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Sample records for multi-slice ct application

  1. Clinical application of multi-slice helical CT volumetric scanning in lumber spine

    International Nuclear Information System (INIS)

    Wang Ling; Ge Yinghui; Zhu Shaocheng; Zhang Ming; Cheng Tianming; Lei Zhidan; Lv Chuanjian; Sun Xiaoping; Wu Minghui; Guo Ying; Ma Qianli; Wen Zeying

    2008-01-01

    Objective: To evaluate the clinical application value of multi-slice helical CT volumetric (VH) scanning in lumber spine. Methods: One thousand of patients with back and leg pain who underwent CT examinations were selected as subjects. We simulated the traditional protocol of single-slice(SS) discrete scanning for L3/4, L4/5, and L5/S1 intervertebral discs. The VH scanning mode was performed with 120 kV, 210 mAs, pitch of 1.5 and coverage of 97.5 mm. The simulated SS scanning mode was performed with 120 kV, 240 mAs and coverage of 45.0 mm. The diagnostic outcomes and the radiation doses were compared between the two scanning modes. Two groups doctors observed ten terms, including the osseous spinal stenosis, narrowed intervertebral space and so on in two scanning modes respectively. Then consistency analysis of the data was carded out. Results: The VH scanning mode showed far more features than the SS mode. The detection rates of the VH mode in the osseous spinal stenosis, narrowed intervertebral space, herniated nucleus pulposus, narrowed lateral recess, vertebral lesion, hypertrophy of L5 transverse process, abnormal direction of facet, facet degeneration, lumbar spondyloschisis, and paraspinal soft tissue were 11.8% (n=118), 38.5% (n=385), 9.3% (n=93), 46.8% (n=468), 31.4% (n=314), 5.7% (n= 57), 25.4% (n=254), 49.7% (n=497), 9.9% (n=99), and 0.6% (n=6) respectively, while the detection rates of the SS mode in ten terms were 5.6% (n=56), 0, 0.6% (n=6), 27.9% (n=279), 22.4% (n=224), 1.2% (n=12), 16.7% (n=167), 37.2% (n=372), 0.5% (n=5), and 0.2% (n=2) respectively. The difference between the two groups had statistically significance (average P 0.05). The detection rates of the VH mode were higher than the SS mode in the osseous spinal stenosis, narrowed intervertebral space, herniated nucleus pulposus, lumbar spondyloschisis, being 6.2% (n=62), 38.5% (n=385), 8.7% (n=87), and 9.4% (n=94), respectively. In addition, VH mode only partially showed the articular

  2. Application of low dose multi-slice helical CT in orbital trauma patients

    International Nuclear Information System (INIS)

    Yang Rui; Dai Limei; Li Jianying; Wang Fengyan; Du Guoquan

    2010-01-01

    Objective: To investigate the most appropriate low radiation dose in multi-slice CT (MSCT) scans for orbital trauma patients. Methods: Thirty trauma patients with suspected orbital fractures who underwent helical CT scans with a 64-MSCT using regular dose were selected. Noise was artificially introduced to the axial images using an image space noise addition tool to simulate 6 sets of lower dose scans with tube current of 30, 70, 100, 140, 170 and 200 mA, respectively. The lowest tube current with adequate image quality for confident diagnosis was determined based on the evaluation of the overall image quality and fracture detection on images at different dose levels. The determined lowest tube current was then validated using clinical scans. Radiation dose related parameters CTDIvol, DLP, ED were also recorded. Image quality was evaluated according to its low-density resolution, noise and structure clarity and characterized into 5-grades of excellent, good, fair, worse and worst. Rank sum test and χ 2 test were used for statistics. Results: In 30 trauma patients with regular dose of 300 mA, there were 30 cases of orbital fracture, 19 cases of intraorbital emphysema, 12 cases of ocular muscle injury and 1 case of intraorbital foreign body. These changes could still be clearly observed and correctly diagnosed when the tube current was reduced to as low as 70 mA. However, the overall image quality was mostly fair. At the simulated dose of 100 mA, the majority of images were characterized as excellent or good, and there was no statistical difference compared with that of regular dose scans (P>0.05). In the clinical evaluation for 20 orbital trauma patients with the reduced tube current of 100 m A , the majority of images were judged to be excellent (9 cases) or good (17 cases) and fair (4 cases). The radiation dose (0.29 mSv) was reduced by 70% compared with that of regular tube current of 300 mA (0.86 mSv). Conclusion: The tube current of MSCT may be used as low as

  3. CT pulmonary angiography using 64-row multi-slice spiral CT: a comparative study in low tube voltage setting combined with personalized contrast agent application

    International Nuclear Information System (INIS)

    Zhou Xuhui; Peng Zhenpeng; Zheng Lili; Li Shurong; Yang Zhiyun; Meng Quanfei; Chen Xing

    2009-01-01

    Objective: To investigate the feasibility of the low tube voltage setting and personalized contrast agent application in 64-row multi-slice spiral CT pulmonary angiography. Methods: Ninety patients with high risk of pulmonary artery embolism were sequentially enrolled in the study and divided into 3 groups employing completely randomized design: (l)Regular group included 30 patients using 120 kV and fixed dose of 70 ml contrast agent, (2)Another 30 patients were in 120 kV group, using 120 kV and the contrast amount was determined according to the patient weight (1.0 ml/kg), (3) The remaining 30 patients were included in 100 kV group, using 100 kV and the contrast amount was also determined according to the patient weight(1.0 ml/kg). Administration of contrast agent was completed within 20 seconds for all the patients, followed by 20 ml of saline. The objective and subjective indexes for assessing CT image quality, CT dose index volume (CTDIvol) and effective received dose (ERD) were compared between 120 kV group and 100 kV group; then the contrast media volume, injection rate, objective CT image indexes and subjective indexes for image quality was compared between the 100 kV group and regular group. The variance analysis and post hoc test were employed for the statistical analysis. Results: Compared with 120 kV group (3.4±0.7), the image quality of 100 kV group (5.2±1.8) had higher noise (52.9%), but subjective index for the image quality demonstrated no differences (q=0.272, P=0.063) in mediastinum window while CTDIvol and ERD decreased for 34.9% [(9.5±0.0) vs (14.6±0.0) mGy] and 36.8% [(3.8±0.6) vs (2.4±0.4) mSv]. The mean CT values on pulmonary artery of 100 kV group[ (269.2±54.7) HU] were 13.4% (31.8/237.4) higher than the 120 kV group [(237.4±62.9)HU], but there was no statistical differences compared to normal group (q=0.172,P=0.260). Conclusion: Using low kV setting (100 kV) to reduce radiation dose is proved to be effective and feasible in 64-MSCT

  4. Multi-slice spiral CT diagnosis of carotid body tumor

    International Nuclear Information System (INIS)

    Li Peiling; Leng Renli; Li Shu; Xie Xiuli; Xu Ke

    2006-01-01

    Objective: to explore the Multi-slice spiral CT (MSCT) findings of carotid body tumor (CBT). Methods: Twelve cases of CBT proved by surgery were collected in this study and all patients accepted contrast-enhanced MSCT examination. Two-dimensional and three-dimensional post-processing were performed at diagnostic workstation using Aquilion 1.42. The CT features of CBT were analyzed. Results Each of 12 patients had one lesion. All lesions demonstrated well-marginated masses of homogeneous soft- tissue density with CT value within 29-48 HU on pre-enhanced images. All lesions were markedly enhanced with CT value over 200 HU on arterial-phase images, and the density of lesions decreased rapidly on delay- phase images. Twelve lesions were all located at the level of carotid artery bifurcation, 3 of them enveloping common carotid artery and internal/external carotid artery, and other 9 of them riding right on the carotid bifurcation. Internal carotid artery usually were shifted toward posterior-lateral, and external carotid artery toward anterior or anterior-medial. Conclusion: Contrast-enhanced MSCT examination not only can make a qualitative diagnosis of CBT, but determine its accurate location. It plays an importantly instructional role in clinical diagnosis and treatment. (authors)

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

    International Nuclear Information System (INIS)

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

    2000-01-01

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

  6. Clinical application of 64 multi-slice CT angiography for the follow-up of endovascular stent-graft exclusion

    International Nuclear Information System (INIS)

    Yin Longlin; Chen Jiayuan; Jiang Jin; Yang Zhigang; Li Zhenlin; Sun Jiayu; Zhu Hongmei

    2009-01-01

    Objective: To investigate the clinical applications of 64-MSCTA for the follow-up of endovascular stent-graft exclusion (EVE). Methods: Between Oct 2006 and Feb 2008, forty-four 64-MSCTA examinations were performed in 30 patients with aortic dissection (AD) and 5 patients with abdominal aortic aneurysm (AAA) who underwent EVE. Imaging reconstruction including MPR, MIP and VR were finished on workstation. The outcomes and complications after EVE of aortic dissection and aortic aneurysm were evaluated. Results: (1) Of 30 patients with aortic dissection, large thrombosis in false lumen was observed in 28 cases and small thrombosis in 2 cases. The cavity of aortic aneurysm outside the stent was thrombosed completely in 5 patients with AAA. (2) Thrombosis in the innominate artery on follow-up CTA after EVE was found in 1 AD patient with the innominate artery involved, Thrombosis in the superior mesenteric artery was observed on 15 days follow-up CTA but thrombolysis on 3 months after EVE in 1 case, Intimal tear in right common iliac artery was found in 1 case. Of 5 patients with AAA, occlusion of right inner iliac artery was observed in 1 case, and instent thrombosis in distal right common iliac artery was found in 1 case. (3) Endoleak was found in 14 patients with AD, including 8 with type I and 6 with type III endoleaks, one type III endoleak was disappeared on follow-up CTA after 3 months. Conclusions: 64-MSCTA with fast, non-invasive and effective merits, combining multiple reconstructive methods, has become one of preferred imaging methods in post-operative evaluation of EVE. (authors)

  7. Slice sensitivity profiles and pixel noise of multi-slice CT in comparison with single-slice CT

    International Nuclear Information System (INIS)

    Schorn, C.; Obenauer, S.; Funke, M.; Hermann, K.P.; Kopka, L.; Grabbe, E.

    1999-01-01

    Purpose: Presentation and evaluation of slice sensitivity profile and pixel noise of multi-slice CT in comparison to single-slice CT. Methods: Slice sensitivity profiles and pixel noise of a multi-slice CT equiped with a 2D matrix detector array and of a single-slice CT were evaluated in phantom studies. Results: For the single-slice CT the width of the slice sensitivity profiles increased with increasing pitch. In spite of a much higher table speed the slice sensitivity profiles of multi-slice CT were narrower and did not increase with higher pitch. Noise in single-slice CT was independent of pitch. For multi-slice CT noise increased with higher pitch and for the higher pitch decreased slightly with higher detector row collimation. Conclusions: Multi-slice CT provides superior z-resolution and higher volume coverage speed. These qualities fulfill one of the prerequisites for improvement of 3D postprocessing. (orig.) [de

  8. Multi-slice CT urography after diuretic injection: initial results

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    Nolte-Ernsting, C.C.A.; Wildberger, J.E.; Schmitz-Rode, T.; Guenther, R.W. [Technische Univ. Aachen (Germany). Dept. of Diagnostic Radiology; Borchers, H. [Technische Univ. Aachen (Germany). Dept. of Urology

    2001-03-01

    Purpose: To investigate the feasibility of CT urography (CTU) using a multi-slice (MS) scanner and to find out whether a low-dose diuretic injection is advantageous for the opacification of the urinary tract. Methods: MS-CTU was performed in 21 patients with urologic diseases. In 5/21 patients, 250 ml of physiologic saline solution were injected. In 16/21 patients, 10 mg of furosemide were injected 3-5 min before contrast material administration. A 4x2.5 mm collimation with a pitch of 1.25 and a tube curent of 100-150 mA were used. Scan time was 12-16 sec. 3 mm thin axial images with an overlap of 67% were reconstructed. Multiplanar maximum intensity projection (MIP) images were postprocessed to obtain urographic views. Bone structures were eliminated using the volume-of-interest method. Results: Furosemide-enhanced MS-CTU achieved either near complete or complete opacification in 30/32 (94%) ureters and in 32/32 (100%) pelvicaliceal systems up to a serum creatinine of 150 {mu}mol/l. In our series, only one CTU scan per patient was needed to obtain a diagnostic urogram after 10 min of contrast material injection. Ureteral compression was not necessary. When physiologic saline solution was used instead of furosemide, the radiopacity inside the enhanced pelvicalices was 4-5 times higher and more inhomogeneous. Diuretic-enhanced MS-CTU was more accurate in the depiction of pelvicaliceal details. In combination with furosemide, calculi were well identified inside the opacified urine and were safely differentiated from phleboliths. Postprocessing times of up to 20 minutes were problematic as were contrast-enhanced superimposing bowel loops on MIP images. Conclusion: Preliminary results demonstrate a good feasibility of furosemide-enhanced MS-CTU for obtaining detailed visualization of the entire upper urinary tract. (orig.) [German] Ziel: Untersuchung zur Durchfuehrbarkeit der CT Urographie (CTU) mit einem Multidetektor(MD)-Computertomographen und ob eine

  9. Pitch dependence of longitudinal sampling and aliasing effects in multi-slice helical computed tomography (CT)

    International Nuclear Information System (INIS)

    La Riviere, Patrick J.; Pan Xiaochuan

    2002-01-01

    In this work, we investigate longitudinal sampling and aliasing effects in multi-slice helical CT. We demonstrate that longitudinal aliasing can be a significant, complicated, and potentially detrimental effect in multi-slice helical CT reconstructions. Multi-slice helical CT scans are generally undersampled longitudinally for all pitches of clinical interest, and the resulting aliasing effects are spatially variant. As in the single-slice case, aliasing is shown to be negligible at the isocentre for circularly symmetric objects due to a fortuitous aliasing cancellation phenomenon. However, away from the isocentre, aliasing effects can be significant, spatially variant, and highly pitch dependent. This implies that measures more sophisticated than isocentre slice sensitivity profiles are needed to characterize longitudinal properties of multi-slice helical CT systems. Such measures are particularly important in assessing the question of whether there are preferred pitches in helical CT. Previous analyses have generally focused only on isocentre sampling patterns, and our more global analysis leads to somewhat different conclusions than have been reached before, suggesting that pitches 3, 4, 5, and 6 are favourable, and that half-integer pitches are somewhat suboptimal. (author)

  10. Detection of hepatocellular carcinoma with multi-slice spiral CT by ...

    African Journals Online (AJOL)

    STORAGESEVER

    2010-06-07

    Jun 7, 2010 ... The purpose of the study is to evaluate the effect of iodine concentration of contrast material on detection of hepatocellular carcinoma with multi-slice spiral computed tomography (CT) by using double-arterial phase and portal venous phase enhanced scanning. Ninety-four (94) patients with hepatocellular ...

  11. Dynamic bowtie filter for cone-beam/multi-slice CT.

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    Fenglin Liu

    Full Text Available A pre-patient attenuator ("bowtie filter" or "bowtie" is used to modulate an incoming x-ray beam as a function of the angle of the x-ray with respect to a patient to balance the photon flux on a detector array. While the current dynamic bowtie design is focused on fan-beam geometry, in this study we propose a methodology for dynamic bowtie design in multi-slice/cone-beam geometry. The proposed 3D dynamic bowtie is an extension of the 2D prior art. The 3D bowtie consists of a highly attenuating bowtie (HB filled in with heavy liquid and a weakly attenuating bowtie (WB immersed in the liquid of the HB. The HB targets a balanced flux distribution on a detector array when no object is in the field of view (FOV. The WB compensates for an object in the FOV, and hence is a scaled-down version of the object. The WB is rotated and translated in synchrony with the source rotation and patient translation so that the overall flux balance is maintained on the detector array. First, the mathematical models of different scanning modes are established for an elliptical water phantom. Then, a numerical simulation study is performed to compare the performance of the scanning modes in the cases of the water phantom and a patient cross-section without any bowtie and with a dynamic bowtie. The dynamic bowtie can equalize the numbers of detected photons in the case of the water phantom. In practical cases, the dynamic bowtie can effectively reduce the dynamic range of detected signals inside the FOV. Furthermore, the WB can be individualized using a 3D printing technique as the gold standard. We have extended the dynamic bowtie concept from 2D to 3D by using highly attenuating liquid and moving a scale-reduced negative copy of an object being scanned. Our methodology can be applied to reduce radiation dose and facilitate photon-counting detection.

  12. The diagnostic value of multi-slice CT on the congenital malformation of coronary sinus

    International Nuclear Information System (INIS)

    Li Wei; Ma Xiaojing; Sun Qingjun

    2012-01-01

    Objective: To investigate the application value of multi-slice spiral CT on the congenital malformation of coronary sinus. Methods: MSCT finding of 98 patients with coronary sinus malformation confirmed by surgery were retrospectively analyzed,and the cases were divided into four categories based on the Mantini theory and comparison was made between the diagnosis from ultrasound and CT. A 2 × 2 table for Chi-square test was also used for statistics analysis. Results: Among 98 patients,there were 72 patients with persistent left superior vena cava reflowed to right atria through coronary sinus, with 48 patients diagnosed by ultrasound and 72 patients by MSCT; there were 13 patients with anomalous pulmonary venous connection to coronary sinus, with 12 patients diagnosed by ultrasound and 13 patients by MSCT diagnosis; there were 10 patients with unroofed coronary sinus syndrome, with 6 patients diagnosed by ultrasound and 8 patients by MSCT, there were 2 patients with coronary sinus atresia, all diagnosed by MSCT; there were 1 patient with coronary sinus anomaly reflow to left arita. The significant difference between 2 modalities (χ 2 =22.7, P<0.01) shows that CT is superior to ultrasound. Conclusion: MSCT is much more better than ultrasound in the diagnosis of malformation of coronary sinus and it can provide reliable diagnosis prior to surgery or interventional therapy. (authors)

  13. The anal verge: localization with multi-slice spiral CT

    International Nuclear Information System (INIS)

    Wang Wei; Tang Guangjian

    2010-01-01

    Objective: To determine and evaluate the method of localization of anal verge by multislice spiral CT. To provide an imaging reference for operative guidance of low-rectal cancer. Methods Forty eight consecutive adult patients suspected of abnormalities other than rectal disease were evaluated with abdominal and pelvic CT scans since August, 2009. They were divided into two groups based on sex and age. There were 23 men and 25 women. The ages of young group were 28 to 50 years and the average age was 41 years. The ages of elderly group were 52 to 81 years and the average age was 64 years. A small cotton ball dipped with contrast media was put at the anal verge as a marker and CT scans were performed with 64-slice spiral CT scanner. The distances between the cotton balls and the lower margin of the pubis combination (La), the lower margin of the Sth sacral vertebra (Lb), the inferior aperture of minor pelvis (Lc) and the lower margin of the basement of external anal sphincter (Ld) were measured on the mid- sagittal images obtained by MPR. The averages, the standard deviations (s), the 95% and 80% confidence intervals of La, Lb, Lc and Ld were calculated. We took the intervals of ±1.96 s or ±1.28 s 0.05) between two different sex groups [male group, (10.0±1.2) mm], female group, (9.6±1.2) mm and between two age groups [young group, (9.6±1.2) mm, elderly group, (9.9±1.3) mm]. Conclusions: The lower margin of the basement of external anal sphincter was a useful anatomic landmark for localizing the anal verge, and could be definitely identified on the middle sagittal pelvic CT image. The distance between the structure and anal verge is constant enough and can be used in measuring distance from low rectal lesion to the anal verge. (authors)

  14. Multi-slice and dual-source CT in cardiac imaging. Principles - protocols - indications - outlook. 2. ed.

    International Nuclear Information System (INIS)

    Ohnesorge, B.M.; Flohr, T.G.; Becker, C.R.; Reiser, M.F.; Knez, A

    2007-01-01

    Cardiac diseases, and in particular coronary artery disease, are the leading cause of death and morbidity in industrialized countries. The development of non-invasive imaging techniques for the heart and the coronary arteries has been considered a key element in improving patient care. A breakthrough in cardiac imaging using CT occurred in 1998, with the introduction of multi-slice computed tomography (CT). Since then, amazing advances in performance have taken place with scanners that acquire up to 64 slices per rotation. This book discusses the state-of-the-art developments in multi-slice CT for cardiac imaging as well as those that can be anticipated in the future. It serves as a comprehensive work that covers all aspects of this technology, from the technical fundamentals and image evaluation all the way to clinical indications and protocol recommendations. This fully reworked second edition draws on the most recent clinical experience obtained with 16- and 64-slice CT scanners by world-leading experts from Europe and the United States. It also includes ''hands-on'' experience in the form of 10 representative clinical case studies, which are included on the accompanying CD. As a further highlight, the latest results of the very recently introduced dual-source CT, which may soon represent the CT technology of choice for cardiac applications, are presented. This book will not only convince the reader that multi-slice cardiac CT has arrived in clinical practice, it will also make a significant contribution to the education of radiologists, cardiologists, technologists, and physicists-whether newcomers, experienced users, or researchers. (orig.)

  15. Multi-slice CT features of annular pancreas in neonates

    International Nuclear Information System (INIS)

    He Mingqing; Zhu Youzhi; Hu Kefei; Yin Chuangao; Hu Jun; Wang Song; Li Xu; Lu Zhongbin; Wang Yue; Liu Xiang

    2013-01-01

    Objective: To investigate the MSCT manifestations and their values in the diagnosis of annular pancreas in neonates. Methods: Retrospective analysis of clinical and CT findings in 27 cases with surgery-proved annular pancreas in neonates was made. The unenhanced and contrast-enhanced CT images were obtained in 20 patients. Two experienced radiologists determined the site and degree of obstruction, the relationship between the head of the pancreas and the obstruction point, and the surrounding tissue structure. Results: The direct signs included the fluid-filled or gas-filled bowel in the head of pancreas in 4 cases, the enhancement of surrounding soft tissue as enhanced pancreas in 17 cases, disappearance of the fat gap between the intestinal wall and the annular pancreas in 17 cases. The indirect signs included intestinal obstruction in 20 cases, 'single-bubble sign' in 2 cases, 'double-bubble sign' in 18 cases, the distal bowel without gas in 5 cases, small amount of gas in the distal bowel in 15 cases. In 12 of 18 cases showing 'double-bubble sign', the ratio of duodenal bubble diameter (Dd) to stomach bubble diameter (Ds)was over 1.0. The site of obstruction was located in the descending duodenum in 20 cases. The form of obstructed point presented with 'nipple sign' in 15 cases, with 'the mouse tail' in 5 cases. The expansion bowel was located in the head of pancreas in 1 case. Gas was found in the pancreatic duct in 1 case, and 'swirl sign' was shown in 2 cases. Conclusions: MSCT combined with three-dimensional reconstruction techniques can clearly demonstrate the annular pancreas' s shape, the site and degree of obstruction and other malformations. It can provide important information for clinical treatment. (authors)

  16. Peripheral pulmonary arteries: identification at multi-slice spiral CT with 3D reconstruction

    International Nuclear Information System (INIS)

    Coche, Emmanuel; Pawlak, Sebastien; Dechambre, Stephane; Maldague, Baudouin

    2003-01-01

    Our objective was to analyze the peripheral pulmonary arteries using thin-collimation multi-slice spiral CT. Twenty consecutive patients underwent enhanced-spiral multi-slice CT using 1-mm collimation. Two observers analyzed the pulmonary arteries by consensus on a workstation. Each artery was identified on axial and 3D shaded-surface display reconstruction images. Each subsegmental artery was measured at a mediastinal window setting and compared with anatomical classifications. The location and branching of every subsegmental artery was recorded. The number of well-visualized sub-subsegmental arteries at a mediastinal window setting was compared with those visualized at a lung window setting. Of 800 subsegmental arteries, 769 (96%) were correctly visualized and 123 accessory subsegmental arteries were identified using the mediastinal window setting. One thousand ninety-two of 2019 sub-subsegmental arteries (54%) identified using the lung window setting were correctly visualized using the mediastinal window setting. Enhanced multi-slice spiral CT with thin collimation can be used to analyze precisely the subsegmental pulmonary arteries and may identify even more distal pulmonary arteries. (orig.)

  17. Multi-slice CT pulmonary function evaluation in emphysema

    International Nuclear Information System (INIS)

    Ge Xiaojun; Zhang Guozhen; Zhu Yanping; Shan Lin; Mao Dingbiao; Ding Qiyong; Hua Yanqing

    2007-01-01

    Objective: To explore the feasibility of evaluating the lung function by MSCT in emphysema. Methods: The MSCT scan and pulmonary function tests (PFT) were respectively performed in 147 receptors within one week. They were randomly divided into 2 groups: group A (120 receptors), including normal, mild, moderate and severe abnormal pulmonary function based on the PFT, for comparing the correlation between pulmonary quantitative indexes of MSCT pulmonary function and PFT and settingup the primary, grade criteria of abnormal pulmonary, function in emphysema, group B (27 receptors) for evaluating the diagnostic accuracy in group A. The total lung was respectively scanned at the full inspiration and full expiration with MSCT. The pulmonary quantitative indexes of MSCT were measured with Siemens Pulmo pulmonary quantitative software. Results: There was correlation between pulmonary quantitative indexes of MSCT and PFT. The Piex/in -910 showed best correlation with FEV 1 % (r= -0. 905, P -910 (χ 2 0.267, P=0.966, accuracy 81.5%), and the primary criteria for abnormal pulmonary, function of emphysema was normal (0-9.9), mild (10.0-34.9), moderate (35.0-74.9) and severe (≥75.0). Conclusion: It is feasible to evaluate the abnormal lung function of emphysema with pulmonary quantitative indexes of CT. The Piex/in 910 was the most effective one in various indexes. (authors)

  18. The diagnostic value of multi-slice spiral CT virtual bronchoscopy in tracheal and bronchial disease

    International Nuclear Information System (INIS)

    Han Ying; Ma Daqing

    2006-01-01

    Objective: To assess the diagnostic value of multi-slice spiral CT virtual bronchoscopy (CTVB) in tracheal and bronchial disease. Methods: Forty-two patients including central lung cancer (n=35), endobronchial tuberculosis (n=3), intrabronchial benign tumor (n=3), and intrabronchial foreign body (n=1) were examined by using multi-slice spiral CT examinations. All the final diagnosis were proved by pathology except 1 patient with endoluminal foreign body was proved by clinic. All patients were scanned on GE Lightspeed 99 scanner, using 10 mm collimation, pitch of 1.35, and reconstructed at 1 mm intervals and 1.25 mm thickness. The chest images of transverse CT and virtual bronchoscopy were viewed by two separate radiologists who were familiar with the tracheal and bronchial anatomy. Results: Among the 42 patients, the tumor of trachea and bronchial lumen appeared as masses in 22 of 35 patients with central lung cancer and bronchial stenosis was found in 13 of 35 patients with central lung cancer, and bronchial wall thickening was revealed on transverse CT in all 35 cases. 3 patients of endobronchial tuberculosis showed bronchial lumen narrowing on CTVB, the bronchial wall thickening was revealed on transverse CT, and the length of the wall thickening was long. 3 patients with intrabronchial benign tumor showed nodules in trachea and bronchial lumen on CTVB, and without wall thickening on transverse CT. CTVB could detect the occlusion of bronchial lumen in 1 patient with intrabronchial foreign body and CTVB was able to visualize the areas beyond stenosis, and the bronchial wall was without thickening on transverse CT. Conclusion: Multi- slice spiral CTVB could reflect the morphology of tracheal and bronchial disease. Combined with transverse CT, it could provide diagnostic reference value for bronchial disease. (authors)

  19. Multi-slice CT angiography in evaluation of extracranial-intracranial bypass

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    Teksam, Mehmet E-mail: mehmetteksam@yahoo.com; McKinney, Alexander; Truwit, Charles L

    2004-12-01

    Multi-slice CT (MSCT) scanners provided significant improvement in vascular applications. In this study, our purpose was to determine the clinical utility of MSCTA in evaluation of extracranial-intracranial (EC-IC) bypass patency. Eleven (4 men and 7 women; mean age, 46 years; age range, 19-68 years) consecutive patients who underwent MSCTA and DSA after EC-IC bypass surgery were evaluated retrospectively. All patients underwent DSA within 3 weeks of MSCTA. The indications for EC-IC bypass were severe stenosis or occlusion of intracranial arteries in seven patients and therapeutic occlusion of intracranial artery for unclippable giant aneurysm in four patients. Ten patients underwent superficial temporal artery (STA)-middle cerebral artery (MCA) bypass and one patient underwent occipital artery-posterior cerebral artery (PCA) bypass. Eight STA-MCA bypasses in six patients were patent on MSCTA which were confirmed on DSA. Two MSCTA bypasses and one occipital artery-posterior cerebral artery (PCA) bypass were occluded in three patients on MSCTA and DSA. In one patient, minimal stenosis of the STA-MCA bypass was identified on MSCTA and DSA. In 1 patient, STA-MCA bypass was not well seen on MSCTA and suspected for occlusion. DSA identified the occlusion of bypass on this patient. MSCTA seems to be a very promising noninvasive technique in evaluation of EC-IC bypass.

  20. Multi-slice CT angiography in evaluation of extracranial-intracranial bypass

    International Nuclear Information System (INIS)

    Teksam, Mehmet; McKinney, Alexander; Truwit, Charles L.

    2004-01-01

    Multi-slice CT (MSCT) scanners provided significant improvement in vascular applications. In this study, our purpose was to determine the clinical utility of MSCTA in evaluation of extracranial-intracranial (EC-IC) bypass patency. Eleven (4 men and 7 women; mean age, 46 years; age range, 19-68 years) consecutive patients who underwent MSCTA and DSA after EC-IC bypass surgery were evaluated retrospectively. All patients underwent DSA within 3 weeks of MSCTA. The indications for EC-IC bypass were severe stenosis or occlusion of intracranial arteries in seven patients and therapeutic occlusion of intracranial artery for unclippable giant aneurysm in four patients. Ten patients underwent superficial temporal artery (STA)-middle cerebral artery (MCA) bypass and one patient underwent occipital artery-posterior cerebral artery (PCA) bypass. Eight STA-MCA bypasses in six patients were patent on MSCTA which were confirmed on DSA. Two MSCTA bypasses and one occipital artery-posterior cerebral artery (PCA) bypass were occluded in three patients on MSCTA and DSA. In one patient, minimal stenosis of the STA-MCA bypass was identified on MSCTA and DSA. In 1 patient, STA-MCA bypass was not well seen on MSCTA and suspected for occlusion. DSA identified the occlusion of bypass on this patient. MSCTA seems to be a very promising noninvasive technique in evaluation of EC-IC bypass

  1. Evaluation of spinal cord vessels using multi-slice CT angiography

    International Nuclear Information System (INIS)

    Chen Shuang; Zhu Ruijiang; Feng Xiaoyuan

    2006-01-01

    Objective: To evaluate the value of Multi-slice spiral CT angiography for spinal cord vessels. Methods: 11 adult subjects with suspected of myelopathy were performed with Multi-slice spiral CT angiography, An iodine contrast agent was injected at 3.5 ml/s, for total 100 ml. The parameters were axial 16 slice mode, 0.625 mm slice thickness, 0.8 s rotation, delay time depending on smartprep(15-25 s), multi-phase scan. The coronal and sagittal MPR and SSD were generated on a workstation compared with spinal digital subtraction angiography (DSA) to analyze normal or abnormal spinal cord vessels. Results: Normal findings at spinal CTA and digital subtraction angiography in six adult normal subjects and spinal cord vascular malformations (1 intradural extramedullary AVF, 4 dural AVFs) in five cases, Recognizable intradural vessels corresponding to anterior median (midline) veins and/or anterior spinal arteries were show in six adult normal subjects. Abnormal intradural vessels were detected in all five spinal cord vascular malformation with CT angiography, in comparison with digital subtraction angiography these vessels were primarily enlarged veins of the coronal venous plexus on the cord surface, radiculomedullary-dural arteries could not be clearly shown in four dural AVF, only one anterior spinal artery was detected in one patient with intradural medullary AVF, which direct shunt between anterior spinal artery and perimedullary vein with tortuous draining vessel. Conclusion: Multi-slice CT angiography is able to visualize the normal or abnormal spinal cord vessels. It could be used as a noninvasive method to screen the spinal cord vascular disease. (authors)

  2. Multi-slice CT for visualization of acute pulmonary embolism: single breath-hold subtraction technique

    International Nuclear Information System (INIS)

    Wildberger, J.E.; Mahnken, A.H.; Spuentrup, E.; Guenther, R.W.; Klotz, E.; Ditt, H.

    2005-01-01

    Purpose: the purpose of our preliminary animal study was to evaluate the feasibility of a new subtraction technique for visualization of perfusion defects within the lung parenchyma in segmental and subsegmental pulmonary embolism (PE). Materials and methods: in three healthy pigs, PE were artificially induced by fresh human clot material. Within a single breath-hold, CT angiography (CTA) was performed on a 16-slice multi-slice CT scanner (SOMATOM Sensation 16; Siemens, Forchheim, Germany) before and after intravenous application of 80 mL of contrast-medium, followed by a saline chaser. Scan parameters were 120 kV and 100 mAs eff. , using a collimation of 16 x 1.5 mm and a table speed/rot. of 36 mm (pitch: 1.5; rotation time: 0.5 s). A new 3D subtraction technique was developed, which is based on automated segmentation, non-linear spatial filtering and non-rigid registration. Data were analysed using a color-encoded ''compound view'' of parenchymal enhancement and CTA information displayed in axial, coronal and sagittal orientation. Results: subtraction was technically feasible in all three data sets. The mean scan time for each series was 4.7 s, interscan delay was 14.7 s, respectively. Therefore, an average breath-hold of approximately 24 s was required for the overall scanning procedure. Downstream of occluded segmental and subsegmental arteries, perfusion defects were clearly assessable, showing lower or missing enhancement compared to normally perfused lung parenchyma. In all pigs, additional peripheral areas with triangular shaped perfusion defects were delineated, considered typical for PE. Conclusions: our initial results from the animal model studied slow that perfusion imaging of PE is feasible within a single breath-hold. It allows a comprehensive assessment of perfusion deficits as the direct proof of a pulmonary embolus, can be combined with an indirect visual quantification of the density changes in the adjacent lung tissue. (orig.)

  3. Diagnostic value of multi-slice spiral CT for atlantoaxial spine injuries in children

    International Nuclear Information System (INIS)

    Xia Chengde; Qin Hongwei; Li Junhong

    2009-01-01

    Objective: To evaluate the diagnostic value of multi-slice spiral CT (MSCT) for the atlantoaxial spine injuries in children. Methods: The CT findings of 21 cases with the atlantoaxial spine injuries in children were reviewed retrospectively. Results: Fractures of dens occurred in 4 cases, isolated atlantoaxial dislocation in 15 cases, subluxation of the C2/3 right vertebra facet in 1 and atlanto-occipital subluxation in 1. CT diagnosis was correct in all cases. And plain film diagnosis was correct ia 13. Conclusion: MSCT could clearly demonstrate the fractures and dislocations of the atlantoaxial spine injuries in children and correctly determine the type of the atlantoaxial spine injuries in children, MSCT is the modality of choice in diagnosis of the atlantoaxial spine injuries in children and should be performed routinely. (authors)

  4. Multi-slice spiral CT detects spread of small laryngeal tumors

    International Nuclear Information System (INIS)

    Bruening, R.; Schoepf, U.; Becker, C.; Reiser, M.; Hong, C.; Sturm, C.; Wollenberg, B.

    1999-01-01

    The purpose of the study was to preoperatively investigate small laryngeal carcinomas using multi-slice spiral CT (MSCT) and subsequent multiplanar reconstructions (MPR) and to compare the results to the detailed spread found a surgery and histology. Nine patients with small (T1, T2) laryngeal cancer were investigated on a MSCT scanner (Siemens plus 4 Volume Zoom, Siemens). A 4x1 mm collimation, 120 kV, 200 mAs and a 0.5 seconds rotation time were used, allowing a coverage of the entire larynx in approximately 10 seconds within a single breathhold. Multiplanar reconstruction's (MPR) in sagittal and coronal plane were reconstructed in all patients and rated in consensus reading. In 8 of nine patients, the glottic spread was detected by MSCT, in one case of a supraglottic tumor a glottic invasion was excluded. The infiltration of the anterior commissure, the infiltration into the subglottic space and the extension into the hypo-pharynx was correctly assessed in all patients. MSCT was not able to predict infiltration of the arythnoids in two patients. The use of multi-slice CT for the preoperative assessment of small laryngeal tumors shows great promise. The detection or exclusion of subtle spread of these tumors into the supra- or subglottic space and along the glottic level was possible with high accuracy. As the examination time is short, artifacts are rare and multiplanar reconstructions gain in clinical importance. (orig.) [de

  5. Evaluation of classification method of lung lobe for multi-slice CT images

    International Nuclear Information System (INIS)

    Sakurai, Kousuke; Matsuhiro, Mikio; Saita, Shinsuke

    2010-01-01

    Recently, due to the introduction of multi-slice CT, to obtain a high resolution 3D CT image is possible in a short time. The temporal and spatial resolutions are high, so a highly accurate 3D image analysis is possible. To develop a structure analysis of the lung is needed and to be used as a fundamental technology for early detection of the disease. By separating the lung into lung lobes may provide important information for analysis, diagnosis and treatment of lung diseases. Therefore in this report, we adapt to abnormality example with the classification algorithms using the anatomical information of the bronchus, the pulmonary vein and interlobar fissure information, we evaluate the classification. (author)

  6. Modelling the Siemens SOMATOM Sensation 64 Multi-Slice CT (MSCT) Scanner

    International Nuclear Information System (INIS)

    Amin, A T Mohd; Rahni, A A Abd

    2017-01-01

    Reconstructing large volumetric 3D images with minimal radiation dosage exposure with reduced scanning time has been one of the main objectives in the advancement of CT development. One of its advancement is the introduction of multi-slice arc detector geometry from a cone-beam source in third generation scanners. In solving this complex geometry, apart from the known vast computations in CT image reconstruction due to large CT images, iterative reconstruction methods are preferred compared to analytic methods due to its flexibility in image reconstruction. A scanner of interest that has this type of geometry is the Siemens SOMATOM Sensation 64 Multi-Slice CT (MSCT) Scanner , which has a total of 32 slices with 672 detector elements on each slice. In this paper, the scanner projection is modelled via the intersecting lengths between each ray (exhibited from the source to the detector elements) with the scanned image voxels, which are evaluated using the classical Siddon’s algorithm to generate the system matrix, H . This is a prerequisite to perform various iterative reconstruction methods, which involves solving the inverse problem arising from the linear equation: S = H· I; where S is the projections produced from the image, I. Due to the ‘cone-beam geometry’ along the z -axis, the effective field-of-view (FOV) with voxel dimensions (0.4×0.4×0.4) mm 3 is 512×512×32 voxels. The scanner model is demonstrated by reconstructing an image from simulated projections using the analytic Feldkamp-Davis-Kress (FDK) method against basic iterative image reconstruction methods. (paper)

  7. Value of multi-slice spiral CT MPVR reconstruction in the diagnosis of acute appendicitis

    International Nuclear Information System (INIS)

    Wang Kang; Zhao Zehua; Wang Zhi; Wang Weizhong; Xu Songsen; Zhang Miao; Liu Wenjin; Zhang Guozhen; Feng Dianxu

    2005-01-01

    Objective: To investigate the value of multi-slice spiral CT MPVR reconstruction in the diagnosis of acute appendicitis. Methods: A total of 39 patients with clinically suspected acute appendicitis underwent surgery from February, 2002 to September, 2003. They were prospectively examined before surgery with routine CT scanning and MPVR reconstruction spiral CT. 31 cases of appendicitis were confirmed after appendectomy. CT scans and surgery-pathology reports were evaluated on a five-grade scale from hyperemic-edematous appendix to abscess (normal appendix: 0 grade). Results: The results of spiral CT MPVR reconstruction were compared with the surgical and pathologic findings at appendectomy, yielding an accuracy of 87.2%, sensitivity of 90.3%, specificity of 75%, positive predictive value of 93.3%, and negative predictive value of 66.7%, respectively. Results of routine CT yielded an accuracy of 38.5%, sensitivity of 38.7%, specificity of 37.5%, positive predictive value of 70.6%, and negative predictive value of 13.6%, respectively. MPVR reconstruction signs of 28 patients with acute appendicitis included enlarged appendix ( > 6 mm) (96.4%), appendicoliths (26.7%), caecal apical thickening (36.7%), periappendiceal inflammation (71.4%), and abscess (10.7%). Conclusion: The use of spiral CT MPVR reconstruction in patients with equivocal clinical presentation suspected of having acute appendicitis can lead to a significant improvement in the preoperative diagnosis and maybe a decrease in surgical-pathologic severity of appendiceal disease. (authors)

  8. Multi-slice CT three dimensional volume measurement of tumors and livers in hepatocellular carcinoma

    International Nuclear Information System (INIS)

    Yu Yuanlong; Li Liangcai; Tang Binghang; Hu Zemin

    2004-01-01

    Objective: To examine the accuracy of multi-slice CT (MSCT) three dimensional (3D) volume measurement of tumors and livers in hepatocellular carcinoma cases by using immersion method as the standard. Methods: (1) The volume of 25 porkling livers was measured using immersion method in experiment group in vitro. Then the models were built according to Matsumoto's method and CT scanning and special software were used to measure the volume of the livers. (2) The volume of the tumors in 25 cases of hepatocellular carcinoma was measured using diameter measurement method and special volume measurement software (tissue measurements). Two tumors of them were measured respectively using MSCT 3D measurement, diameter measurement before the operation and immersion method after the operation. The data of the two groups were examined using pairing t test. Results: (1) The volume range of 25 porkling livers was 68.50-1150.10 ml using immersion method and 69.78-1069.97 ml using MSCT 3D measurement. There was no significant difference of the data in these two groups using t-test (t=1.427, P>0.05). (2) The volume range of 25 hepatocellular tumors was 395.16-2747.7 ml using diameter measurement and 203.10-1463.19 ml using MSCT 3D measurement before the operation. There was significant difference of the data in these two groups using t-test (t=7.689, P<0.001). In 2 ablated tumors, 1 case's volume was (21.75±0.60) ml using MSCT 3D measurement and 33.73 ml using diameter measurement before the operation and 21.50 ml using immersion measurement after the operation. The other case's volume was (696.13±5.30) ml using MSCT 3D measurement and 1323.51 ml using diameter measurement before the operation and 685.50 ml using immersion measurement after the operation. Conclusion: MSCT 3D volume measurement can accurately measure the volume of tumor and liver and has important clinical application value. There is no significant difference between MSCT 3D volume measurement and immersion method

  9. Budd-Chiari syndrome: dynamic enhancement findings with multi-slice helical CT and CT angiography analysis

    International Nuclear Information System (INIS)

    Meng Xiaochun; Shan Hong; Zhu Kangshun; Xu Chuan; Zhang Jiansheng; Liu Lingyun; Ye Binbin

    2005-01-01

    Objective: To investigate the dynamic enhancement regulations of liver and their mechanism in Budd-Chiari syndrome (BCS) by using multi-slice CT and evaluate the value of CT angiography in the diagnosis of BCS. Methods: 28 cases with BCS confirmed by digital subtraction angiography (DSA) were retrospectively analyzed. All patients underwent dynamic enhancement examinations with multi-slice CT within 1 week before DSA. The relevant vessels were reconstructed respectively with MIP, VR and MPR. Compared with the results of DSA, we analyzed the dynamic enhancement regulations of liver in BCS, estimated the value of dynamic enhancement CT exams and CTA techniques in judging the obstruction level and showing collateral vessels. Results: Of all 28 cases, CT correctly showed the obstruction level in 26 cases, and 2 had incorrect results which proved to be membranous obstruction of the inferior vena cava superior to diaphragm. In 22 cases with hepatic vein obstructions, hepatic parenchyma displayed typical patchy enhancement in 19, atypical patchy enhancement in 3.8 cases among these showed benign nodules. Simultaneously, CT showed stenosis and rigidity of portal vein branches in 20, enlargement of hepatic artery in 14, hepatic collateral vessels in 20 out of 22 cases. In 6 cases with simple obstruction of inferior vena cava, hepatic changes were not found. Collateral circulations in or out of liver corresponded to the obstruction level. Conclusion: Dynamic enhancement examinations with multi-slice CT can correctly reflect the hepatic hemodynamic changes. Transverse images, combined with CTA, can explicitly display the obstruction level of vascular lesions and collateral circulations in BCS. (authors)

  10. Relationship of radiation dose and spiral pitch for multi-slice CT system

    International Nuclear Information System (INIS)

    Song Shaojuan; Wang Wei; Liu Chuanya

    2006-01-01

    Objective: To study the relations of radiation dose and spiral pitch for multi-slice CT system. Methods: 16 mm dose phantom with solidose 300/400 pen-style ion chamber inserted into each of five holes in turn was scanned with different spiral pitch by LightSpeed 16-slice CT and Sensation 16-slice and 64-slice CT and radiation dose. Results: CTDI vol of axial scan and spiral scan for the three types of CT system are: (1) LightSpeed 16-slice CT: 28.9 (axial), 51.4 (pitch 0.562), 30.8 (pitch 0.938) and 16.5 ( pitch 1.75 ); (2) Sensation 16-slice CT: 41.2(axial) and 40.3(pitch 0.5) ,41.5(pitch 1) and 43.2(pitch 1.5); (3) Sensation 64- slice CT: 41.2(axial) and 40.3(pitch 0.5),41.5(pitch 1),43.2(pitch 1.5). Conclusions: For LightSpeed 16-slice CT, the measured radiation dose decreased with the increase of spiral pitch, the image quality could keep constant only if we increase mAs. While for Sensation 16-slice and 64-slice CT system, the measured radiation dose was identical for different pitch, and the image quality was identical because of the use of mAs auto control technique The mAs should be adjusted in different way according to the type of CT system when the pitch is changed in daily operation. (authors)

  11. Evaluation of TSE- and T1-3D-GRE-sequences for focal cartilage lesions in vitro in comparison to ultrahigh resolution multi-slice CT

    International Nuclear Information System (INIS)

    Stork, A.; Schulze, D.; Koops, A.; Kemper, J.; Adam, G.

    2002-01-01

    Purpose: Evaluation of TSE- and T 1 -3D-GRE-sequences for focal cartilage lesions in vitro in comparison to ultrahigh resolution multi-slice CT. Materials and methods: Forty artificial cartilage lesions in ten bovine patellae were immersed in a solution of iodinated contrast medium and assessed with ultrahigh resolution multi-slice CT. Fat-suppressed TSE images with intermediate- and T 2 -weighting at a slice thickness of 2, 3 and 4 mm as well as fat-suppressed T 1 -weighted 3D-FLASH images with an effective slice thickness of 1, 2 and 3 mm were acquired at 1.5 T. After adding Gd-DTPA to the saline solution containing the patellae, the T 1 -weighted 3D-FLASH imaging was repeated. Results: All cartilage lesions were visualised and graded with ultrahigh resolution multi-slice CT. The TSE images had a higher sensitivity and a higher inter- and intraobserver kappa compared to the FLASH-sequences (TSE: 70-95%; 0.82-0.83; 0.85-0.9; FLASH: 57.5-85%; 0.53-0.72; 0.73-0.82, respectively). An increase in slice thickness decreased the sensitivity, whereby deep lesions were even reliably depicted on TSE images at a slice thickness of 3 and 4 mm. Adding Gd-DTPA to the saline solution increased the sensitivity by 10% with no detectable advantage over the T 2 -weighted TSE images. Conclusion: TSE sequences and application of Gd-DTPA seemed to be superior to T 1 -weighted 3D-FLASH sequences without Gd-DTPA in the detection of focal cartilage lesions. The ultrahigh resolution multi-slice CT can serve as in vitro reference standard for focal cartilage lesions. (orig.) [de

  12. Usefulness of simulation with multi-slice CT for laparoscopic nephrectomy

    Energy Technology Data Exchange (ETDEWEB)

    Akiyama, Yuji; Ishifuro, Minoru; Ookubo, Masaomi [Hiroshima Univ. (Japan). Hospital] (and others)

    2002-12-01

    In recent years, laparoscopic surgery has attracted attention as a minimally invasive type of surgery because of the small surgical wounds and early recovery it provides. We carry out this technique on the basis of volume data that we make use of in multi-slice CT imaging technology in laparoscopic nephrectomy by the retroperitoneal approach, and we have created CT virtual laparoscopy by virtual endoscopic display as an intra-operative navigator with an image analysis system. We provide information on detailed vascular anatomy to form intra-operative images that act as similar support images. With the provision of this volume data, we consider virtual endoscopic display the most suitable method for surgery. When we perform virtual laparoscopy, we simulate the insertion point and angle, the order of vascular structures and their locations, the number of arteries and veins, and their bifurcation points and ligation points in conjunction with the surgeon prior to operation. As the branch patterns of the renal artery are varied, perioperative confusion and surgical mishaps can be avoided through the information that is provided beforehand. Thus surgery is more accurate and proceeds more smoothly, because the surgeon has accurate anatomical information. In addition, the time required for surgery is decreased, reducing risk and the possibility of complications. (author)

  13. The significance of multi-slice helical CT multiplanar reconstruction in the diagnoses of laryngeal carcinoma

    International Nuclear Information System (INIS)

    Li Lin; Luo Dehong; Zhou Chunwu; Zhao Xinming; Jiang Liming; Huang Yao; Jiang Lingxia; Li Jing; Wu Ning

    2006-01-01

    Objective: To evaluate the significance of multi-slice helical CT with multiplanar reconstruction in laryngeal carcinoma. Methods: Thirty-five patients with laryngeal carcinoma were studied by helical CT, MPR were subsequently done. The lesion extent of the axial image findings, MPR findings and the combined image findings were compared with the pathological results respectively. The data were statistically analyzed. Results: In the evaluation of the anterior commissure, the axial image findings, MPR findings and the combined image findings were 82.9%, 68.6% and 91.4% in accuracy respectively, the results were statistically different (P 0.05). The combined images were superior to the axial images and the MPR images in sensitivity, specificity and accuracy of the lesion extent. Conclusion: The axial images could show the shape, size, extension of the tumor and the lymphadenopathy, MPR images displayed the shape, size and extension roundly and directly, they were the supplement for the axial images. Axial images combined with MPR could improve the accuracy in the diagnoses of laryngeal carcinoma. (authors)

  14. The role of multi-slice CT in preoperative staging of colonic tumors

    International Nuclear Information System (INIS)

    Zhang Miao; Chen Kemin; Zhao Zehua; Ling Huawei

    2005-01-01

    Objective: To determine the accuracy of multi-slice CT pneumocolon in the staging of colonic carcinomas. Methods: Thirty-six patients, who were strongly suspected to have colonic disorders, underwent CT pneumocolon before and after intravenous injection of iodinated contrast agent. CTVE, MPR, SSD, and Raysum images were then obtained by using 4 different softwares in workstation (ADW3.1). 33 positive cases were staged preoperatively according to TNM standard. All cases were proved by surgical or colonoscopic histology. Sensitivity and accuracy of MSCT were determined for the detection of cancers, lymph nodes, and metastases. Results: MSCT pneumocolon examinations demonstrated 32 lesions, missing one case. Sensitivity and positive accuracy value for T staging were 96.97% (32/33) and 87.88% (29/33), respectively; Sensitivity and positive accuracy value for lymph node involvement were 73.91% (17/23) and 69.57% (16/23), respectively. The density of metastatic lymph node was higher than that of normal one. Five cases in M stage were all diagnosed correctly. Conclusion: MSCT pneumocolon is a better method of depicting the colorectal carcinoma. It allows for accurate staging of the colorectal carcinoma, especially detecting the invasion of adjacent tissues and distant metastasis. However the value for early T staging in colorectal carcinoma and minute metastasis of lymph nodes is limited. It is helpful to combine all the findings of lymph nodes, including the size, density, and location, to make a correct diagnosis. (authors)

  15. Usefulness of simulation with multi-slice CT for laparoscopic nephrectomy

    International Nuclear Information System (INIS)

    Akiyama, Yuji; Ishifuro, Minoru; Ookubo, Masaomi

    2002-01-01

    In recent years, laparoscopic surgery has attracted attention as a minimally invasive type of surgery because of the small surgical wounds and early recovery it provides. We carry out this technique on the basis of volume data that we make use of in multi-slice CT imaging technology in laparoscopic nephrectomy by the retroperitoneal approach, and we have created CT virtual laparoscopy by virtual endoscopic display as an intra-operative navigator with an image analysis system. We provide information on detailed vascular anatomy to form intra-operative images that act as similar support images. With the provision of this volume data, we consider virtual endoscopic display the most suitable method for surgery. When we perform virtual laparoscopy, we simulate the insertion point and angle, the order of vascular structures and their locations, the number of arteries and veins, and their bifurcation points and ligation points in conjunction with the surgeon prior to operation. As the branch patterns of the renal artery are varied, perioperative confusion and surgical mishaps can be avoided through the information that is provided beforehand. Thus surgery is more accurate and proceeds more smoothly, because the surgeon has accurate anatomical information. In addition, the time required for surgery is decreased, reducing risk and the possibility of complications. (author)

  16. The relationship between image quality and CT dose index of multi-slice low-dose chest CT

    International Nuclear Information System (INIS)

    Zhu Xiaohua; Shao Jiang; Shi Jingyun; You Zhengqian; Li Shijun; Xue Yongming

    2003-01-01

    Objective: To explore the rationality and possibility of multi-slice low-dose CT scan in the examination of the chest. Methods: (1) X-ray dose index measurement: 120 kV tube voltage, 0.75 s rotation, 8 mm and 3 mm slice thickness, and the tube current setting of 115.0, 40.0, 25.0, and 7.5 mAs were employed in every section. The X-ray radiation dose was measured and compared statistically. (2) phantom measurement of homogeneity and noise: The technical parameters were 120 kV, 0.75 s, 8 mm and 3 mm sections, and every slice was scanned using tube current of 115.0, 40.0, 25.0, and 7.5 mAs. Five same regions of interest were measured on every image. The homogeneity and noise level of CT were appraised. (3) The multi-slice low-dose CT in patients: 30 patients with mass and 30 with patch shadow in the lung were selected randomly. The technical parameters were 120 kV, 0.75 s, 8 mm and 3 mm slice thickness. 115.0, 40.0, 25.0, 15.0, and 7.5 mAs tube current were employed in each same slice. Otherwise, 15 cases with helical scan were examined using 190, 150, 40, 25, and 15 mAs tube current. The reconstruction images of MIP, MPR, CVR, HRCT, 3D, CT virtual endoscopy, and variety of interval reconstruction were compared. (4) Evaluation of image quality: CT images were evaluated by four doctors using single-blind method, and 3 degrees including normal image, image with few artifact, and image with excessive artifact, were employed and analyzed statistically. Results: (1) The CT dose index with 115.0 mAs tube current exceeded those of 40.0, 25.0, and 7.5 mAs by about 60%, 70%, and 85%, respectively. (2) The phantom measurement showed that the lower of CT dose the lower of homogeneity, the lower of CT dose the higher of noise level. (3) Result of image quality evaluation: The percentage of the normal image had no significant difference between 8 and 3 mm in 115, 40, and 25 mAs (P>0.05). Conclusion: Multi-slice low-dose chest CT technology may protect the patients and guarantee the

  17. Basic examination of in-plane spatial resolution in multi-slice CT

    International Nuclear Information System (INIS)

    Hara, Takanori; Kato, Hideki; Akiyama, Mitsutoshi; Murata, Katsutoshi

    2002-01-01

    In computed tomography (single-slice spiral CT, conventional CT), in-plane (x-y plane) spatial resolution is consistently identified as depending on the detector density of the in-plane (x-y plane). However, we considered that the in-plane (x-y plane) spatial resolution of multi-slice CT (MSCT) was influenced by an error in the detector's sensitivity to the Z-axis and by the frequency of use of direct row data and complementary row data when the image of spiral pitches (SP) was reconstructed. Our goal in this experiment was to analyze the relationship of the in-plane (x-y plane) spatial resolution of an asymmetric-type detector in MSCT to SP, tube current, and rotation time. By employing a tungsten wire phantom of 0.2 mm in diameter, we examined modulation transfer functions (MTF) by point-spread functions (PSF) of CT-images. Next, using the mean-square-root bandwidth theory, we analyzed the MTF of wire phantoms. The analysis of in-plane (x-y plane) spatial resolution revealed that various tube currents had no effect on the value of the mean-square-root bandwidth. However, rotation time and high spiral pitch did have an effect on mean-square-root bandwidth. Considering the results mentioned above, spiral pitch (z-axis reconstruction algorithm) had a slight effect on in-plane (x-y plane) spatial resolution of asymmetric-type detectors in MSCT. Accordingly, we proposed a new general view of VDDz (view/mm) in MSCT that considered view data density on the Z-axis according to spiral pitch (mm/rotation), rotation time (view/rotation), and slice collimation. (author)

  18. Evaluation of hepatic alveolar echinococcosis with multi-slices spiral CT

    International Nuclear Information System (INIS)

    Liu Wenya; Lou Jianru; Xing Yan; Wang Jing; Wang Haitao

    2005-01-01

    Objective: To analyze the multi-slices spiral CT (MSCT) findings of hepatic alveolar echinococcosis (HAE), and to evaluate the value of MSCT for diagnosis of HAE. Methods: Twenty-six cases with HAE were scanning by MSCT. The raw data were transmitted to advanced workstation for reconstruction imaging. Correlated studies were made between the CT features and pathology or other imaging results. Results: Altogether 28 lesions were detected. They all revealed as heterogeneous hypodense mass with ill-defined boundary in plain CT but were easily being distinguished from surrounding parenchyma after contrast medium injection. Characteristics of the lesions include different amount of calcification (26/26), liquefied necrosis in center area (20/26), peripheral lacunae or alveolar signs (15/26 ), compensatory hypertrophy of healthy hepatic part (18/26) and the retraction in the involved hepatic lobe or segment (12/26). The lesions that located at or extended to hepatic hilum caused dilatation of intra-hepatic biliary ducts (9/26), splenomegaly (12/26 ), and ascites (1/26). MSCT angiography (CTA) depicted signs of abnormalities of hepatic vessels such as compression, displacement, encasement and occlusion. Compared with findings of operation, the sensitivity, specificity and positive prediction value of CTA for evaluating the hepatic artery system disorders were 88%, 96% and 93%, respectively; and for portal venous system were 95%, 100% and 95%, respectively; while for hepatic venous system were 96%, 86% and 96%, respectively. Conclusion: MSCT is able to comprehensive display the CT features and vessels complication of HAE. It provides reliable imaging for both accuracy diagnosis and proper treatment of the disease. (authors)

  19. MSCT在主动脉壁内血肿诊断和转归中的应用%Application of multi-slice spiral CT in diagnosis and prognosis of aortic artery intramural hematoma

    Institute of Scientific and Technical Information of China (English)

    黄源义; 谢欢; 邬正宏; 刘四斌

    2011-01-01

    Objective To investigate the applied value of multi-slice spiral CT in diagnosis and prognoses of aortic artery intramural hematoma(IMH). Methods 11 patients with IMH underwent plain CT scan and CT angiography with 16-slice spiral CT of GE. Endovascular stent for the treatment in 3 cases and conservative treatment in 8 cases was performed. All patients were followed-up twice or 4 times for 15 - 210 days(mean 112. 5 days). Results 3 cases with Stanford A and 8 cases with Stanford B IMH were diagnosed. The main CT findings were as follows: Crescent or circular thickening(>5 mm)of aortic wall with higher density or isodensi-ty without intimal flap as well as true and false lumen in 11 cases;atherosclerosis in 7 cases;intimal calcification ingression in 4 cases; intimal leakages in 3 cases;penetrating ulcer in 3 cases. The hematomas in 7 cases were completely absorbed,incomplete absorbed in 2 cases,while 2 cases were transformed to dissecting aneurysm. Conclusion MSCT is a significant method in diagnosis and follow-ing-up of IMH, and can provide important informations for clinical treatment.%目的 探讨MSCT在主动脉壁内血肿(IMH)诊断和转归中的应用价值.方法 采用GE 16排螺旋CT对11例IMH行平扫和CTA扫描.3例行腔内支架隔绝术,8例保守治疗.所有病例治疗后随访2~4次,随访时间15~210 d(平均112.5 d).结果 A型IMH 3例,B 型IMH 8例.MSCT主要征象为:11例主动脉壁新月形或环形增厚>5 mm,呈等密度或高密度,无内膜片撕裂及真、假两腔形成;主动脉粥样硬化7例;内膜钙化内移4例;内膜渗漏3例;穿透性溃疡3例.7例完全吸收,2例部分吸收,2例进展成夹层动脉瘤.结论 MSCT能对IMH作出明确的诊断,并可作为IMH随访的重要检查手段,对临床治疗有重要的指导意义.

  20. Primary research on direct multi-slice spiral CT venography in inferior vena cava

    International Nuclear Information System (INIS)

    Gong Peiyou; Liu Fengli; Ma Xianying; Zhao Li; Wang Liping; Li Xuehua; Li Jian

    2010-01-01

    Objective: To investigate the superiority of direct multi-slice spiral CT venography in inferior vena cava. Methods: Twenty-eight patients performed MSCT venography in inferior vena cava, including 2 cases with both indirect and direct venography, 10 cases with indirect venography, 20 cases with direct venography through unilateral or bilateral lower extremity venous injection. The image quality and enhancement degree of the inferior vena cava were compared in double-blind method. Results: Of 10 cases with indirect venography of inferior vena cava, 1 case was failed due to mild enhancement in inferior vena cava. Image quality was good in 2 cases, poor in 7 cases, no excellent case. Of 20 cases with direct venography of inferior vena cava, the enhancement degree was scored 1, 2 degree in 16, 4 cases respectively and no case was scored 3 degree, the image quality was excellent, good in 16, 4 cases and no case was bad. The success rate was 100%. Conclusion: The image quality of direct MSCT venography in inferior vena cava is better than that of indirect method. (authors)

  1. The Role of Multi-slice Spiral CT Angiography in Patient Management After Endovascular Therapy

    International Nuclear Information System (INIS)

    Peloschek, P.; Sailer, J.; Loewe, C.; Schillinger, M.; Lammer, J.

    2006-01-01

    Objectives. To bring out the role of multi-slice spiral CT angiography (MS-CTA) in patient management after endovascular therapy of subclavian artery stenosis. Methods. Twenty-one consecutive patients with clinically suspected restenosis after endovascular treatment of subclavian artery stenosis or occlusion were included in the study. Eleven patients had been treated with percutaneous transluminal angioplasty (PTA) alone and 10 with PTA and stenting. The mean follow-up period after PTA or stenting was 57 (±27 SD) months. CTA was performed using a bolus-triggered high-resolution protocol with biphasic intravenous contrast medium injection. Axial images and curved planar reformations (CPRs) were rated by three readers with regard to patency of supra-aortic vessels. Imaging findings were correlated with a standardized clinical assessment. Results. All examinations were of diagnostic quality. Of 21 referred patients, 7 had significant reobstruction of the treated subclavian artery. Six of the 7 patients with significant restenosis on CTA were treated conservatively (antiplatelet agents), despite 2 of them being symptomatic on the standardized clinical assessment, which showed a sensitivity and specificity of 86% in predicting stenosis. One patient was treated with PTA and stent deployment because of strong subjective suffering. Conclusion. MS-CTA is useful for exclusion or quantification of clinically suspected restenosis in carefully selected patients after endovascular therapy where ultrasound is inconclusive and/or contrast-enhanced magnetic resonance angiography is contraindicated

  2. Radiation exposure in multi-slice versus single-slice spiral CT: results of a nationwide survey

    International Nuclear Information System (INIS)

    Brix, G.; Nagel, H.D.; Stamm, G.; Veit, R.; Lechel, U.; Griebel, J.; Galanski, M.

    2003-01-01

    Multi-slice (MS) technology increases the efficacy of CT procedures and offers new promising applications. The expanding use of MSCT, however, may result in an increase in both frequency of procedures and levels of patient exposure. It was, therefore, the aim of this study to gain an overview of MSCT examinations conducted in Germany in 2001. All MSCT facilities were requested to provide information about 14 standard examinations with respect to scan parameters and frequency. Based on this data, dosimetric quantities were estimated using an experimentally validated formalism. Results are compared with those of a previous survey for single-slice (SS) spiral CT scanners. According to the data provided for 39 dual- and 73 quad-slice systems, the average annual number of patients examined at MSCT is markedly higher than that examined at SSCT scanners (5500 vs 3500). The average effective dose to patients was changed from 7.4 mSv at single-slice to 5.5 mSv and 8.1 mSv at dual- and quad-slice scanners, respectively. There is a considerable potential for dose reduction at quad-slice systems by an optimisation of scan protocols and better education of the personnel. To avoid an increase in the collective effective dose from CT procedures, a clear medical justification is required in each case. (orig.)

  3. Multi-slice spiral CT perfusion imaging of chronic obstructive pulmonary disease

    International Nuclear Information System (INIS)

    Shao Yanhui; Qian Nong; Xue Yuejun; Dao Yinhong

    2008-01-01

    Objective: To evaluate the diagnostic value of multi-slice spiral CT (MSCT) perfusion imaging in chronic obstructive pulmonary disease (COPD). Methods: Twenty COPD patients and 20 volunteers underwent 8-row detector spiral CT (MSCT) perfusion imaging using cine scan mode with 5 mm slice thickness, 0.5 s rotation time and a total scan time of 45 s with 5 s intervals. 60 ml contrast agent (300 nag I/ml) were administered at a rate of 4 ml/s from the forearm superficial vein. The imaging data were transferred to a workstation. A time-density curve and pseudo-color map were generated automatically with GE CT perfusion 3 software, the blood flow (BF), blood volume (BV), mean transit time (MTT) and permeability surface (PS) were measured. Results: Time-density curve was flatter and the peak of the curve was obviously lower in COPD patients than the volunteers. The BF, BV, PS in COPD patients was (24.77±11.49) ml·min -1 ·100 g -1 , (2.48±1.02) ml/100 g and (2.75±1.13) ml· min -1 ·100 g -1 respectively. In volunteers was (290.14±107.59) ml·min -1 ·100 g -1 , (16.51 ± 5.98) ml/100 g, (8.80±3.03) ml·min -1 ·100 g -1 respectively. The MTT in COPD patients and volunteers was (10.58±4.85) s and (4.50±1.71)s respectively. The BF, BV and PS in COPD patients was lower than the volunteers, the MTY was higher (P<0.01). Conclusion: MSCT perfusion imaging is helpful for the diagnosis of COPD. (authors)

  4. The comparative study between multi-slice spiral CT angiography and color flow ultrasonography in hepatic and splenic trauma

    International Nuclear Information System (INIS)

    Yan Youxia; Zhang Jin'e; Chen Xiaocong; Cai Shufang

    2007-01-01

    Objective: To investigate the clinical value of multi-slice spiral CT angiography and color flow ultra- sonography in hepatic and splenic trauma. Methods Thirty-six cases of hepatic and splenic trauma were collected, the MSCT were analyzed and compared with that of color flow ultrasonography. Results: Seventeen cases were Hepatic trauma including nine cases of hepatic contusion, six cases of sub-envelope hematoma, two cases of both sub-envelope hematoma and hepatic contusion. Nineteen cases were splenic trauma including nine cases of splenic contusion, ten cases of sub-envelope hematoma. Conclusion: Multi-slice spiral CT angiography show hepatic and splenic trauma clearer than that of color flow ultrasonography, and can provide reliable basis for clinic diagnosis and therapy. (authors)

  5. Evaluation of the nutcracker syndrome using multi-slice spiral CT

    International Nuclear Information System (INIS)

    Shi Heshui; Fan Yanqing; Han Ping; Zhou Chengkai; Zhao Long; Wu Hongying; Yu Qun; Liu Yonghua

    2007-01-01

    Objective: To evaluate the ability of multi-slice spiral CT (MSCT) in diagnosing nutcracker syndrome(NCS). Methods: MSCT angiography (MSCTA) or contrast enhanced CT data of 16 patients clinically diagnosed as NCS( patient group) and 80 subjects with nomal kidneys and renal vessels (control group ) were retrospectively reviewed. The anatomy, course and relationship to the adjacent structure of left renal vein (LRV) and its branches were observed. The angle (a) between SMA and the abdominal aorta (AA), the distance (d) between SMA and AA at the level of LRV passing through, the cross areas of LRV through the angle (s1) and at the largest diameter near the renal hilar (s2) were measured and the ratio(q) of s2 to sl was calculated. Results: All LRVs were compressed and showed dilated, 7 of them with the genesial gland vein enlargement. The causes of the LRV narrowing and obstruction were small angle (a) in 14 patients and abnormal path of LRV posterior to AA in 2 cases. The value of a,d,s1,s2 and q in the patient group and the control group were: (21±4) degree, (0.53±0.11) cm, (0.28±0.06) cm 2 , (1.42±0.48) cm 2 , 5.26 and (52±24) degree, (1.39±0.70) cm, (0.81±0.32) cm 2 , (1.21±0.35) cm 2 , 1.52, respectively. The differences were significant between the two groups (P< 0.05). Conclusion: The appearance and its path of the LRV could be well delineated on the MSCT, allowing a accurate evaluation of the LRV narrowing non-invasively. (authors)

  6. Value of multi-slice CT in the classification diagnosis of hilar cholangiocarcinoma

    International Nuclear Information System (INIS)

    Qian Yi; Zeng Mengsu; Ling Zhiqing; Rao Shengxiang; Liu Yalan

    2008-01-01

    Objective: To evaluate the value of multi-slice CT (MSCT) classification in the assessment of the hilar cholangiocarcinoma resectability. Methods: Thirty patients with surgically and histopathologically proved hilar cholangiocarcinomas who underwent preoperative MSCT and were diagnosed correctly were included in present study. Transverse images and reconstructed MPR images were reviewed for Bismuth-Corlette classification and morphological classification of hilar cholangiocarcinoma. Then MSCT classification was compared with findings of surgery and histopathology. Curative resectabilty of different types according to Bismuth-Corlette classification and morphological classification were analyzed with chi-square test. Results: In 30 cases, the numbers of Type I, II, IIIa, IIIb and IV according to Bismuth-Corlette classification were 1, 3, 4, 5 and 17. Seventeen patients underwent curative resections, among which 1, 2, 1, 4 and 9 belonged to Type I, II, IIIa, IIIb and IV respectively. However, there was no significant difference in curative resectability among different types of Bismuth-Corlette classification (χ 2 = 0.9875, P>0.05). In present study, the accuracy of MSCT in Bismuth-Corlette classification reached 86.7% (26/30). The numbers of periductal infiltrating, mass forming and intraductal growing type were 13, 13 and 4, while 6, 8 and 3 cases of each type underwent curative resections. There was no significant difference in curative resectability among different types of morphological classification (χ 2 =1.2583, P>0.05). The accuracy of MSCT in morphological classification was 100% (30/30) in this study group. Conclusion: MSCT can make accurate diagnosis of Bismuth-Corlette classification and morphological classification, which is helpful in preoperative respectability assessment of hilar cholangiocarcinoma. (authors)

  7. A comparative evaluation of Cone Beam Computed Tomography (CBCT) and Multi-Slice CT (MSCT)

    International Nuclear Information System (INIS)

    Liang Xin; Jacobs, Reinhilde; Hassan, Bassam; Li Limin; Pauwels, Ruben; Corpas, Livia; Souza, Paulo Couto; Martens, Wendy; Shahbazian, Maryam; Alonso, Arie

    2010-01-01

    Aims: To compare image quality and visibility of anatomical structures in the mandible between five Cone Beam Computed Tomography (CBCT) scanners and one Multi-Slice CT (MSCT) system. Materials and methods: One dry mandible was scanned with five CBCT scanners (Accuitomo 3D, i-CAT, NewTom 3G, Galileos, Scanora 3D) and one MSCT system (Somatom Sensation 16) using 13 different scan protocols. Visibility of 11 anatomical structures and overall image noise were compared between CBCT and MSCT. Five independent observers reviewed the CBCT and the MSCT images in the three orthographic planes (axial, sagittal and coronal) and assessed image quality on a five-point scale. Results: Significant differences were found in the visibility of the different anatomical structures and image noise level between MSCT and CBCT and among the five CBCT systems (p = 0.0001). Delicate structures such as trabecular bone and periodontal ligament were significantly less visible and more variable among the systems in comparison with other anatomical structures (p = 0.0001). Visibility of relatively large structures such as mandibular canal and mental foramen was satisfactory for all devices. The Accuitomo system was superior to MSCT and all other CBCT systems in depicting anatomical structures while MSCT was superior to all other CBCT systems in terms of reduced image noise. Conclusions: CBCT image quality is comparable or even superior to MSCT even though some variability exists among the different CBCT systems in depicting delicate structures. Considering the low radiation dose and high-resolution imaging, CBCT could be beneficial for dentomaxillofacial radiology.

  8. A comparative evaluation of Cone Beam Computed Tomography (CBCT) and Multi-Slice CT (MSCT)

    Energy Technology Data Exchange (ETDEWEB)

    Liang Xin, E-mail: Xin.Liang@med.kuleuven.b [Oral Imaging Centre, School of Dentistry, Oral Pathology and Maxillofacial Surgery, Faculty of Medicine, Catholic University of Leuven (Belgium); College of Stomatology, Dalian Medical University (China); Jacobs, Reinhilde, E-mail: Reinhilde.Jacobs@uz.kuleuven.b [Oral Imaging Centre, School of Dentistry, Oral Pathology and Maxillofacial Surgery, Faculty of Medicine, Catholic University of Leuven (Belgium); Hassan, Bassam, E-mail: b.hassan@acta.n [Department of Oral Radiology, Academic Centre for Dentistry Amsterdam (ACTA), Amsterdam (Netherlands); Li Limin, E-mail: Limin.Li@uz.kuleuven.b [Department of Paediatric Dentistry and Special Dental Care, School of Dentistry, Oral Pathology and Maxillofacial Surgery, Faculty of Medicine, Catholic University of Leuven (Belgium); Pauwels, Ruben, E-mail: Ruben.Pauwels@med.kuleuven.b [Oral Imaging Centre, School of Dentistry, Oral Pathology and Maxillofacial Surgery, Faculty of Medicine, Catholic University of Leuven (Belgium); Corpas, Livia, E-mail: LiviaCorpas@gmail.co [Oral Imaging Centre, School of Dentistry, Oral Pathology and Maxillofacial Surgery, Faculty of Medicine, Catholic University of Leuven (Belgium); Souza, Paulo Couto, E-mail: Paulo.CoutoSouza@med.kuleuven.b [Oral Imaging Centre, School of Dentistry, Oral Pathology and Maxillofacial Surgery, Faculty of Medicine, Catholic University of Leuven (Belgium); Martens, Wendy, E-mail: wendy.martens@uhasselt.b [Department of Basic Medical Sciences, Faculty of Medicine, University of Hasselt, Diepenbeek (Belgium); Shahbazian, Maryam, E-mail: Maryam.Shahbazian@student.kuleuven.b [Oral Imaging Centre, School of Dentistry, Oral Pathology and Maxillofacial Surgery, Faculty of Medicine, Catholic University of Leuven (Belgium); Alonso, Arie, E-mail: ariel.alonso@uhasselt.b [Department of Biostatistics and Statistical Bioinformatics, Universiteit Hasselt (Belgium)

    2010-08-15

    Aims: To compare image quality and visibility of anatomical structures in the mandible between five Cone Beam Computed Tomography (CBCT) scanners and one Multi-Slice CT (MSCT) system. Materials and methods: One dry mandible was scanned with five CBCT scanners (Accuitomo 3D, i-CAT, NewTom 3G, Galileos, Scanora 3D) and one MSCT system (Somatom Sensation 16) using 13 different scan protocols. Visibility of 11 anatomical structures and overall image noise were compared between CBCT and MSCT. Five independent observers reviewed the CBCT and the MSCT images in the three orthographic planes (axial, sagittal and coronal) and assessed image quality on a five-point scale. Results: Significant differences were found in the visibility of the different anatomical structures and image noise level between MSCT and CBCT and among the five CBCT systems (p = 0.0001). Delicate structures such as trabecular bone and periodontal ligament were significantly less visible and more variable among the systems in comparison with other anatomical structures (p = 0.0001). Visibility of relatively large structures such as mandibular canal and mental foramen was satisfactory for all devices. The Accuitomo system was superior to MSCT and all other CBCT systems in depicting anatomical structures while MSCT was superior to all other CBCT systems in terms of reduced image noise. Conclusions: CBCT image quality is comparable or even superior to MSCT even though some variability exists among the different CBCT systems in depicting delicate structures. Considering the low radiation dose and high-resolution imaging, CBCT could be beneficial for dentomaxillofacial radiology.

  9. The influence factors in image quality of multi-slice spiral CT coronary angiography (MSCTA)

    International Nuclear Information System (INIS)

    Zeng Huiliang; Zhu Xinjin; Liang Jianhao; Zhong Yingze; Chen Xueguang; Ou Weiqian; Wen Haomao; Li Peiwen

    2007-01-01

    Objective: To evaluate the influence of heart rate on image quality of multi-slice spiral CT coronary angiography(MSCTA) and the optimization of image reconstruction windows. Methods: Retrospectively ECG-gated MSCT coronary angiography were performed in 67 cases. The cases were divided into four groups by heart rate, groupl with heart rate less than 60 beats per minute(bpm), group 2 with heart rate 61-70 bpm, group 3 with heart rate 71-80 bpm and group 4 with heart rate over 81 bpm. The impact of heart rate on image quality of MSCTA and the optimization of image reconstruction windows were evaluated. Results: 4 coronary (RCA,LM,LAD,LCX) segments were analyzed in each patients with regard to image quality. 86.7%(112/128) of the coronary segments were sufficient for analysis in patients with heart rate less than 60 bpm,62.5%(55/88) with 61-70 bpm,40%(8/20) with 71-80 bpm and 12.5%(2/16) with heart rate over 81 bpm, respectively. There were statistically significances between every coronary segments of group 1 and 2, group 3 and 4 (P<0.05). All coronary segments of group 1 were optimally visualized on the image reconstructed at 75% image reconstruction window of' cardiac cycle; 89.5% cases at 75% in group 2; for group 3.55% of coronary artery were best presented at 75% image reconstruction window, 45% of coronary artery at 45%; All coronary segments of group 4 were optimally visualized on the image reconstructed at 45% image reconstruction window. Conclusion: Image quality of MSCT coronary angiography is highly dependent on heart rate. Coronary artery is usually best shown at 75% image reconstruction window of cardiac cycle for those with heart rate less than 70 bpm. 30%-90% image reconstruction should be performed when heart rate is over 71 bpm. (authors)

  10. Experimental study of quantity to be taken as patient dose in helical multi-slice CT scan

    International Nuclear Information System (INIS)

    Liu Lantao; Wei Kedao; Yue Brorong; Wang Jianchao

    2009-01-01

    Objective: To bring forward a novel quantity which is used to be taken as effective dose in helical multi - slice CT scan and to validate it by experiment. Methods: Dot chamber and pencil-chamber were used to measure the doses which were performed under axial mode and helical multi-slice mode. Then the readings of doses were compared and analyzed. Results: The dose reading from dot chamber was close to the one from pencil - chamber under axial mode. The ratio is 1.14 for the readings from dot chamber under two scan modes and is 2.88 for the readings from pencil-chamber under two scan modes. Conclusions: The dose measured from dot chamber is an effective quantity to be taken as effective dose. However it is insufficient that the CTDI and DLP be used to be taken as effective dose as the limitation of pencil-chamber in length. (authors)

  11. The value of multi-slice spiral CT in the preoperative assessment of living renal donor

    International Nuclear Information System (INIS)

    Li Qinghai; Yan Fuhua; Xu Pengju; Zhou Meiling; Zhu Tongyu; Xu Ming; Wang Guomin

    2008-01-01

    Objective: The purpose of this study is to assess the value of multi-slice spiral CT (MSCT) in the preoperative evaluation of living renal donor as a all in one modality. Methods: Thirty-six potential living renal donors underwent the examination using a GE light VCT scanner. Informed consent was obtained from all participants. The plain scan, early arterial phase, late arterial phase and excretory phase scans are performed in the former 25 donors (injection rate 5 rolls, total volume 100 mi, tube tension 120 kV). While in the later 11 donors (2 ml/s 40 ml +4 ml/s 60 ml), the scanning protocol included the plain scan ( 100 kV), vascular phase and excretory phase scans (100 kV). The excretory phase data were used in the reconstruction of CT urography in both groups. All images were reviewed by one radiologist and one urologist, and the findings of MSCT were compared with intraoperative findings for 33 donors, to investigate the utilities of MSCT in assessing renal vascularity, urinary tract and lesions of renal parenchyma. When discrepancies are found between the two reviewers, consensus was obtained via discussion. Au data was statiscally processed with SPSS for Windows. Results: MSCT angiography is in accordance with intraoperative findings in demonstrating the anatomy of renal arteries and renal vein trunk, accesary arteries, early branching of renal artery. The findings from CTA are highly in accordance with the intraoperative findings, which facilitate intraoperative ligation and reduce relevant complications. CTU demonstrates the anatomy of urinary, tract in good agreement with the intraoperative findings. The image quality of 3D vascularity and CTU between the two groups, scored 4.4 ± 1.2 vs 4.2 ± 1.3 and 4.6 ± 0.8 vs 4.4 ± 0.9 respectively, no statistical between-groups difference was found (Z=-0.89, -0.47, P>0.05). Conclusion: MSCT multiphase scanning combined with CTA and CTU play a important role in the evaluation of living renal donor, which

  12. Study of the usefulness of large intestine screening inspections using multi-slice CT (MSCT)

    International Nuclear Information System (INIS)

    Yamasaki, Michihiro; Nonogaki, Hidehiko; Hara, Koji; Naruse, Yutaka; Hara, Hiroto; Suematsu, Seiji; Yanase, Tadahiko; Otou, Taiji

    2005-01-01

    CT-colonography (CT-C), a new diagnostic imaging technique for cancer of the large intestine-which is increasing rapidly owing to westernized eating habits-has advanced from the developmental stage to the stage of practical application, thanks to progress in MSCT and workstation development. Therefore, based on the results of CT-C application using 16 lines of MSCT to a screening test, we reviewed the usefulness of CT-C in our clinic. We supplemented defective depiction, and found that change of position was effective for virtual image exclusion. We consider that CT-C can support diagnosis if the target of screening tests is a polypoid lesion of more than 6 mm. In addition, it is expected that the number of examinations performed during office visits will increase because of the decreased invasiveness of the procedure, its lack of pain, and its ability to provide early lesion detection. (author)

  13. The effects of slice thickness and reconstructive parameters on VR image quality in multi-slice CT

    International Nuclear Information System (INIS)

    Gao Zhenlong; Wang Qiang; Liu Caixia

    2005-01-01

    Objective: To explore the effects of slice thickness, reconstructive thickness and reconstructive interval on VR image quality in multi-slice CT, in order to select the best slice thickness and reconstructive parameters for the imaging. Methods: Multi-slice CT scan was applied on a rubber dinosaur model with different slice thickness. VR images were reconstructed with different reconstructive thickness and reconstructive interval. Five radiologists were invited to evaluate the quality of the images without knowing anything about the parameters. Results: The slice thickness, reconstructive thickness and reconstructive interval did have effects on VR image quality and the effective degree was different. The effective coefficients were V 1 =1413.033, V 2 =563.733, V 3 =390.533, respectively. The parameters interacted with the others (P<0.05). The smaller of those parameters, the better of the image quality. With a small slice thickness and a reconstructive slice equal to slice thickness, the image quality had no obvious difference when the reconstructive interval was 1/2, 1/3, 1/4 of the slice thickness. Conclusion: A relative small scan slice thickness, a reconstructive slice equal to slice thickness and a reconstructive interval 1/2 of the slice thickness should be selected for the best VR image quality. The image quality depends mostly on the slice thickness. (authors)

  14. Evaluation of the retrospective ECG-gated helical scan using half-second multi-slice CT. Motion phantom study for volumetry

    International Nuclear Information System (INIS)

    Yamamoto, Shuji; Matsumoto, Takashi; Nakanishi, Shohzoh; Hamada, Seiki; Takahei, Kazunari; Naito, Hiroaki; Ogata, Yuji

    2002-01-01

    ECG synchronized technique on multi-slice CT provide the thinner (less 2 mm slice thickness) and faster (0.5 sec/rotation) scan than that of the single detector CT and can acquire the coverage of the entire heart volume within one breath-hold. However, temporal resolution of multi-slice CT is insufficient on practical range of heart rate. The purpose of this study was to evaluate the accuracy of volumetry on cardiac function measurement in retrospective ECG-gated helical scan. We discussed the influence of the degradation of image quality and limitation of the heart rate in cardiac function measurement (volumetry) using motion phantom. (author)

  15. Imaging skeletal anatomy of injured cervical spine specimens: comparison of single-slice vs multi-slice helical CT

    Energy Technology Data Exchange (ETDEWEB)

    Obenauer, S.; Alamo, L.; Herold, T.; Funke, M.; Kopka, L.; Grabbe, E. [Department of Radiology, Georg August-University Goettingen, Robert-Koch-Strasse 40, 37075 Goettingen (Germany)

    2002-08-01

    Our objective was to compare a single-slice CT (SS-CT) scanner with a multi-slice CT (MS-CT) scanner in the depiction of osseous anatomic structures and fractures of the upper cervical spine. Two cervical spine specimens with artificial trauma were scanned with a SS-CT scanner (HighSpeed, CT/i, GE, Milwaukee, Wis.) by using various collimations (1, 3, 5 mm) and pitch factors (1, 1.5, 2, 3) and a four-slice helical CT scanner (LightSpeed, QX/i, GE, Milwaukee, Wis.) by using various table speeds ranging from 3.75 to 15 mm/rotation for a pitch of 0.75 and from 7.5 to 30 mm/rotation for a pitch of 1.5. Images were reconstructed with an interval of 1 mm. Sagittal and coronal multiplanar reconstructions of the primary and reconstructed data set were performed. For MS-CT a tube current resulting in equivalent image noise as with SS-CT was used. All images were judged by two observers using a 4-point scale. The best image quality for SS-CT was achieved with the smallest slice thickness (1 mm) and a pitch smaller than 2 resulting in a table speed of up to 2 mm per gantry rotation (4 points). A reduction of the slice thickness rather than of the table speed proved to be beneficial at MS-CT. Therefore, the optimal scan protocol in MS-CT included a slice thickness of 1.25 mm with a table speed of 7.5 mm/360 using a pitch of 1.5 (4 points), resulting in a faster scan time than when a pitch of 0.75 (4 points) was used. This study indicates that MS-CT could provide equivalent image quality at approximately four times the volume coverage speed of SS-CT. (orig.)

  16. Application of the FDK algorithm for multi-slice tomographic image reconstruction; Aplicacao do algoritmo FDK para a reconstrucao de imagens tomograficas multicortes

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Paulo Roberto, E-mail: pcosta@if.usp.b [Universidade de Sao Paulo (IFUSP), SP (Brazil). Inst. de Fisica. Dept. de Fisica Nuclear; Araujo, Ericky Caldas de Almeida [Fine Image Technology, Sao Paulo, SP (Brazil)

    2010-08-15

    This work consisted on the study and application of the FDK (Feldkamp- Davis-Kress) algorithm for tomographic image reconstruction using cone-beam geometry, resulting on the implementation of an adapted multi-slice computed tomography system. For the acquisition of the projections, a rotating platform coupled to a goniometer, an X-ray equipment and a digital image detector charge-coupled device type were used. The FDK algorithm was implemented on a computer with a Pentium{sup R} XEON{sup TM} 3.0 processor, which was used for the reconstruction process. Initially, the original FDK algorithm was applied considering only the ideal physical conditions in the measurement process. Then some artifacts corrections related to the projections measurement process were incorporated. The implemented MSCT system was calibrated. A specially designed and manufactured object with a known linear attenuation coefficient distribution ({mu}(r)) was used for this purpose. Finally, the implemented MSCT system was used for multi-slice tomographic reconstruction of an inhomogeneous object, whose distribution {mu}(r) was unknown. Some aspects of the reconstructed images were analyzed to assess the robustness and reproducibility of the system. During the system calibration, a linear relationship between CT number and linear attenuation coefficients of materials was verified, which validate the application of the implemented multi-slice tomographic system for the characterization of linear attenuation coefficients of distinct several objects. (author)

  17. Studies on intracranial collateral circulation with multi-slice CT angiography in patients with symptomatic cerebral artery stenosis

    Directory of Open Access Journals (Sweden)

    Shu-qing ZHOU

    2011-06-01

    Full Text Available Objective To explore the features of intracranial collateral circulation in patients with symptomatic cerebral artery stenosis.Method Ninety-four patients with ischemic cerebrovascular disease admitted from Apr.2004 to Jun.2009 were involved in present study.All the patients were examined with cerebral multi-slice CT angiography,and the features of cerebral artery stenosis and intracranial collateral circulation were evaluated using maximum intensity projection(MIP and volume rendering(VR images of CT angiography.Result Of the 94 patients involved,48 were diagnosed as cerebral artery stenosis,including 29 cases of cerebral infarction,18 of transient ischemic attack(TIA and 1 of moyamoya disease(MMD.Among the 14 cases of severe cerebral artery stenosis or occlusion,cerebral infarction was found in 6 cases with lesser intracranial collateral vessels(including massive cerebral infarction in 4 cases and watershed infarction in 2 cases,and focal infarction of central semi-ovale in 1 case and TIA in 7 cases were found with abundant intracranial collateral vessels.Multiple lacunar infarction was found in 22 cases of mild or moderate cerebral artery stenosis,but there was no significant correlation between the stenosed arteries and infarction sites.Abundant intracranial collateral vessels were found in one patient with Moyamoya disease but no infarction was observed.Conclusions Intracranial collateral circulation plays an important role of compensation in patients with severe cerebral artery stenosis or occlusion.Cerebral angiography with multi-slice CT is of great significance in evaluation of cerebral artery stenosis and intracranial collateral circulation.

  18. Multi-slice spiral CT coronary angiography: influence of heart rate and reconstruction window on image quality

    International Nuclear Information System (INIS)

    Mao Dingbiao; Hua Yanqing; Wang Mingpeng; Zhang Guozhen; Wu Weilan; Hu Fei; Ge Xiaojun; Ding Qiyong

    2004-01-01

    Objective: To evaluate the influence of heart rate and reconstruction window on image quality of multi-slice spiral CT coronary angiography. Methods: Retrospectively ECG-gated MSCT coronary angiography were performed in 80 healthy cases. Results: Four coronary (RCA, LM, LAD, LCX) segments were analyzed in each patient with regard to image quality. 82.1% (46/56) of the coronary segments were sufficient for analysis in patients with heart rate ≤60 bpm, 63.4% (104/164) with 61-70 bpm, 41.2%(28/68) with 71-80 bpm, and 31.2%(10/32) with>80 bpm, respectively. The left anterior descending artery, left circumflex artery, and the right coronary artery were best visualized when the reconstruction window was 60%-70%, 50%-60%, and 50%-70%, respectively. Conclusion: Image quality of MSCT coronary angiography is highly dependent on heart rate and reconstruction window

  19. Correlation between a 2D Channelized Hotelling Observer and Human Observers in a Low-contrast Detection Task with Multi-slice Reading in CT

    Science.gov (United States)

    Yu, Lifeng; Chen, Baiyu; Kofler, James M.; Favazza, Christopher P.; Leng, Shuai; Kupinski, Matthew A.; McCollough, Cynthia H.

    2017-01-01

    Purpose Model observers have been successfully developed and used to assess the quality of static 2D CT images. However, radiologists typically read images by paging through multiple 2D slices (i.e. multi-slice reading). The purpose of this study was to correlate human and model observer performance in a low-contrast detection task performed using both 2D and multi-slice reading, and to determine if the 2D model observer still correlate well with human observer performance in multi-slice reading. Methods A phantom containing 18 low-contrast spheres (6 sizes × 3 contrast levels) was scanned on a 192-slice CT scanner at 5 dose levels (CTDIvol = 27, 13.5, 6.8, 3.4, and 1.7 mGy), each repeated 100 times. Images were reconstructed using both filtered-backprojection (FBP) and an iterative reconstruction (IR) method (ADMIRE, Siemens). A 3D volume of interest (VOI) around each sphere was extracted and placed side-by-side with a signal-absent VOI to create a 2-alternative forced choice (2AFC) trial. Sixteen 2AFC studies were generated, each with 100 trials, to evaluate the impact of radiation dose, lesion size and contrast, and reconstruction methods on object detection. In total, 1600 trials were presented to both model and human observers. Three medical physicists acted as human observers and were allowed to page through the 3D volumes to make a decision for each 2AFC trial. The human observer performance was compared with the performance of a multi-slice channelized Hotelling observer (CHO_MS), which integrates multi-slice image data, and with the performance of previously validated CHO, which operates on static 2D images (CHO_2D). For comparison, the same 16 2AFC studies were also performed in a 2D viewing mode by the human observers and compared with the multi-slice viewing performance and the two CHO models. Results Human observer performance was well correlated with the CHO_2D performance in the 2D viewing mode (Pearson product-moment correlation coefficient R=0

  20. Four-dimensional measurement of intrafractional respiratory motion of pancreatic tumors using a 256 multi-slice CT scanner

    International Nuclear Information System (INIS)

    Mori, Shinichiro; Hara, Ryusuke; Yanagi, Takeshi; Sharp, Gregory C.; Kumagai, Motoki; Asakura, Hiroshi; Kishimoto, Riwa; Yamada, Shigeru; Kandatsu, Susumu; Kamada, Tadashi

    2009-01-01

    Purpose: To quantify pancreas and pancreatic tumor movement due to respiratory motion using volumetric cine CT images. Materials and methods: Six patients with pancreatic tumors were scanned in cine mode with a 256 multi-slice CT scanner under free breathing conditions. Gross tumor volume (GTV) and pancreas were manually contoured on the CT data set by a radiation oncologist. Intrafractional respiratory movement of the GTV and pancreas was calculated, and the results were compared between the respiratory ungated and gated phases, which is a 30% duty cycle around exhalation. Results: Respiratory-induced organ motion was observed mainly in the anterior abdominal side than the posterior side. Average GTV displacement (ungated/gated phases) was 0.7 mm/0.2 mm in both the left and right directions, and 2.5 mm/0.9 mm in the anterior, 0.1 mm/0 mm in the posterior, and 8.9 mm/2.6 mm in the inferior directions. Average pancreas center of mass displacement relative to that at peak exhalation was mainly in the inferior direction, at 9.6 mm in the ungated phase and 2.3 mm in the gated phase. Conclusions: By allowing accurate determination of the margin, quantitative analysis of tumor and pancreas displacement provides useful information in treatment planning in all radiation approaches for pancreatic tumors.

  1. Optimization of multi-slice helical respiration-correlated CT: the effects of table speed and rotation time

    International Nuclear Information System (INIS)

    Wink, Nicole M; McNitt-Gray, Michael F; Solberg, Timothy D

    2005-01-01

    While respiration-correlated CT is gaining acceptance in clinical radiotherapy, the effect of scanning parameters on the image quality has yet to be addressed. The intent of this study was to characterize the effects of gantry rotation and table speed on various image quality characteristics in multi-slice, helical, retrospectively-gated CT images. Images of stationary and moving phantoms were obtained in helical mode on a 20-slice CT scanner. Motion was generated by a computer-controlled platform capable of moving simultaneously in two dimensions. Motion was monitored using a pressure gauge inserted inside an adjustable belt. Selected scans were retrospectively gated into ten phases based on the monitored motion. Gantry rotation speeds of 0.5 s and 1.0 s were evaluated with pitches ranging from 0.1 to 0.45. Several parameters, including calculated object volumes, trajectory (movement from peak to trough), deformation (actual volume divided by volume created with the maximum diameter of contoured object) and z-axis resolution, were used to characterize image quality. These studies indicate that for objects in the peak phase of a movement pattern that simulates breathing, retrospectively gated scans using fast gantry rotation speeds produce volume, trajectory, deformation and z-axis resolution results comparable with those of a stationary object

  2. Establishing a pattern of 64-multi slice CT of polytraumatic patients

    International Nuclear Information System (INIS)

    Richter, B.; Walecka, A.; Burak, M.; Pakulski, C.

    2009-01-01

    Background: Due to great technological progress made over the last decade in computer tomography, CT Has become a very successful tool for diagnostic imaging in polytraumatic patients. The purpose of this study is an optimum selection of parameters to detect all post-traumatic pathologies in polytraumatic patients, with the application of minimum ionizing radiation. Material/Methods: 131 patients with a suspected polytrauma were studied following various scanning patterns with a 64-slice CT of the head, neck, thorax and abdominal cavity with pelvis. The patients were divided into three groups in accordance with the chosen scheme. Materials were analyzed with the following in view: increasing the efficacy of detecting pathologies, decreasing radiation dose, simplifying assessment and facilitating image archiving. Results: The following mean numbers of serious post-traumatic pathologies were diagnosed during one examination: group I - 1.8, group II - 2.8, and group III - 2.1. There was a statistically significant reduction in the number of reconstructions performed during one examination from 11.8 in group I, 8.3 in group II, to 7.2 in group III. Additionally, statistically significant reductions were obtained in the mean values of the dose-length product (DLP): 3361 mGy · cm (group I), 2805 mGy 8· cm (group II), 2583 mGy · cm (group III). Conclusions: The third scanning pattern, which comprised multiple adjacent sections scanned jointly, including a single trunk scan following the administration of a contrast material, is best in terms of evaluation comfort and the lowest radiation dose absorbed by the patient. Patterns II and III are most effective in detecting pathologies. (authors)

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

    International Nuclear Information System (INIS)

    Wang Jue; Wang Fuquan; Jiang Zenghui

    2008-01-01

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

  4. Assessment of sphenoid sinus volume in order to determine sexual identity, using multi-slice CT images

    Directory of Open Access Journals (Sweden)

    Habibeh Farazdaghi

    2017-02-01

    Full Text Available Background and Aims: Gender determination is an important step in identification. For gender determination, anthropometric evaluation is one of the main forensic evaluations. The aim of this study was the assessment of sphenoid sinus volume in order to determine sexual identity, using multi-slice CT images. Materials and Methods: For volumetric analysis, axial paranasal sinus CT scan with 3-mm slice thickness was used. For this study, 80 images (40 women and 40 men older than 18 years were selected. For the assessment of sphenoid sinus volume, Digimizer software was used. The volume of sphenoid sinus was calculated using the following equation: v=∑ (area of each slice × thickness of each slice. Statistical analysis was performed by independent T-test. Results: The mean volume of sphenoid sinus was significantly greater in male gender (P=0.01.The assessed Cut off point was 9/35 cm3, showing that 63.4% of volume assessments greater than cut off point was supposed to be male and 64.1% of volumetry lesser than cut off point were female. Conclusion: According to the area under Roc curve (1.65%, sphenoid sinus volume is not an appropriate factor for differentiation of male and female from each other, which means the predictability of cut off point (9/35 cm3 is 65/1% close to reality.

  5. Biliary complications after liver transplantation: diagnosis with multi-slice CT

    International Nuclear Information System (INIS)

    Zhu Kangshun; Meng Xiaochun; Xu Changmou; Shen Min; Qian Jiesheng; Pang Pengfei; Guan Shouhai; Jiang Zaibo; Shan Hong

    2009-01-01

    Objective: To evaluate multislice CT in the diagnosis of biliary complications after liver transplantation. Methods: Eighty-three consecutive patients who had undergone orthotopic liver transplantation (OLT) presented with clinical or biochemical signs of biliary complications and underwent contrast-enhancement CT examination. Three experienced radiologists, who were blinded to patient's clinical data, assessed CT images for the detection of biliary complications in consensus. Diagnostic confirmation of biliary complications was obtained with direct cholangiography in 69 patients, histologic study in 11 patients and hepaticojejunostomy in 3 patients. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of CT for the detection of biliary complications were calculated. In addition, CT features of anastomotic biliary stricture (ABS) were compared with those of non-anastomotic biliary stricture (NABS) using χ 2 test. Results: A total of 62 biliary complications (74.7%) was eventually confirmed in the 83 patients, including ABS in 32 patients, NABS in 21 patients, biliary duct stones in 16 patients (of which 12 patients with biliary stricture) , anastomotic bile leakage in 5 patients, biloma in 4 patients with biliary stricture, and biliogenic abscess in 2 patients with biliary stricture. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of CT for the detection of biliary stricture were 90.6%, 86.7%, 89.2%, 92.3% and 83.9%, respectively. Other biliary complications, including biliary duct stones (16 cases), anastomotic bile leak (5 cases), biloma (4 cases), and biliogenic abscess (2 cases), were correctly diagnosed by CT; there was no false-positive or false-negative result. The incidence of irregular dilatation of bile duct was 71.4% (15/21), which was significantly higher in NABS cases than in ABS of 25.0% (8/32, P<0.01); whereas the incidence of extrahepatic biliary dilatation

  6. Low-dose multi-slice CT (LMCT) assessment of pulmonary emphysema in public-school teachers

    International Nuclear Information System (INIS)

    Horiuchi, Noriaki; Yamazaki, Yasuhiro; Fujita, Jiro; Suemitsu, Ichizou; Kamei, Tadashi; Tada, Shinya; Ueda, Nobuo

    2003-01-01

    Although rates of emphysematous change in smokers have been reported previously, the precise effects of smoking on emphysematous change have not been established because the study subjects of previous reports were heterogeneous. This study was designed to determine the incidence of emphysematous change identified by low-dose multi-slice CT (LMCT) imaging in public-school teachers. We reviewed 1776 consecutive subjects (ages from 31 to 61 years) who had undergone LMCT scanning during health care examinations. In addition, their replies to questionnaires about smoking were obtained. Emphysematous change was found by LMCT imaging in 22 male smokers. In these 22 smokers, the scores of emphysematous change according to Goddard's method was well correlated with smoking history. According to the questionnaires, the smoking rates of male and female teachers were 56.7% and 4%, respectively. Eighty-five percent of the teachers worked in offices separated from smokers. Most smokers wished to quit smoking and most teachers knew the risk of nicotine as well as the rate of smoking among high school students. However, knowledge of the relationships between smoking and lung cancer, myocardial infarction, and subarachnoid hemorrhage were not adequate. Our present study clearly demonstrated the incidence of emphysematous change in school teachers. In addition, early exposure to information about the risks of smoking is believed to be important for students, but school teachers did not have enough of such information. (author)

  7. Noninvasive detection of coronary abnormalities in pediatric patients with Kawassaki disease using multi-slice spiral CT

    International Nuclear Information System (INIS)

    Hou Yang; Guo Wenli; Yue Yong; Chen Liying; Guo Qiyong; Yu Xianyi; Wang Hong

    2006-01-01

    Objective: To evaluate the feasibility and value of detecting coronary artery lesions in Kawasaki disease using multi-slice computed tomography (MSCT). Methods: Thirty-four pediatric patients underwent 16-slice or 64-slice CT coronary, angiography. 18 patients were also examined with 2 dimension echocardiography (2DE). In all cases, visibility of coronary artery segment was recorded. The diameter of the LCA, RCA were measured in MSCTA and compared with 2DE. Correlation coefficient of dimension and coincidence rate of two methods were calculated. Results: Coronary artery lesions were found in 14 patients (22 branches) of the 34 cases with KD on MSCT. Six cases were dialated, 3 cases were dialated with aneurysms, 2 cases had aneurysms without dialation. Coronary artery stenosis in 1 eases, calcification in 2 cases. Three cases had multiple aneurysms with the presence of alternate stenosis that made the artery a bead-like appearance. CC of LM and RCA were 0.85, 0.91, respectively (P>0.05). Three coronary artery aneurysm in the distal RCA was missed by 2DE. MSCT could not detect slight or moderate mitral regurgitation in 2 patients and artery wall thickening in 5 patients. Conclusion: MSCT would be an effective complementary or alternative method for CDEC to evaluate coronary artery lesions non-invasively in pediatric patients with Kawasaki disease. (authors)

  8. Approximations of noise covariance in multi-slice helical CT scans: impact on lung nodule size estimation.

    Science.gov (United States)

    Zeng, Rongping; Petrick, Nicholas; Gavrielides, Marios A; Myers, Kyle J

    2011-10-07

    Multi-slice computed tomography (MSCT) scanners have become popular volumetric imaging tools. Deterministic and random properties of the resulting CT scans have been studied in the literature. Due to the large number of voxels in the three-dimensional (3D) volumetric dataset, full characterization of the noise covariance in MSCT scans is difficult to tackle. However, as usage of such datasets for quantitative disease diagnosis grows, so does the importance of understanding the noise properties because of their effect on the accuracy of the clinical outcome. The goal of this work is to study noise covariance in the helical MSCT volumetric dataset. We explore possible approximations to the noise covariance matrix with reduced degrees of freedom, including voxel-based variance, one-dimensional (1D) correlation, two-dimensional (2D) in-plane correlation and the noise power spectrum (NPS). We further examine the effect of various noise covariance models on the accuracy of a prewhitening matched filter nodule size estimation strategy. Our simulation results suggest that the 1D longitudinal, 2D in-plane and NPS prewhitening approaches can improve the performance of nodule size estimation algorithms. When taking into account computational costs in determining noise characterizations, the NPS model may be the most efficient approximation to the MSCT noise covariance matrix.

  9. Segmentation algorithm of colon based on multi-slice CT colonography

    Science.gov (United States)

    Hu, Yizhong; Ahamed, Mohammed Shabbir; Takahashi, Eiji; Suzuki, Hidenobu; Kawata, Yoshiki; Niki, Noboru; Suzuki, Masahiro; Iinuma, Gen; Moriyama, Noriyuki

    2012-02-01

    CT colonography is a radiology test that looks at people's large intestines(colon). CT colonography can screen many options of colon cancer. This test is used to detect polyps or cancers of the colon. CT colonography is safe and reliable. It can be used if people are too sick to undergo other forms of colon cancer screening. In our research, we proposed a method for automatic segmentation of the colon from abdominal computed Tomography (CT) images. Our multistage detection method extracted colon and spited colon into different parts according to the colon anatomy information. We found that among the five segmented parts of the colon, sigmoid (20%) and rectum (50%) are more sensitive toward polyps and masses than the other three parts. Our research focused on detecting the colon by the individual diagnosis of sigmoid and rectum. We think it would make the rapid and easy diagnosis of colon in its earlier stage and help doctors for analysis of correct position of each part and detect the colon rectal cancer much easier.

  10. [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.

  11. A comparison of shielding calculation methods for multi-slice computed tomography (CT) systems

    International Nuclear Information System (INIS)

    Cole, J A; Platten, D J

    2008-01-01

    Currently in the UK, shielding calculations for computed tomography (CT) systems are based on the BIR-IPEM (British Institute of Radiology and Institute of Physics in Engineering in Medicine) working group publication from 2000. Concerns have been raised internationally regarding the accuracy of the dose plots on which this method depends and the effect that new scanner technologies may have. Additionally, more recent shielding methods have been proposed by the NCRP (National Council on Radiation Protection) from the USA. Thermoluminescent detectors (TLDs) were placed in three CT scanner rooms at different positions for several weeks before being processed. Patient workload and dose data (DLP: the dose length product and mAs: the tube current-time product) were collected for this period. Individual dose data were available for more than 95% of patients scanned and the remainder were estimated. The patient workload data were used to calculate expected scatter radiation for each TLD location by both the NCRP and BIR-IPEM methods. The results were then compared to the measured scattered radiation. Calculated scattered air kerma and the minimum required lead shielding were found to be frequently overestimated compared to the measured air kerma, on average almost five times the measured scattered air kerma.

  12. Primitive experience of three dimensional multi-slice spiral CT angiography for the follow-up of intracranial aneurysm clipping

    International Nuclear Information System (INIS)

    Yang Yunjun; Chen Weijian; Hu Zhangyong; Wu Enfu; Wang Meihao; Zhuge Qichuan; Zhongming; Cheng Jingliang; Ren Cuiping; Zhang Yong

    2008-01-01

    Objective To evaluate multi-slice three-dimensional CT angiography (MS 3D-CTA) for the follow-up of intracranial aneurysm clipping. Methods: MS 3D-CTA of 16 patients with intracranial aneurysm clipping were retrospectively analyzed. The patients were scanned on a 16-slice spiral CT (GE Lightspeed pro). Volume rendering(VR), thin maximum intensity projection(thin MIP) and multi-planar reconstruction (MPR) were employed in image postprocessing in all cases. Results: There were 17 clips in the 16 patients with aneurysm clipping. Six clips were located at the posterior communicating artery, 5 at the anterior communicating artery, 4 at the middle cerebral artery, and the remaining 2 clips were located at the pericallosal artery, in 1 patient. There were no abnormalities found in the aneurysm clipping region in 7 cases by MS 3D- CTA. There were residual aneurysm in 2 cases, parent artery stenosis in 4 cases, and artery spasm in 3 eases. There was no parent artery occlusion and clip displacement in all cases. VR showed excellent 3D spacial relations between the clip and parent artery in 12 cases, and showed good relations in 3 cases. The 1 case with 2 clips in the pericallosal artery showed heavy beam-hardening artifacts. The size and shape of aneurysm clips were clearly depicted by MPR and thin MIP, while 3D spacial relation of aneurysm clip and parent artery were poorly showed. Conclusion: MS 3D-CTA is a safe and efficient method for the follow-up of intracranialaneurysm clipping. Combined VR with MPR or thin MIP can well reveal postoperative changes after aneurysm clipping. (authors)

  13. Choice ofoptimal phase for liver angiography and multi-phase scanning with multi-slice spiral CT

    International Nuclear Information System (INIS)

    Fang Hong; Song Yunlong; Bi Yongmin; Wang Dong; Shi Huiping; Zhang Wanshi; Zhu Hongxian; Yang Hua; Ji Xudong; Fan Hongxia

    2008-01-01

    Objective: To evaluate the efficacy of test bolus technique with multi-slice spiral CT (MSCT) for determining the optimal scan delay time in CT Hepatic artery (HA)-portal vein (PV) angiography and multi-phase scanning. Methods: MSCT liver angiography and multi-phase scanning were performed in 187 patients divided randomly into two groups. In group A (n=59), the scan delay time was set according to the subjective experiences of operators; in group B (n=128), the scan delay time was determined by test bolus technique. Abdominal aorta and superior mesenteric, vein were selected as target blood vessels, and 50 HU was set as enhancement threshold value. 20 ml contrast agent was injected intravenously and time-density curve of target blood vessels were obtained, then HA-PV scanning delay time were calculated respectively. The quality of CTA images obtained by using these 2 methods were compared and statistically analysed using Chi-square criterion. Results: For hepatic artery phase, the images of group A are: excellent in 34 (58%), good in 17 (29%), and poor in 8 (13%), while those of group B are excellent in 128(100%), good in 0(0%), and poor in 0(0%). For portal vein phase, the images of group A are: excellent in 23 (39%), good in 27 (46%), and poor in 9 (15%), while those of group B are excellent in 96 (75%), good in 28 (22%), and poor in 4 (3%) respectively. There was statistically significant difference between the ratios of image quality in group A and group B (χ 2 =14.97, 9.18, P< 0.05). Conclusion: Accurate scan delay time was best determined by using test bolus technique, which can improve the image quality of liver angiography and multi-phase scanning. (authors)

  14. Assessment of colonic disease by multi-slice CT pneumocolon after incomplete colonoscopy

    International Nuclear Information System (INIS)

    Zhao Zehua; Liu Wenjin; Xu Songsen; Wang Kang; Wang Weizhong

    2004-01-01

    Objective: To evaluate the use of preoperative MSCT in patients with clinically suspected colorectal disease after incomplete colonoscopy. Methods: After incomplete colonoscopy, 31 patients underwent MSCT before and after intravenous injection of iodinated contrast agent. CT virtual colonography (CTVC), multiplanar reformation (MPR), shaded surface display (SSD), and Raysum images were obtained by using 4 different software in workstation. The results of MSCT were compared with the findings of colonoscopy, intraoperative colon palpation, and postoperative pathology. Results: After incomplete colonoscopy, MSCT was successfully performed in all 31 cases. Postoperative pathology revealed 22 colorectal cancers (one synchronous cancers, two with polyps) and 9 benign disease. 22 colonic carcinomas were all correctly diagnosed by MSCT (including synchronous disease), 2 benign diseases were misdiagnosed as malignancy, and one polyp was missed. Conclusion: MSCT is a feasible and useful method for evaluating the entire colon before surgery in patients with occlusive disease. (author)

  15. A differentiated approach to the diagnosis of pulmonary embolism and deep venous thrombosis using multi-slice CT

    International Nuclear Information System (INIS)

    Wildberger, J.E.; Mahnken, A.H.; Stargardt, A.; Haage, P.; Guenther, R.W.; Sinha, A.M.; Schaller, S.

    2002-01-01

    Purpose: To establish a differentiated protocol for multi-slice CT (MSCT) examinations in cases of clinically suspected pulmonary embolism (PE) using pulmonary CT-angiography (CTA) and indirect CT-phlebography (CTP). Materials and Methods: 161 patients with suspected PE were examined using an MSCT (SOMATOM Volume Zoom; Siemens, Forchheim, Germany). After intravenous administration of 120 ml of contrast material, a thin collimation chest-CT scan was performed (120 kV, 100 mAs, collimation: 4 x 1 mm). If PE was present, or previous examinations and clinical signs suggested deep venous thrombosis (DVT), a CTP was subsequently completed. CTPs were performed using a 4 x 5 mm protocol (120 kV, 170 mAs). Venous phase scanning, starting from the pelvic crest, was completed in the popliteal fossa three minutes after contrast material injection. In 73 extremities, CTP were compared to the results of ultrasound, phlebography and autopsy. Scan ranges were documented in all patients. Cumulative doses were calculated for male and female subgroups. Results: 62 patients in our series suffered from PE and in 47 of these patients deep venous thrombosis was seen additionally. Of the 99 patients without PE, 47 also received indirect CTP. CTP confirmed the suspicion and extent of DVT in 8 patients. Only in 2 of 39 patients (5.1%) was previously unknown DVT found, despite the exclusion of PE. Regarding DVT, sensitivity was 94.3% and specificity was 92.1% for indirect CTP. Cumulative chest CT doses averaged 3.3 mSv for males and 4.2 mSv for females, the calculated CTP dosage was 9.3 mSv (according to ICRP 60). Conclusions: the examination protocol presented its suitable for clinical usage in patients with suspected PE. If PE is confirmed, indirect CTP is justified, so that detailed information of the venous system can be obtained. However, the relatively high radiation dosage of an additional CTP requires a strict indication regiment in patients with a negative CTA. (orig.) [de

  16. Comparative study of multi-slice spiral CT angiography and color doppler ultrasound in diagnosis of arteriosclerotic occlusive disease of lower extremity

    International Nuclear Information System (INIS)

    Li Wanjun; Lai Zhenhui; Cui Dong; Lin Xiupeng; Du Muxuan

    2010-01-01

    Objective: To compare the difference between multi-slice spiral CT angiography (MSCTA) and color doppler ultrasound in diagnosis of arteriosclerotic occlusive disease of lower extremity. Methods: Patients with arteriosclerosis occlusion were assessed by color doppler ultrasound, multi-slice spiral CT angiography and digital subtraction angiography (DSA). The image information of color doppler ultrasound and MSCTA were compared with that of DSA. Results: Color doppler ultrasound showed the anatomical shape and hemodynamics of the arteries of lower extremity. The sensitivity, specificity, and accuracy for diagnosis arteriosclerotic occlusive disease of lower extremity were 88.04%, 90.69% and 88.77% respectively. MSCTA showed the three dimensional structure of the arteries of lower extremity as well as the collateral arteries and the distal arterials. The sensitivity, specificity and accuracy of MSCTA were 97.69%, 96.90% and 97.66%, respectively. Conclusion: Multi-slice spiral CT angiography is an ideal imaging method for the diagnosis of arteriosclerotic occlusive disease of lower extremity. (authors)

  17. Experimental study of multi-slice CT for the evaluation of atherosclerotic plaques

    International Nuclear Information System (INIS)

    Tang Xiang; Lv Bin; Wu Wenhui; Lu Jinguo; Dai Ruping; Bai Hua; Tang Yue; Lv Fengying; Jiang Shiliang

    2009-01-01

    Objective: To evaluate the diagnostic values of MSCT for detecting atherosclerotic plaques on New Zealand rabbits models in comparison with pathologic results. Methods: Fifteen New Zealand rabbits were enrolled in this study, including 5 with balloon injury and high-fat diet (group A), 5 with high-fat diet only (group B) and 5 with regular feed (group C). 16th week late, contrast-enhanced MSCT scan was performed in all rabbits with 16 slice MSCT (16-MSCT) in group A and 64 slice MSCT (64-MSCT) in group B and C. The CT and pathological findings were compared in a double-blind manner. The sensitivities and specificities of 16-MSCT and 64-MSCT for detecting atherosclerotic plaques were evaluated by using Fisher test and χ 2 test. Results: Sixty and seventy-five images on 16-MSCT and 64-MSCT had corresponding pathological slices. The sensitivities for the detection of plaques on 16-MSCT and 64-MSCT were 41.5% (22/53) and 64.9% (24/37), and specificities of 85.7% (6/7) and 89.5% (34/38), respectively. Conclusions: 64-MSCT has a higher sensitivity in the detection of atherosclerotic plaques than 16-MSCT. Both scanners can be used to preclude the diagnosis of atherosclerosis. (authors)

  18. Dual-phase contrast enhancement multi-slice CT in grading pancreatic neuroendocrine tumors

    International Nuclear Information System (INIS)

    Zhou Yan; Liu Jianyu; Zhu Xiang

    2013-01-01

    Objective: To evaluate characteristic clinical and imaging findings of pancreatic neuroendocrine tumors (NET) in dual-phase contrast enhancement MSCT. Methods: The dual-phase contrast enhancement MSCT images of 23 lesions in 20 patients with histologically confirmed pancreatic NET were studied retrospectively. Their clinical presentations, imaging characters as well as the intensities of lesions and normal pancreas in each phase were measured, and the following indices were calculated. First, the absolute enhancement of lesions, including the increasing of CT value of the maximum enhancement area within a tumor in arterial phase, that was named A1 in short, and that of the minimum enhancement area was labeled as A2. The same ROI measured increasing CT values in portal venous phase was labeled as V1 and V2 respectively. Secondly, the relatively enhancement indices comparing with the normal pancreas in the same patient within the same phase were calculated. This included the differences between the maximum, as well as the minimum, enhancement areas of tumors and the normal pancreas in arterial phase, which was named as AP1 and AP2 respectively, and those differences in portal venous phase, which were labeled as VP1 and VP2 respectively. All of the tumors were graded as G1 to G3 according to the WHO classification in 2010. A Kruskal Wallis test were performed to compare differences of tumor diameters and the enhancement indices. The change trend of enhancement indices varying with pathology grading were described. Fisher exact test was used to find differences of clinical and imaging characters. Results: Twenty-three lesions in 20 patients included 13 lesions in grade 1 (G1), 8 in G2, and 2 in G3. Among the 10 patients with G1 NET, 7 of them had no endocrine symptoms, while the other 3 had endocrine symptoms. Six of them had no abdominal pain, while 4 of them complained of it. All of the 10 patients with G1 NET had no hepatic metastasis. Among 8 patients with G2 NET

  19. 16 multi-slice CT three-dimensional and multiplanar reconstruction for evaluation of pediatric congenital scoliosis

    International Nuclear Information System (INIS)

    Peng Yun; Zhang Ningning; Zhang Xuejun; Sun Guoqiang; Zeng Jinjin

    2006-01-01

    Objective: Our study is to use of 16 MSCT three-dimensional images and multiplanar reconstruction images in the preoperative investigation of patients with congenital scoliosis, to study its technical advantage and work out surgical plan. Methods: Twenty-seven pediatric patients with congenital scoliosis processing between April to October 2004 were reviewed, including 13 boys and 14 girls. X-ray plain film and sixteen multi-slice CT examination on curved/standard multiplanar reconstruction and three- dimensional computed tomographic imaging may offer, many potential advantages for defining congenital spine anomalies liable to cause progression of scoliosis, including visualization of the deformity in any plane, from any angle, with the overlying structures subtracted. Results: Ten patients had segmentation defects, 6 patients underwent formation defects, 11 patients had complex, unclassifiable anomalies. The patients of rib deformity were found in 15 patients, the most prominent part of the rib cage deformity was at the same level as the most rotated vertebra in 7 patients; 8 patients had vertebral anomalies accompanied with diastematomyelie, including 6 patients with uncompleted or completed bony spur. In 19 of 27 cases, the muhiplanar reconstruction and three-dimensional images allowed identification of unrecognized malformations and completely evaluated the degree of scoliosis, during conventional X-ray images and axial CT images, including volume 3D imaging evaluated approximately classification and modality of complex anomalies in 11 cases, which were unclassifiable malformation in 7 cases and unsegmented bar with contralateral hemivertebrae; 4 children had segmentation defects revealed unilateral unsegmented bar (3 cases) and bilateral block vertebra (1 case) in volume 3D reconstruction images; 2 children were found occultation hemivertebrae which were not been discovered during conventional X-ray images and axial CT images; and 2 children were revaluated

  20. Conventional multi-slice computed tomography (CT) and cone-beam CT (CBCT) for computer-aided implant placement. Part II: reliability of mucosa-supported stereolithographic guides.

    Science.gov (United States)

    Arisan, Volkan; Karabuda, Zihni Cüneyt; Pişkin, Bülent; Özdemir, Tayfun

    2013-12-01

    Deviations of implants that were placed by conventional computed tomography (CT)- or cone beam CT (CBCT)-derived mucosa-supported stereolithographic (SLA) surgical guides were analyzed in this study. Eleven patients were randomly scanned by a multi-slice CT (CT group) or a CBCT scanner (CBCT group). A total of 108 implants were planned on the software and placed using SLA guides. A new CT or CBCT scan was obtained and merged with the planning data to identify the deviations between the planned and placed implants. Results were analyzed by Mann-Whitney U test and multiple regressions (p < .05). Mean angular and linear deviations in the CT group were 3.30° (SD 0.36), and 0.75 (SD 0.32) and 0.80 mm (SD 0.35) at the implant shoulder and tip, respectively. In the CBCT group, mean angular and linear deviations were 3.47° (SD 0.37), and 0.81 (SD 0.32) and 0.87 mm (SD 0.32) at the implant shoulder and tip, respectively. No statistically significant differences were detected between the CT and CBCT groups (p = .169 and p = .551, p = .113 for angular and linear deviations, respectively). Implant placement via CT- or CBCT-derived mucosa-supported SLA guides yielded similar deviation values. Results should be confirmed on alternative CBCT scanners. © 2012 Wiley Periodicals, Inc.

  1. Value of multi-slice spiral CT in diagnosis the detection of fish bone impaction in the esophagus

    International Nuclear Information System (INIS)

    Luo Min; Hu Daoyu; Wang Qiuxia; Pei Yigang

    2009-01-01

    Objective: To investigate the detection rate and diagnostic value of multi-slice spiral CT scan in detecting fish bone impaction in the esophagus. Methods: Experimental group: 30 fresh water fish bones from three variety classes were divided into three groups with length of (23.36±0.15), (28.51± 0.07) and (30.89±0.10) mm, and diameter of (4.49±0.31), (1.78±0.09) and (0.49±0.07) mm. The fish bones were put into esophagus models in three different types including parallel, perpendicular and oblique. MSCT with axial scan combined with three dimensional reconstruction technique and plain X-ray film ( CR and DR) were used to examine the model. The relations of the number and rate of fish bones were compared between MSCT and X-ray film. Clinical group: MSCT imaging were performed in 20 cases proved by esophageal endoscope or clinical operation, among which 11 cases received plain X-ray film (CR and DR), 15 cases received Barium-soaked cotton and 17 cases received endoscope. Paired Chi-square test was used to compare the differences of detection of fishbone by the different ways. Results: In experimental group: All the 90 cases (100%) fish bones of three different species were clearly revealed on MSCT image; only 60 cases (66.7%) fish bones were revealed by plain X-ray film (CR and DR). The number and rate of fish bones detected by MSCT was higher than that of plain X-ray film (CR and DR) (χ 2 =28.03, P 2 =7.11, P 2 =4.17, P<0.05). Conclusions: The sensitivity and detection rate of fish bone with MSCT was high and could evaluate the surrounding and complications of the esophagus. MSCT could be used as the first examination of impacted fish bones in the esophagus. (authors)

  2. The investigation of the lateral atlanto-dental interval of atlanto-axial joint by multi-slice spiral CT

    International Nuclear Information System (INIS)

    Cui Wei; Peng Lei; Wang Jincai; Liu Jihua; Feng Weihua

    2010-01-01

    Objective: To explore imaging features of the lateral atlanto-dental interval (LADI) of atlanto-axial joint and its value in the diagnosis of atlanto-axial joint dislocation/subluxation. Methods: Two hundred and forty healthy volunteers without atlanto-axial joint dysfunction and 32 patients with torticollis and/or functional impairment at atlanto-axial.joint were enrolled into this study. All subjects were examined with multi-slice CT in both neutral and max rotation positions to the left/right. Clinical endpoints including VBLADI, variance range of the VBLADI and asymmetric conditions were evaluate. χ 2 test is used to evaluate the variance of incidence of bilateral LADI asymmetry in different age groups, Pearson-test (2-tailed) is used to evaluate the correlation between VBLADI and rotary function of atlanto-axial joint, precise test of fourfold table is used to compare normal group with patient groups. Results: (1) In the normal control group: asymmetry of bilateral LADI were observed in 204 among 240 (85.00%) healthy volunteers including 60 youngsters ( 95% of ∣ VBLADI ∣ were 0.850 mm, 2.450 mm in the young ( 95% in the young and in the adult respectively. There was no correlation between VBLADI(-2.146 to 2.114 mm, Median 0.000 mm) and LA (22.949° to 44.649°, Median 34.500°), RA (25.284° to 45.334°, Median 35.300°), VLRA (-11.643° to 8.623°, median 0.000°) respectively in normal people (r=-0.030, -0.005, 0.026, P>0.05). (2) In the study with 32 patients including 25 youngsters ( 95% in group AALSD and group AACD than in abnormal group (P<0.01), but there is no difference between group AARD and normal group (P=0.738). Conclusion: The imaging finding of 'asymmetry of bilateral LADI' may be either a physiological variation or a pathological condition, clinical manifestations and other imaging findings should be evaluated to make a diagnosis. (authors)

  3. A comparative study for spatial resolution and subjective image characteristics of a multi-slice CT and a cone-beam CT for dental use

    International Nuclear Information System (INIS)

    Watanabe, Hiroshi; Honda, Eiichi; Tetsumura, Akemi; Kurabayashi, Tohru

    2011-01-01

    Purpose: Multi-slice CT (MSCT) and cone-beam CT (CBCT) are widely used in dental practice. This study compared the spatial resolution of these CT systems to elucidate which CT modalities should be selected for various clinical cases. Materials and methods: As MSCT and CBCT apparatuses, Somatom Sensation 64 and 3D Accuitomo instruments, respectively, were used. As an objective evaluation of spatial resolution of these CT systems, modulation transfer function (MTF) analysis was performed employing an over-sampling method. The results of MTF analysis were confirmed with a line-pair test using CATPHAN. As a subjective evaluation, a microstructure visualization ability study was performed using a Jcl:SD rat and a head CT phantom. Results: MTF analysis showed that for the in-plane direction, the z-axis ultrahigh resolution mode (zUHR) of the Sensation 64 and 3D Accuitomo instruments had higher spatial resolutions than the conventional mode (64x) of the Sensation 64, but for the longitudinal direction, the 3D Accuitomo had clearly higher spatial resolution than either mode of the Sensation 64. A line-pair test study and microstructure visualization ability studies confirmed the results for MTF analysis. However, images of the rat and the CT phantom revealed that the 3D Accuitomo demonstrated the failure to visualize the soft tissues along with aliasing and beam-hardening artifacts, which were not observed in the Sensation 64. Conclusions: This study successfully applied spatial resolution analysis using MSCT and CBCT systems in a comparative manner. These findings could help in deciding which CT modality should be selected for various clinical cases.

  4. Study of low dose and dynamic multi-slice CT about obstructive sleep apnea syndrome in sleeping

    International Nuclear Information System (INIS)

    Shen Jie; Qi Ji; Yin Jianzhong

    2006-01-01

    Objective: To perform Low dose dynamic MSCT(multi-slice CT) in sleeping obstructive sleep apnea syndrome (OSAS) patients correcting the imprecise measure values in waking state, and to exactly analyse the location and extension of the dynamic changes about the condition. Methods: Sixteen OSAS patients were scanned both in waking and naturally sleeping period (end phase of inspiration and expiration). Measured at the narrowest part of the retropalatal (RP) and retroglossal (RG) and 5 mm under the tip of epiglottis at the epiglottal (EPG)at the end period of inspiration in sleeping, respectively, and compared the accurate position of the narrowest or occlusive level in 3 phases. All patients were also scanned using cine mode at the narrowest level at the end period of inspiration in sleeping to show the pharyngeal cavity changes during sleep. Results: The smallest XSA of RP region (M w =47.50 mm 2 , M e =73.00 mm 2 , M i =2.00 mm 2 ; Z we =2.897, P we =0.003; Z wi =4.192, P wi ie =4.538, P ie w =8.00 mm, M e =9.50 mm, M i =1.50 mm; Z we =1.933, P we =0.056; Z wi =3.720, P wi ie =4.230, P ie w =8.00 mm, M e =9.00 mm, M i =1.00 mm; Z we =1.210, P we =0.246; Z wi =4.203, P wi ie =4.557, P ie w =4.00 mm 3 , M e =5.50 mm 3 , M i =1.50 mm 3 ; Z we =1.576, P we =0.125; Z wi =3.532, P wi ie =4.077, P ie w =7.00 mm, M e =6.00 mm, M i =10.50 mm; Z we =0.557, P we =0.603; Z wi =2.541, P wi =0.011; Z ie =2.852, P ie =0.004) and RG regions (M w =5.00 mm, M e =3.00 mm, M i =9.50 mm; Z we =0.747, P we =0.482; Z wi =2.657, P wi =0.007; Z ie =3.075, P ie =0.001), were different between inspiration and expiration of sleeping or awake. The dynamic cine CT scan during sleeping could show pharyngeal change, clearly. Conclusion: At the end period of inspiration in sleeping, the location of narrow or obstructive of airway is the most precise and sensitive and the false negative at the waking could be obviously reduced. Low dose MSCT scan reduced exposure and expense. (authors)

  5. Blood flow patterns of solitary pulmonary nodules with enhancement: clinical value of multi-slice spiral CT

    International Nuclear Information System (INIS)

    Li Shenjiang; Xiao Xiangsheng; Liu Shiyuan; Liu Huimin; Li Yuli; Li Huimin; Li Chengzhou; Zhang Chenshi; Tao Zhiwei; Yang Chunshan; Jiang Qingjun; Ouyang Lin; Yu Hong

    2004-01-01

    Objective: To evaluate the efficacy of dynamic multi-slice spiral computed tomography (MSCT) for providing quantitative information about blood flow patterns of solitary pulmonary nodules (SPNs) and the correlation of vascular endothelial growth factor (VEGF)-positive tumor angiogenesis and the quantifiable parameters of blood flow pattern in solitary bronchogenic adenocarcinoma. Methods Seventy-eight patients with SPNs (with strong enhancement) (diameter ≤4 cm; 68 malignant; 10 active inflammatory) underwent multi-location dynamic contrast enhanced (nonionic contrast material was administrated via the antecubital vein at a rate of 4 ml/s by using an autoinjector) serial CT. Precontrast and postcontrast attenuation on every scan was recorded. Perfusion, peak height, and ratio of peak height of the SPN to that of the aorta were calculated. Perfusion was calculated from the maximum gradient of the time-attenuation curve and the peak height of the aorta. The quantifiable parameters (perfusion, peak height, ratio of peak height of the bronchogenic adenocarcinoma to that of the aorta and mean transit time) of blood flow pattern in 30 VEGF-positive solitary bronchogenic adenocarcinoma were compared with microvessel densities (MVD) and VEGF expression by immunohistochemistry. Results: No statistically significant difference in the peak height was found between malignant (35.79 ± 10.76) HU and active inflammatory (39.76 ± 4.59) HU nodules (t=1.148, P=0.255). SPN-to-aorta ratio (14.27 ± 4.37)% and perfusion value (3.02 ± 0.96)ml -1 ·min -1 ·kg -1 in malignant SPNs were significantly lower than those of active inflammatory nodules(18.51 ± 2.71)%, (6.34 ± 4.39)ml -1 ·min -1 ·kg -1 (t=2.978, P=0.004, t=5.590, P -1 ·min -1 ·kg -1 , mean transit time (14.86 ± 5.84) s, and MVD (70.15 ± 20.03). Each of peak height, ratio of peak height of the bronchogenic adenocarcinoma to that of the aorta, and perfusion correlated positively with MVD (r=0.781, P<0.0001; r=0

  6. Study on bone mineral density and bone structure of lumbar vertebrae in osteoporotic elderly women with multi-slice CT

    International Nuclear Information System (INIS)

    Wu Shengyong; Qi Ji; Wang Bin; Wen Lianqing

    2005-01-01

    Objective: To evaluate the ability of volumetric bone mineral density (BMD) parameters of lumbar vertebrae in differentiating osteoporotic fractured from nonfractured elderly women with vQCT technique, and to compare the bony structural conditions of osteoporotic elderly women with healthy elderly women. Methods: Multi-slice CT spinal scans of L1 and L2 were acquired in 26 osteoporotic vertebral fractured elderly women (group one) and 30 nonfractured osteoporotic subjects (group two). All the retro-reconstructed images of L1 and L2 were sent to the workstation and processed by volume rendering (VR) technique to measure volumetric BMD (3D-INTGL, 3D-CORT, 3D-TRAB) and trabecular and integral BMD (2D-TRAB, 2D-INTGL) by conventional QCT technique. BMD indexes in DXA were AP-SPINE and bone mineral apparent density (BMAD) in anteroposterior position. The seven parameters between the two group s were compared. Ten healthy elderly women were selected as normal group to reformate 3D-VR images from MSCT images to analyze the bony structure and calculate the ratio of bone volume to total volume (BV/TV) in the center of L1 vertebrae, and to compare the index between the normal group and tenpatients randomly selected from the 56 osteoporotic women. Results: DXA measurements in group one: AP-SPINE and BMAD were (0.796±0.170)g/cm 2 and (272.7±27.7) mg/cm 3 , respectively, showing no statistically significant differences comparing with (0.817±0.140) g/cm 2 and (249.5 ± 26.5) mg/cm 3 in group two. Volumetric BMD in group one included 2D-TRAB (70.4 ± 22.2) mg/cm 3 , 2D-INTGL (138.3±35.1) mg/cm 3 , 3D-INTGL (139.4±34.9 ) mg/cm 3 , 3D-CORT (133.8±26.9) mg/cm 3 , and 3D-TRAB (69.9 ±18.6) mg/cm 3 , respectively, showing statistically differences with (89.1±21.8) mg/cm 3 , (170.6±34.5) mg/cm 3 , (180.5±28.2) mg/cm 3 , (163.2±27.5) mg/cm 3 , and (83.8 ± 17.1) mg/cm 3 in group two (the decrements 18%-23%). The mean value of BV/TV of L1 vertebrae was (8.12 ± 1.96)% in

  7. TH-CD-207B-06: Swank Factor of Segmented Scintillators in Multi-Slice CT Detectors: Pulse Height Spectra and Light Escape

    Energy Technology Data Exchange (ETDEWEB)

    Howansky, A; Peng, B; Lubinsky, A; Zhao, W [Stony Brook University, Stony Brook, NY (United States)

    2016-06-15

    Purpose: Pulse height spectra (PHS) have been used to determine the Swank factor of a scintillator by measuring fluctuations in its light output per x-ray interaction. The Swank factor and x-ray quantum efficiency of a scintillator define the upper limit to its imaging performance, i.e. DQE(0). The Swank factor below the K-edge is dominated by optical properties, i.e. variations in light escape efficiency from different depths of interaction, denoted e(z). These variations can be optimized to improve tradeoffs in x-ray absorption, light yield, and spatial resolution. This work develops a quantitative model for interpreting measured PHS, and estimating e(z) on an absolute scale. The method is used to investigate segmented ceramic GOS scintillators used in multi-slice CT detectors. Methods: PHS of a ceramic GOS plate (1 mm thickness) and segmented GOS array (1.4 mm thick) were measured at 46 keV. Signal and noise propagation through x-ray conversion gain, light escape, detection by a photomultiplier tube and dynode amplification were modeled using a cascade of stochastic gain stages. PHS were calculated with these expressions and compared to measurements. Light escape parameters were varied until modeled PHS agreed with measurements. The resulting estimates of e(z) were used to calculate PHS without measurement noise to determine the inherent Swank factor. Results: The variation in e(z) was 67.2–89.7% in the plate and 40.2–70.8% in the segmented sample, corresponding to conversion gains of 28.6–38.1 keV{sup −1} and 17.1–30.1 keV{sup −1}, respectively. The inherent Swank factors of the plate and segmented sample were 0.99 and 0.95, respectively. Conclusion: The high light escape efficiency in the ceramic GOS samples yields high Swank factors and DQE(0) in CT applications. The PHS model allows the intrinsic optical properties of scintillators to be deduced from PHS measurements, thus it provides new insights for evaluating the imaging performance of

  8. The measurement of organic radiation dose of multi-slice CT scanning by using the Chinese anthropomorphic chest phantom

    International Nuclear Information System (INIS)

    Peng Gang; Zeng Yongming; Luo Tianyou; Zhao Feng; Zhang Zhiwei; Yu Renqiang; Peng Shengkun

    2011-01-01

    Objective: Using the Chinese anthropomorphic chest phantom to measure the absorbed dose of various tissues and organs under different noise index, and to assess the radiation dose of MSCT chest scanning with the effective dose (ED). Methods: The equivalence of the Chinese anthropomorphic chest phantom (CDP-1 C) and the adult chest on CT sectional anatomy and X-ray attenuation was demonstrated. The absorbed doses of various tissues and organs under different noise index were measured by laying thermoluminescent dosimeters (TLD) inside the phantom, and the corresponding dose-length products (DLP) were recorded. Both of them were later converted into ED and comparison was conducted to analyze the dose levels of chest CT scanning with automatic tube current modulation (ATCM) under different noise index. Student t-test was applied using SPSS 12.0 statistical software. Results: The Phantom was similar to the human body on CT sectional anatomy. The average CT value of phantom are - 788.04 HU in lung, 45.64 HU in heart, 65.84 HU in liver, 254.32 HU in spine and the deviations are 0.10%, 3.04%, 4.49% and 4.36% respectively compared to humans. The difference of average CT value of liver was statistically significant (t=-8.705, P 0.05). As the noise index increased from 8.5 to 22.5, the DLP decreased from 393.57 mGy · cm to 78.75 mGy · cm and the organs dose declined. For example, the average absorbed dose decreased from 22.38 mGy to 3.66 mGy in lung. Compared to ED calculating by absorbed dose, the ED calculating by DLP was lower. The ED values of the two methods were 6.69 mSv and 8.77 mSv when the noise index was set at 8.5. Conclusions: Application of the Chinese anthropomorphic chest phantom to carry out CT dose assessment is more accurate. The noise index should be set more than 8.5 during the chest CT scanning based on ATCM technique. (authors)

  9. Evaluation of experimental cartilage lesions with ultrahigh-resolution multi-slice-CT in comparison to histology

    International Nuclear Information System (INIS)

    Stork, A.; Kemper, J.; Begemann, P. G. C.; Habermann, C.R.; Adam, G.; Priemel, M.; Kummer, T.; Amling, M.

    2004-01-01

    Purpose: histologic validation of ultrahigh-resolution multislice (MS)-CT for the evaluation of focal, experimental cartilage lesions with special regard to the subchondral bone. Testing of micro-CTCT) as alternative reference standard. Methods: 32 experimental cartilage lesions in bovine patellae were imaged surrounded by air (MS-CT-air) and immersed in a contrast material solution (MS-CT-CM) with MS-CT (collimation 2 x 0,5 mm). After the μCT (8 μm-voxelsite) examination in three specimen and histologic work-up of 29 specimen two radiologist graded the defects on MS-CT images in consensus (subchondral bone involvement yes or no) and results were compared to the results of histomorphometry and μCT. Results: the MS-CT-air and -CM had an accuracy of 94% (30/32) and 88% (28/32), respectively. MS-CT-air led to one false-positive (remaining cartilage: = 0,1 mm) and false-negative result, each. MS-CT-CM showed false-positive results if the remaining cartilage was [de

  10. Concept and development of measurement method of time sensitivity profile (TSP) in X-ray CT. Comparison of non-helical, single-slice helical, and multi-slice helical scans

    International Nuclear Information System (INIS)

    Tsujioka, Katsumi; Ida, Yoshihiro; Ohtsubo, Hironori; Takahashi, Yasukata; Niwa, Masayoshi

    2000-01-01

    We focused on the time element contained in a single CT image, and devised the concept of a time-sensitivity profile (TSP) describing how the time element is translated into an image. We calculated the data collection time range when the helical pitch is changed in non helical scans, single slice helical scans, and multi slice helical scans. We then calculated the time sensitivity profile (TSP) from the weighting applied when the data collection time range is translated into an image. TSP was also measured for each scanning method using our self-made moving phantom. TSPs obtained from the calculation and the experiments were very close. TSP showed interesting characteristics with each scanning method, especially in the case of multi slice helical scanning, in which TSP became shorter as helical pitch increased. We referred to the TSP's FWHM as the effective scanning time. When we conducted multi slice helical scanning at helical pitch 3, the effective scanning time increased to about 24% longer than that of a non helical scan. When we conducted multi slice helical scanning at helical pitch 5 or 6, the effective scanning time was about half that of a non helical scan. The time sensitivity profile (TSP) is a totally new concept that we consider an important element in discussing the time resolution of a CT scanner. The results of this review will provide significant data in determining the scanning parameters when scanning a moving object. (author)

  11. 3D visualisation of the middle ear and adjacent structures using reconstructed multi-slice CT datasets, correlating 3D images and virtual endoscopy to the 2D cross-sectional images

    International Nuclear Information System (INIS)

    Rodt, T.; Ratiu, P.; Kacher, D.F.; Anderson, M.; Jolesz, F.A.; Kikinis, R.; Becker, H.; Bartling, S.

    2002-01-01

    The 3D imaging of the middle ear facilitates better understanding of the patient's anatomy. Cross-sectional slices, however, often allow a more accurate evaluation of anatomical structures, as some detail may be lost through post-processing. In order to demonstrate the advantages of combining both approaches, we performed computed tomography (CT) imaging in two normal and 15 different pathological cases, and the 3D models were correlated to the cross-sectional CT slices. Reconstructed CT datasets were acquired by multi-slice CT. Post-processing was performed using the in-house software ''3D Slicer'', applying thresholding and manual segmentation. 3D models of the individual anatomical structures were generated and displayed in different colours. The display of relevant anatomical and pathological structures was evaluated in the greyscale 2D slices, 3D images, and the 2D slices showing the segmented 2D anatomy in different colours for each structure. Correlating 2D slices to the 3D models and virtual endoscopy helps to combine the advantages of each method. As generating 3D models can be extremely time-consuming, this approach can be a clinically applicable way of gaining a 3D understanding of the patient's anatomy by using models as a reference. Furthermore, it can help radiologists and otolaryngologists evaluating the 2D slices by adding the correct 3D information that would otherwise have to be mentally integrated. The method can be applied to radiological diagnosis, surgical planning, and especially, to teaching. (orig.)

  12. Detection and classification of focal liver lesions in patients with colorectal cancer: Retrospective comparison of diffusion-weighted MR imaging and multi-slice CT

    International Nuclear Information System (INIS)

    Eiber, Matthias; Fingerle, Alexander A.; Brügel, Melanie; Gaa, Jochen; Rummeny, Ernst J.; Holzapfel, Konstantin

    2012-01-01

    Objectives: To compare the diagnostic performance of diffusion-weighted MR imaging (DWI) with multi-slice CT (MS-CT) in the detection and classification of focal liver lesions in patients with colorectal cancer. Methods: In a retrospective study 68 patients who underwent DWI at 1.5 T (b-values of 50, 300 and 600 s/mm 2 ) and contrast-enhanced MS-CT were analysed by two radiologists blinded to the clinical results. Imaging results were correlated with intraoperative surgical and ultrasound findings (n = 24), imaging follow-up or PET (n = 44). Sensitivity of DWI and MS-CT in detection of focal liver lesions was compared on a per-lesion and a per-segment basis. Receiver operator-characteristic (ROC) curves to determine the diagnostic performance and the sensitivities of correctly identifying liver metastases on a segmental base were calculated. Results: For lesion detection, DWI was significantly superior to MS-CT both on a per-lesion (difference in sensitivities for reader 1 and 2 22.65% and 19.06%, p < 0.0001) and a per-segment basis (16.86% and 11.76%, p < 0.0001). Especially lesions smaller than 10 mm were better detected with DWI compared to MS-CT (difference 41.10% and 29.45%, p < 0.0001). ROC-analysis showed superiority for lesions classification (p < 0.0001) of DWI (AUC: 0.949 and 0.951) as compared to MS-CT (AUC: 0.879 and 0.892, p < 0.0001 and p = 0.005). DWI was able to filter out metastatic segments with a higher sensitivity (88.2 and 86.5%) compared to MS-CT (68.0 and 67.4%, p < 0.0001 and p = 0.005, respectively). Conclusion: Compared to MS-CT DWI is both more sensitive in the detection of liver lesions and more accurate in determining the extent of metastatic disease in patients with colorectal cancer and therefore might help to optimize therapeutic management in those patients.

  13. A comparative evaluation of Cone Beam Computed Tomography (CBCT) and Multi-Slice CT (MSCT). Part II: On 3D model accuracy

    International Nuclear Information System (INIS)

    Liang Xin; Lambrichts, Ivo; Sun Yi; Denis, Kathleen; Hassan, Bassam; Li Limin; Pauwels, Ruben; Jacobs, Reinhilde

    2010-01-01

    Aim: The study aim was to compare the geometric accuracy of three-dimensional (3D) surface model reconstructions between five Cone Beam Computed Tomography (CBCT) scanners and one Multi-Slice CT (MSCT) system. Materials and methods: A dry human mandible was scanned with five CBCT systems (NewTom 3G, Accuitomo 3D, i-CAT, Galileos, Scanora 3D) and one MSCT scanner (Somatom Sensation 16). A 3D surface bone model was created from the six systems. The reference (gold standard) 3D model was obtained with a high resolution laser surface scanner. The 3D models from the five systems were compared with the gold standard using a point-based rigid registration algorithm. Results: The mean deviation from the gold standard for MSCT was 0.137 mm and for CBCT were 0.282, 0.225, 0.165, 0.386 and 0.206 mm for the i-CAT, Accuitomo, NewTom, Scanora and Galileos, respectively. Conclusion: The results show that the accuracy of CBCT 3D surface model reconstructions is somewhat lower but acceptable comparing to MSCT from the gold standard.

  14. The multi-slice CT perfusion imaging in evaluating the prevention and treatment by edaravone on lung ischemia-reperfusion injury after pulmonary thromboembolism

    Energy Technology Data Exchange (ETDEWEB)

    Jianjun, Li; Renyou, Zhai; Dongpo, Zhang; Qiang, Huang; Dingke, Dai; Ping, Yu; Na, Bao [Department of Radiology, Beijing Chaoyang Hospital, Capital Medical Univ., Beijing (China)

    2008-10-15

    Objective: To evaluate the multi-slice CT perfusion imaging in investigating whether edaravone can prevent and treat pulmonary thromboembolism ischemia-reperfusion injury (PTE-IRI). Methods: Twenty mongrel canines were included. A Swan-Ganz catheter was introduced into the right internal jugular vein using the Seldinger technique, and then was inserted into the pulmonary artery. Balloon occlusion of the right inferior lobe pulmonary artery for 4 h was followed by removing catheter and 4 h o reperfusion. Animals were divided into four groups of A (no edaravone during ischenmia and reperfusion), B (edaravone used only during ischemia), C (edaravone used during both ischemia and reperfusion) and D group (edaravone used only during reperfusion) (n=5 per group). Every group was divided into three time points including before ischemia, 4 h after ischemia and 4 h after reperfusion. CT scan and CT perfusion were performed at the three time points. The blood flow (BF), blood volume (BV) and mean transit time (MTT) of the bilateral inferior regional lung parenchyma were measured with the software of perfusion 3. Results: CT examination showed pulmonary edema in the right inferior lung lobe at 4 h after reperfusion. (1) The BF and MTT of A, B, C and D group were[(259.4{+-}15.7)ml{center_dot}min{sup -1{center_dot}}100 g{sup -1}, (293.7{+-} 7.9) ml{center_dot}min{sup -1{center_dot}}100 g {sup -1}, (379.4{+-}14.5)ml{center_dot}min{sup -1{center_dot}}100 g{sup -1}, (382.5{+-}16.6)ml{center_dot}min{sup -1{center_dot}}. 100 g{sup -1}] and [(3.1{+-}0.2)s, (2.6{+-}0.2)s, (2.2{+-}0.1)s, (1.9{+-}0.2)s] respectively at 4 h after reperfusion. The BF and MTT were statistically different (P<0.01) between groups (A and B, A and C, A and D, B and C, B and D) except between group C and D (the P value >0.05) at 4 h after reperfusion, but the BV was not statistically different between groups (P>0.05). (2) The BF [(397.2{+-} 19.2)ml{center_dot}min{sup -1{center_dot}}100 g{sup -1} and (259

  15. The multi-slice CT perfusion imaging in evaluating the prevention and treatment by edaravone on lung ischemia-reperfusion injury after pulmonary thromboembolism

    International Nuclear Information System (INIS)

    Li Jianjun; Zhai Renyou; Zhang Dongpo; Huang Qiang; Dai Dingke; Yu Ping; Bao Na

    2008-01-01

    Objective: To evaluate the multi-slice CT perfusion imaging in investigating whether edaravone can prevent and treat pulmonary thromboembolism ischemia-reperfusion injury (PTE-IRI). Methods: Twenty mongrel canines were included. A Swan-Ganz catheter was introduced into the right internal jugular vein using the Seldinger technique, and then was inserted into the pulmonary artery. Balloon occlusion of the right inferior lobe pulmonary artery for 4 h was followed by removing catheter and 4 h o reperfusion. Animals were divided into four groups of A (no edaravone during ischenmia and reperfusion), B (edaravone used only during ischemia), C (edaravone used during both ischemia and reperfusion) and D group (edaravone used only during reperfusion) (n=5 per group). Every group was divided into three time points including before ischemia, 4 h after ischemia and 4 h after reperfusion. CT scan and CT perfusion were performed at the three time points. The blood flow (BF), blood volume (BV) and mean transit time (MTT) of the bilateral inferior regional lung parenchyma were measured with the software of perfusion 3. Results: CT examination showed pulmonary edema in the right inferior lung lobe at 4 h after reperfusion. (1) The BF and MTT of A, B, C and D group were[(259.4±15.7)ml·min -1 ·100 g -1 , (293.7± 7.9) ml·min -1 ·100 g -1 , (379.4±14.5)ml·min -1 ·100 g -1 , (382.5±16.6)ml·min -1 ·. 100 g -1 ] and [(3.1±0.2)s, (2.6±0.2)s, (2.2±0.1)s, (1.9±0.2)s] respectively at 4 h after reperfusion. The BF and MTT were statistically different (P 0.05) at 4 h after reperfusion, but the BV was not statistically different between groups (P>0.05). (2) The BF [(397.2± 19.2)ml·min -1 ·100 g -1 and (259.4±15.7) ml·min -1 ·100 g -1 in group A, (393.2±16.1) ml· min -1 ·100 g -1 and (293.7±7.9) ml·min -1 ·100 g -1 in group B] and MTF [(1.8±0.1)s and (3.1±0.2) s in group A, (1.8±0.2) s and (2.6±0.2) s in group B] were statistically different (P 0.05) between groups

  16. Multi-slice spiral CT of the coronary arteries: improved vessel presentation by means of a standard software

    International Nuclear Information System (INIS)

    Schmitt, R.; Froehner, S.; Coblenz, G.; Christopoulos, G.; Brunn, J.; Mueller, M.; Kerber, S.; Fellner, F.

    2001-01-01

    Material and methods: Image data of 151 patients suffering from coronary artery disease were calculated by means of retrospective triggering at four different diastolic delay times in contrast-enhanced CT. The large coronary segments were subsequently reconstructed in two planes with multiplanar volume reconstruction (MPVR). Results: On the pre-condition that data sets were acquired at sinus rhythm and at a heart beat rate lower than 65/min coronary arteries could be depicted over a long distance in single or double angulated reconstruction planes with the help of MPVR. Time consumption for image reconstruction was reasonable. Additionally to the anatomy of the coronary arteries in two different planes, typical CT findings in occluding coronary artery disease are presented. (orig.) [de

  17. Generalized multi-dimensional adaptive filtering for conventional and spiral single-slice, multi-slice, and cone-beam CT

    International Nuclear Information System (INIS)

    Kachelriess, Marc; Watzke, Oliver; Kalender, Willi A.

    2001-01-01

    In modern computed tomography (CT) there is a strong desire to reduce patient dose and/or to improve image quality by increasing spatial resolution and decreasing image noise. These are conflicting demands since increasing resolution at a constant noise level or decreasing noise at a constant resolution level implies a higher demand on x-ray power and an increase of patient dose. X-ray tube power is limited due to technical reasons. We therefore developed a generalized multi-dimensional adaptive filtering approach that applies nonlinear filters in up to three dimensions in the raw data domain. This new method differs from approaches in the literature since our nonlinear filters are applied not only in the detector row direction but also in the view and in the z-direction. This true three-dimensional filtering improves the quantum statistics of a measured projection value proportional to the third power of the filter size. Resolution tradeoffs are shared among these three dimensions and thus are considerably smaller as compared to one-dimensional smoothing approaches. Patient data of spiral and sequential single- and multi-slice CT scans as well as simulated spiral cone-beam data were processed to evaluate these new approaches. Image quality was assessed by evaluation of difference images, by measuring the image noise and the noise reduction, and by calculating the image resolution using point spread functions. The use of generalized adaptive filters helps to reduce image noise or, alternatively, patient dose. Image noise structures, typically along the direction of the highest attenuation, are effectively reduced. Noise reduction values of typically 30%-60% can be achieved in noncylindrical body regions like the shoulder. The loss in image resolution remains below 5% for all cases. In addition, the new method has a great potential to reduce metal artifacts, e.g., in the hip region

  18. Multi-slice spiral CT multiplanar reconstruction findings of localized fat collection adjection to the subdiaphragmatic inferior vena cava

    International Nuclear Information System (INIS)

    Cao Hetao; Lu Jian; Zhao Jinli; Liu Tingting; Qin Jufeng; Xu Wen; Qin Jiangchun; Jiang Junkang

    2012-01-01

    Objective: To discusses the MSCT multiplanar reconstruction manifestation (MPR) of localized fat collection adjection to subdiaphragmatic inferior vena cava (IVC fat ). Methods: The thoracic and abdominal MSCT scan data of 8246 patients were browsed,45 patients with presumed IVC fat on axial CT scans were further studied prospectively with MSCT MPR. The predisposing position of IVC fat and its relationship with IVC were observed. It was divided into two kinds of intraluminal type and extraluminal type according to the angle of IVC fat with respect of the wall of IVC.The other 50 patients without IVC fat were randomly selected as the control group. The sagittal inclination angle (SIA) and diameter ratio (DR) between supra- and sub-diaphragmatic IVC between the two groups were compared by using t test. Results: The detection rate was 0.55% (45/8246). Of which hepatic vein lacuna 8 patients, subdiaphragmatic gap medial to IVC 28 patients and IVC groove 9 patients. The shape of IVC fat showed mainly for the round, oval and crescents on axial CT scans, of 15 patients intraluminal type, 4 showed 'target signs'. The shape of IVC fat showed mainly for 'half-moon' at MPR.The SIA and DR at IVC fat group were 21.62° ± 8.42° and 2.01 ±0.84 respectively, at control group were 16.75° ±7.82° (t=1.594, P>0.05) and 1.31 ±0.28 (t=2.341, P<0.05) respectively. Conclusion: The round, oval or half of limited fat density shadow adjection to subdiaphragmatic inferior vena cava which similar to in the lumen is the characteristic performance of IVC fat , it may be an anatomical variation. (authors)

  19. The value of multi-slice spiral CT liver perfusion imaging to evaluate the chronic hepatic fibrosis and cirrhosis

    International Nuclear Information System (INIS)

    Long Liling; Huang Zhongkui; Ding Ke; Liao Jinyuan; Jiang Jianning

    2012-01-01

    Objective: To investigate the value of the MSCT liver perfusion imaging parameters in the evaluation of the chronic hepatic fibrosis and cirrhosis. Methods: Liver CT perfusion (CTP) was performed in 107 participants,including 31 patients with mild hepatic fibrosis (S1, S2), 34 patients with severe hepatic fibrosis (S3, S4) and early stage of hepatic cirrhosis which conformed by liver pathologic biopsy, 42 patients with hepatic cirrhosis who had typical clinical and image signs, and 30 healthy subjects as control group. The data of CTP (HAP, PVP, LTP, HPI and TTP) at different stages were obtained with Body perfect CT-syngo CT2007A and control study with histopathologic stage. Compared the study index by the one-way ANOVA analysis. Used Spearman rank correlation to analysis the relationship between liver perfusion imaging parameters and the degrees of the chronic hepatic fibrosis. Used Logistic regression to analysis the maximum regression coefficient among the liver perfusion imaging parameters, which affected the histopathologic stage mostly. Results: In the subgroups of the chronic hepatic fibrosis S1, S2, S3, S4 to the hepatic cirrhosis,HAP values was (28.9 ±8.6), (24.6 ±2.4), (29.2 ±2.3) and (38.9 ± 7.0) ml · 100 ml -1 · min -1 , respectively. HAP decreased firstly,then increased. Statistic analysis showed the difference of HAP between later-stage cirrhosis and other groups (F=40.26, P<0.01). PVP values of above subgroups was (111.3 ± 18.1), (92.9 ±5.3), (73.0 ±9.0) and (54.1 ± 13.8) ml · 100 ml -1 ·min -1 , respectively. TLP values of above subgroups was (140.2 ± 25.9), (117.1 ± 4.5), (102.3 ± 8.7)and (93.0 ± 11.8) ml · 100 ml -1 ·min -1 , respectively. The difference of PVP, TLP among each subgroup was significant (F=136.79, 67.40, respectively, P<0.01). HPI values of above subgroups was (20.4 ± 2.6)%, (21.0 ±2.1)%, (28.5 ±3.1)% and (42.6± 11.1)%, respectively. TTP values of above subgroups was (123.7±22.2), (137.1 ±27.1), (145.0 ±28

  20. Type 2 Endoleaks: The Diagnostic Performance of Non-Specialized Readers on Arterial and Venous Phase Multi-Slice CT Angiography.

    Directory of Open Access Journals (Sweden)

    Richard Nolz

    Full Text Available To define the diagnostic precision of non-specialized readers in the detection of type 2 endoleaks (T2EL in arterial versus venous phase acquisitions, and to evaluate an approach for radiation dose reduction.The pre-discharge and final follow-up multi-slice CT angiographies of 167 patients were retrospectively analyzed. Image data were separated into an arterial and a venous phase reading set. Two radiology residents assessed the reading sets for the presence of a T2EL, feeding vessels, and aneurysm sac size. Findings were compared with a standard of reference established by two experts in interventional radiology. The effective dose was calculated.Overall, experts detected 131 T2ELs, and 331 feeding vessels in 334 examinations. Persistent T2ELs causing aneurysm sac growth > 5 mm were detected in 20 patients. Radiation in arterial and venous phases contributed to a mean of 58.6% and 39.0% of the total effective dose. Findings of reader 1 and 2 showed comparable sensitivities in arterial sets of 80.9 versus 85.5 (p = 0.09, and in venous sets of 73.3 versus 79.4 (p = 0.15, respectively. Reader 1 and 2 achieved a significant higher detection rate of feeding vessels with arterial compared to venous set (p = 0.04, p < 0.01. Both readers correctly identified T2ELs with growing aneurysm sac in all cases, independent of the acquisition phase.Arterial acquisitions enable non-specialized readers an accurate detection of T2ELs, and a significant better identification of feeding vessels. Based on our results, it seems reasonable to eliminate venous phase acquisitions.

  1. Comparison of multi-slice CT (MSCT) and TI-201 myocardial SPECT in detection of coronary artery disease: relation to coronary arteriography

    Energy Technology Data Exchange (ETDEWEB)

    Pai, M. S.; Kim, Y. K.; Shim, S. S. [College of Medicine, Univ. of Ewha Womens, Seoul (Korea, Republic of)

    2003-07-01

    To evaluate the diagnostic potentials of MSCT and TI-201 SPECT in the assessment of coronary artery disease. Twenty-four patients (15 men, 9 women, 42-79 years) with clinically suspected coronary artery disease were studied by TI-201 myocardial SPECT and MSCT. MSCT data were obtained with 12 x 0.75 mm, 420ms rotation, multi-slice CT scanner (SOMATOM Sensation, Siemens) using non-ionic contrast, 80ml, 4ml/sec. Multiplanar reconstruction techniques were used for evaluation of coronary arteries. TI-201 myocardial SPECT were performed at stress with adenosine and at rest. Data from MSCT and TI-201 SPECT were compared territory by territory (divided into two segments; LAD and RCA/LCx) and related to coronary arteriography, in which more than 60% stenoses are regarded as significant. MSCT and TI-201 SPECT showed agreement in 37 out of 48 segments (77.1%). Out of 11 disagreed segments (22.9), TI-201 SPECT was superior in 6 segments and MSCT was superior in 5 segments. Sensitivities and specificities of MSCT and TI-201 SPECT by coronary arteriography are 81.8%, 69.2% and 86.3%, 76.9%, respectively. Agreed 4 segments between MSCT and TI-201 SPECT exhibited results that differ from the results of coronary arteriography. Myocardial bridge in two cases were detected as significant stenoses by MSCT but showed normal perfusion in TI-201 SPECT. Agreement between MSCT and TI-201 SPECT in the assessment of coronary artery disease was good but TI-201 SPECT has higher sensitivity and specificity for the detection of jeopardized myocardium than MSCT. MSCT and TI-201 SPECT provide complementary information in the assessment of coronary artery disease and could help reduce probable mistake in the interpretation of hemo dynamically insignificant lesion in coronary arteriography.

  2. PET/CT和MSCT联合应用在孤立性肺结节诊断中的价值%PET-CT with multi-slice spiral CT in the diagnosis of SPN

    Institute of Scientific and Technical Information of China (English)

    汪世存; 方雷; 潘博; 展凤麟; 谢强; 谢吉奎

    2009-01-01

    目的 探讨18F-脱氧葡萄糖正电子发射显像/电子计算机断层扫描成像(18F-deoxyglucose positron emission tomography /computer tomography 18F-FDG PET/CT)和多排CT( multi-slice spiral CT,MSCT)联合应用在孤立性肺结节(SPN)诊断中的价值.方法 87例SPN患者均行PET/CT及肺部病灶MSCT检查,影像诊断结果 与病理对照,进行统计分析.结果 87例SPN中,MSCT诊断正确64例,误诊23例,误诊率26.4%.PET/CT诊断正确70例,误诊17例,误诊率19.5%.MSCT和PET/CT联合诊断,80例诊断正确,7例误诊,误诊率8.0%.MSCT、PET/CT及两者联合诊断的敏感性、特异性和准确性分别为87.2%、68.1%、79.8%;89.5%、61.3%、81.4%和97.7%、74.2%、91.5%.MSCT和PET/CT单独诊断SPN的准确性无统计学意义(χ2=0.625,P=0.239),MSCT、PET/CT与两者联合应用诊断SPN的准确性均有统计学意义(χ2=7.762和5.318,P=0.005和0.021).结论 SPN的MSCT和PET/CT影像特征均有一定的重叠.单独采用MSCT或PET/CT诊断肺结节无明显统计学差异,MSCT和PET-CT协同诊断的准确性高于MSCT或PET/CT单独诊断.%Aim To evaluate the value of a combination of 18F-FDG PET-CT with multi-slice spiral CT in the diagnosis of SPN.Methods 18F-FDG PET-CT and multi-slice spiral CT were performed in 87 patients with SPN.The pathologically-proved findings were compared with findings diagnosed by MSCT and retrospectively analyzed.Results In 87 cases,the numbers of correct diagnosis and misdiagnosis with MSCT were 64 and 23 respectively,the misdiagnosis rate 26.4%,while the numbers of correct diagnosis and misdiagnosis with PET/CT were 70 and 17,the misdiagnosis rate 19.5%,but 50 cases were correctly diagnosed and 7 cases were misdiagnosed by combining 18F-FDG PET-CT with MSCT,the misdiagnosis rate 8.0%.The sensitivity,specificity,positive predictive value,negative predictive value,and accuracy of MSCT,PET/CT,and MSCT combined with PET /CT were 87.2%,68.1%,79.8%;89.5%,61.3%,81.4% and 97

  3. Dose reduction in multi-slice CT of the heart by use of ECG-controlled tube current modulation (''ECG pulsing''): phantom measurements

    International Nuclear Information System (INIS)

    Poll, L.W.; Cohnen, M.; Brachten, S.; Moedder, U.; Ewen, K.

    2002-01-01

    To evaluate the effect of ECG-controlled tube current modulation on radiation exposure in retrospectively-ECG-gated multislice CT (MSCT) of the heart. Material and methods: Three different cardiac MSCT protocols with different slice collimation (4 x 1, and 4 x 2.5 mm), and a pitch-factor of 1.5 and 1.8 were investigated at a multi-slice CT scanner Somatom Volume Zoom, Siemens. An anthropomorphic Alderson-Rando phantom was equipped with LiF-Thermoluminescence dosimeters at several organ sites, and effective doses were calculated using ICRP-weighting factors. Scan protocols were performed with ECG-controlled tube current modulation ('ECG pulsing') at two different heart rates (60 and 80 bpm). These data were compared to previous data from MSCT of the heart without use of 'ECG pulsing'. Results: Radiation exposure with (60 bpm) and without tube current modulation using a 2.5 mm collimation was 1.8 mSv and 2.9 mSv for females, and 1.5 mSv and 2.4 mSv for males, respectively. For protocols using a 1 mm collimation with a pitch-factor of 1.5 (1.8), radiation exposure with and without tube current modulation was 5.6 (6.3) mSv and 9.5 (11.2) mSv for females, and 4.6 (5.2) mSv and 7.7 (9.2) mSv for males, respectively. At higher heart rates (80 bpm) radiation exposure is increased from 1.5-1.8 mSv to 1.8-2.1 mSv, using the 2.5 mm collimation, and from 4.6-5.6 mSv to 5.9-7.2 mSv, for protocols using 1 mm collimation. Conclusions: The ECG-controlled tube current modulation allows a dose reduction of 37% to 44% when retrospectively ECG-gated MSCT of the heart is performed. The tube current - as a function over time - and therefore the radiation exposure is dependent on the heart rate. (orig.) [de

  4. Comparative analysis of multi-slice spiral CT and positron emission tomography-CT in evaluation of axillary lymph nodes in breast cancer patients

    International Nuclear Information System (INIS)

    Sun Xianchang; Zhang Ruyi; Liu Qingwei; Zhao Suhong; Zu Degui; Li Xin

    2008-01-01

    Objective: To evaluate and compare spiral CT and positron emission tomography-CT (PET-CT) in characterization of of axillary lymph nodes in breast cancer patients. Methods: Forty patients with pathologically proven breast cancer underwent contrast-enhanced spiral CT of the breast and axilla, 13 of them also underwent PET-CT examination. One hundred and fifty-eight axillary lymph nodes were found in the 40 patients through contrast enhanced spiral CT, while 57 lymph nodes were found in the 13 patients through PET-CT. Three radiologists rated the lymph nodes found in CT images on a five-point scale. If the score was equal to or greater than 3, it was defined as positive (metastatic), otherwise negative. Visual observation and semiquantitative analysis were used to classify lymph nodes in PET-CT images. The results of spiral CT observation and PET-CT observation of lymph nodes were compared with pathological results. The relative value of CT and PET-CT was analyzed. Exact probability statistics were employed. Results: One hundred and fifty eight lymph nodes of 40 patients were detected by spiral CT, 91 of them were diagnosed as positive and 67 as negative Among the lymph nodes found in spiral CT, 99 were positive and 59 were negative pathologicall. A total of 57 lymph nodes were found by PET-CT. Thirty-nine of them were defined as positive and 18 as negative. Among the lymph nodes found in PET-CT, 39 were positive and 18 were negative pathologically. The sensitivity, specificity, accuracy, positive and negative predictive values in CT prediction in axillary lymph nodes metastases were 88.89%, 94.91%, 91.14%, 96.70%, and 83.58%, respectively. The sensitivity, specificity, accuracy, positive and negative predictive values in PET-CT prediction in axillary lymph nodes metastases were 97.44%, 94.44%, 96.49%, 97.44%, and 94.44%, respectively. PET-CT had no significant difference with spiral CT in sensitivity, accuracy, positive and negative predictive values for detection

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

    Directory of Open Access Journals (Sweden)

    Ai-Jun Wu

    2016-12-01

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

  6. Clinical application of Half Fourier Acquisition Single Shot Turbo Spin Echo (HASTE) imaging accelerated by simultaneous multi-slice acquisition.

    Science.gov (United States)

    Schulz, Jenni; P Marques, José; Ter Telgte, Annemieke; van Dorst, Anouk; de Leeuw, Frank-Erik; Meijer, Frederick J A; Norris, David G

    2018-01-01

    As a single-shot sequence with a long train of refocusing pulses, Half-Fourier Acquisition Single-Shot Turbo-Spin-Echo (HASTE) suffers from high power deposition limiting use at high resolutions and high field strengths, particularly if combined with acceleration techniques such as simultaneous multi-slice (SMS) imaging. Using a combination of multiband (MB)-excitation and PINS-refocusing pulses will effectively accelerate the acquisition time while staying within the SAR limitations. In particular, uncooperative and young patients will profit from the speed of the MB-PINS HASTE sequence, as clinical diagnosis can be possible without sedation. Materials and MethodsMB-excitation and PINS-refocusing pulses were incorporated into a HASTE-sequence with blipped CAIPIRINHA and TRAPS including an internal FLASH reference scan for online reconstruction. Whole brain MB-PINS HASTE data were acquired on a Siemens 3T-Prisma system from 10 individuals and compared to a clinical HASTE protocol. ResultsThe proposed MB-PINS HASTE protocol accelerates the acquisition by about a factor 2 compared to the clinical HASTE. The diagnostic image quality proved to be comparable for both sequences for the evaluation of the overall aspect of the brain, the detection of white matter changes and areas of tissue loss, and for the evaluation of the CSF spaces although artifacts were more frequently encountered with MB-PINS HASTE. ConclusionsMB-PINS HASTE enables acquisition of slice accelerated highly T2-weighted images and provides good diagnostic image quality while reducing acquisition time. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Conventional multi-slice computed tomography (CT) and cone-beam CT (CBCT) for computer-assisted implant placement. Part I: relationship of radiographic gray density and implant stability.

    Science.gov (United States)

    Arisan, Volkan; Karabuda, Zihni Cüneyt; Avsever, Hakan; Özdemir, Tayfun

    2013-12-01

    The relationship of conventional multi-slice computed tomography (CT)- and cone beam CT (CBCT)-based gray density values and the primary stability parameters of implants that were placed by stereolithographic surgical guides were analyzed in this study. Eighteen edentulous jaws were randomly scanned by a CT (CT group) or a CBCT scanner (CBCT group) and radiographic gray density was measured from the planned implants. A total of 108 implants were placed, and primary stability parameters were measured by insertion torque value (ITV) and resonance frequency analysis (RFA). Radiographic and subjective bone quality classification (BQC) was also classified. Results were analyzed by correlation tests and multiple regressions (p < .05). CBCT-based gray density values (765 ± 97.32 voxel value) outside the implants were significantly higher than those of CT-based values (668.4 ± 110 Hounsfield unit, p < .001). Significant relations were found among the gray density values outside the implants, ITV (adjusted r(2)  = 0.6142, p = .001 and adjusted r(2)  = 0.5166, p = .0021), and RFA (adjusted r(2)  = 0.5642, p = .0017 and adjusted r(2)  = 0.5423, p = .0031 for CT and CBCT groups, respectively). Data from radiographic and subjective BQC were also in agreement. Similar to the gray density values of CT, that of CBCT could also be predictive for the subjective BQC and primary implant stability. Results should be confirmed on different CBCT scanners. © 2012 Wiley Periodicals, Inc.

  8. TU-EF-204-11: Impact of Using Multi-Slice Training Sets On the Performance of a Channelized Hotelling Observer in a Low-Contrast Detection Task in CT

    Energy Technology Data Exchange (ETDEWEB)

    Favazza, C; Yu, L; Leng, S; McCollough, C [Mayo Clinic, Rochester, MN (United States)

    2015-06-15

    Purpose: To investigate using multiple CT image slices from a single acquisition as independent training images for a channelized Hotelling observer (CHO) model to reduce the number of repeated scans for CHO-based CT image quality assessment. Methods: We applied a previously validated CHO model to detect low contrast disk objects formed from cross-sectional images of three epoxy-resin-based rods (diameters: 3, 5, and 9 mm; length: ∼5cm). The rods were submerged in a 35x 25 cm2 iodine-doped water filled phantom, yielding-15 HU object contrast. The phantom was scanned 100 times with and without the rods present. Scan and reconstruction parameters include: 5 mm slice thickness at 0.5 mm intervals, 120 kV, 480 Quality Reference mAs, and a 128-slice scanner. The CHO’s detectability index was evaluated as a function of factors related to incorporating multi-slice image data: object misalignment along the z-axis, inter-slice pixel correlation, and number of unique slice locations. In each case, the CHO training set was fixed to 100 images. Results: Artificially shifting the object’s center position by as much as 3 pixels in any direction relative to the Gabor channel filters had insignificant impact on object detectability. An inter-slice pixel correlation of >∼0.2 yielded positive bias in the model’s performance. Incorporating multi-slice image data yielded slight negative bias in detectability with increasing number of slices, likely due to physical variations in the objects. However, inclusion of image data from up to 5 slice locations yielded detectability indices within measurement error of the single slice value. Conclusion: For the investigated model and task, incorporating image data from 5 different slice locations of at least 5 mm intervals into the CHO model yielded detectability indices within measurement error of the single slice value. Consequently, this methodology would Result in a 5-fold reduction in number of image acquisitions. This project

  9. TU-EF-204-11: Impact of Using Multi-Slice Training Sets On the Performance of a Channelized Hotelling Observer in a Low-Contrast Detection Task in CT

    International Nuclear Information System (INIS)

    Favazza, C; Yu, L; Leng, S; McCollough, C

    2015-01-01

    Purpose: To investigate using multiple CT image slices from a single acquisition as independent training images for a channelized Hotelling observer (CHO) model to reduce the number of repeated scans for CHO-based CT image quality assessment. Methods: We applied a previously validated CHO model to detect low contrast disk objects formed from cross-sectional images of three epoxy-resin-based rods (diameters: 3, 5, and 9 mm; length: ∼5cm). The rods were submerged in a 35x 25 cm2 iodine-doped water filled phantom, yielding-15 HU object contrast. The phantom was scanned 100 times with and without the rods present. Scan and reconstruction parameters include: 5 mm slice thickness at 0.5 mm intervals, 120 kV, 480 Quality Reference mAs, and a 128-slice scanner. The CHO’s detectability index was evaluated as a function of factors related to incorporating multi-slice image data: object misalignment along the z-axis, inter-slice pixel correlation, and number of unique slice locations. In each case, the CHO training set was fixed to 100 images. Results: Artificially shifting the object’s center position by as much as 3 pixels in any direction relative to the Gabor channel filters had insignificant impact on object detectability. An inter-slice pixel correlation of >∼0.2 yielded positive bias in the model’s performance. Incorporating multi-slice image data yielded slight negative bias in detectability with increasing number of slices, likely due to physical variations in the objects. However, inclusion of image data from up to 5 slice locations yielded detectability indices within measurement error of the single slice value. Conclusion: For the investigated model and task, incorporating image data from 5 different slice locations of at least 5 mm intervals into the CHO model yielded detectability indices within measurement error of the single slice value. Consequently, this methodology would Result in a 5-fold reduction in number of image acquisitions. This project

  10. Measurement of modulation transfer function in z-axis for multi-slice spiral CT using the micro-disk method. Comparison with the bead method and examination of geometric influence

    International Nuclear Information System (INIS)

    Hara, Takanori

    2003-01-01

    Many methods of measuring the section-sensitive profile (SSP) of computed tomography (CT) by the input of a delta function have been reported. In Japan, the bead method is used as a common measurement because of the high flexibility of the multi-purpose method. However, the intensity of the response of the bead method tends to decline, creating a relatively large error in the base of SSPs. A problem is considered to be the accuracy of measurement in evaluating spatial resolution along the z-axis in multi-slice spiral/helical CT (MSCT). We therefore evaluated the modulation transfer function (MTF) by conducting research with the micro-disk method (100 μm thickness and 1.0 mmφ diameter) and the bead method (1.0 mmφ diameter) for the same input width. Moreover, in the micro-disk method, we also examined alignment, circular region of interest (ROI), and the energy characteristic. Our comparison of MTFs obtained by the micro-disk method and the bead method showed that the former resulted in a higher value and lower standard deviation. The difference was significant at p<0.01. Measurement using the micro-disk method did not show significant differences in terms of alignment and ROIs. Moreover, the energy characteristic was not indicated. This research demonstrated that the accuracy of MTF measurement with the micro-disk method was greater than that with the bead method, and it was found that there was no influence on the actual measurement level of the geometric structure with the micro-disk method. (author)

  11. Creation of individual ideally shaped stents using multi-slice CT: in vitro results from the semi-automatic virtual stent (SAVS) designer

    International Nuclear Information System (INIS)

    Hyodoh, Hideki; Katagiri, Yoshimi; Hyodoh, Kazusa; Akiba, Hidenari; Hareyama, Masato; Sakai, Toyohiko

    2005-01-01

    To plan stent-grafting for thoracic aortic aneurysm with complicated morphology, we created a virtual stent-grafting program [Semi Automatic Virtual Stent (SAVS) designer] using three-dimensional CT data. The usefulness of the SAVS designer was evaluated by measurement of transformed anatomical and straight stents. Curved model images (source, multi-planer reconstruction and volume rendering) were created, and a hollow virtual stent was produced by the SAVS designer. A straight Nitinol stent was transformed to match the curved configuration of the virtual stent. The accuracy of the anatomical stent was evaluated by experimental strain phantom studies in comparison with the straight stent. Mean separation length was 0 mm in the anatomical stent [22 mm outer diameter (OD)] and 5 mm in the straight stent (22 mm OD). The straight stent strain voltage was four times that of the anatomical stent at the stent end. The anatomical stent is useful because it fits the curved structure of the aorta and reduces the strain force compared to the straight stent. The SAVS designer can help to design and produce the anatomical stent. (orig.)

  12. Multi-slice CT (MSCT) in cardiac function imaging: threshold-value-supported 3D volume reconstructions to determine the left ventricular ejection fraction in comparison to MRI

    International Nuclear Information System (INIS)

    Ehrhard, K.; Oberholzer, K.; Gast, K.; Mildenberger, P.; Kreitner, K.F.; Thelen, M.

    2002-01-01

    Purpose: To assess MSCT of the heart to determining left ventricular ejection fraction (EF) based on threshold-value-supported 3D volume reconstructions compared to MRI. Methods: Cardiac MSCT was performed in 7 patients. Images were reconstructed during end-systolic and end-diastolic phases of the cardiac cycle and transformed to 3D volumes to determine end-systolic (ESV) and end-diastolic volume (EDV) by using different lower threshold values: besides fixed lower threshold values, identical for each image sequence, individual lower threshold values dependent on contrast enhancement of the left ventricle were applied. The latter represent the mean value calculated by combining the average CT-density of the myocardium and the contrast-enhanced blood in the left ventricle. The EF derived from ESV and EDV. Results: The best correlation with MR imaging was obtained for ESV and EDV by using the individual lower threshold values for the respective sequence. The correlation coefficient for ESV was 0.95 and for EDV it was 0.93. On average, the ESV was overestimated by 3.72 ml, while the ESD was underestimated by 2.85 ml. The respective standard deviation for the ESV was 14,87 ml, for the EDV it was 26.83 ml. On average, the EF was underestimated by 3.57% with a standard deviation of 9.43% and a correlation coefficient of 0.83 in comparison to MRI. Conclusion: The threshold-value-supported 3D volume reconstruction of the left ventricle represents a good method to determine the left ventricular function parameters. Due to the differences in the contrast enhancement, the use of an individual lower threshold value for every image sequence is of particular importance. (orig.) [de

  13. Evaluation of the upper airway measurements by multi-slice CT before and after operations in obstructive sleep apnoea syndrome patients

    International Nuclear Information System (INIS)

    Tao Ping; Dang Yuqing; Chang Bei; Wang Xiao; Jin Zhengyu; Li Wuyi; Huo Hong

    2009-01-01

    Objective: To evaluate the changes of the upper airway of the patients with obstructive sleep apnoea syndrome (OSAS) before and after operations and to know the effects of operations by MSCT. Methods: The upper airway dimensions of 26 patients with OSAS were measured on multiplanar reformatted (MPR), curved-planar reformatted (CPR), volume rendering (VR) images of 16-slice spiral CT. The measurements include the anteroposterior calibres and the areas on the reformatted axial images on the pharyngeal cavity levels, the calibres and the minimum areas in retropalatal and retroglossal regions, the areas of the soft palate and uvula on the reformatted sagittal view with maximum thickness, the maximum wall thickness of the right and left the upper airway on the coronary images, the volume of the upper airway before and after the operations. The measurements were correlated with the polysomnography (PSG) records. The data were analyzed paired-samples t-test and Pearson correlations. Results: By comparison, the anteroposterior calibres and the cross-sectional areas on the reformatted axial view of the lower retropalatal region (slice 4) of the upper airway increased significantly after operations. The anteroposterior diameter increased from 5.9 mm before operations to 12.8 mm after operations, where t=-5.506, P 2 before operations to 275.0 mm 2 after operations, where t=-5.011, P 2 before operations to 128.0 mm 2 after operations, where t=3.087, P 2 before operation to 10.9 mm, 76.0 mm 2 after operation, where t=-3.413, -2.216, respectively and P 2 before operations to 76.0 mm 2 after operations, were t=-4.932, P<0.05. The anteroposterior calibres increased from 4.6 mm before operations to 6.6 mm after operations, where t=-7.308, P<0.05. The L-R calibres increased from 8.3 mm before operations to 13.6 mm after operations, where t=-4.320, P<0.05. Conclusions: MPR, CPR, VR of MSCT can evaluate the not only the morphology but the function changes of the upper airways on the

  14. Analysis on the value of the multi-slice spiral CT and MRI scanning for applying to the identifying diagnosis of the new and old vertebral compresion fracture

    International Nuclear Information System (INIS)

    Huo Zhiyi; Gao Shuming; Li Dasheng; Pei Lijun; Qu Hui

    2008-01-01

    Objective: To analyze and explore the value of the mutislice spiral CT (MSCT) scanning, its reconstructive technology and MRI scanning for applying to the identifying diagnosis of new and old vertebral compresion fracture. Methods: One hundred and sixty-seven cases with the new and old vertebral compresion fracture who have 189 vertebrae in total were examined using the MSCT scanning, their imaging information were postprocessed with 2D and 3D reconstruction at the work station. Thirty-four patients with overall 43 vertebrae were carried out by MRI scanning and their images were compared with those of MSCT. Results: They had the highest proportion of vertebrae in L1 with accounting for 27.68% (31/112) and 35.06% (27/77) among the patients with new and old vertebral compresion fracture, respectively. The next was T12, L2 and T11. There were statistically significant differences between new and old cases in such appearance as fracture line clear and sharp (102 and 21), contusion and hemorrhage of spinal cord (15 and 0), parenchyma shadow beside vertebrae(103 and 11), appendant fracture(26 and 5), organ's lacerated wound around vertebral body (30 and 0), discus intervertebrales vacuum (10 and 36), derangement and hardening of vertebral bone trabecularism (29 and 51) (P 1 WI signal, 27 vertebrae with the T 2 WI fat-suppresion irregular high signal were demonstrated in MRI scanning among 27 vertebrae of 21 cases with new vertebral compresion fracture. While 16 vertebrae with the T 1 WI and T 2 WI signals were the same as those of the normal vertebrae, 16 vertebrae were the T 2 WI fat-suppresion low signal among 13 cases with old vertebral compresion fracture. Conclusions: The MSCT plays an important role in identifying diagnosis for the most of the patients with the new and old vertebral compresion fracture, while MRI scanning may reflect the pathophysiological characteristics in diagnosis of the spinal cord and the ligament lesion. Therefore, the MSCT and MRI scanning

  15. Multi-slice Computed Tomography Appearance of Abscess of Cavum Septum Pellucidum: A Case Report and Review of the Literature

    Energy Technology Data Exchange (ETDEWEB)

    Vasudev, M.K.; Chavan, R.G.; Nagarajan, K.; Shukla, D.; Devi, B.I. [National Inst. of Mental Health and Neurosciences, Bangalore (India). Depts. of Neuroimaging and Interventional Radiology and of Neurosurgery

    2006-04-15

    Abscesses involving the cavum septum pellucidum are rare and, owing to their location, detection may be difficult with routine conventional computed tomography (CT). Only a few isolated cases have been reported and mostly in children. We report a case of abscess involving the cavum septum pellucidum in an adult and its appearance on multi-slice spiral CT Abscess, cavum septum pellucidum, multi-slice CT, surgery.

  16. Dose reduction in coronary artery imaging with 64-row multi-slice helical CT with body mass index-dependent mA selection

    International Nuclear Information System (INIS)

    Gao Jianhua; Wang Guisheng; Zheng Jingchen; Li Jianying; Sun Xianchang; Gao Caihong; Dai Ruping

    2008-01-01

    Objective: To evaluate the robustness of body mass index (BMI) adapted tube current selection method for obtaining consistent image quality in MSCT coronary artery imaging. Methods: Initially one hundred patients in the control group (C group) underwent cardiac scans using GE 64-row VCT with standard scan protocol (640 mA, 120 kV, 0.35 sec, body bowtie, C 2 filter). Noise measurement was obtained for each patient using the average of three consecutive slices in the ascending aorta with ROI of 10 mm x 10 mm to establish the relationship between BMI, desired image noise (IN) and required mA. An excel table was established to predict the required mA to achieve a desired IN for each patient with different BMI. A second group of one hundred cardiac patients (L group) was scanned with BMI-adapted mA from the table to evaluate the practicability of this method. BMI, IN, CT dose index (CTDI), effective dose (ED) were all recorded. Results: For the control group of 100 patients, the mean values and standard deviations of image quality score (IQS), BMI, IN and ED were 3.71±0.54, 25.08±2.63, 24.56±5.03 and (17.63±1.68) mSv (with range of 15-22 mSv). Regression analysis indicated linear relationship between BMI and image noise with fixed mA. Using the relationship between tube current and image noise and noise ratio between large bowtie and cardiac bowtie, the following equation for the required tube current Xma to achieve present image noise of INa for patient with certain BMI value when using cardiac bowtie could be then obtained: Xma=Fma x [(k 1 x BMI + c 1 )/Ina] 2 , where Fma=640 mA, k 1 =1.033, c 1 = -3.2, INa=27 in the study. (2) For the patients in L group, the mean values and standard deviations of IQS, BMI, and IN were 3.69±0.53, 25.07±2.91, and 26.61±3.44, respectively. The average tube current used was (469.95±113.45) mA, depending on patient's BMI values. The average effectively dose was (9.08±2.25) mSv. There was no statistically difference between the

  17. High-resolution multi-slice PET

    International Nuclear Information System (INIS)

    Yasillo, N.J.; Chintu Chen; Ordonez, C.E.; Kapp, O.H.; Sosnowski, J.; Beck, R.N.

    1992-01-01

    This report evaluates the progress to test the feasibility and to initiate the design of a high resolution multi-slice PET system. The following specific areas were evaluated: detector development and testing; electronics configuration and design; mechanical design; and system simulation. The design and construction of a multiple-slice, high-resolution positron tomograph will provide substantial improvements in the accuracy and reproducibility of measurements of the distribution of activity concentrations in the brain. The range of functional brain research and our understanding of local brain function will be greatly extended when the development of this instrumentation is completed

  18. Association between the mean CT value on a scout view and the dependent mA selection method in coronary artery imaging on 64-row multi-slice spiral CT

    International Nuclear Information System (INIS)

    Gao Jianhua; Li Tao; Mi Fengtang; Li Na; Cui Ying; Dai Ruping; Li Jianying

    2009-01-01

    Objective: To characterize the association between the mean CT value on a scout view and the dependent mA selection method, and to evaluate the clinical value of a mA selection method based on scout view mean CT value in obtaining individualized scan protocol and consistent image quality for patient population on 64-row MSCT CT coronary angiography (CTCA). Methods: One hundred patients (group A) underwent CTCA consecutively using standard protocol with a fixed mA. The mean CT value of a fixed ROI (region of interest) from the scout AP view and the CTCA image noise (standard deviation on the root of ascending aorta) were measured. The correlation between CT values and noise was studied to establish a formula and a list to determine the required mA for obtaining a consistent CTCA image noise based on the measured SV CT value. Another 100 patients (group B) were scanned using the same parameters as group A except the mA and the CT value was also measured. The mA was determined by the list established previously. The CTCA image quality (IQ) as well as the image noise (IN) and the effective dose (ED) from the two groups were statistically analyzed using t-test. The CT findings for the 32 patients in the group B were also compared with the selective coronary angiography (SCA) results. The sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of CTCA for detection of significant stenosis were obtained. Results: The formula between the required mA and the CT value was: XmA=FmA x [(K 1 x CTscout + C 1 )/INa] 2 . The CTCA images in B group had statistically higher IN (27.66±2.57, 22.22±4.17, t=11.33, P=0.000), but no statistical difference between IQ scores for the two groups (3.29±0.66, 3.37±0.67, t=0.009, P=0.990), and ED [(8.72±2.51) versus (12.53±0.90) mSv] was 30% lower for the B group (P<0.01). For the 32 patients in the B group who had SCA, the CTCA sensitivity, specificity, positive predictive value, negative

  19. Multi-slice computed tomography assessment of bronchial compression with absent pulmonary valve

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Yu-Min; Sun, Ai-Min; Wang, Qian; Zhu, Ming; Qiu, Hai-Sheng [Shanghai Children' s Medical Center and Shanghai Jiao Tong University Medical School, Department of Radiology, Shanghai (China); Jaffe, Richard B. [Primary Children' s Medical Center, Department of Medical Imaging, Salt Lake City, UT (United States); Liu, Jin-Fen [Shanghai Children' s Medical Center, Department of Cardiothoracic Surgery, Shanghai (China); Gao, Wei [Shanghai Children' s Medical Center and Shanghai Jiao Tong University Medical School, Department of Cardiology, Shanghai (China); Berdon, Walter E. [Children' s Hospital of New York, Department of Radiology, New York, NY (United States)

    2014-07-15

    Absent pulmonary valve is a rare cardiovascular anomaly that can result in profound tracheobronchial compression. To demonstrate the advantage of multi-slice CT in diagnosing tracheobronchial compression, its severity as related to the adjacent dilated pulmonary arteries, and associated lung and cardiac lesions. We included children with absent pulmonary valve who were reviewed by multi-slice CT during a 17-year period. The number and locations of stenoses and lung lesions were noted and the severity of stenosis was categorized. The diameter of the pulmonary artery was measured and associated cardiac defects were demonstrated. Thirty-one children (14 girls and 17 boys) were included. Of these, 29 had ventricular septal defect and 2 had an intact ventricular septum. Twenty-nine children (94%) had tracheobronchial compression, judged to be mild in nine children (31%), moderate in 10 (34%) and severe in 10 (34%). The different locations of the stenosis (carina, main bronchi, lobar and segmental bronchi) were observed. And the number and location of lung lesions demonstrated that the right middle and left upper and lower lobes were often affected. The diameter of the pulmonary artery in these children was well above normal published values, and Spearman rank correlation analysis showed a correlation between the size of the pulmonary artery and the severity of the tracheobronchial stenosis. Nineteen children (61%) underwent surgery and 4 of these children had a multi-slice CT post-operative follow-up study. Absent pulmonary valve can cause significant morbidity and mortality in children. Multi-slice CT can accurately depict areas of tracheobronchial compression, associated lung lesions and cardiac defects, helping to direct the surgeon. (orig.)

  20. Application of CT three-dimensional reconstruction in elbow injury

    International Nuclear Information System (INIS)

    Liang Wenhua; Qian Li

    2009-01-01

    Objective: To investigate the application of multi-slice spiral CT in fracture of elbow, and to study the value of different methods of the reconstruction. Methods: Thin line cross-section spiral CT scan was carried out in 13 cases with elbow injury, three-dimensional reconstruction was completed later. Several reconstructed image quality to display f the elbow fracture and dislocation were analyzed and compared. Results: 13 cases (17) elbow trauma included humeral media epicondyle fracture, humeral external epicondyle fracture, intercondylar fracture, olecranal fracture and radial head fracture. Among them, X-ray film showed negative in three sites, showed suspect fractures in 2 cases, and only showed single fracture in 2 cases. MPR reconstruction image could not only identify the diagnosis of fracture, but also provide further multi-angle display on fracture line and the extent of articular surface involvement. Surface reconstruction technology could exclude the impact of passive elbow flexion and display elbow injury more intuitively. Conclusion The elbow fracture dislocation could be showed clearly in multi-slice spiral CT, especially for complex fractures, with unmatched advantages compared to X-ray for clinical diagnosis and treatment determination. (authors)

  1. Visualisation of animal anatomy using MRI and CT

    DEFF Research Database (Denmark)

    Lauridsen, Henrik; Hansen, Kasper; Pedersen, Michael

    imaging (MRI) and CT. Various species (tarantula, horseshoe crab, carp, haddock, lungfish, axolotl) were subjected to multi-slice MRI and CT protocols to produce 2D images of body slices, followed by volume rendering producing 3D digital models of animal anatomy with applications for visualising specific...

  2. On the way to isotopic spatial resolution: technical principles and applications of 16-slice CT

    International Nuclear Information System (INIS)

    Flohr, T.; Ohnesorge, B.; Stierstorfer, K.

    2005-01-01

    The broad introduction of multi-slice CT by all major vendors in 1998 was a milestone with regard to extended volume coverage, improved axial resolution and better utilization of the tube output. New clinical applications such as CT-examinations of the heart and the coronary arteries became possible. Despite all promising advances, some limitations remain for 4-slice CT systems. They come close to isotropic resolution, but do not fully reach it in routine clinical applications. Cardiac CT-examinations require careful patient selection. The new generation of multi-slice CT-systems offer simultaneous acquisition of up to 16 sub-millimeter slices and improved temporal resolution for cardiac examinations by means of reduced gantry rotation time (0.4 s). In this overview article we present the basic technical principles and potential applications of 16-slice technology for the example of a 16-slice CT-system (SOMATOM Sensation 16, Siemens AG, Forchheim). We discuss detector design and dose efficiency as well as spiral scan- and reconstruction techniques. At comparable slice thickness, 16-slice CT-systems have a better dose efficiency than 4-slice CT-systems. The cone-beam geometry of the measurement rays requires new reconstruction approaches, an example is the adaptive multiple plane reconstruction, AMPR. First clinical experience indicates that sub-millimeter slice width in combination with reduced gantry rotation-time improves the clinical stability of cardiac examinations and expands the spectrum of patients accessible to cardiac CT. 16-slice CT-systems have the potential to cover even large scan ranges with sub-millimeter slices at considerably reduced examination times, thus approaching the goal of routine isotropic imaging [de

  3. Multi-slice computed tomography-assisted endoscopic transsphenoidal surgery for pituitary macroadenoma: a comparison with conventional microscopic transsphenoidal surgery.

    Science.gov (United States)

    Tosaka, Masahiko; Nagaki, Tomohito; Honda, Fumiaki; Takahashi, Katsumasa; Yoshimoto, Yuhei

    2015-11-01

    Intraoperative computed tomography (iCT) is a reliable method for the detection of residual tumour, but previous single-slice low-resolution computed tomography (CT) without coronal or sagittal reconstructions was not of adequate quality for clinical use. The present study evaluated the results of multi-slice iCT-assisted endoscopic transsphenoidal surgery for pituitary macroadenoma. This retrospective study included 30 consecutive patients with newly diagnosed or recurrent pituitary macroadenoma with supradiaphragmatic extension who underwent endoscopic transsphenoidal surgery using iCT (eTSS+iCT group), and control 30 consecutive patients who underwent conventional endoscope-assisted transsphenoidal surgery (cTSS group). The tumour volume was calculated by multiplying the tumour area by the slice thickness. Visual acuity and visual field were estimated by the visual impairment score (VIS). The resection extent, (preoperative tumour volume - postoperative residual tumour volume)/preoperative tumour volume, was 98.9% (median) in the eTSS+iCT group and 91.7% in the cTSS group, and had significant difference between the groups (P = 0.04). Greater than 95 and >90% removal rates were significantly higher in the eTSS+iCT group than in the cTSS group (P = 0.02 and P = 0.001, respectively). However, improvement in VIS showed no significant difference between the groups. The rate of complications also showed no significant difference. Multi-slice iCT-assisted endoscopic transsphenoidal surgery may improve the resection extent of pituitary macroadenoma. Multi-slice iCT may have advantages over intraoperative magnetic resonance imaging in less expensive, short acquisition time, and that special protection against magnetic fields is not needed.

  4. Multi-slice spiral CT diagnosis of arterial sequestration

    International Nuclear Information System (INIS)

    Yu Hong; Li Huimin; Liu Shiyuan; Xiao Xiangsheng

    2010-01-01

    Objective: The purpose of this study was to present the characteristic features on MSCT angiography of arterial sequestration. Methods: The MSCT images of 5 patients with arterial sequestration were retrospectively reviewed. All patients underwent MSCT contrast-enhanced angiography. 3D rendering was made to evaluate the lung parenchyma, bronchial system, and vascular anatomy. Results: All 5 cases demonstrated the anomalous systemic artery (ASA) as an isolated and tortuous artery arising from the descending thoracic aorta, taking a sigmoid course and running along with airway, entering the basal segments of the left lowed lobe. The inferior pulmonary vein (IPV) was significantly engorged. The typical AS was diagnosed in 4 patients. Its ASA intercrossed with the IPV and two branches entering segments 7 and 8 over the IPV, and two branches entering segments 9 and 10 under the IPV. The volume of involved lung shrunk with the artery markedly engorged. A characteristic avascular section was found between the pulmonary artery supplying area and the ASA supplying area, and the bronchi did not accompany the arteries. One was diagnosed atypical AS because of coexistence with bronchial atresia. Conclusion: The arterial sequestration had characteristic MSCT findings. The typical type can be definitely diagnosed, but the atypical type needs further three-dimensional analysis. (authors)

  5. Establishment of multi-slice computed tomography (MSCT) reference level in Johor, Malaysia

    Science.gov (United States)

    Karim, M. K. A.; Hashim, S.; Bakar, K. A.; Muhammad, H.; Sabarudin, A.; Ang, W. C.; Bahruddin, N. A.

    2016-03-01

    Radiation doses from computed tomography (CT) are the highest and most hazardous compared to other imaging modalities. This study aimed to evaluate radiation dose in Johor, Malaysia to patients during computed tomography examinations of the brain, chest and abdomen and to establish the local diagnostic reference levels (DRLs) as are present with the current, state- of-art, multi-slice CT scanners. Survey forms were sent to five centres performing CT to obtain data regarding acquisition parameters as well as the dose information from CT consoles. CT- EXPO (Version 2.3.1, Germany) was used to validate the dose information. The proposed DRLs were indicated by rounding the third quartiles of whole dose distributions where mean values of CTDIw (mGy), CTDIvol (mGy) and DLP (mGy.cm) were comparable with other reference levels; 63, 63, and 1015 respectively for CT Brain; 15, 14, and 450 respectively for CT thorax and 16, 17, and 590 respectively for CT abdomen. The study revealed that the CT practice and dose output were revolutionised, and must keep up with the pace of introductory technology. We suggest that CTDIvol should be included in current national DRLs, as modern CTs are configured with a higher number of detectors and are independent of pitch factors.

  6. Establishment of multi-slice computed tomography (MSCT) reference level in Johor, Malaysia

    International Nuclear Information System (INIS)

    Karim, M K A; Hashim, S; Ang, W C; Bahruddin, N A; Bakar, K A; Muhammad, H; Sabarudin, A

    2016-01-01

    Radiation doses from computed tomography (CT) are the highest and most hazardous compared to other imaging modalities. This study aimed to evaluate radiation dose in Johor, Malaysia to patients during computed tomography examinations of the brain, chest and abdomen and to establish the local diagnostic reference levels (DRLs) as are present with the current, state- of-art, multi-slice CT scanners. Survey forms were sent to five centres performing CT to obtain data regarding acquisition parameters as well as the dose information from CT consoles. CT- EXPO (Version 2.3.1, Germany) was used to validate the dose information. The proposed DRLs were indicated by rounding the third quartiles of whole dose distributions where mean values of CTDI w (mGy), CTDI vol (mGy) and DLP (mGy.cm) were comparable with other reference levels; 63, 63, and 1015 respectively for CT Brain; 15, 14, and 450 respectively for CT thorax and 16, 17, and 590 respectively for CT abdomen. The study revealed that the CT practice and dose output were revolutionised, and must keep up with the pace of introductory technology. We suggest that CTDI vol should be included in current national DRLs, as modern CTs are configured with a higher number of detectors and are independent of pitch factors. (paper)

  7. Simultaneous multi-slice echo planar diffusion weighted imaging of the liver and the pancreas: Optimization of signal-to-noise ratio and acquisition time and application to intravoxel incoherent motion analysis

    Energy Technology Data Exchange (ETDEWEB)

    Boss, Andreas, E-mail: andreas.boss@usz.ch [Institute of Diagnostic and Interventional Radiology, University Hospital Zurich (Switzerland); Barth, Borna; Filli, Lukas; Kenkel, David; Wurnig, Moritz C. [Institute of Diagnostic and Interventional Radiology, University Hospital Zurich (Switzerland); Piccirelli, Marco [Institute of Neuroradiology, University Hospital of Zurich (Switzerland); Reiner, Caecilia S. [Institute of Diagnostic and Interventional Radiology, University Hospital Zurich (Switzerland)

    2016-11-15

    Purpose: To optimize and test a diffusion-weighted imaging (DWI) echo-planar imaging (EPI) sequence with simultaneous multi-slice (SMS) excitation in the liver and pancreas regarding acquisition time (TA), number of slices, signal-to-noise ratio (SNR), image quality (IQ), apparent diffusion coefficient (ADC) quantitation accuracy, and feasibility of intravoxel incoherent motion (IVIM) analysis. Materials and methods: Ten healthy volunteers underwent DWI of the upper abdomen at 3T. A SMS DWI sequence with CAIPIRINHA unaliasing technique (acceleration factors 2/3, denoted AF2/3) was compared to standard DWI-EPI (AF1). Four schemes were evaluated: (i) reducing TA, (ii) keeping TA identical with increasing number of averages, (iii) increasing number of slices with identical TA (iv) increasing number of b-values for IVIM. Acquisition schemes i-iii were evaluated qualitatively (reader score) and quantitatively (ADC values, SNR). Results: In scheme (i) no differences in SNR were observed (p = 0.321 − 0.038) with reduced TA (AF2 increase in SNR/time 75.6%, AF3 increase SNR/time 102.4%). No SNR improvement was obtained in scheme (ii). Increased SNR/time could be invested in acquisition of more and thinner slices or higher number of b-values. Image quality scores were stable for AF2 but decreased for AF3. Only for AF3, liver ADC values were systematically lower. Conclusion: SMS-DWI of the liver and pancreas provides substantially higher SNR/time, which either may be used for shorter scan time, higher slice resolution or IVIM measurements.

  8. Simultaneous multi-slice echo planar diffusion weighted imaging of the liver and the pancreas: Optimization of signal-to-noise ratio and acquisition time and application to intravoxel incoherent motion analysis

    International Nuclear Information System (INIS)

    Boss, Andreas; Barth, Borna; Filli, Lukas; Kenkel, David; Wurnig, Moritz C.; Piccirelli, Marco; Reiner, Caecilia S.

    2016-01-01

    Purpose: To optimize and test a diffusion-weighted imaging (DWI) echo-planar imaging (EPI) sequence with simultaneous multi-slice (SMS) excitation in the liver and pancreas regarding acquisition time (TA), number of slices, signal-to-noise ratio (SNR), image quality (IQ), apparent diffusion coefficient (ADC) quantitation accuracy, and feasibility of intravoxel incoherent motion (IVIM) analysis. Materials and methods: Ten healthy volunteers underwent DWI of the upper abdomen at 3T. A SMS DWI sequence with CAIPIRINHA unaliasing technique (acceleration factors 2/3, denoted AF2/3) was compared to standard DWI-EPI (AF1). Four schemes were evaluated: (i) reducing TA, (ii) keeping TA identical with increasing number of averages, (iii) increasing number of slices with identical TA (iv) increasing number of b-values for IVIM. Acquisition schemes i-iii were evaluated qualitatively (reader score) and quantitatively (ADC values, SNR). Results: In scheme (i) no differences in SNR were observed (p = 0.321 − 0.038) with reduced TA (AF2 increase in SNR/time 75.6%, AF3 increase SNR/time 102.4%). No SNR improvement was obtained in scheme (ii). Increased SNR/time could be invested in acquisition of more and thinner slices or higher number of b-values. Image quality scores were stable for AF2 but decreased for AF3. Only for AF3, liver ADC values were systematically lower. Conclusion: SMS-DWI of the liver and pancreas provides substantially higher SNR/time, which either may be used for shorter scan time, higher slice resolution or IVIM measurements.

  9. Clinical application of multi-detector CT-guided percutaneous coaxial biopsy for pulmonary lesions

    International Nuclear Information System (INIS)

    Jia Ningyang; Liu Shiyuan; Zhang Dianbo; Xiao Xiangsheng; Li Wentao; Li Chenzhou

    2008-01-01

    Objective: To evaluate the clinical application of multi-slice CT-guided percutaneous transthoracic lung coaxial-biopsy for pulmonary lesions. Methods: 152 times of 143 patients were performed with percutaneous transthoracic coaxial biopsy under multiple-slice CT-guidance. Analysis was carried out to investigate the diagnostic accuracy and the relationship between the size of the lesions for coaxial biopsy, together with the complications. Results: The diagnostic accuracy was 94.9% with specificity of 100%, including malignant tumors 116 cases (squamous cell cancer 48 cases, adenocarcinoma 34, small cell undifferentiated carcinoma 6, large cell carcinoma 4, bronchial alveolar carcinoma 8, metastatic carcinoma 16) and 19 cases of benign ones(TB 7 cases, inflammatory pseudotumor 9, hematoma 1, lung abscess 1). The size of lesion had a significant influence on the diagnostic accuracy. Conclusions: Percutaneous transthoracic coaxial lung biopsy is a safety method, possessing a high diagnostic accuracy. (authors)

  10. Clinical Applications of FDG PET and PET/CT in Head and Neck Cancer

    Directory of Open Access Journals (Sweden)

    Akram Al-Ibraheem

    2009-01-01

    Full Text Available 18F-FDG PET plays an increasing role in diagnosis and management planning of head and neck cancer. Hybrid PET/CT has promoted the field of molecular imaging in head and neck cancer. This modality is particular relevant in the head and neck region, given the complex anatomy and variable physiologic FDG uptake patterns. The vast majority of 18F-FDG PET and PET/CT applications in head and neck cancer related to head and neck squamous cell carcinoma. Clinical applications of 18F-FDG PET and PET/CT in head and neck cancer include diagnosis of distant metastases, identification of synchronous 2nd primaries, detection of carcinoma of unknown primary and detection of residual or recurrent disease. Emerging applications are precise delineation of the tumor volume for radiation treatment planning, monitoring treatment, and providing prognostic information. The clinical role of 18F-FDG PET/CT in N0 disease is limited which is in line with findings of other imaging modalities. MRI is usually used for T staging with an intense discussion concerning the preferable imaging modality for regional lymph node staging as PET/CT, MRI, and multi-slice spiral CT are all improving rapidly. Is this review, we summarize recent literature on 18F-FDG PET and PET/CT imaging of head and neck cancer.

  11. CT technology update

    International Nuclear Information System (INIS)

    Edyvean, S.

    2004-01-01

    Full text: The capabilities of CT scanning as a diagnostic imaging medium increased dramatically with the introduction of four slice scanners in the second half of 1998. The ability to acquire four sets of scan projection data per revolution of the scanner gantry can be exploited by imaging a scan volume faster, or with greater z-axis resolution than a single slice scanner, or scanning larger volumes in the same total time. This has improved the quality of a number of clinical applications, as well as enabling new techniques that were not previously possible. This workshop will review the advances in CT scanning that have lead to modern multi-slice scanning. The operation of scanners will be explored looking at the hardware required and the changes in reconstruction techniques necessary with the higher number of imaged slices. The advantages and disadvantages of multi-slice scanners over their single-slice equivalents will be investigated, and image quality and dose issues will be discussed. An overview of the clinical applications that benefit from multi-slice technology will be given. The talk will end with a glimpse into the future where we have 64 and 256 slice, as well as flat panel, systems currently being trialled. Copyright (2004) Australasian College of Physical Scientists and Engineers in Medicine

  12. Ground-glass opacity: High-resolution computed tomography and 64-multi-slice computed tomography findings comparison

    International Nuclear Information System (INIS)

    Sergiacomi, Gianluigi; Ciccio, Carmelo; Boi, Luca; Velari, Luca; Crusco, Sonia; Orlacchio, Antonio; Simonetti, Giovanni

    2010-01-01

    Objective: Comparative evaluation of ground-glass opacity using conventional high-resolution computed tomography technique and volumetric computed tomography by 64-row multi-slice scanner, verifying advantage of volumetric acquisition and post-processing technique allowed by 64-row CT scanner. Methods: Thirty-four patients, in which was assessed ground-glass opacity pattern by previous high-resolution computed tomography during a clinical-radiological follow-up for their lung disease, were studied by means of 64-row multi-slice computed tomography. Comparative evaluation of image quality was done by both CT modalities. Results: It was reported good inter-observer agreement (k value 0.78-0.90) in detection of ground-glass opacity with high-resolution computed tomography technique and volumetric Computed Tomography acquisition with moderate increasing of intra-observer agreement (k value 0.46) using volumetric computed tomography than high-resolution computed tomography. Conclusions: In our experience, volumetric computed tomography with 64-row scanner shows good accuracy in detection of ground-glass opacity, providing a better spatial and temporal resolution and advanced post-processing technique than high-resolution computed tomography.

  13. Multi-slice computed tomography urography after diuretic injection in children with urinary tract dilatation

    Energy Technology Data Exchange (ETDEWEB)

    Kosucu, P.; Ahmetoglu, A.; Imamoglu, M.; Cay, A.; Ozdemir, O.; Dinc, H.; Kosucu, M.; Sari, A.; Saruhan, H.; Gumele, H.R. [Farabi Hospital, Trabzon (Turkey). Dept. of Radiology

    2004-02-01

    To evaluate the potential use of multi-slice computed tomography urography (MSCTU) after diuretic injection in children with urinary tract dilatation. MSCTU was performed in 19 patients (11 boys, 8 girls, mean age 5.4 years) with suspicion of urinary tract obstruction and dilatation. Furosemide, 1 mg/kg, was injected 3 min before contrast material administration and followed by a bolus of 30 ml of physiologic saline solution immediately after application of contrast material. Excretory-phase images were obtained through the abdomen and pelvis beginning 10 min after initiation of the injection of contrast material. Maximum intensity projection (MIP) and volume rendering (VR) images were post-processed to obtain urographic views. MSCTU revealed pathology in 16 of 19 patients, while 3 patients had normal findings. Ureteropelvic obstruction was found in 4 patients, obstructive megaureter in 8. Both ureteropelvic obstruction and obstructive megaureter were disclosed in 1 patient, partial ureteral duplication in 1 patient, and both complete ureteral duplication and ureterocele in 2 patients. In all patients, MIP and VR images could satisfactorily show the pathologies of the urinary tract. The estimated effective average doses of MSCTU were higher than IVU. Preliminary results of furosemide-enhanced MSCTU demonstrated consistently dilated urinary tracts, obstruction levels, and underlying pathologies better than US and IVU.

  14. [Diagnostic significance of multi-slice computed tomography imaging in congenital inner ear malformations].

    Science.gov (United States)

    Ma, Hui; Han, Ping; Liang, Bo; Liu, Fang; Tian, Zhi-Liang; Lei, Zi-Qiao; Li, You-Lin; Kong, Wei-Jia

    2005-04-01

    To evaluate the feasibility and usability of multi-slice computed tomography (MSCT) in congenital inner ear malformations. Fourty-four patients with sensorineural hearing loss (SNHL) were examined by a Somatom Sensation 16 (siemens, Germany) CT scanner with following parameters: 120 kV, 100 mAs, 0.75 mm collimation, 1 mm reconstruction increment, a pitch factor of 1 and a field of view of 100 mm. The axial images of interested ears were reconstructed with 0.1 mm reconstruction increment, and a field of view of 50 mm. The 3D reconstructions were done with volume rendering technique (VRT) on the workstation (3D Virtuoso and Wizard,siemens). Twenty-five patients were normal and 19 patients (36 ears) were congenital inner ear malformations among 44 patients scanned with MSCT. Of the malformations, all the axial, MPR and VRT images can display the site and degree in 33 ears. VRT images were superior to the axial images in displaying the malformations in 3 ears with the small lateral semicircular canal malformations. The malformations were Michel deformity (1 ear), common cavity deformity (3 ears), incomplete partition I (3 ears), incomplete partition II (Mondini deformity, 5 ears), vestibular and semicircular canal malformations( 14 ears), vestibular aqueduct dilate( 16 ears, of which 6 ears accompanied by other malformations), the internal auditory canal malformation(8 ears, all accompanied by other malformations). MSCT allows a comprehensively assessing various congenital ear malformations through high quality MPR and VRT reconstructions. VRT images can display the site and degree of the malformations three-dimensionally and intuitionisticly. It is very useful to the cochlear implantation.

  15. Preliminary feasibility assessment on the investigation of bronchogenic adenocarcinoma angiogenesis with dynamic multi-slice spiral computed tomography

    International Nuclear Information System (INIS)

    Li Shenjiang; Xiao Xiangsheng; Li Huimin; Liu Shiyuan; Li Chengzhou; Zhang Chenshi; Tao Zhiwei

    2003-01-01

    Objective: To evaluate the feasibility on the investigation of bronchogenic adenocarcinoma angiogenesis with dynamic multi-slice spiral computed tomography (MSCT) . Methods: 27 patients with bronchogenic adenocarcinomas (diameter ≤4 cm) underwent multi-location dynamic contrast material-enhanced (90 ml, 4 ml/s) serial CT. These dynamic images were processed with the 'time lapse' software and the 'functional CT' software. Peak heights of bronchogenic adenocarcinoma and the aorta, perfusion and mean transit time (MTT) were measured. Ratio of peak height of the bronchogenic adenocarcinoma to that of the aorta was calculated. Perfusion and mean transit time images were obtained. Results: Peak height of bronchogenic adenocarcinoma was (36.66 ± 13.53) HU. No statistically significant difference in the peak height was found between our results and the results of Ukihide et al (mean peak height 34.1 HU) (t =0.981, P = 0.335). Bronchogenic adenocarcinoma-to-aorta ratio was (15.72±4.66 )%. The difference in bronchogenic adenocarcinoma -to-aorta ratio between our results and the results of Zhang and Kono (mean malignant SPN-to-aorta ratio 14.6%) did not reach statistical significance (t=1.244, P=0.225). The mean perfusion value (3.278 ml·min - · kg -1 ) was in the range of that (1.36-2.98 ml·min -1 ·kg -1 ) measured with a single photon emission CT (SPECT). Mean transit time was (17.60 ± 4.52) s. Conclusion: It is feasible to investigate bronchogenic adenocarcinoma angiogenesis with dynamic MSCT

  16. Unsupervised motion-compensation of multi-slice cardiac perfusion MRI

    DEFF Research Database (Denmark)

    Stegmann, Mikkel Bille; Ólafsdóttir, Hildur; Larsson, Henrik B. W.

    2005-01-01

    This paper presents a novel method for registration of single and multi-slice cardiac perfusion MRI. Utilising computer intensive analyses of variance and clustering in an annotated training set off-line, the presented method is capable of providing registration without any manual interaction...... in less than a second per frame. Changes in image intensity during the bolus passage are modelled by a slice-coupled active appearance model, which is augmented with a cluster analysis of the training set. Landmark correspondences are optimised using the MDL framework due to Davies et al. Image search...

  17. A multi-slice gradient sequence for contrast enhanced MR diagnosis of intracranial tumours

    International Nuclear Information System (INIS)

    Schoerner, W.; Sander, B.; Kornmesser, W.; Laniado, M.; Nakamura, T.; Felix, R.

    1988-01-01

    A multi-slice gradient echo sequence (FLASH) was compared with a conventional spin-echo (SE) technique with regard to its value for contrast enhanced MR diagnosis. In 28 patients with cerebral tumours, SE images (SE 400/30; four images/3.4 minutes) and FLASH images (FLASH 315/14; 15 images/1.4 minutes) were obtained before and after gadolinium DTPA. After gadolinium-DTPA results were comparable for both techniques with respect to contrast enhancement, tumor contrast and delineation. Because of the higher efficiency of the FLASH 315/14 technique, this sequence is the method of choice for contrast enhanced cerebral MR imaging. (orig.) [de

  18. Trabecular bone structure parameters from 3D image processing of clinical multi-slice and cone-beam computed tomography data

    Energy Technology Data Exchange (ETDEWEB)

    Klintstroem, Eva; Smedby, Oerjan [Linkoeping University, Center for Medical Image Science and Visualization (CMIV), Linkoeping (Sweden); UHL County Council of Oestergoetland, Department of Radiology, Linkoeping (Sweden); Linkoeping University, Department of Medical and Health Sciences (IMH)/Radiology, Linkoeping (Sweden); Moreno, Rodrigo [Linkoeping University, Center for Medical Image Science and Visualization (CMIV), Linkoeping (Sweden); Linkoeping University, Department of Medical and Health Sciences (IMH)/Radiology, Linkoeping (Sweden); Brismar, Torkel B. [KUS Huddinge, Department of Clinical Science, Intervention and Technology at Karolinska Institutet and Department of Radiology, Stockholm (Sweden)

    2014-02-15

    Bone strength depends on both mineral content and bone structure. The aim of this in vitro study was to develop a method of quantitatively assessing trabecular bone structure by applying three-dimensional image processing to data acquired with multi-slice and cone-beam computed tomography using micro-computed tomography as a reference. Fifteen bone samples from the radius were examined. After segmentation, quantitative measures of bone volume, trabecular thickness, trabecular separation, trabecular number, trabecular nodes, and trabecular termini were obtained. The clinical machines overestimated bone volume and trabecular thickness and underestimated trabecular nodes and number, but cone-beam CT to a lesser extent. Parameters obtained from cone beam CT were strongly correlated with μCT, with correlation coefficients between 0.93 and 0.98 for all parameters except trabecular termini. The high correlation between cone-beam CT and micro-CT suggest the possibility of quantifying and monitoring changes of trabecular bone microarchitecture in vivo using cone beam CT. (orig.)

  19. The application and shielding value of low-dose CT scanning in hypoxic ischemic encephalopathy of neonate

    International Nuclear Information System (INIS)

    Wu Aiqin; Zheng Wenlong; Xu Chongyong; Cheng Jianmin; Chen Yu; Chen Tinggang

    2006-01-01

    Objective: To investigate the application and shielding value of multi-slice spiral CT scanning with low-dose in hypoxic ischemic encephalopathy (HIE) of neonate. Methods: 60 neonates with HIE diagnosed by clinic were prospectively selected and randomly divided into two groups averagely. The technical parameters were tube tension 120 kV, slice thickness and gap 6 mm, conventional tube current 250 mAs and low dose 50 mAs. Weighted CT dose index (CTDI w ) and dose length product (DLP) were compared to each other. The image noise were analyzed with water phantom of children's skull. The mean and standard deviation of CT value were statistically analyzed. The image quality was blindly evaluated in two different dose groups. Results: (1) The mAs, CTDI w and DLP in low dose group were 20 % of conventional dose group; (2) The noise of water phantom in low dose group was larger than in conventional dose group with the significant difference (t=34.533, P < 0.01 ); (3) The imaging quality in low dose group was mostly better, but inferior to conventional dose group, while there is no poor images to influence the diagnosis of HIE. Conclusions: The low dose scanning will be practical in diagnosis of HIE, and beneficial to protect the newborn which corresponds to the optimizing principle of ICRP in medical radiation protection. (authors)

  20. Multi-slice helical CT: biggest pitch does not mean dosimetric bargain

    International Nuclear Information System (INIS)

    Cordoliani, Y.S.

    2000-01-01

    This article explains the point of the definition of the pitch, definition different from the point of view of the constructor and the definition used in the normalisation documents. It is important to dissociate the detection step ( displacement of the way divided by the thickness of the reconstructed hits) and the acquisition step (displacement of the way divided by the product of the number of hits simultaneously achieved by the nominal thickness of hit). This last one is the only step that answers to the step definition, still current in the normalisation documents and it should be the only used by the constructors. As irradiation is inversely proportional to the pitch, the definition of this one becomes a part of radiation protection and explains why different radiation doses can be gotten. (N.C.)

  1. Quantitative assessment of pulmonary function using low dose multi-slice spiral CT in smoker

    International Nuclear Information System (INIS)

    Chen Huai; Zeng Qingsi; Zheng Jinping; Guan Yubao; Zhang Chaoliang; Cen Renli

    2012-01-01

    Objective: To evaluate the clinical feasibility of low dose MSCT for quantitative assessment of pulmonary function in smokers. Methods: One hundred and forty-six patients with chronic objective pulmonary disease (COPD) including 109 smokers (74.6%) and 37 non-smokers (25.3%) underwent pulmonary function test and low-dose MSCT scan. All data were analyzed using computer-aided lung analysis software. Pulmonary function parameters from low-dose MSCT were compared between smokers and non-smokers and also compared with pulmonary function test in non-smokers (Pearson test). Results: In smokers, the average volume at full inspiratory phase (Vin) was (5125 ± 862 ) ml, mean lung attenuation was (-902 ± 26) HU, mean lung density was (0.0984 ± 0.0260 ) g/cm 3 , emphysema volume was (2890 ±1370) ml. The average volume at full expiratory phase (Vex) was (2756 ±1027) ml, mean lung attenuation was (-811 ±62) HU, mean lung density was (0.1878 ±0.0631) g/cm 3 , emphysema volume was (685 ±104) ml. In non-smokers, the average Vin was (3734 ± 759) ml, mean lung attenuation was (-876 ±40) HU,mean lung density was (0.1244 ±0.0401)g/cm 3 , emphysema volume was ( 1503 ± 1217) ml. The average Vex was (1770 ± 679) ml, mean lung attenuation was (-765 ± 56) HU, mean lung density was (0.2360 ± 0.0563) g/cm 3 , emphysema volume was (156 ± 45) ml. There were significant differences between smokers and non-smokers (P<0.01). The Vex/Vin was correlated with residual volume/total lung capacity (RV/TLC, r=0.60, P<0.01), and Vin was correlated with TLC (r=0.58, P<0.01), Vex with RV (r=0.59, P<0.01). Pixel index (PI) -950 in was correlated with FEV 1% pre and FEV1/FVC% (r=-0.53, -0.62, respective, P<0.01), Pl-950ex was correlated with FEV1 % pre and FEV1/FVC% (r=-0.71, -0.77, respective, P<0.01). Conclusion: Low-dose MSCT can be a potential imaging tool for quantitative pulmonary function assessment in smokes. (authors)

  2. Detection and severity of coronary disease: comparison between Framingham and calcium scores using multi-slice tomography

    International Nuclear Information System (INIS)

    Rodriguez Gomez, Maria Liliana; Montenegro, Edison; Ruiz, Angela Maria; Ardila, Jaime

    2011-01-01

    Introduction: multiple studies have shown that the coronary calcium index is an independent, more accurate predictor of future coronary events in relation to traditional risk factors. However, these studies have not been conducted in populations of developing countries like Colombia. Objective: to compare the strength of association between the Framingham index and the coronary calcium score in detecting the presence and severity of coronary disease as defined by 64-channel multi-slice angio-CT in order to provide additional information for decision-making in our asymptomatic coronary population. Methodology: we reviewed the written reports of coronary angiography scans performed in past 3 years. Based on this information, bivariate (calculation of Spearman rho correlation coefficients) and multivariate (logistic regression) analyses were performed. Results: the coronary calcium score showed a higher correlation with the presence and severity of coronary disease, Spearman Rho coefficient, compared with the Framingham index, Spearman's Rho coefficient of 0.30 (p<0.001). The moderate Framingham index (10-19%) shows no strength of association with significant and non-significant coronary artery disease, OR = 2, 51 CI 95% (0.7-8.9) and OR = 2.3 CI 95% (0.86-6.15), respectively. Patients with calcium values = 100 showed significant strength of association, OR = 182, 95% (17.4 -190.2), with significant coronary disease compared with high Framingham index values (=20%), OR = 18.6, CI 95% (1.75-198). Conclusions: the coronary calcium score has a higher correlation with the presence and severity of coronary disease when compared with the Framingham index. There is a low correlation between the index and Framingham coronary calcium.

  3. Clinical applications of SPECT-CT

    Energy Technology Data Exchange (ETDEWEB)

    Ahmadzadehfar, Hojjat; Biersack, Hans-Juergen (eds.) [University Hospital Bonn (Germany). Dept. of Nuclear Medicine

    2014-06-01

    Covers the full spectrum of clinical applications of SPECT/CT in diagnosis of benign and malignant diseases. Includes chapters on the use of SPECT/CT for dosimetry and for therapy planning. Completely up to date. Many helpful illustrations. SPECT/CT cameras have considerably improved diagnostic accuracy in recent years. Such cameras allow direct correlation of anatomic and functional information, resulting in better localization and definition of scintigraphic findings. In addition to this anatomic referencing, CT coregistration provides superior quantification of radiotracer uptake based on the attenuation correction capabilities of CT. Useful applications of SPECT/CT have been identified not only in oncology but also in other specialties such as orthopedics and cardiology. This book covers the full spectrum of clinical applications of SPECT/CT in diagnosis and therapy planning of benign and malignant diseases. Opening chapters discuss the technology and physics of SPECT/CT and its use for dosimetry. The role of SPECT/CT in the imaging of a range of pathologic conditions is then addressed in detail. Applications covered include, among others, imaging of the thyroid, bone, and lungs, imaging of neuroendocrine tumors, cardiac scintigraphy, and sentinel node scintigraphy. Individual chapters are also devoted to therapy planning in selective internal radiation therapy of liver tumors and bremsstrahlung SPECT/CT. Readers will find this book to be an essential and up-to-date source of information on this invaluable hybrid imaging technique.

  4. A simultaneous multi-slice selective J-resolved experiment for fully resolved scalar coupling information

    Science.gov (United States)

    Zeng, Qing; Lin, Liangjie; Chen, Jinyong; Lin, Yanqin; Barker, Peter B.; Chen, Zhong

    2017-09-01

    Proton-proton scalar coupling plays an important role in molecular structure elucidation. Many methods have been proposed for revealing scalar coupling networks involving chosen protons. However, determining all JHH values within a fully coupled network remains as a tedious process. Here, we propose a method termed as simultaneous multi-slice selective J-resolved spectroscopy (SMS-SEJRES) for simultaneously measuring JHH values out of all coupling networks in a sample within one experiment. In this work, gradient-encoded selective refocusing, PSYCHE decoupling and echo planar spectroscopic imaging (EPSI) detection module are adopted, resulting in different selective J-edited spectra extracted from different spatial positions. The proposed pulse sequence can facilitate the analysis of molecular structures. Therefore, it will interest scientists who would like to efficiently address the structural analysis of molecules.

  5. Errors during MRT measurements of the left ventricular volume using a multi-slice technique

    International Nuclear Information System (INIS)

    Pitton, M.B.; Just, M.; Grebe, P.; Kreitner, K.F.; Erbel, R.; Thelen, M.

    1992-01-01

    A multi-slice technique for MRT measurements of the left ventricular volume is much faster than the use of single-slice methods and is therefore better tolerated, leaving time for additional measurements. The end-diastolic left ventricular volume can be reliably measured by this method (123.3±13.5 ml vs. 124.1±ml). The end-systolic volume is consistently overestimated by 23.7±18,3% compared with the reference value obtained by single slice measurements (47.9±8.9 ml vs 39.1±7.9 ml). Correspondingly, stroke volume and ejection fraction is underestimated on average by 10.6±9.7% and 10.6±7.6% respectively). (orig.) [de

  6. CT applications of medical computer graphics

    International Nuclear Information System (INIS)

    Rhodes, M.L.

    1985-01-01

    Few applications of computer graphics show as much promise and early success as that for CT. Unlike electron microscopy, ultrasound, business, military, and animation applications, CT image data are inherently digital. CT pictures can be processed directly by programs well established in the fields of computer graphics and digital image processing. Methods for reformatting digital pictures, enhancing structure shape, reducing image noise, and rendering three-dimensional (3D) scenes of anatomic structures have all become routine at many CT centers. In this chapter, the authors provide a brief introduction to computer graphics terms and techniques commonly applied to CT pictures and, when appropriate, to those showing promise for magnetic resonance images. Topics discussed here are image-processing options that are applied to digital images already constructed. In the final portion of this chapter techniques for ''slicing'' CT image data are presented, and geometric principles that describe the specification of oblique and curved images are outlined. Clinical examples are included

  7. Intersection Based Motion Correction of Multi-Slice MRI for 3D in utero Fetal Brain Image Formation

    Science.gov (United States)

    Kim, Kio; Habas, Piotr A.; Rousseau, Francois; Glenn, Orit A.; Barkovich, Anthony J.; Studholme, Colin

    2012-01-01

    In recent years post-processing of fast multi-slice MR imaging to correct fetal motion has provided the first true 3D MR images of the developing human brain in utero. Early approaches have used reconstruction based algorithms, employing a two step iterative process, where slices from the acquired data are re-aligned to an approximate 3D reconstruction of the fetal brain, which is then refined further using the improved slice alignment. This two step slice-to-volume process, although powerful, is computationally expensive in needing a 3D reconstruction, and is limited in its ability to recover sub-voxel alignment. Here, we describe an alternative approach which we term slice intersection motion correction (SIMC), that seeks to directly co-align multiple slice stacks by considering the matching structure along all intersecting slice pairs in all orthogonally planned slices that are acquired in clinical imaging studies. A collective update scheme for all slices is then derived, to simultaneously drive slices into a consistent match along their lines of intersection. We then describe a 3D reconstruction algorithm that, using the final motion corrected slice locations, suppresses through-plane partial volume effects to provide a single high isotropic resolution 3D image. The method is tested on simulated data with known motions and is applied to retrospectively reconstruct 3D images from a range of clinically acquired imaging studies. The quantitative evaluation of the registration accuracy for the simulated data sets demonstrated a significant improvement over previous approaches. An initial application of the technique to studying clinical pathology is included, where the proposed method recovered up to 15 mm of translation and 30 degrees of rotation for individual slices, and produced full 3D reconstructions containing clinically useful additional information not visible in the original 2D slices. PMID:19744911

  8. Multi-slicing strategy for the three-dimensional discontinuity layout optimization (3D DLO).

    Science.gov (United States)

    Zhang, Yiming

    2017-03-01

    Discontinuity layout optimization (DLO) is a recently presented topology optimization method for determining the critical layout of discontinuities and the associated upper bound limit load for plane two-dimensional and three-dimensional (3D) problems. The modelling process (pre-processing) for DLO includes defining the discontinuities inside a specified domain and building the target function and the global constraint matrix for the optimization solver, which has great influence on the the efficiency of the computation processes and the reliability of the final results. This paper focuses on efficient and reliable pre-processing of the discontinuities within the 3D DLO and presents a multi-slicing strategy, which naturally avoids the overlapping and crossing of different discontinuities. Furthermore, the formulation of the 3D discontinuity considering a shape of an arbitrary convex polygon is introduced, permitting the efficient assembly of the global constraint matrix. The proposed method eliminates unnecessary discontinuities in 3D DLO, making it possible to apply 3D DLO for solving large-scale engineering problems such as those involving landslides. Numerical examples including a footing test, a 3D landslide and a punch indentation are considered, illustrating the effectiveness of the presented method. © 2016 The Authors. International Journal for Numerical and Analytical Methods in Geomechanics published by John Wiley & Sons Ltd.

  9. Accelerating Magnetic Resonance Fingerprinting (MRF) using t-Blipped Simultaneous Multi-Slice (SMS) acquisition

    Science.gov (United States)

    Ye, Huihui; Ma, Dan; Jiang, Yun; Cauley, Stephen F.; Du, Yiping; Wald, Lawrence L.; Griswold, Mark A.; Setsompop, Kawin

    2015-01-01

    Purpose We incorporate Simultaneous Multi-Slice (SMS) acquisition into MR Fingerprinting (MRF) to accelerate the MRF acquisition. Methods The t-Blipped SMS-MRF method is achieved by adding a Gz blip before each data acquisition window and balancing it with a Gz blip of opposing polarity at the end of each TR. Thus the signal from different simultaneously excited slices are encoded with different phases without disturbing the signal evolution. Further, by varying the Gz blip area and/or polarity as a function of TR, the slices’ differential phase can also be made to vary as a function of time. For reconstruction of t-Blipped SMS-MRF data, we demonstrate a combined slice-direction SENSE and modified dictionary matching method. Results In Monte Carlo simulation, the parameter mapping from Multi-band factor (MB)=2 t-Blipped SMS-MRF shows good accuracy and precision when compared to results from reference conventional MRF data with concordance correlation coefficients (CCC) of 0.96 for T1 estimates and 0.90 for T2 estimates. For in vivo experiments, T1 and T2 maps from MB=2 t-Blipped SMS-MRF have a high agreement with ones from conventional MRF. Conclusions The MB=2 t-Blipped SMS-MRF acquisition/reconstruction method has been demonstrated and validated to provide more rapid parameter mapping in the MRF framework. PMID:26059430

  10. A multi-slice sliding cell technique for diffusion measurements in liquid metals

    Science.gov (United States)

    Zhong, Langxiang; Hu, Jinliang; Geng, Yongliang; Zhu, Chunao; Zhang, Bo

    2017-09-01

    The long capillary and shear-cell techniques are traditionally used for diffusion measurements in liquid metals. Inspired by the idea of the shear-cell method, we have built a multi-slice sliding cell device for inter-diffusion measurements in liquid metals. The device is designed based on a linear sliding movement rather than a rotational shearing as used in the traditional shear-cell method. Compared with the normal shear-cell method, the present device is a more compact setup thus easier to handle. Also, it is expected to be easier to monitor with X-rays or neutrons if used in in situ experiments. A series of benchmark time-dependent diffusion experiments in Al-Cu melts carried out with the present technique reveal that accurate diffusion constants can be achieved only after a sufficient time. For short annealing times, the initial shearing process causing convective flow dominates the measurement and leads to an increase of the measured diffusion coefficient by a factor three. The diffusion data obtained for Al-Cu liquids are consistent with the most accurate data measured by the in situ X-ray radiography method under well controlled conditions of no temperature gradient or other perturbation. High accuracy and easy handling as well as superior adaptability make the present technique suitable for diffusion studies in liquid metals.

  11. Evaluation of the accuracy of linear measurements on multi-slice and cone beam computed tomography scans to detect the mandibular canal during bilateral sagittal split osteotomy of the mandible.

    Science.gov (United States)

    Freire-Maia, B; Machado, V deC; Valerio, C S; Custódio, A L N; Manzi, F R; Junqueira, J L C

    2017-03-01

    The aim of this study was to compare the accuracy of linear measurements of the distance between the mandibular cortical bone and the mandibular canal using 64-detector multi-slice computed tomography (MSCT) and cone beam computed tomography (CBCT). It was sought to evaluate the reliability of these examinations in detecting the mandibular canal for use in bilateral sagittal split osteotomy (BSSO) planning. Eight dry human mandibles were studied. Three sites, corresponding to the lingula, the angle, and the body of the mandible, were selected. After the CT scans had been obtained, the mandibles were sectioned and the bone segments measured to obtain the actual measurements. On analysis, no statistically significant difference was found between the measurements obtained through MSCT and CBCT, or when comparing the measurements from these scans with the actual measurements. It is concluded that the images obtained by CT scan, both 64-detector multi-slice and cone beam, can be used to obtain accurate linear measurements to locate the mandibular canal for preoperative planning of BSSO. The ability to correctly locate the mandibular canal during BSSO will reduce the occurrence of neurosensory disturbances in the postoperative period. Copyright © 2016 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  12. Intraoperative cone-beam computed tomography and multi-slice computed tomography in temporal bone imaging for surgical treatment.

    Science.gov (United States)

    Erovic, Boban M; Chan, Harley H L; Daly, Michael J; Pothier, David D; Yu, Eugene; Coulson, Chris; Lai, Philip; Irish, Jonathan C

    2014-01-01

    Conventional computed tomography (CT) imaging is the standard imaging technique for temporal bone diseases, whereas cone-beam CT (CBCT) imaging is a very fast imaging tool with a significant less radiation dose compared with conventional CT. We hypothesize that a system for intraoperative cone-beam CT provides comparable image quality to diagnostic CT for identifying temporal bone anatomical landmarks in cadaveric specimens. Cross-sectional study. University tertiary care facility. Twenty cadaveric temporal bones were affixed into a head phantom and scanned with both a prototype cone-beam CT C-arm and multislice helical CT. Imaging performance was evaluated by 3 otologic surgeons and 1 head and neck radiologist. Participants were presented images in a randomized order and completed landmark identification questionnaires covering 21 structures. CBCT and multislice CT have comparable performance in identifying temporal structures. Three otologic surgeons indicated that CBCT provided statistically equivalent performance for 19 of 21 landmarks, with CBCT superior to CT for the chorda tympani and inferior for the crura of the stapes. Subgroup analysis showed that CBCT performed superiorly for temporal bone structures compared with CT. The radiologist rated CBCT and CT as statistically equivalent for 18 of 21 landmarks, with CT superior to CBCT for the crura of stapes, chorda tympani, and sigmoid sinus. CBCT provides comparable image quality to conventional CT for temporal bone anatomical sites in cadaveric specimens. Clinical applications of low-dose CBCT imaging in surgical planning, intraoperative guidance, and postoperative assessment are promising but require further investigation.

  13. Clinical application of helical CT colonography

    International Nuclear Information System (INIS)

    Zeng Huiliang; Zhu Xinjin; Liang Rujian; Liang Jianhao; Ou Weiqian; Wen Haomao

    2009-01-01

    Objective: To investigate the clinical value of 16-slice helical CT colonography in the diagnosis of colon tumor and polypus. Methods: 16-slice helical CT volumetric scanning was performed in 18 patients with colonic disease, including colonic tumor (n=16) and colonic polypus (n=2). 3D images, virtual endoscopy and multiplanar reformation were obtained in the AW4.1 workstation. CT appearances were compared with operation and fiberoptic colonoscopy. Results: Satisfied results were achieved from 18 patients, no difference found in results between CT colonography and operation in 16 patients with colonic tumor. Conclusion: 16-slice helical CT colonography is of great value in preoperative staging of colonic tumor and have a high value in clinical application. (authors)

  14. Multi-slice ultrasound image calibration of an intelligent skin-marker for soft tissue artefact compensation.

    Science.gov (United States)

    Masum, M A; Pickering, M R; Lambert, A J; Scarvell, J M; Smith, P N

    2017-09-06

    In this paper, a novel multi-slice ultrasound (US) image calibration of an intelligent skin-marker used for soft tissue artefact compensation is proposed to align and orient image slices in an exact H-shaped pattern. Multi-slice calibration is complex, however, in the proposed method, a phantom based visual alignment followed by transform parameters estimation greatly reduces the complexity and provides sufficient accuracy. In this approach, the Hough Transform (HT) is used to further enhance the image features which originate from the image feature enhancing elements integrated into the physical phantom model, thus reducing feature detection uncertainty. In this framework, slice by slice image alignment and calibration are carried out and this provides manual ease and convenience. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Is correction necessary when clinically determining quantitative cerebral perfusion parameters from multi-slice dynamic susceptibility contrast MR studies?

    International Nuclear Information System (INIS)

    Salluzzi, M; Frayne, R; Smith, M R

    2006-01-01

    Several groups have modified the standard singular value decomposition (SVD) algorithm to produce delay-insensitive cerebral blood flow (CBF) estimates from dynamic susceptibility contrast (DSC) perfusion studies. However, new dependences of CBF estimates on bolus arrival times and slice position in multi-slice studies have been recently recognized. These conflicting findings can be reconciled by accounting for several experimental and algorithmic factors. Using simulation and clinical studies, the non-simultaneous measurement of arterial and tissue concentration curves (relative slice position) in a multi-slice study is shown to affect time-related perfusion parameters, e.g. arterial-tissue-delay measurements. However, the current clinical impact of relative slice position on amplitude-related perfusion parameters, e.g. CBF, can be expected to be small unless any of the following conditions are present individually or in combination: (a) high concentration curve signal-to-noise ratios, (b) small tissue mean transit times, (c) narrow arterial input functions or (d) low temporal resolution of the DSC image sequence. Recent improvements in magnetic resonance (MR) technology can easily be expected to lead to scenarios where these effects become increasingly important sources of inaccuracy for all perfusion parameter estimates. We show that using Fourier interpolated (high temporal resolution) residue functions reduces the systematic error of the perfusion parameters obtained from multi-slice studies

  16. Absorbed dose in CT. Comparison by CT dose index

    International Nuclear Information System (INIS)

    Yamamoto, Kenji; Akazawa, Hiroshi; Andou, Takashi

    2002-01-01

    Few reports have discussed the absorbed dose on CT units with increased scanning capacity even with the current widespread adoption of multi-slice CT units. To compare and investigate the dose indexes among CT units, we measured the absorbed dose on CT units operating in Nagano Prefecture Japan. The measurements showed proportionality between phantom absorbed dose and the exposured mAs values in conventional scanning operation. Further, the measurements showed that the absorbed dose in the center of the phantom differed by about 2.1-fold between the highest and lowest levels on individual CT units. Within a single company, multi-slice CT units of the same company gave absorbed doses of about 1.3 to 1.5 times those of conventional single-slice CT units under the same exposured conditions of conventional scanning. When the scanning pitch was reduced in helical scanning, the absorbed dose at the center of the phantom increased. (author)

  17. Clinical applications of PET/CT

    International Nuclear Information System (INIS)

    Le Ngoc Ha

    2011-01-01

    The purpose of this article is to review the evolution of PET, PET/CT focusing on the technical aspects, PET radiopharmaceutical developments and current clinical applications as well. The newest technologic advances have been reviewed, including improved crystal design, acquisition modes, reconstruction algorithms, etc. These advancements will continue to improve contrast, decrease noise, and increase resolution. Combined PET/CT system provides faster attenuation correction and useful anatomic correlation to PET functional information. A number of new radiopharmaceuticals used for PET imaging have been developed, however, FDG have been considered as the principal PET radiotracer. The current clinical applications of PET and PET/CT are widespread and include oncology, cardiology and neurology. (author)

  18. Multi-slice Fractional Ventilation Imaging in Large Animals with Hyperpolarized Gas MRI

    Science.gov (United States)

    Emami, Kiarash; Xu, Yinan; Hamedani, Hooman; Xin, Yi; Profka, Harrilla; Rajaei, Jennia; Kadlecek, Stephen; Ishii, Masaru; Rizi, Rahim R.

    2012-01-01

    Noninvasive assessment of regional lung ventilation is of critical importance in quantifying the severity of disease and evaluating response to therapy in many pulmonary diseases. This work presents for the first time the implementation of a hyperpolarized (HP) gas MRI technique for measuring whole-lung regional fractional ventilation (r) in Yorkshire pigs (n = 5) through the use of a gas mixing and delivery device in supine position. The proposed technique utilizes a series of back-to-back HP gas breaths with images acquired during short end-inspiratory breath-holds. In order to decouple the RF pulse decay effect from ventilatory signal build-up in the airways, regional distribution of flip angle (α) was estimated in the imaged slices by acquiring a series of back-to-back images with no inter-scan time delay during a breath-hold at the tail-end of the ventilation sequence. Analysis was performed to assess the multi-slice ventilation model sensitivity to noise, oxygen and number of flip angle images. The optimal α value was determined based on minimizing the error in r estimation; αopt = 5–6° for the set of acquisition parameters in pigs. The mean r values for the group of pigs were 0.27±0.09, 0.35±0.06, 0.40±0.04 for ventral, middle and dorsal slices, respectively, (excluding conductive airways r > 0.9). A positive gravitational (ventral-dorsal) ventilation gradient effect was present in all animals. The trachea and major conductive airways showed a uniform near-unity r value, with progressively smaller values corresponding to smaller diameter airways, and ultimately leading to lung parenchyma. Results demonstrate the feasibility of measurements of fractional ventilation in large species, and provides a platform to address technical challenges associated with long breathing time scales through the optimization of acquisition parameters in species with a pulmonary physiology very similar to that of human beings. PMID:22290603

  19. Clinical application of positron CT

    International Nuclear Information System (INIS)

    Takashima, Tsuneo; Yamaura, Akira; Shishido, Fumio; Tateno, Yukio.

    1981-01-01

    A newley designed positron CT has been applied for neurosurgical patients. The radiopharmaceuticals administered are 13 N-ammonia, 11 C-CO, and 18 F-fluorodeoxyglucose, which are produced and synthesized in the institute using the cyclotron. 13 N-ammonia and 18 F-fluorodeoxyglucose are administered by intravenous injection but 11 C-CO is administered by inhaling. 13 N-ammonia acts as a diffusible tracer and is readily metabolized to glutamine in the brain tissue, but the extraction fraction of the glutamine is so slow that the 13 N-ammonia imaging reflects the distribution of the crebral perfusion. 11 C-CO is combined with the hemoglobin and undiffusible in behavior. This makes the 11 C-CO images conduct the cerebral blood pooling distribution. 18 F-fluorodeoxyglucose is an analogous substance of glucose and is transported within the brain tissue competitively. Then, fluorodeoxyglucose is metabolized to fluorodeoxyglucose-6-phosphate but no further. This characteristic property of fluorodeoxyglucose let 18 F-fluorodeoxyglucose images convey the local cerebral metabolic rate of glucose. In normal volunteer subjects, the distribution of 13 N-ammonia and 18 F-fluorodeoxyglucose appeared in a similar fashion, and was in accordance with the brain tissue. Both tracers were accumulated in particularly high concentrations in the gray matter and the basal ganglia. 11 C-CO activity was prominently accumulated in various dural sinuses and the vascular areas. In stroke patients, old lesions showed a lack of perfusion but fresh lesions showed hyperperfusion surrounded by a decreased perfused area. 18 F-fluorodeoxyglucose activity was decreased in the lesion in spite of the hyperperfusion. (J.P.N.)

  20. Clinical application of gated CT and dynamic CT

    Energy Technology Data Exchange (ETDEWEB)

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

    1980-03-01

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

  1. Multi-slice MRI reveals heterogeneity in disease distribution along the length of muscle in Duchenne muscular dystrophy.

    Science.gov (United States)

    Chrzanowski, Stephen M; Baligand, Celine; Willcocks, Rebecca J; Deol, Jasjit; Schmalfuss, Ilona; Lott, Donovan J; Daniels, Michael J; Senesac, Claudia; Walter, Glenn A; Vandenborne, Krista

    2017-09-01

    Duchenne muscular dystrophy (DMD) causes progressive pathologic changes to muscle secondary to a cascade of inflammation, lipid deposition, and fibrosis. Clinically, this manifests as progressive weakness, functional loss, and premature mortality. Though insult to whole muscle groups is well established, less is known about the relationship between intramuscular pathology and function. Differences of intramuscular heterogeneity across muscle length were assessed using an ordinal MRI grading scale in lower leg muscles of boys with DMD and correlated to patient's functional status. Cross sectional T 1 weighted MRI images with fat suppression were obtained from ambulatory boys with DMD. Six muscles (tibialis anterior, extensor digitorum longus, peroneus, soleus, medial and lateral gastrocnemii) were graded using an ordinal grading scale over 5 slice sections along the lower leg length. The scores from each slice were combined and results were compared to global motor function and age. Statistically greater differences of involvement were observed at the proximal ends of muscle compared to the midbellies. Multi-slice assessment correlated significantly to age and the Vignos functional scale, whereas single-slice assessment correlated to the Vignos functional scale only. Lastly, differential disease involvement of whole muscle groups and intramuscular heterogeneity were observed amongst similar age subjects. A multi-slice ordinal MRI grading scale revealed that muscles are not uniformly affected, with more advanced disease visible near the tendons in a primarily ambulatory population with DMD. A geographically comprehensive evaluation of the heterogeneously affected muscle in boys with DMD may more accurately assess disease involvement.

  2. A z-gradient array for simultaneous multi-slice excitation with a single-band RF pulse.

    Science.gov (United States)

    Ertan, Koray; Taraghinia, Soheil; Sadeghi, Alireza; Atalar, Ergin

    2018-07-01

    Multi-slice radiofrequency (RF) pulses have higher specific absorption rates, more peak RF power, and longer pulse durations than single-slice RF pulses. Gradient field design techniques using a z-gradient array are investigated for exciting multiple slices with a single-band RF pulse. Two different field design methods are formulated to solve for the required current values of the gradient array elements for the given slice locations. The method requirements are specified, optimization problems are formulated for the minimum current norm and an analytical solution is provided. A 9-channel z-gradient coil array driven by independent, custom-designed gradient amplifiers is used to validate the theory. Performance measures such as normalized slice thickness error, gradient strength per unit norm current, power dissipation, and maximum amplitude of the magnetic field are provided for various slice locations and numbers of slices. Two and 3 slices are excited by a single-band RF pulse in simulations and phantom experiments. The possibility of multi-slice excitation with a single-band RF pulse using a z-gradient array is validated in simulations and phantom experiments. Magn Reson Med 80:400-412, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

  3. Acute and chronic myocardial infarction in a pig model: Utility of multi-slice cardiac computed tomography in assessing myocardial viability and infarct parameters

    International Nuclear Information System (INIS)

    Qu Xinkai; Fang Weiyi; Ye Jianding; Koh, Angela S.; Xu Yingjia; Guan Shaofeng; Li Ruogu; Shen Yan

    2012-01-01

    Objectives: The aim of this study was to determine the feasibility of multi-slice computed tomography (MSCT) biphasic imaging in assessing myocardial viability and infarct parameters in both acutely and chronically infarcted pig models. Materials and methods: Seven pigs underwent ligation of the distal left anterior descending artery. Imaging was performed on the day of infarction and 3 months post-infarct, with contrast infusion followed by MSCT scan acquisition at different time-points. Left ventricular ejection fractions (LVEFs) were obtained by left ventriculography (LVG) after 3 months. Infarcted locations found using MSCT were compared with those obtained using SPECT. Infarcted areas were also analysed histopathologically and compared with the findings from MSCT. Results: Chronic phase images had perfusion defects with lower CT values relative to normal myocardium (43 ± 10 HU vs. 156 ± 13 HU, p = 0.001) on the early images but no residual defects on delayed images. However, we found hyperenhancing regions on delayed images (244 ± 20 HU vs. 121 ± 25 HU, p = 0.001), and good correlation between MSCT- and LVG-derived LVEFs (60.56 ± 7.56%). The areas identified by MSCT corresponded to the location of 201 Tl SPECT-/pathologic staining-derived regions in all models. Infarct size was in good agreement with MSCT and pathological analyses of chronic phase models. Conclusions: Necrotic myocardium in different stages after infarction could be qualitatively and quantitatively assessed using MSCT biphasic imaging, as could the status of microcirculation formation. MSCT-measured LVEFs matched well with other modalities, and hence MSCT is a useful tool in assessing post-infarct cardiac function.

  4. Clinical applications of SPECT/CT: advantages and limitations

    International Nuclear Information System (INIS)

    Rigo, P.

    2006-01-01

    The application of hybrid SPECT cameras in Nuclear Medicine follows the revolutionary introduction of PET/CT. This review focuses on the advantages and limitations of SPECT/CT in its various clinical indications. It appears that SPECT/CT will be a clear factor of progress for Nuclear Medicine. (author)

  5. Subtraction imaging of the ECG gated cardiac CT

    Energy Technology Data Exchange (ETDEWEB)

    Tanegashima, K.; Fukui, M.; Hyodo, H.

    1987-05-01

    The subtracting manipulation of contrast-enhanced gated cardiac CT (GCCT) images was experimentally studied with TCT 60A - 30 type (Toshiba) for clinical use, thereby reducing the amount of contrast medium (CM). Initially the optimum relationship between the concentration of CM and its injected velocity was determined using the model of resected canine hearts and in actual dogs. The emphasized good-subtracted images were obtained when the difference of CT values was approximately 40 H.U. between cardiac cavity and myocardium. Such condition was feasible in the use of 25 % Diatrizoic acid and its injected velocity of 0.02 ml/kg/sec. Finally the reduction of the amount of CM by 1/3 became possible in clinical settings. The method is applicable to multi-slice GCCT in various heart diseases.

  6. Multi-slice spiral CT in the diagnosis of congenital heart diseases associated with tracheobronchial stenosis in children

    International Nuclear Information System (INIS)

    Wang Rongpin; Liang Changhong; Huang Meiping; Liu Hui; Cui Yanhai; Liu Qishun

    2010-01-01

    Objective: To explore the diagnostic value of post processing techniques of MSCT for diagnosing congenital heart disease associated with tracheobronchial stenosis in children. Methods: Thirty four patients with congenital heart disease complicated by tracheobronchial stenosis were evaluated with MSCT. MPR, CPR, MinIP and VR were performed to show the tracheobronchial morphology. Findings in 43 segments of 32 cases were compared with the findings of surgical operation. Mann-Whitney test was employed to assess the significance of measurement between the post processing techniques and the operation. Results: The length of stenotic segments were variable seen at operation, with values between 4- 39 mm in trachea, 4-33 mm in main bronchi and 3-12 mm in lobe bronchi, respectively. The biggest difference between the measurement of operation and MSCT was 4 mm (3 segments). Other differences of stenotic segments were within 3 mm. Six segments exhibited mild, 16 moderate and 21 severe stenosis at surgery. By contrast, five segments exhibited mild, 17 moderate and 21 severe stenosis by MPR or CPR, 2 mild, 9 moderate and 32 severe stenosis by MinIP and 4 mild, 11 moderate and 28 sever stenosis by VR, respectively. There was no significant difference in measuring the degree of tracheobronchial stenosis between MPR or CPR, VR and the surgery (Z=-0.105, -1.479; P>0.05), while MinIP frequently overrated the degree of stenosis compared with the measurement at surgery (Z=-2.484, P=0.013). Conclusion: The integrated three dimensional reformations of MSCT scan can accurately evaluate the degree and extent of congenital heart disease associated with tracheobronchial stenosis in children and provide valuable information for clinical management. (authors)

  7. Can multi-slice or navigator-gated R2* MRI replace single-slice breath-hold acquisition for hepatic iron quantification?

    International Nuclear Information System (INIS)

    Loeffler, Ralf B.; McCarville, M.B.; Song, Ruitian; Hillenbrand, Claudia M.; Wagstaff, Anne W.; Smeltzer, Matthew P.; Krafft, Axel J.; Hankins, Jane S.

    2017-01-01

    Liver R2* values calculated from multi-gradient echo (mGRE) magnetic resonance images (MRI) are strongly correlated with hepatic iron concentration (HIC) as shown in several independently derived biopsy calibration studies. These calibrations were established for axial single-slice breath-hold imaging at the location of the portal vein. Scanning in multi-slice mode makes the exam more efficient, since whole-liver coverage can be achieved with two breath-holds and the optimal slice can be selected afterward. Navigator echoes remove the need for breath-holds and allow use in sedated patients. To evaluate if the existing biopsy calibrations can be applied to multi-slice and navigator-controlled mGRE imaging in children with hepatic iron overload, by testing if there is a bias-free correlation between single-slice R2* and multi-slice or multi-slice navigator controlled R2*. This study included MRI data from 71 patients with transfusional iron overload, who received an MRI exam to estimate HIC using gradient echo sequences. Patient scans contained 2 or 3 of the following imaging methods used for analysis: single-slice images (n = 71), multi-slice images (n = 69) and navigator-controlled images (n = 17). Small and large blood corrected region of interests were selected on axial images of the liver to obtain R2* values for all data sets. Bland-Altman and linear regression analysis were used to compare R2* values from single-slice images to those of multi-slice images and navigator-controlled images. Bland-Altman analysis showed that all imaging method comparisons were strongly associated with each other and had high correlation coefficients (0.98 ≤ r ≤ 1.00) with P-values ≤0.0001. Linear regression yielded slopes that were close to 1. We found that navigator-gated or breath-held multi-slice R2* MRI for HIC determination measures R2* values comparable to the biopsy-validated single-slice, single breath-hold scan. We conclude that these three R2* methods can be

  8. Can multi-slice or navigator-gated R2* MRI replace single-slice breath-hold acquisition for hepatic iron quantification?

    Energy Technology Data Exchange (ETDEWEB)

    Loeffler, Ralf B.; McCarville, M.B.; Song, Ruitian; Hillenbrand, Claudia M. [St. Jude Children' s Research Hospital, Diagnostic Imaging, Memphis, TN (United States); Wagstaff, Anne W. [St. Jude Children' s Research Hospital, Diagnostic Imaging, Memphis, TN (United States); Rhodes College, Memphis, TN (United States); University of Alabama at Birmingham School of Medicine, Birmingham, AL (United States); Smeltzer, Matthew P. [St. Jude Children' s Research Hospital, Department of Biostatistics, Memphis, TN (United States); University of Memphis, Division of Epidemiology, Biostatistics, and Environmental Health, School of Public Health, Memphis, TN (United States); Krafft, Axel J. [St. Jude Children' s Research Hospital, Diagnostic Imaging, Memphis, TN (United States); University Hospital Center Freiburg, Department of Radiology, Freiburg (Germany); Hankins, Jane S. [St. Jude Children' s Research Hospital, Department of Hematology, Memphis, TN (United States)

    2017-01-15

    Liver R2* values calculated from multi-gradient echo (mGRE) magnetic resonance images (MRI) are strongly correlated with hepatic iron concentration (HIC) as shown in several independently derived biopsy calibration studies. These calibrations were established for axial single-slice breath-hold imaging at the location of the portal vein. Scanning in multi-slice mode makes the exam more efficient, since whole-liver coverage can be achieved with two breath-holds and the optimal slice can be selected afterward. Navigator echoes remove the need for breath-holds and allow use in sedated patients. To evaluate if the existing biopsy calibrations can be applied to multi-slice and navigator-controlled mGRE imaging in children with hepatic iron overload, by testing if there is a bias-free correlation between single-slice R2* and multi-slice or multi-slice navigator controlled R2*. This study included MRI data from 71 patients with transfusional iron overload, who received an MRI exam to estimate HIC using gradient echo sequences. Patient scans contained 2 or 3 of the following imaging methods used for analysis: single-slice images (n = 71), multi-slice images (n = 69) and navigator-controlled images (n = 17). Small and large blood corrected region of interests were selected on axial images of the liver to obtain R2* values for all data sets. Bland-Altman and linear regression analysis were used to compare R2* values from single-slice images to those of multi-slice images and navigator-controlled images. Bland-Altman analysis showed that all imaging method comparisons were strongly associated with each other and had high correlation coefficients (0.98 ≤ r ≤ 1.00) with P-values ≤0.0001. Linear regression yielded slopes that were close to 1. We found that navigator-gated or breath-held multi-slice R2* MRI for HIC determination measures R2* values comparable to the biopsy-validated single-slice, single breath-hold scan. We conclude that these three R2* methods can be

  9. Application of neural network to CT

    International Nuclear Information System (INIS)

    Ma, Xiao-Feng; Takeda, Tatsuoki

    1999-01-01

    This paper presents a new method for two-dimensional image reconstruction by using a multilayer neural network. Multilayer neural networks are extensively investigated and practically applied to solution of various problems such as inverse problems or time series prediction problems. From learning an input-output mapping from a set of examples, neural networks can be regarded as synthesizing an approximation of multidimensional function (that is, solving the problem of hypersurface reconstruction, including smoothing and interpolation). From this viewpoint, neural networks are well suited to the solution of CT image reconstruction. Though a conventionally used object function of a neural network is composed of a sum of squared errors of the output data, we can define an object function composed of a sum of residue of an integral equation. By employing an appropriate line integral for this integral equation, we can construct a neural network that can be used for CT. We applied this method to some model problems and obtained satisfactory results. As it is not necessary to discretized the integral equation using this reconstruction method, therefore it is application to the problem of complicated geometrical shapes is also feasible. Moreover, in neural networks, interpolation is performed quite smoothly, as a result, inverse mapping can be achieved smoothly even in case of including experimental and numerical errors, However, use of conventional back propagation technique for optimization leads to an expensive computation cost. To overcome this drawback, 2nd order optimization methods or parallel computing will be applied in future. (J.P.N.)

  10. Comparison SPECT-CT with PET-CT in several applications of small-animal models

    International Nuclear Information System (INIS)

    Pan Yifan; Song Shaoli; Huang Gang

    2009-01-01

    With the development of medical science, monitoring dynamic biologic processes in small-animal models of diseases has become one of the most important approaches in medical studies. Important physiologic parameters that traditionally have been characterized by nuclear medicine imaging include blood flow, biochemical metabolism, and cellular receptors. Recently, nuclear medicine has been greatly facilitated by the newer development of dual-modality integrated imaging systems (SPECT-CT and PET-CT), which provide functional and anatomical images in the same scanning session, with the acquired images co-registered by means of the hardware. The purpose of this review is to compare SPECT-CT with PET-CT in several applications of small-animal models. Conclusicn: PET-CT for small animal modes in nledical research in the applications has great advantages, but SPECT-CT is still a very important role, and research low cost. (authors)

  11. Three-dimensional display of the pelvic viscera using multi-sliced MR images

    International Nuclear Information System (INIS)

    Ueno, Shigeru; Suto, Yasuzo.

    1995-01-01

    Accurate reconstruction of the pelvic structure is the most important factor to obtain desirable results after anorectal surgery. Preoperative evaluation of the anatomy is indispensable for choosing an appropriate operative method in each case. To facilitate the preoperative evaluation, three dimensional images of the pelvic structure of patients with anorectal malformations were constructed by computer graphics based upon two dimensional images obtained from MR-CT. Graphic data from MR images were transferred to a graphic work station. The anorectum, bladder and sphincter musculature were displayed three-dimensionally after segmenting these organs by (1) manually regioning the area containing the specific organ and (2) thresholding the area by the T 1 intensity level. The anatomy of each type of anomaly is easily recognized by the 3-D visualization of pelvic viscera and sphincter musculature with emphasis on position and shape of the musculature although there are some difficulties to visualize soft tissue organs. The advanced programs could show the graphic images from any desirable angle quickly enough to be helpful for the simulation of the surgery. Three-dimensional display can be very useful for better understanding of each anomaly and determining the operative method prior to surgery. (author)

  12. Description of patellar movement by 3D parameters obtained from dynamic CT acquisition

    Science.gov (United States)

    de Sá Rebelo, Marina; Moreno, Ramon Alfredo; Gobbi, Riccardo Gomes; Camanho, Gilberto Luis; de Ávila, Luiz Francisco Rodrigues; Demange, Marco Kawamura; Pecora, Jose Ricardo; Gutierrez, Marco Antonio

    2014-03-01

    The patellofemoral joint is critical in the biomechanics of the knee. The patellofemoral instability is one condition that generates pain, functional impairment and often requires surgery as part of orthopedic treatment. The analysis of the patellofemoral dynamics has been performed by several medical image modalities. The clinical parameters assessed are mainly based on 2D measurements, such as the patellar tilt angle and the lateral shift among others. Besides, the acquisition protocols are mostly performed with the leg laid static at fixed angles. The use of helical multi slice CT scanner can allow the capture and display of the joint's movement performed actively by the patient. However, the orthopedic applications of this scanner have not yet been standardized or widespread. In this work we present a method to evaluate the biomechanics of the patellofemoral joint during active contraction using multi slice CT images. This approach can greatly improve the analysis of patellar instability by displaying the physiology during muscle contraction. The movement was evaluated by computing its 3D displacements and rotations from different knee angles. The first processing step registered the images in both angles based on the femuŕs position. The transformation matrix of the patella from the images was then calculated, which provided the rotations and translations performed by the patella from its position in the first image to its position in the second image. Analysis of these parameters for all frames provided real 3D information about the patellar displacement.

  13. Mid-term results of off-pump coronary artery bypass grafting assessed by multi-slice computed tomography

    International Nuclear Information System (INIS)

    Yoshida, Seijiro; Nitta, Yoshio; Oda, Katsuhiko

    2004-01-01

    Off-pump coronary artery bypass (OPCAB) has recently increased in popularity, but the long-term results are still unknown. We evaluated the mid-term results of OPCAB surgery using multi-slice computed tomography (MSCT), which is a non-invasive postoperative evaluation method. Thirty-one consecutive patients who underwent OPCAB surgery at least 2 years prior to the study were selected. The age was 50 to 79 years (66.9±6.5) and the ratio of men to women was 26:5. Coronary angiography was performed in all patients at 2 weeks postoperatively. The follow-up was complete, and mean follow-up was 30.9 months. There were no hospital deaths and 1 non-cardiac late death. The graft patency rate in coronary angiography was left internal thoracic artery (LITA) 30/30 (100%), right internal thoracic artery (RITA) 2/2 (100%), radial artery (RA) 14/15 (93%), saphenous vein graft (SVG) 15/17 (88%). No graft became occluded on MSCT study and all patients have been angina-free during the follow-up period. We suggest that OPCAB is feasible in most patients with good patency and low mortality. MSCT is an effective follow up method for the morphological findings and noninvasive quantitative evaluation of the bypass grafts. (author)

  14. Measurement of multi-slice computed tomography dose profile with the Dose Magnifying Glass and the MOSkin radiation dosimeter

    International Nuclear Information System (INIS)

    Lian, C.P.L.; Wong, J.H.D.; Young, A.; Cutajar, D.; Petasecca, M.; Lerch, M.L.F.; Rosenfeld, A.B.

    2013-01-01

    This study describes the application of two in-house developed dosimeters, the Dose Magnifying Glass (DMG) and the MOSkin dosimeter at the Centre for Medical Radiation Physics, University of Wollongong, Australia, for the measurement of CT dose profiles for a clinical diagnostic 16-slice MSCT scanner. Two scanner modes were used; axial mode and helical mode, and the effect of varying beam collimation and pitch was studied. With an increase in beam collimation in axial mode and an increase of CT pitch in helical mode, cumulative point dose at scanner isocentre decreased while FWHM increased. There was generally good agreement to within 3% between the acquired dose profiles obtained by the DMG and the film except at dose profile tails, where film over-responded by up to 30% due to its intrinsic depth dose dependence at low doses. -- Highlights: ► This study shows the CT beam profiles acquired with our institution's detectors. ► The DMG is a relative dosimeter calibrated to absolute MOSkin readings. ► There was good agreement between dose profiles acquired by the DMG and the film

  15. The clinical application of PET/CT: a contemporary review

    International Nuclear Information System (INIS)

    Brady, Z.; Partridge, M.; Trapp, J.V.

    2008-01-01

    Full text: The combination of positron emission tomography (PET) scanners and x-ray computed tomography (CT) scanners into a single PET CT scanner has resulted in significant improvements in the diagnosis and staging of disease, particularly in the field of oncology. A decade on from the publication of the details of the first PET/CT scanner, we review the technology and applications of the modality. We examine the design aspects of combining two different imaging types into a single scanner, and the artefacts produced such as attenuation correction, motion and CT truncation artefacts. The article also provides a discussion and literature review of the applications of PET/CT to date, covering detection of tumours, radiotherapy treatment planning, patient management, and applications external to the field of oncology.

  16. Application of industrial CT in reverse engineering technology

    International Nuclear Information System (INIS)

    Fang Liyong; Li Hui; Bai Jinping; Li Bailin

    2013-01-01

    The basic principle and basic steps of reverse engineering technology based on industrial CT are described. The recent research progresses and situation at home and abroad of reverse engineering technology based on industrial CT image are respectively described, analyzed and summarized from two routes which are surface segmentation and volume segmentation. An example of conch is used to exhibit the results from the two routes in reverse engineering technology based on industrial CT image. Finally, some difficulties in application and the future developments of reverse engineering technology based on industrial CT are prospected. (authors)

  17. Global and regional left ventricular function: a comparison between gated SPECT, 2D echocardiography and multi-slice computed tomography

    International Nuclear Information System (INIS)

    Henneman, Maureen M.; Bax, Jeroen J.; Holman, Eduard R.; Schuijf, Joanne D.; Jukema, J.W.; Wall, Ernst E. van der; Stokkel, Marcel P.M.; Lamb, Hildo J.; Roos, Albert de

    2006-01-01

    Global and regional left ventricular (LV) function are important indicators of the cardiac status in patients with coronary artery disease (CAD). Therapy and prognosis are to a large extent dependent on LV function. Multi-slice computed tomography (MSCT) has already earned its place as an imaging modality for non-invasive assessment of the coronary arteries, but since retrospective gating to the patient's ECG is performed, information on LV function can be derived. In 49 patients with known or suspected CAD, coronary angiography with MSCT imaging was performed, in addition to gated SPECT and 2D echocardiography. LV end-diastolic and LV end-systolic volumes and LV ejection fraction were analysed with dedicated software (CMR Analytical Software System, Medis, Leiden, The Netherlands for MSCT; gated SPECT by QGS, Cedars-Sinai Medical Center, Los Angeles, CA, USA), and by the biplane Simpson's rule for 2D echocardiography. Regional wall motion was evaluated according to a 17-segment model and a three-point score system. Correlations were fairly good between gated SPECT and MSCT (LVEDV: r=0.65; LVESV: r=0.63; LVEF: r=0.60), and excellent between 2D echocardiography and MSCT (LVEDV: r=0.92; LVESV: r=0.93; LVEF: r=0.80). Agreement for regional wall motion was 95% (κ=0.66) between gated SPECT and MSCT, and 96% (κ=0.73) between 2D echocardiography and MSCT. Global and regional LV function and LV volumes can be adequately assessed with MSCT. Correlations with 2D echocardiography are stronger than with gated SPECT. (orig.)

  18. Assessment of left atrial volume and function: a comparative study between echocardiography, magnetic resonance imaging and multi slice computed tomography.

    Science.gov (United States)

    Kühl, J Tobias; Lønborg, Jacob; Fuchs, Andreas; Andersen, Mads J; Vejlstrup, Niels; Kelbæk, Henning; Engstrøm, Thomas; Møller, Jacob E; Kofoed, Klaus F

    2012-06-01

    Measurement of left atrial (LA) maximal volume (LA(max)) using two-dimensional transthoracic echocardiography (TTE) provides prognostic information in several cardiac diseases. However, the relationship between LA(max) and LA function is poorly understood and TTE is less well suited for measuring dynamic LA volume changes. Conversely, cardiac magnetic resonance imaging (CMR) and multi-slice computed tomography (MSCT) appears more appropriate for such measures. We sought to determine the relationship between LA size assessed with TTE and LA size and function assessed with CMR and MSCT. Fifty-four patients were examined 3 months post myocardial infarction with echocardiography, CMR and MSCT. Left atrial volumes and LA reservoir function were assessed by TTE. LA time-volume curves were determined and LA reservoir function (cyclic change and fractional change), passive emptying function (reservoir volume) and pump function (left atrial ejection fraction-LAEF) were derived using CMR and MSCT. Left atrial fractional change and left atrial ejection fraction (LAEF) determined with CMR and MSCT were unrelated to LA(max) enlargement by echocardiography (P = NS). There was an overall good agreement between CMR and MSCT, with a small to moderate bias in LA(max) (4.9 ± 10.4 ml), CC (3.1 ± 9.1 ml) and reservoir volume (3.4 ± 9.1 ml). TTE underestimates LA(max) with up to 32% compared with CMR and MSCT (P fractional change and LAEF is not significantly related to LA(max) measured by TTE. TTE systematically underestimated LA volumes, whereas there are good agreements between MSCT and CMR for volumetric and functional properties.

  19. Patient doses from CT examinations in the United Arab Emirates

    International Nuclear Information System (INIS)

    Janeczek, J.

    2006-01-01

    Full text of publication follows: The main goal of the study was to estimate effective patient doses from the 6 most common CT examinations for different types of CT scanners within the United Arab Emirates. The results were used to assess future trends in patient CT doses following rapid replacement of axial and single-slice spiral scanners by multi-slice scanners. At present all three types of scanner technology exist: axial, spiral and multi-slice with axial scanners being gradually replaced by multi-slice scanners as the medical infrastructure of the country is modernized. Altogether there are more than 30 CT scanners in the country with a population of 4 million. Out of these 11 scanners are 16-slice models with tube-current modulation system. The majority of larger United Arab Emirates hospitals have at least two CT scanners: a single slice and 4 or 16-slice scanner. The survey was carried out with data collection forms distributed to the majority of CT scanner users in the United Arab Emirates hospitals, both private and government. Effective doses for different examinations were calculated from T.L.D. measurements using an Alderson Rando phantom simulating an average size patient. Our results show that effective doses to patients initially increased with the introduction of 4-slice scanners. Multi-slice scanners with 16 and more slices have tube-current modulation system as a standard. It is routinely used by radiographers in almost all examinations resulting in patient dose reduction up to 40 % in certain examinations. Another factor affecting population dose is the increased number of patients examined using multi-slice scanners. In the United Arab Emirates there was an increase of more than 30 % in the annual number of patients examined using multi-slice scanners in comparison to single-slice scanners. This fact is attributed to the ease and speed of operation of multi-slice scanners. Rapid increase in number of CT examinations is of concern. Medical

  20. Cine CT: a new technology for cardiac computed tomography

    International Nuclear Information System (INIS)

    Boyd, D.P.; Peschmann, K.R.; Rand, R.E.; Napel, S.A.; Gould, R.; Farmer, D.W.; Lipton, M.J.; Higgins, C.B.; Couch, J.L.

    1987-01-01

    The technical requirements for adequate evaluation of cardiac anatomy and physiology, namely scan speeds in the 33-100 msec range, simultaneous multi-slice capability, 15-20 multi-level scans/second and a repeat multi-slice study at one per second, have been realized with the inception of the Cine-CT scanner. This scanner acquires scan data in 50 milliseconds by eliminating moving parts and using a scanning electron beam to produce a high speed X-ray source. The authors describe this scanner and the three scanning modes available: continuous or cine mode; flow or triggered mode; and full resolution mode. (Auth.)

  1. PET/CT applications in oncology

    International Nuclear Information System (INIS)

    Oliva González, Juan Perfecto; Martínez Ramírez, Aldo; Baum, Richard Paul

    2017-01-01

    PET means Positron Emission Tomography, it is a nuclear medicine technique in which radiopharmaceuticals labeled with positron emitters are used to obtain biochemical-metabolic images of the human body. The use of PET / CT contributes to obtain multimodal images that combine anatomical and metabolic information, allowing a more reliable diagnosis of a tumor or local or distant metastases in an organ or tissue. Other multimodal devices combine metabolic imaging with nuclear magnetic resonance. PET/CT is mainly used in Oncology (85-90%), Neurology, Cardiology, Inflammation and Infection although it is currently also used in different medical and surgical pathologies. The present work is aimed at showing what PET/CT is and how useful it is in Oncology. (author)

  2. CT appearances of emphysema and clinical application

    International Nuclear Information System (INIS)

    Wang Xinlian; Ma Daqing; Chen Budong; He Wen; Guan Yansheng; Zhang Yansong; Tang Hongqu; Wang Zhenguang

    2006-01-01

    Objective: To investigate CT appearances of different types of emphysema and to determine the clinic value for differential diagnosis. Methods: Twenty-three specimens with emphysema selected from 33 autopsy specimens were included in this study. All specimens were inflated and fixed by Heitzman's method, then examined by spiral CT scan. The CT appearances of different types of emphysema in every specimen were analyzed. After the specimens were cut into 10 mm thickness slices, the CT- pathologic correlation was done. Fifteen clinical cases confirmed by pathology or clinical process were all performed spiral CT scan and analyzed, including emphysema-accompanying pneumonia 11 cases, emphysema-accompanying nodule 4 cases. Result: Centriacinar emphysema (CAE)can be seen in 21 of 23 specimens, pancinar emphysema(PAE) can be seen in 5 of 23 specimens, all coexisting with CAE. Distal acinar emphysema(DAE) can be seen in 19 of 23 specimens, irregular emphysema can be seen in 3 of 23 specimens. In all specimens, emphysema can be seen in bilateral lung fields, distributing similarly. Seventeen of 23 eases (17/23) showed no less than two types of emphysema. Fourteen cases of emphysema- accompanying pneumonia (clinic: 11 cases, specimen: 3 cases) showed 'pseudocavity' or 'pseudohoneycombing' (emphysema lesion that had not been filled in the consolidation). Four eases of emphysema-accompanying nodule showed 'pseudopleuralhollow' (wall of DAE or bulla connecting with nodule). Conclusion: The CT manifestations of emphysema, the characteristics of distribution and multi- type of emphysema coexisting can help differentiate cystic air space diseases. The characteristics of complications of emphysema, the 'pseudocavity', 'pseudohoneycombing' and 'pseudopleuralhollow', may be help for differential diagnosis. (authors)

  3. Brain perfusion: computed tomography applications

    International Nuclear Information System (INIS)

    Miles, K.A.

    2004-01-01

    Within recent years, the broad introduction of fast multi-detector computed tomography (CT) systems and the availability of commercial software for perfusion analysis have made cerebral perfusion imaging with CT a practical technique for the clinical environment. The technique is widely available at low cost, accurate and easy to perform. Perfusion CT is particularly applicable to those clinical circumstances where patients already undergo CT for other reasons, including stroke, head injury, subarachnoid haemorrhage and radiotherapy planning. Future technical developments in multi-slice CT systems may diminish the current limitations of limited spatial coverage and radiation burden. CT perfusion imaging on combined PET-CT systems offers new opportunities to improve the evaluation of patients with cerebral ischaemia or tumours by demonstrating the relationship between cerebral blood flow and metabolism. Yet CT is often not perceived as a technique for imaging cerebral perfusion. This article reviews the use of CT for imaging cerebral perfusion, highlighting its advantages and disadvantages and draws comparisons between perfusion CT and magnetic resonance imaging. (orig.)

  4. Spiral CT pneumocolon: applications, status and limitations

    International Nuclear Information System (INIS)

    Harvey, C.J.; Renfrew, I.; Taylor, S.; Gillams, A.R.; Lees, W.R.

    2001-01-01

    CT pneumocolon is a promising new technique in the diagnosis and management of colon pathology. CT pneumocolon can detect (sensitivity >95%) and stage (accuracy 79%) colorectal cancer and is very accurate in the differentiation of malignant from benign colonic pathologies. It has excellent detection rates for polyps >10 mm in diameter. Several studies using 3D virtual colonoscopy have already proven its high sensitivity and specificity in polyp detection making this technique robust as a screening tool. The combined results for virtual colonoscopy, from all centres, show a sensitivity of >85% in the detection of polyps 10 mm or greater in size, 70-80% for 5-9 mm polyps and an overall specificity of 90%. CT pneumocolon is a safe, non-invasive and cost-effective method for detecting colonic carcinomas and adenomas and correctly identifying which patients need further colonoscopy. The technique is quick, well tolerated and non-operator dependent. It can also image the proximal colon when distal stenoses prevent endoscopic and barium examination. CT pneumocolon is able to identify the features and complications of inflammatory bowel disease. Further research is warranted to fully assess its impact in terms of a screening tool, acceptability, availability and cost benefit. (orig.)

  5. Exploiting sparsity and low-rank structure for the recovery of multi-slice breast MRIs with reduced sampling error.

    Science.gov (United States)

    Yin, X X; Ng, B W-H; Ramamohanarao, K; Baghai-Wadji, A; Abbott, D

    2012-09-01

    It has been shown that, magnetic resonance images (MRIs) with sparsity representation in a transformed domain, e.g. spatial finite-differences (FD), or discrete cosine transform (DCT), can be restored from undersampled k-space via applying current compressive sampling theory. The paper presents a model-based method for the restoration of MRIs. The reduced-order model, in which a full-system-response is projected onto a subspace of lower dimensionality, has been used to accelerate image reconstruction by reducing the size of the involved linear system. In this paper, the singular value threshold (SVT) technique is applied as a denoising scheme to reduce and select the model order of the inverse Fourier transform image, and to restore multi-slice breast MRIs that have been compressively sampled in k-space. The restored MRIs with SVT for denoising show reduced sampling errors compared to the direct MRI restoration methods via spatial FD, or DCT. Compressive sampling is a technique for finding sparse solutions to underdetermined linear systems. The sparsity that is implicit in MRIs is to explore the solution to MRI reconstruction after transformation from significantly undersampled k-space. The challenge, however, is that, since some incoherent artifacts result from the random undersampling, noise-like interference is added to the image with sparse representation. These recovery algorithms in the literature are not capable of fully removing the artifacts. It is necessary to introduce a denoising procedure to improve the quality of image recovery. This paper applies a singular value threshold algorithm to reduce the model order of image basis functions, which allows further improvement of the quality of image reconstruction with removal of noise artifacts. The principle of the denoising scheme is to reconstruct the sparse MRI matrices optimally with a lower rank via selecting smaller number of dominant singular values. The singular value threshold algorithm is performed

  6. Short-scan-time multi-slice diffusion MRI of the mouse cervical spinal cord using echo planar imaging.

    Science.gov (United States)

    Callot, Virginie; Duhamel, Guillaume; Cozzone, Patrick J; Kober, Frank

    2008-10-01

    Mouse spinal cord (SC) diffusion-weighted imaging (DWI) provides important information on tissue morphology and structural changes that may occur during pathologies such as multiple sclerosis or SC injury. The acquisition scheme of the commonly used DWI techniques is based on conventional spin-echo encoding, which is time-consuming. The purpose of this work was to investigate whether the use of echo planar imaging (EPI) would provide good-quality diffusion MR images of mouse SC, as well as accurate measurements of diffusion-derived metrics, and thus enable diffusion tensor imaging (DTI) and highly resolved DWI within reasonable scan times. A four-shot diffusion-weighted spin-echo EPI (SE-EPI) sequence was evaluated at 11.75 T on a group of healthy mice (n = 10). SE-EPI-derived apparent diffusion coefficients of gray and white matter were compared with those obtained using a conventional spin-echo sequence (c-SE) to validate the accuracy of the method. To take advantage of the reduction in acquisition time offered by the EPI sequence, multi-slice DTI acquisitions were performed covering the cervical segments (six slices, six diffusion-encoding directions, three b values) within 30 min (vs 2 h for c-SE). From these measurements, fractional anisotropy and mean diffusivities were calculated, and fiber tracking along the C1 to C6 cervical segments was performed. In addition, high-resolution images (74 x 94 microm(2)) were acquired within 5 min per direction. Clear delineation of gray and white matter and identical apparent diffusion coefficient values were obtained, with a threefold reduction in acquisition time compared with c-SE. While overcoming the difficulties associated with high spatially and temporally resolved DTI measurements, the present SE-EPI approach permitted identification of reliable quantitative parameters with a reproducibility compatible with the detection of pathologies. The SE-EPI method may be particularly valuable when multiple sets of images

  7. Substantial dose reduction in modern multi-slice spiral computed tomography (MSCT)-guided craniofacial and skull base surgery

    International Nuclear Information System (INIS)

    Widmann, G.; Fasser, M.; Jaschke, W.; Bale, R.; Schullian, P.; Zangerl, A.; Puelacher, W.; Kral, F.; Riechelmann, H.

    2012-01-01

    Purpose: Reduction of the radiation exposure involved in image-guided craniofacial and skull base surgery is an important goal. The purpose was to evaluate the influence of low-dose protocols in modern multi-slice spiral computed tomography (MSCT) on target registration errors (TREs). Materials and Methods: An anthropomorphic skull phantom with target markers at the craniofacial bone and the anterior skull base was scanned in Sensation Open (40-slice), LightSpeed VCT (64-slice) and Definition Flash (128-slice). Identical baseline protocols (BP) at 120 kV/100 mAs were compared to the following low-dose protocols (LD) in care dose/dose modulation: (LD-I) 100 kV/35ref. mAs, (LD-II) 80 kV/40 - 41ref. mAs, and (LD-III) 80 kV/15 - 17ref. mAs. CTDIvol and DLP were obtained. TREs using an optical navigation system were calculated for all scanners and protocols. Results were statistically analyzed in SPSS and compared for significant differences (p ≤ 0.05). Results: CTDIvol for the Sensation Open/LightSpeed VCT/Definition Flash showed: (BP) 22.24 /32.48 /14.32 mGy; (LD-I) 4.61 /3.52 /1,62 mGy; (LD-II) 3.15 /2.01 /0.87 mGy; and (LD-III) na/0.76 /0.76 mGy. Differences between the BfS (Bundesamt fuer Strahlenschutz) reference CTDIvol of 9 mGy and the lowest CTDIvol were approximately 3-fold for Sensation Open, and 12-fold for the LightSpeed VCT and Definition Flash. A total of 33 registrations and 297 TRE measurements were performed. In all MSCT scanners, the TREs did not significantly differ between the low-dose and the baseline protocols. Conclusion: Low-dose protocols in modern MSCT provided substantial dose reductions without significant influence on TRE and should be strongly considered in image-guided surgery. (orig.)

  8. Clinical applications of SPECT/CT in imaging the extremities

    International Nuclear Information System (INIS)

    Huellner, Martin W.; Strobel, Klaus

    2014-01-01

    Today, SPECT/CT is increasingly used and available in the majority of larger nuclear medicine departments. Several applications of SPECT/CT as a supplement to or replacement for traditional conventional bone scintigraphy have been established in recent years. SPECT/CT of the upper and lower extremities is valuable in many conditions with abnormal bone turnover due to trauma, inflammation, infection, degeneration or tumour. SPECT/CT is often used in patients if conventional radiographs are insufficient, if MR image quality is impaired due to metal implants or in patients with contraindications to MR. In complex joints such as those in the foot and wrist, SPECT/CT provides exact anatomical correlation of pathological uptake. In many cases SPECT increases the sensitivity and CT the specificity of the study, increasing confidence in the final diagnosis compared to planar images alone. The CT protocol should be adapted to the clinical question and may vary from very low-dose (e.g. attenuation correction only), to low-dose for anatomical correlation, to normal-dose protocols enabling precise anatomical resolution. The aim of this review is to give an overview of SPECT/CT imaging of the extremities with a focus on the hand and wrist, knee and foot, and for evaluation of patients after joint arthroplasty. (orig.)

  9. Clinical applications of SPECT/CT in imaging the extremities

    Energy Technology Data Exchange (ETDEWEB)

    Huellner, Martin W. [University Hospital Zurich, Department of Medical Radiology, Division of Nuclear Medicine, Zurich (Switzerland); Strobel, Klaus [Lucerne Cantonal Hospital, Department of Nuclear Medicine and Radiology, Lucerne (Switzerland)

    2014-05-15

    Today, SPECT/CT is increasingly used and available in the majority of larger nuclear medicine departments. Several applications of SPECT/CT as a supplement to or replacement for traditional conventional bone scintigraphy have been established in recent years. SPECT/CT of the upper and lower extremities is valuable in many conditions with abnormal bone turnover due to trauma, inflammation, infection, degeneration or tumour. SPECT/CT is often used in patients if conventional radiographs are insufficient, if MR image quality is impaired due to metal implants or in patients with contraindications to MR. In complex joints such as those in the foot and wrist, SPECT/CT provides exact anatomical correlation of pathological uptake. In many cases SPECT increases the sensitivity and CT the specificity of the study, increasing confidence in the final diagnosis compared to planar images alone. The CT protocol should be adapted to the clinical question and may vary from very low-dose (e.g. attenuation correction only), to low-dose for anatomical correlation, to normal-dose protocols enabling precise anatomical resolution. The aim of this review is to give an overview of SPECT/CT imaging of the extremities with a focus on the hand and wrist, knee and foot, and for evaluation of patients after joint arthroplasty. (orig.)

  10. The development of remote teaching laboratory access software for multi-slice computed optical tomography for use in undergraduate nuclear education

    Energy Technology Data Exchange (ETDEWEB)

    Price, T.J.; Nichita, E., E-mail: Terry.Price@gmail.com [Univ. of Ontario Inst. of Technology, Oshawa, Ontario (Canada)

    2013-07-01

    Internet-based laboratory exercises were developed for a course on biomedical imaging at the University of Ontario Institute of Technology. These exercises used a multi-slice computed optical tomography machine named DeskCAT to instruct students on the principals of computed tomography. User management software was developed which enabled course instructors to quickly set up a computer to accept a series of scheduled remote user connections for a classroom. Laboratory exercises using the DeskCAT machine were developed to be conducted remotely. (author)

  11. The development of remote teaching laboratory access software for multi-slice computed optical tomography for use in undergraduate nuclear education

    International Nuclear Information System (INIS)

    Price, T.J.; Nichita, E.

    2013-01-01

    Internet-based laboratory exercises were developed for a course on biomedical imaging at the University of Ontario Institute of Technology. These exercises used a multi-slice computed optical tomography machine named DeskCAT to instruct students on the principals of computed tomography. User management software was developed which enabled course instructors to quickly set up a computer to accept a series of scheduled remote user connections for a classroom. Laboratory exercises using the DeskCAT machine were developed to be conducted remotely. (author)

  12. SPECT/CT: main applications in nuclear medicine

    International Nuclear Information System (INIS)

    Perera Pintado, Alejandro; Torres Aroche, Leonel A.; Vergara Gil, Alex; Batista Cuéllar, Juan F.; Prats Capote, Anaís

    2017-01-01

    SPECT/CT has represented not only the possibility of acquiring anatomical and functional images in one single study, but also a revolution for the clinical management of several diseases, taking the better of each one of these imaging modalities. The present work is aimed at presenting an overview of the most important applications of the SPECT/CT in the field of oncology, cardiology and neurology. New technological advances in the design of innovative solid state detectors and related equipment have had a positive effect on the performance of this kind of dual modality. This hybrid technique improves the sensitivity and the specificity of gammagraphic studies, as well as shortens the acquisition times and gives attenuation correction of co-registered images, which, in turn, makes their analysis easier. Some of the main applications for the study of oncological diseases are the following: localization and follow-up of different kinds of tumors, their metastasis and relapses, as well as the optimization of radiotherapy doses. This technique has been useful to evaluate the coronary artery disease allowing an adequate attenuation correction of images, the determination of calcium score, and performing angio-CT studies, according to the CT quality. SPECT/CT has also gained ground in the assessment of some neurological diseases. Conclusions: The introduction of new technological advances and radiopharmaceuticals thus predicting a more relevant place for SPECT/CT in clinical practice. (author)

  13. Application of CPLD in the industrial CT system

    International Nuclear Information System (INIS)

    Qi Mingrui; Li Jianmin; Zhao Haotong

    2004-01-01

    The application of CPLD (Complex Programmable Logic Devices) in the industrial CT system is discussed. The paper gives an architecture design and the realization of synchronized trigger module in the scan control sub-system; and also presents the circuit diagram and some result in detail. In the experimental CT system, it is well proved that the application of in-system programmable device supplies many advantages: the complexion of system and circuit is reduced; the process of debug and test is very simple; the system is flexible and the testing time is short. (authors)

  14. Metabolomics of Therapy Response in Preclinical Glioblastoma: A Multi-Slice MRSI-Based Volumetric Analysis for Noninvasive Assessment of Temozolomide Treatment

    Science.gov (United States)

    Arias-Ramos, Nuria; Ferrer-Font, Laura; Lope-Piedrafita, Silvia; Mocioiu, Victor; Julià-Sapé, Margarida; Pumarola, Martí; Arús, Carles; Candiota, Ana Paula

    2017-01-01

    Glioblastoma (GBM) is the most common aggressive primary brain tumor in adults, with a short survival time even after aggressive therapy. Non-invasive surrogate biomarkers of therapy response may be relevant for improving patient survival. Previous work produced such biomarkers in preclinical GBM using semi-supervised source extraction and single-slice Magnetic Resonance Spectroscopic Imaging (MRSI). Nevertheless, GBMs are heterogeneous and single-slice studies could prevent obtaining relevant information. The purpose of this work was to evaluate whether a multi-slice MRSI approach, acquiring consecutive grids across the tumor, is feasible for preclinical models and may produce additional insight into therapy response. Nosological images were analyzed pixel-by-pixel and a relative responding volume, the Tumor Responding Index (TRI), was defined to quantify response. Heterogeneous response levels were observed and treated animals were ascribed to three arbitrary predefined groups: high response (HR, n = 2), TRI = 68.2 ± 2.8%, intermediate response (IR, n = 6), TRI = 41.1 ± 4.2% and low response (LR, n = 2), TRI = 13.4 ± 14.3%, producing therapy response categorization which had not been fully registered in single-slice studies. Results agreed with the multi-slice approach being feasible and producing an inverse correlation between TRI and Ki67 immunostaining. Additionally, ca. 7-day oscillations of TRI were observed, suggesting that host immune system activation in response to treatment could contribute to the responding patterns detected. PMID:28524099

  15. Metabolomics of Therapy Response in Preclinical Glioblastoma: A Multi-Slice MRSI-Based Volumetric Analysis for Noninvasive Assessment of Temozolomide Treatment

    Directory of Open Access Journals (Sweden)

    Nuria Arias-Ramos

    2017-05-01

    Full Text Available Glioblastoma (GBM is the most common aggressive primary brain tumor in adults, with a short survival time even after aggressive therapy. Non-invasive surrogate biomarkers of therapy response may be relevant for improving patient survival. Previous work produced such biomarkers in preclinical GBM using semi-supervised source extraction and single-slice Magnetic Resonance Spectroscopic Imaging (MRSI. Nevertheless, GBMs are heterogeneous and single-slice studies could prevent obtaining relevant information. The purpose of this work was to evaluate whether a multi-slice MRSI approach, acquiring consecutive grids across the tumor, is feasible for preclinical models and may produce additional insight into therapy response. Nosological images were analyzed pixel-by-pixel and a relative responding volume, the Tumor Responding Index (TRI, was defined to quantify response. Heterogeneous response levels were observed and treated animals were ascribed to three arbitrary predefined groups: high response (HR, n = 2, TRI = 68.2 ± 2.8%, intermediate response (IR, n = 6, TRI = 41.1 ± 4.2% and low response (LR, n = 2, TRI = 13.4 ± 14.3%, producing therapy response categorization which had not been fully registered in single-slice studies. Results agreed with the multi-slice approach being feasible and producing an inverse correlation between TRI and Ki67 immunostaining. Additionally, ca. 7-day oscillations of TRI were observed, suggesting that host immune system activation in response to treatment could contribute to the responding patterns detected.

  16. Mikro-CT: Technology and applications for assessing bone structure

    International Nuclear Information System (INIS)

    Engelke, K.; Karolczak, M.; Lutz, A.; Seibert, U.; Schaller, S.; Kalender, W.

    1999-01-01

    The strength and fracture resistance of bone is determined by the structure of the trabecular network and the cortical shell. While standard 2D techniques like histomorphometry are inadequate to assess the 3D nature of the trabecular network, isotropic 3D datasets of this network can be acquired with the new imaging modality of μCT. However, so far the quantitative analysis of the generated datasets, in particular the extraction of appropriate parameters describing the bone structure, has not been finally solved. In this article we describe the technology and applications of μCT systems relevant in the field of osteology. The most important technical features of current μCT systems in this context are: 1. A spatial resolution down to 5-10 μm can be achieved. 2. The maximum sample size is related to the desired resolution by a factor of approximately 1000, that is, a resolution of 10 μm limits the maximum sample size to approximately 1 cm. 3. Scan times for μCT systems vary between minutes and hours. Currently five areas for the application of μCT systems in osteology can be identified: 1. The search of parameters characterizing the 3D trabecular structure. 2. The application of finite element models to determine the biochemical competence of the structural parameters. 3. The use of μCT in preclinical trials to study drug effects in small animals. 4. The validation of analysis methods used in high-resolution in-vivo imaging systems. 5. The 3D quantification of modeling and remodeling processes. (orig.) [de

  17. The application of PET-CT in gastrointestinal stromal tumor

    International Nuclear Information System (INIS)

    Xian Weijun; Feng Yanlin

    2009-01-01

    Gastrointestinal stromal tumor (GIST) is a mesenchymal neoplasm of uncertain malignant potential that arises predominantly in the gastrointestinal tract. Due to lack of specific physical signs, imagin g-x examination is an important auxiliary means in diagnosing gastrointestinal stromal tumor. Compared to other conventional imaging examinations, PET-CT has demonstrated unique superiority in staging, response evaluation and follow-up of gastrointestinal stromal tumor. And now it presents an overview of the application valuation of PET-CT and related imaging technology in gastrointestinal stromal tumor as follow. (authors)

  18. Application of three-dimensional CT reconstruction cranioplasty

    International Nuclear Information System (INIS)

    Yan Shuli; Yun Yongxing; Wan Kunming; Qiu Jian

    2011-01-01

    Objective: To study the application of three-dimensional CT reconstruction in cranioplasty. Methods: 46 patients with skull defect were divided into two group. One group underwent CT examination and three-dimensional reconstruction, and then the Titanium nets production company manufactured corresponding titanium meshes were shaped those data before the operation. The other group received traditional operation in which titanium meshes were shaped during operation. The average time of operation were compared. Results: The average time of operation of the first group is 86.6±13.6 mins, and that of the second group is 115±15.0 mins. The difference of average operation time between the two groups was statistically significant. Conclusion: Three-dimensional CT reconstruction techniques contribute to shorten the average operation time, reduce the intensity of neurosurgeon's work and the patien's risk. (authors)

  19. Investigation of the slice sensitivity profile for step-and-shoot mode multi-slice computed tomography

    International Nuclear Information System (INIS)

    Hsieh Jiang

    2001-01-01

    Multislice computed tomography (MCT) is one of the recent technology advancements in CT. Compared to single slice CT, MCT significantly improves examination time, x-ray tube efficiency, and contrast material utilization. Although the scan mode of MCT is predominately helical, step-and-shoot (axial) scans continue to be an important part of routine clinical protocols. In this paper, we present a detailed investigation on the slice sensitivity profile (SSP) of MCT in the step-and-shoot mode. Our investigation shows that, unlike single slice CT, the SSP for MCT exhibits multiple peaks and valleys resulting from intercell gaps between detector rows. To fully understand the characteristics of the SSP, we developed an analytical model to predict the behavior of MCT. We propose a simple experimental technique that can quickly and accurately measure SSP. The impact of the SSP on image artifacts and low contrast detectability is also investigated

  20. Motion estimation and compensation in dynamic spiral CT reconstruction

    International Nuclear Information System (INIS)

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

    2004-01-01

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

  1. Parametric boundary reconstruction algorithm for industrial CT metrology application.

    Science.gov (United States)

    Yin, Zhye; Khare, Kedar; De Man, Bruno

    2009-01-01

    High-energy X-ray computed tomography (CT) systems have been recently used to produce high-resolution images in various nondestructive testing and evaluation (NDT/NDE) applications. The accuracy of the dimensional information extracted from CT images is rapidly approaching the accuracy achieved with a coordinate measuring machine (CMM), the conventional approach to acquire the metrology information directly. On the other hand, CT systems generate the sinogram which is transformed mathematically to the pixel-based images. The dimensional information of the scanned object is extracted later by performing edge detection on reconstructed CT images. The dimensional accuracy of this approach is limited by the grid size of the pixel-based representation of CT images since the edge detection is performed on the pixel grid. Moreover, reconstructed CT images usually display various artifacts due to the underlying physical process and resulting object boundaries from the edge detection fail to represent the true boundaries of the scanned object. In this paper, a novel algorithm to reconstruct the boundaries of an object with uniform material composition and uniform density is presented. There are three major benefits in the proposed approach. First, since the boundary parameters are reconstructed instead of image pixels, the complexity of the reconstruction algorithm is significantly reduced. The iterative approach, which can be computationally intensive, will be practical with the parametric boundary reconstruction. Second, the object of interest in metrology can be represented more directly and accurately by the boundary parameters instead of the image pixels. By eliminating the extra edge detection step, the overall dimensional accuracy and process time can be improved. Third, since the parametric reconstruction approach shares the boundary representation with other conventional metrology modalities such as CMM, boundary information from other modalities can be directly

  2. Clinical applications of the imatron fast CT scanner

    International Nuclear Information System (INIS)

    Stanford, W.

    1986-01-01

    Utilizing three imaging modes, Cine CT has proven satisfactory in the assessment of left ventricular mass and function including ejection fractions and abnormalities of wall motion. It is helpful in documenting pericardial constrictions, as well as in assessing intracavitary tumors and thrombi. In the lungs, it is used to document AV fistulae and to evaluate the vascularity of mediastinal masses and to exclude invasion or major thoracic vessels. It can be used, as in the conventional scanner, for needle directed lung and chest well biopsies. It is frequently used in a airway studies to differentiate fixed from physiologic constrictions and to assess tracheomalacia and bronchopulmonary dysplasias. It can be used to plan radiation ports in the treatment of breast carcinoma. In the abdomen, successful applications include its use in the assessment of renal blood flow and the evaluation of cavernous hemangiomas of the liver as well as in screening of possible aortic aneurysms. In orthopedics, Cine CT is used to evaluate patellofermoral tracking in subluxations of the patella and used to evaluate subluxations and dislocations of the radio-ulnar joint. Cine CT by virtue of its speed and satisfactory spatial resolution is a significant imaging modality for evaluating the beating heart. Other applications include the evaluation of aortic aneurysms and dissections, para-aortic mass lesions, airway obstructions and patellar tracking and forearm subluxations

  3. Spinal CT-guided injections. Clinical applications-limitations

    International Nuclear Information System (INIS)

    Stamatakis, V.; Vlachou, I.; Petrocheilou, G.; Safarika, V.; Geroukis, I.; Petinelli, A.; Stathopoulou, S.; Kokkinis, C.

    2012-01-01

    Full text: Introduction: Chronic spinal pain is an important health issue with serious social and financial consequences. Thus, application of minimal invasive procedures is a popular technique for immediate relief of pain. Objectives and tasks: Our purpose is to present CT guided intraspinal injection of pharmaceutical agents for the relief of persistent pain. Material and methods: Chronic localized or radicular spinal pain may be treated safely and efficiently with injection of various pharmaceutical agents (local anesthetic, opioid analgesic and steroids or combination of these). The possible sites of infiltration include: a) intervertebral joints (facets), b) sacroiliac joints, c)perineural infiltration of the affected nerve roots and d) the epidural space. We will mention the patients choice criteria (combination of clinical symptoms and specific pain evaluation questionnaire) as they are reported in the international bibliography. Finally, we will discuss the repeatability criteria of the method as well as its limitations. Results: CT-guided pharmaceutical agents injection for the relief of persistent spinal pain have an advantage against other methods because of the precision and safety that they offer to the localization and diagnosis of the pain cause. Conclusion: Small complications percentage and satisfactory results have made CT-guided spinal injections a popular technique for chronic back pain relief. In order to apply these techniques the good knowledge of the method, its possibilities and limitations is necessary

  4. Accelerated magnetic resonance diffusion tensor imaging of the median nerve using simultaneous multi-slice echo planar imaging with blipped CAIPIRINHA.

    Science.gov (United States)

    Filli, Lukas; Piccirelli, Marco; Kenkel, David; Boss, Andreas; Manoliu, Andrei; Andreisek, Gustav; Bhat, Himanshu; Runge, Val M; Guggenberger, Roman

    2016-06-01

    To investigate the feasibility of MR diffusion tensor imaging (DTI) of the median nerve using simultaneous multi-slice echo planar imaging (EPI) with blipped CAIPIRINHA. After federal ethics board approval, MR imaging of the median nerves of eight healthy volunteers (mean age, 29.4 years; range, 25-32) was performed at 3 T using a 16-channel hand/wrist coil. An EPI sequence (b-value, 1,000 s/mm(2); 20 gradient directions) was acquired without acceleration as well as with twofold and threefold slice acceleration. Fractional anisotropy (FA), mean diffusivity (MD) and quality of nerve tractography (number of tracks, average track length, track homogeneity, anatomical accuracy) were compared between the acquisitions using multivariate ANOVA and the Kruskal-Wallis test. Acquisition time was 6:08 min for standard DTI, 3:38 min for twofold and 2:31 min for threefold acceleration. No differences were found regarding FA (standard DTI: 0.620 ± 0.058; twofold acceleration: 0.642 ± 0.058; threefold acceleration: 0.644 ± 0.061; p ≥ 0.217) and MD (standard DTI: 1.076 ± 0.080 mm(2)/s; twofold acceleration: 1.016 ± 0.123 mm(2)/s; threefold acceleration: 0.979 ± 0.153 mm(2)/s; p ≥ 0.074). Twofold acceleration yielded similar tractography quality compared to standard DTI (p > 0.05). With threefold acceleration, however, average track length and track homogeneity decreased (p = 0.004-0.021). Accelerated DTI of the median nerve is feasible. Twofold acceleration yields similar results to standard DTI. • Standard DTI of the median nerve is limited by its long acquisition time. • Simultaneous multi-slice acquisition is a new technique for accelerated DTI. • Accelerated DTI of the median nerve yields similar results to standard DTI.

  5. 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)

  6. Research on comparison of exposure with electrocardiographic gated mA modulation (ECG) and ECG and CAREDose 4D mode in coronary multi-slice spiral CT angiography

    International Nuclear Information System (INIS)

    Liu Bin; Guo Senlin; Wei Lan; Fei Xiaolu; Bai Mei

    2009-01-01

    Objective: The objective of this article was to compare patients dose with electrocardiographic gated mA modulation (ECG) and ECG and CAREDose 4D mode during coronary MSCT angiography. Methods: The research was based on phantom experiment and computer simulation to get the mean value of peak skin dose data and effective dose data respectively and to analyze deterministic and stochastic radiation risk. Results: The peak skin dose using ECG mode alone and using ECG and CAREDose 4D mode with the same image noise level was (87.4 ± 0.9) and (45.9 ± 1.2) mGy respectively. Effective dose was 17 and 10 rosy for ECG mode and ECG and CAREDose 4D mode respectively. Comparing with ECG mode alone, ECG and CAREDose 4D mode reduced organ dose of gonad, red marrow, lung, stomach, breast and thyroid by 40.0%, 36.7%, 39.3%, 37.7%, 38.8% and 38.9%, respectively. Conclusion: Results showed that ECG and CAREDose 4D mode can reduce radiation dose effectively comparing using ECG mode alone, and that ECG and CAREDose 4D mode should be widely applied clinically with appropriate initial settings. (authors)

  7. Comparison of multi-slice CT findings between malignant focal pulmonary ground-glass opacity nodules and solid nodules of 3 cm or less

    International Nuclear Information System (INIS)

    Fan Li; Yu Hong; Liu Shiyuan; Li Qingchu; Jiang Tao; Xiao Xiangsheng

    2010-01-01

    Objective: To compare the MSCT findings of malignant focal pulmonary ground-glass opacity nodules (fGGO) and solid nodules of 3 cm or less, and try to find specific signs in fGGO. Methods: Clinical data (sex ratio, age), size of lesion and MSCT findings (shape, margin, interface, internal characteristics, adjacent structure) of 105 cases pathologically confirmed to have solid lung cancers and 48 cases with fGGO less than 3 cm were retrospectively analyzed. Differences were analyzed by using the Fisher exact test or Mann-Whitney U test. Results: The male and female ratio of solid lung cancer(60:45) were higher than that of fGGO (18:30, X 2 value 5.09, P 2 values were 11.48, 4.07, 29.70 and 22.38 respectively, P 2 values 1.00, 2.20, 0.00, 0.15, 4.43, 1.50, 0.00, P>0.05). Conclusions: Malignant fGGO and solid lung cancer manifest mostly similar MSCT features. The frequency of irregular shape, vacuole sign and air bronchograms was higher in fGGO than in solid lung cancer to some degree, but speculation is more infrequent in fGGO, which may be attribute to thepathological type and basis of tumor. (authors)

  8. Clinical application of CT and CT-guided percutaneous transthoracic needle biopsy in patients with indeterminate pulmonary nodules

    Energy Technology Data Exchange (ETDEWEB)

    Cardoso, Luciana Vargas; Souza Júnior, Arthur Soares, E-mail: fabianonatividade@terra.com.br [Rio Preto-Ultra-X Radiological Diagnosis Institute, São José do Rio Preto, SP (Brazil)

    2014-07-15

    Objective: To investigate the clinical application of CT and CT-guided percutaneous transthoracic needle biopsy (CT-PTNB) in patients with indeterminate pulmonary nodules (IPNs). Methods: We retrospectively studied 113 patients with PNs undergoing CT and CT-PTNB. Variables such as gender, age at diagnosis, smoking status, CT findings, and CT-PTNB techniques were analyzed. Data analysis was performed with the Student's t-test for independent samples the chi-square test, and normal approximation test for comparison of two proportions. Results: Of the 113 patients studied, 68 (60.2%) were male and 78 (69%) were smokers. The diameter of malignant lesions ranged from 2.6 cm to 10.0 cm. Most of the IPNs (85%) were located in the peripheral region. The biopsied IPNs were found to be malignant in 88 patients (77.8%) and benign in 25 (22.2%). Adenocarcinoma was the most common malignant tumor, affecting older patients. The IPN diameter was significantly greater in patients with malignant PNs than in those with benign IPNs (p < 0.001). Having regular contour correlated significantly with an IPN being benign (p = 0.022), whereas spiculated IPNs and bosselated IPNs were more often malignant (in 50.7% and 28.7%, respectively). Homogeneous attenuation and necrosis were more common in patients with malignant lesions (51.9% and 26.9%, respectively). Conclusions: In our sample, CT and CT-PTNB were useful in distinguishing between malignant and benign IPNs. Advanced age and smoking were significantly associated with malignancy. Certain CT findings related to IPNs (larger diameter, spiculated borders, homogeneous attenuation, and necrosis) were associated with malignancy. (author)

  9. [Application of SPECT/CT in neurosurgical practice].

    Science.gov (United States)

    Golanov, A V; Kotel'nikova, T M; Melikian, A G; Dolgushin, M B; Sorokin, V S; Soboleva, O I; Khokhlova, E V; Gorlachev, G E; Krasnianskiĭ, S A

    2012-01-01

    The paper presents the experience of application of single-photon emission computed tomography (SPECT) and CT in neurosurgery. Combination of these two techniques in the single system provides higher precision of both methods. The novel technique allows assessment of tumor spread in the brain, differential diagnosis of tumor regrowth and radiation-induced necrosis, evaluation of cerebral perfusion in epilepsy, traumatic brain injury (TBI), and diagnostics of secondary CNS lesions. Examples of primary diagnosis, dynamic follow-up and differential diagnosis of cerebral neoplasms, localization of epileptogenic foci in planning of surgery, prediction of outcome after TBI and evaluation of spread of metastatic skeletal involvement and further application of acquire data are presented.

  10. Optimal CT scanning parameters for commonly used tumor ablation applicators

    International Nuclear Information System (INIS)

    Eltorai, Adam E.M.; Baird, Grayson L.; Monu, Nicholas; Wolf, Farrah; Seidler, Michael; Collins, Scott; Kim, Jeomsoon; Dupuy, Damian E.

    2017-01-01

    Highlights: • This study aimed to determine optimal scanning parameters for commonly-used tumor ablation applicators. • The findings illustrate the overall interaction of the effects of kVp, ASiR, and reconstruction algorithm within and between probes, so that radiologists may easily reference optimal imaging performance. • Optimum combinations for each probe are provided. - Abstract: Purpose: CT-beam hardening artifact can make tumor margin visualization and its relationship to the ablation applicator tip challenging. To determine optimal scanning parameters for commonly-used applicators. Materials and methods: Applicators were placed in ex-vivo cow livers with implanted mock tumors, surrounded by bolus gel. Various CT scans were performed at 440 mA with 5 mm thickness changing kVp, scan time, ASiR, scan type, pitch, and reconstruction algorithm. Four radiologists blindly scored the images for image quality and artifact quantitatively. Results: A significant relationship between probe, kVp level, ASiR level, and reconstruction algorithm was observed concerning both image artifact and image quality (both p = <0.0001). Specifically, there are certain combinations of kVp, ASiR, and reconstruction algorithm that yield better images than other combinations. In particular, one probe performed equivalently or better than any competing probe considered here, regardless of kVp, ASiR, and reconstruction algorithm combination. Conclusion: The findings illustrate the overall interaction of the effects of kVp, ASiR, and reconstruction algorithm within and between probes, so that radiologists may easily reference optimal imaging performance for a certain combinations of kVp, ASiR, reconstruction algorithm and probes at their disposal. Optimum combinations for each probe are provided.

  11. Optimal CT scanning parameters for commonly used tumor ablation applicators

    Energy Technology Data Exchange (ETDEWEB)

    Eltorai, Adam E.M. [Warren Alpert Medical School of Brown University (United States); Baird, Grayson L. [Department of Diagnostic Imaging (United States); Warren Alpert Medical School of Brown University (United States); Lifespan Biostatistics Core (United States); Rhode Island Hospital (United States); Monu, Nicholas; Wolf, Farrah; Seidler, Michael [Department of Diagnostic Imaging (United States); Warren Alpert Medical School of Brown University (United States); Rhode Island Hospital (United States); Collins, Scott [Department of Diagnostic Imaging (United States); Rhode Island Hospital (United States); Kim, Jeomsoon [Department of Medical Physics (United States); Rhode Island Hospital (United States); Dupuy, Damian E., E-mail: ddupuy@comcast.net [Department of Diagnostic Imaging (United States); Warren Alpert Medical School of Brown University (United States); Rhode Island Hospital (United States)

    2017-04-15

    Highlights: • This study aimed to determine optimal scanning parameters for commonly-used tumor ablation applicators. • The findings illustrate the overall interaction of the effects of kVp, ASiR, and reconstruction algorithm within and between probes, so that radiologists may easily reference optimal imaging performance. • Optimum combinations for each probe are provided. - Abstract: Purpose: CT-beam hardening artifact can make tumor margin visualization and its relationship to the ablation applicator tip challenging. To determine optimal scanning parameters for commonly-used applicators. Materials and methods: Applicators were placed in ex-vivo cow livers with implanted mock tumors, surrounded by bolus gel. Various CT scans were performed at 440 mA with 5 mm thickness changing kVp, scan time, ASiR, scan type, pitch, and reconstruction algorithm. Four radiologists blindly scored the images for image quality and artifact quantitatively. Results: A significant relationship between probe, kVp level, ASiR level, and reconstruction algorithm was observed concerning both image artifact and image quality (both p = <0.0001). Specifically, there are certain combinations of kVp, ASiR, and reconstruction algorithm that yield better images than other combinations. In particular, one probe performed equivalently or better than any competing probe considered here, regardless of kVp, ASiR, and reconstruction algorithm combination. Conclusion: The findings illustrate the overall interaction of the effects of kVp, ASiR, and reconstruction algorithm within and between probes, so that radiologists may easily reference optimal imaging performance for a certain combinations of kVp, ASiR, reconstruction algorithm and probes at their disposal. Optimum combinations for each probe are provided.

  12. The application of dose-reduction simulation in neonatal head CT scan

    International Nuclear Information System (INIS)

    Liu Yue; Peng Yun; Zeng Jinjin; Zhang Qifeng; Li Jianying

    2009-01-01

    Objective: To determine the effects of dose reduction on multi-slice spiral CT (MSCT) of neonatal head and assess the lowest possible radiation for acceptable clinical images. Methods: Fifty-seven newborns suspected intracranial hemorrhage were entered into the study and underwent MSCT scans. Original images at three anatomic levels (posterior fossa, basal ganglia, centrum semiovale) were collected and synthetic noise was added so as to simulate dose reductions of 25%, 40%, 50% and 70%, respectively by using the noise addition tool. A total of 855 image data sets were obtained for the 57 patients. Original and simulated dose-reduction scan images were analyzed. Image noise and image quality were assessed by two independent experienced pediatric radiologists using diagnostic acceptability score, subjective image noise score on a 5-point scale and objective noise index. Image noise was measured by respectively placing region of interest (ROI) at cerebellum, thalamus and corona radiata of 3 different slices. And the noise index and mean value was calculated. The degree of inter-observer concordance was determined by Kappa statistical analysis. The Spearman statistical correlations between the noise index and diagnostic acceptability score were performed. Results: On the images of original dose and simulated dose reductions of 25%, 40%, 50% and 70%, the diagnostic acceptability was 4.47±0.51, 3.96±0.33, 3.21±0.45, 2.92±0.32, and 1.85±0.57, respectively, the subjective image scores were 1.62±0.48, 1.99±0.48, 2.76±0.81, 3.19±0.67, and 4.27±0.54, respectively, the noise index were 1.90±0.19, 2.17±0.20. 2.44± 0.25, 2.68±0.28, and 3.37±0.39, respectively. The two radiologists had good interobserver agreement for diagnostic acceptability (K=0.860, P=0.017) and for image noise scoring(K=0.630, P=0.022). There was significant statistical correlation between image noise index and diagnostic acceptability (r= 0.826,P=0.001). At 40% dose reduction to the standard

  13. CT colonography after colostomy - clinical application and technical feasibility

    International Nuclear Information System (INIS)

    Nedevska, A.

    2013-01-01

    Full text:Introduction: The aim of this study was to evaluate the clinical application and technical implementation of computed tomographic (CT ) colonoscopy in patients undergoing sigmoid or rectal resection and following sigmoid colostomy in the course of standard diagnostic postoperative follow-up and prior to the reconstructive colon surgery. Materials and Methods: The study included 48 patients who underwent anterior abdomen-perineal or rectal resection and subsequent sigmoid colostomy in case of sigma or rectum carcinoma. The pre-procedure bowel preparation included a full colon cleansing and barium-based fecal tagging. The balloon catheter (18 F) is placed in the colonic stoma. The balloon is insufflated with 15-30 ml saline or air. The balloon was gently pulled until opening of the stoma has been closed completely. In 15 patients, a second catheter was placed in the remaining rectum. Contrast scanning in supination was done for all patients. An additional scanning in left and right lateral position was necessary for 9 patients. Results: All studies were carried out without any major complications. All patients tolerated the intubation and insufflation of air into the intestinal lumen. Two patients (4%) have evaluated the examination as uncomfortable. In 6 patients (12.5 %) it was impossible to evaluate the intestinal segments because due to a collapse of the wall. Five of them were localized in the descending colon. In 5 patients there was a significant amount of residual intestinal contents. The fecal tagging and intravenous contrast enhancing allowed the assessment of these intestinal segments. The rectal residue was correctly assessed in all patients in terms of length, position and wall changes. Conclusion: CT colonoscopy is applicable after sigmostoma in patients with abdomen-perineal and anterior rectal resection. Further in-depth studies are needed to determine the clinical indications and reliability of the method

  14. The evaluation of anti-angiogenic treatment effects for implanted rabbit VX2 breast tumors using functional multi-slice spiral computed tomography (f-MSCT)

    Energy Technology Data Exchange (ETDEWEB)

    Lei Zhen, E-mail: leizhen2004@163.com [Department of Anatomy, Chinese Medical University, No. 92, Beiermalu Road, Heping District, Shenyang, 110001 (China) and Department of Radiology, The First Hospital of Liaoning Medical College, No. 2, Wuduan, Renmin Street, Jinzhou, 121001 (China); Ma Heji, E-mail: maheji9831@sina.com [Department of Radiology, The First Hospital of Liaoning Medical College, No. 2, Wuduan, Renmin Street, Jinzhou, 121001 (China); Xu Na, E-mail: xuna821230@sohu.com [Department of Radiology, The First Hospital of Liaoning Medical College, No. 2, Wuduan, Renmin Street, Jinzhou, 121001 (China); Xi Huanjiu, E-mail: xihuanjiu2004@yahoo.cn [Anthropology Institute, Liaoning Medical College, No. 40, Sanduan, Songpo Rd, Jinzhou, 121001 (China)

    2011-05-15

    Objective: Investigate the benefit of functional multi-slice spiral computed tomography (f-MSCT) perfusion imaging in the non-invasive assessment of targeted anti-angiogenesis therapy on an implanted rabbit VX2 breast tumor model. Method: 69 female pure New Zealand white rabbits were randomly assigned to one of the 4 groups and received treatment accordingly: control (saline), Endostar, neoadjuvant chemotherapy (Cyclophosphamide, Epirubicin and 5-Fluorouracil, CEF), combination therapy (Endostar and CEF). After 2 weeks of treatment, f-MSCT perfusion scannings were performed for all rabbits and information about blood flow (BF), blood volume (BV), mean transit time (MTT) and surface permeability (SP) was collected. After perfusion imaging, tumor tissues were sampled for immunohistochemistry and the Western blot test of VEGF protein expression. Results: (1) The VEGF expression level, measured by immunohistochemistry and Western blot, decreased by treatment group (control > Endostar > CEF > combination therapy). The same was true for the mean BF, BV, MTT and PS, which decreased from the control group to the combination therapy group gradually. The mean MTT level increased in reverse order from the control to the combination therapy group. The difference between any 2 groups on these measures was statistically significant (P < 0.05). (2) There was moderate positive correlation between VEGF expression and BE, BV, or PS level (P < 0.05) and a negative correlation between VEGF expression and MTT level for all 4 groups (P < 0.05). Conclusion: Therefore, f-MSCT can be used as a non-invasive approach to evaluate the effect of anti-angiogenic therapy for implanted rabbit VX2 breast tumors.

  15. Genetic association of glutathione peroxidase-1 with coronary artery calcification in type 2 diabetes: a case control study with multi-slice computed tomography

    Directory of Open Access Journals (Sweden)

    Fujimoto Kei

    2007-09-01

    Full Text Available Abstract Background Although oxidative stress by accumulation of reactive oxygen species (ROS in diabetes has become evident, it remains unclear what genes, involved in redox balance, would determine susceptibility for development of atherosclerosis in diabetes. This study evaluated the effect of genetic polymorphism of enzymes producing or responsible for reducing ROS on coronary artery calcification in type 2 diabetes (T2D. Methods An index for coronary-arteriosclerosis, coronary artery calcium score (CACS was evaluated in 91 T2D patients using a multi-slice computed tomography. Patients were genotyped for ROS-scavenging enzymes, Glutathione peroxidase-1 (GPx-1, Catalase, Mn-SOD, Cu/Zn-SOD, as well as SNPs of NADPH oxidase as ROS-promoting elements, genes related to onset of T2D (CAPN10, ADRB3, PPAR gamma, FATP4. Age, blood pressure, BMI, HbA1c, lipid and duration of diabetes were evaluated for a multivariate regression analysis. Results CACS with Pro/Leu genotype of the GPx-1 gene was significantly higher than in those with Pro/Pro (744 ± 1,291 vs. 245 ± 399, respectively, p = 0.006. In addition, genotype frequency of Pro/Leu in those with CACS ≥ 1000 was significantly higher than in those with CACS OR = 3.61, CI = 0.97–13.42; p = 0.045 when tested for deviation from Hardy-Weinberg's equilibrium. Multivariate regression analyses revealed that CACS significantly correlated with GPx-1 genotypes and age. Conclusion The presence of Pro197Leu substitution of the GPx-1 gene may play a crucial role in determining genetic susceptibility to coronary-arteriosclerosis in T2D. The mechanism may be associated with a decreased ability to scavenge ROS with the variant GPx-1.

  16. Left atrial accessory appendages, diverticula, and left-sided septal pouch in multi-slice computed tomography. Association with atrial fibrillation and cerebrovascular accidents.

    Science.gov (United States)

    Hołda, Mateusz K; Koziej, Mateusz; Wszołek, Karolina; Pawlik, Wiesław; Krawczyk-Ożóg, Agata; Sorysz, Danuta; Łoboda, Piotr; Kuźma, Katarzyna; Kuniewicz, Marcin; Lelakowski, Jacek; Dudek, Dariusz; Klimek-Piotrowska, Wiesława

    2017-10-01

    The aim of this study is to provide a morphometric description of the left-sided septal pouch (LSSP), left atrial accessory appendages, and diverticula using cardiac multi-slice computed tomography (MSCT) and to compare results between patient subgroups. Two hundred and ninety four patients (42.9% females) with a mean of 69.4±13.1years of age were investigated using MSCT. The presence of the LSSP, left atrial accessory appendages, and diverticula was evaluated. Multiple logistic regression analysis was performed to check whether the presence of additional left atrial structures is associated with increased risk of atrial fibrillation and cerebrovascular accidents. At least one additional left atrial structure was present in 51.7% of patients. A single LSSP, left atrial diverticulum, and accessory appendage were present in 35.7%, 16.0%, and 4.1% of patients, respectively. After adjusting for other risk factors via multiple logistic regression, patients with LSSP are more likely to have atrial fibrillation (OR=2.00, 95% CI=1.14-3.48, p=0.01). The presence of a LSSP was found to be associated with an increased risk of transient ischemic attack using multiple logistic regression analysis after adjustment for other risk factors (OR=3.88, 95% CI=1.10-13.69, p=0.03). In conclusion LSSPs, accessory appendages, and diverticula are highly prevalent anatomic structures within the left atrium, which could be easily identified by MSCT. The presence of LSSP is associated with increased risk for atrial fibrillation and transient ischemic attack. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. The evaluation of anti-angiogenic treatment effects for implanted rabbit VX2 breast tumors using functional multi-slice spiral computed tomography (f-MSCT)

    International Nuclear Information System (INIS)

    Lei Zhen; Ma Heji; Xu Na; Xi Huanjiu

    2011-01-01

    Objective: Investigate the benefit of functional multi-slice spiral computed tomography (f-MSCT) perfusion imaging in the non-invasive assessment of targeted anti-angiogenesis therapy on an implanted rabbit VX2 breast tumor model. Method: 69 female pure New Zealand white rabbits were randomly assigned to one of the 4 groups and received treatment accordingly: control (saline), Endostar, neoadjuvant chemotherapy (Cyclophosphamide, Epirubicin and 5-Fluorouracil, CEF), combination therapy (Endostar and CEF). After 2 weeks of treatment, f-MSCT perfusion scannings were performed for all rabbits and information about blood flow (BF), blood volume (BV), mean transit time (MTT) and surface permeability (SP) was collected. After perfusion imaging, tumor tissues were sampled for immunohistochemistry and the Western blot test of VEGF protein expression. Results: (1) The VEGF expression level, measured by immunohistochemistry and Western blot, decreased by treatment group (control > Endostar > CEF > combination therapy). The same was true for the mean BF, BV, MTT and PS, which decreased from the control group to the combination therapy group gradually. The mean MTT level increased in reverse order from the control to the combination therapy group. The difference between any 2 groups on these measures was statistically significant (P < 0.05). (2) There was moderate positive correlation between VEGF expression and BE, BV, or PS level (P < 0.05) and a negative correlation between VEGF expression and MTT level for all 4 groups (P < 0.05). Conclusion: Therefore, f-MSCT can be used as a non-invasive approach to evaluate the effect of anti-angiogenic therapy for implanted rabbit VX2 breast tumors.

  18. Accelerated magnetic resonance diffusion tensor imaging of the median nerve using simultaneous multi-slice echo planar imaging with blipped CAIPIRINHA

    Energy Technology Data Exchange (ETDEWEB)

    Filli, Lukas; Kenkel, David; Boss, Andreas; Manoliu, Andrei; Andreisek, Gustav; Runge, Val M.; Guggenberger, Roman [University Hospital of Zurich, University of Zurich, Institute of Diagnostic and Interventional Radiology, Zurich (Switzerland); Piccirelli, Marco [University Hospital of Zurich, Department of Neuroradiology, Zurich (Switzerland); Bhat, Himanshu [Siemens Medical Solutions USA Inc, Charlestown, MA (United States)

    2016-06-15

    To investigate the feasibility of MR diffusion tensor imaging (DTI) of the median nerve using simultaneous multi-slice echo planar imaging (EPI) with blipped CAIPIRINHA. After federal ethics board approval, MR imaging of the median nerves of eight healthy volunteers (mean age, 29.4 years; range, 25-32) was performed at 3 T using a 16-channel hand/wrist coil. An EPI sequence (b-value, 1,000 s/mm{sup 2}; 20 gradient directions) was acquired without acceleration as well as with twofold and threefold slice acceleration. Fractional anisotropy (FA), mean diffusivity (MD) and quality of nerve tractography (number of tracks, average track length, track homogeneity, anatomical accuracy) were compared between the acquisitions using multivariate ANOVA and the Kruskal-Wallis test. Acquisition time was 6:08 min for standard DTI, 3:38 min for twofold and 2:31 min for threefold acceleration. No differences were found regarding FA (standard DTI: 0.620 ± 0.058; twofold acceleration: 0.642 ± 0.058; threefold acceleration: 0.644 ± 0.061; p ≥ 0.217) and MD (standard DTI: 1.076 ± 0.080 mm{sup 2}/s; twofold acceleration: 1.016 ± 0.123 mm{sup 2}/s; threefold acceleration: 0.979 ± 0.153 mm{sup 2}/s; p ≥ 0.074). Twofold acceleration yielded similar tractography quality compared to standard DTI (p > 0.05). With threefold acceleration, however, average track length and track homogeneity decreased (p = 0.004-0.021). Accelerated DTI of the median nerve is feasible. Twofold acceleration yields similar results to standard DTI. (orig.)

  19. A comparative study of accuracy of linear measurements using cone beam and multi-slice computed tomographies for evaluation of mandibular canal location in dry mandibles.

    Science.gov (United States)

    Naser, Asieh Zamani; Mehr, Bahar Behdad

    2013-01-01

    Cross- sectional tomograms have been used for optimal pre-operative planning of dental implant placement. The aim of the present study was to assess the accuracy of Cone Beam Computed Tomography (CBCT) measurements of specific distances around the mandibular canal by comparing them to those obtained from Multi-Slice Computed Tomography (MSCT) images. Ten hemi-mandible specimens were examined using CBCT and MSCT. Before imaging, wires were placed at 7 locations between the anterior margin of the third molar and the anterior margin of the second premolar as reference points. Following distances were measured by two observers on each cross-sectional CBCT and MSCT image: Mandibular Width (W), Length (L), Upper Distance (UD), Lower Distance (LD), Buccal Distance (BD), and Lingual Distance (LID). The obtained data were evaluated using SPSS software, applying paired t-test and intra-class correlation coefficient (ICC). There was a significant difference between the values obtained by MSCT and CBCT measurement for all areas such as H, W, UD, LD, BD, and LID, (P < 0.001), with a difference less than 1 mm. The ICC for all distances by both techniques, measured by a single observer with a one week interval and between 2 observers was 99% and 98%, respectively. Comparing the obtained data of both techniques indicates that the difference between two techniques is 2.17% relative to MSCT. The results of this study showed that there is significant difference between measurements obtained by CBCT and MSCT. However, the difference is not clinically significant.

  20. Clinical feasibility of simultaneous multi-slice imaging with blipped-CAIPI for diffusion-weighted imaging and diffusion-tensor imaging of the brain.

    Science.gov (United States)

    Yokota, Hajime; Sakai, Koji; Tazoe, Jun; Goto, Mariko; Imai, Hiroshi; Teramukai, Satoshi; Yamada, Kei

    2017-12-01

    Background Simultaneous multi-slice (SMS) imaging is starting to be used in clinical situation, although evidence of clinical feasibility is scanty. Purpose To prospectively assess the clinical feasibility of SMS diffusion-weighted imaging (DWI) and diffusion-tensor imaging (DTI) with blipped-controlled aliasing in parallel imaging for brain lesions. Material and Methods The institutional review board approved this study. This study included 156 hyperintense lesions on DWI from 32 patients. A slice acceleration factor of 2 was applied for SMS scans, which allowed shortening of the scan time by 41.3%. The signal-to-noise ratio (SNR) was calculated for brain tissue of a selected slice. The contrast-to-noise ratio (CNR), apparent diffusion coefficient (ADC), and fractional anisotropy (FA) were calculated in 36 hyperintense lesions with a diameter of three pixels or more. Visual assessment was performed for all 156 lesions. Tractography of the corticospinal tract of 29 patients was evaluated. The number of tracts and averaged tract length were used for quantitative analysis, and visual assessment was evaluated by grading. Results The SMS scan showed no bias and acceptable 95% limits of agreement compared to conventional scans in SNR, CNR, and ADC on Bland-Altman analyses. Only FA of the lesions was higher in the SMS scan by 9% ( P = 0.016), whereas FA of the surrounding tissues was similar. Quantitative analysis of tractography showed similar values. Visual assessment of DWI hyperintense lesions and tractography also resulted in comparable evaluation. Conclusion SMS imaging was clinically feasible for imaging quality and quantitative values compared with conventional DWI and DTI.

  1. Reconstruction of a ring applicator using CT imaging: impact of the reconstruction method and applicator orientation

    International Nuclear Information System (INIS)

    Hellebust, Taran Paulsen; Tanderup, Kari; Bergstrand, Eva Stabell; Knutsen, Bjoern Helge; Roeislien, Jo; Olsen, Dag Rune

    2007-01-01

    The purpose of this study is to investigate whether the method of applicator reconstruction and/or the applicator orientation influence the dose calculation to points around the applicator for brachytherapy of cervical cancer with CT-based treatment planning. A phantom, containing a fixed ring applicator set and six lead pellets representing dose points, was used. The phantom was CT scanned with the ring applicator at four different angles related to the image plane. In each scan the applicator was reconstructed by three methods: (1) direct reconstruction in each image (DR) (2) reconstruction in multiplanar reconstructed images (MPR) and (3) library plans, using pre-defined applicator geometry (LIB). The doses to the lead pellets were calculated. The relative standard deviation (SD) for all reconstruction methods was less than 3.7% in the dose points. The relative SD for the LIB method was significantly lower (p < 0.05) than for the DR and MPR methods for all but two points. All applicator orientations had similar dose calculation reproducibility. Using library plans for applicator reconstruction gives the most reproducible dose calculation. However, with restrictive guidelines for applicator reconstruction the uncertainties for all methods are low compared to other factors influencing the accuracy of brachytherapy

  2. 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)

  3. Neural network and its application to CT imaging

    Energy Technology Data Exchange (ETDEWEB)

    Nikravesh, M.; Kovscek, A.R.; Patzek, T.W. [Lawrence Berkeley National Lab., CA (United States)] [and others

    1997-02-01

    We present an integrated approach to imaging the progress of air displacement by spontaneous imbibition of oil into sandstone. We combine Computerized Tomography (CT) scanning and neural network image processing. The main aspects of our approach are (I) visualization of the distribution of oil and air saturation by CT, (II) interpretation of CT scans using neural networks, and (III) reconstruction of 3-D images of oil saturation from the CT scans with a neural network model. Excellent agreement between the actual images and the neural network predictions is found.

  4. Rapid whole-brain resting-state fMRI at 3 T: Efficiency-optimized three-dimensional EPI versus repetition time-matched simultaneous-multi-slice EPI.

    Science.gov (United States)

    Stirnberg, Rüdiger; Huijbers, Willem; Brenner, Daniel; Poser, Benedikt A; Breteler, Monique; Stöcker, Tony

    2017-12-01

    State-of-the-art simultaneous-multi-slice (SMS-)EPI and 3D-EPI share several properties that benefit functional MRI acquisition. Both sequences employ equivalent parallel imaging undersampling with controlled aliasing to achieve high temporal sampling rates. As a volumetric imaging sequence, 3D-EPI offers additional means of acceleration complementary to 2D-CAIPIRINHA sampling, such as fast water excitation and elliptical sampling. We performed an application-oriented comparison between a tailored, six-fold CAIPIRINHA-accelerated 3D-EPI protocol at 530 ms temporal and 2.4 mm isotropic spatial resolution and an SMS-EPI protocol with identical spatial and temporal resolution for whole-brain resting-state fMRI at 3 T. The latter required eight-fold slice acceleration to compensate for the lack of elliptical sampling and fast water excitation. Both sequences used vendor-supplied on-line image reconstruction. We acquired test/retest resting-state fMRI scans in ten volunteers, with simultaneous acquisition of cardiac and respiration data, subsequently used for optional physiological noise removal (nuisance regression). We found that the 3D-EPI protocol has significantly increased temporal signal-to-noise ratio throughout the brain as compared to the SMS-EPI protocol, especially when employing motion and nuisance regression. Both sequence types reliably identified known functional networks with stronger functional connectivity values for the 3D-EPI protocol. We conclude that the more time-efficient 3D-EPI primarily benefits from reduced parallel imaging noise due to a higher, actual k-space sampling density compared to SMS-EPI. The resultant BOLD sensitivity increase makes 3D-EPI a valuable alternative to SMS-EPI for whole-brain fMRI at 3 T, with voxel sizes well below 3 mm isotropic and sampling rates high enough to separate dominant cardiac signals from BOLD signals in the frequency domain. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. The role of hybrid SPECT-CT in oncology: current and emerging clinical applications

    International Nuclear Information System (INIS)

    Chowdhury, F.U.; Scarsbrook, A.F.

    2008-01-01

    Single photon emission computed tomography - computed tomography (SPECT-CT) is an emerging dual-modality imaging technique with many established and potential clinical applications in the field of oncology. To date, there has been a considerable emphasis on the benefits of integrated positron emission tomography - computed tomography (PET-CT) in oncology, but relatively little focus on the clinical utility of SPECT-CT. As with PET-CT, accurate co-registration of anatomical and functional data from a combined SPECT-CT camera often provides complementary diagnostic information. Both sensitivity (superior disease localization) and specificity (exclusion of false-positives due to physiological tracer uptake) are improved, and the functional significance of indeterminate lesions detected on cross-sectional imaging can be defined. This article will review the scope of hybrid SPECT-CT in oncology and illustrate both current and emerging clinical applications

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

    International Nuclear Information System (INIS)

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

    2013-01-01

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

  7. Correlation between model observers in uniform background and human observers in patient liver background for a low-contrast detection task in CT

    Science.gov (United States)

    Gong, Hao; Yu, Lifeng; Leng, Shuai; Dilger, Samantha; Zhou, Wei; Ren, Liqiang; McCollough, Cynthia H.

    2018-03-01

    Channelized Hotelling observer (CHO) has demonstrated strong correlation with human observer (HO) in both single-slice viewing mode and multi-slice viewing mode in low-contrast detection tasks with uniform background. However, it remains unknown if the simplest single-slice CHO in uniform background can be used to predict human observer performance in more realistic tasks that involve patient anatomical background and multi-slice viewing mode. In this study, we aim to investigate the correlation between CHO in a uniform water background and human observer performance at a multi-slice viewing mode on patient liver background for a low-contrast lesion detection task. The human observer study was performed on CT images from 7 abdominal CT exams. A noise insertion tool was employed to synthesize CT scans at two additional dose levels. A validated lesion insertion tool was used to numerically insert metastatic liver lesions of various sizes and contrasts into both phantom and patient images. We selected 12 conditions out of 72 possible experimental conditions to evaluate the correlation at various radiation doses, lesion sizes, lesion contrasts and reconstruction algorithms. CHO with both single and multi-slice viewing modes were strongly correlated with HO. The corresponding Pearson's correlation coefficient was 0.982 (with 95% confidence interval (CI) [0.936, 0.995]) and 0.989 (with 95% CI of [0.960, 0.997]) in multi-slice and single-slice viewing modes, respectively. Therefore, this study demonstrated the potential to use the simplest single-slice CHO to assess image quality for more realistic clinically relevant CT detection tasks.

  8. Application of decision-making methodology to certificate-of-need applications for CT scanners

    International Nuclear Information System (INIS)

    Gottinger, H.W.; Shapiro, P.

    1985-01-01

    This paper describes a case study and application of decision-making methodology to two competing Certificate of Need (CON) applications for CT body scanners. We demonstrate the use of decision-making methodology by evaluating the CON applications. Explicit value judgements reflecting the monetary equivalent of the different categories of benefit are introduced to facilitate this comparison. The difference between the benefits (measured in monetary terms) and costs is called the net social value. Any alternative with positive net social value is judged economically justifiable, and the alternative with the greatest net social value is judged the most attractive. (orig.)

  9. 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.

  10. Gynecological applications of helical CT using SmartPrep

    Energy Technology Data Exchange (ETDEWEB)

    Sakurada, Akira; Kakizaki, Dai; Abe, Kimihiko [Tokyo Medical Coll. (Japan)

    1999-11-01

    SmartPrep is software program for scanning a given region of interest (ROI) at optimal contrast density. An operator can arbitrarily define ROI and preset the CT value at which scanning should be started. After the injection of a contrast medium, system conducts continuous monitoring of the ROI and the operator starts helical scanning of the planned region when the present CT value has been reached. In comparison with conventional helical CT that requires a period of time from the beginning of contrast medium injection to the beginning of scanning, SmartPrep minimizes personal error and better depicts the artery-predominant phase under optimal conditions. In this study we examine the usefulness of contrast-enhanced helical CT using SmartPrep in the evaluation of gynecological disease. When the contrast medium was injected into the dorsal vein of the hand at a rate of 3 ml/sec, strong staining of pelvic arteries was observed in the CT images started at 17 to 23 sec after injection. The early-phase helical CT obtained under these conditions provided good depiction of lesions in cases of placenta accreta and invasive mole, as well as clear demonstration of tumor angiogenesis and evaluation of laterality in cases of cervical cancer. Comparison of the early and delayed phase also facilitated easier evaluation of lymph nodes than conventional comparison of simple and contrast-enhanced CT. The results thus suggest the usefulness of contrast-enhanced helical CT using SmartPrep in gynecology. (author)

  11. Application of multislice spiral CT in children urinary tract injuries

    International Nuclear Information System (INIS)

    Feng Hui; Chen Jing

    2012-01-01

    Objective: To investigate the application value of three-dimensional reconstruction technique of multislice spiral CT(MSCT) in children urinary tract injuries. Methods: Forty-three patients with urinary tract injury performed MSCT scan, and three-dimensional reconstruction technique was used for volume rendering, maximum intensity projection and multi-planar reformation, urinary tract imaging was acquired completely. The images were reviewed by two experienced radiologists. Results: Of the 43 cases,there were 5 simple contusion of kidney, 5 contusion and laceration of kidney accompanied with subcapsular haematoma, 4 contusion and laceration of kidney accompanied with perinephric haematoma, 2 contusion and laceration of kidney accompanied with adrenal haematoma, 13 shattered kidney accompanied with extravasation of urine, 3 shattered kidney accompanied with renal pedicle injury, 6 shattered kidney accompanied with ureter injury, 2 pelvic fracture accompanied with posterior urethra split, 3 contusion of urinary bladder wall accompanied with blood clot in the urinary bladder. Conclusion: MSCT has the characteristic of high scanning speed, wide overlay scope,high image quality and thin slice scan. It is an effective modality in the evaluation of children urinary tract injuries. (authors)

  12. Material Separation Using Dual-Energy CT: Current and Emerging Applications.

    Science.gov (United States)

    Patino, Manuel; Prochowski, Andrea; Agrawal, Mukta D; Simeone, Frank J; Gupta, Rajiv; Hahn, Peter F; Sahani, Dushyant V

    2016-01-01

    Dual-energy (DE) computed tomography (CT) offers the opportunity to generate material-specific images on the basis of the atomic number Z and the unique mass attenuation coefficient of a particular material at different x-ray energies. Material-specific images provide qualitative and quantitative information about tissue composition and contrast media distribution. The most significant contribution of DE CT-based material characterization comes from the capability to assess iodine distribution through the creation of an image that exclusively shows iodine. These iodine-specific images increase tissue contrast and amplify subtle differences in attenuation between normal and abnormal tissues, improving lesion detection and characterization in the abdomen. In addition, DE CT enables computational removal of iodine influence from a CT image, generating virtual noncontrast images. Several additional materials, including calcium, fat, and uric acid, can be separated, permitting imaging assessment of metabolic imbalances, elemental deficiencies, and abnormal deposition of materials within tissues. The ability to obtain material-specific images from a single, contrast-enhanced CT acquisition can complement the anatomic knowledge with functional information, and may be used to reduce the radiation dose by decreasing the number of phases in a multiphasic CT examination. DE CT also enables generation of energy-specific and virtual monochromatic images. Clinical applications of DE CT leverage both material-specific images and virtual monochromatic images to expand the current role of CT and overcome several limitations of single-energy CT. (©)RSNA, 2016.

  13. The performance and application of 18F-FDG PET/CT in diagnosis of tumor

    International Nuclear Information System (INIS)

    Wang Junqi

    2004-01-01

    Positron emission tomography (PET)/computed tomography (CT) inline scanner combined with high performance PET and CT have been introduced to clinical in recent years. The application of PET/CT in oncology are rapid increasing. The addition of CT to PET offers many advantages, including obtaining a fast and relatively accurate transmission map, shortening the duration of the examination, adding precise anatomical information to PET imaging, and providing additional diagnostic information. However, using CT for attenuation correction can led to some artifacts; quantitative measurements may be altered, high density IV and oral metallic objects may produce artifacts, and the registration of PET and CT may occasionally suboptimal. In head and neck tumor PET/CT offers particular potential advantages as well as abdomen and pelvic tumor. Even in the thorax, which the physical movement may produce unsatisfactory results, offers some advantages also. Preliminary results of PET/CT over PET or CT in oncology are very encouraging. It is clear the PET/CT fusion technology has an more and more impact on both diagnostic and therapeutic aspects of patient management

  14. Accurate localization of intracavitary brachytherapy applicators from 3D CT imaging studies

    International Nuclear Information System (INIS)

    Lerma, F.A.; Williamson, J.F.

    2002-01-01

    Purpose: To present an accurate method to identify the positions and orientations of intracavitary (ICT) brachytherapy applicators imaged in 3D CT scans, in support of Monte Carlo photon-transport simulations, enabling accurate dose modeling in the presence of applicator shielding and interapplicator attenuation. Materials and methods: The method consists of finding the transformation that maximizes the coincidence between the known 3D shapes of each applicator component (colpostats and tandem) with the volume defined by contours of the corresponding surface on each CT slice. We use this technique to localize Fletcher-Suit CT-compatible applicators for three cervix cancer patients using post-implant CT examinations (3 mm slice thickness and separation). Dose distributions in 1-to-1 registration with the underlying CT anatomy are derived from 3D Monte Carlo photon-transport simulations incorporating each applicator's internal geometry (source encapsulation, high-density shields, and applicator body) oriented in relation to the dose matrix according to the measured localization transformations. The precision and accuracy of our localization method are assessed using CT scans, in which the positions and orientations of dense rods and spheres (in a precision-machined phantom) were measured at various orientations relative to the gantry. Results: Using this method, we register 3D Monte Carlo dose calculations directly onto post insertion patient CT studies. Using CT studies of a precisely machined phantom, the absolute accuracy of the method was found to be ±0.2 mm in plane, and ±0.3 mm in the axial direction while its precision was ±0.2 mm in plane, and ±0.2 mm axially. Conclusion: We have developed a novel, and accurate technique to localize intracavitary brachytherapy applicators in 3D CT imaging studies, which supports 3D dose planning involving detailed 3D Monte Carlo dose calculations, modeling source positions, shielding and interapplicator shielding

  15. Motion estimation and compensation in dynamic spiral CT reconstruction; Estimation et compensation de mouvement en reconstruction dynamique de tomodensitometrie helicoidale

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-07-01

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

  16. Reducing Radiation Doses in Female Breast and Lung during CT Examinations of Thorax: A new Technique in two Scanners

    Directory of Open Access Journals (Sweden)

    Mehnati P.

    2017-09-01

    Full Text Available Background: Chest CT is a commonly used examination for the diagnosis of lung diseases, but a breast within the scanned field is nearly never the organ of interest. Objective: The purpose of this study is to compare the female breast and lung doses using split and standard protocols in chest CT scanning. Materials and Methods: The sliced chest and breast female phantoms were used. CT exams were performed using a single-slice (SS- and a 16 multi-slice (MS- CT scanner at 100 kVp and 120 kVp. Two different protocols, including standard and split protocols, were selected for scanning. The breast and lung doses were measured using thermo-luminescence dosimeters which were inserted into different layers of the chest and breast phantoms. The differences in breast and lung radiation doses in two protocols were studied in two scanners, analyzed by SPSS software and compared by t-test. Results: Breast dose by split scanning technique reduced 11% and 31% in SS- and MS- CT. Also, the radiation dose of lung tissue in this method decreased 18% and 54% in SS- and MS- CT, respectively. Moreover, there was a significant difference (p< 0.0001 in the breast and lung radiation doses between standard and split scanning protocols. Conclusion: The application of a split scan technique instead of standard protocol has a considerable potential to reduce breast and lung doses in SS- and MS- CT scanners. If split scanning protocol is associated with an optimum kV and MSCT, the maximum dose decline will be provided.

  17. Clinical application of early PET-CT imaging after radiofrequency ablation of liver neoplasms

    International Nuclear Information System (INIS)

    Liu Zhaoyu; Chang Zhihui; Lu Zaiming; Xin Jun; Wang Xiaoming; Guo Qiyong

    2009-01-01

    Objective: To evaluate the application of early 18 F-FDG PET-CT imaging after radiofrequency ablation (RFA) of hepatic malignancies. Methods: Fifteen patients with liver tumors (five hepatocellular carcinoma, ten colorectal cancer liver metastasis) underwent RFA as part of clinical management. The lesions were all hypermetabolic on PET-CT performed within 2 weeks prior to RFA. All subjects underwent 18 F-FDG PET-CT (early PET-CT) within 24 hours after RFA. Total photopenia, focal uptake, and rim-shaped uptake were regarded as complete ablation, residual tumor, and inflammation, respectively. Follow-up PET-CT scans were performed as the reference standard. Results: Twelve patients showed total photopenia at the ablation site on the early PET-CT scan, and in all of these patients, total photopenia at the ablation sites was seen on the follow-up PET-CT scans. Two patients had focal uptake at the ablation sites on the early PET-CT scan, and both of these foci increased in size and intensity, which were compatible with residual tumors at the time of ablation. Only one patient had rim-shaped uptake on the early PET-CT scan. The rim-shaped uptake disappeared on PET-CT performed 3 months later, which indicated the nature of inflammation. Conclusions: There is infrequent inflammatory uptake at the RFA site of liver tumors on 18 F-FDG PET-CT if scanning is performed within 24 hours after ablation. Thus, early PET- CT has the potential to evaluate the efficacy of an RFA procedure by indicating tumor-free as total photopenia and residual tumors as focal uptake. (authors)

  18. Study of CdTe:Cl and CdZnTe detectors for medical multi-slices X-ray Computed Tomography

    International Nuclear Information System (INIS)

    Ricq, St.

    1999-01-01

    The application of CdTe and CdZnTe detectors to medical X-ray Computed Tomography have been investigated. Different electrodes (Au, Pt, In) have been deposited on CdZnTe HPBM and on CdTe:ClTHM. Their injection properties have been determined with Current-Voltage characteristics. Under X-ray in CT conditions, injection currents measurements reveal trapped carriers space-charges formation. The same way, the comparisons of the responses to X-beam cut-off with various injection possibilities enable to follow the space-charges evolutions and then to determine the predominant traps types. Nevertheless, both hole and electron traps are responsible for the memory effect e.g. the currents levels dependence with irradiation history. This effect is noticed in particular on responses to fast flux variations that simulate scanner's conditions. Trap levels probably corresponding to native defects are responsible for these limitations. In order to make such detectors suitable for X-ray Computed Tomography, significant progresses in CdTe for CdZnTe crystal growth with an important defects densities reduction (factor 10), or possibly counting mode operation, seem necessary. (author)

  19. Multiplanar reformatted CT applications in the lumbar spine

    International Nuclear Information System (INIS)

    Ueda, Takafumi; Kojima, Shinsaburo; Araki, Nobuto; Miyauchi, Sumihiko

    1986-01-01

    Diagnostic value and limitations of multiplanar reformatted CT were evaluated in 55 patients with lumbar diseases. Reformatted images in coronal, sagittal, paraxial, and oblique planes were acquired from the transverse axial images, thereby allowing three-dimensional visualization of lesions in the lumbar spine. Oblique images that were reformmated along the nervous root were useful in visualizing lesions in the root canal, which were not available on either conventional myelography or transverse axial CT. A definitive plane determination is required for reformation of images, taking curvature of the spinal column into account. (Namekawa, K.)

  20. Real time CT-fluoroscopy: diagnostic and therapeutic applications

    International Nuclear Information System (INIS)

    Mey, J. de; Op de Beeck, B.; Meysman, M.; Noppen, M.; Maeseneer, M. de; Vanhoey, M.; Vincken, W.; Osteaux, M.

    2000-01-01

    The synergetic progression of CT technology and computer hardware has made ultrafast acquisition and image reconstruction possible. This has lead to the availability of CT interactive diagnosis and therapeutic procedures. Making use of our own material (337 intervention procedures during the last 17 months), we have compared our techniques and results to the recent literature data. One of the advantages of the biopsy technique is an improved sensitivity for neoplastic lesions, most certainly in cases of intrapulmonary lesions, surrounded by aerated tissue (now 94% compared to 87% in our previous study). A second advantage is the safety of the technique (only one major complication in our series). Fluid collection drainages, and more complex interventions like local injection of drugs, radio-frequency ablation, wire hook placement and ethanol injection were performed without complication. Yet another interesting feature is the shortening of the procedure time (reduced in average to an 'in-room' time of less than 30 min), which has definite economical implications. Furthermore it increases the patient's comfort and safety, and extends the scope of outpatient procedures (80% outpatient procedures in our material). On the other side the radiation exposure can be raised as an issue, especially when we consider the operator's hands. However, the described technique and the use of dedicated tools can alleviate the problem. As a conclusion, real time CT fluoroscopy has given a new input and broadens the scope of clinical indications of CT-guided diagnostic and therapeutic procedures

  1. Three-dimensional CT endoscopic images of the larynx. Clinical application of helical CT

    International Nuclear Information System (INIS)

    Yumoto, Eiji; Sanuki, Tetsuji; Yasuhara, Yoshifumi; Ochi, Takashi

    1998-01-01

    Twenty-seven patients with several laryngeal ailments underwent helical computed tomography (CT) on 37 occasions. Ten of these 27 patients suffered from unilateral vocal fold paralysis (UVFP). Three-dimensional (3D) images of the laryngeal lumen viewed from various angles were produced for all sets of CT volumetric data, except for three which contained excessive motion artifacts. The present paper examined whether 3D endoscopic images could offer useful diagnostic and therapeutic information about UVFP. The 3D endoscopic images viewed from the tracheal side and the hemilaryngeal images viewed from the opposite side could delineate the vocal folds, ventricular fold and ventricle three-dimensionally. Atrophy and hypotonic changes to the vocal fold and expansion of the ventricle on the affected side were clearly shown. The 3D endoscopic images accurately showed the phonosurgical effects on the laryngeal structures. The 3D endoscopic images could be produced even when the vocal folds could not be observed with conventional endoscopy due to their overadduction. Multiplanar reconstruction (MPR) images in the coronal plane were reconstructed at a right angle to the glottic axis when the whole larynx was deviated. In addition, coronal MPR images showed a better resolution among the different layers of the vocal fold soft tissue than X-ray tomography. In conclusion, 3D endoscopic images combined with coronal MPR images can provide useful diagnostic an therapeutic information about UVFP, although motion artifacts may occur. (author)

  2. Reconstruction of MRI/CT compatible ring and tandem applicators in CT or MRI images used for treatment planning in brachytherapy

    International Nuclear Information System (INIS)

    Surendran, N.; Kim, Hayeon; Beriwal, Sushil; Saiful Huq, M.

    2008-01-01

    Brachytherapy (BT) plays a crucial role in the management of invasive cervix cancer from stage I to IV. Intracavitary techniques are based on afterloading devices, with different types of applicators. CT and/or MRI compatible applicators allow a sectional image based approach with a better assessment of gross tumour volume (GTV) and definition and delineation of target volume (CTV) compared to traditional approaches. To evaluate reconstruction of MRI/CT compatible ring and tandem applicators in 3D CT or MRI images used for treatment planning in Brachytherapy

  3. Application of CT perfusion imaging in radiotherapy for lung cancer

    International Nuclear Information System (INIS)

    Xia Guangrong; Liu Guimei; He Wen; Jin Guohua; Xie Ruming; Xu Yongxiang; Li Xiaobo; Li Xuebing

    2011-01-01

    Objective: To investigate the value of CT perfusion imaging in evaluation of therapeutic effect and prognosis in radiotherapy for lung cancer. Methods: Fifty-one cases of lung cancer who were unable or refused to be operated on, 36 males and 15 females, aged 37-80, underwent CT perfusion imaging, 29 of which only before radiotherapy and 22 before and after radiotherapy twice. The images were collected by cine dynamic scanning (5 mm/4 slices) and input into the GE AW4.0 workstation for data processing. The slice positions of CT imaging were determined according to the largest tumor size in CT scan. Regions of interest of tumor were drawn at the region corresponding to the original images of CT perfusion. Radiotherapy was performed after CT perfusion imaging. Relevant parameters, including blood flow (BF), blood volume (BV), mean transit time (MTT), and permeability surface (PS) were calculated. The treatment response after radiotherapy was evaluated by RECIST. At 2 -4 weeks after the treatment, CT examination was conducted once more. Results: The tests of the 51 patients showed that the BV was 13.6 ml·100 g -1 , the BF was 129.5 ml·min -1 ·100 g -1 , the MTT was 9.1 s, and the PS was 10.0 ml· min -1 · 100 g -1 before radiotherapy. The tests of the 22 of the 51 patients showed that the values of BV and BF after radiotherapy were 7.6 ml· 100 g -1 and 97.8 ml·min -1 · 100 g -1 , respectively, both lower than those before radiotherapy (11.2 and 108.7 ml·min -1 ·100 g -1 , respectively), however, both not significantly (t=1.28, 0.40, P>0.05); and the values of MTT and PS after radiotherapy were 8.9 s and 7.8 ml·min -1 · 100 g -1 , respectively, both not significantly higher than those before radiotherapy (7.2 s and 6.8 ml· min -1 · 100 g -1 , respectively, t=-1.15, -0.57, P>0.05). The mean area of tumor after radiotherapy was 1189.6 mm 2 , significantly less than that before radiotherapy (1920.3 mm 2 , t=3.98, P<0.05). The MTT of the SCLC patients was 12

  4. Study on the application of PET-CT in gynecology tumors

    International Nuclear Information System (INIS)

    Wen Lilian

    2012-01-01

    Gynecology tumors seriously threatened the health of female. With the development of imageology, PET, a functionality examination method, has been widely used in the early diagnosis and monitoring of curative effect in gynecology tumors. PET-CT has the good future in its development because it combined with the advantage of functional and structural imaging. The characters and application of PET-CT in gynecology tumors were reviewed in this paper. (author)

  5. Application of Simulated Three Dimensional CT Image in Orthognathic Surgery

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyun Don; Park, Chang Seo [Dept. of Dental Radiology, College of Dentistry, Yensei University, Seoul (Korea, Republic of); Yoo, Sun Kook; Lee, Kyoung Sang [Dept. of Medical Engineering, College of Medicine, Yensei University, Seoul (Korea, Republic of)

    1998-08-15

    In orthodontics and orthognathic surgery, cephalogram has been routine practice in diagnosis and treatment evaluation of craniofacial deformity. But its inherent distortion of actual length and angles during projecting three dimensional object to two dimensional plane might cause errors in quantitative analysis of shape and size. Therefore, it is desirable that three dimensional object is diagnosed and evaluated three dimensionally and three dimensional CT image is best for three dimensional analysis. Development of clinic necessitates evaluation of result of treatment and comparison before and after surgery. It is desirable that patient that was diagnosed and planned by three dimensional computed tomography before surgery is evaluated by three dimensional computed tomography after surgery, too. But Because there is no standardized normal values in three dimension now and three dimensional Computed Tomography needs expensive equipment and because of its expenses and amount of exposure to radiation, limitations still remain to be solved in its application to routine practice. If postoperative three dimensional image is constructed by pre and postoperative lateral and postero-anterior cephalograms and preoperative three dimensional computed tomogram, pre and postoperative image will be compared and evaluated three dimensionally without three dimensional computed tomography after surgery and that will contribute to standardize normal values in three dimension. This study introduced new method that computer-simulated three dimensional image was constructed by preoperative three dimensional computed tomogram and pre and postoperative lateral and postero-anterior cephalograms, and for validation of new method, in four cases of dry skull that position of mandible was displaced and four patients of orthognathic surgery, computer-simulated three dimensional image and actual postoperative three dimensional image were compared. The results were as follows. 1. In four cases of

  6. Application of Simulated Three Dimensional CT Image in Orthognathic Surgery

    International Nuclear Information System (INIS)

    Kim, Hyun Don; Park, Chang Seo; Yoo, Sun Kook; Lee, Kyoung Sang

    1998-01-01

    In orthodontics and orthognathic surgery, cephalogram has been routine practice in diagnosis and treatment evaluation of craniofacial deformity. But its inherent distortion of actual length and angles during projecting three dimensional object to two dimensional plane might cause errors in quantitative analysis of shape and size. Therefore, it is desirable that three dimensional object is diagnosed and evaluated three dimensionally and three dimensional CT image is best for three dimensional analysis. Development of clinic necessitates evaluation of result of treatment and comparison before and after surgery. It is desirable that patient that was diagnosed and planned by three dimensional computed tomography before surgery is evaluated by three dimensional computed tomography after surgery, too. But Because there is no standardized normal values in three dimension now and three dimensional Computed Tomography needs expensive equipment and because of its expenses and amount of exposure to radiation, limitations still remain to be solved in its application to routine practice. If postoperative three dimensional image is constructed by pre and postoperative lateral and postero-anterior cephalograms and preoperative three dimensional computed tomogram, pre and postoperative image will be compared and evaluated three dimensionally without three dimensional computed tomography after surgery and that will contribute to standardize normal values in three dimension. This study introduced new method that computer-simulated three dimensional image was constructed by preoperative three dimensional computed tomogram and pre and postoperative lateral and postero-anterior cephalograms, and for validation of new method, in four cases of dry skull that position of mandible was displaced and four patients of orthognathic surgery, computer-simulated three dimensional image and actual postoperative three dimensional image were compared. The results were as follows. 1. In four cases of

  7. Application of SPECT/CT imaging in the diagnosis of benign diseases

    International Nuclear Information System (INIS)

    Garcheva, M.; Demirev, A.

    2014-01-01

    The application of recently introduced hybrid nuclear medicine methods gains importance in a variety of clinical fields, mainly because of the unique combination between functional and anatomical data provided by those methods and their capability for a precise localization of pathological processes. Single photon emission computed tomography, combined with computed tomography (SPECT/CT) is one of those methods. Its role in nuclear cardiology is important, because it provides quick attenuation correction and calculates the calcium score. In nuclear endocrinology SPECT/CT participates in thyroid and parathyroid examinations, especially in cases, where there is a need for localization of ectopic parathyroid or thyroid tissue. In nuclear pulmonology, one of the best ways to attribute certain changes seen on the SPECT, to the zone of interest on the CT, is to study the fused images obtained from the SPECT/ CT scanner. In cases of suspected infection and inflammation, fused images are indispensable for accurate localization of the involved tissue (structure) and for discrimination between normal/abnormal uptake. Careful reading of the CT component (even low-dose) is related (in 10% of cases) to clinically important incidental findings: effusions, tumors, metastases or lymph node pathology. SPECT/CT increases the specificity of the examinations and improves significantly the localization of pathological processes. It provides additional information, shortens the diagnostic algorithm and influences the extent of surgical procedures. In many hybrid examinations the preferred CT component is a low-dose one, without considerable radiation exposure. The opportunity to combine nuclear medicine techniques and contrast CT images, aiming at better diagnosis needs further development. SPECT/CT provides important additional information and more accurate diagnostics in patients with benign diseases. (authors) Key words: SPECT/CT. BENIGN DISEASES

  8. A study on optimal scan conditions of big bore multi-slice computed tomography based on radiation dose and image noise

    International Nuclear Information System (INIS)

    Lee, J. S.; Ye, S. J.; Kim, E. H.

    2011-01-01

    The newly introduced Big Bore computed tomography (CT) has a possibility to increase the tube current product scan time (mA s) for compensation of image degradation due to larger gentry opening without sound guideline. The objective of this paper is to derive optimal scan conditions for Big Bore CT scanner, mainly relating to the dose of diagnostic CT. The weighted CT dose index (CTDI w ) was estimated at five typical protocols, such as head and neck, brain, paediatric, chest and abdomen. Noises were analysed in a circle of 1 or 2 cm of diameter in CT image slice. The results showed that measured CTDI w values generally follow the theoretical rule at all scanning conditions of every protocol. Although image noises decrease with increment of mA s, analysed image noises do follow the theoretical rule, but only in specific protocols. This phenomenon is presumed to result from the photon energy spectra arriving at the detection system of the Big Bore scanner. (authors)

  9. 76 FR 40688 - Foreign-Trade Zone 71-Windsor Locks, CT Application for Expansion

    Science.gov (United States)

    2011-07-11

    ... Locks, CT Application for Expansion An application has been submitted to the Foreign-Trade Zones Board... 2 (390 acres)--within the 600-acre New England Tradeport business park located at the intersection... distribution services to area businesses. No specific manufacturing authority is being requested at this time...

  10. Clinical applications of SPECT/CT: New hybrid nuclear medicine imaging system

    International Nuclear Information System (INIS)

    2008-08-01

    Interest in multimodality imaging shows no sign of subsiding. New tracers are spreading out the spectrum of clinical applications and innovative technological solutions are preparing the way for yet more modality marriages: hybrid imaging. Single photon emission computed tomography (SPECT) has enabled the evaluation of disease processes based on functional and metabolic information of organs and cells. Integration of X ray computed tomography (CT) into SPECT has recently emerged as a brilliant diagnostic tool in medical imaging, where anatomical details may delineate functional and metabolic information. SPECT/CT has proven to be valuable in oncology. For example, in the case of a patient with metastatic thyroid cancer, neither SPECT nor CT alone could identify the site of malignancy. SPECT/CT, a hybrid image, precisely identified where the surgeon should operate. However SPECT/CT is not just advantageous in oncology. It may also be used as a one-stop-shop for various diseases. Clinical applications with SPECT/CT have started and expanded in developed countries. It has been reported that moving from SPECT alone to SPECT/CT could change diagnoses in 30% of cases. Large numbers of people could therefore benefit from this shift all over the world. This report presents an overview of clinical applications of SPECT/CT and a relevant source of information for nuclear medicine physicians, radiologists and clinical practitioners. This information may also be useful for decision making when allocating resources dedicated to the health care system, a critical issue that is especially important for the development of nuclear medicine in developing countries. In this regard, the IAEA may be heavily involved in the promotion of programmes aimed at the IAEA's coordinated research projects and Technical Cooperation projects

  11. A great number of old vertebral fractures expressing instability are pedicle fractures. With the use of 64-line multi slice computerized tomography

    International Nuclear Information System (INIS)

    Kobayashi, Akihiko; Nishida, Kenki; Ogawa, Koichi; Takahashi, Yuichi; Nakahara, Masayuki; Hijikata, Yasukazu

    2008-01-01

    We examined old vertebral fractures expressing instability with the use of 64-line CT. From April 2006 to December 2006, CT photographic images of 15 unstable fractures were examined in detail. We confirmed gas or liquid in all vertebral bodies. In 5 cases (33%), vertebral body protruding into the canal was observed. Four cases (23%) had other vertebral fractures. In addition, 12 pedicle fractures (73%) were seen. We confirmed many pedicle fractures in vertebral fractures expressing instability. These results suggest that pedicle fracture is a risk factor for back pain associated with vertebral fracture. (author)

  12. Applicability of 3D-CT facial reconstruction for forensic individual identification

    International Nuclear Information System (INIS)

    Rocha, Sara dos Santos; Ramos, Dalton Luiz de Paula; Cavalcanti, Marcelo de Gusmao Paraiso

    2003-01-01

    Computed tomography (CT) is used in several clinical dentistry applications even by axial slices and two and three-dimensional reconstructed images (2D-CT and 3D-CT). The purpose of the current study is to assess the precision of linear measurements made in 3D-CT using cranio metric patterns for individual identification in Forensic Dentistry. Five cadaver heads were submitted to a spiral computed tomography using axial slices, and 3D-CT reconstructions were obtained by volume rendering technique with computer graphics tools. Ten (10) cranio metric measurements were determined in 3D-CT images by two examiners independently, twice each, and the standard error of intra- and inter-examiner measurements was assessed. The results demonstrated a low standard error of those measurements, from 0.85% to 3.09%. In conclusion, the linear measurements obtained in osseous and soft tissue structures were considered to be precise in 3D-CT with high imaging quality and resolution. (author)

  13. Applicability of 3D-CT facial reconstruction for forensic individual identification

    Energy Technology Data Exchange (ETDEWEB)

    Rocha, Sara dos Santos [Sao Paulo Univ., SP (Brazil). Odontologia Forense; Ramos, Dalton Luiz de Paula [Sao Paulo Univ., SP (Brazil). Dept. of Odontologia Social; Cavalcanti, Marcelo de Gusmao Paraiso [Sao Paulo Univ., SP (Brazil). Dept. de Radiologia

    2003-03-01

    Computed tomography (CT) is used in several clinical dentistry applications even by axial slices and two and three-dimensional reconstructed images (2D-CT and 3D-CT). The purpose of the current study is to assess the precision of linear measurements made in 3D-CT using cranio metric patterns for individual identification in Forensic Dentistry. Five cadaver heads were submitted to a spiral computed tomography using axial slices, and 3D-CT reconstructions were obtained by volume rendering technique with computer graphics tools. Ten (10) cranio metric measurements were determined in 3D-CT images by two examiners independently, twice each, and the standard error of intra- and inter-examiner measurements was assessed. The results demonstrated a low standard error of those measurements, from 0.85% to 3.09%. In conclusion, the linear measurements obtained in osseous and soft tissue structures were considered to be precise in 3D-CT with high imaging quality and resolution. (author)

  14. Application of CT texture analysis in predicting histopathological characteristics of gastric cancers

    International Nuclear Information System (INIS)

    Liu, Shunli; Liu, Song; Ji, Changfeng; Zheng, Huanhuan; Pan, Xia; Zhang, Yujuan; He, Jian; Zhou, Zhengyang; Guan, Wenxian; Chen, Ling; Guan, Yue; Li, Weifeng; Ge, Yun

    2017-01-01

    To explore the application of computed tomography (CT) texture analysis in predicting histopathological features of gastric cancers. Preoperative contrast-enhanced CT images and postoperative histopathological features of 107 patients (82 men, 25 women) with gastric cancers were retrospectively reviewed. CT texture analysis generated: (1) mean attenuation, (2) standard deviation, (3) max frequency, (4) mode, (5) minimum attenuation, (6) maximum attenuation, (7) the fifth, 10th, 25th, 50th, 75th and 90th percentiles, and (8) entropy. Correlations between CT texture parameters and histopathological features were analysed. Mean attenuation, maximum attenuation, all percentiles and mode derived from portal venous CT images correlated significantly with differentiation degree and Lauren classification of gastric cancers (r, -0.231 ∝-0.324, 0.228 ∝ 0.321, respectively). Standard deviation and entropy derived from arterial CT images also correlated significantly with Lauren classification of gastric cancers (r = -0.265, -0.222, respectively). In arterial phase analysis, standard deviation and entropy were significantly lower in gastric cancers with than those without vascular invasion; however, minimum attenuation was significantly higher in gastric cancers with than those without vascular invasion. CT texture analysis held great potential in predicting differentiation degree, Lauren classification and vascular invasion status of gastric cancers. (orig.)

  15. Application of CT texture analysis in predicting histopathological characteristics of gastric cancers

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Shunli; Liu, Song; Ji, Changfeng; Zheng, Huanhuan; Pan, Xia; Zhang, Yujuan; He, Jian; Zhou, Zhengyang [The Affiliated Hospital of Nanjing University Medical School, Department of Radiology, Nanjing Drum Tower Hospital, Nanjing, Jiangsu Province (China); Guan, Wenxian [The Affiliated Hospital of Nanjing University Medical School, Department of Gastrointestinal Surgery, Nanjing Drum Tower Hospital, Nanjing (China); Chen, Ling [The Affiliated Hospital of Nanjing University Medical School, Department of Pathology, Nanjing Drum Tower Hospital, Nanjing, Jiangsu Province (China); Guan, Yue; Li, Weifeng; Ge, Yun [Nanjing University, School of Electronic Science and Engineering, Nanjing (China)

    2017-12-15

    To explore the application of computed tomography (CT) texture analysis in predicting histopathological features of gastric cancers. Preoperative contrast-enhanced CT images and postoperative histopathological features of 107 patients (82 men, 25 women) with gastric cancers were retrospectively reviewed. CT texture analysis generated: (1) mean attenuation, (2) standard deviation, (3) max frequency, (4) mode, (5) minimum attenuation, (6) maximum attenuation, (7) the fifth, 10th, 25th, 50th, 75th and 90th percentiles, and (8) entropy. Correlations between CT texture parameters and histopathological features were analysed. Mean attenuation, maximum attenuation, all percentiles and mode derived from portal venous CT images correlated significantly with differentiation degree and Lauren classification of gastric cancers (r, -0.231 ∝-0.324, 0.228 ∝ 0.321, respectively). Standard deviation and entropy derived from arterial CT images also correlated significantly with Lauren classification of gastric cancers (r = -0.265, -0.222, respectively). In arterial phase analysis, standard deviation and entropy were significantly lower in gastric cancers with than those without vascular invasion; however, minimum attenuation was significantly higher in gastric cancers with than those without vascular invasion. CT texture analysis held great potential in predicting differentiation degree, Lauren classification and vascular invasion status of gastric cancers. (orig.)

  16. Clinical application of low-dose spiral CT for orthodontics

    International Nuclear Information System (INIS)

    Xie Na; Gan Yungen; Shu Huang; Lin FeiFei; Li Zhiyong; Sun Jie

    2009-01-01

    Objective: To determine the effect of reducing the value of mA or kV on the image quality and the radiation dose of the patients undergoing low-dose spiral CT for orthodontics. Methods: Thirty patients were divided into three groups, each group has 10 patients. They were group 1 (80 kV and 200 mA), group 2 (120 kV and 80 mA), group 3 (120 kV and 200 mA) The volume CT dose index (CTDI) was recorded and the average dose-length produce (DLP) was calculated in three groups,respectively. Image quality of three groups were compared and scored by two radiologists, and the results were statistically analysed. Results: The CTDI and DLP of 80 kV group (group 2) were 8.7 mGy and (36.80 ± 3.60) mGy · cm, respectively, those of 80 mA group (group 3) were 19.6 mGy and (82.14 ± 7.18) mGy · cm, respectively, and those of conventional-dose group (group 1) were 19.6 mGy and (82.14 ± 7.18) mGy · cm, respectively. There was no significant difference among three groups in diagnostic image quality. Conclusions: Low-dose spiral CT for orthodontics, especially the low-kV scan, may decrease the radiation exposure and guarantee the image quality. (authors)

  17. Evaluation of changes in the parameters of brain tissue perfusion in multi-slice computed tomography in patients after carotid artery stenting

    NARCIS (Netherlands)

    Szarmach, Arkadiusz; Halena, Grzegorz; Buczny, Jacek; Studniarek, Michał; Markiet, Karolina; Szurowska, Edyta; Retkowski, Mariusz; Piskunowicz, Maciej

    BACKGROUND: CT perfusion of the brain allows functional evaluation of cerebral blood flow. Patients with chronic internal carotid artery (ICA) stenosis may suffer from malperfusion. Improvement of cerebral blood flow and remission of neurological symptoms indicate the effectiveness of treatment of

  18. Applications of contrast enhanced CT through external jugular access

    International Nuclear Information System (INIS)

    Xu Qiaolan; Zou Wenxing; Chen Meixia; Xie Hongbo

    2005-01-01

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

  19. Applications of contrast enhanced CT through external jugular access

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-09-15

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

  20. Quality assurance of CT scanning for industrial applications

    DEFF Research Database (Denmark)

    Angel, Jais Andreas Breusch

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

  1. Clinical application of CT-controlled stereotactic aspiration for intracerebral hematoma

    International Nuclear Information System (INIS)

    Chen Weijian; Zhuge Qichuan; Zheng Rongyuan; Guo Xianzhong; Zhong Ming; Wu Jinsen; Qu Xuanxing

    2002-01-01

    Objective: To evaluate the clinical application of CT-controlled stereotactic aspiration for intracerebral hematoma. Methods: CT-guided stereotactic system was installed on the CT bed, and checked against a standard of the coordinate. According to controlled CT scan, the target can be adjusted at any time in the operation. 860 patients with cerebral hematoma underwent CT-controlled stereotactic aspiration. Of the 860 cases, basal ganglion hematoma was present in 408, thalamus and posterior limb of internal capsule hematoma in 136, cerebral lobe hematoma in 261, cerebellar hematoma in 5, ventricular hemorrhage in 10, midbrain and pons hemorrhage in 37, and medulla hemorrhage in 3. Results: Easy drainage of hematoma by aspiration was achieved in 586 cases, stickiness of hematoma with clearing away more than 50% was performed in 202 and less than 50% in 68. The operation duration ranged from 25 to 120 minutes (average 45 minutes). 693 cases survived and 167 cases died. According to the evaluation by active day life (ADL) after 3 months in survivors, ADL 1-2, ADL 3, ADL 4 and ADL 5 results were achieved in 378 cases, 166 cases, 107 cases, and 28 cases, respectively. In addition, 14 cases were lost beyond recall. Conclusion: CT-controlled stereotactic aspiration for intracerebral hematoma is a handy, less invasive, and safe procedure with high accuracy and curative effect, it is worth while popularizing the procedure

  2. Dual- and Multi-Energy CT: Principles, Technical Approaches, and Clinical Applications

    Science.gov (United States)

    Leng, Shuai; Yu, Lifeng; Fletcher, Joel G.

    2015-01-01

    In x-ray computed tomography (CT), materials having different elemental compositions can be represented by identical pixel values on a CT image (ie, CT numbers), depending on the mass density of the material. Thus, the differentiation and classification of different tissue types and contrast agents can be extremely challenging. In dual-energy CT, an additional attenuation measurement is obtained with a second x-ray spectrum (ie, a second “energy”), allowing the differentiation of multiple materials. Alternatively, this allows quantification of the mass density of two or three materials in a mixture with known elemental composition. Recent advances in the use of energy-resolving, photon-counting detectors for CT imaging suggest the ability to acquire data in multiple energy bins, which is expected to further improve the signal-to-noise ratio for material-specific imaging. In this review, the underlying motivation and physical principles of dual- or multi-energy CT are reviewed and each of the current technical approaches is described. In addition, current and evolving clinical applications are introduced. © RSNA, 2015 PMID:26302388

  3. First experiences of application of computer tomography (CT) in pediatric neurology

    International Nuclear Information System (INIS)

    Nagy, I.; Deak, Gy.; Paraicz, E.

    1980-01-01

    79 children were examined by the first Hungarian CT equipment (Medicor-CGR Densitome connected to a PDP 11/55 computer). The advantages of the method in the diagnosis of malformations, perinatal injuries, hydrocephalus, skull injuries and cerebral tumours are demonstrated. The problems arising from the application of instruments requiring long examination time are discussed. (L.E.)

  4. First experiences of application of computer tomography (CT) in pediatric neurology

    Energy Technology Data Exchange (ETDEWEB)

    Nagy, I; Deak, Gy; Paraicz, E [Orszagos Idegsebeszeti Tudomanyos Intezet, Budapest (Hungary)

    1980-01-01

    79 children were examined by the first Hungarian CT equipment (Medicor-CGR Densitome connected to a PDP 11/55 computer). The advantages of the method in the diagnosis of malformations, perinatal injuries, hydrocephalus, skull injuries and cerebral tumours are demonstrated. The problems arising from the application of instruments requiring long examination time are discussed.

  5. CT examination after intrathecal or intraventricular application of metrizamide in 110 patients for neurosurgery

    International Nuclear Information System (INIS)

    Krakow, D.

    1983-01-01

    The CT scans were done in 110 patients for examination of the liquor carrying cerebral brain compartments, especially the cisterns, after intrathecal application of the radiopaque medium metrizamide. The properties of the medium are explained in detail. (orig./MG) [de

  6. Filtered Backprojection using Algebraic Filters; Application to Biomedical Micro-CT Data

    NARCIS (Netherlands)

    L. Plantagie (Linda); W. van Aarle (Wim); J. Sijbers (Jan); K.J. Batenburg (Joost)

    2015-01-01

    htmlabstractFor computerized tomography (CT) imaging in (bio)medical applications, radiation dose reduction is extremely important. This can be achieved simply by reducing the number of projection images taken. In order to obtain accurate reconstructions from few projections, however, common

  7. Application status of three-dimensional CT reconstruction in hepatobiliary surgery

    Directory of Open Access Journals (Sweden)

    JIANG Chao

    2017-02-01

    Full Text Available With the development of imaging technology, three-dimensional CT reconstruction has been widely used in hepatobiliary surgery. Three-dimensional CT reconstruction can divide and reconstruct two-dimensional images into three-dimensional images and clearly show the location of lesion and its relationship with the intrahepatic bile duct system. It has an important value in the preoperative assessment of liver volume, diagnosis and treatment decision-making process, intraoperative precise operation, and postoperative individualized management, and promotes the constant development of hepatobiliary surgery and minimally invasive technology, and therefore, it holds promise for clinical application.

  8. The application of PET/CT in immunoglobulin G4-related disease

    International Nuclear Information System (INIS)

    Zhang Huiwei; Zhao Jun

    2013-01-01

    Immunoglobulin G4 (IgG4)-related disease is a kind of new systemic entity characterized by mass-forming lesions in various organs that consist of lymphoplasmacytic infiltrates and fibrosclerosis with numerous IgG4-positive plasma cells. PET/CT has been widely used in clinical as a whole body examination that earned plenty of successful experience, especially in multiple locations and organs cancer such as lymphoma. PET/CT also has a potential application in IgG4-related diseases as its feature of systemic. (authors)

  9. Application of PET and PET/CT imaging for cancer screening

    International Nuclear Information System (INIS)

    Chen Yenkung; Hu Fenglan; Shen Yehyou; Liao, A.C.; Hung, T.Z.; Su, Chentau; Chen Liangkuang

    2004-01-01

    The aim of this study was to evaluate the potential application of 18F-fluorodeoxyglucose (FDG) Positron Emission Tomography (PET) and PET/CT for cancer screening in asymptomatic individuals. Methods: The subjects consisted of 3631 physical check up examinees (1947 men, 1684 women; mean age ±SD, 52.1±8.2 y) with non-specific medical histories. Whole-body FDG PET (or PET/CT), ultrasound and tumor markers were performed on all patients. Focal hypermetabolic areas with intensities equal to or exceeding the level of FDG uptake in the brain and bladder were considered abnormal and interpreted as neoplasia. Follow-up periods were longer than one year. Results: Among the 3631 FDG PET (including 1687 PET/CT), ultrasound and tumor markers examinations, malignant tumors were discovered in 47 examinees (1.29%). PET findings were true-positive in 38 of the 47 cancers (80.9%). In addition, 32 of the 47 cancers were performed with the PET-CT scan. PET detected cancer lesions in 28 of the 32 examinees. However, the CT detected cancer lesions in only 15 of 32 examinees. Conclusion: The sensitivity of FDG PET in the detection of a wide variety of cancers is high. Most cancer can be detected with FDG PET in a resectable stage. CT of the PET/CT for localization and characteristics of the lesion shows an increased specificity of the PET scan. Using ultrasound and tumor markers may complement the PET scan in cancer screening for hepatic and urologic neoplasms. (authors)

  10. Low-dosage helical CT applications for chest medical checkup and lung cancer screening

    International Nuclear Information System (INIS)

    Wang Ping; Cui Fa; Liang Huanqing; Zheng Minfei

    2005-01-01

    Objective: A discussion on low-dosage helical CT applications on chest medical checkup and lung cancer screening. Methods: On the 100 chest medical check up with three different of protocols, including standard-dosage (the tube current was 230 mAs) were compared with low-dose (tube current was 50 mAs or 30 mAs). Results: Low-dosage helical CT scan provides excellent images. In 100 chest medical checkup, 39 nodules or masses were revealed, enlarged lymph node was noted in 1 case; emphysema or bullae was demonstrated in 3 segments; thickening of bronchial wall was shown in 2 cases; and localized pleural thickening was found in 1 case. Conclusion: In chest checkup or lung cancer screening low-dosage helical CT (tube current 30 mAs) will not only guarantee image quality but also reduce the radiation dose during the examination. (authors)

  11. Clinical application of percutaneous needling lung abscess drairnage under CT guidance

    International Nuclear Information System (INIS)

    Hu Xiaokun; Wang Mingyou; Li Chenjun; Lv Dongfang; Li Xiaodong; Yu Zhaocun

    2004-01-01

    Objective: To discuss the clinical application of drainage for lung abscess by needle puncture under CT guidance. Methods: 18 cases of lung abscess were drainaged by needle puncture under CT guidance, including direct aspiration by puncture needle 1-3 times (n=8) and retaining drainage tube continuously (n=10). Results: 17 cases with this procedure were succeeded possessing success rate of 94.7%(17/18). The patients were followed up for 11-35 days with symptom relieving better obviously and the focus shrinkage or disappeared (n=16), the curative rate reached 88.9%(16/18). The main complication was pneumothorax with capacities of 30%(n=1). Conclusions: The curative course of lung abscess can be shortened greatly by percutaneous needling drainage under CT guidance with mild trauma. The procedure is simple with high successful rate and less complication. (authors)

  12. The application of DynaCT in performing the placement of intracranial stent

    International Nuclear Information System (INIS)

    Shen Hui; Wang Yongchun; Wang Minjie; Ding Hailing; Qin Yashan; Mao Yaqin; Li Songhua; Mao Yanjun; Hao Qiang

    2011-01-01

    Objective: To evaluate the clinical application of DynaCT technique in performing intracranial stent implantation. Methods: Thirty-nine patients who were planed to receive intracranial stent implantation were involved in this study. During the procedure DynaCT scanning was employed to monitor the real-time situation of stent implantation. Results: A total of 47 stents were implanted in intracranial vessels in the 39 patients. By using conventional angiography during operation the position of these stents was observed and was assured to be in the proper position. The adherence of these stents to the vascular wall was demonstrated with DynaCT multi-planar reconstruction images and the stent adherence in good condition was ensured. Conclusion: DynaCT applied during and after intracranial stent implantation is very helpful for displaying the contours of the stents as well as the vascular lumen and for providing a detail picture of the relationship between the stent and the surrounding anatomy. Therefore, DynaCT scanning is of great clinical significance for performing the intracranial stent implantation. (authors)

  13. Virtual non-contrast of liver from dual energy CT: a clinical application

    International Nuclear Information System (INIS)

    Qian Yu'e; Hu Hongjie; Zhang Qiaowei; Hu Peng; Shen Guohui

    2011-01-01

    Objective: To assess the virtual non-contrast liver CT from dual-energy CT for the clinical application. Methods: In total, 51 patients were included in the study, and all patients underwent multi-phase liver CT on a dual-source CT. The True non-contrast liver CT (TNCT) was performed in a single-energy acquisition mode, but the arterial and portovenous liver CT (VNCT) were performed in a dual- energy mode of 110 kV and 140 kV respectively. The virtual non-contrast CT images were derived from the arterial data using liver virtual non-contrast software. Between the true non-contrast CT and the virtual non- contrast CT, the image quality, mean CT HU values in the liver and muscle, signal to noise (SNR), the radiation dose of volume CT dose index (CTDIvol) and dose length product (DLP) in a single phase and total examination were compared with t test. Results: There was no significant difference in the detection of' liver lesions between TNCT and VNCT. The CT Hu values of muscle on both TNCT and VNCT images were almost equal. The CT HU values of liver on VNCT images were higher than that on TNCT images and the difference was significant [61.32±6.04 vs. (56.85±4.80) HU, t=-3.927, P<0.01]. There was also significant difference of SNR between TNCT (11.28±2.78) and VNCT (8.65±1.56) images (t=-5.590, P<0.01). The CTDIvol and DLP of single phase were (7.07±0.85) mGy and (155.11± 22.52) mGy · cm respectively in TNCT, and (7.05±0.87) mGy and (154.48±23.12) mGy · cm in VNCT. The total CTDIvol and DLP in VNCT were (14.35±1.66) mGy and (313.91±45.08) mGy · cm respectively, but in TNCT the total CTDIvol and DLP reached (21.43±2.46) mGy and (469.02± 66.22) mGy · cm. The difference of CTDIvol and DLP in single phase between TNCT and VNCT showed no significance, but the total CTDIvol and DLP were significantly different (t=16.168 and 13.132, P< 0.01). Conclusion: With the consequent reduction in radiation dose, the VNCT can replace TNCT as an imaging protocol in multi

  14. TH-EF-BRA-08: A Novel Technique for Estimating Volumetric Cine MRI (VC-MRI) From Multi-Slice Sparsely Sampled Cine Images Using Motion Modeling and Free Form Deformation

    International Nuclear Information System (INIS)

    Harris, W; Yin, F; Wang, C; Chang, Z; Cai, J; Zhang, Y; Ren, L

    2016-01-01

    Purpose: To develop a technique to estimate on-board VC-MRI using multi-slice sparsely-sampled cine images, patient prior 4D-MRI, motion-modeling and free-form deformation for real-time 3D target verification of lung radiotherapy. Methods: A previous method has been developed to generate on-board VC-MRI by deforming prior MRI images based on a motion model(MM) extracted from prior 4D-MRI and a single-slice on-board 2D-cine image. In this study, free-form deformation(FD) was introduced to correct for errors in the MM when large anatomical changes exist. Multiple-slice sparsely-sampled on-board 2D-cine images located within the target are used to improve both the estimation accuracy and temporal resolution of VC-MRI. The on-board 2D-cine MRIs are acquired at 20–30frames/s by sampling only 10% of the k-space on Cartesian grid, with 85% of that taken at the central k-space. The method was evaluated using XCAT(computerized patient model) simulation of lung cancer patients with various anatomical and respirational changes from prior 4D-MRI to onboard volume. The accuracy was evaluated using Volume-Percent-Difference(VPD) and Center-of-Mass-Shift(COMS) of the estimated tumor volume. Effects of region-of-interest(ROI) selection, 2D-cine slice orientation, slice number and slice location on the estimation accuracy were evaluated. Results: VCMRI estimated using 10 sparsely-sampled sagittal 2D-cine MRIs achieved VPD/COMS of 9.07±3.54%/0.45±0.53mm among all scenarios based on estimation with ROI_MM-ROI_FD. The FD optimization improved estimation significantly for scenarios with anatomical changes. Using ROI-FD achieved better estimation than global-FD. Changing the multi-slice orientation to axial, coronal, and axial/sagittal orthogonal reduced the accuracy of VCMRI to VPD/COMS of 19.47±15.74%/1.57±2.54mm, 20.70±9.97%/2.34±0.92mm, and 16.02±13.79%/0.60±0.82mm, respectively. Reducing the number of cines to 8 enhanced temporal resolution of VC-MRI by 25% while

  15. TH-EF-BRA-08: A Novel Technique for Estimating Volumetric Cine MRI (VC-MRI) From Multi-Slice Sparsely Sampled Cine Images Using Motion Modeling and Free Form Deformation

    Energy Technology Data Exchange (ETDEWEB)

    Harris, W; Yin, F; Wang, C; Chang, Z; Cai, J; Zhang, Y; Ren, L [Duke University Medical Center, Durham, NC (United States)

    2016-06-15

    Purpose: To develop a technique to estimate on-board VC-MRI using multi-slice sparsely-sampled cine images, patient prior 4D-MRI, motion-modeling and free-form deformation for real-time 3D target verification of lung radiotherapy. Methods: A previous method has been developed to generate on-board VC-MRI by deforming prior MRI images based on a motion model(MM) extracted from prior 4D-MRI and a single-slice on-board 2D-cine image. In this study, free-form deformation(FD) was introduced to correct for errors in the MM when large anatomical changes exist. Multiple-slice sparsely-sampled on-board 2D-cine images located within the target are used to improve both the estimation accuracy and temporal resolution of VC-MRI. The on-board 2D-cine MRIs are acquired at 20–30frames/s by sampling only 10% of the k-space on Cartesian grid, with 85% of that taken at the central k-space. The method was evaluated using XCAT(computerized patient model) simulation of lung cancer patients with various anatomical and respirational changes from prior 4D-MRI to onboard volume. The accuracy was evaluated using Volume-Percent-Difference(VPD) and Center-of-Mass-Shift(COMS) of the estimated tumor volume. Effects of region-of-interest(ROI) selection, 2D-cine slice orientation, slice number and slice location on the estimation accuracy were evaluated. Results: VCMRI estimated using 10 sparsely-sampled sagittal 2D-cine MRIs achieved VPD/COMS of 9.07±3.54%/0.45±0.53mm among all scenarios based on estimation with ROI-MM-ROI-FD. The FD optimization improved estimation significantly for scenarios with anatomical changes. Using ROI-FD achieved better estimation than global-FD. Changing the multi-slice orientation to axial, coronal, and axial/sagittal orthogonal reduced the accuracy of VCMRI to VPD/COMS of 19.47±15.74%/1.57±2.54mm, 20.70±9.97%/2.34±0.92mm, and 16.02±13.79%/0.60±0.82mm, respectively. Reducing the number of cines to 8 enhanced temporal resolution of VC-MRI by 25% while

  16. The use of 2D pixel detectors in micro- and nano-CT applications

    International Nuclear Information System (INIS)

    Dierick, Manuel; Hoorebeke, Luc van; Jacobs, Patric; Masschaele, Bert; Vlassenbroeck, Jelle; Cnudde, Veerle; De Witte, Yoni

    2008-01-01

    Computed tomography or CT is a non-destructive imaging technique that uses penetrating radiation (mostly X-rays) to visualize the internal structure of a sample. The best-known example is the medical CT scanner, which has become a standard diagnostic tool in medicine, providing detailed views of the body with spatial resolutions below 1 mm. In recent years another type of CT scanner has been developed for mostly industrial and scientific applications, namely micro-CT scanners. These reached spatial resolutions down to a few microns. During 2005 the Radiation Physics research group (Department of Subatomic and Radiation Physics) and the Sedimentary Geology and Engineering Geology research group (Department of Geology and Soil Science) of the Ghent University jointly developed a modular micro-CT setup. The two main goals were to achieve a spatial resolution below 1 μm and to have a very versatile tool providing high-quality images. The source is a dual-head X-ray tube with a transmission type head with a nominal focal spot size of 900 nm below 40 kV tube voltage for high-resolution applications and a directional high-power head (up to 160 kV, up to 150 W), which enables scanning of larger samples. A six-axis sample manipulator system was assembled. The crucial component in this is an ultra-high-precision air-bearing rotation stage to keep all motion errors during rotation well below 1 μm. Depending on the application we have the choice between a number of detectors, each with its own advantages in terms of size, pixel resolution and energy sensitivity

  17. Report on the development and application of PET/CT in mainland China.

    Science.gov (United States)

    Chen, Yumei; Chen, Ruohua; Zhou, Xiang; Liu, Jianjun; Huang, Gang

    2017-09-08

    To examine the development and application of systems combining positron emission and x-ray-computed tomography systems (PET/CTs) in mainland China. Using a questionnaire, we surveyed Chinese medical institutions on a variety topics relating to their PET/CT systems and its use. The respondents had PET/CTs installed and in clinical use before 31 December 2015. We examined the clinical scenarios to which Chinese PET/CTs were applied by reviewing the related Chinese and international literature from the start of 1995 to the end of 2013; these papers were found by searching the Wanfang and PubMed databases, respectively. The data were then classified and analyzed statistically. At the end of 2015, there were 240 PET/CTs and 101 medical cyclotrons in mainland China. The total number of PET studies performed in 2015 was 469,364. The main clinical applications of PET were found to be diagnostic fludeoxyglucose ( 18 F-FDG) imaging and oncological imaging. A minority of PET/CT studies were performed using 11 C-choline and other imaging agents. The number of papers relating to clinical use of PET/CT in mainland China increased each year over the period of study, in both the Chinese and international literature. Despite this progress, important problems were also apparent, including unbalanced regional development and the limited quality of the research. This study provides detailed information for understanding the development PET/CT technology in mainland China, along with its geographical distribution and clinical application. It may thus prove a useful reference for all those involved in planning the future of PET/CT in China.

  18. Evaluation of a metal artifact reduction algorithm applied to post-interventional flat detector CT in comparison to pre-treatment CT in patients with acute subarachnoid haemorrhage

    Energy Technology Data Exchange (ETDEWEB)

    Mennecke, Angelika; Svergun, Stanislav; Doerfler, Arnd; Struffert, Tobias [University of Erlangen-Nuremberg, Department of Neuroradiology, Erlangen (Germany); Scholz, Bernhard [Siemens Healthcare GmbH, Forchheim (Germany); Royalty, Kevin [Siemens Medical Solutions, USA, Inc., Hoffman Estates, IL (United States)

    2017-01-15

    Metal artefacts can impair accurate diagnosis of haemorrhage using flat detector CT (FD-CT), especially after aneurysm coiling. Within this work we evaluate a prototype metal artefact reduction algorithm by comparison of the artefact-reduced and the non-artefact-reduced FD-CT images to pre-treatment FD-CT and multi-slice CT images. Twenty-five patients with acute aneurysmal subarachnoid haemorrhage (SAH) were selected retrospectively. FD-CT and multi-slice CT before endovascular treatment as well as FD-CT data sets after treatment were available for all patients. The algorithm was applied to post-treatment FD-CT. The effect of the algorithm was evaluated utilizing the pre-post concordance of a modified Fisher score, a subjective image quality assessment, the range of the Hounsfield units within three ROIs, and the pre-post slice-wise Pearson correlation. The pre-post concordance of the modified Fisher score, the subjective image quality, and the pre-post correlation of the ranges of the Hounsfield units were significantly higher for artefact-reduced than for non-artefact-reduced images. Within the metal-affected slices, the pre-post slice-wise Pearson correlation coefficient was higher for artefact-reduced than for non-artefact-reduced images. The overall diagnostic quality of the artefact-reduced images was improved and reached the level of the pre-interventional FD-CT images. The metal-unaffected parts of the image were not modified. (orig.)

  19. Evaluation of a metal artifact reduction algorithm applied to post-interventional flat detector CT in comparison to pre-treatment CT in patients with acute subarachnoid haemorrhage

    International Nuclear Information System (INIS)

    Mennecke, Angelika; Svergun, Stanislav; Doerfler, Arnd; Struffert, Tobias; Scholz, Bernhard; Royalty, Kevin

    2017-01-01

    Metal artefacts can impair accurate diagnosis of haemorrhage using flat detector CT (FD-CT), especially after aneurysm coiling. Within this work we evaluate a prototype metal artefact reduction algorithm by comparison of the artefact-reduced and the non-artefact-reduced FD-CT images to pre-treatment FD-CT and multi-slice CT images. Twenty-five patients with acute aneurysmal subarachnoid haemorrhage (SAH) were selected retrospectively. FD-CT and multi-slice CT before endovascular treatment as well as FD-CT data sets after treatment were available for all patients. The algorithm was applied to post-treatment FD-CT. The effect of the algorithm was evaluated utilizing the pre-post concordance of a modified Fisher score, a subjective image quality assessment, the range of the Hounsfield units within three ROIs, and the pre-post slice-wise Pearson correlation. The pre-post concordance of the modified Fisher score, the subjective image quality, and the pre-post correlation of the ranges of the Hounsfield units were significantly higher for artefact-reduced than for non-artefact-reduced images. Within the metal-affected slices, the pre-post slice-wise Pearson correlation coefficient was higher for artefact-reduced than for non-artefact-reduced images. The overall diagnostic quality of the artefact-reduced images was improved and reached the level of the pre-interventional FD-CT images. The metal-unaffected parts of the image were not modified. (orig.)

  20. Application of 3D X-ray CT data sets to finite element analysis

    International Nuclear Information System (INIS)

    Bossart, P.L.; Martz, H.E.; Brand, H.R.; Hollerbach, K.

    1995-01-01

    Finite Element Modeling (FEM) is becoming more important as industry drives toward concurrent engineering. A fundamental hindrance to fully exploiting the power of FEM is the human effort required to acquire complex part geometry, particularly as-built geometry, as a FEM mesh. Many Quantitative Non Destructive Evaluation (QNDE) techniques that produce three-dimensional (3D) data sets provide a substantial reduction in the effort required to apply FEM to as-built parts. This paper describes progress at LLNL on the application of 3D X-ray computed tomography (CT) data sets to more rapidly produce high-quality FEM meshes of complex, as-built geometries. Issues related to the volume segmentation of the 3D CT data as well as the use of this segmented data to tailor generic hexahedral FEM meshes to part specific geometries are discussed. The application of these techniques to FEM analysis in the medical field is reported here

  1. [Progress in Application of Measuring Skeleton by CT in Forensic Anthropology Research].

    Science.gov (United States)

    Miao, C Y; Xu, L; Wang, N; Zhang, M; Li, Y S; Lü, J X

    2017-02-01

    Individual identification by measuring the human skeleton is an important research in the field of forensic anthropology. Computed tomography (CT) technology can provide high-resolution image of skeleton. Skeleton image can be reformed by software in the post-processing workstation. Different skeleton measurement indexes of anthropology, such as diameter, angle, area and volume, can be measured on section and reformative images. Measurement process is barely affected by human factors. This paper reviews the literatures at home and abroad about the application of measuring skeleton by CT in forensic anthropology research for individual identification in four aspects, including sex determination, height infer, facial soft tissue thickness measurement and age estimation. The major technology and the application of CT in forensic anthropology research are compared and discussed, respectively. Copyright© by the Editorial Department of Journal of Forensic Medicine.

  2. The application value of PET-CT in the diagnosis of breast cancer

    International Nuclear Information System (INIS)

    Li Haitao

    2005-01-01

    Breast cancer is the most common malignancy in women in most of countries. During the past decades, the application of PET with 18 f-fluoro-2-deoxy-D-glocuse ( 18 F-FDG) has remarkably improved the management of breast cancer. Nevertheless, due to anatomical localisation of 18 F-FDG uptake was difficult, the clinical interpretation of 18 F-FDG PET scan could not be exactly. A novel combined PET-CT system has largely improved the capacity of sensitivity and specificity in the diagnosis of breast cancer. In this artiacal we focus on the application value of PET-CT to breast cancer diagnosis, with respect to dissease re-staging, treatment monitoring, preoperative staging and radiotherapy planning. (authors)

  3. Clinical Applications of a CT Window Blending Algorithm: RADIO (Relative Attenuation-Dependent Image Overlay).

    Science.gov (United States)

    Mandell, Jacob C; Khurana, Bharti; Folio, Les R; Hyun, Hyewon; Smith, Stacy E; Dunne, Ruth M; Andriole, Katherine P

    2017-06-01

    A methodology is described using Adobe Photoshop and Adobe Extendscript to process DICOM images with a Relative Attenuation-Dependent Image Overlay (RADIO) algorithm to visualize the full dynamic range of CT in one view, without requiring a change in window and level settings. The potential clinical uses for such an algorithm are described in a pictorial overview, including applications in emergency radiology, oncologic imaging, and nuclear medicine and molecular imaging.

  4. Application of the optically stimulated luminescence (OSL) technique for mouse dosimetry in micro-CT imaging

    Energy Technology Data Exchange (ETDEWEB)

    Vrigneaud, Jean-Marc; Courteau, Alan; Oudot, Alexandra; Collin, Bertrand [Department of Nuclear Medicine, Centre Georges-François Leclerc, 1 rue Professeur Marion, Dijon 21079 Cedex (France); Ranouil, Julien [Landauer Europe, 33 avenue du Général Leclerc, Fontenay-aux-Roses 92266 Cedex (France); Morgand, Loïc; Raguin, Olivier [Oncodesign, 20 rue Jean Mazen, Dijon 21076 Cedex (France); Walker, Paul [LE2i CNRS UMR 5158, Faculty of Medicine, BP 87900, 21079 Dijon Cedex (France); Brunotte, François [Department of Nuclear Medicine, Centre Georges-François Leclerc, 1 rue Professeur Marion, Dijon 21079 Cedex, France and LE2i CNRS UMR 5158, Faculty of Medicine, BP 87900, 21079 Dijon Cedex (France)

    2013-12-15

    Purpose: Micro-CT is considered to be a powerful tool to investigate various models of disease on anesthetized animals. In longitudinal studies, the radiation dose delivered by the micro-CT to the same animal is a major concern as it could potentially induce spurious effects in experimental results. Optically stimulated luminescence dosimeters (OSLDs) are a relatively new kind of detector used in radiation dosimetry for medical applications. The aim of this work was to assess the dose delivered by the CT component of a micro-SPECT (single-photon emission computed tomography)/CT camera during a typical whole-body mouse study, using commercially available OSLDs based on Al{sub 2}O{sub 3}:C crystals.Methods: CTDI (computed tomography dose index) was measured in micro-CT with a properly calibrated pencil ionization chamber using a rat-like phantom (60 mm in diameter) and a mouse-like phantom (30 mm in diameter). OSLDs were checked for reproducibility and linearity in the range of doses delivered by the micro-CT. Dose measurements obtained with OSLDs were compared to those of the ionization chamber to correct for the radiation quality dependence of OSLDs in the low-kV range. Doses to tissue were then investigated in phantoms and cadavers. A 30 mm diameter phantom, specifically designed to insert OSLDs, was used to assess radiation dose over a typical whole-body mouse imaging study. Eighteen healthy female BALB/c mice weighing 27.1 ± 0.8 g (1 SD) were euthanized for small animal measurements. OLSDs were placed externally or implanted internally in nine different locations by an experienced animal technician. Five commonly used micro-CT protocols were investigated.Results: CTDI measurements were between 78.0 ± 2.1 and 110.7 ± 3.0 mGy for the rat-like phantom and between 169.3 ± 4.6 and 203.6 ± 5.5 mGy for the mouse-like phantom. On average, the displayed CTDI at the operator console was underestimated by 1.19 for the rat-like phantom and 2.36 for the mouse

  5. Evaluating applicability of metal artifact reduction algorithm for head and neck radiation treatment planning CT

    International Nuclear Information System (INIS)

    Son, Sang Jun; Park, Jang Pil; Kim, Min Jeong; Yoo, Suk Hyun

    2014-01-01

    The purpose of this study is evaluation for the applicability of O-MAR(Metal artifact Reduction for Orthopedic Implants)(ver. 3.6.0, Philips, Netherlands) in head and neck radiation treatment planning CT with metal artifact created by dental implant. All of the in this study's CT images were scanned by Brilliance Big Bore CT(Philips, Netherlands) at 120 kVp, 2 mm sliced and Metal artifact reduced by O-MAR. To compare the original and reconstructed CT images worked on RTPS(Eclipse ver 10.0.42, Varian, USA). In order to test the basic performance of the O-MAR, The phantom was made to create metal artifact by dental implant and other phantoms used for without artifact images. To measure a difference of HU in with artifact images and without artifact images, homogeneous phantom and inhomogeneous phantoms were used with cerrobend rods. Each of images were compared a difference of HU in ROIs. And also, 1 case of patient's original CT image applied O-MAR and density corrected CT were evaluated for dose distributions with SNC Patient(Sun Nuclear Co., USA). In cases of head and neck phantom, the difference of dose distribution is appeared 99.8% gamma passing rate(criteria 2 mm / 2%) between original and CT images applied O-MAR. And 98.5% appeared in patient case, among original CT, O-MAR and density corrected CT. The difference of total dose distribution is less than 2% that appeared both phantom and patient case study. Though the dose deviations are little, there are still matters to discuss that the dose deviations are concentrated so locally. In this study, The quality of all images applied O-MAR was improved. Unexpectedly, Increase of max. HU was founded in air cavity of the O-MAR images compare to cavity of the original images and wrong corrections were appeared, too. The result of study assuming restrained case of O-MAR adapted to near skin and low density area, it appeared image distortion and artifact correction simultaneously. In O-MAR CT, air cavity area

  6. Novel Application of Postmortem CT Angiography for Evaluation of the Intracranial Vascular Anatomy in Cadaver Heads.

    Science.gov (United States)

    van Eijk, Ruben P A; van der Zwan, Albert; Bleys, Ronald L A W; Regli, Luca; Esposito, Giuseppe

    2015-12-01

    Postmortem CT angiography is a common procedure used to visualize the entire human vasculature. For visualization of a specific organ's vascular anatomy, casting is the preferred method. Because of the permanent and damaging nature of casting, the organ cannot be further used as an experimental model after angiography. Therefore, there is a need for a minimally traumatic method to visualize organ-specific vascular anatomy. The purpose of this study was to develop and evaluate a contrast enhancement technique that is capable of visualizing the intracranial vascular anatomy while preserving the anatomic integrity in cadaver heads. Seven human heads were used in this study. Heads were prepared by cannulating the vertebral and internal carotid arteries. Contrast agent was injected as a mixture of tap water, polyethylene glycol 600, and an iodinated contrast agent. Postmortem imaging was executed on a 64-MDCT scanner. Primary image review and 3D reconstruction were performed on a CT workstation. Clear visualization of the major cerebral arteries and smaller intracranial branches was achieved. Adequate visualization was obtained for both the anterior and posterior intracranial circulation. The minimally traumatic angiography method preserved the vascular integrity of the cadaver heads. A novel application of postmortem CT angiography is presented here. The technique can be used for radiologic evaluation of the intracranial circulation in cadaver heads. After CT angiography, the specimen can be used for further experimental or laboratory testing and teaching purposes.

  7. The clinical application studies of CT spinal angiography with 64-detector row spiral CT in diagnosing spinal vascular malformations

    International Nuclear Information System (INIS)

    Gao Sijia; Zhang Mengwei; Liu Xiping; Zh Yushen; Liu Jinghong; Wang Zhonghui; Zang Peizhuo; Shi Qiang; Wang Qiang; Liang Chuansheng; Xu Ke

    2009-01-01

    Background and purpose: To explore the value of CT spinal angiography with 64-detector row spiral CT in diagnosing spinal vascular malformations. Methods: Seventeen patients with initial MR and clinical findings suggestive of spinal vascular diseases underwent CT spinal angiography. Among these, 14 patients took DSA examination within 1 week after CT scan, 7 patients underwent surgical treatment, and 6 patients underwent vascular intervention embolotheraphy. CT protocol: TOSHIBA Aquilion 64 Slice CT scanner, 0.5 mm thickness, 0.5 s/r, 120 kV and 350 mA, positioned at the aortic arch level, and applied with 'sure start' technique with CT threshold of 180 Hu. Contrast agent Iohexol (370 mg I/ml) was injected at 6 ml/s velocity with total volume of 80 ml. The post-processing procedures included MPR, CPR, MIP, VR, etc. Among the 17 patients, four patients underwent fast dynamic contrast-enhanced 3D MR angiography imaging. CT spinal angiography and three-dimensional contrast-enhanced MR angiography (3D CE-MRA) images were compared and evaluated with DSA and operation results based on disease type, lesion range, feeding arteries, fistulas, draining veins of vascular malformation by three experienced neuroradiologists independently, using double blind method. The data were analyzed using SPSS analytic software with χ 2 -test. We compared the results with DSA and operation results. Results: The statistical analysis of the diagnostic results by the three experienced neuroradiologists had no statistical difference (P > 0.05). All of the 17 patients showed clearly the abnormality of spinal cord vessels and the range of lesions by CT spinal angiography. Among them, one patient was diagnosed as arteriovenous fistulas (AVF) by MRI and CT spinal angiography, which was verified by surgical operation. DSA of the same patient, however, did not visualize the lesion. One case was diagnosed as AVM complicated with AVF by DSA, but CT spinal angiography could only show AVM not AVF. The

  8. The clinical application studies of CT spinal angiography with 64-detector row spiral CT in diagnosing spinal vascular malformations

    Energy Technology Data Exchange (ETDEWEB)

    Gao Sijia [Department of Radiology, No. 1 Affiliated Hospital of China Medical University, Shenyang 110001 (China)], E-mail: scarlettgao@126.com; Zhang Mengwei; Liu Xiping; Zh Yushen; Liu Jinghong; Wang Zhonghui [Department of Radiology, No. 1 Affiliated Hospital of China Medical University, Shenyang 110001 (China); Zang Peizhuo [Department of Neurosurgery, No. 1 Affiliated Hospital of China Medical University, Shenyang 110001 (China); Shi Qiang; Wang Qiang [Department of Radiology, No. 1 Affiliated Hospital of China Medical University, Shenyang 110001 (China); Liang Chuansheng [Department of Neurosurgery, No. 1 Affiliated Hospital of China Medical University, Shenyang 110001 (China); Xu Ke [Department of Radiology, No. 1 Affiliated Hospital of China Medical University, Shenyang 110001 (China)

    2009-07-15

    Background and purpose: To explore the value of CT spinal angiography with 64-detector row spiral CT in diagnosing spinal vascular malformations. Methods: Seventeen patients with initial MR and clinical findings suggestive of spinal vascular diseases underwent CT spinal angiography. Among these, 14 patients took DSA examination within 1 week after CT scan, 7 patients underwent surgical treatment, and 6 patients underwent vascular intervention embolotheraphy. CT protocol: TOSHIBA Aquilion 64 Slice CT scanner, 0.5 mm thickness, 0.5 s/r, 120 kV and 350 mA, positioned at the aortic arch level, and applied with 'sure start' technique with CT threshold of 180 Hu. Contrast agent Iohexol (370 mg I/ml) was injected at 6 ml/s velocity with total volume of 80 ml. The post-processing procedures included MPR, CPR, MIP, VR, etc. Among the 17 patients, four patients underwent fast dynamic contrast-enhanced 3D MR angiography imaging. CT spinal angiography and three-dimensional contrast-enhanced MR angiography (3D CE-MRA) images were compared and evaluated with DSA and operation results based on disease type, lesion range, feeding arteries, fistulas, draining veins of vascular malformation by three experienced neuroradiologists independently, using double blind method. The data were analyzed using SPSS analytic software with {chi}{sup 2}-test. We compared the results with DSA and operation results. Results: The statistical analysis of the diagnostic results by the three experienced neuroradiologists had no statistical difference (P > 0.05). All of the 17 patients showed clearly the abnormality of spinal cord vessels and the range of lesions by CT spinal angiography. Among them, one patient was diagnosed as arteriovenous fistulas (AVF) by MRI and CT spinal angiography, which was verified by surgical operation. DSA of the same patient, however, did not visualize the lesion. One case was diagnosed as AVM complicated with AVF by DSA, but CT spinal angiography could only show

  9. 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.)

  10. Characteristics and application of inner ear CT in 20 cases of sensorineural hearing loss in children.

    Science.gov (United States)

    Huo, Liang; Wang, Hua

    2012-12-01

    This study shows that a number of children with sensorineural hearing loss (SNHL) have inner ear malformations demonstrated by multi-slice spiral computed tomography (MSCT). MSCT allows a comprehensive assessment of various congenital inner ear malformations through high quality multiplanar reformation (MPR) and can display the site and degree of the malformation three-dimensionally and intuitively. This is very useful for cochlear implantation. To evaluate the feasibility and usability of MSCT in pediatric SNHL with inner ear malformations. Sixty-five patients were diagnosed with SNHL by brainstem auditory evoked response (BAER). Inner ear MSCT scan and coronal MPR reconstruction were performed in all cases. This study demonstrated 20 cases (33 ears) with inner ear malformations, which included 10 ears with cochlear malformations, 7 with vestibular malformations, 5 with semicircular canal malformations, 8 with internal auditory canal (IAC) malformations, and 15 with vestibular malformations. Cochlear malformations included one ear with Michel deformity, two ears with common cavity deformity, one with cochlear aplasia, one with hypoplastic cochlea, two with incomplete partition type I, and three with incomplete partition type II (Mondini deformity).

  11. Helical CT for lung-cancer screening. 3. Fundamental study for ultra-low-dose CT by application of small tube current and filter

    International Nuclear Information System (INIS)

    Itoh, Shigeki; Koyama, Shuji; Tusaka, Masatoshi; Maekoshi, Hisashi; Satake, Hiroko; Ishigaki, Takeo.

    1996-01-01

    In order to develop ultra-low-dose helical CT for lung cancer screening, the effect of reduction of the tube current to 20 mA and application of a 10 mm thick aluminium filter upon radiation dose and image quality was evaluated with a phantom. Exposure dose at the center of a gantry and absorbed dose at the center of an acrylic phantom at 20 mA with the filter were 15% and 29% of the dose at 50 mA without the filter, respectively. For reduction of absorbed dose, reduction of the tube current was more useful than application of the filter. Image noise at 20 mA with the filter was double that at 50 mA without the filter. Neither reduction of the tube current nor application of the filter changed full width at half maximum on section sensitivity of the Z-axis. Although reduction of the tube current did not affect the difference in CT values between an acrylic sphere and styroform, application of the filter caused a reduction of 4.5% in the difference in CT values. Neither reduction of the tube current nor application of the filter affected the contrast resolution of the high-contrast phantom; however, that of the low-contrast phantom deteriorated. Although improvement of the filter and evaluation of clinical images are necessary, reduction of the tube current to 20 mA and application of the aluminium filter appear to be a promising method for ultra-low-dose helical CT of the lung. (author)

  12. Clinical applications of 2D and 3D CT imaging of the airways - a review

    International Nuclear Information System (INIS)

    Salvolini, Luca; Bichi Secchi, Elisabetta; Costarelli, Leonardo; De Nicola, Maurizio

    2000-01-01

    Hardware and software evolution has broadened the possibilities of 2D and 3D reformatting of spiral CT and MR data set. In the study of the thorax, intrinsic benefits of volumetric CT scanning and better quality of reconstructed images offer us the possibility to apply additional rendering techniques to everyday clinical practice. Considering the large number and redundancy of possible post-processing imaging techniques that we can apply to raw CT sections data, it is necessary to precisely set a well-defined number of clinical applications of each of them, by careful evaluation of their benefits and possible pitfalls in each clinical setting. In diagnostic evaluation of pathological processes affecting the airways, a huge number of thin sections is necessary for detailed appraisal and has to be evaluated, and information must then be transferred to referring clinicians. By additional rendering it is possible to make image evaluation and data transfer easier, faster, and more effective. In the study of central airways, additional rendering can be of interest for precise evaluation of the length, morphology, and degree of stenoses. It may help in depicting exactly the locoregional extent of central tumours by better display of relations with bronchovascular interfaces and can increase CT/bronchoscopy sinergy. It may allow closer radiotherapy planning and better depiction of air collections, and, finally, it could ease panoramic evaluation of the results of dynamic or functional studies, that are made possible by increased speed of spiral scanning. When applied to the evaluation of peripheral airways, as a completion to conventional HRCT scans, High-Resolution Volumetric CT, by projection slabs applied to target areas of interest, can better depict the profusion and extension of affected bronchial segments in bronchiectasis, influence the choice of different approaches for tissue sampling by better evaluation of the relations of lung nodules with the airways, or help

  13. Clinical applications of 2D and 3D CT imaging of the airways - a review

    Energy Technology Data Exchange (ETDEWEB)

    Salvolini, Luca E-mail: u.salvolini@popcsi.unian.it; Bichi Secchi, Elisabetta; Costarelli, Leonardo; De Nicola, Maurizio

    2000-04-01

    Hardware and software evolution has broadened the possibilities of 2D and 3D reformatting of spiral CT and MR data set. In the study of the thorax, intrinsic benefits of volumetric CT scanning and better quality of reconstructed images offer us the possibility to apply additional rendering techniques to everyday clinical practice. Considering the large number and redundancy of possible post-processing imaging techniques that we can apply to raw CT sections data, it is necessary to precisely set a well-defined number of clinical applications of each of them, by careful evaluation of their benefits and possible pitfalls in each clinical setting. In diagnostic evaluation of pathological processes affecting the airways, a huge number of thin sections is necessary for detailed appraisal and has to be evaluated, and information must then be transferred to referring clinicians. By additional rendering it is possible to make image evaluation and data transfer easier, faster, and more effective. In the study of central airways, additional rendering can be of interest for precise evaluation of the length, morphology, and degree of stenoses. It may help in depicting exactly the locoregional extent of central tumours by better display of relations with bronchovascular interfaces and can increase CT/bronchoscopy sinergy. It may allow closer radiotherapy planning and better depiction of air collections, and, finally, it could ease panoramic evaluation of the results of dynamic or functional studies, that are made possible by increased speed of spiral scanning. When applied to the evaluation of peripheral airways, as a completion to conventional HRCT scans, High-Resolution Volumetric CT, by projection slabs applied to target areas of interest, can better depict the profusion and extension of affected bronchial segments in bronchiectasis, influence the choice of different approaches for tissue sampling by better evaluation of the relations of lung nodules with the airways, or help

  14. Determination of vitality in myocardial infarction. Comparison of single- and multi-slice MRI techniques with TurboFlash and TrueFISP sequences

    International Nuclear Information System (INIS)

    Huber, A.; Schoenberg, S.O.; Spannagl, B.; Rieber, J.; Klauss, V.; Reiser, M.F.

    2004-01-01

    The aim of the study was to compare the diagnostic accuracy in imaging viability of the myocardium with a multislice inversions recovery 2D single shot TrueFISP sequence and an established inversion recovery TurboFlash sequence. Twelve patients with myocardial infarction were examined at a 1.5 tesla MR system (Sonata, Siemens, Medical Systems) 10 min after application of a single dose multihance (0,1 mmol/kg body weight) with a 2D multislice technique (inversion recovery single shot TrueFISP), that allows to image the entire short axis during one breathhold and a 2D single slice technique (inversion recovery TurboFlash), that requires one breathhold per slice. Signal intensity was determined in normal myocardium, in the infarcted myocardium and in the left ventricle. The contrast/noise ratio of normal and infarcted myocardium was determined. The areas of hyperintense infarction were compared for both sequence techniques. The multislice single shot 2D IR-TrueFisp sequence has a lower contrast/noise ratio than the IR-TurboFlash sequence (mean values 6.9 vs. 12.5) for viable and non viable myocardium. The assessment of the volume of the infarction is possible with excellent correlation of both techniques (r=0.97, p [de

  15. 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...

  16. The application of digital tomosynthesis to the diagnosis of the styloid process syndrome

    International Nuclear Information System (INIS)

    Ge Hequan; Zheng Kuihong; Wang Zijun; Huang Minhua; Ying Ligang

    2011-01-01

    Objective: To investigate the clinical value of digital tomosynthesis in the diagnosis of the styloid process syndrome. Methods: The thirty patients suspected of the styloid process syndrome underwent both multi-slice spiral CT scanning and digital tomosynthesis scanning. Two kinds of imaging were analyzed, and the length and angle of styloid on lateral and AP views were measured. Results: Both images could clearly show the styloid length, size, shape, direction and the relationship with surrounding structures. There was no significant difference in the length, medial angle in the AP position and anterior angle in the lateral position between multi-slice spiral CT scanning and digital tomosynthesis scanning (P>0.1). The styloid length on lateral digital tomosynthesis was significant smaller than that on multi-slice spiral CT scanning (P<0.01). Conclusions: The length of styloid measured should take the AP position as the standard using the digital tomosynthesis technique, which improve the image quality during the diagnosis of the styloid process syndrome and is less coitly and at a lower dose of radiation. Digital tomosynthesis could provide extensive clinical information and preoperative preparation of the very high referential value as CT canning. (authors)

  17. Clinical application of helical CT 3D reconstruction for the dental orthopaedics

    International Nuclear Information System (INIS)

    Han Benyi; Jiang Xiaolu; Li Hongru

    2005-01-01

    Objective: To evaluate the clinical application of helical CT 3D reconstruction technique in the dental orthopaedics. Methods: The helical CT was performed with 3.0 mm slice thickness and 1.0 pitch in 41 patients with dental orthopaedics. The 3D reconstructions, including maximum intensity projection (MIP), surface shaded display (SSD), and multiplanar reconstructions (MPR), were made for all the cases. Results: Thirty-seven of the 41 patients showed malalignment, tilt, rotation, overlap of the teeth and the different space between the longitudinal axes of the teeth. Twenty-five cases of them have shown 36 buried teeth in all. The axial images covered all the information. SSD demonstrated the external contours and entire morphologies of the teeth and the mandible with the relationship of the teeth alignment and the mandible. MIP clearly manifested the full view and the longitudinal alignment of the teeth. Among the 36 buried teeth, there were 29 palatally and 7 labially presented teeth, and they were morphologically delineated on MIP through various angles. Conclusion: The helical CT 3D reconstruction is a new technique to display the stereoscopic configuration of teeth. The combination of axial images and MIP, SSD, and MPR provides valuable anatomic and diagnostic information helpful for the surgeons to structure and determine the treatment protocol for the dental orthopaedics. (authors)

  18. Clinical application of 3D spiral CT of the auditory ossicular chain and labyrinth: Preliminary report

    International Nuclear Information System (INIS)

    Huang Yong; Wang Yisheng

    1998-01-01

    Purpose: To assess the clinical application and limitation of 3D spiral CT of the auditory ossicular chain and labyrinth. Methods: 3D reconstruction of the auditory ossicular chain and labyrinth, including multiplanar reformation (MPR), minimum or maximum intensity projection (MinIP or MaxIP) and shaded surface display (SSD), were performed with 1 mm slice thickness, 5 cm field of view and 0.1 mm reconstruction interval spiral CT in 14 normal subjects, 15 patients with middle ear diseases. Results: With use of 3D reconstruction images in 14 normal subjects, 13 cases of ossicular chain showed that the long process of the incus was parallel to the manubrium and projected inferomedian toward the cochlear promontory, the incus-stapedial joint was like a 'L-shape' structure, and in 8 cases of labyrinth reconstruction, the cochlea and the three semicircular canals were demonstrated. 9 cholesteatomas of 13 chronic otitis media demonstrated destruction of ossicular chain of varying degrees. In 2 cases with congenital abnormality, ossicle dysplasia was seen. Conclusion: 3D CT is a useful technique for evaluating anatomic malformations and diseases of middle and inner ear, but there are still few pitfalls

  19. What is the difference in the hybrid imaging techniques - SPECT/CT and PET-CT and is there any advantage of their application?

    International Nuclear Information System (INIS)

    Kostadinova, I.

    2012-01-01

    The hybrid imaging methods - Single Photon Emission Tomography-Computer Tomography /SPECT-CT / and Positron Emission Tomography-Computer Tomography / PET-CT/ allow receiving of combined image of two different techniques. In such a way it is possible to superimpose detailed anatomical image of the multislice spiral computer tomography with specific and sensitive molecular images of the SPECT and PET in a single study, allowing utilization of the full possibilities of the both techniques. They have advantages and disadvantages, which basically stem from the differences in the used radiopharmaceuticals and their physical properties. In PET- CT - positron emitters are applied, most often 18F and 11C, while in SPECT-CT - single photon emitters, most often 99m Tc and 131 I. A disadvantage of PET is a high cost, which is produced in cyclotron and its logistics is complicated. The great advantage of PET is its better spatial resolution, compared to SPECT, because of the possibility for simultaneous detection of pared photons and better registration. These techniques, especially PET-CT are nowadays the most increasing imaging methods in the world in making diagnosis, staging and following the effect of treatment in patients with oncological, neurological, cardiological, orthopedic diseases and infections. Recently, they are applied for the purposes of radiotherapy planning on the basis of the metabolically active tumor. As a final result, compared to the conventional techniques - roentgenography, CT and MRI, it is possible in many cases to make an early and more precise diagnosis, saving patients' time and using most appropriate treatment. As a conclusion it is clear, that the hybrid imaging has future and its application will increase. (author)

  20. Diagnosis of pelvic wall tumor on multislice CT

    International Nuclear Information System (INIS)

    Zhang Keyun; Deng Lequn; Lei Hongwei

    2011-01-01

    Objective: To evaluate the value of multi-slice CT (MSCT) in diagnosing pelvic wall tumors. Methods: MSCT of 21 cases of pelvic wall tumors including metastasis (10), neurogenic tumor (5), chondrosarcoma (2), chordoma (1), aneurysmal bone cyst (1), giant cell tumor (1), and osteochondroma (1) was retrospectively analyzed. Results: CT appearances of pelvic wall tumors include bony destruction and soft tissue masses. Common features were bone destruction in metastasis, expansion of the neuroforamen in neurogenic tumor, pleomorphic calcification in chondrosarcoma, lower sacral vertebral location of chordoma, iliac crest bone destruction in giant cell tumor, cauliflower-like nodules in osteochondroma. Conclusion: MSCT with three-dimensional volume rendering demonstrates well the tumor shape, size, extent, internal structure and relationship with the surrounding organs to aid diagnosis of pelvic wall tumors. (authors)

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

    International Nuclear Information System (INIS)

    Wang Jue; Jiang Zenghui; Wang Fuquan

    2008-01-01

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

  2. Comparison between effective radiation dose of CBCT and MSCT scanners for dentomaxillofacial applications

    NARCIS (Netherlands)

    Loubele, M.; Bogaerts, R.; van Dijck, E.; Pauwels, R.; Vanheusden, S.; Seutens, P.; Marchal, G.; Sanderink, G.; Jacobs, R.

    2009-01-01

    Objectives: To compare the effective dose levels of cone beam computed tomography (CBCT) for maxillofacial applications with those of multi-slice computed tomography (MSCT). Study design: The effective doses of 3 CBCT scanners were estimated (Accuitomo 3D®, i-CAT®, and NewTom 3G®) and compared to

  3. Tracking fuzzy borders using geodesic curves with application to liver segmentation on planning CT

    International Nuclear Information System (INIS)

    Yuan, Yading; Chao, Ming; Sheu, Ren-Dih; Rosenzweig, Kenneth; Lo, Yeh-Chi

    2015-01-01

    Purpose: This work aims to develop a robust and efficient method to track the fuzzy borders between liver and the abutted organs where automatic liver segmentation usually suffers, and to investigate its applications in automatic liver segmentation on noncontrast-enhanced planning computed tomography (CT) images. Methods: In order to track the fuzzy liver–chestwall and liver–heart borders where oversegmentation is often found, a starting point and an ending point were first identified on the coronal view images; the fuzzy border was then determined as a geodesic curve constructed by minimizing the gradient-weighted path length between these two points near the fuzzy border. The minimization of path length was numerically solved by fast-marching method. The resultant fuzzy borders were incorporated into the authors’ automatic segmentation scheme, in which the liver was initially estimated by a patient-specific adaptive thresholding and then refined by a geodesic active contour model. By using planning CT images of 15 liver patients treated with stereotactic body radiation therapy, the liver contours extracted by the proposed computerized scheme were compared with those manually delineated by a radiation oncologist. Results: The proposed automatic liver segmentation method yielded an average Dice similarity coefficient of 0.930 ± 0.015, whereas it was 0.912 ± 0.020 if the fuzzy border tracking was not used. The application of fuzzy border tracking was found to significantly improve the segmentation performance. The mean liver volume obtained by the proposed method was 1727 cm 3 , whereas it was 1719 cm 3 for manual-outlined volumes. The computer-generated liver volumes achieved excellent agreement with manual-outlined volumes with correlation coefficient of 0.98. Conclusions: The proposed method was shown to provide accurate segmentation for liver in the planning CT images where contrast agent is not applied. The authors’ results also clearly demonstrated

  4. The impact of different cone beam computed tomography and multi-slice computed tomography scan parameters on virtual three-dimensional model accuracy using a highly precise ex vivo evaluation method.

    Science.gov (United States)

    Matta, Ragai-Edward; von Wilmowsky, Cornelius; Neuhuber, Winfried; Lell, Michael; Neukam, Friedrich W; Adler, Werner; Wichmann, Manfred; Bergauer, Bastian

    2016-05-01

    Multi-slice computed tomography (MSCT) and cone beam computed tomography (CBCT) are indispensable imaging techniques in advanced medicine. The possibility of creating virtual and corporal three-dimensional (3D) models enables detailed planning in craniofacial and oral surgery. The objective of this study was to evaluate the impact of different scan protocols for CBCT and MSCT on virtual 3D model accuracy using a software-based evaluation method that excludes human measurement errors. MSCT and CBCT scans with different manufacturers' predefined scan protocols were obtained from a human lower jaw and were superimposed with a master model generated by an optical scan of an industrial noncontact scanner. To determine the accuracy, the mean and standard deviations were calculated, and t-tests were used for comparisons between the different settings. Averaged over 10 repeated X-ray scans per method and 19 measurement points per scan (n = 190), it was found that the MSCT scan protocol 140 kV delivered the most accurate virtual 3D model, with a mean deviation of 0.106 mm compared to the master model. Only the CBCT scans with 0.2-voxel resolution delivered a similar accurate 3D model (mean deviation 0.119 mm). Within the limitations of this study, it was demonstrated that the accuracy of a 3D model of the lower jaw depends on the protocol used for MSCT and CBCT scans. Copyright © 2016 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  5. Clinical application of 64-slice spiral CT in the diagnosis of the Tetralogy of Fallot

    International Nuclear Information System (INIS)

    Wang Ximing; Wu Lebin; Sun Cong; Liu Cheng; Chao, Bao-Ting; Han Bo; Zhang Yunting; Chen Haisong; Li Zhenjia

    2007-01-01

    Objective: To explore the clinical application of 64-slice spiral CT in the diagnosis of the Tetralogy of Fallot. Methods: Eighteen patients with diagnosed Tetralogy of Fallot underwent cardiac CT angiography with 64-slice CT (CTA). Two- and three-dimensional images were used for diagnosing in all cases by means of MPR (coronal, sagital and oblique), cMPR, MIP and VRT. Results: All patients had ventricular septal defect, pulmonary stenosis and hypertrophy of right ventricle. The morphologic features of Tetralogy of Fallot were equal to echocardiography. Patent ductus arteriosus (PDA) were detected on eight patients. Main coronary artery branches and partial sub-branches were visualized in all patients. Abnormal coronary arteries were found in seven cases: both left and right main coronary artery arising from the right aortic sinus one case, right main coronary artery and circumflex (CX) arising from the right aortic sinus one case, left anterior descending (LAD) and CX arising from left aortic sinus directly one case, left and right coronary artery arising from back and front of the aortic sinus, respectively, three cases. Pulmonary artery branch stenosis was found in 12 cases and branch pulmonary artery dilation noticed in 1 case. Double superior vena cava was also found in one case. According to the surgery the diagnostic accuracy of CT and Echocardiography was 95.45 and 83.33%, respectively. Conclusion: Two- and three-dimensional 64-slice CTA not only show the overall anatomical structure of the heart, but also show coronary and pulmonary arteries. With these results, evaluation of coronary anomalies and pulmonary artery stenosis with 64-MSCT is extremely valuable for planning the operative procedure on the patients with Tetralogy of Fallot

  6. Clinical application of 64-slice spiral CT in the diagnosis of the Tetralogy of Fallot

    Energy Technology Data Exchange (ETDEWEB)

    Wang Ximing [Tianjin Medical University, Tianjin City (China) and Shandong Medical Imaging Research Institute, Jinan City, Shandong Province 250021 (China)], E-mail: wxming369@163.com.cn; Wu Lebin [Shandong Medical Imaging Research Institute, Jinan City, Shandong Province 250021 (China); Sun Cong [Shandong Medical Imaging Research Institute, Jinan City, Shandong Province 250021 (China); Shandong University Medical College, Shandong Jinan 250012 (China); Liu Cheng [Shandong Medical Imaging Research Institute, Jinan City, Shandong Province 250021 (China); Chao, Bao-Ting [Shandong University Medical College, Shandong Jinan 250012 (China); Han Bo [Shandong Provincial Hospital Pediatric Department, Shandong, Jinan 250021 (China); Zhang Yunting [Tianjin Medical University, General Hospital MR Department, Tianjin City (China); Chen Haisong [Shandong Medical Imaging Research Institute, Jinan City, Shandong Province 250021 (China); Shandong University Medical College, Shandong Jinan 250012 (China); Li Zhenjia [Shandong Medical Imaging Research Institute, Jinan City, Shandong Province 250021 (China)

    2007-11-15

    Objective: To explore the clinical application of 64-slice spiral CT in the diagnosis of the Tetralogy of Fallot. Methods: Eighteen patients with diagnosed Tetralogy of Fallot underwent cardiac CT angiography with 64-slice CT (CTA). Two- and three-dimensional images were used for diagnosing in all cases by means of MPR (coronal, sagital and oblique), cMPR, MIP and VRT. Results: All patients had ventricular septal defect, pulmonary stenosis and hypertrophy of right ventricle. The morphologic features of Tetralogy of Fallot were equal to echocardiography. Patent ductus arteriosus (PDA) were detected on eight patients. Main coronary artery branches and partial sub-branches were visualized in all patients. Abnormal coronary arteries were found in seven cases: both left and right main coronary artery arising from the right aortic sinus one case, right main coronary artery and circumflex (CX) arising from the right aortic sinus one case, left anterior descending (LAD) and CX arising from left aortic sinus directly one case, left and right coronary artery arising from back and front of the aortic sinus, respectively, three cases. Pulmonary artery branch stenosis was found in 12 cases and branch pulmonary artery dilation noticed in 1 case. Double superior vena cava was also found in one case. According to the surgery the diagnostic accuracy of CT and Echocardiography was 95.45 and 83.33%, respectively. Conclusion: Two- and three-dimensional 64-slice CTA not only show the overall anatomical structure of the heart, but also show coronary and pulmonary arteries. With these results, evaluation of coronary anomalies and pulmonary artery stenosis with 64-MSCT is extremely valuable for planning the operative procedure on the patients with Tetralogy of Fallot.

  7. MR-urography and CT-urography: principles, examination techniques, applications

    International Nuclear Information System (INIS)

    Nolte-Ernsting, C.; Adam, G.; Staatz, G.; Wildberger, J.

    2003-01-01

    MR-urography (MRU) and CT-urography (CTU) provide refined imaging of the upper urinary tract not achievable with conventional intravenous urography (IVU). The traditional MR-urographic technique utilizes unenhanced, heavily T 2 -weighted turbo spin-echo sequences for obtaining static fluid images of the urinary tract independent of the excretory renal function. T 2 -weighted MR-urograms have proved to be excellent in visualizing the dilated urinary tract, even in non-excreting kidneys. In contrast, T 1 -weighted MRU reflects the excretory renal function and displays the urine flow through the upper tract after renal excretion of an intravenously administered gadolinium chelate. The gadolinium-enhanced urine is visualized with fast T 1 -weighted 3D-gradient-echo sequences. The combination of gadolinium and low-dose furosemide (5-10 mg) is the key for achieving a uniform distribution of gadolinium in the collecting system and for avoiding susceptibility artifacts (T 2 *-effects) in the urine. T 1 -weighted excretory MRU provides impressive urograms of both non-dilated and obstructed collecting systems in patients with normal or moderately impaired renal function. Multislice-CT-urography (MS-CTU) is also an excretory urography like T 1 -weighted MRU. Furthermore, MS-CTU can be combined with low-dose furosemide for accelerated passage of excreted contrast material obviating the need for abdominal compression. CT-urography is limited by its radiation burden and the nephrotoxicity of radiographic contrast media. Combining MRU or MS-CTU with conventional MRI or CT offers several applications, e.g., diagnosis of intrinsic and extrinsic tumors. Meanwhile, MRU has replaced IVU in pediatric uroradiology and is also recommended for the assessment of renal transplants. MS-CTU may provide valuable information in chronic urolithiasis, especially if associated with a distorted urinary tract anatomy. Both MRU and MS-CTU will play an important role in modern uroradiology. (orig

  8. Computer aided detection system for Osteoporosis using low dose thoracic 3D CT images

    Science.gov (United States)

    Tsuji, Daisuke; Matsuhiro, Mikio; Suzuki, Hidenobu; Kawata, Yoshiki; Niki, Noboru; Nakano, Yasutaka; Harada, Masafumi; Kusumoto, Masahiko; Tsuchida, Takaaki; Eguchi, Kenji; Kaneko, Masahiro

    2018-02-01

    The patient of osteoporosis is about 13 million people in Japan and it is one of healthy life problems in the aging society. It is necessary to do early stage detection and treatment in order to prevent the osteoporosis. Multi-slice CT technology has been improving the three dimensional (3D) image analysis with higher resolution and shorter scan time. The 3D image analysis of thoracic vertebra can be used for supporting to diagnosis of osteoporosis. This analysis can be used for lung cancer detection at the same time. We develop method of shape analysis and CT values of spongy bone for the detection osteoporosis. Osteoporosis and lung cancer screening show high extraction rate by the thoracic vertebral evaluation CT images. In addition, we created standard pattern of CT value per thoracic vertebra for male age group using 298 low dose data.

  9. Techniques, clinical applications and limitations of 3D reconstruction in CT of the abdomen

    Energy Technology Data Exchange (ETDEWEB)

    Maher, Michael M.; Kalra, Mannudeep K.; Sahani, Dushyant V.; Perumpillichira, James J.; Rizzo, Stephania; Saini, Sanjay; Mueller, Peter R. [Massachusetts General Hospital and Harvard Medical School, Boston (United States)

    2004-03-15

    Enhanced z-axis coverage with thin overlapping slices in breath-hold acquisitions with multidetector CT (MDCT) has considerably enhanced the quality of multiplanar 3D reconstruction. This pictorial essay describes the improvements in 3D reconstruction and technical aspects of 3D reconstruction and rendering techniques available for abdominal imaging. Clinical applications of 3D imaging in abdomen including liver, pancreaticobiliary system, urinary and gastrointestinal tracts and imaging before and after transplantation are discussed. In addition, this article briefly discusses the disadvantages of this-slice acquisitions including increasing numbers of transverse images, which must be reviewed by the radiologist.

  10. Techniques, clinical applications and limitations of 3D reconstruction in CT of the abdomen

    International Nuclear Information System (INIS)

    Maher, Michael M.; Kalra, Mannudeep K.; Sahani, Dushyant V.; Perumpillichira, James J.; Rizzo, Stephania; Saini, Sanjay; Mueller, Peter R.

    2004-01-01

    Enhanced z-axis coverage with thin overlapping slices in breath-hold acquisitions with multidetector CT (MDCT) has considerably enhanced the quality of multiplanar 3D reconstruction. This pictorial essay describes the improvements in 3D reconstruction and technical aspects of 3D reconstruction and rendering techniques available for abdominal imaging. Clinical applications of 3D imaging in abdomen including liver, pancreaticobiliary system, urinary and gastrointestinal tracts and imaging before and after transplantation are discussed. In addition, this article briefly discusses the disadvantages of this-slice acquisitions including increasing numbers of transverse images, which must be reviewed by the radiologist

  11. Discovering Hominins - Application of Medical Computed Tomography (CT) to Fossil-Bearing Rocks from the Site of Malapa, South Africa.

    Science.gov (United States)

    Smilg, Jacqueline S; Berger, Lee R

    2015-01-01

    In the South African context, computed tomography (CT) has been used applied to individually prepared fossils and small rocks containing fossils, but has not been utilized on large breccia blocks as a means of discovering fossils, and particularly fossil hominins. Previous attempts at CT imaging of rocks from other South African sites for this purpose yielded disappointing results. For this study, 109 fossil- bearing rocks from the site of Malapa, South Africa were scanned with medical CT prior to manual preparation. The resultant images were assessed for accuracy of fossil identification and characterization against the standard of manual preparation. The accurate identification of fossils, including those of early hominins, that were not visible on the surface of individual blocks, is shown to be possible. The discovery of unexpected fossils is reduced, thus lowering the potential that fossils could be damaged through accidental encounter during routine preparation, or even entirely missed. This study should significantly change the way fossil discovery, recovery and preparation is done in the South African context and has potential for application in other palaeontological situations. Medical CT imaging is shown to be reliable, readily available, cost effective and accurate in finding fossils within matrix conglomerates. Improvements in CT equipment and in CT image quality are such that medical CT is now a viable imaging modality for this palaeontological application.

  12. CT imaging features of anaplastic thyroid carcinoma

    International Nuclear Information System (INIS)

    Shi Zhenshan; You Ruixiong; Cao Dairong; Li Yueming; Zhuang Qian

    2013-01-01

    Objective: To investigate the CT characteristics of anaplastic thyroid carcinoma and evaluate the diagnostic value of CT in this disease. Methods: The CT findings of 10 patients with pathologically proved anaplastic thyroid carcinoma were retrospectively reviewed. The patients included 7 females and 3 males. Their age ranged from 25.0 to 78 years with median of 61 years. Multi-slices plain and post contrast CT scans were performed in all patients. Results: Unilateral thyroid was involved in 6 patients. Unilateral thyroid and thyroid isthmus were both involved in 2 patients due to big size. Bilateral thyroid were involved in 2 patients. The maximum diameter of anaplastic thyroid carcinoma ranged from 2.9-12.8 cm with mean of (4.5 ± 1.4) cm. All lesions demonstrated unclear margins and envelope invasion. The densities of all lesions were heterogeneous and obvious necrosis areas were noted on precontrast images. Seven lesions showed varied calcifications, and coarse granular calcifications were found in 5 lesions among them. All lesions showed remarkable heterogenous enhancement on post-contrast CT. The CT value of solid portion of the tumor increased 40 HU after contrast media administration. The ratios of CT value which comparing of the tumor with contralateral sternocleidomastoid muscle were 0.69-0.82 (0.76 ± 0.18) and 1.25-1.41 (1.33 ± 0.28) on pre and post CT, respectively. Enlarged cervical lymph nodes were found in 6 cases (60.0%). It showed obvious homogeneous enhancement or irregular ring-like enhancement on post-contrast images and dot calcifications were seen in 1 case. Conclusions: Relative larger single thyroid masses with coarse granular calcifications, necrosis,envelope invasion, remarkable heterogeneous enhancing and enlarged lymph nodes on CT are suggestive of anaplastic thyroid carcinoma. (authors)

  13. Formation of multifunctional Fe3O4/Au composite nanoparticles for dual-mode MR/CT imaging applications

    International Nuclear Information System (INIS)

    Hu Yong; Li Jing-Chao; Shen Ming-Wu; Shi Xiang-Yang

    2014-01-01

    Recent advances with iron oxide/gold (Fe 3 O 4 /Au) composite nanoparticles (CNPs) in dual-modality magnetic resonance (MR) and computed tomography (CT) imaging applications are reviewed. The synthesis and assembly of “dumbbelllike” and “core/shell” Fe 3 O 4 /Au CNPs is introduced. Potential applications of some developed Fe 3 O 4 /Au CNPs as contrast agents for dual-mode MR/CT imaging applications are described in detail. (topical review - magnetism, magnetic materials, and interdisciplinary research)

  14. Dynamic computed tomography (CT) in the rat kidney and application to acute renal failure models

    International Nuclear Information System (INIS)

    Ishikawa, Isao; Saito, Tadashi; Ishii, Hirofumi; Bansho, Junichi; Koyama, Yukinori; Tobita, Akira

    1995-01-01

    Renal dynamic CT scanning is suitable for determining the excretion of contrast medium in the cortex and medulla of the kidney, which is valuable for understanding the pathogenesis of disease processes in various conditions. This form of scanning would be convenient for use, if a method of application to the rat kidney were available. Therefore, we developed a method of applying renal dynamic CT to rats and evaluated the cortical and medullary curves, e.g., the corticomedullary junction time which is correlated to creatinine clearance, in various rat models of acute renal failure. The rat was placed in a 10deg oblique position and a bilateral hilar slice was obtained before and 5, 10, 15, 20, 25, 30, 40, 50, 60, 80, 100, 120, 140, 160 and 180 sec after administering 0.5 ml of contrast medium using Somatom DR. The width of the slice was 4 mm and the scan time was 3 sec. The corticomedullary junction time in normal rats was 23.0±10.5 sec, the peak value of the cortical curve was 286.3±76.7 Hounsfield Unit (HU) and the peak value of the medullary curve was 390.1±66.2 HU. Corticomedullary junction time after exposure of the kidney was prolonged compared to that of the unexposed kidney. In rats with acute renal failure, the excretion pattern of contrast medium was similar in both the glycerol- and HgCl2-induced acute renal failure models. The peak values of the cortical curve were maintained three hours after a clamp was placed at the hilar region of the kidney for one hour, and the peak values of the medullary curve were maintained during the administration of 10μg/kg/min of angiotensin II. Dynamic CT curves in the acute renal failure models examined were slightly different from those in human acute renal failure. These results suggest that rats do not provide an ideal model for human acute renal failure. However, the application of dynamic CT to the rat kidney models was valuable for estimating the pathogenesis of various human kidney diseases. (author)

  15. Classification decision tree in CT imaging: application to the differential diagnosis of solitary pulmonary nodules

    International Nuclear Information System (INIS)

    Ma Hongxia; Guo Yulin; Wang Qiuping; Qiang Yongqian; Liu Min; Guo Xiaojuan; Guo Youmin; Chen Qihang

    2008-01-01

    Objective: To establish classification and regression tree (CART) for differentiating benign from malignant solitary pulmonary nudules (SPN). Methods: One hundred and sixteen consecutive cases with 116 solitary pulmonary nodules, which finally were pathologically proven 54 malignant nodules and 62 benign nodules, were prospectively registered in this research. Twelve clinical presentations and 22 CT findings were collected as predictors. A classification tree was established to distinguish benign SPNs from malignant ones. In the observer test, two groups (one made of junior radiologists and one of senior radiologists) were independently presented with clinical information and CT images without knowing the pathologic and machine-learning results. Performance of observers and CART were compared by receiver operating characteristic analysis. Results: Receiver operating characteristic analysis showed areas under the curve of CART, senior radiologists and junior radiologists respectively were 0.910±0.029, 0.827±0.038, 0.612±0.052. Difference between areas(DBF) between CART and junior radiologists was 0.297(P<0.01). DBF between CART and senior radiologists was 0.083 (P<0.05). DBF between senior and junior radiologists was 0.214 (P<0.01). CART showed a best diagnostic efficiency, followed by junior radiologists, and then senior radiologists. Conclusion: Our data mining techniques using CART prove a high accuracy in differentiating benign from malignant pulmonary nodules based on clinical variables and CT findings. It will be a potentially useful tool in further application of artificial intelligence in the imaging diagnosis. (authors)

  16. Application of emission CT on nano-robot radiation imaging tracing and isotope sign in nano-robot

    International Nuclear Information System (INIS)

    Wang Xuewu; Cheng Jianping; Kang Kejun

    2000-01-01

    Nano-technology has been a scientific and technical frontier with major trends foreseen in several disciplines. Nano-robot is the most remarkable imagination of the application of nano-technology. And it should be concerned of tracing technology along with nano-robot. The character of nano-robot is deeply analyzed, the development status of emission CT is integrated, and the application of emission CT on nano-robot radiation imaging tracing is discussed. The isotope sign of nano-robot is especially calculated and analyzed

  17. CT virtual endoscopy of the auditory ossicular chain and its preliminary clinical application

    International Nuclear Information System (INIS)

    Wang Dong; Zhang Wanshi; Xiong Minghui; Xu Jiaxing; Yu Min; Xu Changyu

    2000-01-01

    Objective: To evaluate the ability of CT virtual endoscopy (CTVE) in visualization of auditory ossicular chain and its clinical application. Methods: CTVE of auditory ossicular chain was performed on GE HiSpeed CT/i with 1.0 mm slice thickness at pitch 1.0, bone algorithm, 9.6 cm FOV, and 0.1 mm reconstruction interval in 10 normal subjects and 21 patients with middle ear diseases, 14 of them were proved by operation. The threshold values for normal and abnormal auditory ossicular chain were -600--200 HU and 50-300 HU respectively. Results: CTVE could clearly demonstrate the shape, size, and relation of the normal auditory ossicular chain. A visualization rate of malleus, incus, and incudomalleal articulation was 100%, and was 32% for the stapedial foot plate. However, in only 21% could the anterior and posterior crura of stapes be distinguished. Cholesteatoma was found in 12 cases with chronic otitis media, in which CTVE demonstrated varying degrees of destruction of the auditory ossicle. In 1 case with congenital anomaly, ossicle dysplasia was seen. Conclusion: CTVE being a new, non-invasive method for demonstrating the three-dimensional image of auditory ossicular chain is useful in evaluating diseases of the ear, especially the auditory ossicles

  18. Current Roles and Future Applications of Cardiac CT: Risk Stratification of Coronary Artery Disease

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Yeonyee Elizabeth [Department of Cardiology, Cardiovascular Center, Seoul National University Bundang Hospital, Seongnam 463-707 (Korea, Republic of); Lim, Tae-Hwan [Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 138-736 (Korea, Republic of)

    2014-07-01

    Cardiac computed tomography (CT) has emerged as a noninvasive modality for the assessment of coronary artery disease (CAD), and has been rapidly integrated into clinical cares. CT has changed the traditional risk stratification based on clinical risk to image-based identification of patient risk. Cardiac CT, including coronary artery calcium score and coronary CT angiography, can provide prognostic information and is expected to improve risk stratification of CAD. Currently used conventional cardiac CT, provides accurate anatomic information but not functional significance of CAD, and it may not be sufficient to guide treatments such as revascularization. Recently, myocardial CT perfusion imaging, intracoronary luminal attenuation gradient, and CT-derived computed fractional flow reserve were developed to combine anatomical and functional data. Although at present, the diagnostic and prognostic value of these novel technologies needs to be evaluated further, it is expected that all-in-one cardiac CT can guide treatment and improve patient outcomes in the near future.

  19. DosedPet application for Nuclear Medicine: Calculation of the volume of medication needed for PET/CT patient

    International Nuclear Information System (INIS)

    Nascimento, Pedro Augusto do; Rodrigues, Araken dos S. Werneck

    2016-01-01

    This paper presents the application (APP) DosePet that calculates the amount of medicament for PET / CT in patients according to the predetermined radiation dose. The software has been designed using the web MIT App Inventor2 tool for Android platform. The application allows the workers to simulate the amount of radiation still existing in the facilities after the applications, increasing security and reducing exposures, and enable greater efficiency in the use of the radiopharmaceutical. (author)

  20. Analysis of hepatic vein variations in healthy people with 64-slice spiral CT

    International Nuclear Information System (INIS)

    Zhang Rong; Li Yong; Shen Jun; Zeng Weike; Li Jieting; Huang Suiqiao; Liang Biling; Liu Chao

    2007-01-01

    Objective: To analyze variations of hepatic vein in healthy people with 64-slice spiral CT. Methods: Seventy-five healthy subjects underwent multi-slice spiral computed (MSCT) hepatic venography. The anatomy of the junction of the hepatic veins with the inferior vena cava and the intrahepatic drainage territory of the hepatic veins and tributaries were evaluated. The hepatic veins were classified according to three anatomic classification (Nakamura's, Marcos's and Kawasaki's classification) methods respectively. Results: There was a common trunk of the middle and left hepatic veins before joining the IVC in 86.7% (65/75)of the cases. In 13.3% (10/75)of the cases, the three main hepatic veins joined the IVC separately. The ratios of Nakamma's classification type A, B, C of hepatic veins were 49.4% (37/75), 37.3% (28/75), and 13.3% (10/75) respectively. The ratios of Marcos's classification type A, B, C of hepatic veins were 56.0% (42/75), 24.0% (18/75), and 20.0% (15/75) respectively. The ratios of Kawasaki's classification type I, II of hepatic vein were 40.0% (30/75) and 60.0% (45/75). Conclusion: Multi-slice spiral CT hepatic venography can provide visualization of peripheral hepatic venous branches in details. (authors)

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

    Science.gov (United States)

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

    2018-01-09

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

  2. Value and clinical application of orthopedic metal artifact reduction algorithm in CT scans after orthopedic metal implantation

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Yi; Pan, Shinong; Zhao, Xudong; Guo, Wenli; He, Ming; Guo, Qiyong [Shengjing Hospital of China Medical University, Shenyang (China)

    2017-06-15

    To evaluate orthopedic metal artifact reduction algorithm (O-MAR) in CT orthopedic metal artifact reduction at different tube voltages, identify an appropriate low tube voltage for clinical practice, and investigate its clinical application. The institutional ethical committee approved all the animal procedures. A stainless-steel plate and four screws were implanted into the femurs of three Japanese white rabbits. Preoperative CT was performed at 120 kVp without O-MAR reconstruction, and postoperative CT was performed at 80–140 kVp with O-MAR. Muscular CT attenuation, artifact index (AI) and signal-to-noise ratio (SNR) were compared between preoperative and postoperative images (unpaired t test), between paired O-MAR and non-O-MAR images (paired Student t test) and among different kVp settings (repeated measures ANOVA). Artifacts' severity, muscular homogeneity, visibility of inter-muscular space and definition of bony structures were subjectively evaluated and compared (Wilcoxon rank-sum test). In the clinical study, 20 patients undertook CT scan at low kVp with O-MAR with informed consent. The diagnostic satisfaction of clinical images was subjectively assessed. Animal experiments showed that the use of O-MAR resulted in accurate CT attenuation, lower AI, better SNR, and higher subjective scores (p < 0.010) at all tube voltages. O-MAR images at 100 kVp had almost the same AI and SNR as non-O-MAR images at 140 kVp. All O-MAR images were scored ≥ 3. In addition, 95% of clinical CT images performed at 100 kVp were considered satisfactory. O-MAR can effectively reduce orthopedic metal artifacts at different tube voltages, and facilitates low-tube-voltage CT for patients with orthopedic metal implants.

  3. Value and clinical application of orthopedic metal artifact reduction algorithm in CT scans after orthopedic metal implantation

    International Nuclear Information System (INIS)

    Hu, Yi; Pan, Shinong; Zhao, Xudong; Guo, Wenli; He, Ming; Guo, Qiyong

    2017-01-01

    To evaluate orthopedic metal artifact reduction algorithm (O-MAR) in CT orthopedic metal artifact reduction at different tube voltages, identify an appropriate low tube voltage for clinical practice, and investigate its clinical application. The institutional ethical committee approved all the animal procedures. A stainless-steel plate and four screws were implanted into the femurs of three Japanese white rabbits. Preoperative CT was performed at 120 kVp without O-MAR reconstruction, and postoperative CT was performed at 80–140 kVp with O-MAR. Muscular CT attenuation, artifact index (AI) and signal-to-noise ratio (SNR) were compared between preoperative and postoperative images (unpaired t test), between paired O-MAR and non-O-MAR images (paired Student t test) and among different kVp settings (repeated measures ANOVA). Artifacts' severity, muscular homogeneity, visibility of inter-muscular space and definition of bony structures were subjectively evaluated and compared (Wilcoxon rank-sum test). In the clinical study, 20 patients undertook CT scan at low kVp with O-MAR with informed consent. The diagnostic satisfaction of clinical images was subjectively assessed. Animal experiments showed that the use of O-MAR resulted in accurate CT attenuation, lower AI, better SNR, and higher subjective scores (p < 0.010) at all tube voltages. O-MAR images at 100 kVp had almost the same AI and SNR as non-O-MAR images at 140 kVp. All O-MAR images were scored ≥ 3. In addition, 95% of clinical CT images performed at 100 kVp were considered satisfactory. O-MAR can effectively reduce orthopedic metal artifacts at different tube voltages, and facilitates low-tube-voltage CT for patients with orthopedic metal implants

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

    International Nuclear Information System (INIS)

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

    1993-01-01

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

  5. TU-AB-204-00: Advances in Cone-Beam CT and Emerging Applications

    International Nuclear Information System (INIS)

    2015-01-01

    This symposium highlights advanced cone-beam CT (CBCT) technologies in four areas of emerging application in diagnostic imaging and image-guided interventions. Each area includes research that extends the spatial, temporal, and/or contrast resolution characteristics of CBCT beyond conventional limits through advances in scanner technology, acquisition protocols, and 3D image reconstruction techniques. Dr. G. Chen (University of Wisconsin) will present on the topic: Advances in C-arm CBCT for Brain Perfusion Imaging. Stroke is a leading cause of death and disability, and a fraction of people having an acute ischemic stroke are suitable candidates for endovascular therapy. Critical factors that affect both the likelihood of successful revascularization and good clinical outcome are: 1) the time between stroke onset and revascularization; and 2) the ability to distinguish patients who have a small volume of irreversibly injured brain (ischemic core) and a large volume of ischemic but salvageable brain (penumbra) from patients with a large ischemic core and little or no penumbra. Therefore, “time is brain” in the care of the stroke patients. C-arm CBCT systems widely available in angiography suites have the potential to generate non-contrast-enhanced CBCT images to exclude the presence of hemorrhage, time-resolved CBCT angiography to evaluate the site of occlusion and collaterals, and CBCT perfusion parametric images to assess the extent of the ischemic core and penumbra, thereby fulfilling the imaging requirements of a “one-stop-shop” in the angiography suite to reduce the time between onset and revascularization therapy. The challenges and opportunities to advance CBCT technology to fully enable the one-stop-shop C-arm CBCT platform for brain imaging will be discussed. Dr. R. Fahrig (Stanford University) will present on the topic: Advances in C-arm CBCT for Cardiac Interventions. With the goal of providing functional information during cardiac interventions

  6. TU-AB-204-00: Advances in Cone-Beam CT and Emerging Applications

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2015-06-15

    This symposium highlights advanced cone-beam CT (CBCT) technologies in four areas of emerging application in diagnostic imaging and image-guided interventions. Each area includes research that extends the spatial, temporal, and/or contrast resolution characteristics of CBCT beyond conventional limits through advances in scanner technology, acquisition protocols, and 3D image reconstruction techniques. Dr. G. Chen (University of Wisconsin) will present on the topic: Advances in C-arm CBCT for Brain Perfusion Imaging. Stroke is a leading cause of death and disability, and a fraction of people having an acute ischemic stroke are suitable candidates for endovascular therapy. Critical factors that affect both the likelihood of successful revascularization and good clinical outcome are: 1) the time between stroke onset and revascularization; and 2) the ability to distinguish patients who have a small volume of irreversibly injured brain (ischemic core) and a large volume of ischemic but salvageable brain (penumbra) from patients with a large ischemic core and little or no penumbra. Therefore, “time is brain” in the care of the stroke patients. C-arm CBCT systems widely available in angiography suites have the potential to generate non-contrast-enhanced CBCT images to exclude the presence of hemorrhage, time-resolved CBCT angiography to evaluate the site of occlusion and collaterals, and CBCT perfusion parametric images to assess the extent of the ischemic core and penumbra, thereby fulfilling the imaging requirements of a “one-stop-shop” in the angiography suite to reduce the time between onset and revascularization therapy. The challenges and opportunities to advance CBCT technology to fully enable the one-stop-shop C-arm CBCT platform for brain imaging will be discussed. Dr. R. Fahrig (Stanford University) will present on the topic: Advances in C-arm CBCT for Cardiac Interventions. With the goal of providing functional information during cardiac interventions

  7. Rich internet application system for patient-centric healthcare data management using handheld devices.

    Science.gov (United States)

    Constantinescu, L; Pradana, R; Kim, J; Gong, P; Fulham, Michael; Feng, D

    2009-01-01

    Rich Internet Applications (RIAs) are an emerging software platform that blurs the line between web service and native application, and is a powerful tool for handheld device deployment. By democratizing health data management and widening its availability, this software platform has the potential to revolutionize telemedicine, clinical practice, medical education and information distribution, particularly in rural areas, and to make patient-centric medical computing a reality. In this paper, we propose a telemedicine application that leverages the ability of a mobile RIA platform to transcode, organise and present textual and multimedia data, which are sourced from medical database software. We adopted a web-based approach to communicate, in real-time, with an established hospital information system via a custom RIA. The proposed solution allows communication between handheld devices and a hospital information system for media streaming with support for real-time encryption, on any RIA enabled platform. We demonstrate our prototype's ability to securely and rapidly access, without installation requirements, medical data ranging from simple textual records to multi-slice PET-CT images and maximum intensity (MIP) projections.

  8. Reconstruction of a ring applicator using CT imaging: impact of the reconstruction method and applicator orientation

    DEFF Research Database (Denmark)

    Hellebust, Taran Paulsen; Tanderup, Kari; Bergstrand, Eva Stabell

    2007-01-01

    in multiplanar reconstructed images (MPR) and (3) library plans, using pre-defined applicator geometry (LIB). The doses to the lead pellets were calculated. The relative standard deviation (SD) for all reconstruction methods was less than 3.7% in the dose points. The relative SD for the LIB method...

  9. Volumetric CT with sparse detector arrays (and application to Si-strip photon counters).

    Science.gov (United States)

    Sisniega, A; Zbijewski, W; Stayman, J W; Xu, J; Taguchi, K; Fredenberg, E; Lundqvist, Mats; Siewerdsen, J H

    2016-01-07

    Novel x-ray medical imaging sensors, such as photon counting detectors (PCDs) and large area CCD and CMOS cameras can involve irregular and/or sparse sampling of the detector plane. Application of such detectors to CT involves undersampling that is markedly different from the commonly considered case of sparse angular sampling. This work investigates volumetric sampling in CT systems incorporating sparsely sampled detectors with axial and helical scan orbits and evaluates performance of model-based image reconstruction (MBIR) with spatially varying regularization in mitigating artifacts due to sparse detector sampling. Volumetric metrics of sampling density and uniformity were introduced. Penalized-likelihood MBIR with a spatially varying penalty that homogenized resolution by accounting for variations in local sampling density (i.e. detector gaps) was evaluated. The proposed methodology was tested in simulations and on an imaging bench based on a Si-strip PCD (total area 5 cm  ×  25 cm) consisting of an arrangement of line sensors separated by gaps of up to 2.5 mm. The bench was equipped with translation/rotation stages allowing a variety of scanning trajectories, ranging from a simple axial acquisition to helical scans with variable pitch. Statistical (spherical clutter) and anthropomorphic (hand) phantoms were considered. Image quality was compared to that obtained with a conventional uniform penalty in terms of structural similarity index (SSIM), image uniformity, spatial resolution, contrast, and noise. Scan trajectories with intermediate helical width (~10 mm longitudinal distance per 360° rotation) demonstrated optimal tradeoff between the average sampling density and the homogeneity of sampling throughout the volume. For a scan trajectory with 10.8 mm helical width, the spatially varying penalty resulted in significant visual reduction of sampling artifacts, confirmed by a 10% reduction in minimum SSIM (from 0.88 to 0.8) and a 40

  10. Clinical application of ECG-gated 256-slice CT angiography for diagnosis of congenital heart disease

    International Nuclear Information System (INIS)

    Tian Xinhua; Liu Jianhua; Gong Tingting; Geng Lili; Sun Yong

    2011-01-01

    Objective: To investigate the clinical application of ECG-gated 256-slice CT angiography for diagnosis of congenital heart disease, and to evaluate the relationship of the image quality and radiation dose between prospective ECG-gated and retrospective ECG-gated cardiac CT angiography (CTA). Methods: Sixty patients who doubt congenital heart disease underwent cardiac CTA, and they were randomly divided into two groups. Thirty patients in group A underwent prospective ECG-gated cardiac CTA, and thirty patients in group B underwent retrospective ECG-gated cardiac CTA. Then the homogeneous enhancement of vascular structures, stair-step artifact, overall image quality and radiation dose were evaluated. Results: The homogeneous enhancement of vascular structures were 2.8±0.3 and 2.7±0.6, respectively, in two groups; and there was no statistical significance (P>0.05). The stair-step artifact were 3.0±0.9 and 3.1±0.9, respectively, in two groups; and there was also no statistical significance (P>0.05). The overall image quality were 3.0±0.8 and 3.1±0.9, respectively, in two group; and there was statistical significance (P>0.05). However, the effective dose were (5.24±0.52) mSv and (16.68±1.49) mSv, respectively, in two groups; and there was statistical significance (P<0.001). Conclusion: Compared with retrospective ECG-gated cardiac CTA, prospective ECG-gated cardiac CTA can reduce radiation dose about 68.6% , while maintaining the image quality which could be made diagnosis. (authors)

  11. Dosimetry of FDG PET/CT and other molecular imaging applications in pediatric patients

    International Nuclear Information System (INIS)

    Gelfand, Michael J.

    2009-01-01

    Effective doses for PET and SPECT imaging of molecular imaging agents depend on the radiopharmaceutical, administered activity and the weight of the patient. Effective doses for the accompanying CT scan depend on the CT protocol being used. CT protocols can be designed to produce diagnostic quality images, localization images or attenuation correction data without imaging. In each case, the co-registered molecular imaging examination (PET or SPECT) and the CT study must be acquired without patient movement. For PET/CT, attention to the respiratory phase during the CT study is also of critical importance. In addition to the molecular imaging agents 18 F-FDG and 123 I-MIBG that are frequently used in children, additional PET and SPECT imaging agents may have promise for molecular imaging in children. (orig.)

  12. Preliminary characterization of a single photon counting detection system for CT application

    International Nuclear Information System (INIS)

    Belcari, N.; Bisogni, M.G.; Carpentieri, C.; Del Guerra, A.; Delogu, P.; Panetta, D.; Quattrocchi, M.; Rosso, V.; Stefanini, A.

    2007-01-01

    The aim of this work is to evaluate the capability of a single photon counting acquisition system based on the Medipix2 read-out chip for Computed Tomography (CT) applications in Small Animal Imaging. We used a micro-focus X-ray source with a W anode. The detection system is based on the Medipix2 read-out chip, bump-bonded to a 1 mm thick silicon pixel detector. The read-out chip geometry is a matrix of 256x256 cells, 55 μmx55 μm each. This system in planar radiography shows a good detection efficiency (about 70%) at the anode voltage of 30 kV and a good spatial resolution (MTF=10% at 16.8 lp/mm). Starting from these planar performances we have characterized the system for the tomography applications with phantoms. We will present the results obtained as a function of magnification with two different background medium compositions. The effect of the reconstruction algorithm on image quality will be also discussed

  13. MR-urography and CT-urography: principles, examination techniques, applications; MR-Urographie und CT-Urographie: Prinzipien, Untersuchungstechniken, Anwendungsmoeglichkeiten

    Energy Technology Data Exchange (ETDEWEB)

    Nolte-Ernsting, C.; Adam, G. [Universitaetsklinikum Hamburg-Eppendorf (Germany). Klinik fuer Diagnostische und Interventionelle Radiologie; Staatz, G.; Wildberger, J. [RWTH Aachen (Germany). Klinik fuer Radiologische Diagnostik

    2003-02-01

    MR-urography (MRU) and CT-urography (CTU) provide refined imaging of the upper urinary tract not achievable with conventional intravenous urography (IVU). The traditional MR-urographic technique utilizes unenhanced, heavily T{sub 2}-weighted turbo spin-echo sequences for obtaining static fluid images of the urinary tract independent of the excretory renal function. T{sub 2}-weighted MR-urograms have proved to be excellent in visualizing the dilated urinary tract, even in non-excreting kidneys. In contrast, T{sub 1}-weighted MRU reflects the excretory renal function and displays the urine flow through the upper tract after renal excretion of an intravenously administered gadolinium chelate. The gadolinium-enhanced urine is visualized with fast T{sub 1}-weighted 3D-gradient-echo sequences. The combination of gadolinium and low-dose furosemide (5-10 mg) is the key for achieving a uniform distribution of gadolinium in the collecting system and for avoiding susceptibility artifacts (T{sub 2}*-effects) in the urine. T{sub 1}-weighted excretory MRU provides impressive urograms of both non-dilated and obstructed collecting systems in patients with normal or moderately impaired renal function. Multislice-CT-urography (MS-CTU) is also an excretory urography like T{sub 1}-weighted MRU. Furthermore, MS-CTU can be combined with low-dose furosemide for accelerated passage of excreted contrast material obviating the need for abdominal compression. CT-urography is limited by its radiation burden and the nephrotoxicity of radiographic contrast media. Combining MRU or MS-CTU with conventional MRI or CT offers several applications, e.g., diagnosis of intrinsic and extrinsic tumors. Meanwhile, MRU has replaced IVU in pediatric uroradiology and is also recommended for the assessment of renal transplants. MS-CTU may provide valuable information in chronic urolithiasis, especially if associated with a distorted urinary tract anatomy. Both MRU and MS-CTU will play an important role in

  14. Computer-aided pulmonary nodule detection. Performance of two CAD systems at different CT dose levels

    International Nuclear Information System (INIS)

    Hein, Patrick Alexander; Rogalla, P.; Klessen, C.; Lembcke, A.; Romano, V.C.

    2009-01-01

    Purpose: To evaluate the impact of dose reduction on the performance of computer-aided lung nodule detection systems (CAD) of two manufacturers by comparing respective CAD results on ultra-low-dose computed tomography (ULD-CT) and standard dose CT (SD-CT). Materials and Methods: Multi-slice computed tomography (MSCT) data sets of 26 patients (13 male and 13 female, patients 31 - 74 years old) were retrospectively selected for CAD analysis. Indication for CT examination was staging of a known primary malignancy or suspected pulmonary malignancy. CT images were consecutively acquired at 5 mAs (ULD-CT) and 75 mAs (SD-CT) with 120kV tube voltage (1 mm slice thickness). The standard of reference was determined by three experienced readers in consensus. CAD reading algorithms (pre-commercial CAD system, Philips, Netherlands: CAD-1; LungCARE, Siemens, Germany: CAD-2) were applied to the CT data sets. Results: Consensus reading identified 253 nodules on SD-CT and ULD-CT. Nodules ranged in diameter between 2 and 41 mm (mean diameter 4.8 mm). Detection rates were recorded with 72% and 62% (CAD-1 vs. CAD-2) for SD-CT and with 73% and 56% for ULD-CT. Median also positive rates per patient were calculated with 6 and 5 (CAD-1 vs. CAD-2) for SD-CT and with 8 and 3 for ULD-CT. After separate statistical analysis of nodules with diameters of 5 mm and greater, the detection rates increased to 83% and 61% for SD-CT and to 89% and 67% for ULD-CT (CAD-1 vs. CAD-2). For both CAD systems there were no significant differences between the detection rates for standard and ultra-low-dose data sets (p>0.05). Conclusion: Dose reduction of the underlying CT scan did not significantly influence nodule detection performance of the tested CAD systems. (orig.)

  15. Application of PET-CT for radiotherapy of the patient with carcinoma

    International Nuclear Information System (INIS)

    Xia; Luo Quanyong; Yuan Zhibin

    2006-01-01

    PET-CT is an advanced imaging instrument combing anatomical and metabolic information into one. Combined with the radiation planning system, PET-CT is playing an increasingly important tool in the diagnosis and staging of malignant disease image-guided therapy planning, and treatment monitoring. Especially, PET-CT has a significant role in the delineation of tumor target volume, optimization of radiation planning. (authors)

  16. Clinical application of the helical CT in patients who are unable to hold their breath

    International Nuclear Information System (INIS)

    Toyama, Yoshihiro; Kimura, Naruhide; Ohkawa, Motoomi; Tanabe, Masatada.

    1997-01-01

    We performed helical CT in eighteen patients who were unable to hold their breath for 10 chest and 8 abdominal regions. Although there were respiratory artifacts in three cases, we could obtain the useful clinical information in all cases. In our experimental examinations, CT value of the phantom by helical scan was lower than that by conventional scan without movement of the phantom. With movement of it, the CT value was further lowered by either scan method, but the lowered rate was smaller by helical scan as the movement becomes faster. We consider that helical CT can be applied to patients who were unable to hold their breath. (author)

  17. Performance evaluation of a compact PET/SPECT/CT tri-modality system for small animal imaging applications

    International Nuclear Information System (INIS)

    Wei, Qingyang; Wang, Shi; Ma, Tianyu; Wu, Jing; Liu, Hui; Xu, Tianpeng; Xia, Yan; Fan, Peng; Lyu, Zhenlei; Liu, Yaqiang

    2015-01-01

    PET, SPECT and CT imaging techniques are widely used in preclinical small animal imaging applications. In this paper, we present a compact small animal PET/SPECT/CT tri-modality system. A dual-functional, shared detector design is implemented which enables PET and SPECT imaging with a same LYSO ring detector. A multi-pinhole collimator is mounted on the system and inserted into the detector ring in SPECT imaging mode. A cone-beam CT consisting of a micro focus X-ray tube and a CMOS detector is implemented. The detailed design and the performance evaluations are reported in this paper. In PET imaging mode, the measured NEMA based spatial resolution is 2.12 mm (FWHM), and the sensitivity at the central field of view (CFOV) is 3.2%. The FOV size is 50 mm (∅)×100 mm (L). The SPECT has a spatial resolution of 1.32 mm (FWHM) and an average sensitivity of 0.031% at the center axial, and a 30 mm (∅)×90 mm (L) FOV. The CT spatial resolution is 8.32 lp/mm @10%MTF, and the contrast discrimination function value is 2.06% with 1.5 mm size cubic box object. In conclusion, a compact, tri-modality PET/SPECT/CT system was successfully built with low cost and high performance

  18. Patient dose simulation in X-ray CT using a radiation treatment-planning system

    International Nuclear Information System (INIS)

    Nakae, Yasuo; Oda, Masahiko; Minamoto, Takahiro

    2003-01-01

    Medical irradiation dosage has been increasing with the development of new radiological equipment and new techniques like interventional radiology. It is fair to say that patient dose has been increased as a result of the development of multi-slice CT. A number of studies on the irradiation dose of CT have been reported, and the computed tomography dose index (CTDI) is now used as a general means of determining CT dose. However, patient dose distribution in the body varies with the patient's constitution, bowel gas in the body, and conditions of exposure. In this study, patient dose was analyzed from the viewpoint of dose distribution, using a radiation treatment-planning computer. Percent depth dose (PDD) and the off-center ratio (OCR) of the CT beam are needed to calculate dose distribution by the planning computer. Therefore, X-ray CT data were measured with various apparatuses, and beam data were sent to the planning computer. Measurement and simulation doses in the elliptical phantom (Mix-Dp: water equivalent material) were collated, and the CT irradiation dose was determined for patient dose simulation. The rotational radiation treatment technique was used to obtain the patient dose distribution of CT, and patient dose was evaluated through simulation of the dose distribution. CT images of the thorax were sent to the planning computer and simulated. The result was that the patient dose distribution of the thorax was obtained for CT examination. (author)

  19. Construction of an Interface Terminology on SNOMED CT Generic Approach and Its Application in Intensive Care

    NARCIS (Netherlands)

    Bakhshi-Raiez, F.; Ahmadian, L.; Cornet, R.; de Jonge, E.; de Keizer, N. F.

    2010-01-01

    Objective: To provide a generic approach for developing a domain-specific interface terminology on SNOMED CT and to apply this approach to the domain of intensive care. Methods: The process of developing an interface terminology on SNOMED CT can be regarded as six sequential phases: domain analysis,

  20. Spiral CT biliary virtual endoscopy: preliminary clinical applications in the detection of biliary calculus

    International Nuclear Information System (INIS)

    Xiong Minghui; Wang Dong; Song Yunlong; Zhang Wanshi; Xu Jiaxing

    2000-01-01

    Objective: To evaluate imaging features and clinical value of CT biliary virtual endoscopy in the detection of biliary calculus. Methods: Eighteen patients with biliary calculi underwent volume scanning using spiral CT (Hispeed Advantage CT/i GE ). All data were transferred to computer workstation, and CT biliary virtual endoscopy images with pseudocolor encoding were generated from the volumetric data using the Navigator Smooth soft-ware. All cases were proved by ultrasound, axial CT or operation. Results: Among 18 cases, gallstones were found 8 in cases, common bile duct stones in 2 cases, gallstones and bile duct stones in 6 cases. The stones were 0.3-3.2 cm in size. CT biliary virtual endoscopy correctly demonstrated the surface details of stones which were viewed from extra- or intraluminal orientation in a 3D fashion. The findings were consistent with those of US, CT or operation. Conclusion: The CT virtual biliary endoscopy is a further development of virtual endoscopy for observing biliary calculus from intra- and extra-luminal views and providing three dimensional information of stone

  1. Inter-laboratory comparison of medical computed tomography (CT) scanners for industrial applications in the slaughterhouses

    DEFF Research Database (Denmark)

    Christensen, Lars Bager; Angel, Jais Andreas Breusch

    2013-01-01

    differences in CT performance. The presented Round Robin scheme has demonstrated its potential as such a method. The benefit of the phantom set is that it provides a convenient way of comparing volume determination between different CT scanners. The suggested phantoms are mimicking important carcass features...

  2. A 3D active shape model driven by fuzzy inference : application to cardiac CT and MR

    NARCIS (Netherlands)

    Assen, van H.C.; Danilouchkine, M.G.; Dirksen, M.S.; Reiber, J.H.C.; Lelieveldt, B.P.F.

    2008-01-01

    Abstract—Manual quantitative analysis of cardiac left ventricular function using Multislice CT and MR is arduous because of the large data volume. In this paper, we present a 3-D active shape model (ASM) for semiautomatic segmentation of cardiac CT and MRvolumes, without the requirement of

  3. Musculoskeletal wide detector CT: Principles, techniques and applications in clinical practice and research

    International Nuclear Information System (INIS)

    Gondim Teixeira, Pedro Augusto; Gervaise, Alban; Louis, Matthias; Lecocq, Sophie; Raymond, Ariane; Aptel, Sabine; Blum, Alain

    2015-01-01

    Highlights: • Wide area-detector CT availability is growing steadily. • Advanced techniques such as Dynamic CT, Perfusion CT and dual energy can be used in clinical practice. • Optimal acquisition protocol is needed to increase diagnostic performance and limit dose exposure. • Guidelines for data acquisition and interpretation may increase diagnostic performance and reproducibility. - Abstract: A progressive increase in the detector width in CT scanners has meant that advanced techniques such as dynamic, perfusion and dual-energy CT are now at the radiologist's disposal. Although these techniques may be important for the diagnosis of various musculoskeletal diseases, data acquisition and interpretation can be challenging. This article offers a practical guide for the use of these tools including acquisition protocol, post-processing options and data interpretation based on 7 years of clinical experience in a tertiary university hospital

  4. 3D intrathoracic region definition and its application to PET-CT analysis

    Science.gov (United States)

    Cheirsilp, Ronnarit; Bascom, Rebecca; Allen, Thomas W.; Higgins, William E.

    2014-03-01

    Recently developed integrated PET-CT scanners give co-registered multimodal data sets that offer complementary three-dimensional (3D) digital images of the chest. PET (positron emission tomography) imaging gives highly specific functional information of suspect cancer sites, while CT (X-ray computed tomography) gives associated anatomical detail. Because the 3D CT and PET scans generally span the body from the eyes to the knees, accurate definition of the intrathoracic region is vital for focusing attention to the central-chest region. In this way, diagnostically important regions of interest (ROIs), such as central-chest lymph nodes and cancer nodules, can be more efficiently isolated. We propose a method for automatic segmentation of the intrathoracic region from a given co-registered 3D PET-CT study. Using the 3D CT scan as input, the method begins by finding an initial intrathoracic region boundary for a given 2D CT section. Next, active contour analysis, driven by a cost function depending on local image gradient, gradient-direction, and contour shape features, iteratively estimates the contours spanning the intrathoracic region on neighboring 2D CT sections. This process continues until the complete region is defined. We next present an interactive system that employs the segmentation method for focused 3D PET-CT chest image analysis. A validation study over a series of PET-CT studies reveals that the segmentation method gives a Dice index accuracy of less than 98%. In addition, further results demonstrate the utility of the method for focused 3D PET-CT chest image analysis, ROI definition, and visualization.

  5. Three dimensional CT of stapes. Stapedial imagings in dry temporal bone and clinical applications

    Energy Technology Data Exchange (ETDEWEB)

    Edamatsu, Hideo; Kubota, Osamu; Yamashita, Koichi [Kanazawa Medical Univ., Ishikawa (Japan)

    1995-03-01

    This study was performed to evaluate the usefulness and limitations of three dimensional (3-D) imagings of stapes in the middle ear by high speed helical CT. One dissected human temporal bone, ten normal and diseased ears were scanned with a slice of 1.0 mm and reconstructed in a thickness of 0.2-0.5 mm. Every specimen of 3-D can be observed in any plane and from any direction. Ossicular imagings of the temporal bone in 3-D were reconstructed as if the malleus, incus and stapes were observed under microscope. The whole structure of stapes was impossible to be represented by two dimensional CT heretofore in use, but 3-D in our study showed the head, crus and foot plate of the stapes in detail. Stapedial imagings of 3-D CT in normal ears showed the same findings as those recorded in temporal bone. Preoperative diagnostic findings of ossicles in the affected ears were very useful. Especially in ossicular anomalies, 3-D CT was positive in diagnosis and its accuracies were confirmed with operative observation. For the postoperative evaluation concerning the ossicular reconstruction, i.e. TORP and PORP, 3-D CT was also important method. It could present an anatomical relation between those prosthesis and the oval window. High speed helical CT can scan an object more quickly and clearly than formerly used CT, and its biological damage for human is less than that of the others. 3-D CT can be more clearly reconstructed with helical CT than former CT. (author).

  6. Optimization of pediatric examinations in a multislice helical CT

    International Nuclear Information System (INIS)

    Ombada, T. H. A.

    2010-12-01

    Radiological protection of pediatric patients undergoing medical imaging procedures involving ionizing radiation has always received special attention. This is due to the fact that children have higher radiation sensitivity and increased likelihood for radiation-induced cancer manifesting in many more years of their life than adults. In computed tomography (CT), such attention is more important because of the potential of relatively higher radiation doses during these procedures. Such high doses are possible with technological developments where volume scanning using faster multi-slice CT systems is now preferred to conventional CT equipment. The task of this study is to assess the optimization of paediatric doses in multi-slice CT examinations. It was carried out in Alrebat University Hospital for 31 pediatric patients, 43 examinations (27 head examination and 16 body (chest, abdomen and pelvis) examinations). Data were collected for scan parameters (kV, m As, pitch, scan length, number of slices and slice thickness) and doses displayed in monitor (CTDI v ol and DLP) for head examinations and body (chest, abdomen and pelvis) examinations. For head CT, displayed CTDI v ol ranged from 1.56 to 69.12 mGy, calculated value from 2.10 to 70.93 mGy. Displayed DLP ranged from 53 to 1817 mGy.cm, calculated from 95.30 to 1532.16 mGy. cm. For body examination, the range of displayed CTDI from 1.63 to 3.92 mGy, calculated value from 2.22 to 5.34 mGy. Displayed DLP ranged from 34 to 194 mGy.cm, for calculated from 45.89 to 161.98 mGy. cm. The calculated values are in agreement with reference study dose values although there are some high values in this study for some examinations, this variation or difference may attribute to variation in pediatric ages (9 days- 15 years), scan length and m As values. There is variation between calculated and displayed values. more optimization for CT doses is needed. (Author)

  7. Optimization of pediatric examinations in a multislice helical CT

    Energy Technology Data Exchange (ETDEWEB)

    Ombada, T H. A. [Atomic Energy Council, Sudan Academy of Sciences (SAS), Khartoum (Sudan)

    2010-12-15

    Radiological protection of pediatric patients undergoing medical imaging procedures involving ionizing radiation has always received special attention. This is due to the fact that children have higher radiation sensitivity and increased likelihood for radiation-induced cancer manifesting in many more years of their life than adults. In computed tomography (CT), such attention is more important because of the potential of relatively higher radiation doses during these procedures. Such high doses are possible with technological developments where volume scanning using faster multi-slice CT systems is now preferred to conventional CT equipment. The task of this study is to assess the optimization of paediatric doses in multi-slice CT examinations. It was carried out in Alrebat University Hospital for 31 pediatric patients, 43 examinations (27 head examination and 16 body (chest, abdomen and pelvis) examinations). Data were collected for scan parameters (kV, m As, pitch, scan length, number of slices and slice thickness) and doses displayed in monitor (CTDI{sub v}ol and DLP) for head examinations and body (chest, abdomen and pelvis) examinations. For head CT, displayed CTDI{sub v}ol ranged from 1.56 to 69.12 mGy, calculated value from 2.10 to 70.93 mGy. Displayed DLP ranged from 53 to 1817 mGy.cm, calculated from 95.30 to 1532.16 mGy. cm. For body examination, the range of displayed CTDI from 1.63 to 3.92 mGy, calculated value from 2.22 to 5.34 mGy. Displayed DLP ranged from 34 to 194 mGy.cm, for calculated from 45.89 to 161.98 mGy. cm. The calculated values are in agreement with reference study dose values although there are some high values in this study for some examinations, this variation or difference may attribute to variation in pediatric ages (9 days- 15 years), scan length and m As values. There is variation between calculated and displayed values. more optimization for CT doses is needed. (Author)

  8. Introduction of X-ray CT application in geotechnical engineering - theory and practice

    International Nuclear Information System (INIS)

    Otani, J; Watanabe, Y; Chevalier, B

    2010-01-01

    In this paper, fundamental issues on the use of X-ray CT to geomaterials were discussed, which were the contents of what you have to know about the use of X-ray CT, especially for geomaterials or granular materials. Then, two of our recent studies were introduced, which are 1) the use of X-ray CT data to quantitative measurements such as deformation and strains and 2) comparison of X-ray CT results with numerical analysis. Here, the triaxial compression test on sand was conducted and the image analysis technique called 'Digital Image Correlation' was used to measure displacement and strain fields in the soils using a large number of CT images. For the second topic, one of the advantages on the use of X-ray CT is to investigate the behavior in three dimensions. Here, so called trap door test was conducted with the materials of glass beads and the shape of the square door. DEM analysis was also conducted for the simulation of this behaviour and both results were compared. Based on all the results in this paper, the effectiveness of the use of X-ray CT in geomechanics and geotechnical engineering was revealed.

  9. Application of artificial neural networks in the CT study of solitary pulmonary nodule

    International Nuclear Information System (INIS)

    Wang Xiaohua; Ma Daqing; Chen Hui; Gao Peiyi; Zhou Xinhua

    2006-01-01

    Objective: To establish a new-type discriminative method in differentiating benign from malignant solitary pulmonary nodule (SPN) on high-resolution CT/thin-section CT by using artificial neural networks theory in the CT diagnostic study of SPN. Methods: Two hundred SPNs pathologically proved by operation or biopsy (primary pulmonary carcinoma 135 eases, benign nodules 65 cases) were collected, 3 clinical characteristics (age, sex, with or without bloody sputum) and 9 high-resolution CT/thin-section CT characteristics (location, long and short diameter, contour, spiculation, halo sign, air-space, relation with the adjacent blood vessels and pleura) were analyzed. 140 cases were randomly selected to form the training samples, on which artificial neural networks model (BP networks) was built and compared with Logistic model from Statistical Package for the Social Science (SPSS) software. Results: The total consistent rate of BP neural networks (98.0%, 196/200) was higher than that of Logistic model (86.0%, 172/200) (P<0.001). Areas under ROC curve were 0.996±0.004 and 0.936±0.017, respectively, and the difference between the two was significant (P<0.001). Conclusion: Using high-resolution CT and thin-section CT in combination with artificial neural networks theory is feasible, and it is expected to become a useful and reliable clinical tool in differentiating benign from malignant SPN. (authors)

  10. [The Clinical Application of Video Mediastinoscopy and CT in the N Staging of Preoperative Lung Cancer.].

    Science.gov (United States)

    Wang, Zhiheng; Qi, Weibo; Zhu, Yong; Lin, Ruobai

    2009-10-20

    Preoperative lung cancer with mediastinal lymph nodes metastasis can be diagnosed by vedio mediastinoscopy (VM) and CT. This study was to explore the value of VM and CT in the diagnosis of N staging of preoperative lung cancer, and to discuss the difference between the two methods. Forty-eight cases diagnosed of lung cancer by CT or PET-CT were examined by VM. The sensitivity, specificity, validity, positive predictive value and negative predictive value of VM and CT were speculated according to the postoperative pathological reports, and the difference between VM and CT in the diagnosis of lung cancer with mediastinal lymph nodes metastasis was discussed. (1)Under the examination of VM, 31 patients with the negative outcome received the direct operation; 14 patients with N2 received 2 courses of neoadjuvant chemotherapy before operation; 3 patients with N3 received chemotherapy and/or radiotherapy. (2)Forty-one cases with final diagnosis of lung cancer were used as samples to speculate the sensitivity, specificity, validity, positive predictive value and negative predictive value of VM. They were 93.3%, 100%, 97.6%, 100%, 96.3%, which of CT were 66.7%, 53.8%, 58.5%, 45.5%, 73.7% (Chi-square=4.083, P=0.039), the difference between VM and CT was statistically significant. (3)In this group, the complications of VM incidence rate was 2.08% (1/48), and the case was pneumothorax. VM is superior to CT in the diagnosis of N staging of preoperative lung cancer; Due to its safety and effectiveness, VM will be wildly used in the field of thoracic surgery.

  11. The Clinical Application of Video Mediastinoscopy and CT in the N Staging of Preoperative Lung Cancer

    Directory of Open Access Journals (Sweden)

    Zhiheng WANG

    2009-10-01

    Full Text Available Background and objective Preoperative lung cancer with mediastinal lymph nodes metastasis can be diagnosed by vedio mediastinoscopy (VM and CT. This study was to explore the value of VM and CT in the diagnosis of N staging of preoperative lung cancer, and to discuss the difference between the 2 methods. Methods 48 cases diagnosed of lung cancer by CT or PET-CT were examined by VM. The sensitivity, specificity, validity, positive predictive value and negative predictive value of VM and CT were speculated according to the postoperative pathological reports, and the difference between VM and CT in the diagnosis of lung cancer with mediastinal lymph nodes metastasis was discussed. Results ①Under the examination of VM, 31 patients with the negative outcome received the direct operation, 14 patients with N2 received 2 courses of neoadjuvant chemotherapy before operation, 3 patients with N3 received chemotherapy and/or radiotherapy. ②Forty-one cases with final diagnosis of lung cancer were used as samples to speculate the sensitivity, specificity, validity, positive predictive value and negative predictive value of VM. They were 93.3%, 100%, 97.6%, 100%, 96.3%, which of CT were 66.7%, 53.8%, 58.5%, 45.5%, 73.7% (χ2=4.083, P=0.039, the difference between VM and CT was statistically significant. ③In this group, the complications of VM incidence rate is 2.08% (1/48, the case is pneumothorax. Conclusion VM is superior to CT in the diagnosis of N staging of preoperative lung cancer, it is safe and effective, and there will be a wide perspective for VM in thoracic surgery.

  12. Energy dispersive CdTe and CdZnTe detectors for spectral clinical CT and NDT applications

    Energy Technology Data Exchange (ETDEWEB)

    Barber, W.C., E-mail: william.barber@dxray.com [DxRay, Inc., Northridge, CA (United States); Interon AS, Asker (Norway); Wessel, J.C. [DxRay, Inc., Northridge, CA (United States); Interon AS, Asker (Norway); Nygard, E. [Interon AS, Asker (Norway); Iwanczyk, J.S. [DxRay, Inc., Northridge, CA (United States)

    2015-06-01

    We are developing room temperature compound semiconductor detectors for applications in energy-resolved high-flux single x-ray photon-counting spectral computed tomography (CT), including functional imaging with nanoparticle contrast agents for medical applications and non-destructive testing (NDT) for security applications. Energy-resolved photon-counting can provide reduced patient dose through optimal energy weighting for a particular imaging task in CT, functional contrast enhancement through spectroscopic imaging of metal nanoparticles in CT, and compositional analysis through multiple basis function material decomposition in CT and NDT. These applications produce high input count rates from an x-ray generator delivered to the detector. Therefore, in order to achieve energy-resolved single photon counting in these applications, a high output count rate (OCR) for an energy-dispersive detector must be achieved at the required spatial resolution and across the required dynamic range for the application. The required performance in terms of the OCR, spatial resolution, and dynamic range must be obtained with sufficient field of view (FOV) for the application thus requiring the tiling of pixel arrays and scanning techniques. Room temperature cadmium telluride (CdTe) and cadmium zinc telluride (CdZnTe) compound semiconductors, operating as direct conversion x-ray sensors, can provide the required speed when connected to application specific integrated circuits (ASICs) operating at fast peaking times with multiple fixed thresholds per pixel provided the sensors are designed for rapid signal formation across the x-ray energy ranges of the application at the required energy and spatial resolutions, and at a sufficiently high detective quantum efficiency (DQE). We have developed high-flux energy-resolved photon-counting x-ray imaging array sensors using pixellated CdTe and CdZnTe semiconductors optimized for clinical CT and security NDT. We have also fabricated high

  13. Application of high resolution synchrotron micro-CT radiation in dental implant osseointegration

    DEFF Research Database (Denmark)

    Neldam, Camilla Albeck; Lauridsen, Torsten; Rack, Alexander

    2015-01-01

    The purpose of this study was to describe a refined method using high-resolution synchrotron radiation microtomography (SRmicro-CT) to evaluate osseointegration and peri-implant bone volume fraction after titanium dental implant insertion. SRmicro-CT is considered gold standard evaluating bone...... microarchitecture. Its high resolution, high contrast, and excellent high signal-to-noise-ratio all contribute to the highest spatial resolutions achievable today. Using SRmicro-CT at a voxel size of 5 μm in an experimental goat mandible model, the peri-implant bone volume fraction was found to quickly increase...

  14. The selection of window width and levels for measuring the airway dimensions with spiral CT scan: an experimental study in Japanese white big-ear rabbits

    International Nuclear Information System (INIS)

    Han Xinwei; Lu Huuibing; Wu Gang; Ma Ji; Wang Nan; Si Jiangtao

    2009-01-01

    Objective: To investigate the optimal window width and window level for measuring the airway dimensions with spiral CT scan in Japanese white big-ear rabbits so as to lay the foundation for airway stenting in animal experiments. Methods: Multi-slice spiral CT scanning of cervico-thoracic region was performed in 30 healthy adult Japanese white big-ear rabbits, the anteroposterior and transversal diameter of the thoracic trachea, the anteroposterior diameter of the right and left bronchus were measured with lung window, mediastinum window and special fat window separately. The revealing rate of the tracheal wall and the measuring results in different windows and levels were recorded and compared with the anatomical data. The differences of the relevant data were statistically analyzed. Results: With lung window, the tracheal wall was well demonstrated, but the relevant data were smaller than that with mediastinum window. With mediastinum window, the data were bigger and the tracheal wall border appeared blurred. The results obtained with fat window were close to the actual anatomical data. Conclusion: For accurately measuring the anteroposterior and transversal diameter of the thoracic trachea in Japanese white big-ear rabbits with multi- slice spiral CT scan, fat window should be adopted, which is helpful for the preparation of tracheal and bronchial stents. (authors)

  15. Image Quality of 3rd Generation Spiral Cranial Dual-Source CT in Combination with an Advanced Model Iterative Reconstruction Technique: A Prospective Intra-Individual Comparison Study to Standard Sequential Cranial CT Using Identical Radiation Dose.

    Science.gov (United States)

    Wenz, Holger; Maros, Máté E; Meyer, Mathias; Förster, Alex; Haubenreisser, Holger; Kurth, Stefan; Schoenberg, Stefan O; Flohr, Thomas; Leidecker, Christianne; Groden, Christoph; Scharf, Johann; Henzler, Thomas

    2015-01-01

    To prospectively intra-individually compare image quality of a 3rd generation Dual-Source-CT (DSCT) spiral cranial CT (cCT) to a sequential 4-slice Multi-Slice-CT (MSCT) while maintaining identical intra-individual radiation dose levels. 35 patients, who had a non-contrast enhanced sequential cCT examination on a 4-slice MDCT within the past 12 months, underwent a spiral cCT scan on a 3rd generation DSCT. CTDIvol identical to initial 4-slice MDCT was applied. Data was reconstructed using filtered backward projection (FBP) and 3rd-generation iterative reconstruction (IR) algorithm at 5 different IR strength levels. Two neuroradiologists independently evaluated subjective image quality using a 4-point Likert-scale and objective image quality was assessed in white matter and nucleus caudatus with signal-to-noise ratios (SNR) being subsequently calculated. Subjective image quality of all spiral cCT datasets was rated significantly higher compared to the 4-slice MDCT sequential acquisitions (pspiral compared to sequential cCT datasets with mean SNR improvement of 61.65% (p*Bonferroni0.05spiral cCT with an advanced model IR technique significantly improves subjective and objective image quality compared to a standard sequential cCT acquisition acquired at identical dose levels.

  16. Clinical application of dual energy spectral CT method in patients with hepatic alveolar echinococcosis

    Directory of Open Access Journals (Sweden)

    Yi Jiang

    2016-09-01

    Conclusions: DESCT could provide more information by using monochromatic images, iodine-based material decomposition images and the quantitative analysis of IC than traditional CT for the diagnosis of HE.

  17. Reconstructing the CT number array from gray-level images and its application in PACS

    Science.gov (United States)

    Chen, Xu; Zhuang, Tian-ge; Wu, Wei

    2001-08-01

    Although DICOM compliant computed tomography has been prevailing in medical fields nowadays, there are some incompliant ones, from which we could hardly get the raw data and make an apropos interpretation due to the proprietary image format. Under such condition, one usually uses frame grabbers to capture CT images, the results of which could not be freely adjusted by radiologists as the original CT number array could. To alleviate the inflexibility, a new method is presented in this paper to reconstruct the array of CT number from several gray-level images acquired under different window settings. Its feasibility is investigated and a few tips are put forward to correct the errors caused respectively by 'Border Effect' and some hardware problems. The accuracy analysis proves it a good substitution for original CT number array acquisition. And this method has already been successfully used in our newly developing PACS and accepted by the radiologists in clinical use.

  18. Clinical Application of F-18 FDG PET (PET/CT) in Malignancy of Unknown Origin

    International Nuclear Information System (INIS)

    Kim, Byung Il

    2008-01-01

    Diagnosis of primary origin site in the management of malignancy of unknown origin (MUO) is the most important issue. According to the histopathologic subtype of primary lesion, specialized treatment can be given and survival gain is expected. F-18 FDG PET (PET/CT) has been estimated as useful in detection of primary lesion with high sensitivity and moderate specificity. F-18 FDG PET (PET/CT) study before conventional studies is also recommended because it has high diagnostic performance compared to conventional studies. Although there has few data, F-18 FDG PET (PET/CT) is expected to be useful in diagnosis of recurrence, restaging, evaluation of treatment effect, considering that PET (PET/CT) has been reported as useful in other malignancies

  19. Clinical application of subtraction CT imaging for evaluation of pulmonary vascular permeability

    International Nuclear Information System (INIS)

    Kato, Shiro; Asai, Toshihiko; Yatagai, Shigeo; Oonuma, Noboru; Ohno, Kunihiko; Nakamoto, Takaaki; Iizuka, Masahiko

    1991-01-01

    In this clinical study, one normal subject, one patient with primary interstitial pneumonia, one patient with segmental pneumonia due to Staphylococcus aureus, one patient with post-operative esophageal carcinoma, and two patients with mitral stenosis were studied. Dynamic CT scan images under continuous injection of low osmotic contrast medium were analyzed in series, in an attempt to evaluate vascular permeability quantitatively. The following results were obtained. Subtraction CT scan image 10 minutes after the start of contrast medium injection in two patients with pneumonia, showed a reduction of pulmonary vascular permeability following therapy. Subtraction CT scan image of the patient with post-operative esophageal carcinoma treated with 25 Gy radiation showed a discrepancy between pulmonary vascular permeability and other findings. In hemodynamically stable patients with mitral stenosis, subtraction CT images demonstrated that pulmonary vascular permeability was not affected by pulmonary congestion, irrespective of its severity. (author)

  20. Means to verify the accuracy of CT systems for metrology applications (In the Absence of Established International Standards)

    International Nuclear Information System (INIS)

    Lettenbauer, H.; Georgi, B.; Weib, D.

    2007-01-01

    X-ray computed tomography (CT) reconstructs an unknown object from X-ray projections and has long been used for qualitative investigation of internal structures in industrial applications. Recently there has been increased interest in applying X-ray cone beam CT to the task of high-precision dimensional measurements of machined parts, since it is a relatively fast method of measuring both inner and outer geometries of arbitrary complexity. The important information for the user in dimensional metrology is if measured elements of a machined part are within the defined tolerances or not. In order to qualify cone beam CT as an established measurement technology, it must be qualified in the same manner as established measurement technologies such as coordinate measurement machines (CMMs) with tactile or optical sensors. In international standards artefacts are defined that are calibrated by certified institutions. These artefacts are defined by certain geometrical elements. CT measurements are performed on the reconstructed object volume, either directly or using an intermediate surface-extraction step. The results of these measurements have to be compared to the values of the calibrated elements; the level of agreement of the results defines the accuracy of the measurements. By using established methods to define measurement uncertainty a very high level of acceptance in dimensional metrology can be reached for the user. Only if results are comparable to standards of the established technologies the barriers of entry into metrology will be removed and all benefits of this technology will be available for the user. (authors)

  1. Application of CT-guided percutaneous thyroid biopsy in basic study of interventional therapy for Graves disease

    International Nuclear Information System (INIS)

    Yi Genfa; Zhao Wei; Hu Jihong; Jin Cangzheng; Yang Huiying

    2007-01-01

    Objective: To evaluate the value of application of CT-guided percutaneous thyroid biopsy in basic study of interventional treatment for Graves disease. Methods: Fifteen patients of hyperthyroidism caused by Graves' disease had been undertaken transcathter arterial embolizsation with PVA micropheres including 52 core needle biopsy(CNB)of pre-or post-interventional procedure. All procedures were divided into 2 groups according to the size of the thyroid enlargement: (1) II degree enlargement (n=19)under palpation puncture. (2) No enlargement or under II degree enlargement (n=33)with palpation and CT-guided puncture. Results: In group (1), 17 of the 19 procedures with palpation puncture were succeeded, reaching a successful rate of 89.5%. For group (2), the successful rate of CT-guided puncture was 91.7%. The difference between the successful rate of two groups showed statistical significance (P<0.05). No complication occurred during procedures in all cases. Conclusions: CT-guided thyroid core needle biopsy is an accurate, safe and high successful procedure providing the basic study for post-interventional treatment of Graves disease. (authors)

  2. PET/CT-guided biopsies of metabolically active bone lesions: applications and clinical impact

    Energy Technology Data Exchange (ETDEWEB)

    Klaeser, Bernd; Wartenberg, Jan; Weitzel, Thilo; Krause, Thomas [Bern University Hospital and University of Bern, Department of Nuclear Medicine, Inselspital, Bern (Switzerland); Wiskirchen, Jakub [Bern University Hospital and University of Bern, Department of Nuclear Medicine, Inselspital, Bern (Switzerland); University Hospital Tuebingen, Department of Radiology, Neuroradiology, and Nuclear Medicine, Tuebingen (Germany); Schmid, Ralph A. [Bern University Hospital and University of Bern, Department of Thoracic Surgery, Inselspital, Bern (Switzerland); Mueller, Michel D. [Bern University Hospital and University of Bern, Department of Obstetrics and Gynaecology, Inselspital, Bern (Switzerland)

    2010-11-15

    In a minority of cases a definite diagnosis and stage grouping in cancer patients is not possible based on the imaging information of PET/CT. We report our experience with percutaneous PET/CT-guided bone biopsies to histologically verify the aetiology of hypermetabolic bone lesions. We retrospectively reviewed the data of 20 consecutive patients who underwent multimodal image-guided bone biopsies using a dedicated PET/CT system in a step-by-step technique. Technical and clinical success rates of PET/CT-guided biopsies were evaluated. Questionnaires were sent to the referring physicians to assess the impact of biopsies on patient management and to check the clinical need for PET/CT-guided biopsies. Clinical indications for biopsy were to histologically verify the aetiology of metabolically active bone lesions without a morphological correlate confirming the suspicion of metastases in 15 patients, to determine the origin of suspected metastases in 3 patients and to evaluate the appropriateness of targeted therapy options in 2 patients. Biopsies were technically successful in all patients. In 19 of 20 patients a definite histological diagnosis was possible. No complications or adverse effects occurred. The result of PET/CT-guided bone biopsies determined a change of the planned treatment in overall 56% of patients, with intramodality changes, e.g. chemotherapy with palliative instead of curative intent, and intermodality changes, e.g. systemic therapy instead of surgery, in 22 and 50%, respectively. PET/CT-guided bone biopsies are a promising alternative to conventional techniques to make metabolically active bone lesions - especially without a distinctive morphological correlate - accessible for histological verification. PET/CT-guided biopsies had a major clinical impact in patients who otherwise cannot be reliably stage grouped at the time of treatment decisions. (orig.)

  3. Application of 18F-FDG PET/CT for the diagnosis of cervical cancer

    International Nuclear Information System (INIS)

    Zhou Wenlan; Wu Hubing; Wang Quanshi; Ye Xianghua

    2008-01-01

    Objective: The purpose of this study was to evaluate the clinical value of 18 F-fluorode-oxyglucose (FDG) PET/CT for staging and re-staging cervical cancer cases. Methods: This retrospective study included 88 patients. Of the 88 patients, 19 were primary cervical cancer, 11 were benign cervical tumor and 58 were cervical cancer patients with post-treatment surveillance. All had either whole body or abdominal-pelvic FDG PET/CT imaging. The diagnosis was established according to the pathologic results of surgery or biopsy, and(or) multi-modality imaging and clinical follow-up for at least six months. Results: For initial diagnosis of cervical cancer, the sensitivity, specificity and accuracy of FDG PET/CT were 17/19 (89.5%), 10/11 (90.9%) and 27/30(90.0%) respectively. For re-staging cervical cancer, the sensitivity, specificity and accuracy of FDG PET/CT were 10/11 (90. 9%), 47/47 (100. 0%) and 57/58 (98.3%) respectively. In all, 41 had metastases. The sensitivity, specificity and accuracy of FDG PET/ CT detecting metastases were 92.7%, 88.9% and 90.9% respectively. Of the metastatic sites, 66.3% were abdominal-pelvic lymph nodes, 26.8% of the metastatic lymph nodes were detected with diameters less than 1.0 cm. Twenty-two of twenty seven (28.6%) patients were identified to have extra-pelvic lesions after PET/CT and were then changed their treatment plans. Conclusions: 18 F-FDG PET/CT is useful in staging and re-staging cervical cancer patients. PET/CT is of great value in identifying small lesions and also in detecting extra-pelvic lesions. (authors)

  4. Application of Super-Resolution Convolutional Neural Network for Enhancing Image Resolution in Chest CT.

    Science.gov (United States)

    Umehara, Kensuke; Ota, Junko; Ishida, Takayuki

    2017-10-18

    In this study, the super-resolution convolutional neural network (SRCNN) scheme, which is the emerging deep-learning-based super-resolution method for enhancing image resolution in chest CT images, was applied and evaluated using the post-processing approach. For evaluation, 89 chest CT cases were sampled from The Cancer Imaging Archive. The 89 CT cases were divided randomly into 45 training cases and 44 external test cases. The SRCNN was trained using the training dataset. With the trained SRCNN, a high-resolution image was reconstructed from a low-resolution image, which was down-sampled from an original test image. For quantitative evaluation, two image quality metrics were measured and compared to those of the conventional linear interpolation methods. The image restoration quality of the SRCNN scheme was significantly higher than that of the linear interpolation methods (p < 0.001 or p < 0.05). The high-resolution image reconstructed by the SRCNN scheme was highly restored and comparable to the original reference image, in particular, for a ×2 magnification. These results indicate that the SRCNN scheme significantly outperforms the linear interpolation methods for enhancing image resolution in chest CT images. The results also suggest that SRCNN may become a potential solution for generating high-resolution CT images from standard CT images.

  5. Exposure dose to gonad and its reduction in CT examinations

    International Nuclear Information System (INIS)

    Suzuki, Shoichi; Menju, Mina; Nakazawa, Masato

    2006-01-01

    Exposure doses to gonad (ovary and uterus) due to scattering at the ordinary CT examinations of head, breast, and abdomen (liver) were measured and their reductions by the protective apron usually used in clinic were evaluated by comparison of the given and International Commission of Radiological Protection (ICRP) data for risk assessment. Multi-slice helical/scanno-helical CT for the regions under ordinary diagnostic conditions was done by the apparatus Toshiba Aquilion 16 for the human body phantom (Alderson) with or without the apron (Hagoromo) equivalent to 0.25 mm thick lead. Doses inside and outside the beam flux were measured by the thermoluminescent dosimeter, of which data were corrected by Radcal Model 300 ionization chamber. The doses in the gonad due to scattering were found to be in the range from 0.01 (head CT) to 1 (liver CT) mGy and to be reduced in 20-30% by the apron. Found dose were far smaller than the ICRP threshold values for inducing teratosis and infertality. (T.I.)

  6. A volumetric pulmonary CT segmentation method with applications in emphysema assessment

    Science.gov (United States)

    Silva, José Silvestre; Silva, Augusto; Santos, Beatriz S.

    2006-03-01

    A segmentation method is a mandatory pre-processing step in many automated or semi-automated analysis tasks such as region identification and densitometric analysis, or even for 3D visualization purposes. In this work we present a fully automated volumetric pulmonary segmentation algorithm based on intensity discrimination and morphologic procedures. Our method first identifies the trachea as well as primary bronchi and then the pulmonary region is identified by applying a threshold and morphologic operations. When both lungs are in contact, additional procedures are performed to obtain two separated lung volumes. To evaluate the performance of the method, we compared contours extracted from 3D lung surfaces with reference contours, using several figures of merit. Results show that the worst case generally occurs at the middle sections of high resolution CT exams, due the presence of aerial and vascular structures. Nevertheless, the average error is inferior to the average error associated with radiologist inter-observer variability, which suggests that our method produces lung contours similar to those drawn by radiologists. The information created by our segmentation algorithm is used by an identification and representation method in pulmonary emphysema that also classifies emphysema according to its severity degree. Two clinically proved thresholds are applied which identify regions with severe emphysema, and with highly severe emphysema. Based on this thresholding strategy, an application for volumetric emphysema assessment was developed offering new display paradigms concerning the visualization of classification results. This framework is easily extendable to accommodate other classifiers namely those related with texture based segmentation as it is often the case with interstitial diseases.

  7. Patient-specific radiation dose and cancer risk estimation in CT: Part II. Application to patients

    Energy Technology Data Exchange (ETDEWEB)

    Li Xiang; Samei, Ehsan; Segars, W. Paul; Sturgeon, Gregory M.; Colsher, James G.; Toncheva, Greta; Yoshizumi, Terry T.; Frush, Donald P. [Medical Physics Graduate Program, Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Medical Physics Graduate Program, Department of Physics, and Department of Biomedical Engineering, Duke University Medical Center, Durham, North Carolina 27705 (United States); Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Medical Physics Graduate Program, Duke University Medical Center, Durham, North Carolina 27705 (United States); Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 and Department of Biomedical Engineering, University of North Carolina, Chapel Hill, North Carolina 27599 (United States); Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Duke Radiation Dosimetry Laboratory, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Duke Radiation Dosimetry Laboratory, Department of Radiology, Medical Physics Graduate Program, Duke University Medical Center, Durham, North Carolina 27705 (United States); Division of Pediatric Radiology, Department of Radiology, Medical Physics Graduate Program, Duke University Medical Center, Durham, North Carolina 27710 (United States)

    2011-01-15

    Purpose: Current methods for estimating and reporting radiation dose from CT examinations are largely patient-generic; the body size and hence dose variation from patient to patient is not reflected. Furthermore, the current protocol designs rely on dose as a surrogate for the risk of cancer incidence, neglecting the strong dependence of risk on age and gender. The purpose of this study was to develop a method for estimating patient-specific radiation dose and cancer risk from CT examinations. Methods: The study included two patients (a 5-week-old female patient and a 12-year-old male patient), who underwent 64-slice CT examinations (LightSpeed VCT, GE Healthcare) of the chest, abdomen, and pelvis at our institution in 2006. For each patient, a nonuniform rational B-spine (NURBS) based full-body computer model was created based on the patient's clinical CT data. Large organs and structures inside the image volume were individually segmented and modeled. Other organs were created by transforming an existing adult male or female full-body computer model (developed from visible human data) to match the framework defined by the segmented organs, referencing the organ volume and anthropometry data in ICRP Publication 89. A Monte Carlo program previously developed and validated for dose simulation on the LightSpeed VCT scanner was used to estimate patient-specific organ dose, from which effective dose and risks of cancer incidence were derived. Patient-specific organ dose and effective dose were compared with patient-generic CT dose quantities in current clinical use: the volume-weighted CT dose index (CTDI{sub vol}) and the effective dose derived from the dose-length product (DLP). Results: The effective dose for the CT examination of the newborn patient (5.7 mSv) was higher but comparable to that for the CT examination of the teenager patient (4.9 mSv) due to the size-based clinical CT protocols at our institution, which employ lower scan techniques for smaller

  8. Three dimensional volume rendering virtual endoscopy of the ossicles using a multi-row detector CT: applications and limitations

    International Nuclear Information System (INIS)

    Kim, Su Yeon; Choi, Sun Seob; Kang, Myung Jin; Shin, Tae Beom; Lee, Ki Nam; Kang, Myung Koo

    2005-01-01

    This study was conducted to know the applications and limitations of three dimensional volume rendering virtual endoscopy of the ossicles using a multi-row detector CT. This study examined 25 patients who underwent temporal bone CT using a 16-row detector CT as a result of hearing problems or trauma. The axial CT scan of the temporal bone was performed with a 0.6 mm collimation, and a reconstruction was carried out with a U70u sharp of kernel value, a 1 mm thickness and 0.5-1.0 mm increments. After observing the ossicles in the axial and coronal images, virtual endoscopy was performed using a three dimensional volume rendering technique with a threshold value of-500 HU. The intra-operative otoendoscopy was performed in 12 ears, and was compared with the virtual endoscopy findings. Virtual endoscopy of the 29 ears without hearing problems demonstrated hypoplastic or an incomplete depiction of the stapes superstructures in 25 ears and a normal depiction in 4 ears. Virtual endoscopy of 21 ears with hearing problems demonstrated no ossicles in 1 ears, no malleus in 3 ears, a malleoincudal subluxation in 6 ears, a dysplastic incus in 5 ears, an incudostapedial subluxation in 9 ears, dysplastic stapes in 2 ears, a hypoplastic or incomplete depiction of the stapes in 16 ears and no stapes in 1 ears. In contrast to the intra-operative otoendoscopy, 8 out of 12 ears showed a hypoplastic or deformed stapes in the virtual endoscopy. Volume rendering virtual endoscopy using a multi-row detector CT is an excellent method for evaluation the ossicles in three dimension, even thought the partial volume effect for the stapes superstructures needs to be considered

  9. Respiratory Motion Management in PET/CT: Applications and Clinical Usefulness.

    Science.gov (United States)

    Guerra, Luca; Ponti, Elena De; Morzenti, Sabrina; Spadavecchia, Chiara; Crivellaro, Cinzia

    2017-01-01

    Breathing movement can introduce heavy bias in both image quality and quantitation in PET/CT. The aim of this paper is a review of the literature to evaluate the benefit of respiratory gating in terms of image quality, quantification and lesion detectability. A review of the literature published in the last 10 years and dealing with gated PET/CT technique has been performed, focusing on improvement in quantification, lesion detectability and diagnostic accuracy in neoplastic lesion. In addition, the improvement in the definition of radiotherapy planning has been evaluated. There is a consistent increase of the Standardized Uptake Value (SUV) in gated PET images when compared to ungated ones, particularly for lesions located in liver and in lung. Respiratory gating can also increase sensitivity, specificity and accuracy of PET/CT. Gated PET/CT can be used for radiation therapy planning, reducing the uncertainty in target definition, optimizing the volume to be treated and reducing the possibility of "missing" during the dose delivery. Moreover, new technologies, able to define the movement of lesions and organs directly from the PET sinogram, can solve some problems that currently are limiting the clinical use of gated PET/CT (i.e.: extended acquisition time, radiation exposure). The published literature demonstrated that respiratory gating PET/CT is a valid technique to improve quantification, lesion detectability of lung and liver tumors and can better define the radiotherapy planning of moving lesions and organs. If new technical improvements for motion compensation will be clinically validated, gated technique could be applied routinely in any PET/CT scan. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  10. Deformable 3D–2D registration for CT and its application to low dose tomographic fluoroscopy

    International Nuclear Information System (INIS)

    Flach, Barbara; Brehm, Marcus; Sawall, Stefan; Kachelrieß, Marc

    2014-01-01

    Many applications in medical imaging include image registration for matching of images from the same or different modalities. In the case of full data sampling, the respective reconstructed images are usually of such a good image quality that standard deformable volume-to-volume (3D–3D) registration approaches can be applied. But research in temporal-correlated image reconstruction and dose reductions increases the number of cases where rawdata are available from only few projection angles. Here, deteriorated image quality leads to non-acceptable deformable volume-to-volume registration results. Therefore a registration approach is required that is robust against a decreasing number of projections defining the target position. We propose a deformable volume-to-rawdata (3D–2D) registration method that aims at finding a displacement vector field maximizing the alignment of a CT volume and the acquired rawdata based on the sum of squared differences in rawdata domain. The registration is constrained by a regularization term in accordance with a fluid-based diffusion. Both cost function components, the rawdata fidelity and the regularization term, are optimized in an alternating manner. The matching criterion is optimized by a conjugate gradient descent for nonlinear functions, while the regularization is realized by convolution of the vector fields with Gaussian kernels. We validate the proposed method and compare it to the demons algorithm, a well-known 3D–3D registration method. The comparison is done for a range of 4–60 target projections using datasets from low dose tomographic fluoroscopy as an application example. The results show a high correlation to the ground truth target position without introducing artifacts even in the case of very few projections. In particular the matching in the rawdata domain is improved compared to the 3D–3D registration for the investigated range. The proposed volume-to-rawdata registration increases the robustness

  11. Study of abdominal CT angiography in low tube voltage setting combined with personalized contrast media application

    International Nuclear Information System (INIS)

    Cao Jianxin; Wang Yiming; Zhang Yu; Tao Wei; Zhang Xiaodong; Wang Aijun; Liu Li; Wang Peng

    2012-01-01

    Objective: To investigate the feasibility of decreasing radiation dose and contrast media dose of abdominal CTA using low tube voltage setting combined with personalized contrast media application. Methods: One hundred and twenty patients were randomly divided into 3 groups, and there were 40 patients in each group. 120 kV tube voltage was used in group A, and 100 kV tube voltage was used in group B and C. Personalized injection flow rate of contrast media which determined according to patient's body mass (injection flow rate =λ × body mass) was used for all groups, and the λ values for group A, B and C were 0.07, 0.07 and 0.06 ml · kg -1 · s -1 respectively. CT dose index volume (CTDIvol) effective dose (ED) and contrast media dose were evaluated,and these parameters were all analyzed using one-way ANOVA analysis. Image quality of abdominal aorta and branch arteries was rated using a three-point ordinal for all 3 groups, and image quality score was analyzed using Kruskal-Wallis test. Results: CTDIvol were (8.2±0.8), (6.0 ±1.0) and (6.1 ±1.1)mGy for group A, B and C, ED were (5.2 ±0.8), (3.5 ± 0.7) and (3.6 ± 0.6) mSv, and contrast media dose were (72.3 ± 10.3),(73.5 ± 11.3) and (61.6 ±9.4) ml, respectively. There were significant differences in CTDIvol, ED and contrast media dose among 3 groups (F=66.094, 77.812,15.919; P=0.000). Compare with group A, the ED of group B was decreased 32.7%, and the ED and contrast media dose of group C were decreased 30.8% and 14.8%, respectively. Image quality was rated as excellent, good, and general for 20, 19 and 1 patients in group A, 25, 15 and 0 patients in group B, and 23, 17 and 0 patients in group C, respectively. There was no significant difference in image quality score among 3 groups (χ 2 =1.492, P=0.474). Conclusions: The radiation dose and contrast media dose can be decreased in abdominal CTA using low tube voltage and personalized contrast media application while image quality can be preserved

  12. Application of microCT to the non-destructive testing of an additive manufactured titanium component

    Directory of Open Access Journals (Sweden)

    Anton du Plessis

    2015-11-01

    Full Text Available In this paper the application of X-ray microCT to the non-destructive testing of an additive manufactured titanium alloy component of complex geometry is demonstrated. Additive manufacturing of metal components is fast growing and shows great promise, yet these parts may contain defects which affect mechanical properties of the components. In this work a layered form of defect is found by microCT, which would have been very difficult or impossible to detect by other non-destructive testing methods due to the object complexity, defect size and shape and because the pores are entirely contained inside the object and not connected to the surface. Additionally, this test part was subjected to hot isostatic pressing (HIPPING and subsequently scanned. Comparing before and after scans by alignment of the volumes allows visualization and quantification of the pore size changes. The application of X-ray microCT to additive manufacturing is thus demonstrated in this example to be an ideal combination, especially for process improvements and for high value components.

  13. Clinical application of three-dimensional imaging with multislice CT for laparoscopic colorectal surgery

    International Nuclear Information System (INIS)

    Matsuki, Mitsuru; Okuda, Jyunji; Yoshikawa, Syushi

    2003-01-01

    Laparoscopic colorectal surgery, while minimally invasive, is a complicated technique. Therefore, prior to this surgery, it is important to determine the anatomical information of colorectal cancer. Fifty-eight cases of patients with a confirmed diagnosis of colon cancer [caecal (n=4), ascending colon (n=6), transverse colon (n=7), descending colon (n=2), sigmoid colon (n=22), and rectal (n=17) cancer] were evaluated using multislice CT before laparoscopic surgery. CT examination was performed in an air-filled colorectum by colon fiberscopy. Contrast-enhanced images on multislice CT were obtained at arterial and venous phases. All images were reviewed on a workstation, and three-dimensional (3D) images of vessels, colorectum, cancer, and swollen lymph nodes were reconstructed by volume rendering and fused (integrated 3D imaging). We evaluated the usefulness of integrated 3D imaging with multislice CT for laparoscopic colorectal surgery. Integrated 3D imaging demonstrated clearly the distribution of arteries feeding the colorectal cancer and the anatomical location of colorectal cancer and arterial and venous systems. Moreover, measurement of the distance between the aortic bifurcation and the origin of the inferior mesenteric artery and that between the base of the inferior mesenteric artery and the origin of the left colic artery on integrated 3D imaging contributed to safe, prompt ligation of the vessels and excision of lymph nodes. Integrated 3D imaging with multislice CT was useful for simulation of laparoscopic colorectal surgery. (author)

  14. Clinical application of three-dimensional imaging with multislice CT for laparoscopic colorectal surgery

    Energy Technology Data Exchange (ETDEWEB)

    Matsuki, Mitsuru; Okuda, Jyunji; Yoshikawa, Syushi [Osaka Medical Coll., Takatsuki (Japan)] (and others)

    2003-03-01

    Laparoscopic colorectal surgery, while minimally invasive, is a complicated technique. Therefore, prior to this surgery, it is important to determine the anatomical information of colorectal cancer. Fifty-eight cases of patients with a confirmed diagnosis of colon cancer [caecal (n=4), ascending colon (n=6), transverse colon (n=7), descending colon (n=2), sigmoid colon (n=22), and rectal (n=17) cancer] were evaluated using multislice CT before laparoscopic surgery. CT examination was performed in an air-filled colorectum by colon fiberscopy. Contrast-enhanced images on multislice CT were obtained at arterial and venous phases. All images were reviewed on a workstation, and three-dimensional (3D) images of vessels, colorectum, cancer, and swollen lymph nodes were reconstructed by volume rendering and fused (integrated 3D imaging). We evaluated the usefulness of integrated 3D imaging with multislice CT for laparoscopic colorectal surgery. Integrated 3D imaging demonstrated clearly the distribution of arteries feeding the colorectal cancer and the anatomical location of colorectal cancer and arterial and venous systems. Moreover, measurement of the distance between the aortic bifurcation and the origin of the inferior mesenteric artery and that between the base of the inferior mesenteric artery and the origin of the left colic artery on integrated 3D imaging contributed to safe, prompt ligation of the vessels and excision of lymph nodes. Integrated 3D imaging with multislice CT was useful for simulation of laparoscopic colorectal surgery. (author)

  15. Basic principles and applications of {sup 18}F-FDG-PET/CT in oral and maxillofacial imaging: A pictorial essay

    Energy Technology Data Exchange (ETDEWEB)

    Omami, Galal [Dept. of Oral Diagnosis and Polyclinics, Faculty of Dentistry, The Hong Kong University, Hong Kong (Hong Kong); Tamimi, Dania [BeamReaders Inc., Orlando (United States); Branstette, Barton F. [Dept. of Otolaryngology and Radiology, University of Pittsburgh School of Medicine, Pittsburgh (United States)

    2014-12-15

    A combination of positron emission tomography (PET) with 18F-labeled fluoro-2-deoxyglucose ({sup 18}F-FDG) and computed tomography ({sup 18}F-FDG-PET/CT) has increasingly become a widely used imaging modality for the diagnosis and management of head and neck cancer. On the basis of both recent literature and our professional experience, we present a set of principles with pictorial illustrations and clinical applications of FDG-PET/CT in the evaluation and management planning of squamous cell carcinoma of the oral cavity and oropharynx. We feel that this paper will be of interest and will aid the learning of oral and maxillofacial radiology trainees and practitioners.

  16. A pilot study of three dimensional color CT images of brain diseases to improve informed consent

    International Nuclear Information System (INIS)

    Tanizaki, Yoshio; Akiyama, Takenori; Hiraga, Kenji; Akaji, Kazunori

    2005-01-01

    We have described brain diseases to patients and their family using monochrome CT images. It is thought that patients have difficulties in giving their consent to our conventional explanation because their understanding of brain diseases is based on three dimensional and color images, however, standard CT images are two dimensional and gray scale images. We have been trying to use three dimensional color CT images to improve the typical patient's comprehension of brain diseases. We also try to simulate surgery using these images. Multi-slice CT accumulates precise isotropic voxel data within a half minute. These two dimensional and monochrome data are converted to three dimensional color CT images by 3D workstation. Three dimensional color CT images of each brain structures (e.g. scalp, skull, brain, ventricles and lesions) are created separately. Then, selected structures are fused together for different purposes. These images are able to rotate around any axis. Because the methods to generate three-dimensional color images have not established, we neurosurgeons must create these images. In particular, when an operation is required, the surgeon should create the images. In this paper, we demonstrate how three-dimensional color CT images can improve informed consent. (author)

  17. Clinical application of lower extremity CTA and lower extremity perfusion CT as a method of diagnostic for lower extremity atherosclerotic obliterans

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Il Bong; Dong, Kyung Rae [Dept. Radiological Technology, Gwangju Health University, Gwangju (Korea, Republic of); Goo, Eun Hoe [Dept. Radiological Science, Cheongju University, Cheongju (Korea, Republic of)

    2016-11-15

    The purpose of this study was to assess clinical application of lower extremity CTA and lower extremity perfusion CT as a method of diagnostic for lower extremity atherosclerotic obliterans. From January to July 2016, 30 patients (mean age, 68) were studied with lower extremity CTA and lower extremity perfusion CT. 128 channel multi-detector row CT scans were acquired with a CT scanner (SOMATOM Definition Flash, Siemens medical solution, Germany) of lower extremity perfusion CT and lower extremity CTA. Acquired images were reconstructed with 3D workstation (Leonardo, Siemens, Germany). Site of lower extremity arterial occlusive and stenosis lesions were detected superficial femoral artery 36.6%, popliteal artery 23.4%, external iliac artery 16.7%, common femoral artery 13.3%, peroneal artery 10%. The mean total DLP comparison of lower extremity perfusion CT and lower extremity CTA, 650 mGy-cm and 675 mGy-cm, respectively. Lower extremity perfusion CT and lower extremity CTA were realized that were never be two examination that were exactly the same legions. Future through the development of lower extremity perfusion CT soft ware programs suggest possible clinical applications.

  18. High-energy x-ray CT and its application for digital engineering

    International Nuclear Information System (INIS)

    Kamimura, H.; Sadaoka, N.

    2005-01-01

    A high-energy x-ray computed tomography system and x-ray CT data handling software have been developed for digital engineering; internal dimension measurement, density analysis, actual and designed shape comparison, STL file generation, and support for reverse engineering and rapid prototyping. The system is designed to collect accurate images in short scanning time (10 s per section) using a MeV-energy electron linear accelerator and highly sensitive semiconductor detectors in order to scan large objects made of aluminum and/or iron. An excellent environment in digital engineering is provided by the software products; 'StereoCooker' for 3D bitmap CAD (rendering, feature extraction, dimensional measurement, and shape comparison, etc.), 'FeatureMaker' for translating bitmap CT data to CAD data including feature information, and 'Wingware' for realizing an Windows PC cluster system 'WINGluster' to apply CT data analysis. (author)

  19. Development and application of an educational 3D X-ray CT instrument

    International Nuclear Information System (INIS)

    Arakawa, Etsuo; Iwami, Ryutaro; Motohisa, Yasuko; Kamezawa, Chika; Kamogawa, Masashi; Voegeli, Wolfgang

    2016-01-01

    A three-dimensional (3D) X-ray computed tomography (CT) instrument for radiation education was developed. The structure of the instrument is such that the main parts, i.e. the X-ray source, specimen rotation stage, and two-dimensional detector can be easily observed. An experiment using a fruit of green pepper as a specimen was performed. CT images and intermediate steps for obtaining them, i.e. radiographs, sinograms after Radon transform, and real and imaginary parts of Fourier components in reciprocal space during inverse Radon transform are shown. We propose that these images will help students to understand the principle and mechanism of X-ray CT instruments visually. (author)

  20. The clinical application of percutaneous auto-biopsy of small lung nodular under CT-Guided

    International Nuclear Information System (INIS)

    Zhou Yuanmin; Ye Genxin; Zhang Chenghui; Wang Yu; Chen Wei

    2008-01-01

    Objective: To evaluated the clinical value of technology of petcutaneous auto-biopsy of small lung nodular under CT- Guide. Methods: 44 cases of small single lung nodular were underwent biopsy with 20G auto-biopsy needle under CT guidance. All cases underwent pathological diagnosis. Results: All 44 cases were punctured successfully. 41 cases were succeeded in first puncturation. The success ratio was 93.02%. Other 3 cases needed second puncturation. 39 of 44 cases pathological diagnosis were malignant. Only 1 case could not be diagnosed. 6 patients had lightly pneumatothorax after biopsy. 10 cases had mild pneumonorrhagia after biopsy. 2 of them had haemptysis. All cases had no complication such as infection, needle track implantation. Conclusion: The technology of CT Guidance auto-biopsy of small lung nodular is safe and effective; it has extreme diagnostic ratio and less complication. (authors)

  1. DosedPet application for Nuclear Medicine: Calculation of the volume of medication needed for PET/CT patient; Aplicativo DosedPet para uso em Medicina Nuclear: calculo do volume de medicamento necessario para paciente de PET/CT

    Energy Technology Data Exchange (ETDEWEB)

    Nascimento, Pedro Augusto do; Rodrigues, Araken dos S. Werneck, E-mail: pedroan88@gmail.com [Universidade de Brasilia (UnB), DF (Brazil). Programa de Pos Graduacao em Ciencias e Tecnologias em Saude

    2016-07-01

    This paper presents the application (APP) DosePet that calculates the amount of medicament for PET / CT in patients according to the predetermined radiation dose. The software has been designed using the web MIT App Inventor2 tool for Android platform. The application allows the workers to simulate the amount of radiation still existing in the facilities after the applications, increasing security and reducing exposures, and enable greater efficiency in the use of the radiopharmaceutical. (author)

  2. Clinical application of PET/CT imaging in search of the primary carcinoma

    International Nuclear Information System (INIS)

    Dang Yaping; Liu Gang; Li Miao

    2004-01-01

    Full text: To explore the clinical value of PET/CT scanning in search of the primary carcinoma, we selected 4 patients who were subjected to PET/CT examination during Oct. 2002 to Dec. 2002. The primary lesion in all these patients was not detected. One of them had metastasis to liver, one had metastases in both lungs and the other two were having metastases to the bones. 18F-FDG in doses of 5.55MBq / kg body weight was injected to a fasting patient (at least 6 hours). PET/CT whole body examination was done using Discovery LS-PET/CT (GE Medical System, U.S.A.) 40-60 minutes later. In the first patient with metastasis to liver, primary lesion was localized in the transverse colon near the liver. The PET/CT showed multiple high radioactive uptake lesions of different sizes in the liver. No obvious change in position of the colon uptake was seen on the delayed images. After PET/CT, barium examination showed thinned cavity of the colon near the liver with coarse ankylosis of colon wall just like saw tooth. The mucous membrane was destroyed. Of the two patients with metastases in the bone, first - a 31 years old, was diagnosed to have primary lung cancer with multiple metastases to the liver and the bones. PET/CT showed high radioactive uptake in the inferior left lobe near the hilum with irregular shaped uneven distribution. A round high radioactive uptake area of 1.82 x 1.84 x 1.46cm size was also seen in the right lobe of the liver having clear edge and uneven distribution. The destroyed bones (L-10, L-11, L-12, T-1 and ala ossis i lii) showed high radioactive uptake. Second patient, 57-year male was diagnosed to have malignant lymphoma. PET/CT fusion showed high radioactive uptake in the marrow of whole body. Few destroyed parts of bones were also seen on CT images. Several cervical and the thoracic vertebrae as well as the ninth rib showed irregular radioactive accumulation with clear edges and well-distributed tracer raising the possibility of multiple myeloma or

  3. Optimization of radiation protection as a result of PET/CT applications

    International Nuclear Information System (INIS)

    Kop, Jos M.M.; Kemerink, Gerrit J.; Pakbiers, Marie Therese W.; Oellers, Michel C.

    2008-01-01

    The aim of the study was to quantify the dose received by nuclear medicine technologists and radiotherapeutic technologists as a result of PET/CT applications with 18 F-FDG as well as optimization of the procedures and working conditions. Thermo-luminescence dosimeters were used for the determination of the equivalent dose on the hands and for ambient dosimetry. Electronic personal dosimeters as well as the obligatory personal dosimeters provided information concerning the total body effective dose to the workers. The shielding of two shipping containers with different lead thickness for delivery of the FDG to the hospital as well as different dispenser designs for the preparation of the syringes and administration to the patient were evaluated..The effect of the use of a lead shield during supporting and positioning of the patient was also studied. All results were related to a single nuclear medicine technologist (NMT) performing 1000 patients/year, each patient receiving an activity of 370 MBq 18 F-FDG. Dispensing the 18 F-FDG into syringes, using a specifically designed shielded lead container, the so-called 'Koenders' system, resulted in a total equivalent dose on the fingers of 8.4 mSv for the MNT, while the use of the less extensively shielded syringe (the Docking station) resulted in an average finger dose of 71 mSv (p=0.000). Administration of the 18 F-FDG to the patient resulted in a finger dose of 4.6 mSv for the 'Koenders' system, 6.3 mSv in case of the use of a ready made syringe and 23 mSv (p=0.000) in case of the Docking station. The proper use of the mobile lead shield during administration to the patient and removal of the intravenous access from the patient resulted in a significant decrease of the effective dose. Combined with the use of the thicker walled delivery container and the 'Koenders' system, the total effective dose for the NMT was 2.7 mSv, nearly half of the dose before optimization. The positioning of patients for the radiotherapy

  4. Cardiac CT

    International Nuclear Information System (INIS)

    Dewey, Marc

    2011-01-01

    Computed tomography of the heart has become a highly accurate diagnostic modality that is attracting increasing attention. This extensively illustrated book aims to assist the reader in integrating cardiac CT into daily clinical practice, while also reviewing its current technical status and applications. Clear guidance is provided on the performance and interpretation of imaging using the latest technology, which offers greater coverage, better spatial resolution, and faster imaging. The specific features of scanners from all four main vendors, including those that have only recently become available, are presented. Among the wide range of applications and issues to be discussed are coronary artery bypass grafts, stents, plaques, and anomalies, cardiac valves, congenital and acquired heart disease, and radiation exposure. Upcoming clinical uses of cardiac CT, such as plaque imaging and functional assessment, are also explored. (orig.)

  5. Cardiac CT

    Energy Technology Data Exchange (ETDEWEB)

    Dewey, Marc [Charite - Universitaetsmedizin Berlin (Germany). Inst. fuer Radiologie

    2011-07-01

    Computed tomography of the heart has become a highly accurate diagnostic modality that is attracting increasing attention. This extensively illustrated book aims to assist the reader in integrating cardiac CT into daily clinical practice, while also reviewing its current technical status and applications. Clear guidance is provided on the performance and interpretation of imaging using the latest technology, which offers greater coverage, better spatial resolution, and faster imaging. The specific features of scanners from all four main vendors, including those that have only recently become available, are presented. Among the wide range of applications and issues to be discussed are coronary artery bypass grafts, stents, plaques, and anomalies, cardiac valves, congenital and acquired heart disease, and radiation exposure. Upcoming clinical uses of cardiac CT, such as plaque imaging and functional assessment, are also explored. (orig.)

  6. The application of PET and PET-CT in cervical cancer

    International Nuclear Information System (INIS)

    Huang Jianmin; Pan Liping; Li Dongxue

    2007-01-01

    Cervical cancer is the common malignancies in woman, 18 F-fluorodeoxyglucose ( 18 F-FDG) PET is a well-established method for detecting, staging, cancer recurrence, therapeutic response and prognosis of cervical cancer. PET-CT can accurately locate the anatomical sites of tracer uptake and improve the diagnostic accuraccy of PET. (authors)

  7. [Application of Low Dose Spiral CT in Diagnosing Impacted Teeth in Children and Adolescents].

    Science.gov (United States)

    Wang, Meng-tian; Li, Xue-sheng; Li, Kai-ming; Bao, Li; Ning, Gang

    2015-09-01

    [ABSTRACT] To determine the value of low dose spiral CT scanning in diagnosing impacted teeth of children and adolescents. A total of 153 children and adolescents with confirmed impacted teeth in West China Second University Hospital, Sichuan University were enrolled in this study. They were divided into 5 groups according to the different spiral CT scan parameters (tube current time product, scanning thickness and collimation value): Group A (n=30, 330 mAs, 6 X 0. 75 mm and 3. 0 mm), Group B (n=30, 140 mAs, 6 X 0. 75 mm and 3. 0 mm), Group C (n=30, 80 mAs, 6 X 0. 75 mm and 3. 0 mm), Group D (n=31, 80 mAs, 6 X 1. 50 mm and 5. 0 mm), and Group E (n=32, 50 mAs, 6 X 1. 50 mm and 5. 0 mm). There were no significant differences in general clinical features (P>0. 05) among the participants of the five groups. The phantoms were used to measure spatial resolution and contrast resolution of the scan images. Dose length product (DLP) was recorded during CT scanning for calculating effective dose (ED) of exposure. The quality of images was evaluated using a list of quality scoring criteria. (1) Under 330, 140, 80, 80 and 50 mAs, the images had a spatial resolution of 1.0 mm, with contrast resolution of 2. 0, 3. 0, 4. 5, 4. 5 and 6. 0 mm, respectively. (2) Significant differences in ED values were found among the five groups (F=1 064. 119, P=0. 000) and between every two of those groups (P0. 05). The diagnostic results of the spiral CT were consistent with those of orthodontic surgery. Low dose spiral CT scanning can meet the image quality requirements for diagnosing impacted teeth, minimizing radiation exposure effectively.

  8. FDG PET/CT in infection and inflammation—current and emerging clinical applications

    International Nuclear Information System (INIS)

    Vaidyanathan, S.; Patel, C.N.; Scarsbrook, A.F.; Chowdhury, F.U.

    2015-01-01

    Integrated positron emission tomography/computed tomography (PET/CT) with the glucose analogue, 2-[ 18 F]-fluoro-2-deoxy-D-glucose (FDG), is an evolving hybrid imaging technique in the evaluation of an important and diverse group of pathological conditions, which are characterised by infection and aseptic inflammation. With a rapidly expanding body of evidence, it is being increasingly recognised that, in addition to its established role in oncological imaging, FDG PET/CT also has clinical utility in suspected infection and inflammation. The technique can identify the source of infection or inflammation in a timely fashion ahead of morphological changes on conventional anatomical imaging techniques, such as computed tomography (CT) and magnetic resonance imaging (MRI), map the extent and severity of disease, identify sites for tissue sampling, and assess therapy response. FDG PET/CT exhibits distinct advantages over traditional radionuclide imaging techniques in terms of shorter duration of examination, higher spatial resolution, non-invasive nature of acquisition, ability to perform quantitative analyses, and the provision of a synergistic combination of functional and anatomical imaging. With the use of illustrative clinico-radiological cases, this article discusses the current and emerging evidence for the use of FDG PET/CT in a broad spectrum of disorders, such as fever of unknown origin, sarcoidosis, large vessel vasculitis, musculoskeletal infections, joint prosthesis or implant-related complications, human immunodeficiency virus (HIV)-related infections, and miscellaneous indications, such as IgG4-related systemic disease. It will also briefly summarise the role of more novel tracers such as FDG-labelled leukocytes and gallium-68 PET tracers in this arena

  9. Clinical application of the three-dimensional reconstruction of spiral CT pneumocolon

    International Nuclear Information System (INIS)

    Yu Shenping; Li Ziping; Xu Dasheng; Lin Erjian; Lin Peizhang; Xu Qiaolan

    2000-01-01

    Objective: To evaluate the clinical role of the 3 types of reconstruction of the spiral CT pneumocolon in the diagnosis of colon lesions. Methods: Three types of reconstruction with spiral CT pneumocolon including air cast imaging (ACI), CT virtual endoscopy (CTVE), and multiple planner reconstruction (MPR) in 34 patients with colorectal cancer or polyps were correlated with surgical pathology respectively. Results: Among the 34 patients, 30 was colorectal cancer and 6 was polyps (2 of which in the proximal lumen of 2 colon cancer). (1) Comparison between the 3 types of the spiral CT pneumocolon reconstruction and pathology in colorectal cancer. 1) ACI: tumor patterns: coincide (n =22), anti-coincide (n = 8); tumor extension: coincide (n = 24), anti-coincide (n = 6); tumor size: coincide (n = 28), anti-coincide (n = 2). 2) CTVE: tumor patterns: coincide (n = 26), anti-coincide (n = 4); tumor extension: coincide (n = 25), anti-coincide ( n 5); tumor size: coincide (n = 23), anti-coincide (n = 7). 3) MPR: tumor patterns: coincide (n = 24), anti-coincide (n = 6); tumor extension: coincide (n = 30), anti-coincide (n = 0); tumor size: coincide (n = 26), anti-coincide (n = 4). (2) Comparison between the 3 types of the spiral CT pneumocolon reconstruction and pathology in colorectal polyps: the lesions were displayed in 4 (ACI) and in 6 (CTVE and MPR). Conclusion: (1) For the diagnosis of colorectal cancers: CTVE was the best means to display the tumor patterns, MPR most correct to judge the tumor extension, and ACI most suitable to measure the tumor size. (2) For the diagnosis of colorectal polyps, ACI can be used for oriented diagnosis, CTVE can well display the intra-luminal three-dimensional structure and can be used for characteristic diagnosis, MPR can be used for differential diagnosis

  10. The effect of inspiration on airway dimensions measured in CT images from the Danish Lung Cancer Screening Trial

    DEFF Research Database (Denmark)

    Petersen, Jens; Wille, Mathilde; Thomsen, Laura

    2013-01-01

    of the same subject using image registration. Mixed effect models were used to predict the relative change in lumen diameter (LD) and wall thickness (WT) in airways of generation 0 (trachea) to 6 based on relative changes in the segmented total lung volume (TLV). Results: On average, 1.0, 2.0, 3.9, 7.6, 15...... and Materials: We selected from the Danish Lung Cancer Screening Trial 978 subjects without COPD who were scanned annually for 5 years with low-dose multi-slice CT. Using in-house developed software, the lungs and airways were automatically segmented and corresponding airway branches were found in all scans......Purpose: Airway dimensions measured from CT are increasingly being used to investigate diseases such as chronic obstructive pulmonary disease (COPD). In this study, we investigate the effect of differences in inspiration level on such measurements in voluntary inspiration breathhold scans. Methods...

  11. The application of 18F-FDG PET/CT for exploring the metastatic carcinoma of spleen

    International Nuclear Information System (INIS)

    Yu Dangfan; Guan Yihui; Zhao Jun; Zuo Chuantao; Lin Xiangtong; Dai Jiazhong

    2005-01-01

    Objective: To investigate the value of 18 F-fluorodeoxyglucose PET/CT for diagnosing the metastatic carcinoma of spleen. Methods: Retrospectively reviewed all the 8 cases with splenic metastases diagnosed by PET/CT, and compared the diagnostic result of PET/CT with that of CT alone, that of PET alone, that of B-ultrasonic scan and that of clinical information, all the diagnoses were refered to the confirmation by the clinical findings during follow-up. Results: All the 8 cases of splenic metastases diagnosed by PET/CT were proved by follow-up. PET revealed 6, CT revealed 4 and B-ultrasonic scan only 1. PET/CT did not miss either of the 2 splenic metastases had been diagnosed before PET/CT. Conclusions: PET/CT determined the location of the splenic metastases better than CT alone or PET alone did. PET/CT could increase the detection rate of splenic metastases. (authors)

  12. Intracavitary application of contrast medium in the follow-up of complicated tube-drained pleural empyema: Conventional radiography vs CT

    International Nuclear Information System (INIS)

    Duex, M.; Bischoff, H.; Schmaehl, A.; Tuengerthal, S.

    1997-01-01

    Purpose: To define the value of conventional radiography compared with CT in the follow-up of complicated, long-term tube drained pleural empyema after intracavitary application of contrast medium. Methods: 28 patients with complicated pleural empyema (stage III) and longterm tube drainage were submitted to fluoroscopy of the pleural cavity and a CT of the thorax after contrast medium had been instilled into the pleural space. Both examinations were judged by the following criteria: Number and morphology of pleural cavities, quality of drainage and accompanying thoracic disease. Results: 49 pleural cavities were diagnosed. Judgement of drainage corresponded in 79% of cases and differed 21% with proof of further not drained cavities only on CT. 4 bronchopleural fistulas were diagnosed by fluoroscopy, of which only 2 were evident on CT. Accompanying thoracic disease was reliably detected by CT only. Conclusions: Diagnosis of bronchopleural fistulas and judgement of the pleural drainage is best possible using fluoroscopy after application of contrast medium into the pleural space. CT is most accurate to detect further cavities that have not been drained, to look for concomitant thoracic disease, and to judge the morphology of the pleural cavity. Conventional radiography of the pleural space is effective and recommended to be used as a first line investigation for the follow-up of stage III empyemas. Patients in poor general condition (fever, elevated blood markers indicating inflammation) should be examined by both fluoroscopy and CT. (orig.) [de

  13. PET/CT image registration: Preliminary tests for its application to clinical dosimetry in radiotherapy

    International Nuclear Information System (INIS)

    Banos-Capilla, M. C.; Garcia, M. A.; Bea, J.; Pla, C.; Larrea, L.; Lopez, E.

    2007-01-01

    The quality of dosimetry in radiotherapy treatment requires the accurate delimitation of the gross tumor volume. This can be achieved by complementing the anatomical detail provided by CT images through fusion with other imaging modalities that provide additional metabolic and physiological information. Therefore, use of multiple imaging modalities for radiotherapy treatment planning requires an accurate image registration method. This work describes tests carried out on a Discovery LS positron emission/computed tomography (PET/CT) system by General Electric Medical Systems (GEMS), for its later use to obtain images to delimit the target in radiotherapy treatment. Several phantoms have been used to verify image correlation, in combination with fiducial markers, which were used as a system of external landmarks. We analyzed the geometrical accuracy of two different fusion methods with the images obtained with these phantoms. We first studied the fusion method used by the PET/CT system by GEMS (hardware fusion) on the basis that there is satisfactory coincidence between the reconstruction centers in CT and PET systems; and secondly the fiducial fusion, a registration method, by means of least-squares fitting algorithm of a landmark points system. The study concluded with the verification of the centroid position of some phantom components in both imaging modalities. Centroids were estimated through a calculation similar to center-of-mass, weighted by the value of the CT number and the uptake intensity in PET. The mean deviations found for the hardware fusion method were: vertical bar Δx vertical bar ±σ=3.3 mm±1.0 mm and vertical bar Δy vertical bar ±σ=3.6 mm±1.0 mm. These values were substantially improved upon applying fiducial fusion based on external landmark points: vertical bar Δx vertical bar ±σ=0.7 mm±0.8 mm and vertical bar Δy vertical bar ±σ=0.3 mm±1.7 mm. We also noted that differences found for each of the fusion methods were similar for

  14. Hemodynamic study on liver cirrhosis: clinical application of CT perfusion imaging

    International Nuclear Information System (INIS)

    Jiang Li; Yang Jianyong; Xie Hongbo; Yang Xufeng; Yan Chaogui; Li Ziping; Zeng Fang

    2004-01-01

    Objective: To estimate hepatic perfusion parameters with helical CT, and to study the relationship between hepatic perfusion parameters and the severity of liver cirrhosis. Methods: Dynamic single-section computed tomography (CT) of the liver was performed in 40 participants, including 27 patients with liver cirrhosis and 13 patients without liver disease (control subjects). CT scans were obtained at a single level to include the liver, spleen, aorta, and portal vein. On each CT scan, the attenuation of these organs was measured in regions of interest to provide time-density curves. The arterial, portal venous, and total perfusion of the liver and the hepatic perfusion index were assessed. Results: In the control group, hepatic arterial perfusion, portal venous perfusion, and total hepatic perfusion were (0.2823 ± 0.0969) ml·min -1 ·ml -1 , (1.1788 ± 0.4004) ml·min -1 ·ml -1 , and (1.4563 ± 0.4439) ml·min -1 ·ml -1 , respectively. Hepatic perfusion index was (19.73 ±5.81)%. These hepatic perfusion parameters correlated significantly with the severity of liver cirrhosis. Hepatic arterial perfusion decreased in Child A and B cirrhotic patients [ (0.1685 ± 0.1068) ml·min -1 ·ml -1 and (0.1921 ± 0.0986) ml·min -1 ·ml -1 , respectively]. Comparing to Child A and B cirrhotic patients, hepatic arterial perfusion in Child C cirrhotic patients [(0.3072 · 0.1145) ml·min -1 ·ml -1 ] raised significantly. Portal venous perfusion decreased significantly in Child B and C cirrhotic patients [(0.6331±0.2070) ml·min -1 ·ml -1 and (0.5702 ± 0.3562) ml·min -1 ·ml -1 , respectively]. Total hepatic blood flow reduced markedly in Child B and C cirrhotic patients [(0.8252 ± 0.2952) ml·min -1 ·ml -1 and (0.8774 ± 0.4118) ml·min -1 ·ml -1 , respectively]. Hepatic perfusion index increased in Child C cirrhotic patients (37.48 ± 16.65)%. Conclusion: Dynamic single-section CT showed potential in quantifying hepatic perfusion parameters, and hepatic perfusion

  15. Application of NMR-CT for the staging of cancer of the digestive organs

    International Nuclear Information System (INIS)

    Ariga, Takamitsu; Ryu, Munemasa; Koh, Jewan

    1986-01-01

    To assess the potential of NMR-CT for demonstrating cancer of the digestive organs, we examined a total of 232 patients (89 with esophageal cancer, 52 with liver cancer, 40 with colorectal cancer, 9 with pancreatic cancer, 9 with gastric cancer, and 33 with other diseases). Our machine is a Picker International NMR-CT using a superconducting magnet of 0.256 tesla. 1. Diagnosis of lymph node involvement of esophageal cancer. Using only the coronal plane, each patient was scanned by the spin echo technique (TE = 40, TR = 400) from the plane of the descending aorta to the plane of the trachea 1 cm in thickness, at 1 cm intervals, continuously. Lymph nodes were identified as intense grey masses in fat tissue of high intensity. Twenty cases were proved by surgery or autopsy, and it was possible to assess 160 lymph-node groups. A total of 25 patients were imaged as having positive lymph nodes, but 17 of them had metastasis-positive nodes. In other 135 nodes imaged as negative lymph nodes, only two had metastasis and 133 were negative for metastasis. Overall accuracy was 93.8 %. 2. Diagnosis of liver cancer. Intrahepatic vessels were clearly imaged without using contrast enhancement in NMR-CT, so it was easy to diagnose the segment containing the tumor and to detect tumor emboli in the portal vein. The capsule was imaged in 84 % (16/19) using IR techniques, although only 37 % (7/19) could be imaged by X-CT. 3. Diagnosis of colorectal cancer. Using the sagittal plane, the sacrum, urinary bladder and other organs were imaged better parallel to their axis, so that the relationship between rectal cancer and surrounding organs could be clearly visualised with NMR-CT. With regard to lymphatic metastasis, coronal imaging was useful for picturing mesenteric and pelvic vessels, so that lymph nodes were imaged as low-intensity masses along the vessels. Lymph metastasis almost 1 cm size can be detected using coronal NMR-CT. (J.P.N.)

  16. Remarkable case of uncorrected type IC tricuspid atresia with adaptive pulmonary trunk dilatation to allow prolonged survival: Case report and CT fly-through

    Directory of Open Access Journals (Sweden)

    Zeke J. McKinney

    2017-06-01

    Full Text Available A remarkable case of a surgically uncorrected Type IC (no great artery transposition, no pulmonary stenosis tricuspid atresia surviving to adulthood is presented. This is a case of an adult female of 30 years of age with an atretic tricuspid valve, an atrial septal defect, a large ventricular septal defect, and a dilated pulmonary trunk. Surgical correction was never conducted on this heart with a significant congenital cardiac defect, and yet the individual survived into a fourth decade. Without surgical correction, survival to adulthood in tricuspid atresia is exceedingly rare. Survival depends on a high degree of ventricular shunting with limited pulmonary outflow obstruction. The resistance of this obstruction must be both low enough to maintain increased pulmonary blood flow and high enough to prevent systemic-level pressures upon the pulmonary vasculature. The unique finding of a significantly dilated pulmonary trunk is described, which presumably allowed this individual to survive to adulthood. This complex physiology is described and augmented with high-resolution images of this cardiac specimen. These were made possible by the application of a plastination process prior to obtaining high-resolution multi-slice computed tomography imaging studies. The result is a study comprised of multiplanar and three-dimensional data detailing the anatomic features of the specimen, which were then used to create reconstructions of the specimen for visualization of the anatomy. An understanding of the development and morphology of tricuspid atresia is essential for successful surgical correction in new patients with this congenital malformation. Keywords: Tricuspid atresia, Pulmonary blood flow, Pulmonary hypertension, Plastination, CT

  17. PET-CT: current applications and new developments in the thorax.

    Science.gov (United States)

    Erasmus, Jeremy J; Mawlawi, Osama; Howard, Brandon; Patz, Edward F

    2014-02-01

    Positron emission tomography computed tomography(PET-CT) imaging has emerged as an essential clinical diagnostic tool in the evaluation of thoracic abnormalities. Currently, its primary role is for tumor imaging; it helps to differentiate benign from malignant nodules, stage tumors, determine response, and follow patients after therapy is complete. It has also been used for nononcologic diseases, but the indications are less well defined. PET is a fundamental component of the molecular imaging initiative, and as new more specific imaging probes and better instrumentation are developed, PET-CT is certain to improve diagnostic accuracy and become even more integrated into the imaging armamentarium. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  18. Application- and patient size-dependent optimization of x-ray spectra for CT

    International Nuclear Information System (INIS)

    Kalender, Willi A.; Deak, Paul; Kellermeier, Markus; Straten, Marcel van; Vollmar, Sabrina V.

    2009-01-01

    Although x-ray computed tomography (CT) has been in clinical use for over 3 decades, spectral optimization has not been a topic of great concern; high voltages around 120 kV have been in use since the beginning of CT. It is the purpose of this study to analyze, in a rigorous manner, the energies at which the patient dose necessary to provide a given contrast-to-noise ratio (CNR) for various diagnostic tasks can be minimized. The authors used cylindrical water phantoms and quasianthropomorphic phantoms of the thorax and the abdomen with inserts of 13 mm diameter mimicking soft tissue, bone, and iodine for simulations and measurements. To provide clearly defined contrasts, these inserts were made of solid water with a 1% difference in density (DD) to represent an energy-independent soft-tissue contrast of 10 Hounsfield units (HU), calcium hydroxyapatite (Ca) representing bone, and iodine (I) representing the typical contrast medium. To evaluate CT of the thorax, an adult thorax phantom (300x200 mm 2 ) plus extension rings up to a size of 460x300 mm 2 to mimic different patient cross sections were used. For CT of the abdomen, we used a phantom of 360x200 mm 2 and an extension ring of 460x300 mm 2 . The CT scanner that the authors used was a SOMATOM Definition (Siemens Healthcare, Forchheim, Germany) at 80, 100, 120, and 140 kV. Further voltage settings of 60, 75, 90, and 105 kV were available in an experimental mode. The authors determined contrast for the density difference, calcium, and iodine, and noise and 3D dose distributions for the available voltages by measurements. Additional voltage values and monoenergetic sources were evaluated by simulations. The dose-weighted contrast-to-noise ratio (CNRD) was used as the parameter for optimization. Simulations and measurements were in good agreement with respect to absolute values and trends regarding the dependence on energy for the parameters investigated. For soft-tissue imaging, the standard settings of 120-140 k

  19. Clinical application of CT-guided percutaneous puncturing biopsy of subcarinal lymph node

    International Nuclear Information System (INIS)

    Yuan Xiaodong; Wang Jianhua; Zuo Changjing; Tian Jianming

    2011-01-01

    Objective: To discuss the safety and clinical significance of CT-guided percutaneous puncturing biopsy of subcarinal lymph node. Methods: During the period of July 2006-July 2010, CT-guided percutaneous puncturing biopsy of subcarinal lymph node was carried out in 17 patients (11 males and 6 females, with an average age of 54 years) with enlarged subcarinal lymph nodes. The clinical data were retrospectively analyzed. Immediately after the puncturing procedure was completed, CT scanning was performed to observe if there any complications and to evaluate the safety of puncturing biopsy. Biopsy specimens were sent for pathological examination to assess the puncturing accuracy and to make the pathologic diagnosis. The clinical usefulness of this technique was evaluated. Results: Of the total 17 cases, successful puncturing into the enlarged subcarinal lymph nodes with single procedure was achieved in 14 and sufficient tissue sample was obtained. The biopsy failed in three cases at initial puncturing procedure as the needle could not be placed into the enlarged subcarinal lymph nodes, the puncturing biopsy had to given up in two patients because of hemoptysis and in another patient the second puncturing biopsy performed one week later was successful. The total technical successful rate was 88.2% (15/17). Of the fifteen cases with successful puncturing, definitive pathological diagnosis was obtained in 13 and the diagnosis was uncertain in the remaining two, with a diagnosis positive rate of 86.7% (13/15). Pathologically, the diagnoses included metastatic lymphadenopathy from lung cancer (n=10), proliferative inflammatory lymphadenopathy (n=2) and tuberculous enlargement of lymph nodes (n=1). Complications occurred in 4 patients (23.5%, 4/17), which mainly were pneumothorax and pulmonary hemorrhage. Conclusion: With high successful rate and diagnostic accuracy, CT-guided percutaneous puncturing biopsy of subcarinal lymph node is a safe and effective technique if the

  20. Clinical application of CT-guided radiofrequency ablation for the treatment of metastatic bone neoplasms

    International Nuclear Information System (INIS)

    Gong Ju; Lu Zhijun; Wang Zhongmin; Zhang Liyun; Zheng Yunfeng; Chen Kemin

    2009-01-01

    Objective: To investigate the clinical efficacy of CT-guided radiofrequency ablation (RFA) for the treatment of metastatic bone neoplasms. Methods: Under intravenous aneaesthesia, CT- guided RFA was performed in 20 patients with metastatic bone tumor. The degree of pain was evaluated at 24 hours, 3 and 6 months after the operation by brief pain inventory (BPI). Results: All patients were followed up for 6 months and survived so far. The average peak pain score before the operation was 8.1 (6-10), which decreased significantly to 6.1, 4.6, 3.3 and 3.0 at 24 hours, 1, 3 and 6 months after the operation respectively (P<0.001). The mean pain score before the operation was 6.3, which decreased significantly to 4.0, 2.3, 2.13 and 1.9 at 24 hours, 1, 3 and 6 months after the operation respectively (P<0.001). After RFA treatment, the KPS scores of all patients increased while the CT values of the bone lesions decreased. No major complications occurred both during and after the operation. One patient with vertebral lamina destruction suffered from lower limb hypoesthesia after RFA procedure, and the lower limb sensation was restored within 48 hours after the injection of prednisone was employed. Conclusion: CT-guided radiofisequency ablation is a safe, effective, minimally-invasive and up-to-date technique for the treatment of metastatic bone neoplasms with excellent anti-pain effect, its short-term response is sure and reliable. (authors)

  1. Framing U-Net via Deep Convolutional Framelets: Application to Sparse-View CT.

    Science.gov (United States)

    Han, Yoseob; Ye, Jong Chul

    2018-06-01

    X-ray computed tomography (CT) using sparse projection views is a recent approach to reduce the radiation dose. However, due to the insufficient projection views, an analytic reconstruction approach using the filtered back projection (FBP) produces severe streaking artifacts. Recently, deep learning approaches using large receptive field neural networks such as U-Net have demonstrated impressive performance for sparse-view CT reconstruction. However, theoretical justification is still lacking. Inspired by the recent theory of deep convolutional framelets, the main goal of this paper is, therefore, to reveal the limitation of U-Net and propose new multi-resolution deep learning schemes. In particular, we show that the alternative U-Net variants such as dual frame and tight frame U-Nets satisfy the so-called frame condition which makes them better for effective recovery of high frequency edges in sparse-view CT. Using extensive experiments with real patient data set, we demonstrate that the new network architectures provide better reconstruction performance.

  2. Application of high resolution synchrotron micro-CT radiation in dental implant osseointegration.

    Science.gov (United States)

    Neldam, Camilla Albeck; Lauridsen, Torsten; Rack, Alexander; Lefolii, Tore Tranberg; Jørgensen, Niklas Rye; Feidenhans'l, Robert; Pinholt, Else Marie

    2015-06-01

    The purpose of this study was to describe a refined method using high-resolution synchrotron radiation microtomography (SRmicro-CT) to evaluate osseointegration and peri-implant bone volume fraction after titanium dental implant insertion. SRmicro-CT is considered gold standard evaluating bone microarchitecture. Its high resolution, high contrast, and excellent high signal-to-noise-ratio all contribute to the highest spatial resolutions achievable today. Using SRmicro-CT at a voxel size of 5 μm in an experimental goat mandible model, the peri-implant bone volume fraction was found to quickly increase to 50% as the radial distance from the implant surface increased, and levelled out to approximately 80% at a distance of 400 μm. This method has been successful in depicting the bone and cavities in three dimensions thereby enabling us to give a more precise answer to the fraction of the bone-to-implant contact compared to previous methods. Copyright © 2015 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  3. MicroCT Scan in paleobiology: application to the study of dental tissues

    Energy Technology Data Exchange (ETDEWEB)

    Rossi, M.; Casali, F. E-mail: casali@bo.infn.it; Romani, D.; Bondioli, L.; Macchiarelli, R.; Rook, L

    2004-01-01

    State of the art in paleoanthropological and paleoprimatological research foresees the use of advanced non-destructive investigative approaches. Microcomputed tomography (microCT) is a fundamental tool, since it offers the opportunity to get high quality morphological information with high spatial resolution. We carried out the set-up of an experimental microCT system able to examine paleobiological samples. The equipment can operate on small objects (size up to 3 cm) with a nominal spatial resolution of 30 {mu}m, allowing their 3D volume reconstruction and morphometric analysis. This approach represents a forefront technique in paleobiological studies, successfully employed only in a limited number of advanced research centers. A specific program of microCT analysis has been planned on a sample of human and non-human fossil primate dentitions, in order to assess the specific nature of a number of tooth lesions (e.g. caries versus abrasion). This currently in progress experimental activity represents the first step for the set-up of a research center specifically devoted to the realization of advanced studies in the field of archaeo-paleobiology.

  4. HDRMC, an accelerated Monte Carlo dose calculator for high dose rate brachytherapy with CT-compatible applicators

    Energy Technology Data Exchange (ETDEWEB)

    Chibani, Omar, E-mail: omar.chibani@fccc.edu; C-M Ma, Charlie [Fox Chase Cancer Center, Philadelphia, Pennsylvania 19111 (United States)

    2014-05-15

    Purpose: To present a new accelerated Monte Carlo code for CT-based dose calculations in high dose rate (HDR) brachytherapy. The new code (HDRMC) accounts for both tissue and nontissue heterogeneities (applicator and contrast medium). Methods: HDRMC uses a fast ray-tracing technique and detailed physics algorithms to transport photons through a 3D mesh of voxels representing the patient anatomy with applicator and contrast medium included. A precalculated phase space file for the{sup 192}Ir source is used as source term. HDRM is calibrated to calculated absolute dose for real plans. A postprocessing technique is used to include the exact density and composition of nontissue heterogeneities in the 3D phantom. Dwell positions and angular orientations of the source are reconstructed using data from the treatment planning system (TPS). Structure contours are also imported from the TPS to recalculate dose-volume histograms. Results: HDRMC was first benchmarked against the MCNP5 code for a single source in homogenous water and for a loaded gynecologic applicator in water. The accuracy of the voxel-based applicator model used in HDRMC was also verified by comparing 3D dose distributions and dose-volume parameters obtained using 1-mm{sup 3} versus 2-mm{sup 3} phantom resolutions. HDRMC can calculate the 3D dose distribution for a typical HDR cervix case with 2-mm resolution in 5 min on a single CPU. Examples of heterogeneity effects for two clinical cases (cervix and esophagus) were demonstrated using HDRMC. The neglect of tissue heterogeneity for the esophageal case leads to the overestimate of CTV D90, CTV D100, and spinal cord maximum dose by 3.2%, 3.9%, and 3.6%, respectively. Conclusions: A fast Monte Carlo code for CT-based dose calculations which does not require a prebuilt applicator model is developed for those HDR brachytherapy treatments that use CT-compatible applicators. Tissue and nontissue heterogeneities should be taken into account in modern HDR

  5. Incidence of dehiscence of the bony roof of the superior semicircular canal by CT imaging

    International Nuclear Information System (INIS)

    Watanabe, Akira

    2003-01-01

    Dehiscence of the bony roof of the superior semicircular canal (SSCC) is rare, but it has been recognized by otologists since Minor et al first described superior canal dehiscence syndrome (SCDS). In this study, dehiscence of the bony roof of SSCC was incidentally detected in three patients with benign paroxysmal positional vertigo out of 49 serial patients with vertigo and dizziness by multi-slice computed tomography. Although detection of dehiscence of the SSCC by ultra-high-resolution CT imaging of the temporal bones has been required for a diagnosis of SCDS, this study showed that dehiscence of the bony roof of the SSCC can be an incidental finding and therefore is not specific for SCDS. (author)

  6. Comparison between traditional laboratory tests, permeability measurements and CT-based fluid flow modelling for cultural heritage applications

    Energy Technology Data Exchange (ETDEWEB)

    De Boever, Wesley, E-mail: Wesley.deboever@ugent.be [UGCT/PProGRess, Dept. of Geology, Ghent University, Krijgslaan 281, 9000 Ghent (Belgium); Bultreys, Tom; Derluyn, Hannelore [UGCT/PProGRess, Dept. of Geology, Ghent University, Krijgslaan 281, 9000 Ghent (Belgium); Van Hoorebeke, Luc [UGCT/Radiation Physics, Dept. of Physics & Astronomy, Ghent University, Proeftuinstraat 86, 9000 Ghent (Belgium); Cnudde, Veerle [UGCT/PProGRess, Dept. of Geology, Ghent University, Krijgslaan 281, 9000 Ghent (Belgium)

    2016-06-01

    In this paper, we examine the possibility to use on-site permeability measurements for cultural heritage applications as an alternative for traditional laboratory tests such as determination of the capillary absorption coefficient. These on-site measurements, performed with a portable air permeameter, were correlated with the pore network properties of eight sandstones and one granular limestone that are discussed in this paper. The network properties of the 9 materials tested in this study were obtained from micro-computed tomography (μCT) and compared to measurements and calculations of permeability and the capillary absorption rate of the stones under investigation, in order to find the correlation between pore network characteristics and fluid management characteristics of these sandstones. Results show a good correlation between capillary absorption, permeability and network properties, opening the possibility of using on-site permeability measurements as a standard method in cultural heritage applications. - Highlights: • Measurements of capillary absorption are compared to in-situ permeability. • We obtain pore size distribution and connectivity by using micro-CT. • These properties explain correlation between permeability and capillarity. • Correlation between both methods is good to excellent. • Permeability measurements could be a good alternative to capillarity measurement.

  7. High throughput static and dynamic small animal imaging using clinical PET/CT: potential preclinical applications

    International Nuclear Information System (INIS)

    Aide, Nicolas; Desmonts, Cedric; Agostini, Denis; Bardet, Stephane; Bouvard, Gerard; Beauregard, Jean-Mathieu; Roselt, Peter; Neels, Oliver; Beyer, Thomas; Kinross, Kathryn; Hicks, Rodney J.

    2010-01-01

    The objective of the study was to evaluate state-of-the-art clinical PET/CT technology in performing static and dynamic imaging of several mice simultaneously. A mouse-sized phantom was imaged mimicking simultaneous imaging of three mice with computation of recovery coefficients (RCs) and spillover ratios (SORs). Fifteen mice harbouring abdominal or subcutaneous tumours were imaged on clinical PET/CT with point spread function (PSF) reconstruction after injection of [18F]fluorodeoxyglucose or [18F]fluorothymidine. Three of these mice were imaged alone and simultaneously at radial positions -5, 0 and 5 cm. The remaining 12 tumour-bearing mice were imaged in groups of 3 to establish the quantitative accuracy of PET data using ex vivo gamma counting as the reference. Finally, a dynamic scan was performed in three mice simultaneously after the injection of 68 Ga-ethylenediaminetetraacetic acid (EDTA). For typical lesion sizes of 7-8 mm phantom experiments indicated RCs of 0.42 and 0.76 for ordered subsets expectation maximization (OSEM) and PSF reconstruction, respectively. For PSF reconstruction, SOR air and SOR water were 5.3 and 7.5%, respectively. A strong correlation (r 2 = 0.97, p 2 = 0.98; slope = 0.89, p 2 = 0.96; slope = 0.62, p 68 Ga-EDTA dynamic acquisition. New generation clinical PET/CT can be used for simultaneous imaging of multiple small animals in experiments requiring high throughput and where a dedicated small animal PET system is not available. (orig.)

  8. Combined X-ray CT and mass spectrometry for biomedical imaging applications

    Science.gov (United States)

    Schioppa, E., Jr.; Ellis, S.; Bruinen, A. L.; Visser, J.; Heeren, R. M. A.; Uher, J.; Koffeman, E.

    2014-04-01

    Imaging technologies play a key role in many branches of science, especially in biology and medicine. They provide an invaluable insight into both internal structure and processes within a broad range of samples. There are many techniques that allow one to obtain images of an object. Different techniques are based on the analysis of a particular sample property by means of a dedicated imaging system, and as such, each imaging modality provides the researcher with different information. The use of multimodal imaging (imaging with several different techniques) can provide additional and complementary information that is not possible when employing a single imaging technique alone. In this study, we present for the first time a multi-modal imaging technique where X-ray computerized tomography (CT) is combined with mass spectrometry imaging (MSI). While X-ray CT provides 3-dimensional information regarding the internal structure of the sample based on X-ray absorption coefficients, MSI of thin sections acquired from the same sample allows the spatial distribution of many elements/molecules, each distinguished by its unique mass-to-charge ratio (m/z), to be determined within a single measurement and with a spatial resolution as low as 1 μm or even less. The aim of the work is to demonstrate how molecular information from MSI can be spatially correlated with 3D structural information acquired from X-ray CT. In these experiments, frozen samples are imaged in an X-ray CT setup using Medipix based detectors equipped with a CO2 cooled sample holder. Single projections are pre-processed before tomographic reconstruction using a signal-to-thickness calibration. In the second step, the object is sliced into thin sections (circa 20 μm) that are then imaged using both matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) and secondary ion (SIMS) mass spectrometry, where the spatial distribution of specific molecules within the sample is determined. The

  9. Application of low-dose radiation protocols in survey CT scans

    International Nuclear Information System (INIS)

    Fu Qiang; Liu Ting; Lu Tao; Xu Ke; Zhang Lin

    2009-01-01

    Objective: To characterize the protocols with low-dose radiation in survey CT scans for localization. Methods: Eighty standard adult patients, head and body phantoms were recruited. Default protocols provided by operator's manual setting were that all the tube voltage for head, chest, abdomen and lumbar was 120 kV; the tube currents were 20,10,20 and 40 mA, respectively. Values of kV and mA in the low-dose experiments were optimized according to the device options. For chest and abdomen, the tube position were compared between default (0 degree) and 180 degree. Phantoms were scanned with above protocols, and the radiation doses were measured respectively. Paired t-test were used for comparisons of standard deviation in CT value, noise and exposure surface dose (ESD) between group with default protocols and group with optimized protocols. Results: The optimized protocols in low-dose CT survey scans were 80 kV, 10 mA for head, 80 kV, 10 mA for chest, 80 kV, 10 mA for abdomen and 100 kV, 10 mA for lumbar. The values of ESD for phantom scan in default and optimized protocols were 0.38 mGy/0.16 mGy in head, 0.30 mGy/0.20 mGy in chest, 0.74 mGy/0.30 mGy in abdomen and 0.81 mGy/0.44 mGy in lumbar, respectively. Compared with default protocols, the optimized protocols reduced the radiation doses 59%, 33%, 59% and 46% in head, chest, abdomen and lumbar. When tube position changed from 0 degree to 180 degree, the ESD were 0.24 mGy/0.20 mGy for chest; 0.37 mGy/0.30 mGy for abdomen, and the radiation doses were reduced 20% and 17%. Conclusion: A certain amount of image noise is increased in low-dose protocols, but image quality is still acceptable without problem in CT localization. The reduction of radiation dose and the radiation harm to patients are the superiority. (authors)

  10. Clinical application of low-dose CT in patients with rib fractures

    International Nuclear Information System (INIS)

    Ge Xiaojun; Wu Hao; Hua Yanqing; Wang Mingpeng; Mao Dingbiao; Tang Ping; Hu Fei; Zhang Guozhen

    2011-01-01

    Objective: To evaluate images quality and diagnostic feasibility of low-dose CT in patients with traumatic rib fractures. Methods: Twenty-five patients presented with thoracic injury were underwent 64-slice spiral CT scanning in inspiration breath-hold technique. Two scan protocols were performed. In one scan protocol noise index (NI) is 11, and in another NI is 21, but the other scan parameters were no difference. The mean value of tube current, the volume CT dose index (CTDI vol ), and effective dose (ED) were recorded. Image quality was scored by 2 experienced radiologists using the 5-points scale. The numbers and degrees of rib fractures were recorded. The data were tested by using the Wilcoxon signed rank sum test. The differences of the inter-observer were determined by Kappa statistics. Results: The mean CTDIvol and ED in scan protocol with NI of 11 were (13.88±5.17) mGy and (8.14± 3.21) mSv, and that with NI of 21 were (3.91±1.57) mGy and (2.31±0.97) mSv. Compared the scan with NI of 11, there was 72% intrinsic dose reduction in the scan with NI of 21. The mean value of tube current in scan with NI of 11 and 21 were (195.88±69.33) mAs and (54.56±21.54) mAs. All patients with Ⅱ and Ⅲ degree and most patients with Ⅰ degree rib fractures that identified by the scan with NI of 11 were detected by the scan with NI of 21. There were no statistical difference between two scans with the Wilcoxon, signed rank sum test. The diagnostic acceptability and image noise score in the scan with NI of 11 were 4.9±0.2 and 4.6±0.5, and that with NI = 21 were 3.5±0.5 and 3.3±0.5. There was prefect concordance in the inter-observers in diagnostic, acceptability on finding of rib fractures, diagnostic acceptability and image noise (Kappa =0.876, 0.820, 0.792, P<0.01) between two scan protocols. Conclusion: Rib fractures can be diagnosed by the low-dose CT using the scan protocol with NI of 21. (authors)

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

    International Nuclear Information System (INIS)

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

    2012-01-01

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

  12. SU-E-I-93: Improved Imaging Quality for Multislice Helical CT Via Sparsity Regularized Iterative Image Reconstruction Method Based On Tensor Framelet

    International Nuclear Information System (INIS)

    Nam, H; Guo, M; Lee, K; Li, R; Xing, L; Gao, H

    2014-01-01

    Purpose: Inspired by compressive sensing, sparsity regularized iterative reconstruction method has been extensively studied. However, its utility pertinent to multislice helical 4D CT for radiotherapy with respect to imaging quality, dose, and time has not been thoroughly addressed. As the beginning of such an investigation, this work carries out the initial comparison of reconstructed imaging quality between sparsity regularized iterative method and analytic method through static phantom studies using a state-of-art 128-channel multi-slice Siemens helical CT scanner. Methods: In our iterative method, tensor framelet (TF) is chosen as the regularization method for its superior performance from total variation regularization in terms of reduced piecewise-constant artifacts and improved imaging quality that has been demonstrated in our prior work. On the other hand, X-ray transforms and its adjoints are computed on-the-fly through GPU implementation using our previous developed fast parallel algorithms with O(1) complexity per computing thread. For comparison, both FDK (approximate analytic method) and Katsevich algorithm (exact analytic method) are used for multislice helical CT image reconstruction. Results: The phantom experimental data with different imaging doses were acquired using a state-of-art 128-channel multi-slice Siemens helical CT scanner. The reconstructed image quality was compared between TF-based iterative method, FDK and Katsevich algorithm with the quantitative analysis for characterizing signal-to-noise ratio, image contrast, and spatial resolution of high-contrast and low-contrast objects. Conclusion: The experimental results suggest that our tensor framelet regularized iterative reconstruction algorithm improves the helical CT imaging quality from FDK and Katsevich algorithm for static experimental phantom studies that have been performed

  13. Clinical application of three-dimensional spiral CT cerebral angiography with volume rendering

    International Nuclear Information System (INIS)

    Duan Shaoyin; Huang Xi'en; Kang Jianghe; Zhang Dantong; Lin Qingchi; Cai Guoxiang; Xu Meixin; Pang Ruilin

    2002-01-01

    Objective: To study the methodology and assess the clinical value of three-dimensional CT angiography (3D-CTA) with volume rendering (VR) in cerebral vessels. Methods: Sixty-two patients were examined by means of 3D-CTA with volume rendering. VR was used in the reconstruction of 3D images, and the demonstration of normal vessels and vascular lesions were particularly analyzed. At the same time, comparisons were made between the images of VR and SSD, MIP, and also between the diagnosis of VR-CTA and DSA or postoperative results. Results: In VR images, cerebral vessel routes and vessel cavities were showed clearly, while the relationship among vascular lesions, surrounding vessels, and neighboring structure was distinguished. 50 cases (80.6%) were found positive, 48 of which were correct and 2 were false-positive compared with DSA or postoperative results. The accurate rate of diagnosis was 96.0%. There was no obvious difference in showing the cerebral vessel among the images of VR, SSD and MIP (P > 0.25). Conclusion: Three-dimensional CT cerebral angiography with VR is a new noninvasive effective method. It can even partly replace the DSA. The 3D-images have the characteristics of showing the cerebral vascular cavity and overlapped vessels without cutting the skull

  14. CT and MRI assessment and characterization using segmentation and 3D modeling techniques: applications to muscle, bone and brain

    Directory of Open Access Journals (Sweden)

    Paolo Gargiulo

    2014-03-01

    Full Text Available This paper reviews the novel use of CT and MRI data and image processing tools to segment and reconstruct tissue images in 3D to determine characteristics of muscle, bone and brain.This to study and simulate the structural changes occurring in healthy and pathological conditions as well as in response to clinical treatments. Here we report the application of this methodology to evaluate and quantify: 1. progression of atrophy in human muscle subsequent to permanent lower motor neuron (LMN denervation, 2. muscle recovery as induced by functional electrical stimulation (FES, 3. bone quality in patients undergoing total hip replacement and 4. to model the electrical activity of the brain. Study 1: CT data and segmentation techniques were used to quantify changes in muscle density and composition by associating the Hounsfield unit values of muscle, adipose and fibrous connective tissue with different colors. This method was employed to monitor patients who have permanent muscle LMN denervation in the lower extremities under two different conditions: permanent LMN denervated not electrically stimulated and stimulated. Study 2: CT data and segmentation techniques were employed, however, in this work we assessed bone and muscle conditions in the pre-operative CT scans of patients scheduled to undergo total hip replacement. In this work, the overall anatomical structure, the bone mineral density (BMD and compactness of quadriceps muscles and proximal femoral was computed to provide a more complete view for surgeons when deciding which implant technology to use. Further, a Finite element analysis provided a map of the strains around the proximal femur socket when solicited by typical stresses caused by an implant press fitting. Study 3 describes a method to model the electrical behavior of human brain using segmented MR images. The aim of the work is to use these models to predict the electrical activity of the human brain under normal and pathological

  15. SU-E-I-60: The Correct Selection of Pitch and Rotation Time for Optimal CT Scanning : The Big Misconception

    International Nuclear Information System (INIS)

    Ranallo, F; Szczykutowicz, T

    2014-01-01

    Purpose: To provide correct guidance in the proper selection of pitch and rotation time for optimal CT imaging with multi-slice scanners. Methods: There exists a widespread misconception concerning the role of pitch in patient dose with modern multi-slice scanners, particularly with the use of mA modulation techniques. We investigated the relationship of pitch and rotation time to image quality, dose, and scan duration, with CT scanners from different manufacturers in a way that clarifies this misconception. This source of this misconception may concern the role of pitch in single slice CT scanners. Results: We found that the image noise and dose are generally independent of the selected effective mAs (mA*time/ pitch) with manual mA technique settings and are generally independent of the selected pitch and /or rotation time with automatic mA modulation techniques. However we did find that on certain scanners the use of a pitch just above 0.5 provided images of equal image noise at a lower dose compared to the use of a pitch just below 1.0. Conclusion: The misconception that the use of a lower pitch over-irradiates patients by wasting dose is clearly false. The use of a lower pitch provides images of equal or better image quality at the same patient dose, whether using manual mA or automatic mA modulation techniques. By decreasing the pitch and the rotation times by equal amounts, both helical and patient motion artifacts can be reduced without affecting the exam time. The use of lower helical pitch also allows better scanning of larger patients by allowing a greater scan effective mAs, if the exam time can be extended. The one caution with the use of low pitch is not related to patient dose, but to the length of the scan time if the rotation time is not set short enough. Partial Research funding from GE HealthCare

  16. Clinical application of stable xenon CT-CBF studies without denitrogenation

    Energy Technology Data Exchange (ETDEWEB)

    Touho, Hajime; Karasawa, Jun; Shishido, Hisashi; Yamada, Keisuke [Osaka Neurological Institute, Toyonaka (Japan)

    1990-08-01

    Noninvasive and simplified methods for estimating regional cerebral blood flow (CBF) and regional partition coefficient ({lambda}) using the inhalation of stable xenon (Xe{sup s}) and computed tomographic (CT) scanning are described. Thirty percent Xe{sup s} in 70% oxygen was inhaled for 240 seconds and exhaled for 160 seconds during serial CT scanning without denitrogenation in 26 patients with cerebrovascular diseases and four volunteer controls. During the investigation, the end-tidal Xe{sup s} concentration was continuously monitored with a thermoconductivity analyzer to determine the build-up range (A value) and build-up rate constant (K value) of the artery by the curve fitting method. Calculated A and K values were corrected by the following formulae reported previously: for patients aged 0-20 years, A{sub e} = 0.75A{sub a} + 2.15, K{sub e} = 0.67K{sub a} + 0.69; 21-40 years, A{sub e} = 0.56A{sub a} + 3.24, K{sub e} = 0.38K{sub a} + 1.12; 41-60 years, A{sub e} = 0.91A{sub a} + 1.95, K{sub e} = 0.38K{sub a} + 1.32; over 61 years, A{sub e} = 0.52A{sub a} + 3.81, K{sub e} = 0.31K{sub a} + 1.55 (A{sub e} and K{sub e} were calculated with end-tidal Xe{sup s} concentration, A{sub a} and K{sub a} were calculated by direct sampling of arterial blood). A CBF map (f map) and {lambda} map made with corrected A and K values demonstrated reliable distribution. The CBF was high in the gray matter, low in the white matter, and much lower in the infarcted area. {lambda} was high in the white matter, low in the gray matter, and much lower in the infarcted area. Eight patients were examined with and without denitrogenation. Both the f map and {lambda} map with denitrogenation were compatible with those without denitrogenation. Xe{sup s} CT-CBF studies without denitrogenation are useful in clinical neurosurgery and outpatients for estimating regional cerebral circulation. (author).

  17. Clinical application of multislice CT enterography with hypertonic mannitol saline as oral contrast

    International Nuclear Information System (INIS)

    Yan Guixin; Wang Haitao; Chen Wenjing; Liu Wenya

    2011-01-01

    Objective: To assess the feasibility and value of multislice CT enterography (MSCTE) with large dose economy and convenience orally administered hypertonic mannitol salt water (2.5% mannitol and 1.5% NaCl salt water) as negative contrast in demonstrating normal and abnormal small bowel. Methods: 81 patients suffered from digestive disease and suspected of various kinds of small intestinal diseases were examined (male/female=47/34, 26-81 years old, average 57.8 years). About 1500 ml∼3000 ml hypertonic mannitol saline was oral administered within 90 minutes and 20 mg of raceanisodamine hydrochloride injection was injected intramuscularly. CT scanning was performed 20 minutes later. Imaging data were post processed with coronal, sagittal and oblique reconstruction, multiplanar reformation (MPR), maximum intensity projection (MIP), and volumer rendering technique (VRT). The filling degree of stomach, intestine and colon was classified as satisfactory, better and unsatisfactory. The length and superposition of small intestine was classified as dense-type, uniformity-type and straggling-type. The maximum outer diameters of duodenum, jejunum, and ileum were measured respectively in different segments. The degree of bowel wall enhancement in arterial phase and venous phase was classified as obvious enhancement (>90 HU), medium enhancement (60-90 HU) and mild enhancement (<60 HU). CT features of various kinds of small bowel diseases were analyzed. Results: The hypertonic mannitol saline was acceptable by patients, except 5 patients with diarrhea. The filling degree of stomach, intestine and and colon was classified as satisfactory in 46 cases, better in 23 cases and unsatisfactory in 12 cases. The maximum outer diameters of small bowel in different segments were 24 mm ± 4.5 mm at duodenum, 24 mm ±3.9 mm at jejunum and 23 mm ±3.3 mm at ileum respectively. The length and superposition of small intestine were classified as dense-type in 7 cases, uniformity-type in 58

  18. Presentation of the DosePet application (APP) for use in Nuclear Medicine: calculation of the amount of medicament for PET / CT patients

    International Nuclear Information System (INIS)

    Nascimento, Pedro Augusto do; Rodrigues, Araken dos S. Werneck

    2016-01-01

    This paper presents the application (APP) DosePet that calculates the amount of medicament for PET / CT in patients according to the predetermined radiation dose. The software has been designed using the web MIT App Inventor2 tool for Android platform. The application allows the workers to simulate the amount of radiation still existing in the premises after the applications, increasing security and reducing exposures, and enable greater efficiency in the use of the radiopharmaceutical. (author)

  19. Application of electronic endoscopy and CT-guided stereotactic aspiration to intracerebral hematoma

    International Nuclear Information System (INIS)

    Kusaka, Masahiko

    1991-01-01

    According to the development of computer technology and operative instruments, stereotactic neurosurgery became more precise, and extended as its indication. CT-guided stereotactic aspiration of intracerebral hematoma is superior operative procedure with rare complications. Using Stereotactic Aqua-Stream and Aspirator at the same time, hematoma was removed sufficiently. However, stereotactic neurosurgery had a major weak points, it was a blind operation. An endoscope (FVS-1000, M and M Co.) and SASA (Marui Medical Co.) were applied in 5 cases of intracerebral hematoma. In physiological saline, the endoscope had 32.9 deg angle of visual field, 1 mm - 25 mm depth of vision, and 16 pair/mm resolution. It was excellent ability for neurosurgery. Using for clinical cases, the bloody fluid in the hematoma cavity disturbed visibility. It was a difficult problem. Influence of bloody fluid concentration to depth of vision and resolution was investigated, and method of making clear visibility was described. (author)

  20. CT perfusion: the clinical application in the diagnosis of breast diseases

    International Nuclear Information System (INIS)

    Ye Zhaoxiang; Song Xiuyu; Xiao Jianyu

    2005-01-01

    Objective: To assess the CT perfusion characteristics of breast diseases. Methods: Twenty-two patients with fibroadenoma accompanied with cyst (n=1), other benign diseases (n=5), and carcinomas (n=16) underwent breast CT scan. CT perfusion was performed for breast with cine mode (0.5 s per rotation ) on a multislice CT scanner, 120 kV, 60 mA, 4 x 5 mm collimation. Contrast injection was done by using 50 ml nonionic contrast agent (300 mg I/ml ), at a flow rate of 4 ml/s with a power injector, 5 seconds delay, and data acquisition lasted for 50 seconds. These data were processed on a GE AW 4.1 workstation using perfusion 3 software package, and the mean BF, BV, MTT and PS were measured and statistically analyzed. Results: The mean BF, BV, MTT and PS in carcinoma were (33.55 ± 28.40) ml·min -1 ·100 g -1 , (5.60±3.08) ml/100 g, (15.37±6.41) s, (18.71±10.42) ml· min -1 ·100 g -1 . The mean BF, BV, MTT and PS in contralateral normal breast of carcinoma were (10.36 ± 9.44) ml·min -1 ·100 g -1 , (0.70±0.22) ml/100 g, (13.55 ± 7.27) s, (1.54±1.74) ml·min -1 ·100 g -1 . The mean BF, BV, and PS between carcinoma and normal breast were statistically significant (P 0.05). The mean BF, BV, MTT and PS in fibroadenoma were (62.57 ± 19.62) ml·min -1 ·100 g -1 , (7.37 ±1.30) ml/100 g, (11.24 ± 3.34) s, (27.63 ± 3.87) ml·min -1 ·100 g -1 . The mean PS between carcinoma and fibroadenoma was statistically significant (P 0.05). The mean BF, BV, MTT and PS in benign lesion were (7.65 ± 10.24) ml·min -1 ·100 g -1 , (1.23 ± 0.97) ml/100 g, (14.94 ± 10.68) s, (1.81 ± 1.72) ml·min -1 ·100 g -1 . The mean BF, BV, and PS between carcinoma and benign lesion were statistically significant (P 0.05). Conclusion: MSCT perfusion may reflect the features of breast diseases, and provide valuable hemodynamic message. These parameters have a value in diagnosis of breast diseases and are helpful for differential diagnosis. (authors)

  1. Coronary CT angiography

    Energy Technology Data Exchange (ETDEWEB)

    Dewey, Marc [Charite - Universitaetsmedizin Berlin (Germany). Inst. fuer Radiologie

    2009-07-01

    Coronary CT angiography has attained increasing scientific attention at academic institutions and has become a highly accurate diagnostic modality. Extending this knowledge into a practice setting is the purpose of 'Coronary CT Angiography'. This book will assist you in integrating cardiac CT into your daily practice, while also giving an overview of the current technical status and applications. The specific features of scanners from all four main vendors are also presented providing an objective overview of noninvasive coronary angiography using CT. (orig.)

  2. Deep learning for biomarker regression: application to osteoporosis and emphysema on chest CT scans

    Science.gov (United States)

    González, Germán.; Washko, George R.; San José Estépar, Raúl

    2018-03-01

    Introduction: Biomarker computation using deep-learning often relies on a two-step process, where the deep learning algorithm segments the region of interest and then the biomarker is measured. We propose an alternative paradigm, where the biomarker is estimated directly using a regression network. We showcase this image-tobiomarker paradigm using two biomarkers: the estimation of bone mineral density (BMD) and the estimation of lung percentage of emphysema from CT scans. Materials and methods: We use a large database of 9,925 CT scans to train, validate and test the network for which reference standard BMD and percentage emphysema have been already computed. First, the 3D dataset is reduced to a set of canonical 2D slices where the organ of interest is visible (either spine for BMD or lungs for emphysema). This data reduction is performed using an automatic object detector. Second, The regression neural network is composed of three convolutional layers, followed by a fully connected and an output layer. The network is optimized using a momentum optimizer with an exponential decay rate, using the root mean squared error as cost function. Results: The Pearson correlation coefficients obtained against the reference standards are r = 0.940 (p < 0.00001) and r = 0.976 (p < 0.00001) for BMD and percentage emphysema respectively. Conclusions: The deep-learning regression architecture can learn biomarkers from images directly, without indicating the structures of interest. This approach simplifies the development of biomarker extraction algorithms. The proposed data reduction based on object detectors conveys enough information to compute the biomarkers of interest.

  3. Micro-CT and FE-SEM enamel analyses of calcium-based agent application after bleaching.

    Science.gov (United States)

    Gomes, Mauricio Neves; Rodrigues, Flávia Pires; Silikas, Nick; Francci, Carlos Eduardo

    2018-03-01

    The objective of the present study is to evaluate the effects of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) on bleached enamel. A bleaching agent (35% hydrogen peroxide) was applied, 4 × 8 min on premolar teeth (n = 8). A CPP-ACP paste was applied for 7 days. Prior and post-treatment, microtomography images were obtained and 3D regions of interest (ROIs) were selected, from outer enamel, extending to 110.2-μm depth. CT parameters of structure: thickness (St.Th), separation (St.Sp), and fragmentation index (Fr.I.) were calculated for each (ROI). Data was submitted to paired t tests at a 95% confidence level. The samples were evaluated at 3000 to 100,000 magnification. Quantitative analysis of enamel mineral content was also determined by SEM EDX. There was a significant increase in structure thickness and calcium content. The phosphorus content increased after bleaching. There was also a decreased separation and fragmentation index on the outer enamel to a depth of 56.2 μm (p spaces between the hydroxyapatite crystals appeared around the enamel prisms, 7 days after the CPP-ACP application. The application of a CPP-ACP provides a compact structure on the enamel's outer surface, for 7 days, due to calcium deposition. CT parameters seem to be a useful tool for mineralizing and remineralizing future studies. CPP-ACP neutralizes any adverse effects on enamel surface when applied during a week after bleaching and minimizes any side effects of the bleaching treatment due to a more compact structure.

  4. Possibilities of the new hybrid technology single photon emission computer technology/computer tomography (SPECT/CT) and the first impressions of its application

    International Nuclear Information System (INIS)

    Kostadinova, I.

    2010-01-01

    With the help of the new hybrid technique SPECT/ CT it is possible, using the only investigation, to acquire a combine image of the investigated organ, visualizing its function and structure. Combining the possibilities of the new multimodality method, which combines the possibilities of the Single Photon Emission Computer Tomography - SPECT and Computer Tomography - CT, it is possible to precisely localize the pathologically changed organs function. With the further combination of the tomographic gamma camera with diagnostic CT, a detailed morphological evaluation of the finding was possible. The main clinical application of the new hybrid diagnostic is in the fields of cardiology, oncology, orthopedics with more and more extension of those, not connected with oncology, such as - thyroid, parathyroid, brain (especially localization of the epileptic foci), visualization of local infection and recently for the purposes of the radiotherapy planning. According to the literature data, around 35% of SPECT-investigations have to be combined with CT in order to increase the specificity of the diagnosis, which changes the interpretation of the result in 56% of the cases. After installation of the SPECT/CT camera in the University hospital 'Alexandrovska' in January 2009, the following changes have been done: the number of the investigated patients have increased, including number of heart, thyroid (especially scintigraphy with 131I), bones and parathyroid glands. As a result of the application of the hybrid technique, a shortage of the investigated time was realized and a decrease prize in comparison with the individual application of the investigations. Summarizing the literature data and the preliminary impression of the first multimodality scanner in our country in the University hospital 'Alexandrovska' it could be said, that there is continuously increasing information for the new clinical applications of SPECT/CT. It is now accepted, that its usage will increase in

  5. Dual energy CT intracranial angiography: image quality, radiation dose and initial application results

    International Nuclear Information System (INIS)

    Chai Xue; Zhang Longjiang; Lu Guangming; Zhou Changsheng

    2009-01-01

    Objective: To assess the clinical value of dual-energy intracranial CT angiography (CTA). Methods: Forty-one patients suspected of intracranial vascular diseases underwent dual-energy intracranial CT angiography, and 41 patients who underwent conventional subtraction CT were enrolled as the control group. Image quality of intracranial and skull base vessels and radiation dose between dual-energy CTA and conventional subtraction CTA were compared using two independent sample nonparametric test and independent-samples t test, respectively. Prevalence and size of lesions detected by dual-energy CTA and digital subtraction CTA were compared using paired-samples t test and Spearman correlative analysis. Results: The percentage of image quality scored 5 was 70.7% (29/41) for dual-energy CTA and 75.6% (31/41) for conventional subtraction CTA. There was no significant difference between the two groups (Z= -0.455, P=0.650). Image quality of vessels at the skull base in conventional subtraction CTA was superior to that in dual-energy CTA, especially for the petrosal and syphon segment (Z=-4.087, P=0.000). Radiation exposure of dual energy CTA and conventional CTA were (396.54±17.43) and (1090.95±114.29) mGy·cm respectively. Radiation exposure was decreased by 64% (t=-38.52, P=0.000) by dual energy CTA compared with conventional subtraction CTA. Out of the 41 patients, 19 patients were diagnosed as intracranial aneurysm, 2 patients as arteriovenous malformation (AVM), 3 patients with Moya-moya's disease, and the remaining 17 patients with negative results. Nine patients with intracranial aneurysm, 2 patients with AVM, 3 patients with Moya-moya's disease, and 2 patients with negative findings underwent DSA or operation, with concordant findings from both techniques. Diameter of aneurysm neck, long axis and minor axis by dual-energy CTA was (2.90±1.61), (5.23±1.68) and (3.83±1.69) mm, respectively; Diameter of aneurysm neck, long axis and minor axis by DSA was (2.95±1

  6. Semantic similarity-based alignment between clinical archetypes and SNOMED CT: an application to observations.

    Science.gov (United States)

    Meizoso García, María; Iglesias Allones, José Luis; Martínez Hernández, Diego; Taboada Iglesias, María Jesús

    2012-08-01

    One of the main challenges of eHealth is semantic interoperability of health systems. But, this will only be possible if the capture, representation and access of patient data is standardized. Clinical data models, such as OpenEHR Archetypes, define data structures that are agreed by experts to ensure the accuracy of health information. In addition, they provide an option to normalize clinical data by means of binding terms used in the model definition to standard medical vocabularies. Nevertheless, the effort needed to establish the association between archetype terms and standard terminology concepts is considerable. Therefore, the purpose of this study is to provide an automated approach to bind OpenEHR archetypes terms to the external terminology SNOMED CT, with the capability to do it at a semantic level. This research uses lexical techniques and external terminological tools in combination with context-based techniques, which use information about structural and semantic proximity to identify similarities between terms and so, to find alignments between them. The proposed approach exploits both the structural context of archetypes and the terminology context, in which concepts are logically defined through the relationships (hierarchical and definitional) to other concepts. A set of 25 OBSERVATION archetypes with 477 bound terms was used to test the method. Of these, 342 terms (74.6%) were linked with 96.1% precision, 71.7% recall and 1.23 SNOMED CT concepts on average for each mapping. It has been detected that about one third of the archetype clinical information is grouped logically. Context-based techniques take advantage of this to increase the recall and to validate a 30.4% of the bindings produced by lexical techniques. This research shows that it is possible to automatically map archetype terms to a standard terminology with a high precision and recall, with the help of appropriate contextual and semantic information of both models. Moreover, the

  7. Impact of electrocardiogram-gated multi-slice computed tomography-based aortic annular measurement in the evaluation of paravalvular leakage following transcatheter aortic valve replacement: the efficacy of the OverSized AortiC Annular ratio (OSACA ratio) in TAVR.

    Science.gov (United States)

    Maeda, Koichi; Kuratani, Toru; Torikai, Kei; Shimamura, Kazuo; Mizote, Isamu; Ichibori, Yasuhiro; Takeda, Yasuharu; Daimon, Takashi; Nakatani, Satoshi; Nanto, Shinsuke; Sawa, Yoshiki

    2013-07-01

    Even mild paravalvular leakage (PVL) after transcatheter aortic valve replacement (TAVR) is associated with increased late mortality. Electrocardiogram-gated multi-slice computed tomography (MSCT) enables detailed aortic annulus assessment. We describe the impact of MSCT for PVL following TAVR. Congruence between the prosthesis and annulus diameters affects PVL; therefore, we calculated the OverSized AortiC Annular ratio (OSACA ratio) and OSACA (transesophageal echocardiography, TEE) ratio as prosthesis diameter/annulus diameter on MSCT or TEE, respectively, and compared their relationship with PVL ≤ trace following TAVR. Of 36 consecutive patients undergoing TAVR (Group A), the occurrence of PVL ≤ trace (33.3%) was significantly related to the OSACA ratio (p = 0.00020). In receiver-operating characteristics analysis, the cutoff value of 1.03 for the OSACA ratio had the highest sum of sensitivity (75.0%) and specificity (91.7%; AUC = 0.87) with significantly higher discriminatory performance for PVL as compared to the OSACA (TEE) ratio (AUC = 0.69, p = 0.028). In nine consecutive patients (Group B) undergoing TAVR based on guidelines formulated from our experience with Group A, PVL ≤ trace was significantly more frequent (88.9%) than that in Group A (p = 0.0060). The OSACA ratio has a significantly higher discriminatory performance for PVL ≤ trace than the OSACA (TEE) ratio, and aortic annular measurement from MSCT is more accurate than that from TEE. © 2013 Wiley Periodicals, Inc.

  8. CT ESP for Yme, Converting the Yme field offshore Norway from a conventional rig-operated field to CT-operated for workover and drilling applications

    Energy Technology Data Exchange (ETDEWEB)

    Baklid, A.; Apeland, O. J.; Teigen, A. S. [Statoil (Norway)

    1998-12-31

    Conventional tubing deployed electrical submersible pump (ESP) was the original choice as the artificial lift method for the Yme field offshore Norway. Several operational problems experienced over the past two years, such as formation damage, complicated and costly workovers and limited access to the reservoir, combined with revised field requirements and a reevaluation of artificial lift methods resulted in a change in completion philosophy. Following these reassessments coiled tubing ESPs utilizing internal power cable were installed and became the preferred method. This paper provides an assessment of the value of installing CT-ESP in a live well, and describes the system design for a true underbalanced CT-ESP installation. Well control and barrier philosophy during installation, production and workover mode is also evaluated. 2 refs., 3 tabs., 5 figs.

  9. The postprocessing techniques in renal artery reconstructions and clinical application with multidetector spiral CT angiography

    International Nuclear Information System (INIS)

    Yu Yuanxin; Liang Changhong; Zhang Zhonglin; Xie Shufei; Liu Yubao; Tang Xiangzhou

    2005-01-01

    Objective: To investigate the value and predominance for imaging postprocessing techniques of renal artery variation and lesions by multidetector spiral CT angiography. Methods: 51 patients with renal artery disease including 12 artery variation, 27 artery stenosis, 3 renal anenrysm, 3 thrombosis of renal artery and 3 dissecting aneurysm of renal artery by SSD, MIP and CPR were enrolled. The effectiveness of these imaging postprocessing methods was compared, 29 of them were confirmed by DSA and 3 by operation, others were checked by MRA and follow up. Results: All abnormalities and diseases were cleariy displayed. The specificity and sensitivity were 100% respectively. In the all imaging postprocessing techniques, MPR can clearly display the calcification of the arteries, stenosis, embolism, aneurysm but do not display the anatomy satisfactorily. MIP can not only clearly display the anatomy but display the different configurations. VR can display the artery figures but can not display the information of lumen of blood vessels. SSD can display the complex vessel anatomy but it was influenced by its threshold selection. CPR can spread and display directly the tortuous renal artery and measure the section area of stenosis. Conclusions: MSCTA is helpful to accurately display the renal artery variation and lesions. Both MIP and VR are the best choice to illustrate the renal artery abnormalities. And MPR and SSD are assistant in the diagnosis of' renal artery lesions. (authors)

  10. Clinical application of 3D reconstruction of tracheobronchial tree with electron beam CT

    International Nuclear Information System (INIS)

    Yao Zhenwei; Shen Tianzhen

    2002-01-01

    Objective: To explore the clinical promise of CT 3D reconstruction of tracheobronchial tree (TBT) by analyzing 73 cases retrospectively. Methods: All the 73 cases were collected from October 1997 to February 2000, who were scanned by EBCT with 130 kV and 630 mA. The scanning method was continuous volume scan, the slice thickness were 3 mm or 1.5 mm. All cross-sectional images were transmitted to the INSIGHT workstation and reconstructed with SSD (shaded surface display), and the threshold setting were -500 to -300 HU. Results: 3D reconstruction of TBT with EBCT could reveal the abnormal changes of TBT by many kinds of diseases including central cancer, inflammation, bronchiectasis, saber-sheath trachea, trachea cancer, congenital disorders, post-surgical changes of lung cancer, and stenoses by adjacent benign or malignant diseases. It could be used to locate the stenoses and measure stenotic extent. Of the 35 central cancer cases with 3D reconstruction, 6 cases were pestle obstructed, 15 cases cone obstructed, 5 cases interrupted irregularly, 8 cases with eccentric stenoses, and 1 case with right stem destroyed and right upper lobe bronchus obstructed. Conclusion: 3D reconstruction of TBT has characteristic sign in the diagnosis or differential diagnosis of central airway's benign or malignant stenoses, and it is of instructional value in clinical use

  11. Balloon pulmonary angioplasty: applicability of C-Arm CT for procedure guidance

    Energy Technology Data Exchange (ETDEWEB)

    Hinrichs, Jan B. [Department for Diagnostic and Interventional Radiology, Member of the German Center for Lung Research (DZL), Hannover Medical School, Hannover (Germany); Institute for Diagnostic and Interventional Radiology, Hannover Medical School, Hannover (Germany); Renne, Julius; Wacker, Frank K.; Meyer, Bernhard C. [Department for Diagnostic and Interventional Radiology, Member of the German Center for Lung Research (DZL), Hannover Medical School, Hannover (Germany); Hoeper, Marius M.; Olsson, Karen M. [Clinic for Pneumology, Member of the German Center for Lung Research (DZL), Hannover Medical School, Hannover (Germany)

    2016-11-15

    To investigate the feasibility of and compare two C-Arm CT (CACT) guidance methods during balloon pulmonary angioplasty (BPA). Forty-two BPAs [27 CTEPH patients (nine males, 70 ± 14y)] targeting 143 pulmonary arteries were included. Twenty-two BPAs were guided by contrast-enhanced CACT acquired immediately before BPA (G3D). In another 20 BPAs (G2D), two orthogonal fluoroscopy images of the chest where acquired to compute a registration of a previously acquired CACT. Volume rendering-based graphic representations (VRT guidance) were generated indicating the origin and course of the vessels. Based on VRT guidance, the intervention was planned. Procedure durations and radiation exposure data were compared between the two groups (Wilcoxon test). The overall intervention time was approximately 2 h in both groups (p = 0.31). BPA was successfully performed in G3D 91 % and G2D 94 %. No significant difference was found concerning the mean dose area product (DAP) related to fluoroscopy (p = 0.38), while DAP related to DSA was slightly higher in G3D (p = 0.048). Overall, DAP was significantly higher in G3D (p = 0.002). The use of CACT for procedure guidance in patients undergoing BPA is feasible and accurate. Image fusion of a pre-acquired CACT can be used to decrease radiation exposure due to multiple BPA sessions. (orig.)

  12. Inter-observer agreement for abdominal CT in unselected patients with acute abdominal pain

    International Nuclear Information System (INIS)

    Randen, Adrienne van; Lameris, Wytze; Nio, C.Y.; Spijkerboer, Anje M.; Meier, Mark A.; Tutein Nolthenius, Charlotte; Smithuis, Frank; Stoker, Jaap; Bossuyt, Patrick M.; Boermeester, Marja A.

    2009-01-01

    The level of inter-observer agreement of abdominal computed tomography (CT) in unselected patients presenting with acute abdominal pain at the Emergency Department (ED) was evaluated. Two hundred consecutive patients with acute abdominal pain were prospectively included. Multi-slice CT was performed in all patients with intravenous contrast medium only. Three radiologists independently read all CT examinations. They recorded specific radiological features and a final diagnosis on a case record form. We calculated the proportion of agreement and kappa values, for overall, urgent and frequently occurring diagnoses. The mean age of the evaluated patients was 46 years (range 19-94), of which 54% were women. Overall agreement on diagnoses was good, with a median kappa of 0.66. Kappa values for specific urgent diagnoses were excellent, with median kappa values of 0.84, 0.90 and 0.81, for appendicitis, diverticulitis and bowel obstruction, respectively. Abdominal CT has good inter-observer agreement in unselected patients with acute abdominal pain at the ED, with excellent agreement for specific urgent diagnoses as diverticulitis and appendicitis. (orig.)

  13. Inter-observer agreement for abdominal CT in unselected patients with acute abdominal pain

    Energy Technology Data Exchange (ETDEWEB)

    Randen, Adrienne van [University of Amsterdam, Department of Radiology, Academic Medical Center, Amsterdam (Netherlands); University of Amsterdam, Department of Surgery, Academic Medical Center, Amsterdam (Netherlands); Academic Medical Center, Amsterdam (Netherlands); Lameris, Wytze [University of Amsterdam, Department of Radiology, Academic Medical Center, Amsterdam (Netherlands); University of Amsterdam, Department of Surgery, Academic Medical Center, Amsterdam (Netherlands); Nio, C.Y.; Spijkerboer, Anje M.; Meier, Mark A.; Tutein Nolthenius, Charlotte; Smithuis, Frank; Stoker, Jaap [University of Amsterdam, Department of Radiology, Academic Medical Center, Amsterdam (Netherlands); Bossuyt, Patrick M. [University of Amsterdam, Department of Clinical Epidemiology, Biostatistics, and Bioinformatics, Academic Medical Center, Amsterdam (Netherlands); Boermeester, Marja A. [University of Amsterdam, Department of Surgery, Academic Medical Center, Amsterdam (Netherlands)

    2009-06-15

    The level of inter-observer agreement of abdominal computed tomography (CT) in unselected patients presenting with acute abdominal pain at the Emergency Department (ED) was evaluated. Two hundred consecutive patients with acute abdominal pain were prospectively included. Multi-slice CT was performed in all patients with intravenous contrast medium only. Three radiologists independently read all CT examinations. They recorded specific radiological features and a final diagnosis on a case record form. We calculated the proportion of agreement and kappa values, for overall, urgent and frequently occurring diagnoses. The mean age of the evaluated patients was 46 years (range 19-94), of which 54% were women. Overall agreement on diagnoses was good, with a median kappa of 0.66. Kappa values for specific urgent diagnoses were excellent, with median kappa values of 0.84, 0.90 and 0.81, for appendicitis, diverticulitis and bowel obstruction, respectively. Abdominal CT has good inter-observer agreement in unselected patients with acute abdominal pain at the ED, with excellent agreement for specific urgent diagnoses as diverticulitis and appendicitis. (orig.)

  14. Analytical equations for CT dose profiles derived using a scatter kernel of Monte Carlo parentage with broad applicability to CT dosimetry problems

    International Nuclear Information System (INIS)

    Dixon, Robert L.; Boone, John M.

    2011-01-01

    Purpose: Knowledge of the complete axial dose profile f(z), including its long scatter tails, provides the most complete (and flexible) description of the accumulated dose in CT scanning. The CTDI paradigm (including CTDI vol ) requires shift-invariance along z (identical dose profiles spaced at equal intervals), and is therefore inapplicable to many of the new and complex shift-variant scan protocols, e.g., high dose perfusion studies using variable (or zero) pitch. In this work, a convolution-based beam model developed by Dixon et al.[Med. Phys. 32, 3712-3728, (2005)] updated with a scatter LSF kernel (or DSF) derived from a Monte Carlo simulation by Boone [Med. Phys. 36, 4547-4554 (2009)] is used to create an analytical equation for the axial dose profile f(z) in a cylindrical phantom. Using f(z), equations are derived which provide the analytical description of conventional (axial and helical) dose, demonstrating its physical underpinnings; and likewise for the peak axial dose f(0) appropriate to stationary phantom cone beam CT, (SCBCT). The methodology can also be applied to dose calculations in shift-variant scan protocols. This paper is an extension of our recent work Dixon and Boone [Med. Phys. 37, 2703-2718 (2010)], which dealt only with the properties of the peak dose f(0), its relationship to CTDI, and its appropriateness to SCBCT. Methods: The experimental beam profile data f(z) of Mori et al.[Med. Phys. 32, 1061-1069 (2005)] from a 256 cha