptake in positron emission tomography (PET) images of chest structures to spread out and misregister with the CT images. This misregistration can alter the attenuation correction and thus the quantisation of PET images. In this paper, we present the first clinical results for a respiratory-gated PET (RG-PET) processing method based on a single breath-hold CT (BH-CT) acquisition, which seeks to improve diagnostic accuracy via better PET-to-CT co-registration. We refer to this method as ''CT-based'' RG-PET processing. Thirteen lesions were studied. Patients underwent a standard clinical PET protocol and then the CT-based protocol, which consists of a 10-min List Mode RG-PET acquisition, followed by a shallow end-expiration BH-CT. The respective performances of the CT-based and clinical PET methods were evaluated by comparing the distances between the lesions' centroids on PET and CT images. SUV MAX and volume variations were also investigated. The CT-based method showed significantly lower (p=0.027) centroid distances (mean change relative to the clinical method =-49%; range =-100% to 0%). This led to higher SUV MAX (mean change =+33%; range =-4% to 69%). Lesion volumes were significantly lower (p=0.022) in CT-based PET volumes (mean change =-39%: range =-74% to -1%) compared with clinical ones. A CT-based RG-PET processing method can be implemented in clinical practice with a small increase in radiation exposure. It improves PET-CT co-registration of lung lesions and should lead to more accurate attenuation correction and thus SUV measurement. (orig.)

  19. CT enteroclysis in the diagnosis of obscure gastrointestinal bleeding: initial results

    International Nuclear Information System (INIS)

    Jain, T.P.; Gulati, M.S.; Makharia, G.K.; Bandhu, S.; Garg, P.K.

    2007-01-01

    Aim: To evaluate the usefulness of computed tomography (CT) enteroclysis in patients with obscure gastrointestinal (GI) bleeding. Materials and methods: In a prospective study, CT enteroclysis was performed in 21 patients (median age 50 years; range 13-71 years) with obscure GI bleeding in which the source of the bleeding could not be detected despite the patient having undergone both upper GI endoscopic and colonoscopic examinations. The entire abdomen and pelvis was examined in the arterial and venous phases using multisection CT after distending the small intestine with 2 l of 0.5% methylcellulose as a neutral enteral contrast medium and the administration of 150 ml intravenous contrast medium. Results: Adequate distension of the small intestine was achieved in 20 of the 21 (95.2%) patients. Potential causes of GI bleeding were identified in 10 of the 21 (47.6%) patients using CT enteroclysis. The cause of the bleeding could be detected nine of 14 (64.3%) patients with overt, obscure GI bleeding. However, for patients with occult, obscure GI bleeding, the cause of the bleeding was identified in only one of the seven (14.3%) patients. The lesions identified by CT enteroclysis included small bowel tumours (n = 2), small bowel intussusceptions (n = 2), intestinal tuberculosis (n = 2), and vascular lesions (n = 3). All vascular lesions were seen equally well in both the arterial and venous phases. Conclusions: The success rate in detection of the cause of bleeding using CT enteroclysis was 47.6% in patients with obscure GI bleeding. The diagnostic yield was higher in patients with overt, obscure GI bleeding than in those with occult obscure GI bleeding

  20. CT enteroclysis in the diagnosis of obscure gastrointestinal bleeding: initial results

    Energy Technology Data Exchange (ETDEWEB)

    Jain, T.P. [Department ofRadiodiagnosis, All India Institute of Medical Sciences, New Delhi (India); Gulati, M.S. [Department of Imaging, Queen Elizabeth Hospital NHS Trust, London (United Kingdom); Makharia, G.K. [Department of Gastroenterology and Human Nutrition, All India Institute of Medical Sciences, New Delhi (India)]. E-mail: govindmakharia@aiims.ac.in; Bandhu, S. [Department ofRadiodiagnosis, All India Institute of Medical Sciences, New Delhi (India); Garg, P.K. [Department of Gastroenterology and Human Nutrition, All India Institute of Medical Sciences, New Delhi (India)

    2007-07-15

    Aim: To evaluate the usefulness of computed tomography (CT) enteroclysis in patients with obscure gastrointestinal (GI) bleeding. Materials and methods: In a prospective study, CT enteroclysis was performed in 21 patients (median age 50 years; range 13-71 years) with obscure GI bleeding in which the source of the bleeding could not be detected despite the patient having undergone both upper GI endoscopic and colonoscopic examinations. The entire abdomen and pelvis was examined in the arterial and venous phases using multisection CT after distending the small intestine with 2 l of 0.5% methylcellulose as a neutral enteral contrast medium and the administration of 150 ml intravenous contrast medium. Results: Adequate distension of the small intestine was achieved in 20 of the 21 (95.2%) patients. Potential causes of GI bleeding were identified in 10 of the 21 (47.6%) patients using CT enteroclysis. The cause of the bleeding could be detected nine of 14 (64.3%) patients with overt, obscure GI bleeding. However, for patients with occult, obscure GI bleeding, the cause of the bleeding was identified in only one of the seven (14.3%) patients. The lesions identified by CT enteroclysis included small bowel tumours (n = 2), small bowel intussusceptions (n = 2), intestinal tuberculosis (n = 2), and vascular lesions (n = 3). All vascular lesions were seen equally well in both the arterial and venous phases. Conclusions: The success rate in detection of the cause of bleeding using CT enteroclysis was 47.6% in patients with obscure GI bleeding. The diagnostic yield was higher in patients with overt, obscure GI bleeding than in those with occult obscure GI bleeding.

  1. Computer-aided detection in CT colonography: initial clinical experience using a prototype system

    International Nuclear Information System (INIS)

    Graser, A.; Geisbuesch, S.; Reiser, M.F.; Becker, C.R.; Kolligs, F.T.; Schaefer, C.; Mang, T.

    2007-01-01

    Computer-aided detection (CAD) algorithms help to detect colonic polyps at CT colonography (CTC). The purpose of this study was to evaluate the accuracy of CAD versus an expert reader in CTC. One hundred forty individuals (67 men, 73 women; mean age, 59 years) underwent screening 64-MDCT colonography after full cathartic bowel cleansing without fecal tagging. One expert reader interpreted supine and prone scans using a 3D workstation with integrated CAD used as ''second reader.'' The system's sensitivity for the detection of polyps, the number of false-positive findings, and its running time were evaluated. Polyps were classified as small (≤5 mm), medium (6-9 mm), and large (≥10 mm). A total of 118 polyps (small, 85; medium, 19; large, 14) were found in 56 patients. CAD detected 72 polyps (61%) with an average of 2.2 false-positives. Sensitivity was 51% (43/85) for small, 90% (17/19) for medium, and 86% (12/14) for large polyps. For all polyps, per-patient sensitivity was 89% (50/56) for the radiologist and 73% (41/56) for CAD. For large and medium polyps, per-patient sensitivity was 100% for the radiologist, and 96% for CAD. In conclusion, CAD shows high sensitivity in the detection of clinically significant polyps with acceptable false-positive rates. (orig.)

  2. Initial CT manifestations of invasive pulmonary aspergillosis in 45 non-HIV immunocompromised patients: association with patient outcome?

    International Nuclear Information System (INIS)

    Horger, Marius; Hebart, Holger; Einsele, Hermann; Lengerke, Claudia; Claussen, C.D.; Vonthein, Reinhard; Pfannenberg, Christina

    2005-01-01

    /46) of IPA episodes. Conclusion: Initial CT findings of invasive pulmonary aspergillosis consist mainly of small nodules or patchy consolidations, showing in 82% of cases an early halo sign. Serious pulmonary hemorrhage was an infrequent clinical complication in our series, with an attributable mortality of 4.3%. IPA-related lethality was 26%, in our cohort. None of the early HRCT signs seemed to predict outcome

  3. F-FDG PET/CT (PET/CT) influences management in patients with known or suspected pancreatic cancer

    International Nuclear Information System (INIS)

    Barber, Thomas W.; Kalff, Victor; Cherk, Martin H.; Yap, Kenneth SK.; Evans, Peter; Kelly, Michael J.

    2009-01-01

    Full text: Objective: To assess the impact on clinical management of PET/CT in patients with known or suspected pancreatic cancer. Methods: Between April 2006 and September 2008,25 PET/CT scans were performed using a dedicated PET/CT (22 scans) or a coincidence hybrid PET/CT camera (3 scans) in 23 patients with known or suspected pancreatic cancer. 17 scans were performed for initial evaluation and 8 for restaging of disease. The pre-PET/CT management plan and for intent were prospectively recorded in all cases. The post-PET/CT management plan was determined from the medical record and for discussions with treating clinicians. The impact of PET/CT on management was classified as High, Medium, Low or None, defined using ANZAPNM PET data collection project criteria. Follow-up was used to reconcile any discordance between PET/CT and conventional imaging. Results: Overall, PET/CT management impact was classified as high (n equal 7), medium (n equal 4), low (n equal 10) or none (n equal 4). Impact was either high or medium in l l/25 patients (44%) (95% confidence interval; 24 - 64%). Impact was high in 4/17 patients imaged for initial evaluation, predominantly by clarifying equivocal lesions on conventional imaging. In restaged patients, PET/CT impact was high in 3/8, and it correctly modified disease extent in 5/8. In the 16 discordant studies, PET/CT assessment was correct in 10, conventional imaging in 4 and there was insufficient information in 2. Conclusion: PET/CT has high or medium management impact in 44% of patients imaged for known or suspected pancreatic cancer, more commonly during restaging. Discordant PET/CT results were usually correct.

  4. A modified VMAT adaptive radiotherapy for nasopharyngeal cancer patients based on CT-CT image fusion

    International Nuclear Information System (INIS)

    Jin, Xiance; Han, Ce; Zhou, Yongqiang; Yi, Jinling; Yan, Huawei; Xie, Congying

    2013-01-01

    To investigate the feasibility and benefits of a modified adaptive radiotherapy (ART) by replanning in the initial CT (iCT) with new contours from a repeat CT (rCT) based on CT-CT image fusion for nasopharyngeal cancer (NPC) patients underwent volumetric modulated arc radiotherapy (VMAT). Nine NPC patients underwent VMAT treatment with a rCT at 23rd fraction were enrolled in this study. Dosimetric differences for replanning VMAT plans in the iCT and in the rCT were compared. Volumetric and dosimetric changes of gross tumor volume (GTV) and organs at risk (OARs) of this modified ART were also investigated. No dosimetric differences between replanning in the iCT and in the rCT were observed. The average volume of GTV decreased from 78.83 ± 38.42 cm 3 in the iCT to 71.44 ± 37.46 cm 3 in the rCT, but with no significant difference (p = 0.42).The average volume of the left and right parotid decreased from 19.91 ± 4.89 cm 3 and 21.58 ± 6.16 cm 3 in the iCT to 11.80 ± 2.79 cm 3 and 13.29 ± 4.17 cm 3 in the rCT (both p < 0.01), respectively. The volume of other OARs did not shrink very much. No significant differences on PTV GTV and PTV CTV coverage were observed for replanning with this modified ART. Compared to the initial plans, the average mean dose of the left and right parotid after re-optimization were decreased by 62.5 cGy (p = 0.05) and 67.3 cGy (p = 0.02), respectively, and the V5 (the volume receiving 5 Gy) of the left and right parotids were decreased by 7.8% (p = 0.01) and 11.2% (p = 0.001), respectively. There was no significant difference on the dose delivered to other OARs. Patients with NPC undergoing VMAT have significant anatomic and dosimetric changes to parotids. Repeat CT as an anatomic changes reference and re-optimization in the iCT based on CT-CT image fusion was accurate enough to identify the volume changes and to ensure safe dose to parotids

  5. Comparison of PET/CT and PET/MRI hybrid systems using a 68Ga-labelled PSMA ligand for the diagnosis of recurrent prostate cancer: initial experience

    International Nuclear Information System (INIS)

    Afshar-Oromieh, A.; Haberkorn, U.; Schlemmer, H.P.; Fenchel, M.; Roethke, M.; Eder, M.; Eisenhut, M.; Hadaschik, B.A.; Kopp-Schneider, A.

    2014-01-01

    68 Ga-labelled HBED-CC-PSMA is a highly promising tracer for imaging recurrent prostate cancer (PCa). The intention of this study was to evaluate the feasibility of PET/MRI with this tracer. Twenty patients underwent PET/CT 1 h after injection of the 68 Ga-PSMA ligand followed by PET/MRI 3 h after injection. Data from the two investigations were first analysed separately and then compared with respect to tumour detection rate and radiotracer uptake in various tissues. To evaluate the quantification accuracy of the PET/MRI system, differences in SUVs between PET/CT and corresponding PET/MRI were compared with differences in SUVs between PET/CT 1 h and 3 h after injection in another patient cohort. This cohort was investigated using the same PET/CT system. With PET/MRI, different diagnostic sequences, higher contrast of lesions and higher resolution of MRI enabled a subjectively easier evaluation of the images. In addition, four unclear findings on PET/CT could be clarified as characteristic of PCa metastases by PET/MRI. However, in PET images of the PET/MRI, a reduced signal was observed at the level of the kidneys (in 11 patients) and around the urinary bladder (in 15 patients). This led to reduced SUVs in six lesions. SUV mean values provided by the PET/MRI system were different in muscles, blood pool, liver and spleen. PCa was detected more easily and more accurately with Ga-PSMA PET/MRI than with PET/CT and with lower radiation exposure. Consequently, this new technique could clarify unclear findings on PET/CT. However, scatter correction was challenging when the specific 68 Ga-PSMA ligand was used. Moreover, direct comparison of SUVs from PET/CT and PET/MR needs to be conducted carefully. (orig.)

  6. PET/CT in lymphoma patients; PET-CT bei Lymphompatienten

    Energy Technology Data Exchange (ETDEWEB)

    Steinert, H.C. [Universitaetsspital Zuerich, Klinik und Poliklinik fuer Nuklearmedizin (Switzerland)

    2004-11-01

    First results of PET/CT in Hodgkin's disease (HD) and aggressive non-Hodgkin's lymphoma (NHL) are reported. From March 2001 to August 2004 822 PET/CT were performed at our clinic in lymphoma patients for primary staging, restaging after therapy, and diagnosis of recurrence. For coregistration non contrast-enhanced low-dose CT were used. Due to the exact anatomic localization of {sup 18}F-FDG accumulating lesions equivocal or false positive PET findings are avoided. In comparison to contrast enhanced CT, PET/CT has a higher sensitivity and specificity in patients with HD and aggressive NHL. Integration of PET/CT in treatment planning of radiation therapy optimizes the field volume. Even in the initial phase of clinical evaluation, PET/CT has proven useful in staging and restaging of lymphoma. The exact anatomic localization of the PET findings is essential for a precise report, for treatment planning of radiation therapy, and for planning surgical biopsy. (orig.) [German] Erste Ergebnisse der PET-CT bei Morbus Hodgkin (HD) und den aggressiven Non-Hodgkin-Lymphomen (NHL) werden beschrieben. Von Maerz 2001 bis August 2004 wurden 822 PET-CT bei Lymphompatienten zum primaeren Staging, zum Restaging nach Therapie und zur Rezidivdiagnostik an unserer Klinik durchgefuehrt. Fuer die Koregistration wurde ein Low-dose-CT ohne i.v.-Kontrastmittel verwendet. Durch die exakte anatomische Zuordnung der {sup 18}F-FDG aufnehmenden Laesionen wurden unklare oder falsch-positive PET-Befunde vermieden. Die PET-CT erzielte im Vergleich zur KM-verstaerkten CT eine hoehere Sensitivitaet und Spezifitaet bei Patienten mit HD und aggressiven NHL. Die Integration der PET-CT in die Planung der Strahlentherapie fuehrte zu einer Optimierung der Feldgrenzen. Die PET-CT hat sich bereits in der Phase der initialen klinischen Evaluation als wertvoll beim Staging und Restaging von Lymphomen erwiesen. Die exakte anatomische Zuordnung der PET-Informationen ist fuer eine sichere Befundung

  7. The origins of SPECT and SPECT/CT

    Energy Technology Data Exchange (ETDEWEB)

    Hutton, Brian F. [University College London, Institute of Nuclear Medicine, London (United Kingdom); University of Wollongong, Centre for Medical Radiation Physics, Wollongong, NSW (Australia)

    2014-05-15

    Single photon emission computed tomography (SPECT) has a long history of development since its initial demonstration by Kuhl and Edwards in 1963. Although clinical utility has been dominated by the rotating gamma camera, there have been many technological innovations with the recent popularity of organ-specific dedicated SPECT systems. The combination of SPECT and CT evolved from early transmission techniques used for attenuation correction with the initial commercial systems predating the release of PET/CT. The development and acceptance of SPECT/CT has been relatively slow with continuing debate as to what cost/performance ratio is justified. Increasingly, fully diagnostic CT is combined with SPECT so as to facilitate optimal clinical utility. (orig.)

  8. Automatic spectral imaging protocol selection and iterative reconstruction in abdominal CT with reduced contrast agent dose: initial experience

    Energy Technology Data Exchange (ETDEWEB)

    Lv, Peijie; Liu, Jie; Chai, Yaru; Yan, Xiaopeng; Gao, Jianbo; Dong, Junqiang [The First Affiliated Hospital of Zhengzhou University, Department of Radiology, Zhengzhou, Henan Province (China)

    2017-01-15

    To evaluate the feasibility, image quality, and radiation dose of automatic spectral imaging protocol selection (ASIS) and adaptive statistical iterative reconstruction (ASIR) with reduced contrast agent dose in abdominal multiphase CT. One hundred and sixty patients were randomly divided into two scan protocols (n = 80) each; protocol A, 120 kVp/450 mgI/kg, filtered back projection algorithm (FBP); protocol B, spectral CT imaging with ASIS and 40 to 70 keV monochromatic images generated per 300 mgI/kg, ASIR algorithm. Quantitative parameters (image noise and contrast-to-noise ratios [CNRs]) and qualitative visual parameters (image noise, small structures, organ enhancement, and overall image quality) were compared. Monochromatic images at 50 keV and 60 keV provided similar or lower image noise, but higher contrast and overall image quality as compared with 120-kVp images. Despite the higher image noise, 40-keV images showed similar overall image quality compared to 120-kVp images. Radiation dose did not differ between the two protocols, while contrast agent dose in protocol B was reduced by 33 %. Application of ASIR and ASIS to monochromatic imaging from 40 to 60 keV allowed contrast agent dose reduction with adequate image quality and without increasing radiation dose compared to 120 kVp with FBP. (orig.)

  9. Automatic spectral imaging protocol selection and iterative reconstruction in abdominal CT with reduced contrast agent dose: initial experience

    International Nuclear Information System (INIS)

    Lv, Peijie; Liu, Jie; Chai, Yaru; Yan, Xiaopeng; Gao, Jianbo; Dong, Junqiang

    2017-01-01

    To evaluate the feasibility, image quality, and radiation dose of automatic spectral imaging protocol selection (ASIS) and adaptive statistical iterative reconstruction (ASIR) with reduced contrast agent dose in abdominal multiphase CT. One hundred and sixty patients were randomly divided into two scan protocols (n = 80) each; protocol A, 120 kVp/450 mgI/kg, filtered back projection algorithm (FBP); protocol B, spectral CT imaging with ASIS and 40 to 70 keV monochromatic images generated per 300 mgI/kg, ASIR algorithm. Quantitative parameters (image noise and contrast-to-noise ratios [CNRs]) and qualitative visual parameters (image noise, small structures, organ enhancement, and overall image quality) were compared. Monochromatic images at 50 keV and 60 keV provided similar or lower image noise, but higher contrast and overall image quality as compared with 120-kVp images. Despite the higher image noise, 40-keV images showed similar overall image quality compared to 120-kVp images. Radiation dose did not differ between the two protocols, while contrast agent dose in protocol B was reduced by 33 %. Application of ASIR and ASIS to monochromatic imaging from 40 to 60 keV allowed contrast agent dose reduction with adequate image quality and without increasing radiation dose compared to 120 kVp with FBP. (orig.)

  10. Puzzling initial conditions in the R{sub h} = ct model

    Energy Technology Data Exchange (ETDEWEB)

    Bengochea, Gabriel R. [CONICET-Universidad de Buenos Aires, Instituto de Astronomia y Fisica del Espacio (IAFE), Buenos Aires (Argentina); Leon, Gabriel [Universidad de Buenos Aires, Ciudad Universitaria, PabI, Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Buenos Aires (Argentina)

    2016-11-15

    In recent years, some studies have drawn attention to the lack of large-angle correlations in the observed cosmic microwave background (CMB) temperature anisotropies with respect to that predicted within the standard ΛCDM model. Lately, it has been argued that such a lack of correlations could be explained in the framework of the so-called R{sub h} = ct model without inflation. The aim of this work is to study whether there is a mechanism to generate, through a quantum field theory, the primordial power spectrum presented by these authors. Specifically, we consider two different scenarios: first, we assume a scalar field dominating the early Universe in the R{sub h} = ct cosmological model, and second, we deal with the possibility of adding an early inflationary phase to the mentioned model. During the analysis of the consistency between the predicted and observed amplitudes of the CMB temperature anisotropies in both scenarios, we run into deep issues which indicate that it is not clear how to characterize the primordial quantum perturbations within the R{sub h} = ct model. (orig.)

  11. Initial investigation of 18F-NaF PET/CT for identification of vertebral sites amenable to surgical revision after spinal fusion surgery

    International Nuclear Information System (INIS)

    Quon, Andrew; Iagaru, Andrei; Dodd, Robert; Abreu, Marcelo Rodrigues de; Sprinz, Clarice; Hennemann, Sergio; Alves Neto, Jose Maria

    2012-01-01

    A pilot study was performed in patients with recurrent back pain after spinal fusion surgery to evaluate the ability of 18 F-NaF PET/CT imaging to correctly identify those requiring surgical intervention and to locate a site amenable to surgical intervention. In this prospective study 22 patients with recurrent back pain after spinal surgery and with equivocal findings on physical examination and CT were enrolled for evaluation with 18 F-NaF PET/CT. All PET/CT images were prospectively reviewed with the primary objective of identifying or ruling out the presence of lesions amenable to surgical intervention. The PET/CT results were then validated during surgical exploration or clinical follow-up of at least 15 months. Abnormal 18 F-NaF foci were found in 16 of the 22 patients, and surgical intervention was recommended. These foci were located at various sites: screws, cages, rods, fixation hardware, and bone grafts. In 6 of the 22 patients no foci requiring surgical intervention were found. Validation of the results by surgery (15 patients) or on clinical follow-up (7 patients) showed that 18 F-NaF PET/CT correctly predicted the presence of an abnormality requiring surgical intervention in 15 of 16 patients and was falsely positive in 1 of 16. In this initial investigation, 18 F-NaF PET/CT imaging showed potential utility for evaluation of recurrent symptoms after spinal fusion surgery by identifying those patients requiring surgical management. (orig.)

  12. Initial Educational Experiences of Tertiary Students. LSAY Briefing Number 14

    Science.gov (United States)

    Hillman, Kylie

    2008-01-01

    This "Briefing" presents information about the initial tertiary education experiences, such as satisfaction with aspects of student life and changes to initial enrolments, of two groups of young people, based on two recent Longitudinal Surveys of Australian Youth (LSAY) research reports. One study focused on the first year experiences of…

  13. Automated ventricular systems segmentation in brain CT images by combining low-level segmentation and high-level template matching

    Directory of Open Access Journals (Sweden)

    Ward Kevin R

    2009-11-01

    Full Text Available Abstract Background Accurate analysis of CT brain scans is vital for diagnosis and treatment of Traumatic Brain Injuries (TBI. Automatic processing of these CT brain scans could speed up the decision making process, lower the cost of healthcare, and reduce the chance of human error. In this paper, we focus on automatic processing of CT brain images to segment and identify the ventricular systems. The segmentation of ventricles provides quantitative measures on the changes of ventricles in the brain that form vital diagnosis information. Methods First all CT slices are aligned by detecting the ideal midlines in all images. The initial estimation of the ideal midline of the brain is found based on skull symmetry and then the initial estimate is further refined using detected anatomical features. Then a two-step method is used for ventricle segmentation. First a low-level segmentation on each pixel is applied on the CT images. For this step, both Iterated Conditional Mode (ICM and Maximum A Posteriori Spatial Probability (MASP are evaluated and compared. The second step applies template matching algorithm to identify objects in the initial low-level segmentation as ventricles. Experiments for ventricle segmentation are conducted using a relatively large CT dataset containing mild and severe TBI cases. Results Experiments show that the acceptable rate of the ideal midline detection is over 95%. Two measurements are defined to evaluate ventricle recognition results. The first measure is a sensitivity-like measure and the second is a false positive-like measure. For the first measurement, the rate is 100% indicating that all ventricles are identified in all slices. The false positives-like measurement is 8.59%. We also point out the similarities and differences between ICM and MASP algorithms through both mathematically relationships and segmentation results on CT images. Conclusion The experiments show the reliability of the proposed algorithms. The

  14. Post transplant lymphoproliferative disease in pediatric solid organ transplant patients: A possible role for [{sup 18}F]-FDG-PET(/CT) in initial staging and therapy monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Falck, C. von [Department of Diagnostic Radiology, Medizinische Hochschule Hannover (Medical School Hanover), Carl-Neuberg-Strasse 1, 30625 Hannover (Germany)], E-mail: Falck.Christian.von@mh-hannover.de; Maecker, B. [Department of Pediatric Hematology and Oncology, Medizinische Hochschule Hannover (Medical School Hanover), Carl-Neuberg-Strasse 1, 30625 Hannover (Germany); Schirg, E. [Department of Diagnostic Radiology, Medizinische Hochschule Hannover (Medical School Hanover), Carl-Neuberg-Strasse 1, 30625 Hannover (Germany); Boerner, A.R.; Knapp, W.H. [Department of Nuclear Medicine, Medizinische Hochschule Hannover (Medical School Hanover), Carl-Neuberg-Strasse 1, 30625 Hannover (Germany); Klein, C. [Department of Pediatric Hematology and Oncology, Medizinische Hochschule Hannover (Medical School Hanover), Carl-Neuberg-Strasse 1, 30625 Hannover (Germany); Galanski, M. [Department of Diagnostic Radiology, Medizinische Hochschule Hannover (Medical School Hanover), Carl-Neuberg-Strasse 1, 30625 Hannover (Germany)

    2007-09-15

    Post transplant lymphoproliferative disease (PTLD) is a severe complication after solid organ or bone marrow transplantation. In pediatric transplant recipients PTLD is the most common malignancy. The aim of this study was to evaluate a possible role for positron emission tomography with [{sup 18}F]-2-fluoro-2-desoxy-glucose (FDG) in the initial staging and in therapy monitoring of pediatric patients suffering from biopsy-proven CD20-positive PTLD after solid organ transplantation. Seven pediatric patients were included. All available imaging studies - CT (n = 15), MRI (n = 16) and PET/PETCT (n = 16) - were reviewed on a lesion by lesion base. The performance of FDG-PET in the initial staging and during therapy with a chimeric anti-CD20 antibody was compared to conventional cross sectional imaging and correlated with the clinical outcome. FDG-PET identified all sites of disease as shown by CT/MRI and helped to clarify the significance of equivocal findings. The initial stage of disease was correctly identified by FDG-PET alone when compared to CT/MRI. During therapy, FDG-PET was superior to conventional cross-sectional imaging in the early evaluation of response.

  15. Aortic aneurysm sac pressure measurements after endovascular repair using an implantable remote sensor: initial experience and short-term follow-up

    International Nuclear Information System (INIS)

    Hoppe, Hanno; Kaufman, John A.; Segall, Jocelyn A.; Liem, Timothy K.; Landry, Gregory J.

    2008-01-01

    The purpose of this single-center study was to report our initial experience with an implantable remote pressure sensor for aneurysm sac pressure measurement in patients post-endovascular aneurysm repair (EVAR) including short-term follow-up. A pressure sensor (EndoSure, Atlanta, GA) was implanted in 12 patients treated with different commercially available aortic endografts for EVAR. Pressure was read pre- and post-EVAR in the operating room. One-month follow-up (30 days ± 6 days) was performed including sac pressure readings and IV contrast CT scans. Variables were compared using the paired Student's t test. An intraprocedure type-I endoleak and a type-III endoleak were successfully treated resulting in decreasing sac pressures. In all patients, post-EVAR systolic sac pressure decreased by an average of 33% (P ≤ 0.005) compared to pre-EVAR measurements. One-month follow-up demonstrated a 47% decrease in systolic sac pressure (P ≤ 0.05). On follow-up CT scans, the average maximum aneurysm diameter pre-EVAR was 6.3 ± 1.6 cm and post-EVAR 6.0 ± 1.7 cm (P≤0.05). The diameter of the aneurysm sac was larger only in one patient with a type-III endoleak. Remote sac pressure measurement may provide important information in addition to imaging and may help to reduce the number of follow-up CT scans. (orig.)

  16. The Interobserver Agreement between Residents and Experienced Radiologists for Detecting Pulmonary Embolism and DVT with Using CT Pulmonary Angiography and Indirect CT Venography

    International Nuclear Information System (INIS)

    Yavas, Ulas Savas; Calisir, Cuneyt; Ozkan; Ibrahim Ragip

    2008-01-01

    We wanted to prospectively evaluate the interobserver agreement between radiology residents and expert radiologists for interpreting CT images for making the diagnosis of pulmonary embolism (PE). We assessed 112 consecutive patients, from April 2007 to August 2007, who were referred for combined CT pulmonary angiography and indirect CT venography for clinically suspected acute PE. CT scanning was performed with a 64x0.5 collimation multi-detector CT scanner. The CT studies were initially interpreted by the radiology residents alone and then the CT images were subsequently interpreted by a consensus of the resident plus an experienced general radiologist and an experienced chest radiologist. Two of the 112 CTs were unable to be interpreted (1.7%). Pulmonary artery clots were seen on 36 of the thoracic CT angiographies (32%). The interobserver agreement between the radiology residents and the consensus interpretation was good (a kappa index of 0.73). All of the disagreements (15 cases) were instances of overcall by the resident on the initial interpretation. Deep venous thrombosis was detected in 72% (26 of 36) of the patients who had PE seen on thoracic CT. The initial and consensus interpretations of the CT venography images disagreed for two cases (kappa statistic: 0.96). It does not seem adequate to base the final long-term treatment of PE on only the resident's reading, as false positives occurred in 13% of such cases. Timely interpretation of the CT pulmonary angiography and CT venography images should be performed by experienced radiologists for the patients with suspected PE

  17. Local Control of Perivascular Malignant Liver Lesions Using Percutaneous Irreversible Electroporation: Initial Experiences

    Energy Technology Data Exchange (ETDEWEB)

    Eller, Achim, E-mail: Achim.Eller@uk-erlangen.de; Schmid, Axel, E-mail: axel.schmid@uk-erlangen.de [University Hospital Erlangen, University of Erlangen-Nuremberg, Department of Radiology (Germany); Schmidt, Joachim, E-mail: joachim.schmidt@kfa.imed.uni-erlangen.de [University Hospital Erlangen, University of Erlangen-Nuremberg, Department of Anesthesiology (Germany); May, Matthias, E-mail: matthias.may@uk-erlangen.de; Brand, Michael, E-mail: michael.brand@uk-erlangen.de; Saake, Marc, E-mail: marc.saake@uk-erlangen.de; Uder, Michael, E-mail: michael.uder@uk-erlangen.de; Lell, Michael, E-mail: michael.lell@uk-erlangen.de [University Hospital Erlangen, University of Erlangen-Nuremberg, Department of Radiology (Germany)

    2015-02-15

    PurposeThis study was designed to assess efficacy and safety in the treatment of perivascular malignant liver lesions using percutaneous, computed tomography (CT)-guided irreversible electroporation (IRE).MethodsFourteen patients (mean age 58 ± 11 years) with 18 malignant liver lesions were consecutively enrolled in this study. IRE was performed in patients not eligible for surgery and lesions abutting large vessels or bile ducts. Follow-up exams were performed using multislice-CT (MS-CT) or MRI.ResultsMedium lesion diameter was 20 ± 5 mm. Ten of 14 (71 %) were successfully treated with no local recurrence to date (mean follow-up 388 ± 160 days). One case left initial tumor control unclear and additional RFA was performed 4 weeks after IRE. Complications occurred in 4 of 14 (29 %) cases. In one case, intervention was terminated and abdominal bleeding required laparotomy. In two cases, a postinterventional hematothorax required intervention. In another case, abdominal bleeding could be managed conservatively. No complications related to the bile ducts occurred.ConclusionsPercutaneous IRE seems to be effective in perivascular lesions but is associated with a higher complication rate compared with thermoablative techniques.

  18. Reliability and error analysis on xenon/CT CBF

    International Nuclear Information System (INIS)

    Zhang, Z.

    2000-01-01

    This article provides a quantitative error analysis of a simulation model of xenon/CT CBF in order to investigate the behavior and effect of different types of errors such as CT noise, motion artifacts, lower percentage of xenon supply, lower tissue enhancements, etc. A mathematical model is built to simulate these errors. By adjusting the initial parameters of the simulation model, we can scale the Gaussian noise, control the percentage of xenon supply, and change the tissue enhancement with different kVp settings. The motion artifact will be treated separately by geometrically shifting the sequential CT images. The input function is chosen from an end-tidal xenon curve of a practical study. Four kinds of cerebral blood flow, 10, 20, 50, and 80 cc/100 g/min, are examined under different error environments and the corresponding CT images are generated following the currently popular timing protocol. The simulated studies will be fed to a regular xenon/CT CBF system for calculation and evaluation. A quantitative comparison is given to reveal the behavior and effect of individual error resources. Mixed error testing is also provided to inspect the combination effect of errors. The experiment shows that CT noise is still a major error resource. The motion artifact affects the CBF results more geometrically than quantitatively. Lower xenon supply has a lesser effect on the results, but will reduce the signal/noise ratio. The lower xenon enhancement will lower the flow values in all areas of brain. (author)

  19. CT after transsphenoidal surgery

    International Nuclear Information System (INIS)

    Tazawa, Satoru

    1991-01-01

    Two hundred and ten CT studies of 95 patients after transsphenoidal surgery were reviewed. Spheno-ethmoid opacificaiton, intrasellar hematoma and gas bubbles were noted within 2 weeks after surgery. Bone defect of the sellar floor and bone stent were seen on coronal scans in most cases. The packing material frequently disappeared on follow-up studies. Hormonal assessment of the functioning tumor, according to which the effect of treatment was evaluated, was correlated with CT findings. Because differentiation between postoperative changes and residual mass was difficult, there was no definite CT criteria to indicate residual functioning tumor except upward convexity of the diaphragma sellae on CT more than 3 months after surgery. Initial follow up CT study is recommended to be performed at about 3 months after surgery, at which time the immediate postoperative inflammatory changes have been disappeared. The incidence of recurrence was 3/47 (6%), which was shown on follow-up CT from 4 to 10 years after surgery. Therefore, subsequent CT study should be done in every year or two, taking the clinical symptoms and hormonal data into consideration. (author)

  20. CT after transsphenoidal surgery

    Energy Technology Data Exchange (ETDEWEB)

    Tazawa, Satoru [Tohoku Univ., Sendai (Japan). School of Medicine

    1991-03-01

    Two hundred and ten CT studies of 95 patients after transsphenoidal surgery were reviewed. Spheno-ethmoid opacificaiton, intrasellar hematoma and gas bubbles were noted within 2 weeks after surgery. Bone defect of the sellar floor and bone stent were seen on coronal scans in most cases. The packing material frequently disappeared on follow-up studies. Hormonal assessment of the functioning tumor, according to which the effect of treatment was evaluated, was correlated with CT findings. Because differentiation between postoperative changes and residual mass was difficult, there was no definite CT criteria to indicate residual functioning tumor except upward convexity of the diaphragma sellae on CT more than 3 months after surgery. Initial follow up CT study is recommended to be performed at about 3 months after surgery, at which time the immediate postoperative inflammatory changes have been disappeared. The incidence of recurrence was 3/47 (6%), which was shown on follow-up CT from 4 to 10 years after surgery. Therefore, subsequent CT study should be done in every year or two, taking the clinical symptoms and hormonal data into consideration. (author).

  1. Initial deuterium pellet experiments on FTU

    International Nuclear Information System (INIS)

    Snipes, J.A.

    1993-01-01

    Initial experiments have been performed with the Single Pellet INjector (SPIN) on FTU. SPIN is a two-stage cryogenic deuterium pellet injector capable of injection,a pellets with velocities up to 2.5 km/s. The nominal pellet mass for these experiments was approximately 1 x 10 20 atoms. These initial pellet experiments concentrated on studying pellet penetration under a variety of plasma conditions to compare with code predictions and to examine toroidal particle transport. The principal diagnostics used were two fast (∼1 μsec) photomultiplier tubes at nearly opposite toroidal locations with H α (D α ) interference filters (λ = 656 nm), a microwave cavity for pellet mass and velocity, a vertical array of soft x ray diodes without filters looking down onto the pellet, a DCN interferometer for electron density profiles, and a Michelson ECE system for electron temperature profiles. The time integral of the absolutely calibrated fast H α signal appears to give reasonable agreement with the expected pellet mass. Toroidal transport of deuterium ions from the pellet to nearly the opposite side of the tokamak agrees with calculated thermal deuterium velocities near the plasma edge. Comparison of the experimental results with code calculations using the Neutral Gas Shielding model show good agreement for the post-pellet electron temperature and density profiles and the H α profiles in some cases. Calculated penetration distances agree within 20%

  2. Comparison of PET/CT and PET/MRI hybrid systems using a {sup 68}Ga-labelled PSMA ligand for the diagnosis of recurrent prostate cancer: initial experience

    Energy Technology Data Exchange (ETDEWEB)

    Afshar-Oromieh, A. [University Hospital Heidelberg, Department of Nuclear Medicine, Heidelberg (Germany); German Cancer Research Center (DKFZ), Department of Radiology, Heidelberg (Germany); Haberkorn, U. [University Hospital Heidelberg, Department of Nuclear Medicine, Heidelberg (Germany); German Cancer Research Center (DKFZ), Clinical Cooperation Unit of Nuclear Medicine, Heidelberg (Germany); Schlemmer, H.P.; Fenchel, M.; Roethke, M. [German Cancer Research Center (DKFZ), Department of Radiology, Heidelberg (Germany); Eder, M.; Eisenhut, M. [German Cancer Research Center (DKFZ), Department of Radiopharmaceutical Chemistry, Heidelberg (Germany); Hadaschik, B.A. [University Hospital Heidelberg, Department of Urology, Heidelberg (Germany); Kopp-Schneider, A. [German Cancer Research Center (DKFZ), Department of Biostatistics, Heidelberg (Germany)

    2014-05-15

    {sup 68}Ga-labelled HBED-CC-PSMA is a highly promising tracer for imaging recurrent prostate cancer (PCa). The intention of this study was to evaluate the feasibility of PET/MRI with this tracer. Twenty patients underwent PET/CT 1 h after injection of the {sup 68}Ga-PSMA ligand followed by PET/MRI 3 h after injection. Data from the two investigations were first analysed separately and then compared with respect to tumour detection rate and radiotracer uptake in various tissues. To evaluate the quantification accuracy of the PET/MRI system, differences in SUVs between PET/CT and corresponding PET/MRI were compared with differences in SUVs between PET/CT 1 h and 3 h after injection in another patient cohort. This cohort was investigated using the same PET/CT system. With PET/MRI, different diagnostic sequences, higher contrast of lesions and higher resolution of MRI enabled a subjectively easier evaluation of the images. In addition, four unclear findings on PET/CT could be clarified as characteristic of PCa metastases by PET/MRI. However, in PET images of the PET/MRI, a reduced signal was observed at the level of the kidneys (in 11 patients) and around the urinary bladder (in 15 patients). This led to reduced SUVs in six lesions. SUV{sub mean} values provided by the PET/MRI system were different in muscles, blood pool, liver and spleen. PCa was detected more easily and more accurately with Ga-PSMA PET/MRI than with PET/CT and with lower radiation exposure. Consequently, this new technique could clarify unclear findings on PET/CT. However, scatter correction was challenging when the specific {sup 68}Ga-PSMA ligand was used. Moreover, direct comparison of SUVs from PET/CT and PET/MR needs to be conducted carefully. (orig.)

  3. The Lung Image Database Consortium (LIDC) and Image Database Resource Initiative (IDRI): A Completed Reference Database of Lung Nodules on CT Scans

    International Nuclear Information System (INIS)

    2011-01-01

    Purpose: The development of computer-aided diagnostic (CAD) methods for lung nodule detection, classification, and quantitative assessment can be facilitated through a well-characterized repository of computed tomography (CT) scans. The Lung Image Database Consortium (LIDC) and Image Database Resource Initiative (IDRI) completed such a database, establishing a publicly available reference for the medical imaging research community. Initiated by the National Cancer Institute (NCI), further advanced by the Foundation for the National Institutes of Health (FNIH), and accompanied by the Food and Drug Administration (FDA) through active participation, this public-private partnership demonstrates the success of a consortium founded on a consensus-based process. Methods: Seven academic centers and eight medical imaging companies collaborated to identify, address, and resolve challenging organizational, technical, and clinical issues to provide a solid foundation for a robust database. The LIDC/IDRI Database contains 1018 cases, each of which includes images from a clinical thoracic CT scan and an associated XML file that records the results of a two-phase image annotation process performed by four experienced thoracic radiologists. In the initial blinded-read phase, each radiologist independently reviewed each CT scan and marked lesions belonging to one of three categories (''nodule≥3 mm,''''nodule<3 mm,'' and ''non-nodule≥3 mm''). In the subsequent unblinded-read phase, each radiologist independently reviewed their own marks along with the anonymized marks of the three other radiologists to render a final opinion. The goal of this process was to identify as completely as possible all lung nodules in each CT scan without requiring forced consensus. Results: The Database contains 7371 lesions marked ''nodule'' by at least one radiologist. 2669 of these lesions were marked ''nodule≥3 mm'' by at least one radiologist, of which 928 (34.7%) received such marks from all

  4. NMR-CT scanner

    International Nuclear Information System (INIS)

    Kose, Katsumi; Sato, Kozo; Sugimoto, Hiroshi; Sato, Masataka.

    1983-01-01

    A brief explanation is made on the imaging methods for a practical diagnostic NMR-CT scanner : A whole-body NMR-CT scanner utilizing a resistive magnet has been developed by Toshiba in cooperation with the Institute for Solid State Physics, the University of Tokyo. Typical NMR-CT images of volunteers and patients obtained in the clinical experiments using this device are presented. Detailed specifications are also shown about the practical NMR-CTs which are to be put on the market after obtaining the government approval. (author)

  5. Coronary CT angiography: Comparison of a novel iterative reconstruction with filtered back projection for reconstruction of low-dose CT—Initial experience

    International Nuclear Information System (INIS)

    Takx, Richard A.P.; Schoepf, U. Joseph; Moscariello, Antonio; Das, Marco; Rowe, Garrett; Schoenberg, Stefan O.; Fink, Christian; Henzler, Thomas

    2013-01-01

    Objective: To prospectively compare subjective and objective image quality in 20% tube current coronary CT angiography (cCTA) datasets between an iterative reconstruction algorithm (SAFIRE) and traditional filtered back projection (FBP). Materials and methods: Twenty patients underwent a prospectively ECG-triggered dual-step cCTA protocol using 2nd generation dual-source CT (DSCT). CT raw data was reconstructed using standard FBP at full-dose (Group 1 a) and 80% tube current reduced low-dose (Group 1 b). The low-dose raw data was additionally reconstructed using iterative raw data reconstruction (Group 2 ). Attenuation and image noise were measured in three regions of interest and signal-to-noise-ratio (SNR) as well as contrast-to-noise-ratio (CNR) was calculated. Subjective diagnostic image quality was evaluated using a 4-point Likert scale. Results: Mean image noise of group 2 was lowered by 22% on average when compared to group 1 b (p 2 compared to group 1 b (p 2 (1.88 ± 0.63) was also rated significantly higher when compared to group 1 b (1.58 ± 0.63, p = 0.004). Conclusions: Image quality of 80% tube current reduced iteratively reconstructed cCTA raw data is significantly improved when compared to standard FBP and consequently may improve the diagnostic accuracy of cCTA

  6. Screening in asymptomatic SDHx mutation carriers: added value of {sup 18}F-FDG PET/CT at initial diagnosis and 1-year follow-up

    Energy Technology Data Exchange (ETDEWEB)

    Lepoutre-Lussey, C.; Deandreis, D.; Berdelou, A.; Nascimento, C.; Lumbroso, J.; Schlumberger, M.; Baudin, E.; Leboulleux, S. [Gustave Roussy Institut, Universite Paris-Sud, Department of Nuclear Medicine and Endocrine Oncology, Villejuif (France); Caramella, C.; Bidault, F.; Deschamps, F. [Gustave Roussy Institut, Department of Radiology, Villejuif (France); Al Ghuzlan, A. [Gustave Roussy Institut, Department of Medical Biology and Pathology, Villejuif (France); Hartl, D.; Dumont, F. [Gustave Roussy Institut, Department of Surgery, Villejuif (France); Borget, I. [Gustave Roussy Institut, Department of Biostatistic and Epidemiology, Villejuif (France); Paris-Sud University, Villejuif (France); Gimenez-Roqueplo, A.P. [Assistance Publique-Hopitaux de Paris, Hopital Europeen Georges Pompidou, Department of Genetics, Paris (France); Paris Descartes University, Faculty of Medicine, Paris (France); Guillaud Bataille, M. [Gustave Roussy Institut, Department of Genetics, Villejuif (France)

    2015-05-01

    Specific recommendations on screening modalities for paraganglioma (PGL) and phaeochromocytoma (PCC) in asymptomatic SDHx mutation carriers (relatives) are still lacking. We evaluated the added value of {sup 18}F-FDG PET/CT in comparison with morphological imaging at initial diagnosis and 1 year of follow-up in this population. The study included 30 consecutive relatives with a proven SDHx mutation who were investigated by {sup 18}F-FDG PET/CT, gadolinium-enhanced magnetic resonance angiography of the head and neck, thoracic/abdominal/pelvic (TAP) contrast-enhanced CT and/or TAP MRI. {sup 123}I-MIBG scintigraphy was performed in 20 subjects and somatostatin receptor scintigraphy (SRS) in 20 subjects. The gold standard was based on pathology or a composite endpoint as defined by any other positive imaging method and persistent tumour on follow-up. Images were considered as false-positive when the lesions were not detected by another imaging method or not confirmed at 1 year. At initial work-up, an imaging abnormality was found in eight subjects (27 %). The final diagnosis was true-positive in five subjects (two with abdominal PGL, one with PCC and two with neck PGL) and false-positives in the other three subjects (detected with {sup 18}F-FDG PET/CT in two and TAP MRI in one). At 1 year, an imaging abnormality was found in three subjects of which one was an 8-mm carotid body PGL in a patient with SDHD mutation and two were considered false-positive. The tumour detection rate was 100 % for {sup 18}F-FDG PET/CT and conventional imaging, 80 % for SRS and 60 % for {sup 123}I-MIBG scintigraphy. Overall, disease was detected in 4 % of the subjects at the 1-year follow-up. {sup 18}F-FDG PET/CT demonstrated excellent sensitivity but intermediate specificity justifying combined modality imaging in these patients. Given the slow progression of the disease, if {sup 18}F-FDG PET/CT and MRI are normal at baseline, the second imaging work-up should be delayed and an examination

  7. X-ray strain tensor imaging: FEM simulation and experiments with a micro-CT.

    Science.gov (United States)

    Kim, Jae G; Park, So E; Lee, Soo Y

    2014-01-01

    In tissue elasticity imaging, measuring the strain tensor components is necessary to solve the inverse problem. However, it is impractical to measure all the tensor components in ultrasound or MRI elastography because of their anisotropic spatial resolution. The objective of this study is to compute 3D strain tensor maps from the 3D CT images of a tissue-mimicking phantom. We took 3D micro-CT images of the phantom twice with applying two different mechanical compressions to it. Applying the 3D image correlation technique to the CT images under different compression, we computed 3D displacement vectors and strain tensors at every pixel. To evaluate the accuracy of the strain tensor maps, we made a 3D FEM model of the phantom, and we computed strain tensor maps through FEM simulation. Experimentally obtained strain tensor maps showed similar patterns to the FEM-simulated ones in visual inspection. The correlation between the strain tensor maps obtained from the experiment and the FEM simulation ranges from 0.03 to 0.93. Even though the strain tensor maps suffer from high level noise, we expect the x-ray strain tensor imaging may find some biomedical applications such as malignant tissue characterization and stress analysis inside the tissues.

  8. Missed rib fractures on evaluation of initial chest CT for trauma patients: pattern analysis and diagnostic value of coronal multiplanar reconstruction images with multidetector row CT.

    Science.gov (United States)

    Cho, S H; Sung, Y M; Kim, M S

    2012-10-01

    The objective of this study was to review the prevalence and radiological features of rib fractures missed on initial chest CT evaluation, and to examine the diagnostic value of additional coronal images in a large series of trauma patients. 130 patients who presented to an emergency room for blunt chest trauma underwent multidetector row CT of the thorax within the first hour during their stay, and had follow-up CT or bone scans as diagnostic gold standards. Images were evaluated on two separate occasions: once with axial images and once with both axial and coronal images. The detection rates of missed rib fractures were compared between readings using a non-parametric method of clustered data. In the cases of missed rib fractures, the shapes, locations and associated fractures were evaluated. 58 rib fractures were missed with axial images only and 52 were missed with both axial and coronal images (p=0.088). The most common shape of missed rib fractures was buckled (56.9%), and the anterior arc (55.2%) was most commonly involved. 21 (36.2%) missed rib fractures had combined fractures on the same ribs, and 38 (65.5%) were accompanied by fracture on neighbouring ribs. Missed rib fractures are not uncommon, and radiologists should be familiar with buckle fractures, which are frequently missed. Additional coronal imagescan be helpful in the diagnosis of rib fractures that are not seen on axial images.

  9. 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.

  10. Coronary computed tomography angiography with 320-row detector and using the AIDR-3D: initial experience

    International Nuclear Information System (INIS)

    Sasdelli Neto, Roberto; Nomura, Cesar Higa; Macedo, Ana Carolina Sandoval; Bianco, Danilo Perussi; Kay, Fernando Uliana; Szarf, Gilberto; Teles, Gustavo Borges da Silva; Shoji, Hamilton; Santana Netto, Pedro Vieira; Passos, Rodrigo Bastos Duarte; Chate, Rodrigo Caruso; Ishikawa, Walther Yoshiharu; Lima, Joao Paulo Bacellar Costa; Rocha, Marcelo Assis; Marcos, Vinicius Neves; Funari, Marcelo Buarque de Gusmao; Failla, Bruna Bonaventura

    2013-01-01

    Coronary computed tomography angiography (coronary CTA) is a powerful non-invasive imaging method to evaluate coronary artery disease. Nowadays, coronary CTA estimated effective radiation dose can be dramatically reduced using state-of-the-art scanners, such as 320-row detector CT (320-CT), without changing coronary CTA diagnostic accuracy. To optimize and further reduce the radiation dose, new iterative reconstruction algorithms were released recently by several CT manufacturers, and now they are used routinely in coronary CTA. This paper presents our first experience using coronary CTA with 320-CT and the Adaptive Iterative Dose Reduction 3D (AIDR-3D). In addition, we describe the current indications for coronary CTA in our practice as well as the acquisition standard protocols and protocols related to CT application for radiation dose reduction. In conclusion, coronary CTA radiation dose can be dramatically reduced following the 'as low as reasonable achievable' principle by combination of exam indication and well-documented technics for radiation dose reduction, such as beta blockers, low-kV, and also the newest iterative dose reduction software as AIDR-3D. (author)

  11. Initial investigation of a novel light-scattering gel phantom for evaluation of optical CT scanners for radiotherapy gel dosimetry

    International Nuclear Information System (INIS)

    Bosi, Stephen; Naseri, Pourandokht; Puran, Alicia; Davies, Justin; Baldock, Clive

    2007-01-01

    There is a need for stable gel materials for phantoms used to validate optical computerized tomography (CT) scanners used in conjunction with radiation-induced polymerizing gel dosimeters. Phantoms based on addition of light-absorbing dyes to gelatine to simulate gel dosimeters have been employed. However, to more accurately simulate polymerizing gels one requires phantoms that employ light-scattering colloidal suspensions added to the gel. In this paper, we present the initial results of using an optical CT scanner to evaluate a novel phantom in which radiation-exposed polymer gels are simulated by the addition of colloidal suspensions of varying turbidity. The phantom may be useful as a calibration transfer standard for polymer gel dosimeters. The tests reveal some phenomena peculiar to light-scattering gels that need to be taken into account when calibrating polymer gel dosimeters

  12. Clinical utility of F-18 FDG PET-CT in the initial evaluation of lung cancer

    DEFF Research Database (Denmark)

    Madsen, Poul Henning; Holdgaard, Paw Christian; Buck Christensen, Janne

    2016-01-01

    the predefined criteria and were read in full to identify relevant original articles on F-18 FDG PET-CT (1) in the evaluation of solitary pulmonary nodules (n = 14), (2) in curative-intent treatment trials (n = 9), and (3) in planning of invasive procedures (n = 18). RESULTS: We found the following important...... results from the literature review: 1) PET-CT can rule out malignancy in most solitary pulmonary nodules due to high sensitivity (recommendation level A). 2) PET-CT reduces the number of futile treatment trials (recommendation level A). 3) The sensitivity of PET-CT in general is insufficient to rule out...... by CT in a structured programme. 2) No curative-intent treatment should be commenced until a PET-CT scan has excluded occult distant metastases. 3) In general, lymph node metastasis in the mediastinum cannot be ruled out on the basis of a negative PET-CT, and confirmative invasive staging should...

  13. CT evaluation of severe renal inflammatory disease in children

    International Nuclear Information System (INIS)

    Montgomery, P.; Kuhn, J.P.; Afshani, E.

    1987-01-01

    We have performed CT scans on 15 children and 2 young adults with severe renal inflammatory disease. Most children with urinary tract infections do not require such evaluation. We have, however, found CT helpful in defining the nature of renal abnormality and in defining the extent of disease in selected patients who either presented as diagnostic dilemmas or who did not respond initially to proper medical treatment. We therefore use CT scanning as our initial examination in such problem patients. (orig.)

  14. Renal computed angiography. Part I: Renal CT arteriography in hypertension

    International Nuclear Information System (INIS)

    Al-Amin, M.; Hadjidekov, V.

    2012-01-01

    Visualization of renal vasculature is needed in several clinical condition among which hypertension is dominant. CT angiography now day replaces catheter angiography as non-invasive method. The goal of this study is to present initial authors experience in visualization of renal arteries using 64 MDCT and to evaluated the utility in hypertensive patients. MDCT assures excellent assessment of renal arteries conditions. Multiplanar reconstruction and allow better delineation in tortuous vessels course and anatomic variants. (authors)

  15. Children's (Pediatric) CT (Computed Tomography)

    Medline Plus

    Full Text Available ... a very detailed multidimensional view of the body's interior. Refinements in detector technology allow new CT scanners ... to read. top of page What will my child experience during and after the procedure? CT exams ...

  16. MR imaging-guided cryoablation of metastatic brain tumours: initial experience in six patients

    International Nuclear Information System (INIS)

    Li, Chengli; Wu, Lebin; Song, Jiqing; Liu, Ming; Lv, Yubo; Sequeiros, Roberto Blanco

    2010-01-01

    The objective was to evaluate the initial experience and safety of magnetic resonance imaging (MRI)-guided transcranial cryoablation in cystic metastatic brain tumours. Seven cystic metastatic brain tumours in six patients were treated with cryoablation. The approval from the local ethics committee and individual patient consent were acquired before the study. Before the procedure the tumours were detected with conventional CT or MRI. The procedure was performed under local anaesthesia and conscious sedation. A 0.23-T open MRI system with optical tracking was used for procedural planning, instrument guidance and procedural monitoring of the ice ball formation. An MR-compatible, argon-based cryoablation system was used. The schedule of follow-up imaging ranged from 12 days to 12 months. Seven treatment sessions were performed. All the cryoprobes were successfully inserted into the target with one pass. All the patients tolerated the procedure well without experiencing any neurological deficits during the treatment phase or during the immediate post-treatment period. One patient died 12 days after cryoablation. MR-guided and monitored metastasis brain tumour cryoablation is technically feasible and may represent an alternative treatment in selected patients. (orig.)

  17. Integrated FDG-PET/CT for detection, therapy monitoring and follow-up of granulocytic sarcoma. Initial results

    Energy Technology Data Exchange (ETDEWEB)

    Aschoff, Philip; Werner, M.K.; Lichy, M.; Pfannenberg, C. [Dept. of Diagnostic and Interventional Radiology, Univ. Hospital, Eberhard-Karls-Univ. Tuebingen (Germany); Haentschel, M.; Vogel, W. [Dept. of Internal Medicine, Univ. Hospital, Eberhard-Karls-Univ. Tuebingen (Germany); Oeksuez, M. [Dept. of Nuclear Medicine, Univ. Hospital, Eberhard-Karls-Univ. Tuebingen (Germany)

    2009-07-01

    Granulocytic sarcomas (GS) are rare extramedullary manifestations of myeloid or lymphoblastic leukaemia. Laboratory examinations are of limited use for diagnosis of extramedullary disease. Radiological imaging based on morphology is challenging. To date, the possible role of FDG-PET/CT as a method for combined metabolic and morphologic imaging is unclear. We present a series of 10 patients to evaluate the potential role of FDG-PET/CT in the management of GS. Patients, materials, methods: a retrospective evaluation of 18 FDG-PET/CT exams in 10 patients with histologically proven GS was performed. All scans included a contrast enhanced CT. The FDG uptake of GS was analyzed and the sensitivity of lesion detection was compared to PET and CT alone. The changes in FDG uptake after therapy were compared to morphological changes detected by CT and follow-up/clinical outcome. Results: 52 untreated or recurrent GS lesions were detected by FDG-PET/CT and all showed an increased FDG uptake with a mean SUVmax and SUVavg of 5.1 and 3.4, respectively. GS was multifocal in 8/10 patients. Combined PET/CT avoided 5 false positive findings compared to PET alone and 13 false negative findings and 1 false positive compared to CT alone. Changes in FDG uptake after therapy correlated with clinical outcome and were more reliable than CT assessment alone. PET/CT identified recurrent GS in 3 patients. Conclusion: viable GS are FDG-avid. Using this metabolic information and morphologic CT criteria, combined FDG-PET/CT was more accurate in lesion detection than FDG-PET or CT alone. Changes in FDG uptake after therapy might be a useful additional parameter for therapy monitoring. Therefore, FDG-PET/CU appears to be a promising diagnostic and monitoring tool in the management of patients with GS. (orig.)

  18. Assessment of pediatric near-drowning victims: is there a role for cranial CT?

    International Nuclear Information System (INIS)

    Romano, C.; Brown, T.; Frewen, T.C.

    1993-01-01

    Previous studies have suggested that CT examinations of the brain in children soon after near-drowning incidents are not helpful in predicting clinical outcome and are not necessary. The clinical and CT findings of 19 pediatric near-drowning victims were reviewed for correlation with clinical and neurologic outcome. As expected, a normal initial CT scan was poorly predictive of outcome, whereas an abnormal CT scan in the initial 36 h following an immersion incident was associated with a dismal prognosis. Three children with abnormal initial CT examinations were identified and all died within 3 days of admission. A CT scan performed in the immediate near-drowning period, therefore, may be helpful in identifying some patients who have sustained severe neurologic injury. (orig.)

  19. Combined CT Angiography and CT Venography in Thromboembolic disease: clinical impact; Angio TC y flebo TC combinados en el diagnostico de la enfermedad tramboembolica: impacto clinico

    Energy Technology Data Exchange (ETDEWEB)

    Bouzas, R.; Migueles, Y.; Gomez, S.; Mallo, R.; Garcia-Tejedor, J. L.; Diaz Vega, M. J. [Complejo Hospitalario Xerar-Cies. Vigo. Pontevedra (Spain)

    2002-07-01

    Combined CT Venography and Pulmonary Angiography was described in 1998 as a tool for diagnostic Thromboembolic Disease. The purpose is to relate our own experience with this technique in a population with suspected pulmonary embolism. 46 consecutive patients with suspected pulmonary embolism underwent combined CT Venography after Pulmonary CT Angiography to depict Deep Venous Thrombosis (DVT). CT Venography where obtained with a 3 minutes delay from injection, without additional intravenous contrast, from upper abdomen to fibular head. A prospective study from emergency reports where used. The reports where aimed by nine different radiologist at diary emergency room (images where not retrospective review). We report if a pulmonary embolus or deep venous thrombus or another alternative diagnostic where done. An endo luminal thrombus in any pulmonary arteries was assessed as a positive study for PE. A Thrombus in the leg veins or in an abdominal vein without diminished size of vein was assessed as an acute DVT. In those patients with a CT negative to Thromboembolic Disease was the clinician who decide if more proves where needed. Those patients without evidence in CT of Thromboembolic Disease where asked for symptoms related to the episode in a 3 months period after initial CT. Patients free of symptoms for 3 months without anticoagulation therapy where considered true negative for CT. CT shows Thromboembolic Disease in 23 of 46 patients. 21PE, 14 DVT 2 of 14 patients with DVT don't show PE, CT excluded thromboembolic disease in 23 patients and in 15 of those patients an alternative diagnostic was shown. In 22 of those 23 patients CT excluded correctly Thromboembolic Disease. One patient result in a false negative CT, Pulmonary Angiography of that patient shows us a subsegmentary embolus. (Author) 9 refs.

  20. 18F-FDG PET/CT in gastric MALT lymphoma: a bicentric experience

    International Nuclear Information System (INIS)

    Albano, Domenico; Bertoli, Mattia; Ferro, Paola; Fallanca, Federico; Gianolli, Luigi; Picchio, Maria; Giubbini, Raffaele; Bertagna, Francesco

    2017-01-01

    The role of 18F-FDG-PET/CT in evaluating gastric MALT lymphoma is still controversial. In the literature the detection rate of 18F-FDG-PET/CT in patients with gastric MALT lymphoma is variable, and the reason for this heterogeneity is not still clear. Our aim was to investigate the particular metabolic behavior of these lymphoma. Sixty-nine patients (26 female, 43 male) with histologically confirmed gastric MALT lymphoma who underwent a 18F-FDG-PET/CT for initial staging from two centers were included. The PET images were analyzed visually and semi-quantitatively by measuring the maximum standardized uptake value (SUVmax), lesion-to-liver SUVmax ratio, and lesion-to-blood pool SUVmax ratio and compared with Ann Arbor stage, epidemiological (age, sex), histological (presence of gastritis, ulcer, H. pylori infection, plasmacytic differentiation, Ki-67 index), and morphological (tumor size, superficial lesions or mass-forming) characteristics. Thirty-six patients (52 %) had positive PET/CT (average SUVmax was 9±6.7; lesion-to-liver SUVmax ratio 3.7±2.6, lesion-to-blood pool SUVmax ratio 4.8±3.3) at the corresponding gastric lesion; the remaining 33 were not 18F-FDG-avid. In the univariate analysis, 18F-FDG avidity was significantly associated with morphological features (mass forming p<0.001 and high maximum diameter p<0.001), Ann Arbor stage (p=0.010), and Ki67 index (p<0.001) and not correlated with age, sex, presence of gastritis, ulcer, Helicobacter pylori infection, and plasmacytic differentiation. In the multivariate analysis, the correlations with gross morphological appearance, Ann Arbor stage, and Ki-67 score were confirmed. SUVmax, lesion-to-liver SUVmax ratio, and lesion-to-blood pool SUVmax ratio correlated significantly only with Ki67 index (p=0.047; p=0.012; p=0.042). 18F-FDG avidity was noted in 52 % of gastric MALT lymphoma and this avidity is correlated with gross morphological characteristics, tumor stage, and Ki-67 index. SUVmax, lesion

  1. 18F-FDG PET/CT in gastric MALT lymphoma: a bicentric experience

    Energy Technology Data Exchange (ETDEWEB)

    Albano, Domenico; Bertoli, Mattia [Nuclear Medicine, Spedali Civili Brescia, Brescia (Italy); University Milano-Bicocca, Milan (Italy); Ferro, Paola [University Milano-Bicocca, Milan (Italy); Fallanca, Federico; Gianolli, Luigi; Picchio, Maria [IRCCS San Raffaele Scientific Institute, Department of Nuclear Medicine, Milan (Italy); Giubbini, Raffaele; Bertagna, Francesco [University of Brescia and Spedali Civili Brescia, Nuclear Medicine, Brescia (Italy)

    2017-04-15

    The role of 18F-FDG-PET/CT in evaluating gastric MALT lymphoma is still controversial. In the literature the detection rate of 18F-FDG-PET/CT in patients with gastric MALT lymphoma is variable, and the reason for this heterogeneity is not still clear. Our aim was to investigate the particular metabolic behavior of these lymphoma. Sixty-nine patients (26 female, 43 male) with histologically confirmed gastric MALT lymphoma who underwent a 18F-FDG-PET/CT for initial staging from two centers were included. The PET images were analyzed visually and semi-quantitatively by measuring the maximum standardized uptake value (SUVmax), lesion-to-liver SUVmax ratio, and lesion-to-blood pool SUVmax ratio and compared with Ann Arbor stage, epidemiological (age, sex), histological (presence of gastritis, ulcer, H. pylori infection, plasmacytic differentiation, Ki-67 index), and morphological (tumor size, superficial lesions or mass-forming) characteristics. Thirty-six patients (52 %) had positive PET/CT (average SUVmax was 9±6.7; lesion-to-liver SUVmax ratio 3.7±2.6, lesion-to-blood pool SUVmax ratio 4.8±3.3) at the corresponding gastric lesion; the remaining 33 were not 18F-FDG-avid. In the univariate analysis, 18F-FDG avidity was significantly associated with morphological features (mass forming p<0.001 and high maximum diameter p<0.001), Ann Arbor stage (p=0.010), and Ki67 index (p<0.001) and not correlated with age, sex, presence of gastritis, ulcer, Helicobacter pylori infection, and plasmacytic differentiation. In the multivariate analysis, the correlations with gross morphological appearance, Ann Arbor stage, and Ki-67 score were confirmed. SUVmax, lesion-to-liver SUVmax ratio, and lesion-to-blood pool SUVmax ratio correlated significantly only with Ki67 index (p=0.047; p=0.012; p=0.042). 18F-FDG avidity was noted in 52 % of gastric MALT lymphoma and this avidity is correlated with gross morphological characteristics, tumor stage, and Ki-67 index. SUVmax, lesion

  2. NMR imaging of the brain: initial impressions

    International Nuclear Information System (INIS)

    Spencer, D.H.; Bydder, G.M.

    1983-01-01

    An NMR imaging system designed and built by Thorn-EMI Ltd was installed at Hammersmith Hospital in March 1981. In the first year of operation 180 patients and 40 volunteers have had cranial examinations and initial impressions bases on this experience are presented. Patients with a wide variety of neurological diseases have been studied to provide a basis for diagnostic interpretation, to define distinctive features, and to evaluate different types of scanning sequences. NMR imaging appears to be of considerable value in neurological diagnosis and has a number of advantages over CT. The detailed evaluation of NMR imaging will require much more work but the initial results are very promising

  3. The Lung Image Database Consortium (LIDC) and Image Database Resource Initiative (IDRI): A Completed Reference Database of Lung Nodules on CT Scans

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-02-15

    Purpose: The development of computer-aided diagnostic (CAD) methods for lung nodule detection, classification, and quantitative assessment can be facilitated through a well-characterized repository of computed tomography (CT) scans. The Lung Image Database Consortium (LIDC) and Image Database Resource Initiative (IDRI) completed such a database, establishing a publicly available reference for the medical imaging research community. Initiated by the National Cancer Institute (NCI), further advanced by the Foundation for the National Institutes of Health (FNIH), and accompanied by the Food and Drug Administration (FDA) through active participation, this public-private partnership demonstrates the success of a consortium founded on a consensus-based process. Methods: Seven academic centers and eight medical imaging companies collaborated to identify, address, and resolve challenging organizational, technical, and clinical issues to provide a solid foundation for a robust database. The LIDC/IDRI Database contains 1018 cases, each of which includes images from a clinical thoracic CT scan and an associated XML file that records the results of a two-phase image annotation process performed by four experienced thoracic radiologists. In the initial blinded-read phase, each radiologist independently reviewed each CT scan and marked lesions belonging to one of three categories (''nodule{>=}3 mm,''''nodule<3 mm,'' and ''non-nodule{>=}3 mm''). In the subsequent unblinded-read phase, each radiologist independently reviewed their own marks along with the anonymized marks of the three other radiologists to render a final opinion. The goal of this process was to identify as completely as possible all lung nodules in each CT scan without requiring forced consensus. Results: The Database contains 7371 lesions marked ''nodule'' by at least one radiologist. 2669 of these lesions were marked &apos

  4. Patient experience of CT colonography and colonoscopy after fecal occult blood test in a national screening programme

    OpenAIRE

    Plumb, Andrew A.; Ghanouni, Alex; Rees, Colin J.; Hewitson, Paul; Nickerson, Claire; Wright, Suzanne; Taylor, Stuart A.; Halligan, Steve; von Wagner, Christian

    2016-01-01

    Objective To investigate patient experience of CT colonography (CTC) and colonoscopy in a national screening programme. Methods Retrospective analysis of patient experience postal questionnaires. We included screenees from a fecal occult blood test (FOBt) based screening programme, where CTC was performed when colonoscopy was incomplete or deemed unsuitable. We analyzed questionnaire responses concerning communication of test risks, test-related discomfort and post-test pain, as well as compl...

  5. Patient experience of CT colonography and colonoscopy after fecal occult blood test in a national screening programme

    OpenAIRE

    Plumb, A. A.; Ghanouni, A.; Rees, C. J.; Hewitson, P.; Nickerson, C.; Wright, S.; Taylor, S. A.; Halligan, S.; von Wagner, C.

    2017-01-01

    OBJECTIVE: To investigate patient experience of CT colonography (CTC) and colonoscopy in a national screening programme. METHODS: Retrospective analysis of patient experience postal questionnaires. We included screenees from a fecal occult blood test (FOBt) based screening programme, where CTC was performed when colonoscopy was incomplete or deemed unsuitable. We analyzed questionnaire responses concerning communication of test risks, test-related discomfort and post-test pain, as well as com...

  6. Sinonasal Wegener's granulomatosis: CT characteristics

    International Nuclear Information System (INIS)

    Benoudiba, F.; Marsot-Dupuch, K.; Rabia, Hadj M.; Lasjaunias, P.; Cabanne, J.; Bobin, S.

    2003-01-01

    Wegener's granulomatosis (WG) is a severe and potentially lethal granulomatosis. Even though no specific radiological criteria exist, CT may suggest the correct diagnosis at an early stage. Recent improvement in the prognosis is related to earlier diagnosis, allowing the initiation of efficient and specific treatment before any severe complications occur. We reviewed a series of WG cases in order to establish the CT diagnostic criteria. (orig.)

  7. Improved overall survival after early recurrence of lung cancer following the introduction of CT-based follow-up for patients initially treated with curative intent by (chemo)radiotherapy (CRT)

    DEFF Research Database (Denmark)

    Hansen, Niels-Chr. G.; Laursen, Christian B.; Jeppesen, Stefan S.

    2017-01-01

    years after the introduction of CT-based follow-up. The difference between the periods is statistically significant (p = 0.009, log rank test).View this table:Conclusion: The CT-based follow-up program has most likely contributed to the improved survival as the survival difference between the periods......Background: After introduction in July 2010 of follow-up by contrast enhanced CT of thorax and upper abdomen every 3 months for two years and then every 6 months for three years we found improved survival after early recurrence in patients initially treated by surgery (Eur Respir J 2015; 46 suppl...

  8. Initial Results from Coaxial Helicity Injection Experiments in NSTX

    International Nuclear Information System (INIS)

    Raman, R.; Jarboe, T.R.; Mueller, D.; Schaffer, M.J.; Maqueda, R.; Nelson, B.A.; Sabbagh, S.; Bell, M.; Ewig, R.; Fredrickson, E.; Gates, D.; Hosea, J.; Ji, H.; Kaita, R.; Kaye, S.M.; Kugel, H.; Maingi, R.; Menard, J.; Ono, M.; Orvis, D.; Paolette, F.; Paul, S.; Peng, M.; Skinner, C.H.; Wilgen, W.; Zweben, S.

    2001-01-01

    Coaxial Helicity Injection (CHI) has been investigated on the National Spherical Torus Experiment (NSTX). Initial experiments produced 130 kA of toroidal current without the use of the central solenoid. The corresponding injector current was 20 kA. Discharges with pulse lengths up to 130 ms have been produced

  9. Preoperative PET/CT in early-stage breast cancer

    DEFF Research Database (Denmark)

    Bernsdorf, M; Berthelsen, A K; Timmermans-Wielenga, Vera

    2012-01-01

    The aim of this study was to assess the diagnostic and therapeutic impact of preoperative positron emission tomography and computed tomography (PET/CT) in the initial staging of patients with early-stage breast cancer.......The aim of this study was to assess the diagnostic and therapeutic impact of preoperative positron emission tomography and computed tomography (PET/CT) in the initial staging of patients with early-stage breast cancer....

  10. Emergency CT in blunt abdominal trauma of multiple injury patients

    International Nuclear Information System (INIS)

    Kinnunen, J.; Kivioja, A.; Poussa, K.; Laasonen, E.M.

    1994-01-01

    Multiple injury patients with blunt abdominal trauma (n = 110) were examined by abdominal CT. An i.v., but not peroral, contrast medium was used, thereby eliminating the delay caused by administering peroral contrast medium and any subsequent delay in making the diagnoses and beginning operative treatment. Eighteen patients underwent emergency laparotomy after the initial CT examination. The preoperative CT findings were compared to the laparotomy findings. CT revealed all but one of the severe parenchymal organ lesions requiring surgery. The one liver laceration that went undetected had caused hemoperitoneum, which was diagnosed by CT. The bowel and mesenteric lesions presented as intra-abdominal blood, and the hemoperitoneum was discovered in every patient with these lesions. Fourteen patients also initially had positive abdominal CT findings; 10 of them underwent an additional abdominal CT within 3 days, but the repeat studies did not reveal any lesions in need of surgery. Omission of the oral contrast medium did not jeopardize making the essential diagnoses, but it did save time. (orig.)

  11. CT diagnosis of acute aortic dissection

    International Nuclear Information System (INIS)

    Ogawa, Noriko; Kobayashi, Takeshi

    1989-01-01

    Sixteen (47.5%) of 35 patients with acute aortic dissection showed a non-opacified crescent in the aorta on an initial contrast CT. Seven of these 16 patients underwent cineangiography soon after the initial CT, and in all 7 patients, neither an intimal tear nor an intimal flap was obtained. All but one of above 16 patients were followed by CT. Mean duration of follow-up was 9.6 months. In 10 of 15 patients with non-opacified false lumen, the false lumen remained non-opacified until the last examination. Moreover, in 6 of these 10 patients, the false lumen shrunk, and in the other 3, it disappeared completely on follow-up CT. On the other hand, in remaining 5 of these 15 patients who were initially diagnosed to have non-opacified false lumen, the false lumen became opacified and enlarged in size on follow-up CT performed in the first 14 weeks. Moreover, in 4 of these 5 patients, the false lumen became opacified in the only first 6 weeks. No matter how intensive care should be paid at least for the first 6 weeks, it seems that patients with aortic dissection which have non-opacified false lumen had good prognosis in comparison to patients with ordinary aortic dissections which have opacified false lumen. We believe aortic dissection with non-opacified false lumen may consist of two type of aortic dissection, one has no intimal tear, the other has some intimal tears and a thrombosed false lumen. In conclusion, CT is the most useful modality in diagnosing acute aortic dissection. The reasons are the incidence of acute aortic dissection with non-opacified false lumen was high, patients with non-opacified false lumen had good prognosis, and it was difficult to diagnose aortic dissection with non-opacified false lumen by conventional cineangiography and/or DSA. (author)

  12. CT of the neonatal head

    International Nuclear Information System (INIS)

    Mohan, S.; Rogan, E.A.; Batty, R.; Raghavan, A.; Whitby, E.H.; Hart, A.R.; Connolly, D.J.A.

    2013-01-01

    Computed tomography (CT) is used less often than other techniques on neonatal units. However, in the acute setting, CT can be invaluable in diagnosing or excluding potentially life-threatening conditions and guiding initial management in neonates. Common indications for scanning include trauma, suspected non-accidental injury, infection, or an acute hypoxic or metabolic event. The aim of this review is to provide an overview of the normal neonatal head at CT and compare this to the common pathological abnormalities. Several key features of each condition will be highlighted. It is important to note that some pathological conditions can have overlapping features at CT and, therefore, the clinical history and additional investigations are also of key importance in determining the diagnosis

  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. Head trauma and CT

    International Nuclear Information System (INIS)

    Samejima, Kanji; Yoshii, Nobuo; Tobari, Chitoshi

    1979-01-01

    It has been said that chronic subdural hematoma cannot be diagnosed by CT. In our cases, CT was used, and the results were described. According to the density of the picture, CT findings of chronic subdural hematoma could be classified into 3 types, those of higher density than that of the cerebral paranchyma, those of isodensity, and those of lower density than that of the cerebral parenchyma. The difference among them appeared to be due to variation in the fluid in hematoma, especially that in hemoglobin concentration. Chronic subdural hematoma was found in 27 of 388 cases of head trauma in which CT was undertaken in our department of surgery for last 2 years. It is difficult to differenciate this disease from subdural edema or subarachnoideal retention of the cerebrospinal fluid. In many cases, use of contrast medium added no change to the CT picture. Cerebral angiography is necessary for definite diagnosis of the disease. Chronic subdural hematoma gives more varieties of findings than other intracranial hematomas. However, if the film is very carefully read, CT is still useful for diagnosing this disease in spite of initially remarked difficulties. (Ueda, J.)

  15. Ex-situ time-lapse x-ray CT study of 3D micro-structural fatigue damage evolution in uni-directional composites

    DEFF Research Database (Denmark)

    Jespersen, Kristine Munk; Wang, Ying; Zangenberg Hansen, Jens

    2016-01-01

    In this study, the progress of damage under tension-tension fatigue of a uni-directional (UD) glass fibre composite made from a non-crimp fabric is studied using transilluminated white light imaging (TWLI) and X-ray computed tomography (CT). TWLI images are automatically captured throughout...... to initiate already after the first cycle, whereas some grow gradually and others appear suddenly during cycling. The off-axis cracks are observed to saturate after a few thousand cycles. The UD fibre fracture damage in the region observed by X-ray CT is probably already saturated at the first interruption...... point, as no significant change is seen between the two X-ray images. However, the study indicates how TWLI can be used as an initial indicator to locate damage regions at an early stage for the future ex-situ X-ray CT experiments....

  16. CT and MRI of hip arthroplasty

    International Nuclear Information System (INIS)

    Cahir, J.G.; Toms, A.P.; Marshall, T.J.; Wimhurst, J.; Nolan, J.

    2007-01-01

    Plain films are the initial imaging method of choice for evaluation of hip arthroplasty. Recent advances in technology and imaging techniques have largely overcome the problems of beam hardening in computed tomography (CT) and magnetic susceptibility artefact in magnetic resonance imaging (MRI). CT and MRI have now become useful imaging techniques in the assessment of hip arthroplasty

  17. Impact of {sup 18}F-FDG PET/CT on the management of adrenocortical carcinoma: analysis of 106 patients

    Energy Technology Data Exchange (ETDEWEB)

    Takeuchi, Satoshi; Macapinlac, Homer A.; Chuang, Hubert H. [The University of Texas MD Anderson Cancer Center, Department of Nuclear Medicine, Houston, TX (United States); Balachandran, Aparna [The University of Texas MD Anderson Cancer Center, Department of Diagnostic Radiology, Houston, TX (United States); Habra, Mouhammed Amir [The University of Texas MD Anderson Cancer Center, Department of Endocrine Neoplasia and Hormonal Disorders, Houston, TX (United States); Phan, Alexandria T. [The University of Texas MD Anderson Cancer Center, Department of Gastrointestinal Medical Oncology, Houston, TX (United States); Bassett, Roland L. [The University of Texas MD Anderson Cancer Center, Department of Biostatistics, Houston, TX (United States)

    2014-11-15

    Adrenocortical carcinoma (ACC) is a rare and aggressive malignancy. Limited data are available about on value of {sup 18}F-FDG PET/CT in ACC. We evaluated the impact of PET/CT on the management of ACC. We performed a retrospective review in patients with ACC who had undergone PET/CT. The impact of PET/CT on the management plan was evaluated by comparing the findings on PET/CT to the findings on contrast-enhanced CT. The sensitivity, specificity, and accuracy of each form of imaging were calculated. The correlations between PET/CT parameters, including maximum standardized uptake value (SUV{sub max}), total lesion glycolysis, and decline in SUV{sub max} after chemotherapy, and clinical outcome were evaluated. Included in the analysis were 106 patients with 180 PET/CT scans. Of the 106 patients, 7 underwent PET/CT only for initial staging, 84 underwent PET/CT only for restaging, and 15 underwent PET/CT for both initial staging and restaging. PET/CT changed the management plan in 1 of 22 patients (5 %) at initial staging and 9 of 99 patients (9 %) at restaging. In 5 of the patients in whom PET/CT changed the management plan, PET/CT showed response to chemotherapy but contrast-enhanced CT showed stable disease. Sensitivity, specificity, and accuracy were 100 %, 100 %, and 100 % for PET/CT at initial staging; 92.6 %, 100 %, and 96.4 % for CT at initial staging; 98.4 %, 100 %, and 99.5 % for PET/CT at restaging; and 96.8 %, 98.6 %, and 98.0 % for CT at restaging, respectively. No PET/CT parameters were associated with survival at either initial diagnosis or recurrence. PET/CT findings could substantially change the management plan in a small proportion of patients with ACC. Although lesion detection was similar between PET/CT and CT, PET/CT may be preferred for chemotherapeutic response assessment because it may predict response before anatomic changes are detected on CT. (orig.)

  18. Applications of SPECT / CT at the Institute of Nephrology

    International Nuclear Information System (INIS)

    Zayas Crespo, Francisco; Batlle Leal, Fernando; Mesa Dueñas, Niurka

    2016-01-01

    The main applications of SPECT-CT in the diagnosis of various diseases, as well as the experiences gained from the operation of this hybrid system are described. To date we have studied more than 100 patients from different hospitals in the capital and other nearby provinces, including. Including major diseases: kidney, bone, oncological and endocrine. So far, the results achieved have enabled diagnostic evaluation of higher accuracy and detail, even improving in a significant number of patients the initial diagnosis or modifying this fully. (author)

  19. Clinical utility of F-18 FDG PET-CT in the initial evaluation of lung cancer

    Energy Technology Data Exchange (ETDEWEB)

    Madsen, Poul Henning [Vejle Hospital, Department of Medicine, Division of Respiratory Medicine, Vejle (Denmark); Holdgaard, Paw Christian [Vejle Hospital, Department of Nuclear Medicine, Vejle (Denmark); Christensen, Janne Buck [Odense University Hospital/University of Southern Denmark, Department of Quality and Research/HTA, Odense University Hospital and Medical Research Library, Odense (Denmark); Hoeilund-Carlsen, Poul Flemming [Odense University Hospital, Department of Nuclear Medicine, Odense (Denmark)

    2016-10-15

    Positron emission tomography-computed tomography (PET-CT) is a resource-demanding imaging modality with increasing popularity in the workup of patients with suspected or proven lung cancer. To review the clinical usefulness of this imaging modality in the diagnosis, staging, and pre-operative evaluation, we conducted a systematic literature search, review, and quality assessment using the rapid evidence assessment toolkit and the Oxford Centre for Evidence-Based Medicine methodology. The literature search resulted in 4,208 records including 918 reviews, of which 139 met the predefined criteria and were read in full to identify relevant original articles on F-18 FDG PET-CT (1) in the evaluation of solitary pulmonary nodules (n = 14), (2) in curative-intent treatment trials (n = 9), and (3) in planning of invasive procedures (n = 18). We found the following important results from the literature review: (1) PET-CT can rule out malignancy in most solitary pulmonary nodules due to high sensitivity (recommendation level A). (2) PET-CT reduces the number of futile treatment trials (recommendation level A). (3) The sensitivity of PET-CT in general is insufficient to rule out mediastinal lymph node metastasis (recommendation level A). (1) With few exceptions, solitary pulmonary nodules can safely be considered benign if the PET-CT scan is negative. Exceptions consist of small (<1 cm) and non-solid, solitary pulmonary nodules. These abnormalities should be followed up by CT in a structured programme. (2) No curative-intent treatment should be commenced until a PET-CT scan has excluded occult distant metastases. (3) In general, lymph node metastasis in the mediastinum cannot be ruled out on the basis of a negative PET-CT, and confirmative invasive staging should be performed in most patients before mediastinal metastasis is confirmed or ruled out. (orig.)

  20. Clinical utility of F-18 FDG PET-CT in the initial evaluation of lung cancer

    International Nuclear Information System (INIS)

    Madsen, Poul Henning; Holdgaard, Paw Christian; Christensen, Janne Buck; Hoeilund-Carlsen, Poul Flemming

    2016-01-01

    Positron emission tomography-computed tomography (PET-CT) is a resource-demanding imaging modality with increasing popularity in the workup of patients with suspected or proven lung cancer. To review the clinical usefulness of this imaging modality in the diagnosis, staging, and pre-operative evaluation, we conducted a systematic literature search, review, and quality assessment using the rapid evidence assessment toolkit and the Oxford Centre for Evidence-Based Medicine methodology. The literature search resulted in 4,208 records including 918 reviews, of which 139 met the predefined criteria and were read in full to identify relevant original articles on F-18 FDG PET-CT (1) in the evaluation of solitary pulmonary nodules (n = 14), (2) in curative-intent treatment trials (n = 9), and (3) in planning of invasive procedures (n = 18). We found the following important results from the literature review: (1) PET-CT can rule out malignancy in most solitary pulmonary nodules due to high sensitivity (recommendation level A). (2) PET-CT reduces the number of futile treatment trials (recommendation level A). (3) The sensitivity of PET-CT in general is insufficient to rule out mediastinal lymph node metastasis (recommendation level A). (1) With few exceptions, solitary pulmonary nodules can safely be considered benign if the PET-CT scan is negative. Exceptions consist of small (<1 cm) and non-solid, solitary pulmonary nodules. These abnormalities should be followed up by CT in a structured programme. (2) No curative-intent treatment should be commenced until a PET-CT scan has excluded occult distant metastases. (3) In general, lymph node metastasis in the mediastinum cannot be ruled out on the basis of a negative PET-CT, and confirmative invasive staging should be performed in most patients before mediastinal metastasis is confirmed or ruled out. (orig.)

  1. Metastatic liver tumor from cystic ovarian carcinomas. CT and MRI appearance

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Yi; Yamashita, Yasuyuki; Ogata, Ichiro; Namimoto, Tomohiro; Abe, Yasuko; Urata, Joji; Takahashi, Mutsumasa [Kumamoto Univ. (Japan). School of Medicine

    1999-08-01

    The initial and follow-up CT and MRI images of ten patients with hepatic metastases from ovarian tumors were retrospectively analyzed to establish their features and sequential changes in appearance. Ten patients with hepatic metastasis from ovarian tumors received initial and follow-up CT and MRI examinations. Six patients were followed up every two to three weeks before surgical tumor resection. Both CT and MR images were analyzed by two radiologists. A total of fourteen lesions were detected by CT and MRI in 10 patients. All 14 lesions were demonstrated as areas of marked hyperintensity on T2-weighted MRI. Eleven cyst-like tumors were demonstrated as round or oval low density lesions on CT and as areas of hypointensity on T1-weighted imaging. Three lesions were shown as solid masses with slightly low attenuation at the initial CT examination and slightly low or iso-intensity areas on T1-weighted imaging, and these lesions showed early peripheral globular enhancement and delayed enhancement on contrast-enhanced CT and MR imaging. Cystic formation was observed two to three weeks later after initial study in all the 3 solid lesions. Rapid subcapsular effusion, which showed obvious enhancement on delayed Gd-DTPA enhanced MR imaging, was observed in two patients. The hepatic metastatic tumor from cystic ovarian carcinoma may manifest as a well-defined cystic lesion or as a solid mass, and the solid mass shows delayed enhancement on contrast-enhanced CT and MR imaging. Furthermore, rapid cystic formation and rapid subcapsular extension is frequently seen. (author)

  2. Magnetohydrodynamic simulation of solid-deuterium-initiated Z-pinch experiments

    International Nuclear Information System (INIS)

    Sheehey, P.T.

    1994-02-01

    Solid-deuterium-initiated Z-pinch experiments are numerically simulated using a two-dimensional resistive magnetohydrodynamic model, which includes many important experimental details, such as ''cold-start'' initial conditions, thermal conduction, radiative energy loss, actual discharge current vs. time, and grids of sufficient size and resolution to allow realistic development of the plasma. The alternating-direction-implicit numerical technique used meets the substantial demands presented by such a computational task. Simulations of fiber-initiated experiments show that when the fiber becomes fully ionized rapidly developing m=0 instabilities, which originated in the coronal plasma generated from the ablating fiber, drive intense non-uniform heating and rapid expansion of the plasma column. The possibility that inclusion of additional physical effects would improve stability is explored. Finite-Larmor-radius-ordered Hall and diamagnetic pressure terms in the magnetic field evolution equation, corresponding energy equation terms, and separate ion and electron energy equations are included; these do not change the basic results. Model diagnostics, such as shadowgrams and interferograms, generated from simulation results, are in good agreement with experiment. Two alternative experimental approaches are explored: high-current magnetic implosion of hollow cylindrical deuterium shells, and ''plasma-on-wire'' (POW) implosion of low-density plasma onto a central deuterium fiber. By minimizing instability problems, these techniques may allow attainment of higher temperatures and densities than possible with bare fiber-initiated Z-pinches. Conditions for significant D-D or D-T fusion neutron production may be realizable with these implosion-based approaches

  3. Double prospectively ECG-triggered high-pitch spiral acquisition for CT coronary angiography: Initial experience

    International Nuclear Information System (INIS)

    Wang, Q.; Qin, J.; He, B.; Zhou, Y.; Yang, J.-J.; Hou, X.-L.; Yang, X.-B.; Chen, J.-H.; Chen, Y.-D.

    2013-01-01

    Aim: To evaluate the feasibility of double prospectively electrocardiogram (ECG)-triggered high-pitch spiral acquisition mode (double high-pitch mode) for coronary computed tomography angiography (CTCA). Materials and methods: One hundred and forty-nine consecutive patients [40 women, 109 men; mean age 58.2 ± 9.2 years; sinus rhythm ≤70 beats/min (bpm) after pre-medication, body weight ≤100 kg] were enrolled for CTCA examinations using a dual-source CT system with 2 × 128 × 0.6 mm collimation, 0.28 s rotation time, and a pitch of 3.4. Double high-pitch mode was prospectively triggered first at 60% and later at 30% of the R–R interval within two cardiac cycles. Image quality was evaluated using a four-point scale (1 = excellent, 4 = non-assessable). Results: From 2085 coronary artery segments, 86.4% (1802/2085) were rated as having a score of 1, 12.3% (257/2085) as score of 2, 1.2% (26/2085) as score of 3, and none were rated as “non-assessable”. The average image quality score was 1.15 ± 0.26 on a per-segment basis. The effective dose was calculated by multiplying the coefficient factor of 0.028 by the dose–length product (DLP); the mean effective dose was 3.5 ± 0.8 mSv (range 1.7–7.6 mSv). The total dosage of contrast medium was 78.7 ± 2.9 ml. Conclusion: Double prospectively ECG-triggered high-pitch spiral acquisition mode provides good image quality with an average effective dose of less than 5 mSv in patients with a heart rate ≤70 bpm

  4. Necrotizing pneumonia: CT findings and its clinical significance

    International Nuclear Information System (INIS)

    Park, Hong Suk; Im, Jung Gi; Ryoo, Jae Wook; Yeon, Kyung Mo; Han, Man Chung

    1995-01-01

    To analyze CT and follow-up chest radiographic findings in patients with necrotizing pneumonia and to evaluate clinical significance of the extent of necrosis. We reviewed medical records and retrospectively analysed CT scans and follow-up chest radiographs of 22 patients with necrotizing pneumonia, confirmed by biopsy (n = 7) and culture (n = 15). Inclusion criteria for necrotizing pneumonia was necrotic low attenuation, with or without cavitation on postcontrast enhanced CT scan. The study group included 15 men and seven women, aged 11-66 years (average: 47 years). The pathogens of necrotizing pneumonia were Klebsiella spp (n = 7), Enterobacter spp (n = 5), Actinomyces spp (n = 4), Pseudomonas spp (n = 4), Nocardia spp (n = 4), and others (n = 5). Average duration of pneumonia was 4.1 months. On CT scan, pneumonic consolidations were well-marginated in 14 patients and there were cavities on initial CT scan in 16 cases. Margins of the necrotic portion on CT scan were well-demarcated in majority of the patients (16/22). Low attenuation areas on initial CT scan resulted in cavitation, fibrosis and volume loss as shown on follow-up chest radiographs. The larger the necrotic areas on CT, the more the volume loss was. CT findings of necrotizing pneumonia were well-marginated air-space consolidation with low attenuation area, with or without cavity. The extent of necrotic area was closely related with the degree of fibrotic change later on. CT is important tool for diagnosis and prediction of parenchymal damage in necrotizing pneumonia

  5. Comparison of the 68Ga-DOTATATA PET/CT, FDG PET/CT, and MIBG SPECT/CT in the Evaluation of Suspected Primary Pheochromocytomas and Paragangliomas.

    Science.gov (United States)

    Jing, Hongli; Li, Fang; Wang, Ling; Wang, Zhenghua; Li, Wei; Huo, Li; Zhang, Jingjing

    2017-07-01

    Anatomical imaging modalities including CT and MRI are the mainstay of evaluation of primary pheochromocytoma or paraganglioma. However, nuclear medicine imaging is frequently necessary to determine the nature of the lesions. The purpose of this investigation is to assess which commonly used nuclear medicine modality might have a better diagnostic value in this clinical setting. Eight patients who had been suspected of having either primary pheochromocytoma or primary paraganglioma and 1 patient with known pheochromocytoma were included in the analysis. Among the 8 patients without known diagnosis, 7 had been suggested by anatomical imaging modalities, whereas one of them presented with initial negative anatomical imaging interpretation. All of 9 patients underwent Ga-DOTATATA PET/CT, FDG PET/CT, and MIBG SPECT/CT for further evaluation. The imaging findings were compared with postsurgical pathology and follow-up. Both Ga-DOTATATA PET/CT and MIBG SPECT/CT accurately identified 9 primary tumors, whereas FDG PET/CT showed increased activity in 8 of 9 primary tumors. Both Ga-DOTATATA and FDG PET/CT are able to detect associated extra-adrenal lesions not shown on MIBG study in patients with multiple endocrine neoplasia syndrome. Ga-DOTATATA PET/CT could be the nuclear medicine imaging choice to evaluate suspected primary pheochromocytoma or paraganglioma, especially in the situation of multiple endocrine neoplasia syndrome.

  6. Metabolic and clinical assessment of efficacy of cryoablation therapy on skeletal masses by 18F-FDG positron emission tomography/computed tomography (PET/CT) and visual analogue scale (VAS): initial experience

    International Nuclear Information System (INIS)

    Masala, Salvatore; Bartolucci, Alberto D.; Mammucari, Matteo; Simonetti, Giovanni; Schillaci, Orazio; Calabria, Ferdinando

    2011-01-01

    Various therapy modalities have been proposed as standard treatments in management of bone metastases. Radiation therapy remains the standard of care for patients with localized bone pain, but up to 30% of them do not experience notable pain relief. Percutaneous cryoablation is a minimally invasive technique that induces necrosis by alternately freezing and thawing a target tissue. This technique is successfully used to treat a variety of malignant and benign diseases in different sites. 18 F-FDG positron emission tomography/computed tomography ( 18 F-FDG PET/CT) is a single technique of imaging that provides in a ''single step'' both morphological and metabolic features of neoplastic lesions of the bone. The aim of this study was to evaluate the efficacy of the cryosurgical technique on secondary musculoskeletal masses according to semi-quantitative PET analysis and clinical-test evaluation with the visual analogue scale (VAS). We enrolled 20 patients with painful bone lesions (score pain that exceeded 4 on the VAS) that were non-responsive to treatment; one lesion per patient was treated. All patients underwent a PET-CT evaluation before and 8 weeks after cryotherapy; maximum standardized uptake value (SUV max ) was measured before and after treatment for metabolic assessment of response to therapy. After treatment, 18 patients (90%) showed considerable reduction in SUV max value (>50%) suggestive of response to treatment; only 2 patients did not show meaningful reduction in metabolic activity. Our preliminary study demonstrates that quantitative analysis provided by PET correlates with response to cryoablation therapy as assessed by CT data and clinical VAS evaluation. (orig.)

  7. Role of CT in management of mesothelioma

    International Nuclear Information System (INIS)

    Godwin, J.D.; Rusch, V.W.; Shuman, W.P.

    1987-01-01

    The authors examined the accuracy of CT in determining the extent of disease and its role in the follow-up of patients with malignant pleural mesothelioma. Twenty patients underwent complex CT-anatomic correlation. CT was unable to demonstrate small tumor implants in the chest wall (four cases), upper abdomen (two cases), or contralateral hemidiaphragm (one case). Occasionally there was difficulty distinguishing tumor invasion of soft tissues from simple contiguity, benign from malignant nodes, and recurrent tumor from surgical changes. In six of eight treated patients, CT demonstrated recurrence -8 months before signs or symptoms appeared. Despite its limitations, CT is essential in the initial evaluation and follow-up of patients with mesothelioma

  8. 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)

  9. Clinical utility of F-18 FDG PET-CT in the initial evaluation of lung cancer.

    Science.gov (United States)

    Madsen, Poul Henning; Holdgaard, Paw Christian; Christensen, Janne Buck; Høilund-Carlsen, Poul Flemming

    2016-10-01

    Positron emission tomography-computed tomography (PET-CT) is a resource-demanding imaging modality with increasing popularity in the workup of patients with suspected or proven lung cancer. To review the clinical usefulness of this imaging modality in the diagnosis, staging, and pre-operative evaluation, we conducted a systematic literature search, review, and quality assessment using the rapid evidence assessment toolkit and the Oxford Centre for Evidence-Based Medicine methodology. The literature search resulted in 4,208 records including 918 reviews, of which 139 met the predefined criteria and were read in full to identify relevant original articles on F-18 FDG PET-CT (1) in the evaluation of solitary pulmonary nodules (n = 14), (2) in curative-intent treatment trials (n = 9), and (3) in planning of invasive procedures (n = 18). We found the following important results from the literature review: 1) PET-CT can rule out malignancy in most solitary pulmonary nodules due to high sensitivity (recommendation level A). 2) PET-CT reduces the number of futile treatment trials (recommendation level A). 3) The sensitivity of PET-CT in general is insufficient to rule out mediastinal lymph node metastasis (recommendation level A). ᅟ 1) With few exceptions, solitary pulmonary nodules can safely be considered benign if the PET-CT scan is negative. Exceptions consist of small (PET-CT scan has excluded occult distant metastases. 3) In general, lymph node metastasis in the mediastinum cannot be ruled out on the basis of a negative PET-CT, and confirmative invasive staging should be performed in most patients before mediastinal metastasis is confirmed or ruled out.

  10. CT-guided biopsy with cutting-edge needle for the diagnosis of malignant lymphoma: Experience of 267 biopsies

    International Nuclear Information System (INIS)

    Agid, R.; Sklair-Levy, M.; Bloom, A.I.; Lieberman, S.; Polliack, A.; Ben-Yehuda, D.; Sherman, Y.; Libson, E.

    2003-01-01

    AIM: We performed a retrospective study of 267 core needle aspiration biopsies in order to estimate the accuracy of CT-guided aspiration core needle biopsies for the diagnosis and subsequent treatment of malignant lymphoma. MATERIALS AND METHODS: Between 1989 and 1999, 267 CT-guided core needle biopsies were performed in 241 patients with either primary or recurrent malignant lymphoma. Patients age ranged from 4--88 years. One hundred and sixty-six (62.2%) nodal and 101 (37.8%) extranodal aspiration biopsies were performed using either 18 G or 20 G Turner needles. Statistical method used was Chi-square analysis. RESULTS: An accurate histological diagnosis was made in 199 (82.5%) patients, the remaining 42 (17.4%) patients had non-diagnostic CT biopsies. Thirty-seven of them were diagnosed by a surgical biopsy, four by bone marrow biopsy and in one patient by paracentesis. One hundred and seventy-nine patients had non-Hodgkin's lymphoma (NHL) and 62 had Hodgkin's disease (HD); 23 (9.54%) patients underwent repeated CT biopsy which was diagnostic in 17 (73.9%) and non-diagnostic in six (26%). CONCLUSION: CT-guided aspiration core biopsies were sufficient to establish a diagnosis in lymphoproliferative disorders in 82.5% of cases. In the light of this experience we suggest that imaging-guided core needle biopsy be used as the first step in the work up of many patients with lymphoma Agid,R. et al. (2003). Clinical Radiology58, 143-147

  11. Preoperative evaluation of renal anatomy and renal masses with helical CT, 3D-CT and 3D-CT angiography.

    Science.gov (United States)

    Toprak, Uğur; Erdoğan, Aysun; Gülbay, Mutlu; Karademir, Mehmet Alp; Paşaoğlu, Eşref; Akar, Okkeş Emrah

    2005-03-01

    The aim of this prospective study was to determine the efficacy of three-dimensional computed tomography (3D-CT) and three-dimensional computed tomographic angiography (3D-CTA) that were reconstructed by using the axial images of the multiphasic helical CT in the preoperative evaluation of renal masses and demonstration of renal anatomy. Twenty patients that were suspected of having renal masses upon initial physical examination and ultrasonographic evaluation were examined through multiphasic helical CT. Two authors executed CT evaluations. Axial images were first examined and then used to reconstruct 3D-CT and 3D- CTA images. Number, location and size of the renal masses and other findings were noted. Renal vascularization and relationships of the renal masses with the neighboring renal structures were further investigated with 3D-CT and 3D-CTA images. Out of 20 patients, 13 had histopathologically proven renal cell carcinoma. The diagnoses of the remaining seven patients were xanthogranulomatous pyelonephritis, abscess, simple cyst, infected cyst, angiomyolipoma, oncocytoma and arteriovenous fistula. In the renal cell carcinoma group, 3 patients had stage I, 7 patients had stage II, and 3 patients had stage III disease. Sizes of renal cell carcinoma masses were between 23 mm to 60 mm (mean, 36 mm). Vascular invasion was shown in 2 renal cell carcinoma patients. Collecting system invasion was identified in 11 of 13 renal cell patients. These radiologic findings were confirmed with surgical specimens. Three-dimensional CT and 3D-CTA are non-invasive, effective imaging techniques for the preoperative evaluation of renal masses.

  12. Neonatal cerebral infarction; Symptoms, CT findings and prognosis

    Energy Technology Data Exchange (ETDEWEB)

    Fujimoto, Shinji; Togari, Hajime; Sobajima, Hisanori; Suzuki, Shigesumi; Wada, Yoshiro (Nagoya City Univ. (Japan). Faculty of Medicine); Yokochi, Kenji; Nishimura, Yutaka; Inukai, Kazuhisa; Futamura, Masahide

    1992-01-01

    In a retrospective multi-center study, we investigated eighteen infants with unilateral cerebral infarctions confirmed by computed tomography (CT) scans. The initial symptoms were observed in all the patients between 0 and 3 days of age. Convulsions or apneic attacks were the initial symptoms in all but one. Only 4 patients had complicated obstetric histories and none showed polycythemia or electrolyte abnormalities. All of the initial CT scans revealed unilaterally localized hypodense areas. In 10, the initial CT scans were performed within 24 hours after the clinical onset. In 16, the lesions were within the territory of the middle cerebral artery, 9 of which also involved the cortico-spinal tract (CST). In the remaining 2 patients, the lesions were located whithin the territory of the posterior cerebral artery. None of the 9 patients without CST involvement developed hemiplegia, whereas 5 (56%) of the 9 with CST involvement had hemiplegia, which is a fairly low incidence compared with that in adult cases. This difference was thought to be related to neonatal brain plasticity. (author).

  13. [Role of PET/CT in primitive non-small cell bronchopulmonary cancer].

    Science.gov (United States)

    Soumia, Fdil; Leila, Achachi; Mohamed, Raoufi; Laila, Herrak; Mustapha, Elftouh

    2017-01-01

    Bronchopulmonary cancer is a real public health problem. Morphological imaging plays a central role in its diagnosis, staging as well as post-therapeutic assessment but it has some limitations. Metabolic imaging is a more recent technique which allows to significantly improve the overall imagery performance. We conducted a retrospective, descriptive and analytical study at the Ibn Sina Hospital and at the Military Hospital of instruction Mohammed V in Rabat over a period of 18 months, between September 2014 and February 2016, in order to evaluate the role of Fluorodeoxyglucose-PET/CT in the staging and restaging of non-small cell bronchopulmonary cancer. Initial staging showed a vast majority of locally advanced and metastatic stages: stage IV (40%), Stage IIIB (36%), Stage IIIA (16%), Stage II (8%). PET-CT allowed to detect new sites which were not initially seen on CT scan in 24 cases: 15 new ganglion sites, 8 new adrenal sites and 6 sites of bone lesions. PET/CT allowed to modify initial tumor stage in 60% of cases: upstaging in 23 patients (46%) and downstaging in 7 patients(14%). The initial stage remained unchanged in 40% of patients. Our study confirms the data from the literature concerning the superiority of PET-CT in comparison with CT scan, but only in the optimization of the non-small cell bronchopulmonary cancer management, in particular in locoregional and distant staging.

  14. The experiences of employees participating in organisational corporate social responsibility initiatives

    Directory of Open Access Journals (Sweden)

    Gretha Cook

    2018-04-01

    Full Text Available Orientation: This article is about the experiences of employees who actively participate in organisational corporate social responsibility (CSR initiatives.   Research purpose: The general aim of this study was to explore the experiences of employees who participate in CSR initiatives within an organisation where a well-developed framework exists.   Motivation for the study: Whilst an emergent number of studies have considered the various dimensions of CSR initiatives, the focus appears to be on stakeholders such as the recipients of CSR, organisations, consumers and shareholders but not the perspective of the employees who actively participate in CSR initiatives.   Research design, approach and method: A qualitative research approach was employed with the intent of exploring the experiences of employees participating in organisational CSR initiatives. Data were collected and analysed from a purposive sample of 12 employees, by means of interactive qualitative analysis.   Main findings: The study revealed that the primary driver that motivates employees to participate in CSR is love. Love sparks a sense of compassion. Compassion, coupled with an enabling environment, stimulates generosity. By being generous, a feeling of hope and inspiration is induced in both the givers and receivers of generosity. A secondary outcome of generosity and hope and inspiration is bringing about change to others, and whilst going through this journey and making a difference in the lives of others, participants experience a progressive change within themselves. This change evokes a feeling of fulfilment, and ultimately a feeling of complete joy.   Contributions or value-add: This research complements existing CSR literature by focussing and reporting on the experiences of the employee as an important stakeholder.

  15. CT diagnosis of unsuspected pneumothorax after blunt abdominal trauma

    Energy Technology Data Exchange (ETDEWEB)

    Wall, S.D. (Univ. of California, San Francisco); Federle, M.P.; Jeffrey, R.B.; Brett, C.M.

    1983-11-01

    Review of abdominal CT scans for evaluation of blunt abdominal trauma yielded 35 cases of pneumothorax, 10 of which had not been diagnosed before CT by clinical examination of plain radiographs. Of the 10 cases initially diagnosed on CT, seven required tube thoracostomy for treatment of the pneumothorax. CT detection of pneumothorax is especially important if mechanical assisted ventilation or general anesthesia is used. Demonstration of pneumothorax requires viewing CT scans of the upper abdomen (lower thorax) at lung windows in addition to the usual soft-tissue windows.

  16. CT diagnosis of unsuspected pneumothorax after blunt abdominal trauma

    International Nuclear Information System (INIS)

    Wall, S.D.; Federle, M.P.; Jeffrey, R.B.; Brett, C.M.

    1983-01-01

    Review of abdominal CT scans for evaluation of blunt abdominal trauma yielded 35 cases of pneumothorax, 10 of which had not been diagnosed before CT by clinical examination of plain radiographs. Of the 10 cases initially diagnosed on CT, seven required tube thoracostomy for treatment of the pneumothorax. CT detection of pneumothorax is especially important if mechanical assisted ventilation or general anesthesia is used. Demonstration of pneumothorax requires viewing CT scans of the upper abdomen (lower thorax) at lung windows in addition to the usual soft-tissue windows

  17. Laparoscopic hand-assisted pancreaticoduodenectomy: initial UK experience.

    Science.gov (United States)

    Ammori, B J

    2004-04-01

    By and large, the limited world experience with laparoscopic pancreaticoduodenectomy (PD) has been unfavorable, but the laparoscopic hand-assisted approach to PD has recently shown promising results. We report the first successful UK experience with laparoscopic hand-assisted PD (LHAPD). A 62-year-old man who presented with painless obstructive jaundice was found at endoscopy, to have an ampullary tumor. Preoperative biopsy specimens confirmed the diagnosis of an adenocarcinoma, and CT showed no evidence of either vascular involvement or metastatic disease. A staging laparoscopy showed no intraabdominal metastases, and an LHAPD was performed using a Gelport. The intraoperative course was uneventful. Two units of blood were transfused intraoperatively, but no postoperative blood transfusion was required. The operative time was 11 h (plus a 30-min break). The patients postoperative recovery was uneventful except for superficial pressure sores over the buttocks and elbows. The patient resumed oral fluid and dietary intake on the 1st and 3rd postoperative days, respectively, and was discharged from hospital on the 9th postoperative day. Histology demonstrated an ampullary adenocarcinoma with clear resection margins and involvement of two of the 13 lymph nodes examined. At 2-month follow-up, the patient remains well and is receiving adjuvant chemotherapy. LHAPD achieves good oncological clearance and can be performed safely in selected patients. The early promising results with this approach will undoubtedly encourage wider adoption of this procedure and are likely to widen the selection criteria.

  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. CT findings in isolated ischemic proctosigmoiditis

    International Nuclear Information System (INIS)

    Wiesner, Walter; Mortele, Koenraad J.; Ji, Hoon; Khurana, Bharti; Ros, Pablo R.; Glickman, Jonathan N.

    2002-01-01

    The purpose of our study was to describe the CT features of ischemic proctosigmoiditis in correlation with clinical, laboratory, endoscopic, and histopathologic findings. Our study included seven patients with isolated ischemic proctosigmoiditis. Patients were identified by a retrospective review of all histopathologic records of colonoscopic biopsies performed during a time period of 4 years. All patients presented with left lower abdominal quadrant pain, bloody stools, and leukocytosis, and four patients had fever at the time of presentation. Four of seven patients suffered from diarrhea, one of seven was constipated and two of seven had normal stool consistency. The CT examinations were reviewed by two authors by consensus and compared with clinical and histopathologic results as well as with the initial CT diagnosis. The CT showed a wall thickening confined to the rectum and sigmoid colon in seven of seven patients, stranding of the pararectal fat in four of seven, and stranding of the perisigmoidal fat in one of seven patients. There were no enlarged lymph nodes, but five of seven patients showed coexistent diverticulosis and in three of these patients CT findings were initially misinterpreted as sigmoid diverticulitis. Endoscopies and histopathologic analyses of endoscopic biopsies confirmed non-transmural ischemic proctosigmoiditis in all patients. Isolated ischemic proctosigmoiditis often presents with unspecific CT features and potentially misleading clinical and laboratory findings. In an elderly patient or a patient with known cardiovascular risk factors the diagnosis of ischemic proctosigmoiditis should be considered when wall thickening confined to the rectum and sigmoid colon is seen that is associated with perirectal fat stranding. (orig.)

  20. Rare case of Primary Pulmonary Extranodal Non-Hodgkin’s Lymphoma in a Patient with Sjogrens Syndrome: Role of FDG-PET/CT in the Initial Staging and Evaluating Response to Treatment

    Directory of Open Access Journals (Sweden)

    Gonca G. Bural

    2012-12-01

    Full Text Available A 64-year old woman with a long standing Sjogren’s syndrome was undergoing evaluation for renal transplant surgery when two pulmonary opacities were detected on chest CT. Subsequent biopsy revealed extranodal marginal B-cell non-Hodgkin’s lymphoma (NHL. An FDG-PET/CT scan was then performed which demonstrated isolated FDG avid pulmonary involvement. After therapy, FDG-PET/CT scans showed good response to treatment with near complete resolution of FDG avidity. This rare case illustrates the rare pulmonary manifestation of extranodal lymphoma in a patient with Sjogren’s syndrome and emphasizes the value of FDG PET/CT in the initial staging and evaluation of response to treatment, which has not previously been published. (MIRT 2012;21:117-120

  1. An experience on the opacificated CT picture with lumbar selective radiculography

    International Nuclear Information System (INIS)

    Yoshida, Tsunemaru; Tanaka, Hideaki; Moriyama, Takeo; Sugiyama, Teruo.

    1982-01-01

    CT was undergone in the cases in which vertebral canal stenosis was suspected. In CT findings, the semicircle of the epidural cavity and the anterolateral surface were visualized as opacificated images, but the vertebral canal sometimes was not visualized, depending on the degree of stenosis. Reconstruction of an image of the ossific vertebral canal seemed to be possible by utilizing the data of the sagittal diameter, form, and CBR of the vertebral canal. Findings of opacificated CT pictures in comparison with other data of roentgenography are useful in searching the causes of vertebral stenosis. (Chiba, N.)

  2. CT of laryngeal trauma

    International Nuclear Information System (INIS)

    Jeffrey, R.B.

    1986-01-01

    Computed tomography has made a significant contribution to the radiologic assessment of the injured larynx. CT is an accurate, noninvasive modality that can rapidly diagnose both soft tissue and cartilaginous injuries. CT of the larynx involves a minimal degree of patient manipulation and discomfort and can be performed in conjunction with CT evaluation of intracranial or facial injuries. Conventional radiologic studies (anteroposterior and lateral soft tissue films of the neck, tomograms, or xerograms) are capable of demonstrating some cartilaginous fractures but are of limited value in defining the extent of soft tissue injury. In the acute trauma setting, laryngography is often technically difficult to perform because of patient discomfort and inability to cooperate. Although the overall experience is somewhat limited, CT appears to overcome many of the limitations of these conventional radiologic methods. The following is a discussion of the role of CT scanning in evaluating injuries to the larynx and cervical soft tissues

  3. SU-E-J-35: Clinical Performance Evaluation of a Phase II Proton CT Scanner

    International Nuclear Information System (INIS)

    Mandapaka, A; Ghebremedhin, A; Farley, D; Giacometti, V; Vence, N; Bashkirov, V; Patyal, B; Schulte, R; Plautz, T; Zatserklyaniy, A; Johnson, R; Sadrozinski, H

    2014-01-01

    Purpose: To develop the methodology to evaluate the clinical performance of a Phase II Proton CT scanner Methods: Range errors on the order of 3%-5% constitute a major uncertainty in current charged particle treatment planning based on Hounsfield Unit (HU)-relative stopping power (RSP) calibration curves. Within our proton CT collaboration, we previously developed and built a Phase I proton CT scanner that provided a sensitive area of 9 cm (axial) × 18 cm (in-plane). This scanner served to get initial experience with this new treatment planning tool and to incorporate lessons learned into the next generation design. A Phase II scanner was recently completed and is now undergoing initial performance testing. It will increase the proton acquisition rate and provide a larger detection area of 9 cm x 36 cm. We are now designing a comprehensive evaluation program to test the image quality, imaging dose, and range uncertainty associated with this scanner. The testing will be performed along the lines of AAPM TG 66. Results: In our discussion of the evaluation protocol we identified the following priorities. The image quality of proton CT images, in particular spatial resolution and low-density contrast discrimination, will be evaluated with the Catphan600 phantom. Initial testing showed that the Catphan uniformity phantom did not provide sufficient uniformity; it was thus replaced by a cylindrical water phantom. The imaging dose will be tested with a Catphan dose module, and compared to a typical cone beam CT dose for comparable image quality. Lastly, we developed a dedicated dosimetry range phantom based on the CIRS pediatric head phantom HN715. Conclusion: A formal evaluation of proton CT as a new tool for proton treatment planning is an important task. The availability of the new Phase II proton CT scanner will allow us to perform this task. This research is supported by the National Institute of Biomedical Imaging and Bioengineering of the NIH under award number R01

  4. Pulmonary langerhans cell histiocytosis in adults: high-resolution CT - pathology comparisons and evolutional changes at CT

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyo Jin; Lee, Ho Yun; Kim, Tae Sung [Sungkyunkwan University School of Medicine, Department of Radiology and Center for Imaging Science, Samsung Medical Center, Seoul (Korea, Republic of); Lee, Kyung Soo [Sungkyunkwan University School of Medicine, Department of Radiology and Center for Imaging Science, Samsung Medical Center, Seoul (Korea, Republic of); Samsung Medical Center, Department of Radiology, Seoul (Korea, Republic of); Johkoh, Takeshi [Kinki Central Hospital of Mutual Aid Association of Public School Teachers, Department of Radiology, Hyoko (Japan); Tomiyama, Noriyuki [Osaka University Graduate School of Medicine, Department of Radiology, Osaka (Japan); Han, Joungho [Sungkyunkwan University School of Medicine, Department of Pathology, Samsung Medical Center, Seoul (Korea, Republic of)

    2011-07-15

    To compare high-resolution (HR) CT and histopathological findings and to evaluate serial CT findings in pulmonary Langerhans cell histiocytosis (PLCH). We reviewed CT of lung lesions in 27 adults (M:F = 20:7, mean age, 41 {+-} 12.3 years) with PLCH. After evaluating lung abnormalities including nodules, micronodules, thick-walled, thin-walled, and bizarre-shaped cysts and reticulation, observers compared CT findings obtained at lung biopsy sites with histopathological findings. The final CT was compared with the initial CT to determine disease extent changes. The most frequently observed patterns of lung abnormalities were micronodules (n = 24, 89%), thick-walled (n = 22, 82%), and thin-walled (n = 22, 82%) cysts. Even thin-walled and bizarre cysts harboured active inflammatory Langerhans cell sheets and eosinophils in their walls. In thin-walled cysts, we noted pericystic inflammatory cell infiltrations along the alveolar walls, as well as pericystic emphysema. Thin-walled or bizarre cysts demonstrated a tendency to coalesce with surrounding cysts via their cystic wall destruction. Fourteen (52%) patients showed improvement and nine (33%) showed progressing disease. More than half of patients with pulmonary PLCH show improvement at follow-up CT. Even thin-walled cysts harbour active inflammatory cells on histopathology and exhibit improvement at follow-up CT. (orig.)

  5. Respiratory management of CT-transmission for accuracy fusion in PET/CT. A comparison between normal expiration and free breathing in 600 experiences

    International Nuclear Information System (INIS)

    Osawa, Atsushi; Takiguchi, Tomohiro; Tamura, Shintaro; Ohashi, Takashi; Miwa, Kenta; Akimoto, Kenta; Wagatsuma, Kei

    2010-01-01

    Image misregistration can occur in fusion positron emission tomography (PET)/CT, because of motion artifacts caused by the management of respiration. The standard imaging protocol of the CT component of PET/CT is normal expiration (NormExp) or free breathing (FB). The objective of this study was to compare NormExp and FB for the optimal breathing protocol for PET/CT scans. A total of 600 consecutive patients were examined using lutetium oxyorthosilicate (LSO)-based PET/CT. CT was acquired during NormExp (id est (i.e.), the level reached when the patient exhaled without forcing expiration and then held the breath) in 300 patients and during FB in 300 patients. The profile of liver measured along body axis was assessed. The distance of profile centers between the PET image and the CT image was measured. The misalignment between profile centers (PET) and profile centers (CT) was compared between NormExp and FB using the histogram of patients. An F test was used to test if the variances of two misalignments are equal. Next, the relationship between misalignment and age was evaluated in two managements of respiration. There was no significant difference between NormExp and FB in the histogram. However, significant misalignments (>10 cm) were found with NormExp. Patient age may have influenced the mismatch. FB is recommended for geriatric patients during acquisition of attenuation correction CT data sets. (author)

  6. Lung cancer screening with low-dose helical CT in Korea: experiences at the Samsung Medical Center.

    Science.gov (United States)

    Chong, Semin; Lee, Kyung Soo; Chung, Myung Jin; Kim, Tae Sung; Kim, Hojoong; Kwon, O Jung; Choi, Yoon-Ho; Rhee, Chong H

    2005-06-01

    To determine overall detection rates of lung cancer by low-dose CT (LDCT) screening and to compare histopathologic and imaging differences of detected cancers between high- and low-risk groups, this study included 6,406 asymptomatic Korean adults with >or=45 yr of age who underwent LDCT for lung cancer screening. All were classified into high- (>or=20 pack-year smoking; 3,353) and low-risk (3,053; <20 pack-yr smoking and non-smokers) groups. We compared CT findings of detected cancers and detection rates between high- and low-risk. At initial CT, 35% (2,255 of 6,406) had at least one or more non-calcified nodule. Lung cancer detection rates were 0.36% (23 of 6,406). Twenty-one non-small cell lung cancers appeared as solid (n=14) or ground-glass opacity (GGO) (n=7) nodules. Cancer likelihood was higher in GGO nodules than in solid nodules (p<0.01). Fifteen of 23 cancers occurred in high-risk group and 8 in low-risk group (p=0.215). Therefore, LDCT screening help detect early stage of lung cancer in asymptomatic Korean population with detection rate of 0.36% on a population basis and may be useful for discovering early lung cancer in low-risk group as well as in high-risk group.

  7. Fast, large field-of-view, telecentric optical-CT scanning system for 3D radiochromic dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, A; Oldham, M, E-mail: ast5@duke.ed [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States)

    2010-11-01

    We describe initial experiences with an in-house, fast, large field-of-view optical-CT telecentric scanner (the Duke Large field of view Optical-CT Scanner (DLOS)). The DLOS system is designed to enable telecentric optical-CT imaging of dosimeters up to 24 cm in diameter with a spatial resolution of 1 mm{sup 3}, in approximately 10 minutes. These capabilities render the DLOS system a unique device at present. The system is a scaled up version of early prototypes in our lab. This scaling introduces several challenges, including the accurate measurement of a greatly increased range of light attenuation within the dosimeter, and the need to reduce even minor reflections and scattered light within the imaging chain. We present several corrections and techniques that enable accurate, low noise, 3D dosimetery with the DLOS system.

  8. CT of chest trauma

    International Nuclear Information System (INIS)

    Goodman, P.C.

    1986-01-01

    There appears to be a limited role for computed tomography in the evaluation of chest trauma. The literature contains few papers specifically addressing the use of CT in the setting of chest trauma. Another series of articles relates anecdotal experiences in this regard. This paucity of reports attests to the remarkable amount of information present on conventional chest radiographs as well as the lack of clear indications for CT in the setting of chest trauma. In this chapter traumatic lesions of various areas of the thorax are discussed. The conventional radiographic findings are briefly described and the potential or proven application of CT is addressed

  9. CT manifestations of ileal dysgenesis

    Energy Technology Data Exchange (ETDEWEB)

    Oberhelman, Amy P.; Herman, Thomas E.; McAlister, William H. [St. Louis Children' s Hospital, Mallinckrodt Institute of Radiology, Washington University School of Medicine, Department of Radiology, St. Louis, MO (United States); Keating, James P. [St. Louis Children' s Hospital, Mallinckrodt Department of Pediatrics, Washington University School of Medicine, Division of Gastroenterology, St. Louis, MO (United States); Rollins, Michael D.; Dillon, Patrick A. [St. Louis Children' s Hospital, Department of Surgery, Washington University School of Medicine, St. Louis, MO (United States)

    2007-02-15

    Ileal dysgenesis is an uncommon condition of unknown etiology occurring in the distal ileum in the region of the vitelline duct. The CT appearance of this lesion, although not previously described to our knowledge, is characteristic. We report a patient with ileal dysgenesis who had an abdominal CT scan to evaluate chronic iron deficiency anemia and protein-losing enteropathy. Recognition of this lesion by pediatric radiologists is important; so that surgical treatment, which is simple and effective, can be initiated quickly. (orig.)

  10. CT manifestations of ileal dysgenesis

    International Nuclear Information System (INIS)

    Oberhelman, Amy P.; Herman, Thomas E.; McAlister, William H.; Keating, James P.; Rollins, Michael D.; Dillon, Patrick A.

    2007-01-01

    Ileal dysgenesis is an uncommon condition of unknown etiology occurring in the distal ileum in the region of the vitelline duct. The CT appearance of this lesion, although not previously described to our knowledge, is characteristic. We report a patient with ileal dysgenesis who had an abdominal CT scan to evaluate chronic iron deficiency anemia and protein-losing enteropathy. Recognition of this lesion by pediatric radiologists is important; so that surgical treatment, which is simple and effective, can be initiated quickly. (orig.)

  11. Automated segmentation of murine lung tumors in x-ray micro-CT images

    Science.gov (United States)

    Swee, Joshua K. Y.; Sheridan, Clare; de Bruin, Elza; Downward, Julian; Lassailly, Francois; Pizarro, Luis

    2014-03-01

    Recent years have seen micro-CT emerge as a means of providing imaging analysis in pre-clinical study, with in-vivo micro-CT having been shown to be particularly applicable to the examination of murine lung tumors. Despite this, existing studies have involved substantial human intervention during the image analysis process, with the use of fully-automated aids found to be almost non-existent. We present a new approach to automate the segmentation of murine lung tumors designed specifically for in-vivo micro-CT-based pre-clinical lung cancer studies that addresses the specific requirements of such study, as well as the limitations human-centric segmentation approaches experience when applied to such micro-CT data. Our approach consists of three distinct stages, and begins by utilizing edge enhancing and vessel enhancing non-linear anisotropic diffusion filters to extract anatomy masks (lung/vessel structure) in a pre-processing stage. Initial candidate detection is then performed through ROI reduction utilizing obtained masks and a two-step automated segmentation approach that aims to extract all disconnected objects within the ROI, and consists of Otsu thresholding, mathematical morphology and marker-driven watershed. False positive reduction is finally performed on initial candidates through random-forest-driven classification using the shape, intensity, and spatial features of candidates. We provide validation of our approach using data from an associated lung cancer study, showing favorable results both in terms of detection (sensitivity=86%, specificity=89%) and structural recovery (Dice Similarity=0.88) when compared against manual specialist annotation.

  12. CT of blunt pancreatic trauma-A pictorial essay

    International Nuclear Information System (INIS)

    Venkatesh, Sudhakar Kundapur; Wan, John Mun Chin

    2008-01-01

    Blunt trauma to pancreas is uncommon and clinical features are often non-specific and unreliable leading to possible delays in diagnosis and therefore increased morbidity. CT has been established as the imaging modality of choice for the diagnosis of abdominal solid-organ injury in the blunt trauma patient. The introduction of multidetector-row CT allows for high resolution scans and multiplanar reformations that improve diagnosis. Detection of pancreatic injuries on CT requires knowledge of the subtle changes produced by pancreatic injury. The CT appearance of pancreatic injury ranges from a normal initial appearance of the pancreas to active pancreatic bleeding. Knowledge of CT signs of pancreatic trauma and a high index of suspicion is required in diagnosing pancreatic injury

  13. Initially curved microplates under electrostatic actuation: theory and experiment

    KAUST Repository

    Saghir, Shahid; Bellaredj, Mohammed Lamine Faycal; Ramini, Abdallah; Younis, Mohammad I.

    2016-01-01

    Microplates are the building blocks of many micro-electro-mechanical systems. It is common for them to experience initial curvature imperfection due to residual stresses caused by the micro fabrication process. Such plates are essentially different

  14. CT of the brain in acute carbon monoxide poisoning

    International Nuclear Information System (INIS)

    Ohno, Masato; Uchino, Akira; Hayashi, Kazuji; Nakata, Hajime.

    1988-01-01

    Cerebral computed tomographic (CT) findings of acute carbon monoxide (Co) poisoning were analized in thirty-six cases treated with hyperbraric oxygen therapy and their relationship with prognosis was evaluated. The cases were classified into there groups, early stage, interval form, and non-interval form groups. In all groups, the initial abnormality was low density areas presumably due to edema, demyelination and/or softening. It was seen in the globus pallidus and/or white matter. Following these initial changes, cerebral hemorrhage, ventricular dilatation, and cerebral atrophy developed in a few cases. The frequency of abnormal CT findings was higher in the interval form group (85 %) or non-interval group (83 %) than the early stage group (41 %). The prognosis was good in most cases with normal CT findings. The possibility of recovery diminished in the patients with abnormal CT findings. The prognosis was particularly poor in cases showing abnormality both in globus pallidus and white matter. We conclude that CT is useful not only for detecting the pathologic change but also for predicting the prognosis of the patient with acute Co poisoning. (author)

  15. Performance of FDG PET/CT in the clinical management of breast cancer.

    Science.gov (United States)

    Groheux, David; Espié, Marc; Giacchetti, Sylvie; Hindié, Elif

    2013-02-01

    In this analysis, the role of metabolic imaging with fluorine 18 fluorodeoxyglucose (FDG) in breast cancer is reviewed. The analysis was limited to recent works by using state-of-the-art positron emission tomography (PET)/computed tomography (CT) technology. The strengths and limitations of FDG PET/CT are examined in various clinical settings, and the following questions are answered: Is FDG PET/CT useful to differentiate malignant from benign breast lesions? Can FDG PET/CT replace sentinel node biopsy for axillary staging? What is the role of FDG PET/CT in initial staging of inflammatory or locally advanced breast cancer? What is the role of FDG PET/CT in initial staging of clinical stage IIA and IIB and primary operable stage IIIA breast cancer? How does FDG PET/CT compare with conventional techniques in the restaging of cancer in patients who are suspected of having disease recurrence? What is the role of FDG PET/CT in the assessment of early response to neoadjuvant therapy and of response to therapy for metastatic disease? Some recommendations for clinical practice are given.

  16. Analysis of the truth loading conditions of a austenitic CT specimen during a SCC experiment

    International Nuclear Information System (INIS)

    Marie, S.; Guerre, C.; Herms, E.

    2012-01-01

    With the aim to investigate the influence of strain hardening on the stainless steels susceptibility to stress corrosion cracking, tests were conducted in PWR environment on CT specimens, taken from a 316L stainless steel sheet cold rolled to 40% in thickness reduction. The initial cracks obtained by the fatigue pre-cracking have an atypical 'V' shape with smaller propagation in the center of the CT thickness compared to nominal propagation observed at both sides. The initial explanation was to consider a stress intensity factor derived from classical reference solution on the basis of a straight crack front, and considering the local value of the crack depth in the equation. This assumption raised several problems analyses in this paper. This particular shape of the initial defect may be related to several factors, and partly to the 40% cold rolling. It is likely that the hardening is not uniform, with a higher rate at the specimen sides than in the central area. In addition, significant residual stresses due to the gradient of mechanical properties are observed. Due to the high rate of work hardening by rolling of the sheet metal, a gradient of the mechanical properties through the thickness was determined, and the residual stresses profile induced by this process was measured. The variations obtained are consistent with each other: the material is more hardened in the vicinity of specimen surface and residual stresses are compressive in nature in the central part of the specimen and of tensile type on the flanks. All these data were firstly considered in order to assess their role regarding the particular form of the initial crack front obtained after fatigue: the 3D finite element calculations taking into account the true shape of the crack front demonstrate the relationship between the characteristics of the experimental crack front obtained after fatigue pre-cracking and the residual stresses. Moreover, from the residual stresses measured on the plate where

  17. First experience with multidetector-CT for the diagnosis of coronary atherosclerosis

    International Nuclear Information System (INIS)

    Becker, C.R.; Hong, C.; Schoepf, U.J.; Reiser, M.F.; Knez, A.; Leber, A.; Treede, H.; Wildhirt, S.; Ohnesorge, B.; Flohr, T.

    2000-01-01

    Purpose: Multirow-detector-spiral-CT (MSCT) allows for 250 ms effective exposure time. The purpose of this study was to demonstrate the possibilities and limitations of this CT technology for non enhanced and contrast enhanced investigation of the coronary arteries. Methods: Investigation of the coronary arteries without contrast medium for quantification of coronary calcifications was performed in an obese patient (140 kg) with MSCT and electron beam CT (EBCT). In 56 patients contrast enhanced CT angiography of the coronary arteries was performed to determine image quality depending on the heart rate. Results: In the obese patient superior image quality could be achieved with MSCT allowing for reliable quantification of coronary calcifications. With MSCT angiography of the coronary arteries good image quality was achieved in patients with a heart rate of 59±8 beats per minute. Conclusion: Even if there are limitations in patients with higher heart rates with an effective exposure time of 250 ms MSCT has clear advantage of image quality in the assessment of non enhanced and contrast enhanced coronary arteries. (orig.) [de

  18. CT interpretation of craniofacial anomalies: a comparative analysis by undergraduate dental students

    International Nuclear Information System (INIS)

    Gaia, Bruno Felipe; Perella, Andreia; Cara, Ana Claudia Ballet de; Antunes, Jose Leopoldo Ferreira; Cavalcanti, Marcelo Gusmao Paraiso

    2005-01-01

    The aim of this study was to evaluate the accuracy and reproducibility of computed tomography (CT) image interpretation made in axial slices (2D-CT) and 3D reconstructed images (3D-CT) of patients with craniofacial anomalies. The analyses were made by undergraduate dental students, and compared with the diagnoses considered upon surgical intervention. Computed tomography of 43 patients were analyzed independently by three calibrated examiners (undergraduate students) with, respectively, one, two, and three semesters of experience in craniofacial CT training and interpretation. The analysis of 2D-CT and 3D-CT images were performed at distinct times using an independent workstation associated with a specific computer graphics software for volumetric images. The analysis of inter-examiner agreement and of the agreement between observers and the gold standard was performed using the Kappa test. The accuracy evaluation presented a progressively higher value for examiners with progressively broader experience in 2D-CT and 3D-CT image interpretation. 3D-CT analyses allowed a higher inter-examiner agreement (1 - 0.896) than 2D-CT analyses (1 - 0.614). 3D-CT was considered more precise and accurate than 2D-CT for all students' evaluations. The reproducibility and accuracy varied according to the experience in CT interpretation, and the most experienced student achieved results closer to the gold standard. (author)

  19. Role of 18F-FDG PET/CT in primary brain lymphoma.

    Science.gov (United States)

    de-Bonilla-Damiá, Á; Fernández-López, R; Capote-Huelva, F J; de la Cruz-Vicente, F; Egea-Guerrero, J J; Borrego-Dorado, I

    To study the usefulness of 18 F-FDG PET/CT in the initial evaluation and in the response assessment in primary brain lymphoma. A retrospective analysis was carried out on 18 patients diagnosed with primary brain lymphoma, a histological subtype of diffuse large B-cell lymphoma, on whom an initial 18 F-FDG PET/CT and MRI was performed, with 7 of the cases being analysed after the completion of treatment in order to assess response and clinical follow up. Initial 18 F-FDG PET/CT showed 26 hypermetabolic foci, whereas 46 lesions were detected by MRI. The average SUV maximum of the lesions was 17.56 with T/N 3.55. The concordance of both tests for identifying the same number of lesions was moderate, obtaining a kappa index of 0.395 (P<.001). In the evaluation of treatment, MRI identified 16 lesions compared to 7 pathological accumulations observed by 18 F-FDG PET/CT. The concordance of both tests to assess type of response to treatment was moderate (kappa index 0.41) (P=.04). In both the initial evaluation and the assessment of the response to treatment, PET/CT led to a change strategy in 22% of patients who had lesions outside the cerebral parenchyma. MRI appears to be the method of choice for detecting brain disease in patients with primary brain lymphoma, whereas 18 F-FDG PET/CT seems to play a relevant role in the assessment of extra-cerebral disease. Copyright © 2017 Elsevier España, S.L.U. y SEMNIM. All rights reserved.

  20. Metabolic and clinical assessment of efficacy of cryoablation therapy on skeletal masses by {sup 18}F-FDG positron emission tomography/computed tomography (PET/CT) and visual analogue scale (VAS): initial experience

    Energy Technology Data Exchange (ETDEWEB)

    Masala, Salvatore; Bartolucci, Alberto D.; Mammucari, Matteo; Simonetti, Giovanni [University Hospital Tor Vergata, Department of Diagnostic and Molecular Imaging, Interventional Radiology and Radiotherapy, Rome (Italy); Schillaci, Orazio; Calabria, Ferdinando [University Hospital Tor Vergata, Department of Diagnostic and Molecular Imaging, Interventional Radiology and Radiotherapy, Rome (Italy); I.R.C.C.S. Neuromed, Department of Nuclear Medicine and Neuroradiology, Pozzilli (Italy); Policlinico Tor Vegata, Department of Diagnostic and Molecular Imaging, Interventional Radiology and Radiotherapy, Rome (Italy)

    2011-02-15

    Various therapy modalities have been proposed as standard treatments in management of bone metastases. Radiation therapy remains the standard of care for patients with localized bone pain, but up to 30% of them do not experience notable pain relief. Percutaneous cryoablation is a minimally invasive technique that induces necrosis by alternately freezing and thawing a target tissue. This technique is successfully used to treat a variety of malignant and benign diseases in different sites. {sup 18}F-FDG positron emission tomography/computed tomography ({sup 18}F-FDG PET/CT) is a single technique of imaging that provides in a ''single step'' both morphological and metabolic features of neoplastic lesions of the bone. The aim of this study was to evaluate the efficacy of the cryosurgical technique on secondary musculoskeletal masses according to semi-quantitative PET analysis and clinical-test evaluation with the visual analogue scale (VAS). We enrolled 20 patients with painful bone lesions (score pain that exceeded 4 on the VAS) that were non-responsive to treatment; one lesion per patient was treated. All patients underwent a PET-CT evaluation before and 8 weeks after cryotherapy; maximum standardized uptake value (SUV{sub max}) was measured before and after treatment for metabolic assessment of response to therapy. After treatment, 18 patients (90%) showed considerable reduction in SUV{sub max} value (>50%) suggestive of response to treatment; only 2 patients did not show meaningful reduction in metabolic activity. Our preliminary study demonstrates that quantitative analysis provided by PET correlates with response to cryoablation therapy as assessed by CT data and clinical VAS evaluation. (orig.)

  1. Value of CT in the diagnosis of pseudomembranous colitis

    International Nuclear Information System (INIS)

    Fishman, E.K.; Merine, D.S.; Kuhlman, J.E.; Jones, B.

    1989-01-01

    With the increasing use of Ct as a primary imaging modality in the patient with abdominal distress, it is not surprising the CT may be the initial study to suggest the diagnosis of pseudomembranous colitis. The authors reviewed the CT scans in 16 patients with proved pseudomembranous colitis. In 12 of these cases, the diagnosis was not considered prior to CT. The CT findings included wall thickening (average, 18 mm), definite ulcerations (11 cases), ascites (two cases), and pseudoperforation (three cases). The pseudoperforation is caused by the trapping of contrast material within the large ulcerated mucosal folds and can simulate contrast extravasation. The various CT appearances of pseudomembranous colitis are addressed, as well as the potential difficulty in distinguishing it from other types of colitis

  2. Diagnostic potential of PET/CT using a {sup 68}Ga-labelled prostate-specific membrane antigen ligand in whole-body staging of renal cell carcinoma: initial experience

    Energy Technology Data Exchange (ETDEWEB)

    Sawicki, Lino M.; Buchbender, Christian; Boos, Johannes; Antoch, Gerald [University Dusseldorf, Medical Faculty, Department of Diagnostic and Interventional Radiology, Dusseldorf (Germany); Giessing, Markus [University Dusseldorf, Medical Faculty, Department of Urology, Dusseldorf (Germany); Ermert, Johannes [Juelich Research Center, Institute of Neuroscience and Medicine, INM-5: Nuclear Chemistry, Juelich (Germany); Antke, Christina; Hautzel, Hubertus [University Dusseldorf, Medical Faculty, Department of Nuclear Medicine, Dusseldorf (Germany)

    2017-01-15

    To evaluate the diagnostic potential of whole-body PET/CT using a {sup 68}Ga-labelled PSMA ligand in renal cell carcinoma (RCC). Six patients with histopathologically proven RCC underwent {sup 68}Ga-PSMA PET/CT. Each PET/CT scan was evaluated in relation to lesion count, location and dignity. SUVmax was measured in primary tumours and PET-positive metastases. Tumour-to-background SUVmax ratios (TBR{sub SUVmax}) were calculated for primary RCCs in relation to the surrounding normal renal parenchyma. Metastasis-to-background SUVmax ratios (MBR{sub SUVmax}) were calculated for PET-positive metastases in relation to gluteal muscle. Five primary RCCs and 16 metastases were evaluated. The mean SUVmax of the primary RCCs was 9.9 ± 9.2 (range 1.7 - 27.2). Due to high uptake in the surrounding renal parenchyma, the mean TBR{sub SUVmax} of the primary RCCs was only 0.2 ± 0.3 (range 0.02 - 0.7). Eight metastases showed focal {sup 68}Ga-PSMA uptake (SUVmax 9.9 ± 8.3, range 3.4 - 25.6). The mean MBR{sub SUVmax} of these PET-positive metastases was 11.7 ± 0.2 (range 4.4 - 28.1). All PET-negative metastases were subcentimetre lung metastases. {sup 68}Ga-PSMA PET/CT appears to be a promising method for detecting RCC metastases. However, no additional diagnostic value in assessing the primary tumour was found. (orig.)

  3. Imaging features of primary Sarcomas of the great vessels in CT, MRI and PET/CT: a single-center experience

    International Nuclear Information System (INIS)

    Falck, Christian von; Meyer, Bernhard; Fegbeutel, Christine; Länger, Florian; Bengel, Frank; Wacker, Frank; Rodt, Thomas

    2013-01-01

    To investigate the imaging features of primary sarcomas of the great vessels in CT, MRI and 18 F-FDG PET/CT. Thirteen patients with a primary sarcoma of the great vessels were retrospectively evaluated. All available images studies including F-18 FDG PET(/CT) (n = 4), MDCT (n = 12) and MRI (n = 6) were evaluated and indicative image features of this rare tumor entity were identified. The median interval between the first imaging study and the final diagnosis was 11 weeks (0–12 weeks). The most frequently observed imaging findings suggestive of malignant disease in patients with sarcomas of the pulmonary arteries were a large filling defect with vascular distension, unilaterality and a lack of improvement despite effective anticoagulation. In patients with aortic sarcomas we most frequently observed a pedunculated appearance and an atypical location of the filling defect. The F-18 FDG PET(/CT) examinations demonstrated an unequivocal hypermetabolism of the lesion in all cases (4/4). MRI proved lesion vascularization in 5/6 cases. Intravascular unilateral or atypically located filling defects of the great vessels with vascular distension, a pedunculated shape and lack of improvement despite effective anticoagulation are suspicious for primary sarcoma on MDCT or MRI. MR perfusion techniques can add information on the nature of the lesion but the findings may be subtle and equivocal. F-18 FDG PET/CT may have a potential role in these patients and may be considered as part of the imaging workup

  4. Dose reduction with adaptive statistical iterative reconstruction for paediatric CT: phantom study and clinical experience on chest and abdomen CT.

    Science.gov (United States)

    Gay, F; Pavia, Y; Pierrat, N; Lasalle, S; Neuenschwander, S; Brisse, H J

    2014-01-01

    To assess the benefit and limits of iterative reconstruction of paediatric chest and abdominal computed tomography (CT). The study compared adaptive statistical iterative reconstruction (ASIR) with filtered back projection (FBP) on 64-channel MDCT. A phantom study was first performed using variable tube potential, tube current and ASIR settings. The assessed image quality indices were the signal-to-noise ratio (SNR), the noise power spectrum, low contrast detectability (LCD) and spatial resolution. A clinical retrospective study of 26 children (M:F = 14/12, mean age: 4 years, range: 1-9 years) was secondarily performed allowing comparison of 18 chest and 14 abdominal CT pairs, one with a routine CT dose and FBP reconstruction, and the other with 30 % lower dose and 40 % ASIR reconstruction. Two radiologists independently compared the images for overall image quality, noise, sharpness and artefacts, and measured image noise. The phantom study demonstrated a significant increase in SNR without impairment of the LCD or spatial resolution, except for tube current values below 30-50 mA. On clinical images, no significant difference was observed between FBP and reduced dose ASIR images. Iterative reconstruction allows at least 30 % dose reduction in paediatric chest and abdominal CT, without impairment of image quality. • Iterative reconstruction helps lower radiation exposure levels in children undergoing CT. • Adaptive statistical iterative reconstruction (ASIR) significantly increases SNR without impairing spatial resolution. • For abdomen and chest CT, ASIR allows at least a 30 % dose reduction.

  5. PET and PET/CT in tumour of undetermined origin; PET y PET/CT en tumor de origen indeterminado

    Energy Technology Data Exchange (ETDEWEB)

    Garcia O, J R [Nuclear Medicine and Molecular Imaging, PET/CT, Centro Medico ABC, Mexico D.F. (Mexico)

    2007-07-01

    In this presentation the following conclusions were obtained regarding the use of PET and PET/CT in patient with cancer of unknown primary: 1. Detection of the primary one in 1/3 at 1/2 of patient. 2. It detects metastases in other places in 50%. 3. It changes the initial therapy planned in 1/3 at 1/2 of patient. 4. Useful in initial phases of protocol study to limit the other procedures. After standard evaluation. Before advanced protocol. 5. PET/CT study increases the % of primary detection, although in a non significant way vs. PET. 6. They are required more studies to value their utility to a more objective manner. (Author)

  6. Translation initiation mediated by nuclear cap-binding protein complex.

    Science.gov (United States)

    Ryu, Incheol; Kim, Yoon Ki

    2017-04-01

    In mammals, cap-dependent translation of mRNAs is initiated by two distinct mechanisms: cap-binding complex (CBC; a heterodimer of CBP80 and 20)-dependent translation (CT) and eIF4E-dependent translation (ET). Both translation initiation mechanisms share common features in driving cap- dependent translation; nevertheless, they can be distinguished from each other based on their molecular features and biological roles. CT is largely associated with mRNA surveillance such as nonsense-mediated mRNA decay (NMD), whereas ET is predominantly involved in the bulk of protein synthesis. However, several recent studies have demonstrated that CT and ET have similar roles in protein synthesis and mRNA surveillance. In a subset of mRNAs, CT preferentially drives the cap-dependent translation, as ET does, and ET is responsible for mRNA surveillance, as CT does. In this review, we summarize and compare the molecular features of CT and ET with a focus on the emerging roles of CT in translation. [BMB Reports 2017; 50(4): 186-193].

  7. First experience of combined cardiac PET/64-detector CT angiography with invasive angiographic validation

    International Nuclear Information System (INIS)

    Groves, Ashley M.; Kayani, Irfan; Endozo, Raymondo; Menezes, Leon J.; Prvulovich, Elizabeth; Ell, Peter J.; Speechly-Dick, Marie-Elsya; McEwan, Jean; Pugliese, Francesca; Habib, Said B.

    2009-01-01

    Despite modern CT systems and expert evaluators, the diagnostic performance of coronary CT angiography is limited by overestimation of vessel stenosis which reduces the positive predictive value (PPV) of the test. The aim of this study was to evaluate the performance of combined cardiac PET/64-detector CT angiography. Included in this retrospective study were 33 consecutive patients (5 women, 28 men; mean age 61.6 years, range 47-87 years, mean BMI 27.3±5.2 kg/m 2 ) with clinically suspected flow-limiting coronary artery disease who underwent combined cardiac PET/64-detector CT angiography and invasive angiography. Combined PET/CT images were reported by an experienced dual-accredited radiologist/nuclear physician. An experienced cardiac CT radiologist re-read the CT images without PET. Stenotic disease was defined as >50% vessel narrowing. Invasive coronary angiography was used as a reference standard. Local ethics committee approval and patient consent were obtained. CT angiography (without PET data) was concordant with invasive angiography in 31/33 patients and at a patient level, the sensitivity in detecting significant coronary artery lesions was 100%, the specificity was 82%, the PPV was 92% and the negative predictive value (NPV) was 100%. Using combined PET/CT angiography the findings were concordant with invasive angiography in 32/33 patients and at a patient level, the sensitivity was 96%, the specificity was 100%, the PPV was 100% and the NPV was 91%. The use of integrated cardiac PET/64-detector CT angiography is feasible and appears to improve some aspects of the diagnostic performance of 64-detector coronary artery angiography in detecting coronary artery disease. (orig.)

  8. X-ray production experiments on the RACE Compact Torus Accelerator

    International Nuclear Information System (INIS)

    Hammer, J.H.; Eddleman, J.L.; Hartman, C.W.; McLean, H.S.; Molvik, A.W.; Gee, M.

    1989-12-01

    The Purpose of the Compact Torus Accelerator (CTA) program at LLNL is to prove the principle of a unique accelerator concept based on magnetically confined compact torus (CT) plasma rings and to study applications. Successful achievement of these goals could lead to a high power-density driver for many applications including an intense x-ray source for nuclear weapons effects simulation and an inertial fusion driver. Fusion applications and a description of the CTA concept are included in a companion paper at this conference. This paper will describe the initial experiments on soft x-ray production conducted on the plasma Ring ACcelerator Experiment (RACE) and compare the results to modeling studies. The experiments on CT stagnation and soft x-ray production were conducted with unfocused rings as a first of CT dynamics and the physics of x-ray production. The x-ray fluences observed are consistent with expectations based on calculations employing a radiation-hydrodynamics code. We conclude with a diffusion of future x-ray production studies that can be conducted on RACE and a possible multi-megajoule upgrade

  9. Accuracy of CT-guided percutaneous core needle biopsy for assessment of pediatric musculoskeletal lesions

    International Nuclear Information System (INIS)

    Hryhorczuk, Anastasia L.; Strouse, Peter J.; Biermann, J.S.

    2011-01-01

    CT-guided percutaneous core needle biopsy has been shown in adults to be an effective diagnostic tool for a large number of musculoskeletal malignancies. To characterize our experience with CT-guided percutaneous core needle biopsy of pediatric bone lesions and determine its utility in diagnosing pediatric osseous lesions, in a population where such lesions are commonly benign. From 2000 to 2009, 61 children underwent 63 CT-guided percutaneous biopsies. Radiological, pathological and clinical records were reviewed. Fourteen biopsies (22%) were performed on malignant lesions, while 49 biopsies (78%) were performed on benign lesions. Forty-nine of the 63 biopsies (78%) were adequate; these children underwent no further tissue sampling. Fourteen of the 63 biopsies (22%) were inadequate or non-conclusive. Of these patients, 12 underwent open biopsy. Retrospective analysis of percutaneous biopsies in these patients demonstrates that 9/12 provided clinically relevant information, and 4/12 patients received final diagnoses that confirmed initial core biopsy findings. No malignancies were diagnosed as benign on percutaneous biopsy. Overall, percutaneous core needle biopsy provided accurate diagnostic information in 84% (53/63) of biopsies. Our results demonstrate that CT-guided percutaneous biopsy is safe and beneficial in children. This study supports the use of CT-guided percutaneous core needle biopsy for primary diagnosis of pediatric bone lesions. (orig.)

  10. Overnight Emergency CT Imaging: A 10-Year Experience at an Irish Tertiary Referral Hospital.

    LENUS (Irish Health Repository)

    2018-01-01

    In recent years there has been increased utilisation of computed tomography (CT) imaging in developed countries, however there is a paucity of data regarding the utilisation of CT in the emergency overnight setting. We retrospectively analysed trends in ‘overnight’ (midnight to 8am) CT utilisation over a ten-year period at a single Irish tertiary referral hospital. Over the study period, we observed a significant increase in the proportion of CT imaging that was carried out overnight. There was no significant variation in the yield of pathological findings over the study period, which remained low (64% of CT studies were normal or had non-critical findings). The multiple factors which have contributed to the increased utilization of overnight emergency CT in recent years, the potential for reporting errors overnight and the implications therein for patient safety warrant consideration.

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

    International Nuclear Information System (INIS)

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

    2006-01-01

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

  12. 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

  13. Oncologic PET/CT: current status and controversies

    International Nuclear Information System (INIS)

    Siegel, B.A.; Dehdashti, F.

    2005-01-01

    The introduction of integrated PET/CT has dramatically increased the worldwide rate of growth for PET, predominantly for oncologic imaging with the glucose analog 18 F-fluorodeoxyglucose (FDG). A rapidly expanding body of literature demonstrates that the use FDG-PET/CT and the resultant ability to interpret coregistered and fused PET and CT images lead to improved observer confidence and improved diagnostic performance by comparison with PET alone, CT alone, and visually correlated PET and CT. The value of PET/CT is likely to be even greater with new PET radiopharmaceuticals under development, many of which produce PET images with even fewer anatomical landmarks than FDG images. PET/CT is also likely to lead to the resurrection of 18 F-fluoride as a principal agent for radionuclide bone imaging. There are a number of controversies related to PET/CT, including minimum training and experience requirements for interpreting physicians and defining new models for technical and professional reimbursement. (orig.)

  14. Perforated appendicitis: accuracy of CT diagnosis and correlation of CT findings with the length of hospital

    International Nuclear Information System (INIS)

    Siddiqui, H.A.; Afzal, S.

    2007-01-01

    To determine the sensitivity and specificity of CT findings in the differentiation of perforated from nonperforated appendicitis and correlate CT diagnosis with the length of hospital stay. The study included 70 patients who presented with right lower quadrant abdominal pain and underwent preoperative CT scan followed by appendectomy. Patients were divided into two groups of having perforated and nonperforated appendicitis on the basis of CT scan findings. The surgical and pathological reports combined were considered the reference standard for the diagnosis of perforated appendicitis. Various CT scan findings and average duration of hospital stay in days was compared by t-test. Twenty-six (37%) of 70 patients had perforated appendicitis. It was correctly identified on pre-operative CT scan in 18 patients. There were 18 true positive diagnoses, 43 true negative diagnoses, 1 false positive diagnosis and 8 false negative diagnoses which yielded a sensitivity of 69%, specificity of 97%, positive predictive value of 94% and negative predictive value of 84%. Mean length of hospital stay in perforated group was 6.3 days and 2.9 days in nonperforated group. Severe periappendiceal inflammation, periappendiceal and or abdominopelvic fluid and abscess were significantly associated with perforated appendicitis and with a significant longer hospital stay (p <.001). CT scan is 69% sensitive and 97% specific for the diagnosis of perforated appendicitis and constellation of CT findings can be used to select patients with perforated appendicitis for initial non-operative management. Presence of CT signs of significant appendiceal inflammation is independent predictor of longer hospital stay. (author)

  15. Sinonasal Wegener's granulomatosis: CT characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Benoudiba, F.; Marsot-Dupuch, K.; Rabia, Hadj M.; Lasjaunias, P. [Neuroradiology Department, Bicetre Hospital, 78 rue du General Leclerc, 94275 Le Kremlin Bicetre (France); Cabanne, J. [Department of Internal Medecine, Saint-Antoine Hospital, 184 rue du Faubourg Saint-Antoine, 75012 Paris (France); Bobin, S. [Head and Neck Department, Bicetre Hospital, 78, rue du General Leclerc, 94275 Le Kremlin Bicetre (France)

    2003-02-01

    Wegener's granulomatosis (WG) is a severe and potentially lethal granulomatosis. Even though no specific radiological criteria exist, CT may suggest the correct diagnosis at an early stage. Recent improvement in the prognosis is related to earlier diagnosis, allowing the initiation of efficient and specific treatment before any severe complications occur. We reviewed a series of WG cases in order to establish the CT diagnostic criteria. (orig.)

  16. Quality control in PET/CT systems. Experiences and requirements

    International Nuclear Information System (INIS)

    Geworski, Lilli; Fitz, Eduard; Knoop, Bernd; Karwarth, Cornelia; Plotkin, Michail

    2010-01-01

    Today, in most cases PET examinations are performed using PET/CT hybrid systems. While acceptance testing and routine control of the basic modalities PET and CT, respectively, are described by appropriate regulations, corresponding instructions with regard to the interface connecting both are still missing. This interface includes the adjustment of gantries and patient bed to each other as well as the energy scaling of attenuation coefficients from CT energy to 511 keV. Measurements checking the mechanical adjustment (determination of off-set parameters) are performed following manufacturer's recommendation, with a typical frequency twice a year. On a Biograph 16 (Siemens, Inc.), these measurements were systematically extended to a weekly frequency over an observation period of 10 months, supplemented by measurements with additional load to the patient bed (up to 135 kg), and different vertical bed positions. The results show, that for the construction tested additional off-set measurements for routine control extending well beyond manufacturer's recommendation are not necessary. The energy scaling of attenuation coefficients is depending on methodological aspects and software implementation, and therefore is not part of routine control. On the contrary, the development of appropriate methods for acceptance testing to assess and to determine the mechanical adjustment in all its degrees of freedom as well as the accuracy of attenuation corrected emission data is urgently needed. (orig.)

  17. Lead arthropathy: radiographic, CT and MRI findings

    International Nuclear Information System (INIS)

    Fernandes, Joao Luiz; Lopes Rocha, Arthemizio Antonio; Veloso Ayrimoraes Soares, Mayra; Lopes Viana, Sergio

    2007-01-01

    Lead arthropathy is a well-known complication of gunshot injuries with retained intra-articular bullets. Although several previous reports have discussed the radiological findings of this entity, computed tomography (CT) and magnetic resonance imaging (MRI) findings have never been described before in this setting. In this paper the authors review the imaging findings of 11 patients with lead arthropathy (1 of whom had clinical signs of lead poisoning as well), all of them studied by means of radiographs. In addition, non-enhanced CT scans were obtained in 3 patients and gadolinium-enhanced MRI in 1. Classic findings of intra-articular speckled lead deposits (occasionally with a ''lead arthrogram'' appearance), joint space narrowing and preserved bone density were found at radiographs in the great majority of cases. Furthermore, extension of intra-articular lead to adjacent tendon sheaths was observed in almost half of the patients, an observation rarely reported in the literature. CT scans and MRI, in their turn, were superior with regard to soft tissue abnormalities, accurately depicting joint effusion and the thickened synovium with lead particles embedded in it. Post-gadolinium MRI had the advantage of showing the enhancement pattern of the inflamed synovium and associated bone marrow edema pattern. Although it is not possible to establish the role of axial imaging in lead arthropathy from the small number of cases studied, this initial experience shows that both methods hold promise in this setting and may be useful, at least in selected cases. (orig.)

  18. Regional nodal staging with 18F-FDG PET–CT in non-small cell lung cancer: Additional diagnostic value of CT attenuation and dual-time-point imaging

    International Nuclear Information System (INIS)

    Li, Meng; Wu, Ning; Liu, Ying; Zheng, Rong; Liang, Ying; Zhang, Wenjie; Zhao, Ping

    2012-01-01

    Background: [Fluorine-18]-fluorodeoxyglucose positron emission tomography/computed tomography ( 18 F-FDG PET–CT) is widely performed in the regional nodal staging of non-small cell lung cancer (NSCLC). However, the uptake of 18 F-FDG by tubercular granulomatous tissues may lead to false-positive diagnosis. This is of special concern in China, where tubercular granulomatous disease is epidemic. Herein, we evaluated the efficacy of an additional CT attenuation and a dual-time-point scan in determining the status of lymph nodes. Methods: Eighty NSCLC patients underwent curative surgical resection after 18 F-FDG PET–CT and separate breath-hold CT examinations. The initial images were analyzed by two methods. In method 1, nodal status was determined by 18 F-FDG uptake only. In Method 2, nodal status was determined by 18 F-FDG uptake associated with CT attenuation. For dual-time-point imaging, the retention index (RI) of benign and malignant nodal groups with positive uptake in the initial scan was examined. Results: A total of 265 nodal groups were documented. On a per-nodal-group basis, the diagnostic sensitivity, specificity, and accuracy of Method 1 were 66.7%, 89.7%, and 85.3%, respectively, whereas those of Method 2 were 64.7%, 96.7%, and 90.6%, respectively. The improvement in diagnostic specificity and accuracy associated with the addition of CT attenuation in Method 2 as compared to Method 1 was statistically significant (p 0.05). Conclusion: 18 F-FDG PET–CT has high diagnostic value for preoperative lymph-node (N) staging of NSCLC patients. We show that 18 F-FDG uptake combined with CT attenuation improves the diagnostic specificity and accuracy of nodal diagnosis in NSCLC. For the lymph nodes with positive uptake in the initial scan, dual-time-point imaging has limited effect in differentiation.

  19. Using cone-beam CT as a low-dose 3D imaging technique for the extremities: initial experience in 50 subjects

    International Nuclear Information System (INIS)

    Huang, Ambrose J.; Chang, Connie Y.; Palmer, William E.; Thomas, Bijoy J.; MacMahon, Peter J.

    2015-01-01

    To prospectively evaluate a dedicated extremity cone-beam CT (CBCT) scanner in cases with and without orthopedic hardware by (1) comparing its imaging duration and image quality to those of radiography and multidetector CT (MDCT) and (2) comparing its radiation dose to that of MDCT. Written informed consent was obtained for all subjects for this IRB-approved, HIPAA-compliant study. Fifty subjects with (1) fracture of small bones, (2) suspected intraarticular fracture, (3) fracture at the site of complex anatomy, or (4) a surgical site difficult to assess with radiography alone were recruited and scanned on an extremity CBCT scanner prior to FDA approval. Same-day radiographs were performed in all subjects. Some subjects also underwent MDCT within 1 month of CBCT. Imaging duration and image quality were compared between CBCT and radiographs. Imaging duration, effective radiation dose, and image quality were compared between CBCT and MDCT. Fifty-one CBCT scans were performed in 50 subjects. Average imaging duration was shorter for CBCT than radiographs (4.5 min vs. 6.6 min, P = 0.001, n = 51) and MDCT (7.6 min vs. 10.9 min, P = 0.01, n = 7). Average estimated effective radiation dose was less for CBCT than MDCT (0.04 mSv vs. 0.13 mSv, P = 0.02, n = 7). CBCT images yielded more diagnostic information than radiographs in 23/51 cases and more diagnostic information than MDCT in 1/7 cases, although radiographs were superior for detecting hardware complications. CBCT performs high-resolution imaging of the extremities using less imaging time than radiographs and MDCT and lower radiation dose than MDCT. (orig.)

  20. Using cone-beam CT as a low-dose 3D imaging technique for the extremities: initial experience in 50 subjects

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Ambrose J.; Chang, Connie Y.; Palmer, William E. [Massachusetts General Hospital, Department of Radiology, Division of Musculoskeletal Imaging and Intervention, Boston, MA (United States); Thomas, Bijoy J. [Universal College of Medical Sciences, Department of Radiology, Bhairahawa (Nepal); MacMahon, Peter J. [Mater Misericordiae University Hospital, Department of Radiology, Dublin 7 (Ireland)

    2015-06-01

    To prospectively evaluate a dedicated extremity cone-beam CT (CBCT) scanner in cases with and without orthopedic hardware by (1) comparing its imaging duration and image quality to those of radiography and multidetector CT (MDCT) and (2) comparing its radiation dose to that of MDCT. Written informed consent was obtained for all subjects for this IRB-approved, HIPAA-compliant study. Fifty subjects with (1) fracture of small bones, (2) suspected intraarticular fracture, (3) fracture at the site of complex anatomy, or (4) a surgical site difficult to assess with radiography alone were recruited and scanned on an extremity CBCT scanner prior to FDA approval. Same-day radiographs were performed in all subjects. Some subjects also underwent MDCT within 1 month of CBCT. Imaging duration and image quality were compared between CBCT and radiographs. Imaging duration, effective radiation dose, and image quality were compared between CBCT and MDCT. Fifty-one CBCT scans were performed in 50 subjects. Average imaging duration was shorter for CBCT than radiographs (4.5 min vs. 6.6 min, P = 0.001, n = 51) and MDCT (7.6 min vs. 10.9 min, P = 0.01, n = 7). Average estimated effective radiation dose was less for CBCT than MDCT (0.04 mSv vs. 0.13 mSv, P = 0.02, n = 7). CBCT images yielded more diagnostic information than radiographs in 23/51 cases and more diagnostic information than MDCT in 1/7 cases, although radiographs were superior for detecting hardware complications. CBCT performs high-resolution imaging of the extremities using less imaging time than radiographs and MDCT and lower radiation dose than MDCT. (orig.)

  1. Early experience with a picture archiving and communication system for X-ray CT

    International Nuclear Information System (INIS)

    Nakano, Y.; Komori, M.; Minato, K.

    1987-01-01

    A network using fiberoptic ring architecture has been implemented to connect an x-ray CT unit with an image work station and optical disk storage unit. The work station has three noninterlaced cathode-ray tube (CRT) monitors of 1,024 X 1,024 pixels. The optical disk system stores 32 optical disk cartridges (2.6 Gbytes per cartridge). A general-purpose interface bus is used for communication between the CT unit and the network interface unit. Transfer time from CT to interface unit is 40 kbyte/second, 5 seconds per image. On-line data acquisition, long-term archiving, and CT interpretation using CRTs have been tested and the system has been working for 3 months in a clinical environment

  2. Algorithms of CT value correction for reconstructing a radiotherapy simulation image through axial CT images

    International Nuclear Information System (INIS)

    Ogino, Takashi; Egawa, Sunao

    1991-01-01

    New algorithms of CT value correction for reconstructing a radiotherapy simulation image through axial CT images were developed. One, designated plane weighting method, is to correct CT value in proportion to the position of the beam element passing through the voxel. The other, designated solid weighting method, is to correct CT value in proportion to the length of the beam element passing through the voxel and the volume of voxel. Phantom experiments showed fair spatial resolution in the transverse direction. In the longitudinal direction, however, spatial resolution of under slice thickness could not be obtained. Contrast resolution was equivalent for both methods. In patient studies, the reconstructed radiotherapy simulation image was almost similar in visual perception of the density resolution to a simulation film taken by X-ray simulator. (author)

  3. CT follow-up of conservatively treated lumbar disc herniation

    International Nuclear Information System (INIS)

    Schumacher, M.; Fischer, R.; Thoden, U.

    1990-01-01

    A CT study was carried out on 43 patients with low back pain and sciatica who were treated conservatively. They were followed up for over 20 months (mean) clinically and monitored by CT before and after treatment. Initially, 38 of them had herniation and 5 had protrusion of the disc. At the time of follow-up only 24 of the initial 40 patients still had neurological deficits. In 76.7% of the patients CT showed an improvement (clear regression in 15 patients, moderate decrease in 18 patients). A favourable tendency towards regression was observed in disc herniation at the L5-S1 level and in cases showing sequestration. The prognosis was unfavourable in herniations at higher levels than L5-S1 and in lateral herniation reaching the intervertebral foramen. (orig.) [de

  4. Indeterminate lesions on planar bone scintigraphy in lung cancer patients: SPECT, CT or SPECT-CT?

    International Nuclear Information System (INIS)

    Sharma, Punit; Kumar, Rakesh; Singh, Harmandeep; Bal, Chandrasekhar; Malhotra, Arun; Julka, Pramod Kumar; Thulkar, Sanjay

    2012-01-01

    The objective of the present study was to compare the role of single photon emission computed tomography (SPECT), computed tomography (CT) and SPECT-CT of selected volume in lung cancer patients with indeterminate lesions on planar bone scintigraphy (BS). The data of 50 lung cancer patients (53 ± 10.3 years; range 30-75; male/female 38/12) with 65 indeterminate lesions on planar BS (January 2010 to November 2010) were retrospectively evaluated. All of them underwent SPECT-CT of a selected volume. SPECT, CT and SPECT-CT images were independently evaluated by two experienced readers (experience in musculoskeletal imaging, including CT: 5 and 7 years) in separate sessions. A scoring scale of 1 to 5 was used, in which 1 is definitely metastatic, 2 is probably metastatic, 3 is indeterminate, 4 is probably benign and 5 is definitely benign. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated for each modality, taking a score ≤2 as metastatic. With receiver operating characteristic (ROC) curve analysis, areas under the curve (AUC) were calculated for each modality and compared. Clinical and imaging follow-up and/or histopathology were taken as reference standard. For both readers SPECT was inferior to CT (P = 0.004, P = 0.022) and SPECT-CT (P = 0.003, P = 0.037). However, no significant difference was found between CT and SPECT-CT for reader 1 (P = 0.847) and reader 2 (P = 0.592). The findings were similar for lytic as well as sclerotic lesions. Moderate inter-observer agreement was seen for SPECT images (κ = 0.426), while almost perfect agreement was seen for CT (κ = 0.834) and SPECT-CT (κ = 0.971). CT alone and SPECT-CT are better than SPECT for accurate characterisation of indeterminate lesions on planar BS in lung cancer patients. CT alone is not inferior to SPECT-CT for this purpose and might be preferred because of shorter acquisition time and wider availability. (orig.)

  5. Use of CT in stapedial otosclerosis

    International Nuclear Information System (INIS)

    Mafee, M.F.; Henrikson, G.C.; Deitch, R.L.; Norouzi, P.; Kumar, A.; Kriz, R.; Valvassori, G.E.

    1985-01-01

    Otosclerosis (otospongiosis) is a primary focal disease of the labyrinthine capsule. The stapes footplate is fixed when the spongiotic focus expands and invades the oval window. Persons with stapedial otosclerosis experience a progressive conductive hearing loss. In many cases, cochlear degeneration is observed, in which a mixed hearing loss occurs. Using computed tomography (CT), the authors studied the ears of 45 selected patients with conductive or mixed hearing loss. CT proved valuable in determining otosclerotic changes of the oval window and otic capsule. Spongiotic changes of the otic capsule are better appreciated by CT than complex motion tomography. The usefulness of CT in diagnosing other causes of conductive or mixed hearing loss is also described

  6. Thoracic manifestation of Wegener's granulomatosis: CT findings in 30 patients

    International Nuclear Information System (INIS)

    Lee, Kyung Soo; Kim, Tae Sung; Kim, Eun A.; Fujimoto, Kiminori; Moriya, Hiroshi; Watanabe, Hideyuki; Tateishi, Ukihide; Ashizawa, Kazuoto; Johkoh, Takeshi; Kwon, O. Jung

    2003-01-01

    Our objective was to describe the CT findings of thoracic Wegener's granulomatosis. At presentation, both conventional and thin-section CT scans were available in 30 patients with Wegener's granulomatosis. Serial CT scans (range of intervals: 1-25 months, mean 4.5 months) were available in 20 patients. The initial and follow-up CT scans were analyzed retrospectively by two observers in terms of pattern and extent of parenchymal and airway lesions. Positive CT findings were seen in 29 of 30 (97%) patients at initial presentation. The most common pattern was nodules or masses seen in 27 of 30 (90%) patients. They were multiple in 23 of 27 (85%) patients, bilateral in 18 (67%), subpleural in 24 (89%), and peribronchovascular in 11 (41%) in distribution. Bronchial wall thickening in the segmental or subsegmental bronchi was seen in 22 (73%) patients. Large airways were also abnormal in 9 (30%) patients. Patchy areas of consolidation and ground-glass opacity were seen in 7 (23%) patients, respectively. In 17 of 20 (85%) patients in whom follow-up CT scans were available, the parenchymal or airway lesion showed complete or partial improvement with treatment. The CT findings of Wegener's granulomatosis, although multiple and variable, consist mainly of bilateral subpleural or peribronchovascular nodules or masses and bronchial wall thickening in the segmental or subsegmental bronchi. Parenchymal and airway lesions improve with treatment in most patients. (orig.)

  7. 111In-Pentetreotide SPECT/CT in Pulmonary Carcinoid.

    Science.gov (United States)

    Chiaravalloti, Agostino; Spanu, Angela; Danieli, Roberta; Dore, Francesca; Piras, Bastiana; Falchi, Antonio; Tavolozza, Mario; Madeddu, Giuseppe; Schillaci, Orazio

    2015-07-01

    We evaluated somatostatin receptor scintigraphy (SRS) with (111)In-pentetreotide incremental value in pulmonary carcinoid (PC) diagnosis compared to contrast enhanced Computed Tomography (ceCT). We enrolled 81 patients with ascertained PC, 39 at initial staging and 42 in follow-up; the primary tumor had already been excised in 68 cases. Single Photon emission Computed Tomography (SPECT) images were reconstructed with the iterative method and fused with non-enhanced Computed tomography (CT) images. Primary PC or metastatic lesions were ascertained in 55/81 patients and SPECT/CT was positive in 50/55 cases, while ceCT was positive in 44/55. Comparing SPECT/CT with ceCT results, we found a sensitivity of 96 vs. 87.5%, and specificity of 92% vs. 97% for the detection of primary lesion or recurrent disease. A total of 198 lesions were ascertained at SPECT/CT, while 161 at ceCT, with values of sensitivity and specificity of 85.5% and 84.6% for SRS and 75.2% and 90.5% respectively. (111)In-Pentetreotide SPECT/CT proved to be more sensitive and accurate than ceCT, thus enhancing its role in evaluating patients with PC. Copyright© 2015 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

  8. Study of metastatic foci by CT in autopsied lung cancer

    International Nuclear Information System (INIS)

    Koga, Mitsuru; Nobe, Yoshifumi; Fujii, Kyoichi.

    1983-01-01

    The authors reexamined all of the image diagnoses made during whole hospitalization in 11 lung cancer cases with autopsy. Of 39 metastatic foci observed at autopsy in the liver, kidney, pancreas, adrenal and brain, 12 had been diagnosed on transverse CT images before death. Three foci were missed at initial readings. The period from CT to autopsy was less than 3 months for 9 of 12 correctly diagnosed foci. For 13 of 27 foci undetected by CT, CT was conducted more than 3 months before death. (Chiba, N)

  9. Likelihood of aneurysmal subarachnoid haemorrhage in patients with normal unenhanced CT, CSF xanthochromia on spectrophotometry and negative CT angiography.

    Science.gov (United States)

    Rana, A K; Turner, H E; Deans, K A

    2013-01-01

    Patients with suspected subarachnoid haemorrhage, a normal noncontrast computed tomography (CT) and cerebrospinal fluid (CSF) evidence of haemoglobin breakdown products often undergo CT angiography (CTA). If this is normal, then invasive catheter angiography may be offered. In current clinical practice, haemoglobin breakdown products are detected by spectrophotometry rather than visible xanthochromia, and CTA is performed on multidetector scanners. The aim of this study was to determine if such patients should still have a catheter angiography, given the associated risks. Patients positive for CSF spectrophotometry (n=26) were retrospectively identified from the clinical biochemistry information system and imaging data from the electronic radiology records were reviewed. Discharge letters were consulted to relate the biochemistry and radiology results to the final diagnosis. 15 patients with CT angiography were found. Nine patients had normal CT angiography. No causative aneurysms had been missed. One patient had small, coincidental aneurysms missed on initial reading of the CTA. The likelihood of a clinically significant aneurysm in a patient who is CT negative, lumbar puncture positive and CTA negative is low. Double reporting of negative CT angiograms may be advisable.

  10. Initial experiences of family caregivers of survivors of a traumatic brain injury

    Directory of Open Access Journals (Sweden)

    Mandi Broodryk

    2015-08-01

    Full Text Available Background: There seems to be a paucity of research on the initial subjective experiences of family caregivers of survivors of a traumatic brain injury (TBI. Objective: To explore the challenges that family caregivers face during the initial stages of recovery of a relative who has sustained a TBI. Methods: Thematic analysis was used to explore the findings from semi-structured interviews that were conducted with 12 female family caregivers of relatives who had sustained a TBI. Results: Family caregivers recalled their initial experiences of the shock at hearing the news about their relative’s TBI, negative experiences in hospital and frustrating interactions with healthcare professionals as particularly challenging. Conclusion: The findings of this study emphasise caregivers’ need for support, information and psycho-education, especially from healthcare professionals, from the very beginning stages of recovery from a TBI. Practical and physical needs with regard to admission to and care in the hospital were also highlighted. This research will hopefully contribute to creating awareness amongst healthcare professionals on how they can contribute to improvement of the services provided by the healthcare system based on the experiences of the caregivers who participated in this study.

  11. Refined staging in hilar bronchial neoplasms with ECG-gated multislice-CT. Case report

    International Nuclear Information System (INIS)

    Ohlmann, S.; Daliri, A.; Froelich, J.J.; Nowak, R.; Michulla, R.

    2008-01-01

    Equivocal initial CT-based staging in 2 patients with hilar bronchial neoplasms was reassessed with retrospective ECG-gated Multislice-CT and optimized examination parameters prior to definition of treatment. An initially suspected irresectable T 4 tumor with mediastinal infiltration was downstaged to T 2 in one case, while tumor infiltration into the left atrium could be confirmed in the other case. In doubtful conditions, ECG-gated multislice CT with optimized examination parameters may be helpful for refined staging in patients with hilar bronchial neoplasma, thus possibly influencing treatment strategies. (orig.)

  12. Follow-up CT Evaluation of the Mural Changes in Active Takayasu Arteritis

    International Nuclear Information System (INIS)

    Kim, Sang Young; Park, Jae Hyung; Chung, Jin Wook; Kim, Hyo Cheol; Lee, Whal; So, Young Ho; Jae, Hwan Jun

    2007-01-01

    We wanted to evaluate the mural changes by CT on the follow-up examination of patients with active Takayasu arteritis. The study included 18 patients, (4 males and 14 females), with active Takayasu arteritis. A total of 44 CT examinations were done during the follow-up period (mean: 55.6 months). At the time of the last follow-up CT, the disease, on the basis of the erythrocyte sedimentation rate (ESR), was found to be inactive in five patients and the disease was active and persistent in 13 patients. The thickness and CT attenuation of the aortic wall on the precontrast, arterial and venous phases were measured on the initial and the follow-up CT examinations. The ratio of the mural attenuation over that of the back muscle on the initial CT was compared with the ratio found on the follow-up CT. The initial CT findings included high density and calcifications of the aortic wall in the precontrast images and a thickened wall with enhancements in the arterial and the venous phases. A low-attenuation ring was demonstrated in the venous phase in 15 patients (83%). On the follow-up evaluation, the mean mural thickness decreased significantly from 4.1 mm to 2.4 mm. The mean mural attenuation ratio in the venous phase decreased significantly from 1.9 to 1.3 (p 0.001). The low attenuation ring was identified in seven patients (39%) who had only with active, persistent Takayasu arteritis. The mural changes demonstrated by the follow-up CT evaluations for the patients with active Takayasu arteritis included a decrease of the mural thickness and enhancement, disappearance of the low-attenuation ring on the venous phase, and an increase of the mural attenuation and calcification on the precontrast phase

  13. Serial CT Findings of Paragonimus Infested Dogs and the Micro-CT Findings of the Worm Cysts

    International Nuclear Information System (INIS)

    Lee, Chang Hyun; Im, Jung Gi; Goo, Jin Mo; Lee, Hyun Ju; Hong, Sung Tae; Shen, Cheng Hua; Chung, Doo Hyun; Son, Kyu Ri; Chang, Jung Min; Eo, Hong

    2007-01-01

    To investigate the serial CT findings of Paragonimus westermani infected dogs and the microscopic structures of the worm cysts using Micro-CT. This study was approved by the committee on animal research at our institution. Fifteen dogs infected with P. westermani underwent serial contrast-enhanced CT scans at pre-infection, after 10 days of infection, and monthly thereafter until six months for determining the radiologic-pathologic correlation. Three dogs (one dog each time) were sacrificed at 1, 3 and 6 months, respectively. After fixation of the lungs, both multi-detector CT and Micro-CT were performed for examining the worm cysts. The initial findings were pleural effusion and/or subpleural groundglass opacities or linear opacities at day 10. At day 30, subpleural and peribronchial nodules appeared with hydropneumothorax and abdominal or chest wall air bubbles. Cavitary change and bronchial dilatation began to be seen on CT scan at day 30 and this was mostly seen together with mediastinal lymphadenopathy at day 60. Thereafter, subpleural ground-glass opacities and nodules with or without cavitary changes were persistently observed until day 180. After cavitary change of the nodules, the migratory features of the subpleural or peribronchial nodules were seen on all the serial CT scans. Micro-CT showed that the cyst wall contained dilated interconnected tubular structures, which had communications with the cavity and the adjacent distal bronchus. The CT findings of paragonimiasis depend on the migratory stage of the worms. The worm cyst can have numerous interconnected tubular channels within its own wall and these channels have connections with the cavity and the adjacent distal bronchus

  14. The Oncogenic Risks of Diagnostic CT Scam Studies in Children

    International Nuclear Information System (INIS)

    Brent, R.

    2004-01-01

    Brenner et al (2001) reported that estimates of the exposure to children from CT scans indicates that the exposures are both higher than from conventional radiographic studies and higher than is necessary to obtain quality examinations. utilizing the oncogenic risk data from the RERF study in Japan, Brenner et al estimated that the oncogenic risk in this population of CT exposed children exposed each year would result in an additional 500 cases of cancer. This risk estimate is supported by the RERF epidemiological data obtained from the populations exposed in Hiroshima and Nagasaki. the increased risks associated with the increased exposure from CT scans have raised concern and stimulated discussion. Although there is little doubt about the benefits of CT scans in improving the health care of children, there is concern about the estimated oncogenic risk, especially since the frequency of CT studies has been increasing. Applying the oncogenic risks of ionizing radiation from the RERF data may not be appropriate for all types of radiation exposure for accurately predicting the incidence of cancer in exposed children because of the impact of 1) partial versus whole-body irradiation, and 2) the protraction of the exposure. Other population of children who have been exposed to radiation and whose incidence of cancer has been studied will be presented and those studies indicate that the risk of cancer is much lower or not increased at all with exposures in the diagnostic range. finally, the dramatic impact of the use of CT scans in clinical pediatric practice saves lives and improves diagnostic accuracy. Therefore, it is crucial that a scholarly evaluation of the risks and benefits should be initiated. The radiology community and the manufacturers have already initiated programs to decrease the exposure significantly. But it is essential that well-planned, retrospective and prospective epidemiology studies should be initiated to study the oncogenic risks. If you want to

  15. CT and MRI in progressive multifocal leukoencephalopathy. CT und MRT der progressiven multifokalen Leukenzephalopathie (PML)

    Energy Technology Data Exchange (ETDEWEB)

    Lanfermann, H. (Inst. und Poliklinik fuer Radiologische Diagnostik, Koeln Univ. (Germany)); Heindel, W. (Inst. und Poliklinik fuer Radiologische Diagnostik, Koeln Univ. (Germany)); Schroeder, R. (Neuropathologie des Inst. fuer Pathologie, Koeln Univ. (Germany)); Lackner, K. (Inst. und Poliklinik fuer Radiologische Diagnostik, Koeln Univ. (Germany))

    1994-07-01

    Radiological findings and course of progressive multifocal leukoencephalopathy in 14 patients (1 woman, 13 men; 13 HIV seropositive, 1 chronic lymphatic leukaemia) were analysed retrospectively and correlated with clinical symptoms. A total of 21 CT and 16 MRI studies were evaluated. CT scans and MR images of 9 patients, which had been obtained in less than two weeks, could be compared to each other. MRI was superior to CT: 6 lesions with a diameter of 1 cm and below were not detected on CT scans, in 5 patients the extent of lesions was underestimated. Cortical involvement, mass effect or signs of atrophy were missing. Only 1 of 65 lesions showed a tiny enhancement after Gd injection. Due to the pattern and spread of lesions, which showed a close correlation to the neurologic symptoms, three different types of PML are suggested: 1. Initial precentral demyelinisation with contralateral hemiparesis (n=8); 2. lesions in temporo-occipital locations with visual disturbances (n=2); 3. predominantly bilateral lesions of cerebellar white matter with ataxia (n=4). (orig.)

  16. British Isles Field Experience: An Initiative in International Education.

    Science.gov (United States)

    Martin, William J.

    The British Isles Field Experience (BIFE) program was initiated at Williamsport Area Community College (WACC) to provide a group of WACC faculty and staff members with individual and group activities of a personal, professional, and cultural nature in order to promote an international perspective that can be infused into student, collegiate, and…

  17. Early detection of metastases using whole-body MRI for initial staging and routine follow-up of myxoid liposarcoma

    Energy Technology Data Exchange (ETDEWEB)

    Gorelik, Natalia; Reddy, Santhosh Mauvva Venkatesh; Powell, Thomas I. [McGill University Health Center, Department of Diagnostic Radiology, Montreal, Quebec (Canada); Turcotte, Robert E.; Goulding, Krista [McGill University Health Center, Division of Orthopaedic Surgery, Montreal, Quebec (Canada); Jung, Sungmi [McGill University Health Center, Department of Pathology, Montreal, Quebec (Canada); Alcindor, Thierry [McGill University Health Center, Gerald Bronfman Department of Oncology, Division of Medical Oncology, Montreal, Quebec (Canada)

    2018-03-15

    To define the role of whole-body MRI (WBMRI) for initial staging and routine follow-up of myxoid liposarcoma (MLS). A retrospective review of all the patients with MLS who underwent WBMRI for initial staging and routine follow-up at our institution between October 1, 2006, and September 30, 2016 was performed. Patient demographics, clinical presentation, imaging findings, tumor histology, and occurrence and location of metastatic disease were recorded. Thirty-three patients who underwent a total of 150 WBMRI examinations were included in the study. Nine patients (27%) were diagnosed with metastases between 0 and 60 months (median 10; interquartile range, 7-13) from the diagnosis of the primary tumor. The initial site of metastatic disease was extrapulmonary in all patients. Only two patients developed pulmonary metastases, which were diagnosed by CT chest 9 and 29 months after the diagnosis of extrapulmonary metastases. The first metastasis was diagnosed by WBMRI in seven patients (78%), by thoracic CT in one patient, and by abdominal CT in one patient. Eight of nine patients (89%) were asymptomatic at the time of diagnosis of the metastases. In seven patients (78%), WBMRI demonstrated metastases included within the field of view of, but occult on a contemporaneous CT scan. Our 10-year institutional experience demonstrates that WBMRI facilitates early detection of extrapulmonary MLS metastases before the onset of clinical symptoms and pulmonary metastases. WBMRI also depicts extrapulmonary metastases that are occult on CT scans. The current surveillance strategies are insufficient for screening for extrapulmonary MLS metastases. (orig.)

  18. 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...

  19. CT of hemodynamically unstable abdominal trauma

    International Nuclear Information System (INIS)

    Petridis, A.; Pilavaki, M.; Vafiadis, E.; Palladas, P.; Finitsis, S.; Drevelegas, A.

    1999-01-01

    This article is an appraisal of the use of CT in the management of patients with unstable abdominal trauma. We examined 41 patients with abdominal trauma using noncontrast dynamic CT. In 17 patients a postcontrast dynamic CT was also carried out. On CT, 25 patients had hemoperitoneum. Thirteen patients had splenic, 12 hepatic, 6 pancreatic, 8 bowel and mesenteric, 12 renal and 2 vascular injuries. Seven patients had retroperitoneal and 2 patients adrenal hematomas. All but five lesions (three renal, one pancreatic, and one splenic) were hypodense when CT was performed earlier than 8 h following the injury. Postcontrast studies (n = 17), revealed 4 splenic, 3 hepatic, 1 pancreatic, 3 renal, and 2 bowel and mesenteric injuries beyond what was found on noncontrast CT. Surgical confirmation (n = 21) was obtained in 81.81 % of splenic, 66.66 % of hepatic, 83.33 % of pancreatic, 100 % of renal, 100 % of retroperitoneal, and 85.71 % of bowel and mesenteric injuries. The majority of false diagnoses was obtained with noncontrast studies. Computed tomography is a remarkable method for evaluation and management of patients with hemodynamically unstable abdominal trauma, but only if it is revealed in the emergency room. Contrast injection, when it could be done, revealed lesions that were not suspected on initial plain scans. (orig.)

  20. Reference dosimetry for CT in the UK

    International Nuclear Information System (INIS)

    Shrimpton, P.C.; Wall, B.F.

    2001-01-01

    Computed tomography is firmly established as a major source of population exposure from diagnostic x-ray examinations and thus a particular focus for radiological protection initiatives. The concept of reference doses is widely recognised as a useful and practical tool for promoting improvements in the optimisation of protection for patients undergoing radiological examinations. National diagnostic reference levels (DRLs) have already been successfully applied in the UK for some conventional x-ray examinations within a framework for advice on patient protection. This approach is being extended to include CT, utilising the robust methodology for reference dosimetry that has been developed by the European Commission (EC) for the particular conditions of exposure in CT. This is based on the dosimetric concepts of weighted computed tomography dose index (CTDI w ) per slice in serial scanning or per rotation in helical scanning, and dose-length product (DLP) per complete examination. Notwithstanding some initial values proposed by the EC, specific national DRLs for CT practice in the UK will be established on the basis of widescale national survey data. (author)

  1. Diagnostic and prognostic impact of 18F-FDG PET/CT in follicular lymphoma

    International Nuclear Information System (INIS)

    Le Dortz, Ludovic; Garin, Etienne; Guibert, Sophie de; Houot, Roch; Bayat, Sahar; Cuggia, Marc; Devillers, Anne; Le Jeune, Florence; Bahri, Haifa; Barge, Marie-Luce; Rolland, Yan; Lamy, Thierry

    2010-01-01

    The aim of this study was to assess the usefulness of positron emission tomography/computed tomography in staging, prognosis evaluation and restaging of patients with follicular lymphoma. A retrospective study was performed on 45 patients with untreated biopsy-proven follicular lymphoma who underwent 18 F-fluorodeoxyglucose PET/CT (FDG PET/CT) and CT before and after chemoimmunotherapy induction treatment (rituximab combined with cyclophosphamide, doxorubicin, vincristine and prednisone). PET/CT detected more nodal (+51%) and extranodal (+89%) lesions than CT. PET/CT modified Ann Arbor staging in eight patients (18%). Five patients (11%) initially considered as being early stage (I/II) were eventually treated as advanced stage (III/IV). In this study, an initial PET/CT prognostic score was significantly more accurate than the Follicular Lymphoma International Prognostic Index score in identifying patients with poor prognosis (i.e. patients with incomplete therapeutic response or early relapse). The accuracy of PET/CT for therapeutic response assessment was higher than that of CT (0.97 vs 0.64), especially due to its ability to identify inactive residual masses. In addition, post-treatment PET/CT was able to predict patients' outcomes. The median progression-free survival was 48 months in the PET/CT-negative group as compared with 17.2 months for the group with residual uptake (p -4 ). FDG PET/CT is useful for staging and assessing the prognosis and therapeutic response of patients with follicular lymphoma. (orig.)

  2. The value of computed tomography (CT) in the treatment of lung cancer

    International Nuclear Information System (INIS)

    Striggaris, K.; Gouliamos, A.; Garmatis, C.; Kaklamanis, N.; Vlahos, L.; Pontifex, G.

    1982-01-01

    The extensive recent literature on computed tomography (CT) includes several reports demonstrating the usefulness of body scanners in radiotherapy treatment planning. This followed earlier experience indicating the potential application of the technique in chest disease. The fast scan-times, possible with newer CT systems, eliminate motion degradation and provide accurate localization of thoracic tumors. This paper reports the authors' experience with CT in treatment planning of 38 patients with bronchogenic carcinoma after pretherapy evaluation by CT. They conclude that the availability of CT-scan data helps to define accurately the target volume and provides the information needed for treatment planning computers in order to estimate the desired dose. (Auth.)

  3. Transient acute tubular dysfunction in the newborn: CT findings

    International Nuclear Information System (INIS)

    McLaughlin, M.G.; Schwartz, J.R.; Swayne, L.C.; Columbia Univ., New York; Rubenstein, J.B.; University of Medicine and Dentistry of New Jersey, Newark, NJ; Block, D.C.

    1990-01-01

    We report the CT and sonographic findings of transient acute tubular disease in a newborn infant, who was dehydrated at birth. The initial CT scan demonstrated focal areas of increased attenuation within the central portions of both kidneys, and sonography showed echogenic medullary pyramids. After adequate hydration, a follow-up examination demonstrated complete spontaneous resolution. (orig.)

  4. The initial experience of trans-rectal ultrasound and biopsy in ...

    African Journals Online (AJOL)

    The initial experience of trans-rectal ultrasound and biopsy in diagnosis of carcinoma prostate in Gezira Hospital for Renal Disease and Surgery (GHRDS). Walaa Eldin Ibraheem, Sami Mahjoub Taha, Mustafa Omran Mansour, Mohammed El Imam Mohamed Ahmed ...

  5. 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)

  6. Obscure pulmonary masses: bronchial impaction revealed by CT

    International Nuclear Information System (INIS)

    Pugatch, R.D.; Gale, M.E.

    1983-01-01

    Dilated bronchi impacted with mucus or tumor are recognized on standard chest radiographs because they are surrounded by aerated pulmonary parenchyma. When imaged in different projections, these lesions produce a variety of appearances that are generally familiar. This report characterizes less familiar computed tomographic (CT) findings in eight patients with pathologic bronchial distension of congenital, neoplastic, or infectious etiologies and correlates them with chest films. In seven patients, CT readily revealed dilated bronchi and/or regional lung hypodensity. In four of these cases, CT led to the initial suspicion of dilated bronchi. CT should be used early in the evaluation of atypical pulmonary mass lesions or to confirm suspected bronchial impaction because of the high probability it will reveal diagnostic features

  7. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... that lasts for at most a minute or two. You may experience a sensation like you have ... CT scanning provides very detailed images of many types of tissue as well as the lungs, bones, ...

  8. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... that lasts for at most a minute or two. You may experience a sensation like you have ... CT scanning provides very detailed images of many types of tissue as well as the lungs, bones, ...

  9. Value of PET/CT versus PET and CT performed as separate investigations in patients with Hodgkin's disease and non-Hodgkin's lymphoma

    International Nuclear Information System (INIS)

    Fougere, Christian la; Broeckel, Nicole; Pfluger, Thomas; Haug, Alexander; Scher, Bernhard; Hacker, Marcus; Hahn, Klaus; Tiling, Reinhold; Hundt, Walter; Reiser, Maximilan

    2006-01-01

    The aim of this study was to assess the clinical benefit of combined [ 18 F]FDG PET/CT in patients with malignant lymphoma as compared to separately performed PET and CT. Overall, 100 patients with Hodgkin's disease (HD) or non-Hodgkin's lymphoma (NHL) were included in this study. Co-registered PET/CT with [ 18 F]FDG and contrast medium was performed in 50 consecutive patients with NHL (n=38) or HD (n=12) for initial staging (IS) (n=12) or re-treatment staging (RS) (n=38). Another 50 patients with NHL (n=32) or HD (n=18) underwent separate PET and CT investigations within a time frame of 10 days for IS (n=22) or RS (n=28). Lymphoma involvement was separately evaluated for seven different regions in each patient. Each patient had clinical follow-up evaluation for >6 months. PET and CT data were analysed separately as well as side-by-side or in fused mode. In the PET/CT group, region-based evaluation for lymphoma involvement suggested a sensitivity/specificity of 85%/91% for CT, 98%/99% for PET and 98%/99% for PET/CT. In the PET and CT group, region-based evaluation showed a sensitivity/specificity of 87%/80% for CT, 98%/99% for PET and 98%/100% for PET and CT read side by side. PET was superior to CT alone and was improved further by side-by-side reading of both examinations. However, no significant difference was observed between PET/CT and separate PET and CT imaging in patients with lymphoma. (orig.)

  10. (18F) FDG PET/CT in patients with fever of unknown origin: AIIMS experience

    International Nuclear Information System (INIS)

    Nazar, A.H.; Naswa, N.; Ramya, S.; Patnecha, M.; Bangkim, Chandra K.H.; Kumar, R.; Bandopadhyay, G.P.; Bal, C.S.; Malhotra, A.

    2010-01-01

    Full text: The aim of this study was to assess the value of ( 18 F) FDG PET/CT in evaluation of patients with Fever of Unknown Origin (FUO). We retrospectively analysed clinical data and ( 18 F) FDG PET scan of 48 patients over a period of 1 year. These patients met the revised definition criteria of FUO (febrile illness of greater than 3 weeks duration, temperature greater than 38.3 C and no diagnosis after appropriate in-patient or out-patient evaluation). Most of the patients recruited in this study had normal clinical and radiological examination. ( 18 F) FDG PET was helpful in making a diagnosis in 24 patients. An infective/inflammatory cause of FUO was found in thirteen (27%) patients, a neoplasm in six (12.5%) patients, autoimmune cause in five (10.4%) patients. A definitive diagnosis could not be made in twenty four (50%) patients. Out of these 24 patients, 15 had normal PET/CT study, 9 had positive PET/CT findings but they lost in follow up and 2 died within 1 month of PET/CT study without any diagnosis. ( 18 F) FDG PET/CT is a useful tool for evaluation of patients with FUO. It provides important diagnostic clues not suggested by other conventional imaging modalities. Patients with positive PET/CT findings but no definitive diagnosis should be followed up further to improve utility of PET/CT

  11. Edge-oriented dual-dictionary guided enrichment (EDGE) for MRI-CT image reconstruction.

    Science.gov (United States)

    Li, Liang; Wang, Bigong; Wang, Ge

    2016-01-01

    In this paper, we formulate the joint/simultaneous X-ray CT and MRI image reconstruction. In particular, a novel algorithm is proposed for MRI image reconstruction from highly under-sampled MRI data and CT images. It consists of two steps. First, a training dataset is generated from a series of well-registered MRI and CT images on the same patients. Then, an initial MRI image of a patient can be reconstructed via edge-oriented dual-dictionary guided enrichment (EDGE) based on the training dataset and a CT image of the patient. Second, an MRI image is reconstructed using the dictionary learning (DL) algorithm from highly under-sampled k-space data and the initial MRI image. Our algorithm can establish a one-to-one correspondence between the two imaging modalities, and obtain a good initial MRI estimation. Both noise-free and noisy simulation studies were performed to evaluate and validate the proposed algorithm. The results with different under-sampling factors show that the proposed algorithm performed significantly better than those reconstructed using the DL algorithm from MRI data alone.

  12. CT of the acetabular fracture

    International Nuclear Information System (INIS)

    Magu, N.K.; Moda, S.K.; Magu, Sarita; Airon, R.K.

    1993-01-01

    Nine patients with 10 injured hips, in whom acetabular fractures with posterior dislocation of the femoral heads were demonstrated on initial radiography, underwent CT. CT was found superior in detecting the presence of intra-articular bony fragments in Group A patients (40%), where conventional radiography exhibited congruous manipulative reduction of the joint surfaces. The spatial position of the intra-articular fragments could not be ascertained on conventional radiography in 40% of the patients in Group B, in whom congruous manipulative reduction could not be achieved and subluxation of the femoral heads was observed. On conventional radiography, it was also difficult to appreciate the presence of intra-articular fragments in 60% of the patients in Group B, in whom either the dislocation could not be reduced (40%) or the femoral head redislocated after close manipulative reduction (20%). CT proved its superiority in detecting the extent of the fractures of the acetabular roof, posterior and anterior acetabular margins, the quadrilateral plate along with rotation of the acetabular columns and displacements of the major fractured fragments. Associated fractures of the sacrum (20%), and traumatic lesions of the sacro-iliac joint (20%), not apparent on conventional radiography were well demonstrated by CT. As a result of CT, the treatment was changed in 60% of the patients in Group A, and 40% in Group B. In addition, CT permitted a better choice of surgical technique in the management of acetabular fractures. (author). 9 refs., 3 figs., 2 tabs

  13. Initial experience with the NRC significance determination process

    International Nuclear Information System (INIS)

    Madison, A.L.

    2001-01-01

    The U.S. Nuclear Regulatory Commission (NRC) has revamped its inspection, assessment, and enforcement programs for commercial nuclear power plants. The new oversight process uses more objective, timely, and safety-significant criteria in assessing performance, while seeking to more effectively and efficiently regulate the industry. The NRC tested the new process at thirteen reactors at nine sites across the country on a pilot basis in 1999 to identify what things worked well and what improvements were called for before beginning Initial Implementation at all US nuclear power plants on April 2, 2000. After a year of experience has been gained with the new oversight process at all US plants, the NRC anticipates making further improvements based on this wider experience. (author)

  14. Initial experience with the NRC significance determination process

    Energy Technology Data Exchange (ETDEWEB)

    Madison, A.L. [Office of Nuclear Reactor Regulation, US Nuclear Regulatory Commission (United States)

    2001-07-01

    The U.S. Nuclear Regulatory Commission (NRC) has revamped its inspection, assessment, and enforcement programs for commercial nuclear power plants. The new oversight process uses more objective, timely, and safety-significant criteria in assessing performance, while seeking to more effectively and efficiently regulate the industry. The NRC tested the new process at thirteen reactors at nine sites across the country on a pilot basis in 1999 to identify what things worked well and what improvements were called for before beginning Initial Implementation at all US nuclear power plants on April 2, 2000. After a year of experience has been gained with the new oversight process at all US plants, the NRC anticipates making further improvements based on this wider experience. (author)

  15. CT staging of lung cancer: the role of artificial pneumothorax

    International Nuclear Information System (INIS)

    Lee, Jin Seong; Im, Jung Gi; Han, Man Chung

    1991-01-01

    To determine the role of artificially induced pneumothorax in the evaluation of the chest wall and mediastinal invasion in patients with peripheral bronchogenic carcinoma. CT scans of 22 patients obtained after induced pneumothorax were evaluated. All patients had peripheral lung mass abutting the pleura on a routine CT scan. Room air of 200-400ml was introduced through intrathoracic negative pressure initially, followed by pressure injection through the 18 gauge long bevelled needle under fluoroscopic control. Conclusively, CT with artificial pneumothorax added more information than conventional CT in the evaluation of the chest wall or mediastinal invasion by lung cancer without notable risk

  16. CT-guided percutaneous cryoablation of osteoid osteoma in children: an initial study

    International Nuclear Information System (INIS)

    Wu, Bin; Xiao, Yue-Yong; Zhang, Xiao; Zhao, Lei; Carrino, John A.

    2011-01-01

    The purpose of this study was to evaluate the safety and efficacy of CT-guided percutaneous cryoablation for osteoid osteoma in children. This study was approved by the institutional ethics committee. From January 2007 to July 2008, six children (four boys, two girls, mean age 12.6 years old) with osteoid osteoma were treated with CT-guided percutaneous cryoablation. The procedures were carried out under conscious sedation and local anesthesia. CT guidance was used for procedural planning, instrument guidance, and monitoring. An argon-based cryoablation system was used. Each cryoablation included two freezing-thawing cycles. Follow-up was performed to assess technical and clinical outcome for a minimum of 12 months. A visual analog scale (VAS) was used to assess severity of pain pre- and post-procedure, and mean VAS for the group was compared pre- and post-procedure with a t-test. The mean clinical follow-up period was 28.7 months (ranging from 18 to 36 months). Cryoablation was technically and clinically successful for all patients. No major immediate or delayed complications were observed. Significant pain relief (P <0.05) was observed in all patients after operation. Mean VAS were 6.57 ± 0.55 pre-procedure and 0.57 ± 0.10 1 month post-procedure. Patients were allowed to fully bear their weight and function without limitation within 3 days after the procedure. Pain recurrence was not observed in any patient. Percutaneous cryoablation is safe and effective for the treatment of osteoid osteomas in children. Notably, this procedure can be accomplished without general anesthesia. (orig.)

  17. Essential requirements of a CT colonography service

    International Nuclear Information System (INIS)

    Hansmann, Anika; Burling, David

    2013-01-01

    There are many potential challenges to developing a high quality, efficient CT colonography service. Some are clear and predictable, for example creating CT capacity and securing financial resources, but some are less obvious, such as harnessing local support or changing referral practice amongst clinical colleagues. Notwithstanding, such barriers will need to be overcome to deliver a well-resourced, successful CT colonography programme. This article utilises the authors’ experience of developing their own CT colonography service from scratch (now examining >1200 patients per annum) and relevant published articles on ‘Standards’ of practice and training to recommend how others might provide CT colonography in their own patient communities. We offer a practical guide and will emphasise the need for a multi-disciplinary approach with locally agreed protocols and service objectives

  18. MRI and CT in alveolar echinococcosis of the liver

    International Nuclear Information System (INIS)

    Duewell, S.; Marincek, B.; Schulthess, G.K. von; Ammann, R.; Zurich Univ.

    1990-01-01

    To compare the value of MRI and CT in evaluating hepatic alveolar echinococcosis a study was conducted on 30 patients. The liver was initially affected in all patients. At the time of examination, 15 patients had undergone partial liver resection. MRI showed no advantage over CT in demonstrating an echinococcal mass lesion. MRI was superior in identifying concomitant pathological changes of the intrahepatic and extrahepatic venous system due to the intrinsic contrast of vascular structures. However, CT was superior in identifying calcifications, an important attribute of the disease. MRI should only be used in imaging alveolar echinococcosis of the liver if diagnostic questions remain open after CT, in particular questions concerning venous pathology. MRI may also be used to replace CT in patients with a contraindication to urographic contrast material. (orig.) [de

  19. Translation initiation on mRNAs bound by nuclear cap-binding protein complex CBP80/20 requires interaction between CBP80/20-dependent translation initiation factor and eukaryotic translation initiation factor 3g.

    Science.gov (United States)

    Choe, Junho; Oh, Nara; Park, Sungjin; Lee, Ye Kyung; Song, Ok-Kyu; Locker, Nicolas; Chi, Sung-Gil; Kim, Yoon Ki

    2012-05-25

    In the cytoplasm of mammalian cells, either cap-binding proteins 80 and 20 (CBP80/20) or eukaryotic translation initiation factor (eIF) 4E can direct the initiation of translation. Although the recruitment of ribosomes to mRNAs during eIF4E-dependent translation (ET) is well characterized, the molecular mechanism for CBP80/20-dependent translation (CT) remains obscure. Here, we show that CBP80/20-dependent translation initiation factor (CTIF), which has been shown to be preferentially involved in CT but not ET, specifically interacts with eIF3g, a component of the eIF3 complex involved in ribosome recruitment. By interacting with eIF3g, CTIF serves as an adaptor protein to bridge the CBP80/20 and the eIF3 complex, leading to efficient ribosome recruitment during CT. Accordingly, down-regulation of CTIF using a small interfering RNA causes a redistribution of CBP80 from polysome fractions to subpolysome fractions, without significant consequence to eIF4E distribution. In addition, down-regulation of eIF3g inhibits the efficiency of nonsense-mediated mRNA decay, which is tightly coupled to CT but not to ET. Moreover, the artificial tethering of CTIF to an intercistronic region of dicistronic mRNA results in translation of the downstream cistron in an eIF3-dependent manner. These findings support the idea that CT mechanistically differs from ET.

  20. Experimental estimation of regional lung water volume by histogram of pulmonary CT numbers

    International Nuclear Information System (INIS)

    Kato, Shiro; Momoki, Shigeru; Asai, Toshihiko; Shimada, Takeshi; Tamano, Masahiro; Nakamoto, Takaaki; Yoshimura, Masaharu

    1989-01-01

    Both in vitro and in vivo experiments were made to assess the ability of pulmonary CT numbers to quantitatively determine regional water volume in cases of pulmonary congestion or edema associated with left heart failure. In vitro experiment revealed a good linear correlation between the volume of injected water and the determined CT number of polyethylene tube packed with sponge. In the subsequent in vivo experiment with 10 adult mongrel dogs, lung water volumes obtained by pulmonary CT numbers were found to be consistent with the actual volumes. Pulmonary CT numbers for water volume proved to become parameters to quantitatively evaluate pulmonary congestion or edema. (Namekawa, K)

  1. Closing in on the K Edge : Coronary CT Angiography at 100, 80, and 70 kV-Initial Comparison of a Second-versus a Third-Generation Dual-Source CT System

    NARCIS (Netherlands)

    Meyer, Mathias; Haubenreisser, Holger; Schoepf, U. Joseph; Vliegenthart, Rozemarijn; Leidecker, Christianne; Allmendinger, Thomas; Lehmann, Ralf; Sudarski, Sonja; Borggrefe, Martin; Schoenberg, Stefan O.; Henzler, Thomas

    2014-01-01

    Purpose: To prospectively evaluate radiation and contrast medium requirements for performing high-pitch coronary computed tomographic (CT) angiography at 70 kV using a third-generation dual-source CT system in comparison to a second-generation dual-source CT system. Materials and Methods: All

  2. CT findings in gastrocolic fistula following percutaneous endoscopic gastrostomy

    International Nuclear Information System (INIS)

    Brown, Suki; McHugh, Kieran; Ledermann, Sarah; Pierro, Agostino

    2007-01-01

    We describe the CT findings in an initially asymptomatic boy aged 2 years 9 months with a gastrocolic fistula following percutaneous endoscopic gastrostomy (PEG) placement. The findings consisted of an unusual configuration of the gastrostomy tubing on an abdominal radiograph and upper gastrointestinal study indicating the possibility of transcolic PEG placement, which was confirmed with limited section CT. This well-known and major complication following a common procedure may be recognized on plain abdominal radiography, but it has not to our knowledge been documented previously on CT in a child. (orig.)

  3. CT findings in gastrocolic fistula following percutaneous endoscopic gastrostomy

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Suki [Great Ormond Street Hospital for Children, Department of Radiology, London (United Kingdom); St. George' s Hospital, Radiology Department, London (United Kingdom); McHugh, Kieran [Great Ormond Street Hospital for Children, Department of Radiology, London (United Kingdom); Ledermann, Sarah [Great Ormond Street Hospital for Children, Department of Nephrology, London (United Kingdom); Pierro, Agostino [Great Ormond Street Hospital for Children, Department of Surgery, London (United Kingdom)

    2007-02-15

    We describe the CT findings in an initially asymptomatic boy aged 2 years 9 months with a gastrocolic fistula following percutaneous endoscopic gastrostomy (PEG) placement. The findings consisted of an unusual configuration of the gastrostomy tubing on an abdominal radiograph and upper gastrointestinal study indicating the possibility of transcolic PEG placement, which was confirmed with limited section CT. This well-known and major complication following a common procedure may be recognized on plain abdominal radiography, but it has not to our knowledge been documented previously on CT in a child. (orig.)

  4. 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)

  5. Spontaneous rectus sheath hematoma: The utility of CT angiography

    Directory of Open Access Journals (Sweden)

    Antonio Pierro, MD

    2018-04-01

    Full Text Available We described the utility of computed tomography (CT angiography in detection of bleeding vessels for a rapid percutaneous arterial embolization of the spontaneous rectus sheath hematoma. A 70-year-old woman comes to our attention with acute abdominal pain and a low hemoglobin level. An unenhanced CT was performed demonstrating a large rectus sheath hematoma. A conservative management was initially established. Despite this therapy, the abdominal pain increased together with a further decrease of hemoglobin values. A CT angiography was then performed, demonstrating an active bleeding within the hematoma and addressing the patient to a rapid percutaneous arterial embolization. Keywords: Rectus sheath hematoma, Acute abdomen, Arterial embolization, CT angiography, Active bleeding

  6. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... procedure work? How is the procedure performed? What will I experience during and after the procedure? Who interprets the results and how do I get them? What are the benefits vs. risks? What are the limitations of CT ...

  7. Abdominal and Pelvic CT

    Medline Plus

    Full Text Available ... procedure work? How is the procedure performed? What will I experience during and after the procedure? Who interprets the results and how do I get them? What are the benefits vs. risks? What are the limitations of CT ...

  8. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... procedure work? How is the procedure performed? What will I experience during and after the procedure? Who interprets the results and how do I get them? What are the benefits vs. risks? What are the limitations of CT ...

  9. Radiation dose levels in pediatric chest CT: experience in 499 children evaluated with dual-source single-energy CT

    Energy Technology Data Exchange (ETDEWEB)

    Martine, Remy-Jardin; Colas, Lucie; Jean-Baptiste, Faivre; Remy, Jacques [CHU Lille (EA 2694) University of Lille, Department of Thoracic Imaging, Hospital Calmette, Lille (France); Santangelo, Teresa [CHU Lille (EA 2694) University of Lille, Department of Thoracic Imaging, Hospital Calmette, Lille (France); Bambino Gesu Children' s Hospital, Department of Imaging, Rome (Italy); Duhamel, Alain [University of Lille (EA 2694), Department of Biostatistics, CHU Lille, Lille (France); Deschildre, Antoine [CHU Lille - University of Lille, Department of Pediatric Pulmonology, Lille (France)

    2017-02-15

    The availability of dual-source technology has introduced the possibility of scanning children at lower kVp with a high-pitch mode, combining high-speed data acquisition and high temporal resolution. To establish the radiation dose levels of dual-source, single-energy chest CT examinations in children. We retrospectively recorded the dose-length product (DLP) of 499 consecutive examinations obtained in children <50 kg, divided into five weight groups: group 1 (<10 kg, n = 129); group 2 (10-20 kg, n = 176); group 3 (20-30 kg, n = 99), group 4 (30-40 kg, n = 58) and group 5 (40-49 kg, n = 37). All CT examinations were performed with high temporal resolution (75 ms), a high-pitch mode and a weight-adapted selection of the milliamperage. CT examinations were obtained at 80 kVp with a milliamperage ranging between 40 mAs and 90 mAs, and a pitch of 2.0 (n = 162; 32.5%) or 3.0 (n = 337; 67.5%). The mean duration of data acquisition was 522.8 ± 192.0 ms (interquartile range 390 to 610; median 490). In the study population, the mean CT dose index volume (CTDIvol{sub 32}) was 0.83 mGy (standard deviation [SD] 0.20 mGy; interquartile range 0.72 to 0.94; median 0.78); the mean DLP{sub 32} was 21.4 mGy.cm (SD 9.1 mGy.cm; interquartile range 15 to 25; median 19.0); and the mean size-specific dose estimate (SSDE) was 1.7 mGy (SD 0.4 mGy; interquartile range 1.5 to 1.9; median 1.7). The DLP{sub 32}, CTDI{sub vol32} and SSDE were found to be statistically significant in the five weight categories (P < 0.0001). This study establishes the radiation dose levels for dual-source, single-kVp chest CT from a single center. In the five weight categories, the median values varied 15-37 mGy.cm for the DLP{sub 32}, 0.78-1.25 mGy for the CTDI{sub vol32} and 1.6-2.1 mGy for the SSDE. (orig.)

  10. Radiation dose levels in pediatric chest CT: experience in 499 children evaluated with dual-source single-energy CT

    International Nuclear Information System (INIS)

    Martine, Remy-Jardin; Colas, Lucie; Jean-Baptiste, Faivre; Remy, Jacques; Santangelo, Teresa; Duhamel, Alain; Deschildre, Antoine

    2017-01-01

    The availability of dual-source technology has introduced the possibility of scanning children at lower kVp with a high-pitch mode, combining high-speed data acquisition and high temporal resolution. To establish the radiation dose levels of dual-source, single-energy chest CT examinations in children. We retrospectively recorded the dose-length product (DLP) of 499 consecutive examinations obtained in children <50 kg, divided into five weight groups: group 1 (<10 kg, n = 129); group 2 (10-20 kg, n = 176); group 3 (20-30 kg, n = 99), group 4 (30-40 kg, n = 58) and group 5 (40-49 kg, n = 37). All CT examinations were performed with high temporal resolution (75 ms), a high-pitch mode and a weight-adapted selection of the milliamperage. CT examinations were obtained at 80 kVp with a milliamperage ranging between 40 mAs and 90 mAs, and a pitch of 2.0 (n = 162; 32.5%) or 3.0 (n = 337; 67.5%). The mean duration of data acquisition was 522.8 ± 192.0 ms (interquartile range 390 to 610; median 490). In the study population, the mean CT dose index volume (CTDIvol 32 ) was 0.83 mGy (standard deviation [SD] 0.20 mGy; interquartile range 0.72 to 0.94; median 0.78); the mean DLP 32 was 21.4 mGy.cm (SD 9.1 mGy.cm; interquartile range 15 to 25; median 19.0); and the mean size-specific dose estimate (SSDE) was 1.7 mGy (SD 0.4 mGy; interquartile range 1.5 to 1.9; median 1.7). The DLP 32 , CTDI vol32 and SSDE were found to be statistically significant in the five weight categories (P < 0.0001). This study establishes the radiation dose levels for dual-source, single-kVp chest CT from a single center. In the five weight categories, the median values varied 15-37 mGy.cm for the DLP 32 , 0.78-1.25 mGy for the CTDI vol32 and 1.6-2.1 mGy for the SSDE. (orig.)

  11. Importance of PET/CT for imaging of colorectal cancer

    International Nuclear Information System (INIS)

    Meinel, F.G.; Schramm, N.; Graser, A.; Reiser, M.F.; Rist, C.; Haug, A.R.

    2012-01-01

    Fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) has emerged as a very useful imaging modality in the management of colorectal carcinoma. Data from the literature regarding the role of PET/CT in the initial diagnosis, staging, radiotherapy planning, response monitoring and surveillance of colorectal carcinoma is presented. Future directions and economic aspects are discussed. Computed tomography (CT), magnetic resonance imaging (MRI) and FDG-PET for colorectal cancer and endorectal ultrasound for rectal cancer. Combined FDG-PET/CT. While other imaging modalities allow superior visualization of the extent and invasion depth of the primary tumor, PET/CT is most sensitive for the detection of distant metastases of colorectal cancer. We recommend a targeted use of PET/CT in cases of unclear M staging, prior to metastasectomy and in suspected cases of residual or recurrent colorectal carcinoma with equivocal conventional imaging. The role of PET/CT in radiotherapy planning and response monitoring needs to be determined. Currently there is no evidence to support the routine use of PET/CT for colorectal screening, staging or surveillance. To optimally exploit the synergy between morphologic and functional information, FDG-PET should generally be performed as an integrated FDG-PET/CT with a contrast-enhanced CT component in colorectal carcinoma. (orig.) [de

  12. An evaluation on CT image acquisition method for medical VR applications

    Science.gov (United States)

    Jang, Seong-wook; Ko, Junho; Yoo, Yon-sik; Kim, Yoonsang

    2017-02-01

    Recent medical virtual reality (VR) applications to minimize re-operations are being studied for improvements in surgical efficiency and reduction of operation error. The CT image acquisition method considering three-dimensional (3D) modeling for medical VR applications is important, because the realistic model is required for the actual human organ. However, the research for medical VR applications has focused on 3D modeling techniques and utilized 3D models. In addition, research on a CT image acquisition method considering 3D modeling has never been reported. The conventional CT image acquisition method involves scanning a limited area of the lesion for the diagnosis of doctors once or twice. However, the medical VR application is required to acquire the CT image considering patients' various postures and a wider area than the lesion. A wider area than the lesion is required because of the necessary process of comparing bilateral sides for dyskinesia diagnosis of the shoulder, pelvis, and leg. Moreover, patients' various postures are required due to the different effects on the musculoskeletal system. Therefore, in this paper, we perform a comparative experiment on the acquired CT images considering image area (unilateral/bilateral) and patients' postures (neutral/abducted). CT images are acquired from 10 patients for the experiments, and the acquired CT images are evaluated based on the length per pixel and the morphological deviation. Finally, by comparing the experiment results, we evaluate the CT image acquisition method for medical VR applications.

  13. {sup 18}F-FDG-PET/CT for systemic staging of newly diagnosed triple-negative breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Ulaner, Gary A.; Castillo, Raychel; Riedl, Christopher C.; Jochelson, Maxine S. [Memorial Sloan Kettering Cancer Center, Department of Radiology, New York, NY (United States); Weill Cornell Medical College, Department of Radiology, New York, NY (United States); Goldman, Debra A.; Goenen, Mithat [Memorial Sloan Kettering Cancer Center, Department of Epidemiology and Biostatistics, New York, NY (United States); Wills, Jonathan [Memorial Sloan Kettering Cancer Center, Department of Information Systems, New York, NY (United States); Pinker-Domenig, Katja [Memorial Sloan Kettering Cancer Center, Department of Radiology, New York, NY (United States)

    2016-10-15

    National Comprehensive Cancer Network guidelines recommend {sup 18}F-FDG-PET/CT, in addition to standard staging procedures, for systemic staging of newly diagnosed stage III breast cancer patients. However, factors in addition to stage may influence PET/CT utility. As breast cancers that are negative for estrogen receptor, progesterone receptor, and human epidermal growth factor receptor (triple-negative breast cancer, or TNBC) are more aggressive and metastasize earlier than other breast cancers, we hypothesized that receptor expression may be one such factor. This study assesses {sup 18}F-FDG-PET/CT for systemic staging of newly diagnosed TNBC. In this Institutional Review Board-approved retrospective study, our Healthcare Information System was screened for patients with TNBC who underwent {sup 18}F-FDG-PET/CT in 2007-2013 prior to systemic or radiation therapy. Initial stage was determined from mammography, ultrasound, magnetic resonance imaging, and/or surgery, if performed prior to {sup 18}F-FDG-PET/CT. {sup 18}F-FDG-PET/CT was evaluated to identify unsuspected extra-axillary regional nodal and distant metastases, as well as unsuspected synchronous malignancies. Kaplan Meier survival estimates were calculated for initial stage IIB patients stratified by whether or not stage 4 disease was detected by {sup 18}F-FDG-PET/CT. A total of 232 patients with TNBC met inclusion criteria. {sup 18}F-FDG-PET/CT revealed unsuspected distant metastases in 30 (13 %): 0/23 initial stage I, 4/82 (5 %) stage IIA, 13/87 (15 %) stage IIB, 4/23 (17 %) stage IIIA, 8/14 (57 %) stage IIIB, and 1/3 (33 %) stage IIIC. Twenty-six of 30 patients upstaged to IV by {sup 18}F-FDG-PET/CT were confirmed by pathology, with the remaining four patients confirmed by follow-up imaging. In addition, seven unsuspected synchronous malignancies were identified in six patients. Initial stage 2B patients who were upstaged to 4 by {sup 18}F-FDG-PET/CT had significantly shorter survival compared to

  14. CT findings of orbital langerhans cell histiocytosis

    International Nuclear Information System (INIS)

    Yi, Gina; Yoon, Hye Kyung; Han, Bokyung Kim; Kim, Kyeong Ah; Choo, In Wook

    2000-01-01

    To evaluate the CT findings in patients with Langerhans cell histiocytosis (LCH) involving the orbit. Orbital CT scans of six children with pathologically proven LCH were retrospectively analyzed. Follow-up CT (n=3D5) and MR (n=3D1) imaging findings were also reviewed. Initial CT scans revealed varying degree of bone destruction with soft-tissue masses, and on nonenhanced images the mean attenuation value was 44 Hounsfield units (HU). All masses showed mild to moderate enhancement with a mean attenuation value of 74 HU. The bony margins abutting onto soft tissue masses were irregular but clearly demarcated. No evidence of calcification or periosteal reaction was noted. Suprasellar mass and rib involvement was noted in one patient and hepatosplenomegaly in two. Follow-up CT and MR images showed that the soft tissue masses were almost completely resolved, with bone remodeling and reossification. A soft tissue mass with irregular but clearly demarcated bone destruction is thought to be a characteristic finding of LCH involving the orbit. Follow-up images after treatment showed bone remodeling and reossification. (author)

  15. Atlas of Skeletal SPECT/CT Clinical Images

    International Nuclear Information System (INIS)

    2016-01-01

    The atlas focuses specifically on single photon emission computed tomography/computed tomography (SPECT/CT) in musculoskeletal imaging, and thus illustrates the inherent advantages of the combination of the metabolic and anatomical component in a single procedure. In addition, the atlas provides information on the usefulness of several sets of specific indications. The publication, which serves more as a training tool rather than a textbook, will help to further integrate the SPECT and CT experience in clinical practice by presenting a series of typical cases with many different patterns of SPECT/CT seen in bone scintigraphy

  16. Dose reduction with adaptive statistical iterative reconstruction for paediatric CT: phantom study and clinical experience on chest and abdomen CT

    Energy Technology Data Exchange (ETDEWEB)

    Gay, F.; Lasalle, S.; Neuenschwander, S.; Brisse, H.J. [Institut Curie, Imaging Department, Paris (France); Pavia, Y.; Pierrat, N. [Institut Curie, Medical Physics Department, Paris (France)

    2014-01-15

    To assess the benefit and limits of iterative reconstruction of paediatric chest and abdominal computed tomography (CT). The study compared adaptive statistical iterative reconstruction (ASIR) with filtered back projection (FBP) on 64-channel MDCT. A phantom study was first performed using variable tube potential, tube current and ASIR settings. The assessed image quality indices were the signal-to-noise ratio (SNR), the noise power spectrum, low contrast detectability (LCD) and spatial resolution. A clinical retrospective study of 26 children (M:F = 14/12, mean age: 4 years, range: 1-9 years) was secondarily performed allowing comparison of 18 chest and 14 abdominal CT pairs, one with a routine CT dose and FBP reconstruction, and the other with 30 % lower dose and 40 % ASIR reconstruction. Two radiologists independently compared the images for overall image quality, noise, sharpness and artefacts, and measured image noise. The phantom study demonstrated a significant increase in SNR without impairment of the LCD or spatial resolution, except for tube current values below 30-50 mA. On clinical images, no significant difference was observed between FBP and reduced dose ASIR images. Iterative reconstruction allows at least 30 % dose reduction in paediatric chest and abdominal CT, without impairment of image quality. (orig.)

  17. Dose reduction with adaptive statistical iterative reconstruction for paediatric CT: phantom study and clinical experience on chest and abdomen CT

    International Nuclear Information System (INIS)

    Gay, F.; Lasalle, S.; Neuenschwander, S.; Brisse, H.J.; Pavia, Y.; Pierrat, N.

    2014-01-01

    To assess the benefit and limits of iterative reconstruction of paediatric chest and abdominal computed tomography (CT). The study compared adaptive statistical iterative reconstruction (ASIR) with filtered back projection (FBP) on 64-channel MDCT. A phantom study was first performed using variable tube potential, tube current and ASIR settings. The assessed image quality indices were the signal-to-noise ratio (SNR), the noise power spectrum, low contrast detectability (LCD) and spatial resolution. A clinical retrospective study of 26 children (M:F = 14/12, mean age: 4 years, range: 1-9 years) was secondarily performed allowing comparison of 18 chest and 14 abdominal CT pairs, one with a routine CT dose and FBP reconstruction, and the other with 30 % lower dose and 40 % ASIR reconstruction. Two radiologists independently compared the images for overall image quality, noise, sharpness and artefacts, and measured image noise. The phantom study demonstrated a significant increase in SNR without impairment of the LCD or spatial resolution, except for tube current values below 30-50 mA. On clinical images, no significant difference was observed between FBP and reduced dose ASIR images. Iterative reconstruction allows at least 30 % dose reduction in paediatric chest and abdominal CT, without impairment of image quality. (orig.)

  18. CT-based injury classification

    International Nuclear Information System (INIS)

    Mirvis, S.E.; Whitley, N.O.; Vainright, J.; Gens, D.

    1988-01-01

    Review of preoperative abdominal CT scans obtained in adults after blunt trauma during a 2.5-year period demonstrated isolated or predominant liver injury in 35 patients and splenic injury in 33 patients. CT-based injury scores, consisting of five levels of hepatic injury and four levels of splenic injury, were correlated with clinical outcome and surgical findings. Hepatic injury grades I-III, present in 33 of 35 patients, were associated with successful nonsurgical management in 27 (82%) or with findings at celiotomy not requiring surgical intervention in four (12%). Higher grades of splenic injury generally required early operative intervention, but eight (36%) of 22 patients with initial grade III or IV injury were managed without surgery, while four (36%) of 11 patients with grade I or II injury required delayed celiotomy and splenectomy (three patients) or emergent rehospitalization (one patient). CT-based injury classification is useful in guiding the nonoperative management of blunt hepatic injury in hemodynamically stable adults but appears to be less reliable in predicting the outcome of blunt splenic injury

  19. A dedicated cone-beam CT system for musculoskeletal extremities imaging: Design, optimization, and initial performance characterization

    International Nuclear Information System (INIS)

    Zbijewski, W.; De Jean, P.; Prakash, P.; Ding, Y.; Stayman, J. W.; Packard, N.; Senn, R.; Yang, D.; Yorkston, J.; Machado, A.; Carrino, J. A.; Siewerdsen, J. H.

    2011-01-01

    Purpose: This paper reports on the design and initial imaging performance of a dedicated cone-beam CT (CBCT) system for musculoskeletal (MSK) extremities. The system complements conventional CT and MR and offers a variety of potential clinical and logistical advantages that are likely to be of benefit to diagnosis, treatment planning, and assessment of therapy response in MSK radiology, orthopaedic surgery, and rheumatology. Methods: The scanner design incorporated a host of clinical requirements (e.g., ability to scan the weight-bearing knee in a natural stance) and was guided by theoretical and experimental analysis of image quality and dose. Such criteria identified the following basic scanner components and system configuration: a flat-panel detector (FPD, Varian 3030+, 0.194 mm pixels); and a low-power, fixed anode x-ray source with 0.5 mm focal spot (SourceRay XRS-125-7K-P, 0.875 kW) mounted on a retractable C-arm allowing for two scanning orientations with the capability for side entry, viz. a standing configuration for imaging of weight-bearing lower extremities and a sitting configuration for imaging of tensioned upper extremity and unloaded lower extremity. Theoretical modeling employed cascaded systems analysis of modulation transfer function (MTF) and detective quantum efficiency (DQE) computed as a function of system geometry, kVp and filtration, dose, source power, etc. Physical experimentation utilized an imaging bench simulating the scanner geometry for verification of theoretical results and investigation of other factors, such as antiscatter grid selection and 3D image quality in phantom and cadaver, including qualitative comparison to conventional CT. Results: Theoretical modeling and benchtop experimentation confirmed the basic suitability of the FPD and x-ray source mentioned above. Clinical requirements combined with analysis of MTF and DQE yielded the following system geometry: a ∼55 cm source-to-detector distance; 1.3 magnification; a 20

  20. Findings chest radiograph and CT in mediastinitis: effcacy of CT in patients with delayed diagnosis

    Energy Technology Data Exchange (ETDEWEB)

    Son, Eun Ju; Hong, Yong Kook; Choe, Kyu Ok [Yonsei Univ. College of Medicine, Seoul (Korea, Republic of)

    1999-01-01

    To analyse the causes the radiologic findings in patients with mediastinitis and to evaluate the efficacy of chest CT scanning in patients with delayed diagnosis. Seventeen patients with histopathologically(n=15) or clinically diagnosed(n=2) mediastinitis were involved in this study. Eleven of the former group underwent surgery, and in four, tube drainage was performed. All underwent chest radiography and CT scanning, and in seven patients, the causes of delayed diagnosis were analysed. The most common cause of mediastinitis was esophageal rupture(n=11). Others were extension from neck abscess to the mediastinum(n=3), complications after a Benthall procedure(n=1), tuberculous lymphadenitis(n=1) and mycotic aneurysm(n=1). Patients with esophageal rupture suffered from underlying diseases such as esophageal cancer(n=2), iatrogenic esophageal rupture(n=2), Boerhaave's syndrome(n=2), and esophagitis(n=1). In patients with neck abscess (n=3), each was secondary to infected cystic hygroma, Ludwig angina, or deep neck infection, respectively. On chest CT, patients with esophageal rupture(n=11) had an abscess in the posterior mediastinum ; nine abscesses extended to the cervical area along the retropharyngeal space, and the patient with Ludwig angina had an abscess involving all compartments of the mediastinum. Among the total of 17 patients, diagnostic delays were found in seven, while five had spontaneous esophageal ruptures and two suffered complications after a Benthall procedure and Tbc lymphadenitis, respectively. The causes of diagnostic delay varied. Among seven patients, pnevmonia was initially diagnosed in two, who were treated ; one had multiorgan failure, and one was suffering from pericardial effusion and lung abscess. In three other patients, chest radiographs initially showed non-specific findings, leading to delayed CT examination. The most common cause of mediastinitis was esophageal rupture, and in these patients, chest radiographs and clinical

  1. Findings chest radiograph and CT in mediastinitis: effcacy of CT in patients with delayed diagnosis

    International Nuclear Information System (INIS)

    Son, Eun Ju; Hong, Yong Kook; Choe, Kyu Ok

    1999-01-01

    To analyse the causes the radiologic findings in patients with mediastinitis and to evaluate the efficacy of chest CT scanning in patients with delayed diagnosis. Seventeen patients with histopathologically(n=15) or clinically diagnosed(n=2) mediastinitis were involved in this study. Eleven of the former group underwent surgery, and in four, tube drainage was performed. All underwent chest radiography and CT scanning, and in seven patients, the causes of delayed diagnosis were analysed. The most common cause of mediastinitis was esophageal rupture(n=11). Others were extension from neck abscess to the mediastinum(n=3), complications after a Benthall procedure(n=1), tuberculous lymphadenitis(n=1) and mycotic aneurysm(n=1). Patients with esophageal rupture suffered from underlying diseases such as esophageal cancer(n=2), iatrogenic esophageal rupture(n=2), Boerhaave's syndrome(n=2), and esophagitis(n=1). In patients with neck abscess (n=3), each was secondary to infected cystic hygroma, Ludwig angina, or deep neck infection, respectively. On chest CT, patients with esophageal rupture(n=11) had an abscess in the posterior mediastinum ; nine abscesses extended to the cervical area along the retropharyngeal space, and the patient with Ludwig angina had an abscess involving all compartments of the mediastinum. Among the total of 17 patients, diagnostic delays were found in seven, while five had spontaneous esophageal ruptures and two suffered complications after a Benthall procedure and Tbc lymphadenitis, respectively. The causes of diagnostic delay varied. Among seven patients, pnevmonia was initially diagnosed in two, who were treated ; one had multiorgan failure, and one was suffering from pericardial effusion and lung abscess. In three other patients, chest radiographs initially showed non-specific findings, leading to delayed CT examination. The most common cause of mediastinitis was esophageal rupture, and in these patients, chest radiographs and clinical symptoms

  2. Real-time CT-video registration for continuous endoscopic guidance

    Science.gov (United States)

    Merritt, Scott A.; Rai, Lav; Higgins, William E.

    2006-03-01

    Previous research has shown that CT-image-based guidance could be useful for the bronchoscopic assessment of lung cancer. This research drew upon the registration of bronchoscopic video images to CT-based endoluminal renderings of the airway tree. The proposed methods either were restricted to discrete single-frame registration, which took several seconds to complete, or required non-real-time buffering and processing of video sequences. We have devised a fast 2D/3D image registration method that performs single-frame CT-Video registration in under 1/15th of a second. This allows the method to be used for real-time registration at full video frame rates without significantly altering the physician's behavior. The method achieves its speed through a gradient-based optimization method that allows most of the computation to be performed off-line. During live registration, the optimization iteratively steps toward the locally optimal viewpoint at which a CT-based endoluminal view is most similar to a current bronchoscopic video frame. After an initial registration to begin the process (generally done in the trachea for bronchoscopy), subsequent registrations are performed in real-time on each incoming video frame. As each new bronchoscopic video frame becomes available, the current optimization is initialized using the previous frame's optimization result, allowing continuous guidance to proceed without manual re-initialization. Tests were performed using both synthetic and pre-recorded bronchoscopic video. The results show that the method is robust to initialization errors, that registration accuracy is high, and that continuous registration can proceed on real-time video at >15 frames per sec. with minimal user-intervention.

  3. SU-F-T-261: Reconstruction of Initial Photon Fluence Based On EPID Images

    Energy Technology Data Exchange (ETDEWEB)

    Seliger, T; Engenhart-Cabillic, R [Philipp University of Marburg, Marburg (Germany); Czarnecki, D; Maeder, U; Zink, K [Technische Hochschule Mittelhessen - University of Applied Sciences, Giessen (Germany); Kussaether, R [MedCom GmbH, Darmstadt (Germany); Poppe, B [University Hospital for Medical Radiation Physics, Pius-Hospital, Medical Campus, Carl von Ossietzky University of Oldenburg (Germany)

    2016-06-15

    Purpose: Verifying an algorithm to reconstruct relative initial photon fluence for clinical use. Clinical EPID and CT images were acquired to reconstruct an external photon radiation treatment field. The reconstructed initial photon fluence could be used to verify the treatment or calculate the applied dose to the patient. Methods: The acquired EPID images were corrected for scatter caused by the patient and the EPID with an iterative reconstruction algorithm. The transmitted photon fluence behind the patient was calculated subsequently. Based on the transmitted fluence the initial photon fluence was calculated using a back-projection algorithm which takes the patient geometry and its energy dependent linear attenuation into account. This attenuation was gained from the acquired cone-beam CT or the planning CT by calculating a water-equivalent radiological thickness for each irradiation direction. To verify the algorithm an inhomogeneous phantom consisting of three inhomogeneities was irradiated by a static 6 MV photon field and compared to a reference flood field image. Results: The mean deviation between the reconstructed relative photon fluence for the inhomogeneous phantom and the flood field EPID image was 3% rising up to 7% for off-axis fluence. This was probably caused by the used clinical EPID calibration, which flattens the inhomogeneous fluence profile of the beam. Conclusion: In this clinical experiment the algorithm achieved good results in the center of the field while it showed high deviation of the lateral fluence. This could be reduced by optimizing the EPID calibration, considering the off-axis differential energy response. In further progress this and other aspects of the EPID, eg. field size dependency, CT and dose calibration have to be studied to realize a clinical acceptable accuracy of 2%.

  4. Pulmonary CT findings in acute mercury vapour exposure

    Energy Technology Data Exchange (ETDEWEB)

    Hashimoto, Manabu; Sato, Kimihiko; Heianna, Jyouiti; Hirano, Yoshinori; Omachi, Kohiti; Izumi, Jyunichi; Watarai, Jiro

    2001-01-01

    AIM: We describe the pulmonary computed tomography (CT) findings in acute mercury poisoning. MATERIALS AND METHODS: Initial (n= 8) and follow-up (n= 6) chest CT examinations in eight patients exposed to mercury vapour while cutting pipes in a sulphuric acid plant were reviewed. Of the eight patients, two were asymptomatic and had normal CT results, two were asymptomatic but had abnormalities on CT, and four had both acute symptoms and positive CT results. The patients were all men whose ages ranged from 37 to 54 years (mean, 49 years). RESULTS: Poorly defined nodules were present in five of six patients with positive CT findings, present alone in two patients or as part of a mixed pattern in three. They were random in distribution. Alveolar consolidation (n= 3) and areas of ground-glass opacity (n= 4) were observed and were more prominent in the most severely affected patients with the highest blood and urine level of mercury, predominantly in the upper and/or middle zone. These abnormal findings on CT resolved with (n= 1) or without (n= 5) steroid therapy. Pathological findings (n= 1) demonstrated acute interstitial changes predominantly with oedema. CONCLUSION: We report CT findings in eight patients acutely exposed to mercury vapour. The pulmonary injury was reversible on CT in these cases. Hashimoto, M. (2001)

  5. First experience with single-source dual-energy computed tomography in six patients with acute arthralgia: a feasibility experiment using joint aspiration as a reference

    International Nuclear Information System (INIS)

    Diekhoff, Torsten; Kiefer, Tobias; Hamm, Bernd; Hermann, Kay-Geert A.; Ziegeler, Katharina; Feist, Eugen; Mews, Juergen

    2015-01-01

    Dual-energy computed tomography (DECT) is an emerging imaging technique for examining patients with suspected gout. Single-source dual-energy CT (S-DECT) is a new way of obtaining DECT information on conventional CT scanners rather than using special dual-source CT systems. We tested the feasibility of S-DECT (320-row CT; Aquilion ONE, Toshiba Medical Systems, Otawara, Japan) in 6 patients (5 men, 1 woman; mean age 61.3, range 48 to 69 years) with acute arthralgia and suspected gout, and compared the S-DECT findings with the results of joint aspiration. Three patients had a diagnosis of gouty arthritis with negatively birefringent crystals in synovial fluid, in addition to gouty tophi in S-DECT. Three patients had no detectable crystals by polarization microscopy and no tophi on DECT. Their final diagnoses were rheumatoid arthritis, activated osteoarthritis, and septic arthritis in one case each. This initial experience suggests that S-DECT might be a valuable alternative to dual-source CT. Hence, more patients may benefit from its additional diagnostic abilities in the future. (orig.)

  6. First experience with single-source dual-energy computed tomography in six patients with acute arthralgia: a feasibility experiment using joint aspiration as a reference

    Energy Technology Data Exchange (ETDEWEB)

    Diekhoff, Torsten; Kiefer, Tobias; Hamm, Bernd; Hermann, Kay-Geert A. [Charite - Universitaetsmedizin Berlin Campus Mitte, Humboldt-Universitaet zu Berlin, Freie Universitaet Berlin, Department of Radiology, Berlin (Germany); Ziegeler, Katharina; Feist, Eugen [Charite - Universitaetsmedizin Berlin Campus Mitte, Humboldt-Universitaet zu Berlin, Freie Universitaet Berlin, Department of Rheumatology and Clinical Immunology, Berlin (Germany); Mews, Juergen [Toshiba Medical Systems Europe, BV, Zoetermeer (Netherlands)

    2015-11-15

    Dual-energy computed tomography (DECT) is an emerging imaging technique for examining patients with suspected gout. Single-source dual-energy CT (S-DECT) is a new way of obtaining DECT information on conventional CT scanners rather than using special dual-source CT systems. We tested the feasibility of S-DECT (320-row CT; Aquilion ONE, Toshiba Medical Systems, Otawara, Japan) in 6 patients (5 men, 1 woman; mean age 61.3, range 48 to 69 years) with acute arthralgia and suspected gout, and compared the S-DECT findings with the results of joint aspiration. Three patients had a diagnosis of gouty arthritis with negatively birefringent crystals in synovial fluid, in addition to gouty tophi in S-DECT. Three patients had no detectable crystals by polarization microscopy and no tophi on DECT. Their final diagnoses were rheumatoid arthritis, activated osteoarthritis, and septic arthritis in one case each. This initial experience suggests that S-DECT might be a valuable alternative to dual-source CT. Hence, more patients may benefit from its additional diagnostic abilities in the future. (orig.)

  7. Experimental research on rear collimator in γ-ray industrial CT

    International Nuclear Information System (INIS)

    Wu Zhifang; Liu Jinhui

    2009-01-01

    Rear collimator is one of the key components in the γ-ray industrial CT, which plays an important role in removing scattering influence and improving the CT spatial resolution. High-performance CT is always associated with a high-quality collimator. By means of experiments, this paper discusses the behavior of collimators with different shapes and structures from the aspects of detector output signal, mass attenuation coefficient of the inspected object and quality of the actual CT image. The qualitative and quantitative results are reached, which are helpful for the design of high-performance industrial CT.

  8. CT of hemodynamically unstable abdominal trauma

    Energy Technology Data Exchange (ETDEWEB)

    Petridis, A.; Pilavaki, M.; Vafiadis, E.; Palladas, P.; Finitsis, S.; Drevelegas, A. [Department of Radiology, General Hospital ``G. Papanikolaou,`` Thessaloniki (Greece)

    1999-03-01

    This article is an appraisal of the use of CT in the management of patients with unstable abdominal trauma. We examined 41 patients with abdominal trauma using noncontrast dynamic CT. In 17 patients a postcontrast dynamic CT was also carried out. On CT, 25 patients had hemoperitoneum. Thirteen patients had splenic, 12 hepatic, 6 pancreatic, 8 bowel and mesenteric, 12 renal and 2 vascular injuries. Seven patients had retroperitoneal and 2 patients adrenal hematomas. All but five lesions (three renal, one pancreatic, and one splenic) were hypodense when CT was performed earlier than 8 h following the injury. Postcontrast studies (n = 17), revealed 4 splenic, 3 hepatic, 1 pancreatic, 3 renal, and 2 bowel and mesenteric injuries beyond what was found on noncontrast CT. Surgical confirmation (n = 21) was obtained in 81.81 % of splenic, 66.66 % of hepatic, 83.33 % of pancreatic, 100 % of renal, 100 % of retroperitoneal, and 85.71 % of bowel and mesenteric injuries. The majority of false diagnoses was obtained with noncontrast studies. Computed tomography is a remarkable method for evaluation and management of patients with hemodynamically unstable abdominal trauma, but only if it is revealed in the emergency room. Contrast injection, when it could be done, revealed lesions that were not suspected on initial plain scans. (orig.) With 6 figs., 5 tabs., 20 refs.

  9. Low-dose CT image reconstruction using gain intervention-based dictionary learning

    Science.gov (United States)

    Pathak, Yadunath; Arya, K. V.; Tiwari, Shailendra

    2018-05-01

    Computed tomography (CT) approach is extensively utilized in clinical diagnoses. However, X-ray residue in human body may introduce somatic damage such as cancer. Owing to radiation risk, research has focused on the radiation exposure distributed to patients through CT investigations. Therefore, low-dose CT has become a significant research area. Many researchers have proposed different low-dose CT reconstruction techniques. But, these techniques suffer from various issues such as over smoothing, artifacts, noise, etc. Therefore, in this paper, we have proposed a novel integrated low-dose CT reconstruction technique. The proposed technique utilizes global dictionary-based statistical iterative reconstruction (GDSIR) and adaptive dictionary-based statistical iterative reconstruction (ADSIR)-based reconstruction techniques. In case the dictionary (D) is predetermined, then GDSIR can be used and if D is adaptively defined then ADSIR is appropriate choice. The gain intervention-based filter is also used as a post-processing technique for removing the artifacts from low-dose CT reconstructed images. Experiments have been done by considering the proposed and other low-dose CT reconstruction techniques on well-known benchmark CT images. Extensive experiments have shown that the proposed technique outperforms the available approaches.

  10. Enabling minimal invasive parathyroidectomy for patients with primary hyperparathyroidism using Tc-99m-sestamibi SPECT–CT, ultrasound and first results of {sup 18}F-fluorocholine PET–CT

    Energy Technology Data Exchange (ETDEWEB)

    Kluijfhout, Wouter P., E-mail: WPKluijfhout@gmail.com [Department of Endocrine Surgery, University Medical Center Utrecht, Utrecht (Netherlands); Vorselaars, Wessel M.C.M., E-mail: W.M.Vorselaars@umcutrecht.nl [Department of Endocrine Surgery, University Medical Center Utrecht, Utrecht (Netherlands); Vriens, Menno R., E-mail: mvriens@umcutrecht.nl [Department of Endocrine Surgery, University Medical Center Utrecht, Utrecht (Netherlands); Borel Rinkes, Inne H.M., E-mail: I.H.M.BorelRinkes@umcutrecht.nl [Department of Endocrine Surgery, University Medical Center Utrecht, Utrecht (Netherlands); Valk, Gerlof D., E-mail: G.D.Valk@umcutrecht.nl [Department of Endocrinology, University Medical Center Utrecht, Utrecht (Netherlands); Keizer, Bart de, E-mail: B.deKeizer@umcutrecht.nl [Department of Nuclear Medicine and Radiology, University Medical Center Utrecht, Utrecht (Netherlands)

    2015-09-15

    Highlights: • We examined an optimal pre-operative imaging strategy. • Goal was to perform minimal invasive parathyroidectomy. • Ultrasound significantly decreased the PPV when added to SPECT–CT. • {sup 18}F-fluorocholine was positive in 4/5 cases with negative conventional imaging. - Abstract: Objective: Assessment of the diagnostic value of ultrasound (US), single photon-emission computed tomography–computed tomography (SPECT–CT) and {sup 18}F-fluorocholine (FCH) PET–CT for preoperative localization of hyper-functioning parathyroid(s) in order to create a more efficient diagnostic pathway and enable minimal invasive parathyroidectomy (MIP) in patients with biochemical proven non-familial primary hyperparathyroidism (pHPT). Methods: A single-institution retrospective study of 63 consecutive patients with a biochemical diagnosis of non-familial pHPT who received a Tc-99m-sestamibi SPECT–CT and neck ultrasound. Surgical findings were used in calculating the sensitivity and the positive predictive value (PPV) of both imaging modalities. Furthermore we present 5 cases who received additional FCH PET–CT. Results: A total of 42 (66.7%) patients underwent MIP. The PPV and sensitivity of SPECT–CT, 93.0% and 80.3%, were significantly higher than those of US with 78.3% and 63.2%, respectively. Adding US to SPECT–CT for initial pre-operative localization did not significantly increase sensitivity but did significantly decrease PPV. Performance of US was significantly better when performed after SPECT–CT. {sup 18}F-fluorocholine PET–CT localized the hyper-functioning parathyroid gland in 4/5 cases with discordant conventional imaging, enabling MIP. Conclusion: SPECT–CT is the imaging modality of choice for initial pre-operative localization of hyper-functioning parathyroid gland(s) in patients with biochemical pHPT. Ultrasound should be performed after SPECT–CT for confirmation of positive SPECT–CT findings and for pre-operative marking

  11. Intraarterial CT Angiography Using Ultra Low Volume of Iodine Contrast – Own Experiences

    International Nuclear Information System (INIS)

    Garcarek, Jerzy; Kurcz, Jacek; Guziński, Maciej; Banasik, Mirosław; Miś, Marcin; Gołębiowski, Tomasz

    2015-01-01

    High volume of intravenous contrast in CT-angiography may result in contrast-induced nephropathy. Intraarterial ultra-low volume of contrast medium results in its satisfactory blood concentration with potentially good image quality. The first main purpose was to assess the influence of the method on function of transplanted kidney in patients with impaired graft function. The second main purpose of the study was to evaluate the usefulness of this method for detection of gastrointestinal and head-and-neck haemorrhages. Between 2010 and 2013 intraarterial CT-angiography was performed in 56 patients, including 28 with chronic kidney disease (CKD). There were three main subgroups: 18 patients after kidney transplantation, 10 patients with gastrointestinal hemorrhage, 8 patients with head-and-neck hemorrhage. Contralateral or ipsilateral inguinal arterial approach was performed. The 4-French vascular sheaths and 4F-catheters were introduced under fluoroscopy. Intraarterial CT was performed using 64-slice scanner. The scanning protocol was as follows: slice thickness 0.625 mm, pitch 1.3, gantry rotation 0.6 sec., scanning delay 1–2 sec. The extent of the study was established on the basis of scout image. In patients with CKD 6–8 mL of Iodixanol (320 mg/mL) diluted with saline to 18–24 mL was administered at a speed of 4–5 mL/s. Vasculature was properly visualized in all patients. In patients with impaired renal function creatinine/eGFR levels remained stable in all but one case. Traditional arteriography failed and CT-angiography demonstrated the site of bleeding in 3 of 10 patients with symptoms of gastrointestinal bleeding (30%). In 8 patients with head-and-neck bleeding CT-angiography did not prove beneficial when compared to traditional arteriography. 1. Ultra-low contrast intraarterial CT-angiography does not deteriorate the function of transplanted kidneys in patients with impaired graft function. 2. 3D reconstructions allow for excellent visualization of

  12. Flat panel computed tomography of human ex vivo heart and bone specimens: initial experience

    Energy Technology Data Exchange (ETDEWEB)

    Nikolaou, Konstantin; Becker, Christoph R.; Reiser, Maximilian F. [Ludwig-Maximilians-University, Department of Clinical Radiology, Munich (Germany); Flohr, Thomas; Stierstorfer, Karl [CT Division, Siemens Medical Solutions, Forchheim (Germany)

    2005-02-01

    The aim of this technical investigation was the detailed description of a prototype flat panel detector computed tomography system (FPCT) and its initial evaluation in an ex vivo setting. The prototype FPCT scanner consists of a conventional radiographic flat panel detector, mounted on a multi-slice CT scanner gantry. Explanted human ex vivo heart and foot specimens were examined. Images were reformatted with various reconstruction algorithms and were evaluated for high-resolution anatomic information. For comparison purposes, the ex vivo specimens were also scanned with a conventional 16-detector-row CT scanner (Sensation 16, Siemens Medical Solutions, Forchheim, Germany). With the FPCT prototype used, a 1,024 x 768 resolution matrix can be obtained, resulting in an isotropic voxel size of 0.25 x 0.25 x 0.25 mm at the iso-center. Due to the high spatial resolution, very small structures such as trabecular bone or third-degree, distal branches of coronary arteries could be visualized. This first evaluation showed that flat panel detector systems can be used in a cone-beam computed tomography scanner and that very high spatial resolutions can be achieved. However, there are limitations for in vivo use due to constraints in low contrast resolution and slow scan speed. (orig.)

  13. A short comparison between mT2 and mCT

    International Nuclear Information System (INIS)

    Serna, Mario

    2008-01-01

    We compare m T2 with m CT ; both are kinematic variables designed to find relationships between masses of pair-produced new states with symmetric decay chains. We find that for massless visible particles m CT equals m T2 in a particular limit. We identify advantages and disadvantages to the use of each variable. Tovey's paper on m CT also introduced a powerful concept of extracting mass information from an analysis at intermediate stages of a symmetric decay chain. We suggest that m T2 is a better tool for performing this analysis than m CT due to m T2 's better properties under initial state radiation.

  14. Comparison of CT numbers between cone-beam CT and multi-detector CT

    International Nuclear Information System (INIS)

    Kim, Dong Soo; Han, Won Jeong; Kim, Eun Kyung

    2010-01-01

    To compare the CT numbers on 3 cone-beam CT (CBCT) images with those on multi-detector CT (MDCT) image using CT phantom and to develop linear regressive equations using CT numbers to material density for all the CT scanner each. Mini CT phantom comprised of five 1 inch thick cylindrical models with 1.125 inches diameter of materials with different densities (polyethylene, polystyrene, plastic water, nylon and acrylic) was used. It was scanned in 3 CBCTs (i-CAT, Alphard VEGA, Implagraphy SC) and 1 MDCT (Somatom Emotion). The images were saved as DICOM format and CT numbers were measured using OnDemand 3D. CT numbers obtained from CBCTs and MDCT images were compared and linear regression analysis was performed for the density, ρ(g/cm 3 ), as the dependent variable in terms of the CT numbers obtained from CBCTs and MDCT images. CT numbers on i-CAT and Implagraphy CBCT images were smaller than those on Somatom Emotion MDCT image (p<0.05). Linear relationship on a range of materials used for this study were ρ=0.001 H+1.07 with R2 value of 0.999 for Somatom Emotion, ρ=0.002 H+1.09 with R2 value of 0.991 for Alphard VEGA, ρ=0.001 H+1.43 with R2 value of 0.980 for i-CAT and ρ=0.001 H+1.30 with R2 value of 0.975 for Implagraphy. CT numbers on i-CAT and Implagraphy CBCT images were not same as those on Somatom Emotion MDCT image. The linear regressive equations to determine the density from the CT numbers with very high correlation coefficient were obtained on three CBCT and MDCT scan.

  15. Comparison of CT numbers between cone-beam CT and multi-detector CT

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dong Soo; Han, Won Jeong; Kim, Eun Kyung [Department of Oral and Maxillofacial Radiology, School of Dentistry, Dankook University, Cheonan (Korea, Republic of)

    2010-06-15

    To compare the CT numbers on 3 cone-beam CT (CBCT) images with those on multi-detector CT (MDCT) image using CT phantom and to develop linear regressive equations using CT numbers to material density for all the CT scanner each. Mini CT phantom comprised of five 1 inch thick cylindrical models with 1.125 inches diameter of materials with different densities (polyethylene, polystyrene, plastic water, nylon and acrylic) was used. It was scanned in 3 CBCTs (i-CAT, Alphard VEGA, Implagraphy SC) and 1 MDCT (Somatom Emotion). The images were saved as DICOM format and CT numbers were measured using OnDemand 3D. CT numbers obtained from CBCTs and MDCT images were compared and linear regression analysis was performed for the density, {rho}(g/cm{sup 3}), as the dependent variable in terms of the CT numbers obtained from CBCTs and MDCT images. CT numbers on i-CAT and Implagraphy CBCT images were smaller than those on Somatom Emotion MDCT image (p<0.05). Linear relationship on a range of materials used for this study were {rho}=0.001 H+1.07 with R2 value of 0.999 for Somatom Emotion, {rho}=0.002 H+1.09 with R2 value of 0.991 for Alphard VEGA, {rho}=0.001 H+1.43 with R2 value of 0.980 for i-CAT and {rho}=0.001 H+1.30 with R2 value of 0.975 for Implagraphy. CT numbers on i-CAT and Implagraphy CBCT images were not same as those on Somatom Emotion MDCT image. The linear regressive equations to determine the density from the CT numbers with very high correlation coefficient were obtained on three CBCT and MDCT scan.

  16. Socio-economics on computed tomography (CT) scanner

    International Nuclear Information System (INIS)

    Niki, Ryu

    1983-01-01

    It was in 1975, only eight years ago, that a CT scanner was first introduced into Japan, which demonstrated enormous power in the early diagnosis of cephalic disease. Since then, CT has spread rapidly in spite of the initial high price of 200 million yen, and has attained 2,120 sets as of December, 1982. The rate of CT propagation in Japan is 18.5 sets per one million persons, or No. 1 in the world. However, its socio-economic investigation has only been done fragmentarily in Japan. In this report, the CT is investigated in three aspects of medical facilities, medical instrument manufacturers, and the medical fee of nation. In Japan, the CT installation has largely increased by 20 times in five years from 1977 to 1981, and has widely spread not only to medium to small scale hospitals but also to general clinics. In this report, the CT is investigated for the number in various facilities and prefectures, and the comparison of the state of use in USA and Japan. Since 1979, the products of domestic manufacturers were at advantage over foreign products in Japan, and Hitachi and Toshiba have been predominant among them. The fee for CT in Japan is only 1/5 as compared with that in the U.S. Setting extremely low fee like this may get into the danger to induce excessive inspection. The significant popularization of CT in Japan is much concerned with the features of Japanese medical care system as well as the medical technological characteristics of the CT. (Wakatsuki, Y.)

  17. Phase-contrast X-ray CT

    Energy Technology Data Exchange (ETDEWEB)

    Momose, Atsushi [Hitachi Ltd., Saitama (Japan). Advanced Research Laboratory; Takeda, Tohoru; Itai, Yuji

    1995-12-01

    Phase-contrast X-ray computed tomography (CT) enabling the observation of biological soft tissues without contrast enhancement has been developed. The X-ray phase shift caused by an object is measured and input to a standard CT reconstruction algorithm. A thousand times increase in the image sensitivity to soft tissues is achieved compared with the conventional CT using absorption contrast. This is because the X-ray phase shift cross section of light elements is about a thousand times larger than the absorption cross section. The phase shift is detected using an X-ray interferometer and computer analyses of interference patterns. Experiments were performed using a synchrotron X-ray source. Excellent image sensitivity is demonstrated in the observation of cancerous rabbit liver. The CT images distinguish cancer lesion from normal liver tissue and, moreover, visualize the pathological condition in the lesion. Although the X-ray energy employed and the present observation area size are not suitable for medical applications as they are, phase-contrast X-ray CT is promising for investigating the internal structure of soft tissue which is almost transparent for X-rays. The high sensitivity also provides the advantage of reducing X-ray doses. (author).

  18. Preliminary results from initial in-pile debris bed experiments

    International Nuclear Information System (INIS)

    Rivard, J.B.

    1977-01-01

    An accident in a liquid metal fast breeder reactor (LMFBR) in which molten core material is suddenly quenched with subcooled liquid sodium could result in extensive fragmentation and dispersal of fuel as subcritical beds of frozen particulate debris within the reactor vessel. Since this debris will continue to generate power due to decay of retained fission products, containment of the debris is threatened if the generated heat is not removed. Therefore, the initial safety question is the capacity which debris beds may have for transfer of the decay heat to overlying liquid sodium by natural processes--i.e., without the aid of forced circulation of the coolant. Up to the present time, all experiments on debris bed behavior either have used substitute materials (e.g., sand and water) or have employed actual materials, but atypical heating methods. Increased confidence in the applicability of debris bed simulations is afforded if the heat is generated within the fuel component of the appropriate fast reactor materials. The initial series of in-pile tests reported on herein constitutes the first experiments in which the internal heating mode has been produced in particulate oxide fuel immersed in liquid sodium. Fission heating of the fully-enriched UO 2 in the experiment while it is contained within Sandia Laboratories Annular Core Pulse Reactor (ACPR), operating in its steady-state mode, approximates the decay heating of debris. Preliminary results are discussed

  19. CT urography of urinary diversions with enhanced CT digital radiography: preliminary experience.

    Science.gov (United States)

    Sudakoff, Gary S; Guralnick, Michael; Langenstroer, Peter; Foley, W Dennis; Cihlar, Krista L; Shakespear, Jonathan S; See, William A

    2005-01-01

    The purpose of this study was to determine if 3D-rendered CT urography (CTU) depicts both normal and abnormal findings in patients with urinary diversions and if the addition of contrast-enhanced CT digital radiography (CTDR) improves opacification of the urinary collecting system. Thirty CTU and contrast-enhanced CTDR examinations were performed in 24 patients who underwent cystectomy for bladder cancer. Indications for evaluation included hematuria, tumor surveillance, or suspected diversion malfunction. All examinations were evaluated without knowledge of the stage or grade of a patient's tumor and were compared with the clinical records. Opacification of the urinary collecting system was evaluated with 3D CTU alone, contrast-enhanced CTDR alone, and combined CTU and CTDR. Nine abnormalities were identified including distal ureteral strictures (n = 4), vascular compression of the mid left ureter (n = 1), scarring of the mid right pole infundibulum (n = 1), bilateral hydronephrosis and hydroureter (n = 1), urinary reservoir calculus (n = 1), and tumor recurrence invading the afferent limb of the neobladder (n = 1). Eight of the nine detected abnormalities were surgically or pathologically confirmed. All abnormalities were identified on all three imaging techniques but were best seen on 3D CTU and enhanced CTDR images. Incomplete opacification of the urinary collecting system occurred in 17 patients with CTU alone, 12 patients with contrast-enhanced CTDR alone, and nine patients with combined CTU and contrast-enhanced CTDR. Compared with CTU alone, the combined technique of 3D CTU and contrast-enhanced CTDR improved opacification by a statistically significant difference (p = 0.037). CTU with 3D rendering can accurately depict both normal and abnormal postoperative findings in patients with urinary diversions. Adding enhanced CTDR can improve visualization of the urinary collecting system.

  20. Analysis of molten fuel-coolant interaction during a reactivity-initiated accident experiment

    International Nuclear Information System (INIS)

    El-Genk, M.S.; Hobbins, R.R.

    1981-01-01

    The results of a reactivity-initiated accident experiment, designated RIA-ST-4, are discussed and analyzed with regard to molten fuel-coolant interaction (MFCI). In this experiment, extensive amounts of molten UO 2 fuel and zircaloy cladding were produced and fragmented upon mixing with the coolant. Coolant pressurization up to 35 MPa and coolant overheating in excess of 940 K occurred after fuel rod failure. The initial coolant conditions were similar to those in boiling water reactors during a hot startup (that is, coolant pressure of 6.45 MPa, coolant temperature of 538 K, and coolant flow rate of 85 cm 3 /s). It is concluded that the high coolant pressure recorded in the RIA-ST-4 experiment was caused by an energetic MFCI and was not due to gas release from the test rod at failure, Zr/water reaction, or to UO 2 fuel vapor pressure. The high coolant temperature indicated the presence of superheated steam, which may have formed during the expansion of the working fluid back to the initial coolant pressure; yet, the thermal-to-mechanical energy conversion ratio is estimated to be only 0.3%

  1. Determination of urinary stone composition using dual-energy spectral CT: Initial in vitro analysis

    International Nuclear Information System (INIS)

    Li, X.-H.; Zhao, R.; Liu, B.; Yu, Y.-Q.

    2013-01-01

    Aim: To evaluate the feasibility of determining the chemical composition of urinary stones using computed tomography (CT) spectral imaging (SI) Materials and methods: Two hundred and ten urinary stones were scanned in vitro using the SI mode and conventional polychromatic imaging (CPI; 120 kVp) mode. The radiodensity at 50 keV and 120 kVp, the mean calcium density (CD), and the water density (WD) were measured using the 50 keV images, 120 kVp images, calcium-based images, and water-based images, respectively. These parameters and the calcium–water ratio (CWR) were compared between different types of stones. CWR was defined as: CWR = ‌calcium density/water density‌. Results: According to the results determined by infrared spectroscopy, 116 pure urinary stones were divided into five groups: uric acid (UA, n = 16), struvite (STR, n = 23), cystine (CYS, n = 10), calcium phosphate (CaP, n = 29), and calcium oxalate (COX, n = 38). CD, CWR, and the radiodensity of stones at 50 keV CT imaging of each group were as follows: UA (−3.55 ± 10.85 mg/ml, 0.03 ± 0.05, 510.08 ± 157.29 HU); STR (224.99 ± 64.28 mg/ml, 0.19 ± 0.07, 1058.58 ± 260.13 HU); CYS (139.67 ± 34.66 mg/ml, 0.13 ± 0.03, 725.75 ± 142.35 HU); CaP (619.39 ± 26.13 mg/ml, 0.69 ± 0.11, 2617.46 ± 186.22 HU); COX (518.61 ± 95.5 mg/ml, 0.58 ± 0.1, 2247.47 ± 379.51 HU). The differences in the CD, CRW, and radiodensity of stones at 50 keV CT imaging among the groups were statistically significant by binary comparison (p < 0.05). There were no significant differences in the radiodensity of stones at 120 keV CT imaging between UA and CYS (p = 0.267), CaP and COX (p = 0.065), and in the WD between STR and CYS (p = 0.108). Conclusion: SI provides a novel method to better characterize pure urinary stones using the mean CD, CWR, and the radiodensity of stones at 50 keV CT imaging

  2. Preliminary experience on the use of PET/CT in the management of pediatric post-transplant lymphoproliferative disorder.

    Science.gov (United States)

    Guerra-García, Pilar; Hirsch, Steffen; Levine, Daniel S; Taj, Mary M

    2017-12-01

    Post-transplant lymphoproliferative disorder (PTLD) is a well-known complication following prolonged immunosuppression. Contrary to other lymphomas, there is no standardized imaging approach to assess PTLD either at staging or for response to therapy. Positron emission tomography/computed tomography (PET/CT) is an imaging modality that has proven to be useful in lymphoma. However, there is still limited data concerning its use in pediatric PTLD. Our study evaluates the use of PET/CT in pediatric PTLD at our institution. To assess the role of PET/CT in pediatric PTLD, we reviewed the pediatric patients with PTLD who had undergone PET/CT at our institution between 2000 and 2016. Nine patients were identified. Six had PET/CT at diagnosis. All lesions seen on CT were identified with PET/CT. Fourteen PET/CTs were done during treatment. Eight PET/CTs were negative, including three where CT showed areas of uncertain significance. In these cases, PET/CT helped us to stop treatment and the patients remain in remission after a long follow-up (mean 74.3 months; range 12.4-180.9 months). PET/CT revealed additional disease in two cases, therefore treatment was intensified. Six biopsies and close follow-up was done to confirm PET/CT results. In one case, PET/CT did not identify central nervous system involvement demonstrated on magnetic resonance imaging. PET/CT may have an important role in the staging and follow-up of pediatric PTLD. In our cohort, PET/CT was helpful in staging and assessing treatment response and in clarifying equivocal findings on other imaging modalities. © 2017 Wiley Periodicals, Inc.

  3. SPECT/CT imaging in children with papillary thyroid carcinoma

    International Nuclear Information System (INIS)

    Kim, Hwa-Young; Gelfand, Michael J.; Sharp, Susan E.

    2011-01-01

    SPECT/CT improves localization of single photon-emitting radiopharmaceuticals. To determine the utility of SPECT/CT in children with papillary thyroid carcinoma. 20 SPECT/CT and planar studies were reviewed in 13 children with papillary thyroid carcinoma after total thyroidectomy. Seven studies used I-123 and 13 used I-131, after elevating TSH by T4 deprivation or intramuscular thyrotropin alfa. Eight children had one study and five children had two to four studies. Studies were performed at initial post-total thyroidectomy evaluation, follow-up and after I-131 treatment doses. SPECT/CT was performed with a diagnostic-quality CT unit in 13 studies and a localization-only CT unit in 7. Stimulated thyroglobulin was measured (except in 2 cases with anti-thyroglobulin antibodies). In 13 studies, neck activity was present but poorly localized on planar imaging; all foci of uptake were precisely localized by SPECT/CT. Two additional foci of neck uptake were found on SPECT/CT. SPECT/CT differentiated high neck uptake from facial activity. In six studies (four children), neck uptake was identified as benign by SPECT/CT (three thyroglossal duct remnants, one skin contamination, two by precise anatomical CT localization). In two children, SPECT/CT supported a decision not to treat with I-131. When SPECT/CT was unable to identify focal uptake as benign, stimulated thyroglobulin measurements were valuable. In three of 13 studies with neck uptake, SPECT/CT provided no useful additional information. SPECT/CT precisely localizes neck iodine uptake. In small numbers of patients, treatment is affected. SPECT/CT should be used when available in thyroid carcinoma patients. (orig.)

  4. Detection of occult, undisplaced hip fractures with a dual-energy CT algorithm targeted to detection of bone marrow edema.

    Science.gov (United States)

    Reddy, T; McLaughlin, P D; Mallinson, P I; Reagan, A C; Munk, P L; Nicolaou, S; Ouellette, H A

    2015-02-01

    The purpose of this study is to describe our initial clinical experience with dual-energy computed tomography (DECT) virtual non-calcium (VNC) images for the detection of bone marrow (BM) edema in patients with suspected hip fracture following trauma. Twenty-five patients presented to the emergency department at a level 1 trauma center between January 1, 2011 and January 1, 2013 with clinical suspicion of hip fracture and normal radiographs were included. All CT scans were performed on a dual-source, dual-energy CT system. VNC images were generated using prototype software and were compared to regular bone reconstructions by two musculoskeletal radiologists in consensus. Radiological and/or clinical diagnosis of fracture at 30-day follow-up was used as the reference standard. Twenty-one patients were found to have DECT-VNC signs of bone marrow edema. Eighteen of these 21 patients were true positive and three were false positive. A concordant fracture was clearly seen on bone reconstruction images in 15 of the 18 true positive cases. In three cases, DECT-VNC was positive for bone marrow edema where bone reconstruction CT images were negative. Four patients demonstrated no DECT-VNC signs of bone marrow edema: two cases were true negative, two cases were false negative. When compared with the gold standard of hip fracture determined at retrospective follow-up, the sensitivity of DECT-VNC images of the hip was 90 %, specificity was 40 %, positive predictive value was 86 %, and negative predictive value was 50 %. Our initial experience would suggest that DECT-VNC is highly sensitive but poorly specific in the diagnosis of hip fractures in patients with normal radiographs. The value of DECT-VNC primarily lies in its ability to help detect fractures which may be subtle or undetectable on bone reconstruction CT images.

  5. Postoperative follow-up study of craniosynostosis using three-dimensional surface reconstruction CT (3D-CT)

    Energy Technology Data Exchange (ETDEWEB)

    Nishimoto, Hiroshi; Tsukiyama, Takashi; Nishimura, Jiro; Fujioka, Mutsuhisa; Tsubokawa, Takashi.

    1988-12-01

    In 1983, Michael W. Vannier and Jeffrey L. Marsh developed a computer method that reconstructs three-dimensional images from high-resolution CT-scan series of the facial skeleton. This method has been applied to craniofacial anomalies, basal encephalocele, and other skeletal pathologies. In this study, the postoperative assessment of craniofacial surgical results has been accomplished using 3D-CT techniques in craniosynostosis. The results are as follows: (1) Postoperative 3D-CTs reveal the bony anatomical details corrected by the craniofacial surgery more precisely and more stereographically than do conventional radiological techniques. (2) Secondary changes in the cranium after the surgery, such as reossification at the area of osteotomies or postoperative asymmetric skull deformities, are more early detected by the 3D-CT imaging technique than by a craniogram. (3) In 3D-CT images, internal views of the skull, such mid-sagittal, rear internal, or top axial views of the intracranial skull base, are most useful in postoperative assessments of the surgical results and of postoperative secondary changes in the cranium. Based on our experience, we expect that 3D-CT imaging techniques will become more important in the management of craniosynostosis.

  6. Postoperative follow-up study of craniosynostosis using three-dimensional surface reconstruction CT (3D-CT)

    International Nuclear Information System (INIS)

    Nishimoto, Hiroshi; Tsukiyama, Takashi; Nishimura, Jiro; Fujioka, Mutsuhisa; Tsubokawa, Takashi.

    1988-01-01

    In 1983, Michael W. Vannier and Jeffrey L. Marsh developed a computer method that reconstructs three-dimensional images from high-resolution CT-scan series of the facial skeleton. This method has been applied to craniofacial anomalies, basal encephalocele, and other skeletal pathologies. In this study, the postoperative assessment of craniofacial surgical results has been accomplished using 3D-CT techniques in craniosynostosis. The results are as follows: 1) Postoperative 3D-CTs reveal the bony anatomical details corrected by the craniofacial surgery more precisely and more stereographically than do conventional radiological techniques. 2) Secondary changes in the cranium after the surgery, such as reossification at the area of osteotomies or postoperative asymmetric skull deformities, are more early detected by the 3D-CT imaging technique than by a craniogram. 3) In 3D-CT images, internal views of the skull, such mid-sagittal, rear internal, or top axial views of the intracranial skull base, are most useful in postoperative assessments of the surgical results and of postoperative secondary changes in the cranium. Based on our experience, we expect that 3D-CT imaging techniques will become more important in the management of craniosynostosis. (author)

  7. Nonoperative treatment of adult splenic trauma: Role of CT

    International Nuclear Information System (INIS)

    Raptopoulos, V.; Fink, M.; Resciniti, A.; Davidoff, A.; Silva, W.E.

    1987-01-01

    Of 27 adult patients with known splenic injuries admitted to a regional referral trauma center and who were initially treated nonoperatively, ten (37%) ultimately required splenectomy. A CT scoring system was developed based on the degree of splenic parenchymal injury and the presence of fluid in the perisplenic region, the upper abdomen, and the pelvis. Adult patients who were successfully treated nonoperatively had a significantly (P=.011) lower total CT score than did patients who required delayed celiotomy. No patient older than 17 years with a total CT score less than 2.5 required delayed operative intervention. CT can be used to select a subset of adults with splenic trauma who are excellent candidates for a trail of nonoperative management

  8. Delayed traumatic hematomas of the brain: the early manifestations of CT

    International Nuclear Information System (INIS)

    Liu Shuyan; Tang Guangjian; Fu Jiazhen; Xu Bing; Yin Yanyu

    2002-01-01

    Objective: To study the CT manifestations of delayed traumatic hematomas of the brain and evaluate their diagnostic significance in predicting the delayed traumatic brain hematoma. Methods: The manifestations of initial CT studies and follow-up CT examinations of 31 delayed traumatic brain hematomas were analyzed. Another 50 CT studies of head trauma without delayed brain hematomas were included randomly as control. Results: The abnormal findings of CT studies of the 31 delayed traumatic brain hematomas included: (1) Decreased density of the local brain parenchyma and disappeared difference between gray and white matter of the same area in 18 cases; (2) Local subarachnoid space hemorrhage in 24 cases; (3) Slight mass effect of local brain parenchyma in 16 cases. (4) Subdural hematoma in 9 cases. The locations of the abnormalities were roughly the same with the delayed hematoma except one local subarachnoid space hemorrhage, which was in the opposite of the delayed hematoma. The appearing rate of those abnormal findings in the control group was low and the difference was statistically significant. Conclusion: The decrease of density of local brain parenchyma, the disappeared difference between the gray and white matter, local subarachnoid space hemorrhage, and local swollen of brain presented in the initial CT study of the patient with heat trauma should be taken as indicators of delayed hemorrhage of the same area of brain, and it is necessary to do follow-up CT studies to exclude it

  9. Prenatal diagnosis of fetal skeletal dysplasia with 3D CT

    International Nuclear Information System (INIS)

    Miyazaki, Osamu; Horiuchi, Tetsuya; Nishimura, Gen; Sago, Haruhiko; Hayashi, Satoshi; Kosaki, Rika

    2012-01-01

    Clinical use of 3D CT for fetal skeletal malformations is controversial. The purpose of this study was to evaluate the efficacy of fetal 3D CT using three protocols with different radiation doses and through comparing findings between fetal CT and conventional postnatal radiographic skeletal survey. Seventeen fetuses underwent CT for suspected skeletal dysplasia. A relay of three CT protocols with stepwise dose-reduction were used over the study period. The concordance between the CT diagnosis and the final diagnosis was assessed. Ninety-three radiological findings identifiable on radiographs were compared with CT. Fetal CT provided the correct diagnosis in all 17 fetuses, the detectability rate of cardinal findings was 93.5 %. In 59 % of the fetuses an US-based diagnosis was changed prenatally due to CT findings. The estimated fetal radiation dose in the final protocol was 3.4 mSv (50 %) of the initial protocol, and this dose reduction did not result in degraded image quality. The capability of fetal CT to delineate the skeleton was almost the same as that of postnatal skeletal survey. The perinatal management was altered due to these more specific CT findings, which aided in counseling and in the management of the pregnancy. (orig.)

  10. Prenatal diagnosis of fetal skeletal dysplasia with 3D CT

    Energy Technology Data Exchange (ETDEWEB)

    Miyazaki, Osamu; Horiuchi, Tetsuya [National Center for Child Health and Development, Department of Radiology, Seatagaya-ku, Tokyo (Japan); Nishimura, Gen [Tokyo Metropolitan Children' s Medical Center, Department of Pediatric Imaging, Fuchu-shi, Tokyo (Japan); Sago, Haruhiko; Hayashi, Satoshi [National Center for Child Health and Development, Department of Perinatal Medicine and Maternal Care, Seatagaya-ku, Tokyo (Japan); Kosaki, Rika [National Center for Child Health and Development, Department of Strategic Medicine, Division of Clinical Genetics and Molecular Medicine, Seatagaya-ku, Tokyo (Japan)

    2012-07-15

    Clinical use of 3D CT for fetal skeletal malformations is controversial. The purpose of this study was to evaluate the efficacy of fetal 3D CT using three protocols with different radiation doses and through comparing findings between fetal CT and conventional postnatal radiographic skeletal survey. Seventeen fetuses underwent CT for suspected skeletal dysplasia. A relay of three CT protocols with stepwise dose-reduction were used over the study period. The concordance between the CT diagnosis and the final diagnosis was assessed. Ninety-three radiological findings identifiable on radiographs were compared with CT. Fetal CT provided the correct diagnosis in all 17 fetuses, the detectability rate of cardinal findings was 93.5 %. In 59 % of the fetuses an US-based diagnosis was changed prenatally due to CT findings. The estimated fetal radiation dose in the final protocol was 3.4 mSv (50 %) of the initial protocol, and this dose reduction did not result in degraded image quality. The capability of fetal CT to delineate the skeleton was almost the same as that of postnatal skeletal survey. The perinatal management was altered due to these more specific CT findings, which aided in counseling and in the management of the pregnancy. (orig.)

  11. Towards truly integrated hardware fusion with PET/CT

    International Nuclear Information System (INIS)

    Beyer, T.

    2005-01-01

    Combined PET/CT imaging is a non-invasive means of acquiring and reviewing both, the anatomy and the molecular pathways of a patient during a quasi-simultaneous examination. Since the introduction of the prototype PET/CT in 1998 this imaging technology has evolved rapidly. State-of-the-art PET/CT tomographs combine the latest technology in spiral, multi-slice CT and PET using novel scintillator materials and image reconstruction techniques. Together with novel patient positioning systems PET/CT tomographs allow to acquire complementary PET and CT data in a single exam with the best intrinsic co-registration. In addition to the hardware integration efforts have been made to integrate the acquisition and viewing software in PET/CT, thus making the diagnostic review and reporting more efficient. Based on the first clinical experiences and the technical evolution of combined imaging technology PET/CT has become a standard in diagnostic oncology. With high-performance imaging technology at hand today, standardized, high-quality PET/CT imaging protocols are needed to provide best oncology patient care. These protocols mandate the joint efforts of a multi-disciplinary team of physicians, physicists and radiochemists. (orig.)

  12. Initial acceptance test experience with FFTF plant equipment

    International Nuclear Information System (INIS)

    Brown, R.K.; Coleman, K.A.; Mahaffey, M.K.; McCargar, C.G.; Young, M.W.

    1978-09-01

    The purpose of this paper is to examine the initial acceptance test experience of certain pieces of auxiliary equipment of the Fast Flux Test Facility (FFTF). The scope focuses on the DHX blowers and drive train, inert gas blowers, H and V containment isolation valves, and the Surveillance and In-service Inspection (SISI) transporter and trolley. For each type of equipment, the discussion includes a summary of the design and system function, installation history, preoperational acceptance testing procedures and results, and unusual events and resolutions

  13. The Community Reclaims Control? Learning Experiences from Rural Broadband Initiatives in the Netherlands

    NARCIS (Netherlands)

    Salemink, Koen; Strijker, Dirk; Bosworth, Gary

    2017-01-01

    Based on four illustrative case studies from the Netherlands, this article discusses learning experiences gained from rural broadband initiatives. As an example of the big society' (or participatiesamenleving' in Dutch), initiatives try to step in where the market and the government fail. The main

  14. Standardized CT examination of the multitraumatized patient

    Energy Technology Data Exchange (ETDEWEB)

    Leidner, B. [Department of Diagnostic Radiology, Oskarshamn Hospital (Sweden)]|[Department of Diagnostic Radiology, Huddinge University Hospital (Sweden); Adiels, M. [Department of Diagnostic Radiology, Oskarshamn Hospital (Sweden); Aspelin, P. [Department of Diagnostic Radiology, Huddinge University Hospital (Sweden); Gullstrand, P.; Wallen, S. [Department of Surgery, Oskarshamn Hospital (Sweden)

    1998-12-01

    The aim of this study was to develop a standardized non-helical-CT protocol including head, body and proximal extremities in order to achieve a good time efficiency and diagnostic accuracy in the initial radiological evaluation of the multitraumatized patient. A total of 111 circulatory stable blunt trauma patients, brought in to a trauma level II-III hospital, were examined according to a standardized CT protocol. After examining the head with contiguous 10-mm slices without IV contrast medium injection, the trunk was examined with 10-mm slices every 30 mm through thorax-abdomen-pelvis with IV contrast medium enhancement (occasionally modified). All data in the medical reports were collected and used as ``end-point``, and the outcome of the CT examination was compared with this final diagnosis. Mean examination time was 20 min (range 12-32 min). In total, 55 head injuries, 89 thoracic injuries, 27 abdominal/pelvic injuries and 62 fractures were found. Computed tomography correctly identified the injuries, except one brain stem injury, one contusion/rupture of the heart, one hepatic injury, two intestinal injuries, eight vertebral injuries and one joint dislocation. A standardized non-helical-CT examination of the head and body may be achieved in 20 min. Its diagnostic accuracy was high, except for vertebral column injuries, which is why we recommend it as the method of choice for initial radiological examination of multitraumatized patients. When available, helical scanning would improve both examination speed and accuracy. (orig.) With 6 figs., 40 refs.

  15. Clinical experience of titanium cerebral aneurysm clips. Evaluation of artifact of CT and MRI

    International Nuclear Information System (INIS)

    Ninomiya, Takashi; Kato, Yoko; Sano, Hirotoshi

    1996-01-01

    The titanium aneurysm clips manufactured by AESCULAP Company are expected to be useful, not only for clinical applications, but also for reducing artifacts in post-operative CT and MRI. We carried out an investigation of the behavior of the new Yasargil titanium clips in a 1.5T MR imager. The new titanium clips showed considerably smaller clip-induced MR and CT artifacts than phynox and elgiloy clips. No movement of the titanium clips was seen by introducing them to the MR imager. Subsequent to these experimental studies, we applied titanium clips to 25 cerebral aneurysms. Post-operative CT, especially helical scanning CT and MR showed minimal artifacts, leading to the conclusion that the titanium clips are better than the other types of clips for the evaluation of post-operative neuroradiological images. (author)

  16. "Elite" Career-Changers and Their Experience of Initial Teacher Education

    Science.gov (United States)

    Wilkins, Chris

    2017-01-01

    This study explores the motivation of "high-status" professionals to change career and enter teaching, and their experience of undertaking initial teacher education (ITE) programmes in England. The study builds on previous research which found that career-changers are disproportionately more likely to fail to complete their ITE studies,…

  17. CT urography

    Energy Technology Data Exchange (ETDEWEB)

    Korobkin, M. [Dept. of Radiology, Univ. of Michigan, Ann Arbor, MI (United States)

    2005-11-15

    With the advent of multidetector row CT scanners, evaluation of the urothelium of the entire urinary tract with high-resolution thin sections during a single breath-hold has become a reality. Multidetector CT urography (MDCTU) is a single examination that allows evaluation of potential urinary tract calculi, renal parenchymal masses, and both benign and malignant urothelial lesions. Initial results with this new technique are encouraging. Current investigations of MDCTU focus on methods to improve opacification and distension of the upper urinary tract - the collecting systems, pelvis, and ureters. The role of abdominal compression, infusion of saline and/or furosemide, and optimal time delay of excretory phase imaging is being explored. Upper tract urothelial malignancies, including small lesions less the 5 mmin diameter, can be detected with high sensitivity. Methods to reduce radiation exposure are being explored, including split-bolus contrast injection techniques that combine nephrographic and excretory phases into a single phase. It is likely that in the near future, radiological evaluation of significant unexplained hematuria or of known or prior urothelial malignancy will consist of a single examination - MDCTU. (orig.)

  18. Ultra-high pitch chest computed tomography at 70 kVp tube voltage in an anthropomorphic pediatric phantom and non-sedated pediatric patients: Initial experience with 3rd generation dual-source CT.

    Science.gov (United States)

    Hagelstein, Claudia; Henzler, Thomas; Haubenreisser, Holger; Meyer, Mathias; Sudarski, Sonja; Schoenberg, Stefan O; Neff, K Wolfgang; Weis, Meike

    2016-12-01

    Minimizing radiation dose while at the same time preserving image quality is of particular importance in pediatric chest CT. Very recently, CT imaging with a tube voltage of 70 kVp has become clinically available. However, image noise is inversely proportional to the tube voltage. We aimed to investigate radiation dose and image quality of pediatric chest CT performed at 70 kVp in an anthropomorphic pediatric phantom as well as in clinical patients. An anthropomorphic pediatric phantom, which resembles a one-year-old child in physiognomy, was scanned on the 3 rd generation dual-source CT (DSCT) system at 70 kVp and 80 kVp and a fixed ultra low tube-current of 8 mAs to solely evaluate the impact of lowering tube voltage. After the phantom measurements, 18 pediatric patients (mean 29.5 months; range 1-91 months; 21 examinations) underwent 3.2 high-pitch chest CT on the same DSCT system at 70 kVp tube voltage without any sedation. Radiation dose and presence of motion artifacts was compared to a retrospectively identified patient cohort examined at 80 kVp on a 16-slice single-source-CT (SSCT; n=15; 14/15 with sedation; mean 30.7 months; range 0-96 months; pitch=1.5) or on a 2 nd generation DSCT without any sedation (n=6; mean 32.8 months; range 4-61 months; pitch=3.2). Radiation dose in the phantom scans was reduced by approximately 40% when using a tube voltage of 70 kVp instead of 80 kVp. In the pediatric patient group examined at 70 kVp age-specific effective dose (ED; mean 0.5±0.2 mSv) was significantly lower when compared to the retrospective cohort scanned at 80 kVp on the 16-slice-SSCT (mean ED: 1.0±0.3 mSv; pCT examinations showed any motion artifacts whereas 13/15 examinations of the retrospective patient cohort scanned at 80 kVp with a pitch of 1.5 showed motion artifacts. 3.2 high-pitch chest CT performed with 70 kVp significantly reduces radiation dose when compared to 80 kVp while at the same time provides good image quality without any motion artifacts

  19. 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)

  20. Summary of US compact torus experiments

    International Nuclear Information System (INIS)

    Hartman, C.W.

    1981-01-01

    During the past several years a rapid increase has occurred in compact torus (CT) research in the United States, reflecting renewed interest in this simplified reactor consequences of this configuration. This paper reviews early approaches to CT formation and results and summarizes present experimental studies. Recent experiments have demonstrated a number of macroscopic aspects of the CT, including the conditions under which a macroscopically stable CT can be formed and maintained. Scaling experiments and more detailed studies of plasma transport in progress are discussed along with experiments under construction

  1. 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)

  2. Initial clinical assessment of CT-MRI image fusion software in localization of the prostate for 3D conformal radiation therapy

    International Nuclear Information System (INIS)

    Kagawa, Kazufumi; Lee, W. Robert; Schultheiss, Timothy E.; Hunt, Margie A.; Shaer, Andrew H.; Hanks, Gerald E.

    1997-01-01

    Purpose: To assess the utility of image fusion software and compare MRI prostate localization with CT localization in patients undergoing 3D conformal radiation therapy of prostate cancer. Materials and Methods: After a phantom study was performed to ensure the accuracy of image fusion procedure, 22 prostate cancer patients had CT and MRI studies before the start of radiotherapy. Immobilization casts used during radiation treatment were also used for both imaging studies. After the clinical target volume (CTV) (prostate or prostate + seminal vesicles) was defined on CT, slices from the MRI study were reconstructed to precisely match the CT slices by identifying three common bony landmarks on each study. The CTV was separately defined on the matched MRI slices. Data related to the size and location of the prostate were compared between CT and MRI. The spatial relationship between the tip of urethrogram cone on CT and prostate apex seen on MRI was also estimated. Results: The phantom study showed the registration discrepancies between CT and MRI smaller than 1.0 mm in any pair in comparison. The patient study showed a mean image registration error of 0.9 (± 0.6) mm. The average prostate volume was 63.0 (± 25.8) cm 3 and 50.9 (± 22.9) cm 3 determined by CT and MRI, respectively. The difference in prostate location with the two studies usually differed at the base and at the apex of the prostate. On the transverse MRI, the prostate apex was situated 7.1 (± 4.5) mm dorsal and 15.1 (± 4.0) mm cephalad to the tip of urethrogram cone. Conclusions: CT-MRI image fusion study made it possible to compare the two modalities directly. MRI localization of the prostate is more accurate than CT, and indicates the distance from cone to apex is 15 mm. CT-MRI image fusion technique provides valuable supplements to CT technology for more precise targeting of the prostate cancer

  3. Formal reporting of second-opinion CT interpretation: experience and reimbursement in the emergency department setting.

    Science.gov (United States)

    Jeffers, Adam B; Saghir, Amina; Camacho, Marc

    2012-06-01

    The purpose of this study is to describe a system for formally reporting second-opinion interpretations of CT imaging exams accompanying patients transferred emergently to a tertiary care center. Second-opinion interpretations of cross-sectional imaging exams rendered in the emergency department setting over 6 months spanning 22 September 2009 to 22 March 2010 were reviewed and tallied by two radiologists and a research assistant, with a focus on professional fee reimbursement rates. A more in depth review was performed of those exams for which a clinical referral request form was available, detailing such information as the clinical history, content and source of available initial interpretation, and congruity of the initial interpretation with clinical data. Discrepancies between outside and second-opinion interpretations were also assessed. This quality assurance exercise was reviewed by our institutional review board, which waived formal informed consent. Formal second-opinion interpretation was rendered for 370 exams on 198 patients (mean age, 53.5 years; 45.1% female), received from 50 referring facilities. Head CT was the most common imaging exam referred for second opinion. Forty-one of 370 exams (11%) were submitted for self-pay, and 43 (12%) were written off as free care. The remaining 286 exams (77%) were submitted for reimbursement of the professional fee only. Ultimately, of the 286 exams submitted, 260 (91%) were reimbursed for professional fees, 199 (70%) on the initial submission. Of 29 health plans contracted with our facility, 22 ultimately approved all claims made. Three plans denied all claims submitted. The largest payer was Medicare, which reimbursed 88 of 90 submitted claims. Clinical intake forms were available for 184 exams on 107 patients (mean age, 52.7 years, 43.0% female). Trauma was the most common indication, or history, provided (55% of 184 exams, 40% of 107 patients). An outside report of some form was available for 112 of the 184

  4. Fixed, object-specific intensity compensation for cone beam optical CT radiation dosimetry

    Science.gov (United States)

    Dekker, Kurtis H.; Hazarika, Rubin; Silveira, Matheus A.; Jordan, Kevin J.

    2018-03-01

    Optical cone beam computed tomography (CT) scanning of radiochromic gel dosimeters, using a CCD camera and a low stray light convergent source, provides fast, truly 3D radiation dosimetry with high accuracy. However, a key limiting factor in radiochromic gel dosimetry at large (⩾10 cm diameter) volumes is the initial attenuation of the dosimeters. It is not unusual to observe a 5–10×  difference in signal intensity through the dosimeter center versus through the surrounding medium in pre-irradiation images. Thus, all dosimetric information in a typical experiment is measured within the lower 10%–20% of the camera sensor’s range, and re-use of gels is often not possible due to a lack of transmission. To counteract this, in this note we describe a simple method to create source compensators by printing on transparent films. This technique, which is easily implemented and inexpensive, is an optical analogue to the bowtie filter in x-ray CT. We present transmission images and solution phantom reconstructions to demonstrate that (1) placing compensators beyond the focal zone of the imaging lens prevents high spatial frequency features of the printed films from generating reconstruction artifacts, and (2) object-specific compensation considerably reduces the range of intensities measured in projection images. This will improve the measurable dose range in optical CT dosimetry, and will enable imaging of larger gel volumes (∼15 cm diameter). Additionally, it should enable re-use of dosimeters by printing a new compensator for a second experiment.

  5. 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

  6. CT in three cases of syringomyelia

    International Nuclear Information System (INIS)

    Ugawa, Yoshikazu; Sakuta, Manabu; Yagishita, Akira; Inoue, Kiyoharu.

    1983-01-01

    We presented the results of our experience with metrizamide computed tomographic myelography (MCTM) and myelography in three cases of syringomyelia. In case 1, MCTM revealed Chiari malformation, even though this malformation was not clear in the myelography. In case 3, Chiari malformation was apparent in MCTM and in the myelography. In case 1, CT of the spinal cord without enhancement (plain CT) showed a syrinx in the cervical spinal cord, and MCTM made the syrinx clearer with enhancement. MCTM also demonstrated a cavity at the levels of Th 6 and L 1 of the vertebra. In case 2, a syrinx was disclosed in MCTM, in spite of normal myelography. In case 3, myelography demonstrated a spinal cord swelling. MCTM made a syrinx less clear than plain CT. Not only MCTM but also plain CT is an excellent method for the recognition of syringomyelia. The non-invasive plain CT is the first choice of the examinations in cases with syrinogomyelia, because MCTM may make a syrinx obscure. CT and MCTM have to be performed at many levels of the spinal cord in case with syringomyelia. CT or MCTM may demonstrate a syrinx or a cavity at the levels of the spinal cord, where no syrinx is suspected to exist by clinical features, as well as at the levels appearing normal in the myelography. (author)

  7. Early CT signs of progressive hemorrhagic injury following acute traumatic brain injury

    Energy Technology Data Exchange (ETDEWEB)

    Tong, Wu-song; Zheng, Ping; Xu, Jun-fa; Guo, Yi-jun; Zeng, Jing-song; Yang, Wen-jin; Li, Gao-yi; He, Bin; Yu, Hui [Pudong New Area People' s Hospital, Department of Neurosurgery, Shanghai (China)

    2011-05-15

    Since progressive hemorrhagic injury (PHI) was introduced in neurosurgical literatures, several studies have been performed, the results of which have influenced doctors but do not define guidelines for the best treatment of PHI. PHI may be confirmed by a serial computerized tomography (CT) scan, and it has been shown to be associated with a fivefold increase in the risk of clinical worsening and is a significant cause of morbidity and mortality as well. So, early detection of PHI is practically important in a clinical situation. To analyze the early CT signs of progressive hemorrhagic injury following acute traumatic brain injury (TBI) and explore their clinical significances, PHI was confirmed by comparing the first and repeated CT scans. Data were analyzed and compared including times from injury to the first CT and signs of the early CT scan. Logistic regression analysis was used to show the risk factors related to PHI. A cohort of 630 TBI patients was evaluated, and there were 189 (30%) patients who suffered from PHI. For patients with their first CT scan obtained as early as 2 h post-injury, there were 116 (77.25%) cases who suffered from PHI. The differences between PHIs and non-PHIs were significant in the initial CT scans showing fracture, subarachnoid hemorrhage (SAH), brain contusion, epidural hematoma (EDH), subdural hematoma (SDH), and multiple hematoma as well as the times from injury to the first CT scan (P < 0.01). Logistic regression analysis showed that early CT scans (EDH, SDH, SAH, fracture, and brain contusion) were predictors of PHI (P < 0.01). For patients with the first CT scan obtained as early as 2 h post-injury, a follow-up CT scan should be performed promptly. If the initial CT scan shows SAH, brain contusion, and primary hematoma with brain swelling, an earlier and dynamic CT scan should be performed for detection of PHI as early as possible and the medical intervention would be enforced in time. (orig.)

  8. Early CT signs of progressive hemorrhagic injury following acute traumatic brain injury

    International Nuclear Information System (INIS)

    Tong, Wu-song; Zheng, Ping; Xu, Jun-fa; Guo, Yi-jun; Zeng, Jing-song; Yang, Wen-jin; Li, Gao-yi; He, Bin; Yu, Hui

    2011-01-01

    Since progressive hemorrhagic injury (PHI) was introduced in neurosurgical literatures, several studies have been performed, the results of which have influenced doctors but do not define guidelines for the best treatment of PHI. PHI may be confirmed by a serial computerized tomography (CT) scan, and it has been shown to be associated with a fivefold increase in the risk of clinical worsening and is a significant cause of morbidity and mortality as well. So, early detection of PHI is practically important in a clinical situation. To analyze the early CT signs of progressive hemorrhagic injury following acute traumatic brain injury (TBI) and explore their clinical significances, PHI was confirmed by comparing the first and repeated CT scans. Data were analyzed and compared including times from injury to the first CT and signs of the early CT scan. Logistic regression analysis was used to show the risk factors related to PHI. A cohort of 630 TBI patients was evaluated, and there were 189 (30%) patients who suffered from PHI. For patients with their first CT scan obtained as early as 2 h post-injury, there were 116 (77.25%) cases who suffered from PHI. The differences between PHIs and non-PHIs were significant in the initial CT scans showing fracture, subarachnoid hemorrhage (SAH), brain contusion, epidural hematoma (EDH), subdural hematoma (SDH), and multiple hematoma as well as the times from injury to the first CT scan (P < 0.01). Logistic regression analysis showed that early CT scans (EDH, SDH, SAH, fracture, and brain contusion) were predictors of PHI (P < 0.01). For patients with the first CT scan obtained as early as 2 h post-injury, a follow-up CT scan should be performed promptly. If the initial CT scan shows SAH, brain contusion, and primary hematoma with brain swelling, an earlier and dynamic CT scan should be performed for detection of PHI as early as possible and the medical intervention would be enforced in time. (orig.)

  9. PET and PET/CT in tumour of undetermined origin

    International Nuclear Information System (INIS)

    Garcia O, J.R.

    2007-01-01

    In this presentation the following conclusions were obtained regarding the use of PET and PET/CT in patient with cancer of unknown primary: 1. Detection of the primary one in 1/3 at 1/2 of patient. 2. It detects metastases in other places in 50%. 3. It changes the initial therapy planned in 1/3 at 1/2 of patient. 4. Useful in initial phases of protocol study to limit the other procedures. After standard evaluation. Before advanced protocol. 5. PET/CT study increases the % of primary detection, although in a non significant way vs. PET. 6. They are required more studies to value their utility to a more objective manner. (Author)

  10. Sedation of children for MR or CT imaging examination using chloral hydrate

    International Nuclear Information System (INIS)

    Song, Jong Gi; Kim, Woo Sun; Kim, In One; Yeon, Kyung Mo; Han, Man Chung

    1994-01-01

    Pediatric sedation is an important factor for obtaining the images of good quality. We performed this study to analyze the efficacy of our sedation protocol using chloral hydrate. We collected prospectively 151 sedation records of children(1 day-15 years old), who were sedated with chloral hydrate for MR(n=112) or CT(n=39) studies. We initially administered 50 mg/Kg orally(n=94) or rectally(n=57) 30 minutes before the scheduled examinations, and then administered additional dose (second dose: 25-35 mg/Kg, third dose: 10-15 mg/Kg) to patients whom initial dose failed to sedate. Satisfactory sedation was achieved by initial administration in 109 patients(72%) without significant difference between oral(per oral; P. O.) and rectal(per rectal: P.R.) administration. Second dose was required in 28% and third dose in 5%. MR and CT examinations required second dose in 36(32%) and 6 patients(15%), respectively. P.O. -patients vomited in 5%. P.R. -patients defecated in 22% after initial administration. There were no other serious complications. Time interval from the drug administration to the start of examinations was 33 minutes in initial-dose-group and 64 minutes in additional-dose-group. Two patients could not complete MR examination due to early arousal. Prolonged sedation, requiring more than 30 minutes for alertness after MR and CT examinations, was encountered in twenty(18%) and two patients(5%) respectively. Our protocol using chloral hydrate(P.O. or P.R.) is thought to be an effective and safe method for pediatric sedation for MR or CT imaging

  11. Dynamic crack initiation toughness : experiments and peridynamic modeling.

    Energy Technology Data Exchange (ETDEWEB)

    Foster, John T.

    2009-10-01

    This is a dissertation on research conducted studying the dynamic crack initiation toughness of a 4340 steel. Researchers have been conducting experimental testing of dynamic crack initiation toughness, K{sub Ic}, for many years, using many experimental techniques with vastly different trends in the results when reporting K{sub Ic} as a function of loading rate. The dissertation describes a novel experimental technique for measuring K{sub Ic} in metals using the Kolsky bar. The method borrows from improvements made in recent years in traditional Kolsky bar testing by using pulse shaping techniques to ensure a constant loading rate applied to the sample before crack initiation. Dynamic crack initiation measurements were reported on a 4340 steel at two different loading rates. The steel was shown to exhibit a rate dependence, with the recorded values of K{sub Ic} being much higher at the higher loading rate. Using the knowledge of this rate dependence as a motivation in attempting to model the fracture events, a viscoplastic constitutive model was implemented into a peridynamic computational mechanics code. Peridynamics is a newly developed theory in solid mechanics that replaces the classical partial differential equations of motion with integral-differential equations which do not require the existence of spatial derivatives in the displacement field. This allows for the straightforward modeling of unguided crack initiation and growth. To date, peridynamic implementations have used severely restricted constitutive models. This research represents the first implementation of a complex material model and its validation. After showing results comparing deformations to experimental Taylor anvil impact for the viscoplastic material model, a novel failure criterion is introduced to model the dynamic crack initiation toughness experiments. The failure model is based on an energy criterion and uses the K{sub Ic} values recorded experimentally as an input. The failure model

  12. Blast experiments for the derivation of initial cloud dimensions after a ''Dirty Bomb'' event

    International Nuclear Information System (INIS)

    Thielen, H.; Schroedl, E.

    2004-01-01

    Basis for the assessment of potential consequences of a ''dirty bomb'' event is the calculation of the atmospheric dispersion of airborne particles. The empirical derivation of parameters for the estimation of the initial pollutant cloud dimensions was the principal purpose for blast experiments performed in the training area Munster in summer 2003 with the participation of several highly engaged German organisations and institutions. The experiments were performed under variation of parameters like mass and kind of explosive, subsurface characteristics or meteorological conditions and were documented by digital video recording. The blasting experiments supplied significant results under reproducible conditions. The initial cloud dimension was primarily influenced by the explosive mass. The influence of other parameters was relatively small and within the range of the experimental uncertainties. Based on these experimental results a new correlation was determined for the empirical estimation of the initial cloud dimensions as a function of explosive mass. The observed initial cloud volumes were more than an order of magnitude smaller than those calculated with other widely-used formulas (e.g. HOTSPOT). As a smaller volume of the initial cloud leads to higher near-ground concentration maxima, our results support an appropriate adjustment of currently employed calculation methods. (orig.)

  13. Ultra-low dose CT attenuation correction for PET/CT

    International Nuclear Information System (INIS)

    Xia Ting; Kinahan, Paul E; Alessio, Adam M; De Man, Bruno; Manjeshwar, Ravindra; Asma, Evren

    2012-01-01

    A challenge for positron emission tomography/computed tomography (PET/CT) quantitation is patient respiratory motion, which can cause an underestimation of lesion activity uptake and an overestimation of lesion volume. Several respiratory motion correction methods benefit from longer duration CT scans that are phase matched with PET scans. However, even with the currently available, lowest dose CT techniques, extended duration cine CT scans impart a substantially high radiation dose. This study evaluates methods designed to reduce CT radiation dose in PET/CT scanning. We investigated selected combinations of dose reduced acquisition and noise suppression methods that take advantage of the reduced requirement of CT for PET attenuation correction (AC). These include reducing CT tube current, optimizing CT tube voltage, adding filtration, CT sinogram smoothing and clipping. We explored the impact of these methods on PET quantitation via simulations on different digital phantoms. CT tube current can be reduced much lower for AC than that in low dose CT protocols. Spectra that are higher energy and narrower are generally more dose efficient with respect to PET image quality. Sinogram smoothing could be used to compensate for the increased noise and artifacts at radiation dose reduced CT images, which allows for a further reduction of CT dose with no penalty for PET image quantitation. When CT is not used for diagnostic and anatomical localization purposes, we showed that ultra-low dose CT for PET/CT is feasible. The significant dose reduction strategies proposed here could enable respiratory motion compensation methods that require extended duration CT scans and reduce radiation exposure in general for all PET/CT imaging. (paper)

  14. Ultra-low dose CT attenuation correction for PET/CT

    Science.gov (United States)

    Xia, Ting; Alessio, Adam M.; De Man, Bruno; Manjeshwar, Ravindra; Asma, Evren; Kinahan, Paul E.

    2012-01-01

    A challenge for PET/CT quantitation is patient respiratory motion, which can cause an underestimation of lesion activity uptake and an overestimation of lesion volume. Several respiratory motion correction methods benefit from longer duration CT scans that are phase matched with PET scans. However, even with the currently-available, lowest dose CT techniques, extended duration CINE CT scans impart a substantially high radiation dose. This study evaluates methods designed to reduce CT radiation dose in PET/CT scanning. Methods We investigated selected combinations of dose reduced acquisition and noise suppression methods that take advantage of the reduced requirement of CT for PET attenuation correction (AC). These include reducing CT tube current, optimizing CT tube voltage, adding filtration, CT sinogram smoothing and clipping. We explored the impact of these methods on PET quantitation via simulations on different digital phantoms. Results CT tube current can be reduced much lower for AC than that in low dose CT protocols. Spectra that are higher energy and narrower are generally more dose efficient with respect to PET image quality. Sinogram smoothing could be used to compensate for the increased noise and artifacts at radiation dose reduced CT images, which allows for a further reduction of CT dose with no penalty for PET image quantitation. Conclusion When CT is not used for diagnostic and anatomical localization purposes, we showed that ultra-low dose CT for PET/CT is feasible. The significant dose reduction strategies proposed here could enable respiratory motion compensation methods that require extended duration CT scans and reduce radiation exposure in general for all PET/CT imaging. PMID:22156174

  15. Postoperative assessment of surgical results using three dimensional surface reconstruction CT (3D-CT) in a craniofacial anomaly

    International Nuclear Information System (INIS)

    Nishimura, Jiro; Sato, Kaoru; Nishimoto, Hiroshi; Tsukiyama, Takashi; Fujioka, Mutsuhisa; Akagawa, Tetsuya.

    1988-01-01

    In 1983, Michael W. Vannier and Jeffrey L. Marsh developed a computer method that reconstructs three dimensional (3D) born and soft tissue surfaces, given a high resolution CT scan-series of the facial skeleton. This method has been applied to craniofacial anomalies, basal encephaloceles, and musculoskeletal anomalies. In this study, a postoperative assessment of the craniofacial surgical results has been accomplished using this 3D-CT in 2 children with craniofacial dysmorphism. The authors discuss the advantages of this 3D-CT imaging method in the postoperative assessments of craniofacial anomalies. Results are detailed in the following listing : 1) a postoperative 3D-CT reveals the anatomical details corrected by the craniofacial surgery more precisely and stereographically than conventional radiological methods ; 2) secondary changes of the cranium after the surgery, such as bony formation in the area of the osteotomy and postoperative asymmetric deformities, are detected early by the 3D-CT imaging technique, and, 3) 3D-CT mid-sagittal and top axial views of the intracranial skull base are most useful in postoperative assessments of the surgical results. Basesd on our experience, we expect that three dimensional surface reconstructions from CT scans will become to be used widely in the postoperative assessments of the surgical results of craniofacial anomalies. (author)

  16. Assessing Patients’ Cognitive Therapy Skills: Initial Evaluation of the Competencies of Cognitive Therapy Scale

    Science.gov (United States)

    Strunk, Daniel R.; Hollars, Shannon N.; Adler, Abby D.; Goldstein, Lizabeth A.; Braun, Justin D.

    2014-01-01

    In Cognitive Therapy (CT), therapists work to help patients develop skills to cope with negative affect. Most current methods of assessing patients’ skills are cumbersome and impractical for clinical use. To address this issue, we developed and conducted an initial psychometric evaluation of self and therapist reported versions of a new measure of CT skills: the Competencies of Cognitive Therapy Scale (CCTS). We evaluated the CCTS at intake and post-treatment in a sample of 67 patients participating in CT. The CCTS correlated with a preexisting measure of CT skills (the Ways of Responding Questionnaire) and was also related to concurrent depressive symptoms. Across CT, self-reported improvements in CT competencies were associated with greater changes in depressive symptoms. These findings offer initial evidence for the validity of the CCTS. We discuss the CCTS in comparison with other measures of CT skills and suggest future research directions. PMID:25408560

  17. PET/CT Based Dose Planning in Radiotherapy

    DEFF Research Database (Denmark)

    Berthelsen, Anne Kiil; Jakobsen, Annika Loft; Sapru, Wendy

    2011-01-01

    radiotherapy planning with PET/CT prior to the treatment. The PET/CT, including the radiotherapy planning process as well as the radiotherapy process, is outlined in detail. The demanding collaboration between mould technicians, nuclear medicine physicians and technologists, radiologists and radiology......This mini-review describes how to perform PET/CT based radiotherapy dose planning and the advantages and possibilities obtained with the technique for radiation therapy. Our own experience since 2002 is briefly summarized from more than 2,500 patients with various malignant diseases undergoing...... technologists, radiation oncologists, physicists, and dosimetrists is emphasized. We strongly believe that PET/CT based radiotherapy planning will improve the therapeutic output in terms of target definition and non-target avoidance and will play an important role in future therapeutic interventions in many...

  18. Comparison of the initial ETA gas propagation experiments with theoretical models

    Energy Technology Data Exchange (ETDEWEB)

    Chambers, F.W.; Clark, J.C.; Fessenden, T.J.

    1982-04-20

    This report contains a description of the initial ETA propagation experiments in air at a beam current of 4.5 kA. The beam was observed to propagate at the pressures anticipated on the basis of previous theory and experiment. A comparison of measured net current waveforms with predictions of the PHOENIX code showed good agreement over the pressure range 0.1 to 200 torr. However, the beam was observed to expand with Z at a faster rate than theory predicts. Excessive transverse beam modulation at injection complicated the experiments and limited their comparison with theory.

  19. Comparison of the initial ETA gas propagation experiments with theoretical models

    International Nuclear Information System (INIS)

    Chambers, F.W.; Clark, J.C.; Fessenden, T.J.

    1982-01-01

    This report contains a description of the initial ETA propagation experiments in air at a beam current of 4.5 kA. The beam was observed to propagate at the pressures anticipated on the basis of previous theory and experiment. A comparison of measured net current waveforms with predictions of the PHOENIX code showed good agreement over the pressure range 0.1 to 200 torr. However, the beam was observed to expand with Z at a faster rate than theory predicts. Excessive transverse beam modulation at injection complicated the experiments and limited their comparison with theory

  20. Shock initiation experiments on ratchet grown PBX 9502

    Energy Technology Data Exchange (ETDEWEB)

    Gustavsen, Richard L [Los Alamos National Laboratory; Thompson, Darla G [Los Alamos National Laboratory; Olinger, Barton W [Los Alamos National Laboratory; Deluca, Racci [Los Alamos National Laboratory; Bartram, Brian D [Los Alamos National Laboratory; Pierce, Timothy H [Los Alamos National Laboratory; Sanchez, Nathaniel J [Los Alamos National Laboratory

    2010-01-01

    This study compares the shock initiation behavior of PBX 9502 pressed to less than nominal density (nominal density is 1.890 {+-} 0.005 g/cm{sup 3}) with PBX 9502 pressed to nominal density and then ''ratchet grown'' to low density. PBX 9502 is an insensitive plastic bonded explosive consisting of 95 weight % dry-aminated tri-amino-tri-nitro-benzene (TATB) and 5 weight % Kel-F 800 plastic binder. ''Ratchet growth'' - an irreversible increase in specific volume - occurs when an explosive based on TATB is temperature cycled. The design of our study is as follows: PBX 9502, all from the same lot, received the following four treatments. Samples in the first group were pressed to less than nominal density. These were not ratchet grown and used as a baseline. Samples in the second group were pressed to nominal density and then ratchet grown by temperature cycling 30 times between -54 C and +80 C. Samples in the final group were pressed to nominal density and cut into 100 mm by 25.4 mm diameter cylinders. During thermal cycling the cylinders were axially constrained by a 100 psi load. Samples for shock initiation experiments were cut perpendicular (disks) and parallel (slabs) to the axial load. The four sample groups can be summarized with the terms pressed low, ratchet grown/no load, axial load/disks, and axial load/slabs. All samples were shock initiated with nearly identical inputs in plate impact experiments carried out on a gas gun. Wave profiles were measured after propagation through 3, 4, 5, and 6 mm of explosive. Side by side comparison of wave profiles from different samples is used as a measure of relative sensitivity. All reduced density samples were more shock sensitive than nominal density PBX 9502. Differences in shock sensitivity between ratchet grown and pressed to low density PBX 9502 were small, but the low density pressings are slightly more sensitive than the ratchet grown samples.

  1. CT and sonographic diagnosis of retained surgical sponge

    International Nuclear Information System (INIS)

    Matsumoto, Syunro; Aikawa, Hisayuki; Miyake, Hidetoshi; Mori, Hiromu; Maeda, Tohru; Nishimura, Hiro; Monzen, Yoshio; Ashizawa, Akira; Isomoto, Ichiro.

    1990-01-01

    Seven cases of pathologically proven retained surgical sponge were reviewed and classified into four types, depending on CT and US findings. CT showed a mass with tiny gas bubbles, and sonogram showed an echogenic area with strong posterior shadow (Type I). CT showed an irregular high density mass with no gas bubble, and sonogram showed an echogenic area with strong posterior shadow (Type II). CT showed a low density mass with irregular internal high density areas, and somogram showed a cystic mass with zigzag internal components (Type III). CT showed an eliptic high density mass with low density area internally. Judging from the experiment and operative findings, these patterns were decided by the number and status of the gauze, volume of the exudate and hematoma, and status of the granulation. The author concludes that these characteristic CT and US findings, together with a history of surgery, permit the correct diagnosis of retained surgical sponge. (author)

  2. CT analysis of pulmonary injuries from blunt chest trauma

    International Nuclear Information System (INIS)

    Konno, Shoko

    1996-01-01

    The purpose of this paper is to analyze the CT findings of pulmonary parenchymal injuries due to blunt chest trauma and to categorize CT findings on the basis of their outcome. The materials of this study consist of 62 patients who had pulmonary injuries on CT obtained within 6 hours after blunt chest trauma. CT findings were analysed with regards to the shape, size, and distribution of the lesions. Follow-up CT scans were obtained in 35 patients at intervals from 1 day to 1 month after the initial CT study. CT showed ill-defined opacities in 59 patients (64 lesions in the peripheral area and 95 in the non-peripheral area) and pulmonary nodules with or without cavitary lesions in 30 patients (7 lesions in the peripheral area and 31 in the non-peripheral area). Follow-up CT allowed the classification of these pulmonary injuries into 3 types; the non-peripheral, ill-defined opacities showing immediate clearing, nodules with or without cavitary lesions over 1 cm in diameter showing prolongation, and the peripheral ill-defined opacities adjacent to the thoracic cage, and small nodules with or without cavitary lesions within 1 cm in diameter, showing various courses. CT has marked advantage over plain chest radiographs not only in the detection rate but in accurate estimation of the prognosis of the lesions. (author)

  3. Intracranial tuberculosis in children : CT findings before and after treatment

    International Nuclear Information System (INIS)

    Jung, Hye Weon; Kim, In One; Kim, Woo Sun; Hwang, Yong Seong; Yeon, Kyung Mo

    1996-01-01

    To analyze the CT findings of intracranial tuberculosis in children at initial stage and during follow-up after treatment. We evaluated 25 patients who were diagnosed by CSF analysis or response to anti-tuberculous medication as suffering from intracranial tuberculosis. There were 13 boys and 12 girls aged between 4 months and 14 years. Twenty-five initial and sixty-three follow-up CT scans were retrospectively analyzed. We evaluated the pattern of cisternal enhancement, the locations of infarction, and the presence of calcification and parenchymal granuloma. The changes of hydrocephalus and related complications, as well as cisternal abnormality during anti-tuberculous medication were also evaluated. The initial findings on CT scan were hydrocephalus(75%), cisternal obliteration in precontrast study(64%), thick-line or ring-shaped cisternal enhancement on postcontrast study(44%), infarctions(32%), calcifications(32%), periventricular edema(28%), and parenchymal granulomas(16%). On follow-up CT scan, hydrocephalus and cisternal enhancement had decreased to 35% and 82%, respectively, and the granulomas had changed to calcified nodules(100%). Ventriculo-peritoneal shunt or external ventricular drainage was needed in nine patient, and ventriculitis or complication of shunt procedure developed in four. Intracranial tuberculosis in children presented predominantly as meningitis involving basal cisterns and was associated with hydrocephalus. Infarction and calcification may be seen as parenchymal lesion. In spite of medical treatment, drainage was needed in about half the patients. During this treatment, the resolution of hydrocephalus, decreased cisternal enhancement, and calcification of the granlomas were seen

  4. Intraoperative CT navigation for glenoid component fixation in reverse shoulder arthroplasty

    Directory of Open Access Journals (Sweden)

    Ashok S Gavaskar

    2013-01-01

    Full Text Available CT navigation has been shown to improve component positioning in total shoulder arthroplasty. The technique can be useful in achieving strong initial fixation of the metal backed glenoid in reverse shoulder arthroplasty. We report a 61 years male patient who underwent reverse shoulder arthroplasty for rotator cuff arthropathy. CT navigation was used intraoperatively to identify best possible glenoid bone and to maximize the depth of the fixation screws that anchor the metaglene portion of the metal backed glenoid component. Satisfactory positioning of screws and component was achieved without any perforation or iatrogenic fracture in the scapula. CT navigation can help in maximizing the purchase of the fixation screws that dictate the initial stability of the glenoid component in reverse shoulder arthroplasty. The technique can be extended to improve glenoid component position [version and tilt] with the availability of appropriate software.

  5. CT of the chest in suspected child abuse using submillisievert radiation dose

    International Nuclear Information System (INIS)

    Sanchez, Thomas R.; Seibert, J.A.; Stein-Wexler, Rebecca; Lee, Justin S.; Coulter, Kevin P.

    2015-01-01

    The cornerstone of child abuse imaging is the skeletal survey, but initial imaging with radiographs may not demonstrate acute and non-displaced fractures, especially those involving the ribs. Given the high mortality of undiagnosed non-accidental trauma, timely diagnosis is crucial. CT is more sensitive in assessing rib fractures; however the effective radiation dose of a standard chest CT is high. We retrospectively identified four children (three boys, one girl; age range 1-4 months) admitted between January 2013 and February 2014 with high suspicion for non-accidental trauma from unexplained fractures of the long bones; these children all had CT of the chest when no rib fractures were evident on the skeletal survey. The absorbed radiation dose estimates for organs and tissue from the four-view chest radiographs and subsequent CT were determined using Monte Carlo photon transport software, and the effective dose was calculated using published tissue-weighting factors. In two children, CT showed multiple fractures of the ribs, scapula and vertebral body that were not evident on the initial skeletal survey. The average effective dose for a four-view chest radiograph across the four children was 0.29 mSv and the average effective dose for the chest CT was 0.56 mSv. Therefore the effective dose of a chest CT is on average less than twice that of a four-view chest radiograph. Our protocol thus shows that a reduced-dose chest CT may be useful in the evaluation of high specificity fractures of non-accidental trauma when the four-view chest radiographs are negative. (orig.)

  6. CT of the chest in suspected child abuse using submillisievert radiation dose

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez, Thomas R.; Seibert, J.A.; Stein-Wexler, Rebecca [Medical Center Children' s Hospital, Division of Pediatric Radiology, University of California-Davis, Sacramento, CA (United States); Lee, Justin S. [University of California-Davis, Department of Radiology, Sacramento, CA (United States); Coulter, Kevin P. [Medical Center Children' s Hospital, Department of Pediatrics, University of California-Davis, Sacramento, CA (United States)

    2015-07-15

    The cornerstone of child abuse imaging is the skeletal survey, but initial imaging with radiographs may not demonstrate acute and non-displaced fractures, especially those involving the ribs. Given the high mortality of undiagnosed non-accidental trauma, timely diagnosis is crucial. CT is more sensitive in assessing rib fractures; however the effective radiation dose of a standard chest CT is high. We retrospectively identified four children (three boys, one girl; age range 1-4 months) admitted between January 2013 and February 2014 with high suspicion for non-accidental trauma from unexplained fractures of the long bones; these children all had CT of the chest when no rib fractures were evident on the skeletal survey. The absorbed radiation dose estimates for organs and tissue from the four-view chest radiographs and subsequent CT were determined using Monte Carlo photon transport software, and the effective dose was calculated using published tissue-weighting factors. In two children, CT showed multiple fractures of the ribs, scapula and vertebral body that were not evident on the initial skeletal survey. The average effective dose for a four-view chest radiograph across the four children was 0.29 mSv and the average effective dose for the chest CT was 0.56 mSv. Therefore the effective dose of a chest CT is on average less than twice that of a four-view chest radiograph. Our protocol thus shows that a reduced-dose chest CT may be useful in the evaluation of high specificity fractures of non-accidental trauma when the four-view chest radiographs are negative. (orig.)

  7. Staging of untreated nasopharyngeal carcinoma with PET/CT: comparison with conventional imaging work-up

    International Nuclear Information System (INIS)

    Ng, Shu-Hang; Chan, Sheng-Chieh; Yen, Tzu-Chen; Liu, Feng-Yuan; Chang, Joseph Tung-Chieh; Fan, Kang-Hsing; Liao, Chun-Ta; Ko, Sheung-Fat; Chin, Shu-Chyn; Hsu, Cheng-Lung

    2009-01-01

    We prospectively compared PET/CT and conventional imaging for initial staging of nasopharyngeal carcinoma (NPC). A total of 111 patients with histologically proven NPC were investigated with PET/CT and conventional imaging (head-and-neck MRI, chest X-ray, abdominal ultrasound, and bone scan) before treatment. The respective findings were reviewed independently and then compared with each other. With regard to T staging, PET/CT showed a discrepancy with head-and-neck MRI in 36 (32.4%) of the study subjects. With regard to N staging, PET/CT showed a discrepancy with head-and-neck MRI in 15 (13.5%) patients. Among the discordant cases, MRI was superior in demonstrating tumor involvement in the parapharyngeal space, skull base, intracranial area, sphenoid sinus, and retropharyngeal nodes while PET/CT was superior in demonstrating neck nodal metastasis. PET/CT disclosed 13 of 16 patients with distant malignancy compared with four patients disclosed by conventional imaging work-up. The false-positive rate of PET/CT was 18.8%. PET/CT correctly modified M staging in eight patients (7.2%) and disclosed a second primary lung malignancy in one patient (0.9%). In NPC patients, MRI appears to be superior to PET/CT for the assessment of locoregional invasion and retropharyngeal nodal metastasis. PET/CT is more accurate than MRI for determining cervical nodal metastasis and should be the better reference for the neck status. PET/CT has an acceptable diagnostic yield and a low false-positive rate for the detection of distant malignancy and can replace conventional work-up to this aim. PET/CT and head-and-neck MRI are suggested for the initial staging of NPC patients. (orig.)

  8. 18F-FDOPA PET/CT-Guided Radiofrequency Ablation of Liver Metastases from Neuroendocrine Tumours: Technical Note on a Preliminary Experience

    Energy Technology Data Exchange (ETDEWEB)

    Cazzato, Roberto Luigi, E-mail: gigicazzato@hotmail.it; Garnon, Julien, E-mail: juleiengarnon@gmail.com [Nouvel Hôpital Civil (Hôpitaux Universitaires de Strasbourg, HUS), Department of Interventional Radiology (France); Ramamurthy, Nitin, E-mail: nitin-ramamurthy@hotmail.com [Norfolk and Norwich University Hospital, Department of Radiology (United Kingdom); Tsoumakidou, Georgia, E-mail: georgia.tsoumakidou@chru-strasbourg.fr [Nouvel Hôpital Civil (Hôpitaux Universitaires de Strasbourg, HUS), Department of Interventional Radiology (France); Imperiale, Alessio, E-mail: alessio.imperiale@chru-strasbourg.fr; Namer, Izzie Jacques, E-mail: izzie.jacques.namer@chru-strasbourg.fr [Hôpital de Hautepierre (Hôpitaux Universitaires de Strasbourg, HUS), Department of Biophysics and Nuclear Medicine (France); Bachellier, Philippe, E-mail: philippe.bachellier@chru-strasbourg.fr [Hôpital de Hautepierre (Hôpitaux Universitaires de Strasbourg, HUS), Hepato-Pancreato-Biliary Surgery and Liver Transplantation (France); Caudrelier, Jean, E-mail: jean.caudrelier@chru-strasbourg.fr; Rao, Pramod, E-mail: pramodrao@me.com; Koch, Guillaume, E-mail: guillaume.koch@chru-strasbourg.fr; Gangi, Afshin, E-mail: gangi@unistra.fr [Nouvel Hôpital Civil (Hôpitaux Universitaires de Strasbourg, HUS), Department of Interventional Radiology (France)

    2016-09-15

    AimTo review our preliminary experience with 6-l-18F-fluorodihydroxyphenylalanine (18F-FDOPA) PET/CT-guided radiofrequency ablation (RFA) of liver metastases from neuroendocrine tumours (NETs).Materials and MethodsThree patients (mean age 51.3 years; range 43–56) with gastro-entero pancreatic NET (GEP-NET) liver metastases underwent 18F-FDOPA PET/CT-guided RFA. Patients were referred with oligometastatic hepatic-confined disease (1–6 metastases; <3 cm) on 18F-FDOPA PET/CT; poor lesion visualisation on US, CT, and MR; and ongoing symptoms. Procedures were performed in an interventional PET/CT scanner under general anaesthesia using a split-dose protocol. Lesion characteristics, procedural duration and technical success (accurate probe placement and post-procedural ablation-zone photopaenia), complications, patient and operator dose, and clinical outcomes were evaluated.ResultsThirteen liver metastases (mean size 11.4 mm, range 8–16) were treated in three patients (two presented with “carcinoid syndrome”). Technical success was 100 % with a mean procedural duration of 173.3 min (range 90–210) and no immediate complications. Mean patient dose was 2844 mGy·cm (range 2104–3686). Operator and radiographer doses were acceptable other than the operator’s right hand in the first case (149 µSv); this normalised in the second case. There was no local tumour or extra-hepatic disease progression at mid-term follow-up (mean 12.6 months; range 6–20); however, two cases progressed with new liver metastases at different sites. There was 100 % clinical success (n = 2) in resolving carcinoid syndrome symptoms.Conclusion18F-FDOPA PET/CT-guided RFA appears technically feasible, safe, and effective in patients with GEP-NETs and low-burden hepatic metastases. Further prospective studies are required to elucidate its precise role in tailored multimodality management of GEP-NET liver metastases.

  9. Initial clinical experience with a 64-MDCT whole-body scanner in an emergency department: better time management and diagnostic quality?

    Science.gov (United States)

    Rieger, Michael; Czermak, Benedikt; El Attal, Rene; Sumann, Günther; Jaschke, Werner; Freund, Martin

    2009-03-01

    The objective of this study was to assess time management and diagnostic quality when using a 64-multidetector-row computed tomography (MDCT) whole-body scanner to evaluate polytraumatized patients in an emergency department. Eighty-eight consecutive polytraumatized patients with injury severity score (ISS) > or = 18 (mean ISS = 29) were included in this study. Documented and evaluated data were crash history, trauma mechanism, number and pattern of injuries, injury severity, diagnostics, time flow, and missed diagnoses. Data were stored in our hospital information system. Seven time intervals were evaluated. In particular, attention was paid to the "acquisition interval," the "reformatting and evaluation time" as well as the "CT time" (time from CT start to preliminary diagnosis). A standardized whole-body CT was performed. The acquired CT data together with automatically generated multiplanar reformatted images ("direct MPR") were transferred to a 3D rendering workstation. Diagnostic quality was determined on the basis of missed diagnoses. Head-to-toe scout images were possible because volume coverage was up to 2 m. Experienced radiologists at an affiliated workstation performed radiologic evaluation of the acquired datasets immediately after acquisition. The "acquisition interval" was 12 minutes +/- 4.9 minutes, the "reformatting and evaluation interval" 7.0 minutes +/- 2.1 minutes, and the "CT time" 19 minutes +/- 6.1 minutes. Altogether, 7 of 486 lesions were recognized but not communicated in the "reformatting and evaluation interval", and 10 injuries were initially missed and detected during follow-up. This study indicates that 64-MDCT saves time, especially in the "reformatting and evaluation interval." Diagnostic quality is high, as reflected by the small number of missed diagnoses.

  10. HDR brachytherapy in carcinoma of cervix: initial experience at AWARE hospitals

    International Nuclear Information System (INIS)

    Rajendran, M.; Reddy, K.D.; Reddy, R.M.; Reddy, J.M.; Reddy, B.V.N.; Kiran Kumar; Gopi, S.; Dharaniraj; Janardhanan

    2002-01-01

    High dose rate (HDR) brachytherapy is well established in the management of gynaecological malignancies. A report on the initial results of one and half year experience with a consistent dose/fractionation schedule and procedure of planning with delivery of treatment schedule is presented

  11. MRI versus CT in the diagnosis of Nelson's syndrome

    International Nuclear Information System (INIS)

    Kasperlik-Zaluska, A.; Walecki, J.; Brzezinski, J.; Jeske, W.; Migdalska, B.; Bonicki, W.; Brzezinska, A.; Makowska, A.

    1997-01-01

    The purpose of the study was to evaluate the utility of MRI and CT in the diagnosis of Nelson's syndrome, i. e. pituitary tumours in patients bilaterally adrenalectomized for Cushing's disease. Thirteen patients, followed up for 5-29 years after adrenalectomy, were studied. In 6 of them CT and MRI revealed no changes in the pituitary gland. In the remaining 7 patients only three CT scans were suggestive of a pituitary adenoma. MRI studies with administration of gadodiamide confirmed the CT diagnosis of Nelson's tumour in 3 patients and disclosed microadenomas in a further 4 patients. Neurosurgical treatment in 4 patients confirmed the MRI findings. Additionally CT and MRI examinations were performed in 5 patients suspected of a recurrent Nelson's tumour 3-11 years after neurosurgery. MRI visualized recurrent adenomas in 3 patients that were not well seen by CT scans. In our experience MRI was more effective than CT in the diagnosis of Nelson's syndrome. (orig.). With 3 figs., 1 tab

  12. Early CT findings to predict early death in patients with traumatic brain injury: Marshall and Rotterdam CT scoring systems compared in the major academic tertiary care hospital in northeastern Japan.

    Science.gov (United States)

    Mata-Mbemba, Daddy; Mugikura, Shunji; Nakagawa, Atsuhiro; Murata, Takaki; Ishii, Kiyoshi; Li, Li; Takase, Kei; Kushimoto, Shigeki; Takahashi, Shoki

    2014-05-01

    Computed tomography (CT) plays a crucial role in early assessment of patients with traumatic brain injury (TBI). Marshall and Rotterdam are the mostly used scoring systems, in which CT findings are grouped differently. We sought to determine the scoring system and initial CT findings predicting the death at hospital discharge (early death) in patients with TBI. We included 245 consecutive adult patients with mild-to-severe TBI. Their initial CT and status at hospital discharge (dead or alive) were reviewed, and both CT scores were calculated. We examined whether each score was related to early death; compared the two scoring systems' performance in predicting early death, and identified the CT findings that are independent predictors of early death. More deaths occurred among patients with higher Marshall and Rotterdam scores (both P death (Marshall, AUC = 0. 85 vs. Rotterdam, AUC = 0.85). Basal cistern absence (odds ratio [OR] = 771.5, P death. Both Marshall and Rotterdam scoring systems can be used to predict early death in patients with TBI. The performance of the Marshall score is at least equal to that of the Rotterdam score. Thus, although older, the Marshall score remains useful in predicting patients' prognosis. Copyright © 2014 AUR. Published by Elsevier Inc. All rights reserved.

  13. Clinical studies on thyroid CT number in Graves' disease and destructive thyrotoxicosis

    Energy Technology Data Exchange (ETDEWEB)

    Kamijo, Keiichi (Kamijo Thyroid and Pituitary Clinic, Sapporo (Japan))

    1994-02-01

    The purpose of the present study was to investigate CT Hounsfield unit (H.U.) of the thyroid in hyperthyroid and euthyroid Graves' disease and destructive thyrotoxicosis. The mean thyroid CT number in 95 controls was 122[+-]18 H.U.([+-]SD) and did not change significatly with advancing age. The mean thyroid CT number ([+-]SD) of 85[+-]22 H.U. in 60 patients with hyperthyroid Graves' disease was significantly lower than either in normal controls or 116[+-]22 H.U. in 11 patients with euthyroid Graves' disease. Comparison of thyroid hormones and TSH receptor Ab values of untreated patients with a normal and an abnormally low thyroid CT number showed that serum total and free T[sub 3] were significantly higher in the latter group than the former group. With respect to the effect of methimazol (MMI) on the thyroid CT number, in the untreated 10 patients with a low thyroid CT number, the initial mean CT number was 65[+-]11 H.U. and increased significantly to 76[+-]14 H.U. after treatment with MMI. In contrast, in 6 patients with a normal thyroid CT number prior to therapy, the initial mean thyroid CT number was 102[+-]11 H.U. and fell significantly to 84[+-]16 H.U. after treatment with MMI. The thyroid CT number in destructive thyrotoxicosis is markedly decreased to less than 70 H.U. and the mean values of 57[+-]7 H.U. in 6 patients with silent thyroiditis and of 61[+-]5 H.U. in 7 with subacute thyroiditis differ significantly from Graves' disease. In conclusion, the thyroid CT number is significantly reduced in hyperthyroid Graves' disease, normal in euthyroid Graves' disease and markedly decreased in destructive thyrotoxicosis. The high T-3 value seemed to play an important role in the pathogenesis of a decline in the thyroid CT number in Graves' disease. An antithyroid drug therapy caused two different changes in the thyroid CT number, depending on whether the thyroid CT number prior to therapy was normal or low. (author).

  14. FDG PET/CT for therapeutic response monitoring in multi-site non-respiratory tuberculosis

    International Nuclear Information System (INIS)

    Geng Tian; Yong Xiao; Bin Chen; Jun Xia; Hong Guan; Qunyi Deng

    2010-01-01

    Background: Tuberculosis (TB) can produce positive signals during 18 F-fluorodeoxyglucose positron emission/computed tomography (FDG PET/CT) scanning. Until now, there has been no better method than clinical assessment to evaluate the therapeutic response of non-respiratory TB (NRTB). Purpose: To retrospectively assess the ability of FDG PET/CT to evaluate the response to anti-TB treatment in patients with NRTB. Material and Methods: Three patients with multi-site NRTB underwent repeat PET/CT scans during anti-TB treatment. Changes in maximal standard uptake value (SUVmax) of the TB lesions on PET/CT images were analyzed between two scans. Initial PET/CT scans were performed before the start of anti-TB treatment, and later scans were performed after completion of the treatment. Results: Patient 1, a 63-year-old female, and patient 2, a 50-year-old male, were diagnosed as multi-site NRTB by biopsy. Patient 3, a 37-year-old male was diagnosed clinically. These patients demonstrated multiple FDG-avid lesions in whole body on initial PET/CT images. The highest SUVmax of patient 1, 2, and 3 were 13.6, 17.7, and 13.9 separately. After completion of the treatment, all positive signals of patient 1, 2, and 3 decreased to undetectable value on repeated PET/CT scans with intervals of 318 days, 258 days, and 182 days separately. Conclusion: FDG PET/CT scan may be useful for monitoring responses to anti-TB treatment in patients with NRTB

  15. Diagnosis and differential diagnosis of cerebro-vascular malformations by CT

    International Nuclear Information System (INIS)

    Schumacher, M.; Stoeter, P.; Voigt, K.

    1980-01-01

    In 38 patients, the diagnosis of a cerebrovascular malformation (17 arteriovenous angiomas including one low-flow- and two venous angiomas; 10 aneurysms; 4 arteriovenous fistulae of the cavernous sinus, the tentorium and one of the Great Vein of Galen; 6 megadolical basilar arteries) was initially made by computertomographic (CT) examination, including contrast enhancement. The characteristic and pathognomonic CT findings are described and compared with those of cerebral angiography also done in these cases. The problems of differential diagnosis and the reasons for a false CT diagnosis in 5 other patients with a cerebro-vascular malformation are investigated; and the diagnostic value of cerebral angiography and CT is discussed and their complementary functions are being pointed out. (orig.) 891 MG/orig. 892 MKO [de

  16. The role of 18FDG, 18FDOPA PET/CT and 99mTc bone scintigraphy imaging in Erdheim–Chester disease

    Energy Technology Data Exchange (ETDEWEB)

    García-Gómez, F.J., E-mail: javier191185@gmail.com [Department of Nuclear Medicine, Virgen del Rocío Universitary Hospital, Seville (Spain); Acevedo-Báñez, I.; Martínez-Castillo, R.; Tirado-Hospital, J.L.; Cuenca-Cuenca, J.I.; Pachón-Garrudo, V.M.; Álvarez-Pérez, R.M.; García-Jiménez, R. [Department of Nuclear Medicine, Virgen del Rocío Universitary Hospital, Seville (Spain); Rivas-Infante, E. [Department of Pathology, Virgen del Rocío Universitary Hospital, Seville (Spain); García-Morillo, J.S. [Department of Internal Medicine, Virgen del Rocío Universitary Hospital, Seville (Spain); Borrego-Dorado, I. [Department of Nuclear Medicine, Virgen del Rocío Universitary Hospital, Seville (Spain)

    2015-08-15

    Highlights: • Erdheim–Chester disease (ECD) is a rare non-Langerhans cell histiocitosis, characterized by multisystemic xanthogranulomatous infiltration by foamy histiocytes. Etiology and pathogenesis are still unknown and only about 500 cases are related in the literature. • Multifocal nature of involvement in ECD can produce a wide variety of clinical signs. In our experience, neurological involvement is associated with mortality in all cases. Characteristic long bone osteosclerosis was a quasi-pathognomonic finding in bone scintigraphy. • To the best of our knowledge, the 18FDOPA-PET/CT not seem useful in the initial staging of ECD based on a single case report. • Bone scintigraphy and the 18FDG-PET/CT that were particularly useful in despite systemic involvement, locate the optimum site for biopsy and treatment response evaluation. In this context, a baseline 18FDG-PET/CT with an optional bone scintigraphy may help in monitoring the disease and could be considered when patients were incidentally diagnosed and periodically follow-up 18FDG-PET/CT must be performed in the follow up to evaluate the treatment response. - Abstract: Erdheim–Chester disease (ECD) is a rare non-Langerhans cell histiocitosis, characterized by multisystemic xanthogranulomatous infiltration by foamy histiocytes that stain positively for CD68 marker but not express CD1a and S100 proteins. Etiology and pathogenesis are still unknown and only about 500 cases are related in the literature. Multisystemic involvement leads to a wide variety of clinical manifestations that results in a poor prognosis although recent advances in treatment. We present the clinical, nuclear medicine findings and therapeutic aspects of a serie of 6 patients with histopathological diagnosis of ECD, who have undergone both bone scintigraphy (BS) and 18F-fluorodeoxyglucose (18FDG)-PET/CT scans in our institution. A complementary 18F-fluorodopa (18FDOPA)-PET/CT was performed in one case. Three different

  17. The role of 18FDG, 18FDOPA PET/CT and 99mTc bone scintigraphy imaging in Erdheim–Chester disease

    International Nuclear Information System (INIS)

    García-Gómez, F.J.; Acevedo-Báñez, I.; Martínez-Castillo, R.; Tirado-Hospital, J.L.; Cuenca-Cuenca, J.I.; Pachón-Garrudo, V.M.; Álvarez-Pérez, R.M.; García-Jiménez, R.; Rivas-Infante, E.; García-Morillo, J.S.; Borrego-Dorado, I.

    2015-01-01

    Highlights: • Erdheim–Chester disease (ECD) is a rare non-Langerhans cell histiocitosis, characterized by multisystemic xanthogranulomatous infiltration by foamy histiocytes. Etiology and pathogenesis are still unknown and only about 500 cases are related in the literature. • Multifocal nature of involvement in ECD can produce a wide variety of clinical signs. In our experience, neurological involvement is associated with mortality in all cases. Characteristic long bone osteosclerosis was a quasi-pathognomonic finding in bone scintigraphy. • To the best of our knowledge, the 18FDOPA-PET/CT not seem useful in the initial staging of ECD based on a single case report. • Bone scintigraphy and the 18FDG-PET/CT that were particularly useful in despite systemic involvement, locate the optimum site for biopsy and treatment response evaluation. In this context, a baseline 18FDG-PET/CT with an optional bone scintigraphy may help in monitoring the disease and could be considered when patients were incidentally diagnosed and periodically follow-up 18FDG-PET/CT must be performed in the follow up to evaluate the treatment response. - Abstract: Erdheim–Chester disease (ECD) is a rare non-Langerhans cell histiocitosis, characterized by multisystemic xanthogranulomatous infiltration by foamy histiocytes that stain positively for CD68 marker but not express CD1a and S100 proteins. Etiology and pathogenesis are still unknown and only about 500 cases are related in the literature. Multisystemic involvement leads to a wide variety of clinical manifestations that results in a poor prognosis although recent advances in treatment. We present the clinical, nuclear medicine findings and therapeutic aspects of a serie of 6 patients with histopathological diagnosis of ECD, who have undergone both bone scintigraphy (BS) and 18F-fluorodeoxyglucose (18FDG)-PET/CT scans in our institution. A complementary 18F-fluorodopa (18FDOPA)-PET/CT was performed in one case. Three different

  18. It's a question of endurance - Patients with head and neck cancer experiences of 18F-FDG PET/CT in a fixation mask.

    Science.gov (United States)

    Andersson, Camilla; Röing, Marta; Tiblom Ehrsson, Ylva; Johansson, Birgitta

    2017-08-01

    This study aimed to explore how patients with head and neck cancer experienced undergoing an 18 F-fluoro-deoxy-glucose positrons emissions tomography/computed tomography ( 18 F-FDG PET/CT) examination in a fixation mask. Interviews were conducted with nine patients with known or suspected head and neck cancer who were scheduled for the examination for the first time. The phenomenological method according to van Manen and his four lifeworld existentials; lived space, lived body, lived time, and lived relation was used to analyse the interviews. The thoughts and feelings of the patients during the PET/CT examination varied, some found it very difficult, while others did not. However, for all the patients, it was an experience that required some form of coping to maintain composure for example distraction. PET/CT examnation in a fixation mask may be strenuous for some patients. Patients need more detailed information, including suggestions for coping behaviours, prior to the examination, as well as higher level of support during and after the examination. The results of this study may be used to improve patient care and optimize the procedure of PET/CT examination in a fixation mask. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Feasibility of prospectively ECG-triggered high-pitch coronary CT angiography with 30 mL iodinated contrast agent at 70 kVp: initial experience

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Long Jiang; Qi, Li; Tang, Chun Xiang; Zhou, Chang Sheng; Ji, Xue Man; Lu, Guang Ming [Medical School of Nanjing University, Department of Medical Imaging, Jinling Hospital, Nanjing, Jiangsu (China); Wang, Jing [Medical School of Nanjing University, Department of Cardiology, Jinling Hospital, Nanjing, Jiangsu (China); Spearman, James V.; De Cecco, Carlo Nicola; Meinel, Felix G. [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); Schoepf, U.J. [Medical School of Nanjing University, Department of Medical Imaging, Jinling Hospital, Nanjing, Jiangsu (China); Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States)

    2014-07-15

    To evaluate the feasibility, image quality and radiation dose of prospectively ECG-triggered high-pitch coronary CT angiography (CCTA) with 30 mL contrast agent at 70 kVp. Fifty-eight patients with suspected coronary artery disease, a body mass index (BMI) of less than 25 kg/m{sup 2}, sinus rhythm and a heart rate (HR) of less than 70 beats per minute (bpm) were prospectively enrolled in this study. Thirty mL of 370 mg I/mL iodinated contrast agent was administrated at a flow rate of 5 mL/s. All patients underwent prospectively ECG-triggered high-pitch CCTA on a second-generation dual-source CT system at 70 kVp using automated tube current modulation. Fifty-six patients (96.6 %) had diagnostic CCTA images and two patients (3.4 %) had one vessel with poor image quality each rated as non-diagnostic. No significant effects of HR, HR variability and BMI on CCTA image quality were observed (all P > 0.05). Effective dose was 0.17 ± 0.02 mSv and the size-specific dose estimate was 1.03 ± 0.13 mGy. Prospectively ECG-triggered high-pitch CCTA at 70 kVp with 30 mL of contrast agent can provide diagnostic image quality at a radiation dose of less than 0.2 mSv in patients with a BMI of less than 25 kg/m{sup 2} and an HR of less than 70 bpm. (orig.)

  20. Clinical studies on thyroid CT number in Graves' disease and destructive thyrotoxicosis

    International Nuclear Information System (INIS)

    Kamijo, Keiichi

    1994-01-01

    The purpose of the present study was to investigate CT Hounsfield unit (H.U.) of the thyroid in hyperthyroid and euthyroid Graves' disease and destructive thyrotoxicosis. The mean thyroid CT number in 95 controls was 122±18 H.U.(±SD) and did not change significatly with advancing age. The mean thyroid CT number (±SD) of 85±22 H.U. in 60 patients with hyperthyroid Graves' disease was significantly lower than either in normal controls or 116±22 H.U. in 11 patients with euthyroid Graves' disease. Comparison of thyroid hormones and TSH receptor Ab values of untreated patients with a normal and an abnormally low thyroid CT number showed that serum total and free T 3 were significantly higher in the latter group than the former group. With respect to the effect of methimazol (MMI) on the thyroid CT number, in the untreated 10 patients with a low thyroid CT number, the initial mean CT number was 65±11 H.U. and increased significantly to 76±14 H.U. after treatment with MMI. In contrast, in 6 patients with a normal thyroid CT number prior to therapy, the initial mean thyroid CT number was 102±11 H.U. and fell significantly to 84±16 H.U. after treatment with MMI. The thyroid CT number in destructive thyrotoxicosis is markedly decreased to less than 70 H.U. and the mean values of 57±7 H.U. in 6 patients with silent thyroiditis and of 61±5 H.U. in 7 with subacute thyroiditis differ significantly from Graves' disease. In conclusion, the thyroid CT number is significantly reduced in hyperthyroid Graves' disease, normal in euthyroid Graves' disease and markedly decreased in destructive thyrotoxicosis. The high T-3 value seemed to play an important role in the pathogenesis of a decline in the thyroid CT number in Graves' disease. An antithyroid drug therapy caused two different changes in the thyroid CT number, depending on whether the thyroid CT number prior to therapy was normal or low. (author)

  1. What is the complementary role of ultrasound evaluation in the diagnosis of acute appendicitis after CT?

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Kyung Mi [Department of Radiology, Hallym University Sacred Heart Hospital, Anyang (Korea, Republic of); Lee, Kwanseop [Department of Radiology, Hallym University Sacred Heart Hospital, Anyang (Korea, Republic of)], E-mail: kwanseop@hallym.or.kr; Kim, Min-Jeong; Yoon, Hoi Soo; Jeon, Eui Yong; Koh, Sung Hye [Department of Radiology, Hallym University Sacred Heart Hospital, Anyang (Korea, Republic of); Min, Kwangseon [Department of Pathology, Hallym University Sacred Heart Hospital, Anyang (Korea, Republic of); Choi, Dongil [Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine (Korea, Republic of)

    2010-04-15

    The objective of our study was to estimate the complementary role of ultrasound evaluation in the diagnosis of acute appendicitis after abdominoplevic CT. A total of 104 patients initially underwent abdominopelvic CT before appendix US due to acute abdominal pain. All CT examinations were evaluated retrospectively for the presence of acute appendicitis. The findings of appendix on CT were classified into five categories (definite appendicitis, probably appendicitis, equivocal CT findings for diagnosis of appendicitis, probably not appendicitis, and normal looking appendix). Appendix US images and their radiologic reports were also evaluated retrospectively. Then, CT and US findings were correlated with clinical or pathologic diagnosis. Three all patients with definite appendicitis initially on CT again showed US findings of appendicitis. In the 32 patients of probably appendicitis on CT, US showed normal looking appendix in seven patients (21.8%, 7 of 32) who improved with medical treatment and discharged. In the 16 patients of equivocal CT findings for diagnosis of appendicitis, US showed appendicitis in seven patients (43.8%, 7 of 16) and normal looking appendix in nine patients. In the 12 patients of probably not appendicitis on CT, US showed acute appendicitis in two patients (16.7%, 2 of 12). In the 41 patients of normal looking appendix on CT, US showed acute appendicitis in five patients (12.2%, 5 of 41). US reevaluation enables us to avoid misdiagnosis of appendicitis on CT and improve diagnostic accuracy of acute appendicitis.

  2. Initial evaluation of commercial optical CT-based 3D gel dosimeter

    International Nuclear Information System (INIS)

    Islam, K.T.S.; Dempsey, James F.; Ranade, Manisha K.; Maryanski, Marek J.; Low, Daniel A.

    2003-01-01

    We evaluated the OCTOPUS-ONE trade mark sign research laser CT scanner developed and manufactured by MGS Research, Inc. (Madison, CT). The scanner is designed for imaging 3D optical density distributions in BANG registered gels. The scanner operates in a translate-rotate configuration with a single scanning laser beam. The rotating cylindrical gel phantom is immersed in a refractive index matching solution and positioned at the center of a square tank made of plastic and glass. A stationary polarized He-Ne laser beam (633 nm) is reflected from a mirror moving parallel to the tank wall and scans the gel. Another mirror moves synchronously along the opposite side of the tank and collects the transmitted light and sends it to a single stationary silicon photodetector. A filtered backprojection algorithm is used to reconstruct projection data in a plane. The laser-mirrors-detector assembly is mounted on a horizontal platform that moves vertically for slice selection. We have tested the mechanical and optical setup, projection centering on the axis of rotation, linearity, and spatial resolution. We found the optical detector to respond linearly to transmitted light from control samples. The spatial resolution of the scanner was determined by employing a split field resolution technique. We obtained the horizontal and vertical full widths at half maxima of the laser beam intensity profiles as 0.6 and 0.8 mm, respectively. Dose calibration tests of the gel were performed using a nine-field (2x2 cm 2 each) dose pattern irradiated at different dose levels. Finally, we compared gel-derived 2D planar dose distribution against radiochromic film measured dose distribution for both the nine-field and a uniform 5x5 cm 2 field of 6 MV x rays. Very similar dose distributions were observed in gel and radiochromic film except in regions of steep dose gradient and highest dose. A dose normalization of 15.6% was required between the two dosimeters due to differences in overall

  3. Contrast opacification for CT from iodine, gadolinium and ytterbium

    International Nuclear Information System (INIS)

    Zwicker, C.; Langer, M.; Ullrich, V.; Felix, R.

    1993-01-01

    The absorption of the elements iodine, gadolinium und ytterbium in various dilutions was studied in relation to CT. Regression analysis and specific CT density measurements showed that absorption decreases from gadolinium to ytterbium and iodine. These results were confirmed by experiments using ten dogs. Boli of 0.5 molar gadolinium used for angio-CT without table movement showed the largest increase in density in the aorta and liver with an average of 190 HU and 21 HU respectively compared with iodine which gave 157 HU and 12 HU respectively. The animal experimental studies suggest that gadolinium and ytterbium are suitable contrast media for dynamic CT investigations. (orig.) [de

  4. Early experiences with crowdsourcing airway annotations in chest CT

    DEFF Research Database (Denmark)

    Cheplygina, Veronika; Perez-Rovira, Adria; Kuo, Wieying

    2016-01-01

    Measuring airways in chest computed tomography (CT) images is important for characterizing diseases such as cystic fibrosis, yet very time-consuming to perform manually. Machine learning algorithms offer an alternative, but need large sets of annotated data to perform well. We investigate whether...... a number of further research directions and provide insight into the challenges of crowdsourcing in medical images from the perspective of first-time users....

  5. CT and MRI in progressive multifocal leukoencephalopathy

    International Nuclear Information System (INIS)

    Lanfermann, H.; Heindel, W.; Schroeder, R.; Lackner, K.

    1994-01-01

    Radiological findings and course of progressive multifocal leukoencephalopathy in 14 patients (1 woman, 13 men; 13 HIV seropositive, 1 chronic lymphatic leukaemia) were analysed retrospectively and correlated with clinical symptoms. A total of 21 CT and 16 MRI studies were evaluated. CT scans and MR images of 9 patients, which had been obtained in less than two weeks, could be compared to each other. MRI was superior to CT: 6 lesions with a diameter of 1 cm and below were not detected on CT scans, in 5 patients the extent of lesions was underestimated. Cortical involvement, mass effect or signs of atrophy were missing. Only 1 of 65 lesions showed a tiny enhancement after Gd injection. Due to the pattern and spread of lesions, which showed a close correlation to the neurologic symptoms, three different types of PML are suggested: 1. Initial precentral demyelinisation with contralateral hemiparesis (n=8); 2. lesions in temporo-occipital locations with visual disturbances (n=2); 3. predominantly bilateral lesions of cerebellar white matter with ataxia (n=4). (orig.) [de

  6. Quality assurance in CT: implementation of the updated national diagnostic reference levels using an automated CT dose monitoring system.

    Science.gov (United States)

    Appel, E; Kröpil, P; Bethge, O T; Aissa, J; Thomas, C; Antoch, G; Boos, J

    2018-03-20

    To evaluate the implementation of the updated computed tomography (CT) diagnostic reference levels (DRLs) from the German Federal Office for Radiation Protection into clinical routine using an automatic CT dose monitoring system. CT radiation exposure was analysed before and after implementing the updated national DRLs into routine clinical work in 2016. After the implementation process, institutional CT protocols were mapped to the anatomical regions for which DRLs were provided. Systematically, protocols that exceeded the thresholds were optimised and analysed in detail. The CT radiation output parameters analysed were volumetric CT dose index (CTDIvol) and dose-length product (DLP). Three radiologists evaluated subjective image quality using a three-point Likert scale. The study included 94,258 CT series (from 27,103 CT examinations) in adult patients performed in 2016. When averaged over all body regions with available DRL, institutional CTDIvol/DLP values were always below the DRLs (65.2±32.9%/67.3±41.5% initially; 59.4±32%/60.5±39.9% after optimisation). Values exceeding the national DRLs were found for pelvis (n=268; CTDIvol 107.7±65.7%/DLP 106.3±79.3%), lumbar spine (n=91; 160.8±74.7%/175.2±104.1%), and facial bones (n=527; 108±39%/152.7±75.7%). After optimisation, CTDIvol and DLP were 87.9±73%/87.8±80.8% for the pelvis, 67.8±33.2%/74.5±50.6% for the lumbar spine and 95.1±45.8%/133.3±74.6% for the viscerocranium. An automatic CT dose monitoring system enabled not only comprehensive monitoring of a DRL implementation process but can also help to optimise radiation exposure. Copyright © 2018 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  7. SU-F-T-626: Intracranial SRS Re-Treatment Without Acquisition of New CT Images

    International Nuclear Information System (INIS)

    Wiant, D; Manning, M; Liu, H; Maurer, J; Hayes, T; Sintay, B

    2016-01-01

    Purpose: Linear accelerator based stereotactic radiosurgery (SRS) for multiple intracranial lesions with frequent surveillance is becoming a popular treatment option. This strategy leads to retreatment with SRS as new lesions arise. Currently, each course of treatment uses magnetic resonance (MR) and computed tomography (CT) images for treatment planning. We propose that new MR images, with course 1 CT images, may be used for future treatment plans with negligible loss of dosimetric accuracy. Methods: Ten patients that received multiple courses of SRS were retrospectively reviewed. The treatment plans and contours from non-initial courses were copied to the initial CTs and recalculated. Doses metrics for the plans calculated on the initial CTs and later CTs were compared. All CT scans were acquired on a Philips CT scanner with a 600 mm field of view and 1 mm slice thickness (Philips Healthcare, Andover, MA). All targets were planned to 20 Gy and calculated in Eclipse V. 13.6 (Varian, Palo Alto, CA) using analytic anisotropic algorithm with 1 mm calculation grid. Results: Sixteen lesions were evaluated. The mean time between courses was 250 +/− 215 days (range 103–979). The mean target volume was 2.0 +/− 2.9 cc (range 0.1–10.1). The average difference in mean target dose between the two calculations was 0.2 +/− 0.3 Gy (range 0.0 – 1.0). The mean conformity index (CI) was 1.28 +/− 0.14 (range 1.07 – 1.82). The average difference in CI was 0.03 +/− 0.16 (range 0.00 – 0.44). Targets volumes < 0.5 cc showed the largest changes in both metrics. Conclusion: Continued treatment based on initial CT images is feasible. Dose calculation on the initial CT for future treatments provides reasonable dosimetric accuracy. Changes in dose metrics are largest for small volumes, and are likely dominated by partial volume effects in target definition.

  8. 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.

  9. Augmented Reality Guidance for the Resection of Missing Colorectal Liver Metastases: An Initial Experience.

    Science.gov (United States)

    Ntourakis, Dimitrios; Memeo, Ricardo; Soler, Luc; Marescaux, Jacques; Mutter, Didier; Pessaux, Patrick

    2016-02-01

    Modern chemotherapy achieves the shrinking of colorectal cancer liver metastases (CRLM) to such extent that they may disappear from radiological imaging. Disappearing CRLM rarely represents a complete pathological remission and have an important risk of recurrence. Augmented reality (AR) consists in the fusion of real-time patient images with a computer-generated 3D virtual patient model created from pre-operative medical imaging. The aim of this prospective pilot study is to investigate the potential of AR navigation as a tool to help locate and surgically resect missing CRLM. A 3D virtual anatomical model was created from thoracoabdominal CT-scans using customary software (VR RENDER(®), IRCAD). The virtual model was superimposed to the operative field using an Exoscope (VITOM(®), Karl Storz, Tüttlingen, Germany). Virtual and real images were manually registered in real-time using a video mixer, based on external anatomical landmarks with an estimated accuracy of 5 mm. This modality was tested in three patients, with four missing CRLM that had sizes from 12 to 24 mm, undergoing laparotomy after receiving pre-operative oxaliplatin-based chemotherapy. AR display and fine registration was performed within 6 min. AR helped detect all four missing CRLM, and guided their resection. In all cases the planned security margin of 1 cm was clear and resections were confirmed to be R0 by pathology. There was no postoperative major morbidity or mortality. No local recurrence occurred in the follow-up period of 6-22 months. This initial experience suggests that AR may be a helpful navigation tool for the resection of missing CRLM.

  10. Sequential analysis of CT findings in herpes simplex encephalitis

    International Nuclear Information System (INIS)

    Kawamura, Mitsuru; Tokumaru, Yukio; Ito, Naoki; Yamada, Tatsuo; Hirayama, Keizo

    1982-01-01

    CT findings of six patients with serologically confirmed herpes simplex encephalitis were analyzed sequentially. The initial change in CT scan in 3 cases was generalized cerebral edema instead of low density areas in the anterior temporal lobes, which have generally been known as the initial findings. Then, bilateral (5 cases) or unilateral (1 case) island-shaped low absorption areas in the insular cortex and the claustrum appeared within 10 days of onset in all 6 cases. These findings, especially the latter, seem to be characteristic of the acute stage and useful in the early diagnosis of herpes simplex encephalitis. The low density areas, then, spread to the temporal lobes, rectal and cingulate gyri in the subacute stage (3 cases) and finally to the frontal and occipital lobes in the chronic stage (2 cases). In the basal ganglia, thalamus, brain stem and cerebellum, however, there were no low density areas. In 2 cases there was no progression of low density areas beyond those of the acute stage. In one case there were high density areas in the temporal lobes and parapontine cisterns bilaterally. This could correspond to the pathological findings in herpes simplex encephalitis. The improvement of CT findings (or arrest at the early stage) was noted in 2 cases in which the clinical state also improved. This might well be the effect of adenine arabinoside. The one case treated with cytosine arabinoside had extensive low density areas in CT and finally died. The importance of CT in the evaluation of adenine arabinoside therapy was stressed. (author)

  11. Development of a cone-beam CT system for radiological technologist education

    International Nuclear Information System (INIS)

    Teramoto, Atsushi; Ohara, Ken; Ozaki, Kaho; Miyashita, Mariko; Ohno, Tomoyuki; Tsuzaka, Masatoshi; Fujita, Hiroshi

    2011-01-01

    For radiological technologists, it is very important to understand the principle of computed tomography (CT) and CT artifacts derived from mechanical and electrical failure. In this study, a CT system for educating radiological technologists was developed. The system consisted of a cone-beam CT scanner and educational software. The cone-beam CT scanner has a simple structure, using a micro-focus X-ray tube and an indirect-conversion flat panel detector. For the educational software, we developed various educational functions of image reconstruction and reconstruction parameters as well as CT artifacts. In the experiments, the capabilities of the system were evaluated using an acrylic phantom. We verified that the system produced the expected results. (author)

  12. Indeterminate findings on oncologic PET/CT: What difference dose PET/MRI make?

    Energy Technology Data Exchange (ETDEWEB)

    Fraum, Tyler J.; Fowler, Kathryn J.; McConathy, Jonathan; Dehdashti, Farokh [Mallinckrodt Institute of Radiology, Washington University School of Medicine, Saint Louis (United States)

    2016-12-15

    Positron emission tomography/computed tomography (PET/CT) with 2-deoxy-2-[{sup 18}F]fluoro-D-glucose (FDG) has become the standard of care for the initial staging and subsequent treatment response assessment of many different malignancies. Despite this success, PET/CT is often supplemented by MRI to improve assessment of local tumor invasion and to facilitate detection of lesions in organs with high background FDG uptake. Consequently, PET/MRI has the potential to expand the clinical value of PET examinations by increasing reader certainty and reducing the need for subsequent imaging. This study evaluates the ability of FDG-PET/MRI to clarify findings initially deemed indeterminate on clinical FDG-PET/CT studies. A total of 190 oncology patients underwent whole-body PET/CT, immediately followed by PET/MRI utilizing the same FDG administration. Each PET/CT was interpreted by our institution's nuclear medicine service as a standard-of-care clinical examination. Review of these PET/CT reports identified 31 patients (16 %) with indeterminate findings. Two readers evaluated all 31 PET/CT studies, followed by the corresponding PET/MRI studies. A consensus was reached for each case, and changes in interpretation directly resulting from PET/MRI review were recorded. Interpretations were then correlated with follow-up imaging, pathology results, and other diagnostic studies. In 18 of 31 cases with indeterminate findings on PET/CT, PET/MRI resulted in a more definitive interpretation by facilitating the differentiation of infection/inflammation from malignancy (15/18), the accurate localization of FDG-avid lesions (2/18), and the characterization of incidental non-FDG-avid solid organ lesions (1/18). Explanations for improved reader certainty with PET/MRI included the superior soft tissue contrast of MRI and the ability to assess cellular density with diffusion-weighted imaging. The majority (12/18) of such cases had an appropriate standard of reference; in all 12 cases

  13. Indeterminate findings on oncologic PET/CT: What difference dose PET/MRI make?

    International Nuclear Information System (INIS)

    Fraum, Tyler J.; Fowler, Kathryn J.; McConathy, Jonathan; Dehdashti, Farokh

    2016-01-01

    Positron emission tomography/computed tomography (PET/CT) with 2-deoxy-2-["1"8F]fluoro-D-glucose (FDG) has become the standard of care for the initial staging and subsequent treatment response assessment of many different malignancies. Despite this success, PET/CT is often supplemented by MRI to improve assessment of local tumor invasion and to facilitate detection of lesions in organs with high background FDG uptake. Consequently, PET/MRI has the potential to expand the clinical value of PET examinations by increasing reader certainty and reducing the need for subsequent imaging. This study evaluates the ability of FDG-PET/MRI to clarify findings initially deemed indeterminate on clinical FDG-PET/CT studies. A total of 190 oncology patients underwent whole-body PET/CT, immediately followed by PET/MRI utilizing the same FDG administration. Each PET/CT was interpreted by our institution's nuclear medicine service as a standard-of-care clinical examination. Review of these PET/CT reports identified 31 patients (16 %) with indeterminate findings. Two readers evaluated all 31 PET/CT studies, followed by the corresponding PET/MRI studies. A consensus was reached for each case, and changes in interpretation directly resulting from PET/MRI review were recorded. Interpretations were then correlated with follow-up imaging, pathology results, and other diagnostic studies. In 18 of 31 cases with indeterminate findings on PET/CT, PET/MRI resulted in a more definitive interpretation by facilitating the differentiation of infection/inflammation from malignancy (15/18), the accurate localization of FDG-avid lesions (2/18), and the characterization of incidental non-FDG-avid solid organ lesions (1/18). Explanations for improved reader certainty with PET/MRI included the superior soft tissue contrast of MRI and the ability to assess cellular density with diffusion-weighted imaging. The majority (12/18) of such cases had an appropriate standard of reference; in all 12 cases, the

  14. Femoral head avascular necrosis: a frequently missed incidental finding on multidetector CT

    International Nuclear Information System (INIS)

    Barille, M.F.; Wu, Jim S.; McMahon, Colm J.

    2014-01-01

    Aim: To determine the incidence of missed femoral head avascular necrosis (AVN) on pelvic computed tomography (CT) performed for clinical indications other than assessment for AVN. Materials and methods: The study was a Health Insurance Portability and Accountability Act (HIPAA)-compliant retrospective study. The picture archiving and communication system (PACS) database was queried for patients with diagnosis of femoral head AVN on magnetic resonance imaging (MRI), who also underwent pelvic multidetector CT after or <30 days before the MRI examination. The MRI and CT images of 144 hips of 72 patients (39 patients with reported AVN on MRI and 33 age-matched controls; mean age = 60 years, 28 male, 44 female), were reviewed in consensus by two readers in a randomized, blinded manner. Using MRI-proven CT-visible AVN as a reference standard, the incidence of missed AVN on initial CT interpretation was determined. Results: Readers confirmed AVN in 33 patients on the MRI images. Nine hips with AVN underwent joint replacement of the affected joint(s) prior to subsequent CT and were excluded. Forty-three MRI-proven AVN cases in 28 patients (15 bilateral, 13 unilateral) were available for analysis. The study readers diagnosed 35/43 (81%) MRI-proven AVN cases in 22/28 (79%) patients. Four of the 35 (11%) cases of MRI-proven, CT-visible AVN were prospectively reported in 3/22 (14%) patients at initial clinical interpretation, with a miss rate of 89% per hip and 86% per patient. Conclusion: Multidetector CT has high accuracy for detection of AVN; however, this is frequently missed as an incidental finding (89% missed in the present study). Assessment for signs of femoral AVN should be part of routine search pattern in interpretation of pelvic CT

  15. Basic principles of magnetic resonance imaging in cerebral ischemia and initial clinical experience

    International Nuclear Information System (INIS)

    Brant-Zawadzki, M.; Solomon, M.; Newton, T.H.; Weinstein, P.; Schmidley, J.; Norman, D.

    1985-01-01

    NMR tomography proved to be a method superior to computerized tomography (CT) in terms of sensitivity in the diagnosis of pathological changes in the brain. The article on hand gives a brief survey on the principle of the method and demonstrates the superiority of NMR tomography to CT exemplified by images taken from a number of cases. Instrumental factors influencing diagnosis of cerebral ischaemie are discussed. Clinical studies performed on more than 20 partients with suspected infarct revealed the superiority of NMR tomography to CT. (MG) [de

  16. CT perfusion for determination of pharmacologically mediated blood flow changes in an animal tumor model.

    Science.gov (United States)

    Hakimé, Antoine; Peddi, Himaja; Hines-Peralta, Andrew U; Wilcox, Carol J; Kruskal, Jonathan; Lin, Shezhang; de Baere, Thierry; Raptopoulos, Vassilios D; Goldberg, S Nahum

    2007-06-01

    To prospectively compare single- and multisection computed tomographic (CT) perfusion for tumor blood flow determination in an animal model. All animal protocols and experiments were approved by the institutional animal care and use committee before the study was initiated. R3230 mammary adenocarcinoma was implanted in 11 rats. Tumors (18-20 mm) were scanned with dynamic 16-section CT at baseline and after administration of arsenic trioxide, which is known to cause acute reduction in blood flow. The concentration of arsenic was titrated (0-6 mg of arsenic per kilogram of body weight) to achieve a defined blood flow reduction (0%-75%) from baseline levels at 60 minutes, as determined with correlative laser Doppler flowmetry. The mean blood flow was calculated for each of four 5-mm sections that covered the entire tumor, as well as for the entire tumor after multiple sections were processed. Measurements obtained with both methods were correlated with laser Doppler flowmetry measurements. Interobserver agreement was determined for two blinded radiologists, who calculated the percentage of blood flow reduction for the "most representative" single sections at baseline and after arsenic administration. These results were compared with the interobserver variability of the same radiologists obtained by summing blood flow changes for the entire tumor volume. Overall correlations for acute blood flow reduction were demonstrated between laser Doppler flowmetry and the two CT perfusion approaches (single-section CT, r=0.85 and r(2)=0.73; multisection CT, r=0.93 and r(2)=0.87; pooled data, P=.01). CT perfusion disclosed marked heterogeneity of blood flow, with variations of 36% +/- 13 between adjacent 5-mm sections. Given these marked differences, interobserver agreement was much lower for single-section CT (standard deviation, 0.22) than for multisection CT (standard deviation, 0.10; P=.01). Multisection CT perfusion techniques may provide an accurate and more reproducible

  17. 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.)

  18. A 3-MA compact-toroid-plasma-flow-switched plasma focus demonstration experiment on Shiva Star

    Energy Technology Data Exchange (ETDEWEB)

    Kiuttu, G F; Degnan, J H [Phillips Lab., Kirtland AFB, NM (United States). High Energy Sources Div.; Graham, J D [Maxwell Labs., Albuquerque, NM (United States); and others

    1997-12-31

    A novel dense plasma focus experiment using the Shiva Star capacitor bank is described. The experiment uses a compact toroid (CT) magnetized plasma flow switch (PFS) to initiate the focus implosion. The CT armature stably and reproducibly translates up to 3 MA from the vacuum feed region through coaxial electrodes to the gas puff central load. The inertia of the 1 mg CT and the work that must be done in compressing the internal magnetic fields during the translation provide a delay in current delivery to the pinch of 5 - 10 {mu}s, which matches the bank quarter cycle time relatively well. Effectiveness of the current delivery was monitored primarily by inductive probes in the PFS region, fast photography of the focus, and x-ray and neutron measurements of the pinch. K shell x-ray yields using neon gas were as high as 1 kJ, and 10{sup 8} neutrons were produced in a deuterium gas focus. (author). 4 figs., 10 refs.

  19. A 3-MA compact-toroid-plasma-flow-switched plasma focus demonstration experiment on Shiva Star

    International Nuclear Information System (INIS)

    Kiuttu, G.F.; Degnan, J.H.

    1996-01-01

    A novel dense plasma focus experiment using the Shiva Star capacitor bank is described. The experiment uses a compact toroid (CT) magnetized plasma flow switch (PFS) to initiate the focus implosion. The CT armature stably and reproducibly translates up to 3 MA from the vacuum feed region through coaxial electrodes to the gas puff central load. The inertia of the 1 mg CT and the work that must be done in compressing the internal magnetic fields during the translation provide a delay in current delivery to the pinch of 5 - 10 μs, which matches the bank quarter cycle time relatively well. Effectiveness of the current delivery was monitored primarily by inductive probes in the PFS region, fast photography of the focus, and x-ray and neutron measurements of the pinch. K shell x-ray yields using neon gas were as high as 1 kJ, and 10 8 neutrons were produced in a deuterium gas focus. (author). 4 figs., 10 refs

  20. Femoral head avascular necrosis: a frequently missed incidental finding on multidetector CT.

    Science.gov (United States)

    Barille, M F; Wu, Jim S; McMahon, Colm J

    2014-03-01

    To determine the incidence of missed femoral head avascular necrosis (AVN) on pelvic computed tomography (CT) performed for clinical indications other than assessment for AVN. The study was a Health Insurance Portability and Accountability Act (HIPAA)-compliant retrospective study. The picture archiving and communication system (PACS) database was queried for patients with diagnosis of femoral head AVN on magnetic resonance imaging (MRI), who also underwent pelvic multidetector CT after or AVN on MRI and 33 age-matched controls; mean age = 60 years, 28 male, 44 female), were reviewed in consensus by two readers in a randomized, blinded manner. Using MRI-proven CT-visible AVN as a reference standard, the incidence of missed AVN on initial CT interpretation was determined. Readers confirmed AVN in 33 patients on the MRI images. Nine hips with AVN underwent joint replacement of the affected joint(s) prior to subsequent CT and were excluded. Forty-three MRI-proven AVN cases in 28 patients (15 bilateral, 13 unilateral) were available for analysis. The study readers diagnosed 35/43 (81%) MRI-proven AVN cases in 22/28 (79%) patients. Four of the 35 (11%) cases of MRI-proven, CT-visible AVN were prospectively reported in 3/22 (14%) patients at initial clinical interpretation, with a miss rate of 89% per hip and 86% per patient. Multidetector CT has high accuracy for detection of AVN; however, this is frequently missed as an incidental finding (89% missed in the present study). Assessment for signs of femoral AVN should be part of routine search pattern in interpretation of pelvic CT. Copyright © 2013 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  1. Dual-energy computed tomographic virtual noncalcium algorithm for detection of bone marrow edema in acute fractures: early experiences.

    Science.gov (United States)

    Reagan, Adrian C; Mallinson, Paul I; O'Connell, Timothy; McLaughlin, Patrick D; Krauss, Bernhard; Munk, Peter L; Nicolaou, Savvas; Ouellette, Hugue A

    2014-01-01

    Computed tomography (CT) is often used to assess the presence of occult fractures when plain radiographs are equivocal in the acute traumatic setting. While providing increased spatial resolution, conventional computed tomography is limited in the assessment of bone marrow edema, a finding that is readily detectable on magnetic resonance imaging (MRI).Dual-energy CT has recently been shown to demonstrate patterns of bone marrow edema similar to corresponding MRI studies. Dual-energy CT may therefore provide a convenient modality for further characterizing acute bony injury when MRI is not readily available. We report our initial experiences of 4 cases with imaging and clinical correlation.

  2. Lung cancer mimicking lung abscess formation on CT images.

    Science.gov (United States)

    Taira, Naohiro; Kawabata, Tsutomu; Gabe, Atsushi; Ichi, Takaharu; Kushi, Kazuaki; Yohena, Tomofumi; Kawasaki, Hidenori; Yamashiro, Toshimitsu; Ishikawa, Kiyoshi

    2014-01-01

    Male, 64 FINAL DIAGNOSIS: Lung pleomorphic carcinoma Symptoms: Cough • fever - Clinical Procedure: - Specialty: Oncology. Unusual clinical course. The diagnosis of lung cancer is often made based on computed tomography (CT) image findings if it cannot be confirmed on pathological examinations, such as bronchoscopy. However, the CT image findings of cancerous lesions are similar to those of abscesses.We herein report a case of lung cancer that resembled a lung abscess on CT. We herein describe the case of 64-year-old male who was diagnosed with lung cancer using surgery. In this case, it was quite difficult to distinguish between the lung cancer and a lung abscess on CT images, and a lung abscess was initially suspected due to symptoms, such as fever and coughing, contrast-enhanced CT image findings showing a ring-enhancing mass in the right upper lobe and the patient's laboratory test results. However, a pathological diagnosis of lung cancer was confirmed according to the results of a rapid frozen section biopsy of the lesion. This case suggests that physicians should not suspect both a lung abscesses and malignancy in cases involving masses presenting as ring-enhancing lesions on contrast-enhanced CT.

  3. Studies of extracerebral space on brain CT of infants

    International Nuclear Information System (INIS)

    Shibakiri, Ippei; Furukawa, Takashi; Fukakusa, Shunichi; Nemoto, Yutaka; Takashima, Sumio.

    1983-01-01

    Frontal extracerebral space (ECS) is frequently noticed on brain CT of infants. Based on 70 infants whose initial CTs were available under 1 year of age and who were observed serially by brain CT, we studied the relation between degrees of ECS enlargement and mental and physical development of infants. Development was assessed by clinical observation and the mental test according to Tsumori and Inage at about 1 year of age. 1) Under 1 year of age, ECS was observed both in the normally developed infants and the infants with retarded development. At 1 year of age, CT of the former showed no or only mild widening, but most CT of the latter showed marked dilatation of ECS. 2) Serial observation of brain CT revealed that ECS of normally developed infants tended to reduce at 1 year of age, but that of infants with retarded development did not. 3) Regarding prediction of infantile development, it is important to observe presence of ECS and of the tendency to reduce on brain CT at 1 year of age. 4) Appearance of ECS of normally developed infants is considered to be a physiological phenomenon. (author)

  4. Pulmonary actinomycosis: CT studies of diagnostic and post-treatment findings

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Su Jung; Song, Sun Wha; Bo, Seal Hwang; Park, Hyun Jin; Kim, Hyeon Sook; Kim, Ki Jun; Kim, Horrim; Park, Seog Hee [College of Medicine, the Catholic University of Korea, Uijeongbu (Korea, Republic of)

    2008-05-15

    To investigate the value of the computed tomography (CT) in the study of diagnostic and post-treatment findings of pulmonary actinomycosis. Clinical data and CT findings were retrospectively analyzed in 10 patients with histopathologically confirmed pulmonary actinomycosis. We analyzed the initial CT findings in search of patterns and distributions which suggest possible lung abnormalities and found the pleura, chest wall, and lymphadenopathy to be involved as part of the indicators of lung abnormalities. We analyzed follow-up CT findings for changes in the lungs after antibiotic therapy and recurrence after surgery. Of the 10 patients analyzed by CT for lung lesions, seven had been diagnosed with alcoholism and nine were male. The initial CTs (n = 10) indicated that all the pulmonary lesions were solitary without chest wall involvement. However, a transfissural extension was observed in 20% of the study population (n = 2). Furthermore, peripheral lung distribution and adjacent pleural thickening was observed in 70% of the study population (n = 7). Within the consolidation (n = 6) or mass (n = 4), a central low density with peripheral enhancement was seen in 70% of the study population (n = 7). A follow-up CT of the seven cases following antiobiotic therapy revealed that four cases showed minimal improvement or aggravation of their lung lesions, whereas three cases showed resolution or improvement. The improvement of the central low density was related to the improvement of consolidation or mass. Furthermore the presence of fibrosis was observed after the resolution of pulmonary lesions (n = 2). No relationship was found between the duration and response of antibiotic therapy. A follow-up CT (n = 4) subsequent to a lung resection revealed the onset of chest wall actinomycosis and a thickened pleura in one case. The results of this study highlight the value of the CT in pulmonary actinomycosis in order to diagnose and evaluate antibiotic responses, complications, or

  5. Commissioning and initial experimental program of the BGO-OD experiment at ELSA

    Science.gov (United States)

    Alef, S.; Bauer, P.; Bayadilov, D.; Beck, R.; Becker, M.; Bella, A.; Bielefeldt, P.; Böse, S.; Braghieri, A.; Brinkmann, K.; Cole, P.; Di Salvo, R.; Dutz, H.; Elsner, D.; Fantini, A.; Freyermuth, O.; Friedrich, S.; Frommberger, F.; Ganenko, V.; Geffers, D.; Gervino, G.; Ghio, F.; Görtz, S.; Gridnev, A.; Gutz, E.; Hammann, D.; Hannappel, J.; Hillert, W.; Ignatov, A.; Jahn, R.; Joosten, R.; Jude, T. C.; Klein, F.; Knaust, J.; Kohl, K.; Koop, K.; Krusche, B.; Lapik, A.; Levi Sandri, P.; Lopatin, I. V.; Mandaglio, G.; Messi, F.; Messi, R.; Metag, V.; Moricciani, D.; Mushkarenkov, A.; Nanova, M.; Nedorezov, V.; Novinskiy, D.; Pedroni, P.; Reitz, B.; Romaniuk, M.; Rostomyan, T.; Rudnev, N.; Schaerf, C.; Scheluchin, G.; Schmieden, H.; Stugelev, A.; Sumachev, V.; Tarakanov, V.; Vegna, V.; Walther, D.; Watts, D.; Zaunick, H.; Zimmermann, T.

    2016-11-01

    BGO-OD is a new meson photoproduction experiment at the ELSA facility of Bonn University. It aims at the investigation of non strange and strange baryon excitations, and is especially designed to be able to detect weekly bound meson-baryon type structures. The setup for the BGO-OD experiment is presented, the characteristics of the photon beam and the detector performances are shown and the initial experimental program is discussed.

  6. Biomechanical analysis of scoliosis and back muscles using CT evaluation and finite element method

    Energy Technology Data Exchange (ETDEWEB)

    Saka, K

    1987-03-01

    The CT observation of back muscles of an idiopathic scoliosis patient showed increased muscle volume and high CT value on the convex side. Following these muscles by digitizer showed that convex muscle volume increased as the vertebra shifted to convexity. These back muscles were suggested to be transversospinalis muscles. Biomechanical analysis using finite element method (FEM) was done to further investigate this increasing volume of back muscles. A Risser experiment using FEM revealed that initial lordosis configuration model only produces rotation to the convex side by unilateral loading. We, therefore, made the model adding posterior element, regarding contraction of M. transversospinalis. In a normal case, the upper vertebra is rotated over the lower towards the side opposite the muscle contraction. The scoliosis model, however, showed rotation towards the side of muscle contraction. M. transversospinalis can be considered as the agent of this rotation force. In a rib cage model, M. transversospinalis also affected the rib cage deformity.

  7. Biomechanical analysis of scoliosis and back muscles using CT evaluation and finite element method

    International Nuclear Information System (INIS)

    Saka, Kenji

    1987-01-01

    The CT observation of back muscles of an idiopathic scoliosis patient showed increased muscle volume and high CT value on the convex side. Following these muscles by digitizer showed that convex muscle volume increased as the vertebra shifted to convexity. These back muscles were suggested to be transversospinalis muscles. Biomechanical analysis using finite element method (FEM) was done to further investigate this increasing volume of back muscles. A Risser experiment using FEM revealed that initial lordosis configuration model only produces rotation to the convex side by unilateral loading. We, therefore, made the model adding posterior element, regarding contraction of M. transversospinalis. In a normal case, the upper vertebra is rotated over the lower towards the side opposite the muscle contraction. The scoliosis model, however, showed rotation towards the side of muscle contraction. M. transversospinalis can be considered as the agent of this rotation force. In a rib cage model, M. transversospinalis also affected the rib cage deformity. (author)

  8. Assessment of the optimal temporal window for intravenous CT cholangiography

    Energy Technology Data Exchange (ETDEWEB)

    Schindera, Sebastian T.; Nelson, Rendon C.; Paulson, Erik K.; DeLong, David M.; Merkle, Elmar M. [Duke University Medical Center, Department of Radiology, P.O. Box 3808, Durham, NC (United States)

    2007-10-15

    The optimal temporal window of intravenous (IV) computed tomography (CT) cholangiography was prospectively determined. Fifteen volunteers (eight women, seven men; mean age, 38 years) underwent dynamic CT cholangiography. Two unenhanced images were acquired at the porta hepatis. Starting 5 min after initiation of IV contrast infusion (20 ml iodipamide meglumine 52%), 15 pairs of images at 5-min intervals were obtained. Attenuation of the extrahepatic bile duct (EBD) and the liver parenchyma was measured. Two readers graded visualization of the higher-order biliary branches. The first biliary opacification in the EBD occurred between 15 and 25 min (mean, 22.3 min {+-} 3.2) after initiation of the contrast agent. Biliary attenuation plateaued between the 35- and the 75-min time points. Maximum hepatic parenchymal enhancement was 18.5 HU {+-} 2.7. Twelve subjects demonstrated poor or non-visualization of higher-order biliary branches; three showed good or excellent visualization. Body weight and both biliary attenuation and visualization of the higher-order biliary branches correlated significantly (P<0.05). For peak enhancement of the biliary tree, CT cholangiography should be performed no earlier than 35 min after initiation of IV infusion. For a fixed contrast dose, superior visualization of the biliary system is achieved in subjects with lower body weight. (orig.)

  9. Generating Evidence for Clinical Benefit of PET/CT in Diagnosing Cancer Patients

    DEFF Research Database (Denmark)

    Vach, Werner; Høilund-Carlsen, Poul Flemming; Gerke, Oke

    2011-01-01

    For diagnostic methods such as PET/CT, not only diagnostic accuracy but also clinical benefit must be demonstrated. However, there is a lack of consensus about how to approach this task. Here we consider 6 clinical scenarios to review some basic approaches to demonstrating the clinical benefit...... of PET/CT in cancer patients: replacement of an invasive procedure, improved accuracy of initial diagnosis, improved accuracy of staging for curative versus palliative treatment, improved accuracy of staging for radiation versus chemotherapy, response evaluation, and acceleration of clinical decisions....... We also develop some guidelines for the evaluation of clinical benefit. First, it should be clarified whether there is a direct benefit of the use of PET/CT or an indirect benefit because of improved diagnostic accuracy. If there is an indirect benefit, then decisi