WorldWideScience

Sample records for 64-slice computed tomography

  1. 64-slice Computed Tomography Assessment of Coronary Artery Stents: a Phantom Study

    Mahnken, A.H.; Muehlenbruch, G.; Seyfarth, T.; Flohr, T.; Stanzel, S.; Wildberger, J.E.; Guenther, R.W.; Kuettner, A. [Aachen Univ. of Technology (Germany). Dept. of Diagnostic Radiology

    2006-02-15

    Purpose: To compare the use of a new 64-slice computed tomography (CT) scanner with 16-slice CT in the visualization of coronary artery stent lumen. Material and Methods: Eight different coronary artery stents, each with a diameter of 3 mm, were placed in a static chest phantom. The phantom was positioned in the CT gantry at an angle of 0 deg and 45 deg towards the z-axis and examined with both a 64-slice and a 16-slice CT scanner. Effective slice thickness was 0.6 mm with 64-slice CT and 1 mm with 16-slice CT. A reconstruction increment of 0.3 mm was applied in both scanners. Image quality was assessed visually using a 5-point grading scale. Stent diameters were measured and compared using paired Wilcoxon tests. Results: Artificial lumen reduction was significantly less with 64-slice than with 16-slice CT. Average visible stent lumen was 53.4% using 64-slice CT and 47.5% with 16-slice MSCT. Most severe artifacts were seen in stents with radiopaque markers. Using 64-slice CT, image noise increased by approximately 30% due to thinner slice thickness. Conclusion: Improved spatial resolution of 64-slice CT resulted in superior assessment of coronary artery stent lumen compared to 16-slice CT. However, a relevant part of the stent lumen is still not assessable with multi-slice CT.

  2. Influence of coronary calcification on the diagnostic accuracy of 64-slice computed tomography coronary angiography

    Abdulla, Jawdat; Pedersen, Kasper; Budoff, Matthew;

    2012-01-01

    To determine via meta-analysis the diagnostic accuracy of 64-slice computed tomography coronary angiography (CTA) for assessment of significant obstructive coronary artery stenosis at different coronary artery calcium score (CACS) levels. Data of 12,053 versus 5,890 segments, 906 versus 758 arter...

  3. Contrast-enhanced 64-slice computed tomography in detection and evaluation of anomalous coronary arteries

    Anomalous coronary artery (ACA) has either an unusual origin or different anatomical course and is associated with sudden cardiac death. The absence or nonspecific symptoms of ACA make its diagnosis difficult. Mostly, ACA is diagnosed coincidentally during invasive coronary angiogram (ICA). A conventional computed tomography (CT) cannot provide detailed images of coronary arteries of the moving heart, but 64-slice CT, with its short acquisition time, can provide detailed anatomy of coronary arteries non-invasively. In this study, we assessed the validity of contrast-enhanced 64-slice CT in the evaluation of ACA. ICA was performed in 7,574 patients for the diagnosis or evaluation of occlusive coronary artery disease and detected coronary anomalies in 56 patients (0.7%). We then performed 64-slice CT in 53 patients out of the 56 patients with demonstrated or suspected coronary anomaly, showing the origin and the course of the ACA along with stenosis, except for one patient who could not be evaluated due to image distortion artifacts. Contrast-enhanced 64-slice CT was also performed in 374 patients with vague signs and symptoms, detecting coronary anomalies in 7 patients (1.2%). Thus, in the total of 59 patients undergone 64-slice CT, we were able to visualize the entire abnormal coronary tree with a high diagnostic image quality. This is the first study to demonstrate the utility of 64-slice CT in a large series of ACA. Contrast-enhanced 64-slice CT is superior to ICA to identify the presence and course of ACA and should be the first line diagnostic tool in the evaluation of ACA. (author)

  4. Diagnostic Accuracy of 64-Slice Multislice Computed Tomography in Assessment of Coronary Artery Bypass Grafts

    A. Arjmand Shabestari

    2007-05-01

    Full Text Available Background and Objective: Nowadays 64-slice mul-tislice computed tomography (MSCT has gained a wide acceptance as a non-invasive diagnostic imaging modality in native coronary arteries. This study was performed to determine the diagnostic accuracy of 64-slice MSCT in assessment of coronary artery by-pass grafting (CABG patency. Materials and Methods: 73 patients underwent both coronary CT-angiography (CTA using 64-slice MSCT scanner and quantitative coronary angiography (QCA were studied. Arterial and venous CABG patency was graded as: a-normal, b-patent with non-significant (<50% diameter reduction stenosis, c-patent with significant (≥50% diameter reduction stenosis or d-totally occluded. The results of CTA and QCA were compared. Results: Totally, 236 CABG were assessed, including 49 arterial and 187 venous grafts. Sensitivity, specific-ity, positive predictive value (PPV and negative pre-dictive value (NPV in detecting normal patency of arterial grafts were 100%, 85%, 95% and 100%, re-spectively and those in finding normal patency of ve-nous grafts all were 100%. The above-mentioned fig-ures for non-significant stenosis were 67% (2 out of 3 patients, 100%, 100% and 98% in arterial and 95%, 100%, 100% and 99% in venous grafts, respectively. Regarding to the significant stenosis, the results were 67% (2 out of 3 patients, 100%, 100% and 98% in arterial and 100%, 99%, 94% and 100% in venous grafts, respectively. All of these numerals were meas-ured being 100% for total occlusion of both arterial and venous grafts. Conclusion: Diagnostic accuracy of 64-slice MSCT in detecting normal patency, non-significant stenosis, significant stenosis and total occlusion of arterial and particularly venous CABG is extremely high so that QCA may be eventually substituted by CTA in a near future.

  5. Evaluation of the Optimal Image Reconstruction Interval for Coronary Artery Imaging Using 64-Slice Computed Tomography

    Background: Cardiac computed tomography (CT) has become an established complement in cardiac imaging. Thus, optimized image quality is diagnostically crucial. Purpose: To prospectively evaluate whether, by using 64-slice CT, a specific reconstruction interval can be identified providing best image quality for all coronary artery segments and each individual coronary artery. Material and Methods: 311 coronary segments of 14 men and seven women were analyzed using 64-slice CT. Data reconstruction was performed in 5% increments from 5-100% of the R-R interval. Four experienced observers independently evaluated image quality of the coronary arteries according to the AHA classification. A three-point ranking scale was applied: 1, very poor, no evaluation possible; 2, diagnostically sufficient quality; 3, highest image quality, no artifacts. Results: The best reconstruction point for all segments was found to be 65% of the R-R interval (mean value 2.4±0.5; P<0.05). On a per-artery basis, best image quality was again achieved at 65% of the R-R interval: RCA 2.2±0.4, LCA 2.4±0.5, LM 2.5±0.2, LAD 2.3±0.4, LCX 2.3±0.5. Conclusion: By using 64-slice CT, the need for adjusting the reconstruction point to each coronary segment might be overcome. Best image quality was achieved with image reconstruction at 65% of the R-R interval for all coronary segments as well as each coronary artery

  6. Quantitative parameters of image quality in 64-slice computed tomography angiography of the coronary arteries

    We explored quantitative parameters of image quality in consecutive patients undergoing 64-slice multi-detector computed tomography (MDCT) coronary angiography for clinical reasons. Forty-two patients (36 men, mean age 61 ± 11 years, mean heart rate 63 ± 10 bpm) underwent contrast-enhanced MDCT coronary angiography with a 64-slice scanner (Siemens Sensation 64, 64 mmx 0.6 mm collimation, 330 ms tube rotation, 850 mAs, 120 kV). Two independent observers measured the overall visualized vessel length and the length of the coronary arteries visualized without motion artifacts in curved multiplanar reformatted images. Contrast-to-noise ratio was measured in the proximal and distal segments of the coronary arteries. The mean length of visualized coronary arteries was: left main 12 ± 6 mm, left anterior descending 149 ± 25 mm, left circumflex 89 ± 30 mm, and right coronary artery 161 ± 38 mm. On average, 97 ± 5% of the total visualized vessel length was depicted without motion artifacts (left main 100 ± 0%, left anterior descending 97 ± 6%, left circumflex 98 ± 5%, and right coronary artery 95 ± 6%). In 27 patients with a heart rate ≤65 bpm, 98 ± 4% of the overall visualized vessel length was imaged without motion artifacts, whereas 96 ± 6% of the overall visualized vessel length was imaged without motion artifacts in 15 patients with a heart rate >65 bpm (p < 0.001). The mean contrast-to-noise ratio in all measured coronary arteries was 14.6 ± 4.7 (proximal coronary segments: range 15.1 ± 4.4 to 16.1 ± 5.0, distal coronary segments: range 11.4 ± 4.2 to 15.9 ± 4.9). In conclusion, 64-slice MDCT permits reliable visualization of the coronary arteries with minimal motion artifacts and high CNR in consecutive patients referred for non-invasive MDCT coronary angiography. Low heart rate is an important prerequisite for excellent image quality

  7. Radiation dose reduction by using 100-kV tube voltage in cardiac 64-slice computed tomography: A comparative study

    Objective: To evaluate a 100-kilovoltage (kV) tube voltage protocol regarding radiation dose and image quality, in comparison with the standard 120 kV setting in cardiac computed tomography angiography (CCTA). Methods: 103 patients undergoing retrospective ECG-gated helical 64-slice CCTA were enrolled (100 kV group: 51 patients; 120 kV group: 52 patients). Inclusion criteria were: (1) BMI 2; (2) weight 25 kg/m2). Conclusions: The 100 kV protocol significantly reduces the radiation dose in CCTA in patients with a low BMI 2 and a low calcium load while maintaining high image quality and the advantages of helical scan algorithm.

  8. 64 slice-coronary computed tomography sensitivity and specificity in the evaluation of coronary artery bypass graft stenosis: A meta-analysis.

    Barbero, Umberto; Iannaccone, Mario; d'Ascenzo, Fabrizio; Barbero, Cristina; Mohamed, Abdirashid; Annone, Umberto; Benedetto, Sara; Celentani, Dario; Gagliardi, Marco; Moretti, Claudio; Gaita, Fiorenzo

    2016-08-01

    A non-invasive approach to define grafts patency and stenosis in the follow-up of coronary artery bypass graft (CABG) patients may be an interesting alternative to coronary angiography. 64-slice-coronary computed tomography is nowadays a diffused non-invasive method that permits an accurate evaluation of coronary stenosis, due to a high temporal and spatial resolution. However, its sensitivity and specificity in CABG evaluation has to be clearly defined, since published studies used different protocols and scanners. We collected all studies investigating patients with stable symptoms and previous CABG and reporting the comparison between diagnostic performances of invasive coronary angiography and 64-slice-coronary computed tomography. As a result, sensitivity and specificity of 64-slice-coronary computed tomography for CABG occlusion were 0.99 (95% CI 0.97-1.00) and 0.99 (95% CI: 0.99-1.00) with an area under the curve (AUC) of 0.99. 64-slice-coronary computed tomography sensitivity and specificity for the presence of any CABG stenosis >50% were 0.98 (95% CI: 0.97-0.99) and 0.98 (95% CI: 0.96-0.98), while AUC was 0.99. At meta-regression, neither the age nor the time from graft implantation had effect on sensitivity and specificity of 64-slice-coronary computed tomography detection of significant CABG stenosis or occlusion. In conclusion 64-slice-coronary computed tomography confirmed its high sensitivity and specificity in CABG stenosis or occlusion evaluation. PMID:27140337

  9. Acute stent thrombosis after bifurcation stenting with the crush technique visualized with 64-slice computed tomography

    Kristensen, T.S.; Engstrom, T.; Kofoed, Klaus Fuglsang

    2008-01-01

    Acute stent thrombosis remains a potential complication after stent implantation. With the introduction of electrocardiographic gated multidetector row computed tomography (MDCT), a new nonnvasive imaging modality has become available that may contribute to the detection of complications after co...... complex interventional procedures. We present a case where CT angiography was performed just prior to the clinical presentation of acute stent thrombosis in a 55-year-old male who was treated with the crush technique in a bifurcation lesion Udgivelsesdato: 2008/7...

  10. Serial changes of coronary atherosclerotic plaque: Assessment with 64-slice multi-detector computed tomography

    Kim, Eun Young; Kang, Doo Kyoung; Sun, Joo Sung; Choi, So Yeon [Ajou University School of Medicine, Suwon (Korea, Republic of)

    2013-12-15

    Evaluate the progression of coronary atherosclerotic plaque during follow-up, and its association with cardiovascular risk factors. Fifty-six atherosclerotic patients with plaque were enrolled in this retrospective study. Patient's plaque was detected on repeat 64-slice multidetector CT scans with a mean interval of 25 ± 10 months changes in calcified and non-calcified plaque volumes and cardiovascular risk factors were assessed over time. Absolute and relative changes in plaque volume were compared, and the association between rapid progression and cardiovascular risk factors was determined. Diameter of the stenosis, length, calcified and non-calcified lesion plaque volumes increased significantly on follow-up CT. Absolute and relative annual changes in plaque volumes were significantly greater in non-calcified plaque (median, 22.7 mm{sup 3}, 90.4%) than in calcified plaque (median, 0.7 mm{sup 3}, 0%). Obesity, smoking, hypertension, hypercholesterolemia, and low high-density lipoprotein were significant predictors of progression of non-calcified plaque. Progression of calcified plaque was not associated with any cardiovascular risk factors. Coronary plaque volume increased significantly on follow-up CT. The rate of progression is related to non-calcified plaque than to calcified plaque. Cardiovascular risk factors are independently associated with the rapid progression of non-calcified plaque volume, but not associated with the progression of calcified plaque.

  11. Serial changes of coronary atherosclerotic plaque: Assessment with 64-slice multi-detector computed tomography

    Evaluate the progression of coronary atherosclerotic plaque during follow-up, and its association with cardiovascular risk factors. Fifty-six atherosclerotic patients with plaque were enrolled in this retrospective study. Patient's plaque was detected on repeat 64-slice multidetector CT scans with a mean interval of 25 ± 10 months changes in calcified and non-calcified plaque volumes and cardiovascular risk factors were assessed over time. Absolute and relative changes in plaque volume were compared, and the association between rapid progression and cardiovascular risk factors was determined. Diameter of the stenosis, length, calcified and non-calcified lesion plaque volumes increased significantly on follow-up CT. Absolute and relative annual changes in plaque volumes were significantly greater in non-calcified plaque (median, 22.7 mm3, 90.4%) than in calcified plaque (median, 0.7 mm3, 0%). Obesity, smoking, hypertension, hypercholesterolemia, and low high-density lipoprotein were significant predictors of progression of non-calcified plaque. Progression of calcified plaque was not associated with any cardiovascular risk factors. Coronary plaque volume increased significantly on follow-up CT. The rate of progression is related to non-calcified plaque than to calcified plaque. Cardiovascular risk factors are independently associated with the rapid progression of non-calcified plaque volume, but not associated with the progression of calcified plaque.

  12. Detection of pulmonary embolism using 64-slice multidetector-row computed tomography: accuracy and reproducibility on different image reconstruction parameters

    Jung, Jung Im; Ahn, Myeong Im; Park, Seog Hee (Dept. of Radiology, Seoul St Mary' s Hospital, College of Medicine, The Catholic Univ. of Korea (Korea, Republic of)), email: jijung@catholic.ac.kr; Kim, Ki Jun (Deparment of Radiology, Incheon St Mary' s Hospital, College of Medicine, The Catholic Univ. of Korea (Korea, Republic of)); Kim, Hyo Rim (Deparment of Radiology, Yeouido St Mary' s Hospital, College of Medicine, The Catholic Univ. of Korea (Korea, Republic of)); Park, Hyun Jin (Dept. of Radiology, St Vincent Hospital, College of Medicine, The Catholic Univ. of Korea (Korea, Republic of)); Jung, SeungHee; Lim, Hyeon Woo (Deparment of Preventive Medicine, College of Medicine, The Catholic Univ. of Korea (Korea, Republic of))

    2011-05-15

    Background Direct comparison of different image reconstruction parameters to detect pulmonary embolism (PE) using 64-slice multidetector-row computed tomography (MDCT) is absent and the most accurate image reconstruction parameters have not yet been proven. Purpose To compare different image reconstruction parameters for detecting PE using 64-slice MDCT in patients suspected of having an acute PE. Material and Methods Forty patients who underwent pulmonary CT angiography with 64-slice MDCT for a suspected PE were included. Different image reconstruction parameters were used for each patient: axial and coronal images with slice thicknesses of 0.625 mm, 1.3 mm, and 2.5 mm and axial maximum intensity projection (MIP) images with slab thicknesses of 1.3 mm, 2.5 mm, and 5 mm. Four experienced radiologists reviewed the images. The diagnosis of a PE was based on consensus review of axial 0.625 mm slice thickness images by two chest radiologists with allowing multiplanar reconstruction. Accuracy and reproducibility (kappa value) were evaluated. Results In 15 of 40 patients, a PE was diagnosed. For detecting lobar PEs, axial images with a slice thickness of 1.25 mm and all coronal re-formatted images showed comparable results to axial images with a slice thickness of 0.625 mm. For detecting segmental PEs, axial images with a slice thickness of 1.25 mm and coronal images with a slice thickness of 0.625 mm re-formatted images showed comparable results to axial images of a slice thickness of 0.625 mm. For detecting subsegmental PEs, axial images with a slice thickness of 0.625 mm showed the highest sensitivity. Better reproducibility was obtained when the thinner slice thickness reconstructions were in axial and coronal images. However, reproducibility of MIP images with slab thicknesses of 2.5 mm and 5 mm was similar for detecting segmental and subsegmental PEs. Conclusion Thin-slice reconstruction of less than 1 mm is mandatory for visualization of PE at the subsegmental

  13. High-resolution ex vivo imaging of coronary artery stents using 64-slice computed tomography - initial experience

    Rist, Carsten; Nikolaou, Konstantin; Wintersperger, Bernd J.; Reiser, Maximilian F.; Becker, Christoph R. [Ludwig-Maximilians University, Department of Clinical Radiology, Munich (Germany); Flohr, Thomas [Siemens Medical Solutions, CT Division, Forchheim (Germany)

    2006-07-15

    The aim of the study was to evaluate the potential of new-generation multi-slice computed tomography (CT) scanner technology for the delineation of coronary artery stents in an ex vivo setting. Nine stents of various diameters (seven stents 3 mm, two stents 2.5 mm) were implanted into the coronary arteries of ex vivo porcine hearts and filled with a mixture of an iodine-containing contrast agent. Specimens were scanned with a 16-slice CT (16SCT) machine; (Somatom Sensation 16, Siemens Medical Solutions), slice thickness 0.75 mm, and a 64-slice CT (64SCT, Somatom Sensation 64), slice-thickness 0.6 mm. Stent diameters as well as contrast densities were measured, on both the 16SCT and 64SCT images. No significant differences of CT densities were observed between the 16SCT and 64SCT images outside the stent lumen: 265{+-}25HU and 254{+-}16HU (P=0.33), respectively. CT densities derived from the 64SCT images and 16SCT images within the stent lumen were 367{+-}36HU versus 402{+-}28HU, P<0.05, respectively. Inner and outer stent diameters as measured from 16SCT and 64SCT images were 2.68{+-}0.08 mm versus 2.81{+-}0.07 mm and 3.29{+-}0.06 mm versus 3.18{+-}0.07 mm (P<0.05), respectively. The new 64SCT scanner proved to be superior in the ex vivo assessment of coronary artery stents to the conventional 16SCT machine. Increased spatial resolution allows for improved assessment of the coronary artery stent lumen. (orig.)

  14. Analysis of shielding calculation methods for 16- and 64-slice computed tomography facilities

    Moreno, C; Cenizo, E; Bodineau, C; Mateo, B; Ortega, E M, E-mail: c_morenosaiz@yahoo.e [Servicio de RadiofIsica Hospitalaria, Hospital Regional Universitario Carlos Haya, Malaga (Spain)

    2010-09-15

    The new multislice computed tomography (CT) machines require some new methods of shielding calculation, which need to be analysed. NCRP Report No. 147 proposes three shielding calculation methods based on the following dosimetric parameters: weighted CT dose index for the peripheral axis (CTDI{sub w,per}), dose-length product (DLP) and isodose maps. A survey of these three methods has been carried out. For this analysis, we have used measured values of the dosimetric quantities involved and also those provided by the manufacturer, making a comparison between the results obtained. The barrier thicknesses when setting up two different multislice CT instruments, a Philips Brilliance 16 or a Philips Brilliance 64, in the same room, are also compared. Shielding calculation from isodose maps provides more reliable results than the other two methods, since it is the only method that takes the actual scattered radiation distribution into account. It is concluded therefore that the most suitable method for calculating the barrier thicknesses of the CT facility is the one based on isodose maps. This study also shows that for different multislice CT machines the barrier thicknesses do not necessarily become bigger as the number of slices increases, because of the great dependence on technique used in CT protocols for different anatomical regions.

  15. The influence of heart rate, slice thickness, and calcification density on calcium scores using 64-slice multidetector computed tomography - A systematic phantom study

    Groen, Jaap M.; Greuter, Marcel J.; Schmidt, Bernhard; Suess, Christoph; Vliegenthart, Rozemarijn; Oudkerk, Matthis

    2007-01-01

    Objective: The purpose of this study was to investigate the influence of heart rate, slice thickness, and calcification density on absolute value and variability of calcium score using 64-slice multidetector computed tomography (MDCT). Methods and Materials: Three artificial arteries containing each

  16. Prognostic value of absence or presence of coronary artery disease determined by 64-slice computed tomography coronary angiography A systematic review and meta-analysis

    Abdulla, Jawdat; Asferg, Camilla Lundegaard; Kofoed, Klaus Fuglsang

    2011-01-01

    To determine via a meta-analysis the prognostic value of 64-slice computed tomography angiography (CTA) by quantifying risk of major adverse cardiac events (MACE) in different patient groups classified according to CT angiographic findings. A systematic literature search and meta-analyses was con...

  17. Beam hardening artifacts by dental implants: Comparison of cone-beam and 64-slice computed tomography scanners

    Farzad Esmaeili

    2013-01-01

    Full Text Available Background: Cone beam computed tomography (CBCT is an alternative to a computed tomography (CT scan, which is appropriate for a wide range of craniomaxillofacial indications. The long-term use of metallic materials in dentistry means that artifacts caused by metallic restorations in the oral cavity should be taken into account when utilizing CBCT and CT scanners. The aim of this study was to quantitatively compare the beam hardening artifacts produced by dental implants between CBCT and a 64-Slice CT scanner. Materials and Methods: In this descriptive study , an implant drilling model similar to the human mandible was used in the present study. The implants (Dentis were placed in the canine, premolar and molar areas. Three series of scans were provided from the implant areas using Somatom Sensation 64-slice and NewTom VGi (CBCT CT scanners. Identical images were evaluated by three radiologists. The artifacts in each image were determined based on pre-determined criteria. Kruskal-Wallis test was used to compare mean values; Mann-Whitney U test was used for two-by-two comparisons when there was a statistical significance ( P < 0.05. Results: The images of the two scanners had similar resolutions in axial sections ( P = 0.299. In coronal sections, there were significant differences in the resolutions of the images produced by the two scanners ( P < 0.001, with a higher resolution in the images produced by NewTom VGi scanner. On the whole, there were significant differences between the resolutions of the images produced by the two CT scanners ( P < 0.001, with higher resolution in the images produced by NewTom VGi scanner in comparison to those of Somatom Sensation. Conclusion: Given the high quality of the images produced by NewTom VGi and the lower costs in comparison to CT, the use of the images of this scanner in dental procedures is recommended, especially in patients with extensive restorations, multiple prostheses and previous implants.

  18. Assessment of right ventricular function for patients with rheumatic mitral stenosis by 64-slice multi-detector row computed tomography: comparison with magnetic resonance imaging

    ZHANG Xiao-chun; YANG Zhi-gang; GUO Yin-kun; ZHANG Rui-ming; WANG Jian; ZHOU Dai-quan; CHENG Lin; CHEN Lin

    2012-01-01

    Background Right ventricular (RV) dysfunction ensues due to rheumatic mitral stenosis (RMS).The evaluation of RV function is clinically important for the diagnosis,treatment,and follow-up for patients with different degrees of RMS.Thepurpose of this study was to determine whether the 64-slice multi-detector row computed tomography (64-slice MDCT)can assess the RV function in RMS with high accuracy and reproducibility when compared to MR imaging (MRI).Methods Right ventricular end-diastolic and end-systolic volumes (RV-EDV and RV-ESV),stroke volume (RV-SV),ejection fraction (RV-EF),cardiac output (RV-CO),and wall mass (RV-Mass) were measured with dedicated cardiac analysis software on 64-slice MDCT and compared with values measured with MRI in 43 consecutive patients with RMS.Agreement between MRI and 64-MDCT results were compared with Bland and Altman analysis and linear regression analysis.Repeated measurements were performed to determine intraobserver and interobserver variability.Results No significant differences were revealed in calculated RV function parameters between the two methods.RV-EDV,RV-ESV,RV-SV,RV-EF,RV-CO,and RV-Mass by 64-slice MDCT were similar to those by MRI (P>0.05).There were good correlations (r=0.98,0.97,0.96,0.96,0.95 and 0.77,respectively) and close agreement (bias=-0.2 ml,-1.0ml,0.8 ml,0.5%,26.1 ml,and 0.5 g,respectively,P>0.05).The variability in 64-slice MDCT measurements was similar to that in MRI values.Conclusion ECG-gated 64-slice MDCT could assess the RV function in RMS with high accuracy and reproducibility when compared to MRI.

  19. Comparison of 64-slice computed tomography angiography and coronary angiography for the detection and assessment of coronary artery disease in patients with angina: A systematic review

    Background: Coronary artery disease (CAD) is the leading cause of death in Western countries. It presents itself in various ways, the commonest being angina. According to the Royal College of Radiologist referral guidelines, Coronary Angiography (CA) is currently the gold standard for diagnosis and evaluation of CAD. However, due to the invasive nature and expense of CA there is a perceived need for a primary non-invasive imaging modality to supersede it. Computed tomography angiography (CTA), utilising 64-slice technology, may be a less invasive alternative to CA. Aim: To consider the research evidence for the current gold standard diagnostic test for CAD. Specifically, which is more sensitive and specific for detecting CAD in patients with angina; 64-slice CTA or CA? Inclusion Criteria: Prospective, non-randomised control trials and diagnostic accuracy studies comparing 64-slice CTA and CA were included. Participants were adults with angina with suspected or known CAD. Method: An electronic search of the databases; AMED, CINAHL, Cochrane Library, EMBASE, MEDLINE and Science Direct, was conducted between January 2004 and April 2012. Secondary hand-searching of grey literature was undertaken. Two reviewers independently determined studies for inclusion, assessed quality, using SIGN50, and extracted data. Diagnostic value of 64-slice CTA and CA was compared and analysed at patient and segment level. Results: Ten studies were included in the critical review enrolling 1188 patients. At patient level sensitivity for 64-slice CTA ranged from 88% to 100%, specificity 64–92%, PPV 86–97% and NPV 76.9–100%. At segment level sensitivity for 64-slice CTA ranged from 73% to 100%, specificity 83–98%, PPV 47–90% and NPV 89–100% Conclusion: At both patient and segment level, 64-slice CTA is a highly sensitive and specific non-invasive alternative to CA for diagnosis of significant stenosis in patients with angina. For standalone diagnosis of CAD current research would

  20. The role of 64-slice multi-detector computed tomography in the detection of subclinical atherosclerosis of the coronary artery.

    Jeong, Hae Chang; Ahn, Youngkeun; Ko, Jum Suk; Lee, Min Goo; Sim, Doo Sun; Park, Keun Ho; Yoon, Nam Sik; Youn, Hyun Ju; Hong, Young Joon; Kim, Kye Hun; Park, Hyung Wook; Kim, Ju Han; Kim, Yun-Hyeon; Jeong, Myung Ho; Cho, Jeong Gwan; Park, Jong Chun; Kang, Jung Chaee

    2010-12-01

    Multi-detector computed tomography (MDCT) has been used for detecting or excluding coronary atherosclerotic stenosis in symptomatic patients. However, the role of MDCT for routine medical examination in asymptomatic, high-risk patients has not been established. We therefore conducted the present study to test the hypothesis that MDCT could be a valuable method for detecting subclinical coronary artery stenosis in asymptomatic patients. An observational, retrospective, single-centre study was conducted with a cohort of 1,529 patients (mean age, 56.4 ± 8.3 years; 1,353 males) who had undergone MDCT as part of their general medical checkups from November 2005 to April 2008. The patients who had a past history of coronary artery disease, typical chest pain, or evidence of myocardial ischemia were excluded. During clinical follow up of these patients, the incidence of subclinical coronary stenosis and the usefulness of MDCT for routine medical examination in asymptomatic patients were investigated. Of the 1,529 enrolled patients, 42.3% had hypertension, 13.5% had diabetes mellitus, 7.7% had hyperlipidemia, and 40.4% were current smokers. Abnormal MDCT findings were noted in 560 (36.6%) patients, who were classified into two groups. One group had the presence coronary calcium with a luminal diameter stenosis of the coronary artery of bridge, and 23 patients (1.5%) presented with significant stenosis. The patients with significant stenosis underwent percutaneous coronary intervention (PCI) with stent implantation. Major adverse cardiac events occurred in only 2 patients who had been treated with PCI during a mean follow-up period of 387 ± 253 days. The incidence of significant subclinical coronary stenosis as detected by MDCT in a general medical check-up was 3.4%, and the false-positive rate of MDCT for detecting significant coronary artery stenosis was 55.8% (29/52). 64-Slice MDCT can be a useful tool for noninvasive evaluation of coronary arteries in

  1. Comparison of 64-slice multi-detector computed tomography coronary angiography between asymptomatic, type 2 diabetes mellitus and impaired glucose tolerance patients

    Cardiovascular disease is the most frequent cause of death and disability for diabetic patients, and patients with diabetes are more likely to have silent ischemia. Multi-detector computed tomography (MDCT) allows non-invasive assessment of coronary artery stenosis and plaque properties. In this study, we investigated whether 64-slice MDCT can non-invasively identify significant coronary artery stenosis in asymptomatic, type 2 diabetes mellitus (T2DM) and impaired glucose tolerance (IGT) patients. The study population consisted of 154 consecutive asymptomatic patients [IGT (n=93), T2DM (n=61)]. All patients underwent contrast-enhanced 64-slice MDCT. The number of diseased coronary segments was classified as showing obstructive (≥50% luminal narrowing) disease or not. Significant coronary stenosis was detected in 43 (27.9%) of 154 enrolled patients. Patients with T2DM showed significantly more coronary stenosis than patients with IGT (41% vs. 19.4%; p<0.01). Twenty-three patients [14.9%; IGT (n=9), T2DM (n=14)] underwent percutaneous coronary intervention (PCI) for severe stenosis. Patients with T2DM showed significantly more calcified plaque than IGT (47.5% vs. 29%; p<0.05), but not significantly more soft plaque (19.7% vs. 15.1%; ns), or significantly different remodeling index (1.05±0.18 vs. 1.04±0.21; ns), respectively. 64-Slice MDCT can non-invasively identify significant coronary artery stenosis in asymptomatic, T2DM and IGT patients. (author)

  2. Quantitative parameters to compare image quality of non-invasive coronary angiography with 16-slice, 64-slice and dual-source computed tomography.

    Burgstahler, Christof; Reimann, Anja; Brodoefel, Harald; Daferner, Ulrike; Herberts, Tina; Tsiflikas, Ilias; Thomas, Christoph; Drosch, Tanja; Schroeder, Stephen; Heuschmid, Martin

    2009-03-01

    Multi-slice computed tomography (MSCT) is a non-invasive modality to visualize coronary arteries with an overall good image quality. Improved spatial and temporal resolution of 64-slice and dual-source computed tomography (DSCT) scanners are supposed to have a positive impact on diagnostic accuracy and image quality. However, quantitative parameters to compare image quality of 16-slice, 64-slice MSCT and DSCT are missing. A total of 256 CT examinations were evaluated (Siemens, Sensation 16: n = 90; Siemens Sensation 64: n = 91; Siemens Definition: n = 75). Mean Hounsfield units (HU) were measured in the cavum of the left ventricle (LV), the ascending aorta (Ao), the left ventricular myocardium (My) and the proximal part of the left main (LM), the left anterior descending artery (LAD), the right coronary artery (RCA) and the circumflex artery (CX). Moreover, the ratio of intraluminal attenuation (HU) to myocardial attenuation was assessed for all coronary arteries. Clinical data [body mass index (BMI), gender, heart rate] were accessible for all patients. Mean attenuation (CA) of the coronary arteries was significantly higher for DSCT in comparison to 64- and 16-slice MSCT within the RCA [347 +/- 13 vs. 254 +/- 14 (64-MSCT) vs. 233 +/- 11 (16-MSCT) HU], LM (362 +/- 11/275 +/- 12/262 +/- 9), LAD (332 +/- 17/248 +/- 19/219 +/- 14) and LCX (310 +/- 12/210 +/- 13/221 +/- 10, all p < 0.05), whereas there was no significant difference between DSCT and 64-MSCT for the LV, the Ao and My. Heart rate had a significant impact on CA ratio in 16-slice and 64-slice CT only (p < 0.05). BMI had no impact on the CA ratio in DSCT only (p < 0.001). Improved spatial and temporal resolution of dual-source CT is associated with better opacification of the coronary arteries and a better contrast with the myocardium, which is independent of heart rate. In comparison to MSCT, opacification of the coronary arteries at DSCT is not affected by BMI. The main advantage of DSCT lies with the

  3. Quantitative parameters to compare image quality of non-invasive coronary angiography with 16-slice, 64-slice and dual-source computed tomography

    Burgstahler, Christof [University Hospital Tuebingen, Department of Cardiology, Tuebingen (Germany)]|[Eberhard-Karls-University Tuebingen, Department of Internal Medicine III-Cardiology, Tuebingen (Germany); Reimann, Anja; Brodoefel, Harald; Tsiflikas, Ilias; Thomas, Christoph; Heuschmid, Martin [University Hospital Tuebingen, Department of Diagnostic Radiology, Tuebingen (Germany); Daferner, Ulrike; Drosch, Tanja; Schroeder, Stephen [University Hospital Tuebingen, Department of Cardiology, Tuebingen (Germany); Herberts, Tina [University of Tuebingen, Department of Medical Biometry, Tuebingen (Germany)

    2009-03-15

    Multi-slice computed tomography (MSCT) is a non-invasive modality to visualize coronary arteries with an overall good image quality. Improved spatial and temporal resolution of 64-slice and dual-source computed tomography (DSCT) scanners are supposed to have a positive impact on diagnostic accuracy and image quality. However, quantitative parameters to compare image quality of 16-slice, 64-slice MSCT and DSCT are missing. A total of 256 CT examinations were evaluated (Siemens, Sensation 16: n=90; Siemens Sensation 64: n=91; Siemens Definition: n=75). Mean Hounsfield units (HU) were measured in the cavum of the left ventricle (LV), the ascending aorta (Ao), the left ventricular myocardium (My) and the proximal part of the left main (LM), the left anterior descending artery (LAD), the right coronary artery (RCA) and the circumflex artery (CX). Moreover, the ratio of intraluminal attenuation (HU) to myocardial attenuation was assessed for all coronary arteries. Clinical data [body mass index (BMI), gender, heart rate] were accessible for all patients. Mean attenuation (CA) of the coronary arteries was significantly higher for DSCT in comparison to 64- and 16-slice MSCT within the RCA [347{+-}13 vs. 254{+-}14 (64-MSCT) vs. 233{+-}11 (16-MSCT) HU], LM (362{+-}11/275 {+-} 12/262{+-}9), LAD (332{+-}17/248{+-}19/219{+-}14) and LCX (310{+-}12/210{+-}13/221{+-}10, all p<0.05), whereas there was no significant difference between DSCT and 64-MSCT for the LV, the Ao and My. Heart rate had a significant impact on CA ratio in 16-slice and 64-slice CT only (p<0.05). BMI had no impact on the CA ratio in DSCT only (p<0.001). Improved spatial and temporal resolution of dual-source CT is associated with better opacification of the coronary arteries and a better contrast with the myocardium, which is independent of heart rate. In comparison to MSCT, opacification of the coronary arteries at DSCT is not affected by BMI. The main advantage of DSCT lies with the heart rate independency

  4. Quantitative parameters to compare image quality of non-invasive coronary angiography with 16-slice, 64-slice and dual-source computed tomography

    Multi-slice computed tomography (MSCT) is a non-invasive modality to visualize coronary arteries with an overall good image quality. Improved spatial and temporal resolution of 64-slice and dual-source computed tomography (DSCT) scanners are supposed to have a positive impact on diagnostic accuracy and image quality. However, quantitative parameters to compare image quality of 16-slice, 64-slice MSCT and DSCT are missing. A total of 256 CT examinations were evaluated (Siemens, Sensation 16: n=90; Siemens Sensation 64: n=91; Siemens Definition: n=75). Mean Hounsfield units (HU) were measured in the cavum of the left ventricle (LV), the ascending aorta (Ao), the left ventricular myocardium (My) and the proximal part of the left main (LM), the left anterior descending artery (LAD), the right coronary artery (RCA) and the circumflex artery (CX). Moreover, the ratio of intraluminal attenuation (HU) to myocardial attenuation was assessed for all coronary arteries. Clinical data [body mass index (BMI), gender, heart rate] were accessible for all patients. Mean attenuation (CA) of the coronary arteries was significantly higher for DSCT in comparison to 64- and 16-slice MSCT within the RCA [347±13 vs. 254±14 (64-MSCT) vs. 233±11 (16-MSCT) HU], LM (362±11/275 ± 12/262±9), LAD (332±17/248±19/219±14) and LCX (310±12/210±13/221±10, all p<0.05), whereas there was no significant difference between DSCT and 64-MSCT for the LV, the Ao and My. Heart rate had a significant impact on CA ratio in 16-slice and 64-slice CT only (p<0.05). BMI had no impact on the CA ratio in DSCT only (p<0.001). Improved spatial and temporal resolution of dual-source CT is associated with better opacification of the coronary arteries and a better contrast with the myocardium, which is independent of heart rate. In comparison to MSCT, opacification of the coronary arteries at DSCT is not affected by BMI. The main advantage of DSCT lies with the heart rate independency, which might have a

  5. Cardiac sarcoidosis evaluated with gadolinium-enhanced magnetic resonance and contrast-enhanced 64-slice computed tomography.

    Smedema, Jan-Peter; Truter, Rene; de Klerk, Petra A; Zaaiman, Leonie; White, Leonie; Doubell, Anton F

    2006-09-20

    Sarcoidosis is a multi-system granulomatous disorder of unknown etiology with symptomatic cardiac involvement in up to 7% of patients. The clinical features of sarcoid heart disease include congestive heart failure, arrhythmias, conduction disturbances, and sudden death. We evaluated the value of contrast-enhanced multi-detector computed tomography in delineating myocardial scar and granulomatous inflammation by comparing our findings with gadolinium magnetic resonance in a patient diagnosed with cardiac sarcoidosis. PMID:16257460

  6. Volumetric analysis of coronary plaque characterization in patients with metabolic syndrome using 64-slice multi-detector computed tomography

    Metabolic syndrome (MetS) is associated with adverse cardiovascular events and mortality, where acute coronary syndrome significantly impacts on mortality and morbidity. In contrast, evidences have accumulated that the lipid-rich plaque might play a critical role in acute coronary syndrome. The study population consisted of 94 patients with suspected angina pectoris who underwent multi-detector computed tomography (MDCT). Of those, we identified 41 with MetS. In MDCT analysis, low-density plaque volume (LDPV) (42±28 vs 24±18 mm3, P=0.0003), moderate-density plaque volume (105±41 vs 82±33 mm(3), P=0.003), total plaque volume (164±70 vs 118±59 mm3), P=0.0008) and %LDPV (24.2±10.0 vs 18.3±7.1%, P=0.01) were significantly increased in the MetS group compared to the non-MetS group. Multivariate linear regression analysis after adjusting for confounding variables revealed that MetS was significantly correlated with an increase in %LDPV (β=0.48, P=0.0001). Multivariate logistic regression analysis for lipid-rich plaque after adjusting for confounding variables indicated that MetS was significantly associated with lipid-rich plaque (odds ratio: 5.99, 95% confidence intervals: 1.94-18.6, P=0.002). Patients with MetS were strongly related to having a lipid-rich composition in their coronary plaque, as detected by MDCT. (author)

  7. 64-slice spiral computed tomography of the coronary arteries: dose reduction using an optimized imaging protocol including individual weight-adaptation of voltage and current-time product

    Radiation dose and image quality were compared between a standard protocol (40 patients, group A) and a weight-adapted protocol of voltage and current-time product (44 patients, group B) using 64-slice coronary multidetector computed tomography (MDCT). Effective dose estimate was lower by 37% in all patients of group B (9.2±2.5 mSv) compared with group A (14.6±2.3 mSv, P<0.0001). Group B patients with a small body mass index (BMI) benefited most with a dose reduction of 53% (6.7±1.5 mSv in group B versus 14.1±1.8 mSv in group A, P < 0.0001). Moderate reductions of 32% and 20% were achieved for patients with a medium and large BMI, respectively. Reduction in radiation dose did not affect the image quality as assessed by image noise, signal-to-noise ratios, and number of coronary segments with good diagnostic image quality. Individual weight-adaptation of voltage and current-time product significantly reduces the radiation dose without loss of image quality. (orig.)

  8. Diagnostic performance of prospectively ECG triggered versus retrospectively ECG gated 64-slice computed tomography coronary angiography in a heterogeneous patient population

    Lehmkuhl, Lukas, E-mail: lukas.lehmkuhl@med.uni-leipzig.de [University of Leipzig - Heart Center, Department of Diagnostic and Interventional Radiology, Struempellstrasse 39, D-04289 Leipzig (Germany); Herz, Franziska; Foldyna, Borek [University of Leipzig - Heart Center, Department of Diagnostic and Interventional Radiology, Struempellstrasse 39, D-04289 Leipzig (Germany); Nagel, Hans Dieter [Dr. HD Nagel - Science and Technology for Radiology, Buchholz (Germany); Grothoff, Matthias; Nitzsche, Stefan [University of Leipzig - Heart Center, Department of Diagnostic and Interventional Radiology, Struempellstrasse 39, D-04289 Leipzig (Germany); Thiele, Holger [University of Leipzig - Heart Center, Department for Cardiology (Germany); Mohr, Friedrich-Wilhelm [University of Leipzig - Heart Center, Department for Cardiovascular Surgery (Germany); Hindricks, Gerhard [University of Leipzig - Heart Center, Department for Cardiology (Germany); Gutberlet, Matthias [University of Leipzig - Heart Center, Department of Diagnostic and Interventional Radiology, Struempellstrasse 39, D-04289 Leipzig (Germany)

    2011-11-15

    Objective: To compare diagnostic performance and applicability of prospectively versus retrospectively gated 64-slice computed tomography coronary angiography (pro-CTCA vs. retro-CTCA) in a heterogeneous patient population compared to invasive coronary angiography. Methods: 77 patients referred to an ECG-gated-CT of the chest were retrospectively included. Pro-CTCA was applied, whenever possible, alternatively retro-CTCA was performed. All coronary artery segments {>=}1.5 mm were analysed and image quality was assessed. Results: In 39 patients retro-CTCA and in 38 patients pro-CTCA was applied, mean heart rate (HR) was 69.5 {+-} 9.1 min{sup -1} and 62.8 {+-} 5.9, respectively. For a stenosis {>=}50% segment-based (patient-based) analysis revealed a sensitivity, specificity, positive (PPV) and negative predictive value (NPV) of 97%, 98%, 71%, 100% (91%, 82%, 67%, 96%) using retro-CTCA and 94%, 97%, 75%, 99% (93%, 96%, 93%, 96%) using pro-CTCA. Sensitivity and NPV increased in the pro-CTCA group in patients with a HR < 65. Vessel-based analysis showed lower diagnostic performance for the right coronary artery (RCA) using pro-CTCA, which increased when HR < 65. Image quality did not differ significantly in both groups. Conclusions: Prospectively triggered CTCA in a heterogeneous patient group has a very high diagnostic accuracy and image quality, when used in HR {<=} 65. A low HR is of special importance for the evaluation of the RCA.

  9. Comparing culprit lesions in ST-segment elevation and non-ST-segment elevation acute coronary syndrome with 64-slice multidetector computed tomography

    Background: Classifying acute coronary syndrome (ACS) as ST elevation ACS (STE-ACS) or non-ST elevation ACS (NSTE-ACS) is critical for clinical prognosis and therapeutic decision-making. Assessing the differences in composition and configuration of culprit lesions between STE-ACS and NSTE-ACS can clarify their pathophysiologic differences. Objective: This study focused on evaluating the ability of 64-slice multidetector computed tomography (MDCT) to investigate these differences in culprit lesions in patients with STE-ACS and NSTE-ACS. Methods: Of 161 ACS cases admitted, 120 who fit study criteria underwent MDCT and conventional coronary angiography. The following MDCT data were analyzed: calcium volume, Agatston calcium scores, plaque area, plaque burden, remodeling index, and plaque density. Results: The MDCT angiography had a good correlation with conventional coronary angiography regarding the stenotic severity of culprit lesions (r = 0.86, p 1.05) was significantly higher in the STE-ACS group (81.5% vs. 63.6%, p = 0.031). The patients with STE-ACS had significantly lower MDCT density of culprit lesions than patients with NSTE-ACS (25.8 ± 13.9 HU vs. 43.5 ± 19.1 HU, p < 0.001). Conclusions: Sixty-four-slice MDCT can accurately evaluate the stenotic severity and composition of culprit lesions in selected patients with either STE-ACS or NSTE-ACS. Culprit lesions in NSTE-ACS patients had significantly lower luminal area stenosis, plaque burden, remodeling index and higher MDCT density, which possibly reflect differences in the composition of vulnerable culprit plaques and thrombi.

  10. Comparing culprit lesions in ST-segment elevation and non-ST-segment elevation acute coronary syndrome with 64-slice multidetector computed tomography

    Huang, W.-C. [School of Medicine, National Yang-Ming University, Taipei, Taiwan (China); Cardiovascular Medical Center, Kaohsiung Veterans General Hospital, No. 386, Dar-Chung First Road, Kaohsiung, Taiwan (China)], E-mail: w.c.huang@yahoo.com.tw; Liu, C.-P. [School of Medicine, National Yang-Ming University, Taipei, Taiwan (China); Cardiovascular Medical Center, Kaohsiung Veterans General Hospital, No. 386, Dar-Chung First Road, Kaohsiung, Taiwan (China)], E-mail: cpliu@isca.vghks.gov.tw; Wu, M.-T. [School of Medicine, National Yang-Ming University, Taipei, Taiwan (China); Department of Radiology, Kaohsiung Veterans General Hospital, No. 386, Dar-Chung First Road, Kaohsiung, Taiwan (China)], E-mail: wu.mingting@gmail.com; Mar, G.-Y. [Cardiovascular Medical Center, Kaohsiung Veterans General Hospital, No. 386, Dar-Chung First Road, Kaohsiung, Taiwan (China)], E-mail: gymar@isca.vghks.gov.tw; Lin, S.-K. [Cardiovascular Medical Center, Kaohsiung Veterans General Hospital, No. 386, Dar-Chung First Road, Kaohsiung, Taiwan (China)], E-mail: skyii89@yahoo.com.tw; Hsiao, S.-H. [Cardiovascular Medical Center, Kaohsiung Veterans General Hospital, No. 386, Dar-Chung First Road, Kaohsiung, Taiwan (China)], E-mail: a841120@ms3.hinet.net; Lin, S.-L. [School of Medicine, National Yang-Ming University, Taipei, Taiwan (China); Cardiovascular Medical Center, Kaohsiung Veterans General Hospital, No. 386, Dar-Chung First Road, Kaohsiung, Taiwan (China)], E-mail: sllin@isca.vghks.gov.tw; Chiou, K.-R. [School of Medicine, National Yang-Ming University, Taipei, Taiwan (China); Cardiovascular Medical Center, Kaohsiung Veterans General Hospital, No. 386, Dar-Chung First Road, Kaohsiung, Taiwan (China)], E-mail: krchiou@isca.vghks.gov.tw

    2010-01-15

    Background: Classifying acute coronary syndrome (ACS) as ST elevation ACS (STE-ACS) or non-ST elevation ACS (NSTE-ACS) is critical for clinical prognosis and therapeutic decision-making. Assessing the differences in composition and configuration of culprit lesions between STE-ACS and NSTE-ACS can clarify their pathophysiologic differences. Objective: This study focused on evaluating the ability of 64-slice multidetector computed tomography (MDCT) to investigate these differences in culprit lesions in patients with STE-ACS and NSTE-ACS. Methods: Of 161 ACS cases admitted, 120 who fit study criteria underwent MDCT and conventional coronary angiography. The following MDCT data were analyzed: calcium volume, Agatston calcium scores, plaque area, plaque burden, remodeling index, and plaque density. Results: The MDCT angiography had a good correlation with conventional coronary angiography regarding the stenotic severity of culprit lesions (r = 0.86, p < 0.001). The STE-ACS culprit lesions (n = 54) had significantly higher luminal area stenosis (78.6 {+-} 21.2% vs. 66.7 {+-} 23.9%, p = 0.006), larger plaque burden (0.91 {+-} 0.10 vs. 0.84 {+-} 0.12, p = 0.007) and remodeling index (1.28 {+-} 0.34 vs. 1.16 {+-} 0.22, p = 0.021) than those with NSTE-ACS (n = 66). The percentage of expanding remodeling index (remodeling index >1.05) was significantly higher in the STE-ACS group (81.5% vs. 63.6%, p = 0.031). The patients with STE-ACS had significantly lower MDCT density of culprit lesions than patients with NSTE-ACS (25.8 {+-} 13.9 HU vs. 43.5 {+-} 19.1 HU, p < 0.001). Conclusions: Sixty-four-slice MDCT can accurately evaluate the stenotic severity and composition of culprit lesions in selected patients with either STE-ACS or NSTE-ACS. Culprit lesions in NSTE-ACS patients had significantly lower luminal area stenosis, plaque burden, remodeling index and higher MDCT density, which possibly reflect differences in the composition of vulnerable culprit plaques and thrombi.

  11. Assessment of Grafts and Coronary Arteries with 64-slice Computer Tomography(CT) Angiography after Coronary Artery Bypass Surgery - our experiences

    Veljanovska, Lidija; Sokolov, V.; Milev, Ivan; Idrizi, Spend; Mitrev, Zan

    2008-01-01

    The use of 64 slice CT (GE Light-Speed VCT) in evaluation of pathway and patency of the grafts, distal anastomosis and native vascular net in patients (pts) after coronary artery bypass grafting (CABG).

  12. Non-invasive detection of aortic and coronary atherosclerosis in homozygous familial hypercholesterolemia by 64 slice multi-detector row computed tomography angiography

    Homozygous familial hypercholesterolemia (HoFH) is a rare disorder characterized by the early onset of atherosclerosis, often at the ostia of coronary arteries. In this study we document for the first time that aortic and coronary atherosclerosis can be detected using 64 slice multiple detector row ...

  13. Non-invasive Detection of Aortic and Coronary Atherosclerosis in Homozygous Familial Hypercholesterolemia by 64 Slice Multi-detector Row Computed Tomography Angiography

    Homozygous familial hypercholesterolemia (HoFH) is a rare disorder characterized by the early onset of atherosclerosis, often at the ostia of coronary arteries. In this study we document for the first time that aortic and coronary atherosclerosis can be detected using 64 slice multiple detector-row ...

  14. Coronary calcium score as gatekeeper for 64-slice computed tomography coronary angiography in patients with chest pain: per-segment and per-patient analysis

    Palumbo, Anselmo Alessandro; Cademartiri, Filippo [Azienda Ospedaliero-Universitaria di Parma, Non-Invasive Cardiovascular Imaging, Department of Radiology and Cardiology, Parma (Italy); Erasmus Medical Center, Department of Radiology and Cardiology, Rotterdam (Netherlands); Maffei, Erica; Martini, Chiara [Azienda Ospedaliero-Universitaria di Parma, Non-Invasive Cardiovascular Imaging, Department of Radiology and Cardiology, Parma (Italy); Tarantini, Giuseppe [University of Padua, Department of Cardiology, Padua (Italy); Di Tanna, Gian Luca; Berti, Elena; Grilli, Roberto [Regional Health Agency, Regione Emilia Romagna, Bologna (Italy); Casolo, Giancarlo [Ospedale Versilia, Department of Cardiology, Viareggio (Italy); Brambilla, Valerio [Don Gnocchi ONLUS, Cardiovascular Rehabilitation Unit, Parma (Italy); Cerrato, Marcella; Rotondo, Antonio [University of Naples, Department of Radiology, Naples (Italy); Weustink, Annick C.; Mollet, Nico R.A. [Erasmus Medical Center, Department of Radiology and Cardiology, Rotterdam (Netherlands)

    2009-09-15

    We sought to investigate the performance of 64-slice CT in symptomatic patients with different coronary calcium scores. Two hundred patients undergoing 64-slice CT coronary angiography for suspected coronary artery disease were enrolled into five groups based on Agatston calcium score using the Mayo Clinic risk stratification: group 1: score 0, group 2: score 1-10, group 3: score 11-100, group 4: score 101-400, and group 5: score > 401. Diagnostic accuracy for the detection of significant ({>=}50% lumen reduction) coronary artery stenosis was assessed on a per-segment and per-patient base using quantitative coronary angiography as the gold standard. For groups 1 through 5, sensitivity was 97, 96, 91, 90, 92%, and specificity was 99, 98, 96, 88, 90%, respectively, on a per-segment basis. On a per-patient basis, the best diagnostic performance was obtained in group 1 (sensitivity 100% and specificity 100%) and group 5 (sensitivity 95% and specificity 100%). Progressively higher coronary calcium levels affect diagnostic accuracy of CT coronary angiography, decreasing sensitivity and specificity on a per-segment base. On a per-patient base, the best results in terms of diagnostic accuracy were obtained in the populations with very low and very high cardiovascular risk. (orig.)

  15. Coronary calcium score as gatekeeper for 64-slice computed tomography coronary angiography in patients with chest pain: per-segment and per-patient analysis

    We sought to investigate the performance of 64-slice CT in symptomatic patients with different coronary calcium scores. Two hundred patients undergoing 64-slice CT coronary angiography for suspected coronary artery disease were enrolled into five groups based on Agatston calcium score using the Mayo Clinic risk stratification: group 1: score 0, group 2: score 1-10, group 3: score 11-100, group 4: score 101-400, and group 5: score > 401. Diagnostic accuracy for the detection of significant (≥50% lumen reduction) coronary artery stenosis was assessed on a per-segment and per-patient base using quantitative coronary angiography as the gold standard. For groups 1 through 5, sensitivity was 97, 96, 91, 90, 92%, and specificity was 99, 98, 96, 88, 90%, respectively, on a per-segment basis. On a per-patient basis, the best diagnostic performance was obtained in group 1 (sensitivity 100% and specificity 100%) and group 5 (sensitivity 95% and specificity 100%). Progressively higher coronary calcium levels affect diagnostic accuracy of CT coronary angiography, decreasing sensitivity and specificity on a per-segment base. On a per-patient base, the best results in terms of diagnostic accuracy were obtained in the populations with very low and very high cardiovascular risk. (orig.)

  16. Myocardial bridging of the right coronary artery inside the right atrial myocardium identified by ECG-gated 64-slice multidetector computed tomography angiography.

    Chen, Chien-Cheng; Chen, Huan-Wu; Fu, Chen-Ju; Lin, Fen-Chiung; Wen, Ming-Shien; Liu, Yuan-Chang

    2010-01-01

    A myocardial bridge (MB) is defined as an intramyocardial course of a major epicardial coronary artery, and it is mainly confined to the left ventricle and the left anterior descending coronary artery. There are rare reports of right coronary MB seen during angiographic examination. Herein, we present a 49 year-old man with right coronary artery MB without luminal narrowing in the diastolic and systolic phases of electrocardiography-gated computed tomography images. The value of multi-detector computed tomography for the detection of anatomical variants in the cardiovascular system is further discussed. PMID:20438676

  17. Myocardial Bridging of the Right Coronary Artery inside the Right Atrial Myocardium Identified by ECG-gated 64-slice Multidetector Computed Tomography Angiography

    Yung-Liang Wan

    2010-04-01

    Full Text Available A myocardial bridge (MB is defined as an intramyocardial course of a major epicardialcoronary artery, and it is mainly confined to the left ventricle and the left anterior descendingcoronary artery. There are rare reports of right coronary MB seen during angiographicexamination. Herein, we present a 49 year-old man with right coronary artery MB withoutluminal narrowing in the diastolic and systolic phases of electrocardiography-gated computedtomography images. The value of multi-detector computed tomography for the detectionof anatomical variants in the cardiovascular system is further discussed.

  18. Comparison of myocardial perfusion SPECT with 64-slice multi-slice computed tomography angiography in cardiac screening of asymptomatic diabetic patients

    Lim, Il Han; Lee, Won Woo; Chang, Hyuck Jae; Choi, Sang II; Kim, Sang Eun [Seoul National Univ. College of Medicine, Seoul (Korea, Republic of)

    2007-07-01

    Asymptomatic diabetic patients may suffer silent ischemia. However, the question that what is the optimal screening tool for detection of cardiac disease in asymptomatic diabetic patients has not been addressed. We prospectively recruited diabetic patients who had not complained chest pain, and obtained myocardial perfusion SPECT (MPS) and cardiac CT angiography (CTA). We compared perfusion status on MPS with findings on CTA. A total of 110 diabetic patients (Age range 41-84, mean age 61.6{+-}7.74; gender, M: F 66:44) without cardiac symptom underwent both MPS and CTA. The MPS protocol was one-day single isotope study, adenosine stress Tc-99m MIBI/rest Tc-99m MIBI. CTA was conducted using 64-slice multi-slice CT (Brillance64, Philips Medical Systems). Perfusion status on MPS was assessed by summed-stress score (SSS) using 20-segment model, and SSS of {>=}4 was considered abnormal. Coronary stenosis of more than 50% luminal narrowing in CTA was considered significant, and coronary artery calcium scoring (CACS) was graded as: < or =10, 11-100, 101-400, or >400. MPS found abnormal perfusion in 11.8% (13/110) and CTA significant coronary stenosis in 20.9% (23/110). Five patients showed both abnormal perfusion and significant coronary stenosis. CACS (n=103 patients) were measured as; < or =10 in 45.6%, 11-100 in 28.1%, 101-400 in 19.4%, and >400 in 6.8%. The patient proportion of abnormal MPS in each CACS group were; 10.6% with < or = 10, 17.2% with 11-100, 5% with 101-400, and 0% with >400. The patient proportion of significant coronary stenosis on CTA in each CACS group were; 2.13% with < or =10, 27.6% with 11-100, 35% with 101-400, and 57.1% with >400. In asymptomatic diabetic patients, coronary stenosis by CTA showed correlation with coronary artery calcium scoring, but myocardial perfusion status by MPS did not. Long-term evaluation is essential for determination of prognostic significance of MPS and cardiac CTA.

  19. Comparison of determinations of left atrial volume by the biplane area-length and Simpson's methods using 64-slice computed tomography

    There is increasing evidence that left atrial (LA) size is an important predictor of adverse cardiovascular outcomes such as atrial fibrillation, stroke, and congestive heart failure. The aim of this study was to determine whether there is a difference in results of quantification of LA volume by the area-length and Simpson's methods using multislice computed tomography (MSCT). The study population consisted of 51 patients with sinus rhythm (sinus group) and 20 patients with atrial fibrillation (af group) clinically indicated for MSCT angiography for evaluation of coronary arteries. Maximum LA volume, obtained at end-systole from the phase immediately preceding mitral valve opening, was measured using the area-length and Simpson's methods. In the sinus group, the mean LA volumes, indexed to body surface area, were 48.4±17.9 ml/m2 with the area-length method and 48.3±17.0 ml/m2 with the Simpson's method. In the af group, the mean indexed LA volumes with the area-length method and the Simposon's method were 91.5±47.5 ml/m2 and 90.3±45.9 ml/m2, respectively. LA volumes calculated by the area-length method exhibited a strong linear relationship and agreement with those calculated using Simpson's method in both the groups (sinus group: r=0.99, P<0.0001, af group: r=0.99, P<0.0001). The area-length method is a simple and reproducible means of assessment of LA volume. Standardization of LA volume assessment using MSCT is important for serial follow-up and meaningful communication of results of testing among institutions and physicians. (author)

  20. Assessment of extracranial-intracranial bypass patency with 64-slice multidetector computerized tomography angiography

    Extracranial-intracranial (EC/IC) bypass is a useful procedure for the treatment of cerebral vascular insufficiency or complex aneurysms. We explored the role of multidetector computed tomography angiography (MDCTA), instead of digital subtraction angiography (DSA), for the postoperative assessment of EC/IC bypass patency. We retrospectively analyzed a consecutive series of 21 MDCTAs from 17 patients that underwent 25 direct or indirect EC/IC bypass procedures between April 2003 and November 2007. Conventional DSA was available for comparison in 13 cases. MDCTA used a 64-slice MDCT scanner (Aquilion 64, Toshiba). The proximal and distal patencies were analyzed independently on MDCTA and DSA by a neuroradiologist and a neurosurgeon. The bypass was considered patent when the entire donor vessel was opacified without discontinuity from proximal to distal ends and was visibly in contact with the recipient vessel. MDCTA depicted the patency status in every patient. Bypasses were patent in 22 cases, stenosed in one, and occluded in two. DSA always confirmed the results of the MDCTA (sensitivity = 100%, 95% CI = 0.655-1.0; specificity 100%, 95% CI = 0.05-1.0). MDCTA is a non-invasive and accurate exam to assess the postoperative EC/IC bypass patency and is a promising technique in routine follow-up. (orig.)

  1. Quantitativa analysis by 64-slice computed tomography in diagnosis of intermediate coronary artery stenosis%64排CT冠状动脉造影定量分析在冠状动脉临界病变中的价值

    施鸿毓; 陈晖; 仇兴标; 曲新凯; 方唯一

    2012-01-01

    目的 评价64排CT冠状动脉造影对临界病变定量分析的可行性.方法 入选2009年5月-2010年8月于上海交通大学附属胸科医院行64排CT冠状动脉造影检查提示为临界病变的91例患者,共205处病变.在2周内进行经皮冠状动脉造影及定量冠状动脉造影(QCA)分析.采用Bland-Altman分析和Pearson相关分析对比64排CT冠状动脉造影定量分析与QCA的结果.结果 64排CT冠状动脉造影检查示,病变参考直径为(3.1±0.4) mm,病变长度为(14.2±11.3)mm;狭窄程度为(57.8±0.7)%,与QCA测定的(58.2±13.9)%的差异无统计学意义(P=0.64).205个经64排CT冠状动脉造影定量分析示冠状动脉狭窄程度为40%~70%的病变中,QCA检查示27个病变(13.2%)的狭窄程度低于40%,43个病变(21.0%)高于70%,135个病变(65.9%)属于冠状动脉狭窄程度为40%~70%的临界病变.64排CT冠状动脉造影定量分析与QCA结果呈中度相关(r=0.599,P<0.001),但一致性较差(平均偏差为0.4%,95%一致性可信区间为-22.1%~22.9%).结论 64排CT冠状动脉造影对临界病变的诊断价值有限,其定量分析与QCA的一致性欠佳,目前临床实用价值有限.%Objective To evaluate the feasibility of quantitative analysis by 64-slice computed tomography (CT) in intermediate coronary artery lesions. Methods Totally 91 patients with 205 lesions were diagnosed as intermediate coronary artery stenosis by 64-slice CT from May 2009 to August 2010. Conventional percutaneous coronary angiography was performed within 2 weeks after CT scan. The results of 64-slice CT quantitative analysis and quantitive coronary angiography (OCA) were compared by Bland-Altman analysis and Pearson correlations. Results The average reference values of lesions were (3.1 ±0.4) mm in diameter and (14.2±11.3) mm in length by CT scan. Diameter stenosis was (57.8 + 0.7)% by CT quantification and (58.2 + 13.91)% by OCAi there was no significant difference

  2. Beam-hardening correction for virtual monochromatic imaging of myocardial perfusion via fast-switching dual-kVp 64-slice computed tomography. A pilot study using a human heart specimen

    Investigate the effectiveness of beam-hardening (BH) correction using ECG-gated dual-kVp computed tomography (CT) for myocardial imaging. A human heart specimen and artificial descending aorta were scanned using both dual-kVp and single 120-kVp modes. The myocardial CT values at the anterior and posterobasal walls were 89.4±6.2 and 87.1±6.9 hounsfield unit (HU) (P=0.59) for the 69-keV images, and 88.3±5.9 and 49.9±13.5 HU (P=0.002) for the 120-kVp images, respectively. Fast-switching dual-kVp technology is feasible for the correction of CT value deficits induced by BH that mimics perfusion defects. (author)

  3. 64-slice coronary computed tomography angiography using low tube voltage of 80 kV in subjects with normal body mass indices: comparative study using 120 kV

    Background. The radiation dose of coronary computed tomography (CT) angiography (CCTA) is generally higher than that of CT scans of other parts of the body, and there is concern that the high radiation dose may result in increased cancer risk. Although various techniques have recently been introduced to lower the radiation dose of CCTA, there has been no direct comparison between protocols with 80 and 120 kV. Purpose. To assess the image quality and radiation dose of 80-kV electrocardiography (ECG)-gated CCTA in subjects with a normal body mass index (BMI), compared to 120-kV ECG-gated CCTA. Material and Methods. This retrospective study was approved by our local ethics board, and the requirement of written informed consent was waived. We analyzed the CCTA images of 100 subjects with BMIs <25 kg/m2. Fifty subjects underwent 120-kV CCTA, and the other 50 subjects underwent 80-kV CCTA. Two blinded observers independently evaluated the subjective image quality of the coronary arteries. The objective image quality (signal-to-noise ratio [SNR] and contrast-to-noise ratio [CNR]) and radiation dose were also measured in each group. Results. Although the objective image quality of the 80-kV protocol images was significantly poorer than that of 120-kV protocol images (mean SNR, 14.9 ± 4.7 vs. 19.8 ± 4.4, P < 0.0001; mean CNR, 15.2 ± 4.8 vs. 21.6 ± 4.7, P < 0.0001), there was no significant difference in the subjective image quality between the two groups (mean image score, 4.7 ± 1.1 vs. 4.5 ± 0.7 for radiologist 1, P 0.273; 5.0 ± 1.0 vs. 4.8 ± 1.0 for radiologist 2, P = 0.197). The radiation dose was reduced by 70% with the 80-kV protocol and by 88% with the 80-kV and ECG-based tube current modulation than with the 120-kV protocol (3.42 ± 1.16 and 2.9 ± 0.8 vs. 11.49 ± 3.62 mSv, P < 0.0001). Conclusion. The low tube voltage CCTA protocol using 80 kV allows significant reduction of the radiation dose without impairing the subjective image quality in subjects with

  4. Introduction to coronary imaging with 64-slice Computed Tomography

    The aim of this article is to illustrate the main technical improvements in the last generation of 64-row CT scanners and the possible applications in coronary angiography. In particular, we describe the new physical components (X-ray tube-detectors system) and the general scan and reconstruction parameters. We then define the scan protocols for coronary angiography with the new generation of 64-row CT scanners to enable radiologists to perform a CT study on the basis of the diagnostic possibilities

  5. Calcium scoring using 64-slice MDCT, dual source CT and EBT : a comparative phantom study

    Groen, Jaap M.; Greuter, Marcel J. W.; Vliegenthart, R.; Suess, C.; Schmidt, B.; Zijlstra, F.; Oudkerk, M.

    2008-01-01

    Purpose Assessment of calcium scoring (Ca-scoring) on a 64-slice multi-detector computed tomography (MDCT) scanner, a dual-source computed tomography (DSCT) scanner and an electron beam tomography (EBT) scanner with a moving cardiac phantom as a function of heart rate, slice thickness and calcium de

  6. Calcium scoring using 64-slice MDCT, dual source CT and EBT: a comparative phantom study

    Groen, Jaap M.; Greuter, Marcel J. W.; Vliegenthart, R.; Suess, C.; Schmidt, B.; Zijlstra, F.; Oudkerk, M.

    2007-01-01

    Purpose Assessment of calcium scoring (Ca-scoring) on a 64-slice multi-detector computed tomography (MDCT) scanner, a dual-source computed tomography (DSCT) scanner and an electron beam tomography (EBT) scanner with a moving cardiac phantom as a function of heart rate, slice thickness and calcium density. Methods and materials Three artificial arteries with inserted calcifications of different sizes and densities were scanned at rest (0 beats per minute) and at 50–110 beats per minute (bpm) w...

  7. Influence of heart rate on image quality of 64-slice spiral computed coronary angiography and optimization on reconstruction of phase window

    Objective: To evaluate the influence of heart rate on the image quality of 64-slice spiral computed coronary angiography (MSCTCA) and optimize the image reconstruction window. Methods: According to the heart rate, 86 patients were classified into 5 groups: group A, the heart rate ≤60 beat per minute(BMP); group B,61-70BMP, group C,71-80BMP, and group D>80BMP. The image quality of MSCTCA was scored 5 grades from 1-5 according to heart motion artifact. The influences of heart rate and reconstruction phase on the image quality of MSCTCA were evaluated. Results: Average heart rate was 64.4 ±10.1BMP. Diagnostic image quality (score>3) was attained in 277 of 344 segments at the best reconstruction interval. There was a significant corxelation between average heart rate and image quality, but there was no difference between relative delay (%) reconstruction and absolute delay (ms) reconstruction on the image quality. Conclusion: Reducing average heart rate is beneficial for improving the image quality. (authors)

  8. Reverse Redistribution in Myocardial Perfusion Imaging: Revisited with 64-slice MDCT

    The authors report myocardial perfusion imaging of a patient showing reverse redistribution (RR) and a 64-slice multidetector-row computed tomography (MDCT) with corresponding findings. The patient had subendocardial myocardial infarction (MI) with positive electrocardiogram (EMG) findings and elevated levels of cardiac isoenzymes. Experiencing this case emphasizes the importance of complementary correlation of a new diagnostic modality that helps us to understand the nature of RR.

  9. Bouveret’s Syndrome: 64-Slice CT Diagnosis and Surgical Management—A Case Report

    Dinesh Sharma

    2012-01-01

    Full Text Available Gastric outlet obstruction caused by duodenal impaction of a large gallstone migrated through a cholecystoduodenal fistula has been referred to as Bouveret’s syndrome. We present a case of gallstone-induced duodenal obstruction in an elderly female patient, diagnosed on a 64-slice MDCT scanner. One-stage surgery, that is, stone removal and cholecystectomy, was performed resulting in relief of obstruction and complete cure. Clinical features, multidetector computed tomography (MDCT findings, and surgical management are discussed.

  10. Impact of 64-slice coronary CT on the management of patients presenting with acute chest pain: results of a prospective two-centre study

    Our two-centre prospective study evaluates the usefulness of 64-slice coronary computed tomography (CCT) to rule out significant coronary artery stenosis in patients admitted in emergency departments (ED) for acute coronary syndromes (ACS) with low-to-intermediate risk score. Patients (175) admitted for acute chest pain (ACP), unmodified electrocardiogram and first troponin measurement within normal ranges were included. A second troponin measurement and a 64-slice CCT within 24 h were performed. Major adverse cardiac events (MACE) were recorded during follow-up (6 months ± 2). 64-slice CCT was either normal or showed non-significant coronary stenosis in the majority of patients (78%). 64-slice CCT depicted significant stenosis (>50% diameter) in 22% of patient whereas initial clinical and biological evaluation was reassuring. For negative CCTs, elevated troponin at second measurement did not modify the strategy or treatment of patients. No MACEs were noted during follow up. In 12% of patients CCT identified unsuspected non-coronary abnormalities. Our study confirms 64-slice CCT utility to rule out significant coronary artery stenosis in 8/10 patients admitted in ED with ACP or ACS with low-to-intermediate risk score. Early discharge with a negative 64-slice CCT is associated with very low risk of cardiac events at 6 months. (orig.)

  11. Preliminary evaluation of 64-slice spiral CT coronary angiography in patients with coronary artery disease

    Objective: To investigate the image quality and diagnostic accuracy using 64-slice spiral computed tomography (64-CTA) scanner in patients with suspected coronary artery disease. Methods: Sixty eight patients with chest pain or post PTCA underwent CT coronary angiography (CTA) and selected coronary angiography (SCA). The SCA results were served as 'gold standard' to evaluate the diagnostic accuracy of CTA, while the sensitivity, positive predictive value (PPV) and negative predictive value (NPV) were calculated, respectively. Results: 64-slice spiral CT could clearly demonstrate the coronary arterial trunk and branchs with stenosis, calcifications abnormal orifise origination and bridge vascular disease; especially with high accuracy in revealing calcification and even with quantification. The sensitivity, specificity, PPV and NPV of the degree of stenosis more than 75% for coronary artery segments evaluated by CTA were significantly higher than those of the degree of stenosis less than 50% for coronary artery segments (P<0.01). Conclusion: CTA is a safe, simple and reliable noninvasive method for screening coronary artery disease in patients with chest pain. Moreover, 64-slice spiral CT could demonstrate not only the more delicate delineation of coronary arterial changes with 3D reconstruction and volume renderting but also the presence and quantity of calcium deposited on the vascular wall. (authors)

  12. Coronary artery dissection with rupture of aortic valve commissure following type A aortic dissection: the role of 64-slice MDCT.

    Das, K M; Abdou, Sayed M; El-Menyar, Ayman; Ayman, El Menyar; Khulaifi, A A; Nabti, A L

    2008-01-01

    A rare case of bilateral coronary artery dissection with rupture of aortic valve commissure following type A aortic dissection is described. 64-slice multidetector computed tomography (MDCT) was able to demonstrate both this findings along with involvement of other neck vessels. TEE demonstrated the severity and mechanisms of aortic valve damage and assisted the surgeon in valve repair. MDCT has played an invaluable role in the diagnosis of the abnormal details of such life-threatening vascular complications. PMID:18384568

  13. Detection of Postcoronary Stent Complication: Utility of 64-Slice Multidetector CT

    Alpa Bharati

    2012-01-01

    Full Text Available Coronary stent fracture is a known complication of coronary arterial stent placements. Multiple long-term risks are also associated with drug eluting stents. 64-slice multidetector CT (MDCT coronary angiography has been shown to detect poststent complications such as instent stenosis, thrombosis, stent migration and stent fractures. We report a case of stent fracture in a patient who underwent RCA stenting with associated RCA perforation and almost complete thrombosis of the RCA and peristent fibrinoid collection. This is a rare case of stent fracture with perforation of the RCA. The paper highlights the role of 64-row multidetector computed tomography (MDCT in evaluation of such poststent placement complications.

  14. Coronary ostial involvement in acute aortic dissection: detection with 64-slice cardiac CT.

    Ryan, E Ronan

    2012-02-01

    A 41-year-old man collapsed after lifting weights at a gym. Following admission to the emergency department, a 64-slice cardiac computed tomography (CT) revealed a Stanford Type A aortic dissection arising from a previous coarctation repair. Multiphasic reconstructions demonstrated an unstable, highly mobile aortic dissection flap that extended proximally to involve the right coronary artery ostium. Our case is an example of the application of electrocardiogram-gated cardiac CT in directly visualizing involvement of the coronary ostia in acute aortic dissection, which may influence surgical management.

  15. Influence of intra-coronary enhancement on diagnostic accuracy with 64-slice CT coronary angiography

    Cademartiri, Filippo [Azienda Ospedaliero-Universitaria di Parma, Department of Radiology and Cardiology, Parma (Italy); Erasmus Medical Center, Department of Radiology and Cardiology, Rotterdam (Netherlands); Azienda Ospedaliero-Universitaria di Parma, Non-invasive Cardiovascular Imaging Unit, Department of Radiology, Parma (Italy); Maffei, Erica; Aldrovandi, Annachiara; Fusaro, Michele; Vignali, Luigi; Menozzi, Alberto [Azienda Ospedaliero-Universitaria di Parma, Department of Radiology and Cardiology, Parma (Italy); Palumbo, Anselmo A. [Azienda Ospedaliero-Universitaria di Parma, Department of Radiology and Cardiology, Parma (Italy); Erasmus Medical Center, Department of Radiology and Cardiology, Rotterdam (Netherlands); Malago, Roberto [University of Verona, Department of Radiology, Verona (Italy); La Grutta, Ludovico; Midiri, Massimo [University of Palermo, Department of Radiology, Palermo (Italy); Meiijboom, W.B.; Mollet, Nico R.A.; Krestin, Gabriel P. [Erasmus Medical Center, Department of Radiology and Cardiology, Rotterdam (Netherlands); Brambilla, Valerio; Coruzzi, Paolo [Don Gnocchi ONLUS, Cardiovascular Rehabilitation Unit, Parma (Italy); Kirchin, Miles A. [Bracco Imaging SpA, Worldwide Medical and Regulatory Affairs, Milan (Italy)

    2008-03-15

    We assessed the effect of intra-coronary attenuation on diagnostic accuracy using 64-slice computed tomography coronary angiography (CT-CA). We enrolled 170 patients with suspected coronary artery disease who underwent conventional coronary angiography (CA) and 64-slice CT-CA (100 ml of Iomeprol 400 mg I/ml at 4 ml/s). The study population was divided into two groups (85 patients each based on median attenuation of 326 HU) based on mean arterial attenuation; group 1 with low attenuation and group 2 with high attenuation. Diagnostic accuracy for the detection of significant coronary artery stenosis was determined for both groups using CA as reference standard. Overall, 163 significant stenoses were detected in 1,030 assessable coronary artery segments in group 1 compared with 160 significant stenoses in 1,020 assessable segments in group 2. The average intra-coronary attenuation was significantly (P < 0.05) higher for group 2 (388 {+-} 46 HU) compared with group 1 (291 {+-} 33 HU). The corresponding sensitivity and specificity values for detection of significant coronary artery stenosis were higher for group 2 (96.3% and 97.6%, respectively) than for group 1 (82.8% and 93.2%, respectively) and were more marked in distal coronary segments than in proximal segments. Higher intra-coronary attenuation on CT-CA results in greater diagnostic accuracy for detection of coronary artery stenosis. (orig.)

  16. Influence of intra-coronary enhancement on diagnostic accuracy with 64-slice CT coronary angiography

    We assessed the effect of intra-coronary attenuation on diagnostic accuracy using 64-slice computed tomography coronary angiography (CT-CA). We enrolled 170 patients with suspected coronary artery disease who underwent conventional coronary angiography (CA) and 64-slice CT-CA (100 ml of Iomeprol 400 mg I/ml at 4 ml/s). The study population was divided into two groups (85 patients each based on median attenuation of 326 HU) based on mean arterial attenuation; group 1 with low attenuation and group 2 with high attenuation. Diagnostic accuracy for the detection of significant coronary artery stenosis was determined for both groups using CA as reference standard. Overall, 163 significant stenoses were detected in 1,030 assessable coronary artery segments in group 1 compared with 160 significant stenoses in 1,020 assessable segments in group 2. The average intra-coronary attenuation was significantly (P < 0.05) higher for group 2 (388 ± 46 HU) compared with group 1 (291 ± 33 HU). The corresponding sensitivity and specificity values for detection of significant coronary artery stenosis were higher for group 2 (96.3% and 97.6%, respectively) than for group 1 (82.8% and 93.2%, respectively) and were more marked in distal coronary segments than in proximal segments. Higher intra-coronary attenuation on CT-CA results in greater diagnostic accuracy for detection of coronary artery stenosis. (orig.)

  17. Diagnostic accuracy of non-invasive 64-slice CT coronary angiography in patients with stable angina pectoris

    Pugliese, Francesca; Krestin, Gabriel P. [Erasmus Medical Center, Department of Radiology, Rotterdam (Netherlands); Mollet, Nico R.A.; deFeyter, Pim J. [Erasmus Medical Center, Department of Radiology, Rotterdam (Netherlands); Erasmus Medical Center, Department of Cardiology, Rotterdam (Netherlands); Runza, Giuseppe [University of Palermo, Department of Radiology, Palermo (Italy); Azienda Ospedaliera di Parma, Department of Radiology, Parma (Italy); Mieghem, Carlos van; Meijboom, Willem B.; Baks, Timo [Erasmus Medical Center, Department of Cardiology, Rotterdam (Netherlands); Malagutti, Patrizia [Erasmus Medical Center, Department of Cardiology, Rotterdam (Netherlands); University of Ferrara, Department of Cardiology, Ferrara (Italy); Cademartiri, Filippo [Erasmus Medical Center, Department of Radiology, Rotterdam (Netherlands); Azienda Ospedaliera di Parma, Department of Radiology, Parma (Italy)

    2006-03-15

    Multislice computed tomography (CT) is an emerging technique for the non-invasive detection of coronary stenoses. While the diagnostic accuracy of 4-slice scanners was limited, 16-slice CT imagers showed promising results due to increased temporal and spatial resolution. These technical advances prompted us to evaluate the diagnostic performance of 64-slice CT coronary angiography in the detection of significant stenoses (defined as {>=} 50% luminal diameter reduction) versus invasive quantitative coronary angiography (QCA). Thirty-five patients with stable angina pectoris underwent CT coronary angiography performed with a 64-slice scanner (gantry rotation time 330 ms, individual detector width 0.6 mm) prior to conventional coronary angiography. Patients with heart rates >70 beats/min received 100 mg metoprolol orally. One hundred millilitres of contrast agent with an iodine concentration of 400 mgl/ml were injected at a rate of 5 ml/s into the antecubital vein. The CT scan was triggered with the bolus tracking technique. The sensitivity, specificity and the positive and negative predictive values of 64-slice CT were 99%, 96%, 78% and 99%, respectively, on a per-segment basis. The values obtained on a per-patient basis were 100%, 90%, 96% and 100%, respectively. When referral to catheterisation is questionable, CT coronary angiography may identify subjects with normal angiograms and consistently decrease the number of unnecessary invasive procedures. (orig.)

  18. Diagnostic accuracy of non-invasive 64-slice CT coronary angiography in patients with stable angina pectoris

    Multislice computed tomography (CT) is an emerging technique for the non-invasive detection of coronary stenoses. While the diagnostic accuracy of 4-slice scanners was limited, 16-slice CT imagers showed promising results due to increased temporal and spatial resolution. These technical advances prompted us to evaluate the diagnostic performance of 64-slice CT coronary angiography in the detection of significant stenoses (defined as ≥ 50% luminal diameter reduction) versus invasive quantitative coronary angiography (QCA). Thirty-five patients with stable angina pectoris underwent CT coronary angiography performed with a 64-slice scanner (gantry rotation time 330 ms, individual detector width 0.6 mm) prior to conventional coronary angiography. Patients with heart rates >70 beats/min received 100 mg metoprolol orally. One hundred millilitres of contrast agent with an iodine concentration of 400 mgl/ml were injected at a rate of 5 ml/s into the antecubital vein. The CT scan was triggered with the bolus tracking technique. The sensitivity, specificity and the positive and negative predictive values of 64-slice CT were 99%, 96%, 78% and 99%, respectively, on a per-segment basis. The values obtained on a per-patient basis were 100%, 90%, 96% and 100%, respectively. When referral to catheterisation is questionable, CT coronary angiography may identify subjects with normal angiograms and consistently decrease the number of unnecessary invasive procedures. (orig.)

  19. Radiation Exposure of Ovarian Cancer Patients: Contribution of CT Examinations Performed on Different MDCT (16 and 64 Slices) Scanners and Image Quality Evaluation

    Rizzo, S; D. Origgi; Brambilla, S.; Maria, F.; Foà, R; Raimondi, S; N. Colombo; Bellomi, M.

    2015-01-01

    Abstract The objective of this study is to compare radiation doses given to ovarian cancer patients by different computed tomographies (CTs) and to evaluate association between doses and subjective and objective image quality. CT examinations included were performed either on a 16-slice CT, equipped with automatic z-axis tube current modulation, or on a 64-slice CT, equipped with z-axis, xy-axis modulation, and adaptive statistical iterative algorithm (ASIR). Evaluation of dose included the f...

  20. Prevalence of anatomical variants and coronary anomalies in 543 consecutive patients studied with 64-slice CT coronary angiography

    Cademartiri, Filippo; La Grutta, Ludovico; Malagò, Roberto; Alberghina, Filippo; Meijboom, Willem B.; Pugliese, Francesca; Maffei, Erica; Palumbo, Anselmo Alessandro; Aldrovandi, Annachiara; Fusaro, Michele; Brambilla, Valerio; Coruzzi, Paolo; Midiri, Massimo; Mollet, Nico R. A.; Krestin, Gabriel P

    2008-01-01

    The aim of our study was to assess the prevalence of variants and anomalies of the coronary artery tree in patients who underwent 64-slice computed tomography coronary angiography (CT-CA) for suspected or known coronary artery disease. A total of 543 patients (389 male, mean age 60.5 ± 10.9) were reviewed for coronary artery variants and anomalies including post-processing tools. The majority of segments were identified according to the American Heart Association scheme. The coronary dominanc...

  1. 64-slice multidetector coronary CT angiography: in vitro evaluation of 68 different stents

    Maintz, David; Seifarth, Harald; Rink, Michael; Oezguen, Murat; Heindel, Walter; Fischbach, Roman [University of Muenster, Department of Clinical Radiology, Muenster (Germany); Raupach, Rainer; Flohr, Thomas [Siemens Medical Solutions, Forchheim (Germany); Sommer, Torsten [University of Bonn, Department of Radiology, Bonn (Germany)

    2006-04-15

    The purpose of this study was to test a large sample of different coronary artery stents using four image reconstruction approaches with respect to lumen visualization, lumen attenuation, and image noise in 64-slice multidetector-row computed tomography (MDCT) in vitro and to provide a catalogue of currently used coronary artery stents when imaged with state-of the-art MDCT. We examined 68 different coronary artery stents (57 stainless steel, four cobalt-chromium, one cobalt-alloy, two nitinol, four tantalum) in a coronary artery phantom (vessel diameter 3 mm, intravascular attenuation 250 HU, extravascular density -70). Stents were imaged in axial orientation with standard parameters: 32x0.6 collimation, pitch 0.24, 680 mAs, 120 kV, rotation time 0.37 s. Four different image reconstructions were obtained with varying convolution kernels and section thicknesses: (1) soft, 0.6 mm, (2) soft, 0.75, (3) medium soft, 0.6, and (4) stent-optimized sharp, 0.6. To evaluate visualization characteristics of of the stent, the lumen diameter, intraluminal density and noise were measured. The high-resolution kernel offered significantly better average lumen visualization (57% {+-}10%) and more realistic lumen attenuation (222 HU {+-}66 HU) at the expense of increased noise (15.3 HU {+-}3.7 HU) compared with the soft and medium-soft CT angiography (CTA) protocol (p<0.001 for all). Stents with a lumen visibility of more than 66% were: Arthos pico, Driver, Flex, Nexus2, S7, Tenax complete, Vision (all 67%), Symbiot, Teneo (70%), and Radius (73%). Only ten stents showed a lumen visibility of less than 50%. Stent lumen visibility largely varies depending on the stent type. Even with the improved spatial resolution of 64-slice CT, a stent-optimized kernel remains beneficial for stent visualization when compared with the standard medium-soft CTA protocol. Using 64-slice CT and high-resolution kernel, the majority of stent products show a lumen visibility of more than 50% of the stent

  2. Evaluation of peripheral artery stent with 64-slice multi-detector row CT angiography: Prospective comparison with digital subtraction angiography

    Li Xiaoming, E-mail: lixiaoming55@hotmail.co [Department of Radiology, Changhai Hospital, Second Military Medical University, Shanghai 200433 (China); Department of Radiology, Xin Hua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200092 (China); Li Yuhua, E-mail: liyuhua2000@hotmail.co [Department of Radiology, Xin Hua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200092 (China); Tian Jianming, E-mail: tianjianming1952@hotmail.co [Department of Radiology, Changhai Hospital, Second Military Medical University, Shanghai 200433 (China); Xiao Yi, E-mail: xiaoyi@188.co [Department of Radiology, Changhai Hospital, Second Military Medical University, Shanghai 200433 (China); Lu Jianping, E-mail: lujianping2000@hotmail.co [Department of Radiology, Changhai Hospital, Second Military Medical University, Shanghai 200433 (China); Jing Zaiping, E-mail: jingzaiping@hotmail.co [Department of Vascular Surgery, Changhai Hospital, Second Military Medical University, Shanghai 200433 (China); Sheng Jing, E-mail: shengjing1997@hotmail.co [Department of Radiology, Changhai Hospital, Second Military Medical University, Shanghai 200433 (China); Edwin, Angela, E-mail: angiedwin@yahoo.co [Department of Emergency, 34 Military Hospital, Wilberforce Barracks, Republic of Sierra Leone Armed Forces, Freetown (Sierra Leone); Wu Fanghong, E-mail: fanghong.wu@siemens.co [Medical Solutions, Shanghai Branch, Siemens Ltd. (China)

    2010-07-15

    Purpose: To assess the accuracy of 64-slice multi-detector row computed tomography (MDCT) angiography in the evaluation of peripheral artery in-stent or peristent restenosis, with conventional digital subtraction angiography (DSA) as the reference standard. Materials and methods: Forty-one patients (30 men, 11 women; mean age, 69.8 {+-} 9.2 years) with symptomatic peripheral arterial occlusive disease after peripheral artery stenting (81 stented lesions) underwent both conventional DSA and 64-slice MDCT angiography. Each stent was classified as evaluable or unevaluable, and every stent was divided into three segments (proximal stent, stent body, and distal stent), resulting in 243 segments. For evaluation, stenosis was graded as follows: 1, none or slight stenosis (<25%); 2, mild stenosis (25-49%); 3, moderate stenosis (50-74%); 4, severe stenosis or total occlusion ({>=}75%). Two readers evaluated all CT angiograms with regard to narrowing of in-stent or peristent restenosis by consensus. Results were compared with findings of the DSA. Results: Of 81 stents, 62 (76.5%) were determined to be assessable. The metal artifact of the gold marker and motion artifact increased uninterpretability of the images of stents. Overall, 24 of 28 in-stent restenosis and 38 of 53 persistent restenosis were correctly detected by MDCT (85.7% and 71.7% sensitivity). In evaluable stents, 21 of 22 in-stent restenoses and 27 of 28 persistent restenosis were correctly detected (95.4% and 96.4% sensitivity). Additionally, as the grade of stenosis increases, the mean level of CT values in the stent lumina decreases linearly accordingly. Conclusion: 64-Slice MDCT has a high accuracy for the detection of significant in-stent or peristent restenosis of assessable stents in patients with peripheral artery stent implantation and therefore can be considered as a valuable noninvasive technique for stent surveillance.

  3. Evaluation of peripheral artery stent with 64-slice multi-detector row CT angiography: Prospective comparison with digital subtraction angiography

    Purpose: To assess the accuracy of 64-slice multi-detector row computed tomography (MDCT) angiography in the evaluation of peripheral artery in-stent or peristent restenosis, with conventional digital subtraction angiography (DSA) as the reference standard. Materials and methods: Forty-one patients (30 men, 11 women; mean age, 69.8 ± 9.2 years) with symptomatic peripheral arterial occlusive disease after peripheral artery stenting (81 stented lesions) underwent both conventional DSA and 64-slice MDCT angiography. Each stent was classified as evaluable or unevaluable, and every stent was divided into three segments (proximal stent, stent body, and distal stent), resulting in 243 segments. For evaluation, stenosis was graded as follows: 1, none or slight stenosis (<25%); 2, mild stenosis (25-49%); 3, moderate stenosis (50-74%); 4, severe stenosis or total occlusion (≥75%). Two readers evaluated all CT angiograms with regard to narrowing of in-stent or peristent restenosis by consensus. Results were compared with findings of the DSA. Results: Of 81 stents, 62 (76.5%) were determined to be assessable. The metal artifact of the gold marker and motion artifact increased uninterpretability of the images of stents. Overall, 24 of 28 in-stent restenosis and 38 of 53 persistent restenosis were correctly detected by MDCT (85.7% and 71.7% sensitivity). In evaluable stents, 21 of 22 in-stent restenoses and 27 of 28 persistent restenosis were correctly detected (95.4% and 96.4% sensitivity). Additionally, as the grade of stenosis increases, the mean level of CT values in the stent lumina decreases linearly accordingly. Conclusion: 64-Slice MDCT has a high accuracy for the detection of significant in-stent or peristent restenosis of assessable stents in patients with peripheral artery stent implantation and therefore can be considered as a valuable noninvasive technique for stent surveillance.

  4. Radiation exposure of ovarian cancer patients: contribution of CT examinations performed on different MDCT (16 and 64 slices) scanners and image quality evaluation: an observational study.

    Rizzo, Stefania; Origgi, Daniela; Brambilla, Sarah; De Maria, Federica; Foà, Riccardo; Raimondi, Sara; Colombo, Nicoletta; Bellomi, Massimo

    2015-05-01

    The objective of this study is to compare radiation doses given to ovarian cancer patients by different computed tomographies (CTs) and to evaluate association between doses and subjective and objective image quality.CT examinations included were performed either on a 16-slice CT, equipped with automatic z-axis tube current modulation, or on a 64-slice CT, equipped with z-axis, xy-axis modulation, and adaptive statistical iterative algorithm (ASIR). Evaluation of dose included the following dose descriptors: volumetric CT dose index (CTDIvol), dose length product (DLP), and effective dose (E). Objective image noise was evaluated in abdominal aorta and liver. Subjective image quality was evaluated by assessment of image noise, spatial resolution and diagnostic acceptability.Mean and median CTDIvol, DLP, and E; correlation between CTDIvol and DLP and patients' weight; comparison of objective noise for the 2 scanners; association between dose descriptors and subjective image quality.The 64-slice CT delivered to patients 24.5% lower dose (P descriptors (CTDIvol, DLP, E) and weight (P descriptors and image noise for the 64-slice CT, and between dose descriptors and spatial resolution for the 16-slice CT.Current dose reduction systems may reduce radiation dose without significantly affecting image quality and diagnostic acceptability of CT exams. PMID:25929914

  5. 64-slice spiral CT in the diagnosis of Caroli disease

    Objective: To investigate the value of 64-slice spiral CT in the diagnosis of Caroli disease. Methods: 64-slice spiral CT of 15 patients with histologically proven Caroli disease was reviewed. Results: All cases were polycystic or multi-tubular hypodensities in the livers communicating with intrahepatic bile ducts. There was no contrast enhancement. The central dot sign was detected on 2 patients. Of 12 patients with type I disease, ancillary findings included multiple hemangiomas and small cysts in the liver (2), bile duct stones (4), pneumobilia (3), and cholangitis (1). Of the remaining 3 patients with type II disease, two had liver cirrhosis and the other cholangitis with periportal fibrosis. Conclusion: 64 slice spiral CT with multiplanar reconstruction allows clear depiction of cystic liver lesions and their relationship with intrahepatic bile ducts. It is valuable in the diagnosis of Caroli disease. (authors)

  6. Diagnostic accuracy of 64-slice multidetector CT for detection of in-stent restenosis in an unselected, consecutive patient population

    Haraldsdottir, Sigurdis, E-mail: sigurdisha@gmail.com [Boston Medical Center, 72 East Concord Street (Evans 124), Boston, MA, 02118 (United States); Gudnason, Thorarinn, E-mail: thorgudn@landspitali.is [Landspitali University Hospital, Hringbraut, 101 Reykjavik (Iceland); Sigurdsson, Axel F., E-mail: axelfsig@landspitali.is [Landspitali University Hospital, Hringbraut, 101 Reykjavik (Iceland); Gudjonsdottir, Jonina, E-mail: jonina@rd.is [Rontgen Domus Medica, Egilsgata 3, 101 Reykjavik (Iceland); Lehman, Sam J., E-mail: slehman@partners.org [Massachusetts General Hospital, 165 Cambridge Street, Suite 400, Boston, MA 02114 (United States); Eyjolfsson, Kristjan, E-mail: kristey@landspitali.is [Landspitali University Hospital, Hringbraut, 101 Reykjavik (Iceland); Scheving, Sigurpall S., E-mail: sigurpal@landspitali.is [Landspitali University Hospital, Hringbraut, 101 Reykjavik (Iceland); Gibson, C. Michael, E-mail: mgibson@perfuse.org [Beth Israel Deaconess Medical Center, 330 Brookline Avenue, Boston, MA 02115 (United States); Hoffmann, Udo, E-mail: uhoffmann@partners.org [Massachusetts General Hospital, 165 Cambridge Street, Suite 400, Boston, MA 02114 (United States); Jonsdottir, Birna, E-mail: birna@rd.is [Rontgen Domus Medica, Egilsgata 3, 101 Reykjavik (Iceland); Andersen, Karl, E-mail: andersen@landspitali.is [Landspitali University Hospital, Hringbraut, 101 Reykjavik (Iceland)

    2010-11-15

    Objectives: To investigate the diagnostic accuracy of 64-slice multidetector computed tomography (64-CT) for detection of in-stent restenosis (ISR) in an unselected, consecutive patient population. Background: Detection of in-stent restenosis by cardiac CT would be a major advance for the evaluation of patients suspected of having ISR. However, the diagnostic accuracy of current generation 64-CT in this context is not fully established. Methods: We conducted a prospective study on patients with stable angina or acute coronary syndrome with no prior history of coronary artery disease. Six months after percutaneous coronary intervention (PCI) with stent placement they underwent a 64-CT scan (Toshiba Multi-Slice Aquilion 64) and consequently a repeat coronary angiography for comparison. Cardiac CT data sets were analyzed for the presence of in-stent restenosis by two independent expert readers blinded to the coronary angiographic data. Results: Ninety-three patients with a total of 140 stents were evaluated. Males comprised 82% of the study group and the mean age was 63 {+-} 10 years. The mean time from PCI to the repeat coronary angiography was 208 {+-} 37 days and the mean time from 64-CT to repeat coronary angiography was 3.7 {+-} 4.9 days. The restenosis rate according to coronary angiography was 26%. Stent diameter, strut thickness, heart rate and body mass index (BMI) significantly affected image quality. The sensitivity, specificity, positive and negative predictive values of 64-CT for detection of in-stent restenosis were 27%, 95%, 67% and 78%, respectively. Conclusions: Current generation, 64-slice CT, remains limited in its ability to accurately detect in-stent restenosis.

  7. Measurement of scattered radiation in a volumetric 64-slice CT scanner using three experimental techniques

    Akbarzadeh, A; Ay, M R; Sarkar, S [Department of Medical Physics and Biomedical Engineering, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Ghadiri, H [Research Center for Science and Technology in Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Zaidi, H [Division of Nuclear Medicine, Geneva University Hospital, CH-1211 Geneva (Switzerland)], E-mail: mohammadreza_ay@tums.ac.ir

    2010-04-21

    Compton scatter poses a significant threat to volumetric x-ray computed tomography, bringing cupping and streak artefacts thus impacting qualitative and quantitative imaging procedures. To perform appropriate scatter compensation, it is necessary to estimate the magnitude and spatial distribution of x-ray scatter. The aim of this study is to compare three experimental methods for measurement of the scattered radiation profile in a 64-slice CT scanner. The explored techniques involve the use of collimator shadow, a single blocker (a lead bar that suppresses the primary radiation) and an array blocker. The latter was recently proposed and validated by our group. The collimator shadow technique was used as reference for comparison since it established itself as the most accurate experimental procedure available today. The mean relative error of measurements in all tube voltages was 3.9 {+-} 5.5% (with a maximum value of 20%) for the single blocker method whereas it was 1.4 {+-} 1.1% (with a maximum value of 5%) for the proposed blocker array method. The calculated scatter-to-primary ratio (SPR) using the blocker array method for the tube voltages of 140 kVp and 80 kVp was 0.148 and 1.034, respectively. For a larger polypropylene phantom, the maximum SPR achieved was 0.803 and 6.458 at 140 kVp and 80 kVp, respectively. Although the three compared methods present a reasonable accuracy for calculation of the scattered profile in the region corresponding to the object, the collimator shadow method is by far the most accurate empirical technique. Nevertheless, the blocker array method is relatively straightforward for scatter estimation providing minor additional radiation exposure to the patient.

  8. Diagnostic Accuracy of 64-Slice MDCT Coronary Angiography for the Assessment of Coronary Artery Disease in Korean Patients with Type 2 Diabetes

    Jun Sung Moon

    2013-02-01

    Full Text Available BackgroundA 64-slice multidetector computed tomography (MDCT is well known to be a useful noninvasive form of angiography for the general population, but not for certain patients with diabetes. The aim of this study was to investigate the diagnostic accuracy and usefulness of 64-slice MDCT coronary angiography for detecting coronary artery disease in Korean patients with type 2 diabetes mellitus (T2DM.MethodsA total of 240 patients were included, 74 of whom had type 2 diabetes (M:F=40:33; 41.8±9.5 years. We compared significant coronary stenosis (>50% luminal narrowing in MDCT with invasive coronary angiography (ICA by segment, artery, and patient. We also evaluated the influence of obesity and coronary calcium score on MDCT accuracy.ResultsOf the 4,064 coronary segments studied, 4,062 segments (T2DM=1,109 were assessed quantitatively by both MDCT and ICA, and 706 segments (T2DM=226 were detected as a significant lesion by ICA in all patients. Sensitivity, specificity, as well as positive and negative predictive values for the presence of significant stenosis in T2DM were: by segment, 89.4%, 96.4%, 85.8%, and 97.4%, respectively; by artery (n=222, 95.1%, 92.9%, 94.4%, and 93.8%, respectively; by patients (n=74, 98.4%, 100.0%, 98.4%, and 90.0%, respectively. Regardless of presence of diabetes, there was no significant difference in diagnostic accuracy. Obesity (≥25 kg/m2 and coronary calcium score did not also affect the diagnostic accuracy of MDCT.ConclusionThe 64-slice MDCT coronary angiography was found to have similar diagnostic accuracy with ICA, regardless of diabetes. These results suggest MDCT may be helpful to reduce unnecessary invasive studies for patients with diabetes.

  9. Computed Tomography (CT) -- Sinuses

    Full Text Available ... News Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Sinuses What is CT (Computed Tomography) of ... of CT of the Sinuses? What is CT (Computed Tomography) of the Sinuses? Computed tomography, more commonly known ...

  10. Computed Tomography (CT) -- Sinuses

    ... Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Sinuses Computed tomography (CT) of the sinuses ... CT of the Sinuses? What is CT (Computed Tomography) of the Sinuses? Computed tomography, more commonly known ...

  11. Computed Tomography (CT) -- Sinuses

    Full Text Available ... Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Sinuses Computed tomography (CT) of the sinuses ... CT of the Sinuses? What is CT (Computed Tomography) of the Sinuses? Computed tomography, more commonly known ...

  12. Myocardial Bridging of the Right Coronary Artery inside the Right Atrial Myocardium Identified by ECG-gated 64-slice Multidetector Computed Tomography Angiography

    Yung-Liang Wan; Ming-Shien Wen; Fen-Chiung Lin; Chen-Ju Fu; Huan-Wu Chen; Chien-Cheng Chen; Yuan-Chang Liu

    2010-01-01

    A myocardial bridge (MB) is defined as an intramyocardial course of a major epicardialcoronary artery, and it is mainly confined to the left ventricle and the left anterior descendingcoronary artery. There are rare reports of right coronary MB seen during angiographicexamination. Herein, we present a 49 year-old man with right coronary artery MB withoutluminal narrowing in the diastolic and systolic phases of electrocardiography-gated computedtomography images. The value of multi-detector com...

  13. 64-multislice detector computed tomography coronary angiography as potential alternative to conventional coronary angiography: a systematic review and meta-analysis

    Abdulla, Jawdat; Abildstrøm, Steen Zabell; Gøtzsche, Ole;

    2007-01-01

    AIMS: To evaluate the diagnostic accuracy of 64-slice multi-detector computed tomography coronary angiography (64-SCTA) compared with the standard reference conventional coronary angiography (CCA). METHODS AND RESULTS: Based on a systematic search, 27 studies including 1740 patients were eligible...

  14. Clinical evaluation of 64-slice CT assessment of global left ventricular function using automated cardiac phase selection

    Left ventricular (LV) function provides prognostic information regarding the morbidity and mortality of patients. An automated cardiac phase selection algorithm has the potential to support the assessment of LV function with computed tomography (CT). This algorithm is clinically evaluated for 64-slice cardiac CT. Examinations of twenty consecutive patients were selected. Electrocardiogram gated contrast-enhanced CT was performed. Reconstructions were performed using an automated and a manual method, followed by the determination of the global LV function. Significances were tested using 2-sided Student's t-tests. Reduction in post processing time and storage capacity were estimated. A slightly smaller mean end-systolic volume was found with the automated method (52±18 ml vs 54±17 ml, p=0.02, r=0.99). The mean LV ejection fraction was slightly larger with the automated method (65±8% vs 64±8%, p=0.004, r=0.99). The estimated reduction in post processing time was maximal 5 min per patient with a potential 80% data storage reduction. Results of the automated phase selection algorithm are similar to the manual method. The automated tool reduces post processing time, reconstruction time and transfer time. (author)

  15. Imaging of Herniated Discs of the Cervical Spine: Inter-Modality Differences between 64-Slice Multidetector CT and 1.5-T MRI

    Yi, Ji Sook; Cha, Jang Gyu [Dept. of Radiology, Soonchunhyang University Bucheon Hospital, Bucheon (Korea, Republic of); Han, Jong Kyu [Dept. of Radiology, Soonchunhyang University Cheonan Hospital, Cheonan (Korea, Republic of); Kim, Hyun Joo [Dept. of Radiology, Soonchunhyang University Seoul Hospital, Seoul (Korea, Republic of)

    2015-08-15

    To assess inter-modality variability when evaluating cervical intervertebral disc herniation using 64-slice multidetector-row computed tomography (MDCT) and magnetic resonance imaging (MRI). Three musculoskeletal radiologists independently reviewed cervical spine 1.5-T MRI and 64-slice MDCT data on C2-3 though C6-7 of 51 patients in the context of intervertebral disc herniation. Interobserver and inter-modality agreements were expressed as unweighted kappa values. Weighted kappa statistics were used to assess the extents of agreement in terms of the number of involved segments (NIS) in disc herniation and epicenter measurements collected using MDCT and MRI. The interobserver agreement rates upon evaluation of disc morphology by the three radiologists were in fair to moderate agreement (k = 0.39-0.53 for MDCT images; k = 0.45-0.56 for MRIs). When the disc morphology was categorized into two and four grades, the inter-modality agreement rates were moderate (k-value, 0.59) and substantial (k-value, 0.66), respectively. The inter-modality agreements for evaluations of the NIS (k-value, 0.78) and the epicenter (k-value, 0.79) were substantial. Also, the interobserver agreements for the NIS (CT; k-value, 0.85 and MRI; k-value, 0.88) and epicenter (CT; k-value, 0.74 and MRI; k-value, 0.70) evaluations by two readers were substantial. MDCT tended to underestimate the extent of herniated disc lesions compared with MRI. Multidetector-row computed tomography and MRI showed a moderate-to-substantial degree of inter-modality agreement for the assessment of herniated cervical discs. MDCT images have a tendency to underestimate the anterior/posterior extent of the herniated disc compared with MRI.

  16. Imaging of Herniated Discs of the Cervical Spine: Inter-Modality Differences between 64-Slice Multidetector CT and 1.5-T MRI

    To assess inter-modality variability when evaluating cervical intervertebral disc herniation using 64-slice multidetector-row computed tomography (MDCT) and magnetic resonance imaging (MRI). Three musculoskeletal radiologists independently reviewed cervical spine 1.5-T MRI and 64-slice MDCT data on C2-3 though C6-7 of 51 patients in the context of intervertebral disc herniation. Interobserver and inter-modality agreements were expressed as unweighted kappa values. Weighted kappa statistics were used to assess the extents of agreement in terms of the number of involved segments (NIS) in disc herniation and epicenter measurements collected using MDCT and MRI. The interobserver agreement rates upon evaluation of disc morphology by the three radiologists were in fair to moderate agreement (k = 0.39-0.53 for MDCT images; k = 0.45-0.56 for MRIs). When the disc morphology was categorized into two and four grades, the inter-modality agreement rates were moderate (k-value, 0.59) and substantial (k-value, 0.66), respectively. The inter-modality agreements for evaluations of the NIS (k-value, 0.78) and the epicenter (k-value, 0.79) were substantial. Also, the interobserver agreements for the NIS (CT; k-value, 0.85 and MRI; k-value, 0.88) and epicenter (CT; k-value, 0.74 and MRI; k-value, 0.70) evaluations by two readers were substantial. MDCT tended to underestimate the extent of herniated disc lesions compared with MRI. Multidetector-row computed tomography and MRI showed a moderate-to-substantial degree of inter-modality agreement for the assessment of herniated cervical discs. MDCT images have a tendency to underestimate the anterior/posterior extent of the herniated disc compared with MRI

  17. Computed Tomography (CT) -- Head

    ... Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Head Computed tomography (CT) of the head uses special x-ray ... What is CT Scanning of the Head? Computed tomography, more commonly known as a CT or CAT ...

  18. Usefulness of 64-slice MDCT for follow-up of young children with coronary artery aneurysm due to Kawasaki disease: Initial experience

    To evaluate the initial application and value of 64-slice multidetector computed tomography as an alternative diagnostic modality in the follow-up of young children with coronary artery aneurysm due to Kawasaki disease. Twelve boys (mean age 5.1 years, range 1.8-7.8 years) for follow-up (time range from 1.1 to 5.1 years) of known Kawasaki disease and coronary artery aneurysm underwent 64-slice MDCT ECG-gated coronary angiography. All data were acquired without breath holding. Two pediatric radiologists independently assessed image quality and the diameter of all coronary segments were measured for each patient. The number, position, shape and size of each coronary artery aneurysm were observed and compared with those of ECHO performed previously. A total of 118/156 segments permitted visualization with diagnostic image quality, the CT measurements showed good inter-observer and intra-observer reliability, coefficients were 0.93 and 0.88, respectively. A total of 30 coronary artery aneurysms were identified with measured mean of 7.5 ± 3.8 mm in diameter, and of 12.4 ± 9.1 mm in longitudinal lengths.10 tumors were small, 8 tumors were medium and 12 tumors were giant aneurysm. The affected segments included LM7/12(58.3%), 9/12(75%) of LAD1, 4/12(33.3%) of LAD2, 2/12(16.7%) of LCX1; 6/12(50%) of RCA1, 9/12(75%) of RCA2 and 4/12(33.3%) of RCA3, including affected two segments in 9 tumors and three segments in 1 tumor. Calcifications were found in 5 aneurysms and 3/5 with thrombosis; six stenotic segments were found. ECHO failed to detect 8 tumors with 2/8 in LAD, 1/8 in LCX and 5/8 in RCA, and those included 4 small aneurysms. The use of 64-slice MDCT angiography proved valuable for monitoring young children with Kawasaki disease. However, further study is necessary to specify the sensitivity and specificity of MDCT in the follow-up.

  19. Diagnostic Value of 64-Slice Dual-Source CT Coronary Angiography in Patients with Atrial Fibrillation: Comparison with Invasive Coronary Angiography

    We wanted to evaluate the image quality and diagnostic value of 64-slice dual-source computed tomography (DSCT) coronary angiography in patients with atrial fibrillation (Afib). The coronary arteries of 22 Afib patients seen on DSCT were classified into 15 segments and the imaging quality (excellent, good, moderate and poor) and significant stenoses (≥ 50%) were evaluated by two radiologists who were blinded to the conventional coronary angiography (CAG) results. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for detecting important coronary artery stenosis were calculated. McNemar test was used to determine any significant difference between DSCT and CAG, and Cohen's Kappa statistics were calculated for the intermodality and interobserver agreement. The mean heart rate was 89 ± 8.3 bpm (range: 80-118 bpm). A range from 250 msec to 300 msec within the RR interval was the optimal reconstruction interval for the patients with Afib. The respective overall sensitivity, specificity, PPV and NPV values were 74%, 97%, 81% and 96% for reader 1 and 72%, 98%, 85% and 96% for reader 2. No significant difference between DSCT and CAG was found for detecting a significant stenosis (reader 1, p = 1.0; reader 2, p = 0.727). Cohen's Kappa statistics demonstrated good intermodality and interobserver agreement. 64-slice DSCT coronary angiography provides good image quality in patients with atrial fibrillation without the need for controlling the heart rate. DSCT can be used for ruling out significant stenosis in patients with atrial fibrillation with its high NPV for detecting in important stenosis.

  20. Diagnostic Value of 64-Slice Dual-Source CT Coronary Angiography in Patients with Atrial Fibrillation: Comparison with Invasive Coronary Angiography

    Zhang, Jian Jun; Liu, Tie; Feng, Yue; Wu, Wei Feng; Mou, Cai Yun; Zhai, Li Hao [Zhejiang Hospital, Hangzhou (China)

    2011-08-15

    We wanted to evaluate the image quality and diagnostic value of 64-slice dual-source computed tomography (DSCT) coronary angiography in patients with atrial fibrillation (Afib). The coronary arteries of 22 Afib patients seen on DSCT were classified into 15 segments and the imaging quality (excellent, good, moderate and poor) and significant stenoses ({>=} 50%) were evaluated by two radiologists who were blinded to the conventional coronary angiography (CAG) results. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for detecting important coronary artery stenosis were calculated. McNemar test was used to determine any significant difference between DSCT and CAG, and Cohen's Kappa statistics were calculated for the intermodality and interobserver agreement. The mean heart rate was 89 {+-} 8.3 bpm (range: 80-118 bpm). A range from 250 msec to 300 msec within the RR interval was the optimal reconstruction interval for the patients with Afib. The respective overall sensitivity, specificity, PPV and NPV values were 74%, 97%, 81% and 96% for reader 1 and 72%, 98%, 85% and 96% for reader 2. No significant difference between DSCT and CAG was found for detecting a significant stenosis (reader 1, p = 1.0; reader 2, p = 0.727). Cohen's Kappa statistics demonstrated good intermodality and interobserver agreement. 64-slice DSCT coronary angiography provides good image quality in patients with atrial fibrillation without the need for controlling the heart rate. DSCT can be used for ruling out significant stenosis in patients with atrial fibrillation with its high NPV for detecting in important stenosis.

  1. Computed Tomography (CT) -- Head

    Full Text Available ... News Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Head What is CT Scanning of the ... Head? What is CT Scanning of the Head? Computed tomography, more commonly known as a CT or CAT ...

  2. Computed Tomography (CT) -- Head

    Full Text Available ... Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Head Computed tomography (CT) of the head uses special x-ray ... What is CT Scanning of the Head? Computed tomography, more commonly known as a CT or CAT ...

  3. Application of 64 slice spiral CT in evaluating the patency of coronary artery after stent implantation

    Yong-Shu Gao; Xing-Can Ma

    2015-01-01

    Objective:To explore the feasibility and effectiveness of 64 slice spiral CT in evaluating the patency of coronary artery after stent implantation.Methods:The 64 slice spiral CT image data of 125 patients after coronary artery stent implantation were collected, meanwhile, the image data of 25 patients underwent coronary angiography were also collected. The feasibility and accuracy of 64 slice spiral CT coronary artery stent imaging were comparatively analyzed. Results: The 64 slice spiral CT imaging quality with a stent diameter greater than 3.00 mm was significantly superior to that with a diameter of 2.25-3.00 mm. The CT imaging quality in the left main coronary artery and anterior descending artery was significantly higher than that in the left circumflex coronary artery. The CT imaging quality in the left main coronary artery was significantly higher than that in the right coronary artery. The CT reconstruction imaging quality in the drug coating stent was significantly superior to that in the bare metal stent. The sensitivity of 64 slice spiral CT was 100.00%, and the accuracy was 100.00%. In detecting the coronary artery with occlusion and stenosis (stent stenosis greater than 50%), the sensitivity was 90.00%, the false negative rate was 10.00%, and the positive predicative value was 100.00%.Conclusions:The effect of 64 slice spiral CT coronary imaging in evaluating the patency of coronary artery after stent implantation is highly consistent with that by coronary angiography, with a simple operation, less risk, and low cost, and thus, it can be completely taken as the imaging method in evaluating the patency of coronary artery after stent implantation.

  4. Stress Computed Tomography Myocardial Perfusion Imaging: A New Topic in Cardiology.

    Seitun, Sara; Castiglione Morelli, Margherita; Budaj, Irilda; Boccalini, Sara; Galletto Pregliasco, Athena; Valbusa, Alberto; Cademartiri, Filippo; Ferro, Carlo

    2016-02-01

    Since its introduction about 15 years ago, coronary computed tomography angiography has become today the most accurate clinical instrument for noninvasive assessment of coronary atherosclerosis. Important technical developments have led to a continuous stream of new clinical applications together with a significant reduction in radiation dose exposure. Latest generation computed tomography scanners (≥ 64 slices) allow the possibility of performing static or dynamic perfusion imaging during stress by using coronary vasodilator agents (adenosine, dipyridamole, or regadenoson), combining both functional and anatomical information in the same examination. In this article, the emerging role and state-of-the-art of myocardial computed tomography perfusion imaging are reviewed and are illustrated by clinical cases from our experience with a second-generation dual-source 128-slice scanner (Somatom Definition Flash, Siemens; Erlangen, Germany). Technical aspects, data analysis, diagnostic accuracy, radiation dose and future prospects are reviewed. PMID:26774540

  5. 64-slice CT imaging in a case of total anomalous pulmonary venous circulation

    For long, catheter angiography has been the investigation of choice for the diagnosis of congenital anomalies of the heart such as total anomalous pulmonary venous circulation (TAPVC). In the last few years, MRI and multislice CT scan have also been introduced for this purpose. We report a case where 64-slice CT scan was found very useful in the evaluation of TAPVC

  6. Computed Tomography (CT) -- Sinuses

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos News Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Sinuses What is CT (Computed Tomography) of the Sinuses? What are ...

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

    ... Site Index A-Z Children's (Pediatric) CT (Computed Tomography) Pediatric computed tomography (CT) is a fast, painless exam that uses ... of Children's CT? What is Children's CT? Computed tomography, more commonly known as a CT or CAT ...

  8. Computed Tomography (CT) -- Head

    Full Text Available ... Videos related to Computed Tomography (CT) - Head About this Site RadiologyInfo.org is produced by: Please note ... you can search the ACR-accredited facilities database . This website does not provide cost information. The costs ...

  9. Computed Tomography (CT) -- Sinuses

    Full Text Available ... Images related to Computed Tomography (CT) - Sinuses About this Site RadiologyInfo.org is produced by: Please note ... you can search the ACR-accredited facilities database . This website does not provide cost information. The costs ...

  10. Computed Tomography (CT) -- Sinuses

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos News Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Sinuses ...

  11. Computed Tomography (CT) -- Head

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos News Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Head ...

  12. Optimizing 64-slice spiral CT angiography in lower extremity arterial disease with individualized injection protocol

    Objective: To explore the optimal protocol of the 64-slice spiral CT angiography (CTA) in lower extremity arterial disease. Methods: Forty -eight patients with clinically suspected lower extremity arterial disease underwent GE LightSpeed VCT using individual and traditional injection protocols. The clinical value of CTA was evaluated using DSA as the standard reference. Results: Satisfactory images were obtained from 47 of 48 cases. Images fulfilling clinical diagnostic requirements after appropriate post -procession on workstation were obtained from 1 case. The image quality of the group with the individualized injection protocol was significantly superior to that of the group with the traditional image protocol. The sensitivity and specificity of CTA in detecting middle-grade and severe arterial stenosis were 86.1% and 86.6%, respectively. Conclusion: 64-slice spiral CT angiography is a reliable method for evaluating the lower extremity arterial disease, and is a more ideal method if using individualized injection protocol. (authors)

  13. The value of 64-slice CT angiography in diagnosing spinal vascular malformations

    Objective: To evaluate 64-slice CT angiography in diagnosing spinal vascular malformations. Methods: Fifteen patients, who were suggestive of spinal vascular malformations by clinical manifestation and MRI, underwent CT angiography with a 64-slice spiral CT (GE lightspeed VCT). DSA were performed later within 1 week in all the patients and four of them were treated with operation as well. We evaluated CTA images in displaying the lesions according to the following aspects: the type of malformation, lesion range, feeding artery, draining vein and possible fistula, and compared those details with DSA and operation findings. Results: All 15 patients acquired their final diagnosis by DSA and operation, which were intramedullary artefiovenous malformation in 6 cases, perimedullary artefiovenous fistula in 2, spinal dural arteriovenous fistula in 3 and Cobb syndrome in 4 cases. CTA was consistent with DSA in the classification of lesions and in the determination of the involved regions and it revealed the main feeding arteries and draining veins in all patients. CTA showed four arteriovenous fistulae confirmed by DSA, but it failed in a complex arteriovenous fistula. In Cobb syndrome patients, not only the intramedullary but also paravertebral and subcutenous vascular malformation could be clearly seen on CTA images. Conclusion: 64-slice CT angiography can be a preliminary method in spinal vascular malformation because it can determine the classification and reveal almost all the main lesions quickly, atraumatically. (authors)

  14. Adolescent Kawasaki disease: usefulness of 64-slice CT coronary angiography for follow-up investigation

    Carbone, Iacopo; Cannata, David; Algeri, Emanuela; Galea, Nicola; Napoli, Alessandro; Catalano, Carlo; Passariello, Roberto; Francone, Marco [Sapienza University of Rome, Department of Radiological, Onchological and Anatomopathological Sciences, Policlinico Umberto I, Rome (Italy); De Zorzi, Andrea [Bambino Gesu Hospital, Cardiology Division, Rome (Italy); Bosco, Giovanna; D' Agostino, Rita [Sapienza University of Rome, Unit of Paediatric Cardiology, Policlinico Umberto I, Rome (Italy); Menezes, Leon [University College of London, Institute of Nuclear Medicine, London (United Kingdom)

    2011-09-15

    Kawasaki disease (KD) is a systemic vasculitis that mainly affects coronary arteries in children, and requires regular follow-up from the time of diagnosis. To evaluate the feasibility of 64-slice CT angiography (CTA) for follow-up of patients with KD using previously performed invasive catheter coronary angiography (CCA) as reference standard. The study group comprised 12 patients (age 17.6 {+-} 2.9 years, mean{+-}SD) with a diagnosis of KD and a previously performed CCA (interval, 32.6 {+-} 13.5 months) who underwent 64-slice cardiac CTA. The quality of the images for establishing the presence of coronary abnormalities was determined by two observers. The CTA findings were compared with those from the prior CCA. Adequate image quality was obtained in all patients. Mean effective dose for CTA was 6.56 {+-} 0.95 mSv. CTA allowed accurate identification, characterization and measurement of all coronary aneurysms (n = 32), stenoses (n = 3) and occlusions (n = 9) previously demonstrated by CCA. One patient with disease progression went on to have percutaneous coronary intervention. Coronary lesions were reliably evaluated by 64-slice CTA in the follow-up of compliant patients with KD, reducing the need for repeated diagnostic invasive CCA. Hence, in an adequately selected patient population, the role of CCA could be limited almost only to therapeutic procedures. (orig.)

  15. Cervical computed tomography

    This book describes the possibilities of cervical computed tomography with the apparatus available at present. The normal anatomy of the cervical region as it appears in computed tomography is described with special regard to its compartimental structure and functional aspects; this is supplemented by anatomically normal measures obtained from cervical computed tomograms of 60 healthy individuals of different age and both sexes. The morphology of cervical anomalies obtained via CT and of the various acquired cervical disease processes is discussed and illustrated by means of the authors' own observations; the diagnostic value of the findings obtained by CT is discussed, a diagnosis is set up. (orig./MG)

  16. The Measurement of Opening Angle and Orifice Area of a Bileaflet Mechanical Valve Using Multidetector Computed Tomography

    Lee, Dong-Hyeon; Youn, Ho-Joong; Shim, Sung-Bo; Lee, Sun-Hee; Jung, Jung-Im; Jung, Seung-Eun; Choi, Yun-Seok; Park, Chul-Soo; Oh, Yong-Seog; Chung, Wook-Sung; Kim, Jae-Hyung

    2009-01-01

    Background and Objectives The aim of this study was to assess mechanical valve function using 64-slice multidetector computed tomography (MDCT). Subjects and Methods In 20 patients (mean age, 50±12 years; male-to-female ratio, 10:10), 30 St. Jude bileaflet mechanical valves (15 aortic and 15 mitral valves) were evaluated using MDCT. We selected images vertical and parallel to the mechanical valve. The valve orifice area (OA) and valve length were determined by manual tracing and the opening a...

  17. Neutron Computed Tomography

    Computed tomography is a non-destructive testing method which can visualize cross-section of materials based on their nuclear characteristics. In the previous work, X-ray was used as its radiation media. The aim of this experiment was to improve the computed tomography technique using neutron beam. For reconstructing the cross-section image of materials, a filtered back projection was used. Result indicated that a minimum hole shown was 3 mm in diameter using a black and white presentation. While using eight colour levels, a hole of 2 mm in diameter could be seen clearly. It is expected that neutron computed tomography can improve the results of non-destructive testing. (author). 5 refs., 6 figs

  18. Diagnostic value of 64-slice CT angiography in coronary artery disease: A systematic review

    Purpose: To perform a systematic review of the diagnostic value of 64-multislice CT (MSCT) angiography in the detection of coronary artery disease (CAD) when compared to conventional coronary angiography. Materials and methods: A search of PUBMED and MEDLINE databases for English literature was performed. Only studies with at least 10 patients comparing 64-slice MSCT angiography with conventional coronary angiography in the detection of CAD were included. Diagnostic value of MSCT angiography compared to coronary angiography was compared and analysed at segment-, vessel- and patient-based assessment. Results: Fifteen studies met selection criteria and were included for analysis. Pooled sensitivity, specificity, positive predictive value and negative predictive value as well as 95% confidence interval (CI) were 97% (94 and 99%), 88% (79 and 97%), 94% (91 and 97%), and 95% (90 and 99%) for patient-based assessment; 92% (85 and 99%), 92% (85 and 99%), 78% (66 and 91%) and 98% (96 and 99%) for vessel-based assessment; 90% (85 and 94%), 96% (95 and 97%), 75%(68 and 82%) and 98% (98 and 99%) for segment-based assessment, respectively. No significant difference was found in the diagnostic accuracy of 64-slice CT in the detection of CAD when comparison was performed either among four main coronary arteries, or between proximal and middle or distal segments (p > 0.05). Conclusion: Our results showed that 64-slice CT angiography has a high-diagnostic value in the detection of CAD. Severe coronary artery calcification seems to be the major factor affecting the visualisation and assessment

  19. Cardiac CT angiography after coronary artery surgery in children using 64-slice CT scan

    Marini, Davide; Agnoletti, Gabriella [Centre de Reference Malformations Cardiaques Congenitales Complexes-M3C, Universite Paris Descartes, UFR Necker-Enfants Malades, Paris (France); Brunelle, Francis [University Paris Descartes, UFR Necker-Enfants Malades, Department of Pediatric Radiology, APHP, Paris (France); Sidi, Daniel; Bonnet, Damien [Centre de Reference Malformations Cardiaques Congenitales Complexes-M3C, Universite Paris Descartes, UFR Necker-Enfants Malades, Paris (France); Ou, Phalla [Centre de Reference Malformations Cardiaques Congenitales Complexes-M3C, Universite Paris Descartes, UFR Necker-Enfants Malades, Paris (France); University Paris Descartes, UFR Necker-Enfants Malades, Department of Pediatric Radiology, APHP, Paris (France)], E-mail: phalla.ou@nck.aphp.fr

    2009-09-15

    Objective: The purpose of this study was to compare the diagnostic accuracy of 64-slice CT with that of invasive angiography in the detection of graft and/or coronary angioplasty stenosis in children who had undergone coronary artery surgery. Population and methods: Fifteen consecutive children (8 male and 7 female; age 9.2 {+-} 6.1 years) underwent 64-slice CT because of chest pain or ECG changes mean 4.8 {+-} 3.7 years after surgical coronary artery surgery; 10 patients had coronary angioplasty using a patch from the saphenous vein, four had mammary artery bypass, and one had saphenous vein bypass. Six main segments of the coronary arteries and all the bypass graft considered as a single segment were analyzed and compared with invasive angiography used as the reference standard. Results: CT correctly identified the four children with coronary angioplasty and mammary graft lesions that were confirmed by conventional angiography: one patient had a significant stenosis (>50% stenosis) at the mammary bypass graft anastomosis site; three other had non-significant stenosis (<50% stenosis) including a mild lesion of the saphenous vein patch in two patients and a mild lesion at the anastomosis site of the mammary bypass in one. All segments identified as normal by CT in the other 11 children were also found to be normal by conventional angiography. Conclusion: In centers expert in this technique, 64-slice CT scanning is a promising, rapid, and useful diagnostic technique for evaluating both coronary angioplasty and bypass graft lesions in children who had undergone coronary artery surge0008.

  20. Cardiac CT angiography after coronary artery surgery in children using 64-slice CT scan

    Objective: The purpose of this study was to compare the diagnostic accuracy of 64-slice CT with that of invasive angiography in the detection of graft and/or coronary angioplasty stenosis in children who had undergone coronary artery surgery. Population and methods: Fifteen consecutive children (8 male and 7 female; age 9.2 ± 6.1 years) underwent 64-slice CT because of chest pain or ECG changes mean 4.8 ± 3.7 years after surgical coronary artery surgery; 10 patients had coronary angioplasty using a patch from the saphenous vein, four had mammary artery bypass, and one had saphenous vein bypass. Six main segments of the coronary arteries and all the bypass graft considered as a single segment were analyzed and compared with invasive angiography used as the reference standard. Results: CT correctly identified the four children with coronary angioplasty and mammary graft lesions that were confirmed by conventional angiography: one patient had a significant stenosis (>50% stenosis) at the mammary bypass graft anastomosis site; three other had non-significant stenosis (<50% stenosis) including a mild lesion of the saphenous vein patch in two patients and a mild lesion at the anastomosis site of the mammary bypass in one. All segments identified as normal by CT in the other 11 children were also found to be normal by conventional angiography. Conclusion: In centers expert in this technique, 64-slice CT scanning is a promising, rapid, and useful diagnostic technique for evaluating both coronary angioplasty and bypass graft lesions in children who had undergone coronary artery surgery.

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

    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

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

    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.

  3. Computed Tomography (CT) -- Head

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos News Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Head What is CT Scanning of the Head? What are some ...

  4. Computed Tomography (CT) -- Head

    Full Text Available ... Safety En Español More Info Images/Videos News Physician Resources Professions Site Index A-Z Computed Tomography ( ... used in your exam. You should inform your physician of all medications you are taking and if ...

  5. Computed Tomography (CT) -- Sinuses

    Full Text Available ... Safety En Español More Info Images/Videos News Physician Resources Professions Site Index A-Z Computed Tomography ( ... used in your exam. You should inform your physician of all medications you are taking and if ...

  6. Chest computed tomography

    Loeve, Martine; Krestin, Gabriel P.; Rosenfeld, Margaret;

    2013-01-01

    are not suitable to study CF lung disease in young children. Chest computed tomography (CT) holds great promise for use as a sensitive surrogate endpoint in CF. A large body of evidence has been produced to validate the use of chest CT as primary endpoint to study CF lung disease. However, before...

  7. Computed Tomography (CT) -- Head

    Full Text Available ... Español More Info Images/Videos News Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Head ... CT exam to be stressful. The technologist or nurse, under the direction of a physician, may offer ...

  8. Computed Tomography (CT) -- Sinuses

    Full Text Available ... Español More Info Images/Videos News Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Sinuses ... visibility of certain tissues or blood vessels. A nurse or technologist will insert an intravenous (IV) line ...

  9. Computed Tomography (CT) -- Sinuses

    Full Text Available ... Computed tomography (CT) of the sinuses uses special x-ray equipment to evaluate the paranasal sinus cavities – hollow, ... is a diagnostic medical test that, like traditional x-rays, produces multiple images or pictures of the inside ...

  10. Computed Tomography (CT) -- Head

    Full Text Available ... Computed tomography (CT) of the head uses special x-ray equipment to help assess head injuries, severe headaches, ... is a diagnostic medical test that, like traditional x-rays, produces multiple images or pictures of the inside ...

  11. The clinical application of 64-slice spiral CT angiography in carotid artery bifurcation disease

    Objective: To explore the clinical value of 64-slice spiral CT angiography (CTA) in carotid stenosis and atherosclerotic plaque. Methods: 40 patients (80 carotid arteries) underwent CTA and DSA. These two examinations within one week. The results of CTA were compared with that of DSA, the sensitivity and specificity of CTA and DSA were figured out. Results: CTA performed well in the detection of mild (0% to 29%) carotid stenosis, as well as carotid occlusion, with values for sensitivity and specificity both near 100%. In determining that a stenosis was >50% by DSA measurement, CTA with a sensitivity, specificity of 89% and 91% respectively. While CTA was quite specific in identifying degrees of stenoses in either the 50% to 69% or the 70% to 99% ranges, in this task it was much less sensitive: 65% and 73% respectively. CTA can detect all kinds of ulcers while DSA can not. Conclusions: 64-slice CTA and DSA were correctly identified in detecting carotid stenosis. CTA could demonstrate ulcers associated with the carotid stenosis, hut DSA only show stenosis. (authors)

  12. Experimental measurement of the scatter fraction in skull and body CT for teams 64- slice computed tomography; Medida experimental de la fraccion de dispersion TC en craneo y cuerpo para equipo de tomografia computarizada de 64 cortes

    Sanchez, G.; Haro, G.; Herrador, M.

    2011-07-01

    Different formalisms for the calculation of shielding in Cf equipment, the proposed document 147 of NCRP are widely accepted. Of the three methods mentioned in the protocol, two involve the use of two independent factor a of equipment, called scatter fraction CT in skull and body. Interestingly, the experimental measurement of the same, especially in those models following the publication of the document, which are also coincides with the highest number of detector channels and overall a greater radiation beam in the z axis.

  13. Noninvasive coronary angiography using 64-slice spiral computed tomography in an unselected patient collective: Effect of heart rate, heart rate variability and coronary calcifications on image quality and diagnostic accuracy

    Objective: The aim of this study was to assess the impact of heart rate, heart rate variability and calcification on image quality and diagnostic accuracy in an unselected patient collective. Subjects and methods: One hundred and two consecutive patients with known or suspected coronary artery disease underwent both 64-MSCT and invasive coronary angiography. Image quality (IQ) was assessed by independent observers using a 4-point scale from excellent (1) to non-diagnostic (4). Accuracy of MSCT regarding detection or exclusion of significant stenosis (>50%) was evaluated on a per segment basis in a modified AHA 13-segment model. Effects of heart rate, heart rate variability, calcification and body mass index (BMI) on IQ and accuracy were evaluated by multivariate regression. IQ and accuracy were further analysed in subgroups of significant predictor variables and simple regression performed to calculate thresholds for adequate IQ. Results: Mean heart rate was 68.2 ± 13.3 bpm, mean heart rate variability 11.5 ± 16.0 beats per CT-examination (bpct) and median Agatston score 226.5. Average IQ score was 2 ± 0.6 whilst diagnostic quality was obtained in 89% of segments. Overall sensitivity, specificity, PPV or NPV was 91.2%, 99.2%, 95.3% or 98.3%. According to multivariate regression, overall IQ was significantly related to heart rate and calcification (P = 0.0038; P < 0.0001). The effect of heart rate variability was limited to IQ of RCA segments (P = 0.018); BMI was not related to IQ (P = 0.52). Calcification was the only predictor variable with significant effect on the number of non-diagnostic segments (P < 0.0001). In a multivariate regression, calcification was also the single factor with impact on diagnostic accuracy (P = 0.0049). Conclusion: Whilst heart rate, heart rate variability and calcification all show an inverse correlation to IQ, severe calcium burden remains the single factor with translation of such effect into decrease of diagnostic accuracy

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

    Full Text Available ... Site Index A-Z Children's (Pediatric) CT (Computed Tomography) Pediatric computed tomography (CT) is a fast, painless exam that uses ... of Children's CT? What is Children's CT? Computed tomography, more commonly known as a CT or CAT ...

  15. Computed Tomography Status

    Hansche, B. D.

    1983-01-01

    Computed tomography (CT) is a relatively new radiographic technique which has become widely used in the medical field, where it is better known as computerized axial tomographic (CAT) scanning. This technique is also being adopted by the industrial radiographic community, although the greater range of densities, variation in samples sizes, plus possible requirement for finer resolution make it difficult to duplicate the excellent results that the medical scanners have achieved.

  16. Computed Tomography. Chapter 11

    After its clinical introduction in 1971, computed tomography (CT) developed from an X ray modality that was limited to axial imaging of the brain in neuroradiology into a versatile 3-D whole body imaging modality for a wide range of applications, including oncology, vascular radiology, cardiology, traumatology and interventional radiology. CT is applied for diagnosis and follow-up studies of patients, for planning of radiotherapy, and even for screening of healthy subpopulations with specific risk factors

  17. The value of multiplanar reconstruction using 64-slice CT myelography in cervical nerve root injury

    Objective: To study the diagnostic value of multi-direction adjusted multiplanar reconstruction (MPR) by 64-slice CT myelography (CTM) in diagnosing cervical nerve injury, and the possibility of the MPR to replace conventional myelography and CT direct-scanning axial images. Methods: Twenty-six patients with cervical nerve root injury were examined by conventional myelography and 64-slice CT using isotropic parameters. Then multi-direction MPR were performed to display nerve roots on coronal and sagittal planes besides axial images. Twenty-six patients were performed surgical operations and diagnosis were obtained. The coincident diagnosing rate with surgical operations results were compared statistically among multi-direction MPR, direct-scanning axial CT images, conventional myelography. The numbers of images were also compared between axial MPR and direct scanning axial CT images. Results: Direct sign of nerve root avulsion was the loss of normal nerve root defect seen in the Isovist filled thecal sac in 64-slice CT, which was found in 31 nerve roots. Indirect signs included: (1) Traumatic pseudomeningocele: 29 nerve roots showed the leak of Isovist into nerve root sheath, and extended into foramina; (2) Arachnoid cyst: 26 nerve roots clearly displays cystic distension in nerve root, which has low-density fine clew form septation from subarachnoid cavity and no nerve root in the cyst; (3) Deformity of the subarachnoid space: deformity of thecal sac, partially lack of Isovist into arachnoid space, which was found in 17 nerve roots. The coincident diagnosing rate of cervical nerve root injury by multi-direction adjusted coronal MPR imaging was 92.6% (50/54), which was higher than by axial CT (77.8%, 42/54) and conventional myelography (68.5%, 37/54), There was significant difference between the conventional myelography, direct-scanning axial CT, multi-direction MPR images (Kappa=0.686, 0.772, 0.920, respectively, P<0.05), the coronal MPR imaging was significantly

  18. Clinical value of 64-slice spiral CT for classification of femoral neck fracture

    Objective: To evaluate the clinical application of 64-slice spiral CT for classification of femoral neck fracture. Methods: The survey was comprised of 46 patients with femoral neck fractures detected with plain radiographs and CT images. Cases were randomly presented in 2 formats: plain radiographs and CT. Garden classification was queried. Modification of garden classification (nondisplaced vs displaced) was taken to compare with plain radiographs and CT in the study. Results: The results of classification for plain radiographs were 2 cases of Garden Ⅰ, 10 cases of Ⅱ, 22 cases of Ⅲ, and 12 cases of Ⅳ. Those for CT were 1 cases of Garden Ⅰ, 4 cases of Ⅱ, 26 cases of Ⅲ, and 15 cases of Ⅳ. CT improved the accuracy of Garden Classification (P<0.05). Conclusion: Garden classification using CT images shows good conformation with results of surgery. 64-Slic CT is better plain radiographs for Garden classification of femoral neck fracture. (authors)

  19. Hybrid cardiac SPECT/64-slice CTA-derived LV function parameters: Correlation and reproducibility assessment

    The purpose of this study is to define the relationship between SPECT and CTA measured parameters of left ventricular (LV) function and volumes obtained in a single session using SPECT/64-slice CT hybrid imaging device, and in addition, to assess the reproducibility of LV parameters measured using 64-slice CTA. Materials and methods: Seventy-six patients with suspected or known coronary artery disease underwent cardiac CTA and GSPECT in one session using a hybrid SPECT/CT device. LV end-diastolic volume (EDV), end-systolic volume (ESV) and ejection fraction (EF) were measured on each component of the hybrid device. For the CTA component, these parameters were re-measured by the same investigator and by a second investigator with an interval of 3-54 weeks. Corresponding GSPECT and CTA measured parameters were compared. For CTA, intra-observer and inter-observer variability of LV function and volume measurements were calculated. Results: A very good correlation was found between the GSPECT and CTA measured LVEF (r = 0.81), ESV (r = 0.90) and EDV (r = 0.82). There was a small positive difference by CTA measured LVEF (3.9 ± 14.2%), and more prominent positive differences by CTA measured ESV and EDV (9.8 ± 14.8 and 44.9 ± 23.1 cm3, respectively). There was excellent reproducibility in the measurements of all parameters with very low intra- and inter-observer variability (r = 0.93 for EF and 0.98 for EDV and ESV). Conclusions: Although a good correlation was found between the EF measurements obtained from CTA and SPECT, interchangeable use of EF measurements between the two modalities should be done cautiously and interchangeable use of LV EDV and ESV should be avoided.

  20. The study of temporal bone scanning at low-dose with 64-slice spiral CT

    Objective: To study the rationality and possibility of 64 slice spiral CT in the examination of the temporal bone at low dose. Methods: The same CT technique and temporal bone mode as those for clinical CT were used, two cranium specimens (four ears) were scanned with Somatom Sensation 64-slice spiral CT at different mA (380, 300, 200, 160, 120, 80), and multi-planar reformation was performed. The CT dose index at different mA groups were measured by 10 em pencil ionization chamber and head dose phantom. Four anatomic structures on axial images (subarcuate fossa, tendon of tensor tympani, facial recess, etc), four anatomic structures on coronal images (scute, crista transversa, fenestra cochleae, etc) and six anatomic structures on double oblique images (malleus, incus, stirrup bone, upper bony semicircular, etc) were chosen to evaluate and grade the reformation images among different mA groups, and to determine the minimum mA value. Ten ears of five patients were used to test the validity of the minimum mA value. Results: CT radiation dose was significantly reduced flora (47.8 ± 2.7) to (20.1 ± 2.0) mGy (P<0.01) when mA decreased from 380 mA to 160 mA. No significant difference in displaying anatomic structures between the two mA protocols. Conclusion: it is a feasible borne temporal scanning method to decrease the radiation dose by decreasing mA appropriately. (authors)

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

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

  2. Evaluation of myocardial bridge with multidetector computed tomography

    The myocardial bridge (MB) is an intramural segment of coronary artery that is covered with myocardial tissue. The current diagnostic methods are coronary angiography, intravascular ultrasound and intracoronary Doppler, which are all invasive modalities. In this study, multidetector computed tomography (MDCT) was used to detect and evaluate the anatomical properties of the MB. The 607 patients with suspected or known coronary artery disease underwent 64-slice MDCT. MB was diagnosed when an intramural segment of coronary artery was visualized on axial and multiplanar reconstruction images. The prevalence, length, myocardial thickness, and location were evaluated. Of the 607 patients, 39 (6.42%) had a MB. In 20 patients (52.6%), the MB was located in the mid left anterior descending artery. The length of tunneled artery was a mean 16.3 mm, from 6.9 mm to 30 mm, and the maximum thickness of the myocardial tissue was between 0.5 mm and 3.9 mm, with a mean of 1.8 mm. The length of the MB correlated significantly with thickness (P=0.049). The incidence of MB and its anatomical properties can be evaluated with MDCT, which might be a useful and noninvasive method of detecting this variant. (author)

  3. Quantitative Computed Tomography

    Balda, Michael

    2011-01-01

    Computed Tomography (CT) is a wide-spread medical imaging modality. Traditional CT yields information on a patient's anatomy in form of slice images or volume data. Hounsfield Units (HU) are used to quantify the imaged tissue properties. Due to the polychromatic nature of X-rays in CT, the HU values for a specific tissue depend on its density and composition but also on CT system parameters and settings and the surrounding materials. The main objective of Quantitative CT (QCT) is measuring ch...

  4. Stored Luminescence Computed Tomography

    Cong, Wenxiang; Wang, Ge

    2013-01-01

    The phosphor nanoparticles made of doped semiconductors, pre-excited by well-collimated X-ray radiation, were recently reported for their light emission upon NIR light stimulation. The characteristics of X-ray energy storage and NIR stimulated emission is highly desirable to design targeting probes and improve molecular and cellular imaging. Here we propose stored luminescence computed tomography (SLCT), perform realistic numerical simulation, and demonstrate a much-improved spatial resolution in a preclinical research context. The future opportunities are also discussed along this direction.

  5. Computed tomography device

    A computed tomography device comprising a subtraction unit which obtains differential data strings representing the difference between each time-serial projection data string of a group of projection data strings corresponding to a prospective reconstruction image generated by projection data strings acquired by a data acquisition system, a convolution unit which convolves each time-serial projection data string of the group of projection data strings corresponding to the prospective reconstruction image, and a back-projection unit which back-projects the convolved data strings

  6. Diagnostic yield and complications of transthoracic computed tomography-guided biopsies

    Vagn-Hansen, Chris Aksel; Pedersen, Malene Roland Vils; Rafaelsen, Søren Rafael

    2016-01-01

    INTRODUCTION: The widespread use of computed tomography (CT) improves detection of pulmonary lesions, which are not only detected at an increased rate but also at a smaller size. CT-guided lung biopsies are now more frequently used than fluoroscopy-guided lung biopsies. The main aim of the present...... paper was to investigate the outcome and complications of the biopsies. METHODS: We retrospectively collected the results and information from 520 CT-guided thorax biopsies. All biopsies were performed with CT-guided “beam-through” technique, using a 64-slice CT scanner. RESULTS: In 86% of the biopsies......, the tissue material was found to be sufficient. In 32% of the biopsies, a complication arose, mostly pneumothorax (30%), but chest drainage was needed in only 15% of the 520 cases. Patients with more than ten cigarette pack-years had a complication risk that was twice as high at that of patients with...

  7. Computed tomography of electronics

    Bossi, Richard H.; Kruse, Robert J.; Knutson, Benjamin W.

    1989-12-01

    The application of Computed Tomography (CT) and laminography was tested on a variety of electronic components. The effort was performed as a preliminary testing task assignment in the Advanced Development of X ray Computed Tomography Application program. A key area for testing was printed circuit boards for the inspection of solder bonds and in particular for leadless chip carrier devices. During the course of the task assignment several other categories of electronic devices were examined including transformers, connectors, switches from solution and contrast sensitivity phantoms developed for the programs were used to establish quantitative measures of capability used to generate images. This preliminary testing of electronics lead to the conclusion that higher resolution CT scanning is needed to resolve details of interest. CT testing on commercially available system could resolve high contrast details in the range of 2 to 4 lp/mm; however, in many electronic components finer resolution is needed to detect microcracking, voiding and other features. Further testing on high resolution system is recommended. Two areas of immediate potential economic payback for electronics inspection were identified; the inspection of high volume printed circuit board production using high speed laminography and nondestructive failure analysis studies components using high-resolution CT.

  8. Coronary calcium mass scores measured by identical 64-slice MDCT scanners are comparable : a cardiac phantom study

    Dijkstra, Hildebrand; Greuter, Marcel J. W.; Groen, Jaap M.; Vliegenthart-Proenca, Rozemarijn; Renema, KlaasJan W. K.; de Lange, Frank; Oudkerk, Matthijs

    2010-01-01

    To assess whether absolute mass scores are comparable or differ between identical 64-slice MDCT scanners of the same manufacturer and to compare absolute mass scores to the physical mass and between scan modes using a calcified phantom. A non-moving anthropomorphic phantom with nine calcifications o

  9. In vitro imaging of coronary artery stents: Are there differences between 16- and 64-slice CT scanners?

    Purpose: To compare the performance of 64-slice with 16-slice CT scanners for the in vitro evaluation of coronary artery stents. Methods and materials: Twelve different coronary artery stents were placed in the drillings of a combined heart and chest phantom, which was scanned with a 16- and 64-slice CT scanner. Coronal reformations were evaluated for artificial lumen narrowing, intraluminal attenuation values, and false widening of the outer stent diameter as an indicator of artifacts outside the stent. Results: Mean artificial lumen narrowing was not significantly different between the 16- and 64-slice CT scanner (44% versus 39%; p = 0.408). The differences between the Hounsfield Units (HU) measurements inside and outside the stents were significantly lower (p = 0.001) with 64- compared to 16-slice CT. The standard deviation of the HU measurements inside the stents was significantly (p = 0.002) lower with 64- than with 16-slice CT. Artifacts outside the stents were not significantly different between the scanners (p = 0.866). Conclusion: Visualization of the in-stent lumen is improved with 64-slice CT when compared with 16-slice CT as quantified by significantly lesser intraluminal image noise and less artificial rise in intraluminal HU measurement, which is the most important parameter for the evaluation of stent patency in vivo

  10. Comparison of digitally reconstructed radiographs (DRRs) generated from 4-slice and 64-slice helical CT scanners, a phantom study

    Full text: Digitally reconstructed radiographs (DRRs) are generated from CT data sets and playa vital role for verifying patient position for many radiotherapy treatments. The present study aimed to investigate the impact on the image quality of DRRs due to changes in the original CT data acquisition; specifically a 4-slice CT scanner and a 64-slice CT scanner have been considered. A specifically designed CT simulation phantom (Nuclear Associates Model 76--417) with test patterns to measure low contrast and modulation transfer function (MTF) was used to evaluate DRR characteristics for Siemens Somatom Sensation 4 and Sensation 64 CT scanners. The phantom was scanned as described in the manufacturer's manual, using the departmental protocol for head CT. The CT images were obtained with 120 kV, 300 mAs, a scanning and reconstruction pitch of I and collimation of I mm. Each of the test patterns from the DRRs was compared for the 4-slice and the 64-slice helical scans. Results The calculated relative MTF (RMTF) showed higher spatial resolution for DRRs generated from 64-slice scans compared with 4-slice scans, Fig. 1. The low contrast values for hole diameter patterns on the DRRs ranged from 0.01-8.04% for 64 slice scans and 0.06-6.15% for 4 slice scans.

  11. Computed tomography in neurocysticercosis

    Three hundred and fifty seven computed tomography (CT) from 100 different patients with neurocysticercosis (NC) were studied between 1979 and 1988. All patients were treated with praziquantel (PZQ). A new classification attempting to recognize the CT evolution profile in NC as well as assigning a possible link between CT findings and biological conditions of cysts is evaluated. It was possible to conclude that: intact cysts remain unchanged in consecutive CTs by 11 months and exhibit signs of degeneration in about 18 months after PZQ drug therapy; degenerating cysts can be detected by 10.5 months, disappear in 11 months and become nodular calcifications in about 25 months. Therefore, a time period of at least 36 months can be estimated for the complete evolution profile of cysts in the brain parenchyma. (author)

  12. Multislice computed tomography coronary angiography

    Cademartiri, Filippo

    2005-01-01

    markdownabstract__Abstract__ Computed Tomography (CT) imaging is also known as "CAT scanning" (Computed Axial Tomography). Tomography is from the Greek word "tomos" meaning "slice" or "section" and "graphia" meaning "describing". CT was invented in 1972 by British engineer Godfrey Hounsfield of EMI Laboratories, England, and independently by South Mrican born physicist Allan Cormack of Tufts University, Massachusetts.1 • 2 Hounsfield was later awarded the Nobel Peace Prize and honoured with K...

  13. Computed Tomography Measuring Inside Machines

    Wozniak, James F.; Scudder, Henry J.; Anders, Jeffrey E.

    1995-01-01

    Computed tomography applied to obtain approximate measurements of radial distances from centerline of turbopump to leading edges of diffuser vanes in turbopump. Use of computed tomography has significance beyond turbopump application: example of general concept of measuring internal dimensions of assembly of parts without having to perform time-consuming task of taking assembly apart and measuring internal parts on coordinate-measuring machine.

  14. Computed tomography of abdominal trauma

    Abdominal lesions following an accident or surgical interventions are becoming more frequently indications for investigations by computed tomography. Changes of spleen, liver, kidneys, pancreas, and of the retroperitoneal space are discussed. Advantages of computed tomography compared to other investigative methods are shown. (orig.)

  15. The prevalence of undiagnosed abnormalities on non-contrast-enhanced computed tomography compared to contrast-enhanced computed tomography of the brain

    Cornelia Minné

    2014-04-01

    Full Text Available Background: Even though magnetic resonance imaging (MRI is the gold standard investigation for intracranial pathology, it is not widely available in developing countries and computed tomography (CT of the brain remains the first-line investigation for patients with suspected intracranial pathology. It is generally accepted that certain intracranial pathology can be missed on non-contrast-enhanced CT (NECT of the brain if a contrast-enhanced CT (CECT is not done. We have to consider on the one hand the risk of delayed or missed diagnosis and on the other hand the cost, increased radiation exposure and contrast-induced reactions. Advances in CT technology have also improved the resolution of CT scan images, making it easier to identify pathology on an NECT of the brain. To date, no study comparing NECT to CECT of the brain, utilising 64-slice CT technology, has been published.Objectives: To determine the prevalence of undiagnosed abnormalities on non-contrast-enhanced computed tomography (NECT scans of the brain reported as normal, on a 64-slice CT scanner.Method: A descriptive retrospective study was undertaken of CT brain scans done during a 12-month period at a tertiary provincial hospital in the Northern Tshwane district of Gauteng, South Africa. The CT brain scans were evaluated by three reviewers (general radiologists. The NECT and contrast-enhanced computed tomography (CECT scans of the brain were reviewed independently on separate occasions. Reviewers were blinded to patient history, each other’s interpretation, and to their own interpretation of the NECT when evaluating the CECT and vice versa. Discrepancies in interpretation were resolved during a consensus meeting between all three reviewers. The reviewers also re-evaluated the NECT scans of the cases with undiagnosed abnormal findings during this session. A decision was made pertaining to the visibility of the abnormal findings on the NECT scan.Results: In this study, 3.28% of cases

  16. Radiation dose and cancer risk from pediatric CT examinations on 64-slice CT: A phantom study

    Objective: To measure the radiation dose from CT scans in an anthropomorphic phantom using a 64-slice MDCT, and to estimate the associated cancer risk. Materials and methods: Organ doses were measured with a 5-year-old phantom and thermoluminescent dosimeters. Four protocols; head CT, thorax CT, abdomen CT and pelvis CT were studied. Cancer risks, in the form of lifetime attributable risk (LAR) of cancer incidence, were estimated by linear extrapolation using the organ radiation doses and the LAR data. Results: The effective doses for head, thorax, abdomen and pelvis CT, were 0.7 mSv, 3.5 mSv, 3.0 mSv, 1.3 mSv respectively. The organs with the highest dose were; for head CT, salivary gland (22.33 mGy); for thorax CT, breast (7.89 mGy); for abdomen CT, colon (6.62 mGy); for pelvis CT, bladder (4.28 mGy). The corresponding LARs for boys and girls were 0.015-0.053% and 0.034-0.155% respectively. The organs with highest LARs were; for head CT, thyroid gland (0.003% for boys, 0.015% for girls); for thorax CT, lung for boys (0.014%) and breast for girls (0.069%); for abdomen CT, colon for boys (0.017%) and lung for girls (0.016%); for pelvis CT, bladder for both boys and girls (0.008%). Conclusion: The effective doses from these common pediatric CT examinations ranged from 0.7 mSv to 3.5 mSv and the associated lifetime cancer risks were found to be up to 0.16%, with some organs of higher radiosensitivity including breast, thyroid gland, colon and lungs.

  17. Accessory left atrial diverticulae: contractile properties depicted with 64-slice cine-cardiac CT.

    Killeen, Ronan P

    2012-02-01

    To assess the contractility of accessory left atrial appendages (LAAs) using multiphasic cardiac CT. We retrospectively analyzed the presence, location, size and contractile properties of accessory LAAs using multiphasic cardiac 64-slice CT in 102 consecutive patients (63 males, 39 females, mean age 57). Multiplanar reformats were used to create image planes in axial oblique, sagittal oblique and coronal oblique planes. For all appendages with an orifice diameter >or= 10 mm, axial and sagittal diameters and appendage volumes were recorded in atrial diastole and systole. Regression analysis was performed to assess which imaging appearances best predicted accessory appendage contractility. Twenty-three (23%) patients demonstrated an accessory LAA, all identified along the anterior LA wall. Dimensions for axial oblique (AOD) and sagittal oblique (SOD) diameters and sagittal oblique length (SOL) were 6.3-19, 3.4-20 and 5-21 mm, respectively. All appendages (>or=10 mm) demonstrated significant contraction during atrial systole (greatest diameter reduction was AOD [3.8 mm, 27%]). Significant correlations were noted between AOD-contraction and AOD (R = 0.57, P < 0.05) and SOD-contraction and AOD, SOD and SOL (R = 0.6, P < 0.05). Mean diverticulum volume in atrial diastole was 468.4 +\\/- 493 mm(3) and in systole was 171.2 +\\/- 122 mm(3), indicating a mean change in volume of 297.2 +\\/- 390 mm(3), P < 0.0001. Stepwise multiple regression analysis revealed SOL to be the strongest independent predictor of appendage contractility (R(2) = 0.86, P < 0.0001) followed by SOD (R(2) = 0.91, P < 0.0001). Accessory LAAs show significant contractile properties on cardiac CT. Those accessory LAAs with a large sagittal height or depth should be evaluated for contractile properties, and if present should be examined for ectopic activity during electrophysiological studies.

  18. Spinal computed tomography

    Sartor, K.

    1980-10-01

    Computed tomography (CT) of the spine and spinal cord is gaining more and more importance as a valuable investigative method in neuroradiology. Performed as a noninvasive procedure, with or without intravenous contrast enhancement, it can be used to diagnose paravertebral soft tissue lesions, constrictive lesions of the bony spinal canal, structure changes of the vertebral column or of individual vertebrae, vascular intraspinal lesions, and intraspinal tumors with abnormally high or abnormally low attenuation values. Performed as an invasive procedure, after intrathecal introduction of metrizamide, spinal CT can in selected cases be used in conjunction with conventional metrizamide myelography as an additional procedure (secondary CT-myelography) or even as initial procedure ( primary CT-myelography), taking advantage of its unique properties, namely to provide a transverse axial image of the spine and related soft tissue structures and to detect even small differences in density. Further improvement of spinal CT, particularly the routine non-invasive demonstration of the intraspinal soft tissues, is to be expected.

  19. Computed tomography apparatus

    In fan-beam computed tomography apparatus, timing reference pulses, normally occurring at intervals t, for data transfer and reset of approx. 500 integrators in the signal path from the detector array, are generated from the scan displacement, e.g. using a graticule and optical sensor to relate the measurement paths geometrically to the body section. Sometimes, a slow scan rate is required to provide a time-averaged density image, e.g. for planning irradiation therapy, and then the sensed impulses will occur at extended intervals and can cause integrator overload. An improvement is described which provides a pulse generator which responds to a reduced scan rate by generating a succession of further transfer and reset pulses at intervals approximately equal to t starting a time t after each timing reference pulse. Then, using an adding device and RAM, all the transferred signals integrated in the interval t' between two successive slow scan reference pulses are accumulated in order to form a corresponding measurement signal. (author)

  20. Quantitative computed tomography

    Adams, Judith E. [Royal Infirmary and University, Manchester (United Kingdom)], E-mail: judith.adams@manchester.ac.uk

    2009-09-15

    Quantitative computed tomography (QCT) was introduced in the mid 1970s. The technique is most commonly applied to 2D slices in the lumbar spine to measure trabecular bone mineral density (BMD; mg/cm{sup 3}). Although not as widely utilized as dual-energy X-ray absortiometry (DXA) QCT has some advantages when studying the skeleton (separate measures of cortical and trabecular BMD; measurement of volumetric, as opposed to 'areal' DXA-BMDa, so not size dependent; geometric and structural parameters obtained which contribute to bone strength). A limitation is that the World Health Organisation (WHO) definition of osteoporosis in terms of bone densitometry (T score -2.5 or below using DXA) is not applicable. QCT can be performed on conventional body CT scanners, or at peripheral sites (radius, tibia) using smaller, less expensive dedicated peripheral CT scanners (pQCT). Although the ionising radiation dose of spinal QCT is higher than for DXA, the dose compares favorably with those of other radiographic procedures (spinal radiographs) performed in patients suspected of having osteoporosis. The radiation dose from peripheral QCT scanners is negligible. Technical developments in CT (spiral multi-detector CT; improved spatial resolution) allow rapid acquisition of 3D volume images which enable QCT to be applied to the clinically important site of the proximal femur, more sophisticated analysis of cortical and trabecular bone, the imaging of trabecular structure and the application of finite element analysis (FEA). Such research studies contribute importantly to the understanding of bone growth and development, the effect of disease and treatment on the skeleton and the biomechanics of bone strength and fracture.

  1. [Computed tomography of the heart

    Kristensen, T.S.; Kofoed, K.F.; der, Recke P. von;

    2009-01-01

    Noninvasive evaluation of the coronary arteries by multi-detector row computed tomography is a promising new alternative to conventional invasive coronary angiography. This article describes the technical background, methods, limitations and clinical applications and reviews current literature th...

  2. Left anterior descending coronary artery myocardial bridging by multislice computed tomography: Correlation with clinical findings

    Objective: To assess the relationship between left anterior descending (LAD) coronary artery myocardial bridging detected by 64-slice computed tomography (CT) and clinical findings. Methods: 221 consecutive patients were examined with coronary 64-slice CT angiography. 21 patients with coronary stenosis >50% were excluded. The length, depth, and luminal narrowing of LAD myocardial bridges during systole and diastole were measured. CT findings were compared with the treadmill ECG-stress test, and clinical symptoms. Results: Myocardial bridges of the LAD were found in 23% of patients (51/221) (length, 14.9 ± 6.5 mm; depth, 2.6 ± 1.6 mm). A significant difference was noted between the LAD luminal diameter before the intramyocardial course and intramyocardially, for both diastole and systole (p 50% was found in 3/25 (8%). 30/51 (59%) of bridges were 'deep' (>2 mm myocardial depth), 21/51 (41%) were 'superficial'. The prevalence of a positive ECG-stress tests for the anterior myocardial region was significantly higher in patients with LAD myocardial bridges (34/50; 68%) compared to those without (28/144; 19.4%) (p < 0.001). There was no difference between 'superficial' and 'deep' LAD myocardial bridges in regard to a positive treadmill ECG-stress test. Typical angina was rare with 6%. Conclusion: LAD myocardial bridges are common findings and can possibly explain a positive exercise ECG-stress test for anterior myocardial ischemia. Intramyocardial LAD segments show mild-to-moderate luminal narrowing at rest, which is higher during end-systolic phase.

  3. Left anterior descending coronary artery myocardial bridging by multislice computed tomography: Correlation with clinical findings

    Jodocy, Daniel; Aglan, Iman [Clinical Department of Radiology II, Innsbruck Medical University, Innsbruck (Austria); Friedrich, Guy [Clinical Department of Cardiology, Innsbruck Medical University, Innsbruck (Austria); Mallouhi, Ammar [Clinical Department of Radiology II, Innsbruck Medical University, Innsbruck (Austria); Pachinger, Otmar [Clinical Department of Radiology II, Innsbruck Medical University, Innsbruck (Austria); Clinical Department of Cardiology, Innsbruck Medical University, Innsbruck (Austria); Jaschke, Werner [Clinical Department of Radiology II, Innsbruck Medical University, Innsbruck (Austria); Feuchtner, Gudrun M. [Clinical Department of Radiology II, Innsbruck Medical University, Innsbruck (Austria)], E-mail: gudrun.feuchtner@i-med.ac.at

    2010-01-15

    Objective: To assess the relationship between left anterior descending (LAD) coronary artery myocardial bridging detected by 64-slice computed tomography (CT) and clinical findings. Methods: 221 consecutive patients were examined with coronary 64-slice CT angiography. 21 patients with coronary stenosis >50% were excluded. The length, depth, and luminal narrowing of LAD myocardial bridges during systole and diastole were measured. CT findings were compared with the treadmill ECG-stress test, and clinical symptoms. Results: Myocardial bridges of the LAD were found in 23% of patients (51/221) (length, 14.9 {+-} 6.5 mm; depth, 2.6 {+-} 1.6 mm). A significant difference was noted between the LAD luminal diameter before the intramyocardial course and intramyocardially, for both diastole and systole (p < 0.001); with a higher diameter reduction of 27% for end-systole compared to end-diastole with 15% (p = 0.006). Systolic LAD intramyocardial luminal narrowing >50% was found in 3/25 (8%). 30/51 (59%) of bridges were 'deep' (>2 mm myocardial depth), 21/51 (41%) were 'superficial'. The prevalence of a positive ECG-stress tests for the anterior myocardial region was significantly higher in patients with LAD myocardial bridges (34/50; 68%) compared to those without (28/144; 19.4%) (p < 0.001). There was no difference between 'superficial' and 'deep' LAD myocardial bridges in regard to a positive treadmill ECG-stress test. Typical angina was rare with 6%. Conclusion: LAD myocardial bridges are common findings and can possibly explain a positive exercise ECG-stress test for anterior myocardial ischemia. Intramyocardial LAD segments show mild-to-moderate luminal narrowing at rest, which is higher during end-systolic phase.

  4. Correlation of radiation dose and heart rate in dual-source computed tomography coronary angiography

    Background: Computed tomography coronary angiography (CTCA) has been widely used since the introduction of 64-slice scanners and dual-source CT technology, but the relatively high radiation dose remains a major concern. Purpose: To evaluate the relationship between radiation exposure and heart rate (HR), in dual-source CTCA. Material and Methods: Data from 218 CTCA examinations, performed with a dual-source 64-slices scanner, were statistically evaluated. Effective radiation dose, expressed in mSv, was calculated as the product of the dose-length product (DLP) times a conversion coefficient for the chest (mSv = DLPx0.017). Heart rate range and mean heart rate, expressed in beats per minute (bpm) of each individual during CTCA, were also provided by the system. Statistical analysis of effective dose and heart rate data was performed by using Pearson correlation coefficient and two-sample t-test. Results: Mean HR and effective dose were found to have a borderline positive relationship. Individuals with a mean HR >65 bpm observed to receive a statistically significant higher effective dose as compared to those with a mean HR =65 bpm. Moreover, a strong correlation between effective dose and variability of HR of more than 20 bpm was observed. Conclusion: Dual-source CT scanners are considered to have the capability to provide diagnostic examinations even with high HR and arrhythmias. However, it is desirable to keep the mean heart rate below 65 bpm and heart rate fluctuation less than 20 bpm in order to reduce the radiation exposure

  5. The comparative study of 64-slices spiral CT angiography with DSA in lower extremity arterial occlusive diseases

    Objective: To study the clinical value of 64-slices spiral CTA with DSA comparatively in diagnosis of lower extremity arterial occlusive diseases. Methods: 31 patients with lower extremity arterial occlusive diseases underwent 64-slice spiral CT angiography of lower extremity arteries and they also underwent digital subtraction angiography (DSA)two weeks later. Reconstruction by maximum intensity projection (MIP), volume render (VR)and multiplanar reformatting (MPR)in working-station was undertaken comparing with the bolus chase DSA and traditional DSA for diagnostic accuracy. Results: The 216 arterial segments of lower extremity were selected, including 157 segments with consistent results in demonstrating degree of stenosis by both examinations. On CT angiography, 5 segmental stenosis were overestimated and 9 were underestimated. When stenosis of detected segments is more than 50%, the sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of CTA were 98.21%, 96.15%, 97.22%, 96.49%, and 98.04%, respectively. Conclusion: 64-slices spiral CT angiography is an effective and reliable method for evaluating the lower extremity arterial occlusive diseases and may provide precious information for planning interventional therapy. (authors)

  6. The value of 64-slice spiral CT angiography based on pre-contrasted raw data in diagnosing pulmonary arteriovenous fistula

    Objective: To evaluate the value of 64-slice spiral CT angiography based on pre- contrasted raw data in diagnosing pulmonary arteriovenous fistula. Methods: 64-slice spiral CT plain scan and enhanced scan was performed in 16 patients with pulmonary arteriovenous fistula, pulmonary angiography based on pre-contrast and post-contrast raw data was performed respectively, including maximum intensity projection (MIP), shaded-surface display (SSD), and volume rendering (VR). According to the results of angiocardiography and surgical findings, comparson of the three methods was made in the display of PAVF in pre-contrast and post-contrast phase images. Results: 8 of the 16 PAVF cases were single lesion, 8 cases were multi-lesions. 30 PAVF lesions were found in all the patients. MIP, SSD and VR based on pre-contrast raw data displayed PAVF lesions in 20, 14, and 22, respectively. The combination of the 3 methods based on pre-contrast raw data could show 26 PAVF lesions. MIP, SSD, and VR based on post-contrast raw data displayed PAVF lesions in 24, 18, and 30, respectively. The combination of the 3 methods based on post-contrast raw data could show 30 PAVF lesions. Conclusion: 64-slice spiral CT angiography based on pre-contrasted raw data can clearly show the position, number, and shape of PAVF lesions, which is of great value in diagnosing PAVF. (authors)

  7. Cardiac carcinoid: tricuspid delayed hyperenhancement on cardiac 64-slice multidetector CT and magnetic resonance imaging.

    Martos, R

    2012-02-01

    INTRODUCTION: Carcinoid heart disease is a rare condition in adults. Its diagnosis can be easily missed in a patient presenting to a primary care setting. We revised the advantages of using coronary multidetector computed tomography (MDCT) and cardiac magnetic resonance imaging (MRI) in diagnosing this condition. MATERIALS AND METHODS: We studied a 65-year-old patient with carcinoid heart disease and right heart failure using transthoracic Doppler-echocardiogram, cardiac MDCT and MRI. Cardiac echocardiogram revealed marked thickening and retraction of the tricuspid leaflets with dilated right atrium and ventricle. Cardiac MDCT and MRI demonstrated fixation and retraction of the tricuspid leaflets with delayed contrast hyperenhancement of the tricuspid annulus. CONCLUSION: This case demonstrates fascinating imaging findings of cardiac carcinoid disease and highlights the increasing utility of contrast-enhanced MRI and cardiac MDCT in the diagnosis of this interesting condition.

  8. 64-Slice CT Angiography in the Detection of Intracranial Aneurysms: Comparison with DSA and Surgical Findings.

    Milošević Medenica, S; V Vućković, V; Prstojević, B

    2010-03-01

    The overall results of CT angiography on 64-slice MSCT published in the last five years are very close to results of DSA which is still a gold standard in the diagnosis of intracranial aneurysms. The aim of this study is to contribute to the confidence in reliability of this method and to try to answer the question of whether CTA should be used as the first diagnostic modality in patients with suspect intracranial aneurysms. In the period from October 2008 to August 2009 we diagnosed 118 aneurysms in 73 patients. We included in this study only those patients who underwent either DSA, surgical treatment or both after MSCTA, and the remainder of the above patients were not treated and are followed up, or died before treatment. So our group comprised 47 patients who were divided into two groups. The first group of 22 patients underwent DSA after MSCTA. We found 36 aneurysms in this group. One aneurysm was falsely positive compared to DSA, while 35 were in concordance with DSA. DSA revealed five aneurysms smaller than 4 mm not disclosed by MSCTA. The second group comprised 25 patients who were operated according to MSCTA findings only. There were 33 aneurysms in this group: 25 aneurysms were operated and surgical findings agreed with MSCTA. Eight aneurysms smaller than 4 mm were not operated and we do not have confirmation for them. In all false positive and false negative cases the misdiagnosed aneurysms were in fact 1-1.5 mm outpouchings that were not responsible for SAH. According to the available literature and our results, MSCTA has proved a very reliable method, simple and safe, competent to be used as a diagnostic modality of choice in the patients with SAH or suspect unruptured aneurysm. DSA should be used in cases of negative or uncertain findings on MSCTA, excluding cases of perimesencephalic SAH with negative MSCTA. The relative disadvantage of this method is its lower sensitivity in the detection of tiny outpouchings, especially in the infraclionid region

  9. High-performance computing and networking as tools for accurate emission computed tomography reconstruction

    Passeri, A. [Dipartimento di Fisiopatologia Clinica - Sezione di Medicina Nucleare, Universita` di Firenze (Italy); Formiconi, A.R. [Dipartimento di Fisiopatologia Clinica - Sezione di Medicina Nucleare, Universita` di Firenze (Italy); De Cristofaro, M.T.E.R. [Dipartimento di Fisiopatologia Clinica - Sezione di Medicina Nucleare, Universita` di Firenze (Italy); Pupi, A. [Dipartimento di Fisiopatologia Clinica - Sezione di Medicina Nucleare, Universita` di Firenze (Italy); Meldolesi, U. [Dipartimento di Fisiopatologia Clinica - Sezione di Medicina Nucleare, Universita` di Firenze (Italy)

    1997-04-01

    It is well known that the quantitative potential of emission computed tomography (ECT) relies on the ability to compensate for resolution, attenuation and scatter effects. Reconstruction algorithms which are able to take these effects into account are highly demanding in terms of computing resources. The reported work aimed to investigate the use of a parallel high-performance computing platform for ECT reconstruction taking into account an accurate model of the acquisition of single-photon emission tomographic (SPET) data. An iterative algorithm with an accurate model of the variable system response was ported on the MIMD (Multiple Instruction Multiple Data) parallel architecture of a 64-node Cray T3D massively parallel computer. The system was organized to make it easily accessible even from low-cost PC-based workstations through standard TCP/IP networking. A complete brain study of 30 (64 x 64) slices could be reconstructed from a set of 90 (64 x 64) projections with ten iterations of the conjugate gradients algorithm in 9 s, corresponding to an actual speed-up factor of 135. This work demonstrated the possibility of exploiting remote high-performance computing and networking resources from hospital sites by means of low-cost workstations using standard communication protocols without particular problems for routine use. The achievable speed-up factors allow the assessment of the clinical benefit of advanced reconstruction techniques which require a heavy computational burden for the compensation effects such as variable spatial resolution, scatter and attenuation. The possibility of using the same software on the same hardware platform with data acquired in different laboratories with various kinds of SPET instrumentation is appealing for software quality control and for the evaluation of the clinical impact of the reconstruction methods. (orig.). With 4 figs., 1 tab.

  10. High-performance computing and networking as tools for accurate emission computed tomography reconstruction

    It is well known that the quantitative potential of emission computed tomography (ECT) relies on the ability to compensate for resolution, attenuation and scatter effects. Reconstruction algorithms which are able to take these effects into account are highly demanding in terms of computing resources. The reported work aimed to investigate the use of a parallel high-performance computing platform for ECT reconstruction taking into account an accurate model of the acquisition of single-photon emission tomographic (SPET) data. An iterative algorithm with an accurate model of the variable system response was ported on the MIMD (Multiple Instruction Multiple Data) parallel architecture of a 64-node Cray T3D massively parallel computer. The system was organized to make it easily accessible even from low-cost PC-based workstations through standard TCP/IP networking. A complete brain study of 30 (64 x 64) slices could be reconstructed from a set of 90 (64 x 64) projections with ten iterations of the conjugate gradients algorithm in 9 s, corresponding to an actual speed-up factor of 135. This work demonstrated the possibility of exploiting remote high-performance computing and networking resources from hospital sites by means of low-cost workstations using standard communication protocols without particular problems for routine use. The achievable speed-up factors allow the assessment of the clinical benefit of advanced reconstruction techniques which require a heavy computational burden for the compensation effects such as variable spatial resolution, scatter and attenuation. The possibility of using the same software on the same hardware platform with data acquired in different laboratories with various kinds of SPET instrumentation is appealing for software quality control and for the evaluation of the clinical impact of the reconstruction methods. (orig.). With 4 figs., 1 tab

  11. What is Computed Tomography?

    ... word "tomography" is from the Greek word "tomos" meaning "slice" or "section" and "graphe" meaning "drawing." A CT imaging system produces cross-sectional ... The patient may receive an injection of a "contrast material" to facilitate visualization of vascular structure. Detectors ...

  12. Neuroanatomy of cranial computed tomography

    Based on the fundamental structures visualized by means of computed tomography, the authors present the functional systems which are relevant in neurology by means of axial cross-sections. All drawings were prepared from original preparations by means of a new technique which is similar to the grey values of X-ray CT and nuclear magnetic resonance tomography. A detailed description is given of the topics of neurofunctional lesions

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

    Objective: To explore an individualized abdominal scan protocol with a 64-slice CT scanner. Methods: From Sep. 2010 to Nov. 2010, one hundred consecutive patients, who underwent twice non-contrast-enhanced abdominal CT scans within 3 months, were enrolled in this study. For each patient, the tube current of 274 eff. mAs and 207 eff. mAs were applied respectively in the first and second abdominal scan. The imaging qualities of the two scans were evaluated retrospectively by 3 reviewers. All the individual variants,including height, weight, body mass index (BMI), the maximum transverse diameter, the anteroposterior diameter and the average maximum diameter of abdomen were recorded. A five-point scale was used for grading the image noise of eight organs, including abdominal aorta, portal vein, liver, spleen, gallbladder, pancreas, renal cortex and renal medulla. Diagnostic acceptability of CT images at three anatomic levels,including porta hepatis, pancreas and the upper pole of renal, was also evaluated by using a five-point scale. The noise value of abdominal aorta was defined as the standard deviation (SD) of CT values of aorta at the level of porta hepatis. Scatter diagram and Pearson correlation analysis were used for evaluating the linear relationship between the individual variants and the noise value of abdominal aorta, and multivariate linear regression analysis was used for evaluating the relevance between the individual variants and the noise value of aorta. Results: In this patients group, the average height was (164.6 ± 7.5) cm,the average weight was (64.3 ± 11.0) kg, the BMI was (23.7 ±3.3) kg/m2, the maximum transverse diameter of abdomen was (29.8 ± 2.3) cm, the anteroposterior diameter of abdomen was (23.1 ± 2.9) cm, and the average maximum diameter of abdomen was (26.5 ± 2.5) cm. Pearson correlation analysis showed significant positive linear correlation between the noise value of abdominal aorta (1 1.7 ± 3.0) and patients' weight (r=0

  14. Computed Tomography (CT) -- Sinuses

    Full Text Available ... ring, called a gantry. The computer workstation that processes the imaging information is located in a separate ... follows a spiral path. A special computer program processes this large volume of data to create two- ...

  15. Computed Tomography (CT) -- Head

    Full Text Available ... ring, called a gantry. The computer workstation that processes the imaging information is located in a separate ... follows a spiral path. A special computer program processes this large volume of data to create two- ...

  16. Computed Tomography (CT) -- Sinuses

    Full Text Available ... images. These images can be viewed on a computer monitor, printed on film or transferred to a ... other in a ring, called a gantry. The computer workstation that processes the imaging information is located ...

  17. Computed Tomography (CT) -- Head

    Full Text Available ... images. These images can be viewed on a computer monitor, printed on film or transferred to a ... other in a ring, called a gantry. The computer workstation that processes the imaging information is located ...

  18. Computer tomography in acute pyelonephritis

    Triller, J.; Scheidegger, J.; Terrier, F.

    1983-07-01

    Computer tomography of the kidneys was performed on 30 patients with acute renal infections (acute suppurative pyelonephritis, acute renal abscess, infected cyst, pyelonephrosis, calculus perforation, retroperitoneal abscess). Computer tomography provided more accurate information concerning the extent of the renal and extra-renal inflammatory process than did the urogram or sonogram. This may significantly affect the choice of treatment, particularly concerning the use of drugs or of surgery. Angiography and retrograde pyelography may be used in selected cases, especially where there is a suspicion of acute bacterial nephritis, renal vein thrombosis or ureteric obstruction.

  19. Computed Tomography (CT) -- Sinuses

    Full Text Available ... ray beam follows a spiral path. A special computer program processes this large volume of data to create two-dimensional cross-sectional images of your body, which are then displayed on a ... by computer software, the result is a very detailed multidimensional ...

  20. Computed Tomography (CT) -- Head

    Full Text Available ... ray beam follows a spiral path. A special computer program processes this large volume of data to create two-dimensional cross-sectional images of your body, which are then displayed on a ... by computer software, the result is a very detailed multidimensional ...

  1. Emission computed tomography

    Although there are many common aspects to x-ray transmission and radionuclide emission (ECT) computerized tomography, there are added difficulties and a number of particular factors which form the basis of ECT. The relationship between the physical factors, system design, methodologic approach and assumptions of ECT is discussed. The instrumentation design and application strategies in ECT at this time are diverse and in a rapid stage of development. The approaches are divided into two major categories of Single Photon Counting (SPC) employing scanner and camera concepts with radionuclides of 99/sup m/Tc, 201Tl, 123I etc., and Annihilation Coincidence Detection (ACD) of positron-emitting radionuclides. Six systems in the former and ten systems in the latter category, with examples of typical studies, illustrate the different approaches

  2. Low-dose ECG-gated 64-slices helical CT angiography of the chest: evaluation of image quality in 105 patients

    D' Agostino, A.G.; Remy-Jardin, M.; Khalil, C.; Remy, J. [University Center of Lille, Department of Thoracic Imaging, Hospital Calmette, Lille (France); Delannoy-Deken, V.; Duhamel, A. [University of Lille, Department of Medical Statistics, Lille (France); Flohr, T. [Siemens Medical, Research and Development Department, CT Division, Forchheim (Germany)

    2006-10-15

    The purpose of this study was to evaluate image quality of low-dose electrocardiogram (ECG)-gated multislice helical computed tomography (CT) angiograms of the chest. One hundred and five consecutive patients with a regular sinus rhythm (72 men; 33 women) underwent ECG-gated CT angiographic examination of the chest without administration of beta blockers using the following parameters: (a) collimation 32 x 0.6 mm with z-flying focal spot for the acquisition of 64 overlapping 0.6-mm slices, rotation time 0.33 s, pitch 0.3; (b) 120 kV, 200 mAs; (c) use of two dose modulation systems, including adjustment of the mAs setting to the patient's size and anatomical shape and an ECG-controlled tube current. Subjective and objective image quality was evaluated by two radiologists in consensus on 3-mm-thick scans reconstructed at 55% of the response rate (RR) interval. The population and protocol characteristics included: (a) a mean [{+-}standard deviation (SD)] body mass index (BMI) of 24.47 ({+-}4.64); (b) a mean ({+-}SD) heart rate of 72.04 ({+-}15.76) bpm; (c) a mean ({+-}SD) scanning time of 18.3 ({+-}2.73) s; (d) a mean ({+-}SD) dose-length product (DLP) value of 260.57 ({+-}83.67) mGy/cm; (e) an estimated average effective dose of 4.95 ({+-}1.59) mSv. Subjective noise was depicted in a total of nine examinations (8.5%), always rated as mild. Objective noise was assessed by measuring the standard deviation of pixel values in a homogeneous region of interest within the trachea and descending aorta; SD was 15.91 HU in the trachea and 22.16 HU in the descending aorta, with no significant difference in the mean value of the standard deviations between the four categories of BMI except for obese patients, who had a higher mean SD within the aorta. Interpolation artefacts were depicted in 22 patients, with a mean heart rate significantly lower than that of patients without interpolation artifacts, rated as mild in 11 patients and severe in 11 patients. The severity of

  3. Computed Tomography (CT) -- Sinuses

    Full Text Available ... special computer program processes this large volume of data to create two-dimensional cross-sectional images of ... Society of Urogenital Radiology note that the available data suggest that it is safe to continue breastfeeding ...

  4. Computed Tomography (CT) -- Head

    Full Text Available ... special computer program processes this large volume of data to create two-dimensional cross-sectional images of ... Society of Urogenital Radiology note that the available data suggest that it is safe to continue breastfeeding ...

  5. Computed Tomography (CT) -- Sinuses

    Full Text Available ... be viewed on a computer monitor, printed on film or transferred to a CD or DVD. CT ... distinguished from one another on an x-ray film or CT electronic image. In a conventional x- ...

  6. Computed Tomography (CT) -- Head

    Full Text Available ... be viewed on a computer monitor, printed on film or transferred to a CD or DVD. CT ... distinguished from one another on an x-ray film or CT electronic image. In a conventional x- ...

  7. Computed Tomography (CT) -- Head

    Full Text Available ... look like? The CT scanner is typically a large, box-like machine with a hole, or short ... spiral path. A special computer program processes this large volume of data to create two-dimensional cross- ...

  8. Computed Tomography (CT) -- Sinuses

    Full Text Available ... look like? The CT scanner is typically a large, box-like machine with a hole, or short ... spiral path. A special computer program processes this large volume of data to create two-dimensional cross- ...

  9. Computed Tomography (CT) -- Head

    Full Text Available ... planes, and can even generate three-dimensional images. These images can be viewed on a computer monitor, ... to reduce the risk of an allergic reaction. These medications generally need to be taken 12 hours ...

  10. Computed Tomography (CT) -- Sinuses

    Full Text Available ... planes, and can even generate three-dimensional images. These images can be viewed on a computer monitor, ... to reduce the risk of an allergic reaction. These medications generally need to be taken 12 hours ...

  11. Computed Tomography (CT) -- Head

    Full Text Available ... a gantry. The computer workstation that processes the imaging information is located in a separate control room, ... which are then displayed on a monitor. CT imaging is sometimes compared to looking into a loaf ...

  12. Computed Tomography (CT) -- Sinuses

    Full Text Available ... a gantry. The computer workstation that processes the imaging information is located in a separate control room, ... which are then displayed on a monitor. CT imaging is sometimes compared to looking into a loaf ...

  13. Computed tomography of intramuscular myxoma

    Computed tomography (CT) was performed in seven patients with intramuscular myxoma. All lesions were well demarcated, of homogeneous appearance and attenuation values ranging from 10 to 60 (HU). The tumor size, as estimated at CT, correlated well with the size of the surgical specimen, which is in contrast to the findings in some high grade malignant sarcomas. (orig.)

  14. X-ray Computed Tomography.

    Michael, Greg

    2001-01-01

    Describes computed tomography (CT), a medical imaging technique that produces images of transaxial planes through the human body. A CT image is reconstructed mathematically from a large number of one-dimensional projections of a plane. The technique is used in radiological examinations and radiotherapy treatment planning. (Author/MM)

  15. Industrial applications of computed tomography

    De Chiffre, Leonardo; Carmignato, S.; Kruth, J. -P.;

    2014-01-01

    The number of industrial applications of Computed Tomography(CT) is large and rapidly increasing. After a brief market overview, the paper gives a survey of state of the art and upcoming CT technologies, covering types of CT systems, scanning capabilities, and technological advances. The paper...

  16. Computed tomography for dimensional metrology

    Kruth, J.P.; Bartscher, M.; Carmignato, S.;

    2011-01-01

    The paper gives a survey of the upcoming use of X-ray computed tomography (CT) for dimensional quality control purposes: i.e. for traceable measurement of dimensions of technical (mechanical) components and for tolerance verification of such components. It describes the basic principles of CT...

  17. Facility for positron computed tomography

    The positron computed tomography facility has got scintillator detector rings simultaneously recording more than one tomogrphic image of different cross-sections of the patient. The detectors in neighboring rings are staggered and can be rotated with respect to each other in order to increase the count rate without loss of efficiency. (DG)

  18. Computed tomography:the details.

    Doerry, Armin Walter

    2007-07-01

    Computed Tomography (CT) is a well established technique, particularly in medical imaging, but also applied in Synthetic Aperture Radar (SAR) imaging. Basic CT imaging via back-projection is treated in many texts, but often with insufficient detail to appreciate subtleties such as the role of non-uniform sampling densities. Herein are given some details often neglected in many texts.

  19. Computed Tomography (CT) -- Head

    Full Text Available ... other medical conditions and whether you have a history of heart disease, asthma, diabetes, kidney disease or ... gantry. The computer workstation that processes the imaging information is located ... in detector technology allow nearly all CT scanners to obtain multiple ...

  20. Computed Tomography (CT) -- Sinuses

    Full Text Available ... other medical conditions and whether you have a history of heart disease, asthma, diabetes, kidney disease or ... gantry. The computer workstation that processes the imaging information is located ... in detector technology allow nearly all CT scanners to obtain multiple ...

  1. Computed Tomography (CT) -- Sinuses

    Full Text Available ... Rotating around you, the x-ray tube and electronic x-ray detectors are located opposite each other in a ring, called a gantry. The computer workstation that processes the imaging information is located in a separate control room, where ...

  2. Computed Tomography (CT) -- Head

    Full Text Available ... Rotating around you, the x-ray tube and electronic x-ray detectors are located opposite each other in a ring, called a gantry. The computer workstation that processes the imaging information is located in a separate control room, where ...

  3. Coronary artery imaging with 64-slice CT in atrial fibrillation patients: scanning method and post-processing techniques

    Objective: To discuss the clinical value of coronary artery imaging using 64-slice CT in patient with atrial fibrillation. Methods: All the cardiac volume data of 31 patients with atrial fibrillation were reconstructed using absolute time method. The images of 12 patients. The images of 31 patients who undeiwent contrast-enhanced CT coronary angiography were evaluated. The presence of stenosis on each segment of coronary arteries was recorded and their degree of stenosis was measured using the vessel analysis software.. The results of conventional coronary angiography (CAG) of the 10 patients were compared with CT coronary angiography. Results: The image quality of 364 coronary vessel segments on the images from 31 patients was evaluated and defined as excellent, fine, moderate or poor. The image quality was excellent, fine, moderate and poor in 194(53.3%), 82(22.5%), 41(11.3%) and 47(12.9%) vessel segments. Comparison was carried out between CTA findings and CAG findings of the 125 segments of the coronary arteries in the 10 patients who underwent CAG. The sensitivity and specificity of CTA for diagnosing vessel with stenosis (≥ 50% narrowing) was 85%(17/20) and 95.2% (100/105). Conclusion: Coronary artery imaging using 64-slice CT is useful in patient with atrial fibrillation. (authors)

  4. Prognostic value of computed tomography coronary angiography in patients with suspected coronary artery disease: a 24-month follow-up study

    The aim of this study was to determine the predictive value of 64-slice computed tomography coronary angiography (CTCA) for major cardiac events in patients with suspected coronary artery disease (CAD). A total of 187 consecutive patients (119 men, age 62.5 ± 10.5 years) without known heart disease underwent single-source 64-slice CTCA (Somatom Sensation 64, Siemens) for clinical suspicion of CAD. Patients underwent follow-up for the occurrence of cardiac death, nonfatal myocardial infarction, unstable angina and cardiac revascularization. In total, 2,822 coronary segments were assessed. Forty-two segments (1.5%) were not assessable because of insufficient image quality. Overall, CTCA revealed absence of CAD in 65 (34.7%) patients, nonobstructive CAD (coronary plaque ≤50%) in 87 (46.5%) patients and obstructive CAD (>50%) in 35 (18.8%) patients. A total of 20 major cardiac events (3 myocardial infarctions, 16 cardiac revascularizations, 1 unstable angina) occurred during a mean follow-up of 24 months. One noncardiac death occurred. Seventeen events occurred in the group of patients with obstructive CAD and three events occurred in the group of nonobstructive CAD. The event rate was 0% among patients with normal coronary arteries at CTCA. CTCA has a 100% negative predictive value for major cardiac events at 24-month follow-up in patients with normal coronary arteries. (orig.)

  5. Prognostic value of computed tomography coronary angiography in patients with suspected coronary artery disease: a 24-month follow-up study

    Aldrovandi, Annachiara; Maffei, Erica; Seitun, Sara; Martini, Chiara; Ruffini, Livia; Crisi, Girolamo; Ardissino, Diego [Azienda Ospedaliero-Universitaria, Department of Radiology and Cardiology, Parma (Italy); Palumbo, Alessandro [Azienda Ospedaliero-Universitaria, Department of Radiology and Cardiology, Parma (Italy); Erasmus Medical Center, Department of Radiology and Cardiology, Rotterdam (Netherlands); Brambilla, Valerio [University of Parma, Cardiovascular Prevention and Rehabilitation Unit, Don Gnocchi ONLUS, Parma (Italy); Zuccarelli, Alessandra [Ospedale di Carrara, Department of Cardiology, Carrara (Italy); Tarantini, Giuseppe [University of Padua, Department of Cardiology, Padua (Italy); Weustink, Annick C.; Mollet, Nico R.; Feyter, Pim J. de; Krestin, Gabriel P. [Erasmus Medical Center, Department of Radiology and Cardiology, Rotterdam (Netherlands); Cademartiri, Filippo [Azienda Ospedaliero-Universitaria, Department of Radiology and Cardiology, Parma (Italy); Erasmus Medical Center, Department of Radiology and Cardiology, Rotterdam (Netherlands); Azienda Ospedaliero-Universitaria di Parma, Department of Radiology, c/o Piastra Tecnica - Piano 0 - CT Section, Parma (Italy)

    2009-07-15

    The aim of this study was to determine the predictive value of 64-slice computed tomography coronary angiography (CTCA) for major cardiac events in patients with suspected coronary artery disease (CAD). A total of 187 consecutive patients (119 men, age 62.5 {+-} 10.5 years) without known heart disease underwent single-source 64-slice CTCA (Somatom Sensation 64, Siemens) for clinical suspicion of CAD. Patients underwent follow-up for the occurrence of cardiac death, nonfatal myocardial infarction, unstable angina and cardiac revascularization. In total, 2,822 coronary segments were assessed. Forty-two segments (1.5%) were not assessable because of insufficient image quality. Overall, CTCA revealed absence of CAD in 65 (34.7%) patients, nonobstructive CAD (coronary plaque {<=}50%) in 87 (46.5%) patients and obstructive CAD (>50%) in 35 (18.8%) patients. A total of 20 major cardiac events (3 myocardial infarctions, 16 cardiac revascularizations, 1 unstable angina) occurred during a mean follow-up of 24 months. One noncardiac death occurred. Seventeen events occurred in the group of patients with obstructive CAD and three events occurred in the group of nonobstructive CAD. The event rate was 0% among patients with normal coronary arteries at CTCA. CTCA has a 100% negative predictive value for major cardiac events at 24-month follow-up in patients with normal coronary arteries. (orig.)

  6. A comparison of perfusion computed tomography and contrast enhanced computed tomography on radiation target volume delineation using rabbit VX2 brain tumor model

    Objective: To compare the accuracy of blood volume perfusion imaging (perfusion CT)with contrast enhanced 64-slice spiral computed tomography (CECT) in the evaluation of gross tumor volume (GTV) and clinical target volume (CTV) using rabbits with VX2 brain tumor. Methods: Perfusion CT and CECT were performed in 20 rabbits with VX2 brain tumor. The GTV and CTV calculated with the maximal and minimal diameter of each tumor in the blood volume (BV) maps and CECT were measured and compared to those in pathological specimens. Results: The mean value of the maximal and minimal diameter of GTV was (8.19 ± 2.29) mm and (4.83 ± 1.31) mm in pathological specimens, (11.98 ±3.29) mm and (7.03±1.82) mm in BV maps, while (6.36±3.85) mm and (3.17±1.93) mm in CECT images, which were significantly different (pathological specimen vs. BV map, t = 7.17, P =0.000;pathological specimen vs. CECT, t = 8.37, P = 0.000, respectively). The mean value of the maximal and minimal diameter of CTV in pathologic specimens was (12.87 ± 3.74) mm and (7.71 ± 2.15) mm, which was significantly different from that of GTV and CTV in CECT (t = - 3. 18, P = 0. 005 and t = - 4.24, P =0.000; t= -11.59,P=0.000 and t= -9.39, P=0.000), while similar with that of GTV in BV maps (t = - 1.95,P = 0. 067; t = - 2. 06, P = 0. 054). For CECT, the margin from GTV to CTV was 81.83% ±40.33% for the maximal diameter and 276.73% ± 131.46% for the minimal. While for BV maps, the margin was 7.93% ± 17. 84% and 12.52% ± 27. 83%, which was significant different from that for CECT images (t=7.36, P=0. 000 and t= -8.78, P=0.000). Conclusions: Compared with CECT, the BV map from 64-slice spiral CT perfusion imaging might have higher accuracy in target volume delineation for brain tumor. (authors)

  7. Pediatric cranial computed tomography

    The introduction of CT in the investigation of intercranial pathology has revolutionized the approach to clinical neurological and neurosurgical practice. This book applies the advances of cranial CT to the pediatric patient. The test is divided into two sections. The first portion describes the practical methodology, anatomy and normal and abnormal CT scan appearance, including high or low density lesions, cystic lesions and ventricular or subarachnoid space dilation. The characteristic scans for various neurological diseases are presented and discussed. The author has given special attention to the CT diagnosis of congenital malformations and cerebral neoplasms. Partial Contents: Normal Computed Tomographic Anatomy/ High Density Lesions/Low Density Lesions/Cystic Lesions; Supratentorial/Cystic Lesions; Infratentorial/Increased Head Circumference/Increased Ventricular Size/Small Ventricular Size/Cranial Lesions/Spinal Lesions/CT Cisternography/Part II CT in Neonates/Congenital Craniocerebral Malformations/Hydrocephalus/Craniosynostosis/Head Trauma/Cerebrovascular Lesions/Intracranial Lesions/Seizure Disorders/Intracranial and Other Chronic Neurological Disorders

  8. Positron emission tomography/computed tomography.

    Townsend, David W

    2008-05-01

    Accurate anatomical localization of functional abnormalities obtained with the use of positron emission tomography (PET) is known to be problematic. Although tracers such as (18)F-fluorodeoxyglucose ((18)F-FDG) visualize certain normal anatomical structures, the spatial resolution is generally inadequate for accurate anatomic localization of pathology. Combining PET with a high-resolution anatomical imaging modality such as computed tomography (CT) can resolve the localization issue as long as the images from the two modalities are accurately coregistered. However, software-based registration techniques have difficulty accounting for differences in patient positioning and involuntary movement of internal organs, often necessitating labor-intensive nonlinear mapping that may not converge to a satisfactory result. Acquiring both CT and PET images in the same scanner obviates the need for software registration and routinely provides accurately aligned images of anatomy and function in a single scan. A CT scanner positioned in line with a PET scanner and with a common patient couch and operating console has provided a practical solution to anatomical and functional image registration. Axial translation of the couch between the 2 modalities enables both CT and PET data to be acquired during a single imaging session. In addition, the CT images can be used to generate essentially noiseless attenuation correction factors for the PET emission data. By minimizing patient movement between the CT and PET scans and accounting for the axial separation of the two modalities, accurately registered anatomical and functional images can be obtained. Since the introduction of the first PET/CT prototype more than 6 years ago, numerous patients with cancer have been scanned on commercial PET/CT devices worldwide. The commercial designs feature multidetector spiral CT and high-performance PET components. Experience has demonstrated an increased level of accuracy and confidence in the

  9. Computed tomography of gynecologic diseases

    Although computed tomography (CT) provides superb images of all areas of the body, sonography, because of its lack of ionizing radiation and its real-time and multiplanar capacities, has become the preferred initial method of evaluating the female pelvis. This has resulted in a relative paucity of information in the literature concerning CT features of benign pelvic disorders in particular and prompted the authors to review our experience with third-generation CT scanning of the uterus and ovaries

  10. Hermaphroditism demonstrated by computed tomography

    The categorization of disorders of gender differentiation is based on chromosome analysis, physical examination, gonadal histology, and endocrine evaluation. In most cases of hermaphroditism, radiologic studies have been limited to assessment of associated urinary tract anomalies before surgical revconstruction. Noninvasive evaluation with computed tomography (CT) or sonography is potentially useful for investigation of internal pelvic anatomy in these cases. A case report of a 65-year-old man is reported

  11. Hermaphroditism demonstrated by computed tomography

    Gale, M.E.

    1983-07-01

    The categorization of disorders of gender differentiation is based on chromosome analysis, physical examination, gonadal histology, and endocrine evaluation. In most cases of hermaphroditism, radiologic studies have been limited to assessment of associated urinary tract anomalies before surgical revconstruction. Noninvasive evaluation with computed tomography (CT) or sonography is potentially useful for investigation of internal pelvic anatomy in these cases. A case report of a 65-year-old man is reported. (KRM)

  12. Cranial computed tomography in paediatrics

    This paper deals mainly with methodical aspects (such as sedation, intravenous and intrathecal application of contrast media) and with common difficulties in interpretation of computed tomography images. The indications for cranial CT are discussed in respect probable therapeutic consequences and expected diagnostic yield. In view of the author CT is, as a rule, not required in assessing chronic headache, generalised epileptic convulsions, non-specific mental retardation and cerebral palsy. (Author)

  13. Coronary artery imaging during preoperative CT staging: preliminary experience with 64-slice multidetector CT in 99 consecutive patients

    Delhaye, Damien; Remy-Jardin, Martine; Rozel, Celine; Remy, Jacques [University Center of Lille, Boulevard Jules Leclerc, Department of Thoracic Imaging, Hospital Calmette, Lille cedex (France); Dusson, Catherine; Wurtz, Alain [University Center of Lille, Department of Thoracic Surgery, Hospital Calmette, Lille cedex (France); Delannoy-Deken, Valerie; Duhamel, Alain [University of Lille, Department of Medical Statistics, Lille cedex (France)

    2007-03-15

    The purpose of this study was to evaluate the clinical feasibility of coronary artery imaging during routine preoperative 64-slice MDCT scans of the chest. Ninety-nine consecutive patients in sinus rhythm underwent a biphasic multidetector-row spiral CT examination of the chest without the administration of beta-blockers, including an ECG-gated acquisition over the cardiac cavities, followed by a non-gated examination of the upper third of the thorax. Data were reconstructed to evaluate coronary arteries and to obtain presurgical staging of the underlying disease. The percentage of assessable segments ranged from 65.4% (972/1,485) when considering all coronary artery segments to 88% (613/693) for the proximal and mid segments, reaching 98% (387/396) for proximal coronary artery segments. The 387 interpretable proximal segments included 97 (97%) LM, 99 (100%) LAD, 96 (97%) LCX and 95 (96%) RCA with a mean attenuation of 280.70{+-}52.93 HU. The mean percentage of assessable segments was significantly higher in patients with a heart rate {<=}80 bpm (n=48) than in patients with a heart rate greater than 80 bpm (n=35) (80{+-}11% vs. 72{+-}13%; P=0.0008). Diagnostic image quality was achieved in all patients for preoperative staging of the underlying disorder. The mean estimated effective dose was 12.06{+-}3.25 mSv for ECG-gated scans and 13.88{+-}3.49 mSv for complete chest examinations. Proximal and mid-coronary artery segments can be adequately evaluated during presurgical CT examinations of the chest obtained with 64-slice MDCT without the administration of {beta}-blockers. (orig.)

  14. Optimal scanning protocols of 64-slice CT angiography in coronary artery stents: An in vitro phantom study

    Purpose: The purpose of the study was to investigate the optimal scanning protocol of 64-slice CT angiography for assessment of coronary artery stents based on a phantom study. Materials and methods: Coronary stents with a diameter of 2.5 mm was implanted in thin plastic tubes with an inner diameter of 3.0 mm to simulate a coronary artery. The tubes were filled with iodinated contrast medium diluted to 178 HU, closed at both ends and positioned in a plastic container filled with vegetable oil (-70 to -100 HU). A series of scans were performed with a 64-slice CT scanner with the following protocols: section thickness: 0.67 mm, 1.0 mm, 1.5 mm, 2.0 mm, pitch value: 0.2, 0.3, 0.5 and reconstruction interval of 50% overlap of the section thickness. 2D axial and multiplanar reformatted images were generated to assess the visibility of stent lumen, while virtual intravascular endoscopy (VIE) was reconstructed to evaluate the artery wall and stent surface. Results: Our results showed that a scanning protocol of 1.0 mm slice thickness with a pitch of 0.3 produced acceptable images with best demonstration of the intrastent lumen and stent surface with minimal image noise or artifacts. In contrast, submillimeter scans with 0.67 mm resulted in moderate artifacts which affected visualization of the coronary lumen, in addition to the increased noise. When the section thickness increased to 1.5 mm and 2.0 mm, visualization of the artery wall and stent surface was compromised, although the intrastent lumen was still visible. Conclusion: Our in vitro study suggested that a scanning protocol of 1.0 mm section thickness with pitch of 0.3 is the optimal protocol for evaluation of coronary artery stents as it allows generation of acceptable images with better visualization of stent lumen, stent surface and coronary artery wall.

  15. Acute subarachnoid hemorrhage: using 64-slice multidetector CT angiography to ''triage'' patients' treatment

    Agid, R.; Lee, S.K.; Willinsky, R.A.; Farb, R.I.; TerBrugge, K.G. [Toronto Western Hospital, Division of Neuroradiology, Department of Medical Imaging, Toronto, Ontario (Canada)

    2006-11-15

    To evaluate the clinical role of CT angiography (CTA) in patients with acute subarachnoid hemorrhage (SAH) for treatment decision-making. Consecutive patients with acute SAH had CTA using a 64-slice scanner for initial clinical decision-making. Image processing included multiplanar volume reformatted (MPVR) maximum intensity projections (MIP) and 3D volume-rendered reconstructions. CTAs were used for (1) evaluating the cause of SAH, and (2) triaging aneurysm-bearing patients to the more appropriate management, either surgical clipping or endovascular coiling. CTA findings were confirmed by neurosurgical exploration or catheter angiography (digital subtraction angiography, DSA). Successful coiling provided evidence that triaging to endovascular treatment was correct. Included in the study were 73 patients. CTA findings were confirmed by DSA or neurosurgical operation in 65 patients, and of these 65, 47 had aneurysmal SAH, 3 had vasculitis, 1 had arterial dissection and 14 had no underlying arterial abnormality. The cause of SAH was detected with CTA in 62 out of the 65 patients (95.4%, sensitivity 94%, specificity 100%). CTA revealed the aneurysm in 46 of 47 patients (98%, sensitivity 98%, specificity 100%, positive predictive value 100%, negative predictive value 82.3%), 1 of 3 vasculitides and 1 of 1 dissection. Of the 46 patients with aneurysm, 44 (95.7%) were referred for treatment based on CTA. In 2 patients (2 of 46, 4.4%) CTA was not informative enough to choose treatment requiring DSA. Of the 44 patients, 27 (61.4%) were referred to endovascular treatment and successful coiling was achieved in 25 (25 of 27, 92.6%). CTA using a 64-slice scanner is an accurate tool for detecting and characterizing aneurysms in acute SAH. CTA is useful in the decision process whether to coil or clip an aneurysm. (orig.)

  16. Optimal scanning protocols of 64-slice CT angiography in coronary artery stents: An in vitro phantom study

    Almutairi, Abdulrahman Marzouq [Discipline of Medical Imaging, Department of Imaging and Applied Physics, Curtin University of Technology, Perth, Western Australia (Australia); Sun Zhonghua [Discipline of Medical Imaging, Department of Imaging and Applied Physics, Curtin University of Technology, Perth, Western Australia (Australia)], E-mail: z.sun@curtin.edu.au; Ng, Curtise [Discipline of Medical Imaging, Department of Imaging and Applied Physics, Curtin University of Technology, Perth, Western Australia (Australia); Al-Safran, Zakariya A.; Al-Mulla, Abeer A.; Al-Jamaan, Abdulaziz I. [Department of Medical Imaging, King Fahad Specialist Hospital, Dammam (Saudi Arabia)

    2010-04-15

    Purpose: The purpose of the study was to investigate the optimal scanning protocol of 64-slice CT angiography for assessment of coronary artery stents based on a phantom study. Materials and methods: Coronary stents with a diameter of 2.5 mm was implanted in thin plastic tubes with an inner diameter of 3.0 mm to simulate a coronary artery. The tubes were filled with iodinated contrast medium diluted to 178 HU, closed at both ends and positioned in a plastic container filled with vegetable oil (-70 to -100 HU). A series of scans were performed with a 64-slice CT scanner with the following protocols: section thickness: 0.67 mm, 1.0 mm, 1.5 mm, 2.0 mm, pitch value: 0.2, 0.3, 0.5 and reconstruction interval of 50% overlap of the section thickness. 2D axial and multiplanar reformatted images were generated to assess the visibility of stent lumen, while virtual intravascular endoscopy (VIE) was reconstructed to evaluate the artery wall and stent surface. Results: Our results showed that a scanning protocol of 1.0 mm slice thickness with a pitch of 0.3 produced acceptable images with best demonstration of the intrastent lumen and stent surface with minimal image noise or artifacts. In contrast, submillimeter scans with 0.67 mm resulted in moderate artifacts which affected visualization of the coronary lumen, in addition to the increased noise. When the section thickness increased to 1.5 mm and 2.0 mm, visualization of the artery wall and stent surface was compromised, although the intrastent lumen was still visible. Conclusion: Our in vitro study suggested that a scanning protocol of 1.0 mm section thickness with pitch of 0.3 is the optimal protocol for evaluation of coronary artery stents as it allows generation of acceptable images with better visualization of stent lumen, stent surface and coronary artery wall.

  17. Single Photon Emission Computed Tomography (SPECT)

    ... Tools & Resources Stroke More Single Photon Emission Computed Tomography (SPECT) Updated:Sep 11,2015 What is a ... Heart Attack Myocardial Perfusion Imaging (MPI) Positron Emission Tomography (PET) Radionuclide Ventriculography, Radionuclide Angiography, MUGA Scan Heart ...

  18. Cardiac Computed Tomography (Multidetector CT, or MDCT)

    ... Blood Pressure Tools & Resources Stroke More Cardiac Computed Tomography (Multidetector CT, or MDCT) Updated:Sep 3,2015 What is Computerized Tomography (CT)? CT is a noninvasive test that uses ...

  19. The history of computed tomography

    New scientific discoveries are often made by the synthetising of other discoveries. Computed tomography is such an example. The three necessary elements were: 1/ the fact that certain simple crystals scintillate when exposed to X-rays, 2/ the advent of electronics and 3/ that of computers. The fact that X-rays cause crystals to scintillate was learnt very shortly after Roentgen's discovery, electronics and computers coming very much later. To put all these together and apply them to diagnostic radiology, and at the same time dismiss the concept so firmly ingrained in everyone's mind that an X-ray picture must be produced on photographic film, required a genius. (orig./VJ)

  20. Quantitative analysis of left ventricular strain using cardiac computed tomography

    Buss, Sebastian J., E-mail: sebastian.buss@med.uni-heidelberg.de [Department of Cardiology, University of Heidelberg, 69120 Heidelberg (Germany); Schulz, Felix; Mereles, Derliz [Department of Cardiology, University of Heidelberg, 69120 Heidelberg (Germany); Hosch, Waldemar [Department of Diagnostic and Interventional Radiology, University of Heidelberg, 69120 Heidelberg (Germany); Galuschky, Christian; Schummers, Georg; Stapf, Daniel [TomTec Imaging Systems GmbH, Munich (Germany); Hofmann, Nina; Giannitsis, Evangelos; Hardt, Stefan E. [Department of Cardiology, University of Heidelberg, 69120 Heidelberg (Germany); Kauczor, Hans-Ulrich [Department of Diagnostic and Interventional Radiology, University of Heidelberg, 69120 Heidelberg (Germany); Katus, Hugo A.; Korosoglou, Grigorios [Department of Cardiology, University of Heidelberg, 69120 Heidelberg (Germany)

    2014-03-15

    Objectives: To investigate whether cardiac computed tomography (CCT) can determine left ventricular (LV) radial, circumferential and longitudinal myocardial deformation in comparison to two-dimensional echocardiography in patients with congestive heart failure. Background: Echocardiography allows for accurate assessment of strain with high temporal resolution. A reduced strain is associated with a poor prognosis in cardiomyopathies. However, strain imaging is limited in patients with poor echogenic windows, so that, in selected cases, tomographic imaging techniques may be preferable for the evaluation of myocardial deformation. Methods: Consecutive patients (n = 27) with congestive heart failure who underwent a clinically indicated ECG-gated contrast-enhanced 64-slice dual-source CCT for the evaluation of the cardiac veins prior to cardiac resynchronization therapy (CRT) were included. All patients underwent additional echocardiography. LV radial, circumferential and longitudinal strain and strain rates were analyzed in identical midventricular short axis, 4-, 2- and 3-chamber views for both modalities using the same prototype software algorithm (feature tracking). Time for analysis was assessed for both modalities. Results: Close correlations were observed for both techniques regarding global strain (r = 0.93, r = 0.87 and r = 0.84 for radial, circumferential and longitudinal strain, respectively, p < 0.001 for all). Similar trends were observed for regional radial, longitudinal and circumferential strain (r = 0.88, r = 0.84 and r = 0.94, respectively, p < 0.001 for all). The number of non-diagnostic myocardial segments was significantly higher with echocardiography than with CCT (9.6% versus 1.9%, p < 0.001). In addition, the required time for complete quantitative strain analysis was significantly shorter for CCT compared to echocardiography (877 ± 119 s per patient versus 1105 ± 258 s per patient, p < 0.001). Conclusion: Quantitative assessment of LV strain

  1. Prior image constrained image reconstruction in emerging computed tomography applications

    Brunner, Stephen T.

    Advances have been made in computed tomography (CT), especially in the past five years, by incorporating prior images into the image reconstruction process. In this dissertation, we investigate prior image constrained image reconstruction in three emerging CT applications: dual-energy CT, multi-energy photon-counting CT, and cone-beam CT in image-guided radiation therapy. First, we investigate the application of Prior Image Constrained Compressed Sensing (PICCS) in dual-energy CT, which has been called "one of the hottest research areas in CT." Phantom and animal studies are conducted using a state-of-the-art 64-slice GE Discovery 750 HD CT scanner to investigate the extent to which PICCS can enable radiation dose reduction in material density and virtual monochromatic imaging. Second, we extend the application of PICCS from dual-energy CT to multi-energy photon-counting CT, which has been called "one of the 12 topics in CT to be critical in the next decade." Numerical simulations are conducted to generate multiple energy bin images for a photon-counting CT acquisition and to investigate the extent to which PICCS can enable radiation dose efficiency improvement. Third, we investigate the performance of a newly proposed prior image constrained scatter correction technique to correct scatter-induced shading artifacts in cone-beam CT, which, when used in image-guided radiation therapy procedures, can assist in patient localization, and potentially, dose verification and adaptive radiation therapy. Phantom studies are conducted using a Varian 2100 EX system with an on-board imager to investigate the extent to which the prior image constrained scatter correction technique can mitigate scatter-induced shading artifacts in cone-beam CT. Results show that these prior image constrained image reconstruction techniques can reduce radiation dose in dual-energy CT by 50% in phantom and animal studies in material density and virtual monochromatic imaging, can lead to radiation

  2. Quantitative assessment of left ventricular systolic wall thickening using multidetector computed tomography

    Kristensen, Thomas S. [Department of Radiology, Diagnostic Centre, Rigshospitalet, University of Copenhagen, Blegdamsvej 9, 2100 Copenhagen (Denmark)], E-mail: tskaarup@yahoo.com; Kofoed, Klaus F. [Department of Cardiology, The Heart Centre, Rigshospitalet, University of Copenhagen, Blegdamsvej 9, 2100 Copenhagen (Denmark)], E-mail: kkofoed@dadlnet.dk; Moller, Daniel V. [Department of Cardiology, Heart Centre, Rigshospitalet, University of Copenhagen, Blegdamsvej 9, 2100 Copenhagen (Denmark)], E-mail: DVEGA@gmx.net; Ersboll, Mads [Department of Cardiology, Heart Centre, Rigshospitalet, University of Copenhagen, Blegdamsvej 9, 2100 Copenhagen (Denmark)], E-mail: ersboell@stud.ku.dk; Kuehl, Tobias [Department of Cardiology, The Heart Centre, Rigshospitalet, University of Copenhagen, Blegdamsvej 9, 2100 Copenhagen (Denmark)], E-mail: tobiaskh@gmail.com; Recke, Peter von der [Department of Radiology, Diagnostic Centre, Rigshospitalet, University of Copenhagen, Blegdamsvej 9, 2100 Copenhagen (Denmark)], E-mail: peter.von.der.recke@rh.regionh.dk; Kober, Lars [Department of Cardiology, Heart Centre, Rigshospitalet, University of Copenhagen, Blegdamsvej 9, 2100 Copenhagen (Denmark)], E-mail: lk@heart.dk; Nielsen, Michael B. [Department of Radiology, Diagnostic Centre, Rigshospitalet, University of Copenhagen, Blegdamsvej 9, 2100 Copenhagen (Denmark)], E-mail: mbn@dadlnet.dk; Kelbaek, Henning [Department of Cardiology, Heart Centre, Rigshospitalet, University of Copenhagen, Blegdamsvej 9, 2100 Copenhagen (Denmark)], E-mail: henning.kelbaek@rh.regionh.dk

    2009-10-15

    Background: Multidetector computed tomography (MDCT) of the heart provides both anatomical and functional information. The objective of this study was to evaluate the accuracy of quantitative assessment of left ventricular contractile function in relation to two-dimensional transthoracic echocardiography (TTE). Materials and methods: Sixty-four patients with known or suspected coronary artery disease underwent ECG-gated 64-slice MDCT and TTE. Regional left ventricular contractile function was measured by percent systolic wall thickening (SWT) in 16 myocardial segments using MDCT, and compared with visual evaluation of wall motion score (WMS) by TTE. Global SWT by MDCT was calculated as the mean SWT of all myocardial segments and compared with wall motion index (WMI) by TTE. Results: Eight hundred and eleven segments (81%) were classified as normokinetic, 142 (14%) as hypokinetic, 41 (4%) as akinetic and 5 (0.5%) as dyskinetic by TTE. A significant inverse linear trend was found between regional SWT by MDCT and WMS by TTE (p < 0.001). Sensitivity and specificity for the identification of regional abnormalities of contractile function were 76% and 78%, respectively. A linear correlation between global SWT by MDCT and WMI by TTE was found (r = -0.8, p < 0.001). Sensitivity and specificity for the identification of WMI > 1.5 using global SWT was 91% and 94%, respectively. Conclusion: Quantification of systolic wall thickening by MDCT provides functional information, which is well correlated to visual assessment of global left ventricular contractile function by TTE.

  3. Evaluation of radiation dose in facial bones and paranasal sinuses examination using computed tomography

    CT has become an established examination in the evaluation of the paranasal sinuses. CT is a diagnostic imaging modality giving higher patient dose in comparison with other radiological procedures, so the evaluation of organ dose in CT exams is very important. This study intends the measurement of patient dose in computed tomography in facial bones, estimate the organ equivalent dose and related risks to critical organs (eye lens, thyroid, parathyroid gland and pituitary gland. Two multi slice CT scanner (MSCT) 64 slice (Toshiba sensation aquilion 64) and (Siemens sensation 16 slice) were used in this study. All quality control tests were carried out for the two machines by expert from Sudan Atomic Energy Commission (SAEC) prior to data collection. Data were collected in regard to exposure parameter in CT procedures performed for 80 adult patients of age ranging from 20 to 90 years. The effective dose in Alamal Hospital was (22.6±8.9) (mSv) for facial bones and for PNS was (10.05±5.94) (mSv) and the effective dose in Ribat University Hospital was (7.87±6.79) mSv for facial bones, and for PNS was (6.00±2.87) mSv. Patient dose rate received in Alamal Hospital was higher than in the other hospital, this result could be due to increasing number of photons and number of slices. The patients doses in two hospitals were higher than the doses in previous studies. (Author)

  4. Biological behavior and disease pattern of carcinoma gallbladder shown on 64-slice CT scanner: A hospital-based retrospective observational study and our experience

    AND Dwivedi

    2012-01-01

    Full Text Available Purpose: The aim of this diagnostic observational study was to assess the spread and biological behavior of gallbladder cancer using 64-slice computerized tomography (CT scanner in this particular geographic belt (eastern Uttar Pradesh, western Bihar, and northern Madhya Pradesh provinces of North India. Indians are ethnically and culturally different from their Western counterparts among whom the incidence of this disease is comparatively low. Subjects and Methods: After systemic examination, all patients (87 were subjected to ultrasonographic examination. All cases were histopathologically proven. Confirmed cases were subjected to volumetric CT examination of abdomen and pelvis, plain, post contrast and delayed phase. Results: Majority of the cases were adenocarcinoma. There was female preponderance with majority belonging to fifth and sixth decades. Commonest presentation was diffuse, irregular, enhancing wall thickening in 49.4%. Majority had invasion of liver parenchyma (74.7%. Cholelithiasis was seen in 48.3% cases. Invasion of biliary radicals was high (13.8-18.4%. Eleven cases had invasion of portal vein and tumor thrombus, with hepatic artery invasion in one case. In two cases, both hepatic artery and portal vein invasion was seen. Portal and peripancreatic nodal metastasis was seen in 58.5%. Distant metastasis was reported. Conclusion: Few studies involving the Indian population have attempted to use multi-row detector CT to define the biological behavior of carcinoma gallbladder. The opinion whether the pathology is operable or non-operable can reasonably be given. This large-scale, single-center study gives insight about the epidemiology and biological behavior of carcinoma gallbladder.

  5. Computed tomography of stress fracture

    An athletic young female developed gradual onset of pain in the right leg. Plain radiographs demonstrated solid periosteal reaction in the tibia compatible with stress fracture. She stopped sport activites but her pain continued. Follow-up radiographs of the tibia revealed changes suspicious for osteoid osteoma. Computed tomography (CT) scan demonstrated periosteal reaction, but in addition, lucent fracture lines in the tibial cortex were evident. CT obviated the need for more invasive diagnostic procedures in this patient. In selected cases CT may be useful to confirm the diagnosis of stress fracture when plain radiographic or routine tomographic studies are not diagnostic. (orig.)

  6. Facility for positron computed tomography

    For positron computed tomography two or more rings of scintillation detectors are used by which three or more sections of the object may be determined at a time. The rings are placed in parallel planes having got some distance from each other, axially movable collimator rings being provided for. Each collimator can be moved towards the opposite collimator and towards a central collimator which also is ring-shaped and is placed between the rows of detectors. The external and internal collimator are used for data selection and image-forming. (DG)

  7. Computed Tomography in Forensic Medicine

    Leth, Peter Mygind

    2015-01-01

    Modern diagnostic imagining techniques are gaining popularity in forensic medicine. Denmark has been involved in the development of this use of imaging techniques from the beginning. The Institute of Forensic Medicine at the University of Southern Denmark acquired a helical computed tomography (CT...... AND METHODS: This thesis investigated 900 forensic cases that were CT-scanned and autopsied at the Institute of Forensic Medicine, University of Southern Denmark, from 2006-2011. The scanner was a Siemens Somatom Spirit dual-slice CT-scanner with a Siemens Syngo MultiModality workstation. Contrast enhancement...

  8. Computed tomography of the spine

    Until the advent of Computed Tomography (CT), axial studies of the spine were limited in the main to gross bony anatomy and to conventional transaxial tomography (TAT). Others studied the upper cervical cord in transverse section during gas myelography and encephalography. The potential role of CT in the evaluation of spinal anatomy and disease was recognized, however, at an early stage in the development of the general purpose CT scanner. CT is not organ specific and therefore provides a uniformly thin (1.5-13 mm) axial section displaying detailed spinal topographical anatomy against a background of paravertebral muscles, vascular structures and body cavity organs. The relationships of the apophyseal joints to the spinal canal and intervertebral foramina are particularly well displayed. The study of neural tissue and pathology within the spinal canal is facilitated by the use of a non-ionic water-soluble contrast medium (viz. metrizamide) in the subarachnoid spaces. The high sensitivity of CT to very small changes in X-ray attenuation permits studies to be continued over several hours. The digital derivation of the sequential CT transaxial sections enables not only interrogation of data and quantitative studies to be made but also makes possible computer-generated reconstructions in other planes

  9. Adaptive Computed Tomography Imaging Spectrometer Project

    National Aeronautics and Space Administration — The present proposal describes the development of an adaptive Computed Tomography Imaging Spectrometer (CTIS), or "Snapshot" spectrometer which can...

  10. Integrated cardio-thoracic imaging with ECG-Gated 64-slice multidetector-row CT: initial findings in 133 patients

    Salem, Randa; Remy-Jardin, Martine; Delhaye, Damien; Khalil, Chadi; Teisseire, Antoine; Remy, Jacques [Hospital Calmette, University Center of Lille, Department of Thoracic Imaging, LILLE cedex (France); Delannoy-Deken, Valerie; Duhamel, Alain [University of Lille, Place de Verdun, Department of Medical Statistics, LILLE cedex (France)

    2006-09-15

    The purpose of this study was to investigate the possibility of assessing the underlying respiratory disease as well as cardiac function during ECG-gated CT angiography of the chest with 64-slice multidetector-row CT (MDCT). One hundred thirty-three consecutive patients in sinus rhythm with known or suspected ventricular dysfunction underwent an ECG-gated CT angiographic examination of the chest without {beta}-blockers using the following parameters: (1) collimation: 32 x 0.6 mm with z-flying focal spot for the acquisition of 64 overlapping 0.6-mm slices (Sensation 64; Siemens); rotation time: 0.33 s; pitch: 0.3; 120 kV; 200 mAs; ECG-controlled dose modulation (ECG-pulsing) and (2) 120 ml of a 35% contrast agent. Data were reconstructed: (1) to evaluate the underlying respiratory disease (1-mm thick lung and mediastinal scans reconstructed at 55% of the R-R interval; i.e., ''morphologic scans'') and (2) to determine right (RVEF) and left (LVEF) ventricular ejection fractions (short-axis systolic and diastolic images; Argus software; i.e., ''functional scans''). The mean heart rate was 73 bpm (range: 42-120) and the mean scan time was 18.11{+-}2.67 s (range: 10-27). A total of 123 examinations (92%) had both lung and mediastinal images rated as diagnostic scans, whereas 10 examinations (8%) had non-diagnostic images altered by the presence of respiratory-motion artifacts (n=4) or cyclic artifacts related to the use of a pitch value of 0.3 in patients with a very low heart rate during data acquisition (n=6). Assessment of right and left ventricular function was achievable in 124 patients (93%, 95% CI: 88-97%). For these 124 examinations, the mean RVEF was 46.10% ({+-}9.5; range: 20-72) and the mean LVEF was 58.23% ({+-}10.88; range: 20-83). In the remaining nine patients, an imprecise segmentation of the right and left ventricular cavities was considered as a limiting factor for precise calculation of end-systolic and end

  11. Noninvasive coronary angioscopy using electron beam computed tomography and multidetector computed tomography

    van Ooijen, PMA; Nieman, K; de Feyter, PJ; Oudkerk, M

    2002-01-01

    With the advent of noninvasive coronary imaging techniques like multidetector computed tomography and electron beam computed tomography, new representation methods such as intracoronary visualization. have been introduced. We explore the possibilities of these novel visualization techniques and comp

  12. Computer simulations to estimate organ doses from clinically validated cardiac, neuro, and pediatric protocols for multiple detector computed tomography scanners

    Ghita, Monica

    Recent advances in Computed Tomography (CT) technology, particularly that of multiple detector CT (MDCT) scanning, have provided increased utilization and more diverse clinical applications including more advanced vascular and cardiac exams, perfusion imaging, and screening exams. Notwithstanding the benefits to the patient undergoing a CT study, the fundamental concern in radiation protection is the minimization of the radiation exposure delivered as well as the implementation of structures to prevent inappropriate ordering and clinical use of these advanced studies. This research work developed a computational methodology for routine clinical use to assess patient organ doses from MDCT scanners. To support the methodology, a computer code (DXS-Diagnostic X-ray Spectra) was developed to accurately and conveniently generate x-ray spectra in the diagnostic energy range (45-140 keV). The two accepted standard radiation transport calculation methods namely, deterministic and Monte Carlo, have been preliminarily investigated for their capability and readiness to support the proposed goal of the work. Thorough tests demonstrated that the lack of appropriate discrete photon interaction coefficients in the aforementioned diagnostic energy range impedes the applicability of the deterministic approach to routine clinical use; improvements in the multigroup treatment may make it more viable. Thus, the open source Monte Carlo code, MCNP5, was adapted to appropriately model an MDCT scan. For this, a new method, entirely based on routine clinical CT measurements, was developed and validated to generate an "equivalent source and filtration" model that obviates the need of proprietary information for a given CT scanner. Computer simulations employing the Monte Carlo methodology and UF's tomographic human phantoms were performed to assess, compare, and optimize pediatric, cardiac and neuro-imaging protocols for the new 320-slice scanner at Shands/UF based on dose considerations

  13. Odontogenic Inflammatory Processes of Head and Neck in Computed Tomography Examinations

    Infections of odontogenic origin are the most common cause of inflammatory disease of head and neck region. Computed tomography allows for defining localization and extent of inflammatory lesions, visualizes soft tissue involvement, presence of an abscess or an osteolytic lesion around causative tooth. The aim of this study was to assess pathways, by which odontogenic infections spread into respective deep head and neck structures in computed tomography examination, taking into account the following criteria: frequency of involvement of respective deep cervical spaces, possibility to determine a probable causative tooth and concordance with the results of clinical examination. Thirty-eight patients cervicofacial inflammatory disease had undergone CT examination of head and neck region with a 64-slice CT scanner after intravenous contrast administration. Abscess was reported in 30 (79%) cases, while inflammatory infiltration was diagnosed in remaining 8 (21%) patients. There was full concordance between radiological report and intraoperative report In 33 cases (87%). The most commonly involved cervical space was masticator space – 31 patients (82%), followed by submandibular space – 27 patients (71%). Dental examination was impossible in 29 patient because of trismus. During analysis of CT studies we evaluated maxillary and mandibular alveolar processes for presence of osteolytic bone lesions around causative teeth roots and we found them in 30 cases (79%). In 32 cases (84%) cervicofacial infection were of mandibular odontogenic origin. In most cases CT study in patients suspected of odontogenic craniofacial infection revealed presence of an abscess, needing urgent surgery. Inflammatory infiltration of dental origin most frequently involves masticator space, followed by submandibular space. In most cases CT scanning allows for identification of causative teeth, especially when trismus makes detailed clinical examination impossible

  14. Computed tomography in sport injuries

    Computed tomography (CT) provides axial slices plane and shows excellent details of bones and different soft tissues, favoring its use in traumatic lesions caused by sporting activities. Complex anatomical structures such as the shoulder, the vertebral column, the pelvis, the knee, the tarsal and carpal bones are often better recognized in detail than by conventional radiography. Fracture lines, localization of bone fragments and involvement of soft tissues are clearly demonstrated. Luxations and bone changes leading to luxations can be shown. CT arthrography provides for the first time a direct visualization of joint cartilage and of cruciate ligaments in the knee joint, so traumatic lesions such as chondropathia patellae or rupture of the cruciate ligaments are shown with a high degree of reliability. (orig.)

  15. Diagnostic usefulness of computed tomography

    Suzuki, K.; Tsugawa, R.; Yamakawa, Y. (Kanazawa Medical Univ., Uchinada, Ishikawa (Japan))

    1981-07-01

    Computed tomography (CT) has been used as a diagnostic technique in various urological diseases. Here demonstrated is a case of ureteral incontinence with double renal pelvis whose upper one has ectopic ureteral orifice. Also a case of ureteral stricture in transplanted kidney and three cases of uric acid calculi are demonstrated. CT provides accurate information in each diagnostic procedure. The use of CT in the diagnosis of urinary stones is estimated. CT number of 75 stones with single component shows specific distribution in relation to the component; ex. calcium stones: 900 - 1000, cystine: 700 - 800, struvite: 600 - 700, uric acid: 400 - 500. Structure and component of the stone is easily demonstrated by CT, especially about nonopaque calculi, whose image is positively displayed only by CT.

  16. Computed tomography in hepatic trauma

    Twenty-five patients with hepatic injury from blunt upper abdominal trauma were examined by computed tomography (CT). The spectrum of CT findings was recorded, and the size of the hepatic laceration and the associated hemoperitoneum were correlated with the mode of therapy used in each case (operative vs nonoperative). While the need for surgery correlated roughly with the size of the hepatic laceration, the size of the associated hemoperitoneum was an important modifying factor. Fifteen patients with hepatic lacerations but little or no hemoperitoneum were managed nonoperatively. CT seems to have significant advantages over hepatic scintigraphy, angiography, and diagnostic peritoneal lavage. By combining inforamtion on the clinical state of the patient and CT findings, therapy of hepatic injury can be individualized and the incidence of nontherapeutic laparotomies decreased

  17. COMPUTED TOMOGRAPHY PERITONEAL CANCER INDEX

    Tiutiuca RC

    2006-07-01

    Full Text Available Peritoneal surface malignancy results from seeding of gastrointestinal cancer or abdomino-pelvic sarcoma, or it can occur as a primary disease, such as peritoneal mesothelioma. In the past, this clinical situation was treated only with palliative intent. Actual treatment options for surgical management uses cytoreductive surgery which combines peritonectomy and visceral resection in an effort to remove all visible cancer within the abdomen and pelvis. Then the peritoneal cavity is flooded with chemotherapy solution. To select patients for this agressive approach quantitative prognostic indicators for carcinomatosis must be evaluated. The peritoneal cancer index (PCI is a synthesis of the distribution of tumor and a lesion size score. In such conditions abdominal medium contrast computed-tomography it is very helpful in identification of neoplasic implants.

  18. Diagnostic usefulness of computed tomography

    Computed tomography (CT) has been used as a diagnostic technique in various urological diseases. Here demonstrated is a case of ureteral incontinence with double renal pelvis whose upper one has ectopic ureteral orifice. Also a case of ureteral stricture in transplanted kidney and three cases of uric acid calculi are demonstrated. CT provides the accurate information in each diagnostic procedure. The use of CT in the diagnosis of urinary stones is estimated. CT number of 75 stones with single component shows specific distribution in relation to the component; ex. calcium stones: 900 - 1000, cystine: 700 - 800, struvite: 600 - 700, uric acid: 400 - 500. Structure and component of the stone is easily demonstrated by CT, especially about nonopaque calculi, whose image is positively displayed only by CT. (author)

  19. The Western Denmark Cardiac Computed Tomography Registry

    Nielsen, Lene Hüche; Nørgaard, Bjarne Linde; Tilsted, Hans Henrik;

    2015-01-01

    BACKGROUND: As a subregistry to the Western Denmark Heart Registry (WDHR), the Western Denmark Cardiac Computed Tomography Registry (WDHR-CCTR) is a clinical database established in 2008 to monitor and improve the quality of cardiac computed tomography (CT) in Western Denmark. OBJECTIVE: We...

  20. Computed tomography and three-dimensional imaging

    Presented here is a brief introduction to two-, three-, and four-dimensional computed tomography. More detailed descriptions of the mathematics of reconstruction and of CT scanner operation are presented elsewhere. The complementary tomographic imaging methods of single-photon-emission tomography (SPECT) positron-emission tomography (PET), nuclear magnetic resonance (NMR) imaging, ulltrasound sector scanning, and ulltrasound computer-assisted tomography [UCAT] are only named here. Each imaging modality ''probes'' the body with a different energy form, yielding unique and useful information about tomographic sections through the body

  1. Preliminary study of X-ray dosage reduction using post-processing filter in 64-slice spiral CT cardiac examination

    Objective: To evaluate the adaptive post-processing filter (C2) on reducing X-ray dosage in 64-slice CT cardiac examinations. Methods: The study was divided into two steps: (1) On 30 consecutive patients (group A) prescribed for cardiac scans on 64-slice CT, the scan protocol was 120 kV, 640 mA, 0.35 s/r, 0.625 mm slice thickness, 0.22-0.24 pitch and large body bowtie. For each patients, cardiac images were reconstructed with and without C2 filter to create two image sets (C2 and NC2, respectively). The image quality was blindly evaluated between C2 and NC2. Image noises were also measured and their means and standard deviations calculated for the two sets. Statistical t-test analysis was performed on the quality scores and the noise between the two data sets. (2) On the 30 consecutive cardiac patients in another group (group B), the protocol was kept the same as in group A except for decreasing the tube current 450 mA based on the results from group A. Images were reconstructed using post-processing filter C2 to create 2C2 image set. Statistical t-test was performed between image sets of 2C2 and NC2 in step 1. (3) CTDIvol values from the 2C2 and NC2 (C2) groups were converted into effective dose (ED) and the ED values of the two groups were compared. Results: (1) The image quality scores for the C2 and NC2 sets were 3.71±0.31 and 3.72±0.29, respectively, with t-test of P>0.05, indicating no significant statistical difference (P>0.05). The noise of C2 and NC2 sets were 22±4, 27±5, respectively, indicating the difference was statistically significant (P2 filter had 18% noise reduction compared to those without C2 filter. (2) The image quality scores for the 2C2 and NC2 sets were 3.67± 0.34, 3.72±0.29, indicating no significant statistical difference (P>0.05). The noise of 2C2 and NC2 sets were 26±3, 27±5, indicating no significant statistical difference (P>0.05). (3) The average CTDIvol values were 60±5 mGy, 88±10 mGy for 2C2 and NC2 (C2) groups

  2. Downstream resource utilization following hybrid cardiac imaging with an integrated cadmium-zinc-telluride/64-slice CT device

    Low yield of invasive coronary angiography and unnecessary coronary interventions have been identified as key cost drivers in cardiology for evaluation of coronary artery disease (CAD). This has fuelled the search for noninvasive techniques providing comprehensive functional and anatomical information on coronary lesions. We have evaluated the impact of implementation of a novel hybrid cadmium-zinc-telluride (CZT)/64-slice CT camera into the daily clinical routine on downstream resource utilization. Sixty-two patients with known or suspected CAD were referred for same-day single-session hybrid evaluation with CZT myocardial perfusion imaging (MPI) and coronary CT angiography (CCTA). Hybrid MPI/CCTA images from the integrated CZT/CT camera served for decision-making towards conservative versus invasive management. Based on the hybrid images patients were classified into those with and those without matched findings. Matched findings were defined as the combination of MPI defect with a stenosis by CCTA in the coronary artery subtending the respective territory. All patients with normal MPI and CCTA as well as those with isolated MPI or CCTA finding or combined but unmatched findings were categorized as ''no match''. All 23 patients with a matched finding underwent invasive coronary angiography and 21 (91%) were revascularized. Of the 39 patients with no match, 5 (13%, p < 0.001 vs matched) underwent catheterization and 3 (8%, p < 0.001 vs matched) were revascularized. Cardiac hybrid imaging in CAD evaluation has a profound impact on patient management and may contribute to optimal downstream resource utilization. (orig.)

  3. Downstream resource utilization following hybrid cardiac imaging with an integrated cadmium-zinc-telluride/64-slice CT device

    Fiechter, Michael; Kaufmann, Philipp A. [University Hospital Zurich, Department of Radiology, Cardiac Imaging, Zurich (Switzerland); University of Zurich, Zurich Center for Integrative Human Physiology (ZIHP), Zurich (Switzerland); Ghadri, Jelena R.; Wolfrum, Mathias; Kuest, Silke M.; Pazhenkottil, Aju P.; Nkoulou, Rene N.; Herzog, Bernhard A.; Gebhard, Catherine; Fuchs, Tobias A.; Gaemperli, Oliver [University Hospital Zurich, Department of Radiology, Cardiac Imaging, Zurich (Switzerland)

    2012-03-15

    Low yield of invasive coronary angiography and unnecessary coronary interventions have been identified as key cost drivers in cardiology for evaluation of coronary artery disease (CAD). This has fuelled the search for noninvasive techniques providing comprehensive functional and anatomical information on coronary lesions. We have evaluated the impact of implementation of a novel hybrid cadmium-zinc-telluride (CZT)/64-slice CT camera into the daily clinical routine on downstream resource utilization. Sixty-two patients with known or suspected CAD were referred for same-day single-session hybrid evaluation with CZT myocardial perfusion imaging (MPI) and coronary CT angiography (CCTA). Hybrid MPI/CCTA images from the integrated CZT/CT camera served for decision-making towards conservative versus invasive management. Based on the hybrid images patients were classified into those with and those without matched findings. Matched findings were defined as the combination of MPI defect with a stenosis by CCTA in the coronary artery subtending the respective territory. All patients with normal MPI and CCTA as well as those with isolated MPI or CCTA finding or combined but unmatched findings were categorized as ''no match''. All 23 patients with a matched finding underwent invasive coronary angiography and 21 (91%) were revascularized. Of the 39 patients with no match, 5 (13%, p < 0.001 vs matched) underwent catheterization and 3 (8%, p < 0.001 vs matched) were revascularized. Cardiac hybrid imaging in CAD evaluation has a profound impact on patient management and may contribute to optimal downstream resource utilization. (orig.)

  4. Assessments of Coronary Artery Visibility and Radiation Dose in Infants with Congenital Heart Disease on Cardiac 128-slice CT and on Cardiac 64-slice CT.

    Cui, Y; Huang, M; Zheng, J; Li, J; Liu, H; Liang, C

    2016-01-01

    The aim of this study was to compare the coronary artery visibility and radiation dose in infants with CHD on cardiac 128-slice CT and on cardiac 64-slice CT. The images of 200 patients were analyzed in this study, 100 patients were selected randomly from a group of 789 infants (ECG-triggered axial scan, and 100 were selected randomly from 911 infants with CHD undergoing 64-slice CT retrospective ECG-gated spiral scan. The visibility of coronary artery segments was graded on a four-point scale. The coronary arteries were considered to be detected or visible when grade was 2 or higher. The visibility of the coronary artery segments and the radiation dose was compared between the two groups. Except for the rate of LM (96 vs. 99%), the detection rates of the total, LAD, LCX, RCA, and the proximal segment of the RCA in the 256-slice CT group were significantly higher than those in the 64-slice CT group (51.7, 53.33, 33.67, 53.33, and 99 vs. 34.8, 34.33, 18, 30.67, and 75%, respectively). The counts of visibility score (4/3/2/1) for the LM and the proximal segment of the RCA were 62/22/12/4 and 56/20/17/7, respectively, in the 128-slice CT group and 17/42/30/1 and 9/30/38/25, respectively, in the 64-slice CT group. There were significant differences, especially for score 4 and 3, between the two groups. The radiation dose in the 128-slice CT group was significantly decreased than those in the 64-slice CT group (CTDIvol 1.88 ± 0.51 vs. 5.61 ± 0.63 mGy; SSDE 4.48 ± 1.15 vs. 13.97 ± 1.52 mGy; effective radiation dose 1.36 ± 0.44 vs. 4.06 ± 0.7 mSv). With reduced radiation dose, the visibility of the coronary artery in infants with CHD via prospective ECG-triggered mode on a 128-slice CT is superior to that of the 64-slice CT using retrospective ECG-gated spiral mode. PMID:26271472

  5. Fracture of the orbit: computed tomography appearance

    The main mechanisms of orbital fractures and their clinical symptoms are exposed. The computed tomographic appearance is described and the implication of computed tomography for therapeutic indications is evaluated as a function of clinical symptoms: visual impairment, anomaly of pupillary reaction to light, ophthalmoplegia, exophthalmos and associated injuries such as intracranial hematomas. The role of computed tomography for the follow-up of these patients is considered

  6. Computed tomography of obstructive jaundice

    It is well known that the computed tomography (CT) is very useful in the evaluation of obstructive jaundice. We have studied 55 cases of obstructive jaundice with whole body scanner from Jun.1980 to Jun. 1981. The results were as follows: 1. The sex distribution was 36 males and 19 females, and 40 cases of obstructive jaundice were seen in fifth, sixth, and seventh decades. 2. Causes of obstructive jaundice were 25 cases of pancreas cancer, 8 cases of common duct cancer, 4 cases of gallbladder cancer, 4 cases of ampulla vater cancer, 12 cases of common duct stone, and 2 cases of common duct stricture. 3. Levels of obstruction were 8 cases of hepatic portion, 15 cases of suprapancreatic portion, 28 cases of pancreatic portion, and 4 cases of ampullary portion. 4. In tumorous condition, CT demonstrated metastasis of other organs, 9 cases of the liver, 1 case of the lung, 3 cases of the pancreas, 3 cases of the common bile duct, 1 case of the stomach, and 12 cases of adjacent lymph nodes. 5. Associated diseases were 12 cases of intrahepatic stone, 4 cases of clonorchiasis, 2 cases of pancreas pseudocyst, 1 cases of hydronephrosis, and 1 case of renal cyst

  7. Computed tomography of obstructive jaundice

    Suh, Jung Hek; Lee, Joong Suk; Chun, Beung He; Suh, Soo Jhi [Kosin Medical College, Busan (Korea, Republic of)

    1982-09-15

    It is well known that the computed tomography (CT) is very useful in the evaluation of obstructive jaundice. We have studied 55 cases of obstructive jaundice with whole body scanner from Jun.1980 to Jun. 1981. The results were as follows: 1. The sex distribution was 36 males and 19 females, and 40 cases of obstructive jaundice were seen in fifth, sixth, and seventh decades. 2. Causes of obstructive jaundice were 25 cases of pancreas cancer, 8 cases of common duct cancer, 4 cases of gallbladder cancer, 4 cases of ampulla vater cancer, 12 cases of common duct stone, and 2 cases of common duct stricture. 3. Levels of obstruction were 8 cases of hepatic portion, 15 cases of suprapancreatic portion, 28 cases of pancreatic portion, and 4 cases of ampullary portion. 4. In tumorous condition, CT demonstrated metastasis of other organs, 9 cases of the liver, 1 case of the lung, 3 cases of the pancreas, 3 cases of the common bile duct, 1 case of the stomach, and 12 cases of adjacent lymph nodes. 5. Associated diseases were 12 cases of intrahepatic stone, 4 cases of clonorchiasis, 2 cases of pancreas pseudocyst, 1 cases of hydronephrosis, and 1 case of renal cyst.

  8. Computed tomography using synchrotron radiation

    X-ray computed tomography (CT) is a widely used method of obtaining cross-sectional views of objects. The high intensity, natural collimation, monochromaticity and energy tunability of synchrotron x-ray sources could potentially be used to provide CT images of improved quality. The advantages of these systems would be that images could be produced more rapidly with better spatial resolution and reduced beam artifacts. In addition, images, in some cases, could be acquired with elemental sensitivity. As a demonstration of the capability of such a system, CT images were obtained of four slices of an excised pig heart in which the arteries and the cardiac chambers were filled with an iodinated medium. Images were taken with incident x-rays tuned successively to energies just above and below the iodine K edge. Iodine specific images were obtained by logarithmically subtracting the low energy image data from the high energy data and then reconstructing the image. CT imaging using synchrotron radiation may become a convenient and non-destructive method of imaging samples difficult to study by other methods

  9. Recent Developments in Computed Tomography

    Computerized Tomography. has become, during the past few years, one of the mostly used apparatus in X-ray diagnosis. Its clinical applications has penetrated to various fields, like operational guidance, cardiac imaging, computer aided surgery etc. The first second-generation CT scanners consisted of a rotate-rotate system detectors array and an X-ray tube. These scanners were capable of acquiring individual single slices, the duration of each being several seconds. The slow scanning rate, and the then poor computers power, limited the application range of these scanners, to relatively stable organs, short body coverage at given resolutions. Further drawbacks of these machines were weak X-ray sources and low efficiency gas detectors. In the late 80's the first helical scanners were introduced by Siemens. Based on a continuous patient couch movement during gantry rotation, much faster scans could be obtained, increasing significantly the volume coverage at a given time. In 1992 the first dual-slice scanners, equipped with high efficiency solid state detectors were introduced by Elscint. The acquisition of data simultaneously from two detector arrays doubled the efficiency of the scan. Faster computers and stronger X-ray sources further improved the performance, allowing for a new range of clinical applications. Yet, the need for even faster machines and bigger volume coverage led to further R and D efforts by the leading CT manufacturers. In order to accomplish the most demanding clinical needs, innovative 2 dimensional 4-rows solid-state detector arrays were developed, together with faster rotating machines and bigger X-ray tubes, all demanding extremely accurate and robust mechanical constructions. Parallel, multi-processor custom computers were made, in order to allow the on-line reconstruction of the growing amounts of raw data. Four-slice helical scanners, rotating at 0.5 sec per cycle are being tested nowadays in several clinics all over the world. This talk

  10. Quantitative evaluation of benign meningioma and hemangiopericytoma with peritumoral brain edema by 64-slice CT perfusion imaging

    REN Guang; CHEN Shuang; WANG Yin; ZHU Rui-jiang; GENG Dao-ying; FENG Xiao-yuan

    2010-01-01

    Background Hemangiopericytomas (HPCs) have a relentless tendency for local recurrence and metastases,differentiating between benign meningiomas and HPCs before surgery is important for both treatment planning and the prognosis appraisal.The purpose of this study was to evaluate the correlations between CT perfusion parameters and microvessel density (MVD) in extra-axial tumors and the possible role of CT perfusion imaging in preoperatively differentiating benign meningiomas and HPCs.Methods Seventeen patients with benign meningiomas and peritumoral edema, 12 patients with HPCs and peritumoral edema underwent 64-slice CT perfusion imaging pre-operation.Perfusion was calculated using the Patlak method.The quantitative parameters, include cerebral blood volume (CBV), permeability surface (PS) of parenchyma, peritumoral edema among benign meningiomas and HPCs were compared respectively.CBV and PS in parenchyma, peritumoral edema of benign meningiomas and HPCs were also compared to that of the contrallateral normal white matter respectively.The correlations between CBV, PS of tumoral parenchyma and MVD were examined.Results The value of CBV and PS in parenchyma of HPCs were significantly higher than that of benign meningiomas (P<0.05), while the values of CBV and PS in peritumoral edema of benign meningiomas and HPCs were not significantly different (P >0.05).MVD in parenchyma of HPCs were significantly higher than that of benign meningiomas (P<0.05).There were positive correlations between CBV and MVD (r=0.648, P<0.05), PS and MVD (r=0.541, P<0.05) respectively.Furthermore, the value of CBV and PS in parenchyma of benign meningiomas and HPCs were significantly higher than that of contrallateral normal white matter (P<0.05), the value of CBV in peritumoral edema of benign meningiomas and HPCs were significantly lower than that of contrallateral normal white matter (P<0.05), while the value of PS in peritumoral edema of benign meningiomas and HPCs were not

  11. Computed tomography in abnormalities of the hip

    The value of computed tomography in the assessment of abnormalities of the hip is demonstrated with the aid of an anatomical preparation and in patients with, respectively, congenital dislocation of a hip, dislocation of the hip in spina bifida, an acetabular fracture and a Ewing tumour. The anteversion of the acetabulum and femur and the instability index of the hip join can be measured by means of computed tomography. (Auth.)

  12. Computed tomography in abnormalities of the hip

    Visser, J.D.; Jonkers, A.; Klasen, H.J. (Rijksuniversiteit Groningen (Netherlands). Academisch Ziekenhuis); Hillen, B. (Rijksuniversiteit Groningen (Netherlands). Lab. voor Anatomie en Embryologie)

    1982-06-26

    The value of computed tomography in the assessment of abnormalities of the hip is demonstrated with the aid of an anatomical preparation and in patients with, respectively, congenital dislocation of a hip, dislocation of the hip in spina bifida, an acetabular fracture and a Ewing tumour. The anteversion of the acetabulum and femur and the instability index of the hip joint can be measured by means of computed tomography.

  13. Computed Tomography For Internal Inspection Of Castings

    Hanna, Timothy L.

    1995-01-01

    Computed tomography used to detect internal flaws in metal castings before machining and otherwise processing them into finished parts. Saves time and money otherwise wasted on machining and other processing of castings eventually rejected because of internal defects. Knowledge of internal defects gained by use of computed tomography also provides guidance for changes in foundry techniques, procedures, and equipment to minimize defects and reduce costs.

  14. Quantitative computed tomography evaluation of pulmonary disease

    McEvoy, Fintan; Buelund, Lene Elisabeth; Strathe, Anders Bjerring;

    2009-01-01

    Objective assessment of pulmonary disease from computed tomography (CT) examinations is desirable but difficult. When such assessments can be made, it is important that they are related to some part of the pathophysiologic process present.......Objective assessment of pulmonary disease from computed tomography (CT) examinations is desirable but difficult. When such assessments can be made, it is important that they are related to some part of the pathophysiologic process present....

  15. Computer tomography of posterior cranial fossa

    Sobota, J.; Dutka, J. (Ustredni Vojenska Nemocnice, Prague (Czechoslovakia))

    1982-11-01

    The problems and possibilities are presented of computer tomography examinations of the posterior cranial fossa. The apparatus used was Somatom 2 by Siemens. Such examinations make it possible to introduce specific measurements and evaluations of pathological processes. Computer tomography in itself, however, may not always be successful in this respect and in the examination of the posterior cranial fossa invasive methods, suitably used, will make the diagnosis more accurate and adequate therapy possible.

  16. Computer tomography of posterior cranial fossa

    The problems and possibilities are presented of computer tomography examinations of the posterior cranial fossa. The apparatus used was Somatom 2 by Siemens. Such examinations make it possible to introduce specific measurements and evaluations of pathological processes. Computer tomography in itself, however, may not always be successful in this respect and in the examination of the posterior cranial fossa invasive methods, suitably used, will make the diagnosis more accurate and adequate therapy possible. (J.O.)

  17. Examination of weld defects by computed tomography

    M. Jovanović

    2012-04-01

    Full Text Available Defects in metal arc gas (MAG welds made in S235JR low carbon steel of 6 mm thickness were examined. A sample containing lack of fusion (LOF and pores was examined by computed tomography – CT. The computed tomography examination was performed in order to define LOF size and position as well as dimensions and distribution of accompanying pores in the weld metal.

  18. Computed tomography of intraventricular hemorrhage

    Computed tomography (CT) is a new non-invasive diagnostic imaging method, which has ability to differentiate C.S.F., hematoma, and even edematous brain from normal brain tissue. Prior to the introduction of the CT, the diagnosis of the intraventricular hemorrhage in living patients was difficult and was confirmed by surgery of autopsy. Intracranial hemorrhages are visible on the CT with density higher than brain tissue in acute phase. CT is an accurate method for detecting of intraventricular hemorrhage including detection of nature, location, amount, and associated changes. CT is also useful as a guidance and in the evaluation of fate of the hematomas by easily performable follow up studies. The causes of the intraventricular hemorrhages are hypertension, rupture of aneurysm, arteriovenous malformation, head trauma, brain tumor, and others. This study included evaluation of CT of 69 patients who show the high density in cerebral ventricular system during the period of 31 months from Feb. 1979 to Aug. 1981 in the Department of Radiology, College of Medicine, Hanyang University. The results were as follows. 1. Age distribution of the total 69 patient was broad ranging from 1 month to 80 years. 28% of patients were in the 6th decade. The mate to female ratio was 2 : 1. 2. The consciousness of patients at CT study: Those were conscious in 11 cases, stuporous in 41 cases and unconscious in 17 cases. 3. The causes of intraventricular hemorrhages were hypertension in 28 cases, head trauma in 12 cases, aneurysm in 4 cases, tumor in 2 cases and others in 23 cases. 4. 9 cases showed intraventricular hematomas only, other 60 cases showed associated intracranial hematomas: Those were intracerebral hematomas in 53 cases including 30 cases of basal ganglial and thalamic hematomas, subarachnoid hemorrhage in 17 cases, epidural hematomas in 3 cases, and subdural hematomas in 2 cases. 5. All cases of the intraventricular hematomas except one sowed hematoma in the lateral

  19. Contrast-enhanced coronary artery visualization by dual-source computed tomography-Initial experience

    Multi-detector computed tomography (CT) scanners, by virtue of their high temporal and spatial resolution, permit imaging of the coronary arteries. However, motion artifacts, especially in patients with higher heart rates, can impair image quality. We thus evaluated the performance of a new dual-source CT (DSCT) with a heart rate independent temporal resolution of 83 ms for the visualization of the coronary arteries in 14 consecutive patients. Methods: Fourteen patients (mean age 61 years, mean heart rate 71 min-1) were studied by DSCT. The system combines two arrays of an X-ray tube plus detector (64 slices) mounted on a single gantry at an angle of 90o With a rotation speed of 330 ms, a temporal resolution of 83 ms (one-quarter rotation) can be achieved independent of heart rate. For data acquisition, intraveous contrast agent was injected at a rate of 5 ml/s. Images were reconstructed with 0.75 slice thickness and 0.5 mm increment. The data sets were evaluated concerning visibility of the coronary arteries and occurrence of motion artifact. Results: Visualization of the coronary arteries was successful in all patients. Most frequently, image reconstruction at 70% of the cardiac cycle provided for optimal image quality (50% of patients). Of a total of 226 coronary artery segments, 222 (98%) were visualized free of motion artifact. In summary, DSCT constitutes a promising new concept for cardiac CT. High and heart rate independent temporal resolution permits imaging of the coronary arteries without motion artifacts in a substantially increased number of patients as compared to earlier scanner generations. Larger and appropriately designed studies will need to determine the method's accuracy for detection of coronary artery stenoses

  20. Late enhanced computed tomography in Hypertrophic Cardiomyopathy enables accurate left-ventricular volumetry

    Late enhancement (LE) multi-slice computed tomography (leMDCT) was introduced for the visualization of (intra-) myocardial fibrosis in Hypertrophic Cardiomyopathy (HCM). LE is associated with adverse cardiac events. This analysis focuses on leMDCT derived LV muscle mass (LV-MM) which may be related to LE resulting in LE proportion for potential risk stratification in HCM. N=26 HCM-patients underwent leMDCT (64-slice-CT) and cardiovascular magnetic resonance (CMR). In leMDCT iodine contrast (Iopromid, 350 mg/mL; 150mL) was injected 7 minutes before imaging. Reconstructed short cardiac axis views served for planimetry. The study group was divided into three groups of varying LV-contrast. LeMDCT was correlated with CMR. The mean age was 64.2 ± 14 years. The groups of varying contrast differed in weight and body mass index (p 0.05). In the group with sufficient contrast LV-MM appeared with 172 ± 30.8 g in leMDCT vs. 165.9 ± 37.8 in CMR (p > 0.05). Overall intra-/inter-observer variability of semiautomatic assessment of LV-MM showed an accuracy of 0.9 ± 8.6 g and 0.8 ± 9.2 g in leMDCT. All leMDCT-measures correlated well with CMR (r > 0.9). LeMDCT primarily performed for LE-visualization in HCM allows for accurate LV-volumetry including LV-MM in > 90 % of the cases. (orig.)

  1. The prevalence of coronary artery variations on coronary computed tomography angiography

    Background: Coronary computed tomography angiography (CCTA) can delineate the coronary artery anatomy precisely. Basic knowledge of the normal coronary artery anatomy and familiarity with its common variations are essential in order to assess CCTA accurately. Purpose: To determine the prevalence of coronary artery variations detected by 64-slice multidetector CT. Material and Methods: CCTA images of 2096 patients were evaluated retrospectively. Relatively unusual coronary artery morphological features that were seen in greater than 1% of the study population were classified as variations. Results: Coronary artery circulation was right dominant in 86.6%, left dominant in 9.6%, and balanced in 3.8% of patients. The conus artery arose from the right coronary artery in 83%, or directly from the aorta with a separate ostium in 17% of cases which was much more common in men than women. The sinoatrial node artery originated from the right coronary artery (65.6%) or the circumflex artery (33.7%). The atrioventricular node artery originated from the right coronary artery in 86.4% or the circumflex artery in 13.6% of cases. The left main coronary artery was shorter than 0.5 cm in 4.7% of cases and trifurcated into the intermediate artery in 31.3% of cases. A myocardial bridge was observed in 21.6%, coronary ectasia-aneurysm in 2%, dual left anterior descending artery (LAD) type 1 in 1.38%, and a variant of type 1 in 0.1% of cases. The presence of coronary atherosclerosis was higher in patients with coronary ectasia-aneurysm than the patients who did not have coronary ectasia-aneurysm (90.5% vs. 72.2%, P = 0.000). Conclusion: CCTA is a non-invasive imaging modality for the depiction of variations of the coronary arteries. The incidence of coronary artery variations is high and various, and readers should be familiar and looking for these conditions during interpretation of CCTA examinations

  2. Late enhanced computed tomography in Hypertrophic Cardiomyopathy enables accurate left-ventricular volumetry

    Langer, Christoph; Lutz, M.; Kuehl, C.; Frey, N. [Christian-Albrechts-Universitaet Kiel, Department of Cardiology, Angiology and Critical Care Medicine, University Medical Center Schleswig-Holstein (Germany); Partner Site Hamburg/Kiel/Luebeck, DZHK (German Centre for Cardiovascular Research), Kiel (Germany); Both, M.; Sattler, B.; Jansen, O; Schaefer, P. [Christian-Albrechts-Universitaet Kiel, Department of Diagnostic Radiology, University Medical Center Schleswig-Holstein (Germany); Harders, H.; Eden, M. [Christian-Albrechts-Universitaet Kiel, Department of Cardiology, Angiology and Critical Care Medicine, University Medical Center Schleswig-Holstein (Germany)

    2014-10-15

    Late enhancement (LE) multi-slice computed tomography (leMDCT) was introduced for the visualization of (intra-) myocardial fibrosis in Hypertrophic Cardiomyopathy (HCM). LE is associated with adverse cardiac events. This analysis focuses on leMDCT derived LV muscle mass (LV-MM) which may be related to LE resulting in LE proportion for potential risk stratification in HCM. N=26 HCM-patients underwent leMDCT (64-slice-CT) and cardiovascular magnetic resonance (CMR). In leMDCT iodine contrast (Iopromid, 350 mg/mL; 150mL) was injected 7 minutes before imaging. Reconstructed short cardiac axis views served for planimetry. The study group was divided into three groups of varying LV-contrast. LeMDCT was correlated with CMR. The mean age was 64.2 ± 14 years. The groups of varying contrast differed in weight and body mass index (p < 0.05). In the group with good LV-contrast assessment of LV-MM resulted in 147.4 ± 64.8 g in leMDCT vs. 147.1 ± 65.9 in CMR (p > 0.05). In the group with sufficient contrast LV-MM appeared with 172 ± 30.8 g in leMDCT vs. 165.9 ± 37.8 in CMR (p > 0.05). Overall intra-/inter-observer variability of semiautomatic assessment of LV-MM showed an accuracy of 0.9 ± 8.6 g and 0.8 ± 9.2 g in leMDCT. All leMDCT-measures correlated well with CMR (r > 0.9). LeMDCT primarily performed for LE-visualization in HCM allows for accurate LV-volumetry including LV-MM in > 90 % of the cases. (orig.)

  3. Determination of computed tomography diagnostic reference levels in North-Central Nigeria

    The aim of this study is to estimate computed tomography (CT) dose levels for common CT examinations in North-Central Nigeria. Dose parameters and scan parameters for the most commonly performed CT examinations (head, chest and abdominal CT scans) were surveyed during a four month period in 4 CT centres with Multislice scanning capabilities (4- 64 slices). Data on CT volume index (CTDIvol) and dose length product (DLP) displayed on scanner console was recorded for a minimum of 10 averaged-sized (70±10kg) patients for each facility to estimate the DRLs. The rounded 75th percentile of the distribution was then used to calculate a DRL for each centre and the region by compiling all results from centres surveyed. Data for 226 patients was collected. CT dosimetry software Impact CT patient dosimetry calculator, version 1.0.4 with National Radiation Protection Board SR250 data set was used to validate and compare surveyed scanner generated dose values. Estimated regional DRLs for head, chest and abdominal scans are (60mG and 1024 mGy.cm), (10mGy and 407mGy.cm) and (15mGy and 757mGy.cm) for CTDIvol and DLP respectively. Mean effective dose values are 1.7mSv, 5mSv and 11.9mSv for head, chest and abdominal scan respectively. A wide variation of mean doses was observed across the centres, however, DRLs estimates were lower than EC (1999) values but above UK (2003) DRLs except for chest examination, this indicates a need for optimization. Validation result show unity (‹10% overall variation) between scanner generated and software calculated dose values. (au)

  4. The effects of computed tomography with iterative reconstruction on solid pulmonary nodule volume quantification.

    Martin J Willemink

    Full Text Available BACKGROUND: The objectives of this study were to evaluate the influence of iterative reconstruction (IR on pulmonary nodule volumetry with chest computed tomography (CT. METHODS: Twenty patients (12 women and 8 men, mean age 61.9, range 32-87 underwent evaluation of pulmonary nodules with a 64-slice CT-scanner. Data were reconstructed using filtered back projection (FBP and IR (Philips Healthcare, iDose(4-levels 2, 4 and 6 at similar radiation dose. Volumetric nodule measurements were performed with semi-automatic software on thin slice reconstructions. Only solid pulmonary nodules were measured, no additional selection criteria were used for the nature of nodules. For intra-observer and inter-observer variability, measurements were performed once by one observer and twice by another observer. Algorithms were compared using the concordance correlation-coefficient (pc and Friedman-test, and post-hoc analysis with the Wilcoxon-signed ranks-test with Bonferroni-correction (significance-level p<0.017. RESULTS: Seventy-eight nodules were present including 56 small nodules (volume<200 mm(3, diameter<8 mm and 22 large nodules (volume≥200 mm(3, diameter≥8 mm. No significant differences in measured pulmonary nodule volumes between FBP, iDose(4-levels 2, 4 and 6 were found in both small nodules and large nodules. FBP and iDose(4-levels 2, 4 and 6 were correlated with pc-values of 0.98 or higher for both small and large nodules. Pc-values of intra-observer and inter-observer variability were 0.98 or higher. CONCLUSIONS: Measurements of solid pulmonary nodule volume measured with standard-FBP were comparable with IR, regardless of the IR-level and no significant differences between measured volumes of both small and large solid nodules were found.

  5. Coronary computed tomography angiography: overview of technical aspects, current concepts, and perspectives

    Multidetector-row electrocardiogram (ECC)-gated cardiac computed tomography (CT) will probably be a major noninvasive imaging option in the near future. Recent developments indicate that this new technology is improving rapidly. This article presents an overview of the current concepts, perspectives, and technical capabilities in coronary CT angiography (CTA). We have reviewed the recent literature on the different applications of this technology; of particular note are the many studies that have demonstrated the high negative predictive value (NPV) of coronary CTA, when performed under optimal conditions, for significant stenoses in native coronary arteries. This new technology's level of performance allows it to be used to evaluate the presence of calcified plaques, coronary bypass graft patency, and the origin and course of congenital coronary anomalies. Despite a high NPV, the robustness of the technology is limited by arrhythmias, the requirement of low heart rates, and calcium-related artifacts. Sonic improvements are needed in the imaging of coronary stents, especially the smaller stents, and in the detection and characterization of noncalcified plaques. Further studies are needed to more precisely determine the role of CTA in various symptomatic and asymptomatic patient groups. Clinical testing of 64-slice scanners has recently begun. As the technology improves, so does the spatial and temporal resolution. To date, this is being achieved through the development of systems with an increased number of detectors and shorter gantry rotation time as well as the development of systems equipped with 2 X-ray tubes and the eventual development of flat-panel technology. Thus further improvement of image quality is expected. (author)

  6. Simple area-based measurement for multidetector computed tomography to predict left ventricular size

    Schlett, Christopher L.; Kwait, Dylan C.; Mahabadi, Amir A.; Hoffmann, Udo [Massachusetts General Hospital, and Harvard Medical School, Cardiac MR PET CT Program, Boston, MA (United States); Bamberg, Fabian [Massachusetts General Hospital, and Harvard Medical School, Cardiac MR PET CT Program, Boston, MA (United States); University Hospitals Munich, and Ludwig Maximilians University, Department of Clinical Radiology, Munich (Germany); O' Donnell, Christopher J. [Lung and Blood Institute' s Framingham Heart Study, National Heart, Framingham (United States); Fox, Caroline S. [Lung and Blood Institute' s Framingham Heart Study, National Heart, Framingham (United States); Brigham and Women' s Hospital, and Harvard Medical School, Division of Endocrinology, Metabolism, and Diabetes, Department of Medicine, Boston, MA (United States)

    2010-07-15

    Measures of left ventricular (LV) mass and dimensions are independent predictors of morbidity and mortality. We determined whether an axial area-based method by computed tomography (CT) provides an accurate estimate of LV mass and volume. A total of 45 subjects (49% female, 56.0 {+-} 12 years) with a wide range of LV geometry underwent contrast-enhanced 64-slice CT. LV mass and volume were derived from 3D data. 2D images were analysed to determine LV area, the direct transverse cardiac diameter (dTCD) and the cardiothoracic ratio (CTR). Furthermore, feasibility was confirmed in 100 Framingham Offspring Cohort subjects. 2D measures of LV area, dTCD and CTR were 47.3 {+-} 8 cm{sup 2}, 14.7 {+-} 1.5 cm and 0.54 {+-} 0.05, respectively. 3D-derived LV volume (end-diastolic) and mass were 148.9 {+-} 45 cm{sup 3} and 124.2 {+-} 34 g, respectively. Excellent inter- and intra-observer agreement were shown for 2D LV area measurements (both intraclass correlation coefficients (ICC) = 0.99, p < 0.0001) and could be confirmed on non-contrast CT. The measured 2D LV area was highly correlated to LV volume, mass and size (r = 0.68; r = 0.73; r = 0.82; all p < 0.0001, respectively). On the other hand, CTR was not correlated to LV volume, mass, size or 2D LV area (all p > 0.27). Compared with traditionally used CTR, LV size can be accurately predicted based on a simple and highly reproducible axial LV area-based measurement. (orig.)

  7. Contrast-enhanced coronary artery visualization by dual-source computed tomography-Initial experience

    Achenbach, Stephan [Department of Cardiology, University of Erlangen-Nuernberg, Ulmenweg 18, 91054 Erlangen (Germany) and Department of Radiology, Massachusetts General Hospital, Boston, MA (United States)]. E-mail: stephan.achenbach@med2.med.uni-erlangen.de; Ropers, Dieter [Department of Cardiology, University of Erlangen-Nuernberg, Ulmenweg 18, 91054 Erlangen (Germany); Kuettner, Axel [Institute for Diagnostic Radiology, University of Erlangen-Nuernberg, Erlangen (Germany); Flohr, Thomas [Siemens Medical Solutions, Forchheim (Germany); Ohnesorge, Bernd [Siemens Medical Solutions, Forchheim (Germany); Bruder, Herbert [Siemens Medical Solutions, Forchheim (Germany); Theessen, Heike [Siemens Medical Solutions, Forchheim (Germany); Karakaya, Meri [Institute of Medical Physics, University of Erlangen-Nuernberg, Erlangen (Germany); Daniel, Werner G. [Department of Cardiology, University of Erlangen-Nuernberg, Ulmenweg 18, 91054 Erlangen (Germany); Bautz, Werner [Institute for Diagnostic Radiology, University of Erlangen-Nuernberg, Erlangen (Germany); Kalender, Willi A. [Institute of Medical Physics, University of Erlangen-Nuernberg, Erlangen (Germany); Anders, Katharina [Institute for Diagnostic Radiology, University of Erlangen-Nuernberg, Erlangen (Germany)

    2006-03-15

    Multi-detector computed tomography (CT) scanners, by virtue of their high temporal and spatial resolution, permit imaging of the coronary arteries. However, motion artifacts, especially in patients with higher heart rates, can impair image quality. We thus evaluated the performance of a new dual-source CT (DSCT) with a heart rate independent temporal resolution of 83 ms for the visualization of the coronary arteries in 14 consecutive patients. Methods: Fourteen patients (mean age 61 years, mean heart rate 71 min{sup -1}) were studied by DSCT. The system combines two arrays of an X-ray tube plus detector (64 slices) mounted on a single gantry at an angle of 90{sup o} With a rotation speed of 330 ms, a temporal resolution of 83 ms (one-quarter rotation) can be achieved independent of heart rate. For data acquisition, intraveous contrast agent was injected at a rate of 5 ml/s. Images were reconstructed with 0.75 slice thickness and 0.5 mm increment. The data sets were evaluated concerning visibility of the coronary arteries and occurrence of motion artifact. Results: Visualization of the coronary arteries was successful in all patients. Most frequently, image reconstruction at 70% of the cardiac cycle provided for optimal image quality (50% of patients). Of a total of 226 coronary artery segments, 222 (98%) were visualized free of motion artifact. In summary, DSCT constitutes a promising new concept for cardiac CT. High and heart rate independent temporal resolution permits imaging of the coronary arteries without motion artifacts in a substantially increased number of patients as compared to earlier scanner generations. Larger and appropriately designed studies will need to determine the method's accuracy for detection of coronary artery stenoses.

  8. Utilizing computed tomography scans for analysis of motorcycle helmets in real-world crashes - biomed 2011.

    Loftis, Kathryn L; Moreno, Daniel P; Tan, Joshua; Gabler, Hampton C; Stitzel, Joel D

    2011-01-01

    In 2008, there were more than 5,000 motorcycle crash fatalities in the United States. Many states have motorcycle helmet laws that are meant to protect riders during a crash. After recruiting motorcycle occupants injured in crashes, a protocol was established to scan three different types of motorcycle helmets commonly worn (cap, ¾ shield, and full face shield) using a computed tomography (CT) scanner. The protocol developed was for a GE 64 slice PET/CT Discovery VCT scanner with axial images from anterior to posterior helmet acquired in helical mode. It had 512x512 resolution and the full face and ¾ face shield helmets were scanned with greater voxels in the axial plane compared to the skull cap helmets. New helmets were scanned as exemplary images for comparison with helmets involved in motorcycle crashes. After CT scans were gathered, three-dimensional reconstructions were made to visualize scratches and impacts to the exterior of the helmets. Initial work was also conducted in analyzing interior components, and a trend was seen in decreased thickness between the interior foam and shell with sides of the exterior helmet thought to have contacted roadside barriers or the ground during motorcycle crashes. These helmet analysis methods have been established, and will be used to investigate multiple motorcycle crashes in conjunction with occupant injuries and direct head impacts to improve helmet design and the understanding of head injuries. This work also establishes the basis for development of finite element models of three of the most common helmet types. PMID:21525626

  9. Planning deep inferior epigastric perforator flaps for breast reconstruction: a comparison between multidetector computed tomography and magnetic resonance angiography

    Cina, A.; Rinaldi, P.; Cipriani, A.; Bonomo, L. [Agostino Gemelli Hospital, Catholic University of Sacred Heart, Department of Radiological Sciences, Rome (Italy); Barone-Adesi, L.; Salgarello, M. [Agostino Gemelli Hospital, Catholic University of Sacred Heart, Department of Surgery, Plastic and Reconstructive Surgery Unit, Rome (Italy); Masetti, R. [Agostino Gemelli Hospital, Catholic University of Sacred Heart, Department of Surgery, Breast Surgery Unit, Rome (Italy)

    2013-08-15

    Deep inferior epigastric perforator (DIEP) flaps have become the state of the art in breast reconstruction. We compared the diagnostic performance of multidetector computed tomography (CTA) and magnetic resonance angiography (MRA) in DIEP flap planning. Twenty-three women (mean age 48.0 years, range 26-72 years) underwent preoperative blinded evaluation using 64-slice CTA and 1.5-T MRA. Perforator identification, measurement of their calibre, intramuscular course (IMC), assessment of direct venous connections (DVC) with main superficial veins, superficial venous communications (SVC) between the right and left hemi-abdomen and deep inferior epigastric artery (DIEA) branching type were performed. Surgery was carried out by the same team. Intraoperative findings were the standard of reference. Accuracy in identifying dominant perforators was 91.3 % for both techniques and mean error in calibre measurement 1.18 {+-} 0.35 mm for CTA and 1.63 {+-} 0.39 mm for MRA. Accuracy in assessing perforator IMCs was 97.1 % for CTA and 88.4 % for MRA, DVC 94.4 % for both techniques, SVC 91.3 % as well, and DIEA branching type 100 % for CTA and 91.3 % for MRA. Image acquisition and interpretation time was 21 {+-} 3 min for CTA (35 {+-} 5 min for MRA). In a strategy to optimise DIEP flap planning avoiding radiation exposure, MRA can be proposed alternatively to CTA. (orig.)

  10. Planning deep inferior epigastric perforator flaps for breast reconstruction: a comparison between multidetector computed tomography and magnetic resonance angiography

    Deep inferior epigastric perforator (DIEP) flaps have become the state of the art in breast reconstruction. We compared the diagnostic performance of multidetector computed tomography (CTA) and magnetic resonance angiography (MRA) in DIEP flap planning. Twenty-three women (mean age 48.0 years, range 26-72 years) underwent preoperative blinded evaluation using 64-slice CTA and 1.5-T MRA. Perforator identification, measurement of their calibre, intramuscular course (IMC), assessment of direct venous connections (DVC) with main superficial veins, superficial venous communications (SVC) between the right and left hemi-abdomen and deep inferior epigastric artery (DIEA) branching type were performed. Surgery was carried out by the same team. Intraoperative findings were the standard of reference. Accuracy in identifying dominant perforators was 91.3 % for both techniques and mean error in calibre measurement 1.18 ± 0.35 mm for CTA and 1.63 ± 0.39 mm for MRA. Accuracy in assessing perforator IMCs was 97.1 % for CTA and 88.4 % for MRA, DVC 94.4 % for both techniques, SVC 91.3 % as well, and DIEA branching type 100 % for CTA and 91.3 % for MRA. Image acquisition and interpretation time was 21 ± 3 min for CTA (35 ± 5 min for MRA). In a strategy to optimise DIEP flap planning avoiding radiation exposure, MRA can be proposed alternatively to CTA. (orig.)

  11. Computer tomography following blunt abdominal trauma

    The computer tomographic appearances of lesions of parenchymatous organs following blunt abdominal trauma are described in 13 patients (five liver, four renal, two splenic and two pancreatic injuries). The value of abdominal computer tomography is discussed in relation to the interval between injury and time of abdominal examination and compared with the diagnostic value of abdominal angiography. (orig.)

  12. Optimisation of contrast medium volume and injection-related factors in CT pulmonary angiography: 64-slice CT study

    Uysal Ramadan, Selma [Ankara Training and Research Hospital, Department of Radiology, Ankara (Turkey); Ankara Training and Research Hospital, Cebeci, Ankara (Turkey); Kosar, Pinar; Sonmez, Iclal; Kosar, Ugur [Ankara Training and Research Hospital, Department of Radiology, Ankara (Turkey); Karahan, Sevilay [Hacettepe University, Department of Biostatistics, Faculty of Medicine, Ankara (Turkey)

    2010-09-15

    To compare the image quality of computed tomography pulmonary angiography (CTPA) obtained with the injection of various low doses of contrast medium (CM) with different injection-related factors. A total of 90 patients (42 females, 48 males; 54.3 {+-} 18.6 years) undergoing CTPA were included. Three CM protocols, each containing 30 patients, were created. Protocols 1, 2 and 3 consisted of a CM of 60 ml, 55 ml and 50 ml, and a bolus trigger level of 120 HU, 90 HU and 75 HU, respectively. Injection was uniphasic for protocols 1 and 2 (flow rate 5 ml/s), and biphasic for protocol 3 (flow rates 5 and 4 ml/s); with saline flushing afterwards. Enhancement was measured in three central and six peripheral pulmonary arteries. The mean attenuation value for pulmonary arteries was over 250 HU for all protocols. There was no difference between the attenuation levels with the protocols (p > 0.05). The percentage of pulmonary arteries exceeding optimal attenuation ({>=}250 HU) showed that protocols 2 and 3 were 90-100% successful (p < 0.05). The use of proper injection-related factors during CTPA, such as a low trigger level and a high flow rate with saline injection following a decreased CM volume (55 ml or 50 ml), will enable adequate pulmonary artery contrast enhancement. (orig.)

  13. Evaluation of organ doses and specific k effective dose of 64-slice CT thorax examination using an adult anthropomorphic phantom

    Hashim, S.; Karim, M. K. A.; Bakar, K. A.; Sabarudin, A.; Chin, A. W.; Saripan, M. I.; Bradley, D. A.

    2016-09-01

    The magnitude of radiation dose in computed tomography (CT) depends on the scan acquisition parameters, investigated herein using an anthropomorphic phantom (RANDO®) and thermoluminescence dosimeters (TLD). Specific interest was in the organ doses resulting from CT thorax examination, the specific k coefficient for effective dose estimation for particular protocols also being determined. For measurement of doses representing five main organs (thyroid, lung, liver, esophagus and skin), TLD-100 (LiF:Mg, Ti) were inserted into selected holes in a phantom slab. Five CT thorax protocols were investigated, one routine (R1) and four that were modified protocols (R2 to R5). Organ doses were ranked from greatest to least, found to lie in the order: thyroid>skin>lung>liver>breast. The greatest dose, for thyroid at 25 mGy, was that in use of R1 while the lowest, at 8.8 mGy, was in breast tissue using R3. Effective dose (E) was estimated using three standard methods: the International Commission on Radiological Protection (ICRP)-103 recommendation (E103), the computational phantom CT-EXPO (E(CTEXPO)) method, and the dose-length product (DLP) based approach. E103 k factors were constant for all protocols, ~8% less than that of the universal k factor. Due to inconsistency in tube potential and pitch factor the k factors from CTEXPO were found to vary between 0.015 and 0.010 for protocols R3 and R5. With considerable variation between scan acquisition parameters and organ doses, optimization of practice is necessary in order to reduce patient organ dose.

  14. Computer axial tomography in geosciences

    Computer Axial Tomography (CAT) is one of the most adequate non-invasive techniques for the investigation of the internal structure of a large category of objects. Initially designed for medical investigations, this technique, based on the attenuation of X- or gamma-ray (and in some cases neutrons), generates digital images which map the numerical values of the linear attenuation coefficient of a section or of the entire volume of the investigated sample. Shortly after its application in medicine, CAT has been successfully used in archaeology, life sciences, and geosciences as well as for the industrial materials non-destructive testing. Depending on the energy of the utilized radiation as well as on the effective atomic number of the sample, CAT can provide with a spatial resolution of 0.01 - 0.5 mm, quantitative as well as qualitative information concerning local density, porosity or chemical composition of the sample. At present two types of axial Computer Tomographs (CT) are in use. One category, consisting of medical as well as industrial CT is equipped with X-ray tubes while the other uses isotopic gamma-ray sources. CT provided with intense X-ray sources (equivalent to 12-15 kCi or 450-550 TBq) has the advantage of an extremely short running time (a few seconds and even less) but presents some disadvantages known as beam hardening and absorption edge effects. These effects, intrinsically related to the polychromatic nature of the X-rays generated by classical tubes, need special mathematical or physical corrections. A polychromatic X-ray beam can be made almost monochromatic by means of crystal diffraction or by using adequate multicomponent filters, but these devices are costly and considerably diminish the output of X-ray generators. In the case of CT of the second type, monochromatic gamma-rays generated by radioisotopic sources, such as 169 Yb (50.4 keV), 241 Am (59 keV), 192 Ir (310.5 and 469.1 keV ) or 137 Cs (662.7 keV), are used in combination with

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

    Full Text Available ... images. These images can be viewed on a computer monitor, printed on film or transferred to a ... a gantry, which rotates around the patient. The computer that processes the imaging information and monitor are ...

  16. Relationship between Willis circle variation and the occurrence of anterior and posterior communicaring artery aneurysms investigated by 64-slice CT angiography%CT血管成像评价颅内Willis环变异与前后交通动脉动脉瘤发生的关系

    王洪生; 徐新文; 王辉; 杨昭伟; 王鹏; 赵佩林; 王阳春

    2011-01-01

    目的 探讨大脑前动脉水平段(A1段)发育异常和胚胎型大脑后动脉与颅内前、后交通动脉动脉瘤形成的关系. 方法 回顾性分析216例64排CT血管成像(CTA)的资料.①将216例中CTA发现有前后交通动脉动脉瘤的126例,分为前交通动脉动脉瘤(ACoAA)组69例和后交通动脉动脉瘤(PCoAA)组57例,其余CTA检查无动脉瘤,但有头痛、头晕的90例患者,作为对照组.②分析动脉瘤的有无,动脉瘤的部位、形态、大小和瘤颈的宽度、瘤顶指向及瘤体与周围结构的关系等.③将判定结果与手术结果进行对照.④同时观察大脑前动脉A1段是否存在发育不良或缺如,是否存在胚胎型大脑后动脉. 结果 ①64排CTA共检出前、后交通动脉动脉瘤126例,其中ACoAA 69例,PCoAA57例,以DSA和手术为判断标准,64排CTA检出动脉瘤的敏感性和特异性均为100%.②ACoAA组中一侧A1段发育不良或缺如达81.7%,明显高于PCoAA组和对照组(P <0.05);PCoAA组中胚胎型大脑后动脉达56.1%,明显高于ACoAA组和对照组(P<0.05).结论 (1)64排CTA检出动脉瘤具有较高的敏感性和特异性;②一侧大脑前动脉Al段发育不良或缺如及胚胎型大脑后动脉与前、后交通动脉动脉瘤的发生密切相关.%Objective To investigate the relationship between the dysplasia of horizontal segment ( A1 segment) of anterior cerebral artery and the formation of anterior and posterior communicating artery aneurysms. Methods The data of 64-slice computed tomography angiography (CTA) of 216 patients were analyzed retrospectively. Of the 216 patients, CTA found 126 patients with aneurysm. They were di-vided into anterior communicating artery aneurysm ( ACoAA) group (n =69) and posterior communicating artery aneurysm (PCoAA)group (re =57). The other patients without aneurysm revealed by CTA but with headache and dizziness (n =90) were used as a control group. The presence or absence of aneurysm

  17. Indication for dental computed tomography. Case reports

    Based on case reports, common indications for dental computed tomography are demonstrated and typical findings are analysed. From a group of 110 patients who had a reformatted computed tomography of the maxilla and mandibula, 10 typical cases were chosen as examples and are presented with a detailed description of the findings. The most important indication was the analysis of the morphology of the alveolar ridge needed in presurgical planning for osseointegrated implants as well as in special cases of postsurgical control. Apart from implantology, the method could be used in cases of mandibular cysts and bony destructions. In conclusion, dental computed tomography has become established mainly in implantology. It can provide valuable results in cases where a demonstration of the bone in all dimensions and free of overlappings and distortions is needed. (orig.)

  18. Evaluation of laryngeal carcinoma by computed tomography

    The limitation of direct or indirect laryngoscopy and laryngogram in determining the exact site and anatomic location of laryngeal carcinoma were well documented by many authors. As compared with laryngoscopy and laryngogram, computed tomographic study for laryngeal cancer is more exact and accurate method demonstrating anatomic sites of involvement, invasion into deep soft tissue spaces of endolarynx, destruction of laryngeal cartilages and cervical metastasis. Fourteen laryngeal cancer patients proven by laryngoscopic biopsy were further examined by computed tomography for staging. The authors compared laryngoscopic findings with those of computed tomography, and their clinical, surgical and computed tomographic findings were analysed. The results were as follows; 1. All patients were proved as squamous cell carcinoma. They were 12 males and 2 females aged over 50 yr. 2. Common clinical symptoms were hoarsense, dysphagia and swallowing difficulty. The primary anatomic sites determined by CT were 8 transglottic, 2 glottic, 2 supraglottic and 1 pyriform sinus respectively. They were 2 T1, 7 T2,1 T3, 3 T4 by TNM systems, respectively. (One case was difficult to evaluate exactly). 3. Invasion into deep soft tissue spaces of endolarynx, cartilage destruction, and neck metastasis were relatively predominant in transglottic carcinomas. 4. Compute tomography was superior in evaluating tumor invasion, especially into deep sift tissue spaces of endolarynx, laryngeal cartilages and metastasis to soft tissue and lymph nodes of neck. However computed tomography had some limitation in determining primary site of laryngeal cancer.

  19. Application of 64-slice spiral computed tomography in measurement of simulated puncture channels of intrahepatic portosystemic shunt%64层螺旋CT在肝内门腔分流模拟穿刺途径测量中的应用

    王剑华; 周庭永; 吕发金; 张琳; 刘本菊; 张本斯; 张志伟

    2009-01-01

    Objective To offer clinical applicable information on morphology by means of measurement of the simulated puncture channel of the right portal branch at 1 and 2 cm and venae hepaticae intermediae and right hepatic veins at 1,2, and 3 cm in patients without liver diseases and those with cirrhosis Child-Pugh grade A and B. Methods Abdominal 64-MSCT scan was performed in 40 cases without liver diseases and 14 cases of cirrhosis after the test of the celiac levels of abdominal aorta was conducted by the smart tracking technology (Smart Prep). The data were processed for imaging on the GE ADW4.2 workstation. Rosults Significant difference was found between the normal group and cirrhosis Child-Pugh grade A and B groups, φMHV1, φRHV1 (P <0.05). The diameter of the normal right hepatic vein at 1-2 cm and that of the middle hepatic vein at 1-2 cm decreased rapidly as compared with that of cirrhosis Child-Pugh grade A and B groups. There was also significant difference (P<0.05) between the normal and cirrhosis Child-Pugh grade A and B groups in the simulated puncture channels of DMHV2-RPV1, DMHV3-RPV1, DMHV3-RPV2, and DRHV1-RPV1. Conclusion 64-MSCT and the three-dimensional reconstruction may be an effective way for accurate measure-ment of the intrinsic liver vessels in vivo. The study of the simulated intrahepatic portosystemic shunt can help to choose the appropriate length and type of the stents.%目的 通过64层螺旋CT(64-MSCT)对非肝病患者及肝硬化Child-Pugh A、B分级组患者门静脉右支1、2 cm处与肝中静脉、肝右静脉1、2、3 cm间模拟穿刺途径进行测量.方法 选取上腹部64-MSCT扫描非肝病被检查组共40例;肝硬化组符合纳入标准14例.用智能追踪技术启动扫描,在GE ADW4.2工作站进行处理.结果 正常组与肝硬化Child-Push A、B分级组φMHV1、φRHV1有统计学差异(P<0.05).正常组肝右静脉1~2 cm处及肝中静脉1~2 cm处直径较肝硬化Child-Pugh A、B分级组减小迅速.正常组与肝硬化Child-Pugh A、B分级组模拟穿刺途径距离DMHV2-RPV1、DMHV3-RPV1、DMHV3-RPV2、DRHV1-RPV1间有统计学差异(P<0.05).结论 64-MSCT及三维重建技术是准确测量活体功能状态下肝内血管的有效方法.肝内门腔分流术模拟穿刺途径的研究有助于选择适当长度和类型的支架.

  20. Epiploic appendicitis - ultrasonography and computed tomography findings

    Epiploic appendicitis is an uncommon inflammatory condition, which is presently better diagnosed by current imaging methods such as computed tomography and ultrasonography that allow a non-invasive and efficient diagnostic approach. The author studied 6 patients with epiploic appendicitis. The patients were submitted to computed tomography that showed paracolic oval lesions of 1 to 2 cm of diameter, fat attenuation and a thin peripheral hyperdense rim associated with adjacent fat stranding. Ultrasound examination performed in two patients showed hyperechoic ovoid noncompressible masses at the site of maximum abdominal tenderness. (author)

  1. Usefulness of computed tomography in recurrent nephrolithiasis

    For five cases of recurrent stone formers we performed Computed Tomography, which revealed non-visualized small stones on KUB and uric acid stones. Case 1 was primary hyperparathyroidism. Case 2 had several episodes of spontaneous stone passage without any stone shadow on routine X-ray examination. Case 3 had single ureteral stone on X-ray film. Case 4 had several episodes of spontaneous passage of mixed stones (uric acid and calcium oxalate). Case 5 had bilateral radiolucent large renal stones. We emphasized the superiority of Computed Tomography in search and prophylactic therapy of the stone formation. (author)

  2. Computed tomography in spinal canal diagnosis

    Sobota, J.; Dutka, J. (Ustredni Vojenska Nemocnice, Prague (Czechoslovakia))

    1983-09-01

    On a sample of 128 patients examined for suspected disorders of the spinal canal by computed tomography, the experience with the diagnostic possibilities of this quick, accurate and noninvasive imaging technique is demonstrated. The methodology of the examination and the range of obtained information in diagnosing congenital anomalies, traumas and degenerative changes are briefly described. Certain problems and limitations of this method for the diagnosis of tumors are presented. For the assessment of vascular changes and inflammatory processes, computed tomography cannot be expected to be used on a wider scale.

  3. Computed tomography in spinal canal diagnosis

    On a sample of 128 patients examined for suspected disorders of the spinal canal by computed tomography, the experience with the diagnostic possibilities of this quick, accurate and noninvasive imaging technique is demonstrated. The methodology of the examination and the range of obtained information in diagnosing congenital anomalies, traumas and degenerative changes are briefly described. Certain problems and limitations of this method for the diagnosis of tumors are presented. For the assessment of vascular changes and inflammatory processes, computed tomography cannot be expected to be used on a wider scale

  4. Multidetector computed tomography angiography of the abdomen

    Multidetector computed tomography (MDCT) angiography has provided excellent opportunities for advancement of computed tomography (CT) technology and clinical applications. It has a wide range of applications in the abdomen including vascular pathologies either occlusive or aneurysmal; enables the radiologist to produce vascular mapping that clearly show tumor invasion of vasculature and the relationship of vessels to mass lesions. MDCTA can be used in preoperative planning for hepatic resection, preoperative evaluation and planning for liver transplantation. MDCTA can also provide extremely valuable information in the evaluation of ischemic bowel disease, active Crohn disease, the extent and location of collateral vessels in cirrhosis

  5. Computed tomography in malignant primary bone tumours

    The importance of computed tomography is examined in malignant primary bone tumours using a strongly defined examination group of 13 Patients (six Ewing's-sarcomas, five osteosarcomas, one chondrosarcoma and one spindle-shaped cell sarcoma). Computed tomography is judged superior compared to plain radiographs in recognition of bone marrow infiltration and presentation of parosteal tumour parts as well as in analysis of tissue components of tumours, CT is especially suitable for therapy planning and evaluating response to therapy. CT does not provide sufficient diagnostic information to determine dignity and exact diagnosis of bone tumours. (orig.)

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

    Full Text Available ... a gantry, which rotates around the patient. The computer that processes the imaging information and monitor are located in ... ray beam follows a spiral path. A special computer program processes this series of pictures, or slices of the ...

  7. Real-time three-dimensional echocardiographic left ventricular ejection fraction and volumes assessment: comparison with cardiac computed tomography

    Background and objective: Few studies addressed the comparison between real-time 3D echocardiography (RT3DE) and cardiac computed tomography (CCT) concerning left ventricular ejection fraction and volumes assessment. We sought to compare both techniques regarding left ventricle (LV) ejection fraction function and volumes analysis. Methods: we studied by RT3DE (Philips IE 33, And, MA, USA) and by CCT (Toshiba, 64-slice, Otawara, Japan) 41 consecutive patients (29 males, 58 ± 11 yrs). We analysed by both techniques LVEF, LVEDV, LVESV. RT3DE and CCT data were compared by coefficients of determination (r: Pearson), Bland and Altman test and linear regression, 95% CI. Results: RT3DE data: LVEF ranged from 56.7 to 78.9 % (65.3 + 5.7 ); LVEDV ranged from 49.6 to 178.2 (88 + 27.5) mL; LVESV from 11.4 to 78 ( 33.9 + 13.7) mL. CCT data: LVEF ranged from 53 to 86 % (67.3 + 7.9 ); LVEDV ranged from 51 to 186 (106.4 + 30.7) mL; LVESV from 7 to 72 ( 35.1 + 13.8) mL. Correlations relative to RT3DE and CCT were: LVEF (r: 0. 7877, p<0.0001, 95 % CI 0.6327 to 0.8853 ); LVEDV (r:0.7671, p<0.0001, 95 % CI 0.5974 to 0.8745); LVESV (r: 0.8121, p<0.0001, 95 % CI 0.6659 to 0.8957). Conclusions: it was observed adequate correlation between real-time 3D echocardiography and cardiac computed tomography concerning ejection fraction and volumes assessment. (author)

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

    Full Text Available ... which are then displayed on a monitor. Special software can also generate three-dimensional (3-D) images ... When the image slices are reassembled by computer software, the result is a very detailed multidimensional view ...

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

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos News Physician Resources Professions Site Index A-Z Children's (Pediatric) CT (Computed ...

  10. Coordinate Metrology by Traceable Computed Tomography

    Müller, Pavel

    X-ray computed tomography (CT) is a measuring technique which has become an important technology in the production environment over the last years. Due to a number of advantages of CT compared to, e.g., coordinate measuring machines (CMMs), CT has been recently spread in the field of manufacturin...

  11. Computed Tomography For Inspection Of Thermistors

    Schaefer, Lloyd A.

    1991-01-01

    Computed tomography (CT) enables identification of cracked thermistors without disassembly of equipment containing them. CT unit used to scan equipment and locate thermistors. Further scans made in various radial orientations perpendicular to plane of devices to find cracks. Cracks invisible in conventional x-radiographs seen.

  12. Analysis of airways in computed tomography

    Petersen, Jens

    Chronic Obstructive Pulmonary Disease (COPD) is major cause of death and disability world-wide. It affects lung function through destruction of lung tissue known as emphysema and inflammation of airways, leading to thickened airway walls and narrowed airway lumen. Computed Tomography (CT) imaging...

  13. Comparison on Computed Tomography using industrial items

    Angel, Jais Andreas Breusch; De Chiffre, Leonardo

    2014-01-01

    In a comparison involving 27 laboratories from 8 countries, measurements on two common industrial items, a polymer part and a metal part, were carried out using X-ray Computed Tomography. All items were measured using coordinate measuring machines before and after circulation, with reference...

  14. Computed Tomography in the Modern Slaughterhouse

    Mosbech, Thomas Hammershaimb

    technology. Recently, the use of X-ray computed tomography (CT) coupled with methods from image analysis has been introduced as a powerful means to optimise production, by providing detailed information on the raw materials. This thesis covers two aspects of the application of CT in the modern abattoir. In...

  15. Inter laboratory comparison on Industrial Computed Tomography

    Angel, Jais Andreas Breusch; De Chiffre, Leonardo

    An interlaboratory comparison on industrial X-ray Computed Tomography (CT) was organized by the Centre for Geometrical Metrology (CGM), Department of Mechanical Engineering, Technical University of Denmark (DTU) and carried out within the project “Centre for Industrial Application of CT scanning...

  16. Investigation of measuring strategies in computed tomography

    Müller, Pavel; Hiller, Jochen; Cantatore, Angela;

    2011-01-01

    Computed tomography has entered the industrial world in 1980’s as a technique for non-destructive testing and has nowadays become a revolutionary tool for dimensional metrology, suitable for actual/nominal comparison and verification of geometrical and dimensional tolerances. This paper evaluates...

  17. Neutron computed tomography of rat lungs

    Metzke, R W; Wall, W A [Institute for Computational Mechanics at Technische Universitaet Muenchen, 85747 Garching (Germany); Runck, H; Stahl, C A; Schneider, M; Guttmann, J [Department of Anesthesiology, Section for Experimental Anesthesiology, University Medical Center Freiburg, 79106 Freiburg (Germany); Schillinger, B; Calzada, E; Muehlbauer, M; Schulz, M [Forschungsneutronenquelle Heinz Maier-Leibnitz (FRM-II) and Fakultaet fuer Physik E21 at Technische Universitaet Muenchen, 85748 Garching (Germany); Priebe, H-J, E-mail: metzke@lnm.mw.tum.d [Department of Anesthesiology, University Medical Center Freiburg, 79106 Freiburg (Germany)

    2011-01-07

    Using conventional methods, three-dimensional imaging of the lung is challenging because of the low contrast between air and tissue and the large differences in dimensions between various pulmonary structures. The small distal airway structures and the high air-to-tissue ratio of lung tissue require an imaging technique which reliably discriminates between air and water. The objective of this study was to assess whether neutron computed tomography would satisfy such a requirement. This method utilizes the unique characteristic of neutrons of directly interacting with the atomic nucleus rather than being scattered by the atomic shell. Neutron computed tomography was tested in rats and allowed differentiation of larger lung structures (e.g., lobes) and distal airways. Airways could be identified reliably down to the sixth bronchial generation, in some cases even down to the tenth generation. The lung could be stabilized for sufficiently long exposure times to achieve an image resolution of 50-60 {mu}m, which is the current physical resolution limit of the neutron computed tomography facility. Neutron computed tomography allowed excellent lung imaging without the need for additional tissue preparation or contrast media. The enhanced structural resolution obtained by applying this new research technique may improve understanding of lung physiology and respiratory therapy. (note)

  18. Sparse Image Reconstruction in Computed Tomography

    Jørgensen, Jakob Sauer

    In recent years, increased focus on the potentially harmful effects of x-ray computed tomography (CT) scans, such as radiation-induced cancer, has motivated research on new low-dose imaging techniques. Sparse image reconstruction methods, as studied for instance in the field of compressed sensing...

  19. Computed tomography of intussusception in adult

    Intussusception is rare in adult and usually caused by organic lesions, although there is a significant number of so-called idiopathic cases. The diagnosis of intussusception have been made by plain abdomen, barium enema and small bowel series. But recently ultrasound and computed tomography make a contribution to diagnose intussusception. Computed tomography is not the primary means for evaluating a gastrointestinal tract abnormality but also provides valuable information in evaluating disorders affecting the hollow viscera of the alimentary tract. Computed tomography image of intussusception demonstrates a whirl like pattern of bowel loops separated by fatty stripe correlating of the intestinal walls. Abdominal ultrasonogram was used as the initial diagnostic test in 2 cases out of total 4 cases, with abdominal mass of unknown cause. It revealed a typical pattern, composed of a round or oval mass with central dense echoes and peripheral poor echoes. We report 4 all cases of intussusception in adult who were performed by computed tomography and/or ultrasound. All cases were correlated with barium enema examination and/or surgical reports.

  20. Computed tomography of intussusception in adult

    Jeon, Hae Jeong; Ahn, Byeong Yeob; Cha, Soon Joo; Seol, Hae Young; Chung, Kyoo Byung; Suh, Won Hyuck [Korea University College of Medicine, Seoul (Korea, Republic of)

    1984-12-15

    Intussusception is rare in adult and usually caused by organic lesions, although there is a significant number of so-called idiopathic cases. The diagnosis of intussusception have been made by plain abdomen, barium enema and small bowel series. But recently ultrasound and computed tomography make a contribution to diagnose intussusception. Computed tomography is not the primary means for evaluating a gastrointestinal tract abnormality but also provides valuable information in evaluating disorders affecting the hollow viscera of the alimentary tract. Computed tomography image of intussusception demonstrates a whirl like pattern of bowel loops separated by fatty stripe correlating of the intestinal walls. Abdominal ultrasonogram was used as the initial diagnostic test in 2 cases out of total 4 cases, with abdominal mass of unknown cause. It revealed a typical pattern, composed of a round or oval mass with central dense echoes and peripheral poor echoes. We report 4 all cases of intussusception in adult who were performed by computed tomography and/or ultrasound. All cases were correlated with barium enema examination and/or surgical reports.

  1. Computed Tomography (CT) Perfusion in Abdominal Cancer

    Hansen, Martin Lundsgaard; Norling, Rikke; Lauridsen, Carsten;

    2013-01-01

    Computed Tomography (CT) Perfusion is an evolving method to visualize perfusion in organs and tissue. With the introduction of multidetector CT scanners, it is now possible to cover up to 16 cm in one rotation, and thereby making it possible to scan entire organs such as the liver with a fixed...

  2. Computed tomography scanning during a traumatic resuscitation

    L.F.M. Beenen; R. Adams; R.W. Koster; T. Otto

    2011-01-01

    In cardiopulmonary resuscitation, computed tomography (CT) imaging could be of decisive importance to therapeutic strategy making but is yet unavailable because of incompatibility of CT scanning and manual chest compressions. In this report, we describe a case in which CT scanning was performed on a

  3. Neutron computed tomography of rat lungs

    Using conventional methods, three-dimensional imaging of the lung is challenging because of the low contrast between air and tissue and the large differences in dimensions between various pulmonary structures. The small distal airway structures and the high air-to-tissue ratio of lung tissue require an imaging technique which reliably discriminates between air and water. The objective of this study was to assess whether neutron computed tomography would satisfy such a requirement. This method utilizes the unique characteristic of neutrons of directly interacting with the atomic nucleus rather than being scattered by the atomic shell. Neutron computed tomography was tested in rats and allowed differentiation of larger lung structures (e.g., lobes) and distal airways. Airways could be identified reliably down to the sixth bronchial generation, in some cases even down to the tenth generation. The lung could be stabilized for sufficiently long exposure times to achieve an image resolution of 50-60 μm, which is the current physical resolution limit of the neutron computed tomography facility. Neutron computed tomography allowed excellent lung imaging without the need for additional tissue preparation or contrast media. The enhanced structural resolution obtained by applying this new research technique may improve understanding of lung physiology and respiratory therapy. (note)

  4. Computed tomography in severe protein energy malnutrition.

    Househam, K C; Villiers, J.F.

    1987-01-01

    Computed tomography of the brain was performed on eight children aged 1 to 4 years with severe protein energy malnutrition. Clinical features typical of kwashiorkor were present in all the children studied. Severe cerebral atrophy or brain shrinkage according to standard radiological criteria was present in every case. The findings of this study suggest considerable cerebral insult associated with severe protein energy malnutrition.

  5. Parallel Computing for the Computed-Tomography Imaging Spectrometer

    Lee, Seungwon

    2008-01-01

    This software computes the tomographic reconstruction of spatial-spectral data from raw detector images of the Computed-Tomography Imaging Spectrometer (CTIS), which enables transient-level, multi-spectral imaging by capturing spatial and spectral information in a single snapshot.

  6. Lung Nodule Detection in Screening Computed Tomography

    Gori, I; Cerello, P; Cheran, S C; De Nunzio, G; Fantacci, M E; Kasae, P; Masala, G L; Pérez-Martínez, A; Retico, A

    2007-01-01

    A computer-aided detection (CAD) system for the identification of pulmonary nodules in low-dose multi-detector helical Computed Tomography (CT) images with 1.25 mm slice thickness is presented. The basic modules of our lung-CAD system, a dot-enhancement filter for nodule candidate selection and a neural classifier for false-positive finding reduction, are described. The results obtained on the collected database of lung CT scans are discussed.

  7. Computed tomography of tuberculous meningitis

    Recently, tuberculous meningitis has become rather rare except in areas where tuberculosis is still endemic. Six adolescents and young adults with tuberculous meningitis were evaluated by means of serial computerized tomography (CT), and the results were correlated with the findings of surgical specimens or autopsies. All cases showed meningeal irritation and fever at onset. CSF cultures revealed the presence of tuberculous bacilli. Four cases advanced rapidly to the clinical stage III and expired in a short period-between two weeks to one month from onset. On initial CT scanning, the disappearance of the basal cistern was a characteristic finding in all these cases. With the progression, an enhancement of the basal cistern on contrast injection, a localized hypodensity in adjacent parenchyma, and symmetrical ventricular dilatation appeared. Two autopsied cases showed tuberculous granulomas with purulent materials, thickened meninges, and caseous necrosis in the parenchyma around the basal cistern. The other two cases progressed rather slowly. CT findings at Stage II showed multiple enhanced spots in the basal subcortical area following contrast injection. Tuberculous granulomas were identified in these parts by means of explorative craniotomy. The authors point out the pathognomonic CT findings of tuberculous meningitis and emphasize the necessity of serial CT for the early detection and management of tuberculous meningitis. (author)

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

    Full Text Available ... child may have, and if there is a history of heart disease, asthma, diabetes, kidney disease or ... the patient. The computer that processes the imaging information and monitor are ... in detector technology allow new CT scanners to obtain multiple slices ...

  9. Computed tomography of thymic abnormalities

    Schnyder, P.; Candardjis, G.

    1987-05-01

    Computed tomographic examinations of 38 patients with surgically and histologically proven diagnosis were reviewed. Twenty subjects (52%) had an invasive thymoma and 16% an hyperplastic thymus. Myasthenia gravis was present in 6 cases (16%) of thymic abnormalities, four (10,5%) with invasive thymoma and two (5%) with thymic hyperplasia. Graves' disease was also present in one case of thymic hyperplasia. We emphasize the contribution of CT to the diagnosis and the prognosis.

  10. Cerebral candidiasis. Computed tomography appearance

    A three year old child who had been suffering from oral candidiasis since the age of 1 year presented with osteitis of the clavicle, 2 cerebral frontal abscesses and an occipital abscess which extended across the calvaria and was associated with osteolysis. Histological and microbiological studies following surgery confirmed the diagnosis of candidiasis in this girl who was found to have IgA immunodefinciency. The authors report the computed tomographic appearance of the cerebral lesions and review the literature. (orig.)

  11. Cerebral candidiasis. Computed tomography appearance

    Chaabane, M.; Ladeb, M.F.; Bouhaouala, M.H.; Ben Hammouda, M.; Ataalah, R.; Gannouni, A.; Krifa, H.

    1989-07-01

    A three year old child who had been suffering from oral candidiasis since the age of 1 year presented with osteitis of the clavicle, 2 cerebral frontal abscesses and an occipital abscess which extended across the calvaria and was associated with osteolysis. Histological and microbiological studies following surgery confirmed the diagnosis of candidiasis in this girl who was found to have IgA immunodefinciency. The authors report the computed tomographic appearance of the cerebral lesions and review the literature. (orig.).

  12. Acute pancreatitis: diagnostic value of ultrasonography and computed tomography

    Blery, M.; Hautefeuille, P.; Jacquenod, P. and others

    1987-09-01

    The value of ultrasonography and computed tomography for the diagnosis, extension, pronostic, complications and etiology of acute pancreatitis is discussed. Ultrasonography and computed tomography guided interventional radiology techniques are valuable in the management of pancreatitis complications such as abscesses.

  13. Acute pancreatitis: diagnostic value of ultrasonography and computed tomography

    The value of ultrasonography and computed tomography for the diagnosis, extension, pronostic, complications and etiology of acute pancreatitis is discussed. Ultrasonography and computed tomography guided interventional radiology techniques are valuable in the management of pancreatitis complications such as abscesses

  14. Real-time computed optical interferometric tomography

    Shemonski, Nathan D.; Liu, Yuan-Zhi; Ahmad, Adeel; Adie, Steven G.; Carney, P. Scott; Boppart, Stephen A.

    2014-03-01

    High-resolution tomography is of great importance to many areas of biomedical imaging, but with it comes several apparent tradeoffs such as a narrowing depth-of-field and increasing optical aberrations. Overcoming these challenges has attracted many hardware and computational solutions. Hardware solutions, though, can become bulky or expensive and computational approaches can require high computing power or large processing times. This study demonstrates memory efficient implementations of interferometric synthetic aperture microscopy (ISAM) and computational adaptive optics (CAO) - two computational approaches for overcoming the depthof- field limitation and the effect of optical aberrations in optical coherence tomography (OCT). Traditionally requiring lengthy post processing, here we report implementations of ISAM and CAO on a single GPU for real-time in vivo imaging. Real-time, camera-limited ISAM processing enabled reliable acquisition of stable data for in vivo imaging, and CAO processing on the same GPU is shown to quickly correct static aberrations. These algorithmic advances hold the promise for high-resolution volumetric imaging in time-sensitive situations as well as enabling aberrationfree cellular-level volumetric tomography.

  15. Computed tomography of tibial plateau fractures

    Twenty patients with tibial plateau fractures were studied by conventional tomography and computed tomography (CT) in order to determine the role and feasibility of CT in management of such patients. CT resulted in less discomfort to the patient and provided optimal visualization of the plateau defect and the split fragments. It proved more accurate than conventional tomography in assessing depressed and split fractures when they involved the anterior or posterior border of the plateau and in demonstrating the extent of fracture comminution. Split fragments with an oblique plane of fracture also were seen better by CT. The degree of fracture depression and separation as measured by the computerized technique was often more accurate than measurements obtained from conventional tomograms

  16. Computed tomography of the medulla

    The medulla was studied in cadavers and in 100 patients both with and without the intrathecal administration of contrast material. The computed tomographic (CT) anatomy was correlated with the appearance on anatomic dissections. The pyramids, olives, and inferior cerebellar peduncles produced characteristic contours on cross sections of the medulla. The hypoglossal nerve by its location and course in the medullary cistern could be distinguished from the glossopharyngeal, vagal, and spinal accessory nerves. For optimal evaluation of the medulla, intrathecal administration of metrizamide and 5- and/or 1.5-mm-thick axial and coronal sections are recommended

  17. Introducing Seismic Tomography with Computational Modeling

    Neves, R.; Neves, M. L.; Teodoro, V.

    2011-12-01

    Learning seismic tomography principles and techniques involves advanced physical and computational knowledge. In depth learning of such computational skills is a difficult cognitive process that requires a strong background in physics, mathematics and computer programming. The corresponding learning environments and pedagogic methodologies should then involve sets of computational modelling activities with computer software systems which allow students the possibility to improve their mathematical or programming knowledge and simultaneously focus on the learning of seismic wave propagation and inverse theory. To reduce the level of cognitive opacity associated with mathematical or programming knowledge, several computer modelling systems have already been developed (Neves & Teodoro, 2010). Among such systems, Modellus is particularly well suited to achieve this goal because it is a domain general environment for explorative and expressive modelling with the following main advantages: 1) an easy and intuitive creation of mathematical models using just standard mathematical notation; 2) the simultaneous exploration of images, tables, graphs and object animations; 3) the attribution of mathematical properties expressed in the models to animated objects; and finally 4) the computation and display of mathematical quantities obtained from the analysis of images and graphs. Here we describe virtual simulations and educational exercises which enable students an easy grasp of the fundamental of seismic tomography. The simulations make the lecture more interactive and allow students the possibility to overcome their lack of advanced mathematical or programming knowledge and focus on the learning of seismological concepts and processes taking advantage of basic scientific computation methods and tools.

  18. 21 CFR 892.1200 - Emission computed tomography system.

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Emission computed tomography system. 892.1200... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1200 Emission computed tomography system. (a) Identification. An emission computed tomography system is a device intended to detect...

  19. Practical management of computed tomography

    For examinations of the spinal canal is used computed myelography as an adjunct to water-soluble conventional myelography. For CT alone about 3.5 g. of metrizamide in isotonic solution is adequate for all investigations. If the constrast medium has to be run into the head by gravity, as in the detection of cerebrospinal fluid fistula or empty sella, or for detailed examination of the basal cisterns, phenobarbitone 100 mg. t.d.s. is commenced on the eve of the examination and continued for 48 hours. A similar dose is also administered to epileptic subject. If fits should occur they are treated with intravenous diazepam and prophylactic phenobarbitone is administered. (orig./AJ)

  20. 64排螺旋CT泌尿系三维成像患者的护理%Nursing of patients undergoing 64-slice CT urography

    高丽; 张金玲; 赵云霞; 申秀芬

    2009-01-01

    目的 探讨护理工作在64排螺旋CT泌尿系三维成像(MSCTU)中的价值.方法 240例患者应用64排螺旋CT进行泌尿系三维成像检查,检查前询问病史及碘过敏史,关注患者的心理状态,做好碘预试验;检查中认真观察患者,对可能出现的任何不良反应进行预判,并制订相应的措施;检查后对症处理出现的各种情况,并做好护理指导.结果 239例患者顺利完成检查,1例在扫描过程中出现药物外渗,扫描失败,经过重新扫描,获得满意图像.结论 利用64排螺旋CT行泌尿系三维成像检查,作为一种无创伤、费用相对较低、安全性高的检查技术,护理操作应贯穿检查的每一步.有效的护理措施直接影响检查结果的准确性,熟练的护理操作及耐心细致的心理护理是MSCTU检查中的重要环节.%Objective To discuss the value of nursing work in 64-slice CT urography. Methods 240 patients participated in the 64-slice CT urography, inquiring medical history and iodine allergic history, paying attention to their psychological state and finishing iodine preliminary test before examination, ob-serving patients carefully, pre-judging any possible adverse effect and formulating corresponding measures during the examination, giving expectant treatment according to the various condition and nursing instruc-tion. Results 239 patients passed through the examination smoothly, agents exosmosis happened in one case and led to failure, but satisfactory image was obtained after rescanning. Conclusions Nursing oper-ation penetrates every step of 64-slice CT urography, which is a non-traumatic, low-expense and high-safety examination. Effect nursing directly influences the accuracy of the results, proficient nursing opera-tion and patient psychological nursing is the important part of it.

  1. Cone beam computed tomography in endodontic

    Durack, Conor; Patel, Shanon, E-mail: conordurack1@hotmail.com [Unit of Endodontology, Department of Conservative Dentistry, King' s College London, London (United Kingdom)

    2012-07-01

    Cone beam computed tomography (CBCT) is a contemporary, radiological imaging system designed specifically for use on the maxillofacial skeleton. The system overcomes many of the limitations of conventional radiography by producing undistorted, three-dimensional images of the area under examination. These properties make this form of imaging particularly suitable for use in endodontic. The clinician can obtain an enhanced appreciation of the anatomy being assessed, leading to an improvement in the detection of endodontic disease and resulting in more effective treatment planning. In addition, CBCT operates with a significantly lower effective radiation dose when compared with conventional computed tomography (CT). The purpose of this paper is to review the current literature relating to the limitations and potential applications of CBCT in endodontic practice. (author)

  2. Cone beam computed tomography in endodontic

    Cone beam computed tomography (CBCT) is a contemporary, radiological imaging system designed specifically for use on the maxillofacial skeleton. The system overcomes many of the limitations of conventional radiography by producing undistorted, three-dimensional images of the area under examination. These properties make this form of imaging particularly suitable for use in endodontic. The clinician can obtain an enhanced appreciation of the anatomy being assessed, leading to an improvement in the detection of endodontic disease and resulting in more effective treatment planning. In addition, CBCT operates with a significantly lower effective radiation dose when compared with conventional computed tomography (CT). The purpose of this paper is to review the current literature relating to the limitations and potential applications of CBCT in endodontic practice. (author)

  3. Possibilities of computer tomography in multiple sclerosis

    Computer tomography was performed in 41 patients with multiple sclerosis, the average age of patients being 40.8 years. Native examinations were made of 17 patients, examinations with contrast medium of 19, both methods were used in the examination of 5 patients. In 26 patients, i.e. in almost two-thirds, cerebral atrophy was found, in 11 of a severe type. In 9 patients atrophy affected only the hemispheres, in 16 also the stem and cerebellum. The stem and cerebellum only were affected in 1 patient. Hypodense foci were found in 21 patients, i.e. more than half of those examined. In 9 there were multiple foci. In most of the 19 examined patients the hypodense changes were in the hemispheres and only in 2 in the cerebellum and brain stem. No hyperdense changes were detected. The value and possibilities are discussed of examinations by computer tomography multiple sclerosis. (author)

  4. Biliary obstruction: Helical computed tomography cholangiography evaluation

    Helical computed tomography cholangiography (HCTC) takes advantage of the improvement in the quality of multiplanar and three-dimensional reconstructions resulting from the volumetric acquisition of data achieved with helical computed tomography and the indirect opacification of the bile ducts provided by cholangiographic contrast media. This method was used to evaluate 31 patients with suspected biliary obstruction over a one-year period and the findings were compared with those of direct cholangiography and/or surgery. Biliary opacification was sufficient to allow three-dimensional reconstructions in 90,3% of cases. Sensitivity was 81% for the diagnosis of choledochoolithiasis and 100% for ascariasis, choledochal cysts and anatomic variants of the biliary tree. Our results indicate that HCTC is a valuable alternative as a diagnostic method prior to direct cholangiography. Direct cholangiography should be reserved for those patients who require it as part of a therapeutic procedure

  5. Spontaneous cerebral intraparenchymatous hematoma: computed tomography findings

    The objective of this study was to identify the most frequent aspects of spontaneous cerebral intraparenchymatous hematoma found at computed tomography examinations. We reviewed, retrospectively, the computed tomography studies of 250 patients with spontaneous intracerebral hemorrhage carried out in three hospitals in Rio de Janeiro, Brazil. The results showed deep intracerebral hematomas showed the highest incidence and were observed in 54.4% of the cases (136 patients) followed by lobar hemorrhage in 34.8% of the cases (87 patients). Cerebellar hemorrhage and brainstem bleeding were more rarely observed, occurring in 8.4% (21 patients) and 2.4% (six patients) of the cases, respectively. Chronic headache was the most frequent symptom whereas hypertension was observed in the majority of the cases. Blood draining into the ventricular system occurred more frequently in patients with deep hematomas. (author)

  6. Computed tomography after radical pancreaticoduodenectomy (Whipple's procedure)

    Whipple's procedure (radical pancreaticoduodenectomy) is currently the only curative option for patients with periampullary malignancy. The surgery is highly complex and involves multiple anastomoses. Complications are common and can lead to significant postoperative morbidity. Early detection and treatment of complications is vital, and high-quality multidetector computed tomography (MDCT) is currently the best method of investigation. This review outlines the surgical technique and illustrates the range of normal postoperative appearances together with the common complications

  7. Computed tomography of ano-rectal anomalies

    Computed tomography (CT) was performed in 9 patients with faecal incontinence more than 8 years after rectoplasty for high imperforate anus. The radiologic findings were correlated with the clinical evaluation of faecal incontinence. No statistically significant correlation was found between function and anatomic findings as demonstrated by CT. Thus, although CT demonstrates the post-operative anatomy in a detailed way, the information does not seem to be directly applicable when selecting the type of reoperation for faecal incontinence. (orig.)

  8. Dose reduction in abdominal computed tomography

    The broad availability and use of multidetector computed tomography (MDCT) in recent years has increased the radiation dose for patients. Multiphase MDCT protocols are used in abdominal imaging for various indications. Dose reduction though novel technologies, such as dual energy CT or adapted contrast injection protocols (split bolus etc.) for reduction of scans. An optimized dose reduction can be achieved by using strict protocols which are adapted to the clinical situation of the patient. (orig.)

  9. Computed tomography diagnostic of chronic rhino sinusitis

    Ordinary conventional roentgenological examinations of paranasal sinuses does not satisfy the latest needs of otorinolaringologysta, especially for functional endoscopic surgery. Computed tomography of paranasal sinuses because more important for diagnostics of chronic rhino sinusitis and for choosing the appropriate therapy of it. The examination enables to localize pathology precisely, to exactly evaluate anatomic structures, ostiomeatalic complex, the status of mucous membrane of paranasal sinuses and the effectiveness of surgical treatment of chronic rhino sinusitis. (author)

  10. Encapsulating peritonitis: computed tomography and surgical correlation

    Kadow, Juliana Santos; Fingerhut, Carla Jeronimo Peres; Fernandes, Vinicius de Barros; Coradazzi, Klaus Rizk Stuhr; Silva, Lucas Marciel Soares; Penachim, Thiago Jose, E-mail: vinicius.barros.fernandes@gmail.com [Pontificia Universidade Catolica de Campinas (PUC-Campinas), Campinas, SP (Brazil). Hospital e Maternidade Celso Pierro

    2014-07-15

    Sclerosing encapsulating peritonitis is a rare and frequently severe entity characterized by total or partial involvement of small bowel loops by a membrane of fibrous tissue. The disease presents with nonspecific clinical features of intestinal obstruction, requiring precise imaging diagnosis to guide the treatment. The present report emphasizes the importance of computed tomography in the diagnosis of this condition and its confirmation by surgical correlation. (author)

  11. Computed Tomography Findings in Xanthogranulomatous Pyelonephritis

    Arumugam Rajesh; George Jakanani; Nick Mayer; Kevin Mulcahy

    2011-01-01

    Background: Xanthogranulomatous pyelonephritis (XGN) is an uncommon condition characterized by chronic suppurative renal inflammation that leads to progressive parenchymal destruction. Purpose: To review the computed tomography (CT) findings of patients diagnosed with XGN. Materials and Methods: A retrospective review of CT findings in patients with histologically proven XGN was carried out. Results: Thirteen CT examinations of 11 patients were analyzed. Renal enlargement was demonstrable on ...

  12. Computed tomography in gastrointestinal stromal tumors

    The aim of this study was to define the imaging characteristics of primary and recurrent gastrointestinal stromal tumors (GIST) in computed tomography with respect to the tumor size. Computed tomography was performed in 35 patients with histologically confirmed gastrointestinal stromal tumors and analyzed retrospectively by two experienced and independent radiologist. The following morphologic tumor characteristics of primary (n=20) and (n=16) recurrent tumors were evaluated according to tumor size, shape, homogeneity, density compared with liver, contrast enhancement, presence of calcifications, ulcerations, fistula or distant metastases and the anatomical relationship to the intestinal wall, and the infiltration of adjacent visceral organs. Small GIST (5-10 cm) demonstrated an irregular shape, inhomogeneous density on unenhanced and contrast-enhanced images, a combined intra- and extraluminal tumor growth with aggressive findings, and infiltration of adjacent organs in 9 primary diagnosed and 2 recurrent tumors. Large GIST (>10 cm), which were observed in 8 primary tumors and 11 recurrent tumors, showed an irregular margin with inhomogeneous density and aggressive findings, and were characterized by signs of malignancy such as distant and peritoneal metastases. Small recurrent tumors had a similar appearance as compared with large primary tumors. Computed tomography gives additional information with respect to the relationship of gastrointestinal stromal tumor to the gastrointestinal wall and surrounding organs, and it detects distant metastasis. Primary and recurrent GIST demonstrate characteristic CT imaging features which are related to tumor size. Aggressive findings and signs of malignancy are found in larger tumors and in recurrent disease. Computed tomography is useful in detection and characterization of primary and recurrent tumors with regard to tumor growth pattern, tumor size, and varied appearances of gastrointestinal stromal tumors, and indirectly

  13. Computed tomography in gastrointestinal stromal tumors

    Ghanem, Nadir; Altehoefer, Carsten; Winterer, Jan; Schaefer, Oliver; Springer, Oliver; Kotter, Elmar; Langer, Mathias [Department of Diagnostic Radiology, University Hospital Freiburg, Hugstetter Strasse 55, 79106, Freiburg (Germany); Furtwaengler, Alex [Department of Abdominal Surgery, University Hospital Freiburg, Hugstetter Strasse 55, 79106, Freiburg (Germany)

    2003-07-01

    The aim of this study was to define the imaging characteristics of primary and recurrent gastrointestinal stromal tumors (GIST) in computed tomography with respect to the tumor size. Computed tomography was performed in 35 patients with histologically confirmed gastrointestinal stromal tumors and analyzed retrospectively by two experienced and independent radiologist. The following morphologic tumor characteristics of primary (n=20) and (n=16) recurrent tumors were evaluated according to tumor size, shape, homogeneity, density compared with liver, contrast enhancement, presence of calcifications, ulcerations, fistula or distant metastases and the anatomical relationship to the intestinal wall, and the infiltration of adjacent visceral organs. Small GIST (<5 cm) showed a sharp tumor margin with homogeneous density and structure on unenhanced and contrast-enhanced images, and were characterized by an intraluminal tumor growth. Intermediate sized GIST (>5-10 cm) demonstrated an irregular shape, inhomogeneous density on unenhanced and contrast-enhanced images, a combined intra- and extraluminal tumor growth with aggressive findings, and infiltration of adjacent organs in 9 primary diagnosed and 2 recurrent tumors. Large GIST (>10 cm), which were observed in 8 primary tumors and 11 recurrent tumors, showed an irregular margin with inhomogeneous density and aggressive findings, and were characterized by signs of malignancy such as distant and peritoneal metastases. Small recurrent tumors had a similar appearance as compared with large primary tumors. Computed tomography gives additional information with respect to the relationship of gastrointestinal stromal tumor to the gastrointestinal wall and surrounding organs, and it detects distant metastasis. Primary and recurrent GIST demonstrate characteristic CT imaging features which are related to tumor size. Aggressive findings and signs of malignancy are found in larger tumors and in recurrent disease. Computed tomography

  14. Analysis of computed tomography of ovarian tumor

    Omura, Makoto; Taniike, Keiko; Nishiguchi, Hiroyasu

    1987-07-01

    One hundred and twenty six patients with ovarian mass were studied with computed tomography (CT) and classified into five groups according to its margin and inner structure. The incidence of malignancy of cystic ovarian mass with smooth margin was low and that of solid ovarian mass with irreglar margin was high. Three cases (6.7 %) of malignant ovarian tumor demonstrated completely cystic pattern. Ovarian teratomas contained well defined component of fat density.

  15. Dynamic computed tomography of the brain

    Dynamic computed tomography (CT) studies of the brain are based on a rapid intravenous bolus injection of radiographic contrast material immediately followed by serial CT scans. The recycling times for this technique are 1 sec or less. Dynamic studies, which are relatively non-invasive, add considerable information to the static cerebral scan as it is presently performed. The resulting time-density patterns are described and typical examples of each are shown. (orig.)

  16. Improvement in computed tomography spatial resolution

    One of the most important recent developments in transmission computed tomography is the improvement in spatial resolution. Applications of this technical advance to the neuroradiographic exploration of such structures as spinal cord, nerve roots and pituitary gland - as well as the orbits and inner and middle ear - is still limited to a few centers. Increased spatial resolution appears to be an effective means to increase our diagnostic capabilities. The higher dosimetry connected with this modality needs to be emphasized. (orig.)

  17. Computed tomography in opportunistic lung infections

    Chest radiography in two teenage boys, one with Wiscott-Aldrich's syndrome and one with acute lymphatic leucemia in remission showed increased interstitial pattern. In both computed tomography (CT) of the lungs showed heavy interstitial pneumonia, rather different in appearance but in both cases equal to the CT findings in opportunistic lung infections known from immunoincompetent patients with for instance pneumocystis carinii and/or cytomegalo virus infections. In both patients the CT findings led to lung biopsy establishing the etiologic agent. (orig.)

  18. HORSESHOE KIDNEY: A MULTIDETECTOR COMPUTED TOMOGRAPHY STUDY

    Sharma V

    2015-06-01

    Full Text Available Background and Objective: Horseshoe kidney is the most common renal fusion anomaly with a reported prevalence of 1 in 400 persons with a male to female ratio of 2:1. In many cases its presence may go unnoticed and undiagnosed because the patient may remain asymptomatic throughout life. The objective of our study is to report radiological and anatomical features of horseshoe kidney detected incidentally during retrospective evaluation of multidetector computed tomography scans. Materials and Methods: Contrast enhanced multidetector computed tomography scans of 682 patients, 355 males and 327 females, were reviewed retrospectively. Results: Seven cases of horseshoe kidney were detected incidentally, six males and one female, with an incidence of 1.02 %. In all cases, malrotation of the kidneys were observed with the hilum facing anteriorly or anterolaterally. The isthmus was made up of parenchymal tissue in all the cases and the fusion was midline in four cases and lateral in three cases. Horseshoe kidney in all cases was supplied by multiple renal arteries, varying from 3 to 6. In three cases symmetrical arterial supply and in the rest asymmetrical supply was observed. Nephrolithiasis and hydronephrosis were noted in two patients. No other associated congenital anomaly was observed in all seven patients. Conclusion: Contrast enhanced multidetector computed tomography evaluation of patients with horseshoe kidney provide excellent information about its vascularity, collecting system and other associated conditions.

  19. Effect of Heart Rate and Body Mass Index on the Interscan and Interobserver Variability of Coronary Artery Calcium Scoring at Prospective ECG-Triggered 64-Slice CT

    To test the effects of heart rate, body mass index (BMI) and noise level on interscan and interobserver variability of coronary artery calcium (CAC) scoring on a prospective electrocardiogram (ECG)-triggered 64-slice CT. One hundred and ten patients (76 patients with CAC) were scanned twice on prospective ECG-triggered scans. The scan parameters included 120 kV, 82 mAs, a 2.5 mm thickness, and an acquisition center at 45% of the RR interval. The interscan and interobserver variability on the CAC scores (Agatston, volume, and mass) was calculated. The factors affecting the variability were determined by plotting it against heart rate, BMI, and noise level (defined as the standard deviation: SD). The estimated effective dose was 1.5 ± 0.2 mSv. The mean heart rate was 63 ± 12 bpm (range, 44-101 bpm). The patient BMIs were 24.5 ± 4.5 kg/m2 (range, 15.5-42.3 kg/m2). The mean and median interscan variabilities were 11% and 6%, respectively by volume, and 11% and 6%, respectively, by mass. Moreover, the mean and median of the algorithms were lower than the Agatston algorithm (16% and 9%, respectively). The mean and median interobserver variability was 10% and 4%, respectively (average of algorithms). The mean noise levels were 15 ± 4 Hounsfield unit (HU) (range, 8-25 HU). The interscan and interobserver variability was not correlated with heart rate, BMI, or noise level. The interscan and interobserver variability of CAC on a prospective ECG-triggered 64-slice CT with high image quality and 45% of RR acquisition is not significantly affected by heart rate, BMI, or noise level. The volume or mass algorithms show reduced interscan variability compared to the Agatston scoring (p < 0.05).

  20. Bicuspid aortic valves: Diagnostic accuracy of standard axial 64-slice chest CT compared to aortic valve image plane ECG-gated cardiac CT

    Objectives: To assess the diagnostic accuracy of standard axial 64-slice chest CT compared to aortic valve image plane ECG-gated cardiac CT for bicuspid aortic valves. Materials and methods: The standard axial chest CT scans of 20 patients with known bicuspid aortic valves were blindly, randomly analyzed for (i) the appearance of the valve cusps, (ii) the largest aortic sinus area, (iii) the longest aortic cusp length, (iv) the thickest aortic valve cusp and (v) valve calcification. A second blinded reader independently analyzed the appearance of the valve cusps. Forty-two age- and sex-matched patients with known tricuspid aortic valves were used as controls. Retrospectively ECG-gated cardiac CT multiphase reconstructions of the aortic valve were used as the gold-standard. Results: Fourteen (21%) scans were scored as unevaluable (7 bicuspid, 7 tricuspid). Of the remainder, there were 13 evaluable bicuspid valves, ten of which showed an aortic valve line sign, while the remaining three showed a normal Mercedes-Benz appearance owing to fused valve cusps. The 35 evaluable tricuspid aortic valves all showed a normal Mercedes-Benz appearance (P = 0.001). Kappa analysis = 0.62 indicating good interobserver agreement for the aortic valve cusp appearance. Aortic sinus areas, aortic cusp lengths and aortic cusp thicknesses of ≥3.8 cm2, 3.2 cm and 1.6 mm respectively on standard axial chest CT best distinguished bicuspid from tricuspid aortic valves (P < 0.0001 for all). Of evaluable scans, the sensitivity, specificity, positive and negative predictive values of standard axial chest CT in diagnosing bicuspid aortic valves was 77% (CI 0.54–1.0), 100%, 100% and 70% respectively. Conclusion: The aortic valve is evaluable in approximately 80% of standard chest 64-slice CT scans. Bicuspid aortic valves may be diagnosed on evaluable scans with good diagnostic accuracy. An aortic valve line sign, enlarged aortic sinuses and elongated, thickened valve cusps are specific CT

  1. Inter laboratory comparison on Industrial Computed Tomography

    Angel, Jais Andreas Breusch; De Chiffre, Leonardo; Larsen, Erik;

    The ‘CIA-CT comparison - Inter laboratory comparison on industrial Computed Tomography” is organized by DTU Department of Mechanical Engineering within the Danish project “Centre for Industrial Application of CT scanning - CIA-CT”. The project is co-financed by the Danish Ministry of Science......, Technology and Innovation. The comparison aims to collect information about measurement performance in state-of the-art industrial CT (Computed Tomography) scanning. Since CT scanning has entered the field of manufacturing and coordinate metrology, evaluation of uncertainty of measurement with assessment of...

  2. Experimental assessment of the influence of beam hardening filters on image quality and patient dose in volumetric 64-slice X-ray CT scanners

    Ay, Mohammad Reza; Mehranian, Abolfazi; Maleki, Asghar; Ghadiri, Hossien; Ghafarian, Pardis; Zaidi, Habib

    2013-01-01

    Beam hardening filters have long been employed in X-ray Computed Tomography (CT) to preferentially absorb soft and low-energy X-rays having no or little contribution to image formation, thus allowing the reduction of patient dose and beam hardening artefacts. In this work, we studied the influence o

  3. Single photon emission computed tomography-guided Cerenkov luminescence tomography

    Hu, Zhenhua; Chen, Xueli; Liang, Jimin; Qu, Xiaochao; Chen, Duofang; Yang, Weidong; Wang, Jing; Cao, Feng; Tian, Jie

    2012-07-01

    Cerenkov luminescence tomography (CLT) has become a valuable tool for preclinical imaging because of its ability of reconstructing the three-dimensional distribution and activity of the radiopharmaceuticals. However, it is still far from a mature technology and suffers from relatively low spatial resolution due to the ill-posed inverse problem for the tomographic reconstruction. In this paper, we presented a single photon emission computed tomography (SPECT)-guided reconstruction method for CLT, in which a priori information of the permissible source region (PSR) from SPECT imaging results was incorporated to effectively reduce the ill-posedness of the inverse reconstruction problem. The performance of the method was first validated with the experimental reconstruction of an adult athymic nude mouse implanted with a Na131I radioactive source and an adult athymic nude mouse received an intravenous tail injection of Na131I. A tissue-mimic phantom based experiment was then conducted to illustrate the ability of the proposed method in resolving double sources. Compared with the traditional PSR strategy in which the PSR was determined by the surface flux distribution, the proposed method obtained much more accurate and encouraging localization and resolution results. Preliminary results showed that the proposed SPECT-guided reconstruction method was insensitive to the regularization methods and ignored the heterogeneity of tissues which can avoid the segmentation procedure of the organs.

  4. Relationship between renal volume calculated by using multislice computed tomography and glomerular filtration rate calculated by using the Cockcroft-Gault and modification of diet in renal disease equations in living kidney donors.

    Adibi, Atoosa; Mortazavi, Mojgan; Shayganfar, Azin; Kamal, Sima; Azad, Roya; Aalinezhad, Marzieh

    2016-01-01

    It is essential to ascertain the state of health and renal function of potential kidney donors before organ removal. In this regard, one of the primary steps is to estimate the donor's glomerular filtration rate (GFR). For this purpose, the modification of diet in renal disease (MDRD) and the Cockcroft-Gault (CG) formulas has been used. However, these two formulas produce different results and finding new techniques with greater accuracy is required. Measuring the renal volume from computed tomography (CT) scan may be a valuable index to assess the renal function. This study was conducted to investigate the correlation between renal volume and the GFR values in potential living kidney donors referred to the multislice imaging center at Alzahra Hospital during 2014. The study comprised 66 subjects whose GFR was calculated using the two aforementioned formulas. Their kidney volumes were measured by using 64-slice CT angiography and the correlation between renal volume and GFR values were analyzed using the Statistical Package for the Social Science software. There was no correlation between the volume of the left and right kidneys and the MDRD-based estimates of GFR (P = 0.772, r = 0.036, P = 0.251, r = 0.143, respectively). A direct linear correlation was found between the volume of the left and right kidneys and the CG-based GFR values (P = 0.001, r = 0.397, P kidney volume derived from multislice CT scan can help predict the GFR value in kidney donors with normal renal function. The limitations of our study include the small sample size and the medium resolution of 64-slice multislice scanners. Further studies with larger sample size and using higher resolution scanners are warranted to determine the accuracy of this method in potential kidney donors. PMID:27424682

  5. Computed tomography to quantify tooth abrasion

    Kofmehl, Lukas; Schulz, Georg; Deyhle, Hans; Filippi, Andreas; Hotz, Gerhard; Berndt-Dagassan, Dorothea; Kramis, Simon; Beckmann, Felix; Müller, Bert

    2010-09-01

    Cone-beam computed tomography, also termed digital volume tomography, has become a standard technique in dentistry, allowing for fast 3D jaw imaging including denture at moderate spatial resolution. More detailed X-ray images of restricted volumes for post-mortem studies in dental anthropology are obtained by means of micro computed tomography. The present study evaluates the impact of the pipe smoking wear on teeth morphology comparing the abraded tooth with its contra-lateral counterpart. A set of 60 teeth, loose or anchored in the jaw, from 12 dentitions have been analyzed. After the two contra-lateral teeth were scanned, one dataset has been mirrored before the two datasets were registered using affine and rigid registration algorithms. Rigid registration provides three translational and three rotational parameters to maximize the overlap of two rigid bodies. For the affine registration, three scaling factors are incorporated. Within the present investigation, affine and rigid registrations yield comparable values. The restriction to the six parameters of the rigid registration is not a limitation. The differences in size and shape between the tooth and its contra-lateral counterpart generally exhibit only a few percent in the non-abraded volume, validating that the contralateral tooth is a reasonable approximation to quantify, for example, the volume loss as the result of long-term clay pipe smoking. Therefore, this approach allows quantifying the impact of the pipe abrasion on the internal tooth morphology including root canal, dentin, and enamel volumes.

  6. Mathematics in computed tomography and related techniques

    The mathematical basis of computed tomography (CT) was formulated in 1917 by Radon. His theorem states that the 2-D function f(x,y) can be determined at all points from a complete set of its line integrals. Modern methods of image reconstruction include three approaches: algebraic reconstruction techniques with simultaneous iterative reconstruction or simultaneous algebraic reconstruction; convolution back projection; and the Fourier transform method. There is no one best approach. Because the experimental data do not strictly satisfy theoretical models, a number of effects have to be taken into account; in particular, the problems of beam geometry, finite beam dimensions and distribution, beam scattering, and the radiation source spectrum. Tomography with truncated data is of interest, employing mathematical approximations to compensate for the unmeasured projection data. Mathematical techniques in image processing and data analysis are also extensively used. 13 refs

  7. Fluorescence Computed Tomography with Polychromatic Source Data

    Fluorescence computed tomography is a synchrotron imaging technique aiming at reconstructing the fluorescence emission within a sample object. For a polychromatic source hitting the object, the amount of fluorescence detected is defined by a linear equation. For the monochromatic case, the operator is a Generalized Attenuated Radon Transform (GART). The main goal is to reconstruct the density function, given the sinogram data and the weight function. An eficient iterative algorithm for the inversion of the GART was presented recently by the authors. This inversion can only be performed if the weight function is previously known, which means that μ = μ(·, ε) and λ are also known. For monochromatic XFCT (acronym for x-rays fluorescence computed tomography), the determination of λ is a dificult task, and we have considered the approximation λ ≈ μ, which is valid for low energies ranging from 3Kev to 10Kev. So, for solving our problem, the first step is to find μ given the polychromatic sinogram. There are different approaches for this in the literature. Recently, an elegant and efficient method for solving this problem was introduced, using a fixed point algorithm. Opposite to this, where μ(·, ε) needs to be computed for all ε element of E, we claim that the integral of μ(·, ε) for all ε has a physical meaning and provides a good aproximation for the solution. Also we present fast algorithm for computations.

  8. Positron computed tomography: current state, clinical results and future trends

    An overview is presented of positron computed tomography: its advantages over single photon emission tomography, its use in metabolic studies of the heart and chemical investigation of the brain, and future trends

  9. Diagnostic Value of 64-slice CTA in Detection of Intracranial Aneurysm in Patients with SAH and Comparison of the CTA Results with 2D-DSA and Intraoperative Findings

    Ergun, Elif; Haberal, Murat; Koşar, Pınar; Yılmaz, Ali; Koşar, Uğur

    2011-01-01

    Objective: To prospectively evaluate the diagnostic value of 64-slice CTA in detecting intracranial aneurysms and to compare it with 2D-DSA and/or intra-operative findings. Material and Methods: 37 cases with SAH according to unenhanced cranial CT were included in the study. A 64-slice CTA was performed to all cases immediately after the nonenhanced cranial CT. DSA was performed in 24-48 hours following CTA. CT images were reviewed by two radiologists experienced in CT vascular imag...

  10. Diagnostic Value of 64-slice CTA in Detection of Intracranial Aneurysm in Patients with SAH and Comparison of the CTA Results with 2D-DSA and Intraoperative Findings

    Elif Ergun; Murat Haberal; Pınar Koşar; Ali Yılmaz; Uğur Koşar

    2011-01-01

    Objective: To prospectively evaluate the diagnostic value of 64-slice CTA in detecting intracranial aneurysms and to compare it with 2D-DSA and/or intra-operative findings.Material and Methods: 37 cases with SAH according to unenhanced cranial CT were included in the study. A 64-slice CTA was performed to all cases immediately after the nonenhanced cranial CT. DSA was performed in 24-48 hours following CTA. CT images were reviewed by two radiologists experienced in CT vascular imaging. The ...

  11. Diagnostic value for extrahepatic metastases of hepatocellular carcinoma in positron emission tomography/computed tomography scan

    2012-01-01

    AIM: To evaluated the value of 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) scan in diagnosis of hepatocellular carcinoma (HCC) and extrahepatic metastases.

  12. SU-E-I-28: Evaluating the Organ Dose From Computed Tomography Using Monte Carlo Calculations

    Purpose: To evaluate organ doses from computed tomography (CT) using Monte Carlo (MC) calculations. Methods: A Philips Brilliance CT scanner (64 slice) was simulated using the GMctdospp (IMPS, Germany) based on the EGSnrc user code. The X-ray spectra and a bowtie filter for MC simulations were determined to coincide with measurements of half-value layer (HVL) and off-center ratio (OCR) profile in air. The MC dose was calibrated from absorbed dose measurements using a Farmer chamber and a cylindrical water phantom. The dose distribution from CT was calculated using patient CT images and organ doses were evaluated from dose volume histograms. Results: The HVLs of Al at 80, 100, and 120 kV were 6.3, 7.7, and 8.7 mm, respectively. The calculated HVLs agreed with measurements within 0.3%. The calculated and measured OCR profiles agreed within 3%. For adult head scans (CTDIvol) =51.4 mGy), mean doses for brain stem, eye, and eye lens were 23.2, 34.2, and 37.6 mGy, respectively. For pediatric head scans (CTDIvol =35.6 mGy), mean doses for brain stem, eye, and eye lens were 19.3, 24.5, and 26.8 mGy, respectively. For adult chest scans (CTDIvol=19.0 mGy), mean doses for lung, heart, and spinal cord were 21.1, 22.0, and 15.5 mGy, respectively. For adult abdominal scans (CTDIvol=14.4 mGy), the mean doses for kidney, liver, pancreas, spleen, and spinal cord were 17.4, 16.5, 16.8, 16.8, and 13.1 mGy, respectively. For pediatric abdominal scans (CTDIvol=6.76 mGy), mean doses for kidney, liver, pancreas, spleen, and spinal cord were 8.24, 8.90, 8.17, 8.31, and 6.73 mGy, respectively. In head scan, organ doses were considerably different from CTDIvol values. Conclusion: MC dose distributions calculated by using patient CT images are useful to evaluate organ doses absorbed to individual patients

  13. SU-E-I-28: Evaluating the Organ Dose From Computed Tomography Using Monte Carlo Calculations

    Ono, T; Araki, F [Faculty of Life Sciences, Kumamoto University, Kumamoto (Japan)

    2014-06-01

    Purpose: To evaluate organ doses from computed tomography (CT) using Monte Carlo (MC) calculations. Methods: A Philips Brilliance CT scanner (64 slice) was simulated using the GMctdospp (IMPS, Germany) based on the EGSnrc user code. The X-ray spectra and a bowtie filter for MC simulations were determined to coincide with measurements of half-value layer (HVL) and off-center ratio (OCR) profile in air. The MC dose was calibrated from absorbed dose measurements using a Farmer chamber and a cylindrical water phantom. The dose distribution from CT was calculated using patient CT images and organ doses were evaluated from dose volume histograms. Results: The HVLs of Al at 80, 100, and 120 kV were 6.3, 7.7, and 8.7 mm, respectively. The calculated HVLs agreed with measurements within 0.3%. The calculated and measured OCR profiles agreed within 3%. For adult head scans (CTDIvol) =51.4 mGy), mean doses for brain stem, eye, and eye lens were 23.2, 34.2, and 37.6 mGy, respectively. For pediatric head scans (CTDIvol =35.6 mGy), mean doses for brain stem, eye, and eye lens were 19.3, 24.5, and 26.8 mGy, respectively. For adult chest scans (CTDIvol=19.0 mGy), mean doses for lung, heart, and spinal cord were 21.1, 22.0, and 15.5 mGy, respectively. For adult abdominal scans (CTDIvol=14.4 mGy), the mean doses for kidney, liver, pancreas, spleen, and spinal cord were 17.4, 16.5, 16.8, 16.8, and 13.1 mGy, respectively. For pediatric abdominal scans (CTDIvol=6.76 mGy), mean doses for kidney, liver, pancreas, spleen, and spinal cord were 8.24, 8.90, 8.17, 8.31, and 6.73 mGy, respectively. In head scan, organ doses were considerably different from CTDIvol values. Conclusion: MC dose distributions calculated by using patient CT images are useful to evaluate organ doses absorbed to individual patients.

  14. Reference absolute and indexed values for left and right ventricular volume, function and mass from cardiac computed tomography

    Left ventricular (LV) and right ventricular (RV) volumetric and functional parameters are important biomarkers for morbidity and mortality in patients with heart failure. To retrospectively determine reference mean values of LV and RV volume, function and mass normalised by age, gender and body surface area (BSA) from retrospectively electrocardiographically gated 64-slice cardiac computed tomography (CCT) by using automated analysis software in healthy adults. The study was approved by the institutional review board with a waiver of informed consent. Seventy-four healthy subjects (49% female, mean age 49.6±11) free of hypertension and hypercholesterolaemia with a normal CCT formed the study population. Analyses of LV and RV volume (end-diastolic, end-systolic and stroke volumes), function (ejection fraction), LV mass and inter-rater reproducibility were performed with commercially available analysis software capable of automated contour detection. General linear model analysis was performed to assess statistical significance by age group after adjustment for gender and BSA. Bland–Altman analysis assessed the inter-rater agreement. The reference range for LV and RV volume, function, and LV mass was normalised to age, gender and BSA. Statistically significant differences were noted between genders in both LV mass and RV volume (P-value<0.0001). Age, in concert with gender, was associated with significant differences in RV end-diastolic volume and LV ejection fraction (P-values 0.027 and 0.03). Bland–Altman analysis showed acceptable limits of agreement (±1.5% for ejection fraction) without systematic error. LV and RV volume, function and mass normalised to age, gender and BSA can be reported from CCT datasets, providing additional information important for patient management.

  15. Computed tomography for preoperative planning in minimal-invasive total hip arthroplasty: Radiation exposure and cost analysis

    Computed tomography (CT) was used for preoperative planning of minimal-invasive total hip arthroplasty (THA). 92 patients (50 males, 42 females, mean age 59.5 years) with a mean body-mass-index (BMI) of 26.5 kg/m2 underwent 64-slice CT to depict the pelvis, the knee and the ankle in three independent acquisitions using combined x-, y-, and z-axis tube current modulation. Arthroplasty planning was performed using 3D-Hip Plan (Symbios, Switzerland) and patient radiation dose exposure was determined. The effects of BMI, gender, and contralateral THA on the effective dose were evaluated by an analysis-of-variance. A process-cost-analysis from the hospital perspective was done. All CT examinations were of sufficient image quality for 3D-THA planning. A mean effective dose of 4.0 mSv (SD 0.9 mSv) modeled by the BMI (p < 0.0001) was calculated. The presence of a contralateral THA (9/92 patients; p = 0.15) and the difference between males and females were not significant (p = 0.08). Personnel involved were the radiologist (4 min), the surgeon (16 min), the radiographer (12 min), and administrative personnel (4 min). A CT operation time of 11 min and direct per-patient costs of 52.80 Euro were recorded. Preoperative CT for THA was associated with a slight and justifiable increase of radiation exposure in comparison to conventional radiographs and low per-patient costs.

  16. Computed tomography for preoperative planning in minimal-invasive total hip arthroplasty: radiation exposure and cost analysis.

    Huppertz, Alexander; Radmer, Sebastian; Asbach, Patrick; Juran, Ralf; Schwenke, Carsten; Diederichs, Gerd; Hamm, Bernd; Sparmann, Martin

    2011-06-01

    Computed tomography (CT) was used for preoperative planning of minimal-invasive total hip arthroplasty (THA). 92 patients (50 males, 42 females, mean age 59.5 years) with a mean body-mass-index (BMI) of 26.5 kg/m(2) underwent 64-slice CT to depict the pelvis, the knee and the ankle in three independent acquisitions using combined x-, y-, and z-axis tube current modulation. Arthroplasty planning was performed using 3D-Hip Plan(®) (Symbios, Switzerland) and patient radiation dose exposure was determined. The effects of BMI, gender, and contralateral THA on the effective dose were evaluated by an analysis-of-variance. A process-cost-analysis from the hospital perspective was done. All CT examinations were of sufficient image quality for 3D-THA planning. A mean effective dose of 4.0 mSv (SD 0.9 mSv) modeled by the BMI (p<0.0001) was calculated. The presence of a contralateral THA (9/92 patients; p=0.15) and the difference between males and females were not significant (p=0.08). Personnel involved were the radiologist (4 min), the surgeon (16 min), the radiographer (12 min), and administrative personnel (4 min). A CT operation time of 11 min and direct per-patient costs of 52.80 € were recorded. Preoperative CT for THA was associated with a slight and justifiable increase of radiation exposure in comparison to conventional radiographs and low per-patient costs. PMID:20022723

  17. Computed tomography for preoperative planning in minimal-invasive total hip arthroplasty: Radiation exposure and cost analysis

    Huppertz, Alexander, E-mail: Alexander.Huppertz@charite.de [Imaging Science Institute Charite Berlin, Robert-Koch-Platz 7, D-10115 Berlin (Germany); Department of Radiology, Medical Physics, Charite-University Hospitals of Berlin, Chariteplatz 1, D-10117 Berlin (Germany); Radmer, Sebastian, E-mail: s.radmer@immanuel.de [Department of Orthopedic Surgery and Rheumatology, Immanuel-Krankenhaus, Koenigstr. 63, D-14109, Berlin (Germany); Asbach, Patrick, E-mail: Patrick.Asbach@charite.de [Department of Radiology, Medical Physics, Charite-University Hospitals of Berlin, Chariteplatz 1, D-10117 Berlin (Germany); Juran, Ralf, E-mail: ralf.juran@charite.de [Department of Radiology, Medical Physics, Charite-University Hospitals of Berlin, Chariteplatz 1, D-10117 Berlin (Germany); Schwenke, Carsten, E-mail: carsten.schwenke@scossis.de [Biostatistician, Scossis Statistical Consulting, Zeltinger Str. 58G, D-13465 Berlin (Germany); Diederichs, Gerd, E-mail: gerd.diederichs@charite.de [Department of Radiology, Medical Physics, Charite-University Hospitals of Berlin, Chariteplatz 1, D-10117 Berlin (Germany); Hamm, Bernd, E-mail: Bernd.Hamm@charite.de [Department of Radiology, Medical Physics, Charite-University Hospitals of Berlin, Chariteplatz 1, D-10117 Berlin (Germany); Sparmann, Martin, E-mail: m.sparmann@immanuel.de [Department of Orthopedic Surgery and Rheumatology, Immanuel-Krankenhaus, Koenigstr. 63, D-14109, Berlin (Germany)

    2011-06-15

    Computed tomography (CT) was used for preoperative planning of minimal-invasive total hip arthroplasty (THA). 92 patients (50 males, 42 females, mean age 59.5 years) with a mean body-mass-index (BMI) of 26.5 kg/m{sup 2} underwent 64-slice CT to depict the pelvis, the knee and the ankle in three independent acquisitions using combined x-, y-, and z-axis tube current modulation. Arthroplasty planning was performed using 3D-Hip Plan (Symbios, Switzerland) and patient radiation dose exposure was determined. The effects of BMI, gender, and contralateral THA on the effective dose were evaluated by an analysis-of-variance. A process-cost-analysis from the hospital perspective was done. All CT examinations were of sufficient image quality for 3D-THA planning. A mean effective dose of 4.0 mSv (SD 0.9 mSv) modeled by the BMI (p < 0.0001) was calculated. The presence of a contralateral THA (9/92 patients; p = 0.15) and the difference between males and females were not significant (p = 0.08). Personnel involved were the radiologist (4 min), the surgeon (16 min), the radiographer (12 min), and administrative personnel (4 min). A CT operation time of 11 min and direct per-patient costs of 52.80 Euro were recorded. Preoperative CT for THA was associated with a slight and justifiable increase of radiation exposure in comparison to conventional radiographs and low per-patient costs.

  18. Current role of cardiac and extra-cardiac pathologies in clinically indicated cardiac computed tomography with emphasis on status before pulmonary vein isolation

    Purpose: The aim of this study was to assess the incidence of cardiac and significant extra-cardiac findings in clinical computed tomography of the heart in patients with atrial fibrillation before pulmonary vein isolation (PVI). Materials and Methods: 224 patients (64 ± 10 years; male 63%) with atrial fibrillation were examined by cardiac 64-slice multidetector CT before PVI. Extra-cardiac findings were classified as 'significant' if they were recommended to additional diagnostics or therapy, and otherwise as 'non-significant'. Additionally, cardiac findings were documented in detail. Results: A total of 724 cardiac findings were identified in 203 patients (91% of patients). Additionally, a total of 619 extra-cardiac findings were identified in 179 patients (80% of patients). Among these extra-cardiac findings 196 (32%) were 'significant', and 423 (68%) were 'non-significant'. In 2 patients (1%) a previously unknown malignancy was detected (esophageal cancer and lung cancer, local stage, no metastasis). 203 additional imaging diagnostics followed to clarify the 'significant' findings (124 additional CT, costs 38,314.69 US dollars). Overall, there were 3.2 cardiac and 2.8 extra-cardiac findings per patient. Extra-cardiac findings appear significantly more frequently in patients over 60 years old, in smokers and in patients with a history of cardiac findings (p < 0.05). Conclusion: Cardiac CT scans before PVI should be screened for extracardiac incidental findings that could have important clinical implications for each patient. (orig.)

  19. Prone position is essential for detection of pulmonary vein pseudostenosis by enhanced multidetector computed tomography in patients who undergo pulmonary vein isolation

    Pulmonary vein (PV) stenosis is a major complication of PV isolation (PVI) by catheter ablation, so in the present study the optimal position for detecting PV stenosis on enhanced multidetector computed tomography (MDCT) image acquisition was determined. The 64-slice enhanced MDCT was carried out before and after PVI in 116 consecutive patients with atrial fibrillation while they were in the prone position, as well as while supine. The supine position MDCT image showed >50% diameter stenosis of the PV in 11 (9%) patients before PVI (% diameter stenosis: mean 55±4%, range 51-65%). Greater than 50% diameter stenosis was seen in the left inferior PV in all 11 patients. The prone position attenuated the PV stenosis findings in the MDCT images in all 11 patients (mean 9±6%, range 2-18%). Stenosis visualized on images acquired in the supine position was, therefore, concluded to be pseudostenosis caused by descending aorta compression. At 3 months after PVI, no significant changes in PV diameter were observed in these 11 patients. The present study demonstrated that the prone position is essential for eliminating PV pseudostenosis observed on supine-position enhanced MDCT images. The results also indicate that preexisting PV organic stenosis is rare. (author)

  20. Sex-specific biatrial volumetric measurements obtained with use of multidetector computed tomography in subjects with and without coronary artery disease.

    Budoff, Matthew J; Pagali, Sandeep R; Hamirani, Yasmin S; Chen, Andy; Cheu, Gordon; Gao, Yanlin; Li, Dong; Mao, SongShou

    2014-06-01

    Atrial volumetric measurement has proven clinical implications. Advances in cardiac imaging, notably the precision enabled by multidetector computed tomography (MDCT), herald the need for new criteria of what constitutes normal volumetric measurements. With use of 64-slice MDCT, we compared the atrial volumes in healthy individuals with those in individuals with coronary artery disease. By means of manual segmentation, we measured biatrial volume in 686 participants who underwent retrospective electrocardiographic-gated MDCT angiographic evaluation. The study population included a control group of 203 persons with no cardiac abnormalities, and a study group of 483 patients with obstructive coronary artery disease. All variables were compared between men and women and between the groups. We found a significant difference in left atrial end-systolic and end-diastolic volumes between men and women in the control group (P <0.05); however, right atrial volumes were similar. In comparison with the entire control group, the coronary artery disease group had significantly higher left atrial volume, significantly lower right atrial stroke volume, and significantly lower biatrial ejection fraction, except for left atrial ejection fraction in men. Right atrial volume and left atrial stroke volume were not significantly different. The results imply that a sex-specific reference value is necessary for left atrial volumetric evaluation, and that left atrial volume and biatrial ejection fraction (excluding left atrial ejection fraction in men) might be useful during diagnosis and prognosis in patients who have coronary artery disease. PMID:24955043

  1. Impact of sirolimus-eluting stent fractures without early cardiac events on long-term clinical outcomes: A multislice computed tomography study

    Ito, Tsuyoshi [Toyohashi Heart Center, Oyama-cho, Toyohashi (Japan); Nagoya City University Graduate School of Medical Sciences, Department of Cardio-Renal Medicine and Hypertension, Nagoya (Japan); Kimura, Masashi; Ehara, Mariko; Terashima, Mitsuyasu; Nasu, Kenya; Kinoshita, Yoshihisa; Habara, Maoto; Tsuchikane, Etsuo; Suzuki, Takahiko [Toyohashi Heart Center, Oyama-cho, Toyohashi (Japan)

    2014-05-15

    This study sought to evaluate the impact of sirolimus-eluting stent (SES) fractures on long-term clinical outcomes using multislice computed tomography (MSCT). In this study, 528 patients undergoing 6- to 18-month follow-up 64-slice MSCT after SES implantation without early clinical events were followed clinically (the median follow-up interval was 4.6 years). A CT-detected stent fracture was defined as a complete gap with Hounsfield units (HU) <300 at the site of separation. The major adverse cardiac events (MACEs), including cardiac death, stent thrombosis, and target lesion revascularisation, were compared according to the presence of stent fracture. Stent fractures were observed in 39 patients (7.4 %). MACEs were more common in patients with CT-detected stent fractures than in those without (46 % vs. 7 %, p < 0.01). Univariate Cox regression analysis indicated a significant relationship between MACE and stent fracture [hazard ratio (HR) 7.65; p < 0.01], age (HR 1.03; p = 0.04), stent length (HR 1.03; p < 0.01), diabetes mellitus (HR 1.77; p = 0.04), and chronic total occlusion (HR 2.54; p = 0.01). In the multivariate model, stent fracture (HR 5.36; p < 0.01) and age (HR 1.03; p = 0.04) remained significant predictors of MACE. An SES fracture detected by MSCT without early clinical events was associated with long-term clinical adverse events. (orig.)

  2. Computed tomography of infantile hepatic hemangioendothelioma

    Computed tomography (CT) was performed on five infants with hepatic hemangioendothelioma. Precontrast scans showed solitary or multiple, homogeneous, circumscribed areas with reduced attenuation values. Tiny tumoral calcifications were identified in two patients. Serial scans, after injection of a bolus of contrast material, showed early massive enhancement, which was either diffuse or peripheral. On delayed scans, multinocular tumors became isodense with surrounding liver, while all solitary ones showed varied degrees of centripetal enhancement and persistent central cleftlike unenhanced areas. The authors believe that these CT features are characteristic and obviate arteriographic confirmation

  3. Multidetector Computed Tomography in Acute Joint Fractures

    Haapamaeki, V.V.; Kiuru, M.J.; Mustonen, A.O.; Koskinen, S.K. [Helsinki Univ. Central Hospital (Finland). Helsinki Medical Imaging Center

    2005-10-01

    Conventional radiography plays an essential diagnostic role in the primary evaluation of acute joint trauma. In complex fractures, however, computed tomography (CT) is an imaging modality often used second to radiography. As a result of technical breakthroughs in the field, multidetector CT (MDCT) allows faster imaging and better temporal, spatial, and contrast resolution compared with conventional single-slice spiral CT. MDCT with multiplanar reformation is helpful in disclosing fracture patterns, particularly in complex joint fractures, where they reveal occult fractures and show the exact number of fracture components and their degree of displacement.

  4. Quantitative computed tomography in assessment of osteoporosis

    Osteoporosis is a common disorder with considerable health risk and medical care cost. Recent advances in technology have provided new opportunities for evaluating bone mass noninvasively that may impact substantially on the detection and course of osteoporotic conditions. The laboratory and clinical results presented herein indicate that quantitative computed tomography provides a reliable means to evaluate and monitor the many forms of osteoporosis and the various interventions aimed at ameliorating this condition. The greatest advantages of spinal QCT for noninvasive bone mineral measurement lie in the high precision of the technique, the high sensitivity of the vertebral spongiosa measurement site, and the potential for widespread application

  5. Multidetector Computed Tomography in Acute Joint Fractures

    Conventional radiography plays an essential diagnostic role in the primary evaluation of acute joint trauma. In complex fractures, however, computed tomography (CT) is an imaging modality often used second to radiography. As a result of technical breakthroughs in the field, multidetector CT (MDCT) allows faster imaging and better temporal, spatial, and contrast resolution compared with conventional single-slice spiral CT. MDCT with multiplanar reformation is helpful in disclosing fracture patterns, particularly in complex joint fractures, where they reveal occult fractures and show the exact number of fracture components and their degree of displacement

  6. Computed tomography of cardiac pseudotumors and neoplasms.

    Anavekar, Nandan S; Bonnichsen, Crystal R; Foley, Thomas A; Morris, Michael F; Martinez, Matthew W; Williamson, Eric E; Glockner, James F; Miller, Dylan V; Breen, Jerome F; Araoz, Philip A

    2010-07-01

    Important features of cardiac masses can be clearly delineated on cardiac computed tomography (CT) imaging. This modality is useful in identifying the presence of a mass, its relationship with cardiac and extracardiac structures, and the features that distinguish one type of mass from another. A multimodality approach to the evaluation of cardiac tumors is advocated, with the use of echocardiography, CT imaging and magnetic resonance imaging as appropriately indicated. In this article, various cardiac masses are described, including pseudotumors and true cardiac neoplasms, and the CT imaging findings that may be useful in distinguishing these rare entities are presented. PMID:20705174

  7. Computed tomography after percutaneous renal stone extraction

    Eighty patients were examined with computed tomography (CT) of the kidney and the retroperitoneal space after percutaneous stone extraction. Most examinations were done within a week after the operation. The morphologic changes were usually small or none. In 7 patients minor renal or perirenal fluid collections were found. Their operations had been complicated by bleeding or leakage. In 66 patients CT was compared with conventional radiographs. Residual stones were more often detected by CT. They were usually small. Percutaneous renal stone extraction is considered a safe and efficient method. (orig.)

  8. Computed tomography studies of human brain movements

    Rhythmic brain movements have been revealed by sets of sequential computed tomography scans of human brains (seen retrospectively to be normal). These scans have shown that both (unenhanced) brain parenchymal density and the shapes of the elements of the supratentorial ventricular/cisternal system are subject to wave motions having similar periods - ranging from 26 s through 56 s, 77-96 s, 109 s and 224 s to 224 X 2 s (or even longer), with good correlation between peak values. These motions, as well as phase variations between the waves, suggest a peristaltic movement of cerebrospinal fluid through the ventricular/cisternal system with progressive axial damping

  9. Calculation of profitability in computer tomography (CT)

    The comments do not refer to a specific type of whole body computer tomography which made it necessary to base the calculations on mean values with regard to both initial costs and operating costs. The calculation of the receipts was based on the resulting costs, mean long-term utilization of the unit and on a reasonable period of amortization. The model calculation indicates that the break-even point is reached with 1,920 annual examinations and a five-year amortization period. (orig.) 891 MG/orig. 892 MB

  10. Emerging clinical applications of computed tomography

    Liguori C

    2015-06-01

    Full Text Available Carlo Liguori,1 Giulia Frauenfelder,2 Carlo Massaroni,3 Paola Saccomandi,3 Francesco Giurazza,4 Francesca Pitocco,4 Riccardo Marano,5 Emiliano Schena,3 1Radiology Unit, AORN A Cardarelli, 2Radiology Unit, AOU Federico II, Naples, 3Measurement and Biomedical Instrumentation Unit, 4Radiology Unit, Università Campus Bio-Medico di Roma, 5Department of Radiological Sciences, Institute of Radiology, Catholic University of Rome, A Gemelli University Hospital, Rome, Italy Abstract: X-ray computed tomography (CT has recently been experiencing remarkable growth as a result of technological advances and new clinical applications. This paper reviews the essential physics of X-ray CT and its major components. Also reviewed are recent promising applications of CT, ie, CT-guided procedures, CT-based thermometry, photon-counting technology, hybrid PET-CT, use of ultrafast-high pitch scanners, and potential use of dual-energy CT for material differentiations. These promising solutions and a better knowledge of their potentialities should allow CT to be used in a safe and effective manner in several clinical applications. Keywords: computed tomography, X-ray, thermometry, dual-energy, ultrafast scanner, guidance, photon-counting technology

  11. Microscopic x-ray luminescence computed tomography

    Zhang, Wei; Zhu, Dianwen; Zhang, Kun; Li, Changqing

    2015-03-01

    X-ray luminescence computed tomography (XLCT) was emerged as a new hybrid imaging modality, in which the x-rays are used to excite phosphors emitting optical photons to be measured for imaging. In this paper, we reported a microscopic x-ray luminescence computed tomography (microXLCT) with a spatial resolution up to hundreds of micrometers for deep targets. We use a superfine x-ray pencil beam to scan the phosphor targets. The superfine x-ray pencil beam is generated by a small collimator mounted in front of a powerful x-ray tube (93212, Oxford Instrument). A CT detector is used to image the x-ray beam. We have generated an x-ray beam with a diameter of 192 micrometers with a collimator of 100 micrometers in diameter. The emitted optical photons on the top surface of phantom are reflected by a mirror and acquired by an electron multiplier charge-coupled device (EMCCD) camera (C9100-13, Hamamatsu Photonics). The microXLCT imaging system is built inside an x-ray shielding and light tight cabinet. The EMCCD camera is placed in a lead box. All the imaging components are controlled by a VC++ program. The optical photon propagation is modeled with the diffusion equation solved by the finite element method. We have applied different regularization methods including L2 and L1 in the microXLCT reconstruction algorithms. Numerical simulations and phantom experiments are used to validate the microXLCT imaging system.

  12. Computed tomography colonography (virtual colonoscopy): review

    Computed tomography examination of the colon performed after bowel cleansing and distension of the lumen with gas goes by several different names-CT colonography (CTC) and CT colography perhaps being the most common. Strictly, the term 'virtual colonoscopy' (VC), should be reserved for the process of examining 3-D, simulated endo-luminal images with a capability to navigate through the bowel using appropriate software. Computed tomography colonography appears to be the name that has gained favour among radiologists, although it is suspected that 'virtual colonoscopy' will persist as a generic term due to its attractive 'high-tech' connotations for non-radiological medical and lay persons. Whatever the name, the technique has been made possible through the advent of fast helical CT scanners which allow acquisition of a volume of data, and of proprietary software which enables multiplanar reformatting and 3-D endoluminal reconstructions. It is evident that if CTC/VC can be shown to be acceptable to patients, safe, affordable and accurate, it has enormous potential as a diagnostic and screening tool for colorectal neoplasia. Copyright (2002) Blackwell Science Pty Ltd

  13. Computed tomography of juvenile nasopharyngeal angiofibroma

    It is well known that computed tomography (CT) is useful in detecting accurately the location, extent, erosion and relationship of angiofibroma to surrounding structures such as pterygopalation fossa. It is well known that computed tomography (CT) is useful in detecting accurately the location, sphenoid sinus, and etc. CT of 20 patients with juvenile angiofibroma, which were examined for 5 yeas from February, 1979 to May, 1984 at Department of Radiology, Seoul National University Hospital, were retrospectively analyzed. The results were as follows: 1. All 20 patients of juvenile angiofibroma had tumors in nasopharynx and posterior nasal cavity showing homogeneously dense-enhancing soft tissue mass on CT. There was extension of the tumor from nasopharynx and posterior nasal cavity into paranasal sinus (60%, 12/20), pterygopalatine fossa (55%, 11/20), infratemporal fossa (30%, 6/20), posterior orbit (10%, 2/20) and cranial cavity (15%, 3/20). 2. Angiogrpahy usually adds little diagnostic information, but is still needed to identify the precise source of blood supply to the tumor, and to perform the pre-operative embolization. The use of CT has deferred angiography until just before surgery, permitting embolization at optimal time. 3. CT is almost always necessary to reveal accurately the full extent of the tumor, especially intracranial space in the axial and coronal planes with contrast enhancement. CT is useful both in diagnosis as a guide to angiography and in planning the adequate therapy of juvenile angiofibroma

  14. Bicuspid aortic valves: Diagnostic accuracy of standard axial 64-slice chest CT compared to aortic valve image plane ECG-gated cardiac CT

    Murphy, David J., E-mail: david.murphy@st-vincents.ie [Department of Radiology, St Vincent' s University Hospital, Elm Park, Dublin 4 (Ireland); McEvoy, Sinead H., E-mail: s.mcevoy@st-vincents.ie [Department of Radiology, St Vincent' s University Hospital, Elm Park, Dublin 4 (Ireland); Iyengar, Sri, E-mail: sri.iyengar@nhs.net [Department of Radiology, Plymouth Hospitals NHS Trust, Plymouth Devon PL6 8DH (United Kingdom); Feuchtner, Gudrun, E-mail: Gudrun.Feuchtner@i-med.ac.at [Department of Radiology, Innsbruck Medical University, Anichstr. 35, A-6020 Innsbruck (Austria); Cury, Ricardo C., E-mail: r.cury@baptisthealth.net [Department of Radiology, Baptist Cardiac and Vascular Institute, 8900 North Kendall Drive, Miami, FL 33176 (United States); Roobottom, Carl, E-mail: carl.roobottom@nhs.net [Department of Radiology, Plymouth Hospitals NHS Trust, Plymouth Devon PL6 8DH (United Kingdom); Plymouth University Peninsula Schools of Medicine and Dentistry (United Kingdom); Baumueller, Stephan, E-mail: Hatem.Alkadhi@usz.ch [Institute for Diagnostic and Interventional Radiology, University Hospital Zurich, Raemistrasse 100, CH-8091 Zurich (Switzerland); Alkadhi, Hatem, E-mail: stephan.baumueller@usz.ch [Institute for Diagnostic and Interventional Radiology, University Hospital Zurich, Raemistrasse 100, CH-8091 Zurich (Switzerland); Dodd, Jonathan D., E-mail: jonniedodd@gmail.com [Department of Radiology, St Vincent' s University Hospital, Elm Park, Dublin 4 (Ireland)

    2014-08-15

    Objectives: To assess the diagnostic accuracy of standard axial 64-slice chest CT compared to aortic valve image plane ECG-gated cardiac CT for bicuspid aortic valves. Materials and methods: The standard axial chest CT scans of 20 patients with known bicuspid aortic valves were blindly, randomly analyzed for (i) the appearance of the valve cusps, (ii) the largest aortic sinus area, (iii) the longest aortic cusp length, (iv) the thickest aortic valve cusp and (v) valve calcification. A second blinded reader independently analyzed the appearance of the valve cusps. Forty-two age- and sex-matched patients with known tricuspid aortic valves were used as controls. Retrospectively ECG-gated cardiac CT multiphase reconstructions of the aortic valve were used as the gold-standard. Results: Fourteen (21%) scans were scored as unevaluable (7 bicuspid, 7 tricuspid). Of the remainder, there were 13 evaluable bicuspid valves, ten of which showed an aortic valve line sign, while the remaining three showed a normal Mercedes-Benz appearance owing to fused valve cusps. The 35 evaluable tricuspid aortic valves all showed a normal Mercedes-Benz appearance (P = 0.001). Kappa analysis = 0.62 indicating good interobserver agreement for the aortic valve cusp appearance. Aortic sinus areas, aortic cusp lengths and aortic cusp thicknesses of ≥3.8 cm{sup 2}, 3.2 cm and 1.6 mm respectively on standard axial chest CT best distinguished bicuspid from tricuspid aortic valves (P < 0.0001 for all). Of evaluable scans, the sensitivity, specificity, positive and negative predictive values of standard axial chest CT in diagnosing bicuspid aortic valves was 77% (CI 0.54–1.0), 100%, 100% and 70% respectively. Conclusion: The aortic valve is evaluable in approximately 80% of standard chest 64-slice CT scans. Bicuspid aortic valves may be diagnosed on evaluable scans with good diagnostic accuracy. An aortic valve line sign, enlarged aortic sinuses and elongated, thickened valve cusps are specific CT

  15. Preliminary Reports on the Accuracy of Coronary CT-Angiography Using 64-slice Multi-slice Spiral CT (MSCT in Iran

    "A. Arjmand Shabestari

    2005-08-01

    Full Text Available Introduction & Background: Coronary artery disease (CAD is the leading cause of death in many western countries. Its prevalence and incidence among Irani-ans particularly in the urban areas are increasing. Ac-cording to the newest Tehran annual mortality re-port, the most common cause of death in Tehran is cardiovascular disease. Diagnostic gold standard in CAD is fluoroscopic coronary angiography (FCA us-ing catheterization. Nevertheless, it is an invasive method and in recent years, some non-invasive or less-invasive imaging modalities such as MRI and CT scans have been used to investigate CAD. One of the most attractive new methods in this regard is Coro-nary CT-Angiography (CCTA, which has gained considerable attention. Multi-slice spiral CT (MSCT scanners with simultaneous acquisition of multiple (up to 64 slices in less than half a second of gantry rotation time (in our study, 0.33 second, have be-come available, resulting in minimally-invasive coro-nary artery imaging. The purpose of this study is to determine the diagnostic accuracy of a new 64-slice MSCT scanner in the diagnosis of coronary artery and/or bypass grafts occlusion or hemodynamically significant stenosis. Parients & Methods: This investigation is underway in patients undergoing elective FCA. A 64-channel per rotation MSCT scanner (Somatom Sensation 64, Siemens Medical Systems, Forchheim, Germany, with 0.6 mm collimation, 0.33 second gantry rotation time and 120 KVp was used to perform CCTA. Ap-proximately 70-90 mL of a nonionic contrast medium was injected intravenously. All coronary artery seg-ments, according to American Heart Association (AHA classification & nomenclature system were analyzed. Patients who had undergone previous coronary artery bypass grafts (CABGs, or used coro-nary stents were enrolled in the study, as well. MSCT scans were carried out within 10 days of catheteriza-tion, and the most dramatically stenotic lesions were analyzed in CCTA by a semi

  16. The application of the reduced dosage of the contrast medium with saline flush in cerebral and carotid angiography with 64-slice spiral CT

    Objective: To utilize the reduced contrast dose with saline flush in cerebral and carotid angiography with 64-slice spiral CT. Methods: According to the contrast dose, 40 patients undergoing cerebral and carotid CTA examination were randomly divided into 2 groups, one group was treated with 50 ml contrast agent and 20 ml saline flush, the other group was administrated with 70 ml contrast agent. With double blindness method, the data were respectively evaluated and analyzed by two radiologists independently. Results: For the two radiologists, on the manifestation of carotid and cerebral arteries, the venous artefact and the CT value measurement aspects, the Kappa value was respectively 0.895, 0.814, 0.702, 0.836. By rank sum test, on the manifestation of carotid arteries aspect, the grading score of the two groups of radiologist A was respectively 1.3, l.2; and that of radiologist B was respectively 1.4, 1.2; the differences between the two groups of the two radiologists have no statistical significance(U=173, P>0.05; U=128, P>0.05). And on the manifestation of cerebral arteries aspect, the grading score of the two groups of radiologist A was respectively 1.4, l.2; and that of radiologist B was respectively 1.2, 1.2; the differences between two groups of the two radiologists both have no statistical significance (U=160, P>0.05; U=106, P>0.05). And on the artefacts produced by the high contrast densities in the right subclavian vein, brachiocephalic vein and vena cava, the grading score of the two groups of radiologist A was respectively 1.3, 2.1; and that of radiologist B was respectively 1.2, 1.9; the differences between the two groups of the two radiologists both have statistical significance (U=75, P0.05). The CT value of the arteries of the two groups from radiologist B was respectively 337.3, 329.5, 239.2, 192.8, 345.6, 341.2, 247.1, 210.5 HU; and the difference between the two groups has no statistical significance (t=0.233, P>0.05). Conclusion: On the CTA

  17. Computed tomography of post-traumatic orbito-palpebral emphysema

    Nose, H.; Kohno, K. (Tsukuba Univ., Sakura, Ibaraki (Japan))

    1981-11-01

    Two cases of orbito-palpebral emphysema are described. Both having a history of recent facial trauma, emphysema occurred after blowing the nose. They were studied by computed tomography and plain x-ray film, including tomograms of the orbit. The emphysema was revealed by computed tomography and x-ray film, but more clearly by the former technique. The fracture lines of the orbit were revealed in only one case by x-ray film, but in both cases by computed tomography. The authors stress that computed tomography is the best technique for the study of orbital emphysema.

  18. Computed tomography of post-traumatic orbito-palpebral emphysema

    Two cases of orbito-palpebral emphysema are described. Both having a history of recent facial trauma, emphysema occurred after blowing the nose. They were studied by computed tomography and plain x-ray film, including tomograms of the orbit. The emphysema was revealed by computed tomography and x-ray film, but more clearly by the former technique. The fracture lines of the orbit were revealed in only one case by x-ray film, but in both cases by computed tomography. The authors stress that computed tomography is the best technique for the study of orbital emphysema. (author)

  19. Coronary imaging quality in routine ECG-gated multidetector CT examinations of the entire thorax: preliminary experience with a 64-slice CT system in 133 patients

    Delhaye, Damien; Remy-Jardin, Martine; Salem, Randa; Teisseire, Antoine; Khalil, Chadi; Remy, Jacques [Hospital Calmette, University Center of Lille, Department of Thoracic Imaging, Lille Cedex (France); Delannoy-Deken, Valerie; Duhamel, Alain [University of Lille, Department of Medical Statistics, Lille Cedex (France)

    2007-04-15

    To evaluate image quality in the assessment of the coronary arteries during routine ECG-gated multidetector CT (MDCT) of the chest. One hundred and thirty three patients in sinus rhythm underwent an ECG-gated CT angiographic examination of the entire chest without {beta}-blockers with a 64-slice CT system. In 127 patients (95%), it was possible to assess the coronary arteries partially or totally; coronary artery imaging failed in six patients (5%), leading to a detailed description of the coronary arteries in 127 patients. Considering ten coronary artery segments per patient, 75% of coronary segments were assessable (948/1270 segments). When the distal segments were excluded from the analysis (i.e., seven coronary segments evaluated per patient), the percentage of assessable segments was 86% (768/889 proximal and mid coronary segments) and reached 93% (474/508) when assessing proximal segments exclusively. The mean number of assessable segments was significantly higher in patients with a heart rate {<=}80 bpm (n=95) than in patients with a heart rate >80 bpm (n=38) (p<0.002). Proximal and mid-coronary segments can be adequately assessed during a whole-chest ECG-gated CT angiographic examination without administration of {beta}-blockers in patients with a heart rate below 80 bpm. (orig.)

  20. Bone Subtraction 3-Dimension CT Angiography Using 64-Slice Multidetector CT for the Evaluation of Steno-Occlusive Intra- and Extracranial Vascular Diseases: Comparison with Digital Subtraction Angiography

    Park, Sung Eun; Choi, Dae Seob; Shin, Hwa Seon; You, Jin Jong; Park, Mi Jung; Cho, Jae Min; Choi, Ho Cheol; Son, Seung Nam [Gyeongsang National University School of Medicine, Jinju (Korea, Republic of); Ryu, Jae Wook [Dept. of Radiology, Samsung Seoul Hospital, Seoul (Korea, Republic of)

    2012-09-15

    To investigate the efficacy of bone subtraction CT angiography (BSCTA) for the evaluation of steno-occlusive intra- and extracranial vascular diseases. Fifty-six patients were examined using 64-slice multidetector CT and digital subtraction angiography (DSA). For BSCTA, both nonenhanced CT and enhanced CT angiography (CTA) data sets were obtained. The stenotic degree of each vascular segment was assessed and classified into 5 grades. With DSA as the standard, CTA images were compared. For the evaluation of the extracranial vessels, 370 arterial segments were analyzed, and the stenotic degree revealed by CTA and DSA agreed in 359 (97.0%). There was a significant correlation between CTA and DSA (Rs = 0.974). For depiction of {>=} 50% stenosis, the sensitivity, specificity, and diagnostic accuracy of BSCTA were 100%, 98.2%, and 98.6%, respectively. For the intracranial arteries, 1029 segments were analyzed, and CTA agreed with DSA in 966 (93.9%). There was a significant correlation between CTA and DSA for stenotic degree (Rs = 0.880). For the depiction of {>=} 50% stenosis, the sensitivity, specificity, and diagnostic accuracy of CTA were 100%, 95.8%, and 96.0%, respectively. In all 74 segments of disagreement, the degree of stenosis was overestimated on CTA. BSCTA is comparable to DSA for the evaluation of steno-occlusive intra- and extracranial vascular diseases. However, the stenotic degree tends to be overestimated on BSCTA, especially in cases of wall calcifications.

  1. Safety and efficacy of a drug regimen to control heart rate during 64-slice ECG-gated coronary CTA in children

    Rigsby, Cynthia K.; Nicholas, Angela C. [Children' s Memorial Hospital, Department of Medical Imaging, 2300 Children' s Plaza, Box 9, Chicago, IL (United States); deFreitas, R.A. [Children' s Memorial Hospital, Department of Pediatrics, Chicago, IL (United States); Leidecker, Christianne [Siemens Medical Solutions, Malvern, PA (United States); Johanek, Andrew J. [Children' s Memorial Hospital, Department of Medical Imaging, 2300 Children' s Plaza, Box 9, Chicago, IL (United States); Provena St. Joseph Medical Center, Department of Radiology, Joliet, IL (United States); Anley, Peter [Children' s Memorial Hospital, Pharmacy Department, Chicago (United States); Wang, Deli [Children' s Memorial Hospital, Biostatistical Research Department, Chicago, IL (United States); Uejima, Tetsu [Children' s Memorial Hospital, Department of Anesthesiology, Chicago, IL (United States)

    2010-12-15

    The adult practice for ECG-gated single-source 64-slice coronary CTA (CCTA) includes administering beta-blockers to reduce heart rate. There are limited data on this process in children. To evaluate the safety and efficacy of a drug regimen to decrease heart rate before performing CCTA in children. IV remifentanil and esmolol infusion were chosen to decrease heart rate in 41 children (mean age 6.5 years) while they were under general anesthesia (GA) for CCTA. Drug doses, changes in heart rate and procedural complications were recorded. CCTA image quality was graded on a scale of 1 to 5. The relationships between image quality and heart rate and image quality and age were evaluated. Patient effective radiation doses were calculated. Heart rates were lowered utilizing esmolol (4 children), remifentanil (2 children) or both (35 children); 26 children received nitroglycerin for coronary vasodilation. The mean decrease in heart rate was 26%. There were no major complications. The average image-quality score was 4.4. Higher heart rates were associated with worse image quality (r = 0.67, P < 0.0001). Older age was associated with better image quality (r = 0.66, P < 0.0001). Effective radiation doses were 0.7 to 7.0 mSv. Heart rate reduction for pediatric CCTA can be safely and effectively achieved while yielding high-quality images. (orig.)

  2. Should computed tomography angiography supersede invasive coronary angiography for the evaluation of graft patency following coronary artery bypass graft surgery?

    Gabriel, Joseph; Klimach, Stefan; Lang, Peter; Hildick-Smith, David

    2015-08-01

    Invasive coronary angiography (ICA) has long been the established gold standard in assessing graft patency following coronary artery bypass graft (CABG). Over the past decade or so however, improvements in computed tomography angiography (CTA) technology have allowed its emergence as a useful clinical tool in graft assessment. The recent introduction of 64-slice and now 128-slice scanners into widespread distribution, and the development of 320-detector row technology allowing volumetric imaging of the entire heart at single points in time within one cardiac cycle, has increased the potential of CTA to supersede ICA in this capacity. This study sought to examine the evidence surrounding this potential. A best evidence topic was constructed according to a structured protocol. The enquiry: In [patients who have undergone coronary artery bypass graft surgery] is [computed tomography angiography or invasive coronary angiography] superior in terms of [graft patency assessment, stenosis detection, radiation exposure and complication rate]? Four hundred and twenty-four articles were identified from the search strategy. Four additional articles were identified from references of key articles. Seventeen articles selected as best evidence were tabulated. The reliability of CTA as a tool in the detection of graft patency and stenosis has continued to improve with each successive generation of multislice technology. The latest 64- and 128-slice CTA techniques are able to detect graft patency and stenosis with very high sensitivities and specificities comparable with ICA, while remaining non-invasive procedures associated with fewer complications (ICA carries a 0.08% risk of myocardial infarction and 0.7% risk of minor complications in clinically stable patients). Present limitations of the technology include the accurate visualization of distal anastomoses and clip artefacts. In addition, the capacity of diagnostic ICA to be combined simultaneously with percutaneous coronary

  3. Detection of a coronary artery vessel wall: performance of 0.3 mm fine-cell detector computed tomography-a phantom study

    Yamada, Minoru [Multi-dimension Biomedical Imaging and Information Laboratory in Research Park, Keio University School of Medicine, Tokyo (Japan); Jinzaki, Masahiro; Tanami, Yutaka; Matsumoto, Kazuhiro; Ueno, Akihisa; Kuribayashi, Sachio [Department of Diagnostic Radiology, Keio University School of Medicine, Tokyo (Japan); Nukui, Masatake; Imai, Yasuhiro; Ishihara, Yotaro; Nishide, Akihiko; Sasaki, Kosuke, E-mail: jinzaki@rad.med.keio.ac.jp [CT Engineering, GE Healthcare Japan, Tokyo (Japan)

    2011-08-21

    The purpose of this study was to evaluate whether experimental fine-cell detector computed tomography with a 0.3125 mm cell (0.3 mm cell CT) can improve the detection of coronary vessel walls compared with conventional 64-slice computed tomography with a 0.625 mm cell (0.6 mm cell CT). A coronary vessel wall phantom was scanned using 0.6 mm cell CT and 0.3 mm cell CT. The data for 0.3 mm cell CT were obtained using four protocols: a radiation dose equal, double, triple or quadruple that were used in the 0.6 mm cell CT protocol. The detectable size of the vessel wall was assessed based on the first and second derivative functions, and the minimum measurable values were compared using a paired t-test. As a result, the minimum detectable wall thickness of 0.6 mm cell CT (1.5 mm) was significantly larger than that of 0.3 mm cell CT performed using the triple- and quadruple-dose protocols (0.9 mm) and the double-dose protocol (1.1 mm). The difference in the minimum detectable vessel wall thickness measured using 0.6 mm cell CT (1.5 {+-} 0.1 mm) and 0.3 mm cell CT (0.9 {+-} 0.1 mm, 1.1 {+-} 0.2 mm) was significant (p < 0.01). We concluded that 0.3 mm cell CT improved the detection of coronary vessel walls when a more than double-dose protocol was used compared with 0.6 mm cell CT.

  4. Technological Evolution on Computed Tomography and Radioprotection

    Computed Tomography (CT) has been available since the 70s and has experienced a dramatic technical evolution. Multi-detector technology is our current standard, offering capabilities unthinkable only a decade ago. Yet, we must nor forget the ionizing nature of CT's scanning energy (X-rays). It represents the most important cause of medical-associated radiation exposure to the general public, with a trend to increase. It is compulsory to intervene with the objective of dose reduction, following ALARA policies. Currently there are some technical advances that allow dose reduction, without sacrificing diagnostic image capabilities. However, human intervention is also essential. We must keep investment on education so that CT exams are don when they are really useful in clinical decision. Alternative techniques should also be considered. Image quality must not be searched disregarding the biological effects of radiation. Generally, it is possible to obtain clinically acceptable images with lower dose protocols. (author)

  5. Computed Tomography findings in Fournier's gangrene

    To assess the utility of computed tomography (CT) as an imaging technique in the diagnosis and determination of the extension of Fournier's gangrene (FG). We report the cases of six patients who had been clinically diagnosed as having FG, CT, enhanced by oral and intravenous contrast media, was performed in all the patients. All six patients presented soft tissue masses and gas in the scrotal region, which were also detected in the perineal region in five. In two patients, the gas extended toward anterior abdominal wall and in one of them, it also observed in anterior and posterior para renal space. The major predisposing factors were diabetes and alcoholism and the most common triggering factor was urologic disease. CT confirms the existence of FG and aids in assessing its extension and, in some cases, in identifying the underlying cause. (Author) 15 refs

  6. Computed tomography of primary intrahepatic biliary malignancy

    Fifteen patients with primary intrahepatic biliary malignancy (cholangiocarcinoma in 13, biliary cystadenocarcinoma in two) were examined by computed tomography (CT). The CT features were classified into three types: (A) a well-defined round cystic mass with internal papillary projections, (B) a localized intrahepatic biliary dilatation without a definite mass lesion, and (C) miscellaneous low-density masses. Intraphepatic biliary dilatation was noted in all cases of Types A and B and half of those of Type C; dilatation of extrahepatic bile ducts occurred in 4/4, 1/3, and 0/8, respectively. CT patterns, such as a well-defined round cystic mass with papillary projections or dilatation of intra- and extrahepatic ducts, give important clues leading to a correct diagnosis of primary intrahepatic biliary malignancy

  7. Radiation Protection in Paediatric Computed Tomography

    The number of examinations with radiation exposure has been increasing mainly due to advances in computed tomography (CT) technology, with a rapid expansion of CT utilization. Annually, 3.6 billion diagnostic and medical and dental examinations involving radiation are performed worldwide. The contribution of CT to collective dose due to medical X rays is up to 47–59%. A 2009 report of the National Council on Radiation Protection and Measurements (NCRP) estimates that 8–10% of CT examinations in the United States of America are performed on children; the growth in CT utilization is higher in the paediatric than adult population in the USA; and there is a particularly pronounced rise in adolescents undergoing chest CT in the emergency department setting for suspected pulmonary embolism or trauma. The reasons for the growing incidence of CT are new indications for CT with the advent of multidetector CT, overcautious ordering related to medico-legal problems and probably financial incentive systems

  8. Radiation Protection of Patients in Computed Tomography

    The use of radiation for medical diagnostic examinations contributes over 95% of human-made radiation exposure and is only exceeded by natural background as a source of exposure to the world’s population. In fact, for several developed countries, the increased use of high dose X ray technology, in particular, computed tomography (CT), has resulted in a situation in which the annual collective and per capita doses of ionizing radiation due to diagnostic radiology have exceeded those from natural background radiation. In light of this marked increase in worldwide collective effective dose from medical diagnostic procedures, and with CT scans accounting for half of this, there is great emphasis on the subject of radiation protection of patients in CT

  9. Quality assessment of clinical computed tomography

    Berndt, Dorothea; Luckow, Marlen; Lambrecht, J. Thomas; Beckmann, Felix; Müller, Bert

    2008-08-01

    Three-dimensional images are vital for the diagnosis in dentistry and cranio-maxillofacial surgery. Artifacts caused by highly absorbing components such as metallic implants, however, limit the value of the tomograms. The dominant artifacts observed are blowout and streaks. Investigating the artifacts generated by metallic implants in a pig jaw, the data acquisition for the patients in dentistry should be optimized in a quantitative manner. A freshly explanted pig jaw including related soft-tissues served as a model system. Images were recorded varying the accelerating voltage and the beam current. The comparison with multi-slice and micro computed tomography (CT) helps to validate the approach with the dental CT system (3D-Accuitomo, Morita, Japan). The data are rigidly registered to comparatively quantify their quality. The micro CT data provide a reasonable standard for quantitative data assessment of clinical CT.

  10. Polychromatic phase-contrast computed tomography

    Polychromatic phase-contrast radiography differs from traditional (absorption-only) radiography in that the method requires at least a partially coherent x-ray source and the resulting images contain information about the phase shifts of x-rays in addition to the traditional absorption information. In a typical embodiment, this effect results in a measurable enhancement in image contrast at the edges of objects. In this study, a phase-contrast imaging system was adapted to allow an object to be imaged at multiple projections, and these projections were used to generate phase-contrast computed tomography images. The images obtained with this technique show edge enhancements surrounding the objects within the image

  11. Data processing device for computed tomography system

    A data processing device applied to a computed tomography system which examines a living body utilizing radiation of X-rays is disclosed. The X-rays which have penetrated the living body are converted into electric signals in a detecting section. The electric signals are acquired and converted from an analog form into a digital form in a data acquisition section, and then supplied to a matrix data-generating section included in the data processing device. By this matrix data-generating section are generated matrix data which correspond to a plurality of projection data. These matrix data are supplied to a partial sum-producing section. The partial sums respectively corresponding to groups of the matrix data are calculated in this partial sum-producing section and then supplied to an accumulation section. In this accumulation section, the final value corresponding to the total sum of the matrix data is calculated, whereby the calculation for image reconstruction is performed

  12. Computed tomography findings in convergent strabismus fixus

    X-ray computed tomography (CT) of the eyeball and orbit revealed the cause of eye movement disorder in convergent strabismus fixus. The findings suggest that the disease can be diagnosed and treated at an early stage. Twelve cases of progressive esotropia with high myopia and 20 cases with normal visual acuity served as subjects in this study. The CT slice was parallel to the German horizontal plane, and the lens and medial and lateral rectus muscles were scanned. The average axial length of the affected eyes was significantly longer than in normal eyes. In progressive esotropia, the characteristic CT findings are an elongated eyeball, mechanical contact between the eyeball and lateral wall of the orbit, and a downward displacement of the lateral rectus muscle. Thus, it is reasonable to conclude that eye movement disorder in convergent strabismus fixus results from weakness of the lateral rectus muscle which has been displaced downward due to compression of the eyeball against the orbital wall. (author)

  13. PRIMA+: a proton computed tomography apparatus

    The proton Computed Tomography (pCT) is a medical imaging method, based on the use of proton beams with kinetic energy of the order of 250 MeV, aimed to directly measure the stopping power distribution of tissues thus improving the present accuracy of treatment planning in hadron therapy. A pCT system should be capable to measure tissue electron density with an accuracy better than 1% and a spatial resolution better than 1 mm. The blurring effect due to multiple Coulomb scattering can be mitigated by single proton tracking technique. As a first step towards pCT the PRIMA+ Collaboration built a prototype capable to carry out a single radiography and a tomographic image of a rotating object. This apparatus includes a silicon microstrip tracker to identify the proton trajectory and a YAG:Ce calorimeter to measure the particle residual energy.

  14. Interpolation method in simple computed tomography scanner

    Wiguna, Gede A.

    2015-03-01

    A method for sinogram data interpolation based on a sinusoidal pattern in computed tomography has been developed. Sampled sinograms were acquired based on angular interval scanning of 5o, 10o, and 20o. Then each resulted sinogram was interpolated following sinusoidal pattern to make a complete full scanning sinogram as if they were sampled at 1o. After that, a formal summation convolved filtered back projection was applied to each sinogram to yield a crosssectional image. This method was successfully interpolated limited number of projections data to obtained complete sinogram. It works for simple and homogenous object. However, for high variation of physical properties, e.g. linear attenuation coefficient values, this method needs more consideration on interpolation strategies to produce good image.

  15. Reporting of Dose in Computed Tomography

    Meaningful measurement and reporting of dose is an ongoing quest in computed tomography (CT). Expressions such as CTDIvol and dose length product are frequently used, but they describe machine output rather than dose to the patient. Further, they can be misleading when certain dose sparing technologies are employed. Size specific dose estimate has been proposed by the American Association of Physicists in Medicine as a more meaningful measure, but it approximates the mean dose to the patient centre rather than the dose to any specific organ. For estimates of patient risk, doses to specific organs are needed, but these are difficult to obtain. Medical physicists continue to try to resolve these issues, so that more meaningful estimates of dose from CT can be acquired. In the meantime, authors of scientific articles should be dissuaded from using meaningless expressions such as ‘low dose’ and ‘ultra-low dose’ in their descriptions of CT procedures. (author)

  16. Advanced proton imaging in computed tomography

    Mattiazzo, S; Giubilato, P; Pantano, D; Pozzobon, N; Snoeys, W; Wyss, J

    2015-01-01

    In recent years the use of hadrons for cancer radiation treatment has grown in importance, and many facilities are currently operational or under construction worldwide. To fully exploit the therapeutic advantages offered by hadron therapy, precise body imaging for accurate beam delivery is decisive. Proton computed tomography (pCT) scanners, currently in their R&D phase, provide the ultimate 3D imaging for hadrons treatment guidance. A key component of a pCT scanner is the detector used to track the protons, which has great impact on the scanner performances and ultimately limits its maximum speed. In this article, a novel proton-tracking detector was presented that would have higher scanning speed, better spatial resolution and lower material budget with respect to present state-of-the-art detectors, leading to enhanced performances. This advancement in performances is achieved by employing the very latest development in monolithic active pixel detectors (to build high granularity, low material budget, ...

  17. Computed tomography of the abnormal thymus

    Baron, R.L.; Lee, J.K.T.; Sagel, S.S.; Levitt, R.G.

    1982-01-01

    Computed tomography (CT) should be the imaging method of choice following plain chest radiographs when a suspected thymic abnormality requires further evaluation. Based upon a six-year experience, including the evaluation of 25 patients with thymic pathology, CT was found useful in suggesting or excluding a diagnosis of thymoma and in distinguishing thymic hyperplasis from thymoma in patients with myasthenia gravis. The thickness of the thymic lobes determined by CT was found to be a more accurate indicator of infiltrative disease (thymic hyperplasia and lymphoma) than the width. CT was helpful in differentiating benign thymic cysts from solid tumors, and in defining the extent of a thymic neoplasms. On occasion, CT may suggest the specific histologic nature of a thymic lesion.

  18. Computer tomography of intracranial tumours and hematomas

    The value of computed tomography (CT) for the diagnosis of intracranial tumors and hematomas was investigated in a retrospective study comprising 220 patients. All C.T.scans are reviewed and described in detail. To assess the diagnostic accuracy, the original interpretation of the C.T.scans was compared with that of conventional neuroradiological and neurophysiological examinations. The aspect on C.T. of the various types of tumors and hematomas proved to vary widely and specific features were seldom seen. This holds particularly for the malignant tumors. Benign tumors such as meningeomas, adenomas and neurilemmomas showed a rather easily identifiable and almost identical picture of the C.T.scan, and diagnosis had to be based mainly on differences in localization. The hematomas, with the exception of the older intracerebral ones, showed the most characteristic C.T.abnormalities. (Auth.)

  19. Computed tomography findings of malignant pleural mesothelioma

    Computed tomography (CT) findings were assessed in 7 patients with malignant mesothelioma. CT findings were also reviewed in 9 patients with lung cancer and pleuritis carcinomatosa and in 11 patients with tuberculous pleuritis. Five patients with malignant mesothelioma underwent CT scans twice, on admission and from 1 to 7 months after admission. Tuberculous pleuritis could be distinguished from pleuritis carcinomatosa and malignant mesothelioma by the presence or absence of pleural nodularity and chest wall invasion. Although it was difficult to identify specific CT features clearly distinguishing malignant mesothelioma from pleuritis carcinomatosa, characteristic findings of malignant mesothelioma appeared to include the rapid development and progression of pleural rind and a tendency to spread directly into the chest wall. We divided the pleural into the four regions; upper anterior, upper posterior, lower anterior and lower posterior regions. Pleural changes were more frequently seen in the lower pleural regions than in the upper pleural regions in malignant mesothelioma. (author)

  20. Computed tomography findings in convergent strabismus fixus

    Ohta, Michitaka; Iwashige, Hiroyasu; Hayashi, Takao; Maruo, Toshio [Teikyo Univ., Tokyo (Japan). Faculty of Medicine

    1995-08-01

    X-ray computed tomography (CT) of the eyeball and orbit revealed the cause of eye movement disorder in convergent strabismus fixus. The findings suggest that the disease can be diagnosed and treated at an early stage. Twelve cases of progressive esotropia with high myopia and 20 cases with normal visual acuity served as subjects in this study. The CT slice was parallel to the German horizontal plane, and the lens and medial and lateral rectus muscles were scanned. The average axial length of the affected eyes was significantly longer than in normal eyes. In progressive esotropia, the characteristic CT findings are an elongated eyeball, mechanical contact between the eyeball and lateral wall of the orbit, and a downward displacement of the lateral rectus muscle. Thus, it is reasonable to conclude that eye movement disorder in convergent strabismus fixus results from weakness of the lateral rectus muscle which has been displaced downward due to compression of the eyeball against the orbital wall. (author).

  1. [Spontaneous intraparenchymatous hemorrhage: findings at computed tomography].

    Soares, Celso Monteiro; Carvalho, Antonio Carlos Pires; Rodrigues, Andréa de Jesus

    2004-09-01

    Computed tomography studies of 250 patients with spontaneous hemorrhage were examined in three hospitals in the city of Rio de Janeiro. The goal of this study was to identify the aspects of this disease that appear most frequently in this type of exam. Deep intracerebral hematomas have had the highest incidence followed by lobar hemorrhage, with thalamus being more frequently affected. Cerebellar hemorrhage was much rarer, with brainstem bleeding observed in few patients. The age group with a peak incidence was at 61 to 70 years. Headache was the most frequently related symptom and elevated levels of blood pressure were found in most of the cases. There was no pronounced difference as to predominance in either sex or side most affected but it was observed that the onset of this disease occurs at an earlier age in men than in women. Blood draining into the ventricular system occurred more frequently in deep hematomas. PMID:15334231

  2. Myocardial hypoperfusion on conventional contrast computed tomography.

    Ching, Shing; Chung, Tak Shun

    2015-10-01

    Non–electrocardiogram (ECG)–gated contrast computed tomography (CT) is commonly performed to exclude aortic dissection in chest pain patients. Besides evaluating the aorta for dissection flap, attention should be paid to the myocardium for areas of hypoenhancement that may suggest ischemia. Current models of multidetector CT enable assessment of myocardial perfusion with minimal motion artifact even without ECG gating. Transmural hypoenhancement with preserved wall thickness in a coronary distribution is highly specific for acute myocardial infarction. We report 2 cases of acute chest pain with initial nondiagnostic studies that underwent CT aortogram to exclude dissection. Instead, the CT showed myocardial hypoenhancement in left anterior descending artery territory. Myocardial hypoenhancement occurred before ST-segment elevation on ECG, suggesting that recognition of this important finding may lead to earlier revascularization decisions. PMID:26321167

  3. Perfusion computed tomography imaging of autoimmune pancreatitis

    Perfusion computed tomography (P-CT) is now available for the analysis of pancreatic blood flow. The aim of this study was to clarify pancreatic blood perfusion in AIP patients and the changes after steroid treatment. Color map imaging of P-CT and pancreatic time CT density curve (TDC) demonstrated that the pancreatic blood flow was attenuated in AIP patients. Pancreatic volumetric blood flow FV values of 11 AIP patients (82.7/min) were significantly lower than those of 12 normal controls (163.5/min, p=0.0006). AIP patients received steroid treatment and were re-examined, of these, 9 patients showed significantly elevated FV values after treatment (76.2/min and 109.8/min, p=0.0391, respectively). However, the changes of the values after the treatment differed in varying degrees among the individuals. P-CT is a useful method for the analysis of the blood flow in pancreatic diseases. (author)

  4. Computed tomography of the pituitary gland

    This book is written entirely to include the imaging of the pituitary gland by computed tomography (CT). The first three chapters illustrated technical aspects of scanning, anatomic depiction of the gland by CT, and the use of dynamic CT scanning for detecting and displaying abnormalities. The chapters discuss and illustrate various types of pathologic processes in and around the pituitary gland. One short but very helpful chapter demonstrates potential pitfalls due to the combination of anatomic variants and the geometry of CT sections. Some illustrations of disease processed are depicted by magnetic resonance imaging. All major types of pituitary diseases are illustrated. Lists of readily available English-language references are available. A small subject index is provided at the end of the book in which the illustrations are identified by use of a special numeric front

  5. Diagnosis of lumbar disc hernia with computed tomography

    Yoshizumi, Atsuro; Ohira, Nobuhiro; Ojima, Tadashi; Oshida, Midori; Horaguchi, Mitsuru (Tohoku Rosai Hospital, Sendai (Japan))

    1982-07-01

    Results of computed tomography performed on patients with clinically diagnosed hernia were compared with those of myelography and operative findings. This comparative study suggested that computed tomography is quite different from other methods and very useful in diagnosis of hernia. Some cases of hernia were shown, and the characteristics of CT were reviewed.

  6. 21 CFR 1020.33 - Computed tomography (CT) equipment.

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Computed tomography (CT) equipment. 1020.33... Computed tomography (CT) equipment. (a) Applicability. (1) The provisions of this section, except for paragraphs (b), (c)(1), and (c)(2) are applicable as specified herein to CT x-ray systems manufactured...

  7. Computed tomography and magnetic resonance findings in lipoid pneumonia.

    Bréchot, J M; Buy, J N; Laaban, J P; Rochemaure, J

    1991-01-01

    A case of exogenous lipoid pneumonia was documented by computed tomography and magnetic resonance imaging. Although strongly suggesting the presence of fat on T1 weighted images, magnetic resonance does not produce images specific for this condition. Computed tomography is the best imaging modality for its diagnosis.

  8. Diagnosis of lumbar disc hernia with computed tomography

    Results of computed tomography performed on patients with clinically diagnosed hernia were compared with those of myelography and operative findings. This comparative study suggested that computed tomography is quite different from other methods and very useful in diagnosis of hernia. Some cases of hernia were shown, and the characteristics of CT were reviewed. (Ueda, J.)

  9. Computed tomography of the central nervous system in small animals

    With computed tomography in 44 small animals some well defined anatomical structures and pathological processes of the central nervous system are described. Computed tomography is not only necessary for the diagnosis of tumors; malformations, inflammatory, degenerative and vascular diseases and traumas are also visible

  10. The role of computed tomography in the laryngeal injury

    Bae, Hoon Sik [Capital Armed Forces General Hospital, Seongnam (Korea, Republic of)

    1984-03-15

    Computed tomography of the larynx represents a major advance in laryngology. Even in severe injury the larynx can be examined easily and conveniently by CT at the same time as the brain and facial structures without moving the patient, who need only lie down and breathe quietly during the study. Computed tomography permitted a much more detailed appraisal of laryngeal dysfunction in patients with blunt laryngeal trauma (3 cases) and strangulation injury (2 cases). Computed tomography of the larynx undoubtedly played a determinant role in patient management. Computed tomography was helpful in evaluating the laryngeal cartilages and deep spaces of the larynx which was difficult to examine by the laryngoscope. Follow-up computed tomography made it possible to evaluate the postoperative results.

  11. The role of computed tomography in the laryngeal injury

    Computed tomography of the larynx represents a major advance in laryngology. Even in severe injury the larynx can be examined easily and conveniently by CT at the same time as the brain and facial structures without moving the patient, who need only lie down and breathe quietly during the study. Computed tomography permitted a much more detailed appraisal of laryngeal dysfunction in patients with blunt laryngeal trauma (3 cases) and strangulation injury (2 cases). Computed tomography of the larynx undoubtedly played a determinant role in patient management. Computed tomography was helpful in evaluating the laryngeal cartilages and deep spaces of the larynx which was difficult to examine by the laryngoscope. Follow-up computed tomography made it possible to evaluate the postoperative results

  12. Terahertz Computed Tomography of NASA Thermal Protection System Materials

    Roth, D. J.; Reyes-Rodriguez, S.; Zimdars, D. A.; Rauser, R. W.; Ussery, W. W.

    2011-01-01

    A terahertz axial computed tomography system has been developed that uses time domain measurements in order to form cross-sectional image slices and three-dimensional volume renderings of terahertz-transparent materials. The system can inspect samples as large as 0.0283 cubic meters (1 cubic foot) with no safety concerns as for x-ray computed tomography. In this study, the system is evaluated for its ability to detect and characterize flat bottom holes, drilled holes, and embedded voids in foam materials utilized as thermal protection on the external fuel tanks for the Space Shuttle. X-ray micro-computed tomography was also performed on the samples to compare against the terahertz computed tomography results and better define embedded voids. Limits of detectability based on depth and size for the samples used in this study are loosely defined. Image sharpness and morphology characterization ability for terahertz computed tomography are qualitatively described.

  13. Computed tomography of normal distal tibiofibular syndesmosis

    The purpose of this study was to determine the shape and measurements of the normal distal tibiofibular syndesmosis on computed tomographic scans and to identify features that could aid in the diagnosis of syndesmotic diastasis using computed tomography (CT). CT scans of 100 patients with normal distal tibiofibular syndesmoses were reviewed retrospectively. In 67% the incisura fibularis was deep, giving the syndesmosis a crescent shape. In 33% the incisura fibularis was shallow, giving the syndesmosis a rectangular shape. The measurements of both types were taken using the same reference points. The mean age of the patients was 40 years, and there were 53 men and 47 women. The mean width of the distal tibiofibular syndesmosis anteriorly between the tip of the anterior tibial tubercle and the nearest point of the fibula was 2 mm. The mean width of the distal tibiofibular syndesmosis posteriorly between the medial border of the fibula and the nearest point of the lateral border of the posterior tibial tubercle was 4 mm. In men the mean width of the distal tibiofibular syndesmosis, anterior and posterior, was 2 mm and 5 mm, respectively, and in women it was 2 mm and 4 mm, respectively. This study provides measurements of the normal tibiofibular syndesmosis to aid in the diagnosis of occult diastasis. (orig.)

  14. Computed tomography of normal distal tibiofibular syndesmosis

    Elgafy, Hossein; Semaan, Hassan B.; Blessinger, Brian; Wassef, Andrew; Ebraheim, Nabil A. [University of Toledo Medical Center, Departments of Orthopaedic Surgery and Radiology, Toledo, OH (United States)

    2010-06-15

    The purpose of this study was to determine the shape and measurements of the normal distal tibiofibular syndesmosis on computed tomographic scans and to identify features that could aid in the diagnosis of syndesmotic diastasis using computed tomography (CT). CT scans of 100 patients with normal distal tibiofibular syndesmoses were reviewed retrospectively. In 67% the incisura fibularis was deep, giving the syndesmosis a crescent shape. In 33% the incisura fibularis was shallow, giving the syndesmosis a rectangular shape. The measurements of both types were taken using the same reference points. The mean age of the patients was 40 years, and there were 53 men and 47 women. The mean width of the distal tibiofibular syndesmosis anteriorly between the tip of the anterior tibial tubercle and the nearest point of the fibula was 2 mm. The mean width of the distal tibiofibular syndesmosis posteriorly between the medial border of the fibula and the nearest point of the lateral border of the posterior tibial tubercle was 4 mm. In men the mean width of the distal tibiofibular syndesmosis, anterior and posterior, was 2 mm and 5 mm, respectively, and in women it was 2 mm and 4 mm, respectively. This study provides measurements of the normal tibiofibular syndesmosis to aid in the diagnosis of occult diastasis. (orig.)

  15. Texture classification of lung computed tomography images

    Pheng, Hang See; Shamsuddin, Siti M.

    2013-03-01

    Current development of algorithms in computer-aided diagnosis (CAD) scheme is growing rapidly to assist the radiologist in medical image interpretation. Texture analysis of computed tomography (CT) scans is one of important preliminary stage in the computerized detection system and classification for lung cancer. Among different types of images features analysis, Haralick texture with variety of statistical measures has been used widely in image texture description. The extraction of texture feature values is essential to be used by a CAD especially in classification of the normal and abnormal tissue on the cross sectional CT images. This paper aims to compare experimental results using texture extraction and different machine leaning methods in the classification normal and abnormal tissues through lung CT images. The machine learning methods involve in this assessment are Artificial Immune Recognition System (AIRS), Naive Bayes, Decision Tree (J48) and Backpropagation Neural Network. AIRS is found to provide high accuracy (99.2%) and sensitivity (98.0%) in the assessment. For experiments and testing purpose, publicly available datasets in the Reference Image Database to Evaluate Therapy Response (RIDER) are used as study cases.

  16. 64层螺旋CT冠状动脉成像影响因素分析%Analysis of Influential Factors of 64-slice Spiral CT Coronary Angiography

    刘伟宾

    2011-01-01

    目的 探讨64层螺旋CT冠状动脉成像的质量影响因素.方法 回顾性分析514例行64层螺旋CT冠状动脉成像的影像资料.结果 根据图像评价方法,本组优321例,占62.5%;良138例,26.8%;差55例,占10.7%,认定为检查失败.127例ECG前瞻式门控扫描检查失败21例,占16.5%;387例回顾式门控扫描检查失败34例,占8.8%.检查时心率波动≤5/min 313例,7例失败,占2.2%;6~10/min 175例,23例检查失败,占13.1%;10~20/min 26例,25例检查失败,占96.2%.检查过程中37例屏气不好,32例检查失败,占86.5%;3例扫描过程中未能控制呛咳、呃逆,检查失败;53例冠状动脉搭桥术后复查者,1例因扫描范围不足而检查失败;3例过于肥胖,1例扫描参数过低而导致检查失败.结论 充分认识64层螺旋CT冠状动脉成像检查中影响成像质量的因素,争取患者最佳配合状态,方能获得更好的图像质量,提高诊断准确性.%Objective To discuss the influential factors of image quality of 64-slice spiral CT coronary angiography (CTCA). Methods The imaging data of 514 patients with coronary artery disease were retrospectively analyzed. Results According to image evaluation method, the results were excellent in 321 patients(62.5% ), good in 138 ( 26. 8% ) , and poor and regarded as failures in 55( 10.7% ). 127 patients underwent prospective electrocardiographic (ECG) gating, but failed in 21 patients (16.5%) ; 387 patients underwent retrospective ECG gating, and failed in 34 patients (8.8%). 313 patients had heart rate fluctuation ≤5 beats per minute( BPM), among whom, 7 (2.2%) failed in examination; 175 patients had heart rate from 6 BPM to 10 BPM, among whom, 23 (13.1%) failed in examination; 26 patients had heart rate from 10 BPM to 20 BPM,among whom, 25 failed in examination; 37 patients had poor breathholding, among whom, 32(86.5% )failed in examination.3 failed in examination due to incontrollable bucking and hiccup during the

  17. Non-invasive assessment of congenital pulmonary vein stenosis in children using cardiac-non-gated CT with 64-slice technology

    Background: Management of congenital pulmonary vein stenosis is a diagnostic challenge. Echocardiography may be insufficient and thus cardiac catheterization remains the reference standard in this setting. The aim of the study was to investigate the accuracy of cardiac-non-gated CT using 64-slice technology in detecting congenital pulmonary vein stenosis in children. Materials and methods: CT examinations were consecutively performed from May 2005 to December 2006 in 13 children aged 1.5-12 months (median 5 months) for suspected congenital pulmonary vein stenosis. Cardiac-non-gated CT acquisitions were performed after the peripheral injection of contrast agent. Pulmonary veins were evaluated for their pattern of connectivity from the lung to the left atrium and for the presence of stenosis. CT findings of pulmonary vein stenosis were compared with combined findings available from echocardiography, catheterization and surgery. Results: Pulmonary veins from the right lung (n = 29) and left lung (n = 26) were evaluated as separate structures (N = 55). Of the 55 structures, 32 had surgical and/or catheterization data and 45 had echocardiography for comparison. CT visualized 100% (55/55) of the investigated structures, while echocardiography visualized 82% (45/55). In the 13 subjects CT identified 10 stenotic pulmonary veins. CT confirmed the echocardiography suspicion of pulmonary vein stenosis in 100% (7/7) and established a new diagnosis in 3 other patients. CT agreed with surgery/catheterization in 100% (10/10) of the available comparisons. Conclusion: Cardiac-non-gated CT assessed the pulmonary veins more completely than echocardiography and should be considered as a viable alternative for invasive pulmonary venography for detecting pulmonary vein stenosis in children.

  18. Validation of a new cardiac image fusion software for three-dimensional integration of myocardial perfusion SPECT and stand-alone 64-slice CT angiography

    Combining the functional information of SPECT myocardial perfusion imaging (SPECT-MPI) and the morphological information of coronary CT angiography (CTA) may allow easier evaluation of the spatial relationship between coronary stenoses and perfusion defects. The aim of the present study was the validation of a novel software solution for three-dimensional (3D) image fusion of SPECT-MPI and CTA. SPECT-MPI with adenosine stress/rest 99mTc-tetrofosmin was fused with 64-slice CTA in 15 consecutive patients with a single perfusion defect and a single significant coronary artery stenosis (≥50% diameter stenosis). 3D fused SPECT/CT images were analysed by two independent observers with regard to superposition of the stenosed vessel onto the myocardial perfusion defect. Interobserver variability was assessed by recording the X, Y, Z coordinates for the origin of the stenosed coronary artery and the centre of the perfusion defect and measuring the distance between the two landmarks. SPECT-MPI revealed a fixed defect in seven patients, a reversible defect in five patients and a mixed defect in three patients and CTA documented a significant stenosis in the respective subtending coronary artery. 3D fused SPECT/CT images showed a match of coronary lesion and perfusion defect in each patient and the fusion process took less than 15 min. Interobserver variability was excellent for landmark detection (r = 1.00 and r = 0.99, p < 0.0001) and very good for the 3D distance between the two landmarks (r = 0.94, p < 0.001). 3D SPECT/CT image fusion is feasible, reproducible and allows correct superposition of SPECT segments onto cardiac CT anatomy. (orig.)

  19. Positron emission tomography alone, positron emission tomography-computed tomography and computed tomography in diagnosing recurrent cervical carcinoma: a systematic review and meta-analysis

    Xiao, Yi; Wei, Jia; Zhang, Yicheng; Xiong, Weining

    2014-01-01

    Introduction The aim of the study was to assess systematically the accuracies of positron emission tomography (PET), PET/computed tomography (CT), and CT in diagnosing recurrent cervical cancer. Material and methods We searched for articles published from January 1980 to June 2013 using the following inclusion criteria: articles were reported in English; the use of PET, interpreted with or without the use of CT; use of CT to detect recurrent cervical cancer; and histopathologic analysis and/o...

  20. Computed tomography of traumatic intracranial lesions

    The cranial computed tomography (CT) is a new radiological technique with which, for the first time, minimal differences an attenuation by intracranial soft tissue can be measured exactly. The basic physical principles of computed tomography have been extensively presented by Hounsfield (1973). It is well established that the attenuation of extravasated blood measures between 35 and 45 Hounsfield units. Therefore no difficulty should be encountered in the recognition and diagnosis of extra-axial hematoma and cerebral contusion since the density of the brain parenchyma never measures more than 25 units. As the constant increase in high velocity accidents and violence, the problem of acute head injury is one of the matters of great importance in today's medical practice. Therefore it is very important to figure out the method that would allow us to diagnose easily and precisely the effects of trauma upon the brain in order to institute the proper treatment at the earliest possible moment. Computed tomography allows us to make a diagnosis quickly and in a non-invasive manner. The CT scan was carried out on 310 head trauma cases in the department of radiology, St. Mary's and Kang Nam St. Mary's Hospital, Catholic Medical College, for 16 months from June 1979 to October 1980. All the scans were obtained with the Hitachi CT-H2 scanner and the scans were repeated following intravenous injection of high dose of contrast media (roughly 1.8 cc per kg body weight of 60% Conray). We have reviewed the CT scans of 310 patients got acute head injury in order to assess the location of brain lesions, the relationship between the CT densities of hematomas and their stage, the shape and mass effect of the extra-axial hematomas, and the effect of contrast enhancement. The results were as follows: 1. Of all 310 cases of the head injuries, epidural hematoma was 13.5%, subdural hematoma was 8.7%, subdural hygroma was 10%, cerebral contusion was 39%, hydrocephalus and atrophy was 3.9% and

  1. Giant hepatic cavernous hemangioma. Findings on computed helical tomography

    Objective: To describe computed helical tomography characteristics of the giant hepatic cavernous hemangioma. Method: During five years, we evaluated 21 patients with 21 giant hepatic cavernous hemangiomas with computed helical and multislice tomography. We included 18 women (86%) and 3 men (14%) with a mean age of 45 years. Results: The mean size of hemangiomas was 10.4 cm. Non enhanced computed tomography Showed 21 hemangiomas with lower density than adjacent hepatic parenchyma , all hemangiomas showed a central cleft area with low density. None hemangioma showed calcifications neither internal septa. In enhanced helical tomography all lesions demonstrated a globular, peripheral enhancing pattern with centripetal filling that begin in the arterial phase and continued in portal and delayed phases. None of the lesions showed complete filling. Conclusion: giant hepatic cavernous hemangiomas showed low attenuation in non enhanced computed tomography. central cleft area was very frequently seen. The enhancement pattern is characteristic, starting at the periphery with centripetal filling but it was never complete.

  2. Reproducibility in the assessment of acute pancreatitis with computed tomography

    Freire Filho, Edison de Oliveira; Vieira, Renata La Rocca; Yamada, Andre Fukunishi; Shigueoka, David Carlos; Bekhor, Daniel; Freire, Maxime Figueiredo de Oliveira; Ajzen, Sergio; D' Ippolito, Giuseppe [Universidade Federal de Sao Paulo (UNIFESP/EPM), SP (Brazil). Dept. of Imaging Diagnosis]. E-mail: eofilho@ig.com.br; eoffilho@uol.com.br

    2007-11-15

    Objective: To evaluate the reproducibility of unenhanced and contrast-enhanced computed tomography in the assessment of patients with acute pancreatitis. Materials and methods: Fifty-one unenhanced and contrast-enhanced abdominal computed tomography studies of patients with acute pancreatitis were blindly reviewed by two radiologists (observers 1 and 2). The morphological index was separately calculated for unenhanced and contrast-enhanced computed tomography and the disease severity index was established. Intraobserver and interobserver reproducibility of computed tomography was measured by means of the kappa index ({kappa}). Results: Interobserver agreement was {kappa} 0.666, 0.705, 0.648, 0.547 and 0.631, respectively for unenhanced and contrast-enhanced morphological index, presence of pancreatic necrosis, pancreatic necrosis extension, and disease severity index. Intraobserver agreement (observers 1 and 2, respectively) was {kappa} = 0.796 and 0.732 for unenhanced morphological index; {kappa} 0.725 and 0.802 for contrast- enhanced morphological index; {kappa} = 0.674 and 0.849 for presence of pancreatic necrosis; {kappa} = 0.606 and 0.770 for pancreatic necrosis extension; and {kappa} = 0.801 and 0.687 for disease severity index at computed tomography. Conclusion: Computed tomography for determination of morphological index and disease severity index in the staging of acute pancreatitis is a quite reproducible method. The absence of contrast- enhancement does not affect the computed tomography morphological index reproducibility. (author)

  3. Reproducibility in the assessment of acute pancreatitis with computed tomography

    Objective: To evaluate the reproducibility of unenhanced and contrast-enhanced computed tomography in the assessment of patients with acute pancreatitis. Materials and methods: Fifty-one unenhanced and contrast-enhanced abdominal computed tomography studies of patients with acute pancreatitis were blindly reviewed by two radiologists (observers 1 and 2). The morphological index was separately calculated for unenhanced and contrast-enhanced computed tomography and the disease severity index was established. Intraobserver and interobserver reproducibility of computed tomography was measured by means of the kappa index (κ). Results: Interobserver agreement was κ 0.666, 0.705, 0.648, 0.547 and 0.631, respectively for unenhanced and contrast-enhanced morphological index, presence of pancreatic necrosis, pancreatic necrosis extension, and disease severity index. Intraobserver agreement (observers 1 and 2, respectively) was κ = 0.796 and 0.732 for unenhanced morphological index; κ 0.725 and 0.802 for contrast- enhanced morphological index; κ = 0.674 and 0.849 for presence of pancreatic necrosis; κ = 0.606 and 0.770 for pancreatic necrosis extension; and κ = 0.801 and 0.687 for disease severity index at computed tomography. Conclusion: Computed tomography for determination of morphological index and disease severity index in the staging of acute pancreatitis is a quite reproducible method. The absence of contrast- enhancement does not affect the computed tomography morphological index reproducibility. (author)

  4. Analysis of the computed tomography in the acute abdomen

    Introduction: This study tends to test the capacity of the computed tomography in assist in the diagnosis and the approach of the acute abdomen. Material and method: This is a longitudinal and prospective study, in which were analyzed the patients with the diagnosis of acute abdomen. There were obtained 105 cases of acute abdomen and after the application of the exclusions criteria were included 28 patients in the study. Results: Computed tomography changed the diagnostic hypothesis of the physicians in 50% of the cases (p 0.05), where 78.57% of the patients had surgical indication before computed tomography and 67.86% after computed tomography (p = 0.0546). The index of accurate diagnosis of computed tomography, when compared to the anatomopathologic examination and the final diagnosis, was observed in 82.14% of the cases (p = 0.013). When the analysis was done dividing the patients in surgical and nonsurgical group, were obtained an accuracy of 89.28% (p 0.0001). The difference of 7.2 days of hospitalization (p = 0.003) was obtained compared with the mean of the acute abdomen without use the computed tomography. Conclusion: The computed tomography is correlative with the anatomopathology and has great accuracy in the surgical indication, associated with the capacity of increase the confident index of the physicians, reduces the hospitalization time, reduces the number of surgeries and is cost-effective. (author)

  5. Computed tomography studies on patients with mucopolysaccharidoses

    The appearances on computed tomography (CT) in eight patients with mucopolysaccharidosis Type I, two with mucopolysaccharidosis Type II and two with mucopolysaccharidosis Type IIIB are presented. Reference is also made to two further cases in which the CT showed special features. Follow-up scans were obtained to assess the evolution of the changes. The place of CT in the diagnosis of complications due to thecal involvement is examined. The density of grey matter on the CT scans was similar to that of normal brain. Inhaled xenon did not produce any special enhancement which could be helpful in assessing the degree of the mucopolysaccharide deposition within cerebral cells. Symmetrical low attenuation in the white matter was a very common finding. This work has shown that the stage in the evolution of the mucopolysaccharidoses at which hydrocephalus develops as a complication is highly variable and CSF diversion procedures are sometimes indicated to improve the quality of the patients' lives. These indications are briefly discussed. We consider that CT is essential for the adequate appraisal of these patients and to identify some treatable complications. (orig./MG)

  6. Radiation Doses from Computed tomography in Iraq

    Radiation doses to Patient during CT scanner and the radiological risk are significant. Patient dose survey has been conducted to investigate the Iraq patient radiation doses received in CT scanners in order to established reference dose levels. These doses are Entrance Surface Dose (ESD),computed tomography dose index(CTDI)), and dose length product (DLP). Two CT scanner were investigated in this study were, Siemens Somatom Plus 4, located in at medical city of Baghdad, and Philips, Optimus located in privet hospital at Baghdad. ESD were measured by TLD and Dosimax ionization chamber for head, chest, and abdomen for both sex and different weights. The TLD results were higher than that measured with Dosimax due to scattered radiation .The scattering factor which is the ratio between dose measured by TLD and that measured by ionization chamber range between (1.14-1.34) compare to international measurement which is range between (1.1-1.5).The (ESD) measured by the two methods were agree well after the subtraction of scattering dose, and have compered with original research. Dose profile were measured using array of TLD chips shows that its full width at half maximum is(7.99 mm) approximately equal the slice thickness(8 mm). Our results compare with reference level at U.K, European Guidelines and

  7. Cranial computed tomography in infantile spasms

    Out of 109 children with infantile spasms (IS), prospectively tested during the years 1976 to 1979 in Denmark, 52 children were examined by cranial computed tomography (CT). The classification of IS into cryptogenic (CR), symptomatic (SY) and doubtful (DO) was done clinically without considering the CT-finding. Sixty per cent of the scannings were abnormal. Only 6/30 (20%) of the children in ACTH treatment were found to develop cerebral atrophy which means that this finding is not an obligatory side-effect of ACTH treatment of children with IS. Normal CT-findings were found in 50% of the CR and 50% of the SY + DO-groups, and could not be used as a prognostic tool for estimating the mental development. This was also the case for children with cerebral atrophy. Abnormal CT-findings (minus atrophy) were highly correlated to the group with clinical symptoms and indicate an extremely unsatisfying long-term mental prognosis. CT-scanning is a valuable tool for the examination of clearing children with infantile spasms. (authors)

  8. Radiation doses from computed tomography in Australia

    Recent surveys in various countries have shown that computed tomography (CT) is a significant and growing contributor to the radiation dose from diagnostic radiology. Australia, with 332 CT scanners (18 per million people), is well endowed with CT equipment compared to European countries (6 to 13 per million people). Only Japan, with 8500 units (78 per million people), has a significantly higher proportion of CT scanners. In view of this, a survey of CT facilities, frequency of examinations, techniques and patient doses has been performed in Australia. It is estimated that there are 1 million CT examinations in Australia each year, resulting in a collective effective dose of 7000 Sv and a per caput dose of 0.39 mSv. This per caput dose is much larger than found in earlier studies in the UK and New Zealand but is less than 0.48 mSv in Japan. Using the ICRP risk factors, radiation doses from CT could be inducing about 280 fatal cancers per year in Australia. CT is therefore a significant, if not the major, single contributor to radiation doses and possible risk from diagnostic radiology. (authors)

  9. Quantitative investigations of megavoltage computed tomography

    Rogers, Myron; Kerr, Andrew; Salomons, Greg; Schreiner, L. John

    2005-04-01

    Megavoltage computed tomography (MVCT) has been an active area of research and development in image guided radiation therapy. We have been investigating a particular implementation of MVCT in conjunction with studies of the potential for tomotherapy with a Cobalt-60 radiation source. In this paper, we present results comparing MVCT using a Co-60 source and a 4 MV linear accelerator to conventional kVCT imaging. The Co-60 and linac MVCT measurements were obtained with a first generation benchtop CT imager; the KVCT measurements were obtained using a Philips AcQSim CT Simulator). Phantoms containing various inserts ranging in density from air, through lung, soft tissue and bone equivalent materials and extending to high atomic number metals were imaged with the three modalities. The results enable characterization of image artifacts, CT number linearity and beam hardening. The MVCT images have sufficient contrast that soft tissue regions with 2.8% difference in electron density can be visualized. In MVCT, a linear relationship between CT numbers and electron densities extends to materials with Z ~ 60. In the 4MV CT imaging there is a position dependence of the CT numbers within a uniform water phantom, which is absent in Co-60 CT images, indicating the presence of beam hardening artifacts in the linac MVCT images. The differences between kVCT and MVCT will be discussed considering the variation of the photon interactions dominating the images. Our investigations indicate that MVCT has properties that may potentially extend its utility beyond radiation therapy.

  10. Computed Tomography Following Body Stuffing Heroin

    Sean P. Nordt

    2015-12-01

    Full Text Available A 37-year-old male presented to the emergency department (ED in police custody for “medical clearance” before being taken to jail. The patient was approached by police officers for suspicion of selling illicit drugs. When approached by police he ran away and was witnessed to swallow several small plastic baggies suspected to contain heroin. He was apprehended and brought to the ED. On arrival, he was asymptomatic with a blood pressure 144/83mmHg, heart rate 67bpm, respiratory rate of 19bpm, oxygen saturation of 99% on room air and afebrile. A Glasgow coma score was 15 and he was alert and oriented to person, place and time. Patient had a negative review of systems. On physical examination pupils were 4mm and reactive to light, lungs clear to auscultation and had normal respiratory rate with normal cardiovascular exam. Abdomen was soft, non-tender and non-distended with present bowel sounds. The patient admitted to ingesting approximately 20 packets of heroin to avoid being charged with possession. The patient declined activated charcoal and whole bowel irrigation (WBI with polyethylene glycol-electrolyte solution (PEG-ELS. The patient declined a urine toxicology immunoassay screen. A computed tomography (CT of his abdomen with contrast was obtained and read as normal except for a cluster of foreign bodies within the distal stomach likely contained within a plastic bag.

  11. Computed tomography findings in fibrosing mediastinitis

    Devaraj, A. [Departments of Radiology, Royal Brompton Hospital, London (United Kingdom)]. E-mail: a.devaraj@rbht.nhs.uk; Griffin, N. [Department of Radiology, Chelsea and Westminster Hospital, London (United Kingdom); Nicholson, A.G. [Department of Histopathology, Royal Brompton Hospital, London (United Kingdom); Padley, S.P.G. [Departments of Radiology, Royal Brompton Hospital, London (United Kingdom)

    2007-08-15

    Aim: To describe the CT features of fibrosing mediastinitis. Materials and methods: The clinical notes, histology, and CT images from 12 patients with fibrosing mediastinitis were reviewed. Clinical data regarding the presentation and suspected aetiology were correlated with location of mediastinal disease, calcification, effect on mediastinal structures, and additional pulmonary findings on computed tomography (CT). Results: The mean age was 40.5 years, with seven female and five male patients. The most common presenting symptom was shortness of breath. Fibrosing mediastinitis diffusely infiltrated the mediastinum in five patients and was localized in seven. Calcification was present in two cases. Eleven of 12 cases had narrowing of mediastinal structures, including five with pulmonary artery narrowing, five with superior vena cava obstruction, four with bronchial narrowing, three with tracheal narrowing, and one with narrowing of the pulmonary vein. The disease was considered idiopathic in seven cases with a demonstrable aetiology in five cases. Eight out of 12 patients had additional pulmonary findings, including all patients with a known aetiology. Conclusions: In the present series of patients, fibrosing mediastinitis more commonly presented as a localized mediastinal mass than as diffuse mediastinal disease, with the anterior mediastinal compartment most frequently involved. Most cases were idiopathic compared with the majority of previous cases at this institution being ascribed to tuberculosis. There is a high incidence of concomitant pulmonary findings, in particular when an identifiable aetiology is present. Obstruction of vital structures frequently gives rise to complications.

  12. Computed tomography findings in pancreas divisum

    In 29 patients with abdominal pain the diagnosis of pancreas divisum (PD) was verified by endoscopic retrograde pancreatography (EPR) via both the major and the minor papilla. Computed tomography (CT) was done in all patients to evaluate contour, volume, antero-posterior diameters and attenuation values of the gland in comparison with a normal reference series. Also, the validity of the CT grading of pancreatitis was assessed in comparison with ERP grading. Patients with PD had an increased cranio-caudal diameter of the pancreatic head (p<0.001). Further, the main pancreatic duct was visualized more often in patients with PD (p<0.01), who also had an increasing frequency of pancreatic calcifications (p<0.05). Otherwise there were no differences compared with the normal series. The observed reduction in the volume of the gland in patients with marked pancreatitis at ERP seemingly reflected the severity of inflammation. No cleavage between the dorsal and ventral anlage was identified. CT was found to be too unspecific to be of any use in grading of pancreatitis. In conclusion, CT findings in patients with PD are sparse, unspecific and preferably a reflection of pancreatitis, if present. ERP remains the ''gold standard'' for the diagnosis. (orig.)

  13. Computed tomography phantom for radiochromic film dosimetry

    To evaluate in detail the dose distribution during computed tomography (CT), a sheet roll CT dosimetry phantom (SRCT-P) with a radiochromic film (RF) was experimentally developed. The SRCT-P was made by rolling up a vinyl chloride sheet in a cylindrical shape to arbitrarily select the SRCT-P diameter, dose measurement position, and depth. The SRCT-P centre core consisted of a plastic hose in which a 10 mm acrylic bar with a RF was inserted. To determine the availability of the SRCT-P, the surface and centre doses (at a 5 mm radius) at each SRCT-P diameter (6-16 cm; every 2 cm) were measured. The ratios of the centre-to-surface doses (Dcentre/Dsuface) systematically increased, from 80 to 111%, for decreasing SRCT-P diameters, between 16 and 6 cm, respectively. The centre dose approached the surface dose as the SRCT-P diameter decreased. To use a RF for a CT dose measurement, further detailed research and analysis is necessary. However, this study has shown that a SRCT-P is useful and beneficial for the measurement of the dose distribution during a CT examination

  14. Computed tomography imaging and angiography - principles.

    Kamalian, Shervin; Lev, Michael H; Gupta, Rajiv

    2016-01-01

    The evaluation of patients with diverse neurologic disorders was forever changed in the summer of 1973, when the first commercial computed tomography (CT) scanners were introduced. Until then, the detection and characterization of intracranial or spinal lesions could only be inferred by limited spatial resolution radioisotope scans, or by the patterns of tissue and vascular displacement on invasive pneumoencaphalography and direct carotid puncture catheter arteriography. Even the earliest-generation CT scanners - which required tens of minutes for the acquisition and reconstruction of low-resolution images (128×128 matrix) - could, based on density, noninvasively distinguish infarct, hemorrhage, and other mass lesions with unprecedented accuracy. Iodinated, intravenous contrast added further sensitivity and specificity in regions of blood-brain barrier breakdown. The advent of rapid multidetector row CT scanning in the early 1990s created renewed enthusiasm for CT, with CT angiography largely replacing direct catheter angiography. More recently, iterative reconstruction postprocessing techniques have made possible high spatial resolution, reduced noise, very low radiation dose CT scanning. The speed, spatial resolution, contrast resolution, and low radiation dose capability of present-day scanners have also facilitated dual-energy imaging which, like magnetic resonance imaging, for the first time, has allowed tissue-specific CT imaging characterization of intracranial pathology. PMID:27432657

  15. Industrial computed tomography image size measurement

    As one of the most useful modern detection technologies, Industrial Computed Tomography (ICT) image size measurement can correctly non-destructively measure the size of workpieces' inner construction, and it is considered as the standard for quality assurance and reverse engineering. In view of the advantages and disadvantages compared to conventional methods, this paper improves the precision of image size measurement with a new algorithm that uses an approximate function to describe edge degradation. First, this algorithm constructs the approximate function and determines the optimal point of edge detection, based on image intensity and inflexions. Then, in order to accurately extract the image edge, this algorithm is used to revise the primary image, completing construction of the CT image. Excellent results are obtained from simulations and experiments. The experimental results indicate that the relative error is 2% for the CT image when the step evolution of the image edge is pooled. The relative error of this method is decreased by as much as 1.5% compared to wavelet transformation and ridgelet transformation. Therefore, this new algorithm demonstrates increased effectiveness in extracting an accurate measurement of the CT image edge.

  16. Dedicated breast computed tomography: Basic aspects

    Sarno, Antonio; Mettivier, Giovanni, E-mail: mettivier@na.infn.it; Russo, Paolo [Dipartimento di Fisica, Università di Napoli Federico II, Via Cintia, Napoli I-80126, Italy and INFN Sezione di Napoli, Napoli I-80126 (Italy)

    2015-06-15

    X-ray mammography of the compressed breast is well recognized as the “gold standard” for early detection of breast cancer, but its performance is not ideal. One limitation of screening mammography is tissue superposition, particularly for dense breasts. Since 2001, several research groups in the USA and in the European Union have developed computed tomography (CT) systems with digital detector technology dedicated to x-ray imaging of the uncompressed breast (breast CT or BCT) for breast cancer screening and diagnosis. This CT technology—tracing back to initial studies in the 1970s—allows some of the limitations of mammography to be overcome, keeping the levels of radiation dose to the radiosensitive breast glandular tissue similar to that of two-view mammography for the same breast size and composition. This paper presents an evaluation of the research efforts carried out in the invention, development, and improvement of BCT with dedicated scanners with state-of-the-art technology, including initial steps toward commercialization, after more than a decade of R and D in the laboratory and/or in the clinic. The intended focus here is on the technological/engineering aspects of BCT and on outlining advantages and limitations as reported in the related literature. Prospects for future research in this field are discussed.

  17. Intraperitoneal tuberculous abscess: computed tomography features

    Peng; Dong; Jing-Jing; Chen; Xi-Zhen; Wang; Ya-Qin; Wang

    2015-01-01

    AIM: To evaluate the computed tomography(CT) features of intraperitoneal tuberculous abscess(IPTA). METHODS: Eight patients with IPTA confirmed by pathology were analyzed retrospectively. The clinical symptoms, medical images, and surgical findings were evaluated. Involvement of the intestine, peritoneum, viscera, and lymph nodes was also assessed. RESULTS: All 8 patients had a history of abdominal discomfort for 1 to 6 mo. Physical examination revealed a palpable abdominal mass in 6 patients. Three patients had no evidence of pulmonary tuberculosis(TB). All IPTAs(11 abscesses) were seen as a multiseptated, peripherally enhanced, hypodense mass with enlarged, rim-enhanced lymph nodes. The largest abscess diameter ranged from 4.5 cm to 12.2 cm. CT showed 2 types of IPTA: Lymph node fusion and encapsulation. Of the 8 patients, one had liver tuberculosis and one had splenic and ovarian tuberculosis. Two cases showed involvement of the terminal ileum and ileocecal junction. Ascites were found in 4 cases. Three patients had peritonitis and mesenteritis. Three patients showed involvement of the omentum. Three patients had histological evidence of caseating granuloma, and 5 had histological evidence of acid-fast bacilli. CONCLUSION: CT is crucial in the detection and characterization of IPTA. Certain CT findings are necessary for correct diagnosis.

  18. Computed tomography of the ovarian tumors

    Computed tomography (CT) provides valuable informations in the diagnosis of the female pelvic masses. CT findings of 109 cases of surgically proved ovarian masses were reviewed regarding number, size, contour, and internal consistency (cystic, solid, and mixed masses). Differentiation between malignant and benign ovarian tumors depended on number and internal consistency of the mass. Most of malignant tumors showed bilateral mixed or solid masses and contained solid components. Most of metastatic ovarian cancer were demonstrated as bilateral mixed or solid masses. They were able to be differentiated from primary ovarian cancer because metastatic tumors contained more solid components than primary ones did and had ill-defined margins between cystic and solid components in mixed masses. In benign ovarian tumors, differentiation between mucinous cystadenomas, endometrial cysts, and dermoid cysts were possible. Mucinous cystadenomas showed the largest mulilocular cystic masses with band like septal thickening and their each locule demonstrated different densities. Endometrial cysts showed uni- or bilocular cystic masses with thick wall. Dermoid cysts were characterized by the presence of fatty component. It was concluded that CT is very useful in the tissue characterization of the ovarian masses by specific CT findings. (author)

  19. Perfusion computed tomography in renal cell carcinoma

    Chandan; J; Das; Usha; Thingujam; Ananya; Panda; Sanjay; Sharma; Arun; Kumar; Gupta

    2015-01-01

    Various imaging modalities are available for the diagnosis, staging and response evaluation of patients with renal cell carcinoma(RCC). While contrast enhanced computed tomography(CT) is used as the standard of imaging for size, morphological evaluation and response assessment in RCC, a new functional imaging technique like perfusion CT(p CT), goes down to the molecular level and provides new perspectives in imaging of RCC. p CT depicts regional tumor perfusion and vascular permeability which are indirect parameters of tumor angiogenesis and thereby provides vital information regarding tumor microenvironment. Also response evaluation using p CT may predate the size criteria used in Response Evaluation Criteria in Solid Tumors, as changes in the perfusion occurs earlier following tissue kinase inhibitors before any actual change in size. This may potentially help in predicting prognosis, better selection of therapy and more accurate and better response evaluation in patients with RCC. This article describes the techniques and role of p CT in staging and response assessment in patients with RCCs.

  20. Dose profile in computed tomography chest scan

    For the optimization of the patient dose in computed tomography (CT), the Brazilian legislation only established the diagnostic reference levels (DRL's) in terms of Multiple Scan Average Dose (MSAD) in a typical adult as a parameter of quality control of CT scanners. Conformity to the DRL's can be verified by measuring the dose distribution in CT scans and MSAD determination. An analysis of the quality of CT scans of the metropolitan region of Belo Horizonte is necessary by conducting pertinent tests to the study that are presented in the ANVISA (National Agency of Sanitary Vigilance) Guide. The purpose of this study is to investigate, in a chest scan, the variation of dose in CT. To measure the dose profile are used lithium fluoride thermoluminescent dosimeters (TLD-100 Rod) distributed in cylinders positioned in peripheral and central regions of a phantom of polymethylmethacrylate (PMMA). The data obtained allow us to observe the variation of the dose profile inside the phantom. The peripheral region shows higher dose values than the central region. The longitudinal variation can be observed and the maximum dose was recorded at the edges of the phantom (41,58±5,10) mGy at the midpoint of the longitudinal axis. The results will contribute to disseminate the proper procedure and optimize the dosimetry and the tests of quality control in CT, as well as make a critical analysis of the DRL's. (author)

  1. Computed tomography findings in middle ear anomaly

    The efficacy of computed tomography (CT) of the temporal bone was studied in 45 ears with a middle ear anomaly but whose tympanic membranes were normal. The plane of the film was 30 degrees oblique to the orbito-meatal line. Four otorhinolaryngologists made radiological diagnoses of the CT film without having any information about the patients. CT films of 40 normal ears were also evaluated and served as controls. The incudo-stapedial joint (I-S joint) and the stapes were visualized in all control group subjects. The percentage of correct diagnoses was 77.8% for separation of the I-S joint, and 75.6% for fixation of the stapes. The monopedal stapes was not visualized. Fixation of the malleus and the incus could not be diagnosed correctly. Abnormalities in the location of the facial nerve were visualized in a few ears. CT of the temporal bone was clinically useful for differentiating I-S joint separation and fixation of the stapes. (author)

  2. Computed tomography of the alveolar bone

    In addition to the conventional radiological methods used in odontology, computed tomography (CT) provides superposition-free images of the mandible and maxilla. Its value has been proved not only in cases of malignancy but also in many other problems. If an examination is performed with a slice thickness of less than 1.5 mm, the form and position of retained teeth in the alveolar bone, as well as subsequent lesions of neighboring permanent teeth, can be visualized so that early treatment can be planned. If the parodontal space of a retained tooth is visible, orthodontic intervention is possible. Precise assessment of horizontal or vertical bone loss is essential in inflammatory dental diseases. The morphology and extent of benign cystic lesions are also shown by CT. With CT surgical strategy of an intended implant therapy can take into account the remaining bone substance and the exact position of nerves and foramina. If such therapy is possible, the location, form and number of implants are easily defined. (orig.)

  3. Computed tomography and magnetic resonance colonography

    Colon cancer is the second leading cause of cancer death in the western world. Adenomatous colorectal polyps, which are found in 30-50% of Americans more than 50 years old, are recognized as important precursors of malignancy. Probably most of the invasive colon carcinomas arise from polyps. For this reason an early detection of these polyps and their complete removal is a recognized strategy for the prevention of colon cancer. So far no single method for an early diagnois of colon polyps or colon cancer offers high sensitivity and specificity along with low cost and good patient accccf Endo-opic colonoscopy allows the accurate detection of very small lesions and has since almost completely replaced fluooscopy. Cross-sectional imaging techniques, including magnetic resonance imaging (MRI) and computed tomography (CT), are increasingly being considered imaging modalities for the detection of colorectal polyps. CT and MR colonography are new techniques for imaging of the colon. In symptomatic patients, these new techniques show promising results for the detection of polyps equal to or larger than 1 cm in diameter. (author)

  4. Computed tomography experiments of Pantex high explosives

    Perkins, D. E.; Martz, H. E.; Hester, L. O.; Sobczak, G.; Pratt, C. L.

    1992-04-01

    X-ray computed tomography is an advanced imaging technique which provide three-dimensional nondestructive characterization of materials, components and assemblies. The CT Project group at Lawrence Livermore National Laboratory (LLNL) and the Pantex Plant are cooperating to examine the use of CT technology to inspect and characterize high-explosives pressings (e.g., PBX-9502, LX-10-2). High-explosives pressings manufactured by Pantex must be characterized prior to assembling into weapons systems; a nondestructive examination of all assembly parts would be preferable to the current sampling and destructive testing. The earlier in the processing cycle this can be done the more cost effective it will be. We have performed experiments that show that this characterization can be performed at the pressed billet stage using CT. We have detected 2-mm inclusions in a 15-cm diameter billet and 3.5-mm voids in a 20-cm diameter billet. Based on these results we show calculations that can be used to design production CT systems for characterization of high-explosives.

  5. Nano-computed tomography. Technique and applications

    Nano-computed tomography (nano-CT) is an emerging, high-resolution cross-sectional imaging technique and represents a technical advancement of the established micro-CT technology. Based on the application of a transmission target X-ray tube, the focal spot size can be decreased down to diameters less than 400 nanometers (nm). Together with specific detectors and examination protocols, a superior spatial resolution up to 400 nm (10 % MTF) can be achieved, thereby exceeding the resolution capacity of typical micro-CT systems. The technical concept of nano-CT imaging as well as the basics of specimen preparation are demonstrated exemplarily. Characteristics of atherosclerotic plaques (intraplaque hemorrhage and calcifications) in a murine model of atherosclerosis (ApoE(-/-)/LDLR(-/-) double knockout mouse) are demonstrated in the context of superior spatial resolution in comparison to micro-CT. Furthermore, this article presents the application of nano-CT for imaging cerebral microcirculation (murine), lung structures (porcine), and trabecular microstructure (ovine) in contrast to micro-CT imaging. This review shows the potential of nano-CT as a radiological method in biomedical basic research and discusses the application of experimental, high resolution CT techniques in consideration of other high resolution cross-sectional imaging techniques.

  6. Computed Tomography Findings in Xanthogranulomatous Pyelonephritis

    Arumugam Rajesh

    2011-01-01

    Full Text Available Background: Xanthogranulomatous pyelonephritis (XGN is an uncommon condition characterized by chronic suppurative renal inflammation that leads to progressive parenchymal destruction. Purpose: To review the computed tomography (CT findings of patients diagnosed with XGN. Materials and Methods: A retrospective review of CT findings in patients with histologically proven XGN was carried out. Results: Thirteen CT examinations of 11 patients were analyzed. Renal enlargement was demonstrable on the affected side in all patients. Nine patients (82% had multiple dilated calyces and abnormal parenchyma. Six patients (55% had a renal pelvis or upper ureteric calculus causing obstruction. Three patients (27% had focal fat deposits identifiable within the inflamed renal parenchyma. Two patients had renal abscesses. Ten patients (91% had extrarenal extension of the inflammatory changes. Three patients (27% demonstrated extensive retroperitoneal inflammation. Conclusion: Unilateral renal enlargement and inflammation were the most consistent findings of XGN on CT. Perinephric inflammation and collections or abscess should also alert the radiologist to the possibility of this diagnosis.

  7. Dynamic X-ray computed tomography

    Paper Dynamic computed tomography (CT) imaging aims at reconstructing image sequences where the dynamic nature of the living human body is of primary interest. Main concerned applications are image-guided interventional procedures, functional studies and cardiac imaging. The introduction of ultra-fast rotating gantries along with multi-row detectors and in near future area detectors allows a huge progress toward the imaging of moving organs with low-contrast resolution. This paper gives an overview of the different concepts used in dynamic CT. A new reconstruction algorithm based on a voxel-specific dynamic evolution compensation is also presented. It provides four-dimensional image sequences with accurate spatio-temporal information, where each frame is reconstructed using a long-scan acquisition mode on several half-turns. In the same time, this technique permits to reduce the dose delivered per rotation while keeping the same signal to noise ratio for every frame using an adaptive motion-compensated temporal averaging. Results are illustrated on simulated data. (authors)

  8. Relevance of computed tomography in gynecological tumors

    Hagemann, J.R.; Hagemann, J.

    1983-11-01

    1. Abdominal CT examination is the method of choice when examining ovarial tumours. 2. Abdominal CT is redundant in the early stages of carcinoma of the collum and if the carcinoma has penetrated into the vagina. 3. In advanced stages of carcinoma of the collum, CT enables accurate staging. CT is at least equal in relevance to gynecological examination in respect of assessment of parametraneous infiltration. Distant metastases, as well as complications of the efferent urinary tract can be visualized. In view of this, the following procedure appears meaningful in advanced carcinoma of the collum: First of all, gynecological examination is performed without anaesthesia to confirm the findings in the regions of the portio and vagina; as far as possible, the existence of the central parametraneous infiltrations is confirmed. For the purpose of further staging of the parametraneous infiltration, as well as of the paraaortal lymphomas and possible metastases, as well as for the purpose of excluding hydronephrosis, computed tomography is performed. This avoids burdening the patient with an examination under anaesthesia, and it also avoids invasive examination methods, such as urography and lymphography.

  9. Relevance of computed tomography in gynaecological tumors

    1. Abdominal CT examination is the method of choice when examining ovarial tumours. 2. Abdominal CT is redundant in the early stages of carcinoma of the collum and if the carcinoma has penetrated into the vagina. 3. In advanced stages of carcinoma of the collum, CT enables accurate staging. CT is at least equal in relevance to gynaecological examination in respect of assessment of parametraneous infiltration. Distant metastases, as well as complications of the efferent urinary tract can be visualized. In view of this, the following procedure appears meaningful in advanced carcinoma of the collum: First of all, gynaecological examination is performed without anaesthesia to confirm the findings in the regions of the portio and vagina; as far as possible, the existence of the central parametraneous infiltrations is confirmed. For the purpose of further staging of the parametraneous infiltration, as well as of the paraaortal lymphomas and possible metastases, as well as for the purpose of excluding hydronephrosis, computed tomography is performed. This avoids burdening the patient with an examination under anaesthesia, and it also avoids invasive examination methods, such as urography and lymphography. (orig.)

  10. Variations in measured computed tomography number values

    Computed Tomography (CT) scans of a water phantom have been performed on a number of different CT scanners, and variations in the measured mean pixel value for a central region have been observed. In addition, a positional variation of mean CT number was noted. In particular, the head rest on an EMI CT1010 scanner had a significant effect on the pixel values. To simulate head scanning, a phantom with a Teflon annulus surrounding a water bath was used. This annulus affected both the mean and standard deviation of the pixels in a central area of the scan. Both an mAS and beam width dependence on CT numbers was noted. The effect of calibration on the measured CT numbers for each reconstruction filter was examined on one machine. The variation of CT number with reconstruction matrix and compensation filter was also investigated. These measurements suggest caution must be exercised when interpreting actual CT number values. This will be particularly relevant when the numbers are used to differentiate between tissue types for diagnostic or therapeutic purposes. (author)

  11. Single photon emission computed tomography (SPECT)

    The functional state of organs can be imaged by their accumulation of single photon emitter like 99mTc (γ-ray energy 140 keV), 201Tl (73 keV) and 201I (159 keV) with computed tomography. The emitted γ-ray is collimated to reach the NaI (Tl) detector for specifying its direction, which is called as the scintillation camera or gamma camera. The camera rotating around the patient gives the SPECT images. The NaI (Tl) detector is suitable for converting 60-300 keV γ-ray to fluorescence through the photoelectric effect. Photomultiplier receiving the fluorescence outputs X/Y signals for the emitting position and Z signal (energy) separately, giving imaging data. 3D images can be re-constructed by either method of the filtered back projection or maximum likelihood-expectation maximization. For quantitative reconstruction, correction of γ-ray absorption in water, of scattering and of collimator opening is necessary. Recently, semiconductor-detectors like CdZnTe and CdTe are being utilized in place of NaI for better resolution, which will reduce the size of the camera. Further, a camera with coincidence circuit for positron has appeared and will be applicable for both SPECT and PET. Compton camera having 2-step detectors without collimator is now under development. (N.I.)

  12. Perfusion computed tomography in renal cell carcinoma.

    Das, Chandan J; Thingujam, Usha; Panda, Ananya; Sharma, Sanjay; Gupta, Arun Kumar

    2015-07-28

    Various imaging modalities are available for the diagnosis, staging and response evaluation of patients with renal cell carcinoma (RCC). While contrast enhanced computed tomography (CT) is used as the standard of imaging for size, morphological evaluation and response assessment in RCC, a new functional imaging technique like perfusion CT (pCT), goes down to the molecular level and provides new perspectives in imaging of RCC. pCT depicts regional tumor perfusion and vascular permeability which are indirect parameters of tumor angiogenesis and thereby provides vital information regarding tumor microenvironment. Also response evaluation using pCT may predate the size criteria used in Response Evaluation Criteria in Solid Tumors, as changes in the perfusion occurs earlier following tissue kinase inhibitors before any actual change in size. This may potentially help in predicting prognosis, better selection of therapy and more accurate and better response evaluation in patients with RCC. This article describes the techniques and role of pCT in staging and response assessment in patients with RCCs. PMID:26217456

  13. Ruptured ectopic pregnancy diagnosed with computed tomography

    The rupture of ectopic pregnancy (EP) still remains the primary and direct cause of death in the first trimester of pregnancy. Ultrasonography is known to be a modality of choice in EP diagnostics. We found a severe discrepancy between the frequency of ectopic pregnancies (EP) and the number of available computed tomography (CT) examinations. A 29-year-old woman was admitted to the emergency department with a history of abdominal pain, nausea, vomiting and collapse. Sonographic findings of a suspected EP were unclear. Moreover, not all features of intrauterine pregnancy were present. Due to the patient’s life-threatening condition, an emergency multi-slice CT with MPR and VRT reconstructions was performed, revealing symptoms of a ruptured EP. In the right adnexal area, a well-vascularized, solid-cystic abnormal mass lesion was found. Intraperitoneal hemorrhage was confirmed intraoperatively, and the right fallopian tube with a tubal EP was resected. In the surgery in situ, as well as in the pathological examination of the tumor mass, a human embryo of approximately 1.5 cm in length (beginning of the 8th week of gestation) was found. Although ultrasonography still remains the first-line imaging examination in EP diagnostics, sometimes the findings of suspected EPs are unclear and not sufficient. The rupture of EP, with serious bleeding and symptoms of shock, may require an emergent pelvic and abdominal CT inspection. A clear correlation was found between the macroscopic CT images and the intraoperatively sampled material

  14. Dedicated breast computed tomography: Basic aspects

    X-ray mammography of the compressed breast is well recognized as the “gold standard” for early detection of breast cancer, but its performance is not ideal. One limitation of screening mammography is tissue superposition, particularly for dense breasts. Since 2001, several research groups in the USA and in the European Union have developed computed tomography (CT) systems with digital detector technology dedicated to x-ray imaging of the uncompressed breast (breast CT or BCT) for breast cancer screening and diagnosis. This CT technology—tracing back to initial studies in the 1970s—allows some of the limitations of mammography to be overcome, keeping the levels of radiation dose to the radiosensitive breast glandular tissue similar to that of two-view mammography for the same breast size and composition. This paper presents an evaluation of the research efforts carried out in the invention, development, and improvement of BCT with dedicated scanners with state-of-the-art technology, including initial steps toward commercialization, after more than a decade of R and D in the laboratory and/or in the clinic. The intended focus here is on the technological/engineering aspects of BCT and on outlining advantages and limitations as reported in the related literature. Prospects for future research in this field are discussed

  15. Patient doses for computed tomography in Hungary

    The latest initiative of the National Patient Dose Evaluation Program was an overall evaluation of patient doses for computed tomography. The aim of the survey was to collect data from which the patient doses of the CT examination of different body parts can be estimated and the most important technical parameters affecting on the patient exposures can be evaluated. The 54 CT scanners in clinical use in Hungary can be categorized into 31 different models from 8 manufacturers. Per caput frequency for CT is about 62.3 examinations per 1000 inhabitants. 59% of all examinations are connected to the head imaging. The highest mean effective dose arising from the chest and pelvis examinations, 6.98 mSv and 6.64 mSv, respectively. The yearly collective effective dose has been estimated at about 1700 manSv. This total dose is as much as the figure of 1785 manSv previously assessed for photofluorography applied in mass chest screening in Hungary. (author)

  16. Computed tomography with selectable image resolution

    A computed tomography system x-ray detector has a central group of half-width detector elements and groups of full-width elements on each side of the central group. To obtain x-ray attenuation data for whole body layers, the half-width elements are switched effectively into paralleled pairs so all elements act like full-width elements and an image of normal resolution is obtained. For narrower head layers, the elements in the central group are used as half-width elements so resolution which is twice as great as normal is obtained. The central group is also used in the half-width mode and the outside groups are used in the full-width mode to obtain a high resolution image of a body zone within a full body layer. In one embodiment data signals from the detector are switched by electronic multiplexing and in another embodiment a processor chooses the signals for the various kinds of images that are to be reconstructed. (author)

  17. Computed tomography guidance. Fluoroscopy and more

    Although ultrasound and magnetic resonance imaging are competitive imaging modalities for the guidance of needle-based interventions, computed tomography (CT) is the only modality suitable for image-guided interventions in all regions of the body, including the lungs and bone. The ongoing technical development of CT involves accelerated image acquisition, significantly improved spatial resolution, CT scanners with an extended gantry diameter, acceleration of the procedure through joystick control of relevant functions of interventional CT by the interventional radiologist and tube current modulation to protect the hands of the examiner and radiosensitive organs of the patient. CT fluoroscopy can be used as a real-time method (the intervention is monitored under continuous CT fluoroscopy) or as a quick check method (repeated acquisitions of individual CT fluoroscopic images after each change of needle or table position). For the two approaches, multislice CT fluoroscopy (MSCTF) technique with wide detectors is particularly useful because even in the case of needle deviation from the center slice the needle tip is simultaneously visualised in the neighboring slices. With the aid of this technique a precise placement of interventional devices is possible even in angled access routes and in the presence of pronounced respiratory organ movements. As the reduction of CT fluoroscopy time significantly reduces radiation exposure for the patient and staff, the combination of a quick check technique and a low milliampere technique with multislice CT fluoroscopy devices is advantageous. (orig.)

  18. Evolution of Computed Tomography Findings in Secondary Aortoenteric Fistula

    Aortoenteric fistula is a rare but significant clinical entity associated with high morbidity and mortality if remain untreated. Clinical presentation and imaging findings may be subtle and prompt diagnosis can be difficult. Herein, we present a patient who initially presented with abdominal pain and computed tomography showed an aortic aneurysm compressing duodenum without any air bubbles. One month later, the patient presented with gastrointestinal bleeding and computed tomography revealed air bubbles within aneurysm. With a diagnosis of aortoenteric fistula, endovascular aneurysm repair was carried out. This case uniquely presented the computed tomography findings in progression of an aneurysm to an aortoenteric fistula

  19. Abdominal alterations in disseminated paracoccidioidomycosis: computed tomography findings

    Objective: to evaluate the incidence and spectrum of abdominal computed tomography imaging findings in patients with paracoccidioidomycosis. Materials and methods: retrospective analysis of abdominal computed tomography images of 26 patients with disseminated paracoccidioidomycosis. Results: abnormal abdominal tomographic findings were observed in 18 patients (69.2%), while no significant finding was observed in the other 8 (30.8%) patients. Conclusion: computed tomography has demonstrated to play a relevant role in the screening and detection of abdominal abnormalities in patients with disseminated paracoccidioidomycosis. (author)

  20. Computed tomography of the llama head: technique and normal anatomy

    Computed tomography was performed on the head of 6 normal adult llamas. The animals were under general anesthesia and positioned in dorsal recumbency on the scanning table. The area scanned was from the external occipital protuberance to the rostral portion of the nasal passage, and the images are presented in both a bone window and a soft tissue window to allow evaluation and identification of the anatomy of the head. Computed tomography of the llama head can be accomplished by most computed tomography scanners utilizing a technique similar to that used in small animals with minor modification of the scanning table

  1. Diagnosis of hoof disease in horses using computed tomography

    Kovač Milomir

    2002-01-01

    Full Text Available This study describes findings of computed tomography investigations at the Bergische Equine Clinic (Germany of 39 horses with hoof diseaseas. The most frequently findings were the navicular syndrome (eight horses, laminitis (seven horses, keratnoma (six horses and ossification of collateral cartilages in the distal phalanx (four horses. The special value of the computed tomography is in evaluating the size and courses fracture/fissure of the navicular and koffin bones, which were diagnose in five horses. In four of horses no pathologic changes of the hoof were determined by computed tomography.

  2. Abdominal alterations in disseminated paracoccidioidomycosis: computed tomography findings

    Vermelho, Marli Batista Fernandes; Correia, Ademir Silva; Michailowsky, Tania Cibele de Almeida; Suzart, Elizete Kazumi Kuniyoshi; Ibanes, Aline Santos; Almeida, Lanamar Aparecida; Khoury, Zarifa; Barba, Mario Flores, E-mail: marlivermelho@globo.com [Instituto de Infectologia Emilio Ribas (IIER), Sao Paulo, SP (Brazil)

    2015-03-15

    Objective: to evaluate the incidence and spectrum of abdominal computed tomography imaging findings in patients with paracoccidioidomycosis. Materials and methods: retrospective analysis of abdominal computed tomography images of 26 patients with disseminated paracoccidioidomycosis. Results: abnormal abdominal tomographic findings were observed in 18 patients (69.2%), while no significant finding was observed in the other 8 (30.8%) patients. Conclusion: computed tomography has demonstrated to play a relevant role in the screening and detection of abdominal abnormalities in patients with disseminated paracoccidioidomycosis. (author)

  3. Diagnosis of sacral perineural cysts by computed tomography.

    Tabas, J H; Deeb, Z L

    1986-07-01

    Three cases of sacral perineural cysts associated with chronic low-back pain are described with their myelography, computed tomography, and plain film findings. Significant findings include multiple cystic dilatations of lumbosacral nerve root sheaths, enlargement of the sacral foramina by masses isodense with cerebrospinal fluid, and asymmetric epidural fat distribution. Recognition of these findings on unenhanced computed tomography scans should preclude further evaluation by myelography and intrathecal metrizamide (Amipaque) computed tomography. These cysts are usually not the primary cause of back and leg pain. PMID:2942338

  4. Diagnosis of hoof diseases in horses using computed tomography

    This study describes findings of computed tomography investigations at the Bergische Equine Clinic (Bergische Tierklinik), Germany, of 39 horses with hoof diseases. The most frequently findings were the navicular syndrome (eight horses), laminitis (seven horses), keratnoma (six horses) and ossification of collateral cartilages in the distal phalanx (four horses). The special value of the computed tomography is in evaluating the size and courses fracture/fissure of the navicular and koffin bones, which were diagnose in five horses. In four of horses no pathologic changes of the hoof were determined by computed tomography

  5. Calcium score of small coronary calcifications on multidetector computed tomography

    Groen, J M; Kofoed, K F; Zacho, M;

    2013-01-01

    Multi detector computed tomography (MDCT) underestimates the coronary calcium score as compared to electron beam tomography (EBT). Therefore clinical risk stratification based on MDCT calcium scoring may be inaccurate. The aim of this study was to assess the feasibility of a new phantom which...

  6. Recurrent ovarian endodermal sinus tumor: demonstration by computed tomography, magnetic resonance imaging, and positron emission tomography

    We report a case of recurrent endodermal sinus tumor of the ovary that was identified and/or clearly depicted by computed tomography, magnetic resonance imaging, and positron emission tomography. The potential roles of various imaging modalities in the detection of recurrent endodermal sinus tumor are discussed. (orig.)

  7. Fluorine-18 fluorodeoxyglucose positron emission tomography-computed tomography in evaluation of residual intramuscular myxoma

    Intramuscular myxoma (IM) is a rare benign neoplasm. In a patient diagnosed with IM of left thigh, we report the utility of a postoperative fluorine-18 fluorodeoxyglucose positron emission tomography-computed tomography scan in assessing the efficacy of surgical excision

  8. Positron emission tomography-computed tomography has a clinical impact for patients with cervical cancer

    Sandvik, Rikke Mulvad; Jensen, Pernille Tine; Hendel, Helle Westergren;

    2011-01-01

    Many studies have found that positron emission tomography-computed tomography (PET-CT) has a high sensitivity and specificity in the identification of metastasis in cervical cancer. Herlev Hospital, Denmark, has been performing PET-CTs in stage I-IV cervical cancer since 1 May 2006. The present...

  9. Volumetric evaluation of dual-energy perfusion CT by the presence of intrapulmonary clots using a 64-slice dual-source CT

    Okada, Munemasa; Nakashima, Yoshiteru; Kunihiro, Yoshie; Nakao, Sei; Matsunaga, Naofumi [Dept. of Radiology, Yamaguchi Univ. Graduate School of Medicine, Yamaguchi (Japan)], e-mail: radokada@yamaguchi-u.ac.jp; Morikage, Noriyasu [Medical Bioregulation Dept. of Organ Regulatory Surgery, Yamaguchi Univ. Graduate School of Medicine, Yamaguchi (Japan); Sano, Yuichi [Dept. of Radiology, Yamaguchi Univ. Hospital, Yamaguchi (Japan); Suga, Kazuyoshi [Dept. of Radiology, St Hills Hospital, Yamaguchi (Japan)

    2013-07-15

    Background: Dual-energy perfusion CT (DE{sub p}CT) directly represents the iodine distribution in lung parenchyma and low perfusion areas caused by intrapulmonary clots (IPCs) are visualized as low attenuation areas. Purpose: To evaluate if volumetric evaluation of DE{sub p}CT can be used as a predictor of right heart strain by the presence of IPCs. Material and Methods: One hundred and ninety-six patients suspected of having acute pulmonary embolism (PE) underwent DE{sub p}CT using a 64-slice dual-source CT. DE{sub p}CT images were three-dimensionally reconstructed with four threshold ranges: 1-120 HU (V{sub 120}), 1-15 HU (V{sub 15}), 1-10 HU (V{sub 10}), and 1-5 HU (V{sub 5}). Each relative ratio per V{sub 120} was expressed as the %V{sub 15}, %V{sub 10}, and %V{sub 5}. Volumetric data-sets were compared with D-dimer, pulmonary arterial (PA) pressure, right ventricular (RV) diameter, RV/left ventricular (RV/LV) diameter ratio, PA diameter, and PA/aorta (PA/Ao) diameter ratio. The areas under the ROC curves (AUCs) were examined for their relationship to the presence of IPCs. This study was approved by the local ethics committee. Results: PA pressure and D-dimer were significantly higher in the patients who had IPCs. In the patients with IPCs, V{sub 15}, V{sub 10}, V{sub 5}, %V{sub 15}, %V{sub 10}, and %V{sub 5} were also significantly higher than those without IPC (P = 0.001). %V{sub 5} had a better correlation with D-dimer (r = 0.30, P < 0.001) and RV/LV diameter ratio (r = 0.27, P < 0.001), and showed a higher AUC (0.73) than the other CT measurements. Conclusion: The volumetric evaluation by DE{sub p}CT had a correlation with D-dimer and RV/LV diameter ratio, and the relative ratio of volumetric CT measurements with a lower attenuation threshold might be recommended for the analysis of acute PE.

  10. The Use of GPUs for Solving the Computed Tomography Problem

    A.E. Kovtanyuk

    2014-07-01

    Full Text Available Computed tomography (CT is a widespread method used to study the internal structure of objects. The method has applications in medicine, industry and other fields of human activity. In particular, Electronic Imaging, as a species CT, can be used to restore the structure of nanosized objects. Accurate and rapid results are in high demand in modern science. However, there are computational limitations that bound the possible usefulness of CT. On the other hand, the introduction of high-performance calculations using Graphics Processing Units (GPUs provides improving quality and performance of computed tomography investigations. Moreover, parallel computing with GPUs gives significantly higher computation speeds when compared with (Central Processing Units CPUs, because of architectural advantages of the former. In this paper a computed tomography method of recovering the image using parallel computations powered by NVIDIA CUDA technology is considered. The implementation of this approach significantly reduces the required time for solving the CT problem.

  11. Computed Tomography diagnosis of skeletal involvement in multiple myeloma

    The authors assess the role of Computed Topography in the diagnosis and management of multiple myeloma (MM) and investigate if Computed Tomography findings can influence the clinical approach, prognosis and treatment. 273 multiple myeloma patients submitted to Computed Tomography June 1994, to December, 1996. The patients were 143 men and 130 women (mean age: 65 years): 143 were stage I, 38 stage II and 92 stage III according to Durie and Salomon's clinical classification. All patients were submitted to blood tests, spinal radiography and Computed Tomography, the latter with serial 5-mm scans on several vertebral bodies. Computed Tomography despicted vertebral arch and process involvement in 3 cases with the vertebral pedicle sign. Moreover, Computed Tomography proved superior to radiography in showing the spread of myelomatous masses into the soft tissues in a case with solitary permeative lesion in the left public bone, which facilitated subsequent biopsy. As for extraosseous localizations, Computed Tomography demonstrated thoracic soft tissue (1 woman) and pelvic (1 man) involvement by myelomtous masses penetrating into surrounding tissues. In our series, only a case of osteosclerotic bone myeloma was observed in the pelvis, associated with lytic abnormalities. Computed Tomography findings do not seem to improve the clinical approach and therapeutic management of the disease. Nevertheless, the authors reccommend Computed Tomography for some myelomatous conditions, namely: a) in the patients with focal bone pain but normal skeletal radiographs; b) in the patients with M protein, bone marrow plasmocytosis and back pain, but with an incoclusive multiple myeloma diagnosis; c) to asses bone spread in the regions which are anatomically complex or difficult to study with radiography and to depict soft tissue involvement; d) for bone biopsy

  12. Dose modulated computed tomography automated dosimetry

    Full text: Computed Tomography (CT) scans contribute a significant portion of the effective radiation dose from medical procedures and generally large effective radiation doses per diagnostic examination. With the advent of Multislice CT, the potential for large radiation exposures increased. This combined with the appeal of the resultant isotropic imaging and the increasing number of applications for which CT could be utilised (including screening procedures) has further increased the need for vigilant monitoring of CT protocols and use with respect to radiation dose. The introduction of dose modulated Computed Tomography has proven an effective method for reducing patient dose and is now widely used by CT manufacturers. This involves lowering the mA when scanning through anatomical regions which do not require a large mA. Many CT investigations now utilise dose modulation. Some of these studies will include over 900 images for which the mA and occasionally other factors could vary. In order to utilise the existing software to perform CT dosimetry a program has been written to automatically extract scan parameters from CT dicom image files and apply the ImPACT CT Patient Dosimetry Calculator, for slices with differing factors. Matlab has been used to write and compile a program which sorts through a folder of dicom images and extracts the appropriate dicom header information. Some manufacturers store different series and reformatted images all within the same folder. The images of the CT study for which the dosimetry is to be performed must be stored within the one folder and must be in a dicom format. The program has been written to accommodate several manufacturers, which all contain different information in their dicom headers. The Matlab program groups the various study/image types, extracting the relevant dicom header information, which is written to an Excel worksheet. An Excel file uses this information to run the ImPACT CT Patient Dosimetry Calculator with

  13. Radiological protection in paediatric computed tomography

    It is well known that paediatric patients are generally at greater risk for the development of cancer per unit of radiation dose compared with adults, due both to the longer life expectancy for any harmful effects of radiation to manifest, and the fact that developing organs and tissues are more sensitive to the effects of radiation. Multiple computed tomography (CT) examinations may cumulatively involve absorbed doses to organs and tissues that can sometimes approach or exceed the levels known from epidemiological studies to significantly increase the probability of cancer development. Radiation protection strategies include rigorous justification of CT examinations and the use of imaging techniques that are non-ionising, followed by optimisation of radiation dose exposure (according to the ‘as low as reasonably achievable’ principle). Special consideration should be given to the availability of dose reduction technology when acquiring CT scanners. Dose reduction should be optimised by adjustment of scan parameters (such as mAs, kVp, and pitch) according to patient weight or age, region scanned, and study indication (e.g. images with greater noise should be accepted if they are of sufficient diagnostic quality). Other strategies include restricting multiphase examination protocols, avoiding overlapping of scan regions, and only scanning the area in question. Newer technologies such as tube current modulation, organ-based dose modulation, and iterative reconstruction should be used when appropriate. Attention should also be paid to optimising study quality (e.g. by image post-processing to facilitate radiological diagnoses and interpretation). Finally, improving awareness through education and advocacy, and further research in paediatric radiological protection are important to help reduce patient dose.

  14. Computed tomography of diffuse pulmonary diseases

    This article summarizes our preliminary results on high resolution computed tomography of 101 patients with various diffuse lung diseases. Instead of pattern recognition routinely done on chest radiogram (nodular, reticular or reticulo-nodular) we emphasized the relation of the lesions with inherent structures of the lung seen on the CT images. For this purpose our ten years radiologic-pathologic correlation on inflated and fixed lung specimens proved quite useful. 1) Centrilobular inflammatory nodules. This was seen in diffuse panbronchiolitis (DPB), allergic broncho-pulmonary aspergillosis, tuberculosis, pneumoconiosis and lobular pneumonia. DPB and bronchogenic spread of tuberculosis were most representative. The nodules produced by these diseases were located at the extreme end of bronchial branchings and separated by 2 to 3 mm from the pleura and pulmonary vein which constitute the edge of the secondary pulmonary lobule. 2) The lesions extending along bronchoarterial sheath and pulmonary vein. The contours of the pulmonary vessels were irregular and their calibers enlarged. These findings were seen in sarcoidosis and lymphangiosis carcinomatosa. 3) Lobular and multilobular lesions. This was seen in diffuse interstitial pneumonia and in alveolar filling diseases. The margins of the lesions were straight or curved slightly suggesting that disease is blocked by the lobular septa. Fine air bronchogram within the lesions was characteristic in chronic interstitial pneumonia. 4) Slight to moderate increase of lung density with multilobular distribution. This was seen in interstitial pneumonia, sarcoidosis and hypersensitivity pneumonitis. We supposed that this finding corresponds to cellular or fibrous thickening of alveolar septa, but direct proof was not available. (J.P.N.)

  15. Computed tomography in Duchenne type muscular dystrophy

    The computed tomography (CT) scan was performed on 91 Duchenne type muscular dystrophy (DMD) patients on the following four levels; (1) at the level of L3 vertebra, (2) 2-3cm above the symphysis pubica, (3) midposition of the thigh, (4) largest-diameter section of the lower leg. The CT of muscles common to most of the DMD patients were as follows: 1. Muscle atrophy: Muscle atrophy was shown as a reduction in the cross-sectional area of the muscles. Very mild muscle atrophy could be detected either by the clearly identified muscle border or by scattered low-density areas of so-called ''moth-eaten'' appearance within muscles. 2. Fat infiltration: The decrease in radio-density of muscles was interpreted as infiltration of fatty tissue. This type of density change was further classified into diffuse, streaked, cobblestone and salt-and-pepper patterns according to the spacial distribution of low-density areas. 3. Selectivity pattern: As the chronological sequence of DMD muscle degeneration is usually different among individual muscles, it may be seen, in some stages, that some of the synergistic muscles are still only slightly involved, while the others are quite severely atrophied with evident fat infiltration. In certain stages of the disease, most of the patients show relative preservation of particular muscles although they assumed a rounded shape. The most resistent muscle was musculus gracilis, followed by the musculus sartorius, musculus semitendinosus (and/or musculus semimembranosus) in that order. According to the severity of the CT changes, 86 of the 91 patients were classed into five stages from A1 to A5. Morphological stages (A1-A5) were well correlated to the functional disability stages by Ueda with a correlation factor of r=0.88. (J.P.N.)

  16. Dose in x-ray computed tomography.

    Kalender, Willi A

    2014-02-01

    Radiation dose in x-ray computed tomography (CT) has become a topic of high interest due to the increasing numbers of CT examinations performed worldwide. This review aims to present an overview of current concepts for both scanner output metrics and for patient dosimetry and will comment on their strengths and weaknesses. Controversial issues such as the appropriateness of the CT dose index (CTDI) are discussed in detail. A review of approaches to patient dose assessment presently in practice, of the dose levels encountered and options for further dose optimization are also given and discussed. Patient dose assessment remains a topic for further improvement and for international consensus. All approaches presently in use are based on Monte Carlo (MC) simulations. Estimates for effective dose are established, but they are crude and not patient-specific; organ dose estimates are rarely available. Patient- and organ-specific dose estimates can be provided with adequate accuracy and independent of CTDI phantom measurements by fast MC simulations. Such information, in particular on 3D dose distributions, is important and helpful in optimization efforts. Dose optimization has been performed very successfully in recent years and even resulted in applications with effective dose values of below 1 mSv. In general, a trend towards lower dose values based on technical innovations has to be acknowledged. Effective dose values are down to clearly below 10 mSv on average, and there are a number of applications such as cardiac and pediatric CT which are performed routinely below 1 mSv on modern equipment. PMID:24434792

  17. The petromastoid canal on computed tomography

    Krombach, G.A.; Schmitz-Rode, T.; Weidner, J.; Guenther, R.W. [Department of Diagnostic Radiology, University of Technology, Pauwelstrasse 30, 52057 Aachen (Germany); Prescher, A. [Department of Anatomy, University of Technology, Pauwelstrasse 30, 52057 Aachen (Germany); DiMartino, E. [Department of Otorhinolaryngology, University of Technology, Pauwelstrasse 30, 52057 Aachen (Germany)

    2002-11-01

    The objective was to assess visibility and anatomy of the petromastoid canal in high-resolution CT. Computed tomography images of 188 patients were reviewed for delineation of the petromastoid canal. This bony canal connects the mastoid antrum with the cranial cavity and houses the subarcuate artery and vein. The diameter, obtained in the middle portion of the canal, was compared with the diameter of the vestibular and cochlear aqueduct in all patients, and absolute values measured in 20 cases. Collimation was 1 mm in 164 and 2 mm in 24 examinations. Additionally, temporal bone of a cadaver was imaged and microdissected. The petromastoid canal was identified bilaterally in all 164 scans that were obtained with a slice thickness of 1 mm. In 5 of the 24 patients imaged with a collimation of 2 mm, the canal was not visible, most probably due to partial-volume effects. The petromastoid canal had the same diameter as the cochlear aqueduct in 42/44 (right/left), exceeded it in 66/61 and was smaller in 75/78 cases. In comparison to the vestibular aqueduct it had an equal diameter in 38/41 (right/left), exceeded it in 63/61, and was rated as smaller in 82/81 temporal bones. Diameters for the canals were: petromastoid canal 0.51{+-}0.04 mm; cochlear aqueduct 0.57{+-}0.03; and vestibular aqueduct 0.63{+-}0.06 mm. Microdissection of the specimen revealed the entire course of the canal and demonstrated a similar appearance of the structure as in the images. The petromastoid canal can easily be identified on high-resolution, thin-slice CT images. Knowledge of the anatomy of this bony canal prevents misinterpretation as pathological structure, such as fracture line, which might occur if this structure is not known. (orig.)

  18. Time Domain Terahertz Axial Computed Tomography Non Destructive Evaluation Project

    National Aeronautics and Space Administration — We propose to demonstrate key elements of feasibility for a high speed automated time domain terahertz computed axial tomography (TD-THz CT) non destructive...

  19. Time Domain Terahertz Axial Computed Tomography Non Destructive Evaluation Project

    National Aeronautics and Space Administration — In this Phase 2 project, we propose to develop, construct, and deliver to NASA a computed axial tomography time-domain terahertz (CT TD-THz) non destructive...

  20. The value of computed tomography in tuberous sclerosis

    The computed tomography (CT) findings in 5 patients with tuberous sclerosis are presented. CT is recommended as a rapid, non-invasive, easily repeated investigative procedure for patients with clinically suspected tuberous sclerosis and epilepsy of unknown origin

  1. Helical x-ray differential phase contrast computed tomography

    Qi, Zhihua; Thériault-Lauzier, Pascal; Bevins, Nicholas; Zambelli, Joseph; Li, Ke; Chen, Guang-Hong

    2011-03-01

    Helical computed tomography revolutionized the field of x-ray computed tomography two decades ago. The simultaneous translation of an image object with a standard computed tomography acquisition allows for fast volumetric scan for long image objects. X-ray phase sensitive imaging methods have been studied over the past few decades to provide new contrast mechanisms for imaging an object. A Talbot-Lau grating interferometer based differential phase contrast imaging method has recently demonstrated its potential for implementation in clinical and industrial applications. In this work, the principles of helical computed tomography are extended to differential phase contrast imaging to produce volumetric reconstructions based on fan-beam data. The method demonstrates the potential for helical differential phase contrast CT to scan long objects with relatively small detector coverage in the axial direction.

  2. Use of computed tomography in nondestructive testing of polymeric materials

    Computed tomography has been used to detect imperfections and to measure cross-link density gradients in polymeric products, such as airplane tires, rubber shock absorbers, and filament-wound high-pressure tanks

  3. Myocardial perfusion with multi-detector computed tomography: quantitative evaluation

    The objective of this work is to evaluate the skill of multidetector computer tomography, to quantify the different patterns of intensification during the evaluation of the myocardial perfusion. 45 patients were studied with suspicion of cardiovascular disease. Multi-detector computed tomography was utilized on patients at rest and in effort with pharmacological stress, after the administration of dipyridamole. Also they were evaluated using nuclear medicine

  4. Diagnosis of hoof disease in horses using computed tomography

    Kovač Milomir; Nowak Michael; Kaufels Nikola; Tambur Zoran

    2002-01-01

    This study describes findings of computed tomography investigations at the Bergische Equine Clinic (Germany) of 39 horses with hoof diseaseas. The most frequently findings were the navicular syndrome (eight horses), laminitis (seven horses), keratnoma (six horses) and ossification of collateral cartilages in the distal phalanx (four horses). The special value of the computed tomography is in evaluating the size and courses fracture/fissure of the navicular and koffin bones, which were diagnos...

  5. Dual energy computed tomography: Physical principles and methods

    Κοντογιάννη, Λουκία

    2013-01-01

    The current thesis concerns Dual Energy Computed Tomography and specifically the physical principles and methods it is based on. Dual Energy CT offers the potential of not only anatomical, but also functional information from Computed Tomography (CT) exams. This is achieved by utilizing the energy dependence of X-rays’ attenuation within matter. In this way, materials are divided into those that are characterized by energy-dependent attenuation (strong spectral behavior), due t...

  6. Computed tomography of the mediastinum in myasthenia gravis

    Computed tomography of the mediastinum was performed in 45 patients with myasthenia gravis. Surgery was carried out in fourteen. Amongst these, there were four thymomas, one thymolipoma, eight thymic hyperplasias and one normal thymus gland. A further patient, who did not have surgery, probably also had a thymic tumour. The normal thymus and thymic hyperplasia cannot be distinguished on computed tomography. Differentiation of small thymomas from normal thymus is not always possible. Invasion by thymomas can only be appreciated with large tumours. (orig.)

  7. Computed tomography of the mediastinum in myasthenia gravis

    Guertler, K.F.; Janzen, R.W.C.; Hagemann, J.; Otto, H.F.

    1982-01-01

    Computed tomography of the mediastinum was performed in 45 patients with myasthenia gravis. Surgery was carried out in fourteen. Amongst these, there were four thymomas, one thymolipoma, eight thymic hyperplasias and one normal thymus gland. A further patient, who did not have surgery, probably also had a thymic tumour. The normal thymus and thymic hyperplasia cannot be distinguished on computed tomography. Differentiation of small thymomas from normal thymus is not always possible. Invasion by thymomas can only be appreciated with large tumours.

  8. Value of positron emission tomography and computer tomography (PET/CT) for urologic malignancies

    Positron emission tomography is a functional imaging technique that allows the detection of the regional metabolic rate, and is often coupled with other morphological imaging technique such as computed tomography. The rationale for its use is based on the clearly demonstrated fact that functional changes in tumor processes happen before morphological changes. Its introduction to the clinical practice added a new dimension in conventional imaging techniques. This review presents the current and proposed indications of the use of positron emission/computed tomography for prostate, bladder and testes, and the potential role of this exam in radiotherapy planning. (authors)

  9. [Value of positron emission tomography and computer tomography (PET/CT) for urologic malignancies].

    Boujelbene, N; Prior, J O; Boubaker, A; Azria, D; Schaffer, M; Gez, E; Jichlinski, P; Meuwly, J-Y; Mirimanoff, R O; Ozsahin, M; Zouhair, A

    2011-07-01

    Positron emission tomography is a functional imaging technique that allows the detection of the regional metabolic rate, and is often coupled with other morphological imaging technique such as computed tomography. The rationale for its use is based on the clearly demonstrated fact that functional changes in tumor processes happen before morphological changes. Its introduction to the clinical practice added a new dimension in conventional imaging techniques. This review presents the current and proposed indications of the use of positron emission/computed tomography for prostate, bladder and testes, and the potential role of this exam in radiotherapy planning. PMID:21507695

  10. Challenges for computed tomography of overweight patients

    In morbidly obese patients, computed tomography frequently represents the only viable option for non-invasive imaging diagnostics. The aim of this study was to analyze the weight limits, dose and image quality with standard CT scanners and to determine the diagnostic value and dose with a dual source XXL mode. A total of 15 patients (average body weight 189.6±42 kg) were retrospectively identified who had been examined with the XXL mode. Of these patients 7 (average body weight 176.4±56 kg) had been examined using both the XXL and standard protocols allowing for an intraindividual comparison in this subcollective. Additionally 14 patients weighing between 90 and 150 kg (average 106.1±19 kg) examined with standard protocols were included as references. Dose, image noise and subjectively assessed image quality (rating scale 1-4) were determined. Additionally, a large abdomen phantom of 48 cm diameter was examined with both protocols at equivalent tube current-time product in order to compare the dose efficiency. The patient groups differed significantly in dose (CTDIvol XXL 72.9±23 versus standard 16.7±11 mGy; intraindividual 64.1±20 versus 27.0±15 mGy). The image noise was generally somewhat higher in the XXL group but significantly lower in the intraindividual comparison (liver 24.2±14 HU versus 36.3±20 HU; p=0.03; fat 15.5±8 HU versus 26.2±12 HU; p=0.02). With ratings of 1.9±0.7 and 1.8±0.7 image quality did not differ significantly in general, whereas there was a clear difference in the intraindividual comparison (1.8±0.8 versus 3.0±1.2) and only the XXL protocol achieved diagnostic quality in all cases, while 43% of the examinations with the standard protocol were rated as non-diagnostic. The quantification of dose efficiency in the phantom scans yielded no significant difference between the protocols. Up to 150 kg body weight, CT can be performed with the standard technique at 120 kVp with tube current modulation. In larger patients diagnostic

  11. Skeletal dosimetry in cone beam computed tomography

    Walters, B. R. B.; Ding, G. X.; Kramer, R.; Kawrakow, I. [Ionizing Radiation Standards, National Research Council of Canada, Ottawa K1A OR6 (Canada); Department of Radiation Oncology, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-5671 (United States); Departamento de Energia Nuclear, Universidade Federal de Pernambuco, Avenida Professor Luiz Freire 1000, Cidade Universitaria, CEP 50740-540, Recife, Pernambuco (Brazil); Ionizing Radiation Standards, National Research Council of Canada, Ottawa K1A OR6 (Canada)

    2009-07-15

    Cone beam computed tomography (CBCT) is a relatively new patient imaging technique that has proved invaluable for treatment target verification and patient positioning during image-guided radiotherapy (IGRT). It has been shown that CBCT results in additional dose to bone that may amount to 10% of the prescribed dose. In this study, voxelized human phantoms, FAX06 (adult female) and MAX06 (adult male), are used together with phase-space data collected from a realistic model of a CBCT imager to calculate dose in the red bone marrow (RBM) and bone surface cells (BSCs), the two organs at risk within the bone spongiosa, during simulated head and neck, chest and pelvis CBCT scans. The FAX06/MAX06 phantoms model spongiosa based on micro-CT images, filling the relevant phantom voxels, which are 0.12x0.12x0.12 cm{sup 3}, with 17x17x17 {mu}m{sup 3} microvoxels to form a micromatrix of trabecular bone and bone marrow. FAX06/MAX06 have already been implemented in an EGSnrc-based Monte Carlo code to simulate radiation transport in the phantoms; however, this study required significant modifications of the code to allow use of phase-space data from a simulated CBCT imager as a source and to allow scoring of total dose, RBM dose and BSC dose on a voxel-by-voxel basis. In simulated CBCT scans, the BSC dose is significantly greater than the dose to other organs at risk. For example, in a simulated head and neck scan, the average BSC dose is 25% higher than the average dose to eye lens ({approx}8.3 cGy), and 80% greater than the average dose to brain (5.7 cGy). Average dose to RBM, on the other hand, is typically only {approx}50% of the average BSC dose and less than the dose to other organs at risk (54% of the dose to eye lens and 76% of dose to brain in a head and neck scan). Thus, elevated dose in bone due to CBCT results in elevated BSC dose. This is potentially of concern when using CBCT in conjunction with radiotherapy treatment.

  12. Skeletal dosimetry in cone beam computed tomography.

    Walters, B R B; Ding, G X; Kramer, R; Kawrakow, I

    2009-07-01

    Cone beam computed tomography (CBCT) is a relatively new patient imaging technique that has proved invaluable for treatment target verification and patient positioning during image-guided radiotherapy (IGRT). It has been shown that CBCT results in additional dose to bone that may amount to 10% of the prescribed dose. In this study, voxelized human phantoms, FAX06 (adult female) and MAX06 (adult male), are used together with phase-space data collected from a realistic model of a CBCT imager to calculate dose in the red bone marrow (RBM) and bone surface cells (BSCs), the two organs at risk within the bone spongiosa, during simulated head and neck, chest and pelvis CBCT scans. The FAX06/MAX06 phantoms model spongiosa based on micro-CT images, filling the relevant phantom voxels, which are 0.12 x 0.12 x 0.12 cm3, with 17 x 17 x 17 microm3 microvoxels to form a micromatrix of trabecular bone and bone marrow. FAX06/ MAX06 have already been implemented in an EGSnrc-based Monte Carlo code to simulate radiation transport in the phantoms; however, this study required significant modifications of the code to allow use of phase-space data from a simulated CBCT imager as a source and to allow scoring of total dose, RBM dose and BSC dose on a voxel-by-voxel basis. In simulated CBCT scans, the BSC dose is significantly greater than the dose to other organs at risk. For example, in a simulated head and neck scan, the average BSC dose is 25% higher than the average dose to eye lens (approximately 8.3 cGy), and 80% greater than the average dose to brain (5.7 cGy). Average dose to RBM, on the other hand, is typically only approximately 50% of the average BSC dose and less than the dose to other organs at risk (54% of the dose to eye lens and 76% of dose to brain in a head and neck scan). Thus, elevated dose in bone due to CBCT results in elevated BSC dose. This is potentially of concern when using CBCT in conjunction with radiotherapy treatment. PMID:19673190

  13. Skeletal dosimetry in cone beam computed tomography

    Cone beam computed tomography (CBCT) is a relatively new patient imaging technique that has proved invaluable for treatment target verification and patient positioning during image-guided radiotherapy (IGRT). It has been shown that CBCT results in additional dose to bone that may amount to 10% of the prescribed dose. In this study, voxelized human phantoms, FAX06 (adult female) and MAX06 (adult male), are used together with phase-space data collected from a realistic model of a CBCT imager to calculate dose in the red bone marrow (RBM) and bone surface cells (BSCs), the two organs at risk within the bone spongiosa, during simulated head and neck, chest and pelvis CBCT scans. The FAX06/MAX06 phantoms model spongiosa based on micro-CT images, filling the relevant phantom voxels, which are 0.12x0.12x0.12 cm3, with 17x17x17 μm3 microvoxels to form a micromatrix of trabecular bone and bone marrow. FAX06/MAX06 have already been implemented in an EGSnrc-based Monte Carlo code to simulate radiation transport in the phantoms; however, this study required significant modifications of the code to allow use of phase-space data from a simulated CBCT imager as a source and to allow scoring of total dose, RBM dose and BSC dose on a voxel-by-voxel basis. In simulated CBCT scans, the BSC dose is significantly greater than the dose to other organs at risk. For example, in a simulated head and neck scan, the average BSC dose is 25% higher than the average dose to eye lens (∼8.3 cGy), and 80% greater than the average dose to brain (5.7 cGy). Average dose to RBM, on the other hand, is typically only ∼50% of the average BSC dose and less than the dose to other organs at risk (54% of the dose to eye lens and 76% of dose to brain in a head and neck scan). Thus, elevated dose in bone due to CBCT results in elevated BSC dose. This is potentially of concern when using CBCT in conjunction with radiotherapy treatment.

  14. Computed tomography of the orbital tumors

    Choi, Jai Korl; Lee, Hwang Bok; Kang, Eun Young; Seol, Hae Young; Suh, Won Hyuck [College of Medicine, Korea University, Seoul (Korea, Republic of); Ahn, Byeong Yeob [Han Mi Hospital, Seoul (Korea, Republic of)

    1987-04-15

    The development of computed tomography (CT) provided a noninvasive safe technique for imaging the orbit in any plane exquisitely demonstrating its normal anatomy as well as its pathologic process. The orbit is an ideal structure to be examined by CT because of large difference of absorption values between the intraorbital fat, muscle, optic nerve and vessels. In this study, the authors reviewed CT findings of 66 pathologically proven orbital tumors and tumorous conditions among the total of 98 cases who had taken orbital CT scan because if exophthalmos, ocular pain, diplopia and other ophthalmologic symptoms suggesting orbital masses during the period of 3 years. For the analysis of characteristic CT findings of the orbital lesions, all lesions are divided into 4 groups according to the site of origin, i.e., tumors arising in the eyeball (group 1); from intraconal space (group 2); from extraconal space (group 3); and from extraorbital regions (group 4). The results are as follows; 1.Extra tumor detection and localization was possible in 63 cases. Thus the detection rate was 95% with CT scan. 2.Among 36 males and 30 females, their age ranged from 10 months to 72 years. 3.Intraocular tumors (group 1) were 10 cases. Retinoblastoma occurred wholly in the young children under 5 years and combined with calcification in 57%. Choroidal melanoma occurred wholly in adults. 4.Intraconal tumors (group 2) were 9 cases. Vascular tumors (7 cases) were the most frequent and well enhancing mass. 5.The tumors arising in the extraconal region (group 3) were pseudotumor (12 cases), lymphoma (3 cases), dermoid cyst (4 cases), metastasis (2 cases), adenoid cystic carcinoma (1 case) and teratoma (1 case). A case of lymphoma demonstrating retrobulbar ill defined mass with scleral l thickening could not be differentiated from the pseudotumor which showing similar finding. 6.The lesions arising from extraorbital region (group 4) were PNS cancer (9 cases), mucocele (3 cases), lid cancer (4

  15. Computed tomography of the orbital tumors

    The development of computed tomography (CT) provided a noninvasive safe technique for imaging the orbit in any plane exquisitely demonstrating its normal anatomy as well as its pathologic process. The orbit is an ideal structure to be examined by CT because of large difference of absorption values between the intraorbital fat, muscle, optic nerve and vessels. In this study, the authors reviewed CT findings of 66 pathologically proven orbital tumors and tumorous conditions among the total of 98 cases who had taken orbital CT scan because if exophthalmos, ocular pain, diplopia and other ophthalmologic symptoms suggesting orbital masses during the period of 3 years. For the analysis of characteristic CT findings of the orbital lesions, all lesions are divided into 4 groups according to the site of origin, i.e., tumors arising in the eyeball (group 1); from intraconal space (group 2); from extraconal space (group 3); and from extraorbital regions (group 4). The results are as follows; 1.Extra tumor detection and localization was possible in 63 cases. Thus the detection rate was 95% with CT scan. 2.Among 36 males and 30 females, their age ranged from 10 months to 72 years. 3.Intraocular tumors (group 1) were 10 cases. Retinoblastoma occurred wholly in the young children under 5 years and combined with calcification in 57%. Choroidal melanoma occurred wholly in adults. 4.Intraconal tumors (group 2) were 9 cases. Vascular tumors (7 cases) were the most frequent and well enhancing mass. 5.The tumors arising in the extraconal region (group 3) were pseudotumor (12 cases), lymphoma (3 cases), dermoid cyst (4 cases), metastasis (2 cases), adenoid cystic carcinoma (1 case) and teratoma (1 case). A case of lymphoma demonstrating retrobulbar ill defined mass with scleral l thickening could not be differentiated from the pseudotumor which showing similar finding. 6.The lesions arising from extraorbital region (group 4) were PNS cancer (9 cases), mucocele (3 cases), lid cancer (4

  16. Computed tomography of orbital diseases in childhood

    We analyzed computed tomography (CT) of 29 cases of various orbital diseases in pediatric age group. Diagnosis were confirmed by either operation or direct ophthalmoscope. The patients were examined during the period of last 3 years. The results were as follows: 1. Of 29 cases, 21 were male and 8 were female, and the age ranged from 20 days to 15 years. 2. Intraorbital tumors were 13 cases consisting of 7 retinoblastoma, 3 pseudotumor, and 1 each of congenital teratoma, cavernous lymphangioma, and optic glioma. Of remaining 16 cases, 6 had orbital fracture, 5 persistent hyperplastic primary vitreous (PHPV), 3 vitreous opacity, and 2 primary glaucoma. 3. The CT findings of the retinoblastoma were a lobulated or oval soft tissue mass density (40-60 HU) extending into the vitreous without significant enhancement on postcontrast scan. Of 7 cases, 4 had calcifications within the tumors. The extraglobal extension of the tumor was shown in 2 patients demonstrating markedly thickened sclera with enhancement and dilated optic nerve. 4. There were 5 patients with PHPV having a history of white pupil since birth, and all were affected unilateraly. Four patients had vitreous opacity and 3 of those showed either liner or branching tree-like densities within the vitreous on the postcontrast scan. Another one had a lobulated increased density protruding into the vitreous which was difficult to differenciate from the similar finding of retinoblastoma. Remaining one case demonstrated a deformed and decreased density in the lesional lens without change in the density of the vitreous. This was confirmed to be caused by persistence of the embryonic hyaloid artery attached to the posterior capsule of he lens. 5. There were 3 patients with vitreous opacity and 2 of them were due to retinal detachment and 1 was caused by retrolental fibroplasia. The CT findings of retinal detachment were homogeneous or heterogenous opacities in the vitreous. In a case of retrolental fibroplasia

  17. Current role of cardiac and extra-cardiac pathologies in clinically indicated cardiac computed tomography with emphasis on status before pulmonary vein isolation

    Sohns, J.M.; Lotz, J. [Goettingen University Medical Center (Germany). Inst. for Diagnostic and Interventional Radiology; German Center for Cardiovascular Research (DZHK), Goettingen (Germany); Menke, J.; Staab, W.; Fasshauer, M.; Kowallick, J.T.; Zwaka, P.A.; Schwarz, A. [Goettingen University Medical Center (Germany). Inst. for Diagnostic and Interventional Radiology; Spiro, J. [Koeln University Hospital (Germany). Radiology; Bergau, L.; Unterberg-Buchwald, C. [Goettingen University Medical Center (Germany). Cardiology and Pneumology

    2014-09-15

    Purpose: The aim of this study was to assess the incidence of cardiac and significant extra-cardiac findings in clinical computed tomography of the heart in patients with atrial fibrillation before pulmonary vein isolation (PVI). Materials and Methods: 224 patients (64 ± 10 years; male 63%) with atrial fibrillation were examined by cardiac 64-slice multidetector CT before PVI. Extra-cardiac findings were classified as 'significant' if they were recommended to additional diagnostics or therapy, and otherwise as 'non-significant'. Additionally, cardiac findings were documented in detail. Results: A total of 724 cardiac findings were identified in 203 patients (91% of patients). Additionally, a total of 619 extra-cardiac findings were identified in 179 patients (80% of patients). Among these extra-cardiac findings 196 (32%) were 'significant', and 423 (68%) were 'non-significant'. In 2 patients (1%) a previously unknown malignancy was detected (esophageal cancer and lung cancer, local stage, no metastasis). 203 additional imaging diagnostics followed to clarify the 'significant' findings (124 additional CT, costs 38,314.69 US dollars). Overall, there were 3.2 cardiac and 2.8 extra-cardiac findings per patient. Extra-cardiac findings appear significantly more frequently in patients over 60 years old, in smokers and in patients with a history of cardiac findings (p < 0.05). Conclusion: Cardiac CT scans before PVI should be screened for extracardiac incidental findings that could have important clinical implications for each patient. (orig.)

  18. Preoperative diagnosis of gastric cancer using plain computed tomography and dynamic computed tomography

    The accuracy of preoperative diagnosis using computed tomography with or without contrast enhancement in detecting the depth of tumor invasion in the gastric wall and the presence or absence of lymph node metastasis was compared based on histological findings in 94 gastric cancer patients who underwent gastrectomy. The diagnostic accuracy rate of plain CT for gastric wall invasion was less than dynamic CT. Particularly in the evaluation of invasion to another organ, the diagnostic accuracy of dynamic CT was higher (84%) than plain CT (56%). The diagnostic accuracy and sensitivity of dynamic CT for lymph node metastasis was significantly higher than that of plain CT. With respect to the detection of metastasis to group 2 lymph nodes (especially No. 7, 8, 9, and 11), the sensitivity of dynamic CT was higher than that of plain CT. We conclude that dynamic CT is an available preoperative diagnostic procedure for detecting lymph node metastasis and serosal invasion. (author)

  19. Endocrine radionuclide scintigraphy with fusion single photon emission computed tomography/computed tomography

    Wong, Ka-Kit; Gandhi, Arpit; Viglianti, Benjamin L; Fig, Lorraine M; Rubello, Domenico; Gross, Milton D

    2016-01-01

    AIM: To review the benefits of single photon emission computed tomography (SPECT)/computed tomography (CT) hybrid imaging for diagnosis of various endocrine disorders. METHODS: We performed MEDLINE and PubMed searches using the terms: “SPECT/CT”; “functional anatomic mapping”; “transmission emission tomography”; “parathyroid adenoma”; “thyroid cancer”; “neuroendocrine tumor”; “adrenal”; “pheochromocytoma”; “paraganglioma”; in order to identify relevant articles published in English during the years 2003 to 2015. Reference lists from the articles were reviewed to identify additional pertinent articles. Retrieved manuscripts (case reports, reviews, meta-analyses and abstracts) concerning the application of SPECT/CT to endocrine imaging were analyzed to provide a descriptive synthesis of the utility of this technology. RESULTS: The emergence of hybrid SPECT/CT camera technology now allows simultaneous acquisition of combined multi-modality imaging, with seamless fusion of three-dimensional volume datasets. The usefulness of combining functional information to depict the bio-distribution of radiotracers that map cellular processes of the endocrine system and tumors of endocrine origin, with anatomy derived from CT, has improved the diagnostic capability of scintigraphy for a range of disorders of endocrine gland function. The literature describes benefits of SPECT/CT for 99mTc-sestamibi parathyroid scintigraphy and 99mTc-pertechnetate thyroid scintigraphy, 123I- or 131I-radioiodine for staging of differentiated thyroid carcinoma, 111In- and 99mTc- labeled somatostatin receptor analogues for detection of neuroendocrine tumors, 131I-norcholesterol (NP-59) scans for assessment of adrenal cortical hyperfunction, and 123I- or 131I-metaiodobenzylguanidine imaging for evaluation of pheochromocytoma and paraganglioma. CONCLUSION: SPECT/CT exploits the synergism between the functional information from radiopharmaceutical imaging and anatomy

  20. Finger fractures imaging: accuracy of cone-beam computed tomography and multislice computed tomography

    Faccioli, Niccolo; Foti, Giovanni; Barillari, Marco; Mucelli, Roberto Pozzi [University of Verona, Department of Radiology, G.B. Rossi Hospital, Verona (Italy); Atzei, Andrea [University of Verona, Department of Hand Surgery, G.B. Rossi Hospital, Verona (Italy)

    2010-11-15

    To compare the diagnostic accuracy and radiation exposure of cone beam computed tomography (CBCT) and multislice computed tomography (MSCT) in the evaluation of finger fractures. In a 3-year period, 57 consecutive patients with post-traumatic fractures of the metacarpal-phalangeal (MCP), proximal interphalangeal (PIP) and distal interphalangeal (DIP) joints with involvement of the articular surface were studied by means of CBCT and MSCT. Student's t test was used to compare CBCT and MSCT accuracy in evaluating the percentage of joint surface involvement and in detecting bone fragments. The average tissue-absorbed doses of CBCT and MSCT were also compared. A value of p < 0.05 was considered statistically significant. Inter-observer agreement was calculated. In all cases, CBCT allowed the percentage of articular involvement to be correctly depicted compared with MSCT, showing 100% sensitivity and specificity (p < 0.001). A total of 103 bone fragments were depicted on MSCT (mean 3.8 per patient, range 1-23). CBCT indicated 92 out of 103 fragments (89.3%) compared with MSCT (mean diameter of missed fragments 0.9 mm, range 0.6-1.3 mm), with no statistically significant difference between CBCT and MSCT (p < 0.025). Multislice CT radiation exposure was significantly higher than that of CBCT (0.18 mSv vs 0.06 mSv, p < 0.0025). Inter-observer agreement was good (overall {kappa} = 0.89-0.96). Cone beam CT may be considered a valuable imaging tool in the preoperative assessment of finger fractures, when MSCT is not available. (orig.)

  1. Computed tomography in penetrating injury to the eye.

    Bhimani, S; Virapongse, C; Sarwar, M; Twist, J F

    1984-05-01

    We used computed tomography to detect and localize foreign bodies in two unusual cases of penetrating injury to the eyes. In one case, a large broken twig appeared to have penetrated the globe and the inferior rectus muscle; in the other, the globe was ruptured by many glass shards . In the first case surgery showed the computed tomographic impression to be incorrect. The globe and the inferior rectus muscle were intact and vision and motility were normal postoperatively. In the second case, swelling made direct visualization impossible, and computed tomography was used to locate the foreign bodies. PMID:6720836

  2. Development of a proton Computed Tomography detector system

    Computer tomography is one of the most promising new methods to image abnormal tissues inside the human body. Tomography is also used to position the patient accurately before radiation therapy. Hadron therapy for treating cancer has become one of the most advantegeous and safe options. In order to fully utilize the advantages of hadron therapy, there is a necessity of performing radiography with hadrons as well. In this paper we present the development of a proton computed tomography system. Our second-generation proton tomography system consists of two upstream and two downstream trackers made up of fibers as active material and a range detector consisting of plastic scintillators. We present details of the detector system, readout electronics, and data acquisition system as well as the commissioning of the entire system. We also present preliminary results from the test beam of the range detector

  3. Development of a proton Computed Tomography Detector System

    Naimuddin, Md; Blazey, G; Boi, S; Dyshkant, A; Erdelyi, B; Hedin, D; Johnson, E; Krider, J; Rukalin, V; Uzunyan, S A; Zutshi, V; Fordt, R; Sellberg, G; Rauch, J E; Roman, M; Rubinov, P; Wilson, P

    2015-01-01

    Computer tomography is one of the most promising new methods to image abnormal tissues inside the human body. Tomography is also used to position the patient accurately before radiation therapy. Hadron therapy for treating cancer has become one of the most advantageous and safe options. In order to fully utilize the advantages of hadron therapy, there is a necessity of performing radiography with hadrons as well. In this paper we present the development of a proton computed tomography system. Our second-generation proton tomography system consists of two upstream and two downstream trackers made up of fibers as active material and a range detector consisting of plastic scintillators. We present details of the detector system, readout electronics, and data acquisition system as well as the commissioning of the entire system. We also present preliminary results from the test beam of the range detector.

  4. Coronary computed tomography angiography indicates complexity of percutaneous coronary interventions

    Stähli, B E; Bonassin, F; Goetti, R; Küest, S M; Frank, M.; Altwegg, L A; Gebhard, C; Levis, A; Wischnewsky, M. B.; Lüscher, T F; Alkadhi, H.; Kaufmann, P A; Maier, W.

    2012-01-01

    BACKGROUND: Coronary computed tomography angiography (CCTA) provides information regarding lesion morphology and three-dimensional coronary anatomy incremental to coronary angiography. We addressed the question whether preprocedural CCTA bears potential for guiding percutaneous coronary interventions (PCI). METHODS AND RESULTS: Sixty-six coronary lesions attempted with PCI within 6 months of preprocedural CCTA were retrospectively assessed. Lesion parameters from unenhanced computed tomogr...

  5. Dose estimation for paediatric cranial computed tomography

    Curci Daros, K.A.; Bitelli Medeiros, R. [Sao Paulo Univ. Federal (Brazil); Curci Daros, K.A.; Oliveira Echeimberg, J. de [Centro Univ. Sao Camilo, Sao Paulo (Brazil)

    2006-07-01

    In the last ten years, the number of paediatric computed tomography (CT) scans have increased worldwide, contributing to higher population radiation dose. Technique diversification in paediatrics and different CT equipment technologies have led to various exposure levels complicating precise evaluation of doses and operational conditions necessary for good quality images. The objective of this study was to establish a quantitative relationship between absorbed dose and cranial region in children up to 6 years old undergoing CT exams. Methods: X-ray was measured on the cranial surface of 64 patients undergoing CT using thermoluminescent (T.L.) dosimeters. Forty T.L.D.100 thermoluminescent dosimeters (T.L.D.) were evenly distributed on each patients skin surface along the sagittal axis. Measurements were performed in facial regions exposed to scatter radiation and in the supratentorial and posterior fossa regions, submitted to primary radiation. T.L.D. were calibrated for 120 kV X-ray over the acrylic phantom. T.L. measurements were made with a Harshaw 4000 system. Patient mean T.L. readings were determined for position, pi, of T.L.D. and normalized to the maximum supratentorial reading. From integrating the linear T.L. density function (?) resulting from radiation distribution in each of the three exposed regions, dose fraction was determined in the region of interest, along with total dose under the technical conditions used in that specific exam protocol. For each T.L.D. position along the patient cranium, there were n T.L. measurements with 2% uncertainty due to T.L. reader, and 5% due to thermal treatment of dosimeters. Also, mean T.L. readings and their uncertainties were calculated for each patient at each position, p. Results: Mean linear T.L. density for the region exposed to secondary radiation defined by position, 0.3{<=}p{<=}6 cm, was {rho}((p)=7.9(4)x10{sup -2}+7(5)x10{sup -5}p{sup 4.5(4)} cm{sup -1}; exposed to primary X-ray for the posterior fossa

  6. Evaluating iterative reconstruction performance in computed tomography

    Purpose: Iterative reconstruction (IR) offers notable advantages in computed tomography (CT). However, its performance characterization is complicated by its potentially nonlinear behavior, impacting performance in terms of specific tasks. This study aimed to evaluate the performance of IR with both task-specific and task-generic strategies. Methods: The performance of IR in CT was mathematically assessed with an observer model that predicted the detection accuracy in terms of the detectability index (d′). d′ was calculated based on the properties of the image noise and resolution, the observer, and the detection task. The characterizations of image noise and resolution were extended to accommodate the nonlinearity of IR. A library of tasks was mathematically modeled at a range of sizes (radius 1–4 mm), contrast levels (10–100 HU), and edge profiles (sharp and soft). Unique d′ values were calculated for each task with respect to five radiation exposure levels (volume CT dose index, CTDIvol: 3.4–64.8 mGy) and four reconstruction algorithms (filtered backprojection reconstruction, FBP; iterative reconstruction in imaging space, IRIS; and sinogram affirmed iterative reconstruction with strengths of 3 and 5, SAFIRE3 and SAFIRE5; all provided by Siemens Healthcare, Forchheim, Germany). The d′ values were translated into the areas under the receiver operating characteristic curve (AUC) to represent human observer performance. For each task and reconstruction algorithm, a threshold dose was derived as the minimum dose required to achieve a threshold AUC of 0.9. A task-specific dose reduction potential of IR was calculated as the difference between the threshold doses for IR and FBP. A task-generic comparison was further made between IR and FBP in terms of the percent of all tasks yielding an AUC higher than the threshold. Results: IR required less dose than FBP to achieve the threshold AUC. In general, SAFIRE5 showed the most significant dose reduction

  7. 3D neutron computed tomography. Requirements and applications

    Other than X-rays, neutrons can penetrate most metals easily while delivering a high contrast for many light-weight elements. Especially their high sensitivity for hydrogen makes them a valuable tool for the detection of organic materials like lubricants, plastics or sealants within metal housings. Neutron radiography and tomography complement the application of X-ray for the inspection of complex and critical components like in automotive and aerospace applications. An overview about the technical and mathematical differences between neutron and X-ray tomography is given and the imperfections and limitations of a neutron setup are shown. Several examples of technical neutron computed tomography are given. (author)

  8. The current concepts of computed tomography for acute stroke

    Stroke is one of a leading cause of death and disability worldwide. The major advances in stroke therapy in particular invasive therapy lead to application of new imaging techniques. The aim of this review is to present state-of-the-art concepts of computed tomography for acute stroke. The goals of a neuroimaging in acute stroke are to establish a diagnosis as early as possible and to evaluate brain perfusion and intracranial vessels' patency. State-of-the-art imaging in the era of multidetector computed tomography (CT) with high spatial and temporal resolution consists of multimodal CT imaging. Non enhanced CT is necessary for depiction of hemorrhage or early ischemic signs. CT angiography evaluates intravascular thrombi or significant stenosis, and CT perfusion demonstrates salvageable tissue at risk. By combining different imaging techniques in multimodal approach we can acquire information necessary for therapeutic planning and could select patients for thrombolysis. The imaging protocol should be tailored to the patient regarding to the time of onset, necessity and availability of CT modalities. (authors) Key words: Stroke. Computed Tomography (CT). Computed Tomography Angiography (CTA). Computed Tomography Perfusion (CTP)

  9. Acute mediastinitis: multidetector computed tomography findings following cardiac surgery

    Macedo, Clarissa Aguiar de [Universidade de Sao Paulo (USP), SP (Brazil). Faculdade de Medicina. Instituto do Coracao (InCor)]. E-mail: clarissaaguiarm@yahoo.com.br; Baena, Marcos Eduardo da Silva [Instituto do Coracao (InCor), Sao Paulo, SP (Brazil). Unit of Ultrasonography; Uezumi, Kiyomi Kato [Instituto do Coracao (InCor), Sao Paulo, SP (Brazil). Unit of Computed Tomography; Castro, Claudio Campi de [Instituto do Coracao (InCor), Sao Paulo, SP (Brazil). Unit of Magnetic Resonance Imaging; Lucarelli, Claudio Luiz [Instituto do Coracao (InCor), Sao Paulo, SP (Brazil). Center of Diagnosis; Cerri, Giovanni Guido [Universidade de Sao Paulo (USP), SP (Brazil). School of Medicine. Dept. of Radiology

    2008-07-15

    Postoperative mediastinitis is defined as an infection of the organs and tissues in the mediastinal space, with an incidence ranging between 0.4% and 5% of cases. This disease severity varies from infection of superficial tissues in the chest wall to fulminant mediastinitis with sternal involvement. Diagnostic criterion for postoperative detection of acute mediastinitis at computed tomography is the presence of fluid collections and gas in the mediastinal space, which might or might not be associated with peristernal abnormalities such as edema of soft tissues, separation of sternal segments with marginal bone resorption, sclerosis and osteomyelitis. Other associated findings include lymphadenomegaly, pulmonary consolidation and pleural/ pericardial effusion. Some of these findings, such as mediastinal gas and small fluid collections can be typically found in the absence of infection, early in the period following thoracic surgery where the effectiveness of computed tomography is limited. After approximately two weeks, computed tomography achieves almost 100% sensitivity and specificity. Patients with clinical suspicion of mediastinitis should be submitted to computed tomography for investigating the presence of fluid collections to identify the extent and nature of the disease. Multidetector computed tomography allows 3D images reconstruction, contributing particularly to the evaluation of the sternum. (author)

  10. Gliomatosis cerebri mimicking encephalitis evaluated using fluorine-18 fluorodeoxyglucose: Positron emission tomography/computed tomography

    Gliomatosis cerebri (GC) is a rare condition in which an infiltrative glial neoplasm spreads through the brain with preservation of the underlying structure. F-18 fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) has an important role in demonstrating the appropriate metabolism and differentiating pathologies mimicking GC on CT and magnetic resonance imaging. We describe imaging findings of FDG PET/CT in GC in a 9-year-old male child mimicking encephalitis

  11. Positron emission tomography-computed tomography has a clinical impact for patients with cervical cancer

    Sandvik, Rikke Mulvad; Jensen, Pernille Tine; Hendel, Helle W;

    2011-01-01

    Many studies have found that positron emission tomography-computed tomography (PET-CT) has a high sensitivity and specificity in the identification of metastasis in cervical cancer. Herlev Hospital, Denmark, has been performing PET-CTs in stage I-IV cervical cancer since 1 May 2006. The present...... study investigates the positive (PPV) and negative predictive value (NPV) of PET-CT in stage I disease and the clinical impact of the scan results in all disease stages....

  12. Fluorodeoxyglucose positron emission tomography-computed tomography findings in a case of xanthogranulomatous pyelonephritis

    Joshi, Prathamesh; Lele, Vikram; Shah, Hardik

    2013-01-01

    Xanthogranulomatous pyelonephritis (XGNP) is an uncommon condition characterized by chronic suppurative renal inflammation that leads to progressive parenchymal destruction. This condition can clinically present as recurrent urinary tract infections, flank pain, hematuria, and occasionally sepsis, and weight loss. This condition is usually associated with obstructing renal calculus. We present 18-fluorodeoxyglucose positron emission tomography-computed tomography (18-FDG PET/CT) findings in a...

  13. Coronary artery visibility in free-breathing young children with congenital heart disease on cardiac 64-slice CT: dual-source ECG-triggered sequential scan vs. single-source non-ECG-synchronized spiral scan

    The potential impact of dual-source ECG-triggered sequential CT scan on coronary artery visibility has not been evaluated in free-breathing young children. To compare coronary artery visibility in free-breathing young children with congenital heart disease on cardiac 64-slice CT between dual-source ECG-triggered sequential (DSET) scan and single-source non-ECG-synchronized spiral (SSNE) scan. In 93 young children, 108 cardiac 64-slice CT examinations were performed during free-breathing. Visibility of coronary arteries and side branches was compared between SSNE and DSET scans. Heart rates and trigger delays for DSET scan were recorded. Effective dose of each scan technique was calculated. Visual grades were significantly higher (P < 0.001 or =0.011) on DSET scan than on SSNE scan except for the distal left anterior descending artery. Coronary arteries were traceable in 79.3% on DSET scan and 54.3% on SSNE scan in the overlapped scan range (P < 0.0001), and 97.1% and 71.9% for the origins and proximal segments (P < 0.0001). Visibility of side branches was improved on DSET scan by a factor of 2.0. Heart rates and trigger delays for DSET scan were 131 ± 24 beats per min and 199 ± 44 ms, respectively. Effective doses of DSET and SSNE scans were 0.36 ± 0.12 mSv and 0.99 ± 0.23 mSv, respectively. DSET scan improves visibility of coronary arteries on cardiac 64-slice CT in free-breathing young children with congenital heart disease, compared with SSNE scan. (orig.)

  14. Coronary artery visibility in free-breathing young children with congenital heart disease on cardiac 64-slice CT: dual-source ECG-triggered sequential scan vs. single-source non-ECG-synchronized spiral scan

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

    2010-10-15

    The potential impact of dual-source ECG-triggered sequential CT scan on coronary artery visibility has not been evaluated in free-breathing young children. To compare coronary artery visibility in free-breathing young children with congenital heart disease on cardiac 64-slice CT between dual-source ECG-triggered sequential (DSET) scan and single-source non-ECG-synchronized spiral (SSNE) scan. In 93 young children, 108 cardiac 64-slice CT examinations were performed during free-breathing. Visibility of coronary arteries and side branches was compared between SSNE and DSET scans. Heart rates and trigger delays for DSET scan were recorded. Effective dose of each scan technique was calculated. Visual grades were significantly higher (P < 0.001 or =0.011) on DSET scan than on SSNE scan except for the distal left anterior descending artery. Coronary arteries were traceable in 79.3% on DSET scan and 54.3% on SSNE scan in the overlapped scan range (P < 0.0001), and 97.1% and 71.9% for the origins and proximal segments (P < 0.0001). Visibility of side branches was improved on DSET scan by a factor of 2.0. Heart rates and trigger delays for DSET scan were 131 {+-} 24 beats per min and 199 {+-} 44 ms, respectively. Effective doses of DSET and SSNE scans were 0.36 {+-} 0.12 mSv and 0.99 {+-} 0.23 mSv, respectively. DSET scan improves visibility of coronary arteries on cardiac 64-slice CT in free-breathing young children with congenital heart disease, compared with SSNE scan. (orig.)

  15. Evaluation of myocardial ischemia by multiple detector computed tomography

    For years, cardiovascular diseases have been the leading cause of death worldwide, bringing on important social and economic consequences. Given this scenario, the search for a method capable of diagnosing coronary artery diseases in an early and accurate way is increasingly higher. The coronary computed tomography angiogram is already widely established for the stratification of coronary artery diseases, and, more recently, the computed tomography myocardial perfusion imaging has been providing relevant information by correlating ischemia and the coronary anatomy. The objective of this review is to describe the evaluation of myocardial ischemia by multiple detector computed tomography. This study will resort to controlled clinical trials that show the possibility of a single method to identify the atherosclerotic load, presence of coronary artery luminal narrowing and possible myocardial ischemia, by means of a fast, practical and reliable method validated by a multicenter study. (author)

  16. Evaluation of myocardial ischemia by multiple detector computed tomography

    Fernandes, Fabio Vieira, E-mail: rccury@me.com [Hospital do Coracao (HCor), Sao Paulo, SP (Brazil); Cury, Roberto Caldeira [Hospital Samaritano, Sao Paulo, SP (Brazil)

    2015-01-15

    For years, cardiovascular diseases have been the leading cause of death worldwide, bringing on important social and economic consequences. Given this scenario, the search for a method capable of diagnosing coronary artery diseases in an early and accurate way is increasingly higher. The coronary computed tomography angiogram is already widely established for the stratification of coronary artery diseases, and, more recently, the computed tomography myocardial perfusion imaging has been providing relevant information by correlating ischemia and the coronary anatomy. The objective of this review is to describe the evaluation of myocardial ischemia by multiple detector computed tomography. This study will resort to controlled clinical trials that show the possibility of a single method to identify the atherosclerotic load, presence of coronary artery luminal narrowing and possible myocardial ischemia, by means of a fast, practical and reliable method validated by a multicenter study. (author)

  17. Computed tomography of the thorax in children with cystic fibrosis

    We studied retrospectively the value of computed tomography of the thorax in patients suffering from cystic fibrosis. Twenty-six patients were studied, which showed as the most frequency pulmonary findings bronchial wall thickening in 22 patients (84.6), followed by bronchiectasis in 16 patients (61.5%). Less frequent finding were ill-defined patch consolidation, mucoid impaction, bullaes and atelectasis. We found a predominant distribution of bronchial wall thickening and bronchiectasis in the upper lobes of the lungs. Computed tomography is the more sensitive technique for early visualization and location of the manifestations of cystic fibrosis bronchopathy. (author)

  18. Importance of computer tomography in diagnosis of deep papillar drusen

    Vladykova, J.; Ciganek, L.; Sobota, J. (Ustredni Vojenska Nemocnice, Prague (Czechoslovakia))

    1983-07-01

    In a 22-year old patient deep peripapillar drusen were observed accompanied by bilateral papillo-edemas and unilateral papillar and peripapillar haemorrhages and bilateral defects of the visual fields which in certain stages assumed the character of left-side hemianopia. The importance is evaluated of computer tomography in the diagnosis of deep peripapillar drusen and the following conclusions are arrived at: 1. computer tomography (CT) has an immense differential diagnosis significance in their quiescent stage; 2. in the acute stage accompanied by vascular and perimetric symptoms, even though deep papillar drusen are accurately shown by CT, further examinations are required to exclude the possibility of simultaneous intracranial lesions.

  19. Importance of computer tomography in diagnosis of deep papillar drusen

    In a 22-year old patient deep peripapillar drusen were observed accompanied by bilateral papillo-edemas and unilateral papillar and peripapillar haemorrhages and bilateral defects of the visual fields which in certain stages assumed the character of left-side hemianopia. The importance is evaluated of computer tomography in the diagnosis of deep peripapillar drusen and the following conclusions are arrived at: 1. computer tomography (CT) has an immense differential diagnosis significance in their quiescent stage; 2. in the acute stage accompanied by vascullar and perimetric symptoms, even though deep papillar drusen are accurately shown by CT, further examinations are required to exclude the possibility of simultaneous intracranial lesions. (author)

  20. Real-time in vivo computed optical interferometric tomography.

    Ahmad, Adeel; Shemonski, Nathan D; Adie, Steven G; Kim, Hee-Seok; Hwu, Wen-Mei W; Carney, P Scott; Boppart, Stephen A

    2013-06-01

    High-resolution real-time tomography of scattering tissues is important for many areas of medicine and biology(1-6). However, the compromise between transverse resolution and depth-of-field in addition to low sensitivity deep in tissue continue to impede progress towards cellular-level volumetric tomography. Computed imaging has the potential to solve these long-standing limitations. Interferometric synthetic aperture microscopy (ISAM)(7-9) is a computed imaging technique enabling high-resolution volumetric tomography with spatially invariant resolution. However, its potential for clinical diagnostics remains largely untapped since full volume reconstructions required lengthy postprocessing, and the phase-stability requirements have been difficult to satisfy in vivo. Here we demonstrate how 3-D Fourier-domain resampling, in combination with high-speed optical coherence tomography (OCT), can achieve high-resolution in vivo tomography. Enhanced depth sensitivity was achieved over a depth-of-field extended in real time by more than an order of magnitude. This work lays the foundation for high-speed volumetric cellular-level tomography. PMID:23956790