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Sample records for retrospectively ecg-gated image

  1. Comparative study of image quality and radiation dose between prospective and retrospective ECG gating technique in coronary artery imaging with 64-slice spiral CT

    International Nuclear Information System (INIS)

    Liu Jianxin; Liu Jian; Dou Yanbin; Wang Jichen; Sun Hongyue

    2009-01-01

    Objective: To compare the image quality and radiation dose between prospective ECG-trigering and retrospective ECG gating technique in coronary artery imaging. Methods: 33 patients suspected coronary artery disease were included in this study and divided into experimental group (prospective ECG-triggering coronary artery imaging, heart rate 0.05). The mean DLP of experimental group (234.4 mGy · cm) was DLP of control group (974.4 mGy · cm) 24.1%. The mean effective dose of prospective ECG gating coronary artery imaging was 3.2 mSv. Effective dose reduced 76.47 %. Conclusions: Prospective ECG gating coronary artery imaging can obtain the similar image quality compared with prospective ECG gating coronary artery imaging but the effective dose reduced 76.47 %. Prospective ECG gating coronary artery imaging has clinical value to peoples who are able to not accept high radiation dose and with low heart rate. (authors)

  2. Noninvasive coronary artery imaging by multislice spiral computed tomography. A novel approach for a retrospectively ECG-gated reconstruction technique

    International Nuclear Information System (INIS)

    Sato, Yuichi; Kanmatsuse, Katsuo; Inoue Fumio

    2003-01-01

    Although the excellent spatial resolution of multislice spiral computed tomography (MSCT) enables the coronary arteries to be visualized, its limited temporal resolution results in poor image reproducibility because of cardiac motion artifact (CMA) and hence limits its widespread clinical use. A novel retrospectively electrocardiogram (ECG)-gated reconstruction method has been developed to minimize CMA. In 88 consecutive patients, the scan data were reconstructed using 2 retrospectively ECG-gated reconstruction methods. Method 1: the end of the reconstruction window (250 ms) was positioned at the peak of the P wave on ECG, which corresponded to the end of the slow filling phase during diastole immediately before atrial contraction. Method 2 (conventional method): relative retrospective gating with 50% referred to the R-R interval was performed so that the beginning of the reconstruction window (250 ms) was positioned at the halfway point between the R-R intervals of the heart cycle. The quality of the coronary artery images was evaluated according to the presence or absence of CMA. The assessment was applied to the left main coronary artery (LMCA), the left anterior descending artery (LAD, segments no.6, no.7, and no.8), the left circumflex artery (LCx, segments no.11 and no.13) and the right coronary artery (RCA, segments no.1, no.2 and no.3). The first diagonal artery (no.9-1), the obtuse marginal artery (no.12-1), the posterior descending artery (no.4-PD), the atrioventricular node branch (no.4-AV) and the first right ventricular branch (RV) were also evaluated. Of the 88 patients, 85 were eligible for image evaluation. Method 1 allowed visualization of the major coronary arteries without CMA in the majority of patients. The left coronary artery (LCA) system (segments no.5-7, no.11 and no.13) and the proximal portion of the RCA were visualized in more than 94% of patients. Artifact-free visualization of the distal portion of the LAD (segment no.8) and RCA (no.4

  3. Prospective ECG triggering versus low-dose retrospective ECG-gated 128-channel CT coronary angiography: comparison of image quality and radiation dose

    International Nuclear Information System (INIS)

    Feng, Q.; Yin, Y.; Hua, X.; Zhu, R.; Hua, J.; Xu, J.

    2010-01-01

    Aim: To evaluate image quality and radiation dose for 128-detector prospective electrocardiogram (ECG)-gated computed tomography coronary angiography (CTCA) compared with a low-dose retrospective ECG-gated imaging protocol. Materials and methods: Thirty-one and 47 patients suspected of having coronary artery disease were enrolled into groups examined using prospective and low-dose retrospective ECG-gated CT protocols respectively. All examinations were performed on a 128-detector CT system (Definition AS, Siemens Healthcare, Forchheim, Germany). Prospective CTCA was performed using following parameters: tube voltage 100 kV; tube current 205 mAs; centre of acquisition window 70% of the RR interval. The tube current for low-dose retrospective ECG-gated CTCA was full dose during 40-70% of the RR interval and partial dose for the rest of RR interval. The pitch varied between 0.2 and 0.5 depending on heart rate and patient size. Image quality of coronary arteries was evaluated using a four-point grading scale. The signal-to-noise ratios (SNRs) of enhanced arteries and myocardium were also measured, corresponding contrast-to-noise ratios (CNRs) were calculated, and the radiation doses received were recorded. Results: There was a significant difference in the image quality scores between the retrospective and prospective gating protocols (Chi-square = 15.331, p = 0.009). There was no significant difference between the SNRs of the contrasted artery and myocardium in these two groups, but the CNRs were increased in the prospective group. The mean radiation dose of prospective gating group was 2.71 ± 0.67 mSv (range, 1.67-3.59 mSv), which was significantly lower than that of the retrospective group (p < 0.001). Conclusion: Prospective CT angiography can achieve lower radiation dose than that of low-dose retrospective CT angiography, with preserved image quality.

  4. Prospective ECG triggering versus low-dose retrospective ECG-gated 128-channel CT coronary angiography: comparison of image quality and radiation dose

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    Feng, Q.; Yin, Y.; Hua, X.; Zhu, R.; Hua, J. [Department of Radiology, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai (China); Xu, J., E-mail: xujianr@hotmail.co [Department of Radiology, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai (China)

    2010-10-15

    Aim: To evaluate image quality and radiation dose for 128-detector prospective electrocardiogram (ECG)-gated computed tomography coronary angiography (CTCA) compared with a low-dose retrospective ECG-gated imaging protocol. Materials and methods: Thirty-one and 47 patients suspected of having coronary artery disease were enrolled into groups examined using prospective and low-dose retrospective ECG-gated CT protocols respectively. All examinations were performed on a 128-detector CT system (Definition AS, Siemens Healthcare, Forchheim, Germany). Prospective CTCA was performed using following parameters: tube voltage 100 kV; tube current 205 mAs; centre of acquisition window 70% of the RR interval. The tube current for low-dose retrospective ECG-gated CTCA was full dose during 40-70% of the RR interval and partial dose for the rest of RR interval. The pitch varied between 0.2 and 0.5 depending on heart rate and patient size. Image quality of coronary arteries was evaluated using a four-point grading scale. The signal-to-noise ratios (SNRs) of enhanced arteries and myocardium were also measured, corresponding contrast-to-noise ratios (CNRs) were calculated, and the radiation doses received were recorded. Results: There was a significant difference in the image quality scores between the retrospective and prospective gating protocols (Chi-square = 15.331, p = 0.009). There was no significant difference between the SNRs of the contrasted artery and myocardium in these two groups, but the CNRs were increased in the prospective group. The mean radiation dose of prospective gating group was 2.71 {+-} 0.67 mSv (range, 1.67-3.59 mSv), which was significantly lower than that of the retrospective group (p < 0.001). Conclusion: Prospective CT angiography can achieve lower radiation dose than that of low-dose retrospective CT angiography, with preserved image quality.

  5. Noninvasive assessment of coronary artery disease by multislice spiral computed tomography using a new retrospectively ECG-gated image reconstruction technique. Comparison with angiographic results

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    Sato, Yuichi; Matsumoto, Naoya; Kato, Masahiko [Nihon Univ., Tokyo (Japan). Surugadai Hospital] [and others

    2003-04-01

    The present study was designed to investigate the accuracy of multislice spiral computed tomography (MSCT) in detecting coronary artery disease, compared with coronary angiography (CAG), using a new retrospectively ECG-gated reconstruction method that reduced cardiac motion artifact. The study group comprised 54 consecutive patients undergoing MSCT and CAG. MSCT was performed using a SOMATOM Volume Zoom (4-detector-row, Siemens, Germany) with slice thickness 1.0 mm, pitch 1.5 (table feed: 1.5 mm per rotation) and gantry rotation time 500 ms. Metoprolol (20-60 mg) was administered orally prior to MSCT imaging. ECG-gated image reconstruction was performed with the reconstruction window (250 ms) positioned immediately before atrial contraction in order to reduce the cardiac motion artifact caused by the abrupt diastolic ventricular movement occurring during the rapid filling and atrial contraction periods. Following inspection of the volume rendering images, multiplanar reconstruction images and axial images of the left main coronary artery (LMCA), left anterior descending artery (LAD), left circumflex artery (LCx) and right coronary artery (RCA) were obtained and evaluated for luminal narrowing. The results were compared with those obtained by CAG. Of 216 coronary arteries, 206 (95.4%) were assessable; 10 arteries were excluded from the analysis because of severe calcification (n=4), stents (n=3) or insufficient contrast enhancement (n=3). The sensitivity to detect coronary stenoses {>=}50% was 93.5% and the specificity to define luminal narrowing <50% was 97.2%. The positive predictive value and the negative predictive value were 93.5% and 97.2%, respectively. The sensitivity was still satisfactory (80.6%) even when non-assessable arteries were included in the analysis. The new retrospectively ECG-gated reconstruction method for MSCT has excellent diagnostic accuracy in detecting significant coronary artery stenoses. (author)

  6. Prospective versus retrospective ECG gating for dual source CT of the coronary stent: Comparison of image quality, accuracy, and radiation dose

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    Zhao Lei, E-mail: zhaolei219@sohu.com [Beijing Anzhen Hospital of the Capital University of Medical Sciences (China); Zhang Zhaoqi; Fan Zhanming; Yang Lin; Du Jing [Beijing Anzhen Hospital of the Capital University of Medical Sciences (China)

    2011-03-15

    Objective: To compare image quality, diagnostic accuracy and radiation dose of prospective and retrospective electrocardiogram (ECG) gated dual source computed tomography (DSCT) for the evaluation of the coronary stent, using conventional coronary angiography (CA) as a standard reference. Design, setting and patients: Sixty patients (heart rates {<=}70 bpm) with previous stent implantation who were scheduled for CA were divided in two groups, receiving either prospective or retrospective ECG gated DSCT separately. Two reviewers scored coronary stent image quality and evaluated stent lumen. Results: There was no significant difference in image quality between the two groups. In the prospective group, there were 86.4% (51/59) stents with interpretable images, in the retrospective group, there were 87.5% (49/56) stents with interpretable images. Image quality was not influenced by age, body mass index or heart rate in either group, but heart rate variability had a weak impact on the image quality of the prospective group. Image noise was higher in the prospective group, but this difference reached statistical significance only by using a smooth kernel reconstruction. Per-stent based sensitivity, specificity, and positive and negative predictive value were 100%, 84.1%, 68.2%, and 100%, respectively, in the prospective CT angiography group and 94.4%, 86.8%, 77.3%, and 97.1%, respectively, in the retrospective CT angiography group. There was a significant difference in the effective radiation dose between the two groups, mean effective dose in the prospective and retrospective group was 2.2 {+-} 0.5 mSv (1.5-3.2 mSv) and 14.6 {+-} 3.3 mSv (10.0-20.4 mSv) (p < .001) respectively. Conclusions: Compared with retrospective CT angiography, prospective CT angiography has a similar performance in assessing coronary stent patency, but a lower effective dose in selected patients with regular heart rates {<=}70 bpm.

  7. Retrospectively ECG-gated multi-detector row CT of the chest: does ECG-gating improve three-dimensional visualization of the bronchial tree?

    International Nuclear Information System (INIS)

    Schertler, T.; Wildermuth, S.; Willmann, J.K.; Crook, D.W.; Marincek, B.; Boehm, T.

    2004-01-01

    Purpose: To determine the impact of retrospectively ECG-gated multi-detector row CT (MDCT) on three-dimensional (3D) visualization of the bronchial tree and virtual bronchoscopy (VB) as compared to non-ECG-gated data acquisition. Materials and Methods: Contrast-enhanced retrospectively ECG-gated and non-ECG-gated MDCT of the chest was performed in 25 consecutive patients referred for assessment of coronary artery bypass grafts and pathology of the ascending aorta. ECG-gated MDCT data were reconstructed in diastole using an absolute reverse delay of -400 msec in all patients. In 10 patients additional reconstructions at -200 msec, -300 msec, and -500 msec prior to the R-wave were performed. Shaded surface display (SSD) and virtual bronchoscopy (VB) for visualization of the bronchial segments was performed with ECG-gated and non-ECG-gated MDCT data. The visualization of the bronchial tree underwent blinded scoring. Effective radiation dose and signal-to-noise ratio (SNR) for both techniques were compared. Results: There was no significant difference in visualizing single bronchial segments using ECG-gated compared to non-ECG-gated MDCT data. However, the total sum of scores for all bronchial segments visualized with non-ECG-gated MDCT was significantly higher compared to ECG-gated MDCT (P [de

  8. Prospective versus retrospective ECG-gated multislice CT coronary angiography: A systematic review of radiation dose and diagnostic accuracy

    International Nuclear Information System (INIS)

    Sun Zhonghua; Ng, Kwan-Hoong

    2012-01-01

    Purpose: To perform a systematic review of the radiation dose and diagnostic accuracy of prospective versus retrospective ECG-gated multislice CT coronary angiography. Materials and methods: A search of Pubmed/Medline and Sciencedirect databases for English literature was performed to identify studies comparing prospective and retrospective ECG-gated multislice CT angiography in the diagnosis of coronary artery disease. Effective dose, dose length product, image quality and diagnostic value were compared between two groups of studies. Results: 22 studies were included for analysis. The mean effective dose of prospective ECG-gated scans was 4.5 mSv (95% CI: 3.6, 5.3 mSv), which is significantly lower than that of retrospective scans, which is 13.8 mSv (95% CI: 11.5, 16.0 mSv) (p < 0.001). The mean dose length product was 225 mGy cm (95% CI: 188, 262 mGy cm) and 822 mGy cm (95% CI: 630, 1013 mGy cm) for the prospective and retrospective ECG-gated scans, respectively, indicating a statistically significant difference between these two protocols (p < 0.0001). The mean sensitivity and specificity of multislice CT angiography in the diagnosis of coronary artery disease was 97.7% (95% CI: 93.7%, 100%) and 92.1% (95% CI: 87.2%, 97%) for prospective ECG-gated scans; 95.2% (95% CI: 91%, 99.5%) and 94.4% (95% CI: 88.5%, 100%) for retrospective ECG-gated scans, respectively, with no significant difference for sensitivity but significant difference for specificity (p = 0.047). Conclusion: Multislice CT coronary angiography with prospective ECG-gating leads to a significant reduction of radiation dose when compared to that of retrospective ECG-gating, while offering comparable image quality and diagnostic value.

  9. ECG-gated myocardial imaging with 201Tl

    International Nuclear Information System (INIS)

    Baehre, M.

    1980-01-01

    ECG-gated myocardial scintigraphy by means of 201 TI was performed in 11 patients. Good scintigrams could be gained by using long imaging times, but there was no additional information when compared with static images. Disadvantages were long imaging time, higher technical expenditure, and the smaller number of projections. Furthermore, there is no possibility of performing myocardial imaging under stress. (orig.) [de

  10. Evaluation of coronary artery disease by helical CT using retrospective ECG-gating

    International Nuclear Information System (INIS)

    Kawawa, Yoko

    2001-01-01

    The purpose of this study is to evaluate the usefulness of helical CT using retrospective ECG-gating for visualization of the coronary artery and detection of coronary artery disease. We performed a coronary artery phantom study and established this new application, with 1-mm collimation, 1-mm table increment, and 0.1-mm reconstruction (0.8 sec/rotation). Helical CT of 31 patients with 39 coronary artery diseases (34 coronary artery stenoses, 1 vasospastic angina, 1 coronary artery dissection, 1 coronary artery ectasia and 2 coronary artery aneurysms) was performed in a single breath hold and ECG-gating without and with intravenous injection of nonionic iodine contrast material. We selected the images which were not affected by cardiac motion from the reconstruction images, in order to visualize the coronary artery for detection of coronary artery disease. The coronary artery was well visualized in 32 out of 39 vessels (82%). A good visualization of the coronary artery was correlated with the heart rate. Further, in this well visualized group, coronary artery diseases were detected in 24 out of 31 cases (77%). One case of vasospastic angina was not included. It was difficult to detect coronary artery disease in cases of heavily calcified vessels or in the left circumflex artery. Helical CT using this retrospective ECG-gating is a useful noninvasive examination for evaluation of coronary artery disease. (author)

  11. Simultaneous ECG-gated PET imaging of multiple mice

    International Nuclear Information System (INIS)

    Seidel, Jurgen; Bernardo, Marcelino L.; Wong, Karen J.; Xu, Biying; Williams, Mark R.; Kuo, Frank; Jagoda, Elaine M.; Basuli, Falguni; Li, Changhui; Griffiths, Gary L.

    2014-01-01

    Introduction: We describe and illustrate a method for creating ECG-gated PET images of the heart for each of several mice imaged at the same time. The method is intended to increase “throughput” in PET research studies of cardiac dynamics or to obtain information derived from such studies, e.g. tracer concentration in end-diastolic left ventricular blood. Methods: An imaging bed with provisions for warming, anesthetic delivery, etc., was fabricated by 3D printing to allow simultaneous PET imaging of two side-by-side mice. After electrode attachment, tracer injection and placement of the animals in the scanner field of view, ECG signals from each animal were continuously analyzed and independent trigger markers generated whenever an R-wave was detected in each signal. PET image data were acquired in “list” mode and these trigger markers were inserted into this list along with the image data. Since each mouse is in a different spatial location in the FOV, sorting of these data using trigger markers first from one animal and then the other yields two independent and correctly formed ECG-gated image sequences that reflect the dynamical properties of the heart during an “average” cardiac cycle. Results: The described method yields two independent ECG-gated image sequences that exhibit the expected properties in each animal, e.g. variation of the ventricular cavity volumes from maximum to minimum and back during the cardiac cycle in the processed animal with little or no variation in these volumes during the cardiac cycle in the unprocessed animal. Conclusion: ECG-gated image sequences for each of several animals can be created from a single list mode data collection using the described method. In principle, this method can be extended to more than two mice (or other animals) and to other forms of physiological gating, e.g. respiratory gating, when several subjects are imaged at the same time

  12. Prospective and retrospective ECG-gating for CT coronary angiography perform similarly accurate at low heart rates

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    Stolzmann, Paul, E-mail: paul.stolzmann@usz.ch [Institute of Diagnostic Radiology, University Hospital Zurich, Raemistrasse 100, 8091 Zurich (Switzerland); Goetti, Robert; Baumueller, Stephan [Institute of Diagnostic Radiology, University Hospital Zurich, Raemistrasse 100, 8091 Zurich (Switzerland); Plass, Andre; Falk, Volkmar [Clinic for Cardiovascular Surgery, University Hospital Zurich (Switzerland); Scheffel, Hans; Feuchtner, Gudrun; Marincek, Borut [Institute of Diagnostic Radiology, University Hospital Zurich, Raemistrasse 100, 8091 Zurich (Switzerland); Alkadhi, Hatem [Institute of Diagnostic Radiology, University Hospital Zurich, Raemistrasse 100, 8091 Zurich (Switzerland); Cardiac MR PET CT Program, Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States); Leschka, Sebastian [Institute of Diagnostic Radiology, University Hospital Zurich, Raemistrasse 100, 8091 Zurich (Switzerland)

    2011-07-15

    Objective: To compare, in patients with suspicion of coronary artery disease (CAD) and low heart rates, image quality, diagnostic performance, and radiation dose values of prospectively and retrospectively electrocardiography (ECG)-gated dual-source computed tomography coronary angiography (CTCA) for the diagnosis of significant coronary stenoses. Materials and methods: Two-hundred consecutive patients with heart rates {<=}70 bpm were retrospectively enrolled; 100 patients undergoing prospectively ECG-gated CTCA (group 1) and 100 patients undergoing retrospectively-gated CTCA (group 2). Coronary artery segments were assessed for image quality and significant luminal diameter narrowing. Sensitivity, specificity, positive predictive values (PPV), negative predictive values (NPV), and accuracy of both CTCA groups were determined using conventional catheter angiography (CCA) as reference standard. Radiation dose values were calculated. Results: Both groups were comparable regarding gender, body weight, cardiovascular risk profile, severity of CAD, mean heart rate, heart rate variability, and Agatston score (all p > 0.05). There was no significant difference in the rate of non-assessable coronary segments between group 1 (1.6%, 24/1404) and group 2 (1.4%, 19/1385; p = 0.77); non-diagnostic image quality was significantly (p < 0.001) more often attributed to stair step artifacts in group 1. Segment-based sensitivity, specificity, PPV, NPV, and accuracy were 98%, 98%, 88%, 100%, and 100% among group 1; 96%, 99%, 90%, 100%, and 98% among group 2, respectively. Parameters of diagnostic performance were similar (all p > 0.05). Mean effective radiation dose of prospectively ECG-gated CTCA (2.2 {+-} 0.4 mSv) was significantly (p < 0.0001) smaller than that of retrospectively ECG-gated CTCA (8.1 {+-} 0.6 mSv). Conclusion: Prospectively ECG-gated CTCA yields similar image quality, performs as accurately as retrospectively ECG-gated CTCA in patients having heart rates {<=}70 bpm

  13. Step-and-shoot prospectively ECG-gated versus retrospectively ECG-gated with tube current modulation coronary CT angiography using the 128-slice MDCT: comparison of image quality and radiation dose

    International Nuclear Information System (INIS)

    Jeong, Dong Wook; Choo, Ki Seok; Baik, Seung Kug; Kim, Yong Woo; Jeon, Ung Bae; Kim, Jeong Soo; Lim, Soo Jin

    2011-01-01

    Background: Little is known regarding image quality and the required radiation dose for step-and-shoot and retrospective coronary computed tomography angiography (CCTA) with tube current modulation (TCM) in 128-slice multidetector CT (MDCT) coronary angiography. Purpose: To compare image quality and radiation dose in patients who underwent 128-slice MDCT by the step-and- shoot method with those in patients who underwent 128-slice MDCT with retrospective CCTA with TCM. Material and Methods: CCTA obtained with 128-slice MDCT was retrospectively evaluated in 160 patients. Two independent reviewers separately scored the subjective image quality of the coronary artery segments (1, excellent; 4, poor) for step-and-shoot (68, mean heart rate [HR]: 59.3±6.8) and retrospective CCTA with TCM (77, mean HR: 59.1±9.8). Interobserver variability was calculated. Effective radiation doses of both scan techniques were calculated with dose-length product. Results: There was good agreement for quality scores of coronary artery segment images between the independent reviewers (k=0.72). The number of coronary artery segments that could not be evaluated was 2.85% (27 of 947) in the step-and-shoot and 1.87% (20 of 1071) in retrospective CCTA with TCM. Image quality scores were not significantly different (P>.05). Mean patient radiation dose was 63% lower for step-and-shoot (1.94±0.70 mSv) than for retrospective CCTA with TCM (4.51±1.18 mSv) (P<0.0001). For patients who underwent step-and-shoot or retrospective CCTA with TCM, an average HR of 63.5 beats per minute was identified as the threshold for the prediction of non-diagnostic image quality for both protocols. There were no significant differences in the image quality of both methods between obese (body mass index [BMI≥25) and non-obese patients (BMI<25), but radiation doses were higher in the obesity group than in the non-obesity group for both methods. Conclusion: Both step-and-shoot and retrospective CCTA with TCM using 128

  14. ECG gated magnetic resonance imaging in cardiovascular disease

    International Nuclear Information System (INIS)

    Park, Jae Hyung; Im, Chung Kie; Han, Man Chung; Kim, Chu Wan

    1985-01-01

    Using KAIS 0.15 Tesla resistive magnetic imaging system, ECG gated magnetic resonance (MR) image of various cardiovascular disease was obtained in 10 patients. The findings of MR image of the cardiovascular disease were analysed and the results were as follows: 1. In 6 cases of acquired and congenital cardiac diseases, there were 2 cases of myocardial infarction, 1 case of mitral stenosis and 3 cases of corrected transportation of great vessels. The others were 3 cases of aortic disease and 1 case of pericardial effusion with lymphoma. 2. Myocardial thinning and left ventricular aneurysm were detected in MR images of myocardial infarction. The left atrium was well delineated and enlarged in the case of mitral stenosis. And segmental analysis was possible in the cases of corrected transposition since all cardiac structures were well delineated anatomically. 3. In aortic diseases, the findings of MR image were enlarged lumen, compressed cardiac chambers in ascending aortic aneurysm, intimal flap, enhanced false lumen in dissecting aneurysm and irregular narrowing of aorta with arterial obstruction in Takayasu's arteritis. 4. Pericardial effusion revealed a conspicuous contrast with neighboring mediastinal fat and cardiac wall due to it low signal encircling cardiac wall. 5. ECG gated MR image is an accurate non-invasive imaging modality for the diagnosis of cardiovascular disease and better results of its clinical application are expected in the future with further development in the imaging system and more clinical experiences

  15. Step-and-shoot prospectively ECG-gated vs. retrospectively ECG-gated with tube current modulation coronary CT angiography using 128-slice MDCT patients with chest pain: diagnostic performance and radiation dose

    International Nuclear Information System (INIS)

    Kim, Jeong Su; Choo, Ki Seok; Jeong, Dong Wook

    2011-01-01

    Background With increasing awareness for radiation exposure, the study of diagnostic accuracy of coronary CT angiography (CCTA) with low radiation dose techniques is mandatory to both radiologist and clinician. Purpose To compare diagnostic performance and effective radiation dose between step-and-shoot prospectively ECG-gated and retrospectively ECG-gated with tube current modulation (TCM) CCTA using 128-slice multidetector computed tomography (MDCT). Material and Methods We retrospectively evaluated 60 patients who underwent CCTA with either of two different low-dose techniques using 128-slice MDCT (23 patients for step-and shoot-prospectively ECG-gated and 37 patients for retrospectively ECG-gated with TCM CCTA) followed by conventional coronary angiography. All coronary arteries and all segments thereof, except anatomical variants or small size (< 1.5 mm) ones, were included in analysis. Results In per-segment analysis, sensitivity, specificity, positive predictive value, and negative predictive value were 91/96%, 95/94%, 75/73%, and 98/99% for step-and-shoot prospectively ECG-gated and retrospectively ECG gated with TCM CCTA, respectively, relative to conventional coronary angiography. Effective radiation dose were 1.75 ± 0.83 mSv, 4.91 ± 1.71 mSv in the step-and-shoot prospectively ECG-gated and retrospectively ECG-gated with TCM CCTA groups, respectively. Conclusion The two low-radiation dose CCTA techniques using 128-slice MDCT yields comparable diagnostic performance for coronary artery disease in symptomatic patients with low heart rates

  16. Assessment of Double Outlet Right Ventricle Associated with Multiple Malformations in Pediatric Patients Using Retrospective ECG-Gated Dual-Source Computed Tomography.

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    Ke Shi

    Full Text Available To evaluate the feasibility and diagnostic accuracy of retrospective electrocardiographically (ECG-gated dual-source computed tomography (DSCT for the assessment of double outlet right ventricle (DORV and associated multiple malformations in pediatric patients.Forty-seven patients <10 years of age with DORV underwent retrospective ECG-gated DSCT. The location of the ventricular septal defect (VSD, alignment of the two great arteries, and associated malformations were assessed. The feasibility of retrospective ECG-gated DSCT in pediatric patients was assessed, the image quality of DSCT and the agreement of the diagnosis of associated malformations between DSCT and transthoracic echocardiography (TTE were evaluated, the diagnostic accuracies of DSCT and TTE were referred to surgical results, and the effective doses were calculated.Apart from DORV, 109 associated malformations were confirmed postoperatively. There was excellent agreement (κ = 0.90 for the diagnosis of associated malformations between DSCT and TTE. However, DSCT was superior to TTE in demonstrating paracardiac anomalies (sensitivity, coronary artery anomalies: 100% vs. 80.00%, anomalies of great vessels: 100% vs. 88.57%, separate thoracic and abdominal anomalies: 100% vs. 76.92%, respectively. Combined with TTE, DSCT can achieve excellent diagnostic performance in intracardiac anomalies (sensitivity, 91.30% vs. 100%. The mean image quality score was 3.70 ± 0.46 (κ = 0.76. The estimated mean effective dose was < 1 mSv (0.88 ± 0.34 mSv.Retrospective ECG-gated DSCT is a better diagnostic tool than TTE for pediatric patients with complex congenital heart disease such as DORV. Combined with TTE, it may reduce or even obviate the use of invasive cardiac catheterization, and thus expose the patients to a much lower radiation dose.

  17. Imaging quality and effective radiation dose of prospective ECG-gated axial multidetector row computed tomography coronary angiography

    International Nuclear Information System (INIS)

    Capunay, C.; Carrascosa, P.; Vallejos, J.; Deviggiano, A.; Pollono, P.M.; Garcia, M.J.

    2011-01-01

    Objective. To determine the imaging quality and effective radiation dose (ERD) of prospective ECG-gated multidetector row computed tomography coronary angiography (PMDCTCA) compared to retrospective ECG-gating (RMDCT-CA). Materials and Methods. Forty-five PMDCT-CA scans were retrospectively reviewed for assessing imaging quality and ERD, and compared to 90 RMDCT-CA scans performed with (n=45) and without (n=45) tube current modulation, selected from our database on the basis of similar demographical characteristics. ERD was compared between all three groups. Imaging quality was assessed by two independent observers and compared to the imaging quality of the group of RMDCT-CA scans performed with tube current modulation. The interobserver variability was also determined. Results. There were no significant differences in imaging quality between the two groups. Interobserver variability was k=0.92 (95 % CI: 0.87-0.96). The ERD (mean ± SD) using PMDCT-CA was 2.88 ± 0.37 mSv compared to 10.50 ± 1.15 mSv (p [es

  18. Subtraction imaging of the ECG gated cardiac CT

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

    1987-05-01

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

  19. Prospectively ECG-triggered sequential dual-source coronary CT angiography in patients with atrial fibrillation: comparison with retrospectively ECG-gated helical CT

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    Xu, Lei; Yang, Lin; Zhang, Zhaoqi [Capital Medical University, Department of Radiology, Beijing Anzhen Hospital, Beijing (China); Wang, Yining; Jin, Zhengyu [Chinese Academy of Medical Sciences, Department of Radiology, Peking Union Medical College Hospital, Beijing (China); Zhang, Longjiang; Lu, Guangming [Nanjing University, Department of Medical Imaging, Jinling Hospital, Clinical School of Medical College, Nanjing, Jiangsu (China)

    2013-07-15

    To investigate the feasibility of applying prospectively ECG-triggered sequential coronary CT angiography (CCTA) to patients with atrial fibrillation (AF) and evaluate the image quality and radiation dose compared with a retrospectively ECG-gated helical protocol. 100 patients with persistent AF were enrolled. Fifty patients were randomly assigned to a prospective protocol and the other patients to a retrospective protocol using a second-generation dual-source CT (DS-CT). Image quality was evaluated using a four-point grading scale (1 = excellent, 2 = good, 3 = moderate, 4 = poor) by two reviewers on a per-segment basis. The coronary artery segments were considered non-diagnostic with a quality score of 4. The radiation dose was evaluated. Diagnostic segment rate in the prospective group was 99.4 % (642/646 segments), while that in the retrospective group was 96.5 % (604/626 segments) (P < 0.001). Effective dose was 4.29 {+-} 1.86 and 11.95 {+-} 5.34 mSv for each of the two protocols (P < 0.001), which was a 64 % reduction in the radiation dose for prospective sequential imaging compared with retrospective helical imaging. In AF patients, prospectively ECG-triggered sequential CCTA is feasible using second-generation DS-CT and can decrease >60 % radiation exposure compared with retrospectively ECG-gated helical imaging while improving diagnostic image quality. (orig.)

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

    International Nuclear Information System (INIS)

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

    2002-01-01

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

  1. Low flip angle spin-echo MR imaging to obtain better Gd-DTPA enhanced imaging with ECG gating

    International Nuclear Information System (INIS)

    Sugimura, Kazuro; Kawamitsu, Hideaki; Yoshikawa, Kazuaki; Kasai, Toshifumi; Yuasa, Koji; Ishida, Tetsuya

    1992-01-01

    ECG-gated spin-echo imaging (ECG-SE) can reduce physiological motion artifact. However, ECG-SE does not provide strong T1-weighted images because repetition time (TR) depends on heart rate (HR). We investigated the usefulness of low flip angle spin-echo imaging (LFSE) in obtaining more T1-dependent contrast with ECG gating. In computer simulation, the predicted image contrast and single-to-noise ratio (SNR) obtained for each flip angle (0-180deg) and each TR (300 msec-1200 msec) were compared with those obtained by conventional T1-weighted spin-echo imaging (CSE: TR=500 msec, TE=20 msec). In clinical evaluation, tissue contrast [contrast index (CI): (SI of lesion-SI of muslce) 2* 100/SI of muscle] obtained by CSE and LFSE were compared in 17 patients. At a TR of 1,000 msec, T1-dependent contrast increased with decreasing flip angle and that at 38deg was identical to that with T1-weighted spin-echo. SNR increased with the flip angle until 100deg, and that at 53deg was identical to that with T1-weighted spin-echo. CI on LFSE (74.0±52.0) was significantly higher than CI on CSE (40.9±35.9). ECG-gated LFSE imaging provides better T1-dependent contrast than conventional ECG-SE. This method was especially useful for Gd-DTPA enhanced MR imaging. (author)

  2. Value of 3D-Volume Rendering in the Assessment of Coronary Arteries with Retrospectively Ecg-Gated Multislice Spiral CT

    International Nuclear Information System (INIS)

    Mahnken, A.H.; Wildberger, J.E.; Dedden, K.; Schmitz-Rode, T.; Guenther, R.W.; Sinha, A.M.; Hoffmann, R.; Stanzel, S.

    2003-01-01

    Purpose: To assess the diagnostic value and measurement precision of 3D volume rendering technique (3D-VRT) from retrospectively ECG-gated multislice spiral CT (MSCT) data sets for imaging of the coronary arteries. Material and Methods: In 35 patients, retrospectively ECG-gated MSCT of the heart using a four detector row MSCT scanner with a standardized examination protocol was performed as well as quantitative X-ray coronary angiography (QCA). The MSCT data was assessed on segmental basis using 3D-VRT exclusively. The coronary artery diameters were measured at the origin of each main coronary branch and 1 cm, 3 cm and 5 cm distally. The minimum, maximum and mean diameters were determined from MSCT angiography and compared to QCA. Results: A total of 353 of 525 (67.2%) coronary artery segments were assessable by MSCT angiography. The proximal segments were more often assessable when compared to the distal segments. Stenoses were detected with a sensitivity of 82.6% and a specificity of 92.8%. According to the Bland-Altman method the mean differences between QCA and MSCT ranged from 0.55 to 1.07 mm with limits of agreement from 2.2 mm to 2.7 mm. Conclusion: When compared to QCA, the ability of 3D-VRT to quantitatively assess coronary artery diameters and coronary artery stenoses is insufficient for clinical purposes

  3. Coronary Artery Stent Evaluation Using a Vascular Model at 64-Detector Row CT: Comparison between Prospective and Retrospective ECG-Gated Axial Scans

    International Nuclear Information System (INIS)

    Suzuki, Shigeru; Furui, Shigeru; Kaminaga, Tatsuro; Miyazawa, Akiyoshi; Ueno, Yasunari; Konno, Kumiko; Kuwahara, Sadatoshi; Mehta, Dhruv

    2009-01-01

    We wanted to evaluate the performance of prospective electrocardiogram (ECG)-gated axial scans for assessing coronary stents as compared with retrospective ECG-gated helical scans. As for a vascular model of the coronary artery, a tube of approximately 2.5-mm inner diameter was adopted and as for stents, three (Bx-Velocity, Express2, and Micro Driver) different kinds of stents were inserted into the tube. Both patent and stenotic models of coronary artery were made by instillating different attenuation (396 vs. 79 Hounsfield unit [HU]) of contrast medium within the tube in tube model. The models were scanned with two types of scan methods with a simulated ECG of 60 beats per minute and using display field of views (FOVs) of 9 and 18 cm. We evaluated the in-stent stenosis visually, and we measured the attenuation values and the diameter of the patent stent lumen. The visualization of the stent lumen of the vascular models was improved with using the prospective ECG-gated axial scans and a 9-cm FOV. The inner diameters of the vascular models were underestimated with mean measurement errors of -1.10 to -1.36 mm. The measurement errors were smaller with using the prospective ECG-gated axial scans (Bx-Velocity and Express2, p < 0.0001; Micro Driver, p = 0.0004) and a 9-cm FOV (all stents: p < 0.0001), as compared with the other conditions, respectively. The luminal attenuation value was overestimated in each condition. For the luminal attenuation measurement, the use of prospective ECG-gated axial scans provided less measurement error compared with the retrospective ECG-gated helical scans (all stents: p < 0.0001), and the use of a 9-cm FOV tended to decrease the measurement error. The visualization of coronary stents is improved by the use of prospective ECG-gated axial scans and using a small FOV with reduced blooming artifacts and increased spatial resolution

  4. Multi detector computed tomography (MDCT) of the aortic root; ECG-gated verses non-ECG-gated examinations

    International Nuclear Information System (INIS)

    Kristiansen, Joanna; Guenther, Anne; Aalokken, Trond Mogens; Andersen, Rune

    2011-01-01

    Purpose: Motion artifacts may degrade a conventional CT examination of the ascending aorta and hinder accurate diagnosis. We quantitatively compared retrospectively electrocardiographic (ECG) -gated multi detector computed tomography (MDCT) with non-ECG-gated MDCT in order to demonstrate whether or not one of the methods should be preferred. Method: The study included seventeen patients with surgically reconstructed aortic root and reimplanted coronary arteries. All patients had undergone both non-gated MDCT and retrospectively ECG-gated MDCT employing a stringently modulated tube current with single phase image reconstruction. The incidence of motion artifacts in the left main coronary artery (LM), proximal right coronary artery (RCA), and aortic root and ascending aorta were rated using a four point scale. The effective dose for each scan was calculated and normalized to a 15 cm scan length. Statistical analysis of motion artifacts and radiation dose was performed using Wilcoxon matched pairs signed rank sum test. Results: A significant reduction in motion artifacts was found in all three vessels in images from the retrospectively ECG-gated scans (LM: P = 0.005, RCA: P = 0.015, aorta: P = 0.003). The mean normalized effective radiation dose was 3.69 mSv (±1.03) for the non-ECG-gated scans and 16.37 mSv (±2.53) for the ECG-gated scans. Conclusion: Retrospective ECG-gating with single phase reconstruction significantly reduces the incidence of motion artifacts in the aortic root and the proximal portion of the coronary arteries but at the expense of a fourfold increase in radiation dose.

  5. Assessment of left ventricular performance by ECG-gated SPECT. Comparison with magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Tadamura, Eiji; Inubushi, Masayuki; Kubo, Shigeto; Matsumoto, Keiichi; Yokoyama, Hiroshi; Fujita, Toru; Konishi, Junji [Kyoto Univ. (Japan). Faculty of Medicine

    1999-10-01

    In the measurement of a left ventricular volume, MIBI-QGS was compared with MRI. Because it became clear by the experiment using phantom that a volume calculated with QGS was smaller than the actual volume, data of clinical study were corrected. Subjects were 20 patients with coronary artery disease. Fourteen patients had anamnesis of myocardial infarct. ECG-gated SPECT was performed one hour after intravenous injection of MIBI (600 MBq) in rest. End diastolic volume (EDV), end systolic volume (ESV) and ejection fraction (EF) were calculated using QGS. Cine-MR image was obtained by using MR system of 1.5 Tesla within 1 week after SPECT. A condition was as follows; segmented k-space gradient echo with view sharing, TR=11 ms, TE=1.4 ms, flip angle 20 degree, field of view 32 cm, matrix 256 x 196, 8 lines per segment. LVEF, ESV and EF were analysed by Bland-Altman method, and the difference between MIBI-gated-SPECT and MRI was no problem. Horizontal dislocation image and vertical major axis dislocation image were provided. Minor axis crossing images of 10-12 slice were also filmed in order to cover all left ventricles. As a result, availability of MIBI-QGS became clear. Some factors which produces the measurement error are examined. (K.H.)

  6. Hybrid ECG-gated versus non-gated 512-slice CT angiography of the aorta and coronary artery: image quality and effect of a motion correction algorithm.

    Science.gov (United States)

    Lee, Ji Won; Kim, Chang Won; Lee, Geewon; Lee, Han Cheol; Kim, Sang-Pil; Choi, Bum Sung; Jeong, Yeon Joo

    2018-02-01

    Background Using the hybrid electrocardiogram (ECG)-gated computed tomography (CT) technique, assessment of entire aorta, coronary arteries, and aortic valve can be possible using single-bolus contrast administration within a single acquisition. Purpose To compare the image quality of hybrid ECG-gated and non-gated CT angiography of the aorta and evaluate the effect of a motion correction algorithm (MCA) on coronary artery image quality in a hybrid ECG-gated aorta CT group. Material and Methods In total, 104 patients (76 men; mean age = 65.8 years) prospectively randomized into two groups (Group 1 = hybrid ECG-gated CT; Group 2 = non-gated CT) underwent wide-detector array aorta CT. Image quality, assessed using a four-point scale, was compared between the groups. Coronary artery image quality was compared between the conventional reconstruction and motion correction reconstruction subgroups in Group 1. Results Group 1 showed significant advantages over Group 2 in aortic wall, cardiac chamber, aortic valve, coronary ostia, and main coronary arteries image quality (all P ECG-gated CT significantly improved the heart and aortic wall image quality and the MCA can further improve the image quality and interpretability of coronary arteries.

  7. Prospective ECG-triggered axial CT at 140-kV tube voltage improves coronary in-stent restenosis visibility at a lower radiation dose compared with conventional retrospective ECG-gated helical CT

    Energy Technology Data Exchange (ETDEWEB)

    Horiguchi, Jun; Fujioka, Chikako; Kiguchi, Masao; Kohno, Shingo [Hiroshima University Hospital, Department of Clinical Radiology, Hiroshima (Japan); Yamamoto, Hideya; Kitagawa, Toshiro [Hiroshima University, Department of Molecular and Internal Medicine, Division of Clinical Medical Science, Programs for Applied Biomedicine, Graduate School of Biomedical Sciences, Hiroshima (Japan); Ito, Katsuhide [Hiroshima University, Department of Radiology, Division of Medical Intelligence and Informatics, Programs for Applied Biomedicine, Graduate School of Biomedical Sciences, Hiroshima (Japan)

    2009-10-15

    The purpose of this study was to compare coronary 64-slice CT angiography (CTA) protocols, specifically prospective electrocardiograph (ECG)-triggered and retrospective ECG-gated CT acquisition performed using a tube voltage of 140 kV and 120 kV, regarding intracoronary stent imaging. Coronary artery stents (n=12) with artificial in-stent restenosis (50% luminal reduction, 40 HU) on a cardiac phantom were examined by CT at heart rates of 50-75 beats per minute (bpm). The subjective visibility of in-stent restenosis was evaluated with a three-point scale (1 clearly visible, 2 visible, and 3 not visible), and artificial lumen narrowing [(inner stent diameter - measured lumen diameter)/inner stent diameter], lumen attenuation increase ratio [(in-stent attenuation - coronary lumen attenuation)/coronary lumen attenuation], and signal-to-noise ratio of in-stent lumen were determined. The effective dose was estimated. The artificial lumen narrowing (mean 43%), the increase of lumen attenuation (mean 46%), and signal-to-noise ratio (mean 7.8) were not different between CT acquisitions (p=0.12-0.91). However, the visibility scores of in-stent restenosis were different (p<0.05) between ECG-gated CTA techniques: (a) 140-kV prospective (effective dose 4.6 mSv), 1.6; (b) 120-kV prospective (3.3 mSv), 1.8; (c) 140-kV retrospective (16.4-18.8 mSv), 1.9; and (d) 120-kV retrospective (11.0-13.4 mSv), 1.9. Thus, 140-kV prospective ECG-triggered CTA improves coronary in-stent restenosis visibility at a lower radiation dose compared with retrospective ECG-gated CTA. (orig.)

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

    International Nuclear Information System (INIS)

    Salem, Randa; Remy-Jardin, Martine; Delhaye, Damien; Khalil, Chadi; Teisseire, Antoine; Remy, Jacques; Delannoy-Deken, Valerie; Duhamel, Alain

    2006-01-01

    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 β-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-diastolic ventricular volumes. The mean (±SD) DLP

  9. Clinical application of ECG-gated 256-slice CT angiography for diagnosis of congenital heart disease

    International Nuclear Information System (INIS)

    Tian Xinhua; Liu Jianhua; Gong Tingting; Geng Lili; Sun Yong

    2011-01-01

    Objective: To investigate the clinical application of ECG-gated 256-slice CT angiography for diagnosis of congenital heart disease, and to evaluate the relationship of the image quality and radiation dose between prospective ECG-gated and retrospective ECG-gated cardiac CT angiography (CTA). Methods: Sixty patients who doubt congenital heart disease underwent cardiac CTA, and they were randomly divided into two groups. Thirty patients in group A underwent prospective ECG-gated cardiac CTA, and thirty patients in group B underwent retrospective ECG-gated cardiac CTA. Then the homogeneous enhancement of vascular structures, stair-step artifact, overall image quality and radiation dose were evaluated. Results: The homogeneous enhancement of vascular structures were 2.8±0.3 and 2.7±0.6, respectively, in two groups; and there was no statistical significance (P>0.05). The stair-step artifact were 3.0±0.9 and 3.1±0.9, respectively, in two groups; and there was also no statistical significance (P>0.05). The overall image quality were 3.0±0.8 and 3.1±0.9, respectively, in two group; and there was statistical significance (P>0.05). However, the effective dose were (5.24±0.52) mSv and (16.68±1.49) mSv, respectively, in two groups; and there was statistical significance (P<0.001). Conclusion: Compared with retrospective ECG-gated cardiac CTA, prospective ECG-gated cardiac CTA can reduce radiation dose about 68.6% , while maintaining the image quality which could be made diagnosis. (authors)

  10. 128-slice CT angiography of the aorta without ECG-gating: efficacy of faster gantry rotation time and iterative reconstruction in terms of image quality and radiation dose

    Energy Technology Data Exchange (ETDEWEB)

    Russo, Vincenzo; Garattoni, Monica; Buia, Francesco; Attina, Domenico; Lovato, Luigi; Zompatori, Maurizio [University Hospital ' ' S.Orsola' ' , Cardio-Thoracic-Vascular Department, Cardio-Thoracic Radiology Unit, Bologna (Italy)

    2016-02-15

    To evaluate image quality and radiation dose of non ECG-gated 128-slice CT angiography of the aorta (CTAA) with fast gantry rotation time and iterative reconstruction. Four hundred and eighty patients underwent non ECG-gated CTAA. Qualitative and quantitative image quality assessments were performed. Radiation dose was assessed and compared with the dose of patients who underwent ECG-gated CTAA (n = 126) and the dose of previous CTAA performed with another CT (n = 339). Image quality (aortic root-ascending portion) was average-to-excellent in more than 94 % of cases, without any non-diagnostic scan. For proximal coronaries, image quality was average-to-excellent in more than 50 %, with only 21.5 % of non-diagnostic cases. Quantitative analysis results were also good. Mean radiation dose for thoracic CTAA was 5.6 mSv versus 20.6 mSv of ECG-gated protocol and 20.6 mSv of 16-slice CTAA scans, with an average dose reduction of 72.8 % (p < 0.001). Mean radiation dose for thoracic-abdominal CTAA was 9.7 mSv, versus 20.9 mSv of 16-slice CTAA scans, with an average dose reduction of 53.6 % (p < 0.001). Non ECG-gated 128-slice CTAA is feasible and able to provide high quality visualization of the entire aorta without significant motion artefacts, together with a considerable dose and contrast media volume reduction. (orig.)

  11. 128-slice CT angiography of the aorta without ECG-gating: efficacy of faster gantry rotation time and iterative reconstruction in terms of image quality and radiation dose

    International Nuclear Information System (INIS)

    Russo, Vincenzo; Garattoni, Monica; Buia, Francesco; Attina, Domenico; Lovato, Luigi; Zompatori, Maurizio

    2016-01-01

    To evaluate image quality and radiation dose of non ECG-gated 128-slice CT angiography of the aorta (CTAA) with fast gantry rotation time and iterative reconstruction. Four hundred and eighty patients underwent non ECG-gated CTAA. Qualitative and quantitative image quality assessments were performed. Radiation dose was assessed and compared with the dose of patients who underwent ECG-gated CTAA (n = 126) and the dose of previous CTAA performed with another CT (n = 339). Image quality (aortic root-ascending portion) was average-to-excellent in more than 94 % of cases, without any non-diagnostic scan. For proximal coronaries, image quality was average-to-excellent in more than 50 %, with only 21.5 % of non-diagnostic cases. Quantitative analysis results were also good. Mean radiation dose for thoracic CTAA was 5.6 mSv versus 20.6 mSv of ECG-gated protocol and 20.6 mSv of 16-slice CTAA scans, with an average dose reduction of 72.8 % (p < 0.001). Mean radiation dose for thoracic-abdominal CTAA was 9.7 mSv, versus 20.9 mSv of 16-slice CTAA scans, with an average dose reduction of 53.6 % (p < 0.001). Non ECG-gated 128-slice CTAA is feasible and able to provide high quality visualization of the entire aorta without significant motion artefacts, together with a considerable dose and contrast media volume reduction. (orig.)

  12. ECG-gating in non-cardiac digital subtraction angiography

    International Nuclear Information System (INIS)

    Gattoni, F.; Baldini, V.; Cairo, F.

    1987-01-01

    This paper reports the results of the ECG-gating in non-cardiac digital subtraction angiography (DSA). One hundred and fifteen patients underwent DSA (126 examinations); ECG-gating was applied in 66/126 examinations: images recorded at 70% of R wave were subtracted. Artifacts produced by vascular movements were evaluated in all patients: only 40 examinations, carried out whithout ECG-gating, showed vascular artifacts. The major advantage of the ECG-gated DSA is the more efficent subtraction because of the better images superimposition: therefore, ECG-gating can be clinically helpful. On the contrary, it could be a problem in arrhytmic or bradycardic patients. ECG-gating is helpful in DSA imaging of the thoracic and abdominal aorta and of the cervical and renal arteries. In the examinations of peripheral vessels of the limbs it is not so efficent as in the trunk or in the neck

  13. Visualization of neonatal coronary arteries on multidetector row CT: ECG-gated versus non-ECG-gated technique

    International Nuclear Information System (INIS)

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

    2007-01-01

    Multidetector CT (MDCT) seems to be a promising tool for detection of neonatal coronary arteries, but whether the ECG-gated or non-ECG-gated technique should be used has not been established. To compare the detection rate and image quality of neonatal coronary arteries on MDCT using ECG-gated and non-ECG-gated techniques. Twelve neonates with complex congenital heart disease were included. The CT scan was acquired using an ECG-gated technique, and the most quiescent phase of the RR interval was selected to represent the ECG-gated images. The raw data were then reconstructed without the ECG signal to obtain non-ECG-gated images. The detection rate and image quality of nine coronary artery segments in the two sets of images were then compared. A two-tailed paired t test was used with P values <0.05 considered as statistically significant. In all coronary segments the ECG-gated technique had a better detection rate and produced images of better quality. The difference between the two techniques ranged from 25% in the left main coronary artery to 100% in the distal right coronary artery. For neonates referred for MDCT, if evaluation of coronary artery anatomy is important for the clinical management or surgical planning, the ECG-gated technique should be used because it can reliably detect the coronary arteries. (orig.)

  14. 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

    International Nuclear Information System (INIS)

    Delhaye, Damien; Remy-Jardin, Martine; Salem, Randa; Teisseire, Antoine; Khalil, Chadi; Remy, Jacques; Delannoy-Deken, Valerie; Duhamel, Alain

    2007-01-01

    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 β-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 β-blockers in patients with a heart rate below 80 bpm. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

    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

  16. Prospective ECG triggering reduces prosthetic heart valve-induced artefacts compared with retrospective ECG gating on 256-slice CT

    NARCIS (Netherlands)

    Symersky, P.; Habets, J.; Westers, P.; Mol, de B.A.J.M.; Prokop, M.; Budde, R.P.J.

    2012-01-01

    Objectives Multidetector computed tomography (MDCT) has diagnostic value for the evaluation of prosthetic heart valve (PHV) dysfunction but it is hampered by artefacts. We hypothesised that image acquisition using prospective triggering instead of retrospective gating would reduce artefacts related

  17. Coronary artery bypass graft imaging using ECG-gated multislice computed tomography: Comparison with catheter angiography

    International Nuclear Information System (INIS)

    Moore, R.K.G.; Sampson, C.; MacDonald, S.; Moynahan, C.; Groves, D.; Chester, M.R.

    2005-01-01

    AIM: To compare the value of multislice computerized tomography (MSCT) in imaging coronary artery bypass grafts (CABGs) by direct quantitative comparison with standard invasive angiography. METHODS: Using MSCT, 50 consecutive patients who had previously undergone CABG surgery and had recently undergone invasive angiography for recurrent angina pectoris, were studied further using MSCT after intravenous injection of non-ionic contrast agent; cardiac imaging was performed during a single breath-hold. Graft anatomy was quantified, using both quantitative coronary angiography (QCA) and MSCT, by different investigators blinded to each other. Reproducibility was quantified using the standard error of the measurement expressed as a percentage in log-transformed values (CV%) and intraclass correlation (ICC). RESULTS: All 150 grafts were imaged using MSCT; only 4 patent grafts were not imaged using selective angiography. Good agreement was achieved between MSCT and QCA on assessment of proximal anastomoses (CV% 25.2, ICC 0.84), mid-vessel luminal diameter (CV% 15.5, ICC 0.91) and aneurysmal dilations (CV% 14.3). Reasonable agreement was reached on assessment of distal anastomoses (CV% 26.7, ICC 0.66) and categorization of distal run-off (ICC 0.73). Good agreement was observed for stenoses of over 50% luminal loss (CV% 8.7, ICC 0.97) but agreement on assessment of less severe lesions was poor (CV% 208.7, ICC 0.51). CONCLUSION: This study demonstrates that CABGs can be quantitatively evaluated using MSCT, and that significant lesions present in all CABG segments can be reliably identified. Agreement between MSCT and QCA for lesions of less than 50% luminal loss was poor

  18. Coronary artery bypass graft imaging using ECG-gated multislice computed tomography: Comparison with catheter angiography

    Energy Technology Data Exchange (ETDEWEB)

    Moore, R.K.G. [Cardiothoracic Centre, Liverpool (United Kingdom)]. E-mail: moore@roger.go-legend.net; Sampson, C. [Cardiothoracic Centre, Liverpool (United Kingdom); MacDonald, S. [Cardiothoracic Centre, Liverpool (United Kingdom); Moynahan, C. [Cardiothoracic Centre, Liverpool (United Kingdom); Groves, D. [National Refractory Angina Centre, Liverpool (United Kingdom); Chester, M.R. [National Refractory Angina Centre, Liverpool (United Kingdom)

    2005-09-01

    AIM: To compare the value of multislice computerized tomography (MSCT) in imaging coronary artery bypass grafts (CABGs) by direct quantitative comparison with standard invasive angiography. METHODS: Using MSCT, 50 consecutive patients who had previously undergone CABG surgery and had recently undergone invasive angiography for recurrent angina pectoris, were studied further using MSCT after intravenous injection of non-ionic contrast agent; cardiac imaging was performed during a single breath-hold. Graft anatomy was quantified, using both quantitative coronary angiography (QCA) and MSCT, by different investigators blinded to each other. Reproducibility was quantified using the standard error of the measurement expressed as a percentage in log-transformed values (CV%) and intraclass correlation (ICC). RESULTS: All 150 grafts were imaged using MSCT; only 4 patent grafts were not imaged using selective angiography. Good agreement was achieved between MSCT and QCA on assessment of proximal anastomoses (CV% 25.2, ICC 0.84), mid-vessel luminal diameter (CV% 15.5, ICC 0.91) and aneurysmal dilations (CV% 14.3). Reasonable agreement was reached on assessment of distal anastomoses (CV% 26.7, ICC 0.66) and categorization of distal run-off (ICC 0.73). Good agreement was observed for stenoses of over 50% luminal loss (CV% 8.7, ICC 0.97) but agreement on assessment of less severe lesions was poor (CV% 208.7, ICC 0.51). CONCLUSION: This study demonstrates that CABGs can be quantitatively evaluated using MSCT, and that significant lesions present in all CABG segments can be reliably identified. Agreement between MSCT and QCA for lesions of less than 50% luminal loss was poor.

  19. Erroneous cardiac ECG-gated PET list-mode trigger events can be retrospectively identified and replaced by an offline reprocessing approach: first results in rodents

    International Nuclear Information System (INIS)

    Böning, Guido; Todica, Andrei; Vai, Alessandro; Lehner, Sebastian; Xiong, Guoming; Mille, Erik; Ilhan, Harun; Fougère, Christian la; Bartenstein, Peter; Hacker, Marcus

    2013-01-01

    The assessment of left ventricular function, wall motion and myocardial viability using electrocardiogram (ECG)-gated [ 18 F]-FDG positron emission tomography (PET) is widely accepted in human and in preclinical small animal studies. The nonterminal and noninvasive approach permits repeated in vivo evaluations of the same animal, facilitating the assessment of temporal changes in disease or therapy response. Although well established, gated small animal PET studies can contain erroneous gating information, which may yield to blurred images and false estimation of functional parameters. In this work, we present quantitative and visual quality control (QC) methods to evaluate the accuracy of trigger events in PET list-mode and physiological data. Left ventricular functional analysis is performed to quantify the effect of gating errors on the end-systolic and end-diastolic volumes, and on the ejection fraction (EF). We aim to recover the cardiac functional parameters by the application of the commonly established heart rate filter approach using fixed ranges based on a standardized population. In addition, we propose a fully reprocessing approach which retrospectively replaces the gating information of the PET list-mode file with appropriate list-mode decoding and encoding software. The signal of a simultaneously acquired ECG is processed using standard MATLAB vector functions, which can be individually adapted to reliably detect the R-peaks. Finally, the new trigger events are inserted into the PET list-mode file. A population of 30 mice with various health statuses was analyzed and standard cardiac parameters such as mean heart rate (119 ms ± 11.8 ms) and mean heart rate variability (1.7 ms ± 3.4 ms) derived. These standard parameter ranges were taken into account in the QC methods to select a group of nine optimal gated and a group of eight sub-optimal gated [ 18 F]-FDG PET scans of mice from our archive. From the list-mode files of the optimal gated group

  20. Assessment of Myocardial Bridge and Mural Coronary Artery Using ECG-Gated 256-Slice CT Angiography: A Retrospective Study

    Directory of Open Access Journals (Sweden)

    En-sen Ma

    2013-01-01

    Full Text Available Recent clinical reports have indicated that myocardial bridge and mural coronary artery complex (MB-MCA might cause major adverse cardiac events. 256-slice CT angiography (256-slice CTA is a newly developed CT system with faster scanning and lower radiation dose compared with other CT systems. The objective of this study is to evaluate the morphological features of MB-MCA and determine its changes from diastole to systole phase using 256-slice CTA. The imaging data of 2462 patients were collected retrospectively. Two independent radiologists reviewed the collected images and the diagnosis of MB-MCA was confirmed when consistency was obtained. The length, diameter, and thickness of MB-MCA in diastole and systole phases were recorded, and changes of MB-MCA were calculated. Our results showed that among the 2462 patients examined, 336 have one or multiple MB-MCA (13.6%. Out of 389 MB-MCA segments, 235 sites were located in LAD2 (60.41%. The average diameter change of MCA in LAD2 from systole phase to diastole phase was  mm, and 34.9% of MCA have more than 50% diameter stenosis in systole phase. This study suggested that 256-slice CTA multiple-phase reconstruction technique is a reliable method to determine the changes of MB-MCA from diastole to systole phase.

  1. Comparison of transaxial source images and 3-plane, thin-slab maximal intensity projection images for the diagnosis of coronary artery stenosis with using ECG-gated cardiac CT

    International Nuclear Information System (INIS)

    Choi, Jin Woo; Seo, Joon Beom; Do, Kyung Hyun

    2006-01-01

    We wanted to compare the transaxial source images with the optimized three plane, thin-slab maximum intensity projection (MIP) images from electrocardiographic (ECG)-gated cardiac CT for their ability to detect hemodynamically significant stenosis (HSS), and we did this by means of performing a receiver operating characteristic (ROC) analysis. Twenty-eight patients with a heart rate less than 66 beats per minute and who were undergoing both retrospective ECG-gated cardiac CT and conventional coronary angiography were included in this study. The contrast-enhanced CT scans were obtained with a collimation of 16 x 0.75-mm and a rotation time of 420 msec. The tranaxial images were reconstructed at the mid-diastolic phase with a 1-mm slice thickness and a 0.5-mm increment. Using the transaxial images, the slab MIP images were created with a 4-mm thickness and a 2-mm increment, and they covered the entire heart in the horizontal long axis (4 chamber view), in the vertical long axis (2 chamber view) and in the short axis. The transaxial images and MIP images were independently evaluated for their ability to detect HSS. Conventional coronary angiograms of the same study group served as the standard of reference. Four radiologists were requested to rank each image with using a five-point scale (1 = definitely negative, 2 = probably negative, 3 = indeterminate, 4 = probably positive, and 5 definitely positive) for the presence of HSS; the data were then interpreted using ROC analysis. There was no statistical difference in the area under the ROC curve between transaxial images and MIP images for the detection of HSS (0.8375 and 0.8708, respectively; ρ > 0.05). The mean reading time for the transaxial source images and the MIP images was 116 and 126.5 minutes, respectively. The diagnostic performance of the MIP images for detecting HSS of the coronary arteries is acceptable and this technique's ability to detect HSS is comparable to that of the transaxial source images

  2. Utility of Electrocardiography (ECG)-Gated Computed Tomography (CT) for Preoperative Evaluations of Thymic Epithelial Tumors.

    Science.gov (United States)

    Ozawa, Yoshiyuki; Hara, Masaki; Nakagawa, Motoo; Shibamoto, Yuta

    2016-01-01

    Preoperative evaluation of invasion to the adjacent organs is important for the thymic epithelial tumors on CT. The purpose of our study was to evaluate the utility of electrocardiography (ECG)-gated CT for assessing thymic epithelial tumors with regard to the motion artifacts produced and the preoperative diagnostic accuracy of the technique. Forty thymic epithelial tumors (36 thymomas and 4 thymic carcinomas) were examined with ECG-gated contrast-enhanced CT using a dual source scanner. The scan delay after the contrast media injection was 30 s for the non-ECG-gated CT and 100 s for the ECG-gated CT. Two radiologists blindly evaluated both the non-ECG-gated and ECG-gated CT images for motion artifacts and determined whether the tumors had invaded adjacent structures (mediastinal fat, superior vena cava, brachiocephalic veins, aorta, pulmonary artery, pericardium, or lungs) on each image. Motion artifacts were evaluated using a 3-grade scale. Surgical and pathological findings were used as a reference standard for tumor invasion. Motion artifacts were significantly reduced for all structures by ECG gating ( p =0.0089 for the lungs and p ECG-gated CT and ECG-gated CT demonstrated 79% and 95% accuracy, respectively, during assessments of pericardial invasion ( p =0.03). ECG-gated CT reduced the severity of motion artifacts and might be useful for preoperative assessment whether thymic epithelial tumors have invaded adjacent structures.

  3. Automatic extraction of left ventricular mass and volumes using parametric images from non-ECG-gated 15O-water PET/CT

    DEFF Research Database (Denmark)

    Nordström, J; Harms, Hans; Lubberink, Mark

    of the present study was to investigate the feasibility of measuring LV geometry using dynamic 15O-water PET/CT without ECG-gating. Methods: Parametric images of MBF, perfusable tissue fraction (PTF) and LV blood pool were generated automatically using kinetic modelling. Segmentation of the LV wall using PTF......Introduction: 15O-water positron emission tomography (PET) is considered the gold standard for non-invasive quantification of myocardial blood flow (MBF). It has been shown to identify patients with significant coronary artery disease (CAD) with high accuracy. Hypertrophy with or without dilatation...... combined to measure stroke volume (SV=EDV-ESV) and ejection fraction (EF=SV/EDV). Accuracy was determined by comparing PET to cardiac magnetic resonance (CMR) in 30 asymptomatic patients with high grade LV regurgitation (group A). Precision was determined as inter-observer variation in group...

  4. Diagnostic value of early post-exercise 99Tcm-MIBI ECG-gated myocardial perfusion imaging in severe coronary artery disease

    International Nuclear Information System (INIS)

    Li Dianfu; Huang Jun; Feng Jianlin; Cheng Xu; Li Xinli; Cao Kejiang

    2005-01-01

    Objective: To study and compare the diagnostic value in severe coronary artery disease (CAD) of 99 Tc m -methoxyisobutylisonitrile (MIBI) electrocardiogram (ECG)-gated early post-exercise myocardial perfusion imaging (G-MPI) with that of non-ECG-gated myocardial perfusion imaging (NG-MPI). Methods: Two hundred and fifteen suspected CAD patients had undergone G-MPI and coronary artery angiography (CAG) within one month were enrolled and distributed into three-vessel and non-three-vessel CAD groups according to CAG results (≥70%); the diagnostic values in severe CAD of G-MPI and NG-MPI were gained and compared to determine which one of the two protocols would be superior in identification of severe three-vessel CAD. Results: When the ≥70% diameter stenosis CAG was the diagnostic standard of severe CAD, the sensitivity of G-MPI and NG-MPI in the diagnosis of severe CAD were 95.3% (143/150) and 90.7% (136/150, χ 2 =2.509, P=0.113), but when the comparison specifically pinpointed to severe three-vessel CAD, there was significant difference between G-MPI [100%(51/51)] and NG-MPI [92.2% (47/51), χ 2 =4.163, P=0.041]. Diagnostic specificity of G-MPI was 80.0% and that of NG-MPI was 72.3% (χ 2 =1.059, P=0.303). Conclusions: The incremental diagnostic sensitivity of G-MPI adding to the NG-MPI in the diagnosis of severe CAD was mainly from the three-vessel subgroup patients. Exercise stress G-MPI has better diagnostic value in severe three-vessel CAD patients than NG-MPI. (authors)

  5. Prognostic significance of stress myocardial ECG-gated perfusion imaging in asymptomatic patients with diabetic chronic kidney disease on initiation of haemodialysis

    Energy Technology Data Exchange (ETDEWEB)

    Momose, Mitsuru; Kondo, Chisato; Kobayashi, Hideki; Kusakabe, Kiyoko [Tokyo Women' s Medical University, School of Medicine, Department of Radiology, Shinjuku-ku, Tokyo (Japan); Babazono, Tetsuya [Tokyo Women' s Medical University, School of Medicine, Diabetes Centre, Shinjuku-ku, Tokyo (Japan); Nakajima, Takatomo [Tokyo Women' s Medical University, School of Medicine, Department of Cardiology, Shinjuku-ku, Tokyo (Japan)

    2009-08-15

    Diabetic patients with chronic kidney disease (CKD) frequently develop cardiac events within several years of the initiation of haemodialysis. The present study assesses the prognostic significance of stress myocardial ECG-gated perfusion imaging (MPI) in patients with diabetic CKD requiring haemodialysis. Fifty-five asymptomatic patients with diabetic stage V CKD and no history of heart disease scheduled to start haemodialysis were enrolled in this study (56{+-}11 years old; 49 with type 2 diabetes mellitus). All patients underwent {sup 201}Tl stress ECG-gated MPI 1 month before or after the initiation of haemodialysis to assess myocardial involvement. We evaluated SPECT images using 17-segment defect scores graded on a 5-point scale, summed stress score (SSS) and summed difference scores (SDS). The patients were followed up for at least 2 years (42{+-}15 months) to determine coronary intervention (CI) and heart failure (HF) as soft events and acute myocardial infarction (AMI) and all causes of deaths as hard events. The frequencies of myocardial ischaemia, resting perfusion defects, low ejection fraction and left ventricular (LV) dilatation were 24,20,29 and 49%, respectively. Ten events (18%) developed during the follow-up period including four CI, one HF, one AMI and four sudden deaths. Multivariate Cox analysis selected SDS (p=0.0011) and haemoglobin A{sub 1c} (HbA{sub 1c}) (p=0.0076) as independent prognostic indicators for all events. Myocardial ischaemia, in addition to glycaemic control, is a strong prognostic marker for asymptomatic patients with diabetic CKD who are scheduled to start haemodialysis. Stress MPI is highly recommended for the management and therapeutic stratification of such patients. (orig.)

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

    International Nuclear Information System (INIS)

    D'Agostino, A.G.; Remy-Jardin, M.; Khalil, C.; Remy, J.; Delannoy-Deken, V.; Duhamel, A.; Flohr, T.

    2006-01-01

    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 interpolation artefacts

  7. Reduction of the estimated radiation dose and associated patient risk with prospective ECG-gated 256-slice CT coronary angiography

    International Nuclear Information System (INIS)

    Efstathopoulos, E P; Kelekis, N L; Pantos, I; Brountzos, E; Argentos, S; Grebac, J; Ziaka, D; Seimenis, I; Katritsis, D G

    2009-01-01

    Computed tomography (CT) coronary angiography has been widely used since the introduction of 64-slice scanners and dual-source CT technology, but high radiation doses have been reported. Prospective ECG-gating using a 'step-and-shoot' axial scanning protocol has been shown to reduce radiation exposure effectively while maintaining diagnostic accuracy. 256-slice scanners with 80 mm detector coverage have been currently introduced into practice, but their impact on radiation exposure has not been adequately studied. The aim of this study was to assess radiation doses associated with CT coronary angiography using a 256-slice CT scanner. Radiation doses were estimated for 25 patients scanned with either prospective or retrospective ECG-gating. Image quality was assessed objectively in terms of mean CT attenuation at selected regions of interest on axial coronary images and subjectively by coronary segment quality scoring. It was found that radiation doses associated with prospective ECG-gating were significantly lower than retrospective ECG-gating (3.2 ± 0.6 mSv versus 13.4 ± 2.7 mSv). Consequently, the radiogenic fatal cancer risk for the patient is much lower with prospective gating (0.0176% versus 0.0737%). No statistically significant differences in image quality were observed between the two scanning protocols for both objective and subjective quality assessments. Therefore, prospective ECG-gating using a 'step-and-shoot' protocol that covers the cardiac anatomy in two axial acquisitions effectively reduces radiation doses in 256-slice CT coronary angiography without compromising image quality.

  8. Abnormal intraluminal signal within the pulmonary arteries on MR imaging: Differentiation between slow blood flow and thrombus using an ECG-gated; multiphasic: Spin-echo technique

    International Nuclear Information System (INIS)

    White, R.D.; Higgins, C.B.

    1986-01-01

    The authors evaluated abnormal MR imaging signal patterns in the pulmonary arteries of 22 patients with pulmonary hypertension (n = 13), pulmonary embolus (n = 4), or both (n = 5). Using multiphasic (five or six phases; 19 patients) or standard (three patients with pulmonary embolus) ECG-gated, double spin-echo techniques, they were able to differentiate between causes of such abnormal signal patterns. The pattern of slow blood flow (abnormal signal in systole with fluctuating distribution during cardiac cycle, and intensity increasing visually from first to second echo) was noted in 89% of patients with pulmonary hypertension alone or in combination with pulmonary embolism, and was characteristic of high systolic pulmonary pressures (12 of 12 patients with pressure > 80 mm Hg, vs. 3 of 5 patients with pressure 55 mm Hg vs. 5 of 7 patients with pressures <55 mm Hg). This pattern was differentiated from that of thrombus (persistent signal with fixed distribution during cardiac cycle, and little to no visible intensity change from first to second echo), which was noted in six of seven proved embolus cases. Thus, gated multiphase MR imaging shows potential for the noninvasive visualization of pulmonary embolus and the differentiation of this entity from the slow blood flow of pulmonary hypertension

  9. Residual motion compensation in ECG-gated interventional cardiac vasculature reconstruction

    International Nuclear Information System (INIS)

    Schwemmer, C; Müller, K; Hornegger, J; Rohkohl, C; Lauritsch, G

    2013-01-01

    Three-dimensional reconstruction of cardiac vasculature from angiographic C-arm CT (rotational angiography) data is a major challenge. Motion artefacts corrupt image quality, reducing usability for diagnosis and guidance. Many state-of-the-art approaches depend on retrospective ECG-gating of projection data for image reconstruction. A trade-off has to be made regarding the size of the ECG-gating window. A large temporal window is desirable to avoid undersampling. However, residual motion will occur in a large window, causing motion artefacts. We present an algorithm to correct for residual motion. Our approach is based on a deformable 2D–2D registration between the forward projection of an initial, ECG-gated reconstruction, and the original projection data. The approach is fully automatic and does not require any complex segmentation of vasculature, or landmarks. The estimated motion is compensated for during the backprojection step of a subsequent reconstruction. We evaluated the method using the publicly available CAVAREV platform and on six human clinical datasets. We found a better visibility of structure, reduced motion artefacts, and increased sharpness of the vessels in the compensated reconstructions compared to the initial reconstructions. At the time of writing, our algorithm outperforms the leading result of the CAVAREV ranking list. For the clinical datasets, we found an average reduction of motion artefacts by 13 ± 6%. Vessel sharpness was improved by 25 ± 12% on average. (paper)

  10. Residual motion compensation in ECG-gated interventional cardiac vasculature reconstruction

    Science.gov (United States)

    Schwemmer, C.; Rohkohl, C.; Lauritsch, G.; Müller, K.; Hornegger, J.

    2013-06-01

    Three-dimensional reconstruction of cardiac vasculature from angiographic C-arm CT (rotational angiography) data is a major challenge. Motion artefacts corrupt image quality, reducing usability for diagnosis and guidance. Many state-of-the-art approaches depend on retrospective ECG-gating of projection data for image reconstruction. A trade-off has to be made regarding the size of the ECG-gating window. A large temporal window is desirable to avoid undersampling. However, residual motion will occur in a large window, causing motion artefacts. We present an algorithm to correct for residual motion. Our approach is based on a deformable 2D-2D registration between the forward projection of an initial, ECG-gated reconstruction, and the original projection data. The approach is fully automatic and does not require any complex segmentation of vasculature, or landmarks. The estimated motion is compensated for during the backprojection step of a subsequent reconstruction. We evaluated the method using the publicly available CAVAREV platform and on six human clinical datasets. We found a better visibility of structure, reduced motion artefacts, and increased sharpness of the vessels in the compensated reconstructions compared to the initial reconstructions. At the time of writing, our algorithm outperforms the leading result of the CAVAREV ranking list. For the clinical datasets, we found an average reduction of motion artefacts by 13 ± 6%. Vessel sharpness was improved by 25 ± 12% on average.

  11. Non-enhanced 3D MR angiography of the lower extremity using ECG-gated TSE imaging with non-selective refocusing pulses. Initial experience

    International Nuclear Information System (INIS)

    Lanzman, R.S.; Blondin, D.; Orzechowski, D.; Scherer, A.; Moedder, U.; Kroepil, P.; Godehardt, E.

    2010-01-01

    Purpose: To evaluate non-enhanced 3D MR angiography using turbo spin echo (TSE) imaging with non-selective refocusing pulses (NATIVE SPACE MRA) for the visualization of the arteries of the lower extremity. Materials and Methods: Three-station imaging (iliac arteries, femoral arteries, arteries of the lower leg) was performed in 8 healthy volunteers and 3 patients with peripheral artery disease (PAD) using a 1.5 T MR scanner. In 8 healthy volunteers, 4 different acquisition schemes were performed with the following imaging parameters: S 1: acquisition with every heartbeat (RR = 1), spoiler gradient of 25 % (SG = 25 %); S 2: RR = 1, SG = 0 %; S 3: RR = 2, SG = 25 %; S 4: RR = 2, SG = 0 %. The subjective image quality on a 4-point-scale (4 = excellent to 1 = not diagnostic) and relative SNR were assessed. In 3 patients with peripheral artery disease (PAD), SPACE MRA was performed for assessment of stenosis. Results: The mean subjective image quality was significantly lower for the iliac arteries compared to the femoral arteries and arteries of the lower leg (p < 0.0001). The subjective image quality for acquisition scheme S 1 was significantly lower than the image quality for S 3 and S 4 for the iliac arteries (p < 0.01), while the subjective image quality for acquisition scheme S 2 was significantly lower than S 3 and S 4 for the femoral arteries and the arteries of the lower leg (p < 0.01). The relative SNR was significantly higher for acquisition schemes S 3 and S 4 as compared to S 1 and S 2 (p < 0.0001) for all regions. SPACE MRA disclosed 7 significant stenoses in 3 PAD patients. Conclusion: ECG-gated SPACE MRA is a promising imaging technique for non-enhanced assessment of the arteries of the lower extremity. (orig.)

  12. Identification and Assessment of Paradoxical Ventricular Wall Motion Using ECG Gated Blood Pool Scan - Comparison of cine Loop , Phase Analysis and Paradox Image -

    International Nuclear Information System (INIS)

    Lee, Jae Tae; Kim, Gwang Weon; Lee, Kyu Bo; Chung, Byung Chun; Whang, Kee Suk; Chae, Sung Chul; Paek, Wee Hyun; Cheon, Jae Eun; Lee, Hyong Woo; Chung, Jin Hong

    1990-01-01

    Sixty-four patients with paradoxical ventricular wall motion noticed both in angiocardiography or 2-dimensional echocardiography were assessed by ECG gated blood pool scan (GBPS). Endless cine loop image, phase and amplitude images and paradox image obtained by visual inspection of each cardiac beat or Fourier transformation of acquired raw data were investigated to determine the incremental value of GBPS with these processing methods for identification of paradoxical ventricular wall motion. The results were as follows:1) Paradoxical wall motions were observed on interventricular septum in 34 cases, left ventricular free wall in 26 and right ventricular wall in 24. Underlying heart diseases were is chemic (23 cases) valvular(9), congenital heart disease (12), cardiomyopathy (5), pericardial effusion(5), post cardiac surgery(3), corpulmonale (2), endocarditis (l) and right ventricular tumor(l). 2) Left ventricular ejection fractions of patients with paradoxical left ventricular wall motion were significantly lower than those with paradoxical septal motion (p <0.005). 3) The sensitivity of each processing methods for detecting paradoxical wall motion was 76.9% by phase analysis, 74.6% by endless cine loop mapping and 68.4% by paradox image manipulation respectively. Paradoxial motions visualized only in phase, paradox or both images were appeared as hypokinesia or akinesia in cine loop image. 4) All events could be identified by at least one of above three processing methods, however only 34 cases (48.4%) showed the paradoxical motions in all of the three images. By these findings, we concluded that simultaneous inspection of all above three processing methods-endless cine loop, phase analysis and paradox image is necessary for accurate identification and assessment of paradoxical ventricular wall motion when performing GBPS.

  13. Identification and Assessment of Paradoxical Ventricular Wall Motion Using ECG Gated Blood Pool Scan - Comparison of cine Loop , Phase Analysis and Paradox Image -

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jae Tae; Kim, Gwang Weon; Lee, Kyu Bo; Chung, Byung Chun; Whang, Kee Suk; Chae, Sung Chul; Paek, Wee Hyun; Cheon, Jae Eun [Kyungpook National University School of Medicine, Daegu (Korea, Republic of); Lee, Hyong Woo; Chung, Jin Hong [Yeongnam National University College of Medicine, Daegu (Korea, Republic of)

    1990-07-15

    Sixty-four patients with paradoxical ventricular wall motion noticed both in angiocardiography or 2-dimensional echocardiography were assessed by ECG gated blood pool scan (GBPS). Endless cine loop image, phase and amplitude images and paradox image obtained by visual inspection of each cardiac beat or Fourier transformation of acquired raw data were investigated to determine the incremental value of GBPS with these processing methods for identification of paradoxical ventricular wall motion. The results were as follows:1) Paradoxical wall motions were observed on interventricular septum in 34 cases, left ventricular free wall in 26 and right ventricular wall in 24. Underlying heart diseases were is chemic (23 cases) valvular(9), congenital heart disease (12), cardiomyopathy (5), pericardial effusion(5), post cardiac surgery(3), corpulmonale (2), endocarditis (l) and right ventricular tumor(l). 2) Left ventricular ejection fractions of patients with paradoxical left ventricular wall motion were significantly lower than those with paradoxical septal motion (p <0.005). 3) The sensitivity of each processing methods for detecting paradoxical wall motion was 76.9% by phase analysis, 74.6% by endless cine loop mapping and 68.4% by paradox image manipulation respectively. Paradoxial motions visualized only in phase, paradox or both images were appeared as hypokinesia or akinesia in cine loop image. 4) All events could be identified by at least one of above three processing methods, however only 34 cases (48.4%) showed the paradoxical motions in all of the three images. By these findings, we concluded that simultaneous inspection of all above three processing methods-endless cine loop, phase analysis and paradox image is necessary for accurate identification and assessment of paradoxical ventricular wall motion when performing GBPS.

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

    Science.gov (United States)

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

    2017-05-01

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

  15. Clinical evaluation of the Tl-201 ECG-gated myocardial SPECT

    International Nuclear Information System (INIS)

    Mochizuki, Teruhito

    1989-01-01

    In order to evaluate the clinical usefulness of the Tl-201 ECG-gated myocardial single photon emission computed tomography (SPECT), we compared the wall motion and the grade of the Tl-201 uptake of the ECG-gated myocardial SPECT with the wall motion of the ECG-gated blood pool SPECT. Materials were 87 patients of 50 old myocardial infarctions (OMIs), 19 hypertrophic cardiomyopathies (HCMs), 2 dilated cardiomyopathies (DCMs) and 16 others. After intravenous injection of 111-185 MBq (3-5 mCi) of Tl-201 at rest, the projection data were acquired using a rotating gamma-camera through 180deg, from RAO 45deg in 24 directions, each of which consisted of 80-100 beats. For the reconstruction of ED, ES and non-gated images, R-R interval was divided into about 20 (18-22) fractions. In 348 regions of interest (anterior, septal, lateral and inferior wall) in 87 cases, wall motion and the Tl-201 uptake were evaluated to three grades (normal, hypokinesis and akinesis; normal, low and defect, respectively), which were compared with the wall motion of the ECG-gated blood pool SPECT. The wall motion and the grade of the Tl-201 uptake of the ECG-gated myocardial SPECT correlated well with the wall motion of the ECG-gated blood pool SPECT (96.6% and 87.9%, respectively). In conclusion, the ECG-gated myocardial SPECT can provide clear perfusion images and is a very useful diagnostic strategy to evaluate the regional wall motion and perfusion simultaneously. (author)

  16. ECG-gated computed tomography: a new role for patients with suspected aortic prosthetic valve endocarditis

    Energy Technology Data Exchange (ETDEWEB)

    Fagman, Erika; Flinck, Agneta; Lamm, Carl [Sahlgrenska University Hospital, Department of Radiology, Gothenburg (Sweden); Perrotta, Sossio [Sahlgrenska University Hospital, Department of Cardiovascular Surgery and Anaesthesia, Gothenburg (Sweden); Bech-Hanssen, Odd [Sahlgrenska University Hospital, Department of Clinical Physiology, Gothenburg (Sweden); Sahlgrenska University Hospital, Department of Cardiology, Gothenburg (Sweden); Olaison, Lars [Sahlgrenska University Hospital, Department of Infectious Diseases, Gothenburg (Sweden); Svensson, Gunnar [Sahlgrenska University Hospital, Department of Cardiovascular Surgery and Anaesthesia, Gothenburg (Sweden); The Sahlgrenska Academy at the University of Gothenburg, Department of Molecular and Clinical Medicine, Institute of Medicine, Gothenburg (Sweden)

    2012-11-15

    The aim of this prospective study was to investigate the agreement in findings between ECG-gated CT and transoesophageal echocardiography (TEE) in patients with aortic prosthetic valve endocarditis (PVE). Twenty-seven consecutive patients with PVE underwent 64-slice ECG-gated CT and TEE and the results were compared. Imaging was compared with surgical findings (surgery was performed in 16 patients). TEE suggested the presence of PVE in all patients [thickened aortic wall (n = 17), vegetation (n = 13), abscess (n = 16), valvular dehiscence (n = 10)]. ECG-gated CT was positive in 25 patients (93 %) [thickened aortic wall (n = 19), vegetation (n = 7), abscess (n = 18), valvular dehiscence (n = 7)]. The strength of agreement [kappa (95 % CI)] between ECG-gated CT and TEE was very good for thickened wall [0.83 (0.62-1.0)], good for abscess [0.68 (0.40-0.97)] and dehiscence [0.75 (0.48-1.0)], and moderate for vegetation [0.55 (0.26-0.88)]. The agreement was good between surgical findings (abscess, vegetation and dehiscence) and imaging for ECG-gated CT [0.66 (0.49-0.87)] and TEE [0.79 (0.62-0.96)] and very good for the combination of ECG-gated CT and TEE [0.88 (0.74-1.0)]. Our results indicate that ECG-gated CT has comparable diagnostic performance to TEE and may be a valuable complement in the preoperative evaluation of patients with aortic PVE. (orig.)

  17. ECG-gated computed tomography: a new role for patients with suspected aortic prosthetic valve endocarditis

    International Nuclear Information System (INIS)

    Fagman, Erika; Flinck, Agneta; Lamm, Carl; Perrotta, Sossio; Bech-Hanssen, Odd; Olaison, Lars; Svensson, Gunnar

    2012-01-01

    The aim of this prospective study was to investigate the agreement in findings between ECG-gated CT and transoesophageal echocardiography (TEE) in patients with aortic prosthetic valve endocarditis (PVE). Twenty-seven consecutive patients with PVE underwent 64-slice ECG-gated CT and TEE and the results were compared. Imaging was compared with surgical findings (surgery was performed in 16 patients). TEE suggested the presence of PVE in all patients [thickened aortic wall (n = 17), vegetation (n = 13), abscess (n = 16), valvular dehiscence (n = 10)]. ECG-gated CT was positive in 25 patients (93 %) [thickened aortic wall (n = 19), vegetation (n = 7), abscess (n = 18), valvular dehiscence (n = 7)]. The strength of agreement [kappa (95 % CI)] between ECG-gated CT and TEE was very good for thickened wall [0.83 (0.62-1.0)], good for abscess [0.68 (0.40-0.97)] and dehiscence [0.75 (0.48-1.0)], and moderate for vegetation [0.55 (0.26-0.88)]. The agreement was good between surgical findings (abscess, vegetation and dehiscence) and imaging for ECG-gated CT [0.66 (0.49-0.87)] and TEE [0.79 (0.62-0.96)] and very good for the combination of ECG-gated CT and TEE [0.88 (0.74-1.0)]. Our results indicate that ECG-gated CT has comparable diagnostic performance to TEE and may be a valuable complement in the preoperative evaluation of patients with aortic PVE. (orig.)

  18. Feasibility of epicardial adipose tissue quantification in non-ECG-gated low-radiation-dose CT: comparison with prospectively ECG-gated cardiac CT

    Energy Technology Data Exchange (ETDEWEB)

    Simon-Yarza, Isabel; Viteri-Ramirez, Guillermo; Saiz-Mendiguren, Ramon; Slon-Roblero, Pedro J.; Paramo, Maria [Dept. of Radiology, Clinica Univ. de Navarra, Pamplona (Spain); Bastarrika, Gorka [Dept. of Radiology, Clinica Univ. de Navarra, Pamplona (Spain); Cardiac Imaging Unit, Clinica Univ. de Navarra, Pamplona (Spain)], e-mail: bastarrika@unav.es

    2012-06-15

    Background: Epicardial adipose tissue (EAT) is an important indicator of cardiovascular risk. This parameter is generally assessed on ECG-gated computed tomography (CT) images. Purpose: To evaluate feasibility and reliability of EAT quantification on non-gated thoracic low-radiation-dose CT examinations with respect to prospectively ECG-gated cardiac CT acquisition. Material and Methods: Sixty consecutive asymptomatic smokers (47 men; mean age 64 {+-} 9.8 years) underwent low-dose CT of the chest and prospectively ECG-gated cardiac CT acquisitions (64-slice dual-source CT). The two examinations were reconstructed with the same range, field of view, slice thickness, and convolution algorithm. Two independent observers blindly quantified EAT volume using commercially available software. Data were compared with paired sample Student t-test, concordance correlation coefficients (CCC), and Bland-Altman plots. Results: No statistically significant difference was observed for EAT volume quantification with low-dose-CT (141.7 {+-} 58.3 mL) with respect to ECG-gated CT (142.7 {+-} 57.9 mL). Estimation of CCC showed almost perfect concordance between the two techniques for EAT-volume assessment (CCC, 0.99; mean difference, 0.98 {+-} 5.1 mL). Inter-observer agreement for EAT volume estimation was CCC: 0.96 for low-dose-CT examinations and 0.95 for ECG-gated CT. Conclusion: Non-gated low-dose CT allows quantifying EAT with almost the same concordance and reliability as using dedicated prospectively ECG-gated cardiac CT acquisition protocols.

  19. Feasibility of epicardial adipose tissue quantification in non-ECG-gated low-radiation-dose CT: comparison with prospectively ECG-gated cardiac CT

    International Nuclear Information System (INIS)

    Simon-Yarza, Isabel; Viteri-Ramirez, Guillermo; Saiz-Mendiguren, Ramon; Slon-Roblero, Pedro J.; Paramo, Maria; Bastarrika, Gorka

    2012-01-01

    Background: Epicardial adipose tissue (EAT) is an important indicator of cardiovascular risk. This parameter is generally assessed on ECG-gated computed tomography (CT) images. Purpose: To evaluate feasibility and reliability of EAT quantification on non-gated thoracic low-radiation-dose CT examinations with respect to prospectively ECG-gated cardiac CT acquisition. Material and Methods: Sixty consecutive asymptomatic smokers (47 men; mean age 64 ± 9.8 years) underwent low-dose CT of the chest and prospectively ECG-gated cardiac CT acquisitions (64-slice dual-source CT). The two examinations were reconstructed with the same range, field of view, slice thickness, and convolution algorithm. Two independent observers blindly quantified EAT volume using commercially available software. Data were compared with paired sample Student t-test, concordance correlation coefficients (CCC), and Bland-Altman plots. Results: No statistically significant difference was observed for EAT volume quantification with low-dose-CT (141.7 ± 58.3 mL) with respect to ECG-gated CT (142.7 ± 57.9 mL). Estimation of CCC showed almost perfect concordance between the two techniques for EAT-volume assessment (CCC, 0.99; mean difference, 0.98 ± 5.1 mL). Inter-observer agreement for EAT volume estimation was CCC: 0.96 for low-dose-CT examinations and 0.95 for ECG-gated CT. Conclusion: Non-gated low-dose CT allows quantifying EAT with almost the same concordance and reliability as using dedicated prospectively ECG-gated cardiac CT acquisition protocols

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

    International Nuclear Information System (INIS)

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

    2008-01-01

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

  1. Dose modulated retrospective ECG-gated versus non-gated 64-row CT angiography of the aorta at the same radiation dose: Comparison of motion artifacts, diagnostic confidence and signal-to-noise-ratios

    International Nuclear Information System (INIS)

    Schernthaner, Ruediger E.; Stadler, Alfred; Beitzke, Dietrich; Homolka, Peter; Weber, Michael; Lammer, Johannes; Czerny, Martin; Loewe, Christian

    2012-01-01

    Purpose: To compare ECG-gated and non-gated CT angiography of the aorta at the same radiation dose, with regard to motion artifacts (MA), diagnostic confidence (DC) and signal-to-noise-ratios (SNRs). Materials and methods: Sixty consecutive patients prospectively randomized into two groups underwent 64-row CT angiography, with or without dose-modulated ECG-gating, of the entire aorta, due to several pathologies of the ascending aorta. MA and DC were both assessed using a four-point scale. SNRs were calculated by dividing the mean enhancement by the standard deviation. The dose-length-product (DLP) of each examination was recorded and the effective dose was estimated. Results: Dose-modulated ECG-gating showed statistically significant advantages over non-gated CT angiography, with regard to MA (p < 0.001) and DC (p < 0.001), at the aortic valve, at the origin of the coronary arteries, and at the dissection membrane, with a significant correlation (p < 0.001) between MA and DC. At the aortic wall, however, ECG-gated CT angiography showed statistically significant fewer MA (p < 0.001), but not a statistically significant higher DC (p = 0.137) compared to non-gated CT angiography. At the supra-aortic vessels and the descending aorta, the ECG-triggering showed no statistically significant differences with regard to MA (p = 0.861 and 0.526, respectively) and DC (p = 1.88 and 0.728, respectively). The effective dose of ECG-gated CT angiography (23.24 mSv; range, 18.43–25.94 mSv) did not differ significantly (p = 0.051) from that of non-gated CT angiography (24.28 mSv; range, 19.37–29.27 mSv). Conclusion: ECG-gated CT angiography of the entire aorta reduces MA and results in a higher DC with the same SNR, compared to non-gated CT angiography at the same radiation dose.

  2. Absolute quantitation of left ventricular wall and cavity parameters using ECG-gated PET

    DEFF Research Database (Denmark)

    Freiberg, Jacob; Hove, Jens D; Kofoed, Klaus F

    2004-01-01

    in a heart phantom and in healthy subjects. Twelve healthy men aged 64 +/- 8 years were studied by use of cine magnetic resonance imaging (MRI) and ECG-gated FDG-PET during euglycemic glucose-insulin clamp. At increasing image noise levels, the estimated cavity volume of the heart phantom was within 2 m...

  3. Iterative model reconstruction: Improved image quality of low-tube-voltage prospective ECG-gated coronary CT angiography images at 256-slice CT

    Energy Technology Data Exchange (ETDEWEB)

    Oda, Seitaro, E-mail: seisei0430@nifty.com [Department of Cardiology, MedStar Washington Hospital Center, 110 Irving Street, NW, Washington, DC 20010 (United States); Department of Diagnostic Radiology, Faculty of Life Sciences, Kumamoto University, 1-1-1 Honjyo, Chuo-ku, Kumamoto, 860-8556 (Japan); Weissman, Gaby, E-mail: Gaby.Weissman@medstar.net [Department of Cardiology, MedStar Washington Hospital Center, 110 Irving Street, NW, Washington, DC 20010 (United States); Vembar, Mani, E-mail: mani.vembar@philips.com [CT Clinical Science, Philips Healthcare, c595 Miner Road, Cleveland, OH 44143 (United States); Weigold, Wm. Guy, E-mail: Guy.Weigold@MedStar.net [Department of Cardiology, MedStar Washington Hospital Center, 110 Irving Street, NW, Washington, DC 20010 (United States)

    2014-08-15

    Objectives: To investigate the effects of a new model-based type of iterative reconstruction (M-IR) technique, the iterative model reconstruction, on image quality of prospectively gated coronary CT angiography (CTA) acquired at low-tube-voltage. Methods: Thirty patients (16 men, 14 women; mean age 52.2 ± 13.2 years) underwent coronary CTA at 100-kVp on a 256-slice CT. Paired image sets were created using 3 types of reconstruction, i.e. filtered back projection (FBP), a hybrid type of iterative reconstruction (H-IR), and M-IR. Quantitative parameters including CT-attenuation, image noise, and contrast-to-noise ratio (CNR) were measured. The visual image quality, i.e. graininess, beam-hardening, vessel sharpness, and overall image quality, was scored on a 5-point scale. Lastly, coronary artery segments were evaluated using a 4-point scale to investigate the assessability of each segment. Results: There was no significant difference in coronary arterial CT attenuation among the 3 reconstruction methods. The mean image noise of FBP, H-IR, and M-IR images was 29.3 ± 9.6, 19.3 ± 6.9, and 12.9 ± 3.3 HU, respectively, there were significant differences for all comparison combinations among the 3 methods (p < 0.01). The CNR of M-IR was significantly better than of FBP and H-IR images (13.5 ± 5.0 [FBP], 20.9 ± 8.9 [H-IR] and 39.3 ± 13.9 [M-IR]; p < 0.01). The visual scores were significantly higher for M-IR than the other images (p < 0.01), and 95.3% of the coronary segments imaged with M-IR were of assessable quality compared with 76.7% of FBP- and 86.9% of H-IR images. Conclusions: M-IR can provide significantly improved qualitative and quantitative image quality in prospectively gated coronary CTA using a low-tube-voltage.

  4. ECG-gated multislice spiral CT for diagnosis of acute pulmonary embolism

    International Nuclear Information System (INIS)

    Marten, K.; Engelke, C.; Funke, M.; Obenauer, S.; Baum, F.; Grabbe, E.

    2003-01-01

    AIM: The purpose of this study was to determine the feasibility of echocardiogram (ECG)-gated multi-slice CT angiography (MCTA) in patients with clinical suspicion of acute venous thromboembolism (VTE), to investigate the effect of ECG-gating on cardiac motion artefacts, and to determine the diagnostic reader agreement of ECG-gated MCTA in comparison with conventional MCTA. MATERIALS AND METHODS: Forty-eight consecutive patients were prospectively enrolled and randomly underwent ECG-gated (n=25, group 1) or non-ECG-gated (n=23, group 2) eight-slice pulmonary MCTA. Image data were evaluated by three independent chest radiologists with respect to the presence or absence of emboli at different arterial levels (main, lobar, segmental, and subsegmental arteries), and with regard to cardiac motion artefacts. Statistical tests used to calculate inter-observer agreement were weighted κ statistics, extended κ statistics and confidence indices indicating three-reader agreement accuracy. RESULTS: Twenty-seven patients (56.3%) were diagnosed to have pulmonary embolism (13 from group 1, 14 from group 2). Cardiac motion artefacts were significantly more frequent in group 2 (70% in group 2 versus 13% in group 1, p=0.0001). The overall diagnostic agreement was excellent with both MCTA techniques (three-reader confidence index for all vascular territories: 0.76 and 0.84 for groups 1 and 2, respectively (extended κ=0.69 and 0.78, respectively); three-reader confidence index for diagnosis of VTE: 0.94 and 0.85 for groups 1 and 2, respectively (extended κ=0.91 and 0.73, respectively), weighted κ=0.81-0.83 and 0.92-0.95 for groups 1 and 2, respectively, and did not differ significantly between the two groups. In addition there was no significant difference of inter-observer agreement in either group at any assessed pulmonary arterial level. CONCLUSION: ECG-gated pulmonary MCTA is feasible in patients with clinical suspicion of VTE. However, ECG-gated image acquisition did not

  5. Evaluation of ECG-gated [(11)C]acetate PET for measuring left ventricular volumes, mass, and myocardial external efficiency.

    Science.gov (United States)

    Hansson, Nils Henrik; Tolbod, Lars; Harms, Johannes; Wiggers, Henrik; Kim, Won Yong; Hansen, Esben; Zaremba, Tomas; Frøkiær, Jørgen; Jakobsen, Steen; Sørensen, Jens

    2016-08-01

    Noninvasive estimation of myocardial external efficiency (MEE) requires measurements of left ventricular (LV) oxygen consumption with [(11)C]acetate PET in addition to LV stroke volume and mass with cardiovascular magnetic resonance (CMR). Measuring LV geometry directly from ECG-gated [(11)C]acetate PET might enable MEE evaluation from a single PET scan. Therefore, we sought to establish the accuracy of measuring LV volumes, mass, and MEE directly from ECG-gated [(11)C]acetate PET. Thirty-five subjects with aortic valve stenosis underwent ECG-gated [(11)C]acetate PET and CMR. List mode PET data were rebinned into 16-bin ECG-gated uptake images before measuring LV volumes and mass using commercial software and compared to CMR. Dynamic datasets were used for calculation of mean LV oxygen consumption and MEE. LV mass, volumes, and ejection fraction measured by CMR and PET correlated strongly (r = 0.86-0.92, P PET (P PET-based MEE, corrected for bias, correlated fairly with PET/CMR-based MEE (r = 0.60, P PET-based MEE bias was strongly associated with LV wall thickness. Although analysis-related improvements in accuracy are recommended, LV geometry estimated from ECG-gated [(11)C]acetate PET correlate excellently with CMR and can indeed be used to evaluate MEE.

  6. Receiver operating characteristics of diagnostic efficacy of resting left ventricular performance (evaluating with a non-imaging ECG gated scintillation detector - nuclear stethoscope)

    International Nuclear Information System (INIS)

    Kotlyarov, E.V.; Reba, R.C.; Lindsay, J.

    1983-01-01

    Receiver operating characteristic (ROC) analysis of left ventricular performance at rest was applied to evaluate diagnostic utility of non-imaging nuclear detector (''Nuclear Stethoscope''), for screening patients with coronary artery disease (CAD). Thirty-one patients without CAD and normal rest and stress radionuclide ventriculography (MUGA) were used as a control group. Another 62 patients with abnormal left ventricular reserve and segmental wall motion abnormalities at rest were also studied. All 93 patients were studied with the Nuclear Stethoscope (30 minutes after conventional MUGA testing) both in beat-to-beat and gated equilibrium modes. ROC analysis showed that along with ejection fraction, stroke and end-diastolic volumes, evaluation of the left ventricular filling phase has a great potential for the identification of patients with a segmental wall motion abnormality and, therefore, significant CAD

  7. ECG gated NMR-CT for cardiovascular diseases

    International Nuclear Information System (INIS)

    Nishikawa, J.; Machida, K.; Iio, M.; Yoshimoto, N.; Sugimoto, T.; Kawaguchi, H.; Mano, H.

    1984-01-01

    The authors applied NMR-CT to cardiac study with ECG gated technique to evaluate the left ventricular (LV) function and compared it with cardiovascular nuclear medicine study (NM). The NMR-CT machine has resistive air-core magnet with 0.15 Tesla. The saturation recovery image or inversion recovery image were obtained as 256 x 256 matrix and 15 mm in thickness. The study population was ten patients who were evaluated both by NMR image and by NM performed within one week interval. The heart muscle was able to be visualized without any contrast material nor radioisotopes in inversion recovery images, whereas saturation recovery images failed to separate heart muscle from blood pool. The wall motions of LV in both methods were well correlated except for inferior wall. The values of ejection fraction in NMR image were moderately low, but two modalities showed satisfactory correlation (r=0.85). The region of myocardial infarction was revealed as wall thinning and/or wall motion abnormality. It is still preliminary to draw a conclusion, however, it can be said that in the evaluation of LV function, method by NMR might be of equal value to those of NM. It can be certain that eventually gated NMR-CT will become more effective method for various aspects of cardiovascular evaluation

  8. Evaluation of retrospectively ECG-gated 4-row multidetector CT in patients planned for minimal invasive coronary artery bypass grafting; Die EKG-getriggerte 4-Zeilen-Spiral-CT des Herzens in der praeoperativen Bildgebung vor minimalinvasiver koronarer Bypass-Operation

    Energy Technology Data Exchange (ETDEWEB)

    Begemann, P.G.C.; Ittrich, H.; Koops, A.; Adam, G.; Weber, C. [Klinik und Poliklinik fuer Diagnostische und Interventionelle Radiologie, Radiologisches Zentrum, Universitaetsklinikum, Hamburg (Germany); Arnold, M.; Detter, C.; Boehm, D.H.; Reichenspurner, H. [Universitaetsklinikum Hamburg-Eppendorf, Herzzentrum, Herz und Gefaesschirurgie, Hamburg (Germany)

    2005-08-01

    Purpose: Minimal invasive direct coronary artery bypass grafting (MIDCAB) or off-pump coronary artery bypass grafting (OPCAB) on the beating heart with full or mini-sternotomy are becoming more common in coronary bypass surgery of the left anterior descending (LAD). In the decision, which surgical approach (MIDCAB, OPCAB or conventional surgery with cardiopulmonary bypass) will be best used, knowledge of the anatomical field is of major importance. The aim of the study was to evaluate retrospective ECG-gated 4-row multidetector CT (MDCT) in patients planned for MIDCAB as additional imaging to coronary angiography. Material and methods: The study included 25 consecutive patients. MSCT was performed as unenhanced (collimation 4 x 2.5 mm) and contrast-enhanced examination (140-170 ml, 300 mg Iodine/ml, collimation 4 x 1 mm). The evaluation included presence of LAD calcifications, distance of LAD and left internal mammarian artery (LIMA), coursek of LAD and LIMA, the presence or absence of bridging through myocardium or epicardial fat and the presence of pleural fibrosis. The MDCT results were correlated with intra-operative findings. Results: All MDCTs could be assessed with reference to the demands. In 20/25 operations, MDCT had direct influence as to the selection of the surgical approach (11 MIDCAB, 7 OPCAB with mini-sternotomy and 5 with full sternotomy, 2 conventional surgeries). The distance of LAD and LIMA varied from 0.9 to 4.5 cm in MDCT. As to calcifications, 3/25 correlated patients had calcifications and 10 patients had no calcifications in the middle LAD. Seven patients had intraoperative fibrosis of the vessel wall without calcification of the middle LAD, which could not be detected with MDCT. Another 5 patients had single calcified plaques in the middle LAD, 4 of these had a fibrosis of the vessel and 1 had a normal vessel at surgery. In these cases, the anastomosis was done between the calcified plaques. No myocardial bridging was detected by MDCT and

  9. Prospective electrocardiogram-gated axial 64-detector computed tomographic angiography vs retrospective gated helical technique to assess coronary artery bypass graft anastomosis. Comparison of image quality and patient radiation dose

    International Nuclear Information System (INIS)

    Machida, Haruhiko; Masukawa, Ai; Tanaka, Isao; Fukui, Rika; Suzuki, Kazufumi; Ueno, Eiko; Kodera, Kojiro; Nakano, Kiyoharu; Shen, Y.

    2010-01-01

    In the present study the effective dose and image quality at distal anastomoses were retrospectively compared between prospective electrocardiogram (ECG)-gated axial and retrospective ECG-gated helical techniques on 64-detector computed tomographic (CT) angiography following coronary artery bypass graft surgery. Following bypass surgery, 52 patients with a heart rate <65 beats/min underwent CT angiography: 26 patients each with prospective and retrospective ECG gating techniques. The effective dose was compared between the 2 groups using a 4-point scale (4, excellent; 1, poor) to grade the quality of curved multiplanar reformation images at distal anastomoses. Patient characteristics of the 2 groups were well matched, and the same CT scan parameters were used for both, except for the interval between surgery and CT examination, tube current, and image noise index. Image quality scores did not differ significantly (3.26±0.95 vs 3.35±0.87; P=0.63), but the effective dose was significantly lower in the prospective (7.3±1.8 mSv) than in the retrospective gating group (23.6±4.5 mSv) (P<0.0001). Following bypass surgery, 64-detector CT angiography using prospective ECG gating is superior to retrospective gating in limiting the radiation dose and maintaining the image quality of distal anastomoses. (author)

  10. MR flow measurements for assessment of the pulmonary, systemic and bronchosystemic circulation: Impact of different ECG gating methods and breathing schema

    International Nuclear Information System (INIS)

    Ley, Sebastian; Ley-Zaporozhan, Julia; Kreitner, Karl-Friedrich; Iliyushenko, Svitlana; Puderbach, Michael; Hosch, Waldemar; Wenz, Heiner; Schenk, Jens-Peter; Kauczor, Hans-Ulrich

    2007-01-01

    Purpose: Different ECG gating techniques are available for MR phase-contrast (PC) flow measurements. Until now no study has reported the impact of different ECG gating techniques on quantitative flow parameters. The goal was to evaluate the impact of the gating method and the breathing schema on the pulmonary, systemic and bronchosystemic circulation. Material and methods: Twenty volunteers were examined (1.5 T) with free breathing phase-contrast flow (PC-flow) measurements with prospective (free-prospective) and retrospective (free-retrospective) ECG gating. Additionally, expiratory breath-hold retrospective ECG gated measurements (bh-retrospective) were performed. Blood flow per minute; peak velocity and time to peak velocity were compared. The clinically important difference between the systemic and pulmonary circulation (bronchosystemic shunt) was calculated. Results: Blood flow per minute was lowest for free-prospective (6 l/min, pulmonary trunc) and highest for bh-retrospective measurements (6.9 l/min, pulmonary trunc). No clinically significant difference in peak velocity was assessed (82-83 cm/s pulmonary trunc, 109-113 cm/s aorta). Time to peak velocity was shorter for retro-gated free-retrospective and bh-retrospective than for pro-gated free-prospective. The difference between systemic and pulmonary measurements was least for the free-retrospective technique. Conclusion: The type of gating has a significant impact on flow measurements. Therefore, it is important to use the same ECG gating method, especially for follow-up examinations. Retrospective ECG gated free breathing measurements allow for the most precise assessment of the bronchosystemic blood flow and should be used in clinical routine

  11. Measurement of ventricular function by ECG gating during atrial fibrillation

    International Nuclear Information System (INIS)

    Bacharach, S.L.; Green, M.V.; Bonow, R.O.; Findley, S.L.; Ostrow, H.G.; Johnston, G.S.

    1981-01-01

    The assumptions necessary to perform ECG-gated cardiac studies are seemingly not valid for patients in atrial fibrillation (AF). To evaluate the effect of AF on equilibrium gated scintigraphy, beat-by-beat measurements of left-ventricular function were made on seven subjects in AF (mean heart rate 64 bpm), using a high-efficiency nonimaging detector. The parameters evaluated were ejection fraction (EF), time to end-systole (TES), peak rates of ejection and filling (PER,PFR), and their times of occurrence (TPER, TPFR). By averaging together single-beat values of EF, PER, etc., it was possible to determine the true mean values of these parameters. The single-beam mean values were compared with the corresponding parameters calculated from one ECG-gated time-activity curve (TAC) obtained by superimposing all the single-beat TACs irrespective of their length. For this population with slow heart rates, we find that the values for EF, etc., produced from ECG-gated time-activity curves, are very similar to those obtained from the single-beat data. Thus use of ECG gating at low heart rates may allow reliable estimation of average cardiac function even in subjects with AF

  12. Optimization of Ecg Gating in Quantitative Femoral Angiography

    International Nuclear Information System (INIS)

    Nilsson, S.; Berglund, I.; Erikson, U.; Johansson, J.; Walldius, G.

    2003-01-01

    Purpose: To determine which phase of the heart cycle would yield the highest reproducibility in measuring atherosclerosis-related variables such as arterial lumen volume and edge roughness. Material and Methods: 35 patients with hypercholesterolemia underwent select ive femoral angiography, repeated four times at 10-min intervals. The angiographies were performed with Ecg-gated exposures. In angiographies 1 and 2 the delay from R-wave maximum to each exposure was 0.1 s, in angiographies 3 and 4 the delay was 0.1, 0.3, 0.5 or 0.7 s or the exposures were performed 1/s without Ecg gating. Arterial lumen volume and edge roughness were measured in a 20-cm segment of the superficial femoral artery using a computer-based densitometric method. Measurement reproducibility was determined by comparing angiographies 1-2 and angiographies 3-4. Results: When measuring arterial lumen volume and edge roughness of a 20-cm segment of the femoral artery, reproducibility was not dependent on Ecg gating. In measuring single arterial diameters and cross-sectional areas, the reproducibility was better when exposures were made 0.1 s after the R-wave maximum than when using other settings of the Ecg gating device or without Ecg gating. Conclusion: The influence of pulsatile flow upon quantitative measurement in femoral angiograms seems to be the smallest possible in early systole, as can be demonstrated when measuring single diameters and cross-sectional areas. In variables based on integration over longer segments, measurement reproducibility seems to be independent of phase

  13. Optimization of Ecg Gating in Quantitative Femoral Angiography

    Energy Technology Data Exchange (ETDEWEB)

    Nilsson, S.; Berglund, I.; Erikson, U. [Univ. Hospital, Uppsala (Sweden). Dept. of Oncology, Radiology and Clinical Immunology; Johansson, J.; Walldius, G. [Karolinska Hospital, Stockholm (Sweden). King Gustav V Research Inst.

    2003-09-01

    Purpose: To determine which phase of the heart cycle would yield the highest reproducibility in measuring atherosclerosis-related variables such as arterial lumen volume and edge roughness. Material and Methods: 35 patients with hypercholesterolemia underwent select ive femoral angiography, repeated four times at 10-min intervals. The angiographies were performed with Ecg-gated exposures. In angiographies 1 and 2 the delay from R-wave maximum to each exposure was 0.1 s, in angiographies 3 and 4 the delay was 0.1, 0.3, 0.5 or 0.7 s or the exposures were performed 1/s without Ecg gating. Arterial lumen volume and edge roughness were measured in a 20-cm segment of the superficial femoral artery using a computer-based densitometric method. Measurement reproducibility was determined by comparing angiographies 1-2 and angiographies 3-4. Results: When measuring arterial lumen volume and edge roughness of a 20-cm segment of the femoral artery, reproducibility was not dependent on Ecg gating. In measuring single arterial diameters and cross-sectional areas, the reproducibility was better when exposures were made 0.1 s after the R-wave maximum than when using other settings of the Ecg gating device or without Ecg gating. Conclusion: The influence of pulsatile flow upon quantitative measurement in femoral angiograms seems to be the smallest possible in early systole, as can be demonstrated when measuring single diameters and cross-sectional areas. In variables based on integration over longer segments, measurement reproducibility seems to be independent of phase.

  14. Impact of ECG gating in contrast-enhanced MR angiography for the assessment of the pulmonary veins and the left atrium anatomy

    Energy Technology Data Exchange (ETDEWEB)

    Katoh, M.; Buecker, A.; Muehlenbruch, G.; Guenther, R.W.; Spuentrup, E. [Klinik fuer Radiologische Diagnostik, Universitaetsklinikum RWTH Aachen (Germany); Schauerte, P. [Medizinische Klinik 1, Universitaetsklinikum RWTH Aachen (Germany)

    2006-02-15

    Purpose: Implementation of ECG gating in contrast-enhanced MR angiography (ceMRA) for improved visualization of the pulmonary veins, the left atrium, and the thoracic vessels. Materials and Methods: CeMRA was performed on twelve patients with a history of recurrent atrial fibrillation for the purpose of an intra-individual comparison with and without ECG gating on a 1.5 Tesla MR system (Gyroscan Intera, Philips Medical Systems, Best, NL). Objective image quality parameters such as the signal-to-noise ratio (SNR) of the blood and the contrast-to-noise ratio (CNR) between the blood and myocardium or lung parenchyma were analyzed. The contour sharpness of the pulmonary veins, left atrium, ascending aorta, and pulmonary trunk was also measured. In addition, the artifact level was subjectively assessed by two observers blinded with respect to the sequence parameters. Statistically significant differences (p<0.05) between the procedures were analyzed using the Wilcoxon test and Pearson Chi-square test. Results: The use of ECG gating in ceMRA significantly reduced artifacts caused by cardiac motion and vessel pulsation. This in turn lead to a significant increase in the contour sharpness of the left atrium and the thoracic vessels. In addition, higher SNR and CNR were found using ECG-gated ceMRA compared to standard ceMRA. Conclusion: The use of ECG gating in ceMRA results in artifact-free and sharper delineation of the structures of the heart and thoracic vessels. (orig.)

  15. Impact of ECG gating in contrast-enhanced MR angiography for the assessment of the pulmonary veins and the left atrium anatomy

    International Nuclear Information System (INIS)

    Katoh, M.; Buecker, A.; Muehlenbruch, G.; Guenther, R.W.; Spuentrup, E.; Schauerte, P.

    2006-01-01

    Purpose: Implementation of ECG gating in contrast-enhanced MR angiography (ceMRA) for improved visualization of the pulmonary veins, the left atrium, and the thoracic vessels. Materials and Methods: CeMRA was performed on twelve patients with a history of recurrent atrial fibrillation for the purpose of an intra-individual comparison with and without ECG gating on a 1.5 Tesla MR system (Gyroscan Intera, Philips Medical Systems, Best, NL). Objective image quality parameters such as the signal-to-noise ratio (SNR) of the blood and the contrast-to-noise ratio (CNR) between the blood and myocardium or lung parenchyma were analyzed. The contour sharpness of the pulmonary veins, left atrium, ascending aorta, and pulmonary trunk was also measured. In addition, the artifact level was subjectively assessed by two observers blinded with respect to the sequence parameters. Statistically significant differences (p<0.05) between the procedures were analyzed using the Wilcoxon test and Pearson Chi-square test. Results: The use of ECG gating in ceMRA significantly reduced artifacts caused by cardiac motion and vessel pulsation. This in turn lead to a significant increase in the contour sharpness of the left atrium and the thoracic vessels. In addition, higher SNR and CNR were found using ECG-gated ceMRA compared to standard ceMRA. Conclusion: The use of ECG gating in ceMRA results in artifact-free and sharper delineation of the structures of the heart and thoracic vessels. (orig.)

  16. Study on motion artifacts in coronary arteries with an anthropomorphic moving heart phantom on an ECG-gated multidetector computed tomography unit

    International Nuclear Information System (INIS)

    Greuter, Marcel J.W.; Dorgelo, Joost; Tukker, Wim G.J.; Oudkerk, Matthijs

    2005-01-01

    Acquisition time plays a key role in the quality of cardiac multidetector computed tomography (MDCT) and is directly related to the rotation time of the scanner. The purpose of this study is to examine the influence of heart rate and a multisector reconstruction algorithm on the image quality of coronary arteries of an anthropomorphic adjustable moving heart phantom on an ECG-gated MDCT unit. The heart phantom and a coronary artery phantom were used on a MDCT unit with a rotation time of 500 ms. The movement of the heart was determined by analysis of the images taken at different phases. The results indicate that the movement of the coronary arteries on the heart phantom is comparable to that in a clinical setting. The influence of the heart rate on image quality and artifacts was determined by analysis of several heart rates between 40 and 80 bpm where the movement of the heart was synchronized using a retrospective ECG-gated acquisition protocol. The resulting reformatted volume rendering images of the moving heart and the coronary arteries were qualitatively compared as a result of the heart rate. The evaluation was performed on three independent series by two independent radiologists for the image quality of the coronary arteries and the presence of artifacts. The evaluation shows that at heart rates above 50 bpm the influence of motion artifacts in the coronary arteries becomes apparent. In addition the influence of a dedicated multisector reconstruction technique on image quality was determined. The results show that the image quality of the coronary arteries is not only related to the heart rate and that the influence of the multisector reconstruction technique becomes significant above 70 bpm. Therefore, this study proves that from the actual acquisition time per heart cycle one cannot determine an actual acquisition time, but only a mathematical acquisition time. (orig.)

  17. Assessment of hypertrophic cardiomyopathy by ECG gated cardiac computed tomography

    International Nuclear Information System (INIS)

    Takeuchi, Kazuhide; Tanaka, Chujiro; Oku, Hisao

    1981-01-01

    The applicability of ECG gated cardiac computed tomography (CT) in 12 patients with hypertrophic cardiomyopathy was examined. Six of the 12 patients had hypertrophic obstructive cardiomyopathy, including one patient with mid-ventricular obstruction. Three of the 12 patients had hypertrophic non-obstructive cardiomyopathy, and three had apical hypertrophic cardiomyopathy. The diagnosis of hypertrophic cardiomyopathy was confirmed by the angiocardiogram in all patients. Cardiac CT was performed after intravenous administration of contrast media usually given as a bolus injection. The gantry was set with positive 20 0 tilt angle. In all patients with hypertrophic obstructive cardiomyopathy except for mid-ventricular obstruction, the hypertrophied interventricular septum in the basal and mid portions was observed, and the left ventricular cavity was narrowed in systole. In a patient with mid-ventricular obstruction, the marked hypertrophied interventricular septum and antero-lateral papillary muscle were observed. In diastole, the left ventricular cavity was narrow and divided into two parts. The apical cavity was completely disappeared in systole. In all patients with hypertrophic non-obstructive cardiomyopathy, the diffuse hypertrophied interventricular septum was observed in diastole. In systole, the apical portion of the left ventricular cavity was markedly narrow and antero-lateral papillary muscle was hypertrophic. In all patients with apical hypertrophic cardiomyopathy, the marked apical hypertrophy of the left ventricular wall was observed in diastole. It is concluded that ECG gated cardiac CT could estimate myocardial wall motion and thickness and differentiate the types of hypertrophic cardiomyopathy each other. (author)

  18. ECG-gated scintillation probe measurement of left ventricular function

    International Nuclear Information System (INIS)

    Bacharach, S.L.; Green, M.V.; Borer, J.S.; Ostrow, H.G.; Redwood, D.R.; Johnston, G.S.

    1977-01-01

    A nonimaging, ECG-gated scintillation-probe system is described that permits real-time quantification, at high temporal resolution, of the time variation of left ventricular (LV) volume over a complete, average cardiac cycle. Linearity between counting rate and volume, probe positioning, and background correction were investigated for both cylindrically collimated (CC) and parallel-hole-collimated (PC) detectors. In 53 patient studies, results obtained with these probes were compared with results obtained from an ECG-gated gamma camera system (CS) with high temporal resolution. Time-activity curves obtained by all three devices were essentially identical in shape (for CC against CS, r = 0.93; for PC against CS, r = 0.98) and in intracycle timing. Left-ventricular ejection fractions obtained with the probes showed workable agreement with the camera: for CC against CS, r = 0.85 (N = 31); for PC against CS, r = 0.90 (N = 21). When LV background is removed as a source of error, the correlation between (PC) probe and camera is improved (r = 0.95, N = 21). This suggests that the portable probe system be used in circumstances where exact knowledge of LV background is minimally important--e.g., continuous bedside monitoring of changes in LV function

  19. Evaluation of left ventricular ejection fraction from radial long-axis tomography. A new reconstruction algorithm for ECG-gated technetium-99m Sestamibi SPECT

    International Nuclear Information System (INIS)

    Tsujimura, Eiichiro; Kusuoka, Hideo; Uehara, Toshiisa

    1997-01-01

    Radial long-axis tomography can provide views similar to contrast left ventriculography (LVG) including the basal and apical areas of the left ventricle, not possible in routine short-axis tomography. We applied this method to ECG-gated Tc-99m Sestamibi (MIBI) myocardial SPECT images to estimate the left ventricular ejection fraction (LVEF). ECG-gated Tc-99m MIBI SPECT was performed with a temporal resolution of 10 frames per R-R interval. LVEF was calculated on the basis of left ventricular volume estimates at end diastole (ED) and end systole (ES) with using an ellipsoid body model. To validate this method, LVEF's derived from ECG-gated Tc-99m MIBI SPECT were compared with those from LVG in 11 patients with coronary artery disease. There was a close linear correlation between LVEF values calculated from Tc-99m MIBI SPECT and those from LVG (r=0.89, p<0.001), although the gated SPECT underestimated LVEF compared to LVG. The technique showed excellent reproducibility (intra-observer variability, r=0.96, p<0.001; inter-observer variability, r=0.71, p<0.005). The radial long-axis tomography technique gives a good estimate of LVEF, in agreement with estimates based on LVG. ECG-gated Tc-99m MIBI SPECT can, therefore, be applicable to assess myocardial perfusion and ventricular function at the same time. (author)

  20. Evaluation of left ventricular ejection fraction from radial long-axis tomography. A new reconstruction algorithm for ECG-gated technetium-99m Sestamibi SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Tsujimura, Eiichiro; Kusuoka, Hideo; Uehara, Toshiisa [Osaka Univ. (Japan). Faculty of Medicine] [and others

    1997-08-01

    Radial long-axis tomography can provide views similar to contrast left ventriculography (LVG) including the basal and apical areas of the left ventricle, not possible in routine short-axis tomography. We applied this method to ECG-gated Tc-99m Sestamibi (MIBI) myocardial SPECT images to estimate the left ventricular ejection fraction (LVEF). ECG-gated Tc-99m MIBI SPECT was performed with a temporal resolution of 10 frames per R-R interval. LVEF was calculated on the basis of left ventricular volume estimates at end diastole (ED) and end systole (ES) with using an ellipsoid body model. To validate this method, LVEF`s derived from ECG-gated Tc-99m MIBI SPECT were compared with those from LVG in 11 patients with coronary artery disease. There was a close linear correlation between LVEF values calculated from Tc-99m MIBI SPECT and those from LVG (r=0.89, p<0.001), although the gated SPECT underestimated LVEF compared to LVG. The technique showed excellent reproducibility (intra-observer variability, r=0.96, p<0.001; inter-observer variability, r=0.71, p<0.005). The radial long-axis tomography technique gives a good estimate of LVEF, in agreement with estimates based on LVG. ECG-gated Tc-99m MIBI SPECT can, therefore, be applicable to assess myocardial perfusion and ventricular function at the same time. (author)

  1. ECG-gated interventional cardiac reconstruction for non-periodic motion.

    Science.gov (United States)

    Rohkohl, Christopher; Lauritsch, Günter; Biller, Lisa; Hornegger, Joachim

    2010-01-01

    The 3-D reconstruction of cardiac vasculature using C-arm CT is an active and challenging field of research. In interventional environments patients often do have arrhythmic heart signals or cannot hold breath during the complete data acquisition. This important group of patients cannot be reconstructed with current approaches that do strongly depend on a high degree of cardiac motion periodicity for working properly. In a last year's MICCAI contribution a first algorithm was presented that is able to estimate non-periodic 4-D motion patterns. However, to some degree that algorithm still depends on periodicity, as it requires a prior image which is obtained using a simple ECG-gated reconstruction. In this work we aim to provide a solution to this problem by developing a motion compensated ECG-gating algorithm. It is built upon a 4-D time-continuous affine motion model which is capable of compactly describing highly non-periodic motion patterns. A stochastic optimization scheme is derived which minimizes the error between the measured projection data and the forward projection of the motion compensated reconstruction. For evaluation, the algorithm is applied to 5 datasets of the left coronary arteries of patients that have ignored the breath hold command and/or had arrhythmic heart signals during the data acquisition. By applying the developed algorithm the average visibility of the vessel segments could be increased by 27%. The results show that the proposed algorithm provides excellent reconstruction quality in cases where classical approaches fail. The algorithm is highly parallelizable and a clinically feasible runtime of under 4 minutes is achieved using modern graphics card hardware.

  2. Automated Agatston score computation in non-ECG gated CT scans using deep learning

    Science.gov (United States)

    Cano-Espinosa, Carlos; González, Germán.; Washko, George R.; Cazorla, Miguel; San José Estépar, Raúl

    2018-03-01

    Introduction: The Agatston score is a well-established metric of cardiovascular disease related to clinical outcomes. It is computed from CT scans by a) measuring the volume and intensity of the atherosclerotic plaques and b) aggregating such information in an index. Objective: To generate a convolutional neural network that inputs a non-contrast chest CT scan and outputs the Agatston score associated with it directly, without a prior segmentation of Coronary Artery Calcifications (CAC). Materials and methods: We use a database of 5973 non-contrast non-ECG gated chest CT scans where the Agatston score has been manually computed. The heart of each scan is cropped automatically using an object detector. The database is split in 4973 cases for training and 1000 for testing. We train a 3D deep convolutional neural network to regress the Agatston score directly from the extracted hearts. Results: The proposed method yields a Pearson correlation coefficient of r = 0.93; p <= 0.0001 against manual reference standard in the 1000 test cases. It further stratifies correctly 72.6% of the cases with respect to standard risk groups. This compares to more complex state-of-the-art methods based on prior segmentations of the CACs, which achieve r = 0.94 in ECG-gated pulmonary CT. Conclusions: A convolutional neural network can regress the Agatston score from the image of the heart directly, without a prior segmentation of the CACs. This is a new and simpler paradigm in the Agatston score computation that yields similar results to the state-of-the-art literature.

  3. ECG-gated blood pool tomography in the determination of left ventricular volume, ejection fraction, and wall motion

    International Nuclear Information System (INIS)

    Underwood, S.R.; Ell, P.J.; Jarritt, P.H.; Emanuel, R.W.; Swanton, R.H.

    1984-01-01

    ECG-gated blood pool tomography promises to provide a ''gold standard'' for noninvasive measurement of left ventricular volume, ejection fraction, and wall motion. This study compares these measurements with those from planar radionuclide imaging and contrast ventriculography. End diastolic and end systolic blood pool images were acquired tomographically using an IGE400A rotating gamma camera and Star computer, and slices were reconstructed orthogonal to the long axis of the heart. Left ventricular volume was determined by summing the areas of the slices, and wall motion was determined by comparison of end diastolic and end systolic contours. In phantom experiments this provided an accurate measurement of volume (r=0.98). In 32 subjects who were either normal or who had coronary artery disease left ventricular volume (r=0.83) and ejection fraction (r=0.89) correlated well with those using a counts based planar technique. In 16 of 18 subjects who underwent right anterior oblique X-ray contrast ventriculography, tomographic wall motion agreed for anterior, apical, and inferior walls, but abnormal septal motion which was not apparent by contrast ventriculography, was seen in 12 subjects tomographically. All 12 had disease of the left anterior descending coronary artery and might have been expected to have abnormal septal motion. ECG-gated blood pool tomography can thus determine left ventricular volume and ejection fraction accurately, and provides a global description of wall motion in a way that is not possible from any single planar image

  4. Design and development of a new pulsating cardiac coronary phantom for ECG-gated CT and its experimental characteristics

    International Nuclear Information System (INIS)

    Shen, Yun; Sato, Munekuni; Kimura, Fumiko; Jinzaki, Masahiro; Kuribayashi, Sachio; Horiguchi, Jun; Ito, Katsuhide

    2005-01-01

    The optimal pulsating cardiac phantom is an important tool for the evaluation of cardiac images and cardiac applications on electrocardiogram (ECG)-gated multidetector-row CT (MDCT). The purpose of this study was to demonstrate the design and fabrication of the pulsating cardiac coronary phantom. The newly developed pulsating cardiac coronary phantom has the following five key advantages: a driver component that uses only one servomotor to move the phantom in three dimensions (X, Y, and Z directions) with 16 presets of different heart types (heartbeat: 0-120 bpm; ejection fraction: 0-90%); versatile pumping and filling phases to simulate a real heart in a cardiac cycle can be incorporated into the driver sequence including shift of patient heartbeat or irregular pulse (maximum: 200 different heart waves in one scan); a cardiac coronary component constituted of an acrylic/silicon/rubber tube (2-6 mm inner diameter) with stent/in-stent restenosis/stenosis/soft plaque/calcification parts and maximum 16 coronary arteries that can be attached to the phantom in the same scan; the complete phantom can be submerged in a tank to simulate the heart and its surrounding tissues; ECG gating can be from interior trigger and exterior trigger. It has been confirmed that the developed pulsating cardiac phantom is very useful to quantitatively assess imaging of the heart and coronary arteries during phantom experiments. (author)

  5. Visibility of the origin and proximal course of coronary arteries on non-ECG-gated heart CT in patients with congenital heart disease

    International Nuclear Information System (INIS)

    Goo, Hyun Woo; Park, In-Sook; Ko, Jae Kon; Kim, Young Hwee; Seo, Dong-Man; Yun, Tae-Jin; Park, Jeong-Jun

    2005-01-01

    There is little information on the ability of non-ECG-gated cardiac CT to demonstrate the coronary arteries of children. To evaluate the visibility of the origin and proximal course of coronary arteries on non-ECG-gated cardiac CT, in which the coronary artery was not of primary diagnostic concern, in children with congenital heart disease. From December 2002 to March 2004, 126 cardiac CT examinations from 104 children (median age 11 months; age range 1 day to 15 years) were evaluated. All patients had ventriculo-arterial concordance and no malformations of the great arteries; those with coronary artery anomalies were excluded. Contrast-enhanced 16-slice spiral CT was performed without ECG-gating and multiplanar images for coronary arteries were obtained. The visibility of coronary artery origins was graded on a three-point scale, while nine segments of the arteries were graded on a four-point scale. CT images in which it was possible to trace the coronary arteries were considered diagnostic. The visibility of each whole coronary artery and the origins and proximal four segments of coronary arteries were calculated. The visibility of coronary arteries was also correlated with patient age. The percentage of CT images of diagnostic quality was 49.3% for the whole coronary artery and 81.7% for the origins and proximal four segments. There was a significant positive correlation between the visibility of coronary arteries and age. Non-ECG-gated cardiac CT, in which the coronary artery is not of primary diagnostic concern, is frequently able to visualize the origin and proximal course of coronary arteries and may be helpful in detecting coronary artery anomalies in children with congenital heart disease. (orig.)

  6. Myocardial enhancement pattern in patients with acute myocardial infarction on two-phase contrast-enhanced Ecg-gated multidetector-row computed tomography

    International Nuclear Information System (INIS)

    Ko, S.M.; Seo, J.B.; Hong, M.K.; Do, K.H.; Lee, S.H.; Lee, J.S.; Song, J.W.; Park, S.J.; Park, S.W.; Lim, T.H.

    2006-01-01

    Aim: To evaluate the myocardial enhancement pattern of the left ventricle on two-phase contrast-enhanced electrocardiogram (ECG)-gated multidetector computed tomography (MDCT) images in patients with acute myocardial infarction (AMI). METHODS: Two-phase contrast-enhanced ECG-gated MDCT examinations were performed in 16 patients with AMI. The presence, location and pattern of myocardial enhancement were evaluated. MDCT findings were compared with the catheter angiographic results. RESULTS: Subendocardial (n=9) or transmural (n=6) area of early perfusion defects of the myocardium was detected in 15 of 16 patients (94%) on early-phase CT images. Variable delayed myocardial enhancement patterns on late-phase CT images were observed in 12 patients (75%): (1) subendocardial residual perfusion defect and subepicardial late enhancement (n=6); (2) transmural late enhancement (n=1); (3) isolated subendocardial late enhancement (n=1); and (4) isolated subendocardial residual perfusion defect (n=2). On catheter angiography, 14 of 15 corresponding coronary arteries showed significant stenosis. CONCLUSION: Variable abnormal myocardial enhancement pattern was seen on two-phase, contrast-enhanced ECG-gated MDCT in patients with AMI. Assessment of myocardial attenuation on CT angiography gives additional information of the location and extent of infarction

  7. Calculation of left ventricular volume and ejection fraction from ECG-gated myocardial SPECT. Automatic detection of endocardial borders by threshold method

    International Nuclear Information System (INIS)

    Fukushi, Shoji; Teraoka, Satomi.

    1997-01-01

    A new method which calculate end-diastolic volume (EDV), end-systolic volume (ESV) and ejection fraction (LVEF) of the left ventricle from myocardial short axis images of ECG-gated SPECT using 99m Tc myocardial perfusion tracer has been designed. Eight frames per cardiac cycle ECG-gated 180 degrees SPECT was performed. Threshold method was used to detect myocardial borders automatically. The optimal threshold was 45% by myocardial SPECT phantom. To determine if EDV, ESV and LVEF can also be calculated by this method, 12 patients were correlated ventriculography (LVG) for 10 days each. The correlation coefficient with LVG was 0.918 (EDV), 0.935 (ESV) and 0.900 (LVEF). This method is excellent at objectivity and reproductivity because of the automatic detection of myocardial borders. It also provides useful information on heart function in addition to myocardial perfusion. (author)

  8. Left ventricular function in response to dipyridamole stress: head-to-head comparison between {sup 82}Rubidium PET and {sup 99m}Tc-sestamibi SPECT ECG-gated myocardial perfusion imaging

    Energy Technology Data Exchange (ETDEWEB)

    Giorgi, Maria Clementina; Meneghetti, Jose Claudio; Soares, Jose; Izaki, Marisa; Falcao, Andrea; Imada, Rodrigo; Chalela, William; Oliveira, Marco Antonio de; Nomura, Cesar [Department of Radiology and Nuclear Medicine and Molecular Imaging Service - Heart Institute of the University of Sao Paulo Medical School, Sao Paulo (Brazil); Verberne, Hein J. [University of Amsterdam, Department of Nuclear Medicine, Academic Medical Center, P.O. Box 22700, Amsterdam (Netherlands)

    2017-05-15

    Myocardial perfusion imaging (MPI) with {sup 99m}Tc-sestamibi (sestamibi) SPECT and rubidium-82 ({sup 82}Rb) PET both allow for combined assessment of perfusion and left ventricular (LV) function. We sought to compare parameters of LV function obtained with both methods using a single dipyridamole stress dose. A group of 221 consecutive patients (65.2 ± 10.4 years, 52.9% male) underwent consecutive sestamibi and {sup 82}Rb MPI after a single dipyridamole stress dose. Sestamibi and {sup 82}Rb summed rest (SRS), stress (SSS) and difference (SDS) scores, and LV end-diastolic (EDV) and end-systolic (ESV) volumes and left ventricular ejection fraction (LVEF) were compared. Bland-Altman analysis showed that with increasing ESV and EDV the difference between the two perfusion tracers increased both at rest and post-stress. The mean difference in EDV and ESV between the two perfusion tracers at rest could both be independently explained by the {sup 82}Rb SDS and the sestamibi SRS. The combined models explained approximately 30% of the variation in these volumes between the two perfusion tracers (R{sup 2} = 0.261, p = 0.005; R{sup 2} = 0.296, p < 0.001, for EDV and ESV respectively). However, the mean difference in LVEF between sestamibi and {sup 82}Rb showed no significant trend post-stress (R{sup 2} = 0.001, p = 0.70) and only a modest linear increase with increasing LVEF values at rest (R{sup 2} = 0.032, p = 0.009). Differences in left ventricular volumes between sestamibi and {sup 82}Rb MPI increase with increasing volumes. However, these differences did only marginally affect LVEF between sestamibi and {sup 82}Rb. In clinical practice these results should be taken into account when comparing functional derived parameters between sestamibi and {sup 82}Rb MPI. (orig.)

  9. The value of low-dose prospective ECG-gated dual-source CT angiography in the diagnosis of coarctation of the aorta in infants and children

    Energy Technology Data Exchange (ETDEWEB)

    Nie, P. [Shandong Provincial Key Laboratory of Diagnosis and Treatment of Cardio-Cerebral Vascular Diseases, Shandong Medical Imaging Research Institute, Shandong University, Jinan, Shandong (China); Wang, X., E-mail: wxming369@yahoo.com.cn [Shandong Provincial Key Laboratory of Diagnosis and Treatment of Cardio-Cerebral Vascular Diseases, Shandong Medical Imaging Research Institute, Shandong University, Jinan, Shandong (China); Cheng, Z.; Duan, Y.; Ji, X. [Shandong Provincial Key Laboratory of Diagnosis and Treatment of Cardio-Cerebral Vascular Diseases, Shandong Medical Imaging Research Institute, Shandong University, Jinan, Shandong (China); Chen, J. [CT Research Collaboration, Siemens, Beijing (China); Zhang, H. [Department of Cardiovascular Surgery, Shandong Provincial Hospital, Jinan, Shandong (China)

    2012-08-15

    Aim: To investigate the value of prospective electrocardiogram (ECG)-gated dual-source computed tomography (DSCT) in the diagnosis of coarctation of the aorta (CoA). Materials and methods: Seventeen patients clinically suspected of having CoA underwent prospective ECG-gated DSCT angiography and transthoracic echocardiography (TTE). Surgery was performed in all patients. The diagnostic accuracy of DSCT angiography and TTE was compared with the surgical findings as the reference standard. Image quality was evaluated using a five-point scale. Effective radiation dose was calculated from the dose-length product (DLP). Results: CoA was diagnosed in 17 patients by DSCT angiography and in 16 patients by TTE. A total of 46 separate cardiovascular abnormalities were confirmed by surgical findings. The diagnostic accuracy of DSCT angiography and TTE was 96.32% and 97.06%, respectively. There was no significant difference in the diagnostic accuracy between DSCT angiography and TTE ({chi}{sup 2} = 0, p > 0.05). The mean score of image quality was 4.2 {+-} 0.8. The mean effective dose was 0.69 {+-} 0.09 mSv. Conclusion: Prospective ECG-gated DSCT with a low radiation dose is a valuable technique in the diagnosis of CoA in infants and children.

  10. Computer-based automated left atrium segmentation and volumetry from ECG-gated coronary CT angiography data. Comparison with manual slice segmentation and ultrasound planimetric methods

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, R.W.; Kraus, B.; Kerl, J.M.; Lehnert, T.; Vogl, T.J. [Universitaetsklinikum Frankfurt (Germany). Inst. fuer Diagnostische und Interventionelle Radiologie; Bernhardt, D.; Vega-Higuera, F. [Siemens AG, Healthcare Sector, Forchheim (Germany). Computed Tomography; Ackermann, H. [Universitaetsklinikum Frankfurt (Germany). Inst. fuer Biostatistik und Mathematische Modellierung

    2010-12-15

    Purpose: Enlargement of the left atrium is a risk factor for cardiovascular or cerebrovascular events. We evaluated the performance of prototype software for fully automated segmentation and volumetry of the left atrium. Materials and Methods: In 34 retrospectively ECG-gated coronary CT angiography scans, the end-systolic (LAVsys) and end-diastolic (LAVdia) volume of the left atrium was calculated fully automatically by prototype software. Manual slice segmentation by two independent experienced radiologists served as the reference standard. Furthermore, two independent observers calculated the LAV utilizing two ultrasound planimetric methods ('area length' and 'prolate ellipse') on CTA images. Measurement periods were compared for all methods. Results: The left atrial volumes calculated with the prototype software were in excellent agreement with the results from manual slice segmentation (r = 0.97 - 0.99; p < 0.001; Bland-Altman) with excellent interobserver agreement between both radiologists (r = 0.99; p < 0.001). Ultrasound planimetric methods clearly showed a higher variation (r = 0.72 - 0.86) with moderate interobserver agreement (r = 0.51 - 0.79). The measurement period was significantly lower with the software (267 {+-} 28 sec; p < 0.001) than with ultrasound methods (431 {+-} 68 sec) or manual slice segmentation (567 {+-} 91 sec). Conclusion: The prototype software showed excellent agreement with manual slice segmentation with the least time consumption. This will facilitate the routine assessment of the LA volume from coronary CTA data and therefore risk stratification. (orig.)

  11. Diagnosis of accessory conduction pathway using ECG-gated emission CT analysis

    International Nuclear Information System (INIS)

    Misaki, Takuro; Mukai, Keiichi; Tsubota, Makoto; Iwa, Takashi; Nakajima, Ken-ichi; Hisada, Kin-ichi

    1987-01-01

    Pinpointing the location of accessory conduction pathway (ACP) is of great importance in the surgical treatment for Wolff-Parkinson-White (WPW) syndrome. For this purpose, this study explored the usefulness of ECG-gated emission computed tomography (Gated-ECT) in 30 patients who preoperatively underwent Gated-ECT. The site of earliest contraction at level of atrioventicular valves, obtained on tomographic phase analysis, was compared with the site of earliest activation, obtained on epicardial mapping during surgery. The concordance rate of the two methods was 94 % (28/30). Among them, one patient was found to have the association of corrected transposition of great arteries on Gated-ECT. Gated-ECT was, however, of limited value in differentiating right posterior ACP from right postseptal ACP. The discordance between the sites of earliest contraction and activation, which was observed in the two others, was likely due to decreased wall motion resulting from myocardial disturbance. Gated-ECT may have a diagnostic potential for the location of ACP, especially in view of providing images that corresponded to the surgical anatomy. (Namekawa, K.)

  12. An integrated bioimpedance—ECG gating technique for respiratory and cardiac motion compensation in cardiac PET

    International Nuclear Information System (INIS)

    Koivumäki, Tuomas; Nekolla, Stephan G; Fürst, Sebastian; Loher, Simone; Schwaiger, Markus; Vauhkonen, Marko; Hakulinen, Mikko A

    2014-01-01

    Respiratory motion may degrade image quality in cardiac PET imaging. Since cardiac PET studies often involve cardiac gating by ECG, a separate respiratory monitoring system is required increasing the logistic complexity of the examination, in case respiratory gating is also needed. Thus, we investigated the simultaneous acquisition of both respiratory and cardiac gating signals using II limb lead mimicking electrode configuration during cardiac PET scans of 11 patients. In addition to conventional static and ECG-gated images, bioimpedance technique was utilized to generate respiratory- and dual-gated images. The ability of the bioimpedance technique to monitor intrathoracic respiratory motion was assessed estimating cardiac displacement between end-inspiration and -expiration. The relevance of dual gating was evaluated in left ventricular volume and myocardial wall thickness measurements. An average 7.6  ±  3.3 mm respiratory motion was observed in the study population. Dual gating showed a small but significant increase (4 ml, p = 0.042) in left ventricular myocardial volume compared to plain cardiac gating. In addition, a thinner myocardial wall was observed in dual-gated images (9.3  ±  1.3 mm) compared to cardiac-gated images (11.3  ±  1.3 mm, p = 0.003). This study shows the feasibility of bioimpedance measurements for dual gating in a clinical setting. The method enables simultaneous acquisition of respiratory and cardiac gating signals using a single device with standard ECG electrodes. (paper)

  13. Assessment of the effect of revascularization early after CABG using ECG-gated perfusion single-photon emission tomography

    International Nuclear Information System (INIS)

    Kubo, Shigeto; Tadamura, Eiji; Kudoh, Takashi; Inubushi, Masayuki; Konishi, Junji; Ikeda, Tadashi; Koshiji, Takaaki; Nishimura, Kazunobu; Komeda, Masashi; Tamaki, Nagara

    2001-01-01

    When an arterial graft is used, reversible perfusion defects on single-photon emission tomography (SPET) perfusion images are occasionally observed early after coronary artery bypass graft surgery (CABG), owing to the restricted flow capacity. The purpose of this study was to determine whether the functional information obtained with electrocardiography (ECG)-gated perfusion SPET could be helpful in evaluating the effect of revascularization early after CABG. Twenty-three patients (18 men and 5 women, mean age 65±9 years) underwent stress/re-injection thallium-201 ECG-gated SPET before and 4 weeks after CABG (13 with exercise and 10 with dipyridamole). Patency of all grafts was confirmed by coronary angiography 1 month after CABG. Cardiac functional data including the left ventricular ejection fraction (LVEF) and the transient ischaemic dilatation (TID) ratio were analysed using a commercially available automated program. The conventional stress and re-injection tomograms were interpreted by means of a five-point scoring system in a nine-segment model. Stress-induced reversible 201 Tl perfusion defects were present in 64% of the myocardial segments bypassed by patent arterial grafts, in contrast to 42% of the myocardial segments bypassed by patent venous grafts (χ 2 =7.8, P=0.005). Of the 23 patients, 12 showed improvement in summed ischaemic scores (group 1), while 11 had no change or deterioration (group 2), although all grafts were patent on postoperative catheterization. The TID ratio improved in both group 1 and group 2 before and after CABG (1.14±0.13 vs 0.99±0.07, P=0.001 and 1.09±0.07 vs 0.94±0.05, P=0.002, respectively). However, LVEF did not significantly improve in group 1 or group 2 after CABG (42.5%±9.9% vs 47.5%±11.8%, and 52.1%±7.5% vs 53.1%±5.9%, respectively). Perfusion imaging or LVEF assessment is of limited value early after CABG. The TID ratio obtained with ECG-gated perfusion SPET may be a useful marker to evaluate the effect of

  14. Use of ECG-gated computed tomography, echocardiography and selective angiography in five dogs with pulmonic stenosis and one dog with pulmonic stenosis and aberrant coronary arteries.

    Science.gov (United States)

    Laborda-Vidal, P; Pedro, B; Baker, M; Gelzer, A R; Dukes-McEwan, J; Maddox, T W

    2016-12-01

    Pulmonic stenosis (PS) is the most common congenital cardiac disease in dogs. Boxers and English bulldogs are among the most commonly affected breeds and also commonly associated with an aberrant coronary artery (CA). If an aberrant CA is suspected and balloon valvuloplasty indicated, an intra-operative angiography is recommended prior to the procedure. ECG-gated computed tomography (CT) can be used to screen for CA anomalies in a quick and minimally-invasive way (preventing side effects associated with selective catheter angiography) and allowing early planning of the procedure. The aim of this case series was to report CT findings associated with PS diagnosed by echocardiography. Our database was retrospectively searched for cases of dogs with PS diagnosed by echocardiography, where an ECG-gated CT was performed. A total of six cases were retrieved: all were diagnosed with severe PS. Four dogs had concurrent congenital defects: two dogs had a patent ductus arteriosus, one dog had a ventricular septal defect and an overriding aorta, one dog had an aberrant CA. Detailed CT findings of all cases were reported, including one case of a patent ductus arteriosus and an overriding aorta not identified by transthoracic echocardiography. In addition, an abnormal single left coronary ostium, with a pre-pulmonic right CA was described. In conclusion, despite echocardiography remaining the gold standard for diagnosis and assessment of PS, ECG-gated-CT angiography is a complementary diagnostic method that may provide additional relevant information, shorten surgery/anaesthesia time and reduce the amount of radiation to which the clinician is subjected. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Diagnostic accuracy of prospective ECG gated coronary computed tomography on a 256 slices scanner: Daily practice experience

    Directory of Open Access Journals (Sweden)

    Ahmed M. Fareed

    2014-03-01

    Conclusions: In a highly prevalence diseased population, prospective ECG-gated CTCA using 256-slice scanner is highly accurate for detection and quantification of the degree of coronary luminal stenosis in comparison to ICA.

  16. Nonenhanced ECG-gated quiescent-interval single-shot MRA (QISS-MRA) of the lower extremities: Comparison with contrast-enhanced MRA

    Energy Technology Data Exchange (ETDEWEB)

    Klasen, J. [Department of Diagnostic and Interventional Radiology, University of Duesseldorf, Medical Faculty, Duesseldorf (Germany); Blondin, D., E-mail: blondin@med.uni-duesseldorf.de [Department of Diagnostic and Interventional Radiology, University of Duesseldorf, Medical Faculty, Duesseldorf (Germany); Schmitt, P. [Siemens AG, Healthcare Sector, Erlangen (Germany); Bi, X. [Siemens Healthcare, Chicago, IL (United States); Sansone, R. [Department of Cardiology, University of Duesseldorf, Medical Faculty, Duesseldorf (Germany); Wittsack, H.-J.; Kroepil, P.; Quentin, M.; Kuhlemann, J.; Miese, F. [Department of Diagnostic and Interventional Radiology, University of Duesseldorf, Medical Faculty, Duesseldorf (Germany); Heiss, C.; Kelm, M. [Department of Cardiology, University of Duesseldorf, Medical Faculty, Duesseldorf (Germany); Antoch, G.; Lanzman, R.S. [Department of Diagnostic and Interventional Radiology, University of Duesseldorf, Medical Faculty, Duesseldorf (Germany)

    2012-05-15

    Aim: To evaluate electrocardiogram (ECG)-gated quiescent-interval single-shot magnetic resonance angiography (QISS-MRA) for nonenhanced assessment of peripheral artery occlusive disease (PAOD) using contrast-enhanced MRA (CE-MRA) as the reference standard. Materials and methods: Twenty-seven patients (mean age 66.6 {+-} 10.8 years) with PAOD were included in the study. QISS-MRA and CE-MRA of the lower extremity were performed using a 1.5 T MR scanner. In each patient, subjective image quality and the degree of stenosis were evaluated on a four-point scale for 15 predefined arterial segments. Results: Twenty-five of the 27 patients were considered for analysis. Subjective image quality of QISS-MRA was significantly lower for the distal aorta, pelvic arteries, and femoral arteries as compared to CE-MRA (p < 0.01), while no significant difference was found for other vascular segments. The degree of stenosis was overestimated with QISS-MRA in 23 of 365 (6.3%) segments and underestimated in two of 365 (0.5%) segments. As compared to CE-MRA, QISS-MRA had a high sensitivity (98.6%), specificity (96%) as well as positive and negative predictive value (88.7 and 99.6%, respectively) for the detection of significant stenosis ({>=}50%). Conclusion: ECG-gated QISS-MRA is a promising imaging technique for reliable assessment of PAOD without the use of contrast material.

  17. Nonenhanced ECG-gated quiescent-interval single-shot MRA (QISS-MRA) of the lower extremities: Comparison with contrast-enhanced MRA

    International Nuclear Information System (INIS)

    Klasen, J.; Blondin, D.; Schmitt, P.; Bi, X.; Sansone, R.; Wittsack, H.-J.; Kröpil, P.; Quentin, M.; Kuhlemann, J.; Miese, F.; Heiss, C.; Kelm, M.; Antoch, G.; Lanzman, R.S.

    2012-01-01

    Aim: To evaluate electrocardiogram (ECG)-gated quiescent-interval single-shot magnetic resonance angiography (QISS-MRA) for nonenhanced assessment of peripheral artery occlusive disease (PAOD) using contrast-enhanced MRA (CE-MRA) as the reference standard. Materials and methods: Twenty-seven patients (mean age 66.6 ± 10.8 years) with PAOD were included in the study. QISS-MRA and CE-MRA of the lower extremity were performed using a 1.5 T MR scanner. In each patient, subjective image quality and the degree of stenosis were evaluated on a four-point scale for 15 predefined arterial segments. Results: Twenty-five of the 27 patients were considered for analysis. Subjective image quality of QISS-MRA was significantly lower for the distal aorta, pelvic arteries, and femoral arteries as compared to CE-MRA (p < 0.01), while no significant difference was found for other vascular segments. The degree of stenosis was overestimated with QISS-MRA in 23 of 365 (6.3%) segments and underestimated in two of 365 (0.5%) segments. As compared to CE-MRA, QISS-MRA had a high sensitivity (98.6%), specificity (96%) as well as positive and negative predictive value (88.7 and 99.6%, respectively) for the detection of significant stenosis (≥50%). Conclusion: ECG-gated QISS-MRA is a promising imaging technique for reliable assessment of PAOD without the use of contrast material.

  18. The effect of relaxing music on heart rate and heart rate variability during ECG GATED-myocardial perfusion scintigraphy.

    Science.gov (United States)

    Tan, Yusuf Ziya; Ozdemir, Semra; Temiz, Ahmet; Celik, Fatmanur

    2015-05-01

    The positive changes in human behavior caused by relaxing music demonstrate the psychological effect of music on human body. A meta-analytical study has shown that relaxing music affects blood pressure and heart rate in coronary heart patients and cancer patients. The aim of our study is to research whether there is a significant effect on heart rate and heart rate variability due to listening to relaxing music during ECG GATED MPS imaging under gamma camera. The music group (n = 50 patients) could choose from 15 different musical types including folk music (no lyric). The other 50 patients were placed in a "no music group" and did not get headphones or any music. There was a statistically significant reduction in the heart rate of patients in the music group compared to those in the control group. Relaxing music provides great benefits to both patient and clinician. There is close relationship between relaxing music and health procedure, can use every area of the health noninvasiv, safe, cheap and is a method don't have side effect. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Experimental and clinical analyses of optimum Fourier filtering in ECG-gated blood pool scintigraphy

    International Nuclear Information System (INIS)

    Shimabukuro, Kunisada

    1988-01-01

    A phantom study was undertaken to determine the optimum order harmonics in Fourier analysis for volume curves obtained by ECG-gated blood pool scintigraphy. The volume curve obtained by Tc-99m scintigraphy was computed by the 1st through 10th order harmonics of Fourier transform. The shape of each volume curve fitted by Fourier transform was compared with the shape of the generated ideal curve. Curves fitted with the 3rd or more order harmonics were approximate to the ideal curve in shape during the systolic phase. The 6th to 10th order harmonics were suitable for the early diastole phase. As determined by peak ejection rate and peak filling rate (PFR), the 6th order harmonics was superior to the 3rd order harmonics in evaluating early diastolic abnormalities. In the clinical settings, there was no difference between the 3rd and 6th order harmonics in evaluating systolic abnormalities; however, the 6th order harmonics was more sensitive than the 3rd order harmonics in evaluating early diastolic abnormalities. The 6th order harmonics significantly reflected PFR in the group of hypertrophic cardiomyopathy (n=10) and time to PFR in the groups of old myocardial infarction (n=10) and angina pectoris (n=10). In conclusion, the 6th to 9th order harmonics of Fourier analysis may be useful in analyzing both systolic and early diastolic phases inf left ventricular volume curves obtained from ECG-gated cardiac blood pool scintigraphy. (Namekawa, K)

  20. MO-DE-207A-06: ECG-Gated CT Reconstruction for a C-Arm Inverse Geometry X-Ray System

    Energy Technology Data Exchange (ETDEWEB)

    Slagowski, JM; Dunkerley, DAP [MA Speidel, University of Wisconsin - Madison, Madison, WI (United States)

    2016-06-15

    Purpose: To obtain ECG-gated CT images from truncated projection data acquired with a C-arm based inverse geometry fluoroscopy system, for the purpose of cardiac chamber mapping in interventional procedures. Methods: Scanning-beam digital x-ray (SBDX) is an inverse geometry fluoroscopy system with a scanned multisource x-ray tube and a photon-counting detector mounted to a C-arm. In the proposed method, SBDX short-scan rotational acquisition is performed followed by inverse geometry CT (IGCT) reconstruction and segmentation of contrast-enhanced objects. The prior image constrained compressed sensing (PICCS) framework was adapted for IGCT reconstruction to mitigate artifacts arising from data truncation and angular undersampling due to cardiac gating. The performance of the reconstruction algorithm was evaluated in numerical simulations of truncated and non-truncated thorax phantoms containing a dynamic ellipsoid to represent a moving cardiac chamber. The eccentricity of the ellipsoid was varied at frequencies from 1–1.5 Hz. Projection data were retrospectively sorted into 13 cardiac phases. Each phase was reconstructed using IGCT-PICCS, with a nongated gridded FBP (gFBP) prior image. Surface accuracy was determined using Dice similarity coefficient and a histogram of the point distances between the segmented surface and ground truth surface. Results: The gated IGCT-PICCS algorithm improved surface accuracy and reduced streaking and truncation artifacts when compared to nongated gFBP. For the non-truncated thorax with 1.25 Hz motion, 99% of segmented surface points were within 0.3 mm of the 15 mm diameter ground truth ellipse, versus 1.0 mm for gFBP. For the truncated thorax phantom with a 40 mm diameter ellipse, IGCT-PICCS surface accuracy measured 0.3 mm versus 7.8 mm for gFBP. Dice similarity coefficient was 0.99–1.00 (IGCT-PICCS) versus 0.63–0.75 (gFBP) for intensity-based segmentation thresholds ranging from 25–75% maximum contrast. Conclusions: The

  1. An evaluation of the ECG gated cardiac CT on old myocardial infarction

    International Nuclear Information System (INIS)

    Tanegashima, Kazuhiro; Tejima, Yasuaki; Nakasone, Noriyo; Hyodo, Haruo

    1984-01-01

    In order to examine the accuracy of ECG gated cardiac CT (G-CCT), G-CCT findings were compared with ECG and cardiac echographic findings in 25 cases of old myocardial infarction. From the detection rate according to the infarct area, abnormal findings in the anterior wall and the septum obtained from G-CCT were in good accordance with those from ECG. Although all of the G-CCT findings did not agree with those of cardiac echography in cases in which abnormal findings were seen in multiple areas, the detection rate of cardiac abnormal findings as a whole by G-CCT was the same as that by cardiac echography. (Namekawa K.)

  2. Accuracy and reliability of noninvasive stroke volume monitoring via ECG-gated 3D electrical impedance tomography in healthy volunteers

    Science.gov (United States)

    Proença, Martin; Adler, Andy; Riedel, Thomas; Thiran, Jean-Philippe; Solà, Josep

    2018-01-01

    Cardiac output (CO) and stroke volume (SV) are parameters of key clinical interest. Many techniques exist to measure CO and SV, but are either invasive or insufficiently accurate in clinical settings. Electrical impedance tomography (EIT) has been suggested as a noninvasive measure of SV, but inconsistent results have been reported. Our goal is to determine the accuracy and reliability of EIT-based SV measurements, and whether advanced image reconstruction approaches can help to improve the estimates. Data were collected on ten healthy volunteers undergoing postural changes and exercise. To overcome the sensitivity to heart displacement and thorax morphology reported in previous work, we used a 3D EIT configuration with 2 planes of 16 electrodes and subject-specific reconstruction models. Various EIT-derived SV estimates were compared to reference measurements derived from the oxygen uptake. Results revealed a dramatic impact of posture on the EIT images. Therefore, the analysis was restricted to measurements in supine position under controlled conditions (low noise and stable heart and lung regions). In these measurements, amplitudes of impedance changes in the heart and lung regions could successfully be derived from EIT using ECG gating. However, despite a subject-specific calibration the heart-related estimates showed an error of 0.0 ± 15.2 mL for absolute SV estimation. For trending of relative SV changes, a concordance rate of 80.9% and an angular error of −1.0 ± 23.0° were obtained. These performances are insufficient for most clinical uses. Similar conclusions were derived from lung-related estimates. Our findings indicate that the key difficulty in EIT-based SV monitoring is that purely amplitude-based features are strongly influenced by other factors (such as posture, electrode contact impedance and lung or heart conductivity). All the data of the present study are made publicly available for further investigations. PMID:29373611

  3. Three-dimensional thoracic aorta principal strain analysis from routine ECG-gated computerized tomography: feasibility in patients undergoing transcatheter aortic valve replacement.

    Science.gov (United States)

    Satriano, Alessandro; Guenther, Zachary; White, James A; Merchant, Naeem; Di Martino, Elena S; Al-Qoofi, Faisal; Lydell, Carmen P; Fine, Nowell M

    2018-05-02

    Functional impairment of the aorta is a recognized complication of aortic and aortic valve disease. Aortic strain measurement provides effective quantification of mechanical aortic function, and 3-dimenional (3D) approaches may be desirable for serial evaluation. Computerized tomographic angiography (CTA) is routinely performed for various clinical indications, and offers the unique potential to study 3D aortic deformation. We sought to investigate the feasibility of performing 3D aortic strain analysis in a candidate population of patients undergoing transcatheter aortic valve replacement (TAVR). Twenty-one patients with severe aortic valve stenosis (AS) referred for TAVR underwent ECG-gated CTA and echocardiography. CTA images were analyzed using a 3D feature-tracking based technique to construct a dynamic aortic mesh model to perform peak principal strain amplitude (PPSA) analysis. Segmental strain values were correlated against clinical, hemodynamic and echocardiographic variables. Reproducibility analysis was performed. The mean patient age was 81±6 years. Mean left ventricular ejection fraction was 52±14%, aortic valve area (AVA) 0.6±0.3 cm 2 and mean AS pressure gradient (MG) 44±11 mmHg. CTA-based 3D PPSA analysis was feasible in all subjects. Mean PPSA values for the global thoracic aorta, ascending aorta, aortic arch and descending aorta segments were 6.5±3.0, 10.2±6.0, 6.1±2.9 and 3.3±1.7%, respectively. 3D PSSA values demonstrated significantly more impairment with measures of worsening AS severity, including AVA and MG for the global thoracic aorta and ascending segment (panalysis is clinically feasible from routine ECG-gated CTA. Appropriate reductions in PSSA were identified with increasing AS hemodynamic severity. Expanded study of 3D aortic PSSA for patients with various forms of aortic disease is warranted.

  4. [Comparison of radiation dose reduction of prospective ECG-gated one beat scan using 320 area detector CT coronary angiography and prospective ECG-gated helical scan with high helical pitch (FlashScan) using 64 multidetector-row CT coronary angiography].

    Science.gov (United States)

    Matsutani, Hideyuki; Sano, Tomonari; Kondo, Takeshi; Fujimoto, Shinichiro; Sekine, Takako; Arai, Takehiro; Morita, Hitomi; Takase, Shinichi

    2010-12-20

    A high radiation dose associated with 64 multidetector-row computed tomography (64-MDCT) is a major concern for physicians and patients alike. A new 320 row area detector computed tomography (ADCT) can obtain a view of the entire heart with one rotation (0.35 s) without requiring the helical method. As such, ADCT is expected to reduce the radiation dose. We studied image quality and radiation dose of ADCT compared to that of 64-MDCT in patients with a low heart rate (HR≤60). Three hundred eighty-five consecutive patients underwent 64-MDCT and 379 patients, ADCT. Patients with an arrhythmia were excluded. Prospective ECG-gated helical scan with high HP (FlashScan) in 64 was used for MDCT and prospective ECG-gated conventional one beat scan, for 320-ADCT. Image quality was visually evaluated by an image quality score. Radiation dose was estimated by DLP (mGy・cm) for 64-MDCT and DLP.e (mGy・cm) for 320-ADCT. Radiation dose of 320-ADCT (208±48 mGy・cm) was significantly (P<0.0001) lower than that of 64-MDCT (484±112 mGy・cm), and image quality score of 320-ADCT (3.0±0.2) was significantly (P=0.0011) higher than that of 64-MDCT (2.9±0.4). Scan time of 320-ADCT (1.4±0.1 s) was also significantly (P<0.0001) shorter than that of 64-MDCT (6.8±0.6 s). 320-ADCT can achieve not only a reduction in radiation dose but also a superior image quality and shortening of scan time compared to 64-MDCT.

  5. The usefulness of treatment evaluation of severe heart failure by ECG-gated myocardial SPECT

    International Nuclear Information System (INIS)

    Ohkoshi, Nobuyuki; Watanabe, Shingo; Matsumoto, Tooru

    2011-01-01

    Our purpose of study was to investigate the usefulness of treatment evaluation of severe heart failure by Electrocardiogram (ECG)-gated myocardial single photon emission computed tomography (SPECT). We evaluated the cardiac function in the case of severe heart failure by gated SPECT and compared it with the cardiac function obtained by left ventriculography (LVG), echocardiography, cardiac MRI, and B-type natriuretic peptide (BNP) values. We investigated the correlation of ejection fraction (EF), time lag of wall motion between the septal and lateral walls of the left ventricle for cardiac resynchronization therapy (CRT) and wall thickening (WT). We classified the left ventricular (LV) into basal, middle and apical areas for comparison of WT. We investigated the effect of a perfusion defect score in these comparisons. The gated SPECT results were correlated with comparative subjects in EF. The results were correlated with MRI on the middle area of the LV in the comparison of WT. We thought it was possible that there was an effect from a perfusion defect score in a time lag comparison of wall motion. Treatment evaluation of severe heart failure by gated SPECT is useful, because it is able to obtain three-dimensional cardiac function analysis, and it offers objectivity and reproducible quantitative evaluation. At the same time, perfusion SPECT is helpful for CRT and LV-plasty. (author)

  6. Ventricular short-axis measurements in patients with pulmonary embolism: Effect of ECG-gating on variability, accuracy, and risk prediction

    International Nuclear Information System (INIS)

    Scheffel, Hans; Stolzmann, Paul; Leschka, Sebastian; Desbiolles, Lotus; Seifert, Burkhardt; Marincek, Borut; Alkadhi, Hatem

    2012-01-01

    Objective: To assess prospectively the intra- and interobserver variability, accuracy, and prognostic value of right and left ventricular short-axis diameter (RVd and LVd) measurements for risk stratification in patients with pulmonary embolism (PE) using ECG-gated compared to non-gated CT. Materials and methods: Sixty consecutive patients (33 women; mean age 58.7 ± 10.3 years) with suspicion of PE underwent both non-gated and ECG-gated chest CT. RVd and LVd on four-chamber views and intra- and interobserver agreements were calculated for both protocols. RVd/LVd ratios were calculated and were related to 30-days adverse clinical events using receiver operating characteristics with area-under-the-curve (AUC) analyses. Results: Both inter- and intraobserver variability showed narrower limits of agreement for all measurements with ECG-gated as compared to non-gated CT. Diameter measurements were significantly lower using non-ECG-gated CT as compared to ECG-gated CT for RVd and LVd (both p < .05). The AUC for the RVd/LVd ratio from ECG-gated CT was significantly larger than that from non-gated CT (0.956, 95% CI: 0.768–0.999 versus 0.675, 95% CI: 0.439–0.860; p = .048). Conclusion: RVd and LVd measurements from ECG-gated chest CT show less intra- and interobserver variability and more accurately reflect ventricular function. In our patient cohort ECG-gated chest CT allows better prediction of short-term outcome of patients with acute PE that needs to be validated in a larger outcome study

  7. ECG-gated quiescent-interval single-shot MR angiography of the lower extremities: Initial experience at 3 T

    International Nuclear Information System (INIS)

    Knobloch, G.; Gielen, M.; Lauff, M.-T.; Romano, V.C.; Schmitt, P.; Rick, M.; Kröncke, T.J.; Huppertz, A.; Hamm, B.; Wagner, M.

    2014-01-01

    Aim: To evaluate the feasibility of unenhanced electrocardiography (ECG)-gated quiescent-interval single-shot magnetic resonance angiography (QISS-MRA) of the lower extremities at 3 T. Materials and methods: Twenty-five patients with known or suspected peripheral arterial disease underwent ECG-gated QISS-MRA and contrast-enhanced MRA (CE-MRA) at 3 T. Two independent readers performed a per-segment evaluation of the MRA datasets. Image quality was rated on a four-point scale (1 = excellent to 4 = non-diagnostic; presented as medians with interquartile range). Diagnostic performance of QISS-MRA was evaluated using CE-MRA as the reference standard. Results: QISS-MRA and CE-MRA of all patients were considered for analysis, resulting in 807 evaluated vessel segments for each MRA technique. Readers 1 and 2 rated image quality of QISS-MRA as diagnostic in 97.3% and 97% of the vessel segments, respectively. CE-MRA was rated diagnostic in all vessel segments. Image quality of the proximal vessel segments, including the infrarenal aorta, iliac arteries, and common femoral artery, was significantly lower on QISS-MRA compared to CE-MRA [image quality score across readers: 2 (1,3) versus 1 (1,1) p < 0.001]. In the more distal vessel segments, image quality of QISS-MRA was excellent and showed no significant difference compared to CE-MRA [image quality score across readers: 1 (1,1) versus 1 (1,1) p = 0.036]. Diagnostic performance of QISS-MRA was as follows (across readers): sensitivity: 87.5% (95% CI: 80.2–92.4%); specificity: 96.1% (95% CI: 93.6–97.6%); diagnostic accuracy: 94.9% (95% CI: 92.6–96.5%). Conclusions: QISS-MRA of the lower extremities is feasible at 3 T and provides high image quality, especially in the distal vessel segments

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

    International Nuclear Information System (INIS)

    Rigsby, Cynthia K.; Nicholas, Angela C.; deFreitas, R.A.; Leidecker, Christianne; Johanek, Andrew J.; Anley, Peter; Wang, Deli; Uejima, Tetsu

    2010-01-01

    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.)

  9. Non-enhanced ECG-gated respiratory-triggered 3-D steady-state free-precession MR angiography with slab-selective inversion: initial experience in visualisation of renal arteries in free-breathing children without renal artery abnormality

    International Nuclear Information System (INIS)

    Klee, Dirk; Lanzman, Rotem Shlomo; Blondin, Dirk; Antoch, Gerald; Schaper, Joerg; Schmitt, Peter; Oh, Jun; Salgin, Burak; Mayatepek, Ertan

    2012-01-01

    ECG-gated non-enhanced balanced steady-state free precession (bSSFP) MR angiography requires neither breath-holding nor administration of contrast material. To investigate the image quality of free-breathing ECG-gated non-enhanced bSSFP MR angiography of renal arteries in children. Fourteen boys and seven girls (mean age, 9.7 years; range, 7 weeks-17 years) with no history of renovascular disease were included. MRI was performed at 1.5 T. Subjective image quality of axial and coronal maximum-intensity-projection reconstructions of four segments (I, aorta and renal artery ostium; II, main renal artery; III, segmental branches; IV, intrarenal vessels) was evaluated using a 4-point scale (4 = excellent, 3 = good, 2 = acceptable, 1 = non-diagnostic). Image quality was excellent for segments I (mean ± SD, 3.9 ± 0.3) and II (4.0 ± 0.1), good for segment III (3.4 ± 0.9) and acceptable for segment IV (2.3 ± 1.1). Mean image quality did not differ between sedated and non-sedated children. bSSFP MR angiography enables visualisation of renal arteries in children. (orig.)

  10. Dual-source cardiac computed tomography angiography (CCTA) in the follow-up of cardiac transplant: comparison of image quality and radiation dose using three different imaging protocols

    International Nuclear Information System (INIS)

    Beitzke, D.; Berger-Kulemann, V.; Unterhumer, S.; Loewe, C.; Wolf, F.; Schoepf, V.; Spitzer, E.; Feuchtner, G.M.; Gyoengyoesi, M.; Uyanik-Uenal, K.; Zuckermann, A.

    2015-01-01

    To prospectively evaluate image quality (IQ) and radiation dose of dual-source cardiac computed tomography (CCTA) using different imaging protocols. CCTA was performed in 150 patients using the retrospective ECG-gated spiral technique (rECG) the prospective ECG-gated technique (pECG), or the prospective ECG-gated technique with systolic imaging and automated tube voltage selection (pECGsys). IQ was rated using a 16-segment coronary artery model. Techniques were compared for overall IQ, IQ of the large and the small coronary artery segments. Effective dose was used for comparison of radiation dose. Overall IQ and IQ of the large segments showed no differences between the groups. IQ analysis of the small segments showed lowered IQ in pECGsys compared to rECG (p = 0.02), but not to pECG (p = 0.6). Effective dose did not differ significantly between rECG and pECG (p = 0.13), but was significantly lower for pECGsys (p < 0.001 vs. rECG and pECG). Radiation dose of dual-source CCTA in heart transplant recipients is significantly reduced by using prospective systolic scanning and automated tube voltage selection, while overall IQ and IQ of the large coronary segments are maintained. IQ appears to be lower compared to retrospective techniques with regard to small coronary segments. (orig.)

  11. Dual-source cardiac computed tomography angiography (CCTA) in the follow-up of cardiac transplant: comparison of image quality and radiation dose using three different imaging protocols

    Energy Technology Data Exchange (ETDEWEB)

    Beitzke, D.; Berger-Kulemann, V.; Unterhumer, S.; Loewe, C.; Wolf, F. [Medical University Vienna, Department of Biomedical Imaging and Image Guided Therapy, Division of Cardiovascular and Interventional Radiology, Vienna (Austria); Schoepf, V. [Medical University Vienna, Department of Biomedical Imaging and Image Guided Therapy, Division of Neuroradiology and Musculoskeletal Radiology, Vienna (Austria); Spitzer, E. [Bern University Hospital, Department of Cardiology, Bern (Switzerland); Feuchtner, G.M. [Innsbruck Medical University, Department of Radiology II, Innsbruck (Austria); Gyoengyoesi, M. [Medical University Vienna, Department of Cardiology, Vienna (Austria); Uyanik-Uenal, K.; Zuckermann, A. [Medical University Vienna, Department of Cardiac Surgery, Vienna (Austria)

    2015-08-15

    To prospectively evaluate image quality (IQ) and radiation dose of dual-source cardiac computed tomography (CCTA) using different imaging protocols. CCTA was performed in 150 patients using the retrospective ECG-gated spiral technique (rECG) the prospective ECG-gated technique (pECG), or the prospective ECG-gated technique with systolic imaging and automated tube voltage selection (pECGsys). IQ was rated using a 16-segment coronary artery model. Techniques were compared for overall IQ, IQ of the large and the small coronary artery segments. Effective dose was used for comparison of radiation dose. Overall IQ and IQ of the large segments showed no differences between the groups. IQ analysis of the small segments showed lowered IQ in pECGsys compared to rECG (p = 0.02), but not to pECG (p = 0.6). Effective dose did not differ significantly between rECG and pECG (p = 0.13), but was significantly lower for pECGsys (p < 0.001 vs. rECG and pECG). Radiation dose of dual-source CCTA in heart transplant recipients is significantly reduced by using prospective systolic scanning and automated tube voltage selection, while overall IQ and IQ of the large coronary segments are maintained. IQ appears to be lower compared to retrospective techniques with regard to small coronary segments. (orig.)

  12. Meta-analysis: diagnostic accuracy of coronary CT angiography with prospective ECG gating based on step-and-shoot, Flash and volume modes for detection of coronary artery disease

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Linfeng; Zhou, Tao; Zhang, Ruijie; Peng, Zhaohui; Ding, Juan; Wang, Sen; Li, Min; Sun, Gang [Jinan Military General Hospital, Department of Medical Imaging, Jinan, Shandong Province (China); Xu, Lin [Jinan Military General Hospital, Department of Medical Cardiology, Jinan, Shandong Province (China)

    2014-10-15

    To investigate the diagnostic performance of coronary computed tomographic angiography (CCTA) with prospective electrocardiograph (ECG) gating based on step-and-shoot (SAS), Flash and volume imaging modes. We searched the electronic databases PubMed for all published studies regarding CCTA. We used an exact binomial rendition of the bivariate mixed-effects regression model developed for synthesis of diagnostic data. A total of 21,852 segments, 4,851 vessels and 1,375 patients were identified using database searches. Patient-level pooled sensitivity was 0.99 (95 % confidence interval [CI], 0.98-1.00); specificity was 0.88 (CI, 0.85-0.91). The results showed that the sensitivity and specificity for detection of significant stenosis did not differ in the three protocols (P = 0.24). No heterogeneity was found at the patient level for sensitivity (Q = 26.23; P = 0.12; I {sup 2} = 27.56 % [CI, 0.00-67.02 %]) and specificity (Q = 19.54; P = 0.42; I {sup 2} = 2.78 % [CI, 0.00-66.26 %]). CCTA with prospective ECG gating has similar high diagnostic value to rule out CAD in all three presented modes. (orig.)

  13. Cardiac magnetic resonance: is phonocardiogram gating reliable in velocity-encoded phase contrast imaging?

    International Nuclear Information System (INIS)

    Nassenstein, Kai; Schlosser, Thomas; Orzada, Stephan; Ladd, Mark E.; Maderwald, Stefan; Haering, Lars; Czylwik, Andreas; Jensen, Christoph; Bruder, Oliver

    2012-01-01

    To assess the diagnostic accuracy of phonocardiogram (PCG) gated velocity-encoded phase contrast magnetic resonance imaging (MRI). Flow quantification above the aortic valve was performed in 68 patients by acquiring a retrospectively PCG- and a retrospectively ECG-gated velocity-encoded GE-sequence at 1.5 T. Peak velocity (PV), average velocity (AV), forward volume (FV), reverse volume (RV), net forward volume (NFV), as well as the regurgitant fraction (RF) were assessed for both datasets, as well as for the PCG-gated datasets after compensation for the PCG trigger delay. PCG-gated image acquisition was feasible in 64 patients, ECG-gated in all patients. PCG-gated flow quantification overestimated PV (Δ 3.8 ± 14.1 cm/s; P = 0.037) and underestimated FV (Δ -4.9 ± 15.7 ml; P = 0.015) and NFV (Δ -4.5 ± 16.5 ml; P = 0.033) compared with ECG-gated imaging. After compensation for the PCG trigger delay, differences were only observed for PV (Δ 3.8 ± 14.1 cm/s; P = 0.037). Wide limits of agreement between PCG- and ECG-gated flow quantification were observed for all variables (PV: -23.9 to 31.4 cm/s; AV: -4.5 to 3.9 cm/s; FV: -35.6 to 25.9 ml; RV: -8.0 to 7.2 ml; NFV: -36.8 to 27.8 ml; RF: -10.4 to 10.2 %). The present study demonstrates that PCG gating in its current form is not reliable enough for flow quantification based on velocity-encoded phase contrast gradient echo (GE) sequences. (orig.)

  14. 128-slice Dual-source Computed Tomography Coronary Angiography in Patients with Atrial Fibrillation: Image Quality and Radiation Dose of Prospectively Electrocardiogram-triggered Sequential Scan Compared with Retrospectively Electrocardiogram-gated Spiral Scan.

    Science.gov (United States)

    Lin, Lu; Wang, Yi-Ning; Kong, Ling-Yan; Jin, Zheng-Yu; Lu, Guang-Ming; Zhang, Zhao-Qi; Cao, Jian; Li, Shuo; Song, Lan; Wang, Zhi-Wei; Zhou, Kang; Wang, Ming

    2013-01-01

    Objective To evaluate the image quality (IQ) and radiation dose of 128-slice dual-source computed tomography (DSCT) coronary angiography using prospectively electrocardiogram (ECG)-triggered sequential scan mode compared with ECG-gated spiral scan mode in a population with atrial fibrillation. Methods Thirty-two patients with suspected coronary artery disease and permanent atrial fibrillation referred for a second-generation 128-slice DSCT coronary angiography were included in the prospective study. Of them, 17 patients (sequential group) were randomly selected to use a prospectively ECG-triggered sequential scan, while the other 15 patients (spiral group) used a retrospectively ECG-gated spiral scan. The IQ was assessed by two readers independently, using a four-point grading scale from excel-lent (grade 1) to non-assessable (grade 4), based on the American Heart Association 15-segment model. IQ of each segment and effective dose of each patient were compared between the two groups. Results The mean heart rate (HR) of the sequential group was 96±27 beats per minute (bpm) with a variation range of 73±25 bpm, while the mean HR of the spiral group was 86±22 bpm with a variationrange of 65±24 bpm. Both of the mean HR (t=1.91, P=0.243) and HR variation range (t=0.950, P=0.350) had no significant difference between the two groups. In per-segment analysis, IQ of the sequential group vs. spiral group was rated as excellent (grade 1) in 190/244 (78%) vs. 177/217 (82%) by reader1 and 197/245 (80%) vs. 174/214 (81%) by reader2, as non-assessable (grade 4) in 4/244 (2%) vs. 2/217 (1%) by reader1 and 6/245 (2%) vs. 4/214 (2%) by reader2. Overall averaged IQ per-patient in the sequential and spiral group showed equally good (1.27±0.19 vs. 1.25±0.22, Z=-0.834, P=0.404). The effective radiation dose of the sequential group reduced significantly compared with the spiral group (4.88±1.77 mSv vs. 10.20±3.64 mSv; t=-5.372, P=0.000). Conclusion Compared with retrospectively

  15. Evaluation of left ventricular function in patients with atrial fibrillation by ECG gated blood pool scintigraphy. Analysis of left ventricular filling and function curve

    Energy Technology Data Exchange (ETDEWEB)

    Inagaki, Suetsugu; Adachi, Haruhiko; Sugihara, Hiroki

    1985-12-01

    ECG gated blood pool scintigraphy (EGBP) is not always valid for the patients with atrial fibrillation (AF), since they have wide variability in cardiac cycle length (CL). To evaluate the left ventricular (LV) function during AF by EGBP, we devised a new processing algorithm to construct multiple gated images discriminated by preceding R-R interval (PRR) from the data acquired in list mode. 18 patients with AF were studied as to; 1) How affect the PRR on cardiac indices such as EF, TES, PER or TPER, 2) Comparison with conventional method getting all CL data, 3) LV filling curves derived by plotting EDV against PRR, 4) The slope and position of LV function curves (LVFC) derived by plotting SV against EDV. In most cases, EF, PER and TES were increased with longer PRR, and those by conventional method nearly corresponded to the average values obtained by our new method. Impairment of ventricular filling was demonstrated in the cases of mitral stenosis and constrictive pericarditis. LVFC of CHF group was situated at right and downward to controls, and left and upward shift was observed after treatment. The slope of LVFC was reduced in relation to the progression of NYHA's functional class. In conclusion, this new algorithm processing irregular CL enables LV filling and function curves to draw, which are useful in the evaluation of cardiac performance in the subjects with AF.

  16. Diagnosis of accessory conduction pathway using ECG-gated emission CT analysis. Studies in patients with WPW syndrome who underwent surgery

    Energy Technology Data Exchange (ETDEWEB)

    Misaki, Takuro; Mukai, Keiichi; Tsubota, Makoto; Iwa, Takashi; Nakajima, Ken-ichi; Hisada, Kin-ichi

    1987-09-01

    Pinpointing the location of accessory conduction pathway (ACP) is of great importance in the surgical treatment for Wolff-Parkinson-White (WPW) syndrome. For this purpose, this study explored the usefulness of ECG-gated emission computed tomography (Gated-ECT) in 30 patients who preoperatively underwent Gated-ECT. The site of earliest contraction at level of atrioventicular valves, obtained on tomographic phase analysis, was compared with the site of earliest activation, obtained on epicardial mapping during surgery. The concordance rate of the two methods was 94 % (28/30). Among them, one patient was found to have the association of corrected transposition of great arteries on Gated-ECT. Gated-ECT was, however, of limited value in differentiating right posterior ACP from right postseptal ACP. The discordance between the sites of earliest contraction and activation, which was observed in the two others, was likely due to decreased wall motion resulting from myocardial disturbance. Gated-ECT may have a diagnostic potential for the location of ACP, especially in view of providing images that corresponded to the surgical anatomy. (Namekawa, K.).

  17. Estimation of the radiation exposure of a chest pain protocol with ECG-gating in dual-source computed tomography

    International Nuclear Information System (INIS)

    Ketelsen, Dominik; Luetkhoff, Marie H.; Thomas, Christoph; Werner, Matthias; Tsiflikas, Ilias; Reimann, Anja; Kopp, Andreas F.; Claussen, Claus D.; Heuschmid, Martin; Buchgeister, Markus; Burgstahler, Christof

    2009-01-01

    The aim of the study was to evaluate radiation exposure of a chest pain protocol with ECG-gated dual-source computed tomography (DSCT). An Alderson Rando phantom equipped with thermoluminescent dosimeters was used for dose measurements. Exposure was performed on a dual-source computed tomography system with a standard protocol for chest pain evaluation (120 kV, 320 mAs/rot) with different simulated heart rates (HRs). The dose of a standard chest CT examination (120 kV, 160 mAs) was also measured. Effective dose of the chest pain protocol was 19.3/21.9 mSv (male/female, HR 60), 17.9/20.4 mSv (male/female, HR 80) and 14.7/16.7 mSv (male/female, HR 100). Effective dose of a standard chest examination was 6.3 mSv (males) and 7.2 mSv (females). Radiation dose of the chest pain protocol increases significantly with a lower heart rate for both males (p = 0.040) and females (p = 0.044). The average radiation dose of a standard chest CT examination is about 36.5% that of a CT examination performed for chest pain. Using DSCT, the evaluated chest pain protocol revealed a higher radiation exposure compared with standard chest CT. Furthermore, HRs markedly influenced the dose exposure when using the ECG-gated chest pain protocol. (orig.)

  18. Feasibility and diagnostic accuracy of Ecg-gated SPECT myocardial perfusion imaging by a two-hour protocol: The Myofast study;Faisabilite et precision diagnostique d'un protocole de scintigraphie myocardique synchronisee a l'ECG en deux heures: l'etude Myofast

    Energy Technology Data Exchange (ETDEWEB)

    Dunet, V.; Costo, S.; Sabatier, R.; Grollier, G.; Bouvard, G.; Agostini, D. [CHU Cote-de-Nacre, Service de medecine nucleaire, 14 - Caen (France)

    2010-04-15

    Aim of the study: To assess the feasibility of early stress and rest myocardial perfusion and function study using a fast {sup 99m}Tc-tetrofosmin gated-SPECT protocol in patients with known coronary artery disease. Materials and methods: Forty-three patients (pts) (37 M, 6 F, mean age 63.8 +- 9.8 years) underwent a {sup 99m}Tc-Tetrofosmin gated-SPECT (Axis Picker-Philips) myocardial study and a coronary angiography (C.A.) within 3 months. Images were acquired (LEHR, eight bins, 40 sec per image) after injection of {sup 99m}Tc-tetrofosmin (200 to 380 MBq) early (15 min) post-stress (36 dipyridamole, two dobutamine and five ergo-metric stress), and at rest after {sup 99m}Tc-tetrofosmin reinjection (600 to 1150 MBq), in a total time not exceeding 2 hours. Processing was performed with Q.G.S. software using the 17-segment model. Pathological study was defined as a summed difference score (SDS) greater than or equal to 4 4, a fixed defect with summed rest score greater than or equal to 4 and/or L.V. dysfunction defined as myocardial stunning (variation between stress and rest L.V.E.F. greater than or equal to 4 5%), stress L.V.E.F. less than or equal to 45% or rest L.V.E.F. less than or equal to 40%. Results were compared with C.A., and stenosis greater than or equal to 4 50% was considered as significant. Results: For 100% the quality of SPECT imaging was good or excellent. For six patients gating was impossible because of arrhythmia. The overall sensitivity, specificity and accuracy were 95%, 50%, and 91%, respectively. The concordance between gated SPECT and C.A. was moderate (kappa = 0.45, S.E. = 0.15). Interestingly, early-gated acquisition permitted to underline left ventricular dysfunction in 11 cases (30%), of whom eight had poly vascular disease. Stunning was detected in six of 37 cases (16%), of whom six had poly vascular disease. Conclusion: A one-day two-hour {sup 99m}Tc-tetrofosmin gated-SPECT protocol to assess left ventricular perfusion and function is

  19. Assessment of left ventricular function in patients with atrial fibrillation by left ventricular filling and function curves determined by ECG gated blood pool scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Inagaki, Suetsugu

    1986-06-01

    Accurate cardiac function in patients with atrial fibrillation (Af) is difficult to assess, since a wide fluctuation of cardiac cycle makes the ventricular hemodynamics variable. Although ECG gated blood pool scintigraphy (EGBPS) is useful to evaluate left ventricular (LV) function, a conventional EGBPS might have a problem in applying to Af. Therefore, a new processing algorithm was devised to make multiple gated images discriminated by preceding R-R intervals (PRR), and LV filling and function curves were obtained in 62 patients with Af to evaluate LV function. LV filling curve, obtained by plotting end-diastolic volume (EDV) againt PRR, demonstrated that the blood filling was impaired in mitral stenosis and constrictive pericarditis, but recovered after mitral commissurotomy. LV function curve, by plotting stroke volume (SV) againt EDV, was quantitatively analysed by the indices such as Slope and Position. Both indices reduced significantly in heart failure. When compared among underlying diseases individually, the indices decreased in the following order; lone Af, hyperthyroidism, senile Af, hypertension, mitral valve disease, ischemic heart disease, dilated cardiomyopathy and aortic regurgitation. After the treatment with digitalis and/or diuretics, left and upward shift of function curve was observed. The rise in heart rate by atropine infusion made Slope and Position unchanged, and which implied that function curve was little influenced by heart rate per se. The rise in systolic blood pressure by angiotensin-II infusion caused shifts in function curve to rightward and downward. Downward shift, mostly seen in patients with gentler slope in control state, may imply afterload mismatch due to a decrease in preload reserve. (J.P.N.).

  20. Evaluation of pleural and pericardial effusions by magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Tscholakoff, D.; Sechtem, U.; De Geer, G.; Schmidt, H.; Higgins, C.B.

    1987-08-01

    MR examinations of 36 patients with pleural and/or pericardial effusions were retrospectively evaluated. The purpose of this study was to determine of MR imaging is capable of differentiating between pleural and pericardial effusions of different compositions using standard electrocardiogram (ECG)-gated and nongated spin echo pulse sequences. Additional data was obtained from experimental pleural effusions in 10 dogs. The results of this study indicate that old haemorhages into the pleural or pericardial space can be differentiated from other pleural or pericardial effusions. However, further differentiation between transudates, exudates and sanguinous effusions is not possible on MR images acquired with standard spin echo pulse sequences. (orig./MG)

  1. Pulmonary artery and right ventricle assessment in pulmonary hypertension. Correlation between functional parameters of ECG-gated CT and right-side heart catheterization

    Energy Technology Data Exchange (ETDEWEB)

    Abel, Elodie; Jankowski, Adrien [Clinique univ. de radiologie et imagerie medicale, CHU Grenoble (France); Pison, Christophe [Clinique univ. de pneumologie, CHU Grenoble (France); Bosson, Jean Luc [Dept. of Statistics, CIC, CHU Grenoble (France); Bouvaist, Helene [Clinique univ. de cardiologie, CHU Grenoble (France); Ferretti, Gilbert R. [Clinique univ. de radiologie et imagerie medicale, CHU Grenoble (France); Univ. J. Fourier, Grenoble (France); INSERM U 823, Inst. A. Bonniot, la Tronche (France)], e-mail: gferretti@chu-grenoble.fr

    2012-09-15

    Background: Right ventricular function predicts outcome in patients with pulmonary hypertension (PH). Therefore accurate assessment of right ventricular function is essential to graduate severity, assess follow-up, and response to therapy. Purpose: To evaluate whether PH severity could be assessed using electrocardiography-gated CT (ECG-gated CT) functional parameters. A further objective was to evaluate cardiac output (CO) using two ECG-gated CT methods: the reference Simpson technique and the fully automatic technique generated by commercially available cardiac software. Material and Methods: Our institutional review board approved this study; patient consent was not required. Twenty-seven patients who had undergone ECG-gated CT and right heart catheterization (RHC) were included. Two independent observers measured pulmonary artery (PA) diameter, PA distensibility, aorta diameter, right ventricular cardiac output (CT-RVCO) and right ventricular ejection fraction (CT-RVEF) with automatic and Simpson techniques on ECG-gated CT. RHC-CO and mean pulmonary arterial pressure (mPAP) were measured on RHC. Relationship between ECG-gated CT and RHC measurements was tested with linear regression analysis. Results: Inter-observer agreement was good for all measurements (r > 0.7) except for CT-RVCO calculated with Simpson's technique (r = 0.63). Pulmonary artery (PA) distensibility was significantly correlated to mPAP (r = -0.426, P = 0.027). CT-RVEF was correlated with mPAP only when issued from Simpson technique (r = -0.417, P = 0.034). CT-RVEF was not significantly correlated to RHC-CO (P > 0.2). CT-RVCO measured with Simpson technique (r = 0.487, P = 0.010) and automatic segmentation (r = 0.549, P 0.005) correlated equally with RHC-CO. Conclusion: CT-RVEF and CT-RVCO measured on ECG-gated CT are significantly correlated, respectively, to mPAP and RHC-CO in this population with severe reduction of the right ventricular ejection fraction and could be useful for

  2. Pulmonary artery and right ventricle assessment in pulmonary hypertension. Correlation between functional parameters of ECG-gated CT and right-side heart catheterization

    International Nuclear Information System (INIS)

    Abel, Elodie; Jankowski, Adrien; Pison, Christophe; Bosson, Jean Luc; Bouvaist, Helene; Ferretti, Gilbert R.

    2012-01-01

    Background: Right ventricular function predicts outcome in patients with pulmonary hypertension (PH). Therefore accurate assessment of right ventricular function is essential to graduate severity, assess follow-up, and response to therapy. Purpose: To evaluate whether PH severity could be assessed using electrocardiography-gated CT (ECG-gated CT) functional parameters. A further objective was to evaluate cardiac output (CO) using two ECG-gated CT methods: the reference Simpson technique and the fully automatic technique generated by commercially available cardiac software. Material and Methods: Our institutional review board approved this study; patient consent was not required. Twenty-seven patients who had undergone ECG-gated CT and right heart catheterization (RHC) were included. Two independent observers measured pulmonary artery (PA) diameter, PA distensibility, aorta diameter, right ventricular cardiac output (CT-RVCO) and right ventricular ejection fraction (CT-RVEF) with automatic and Simpson techniques on ECG-gated CT. RHC-CO and mean pulmonary arterial pressure (mPAP) were measured on RHC. Relationship between ECG-gated CT and RHC measurements was tested with linear regression analysis. Results: Inter-observer agreement was good for all measurements (r > 0.7) except for CT-RVCO calculated with Simpson's technique (r = 0.63). Pulmonary artery (PA) distensibility was significantly correlated to mPAP (r = -0.426, P = 0.027). CT-RVEF was correlated with mPAP only when issued from Simpson technique (r = -0.417, P = 0.034). CT-RVEF was not significantly correlated to RHC-CO (P > 0.2). CT-RVCO measured with Simpson technique (r = 0.487, P = 0.010) and automatic segmentation (r = 0.549, P 0.005) correlated equally with RHC-CO. Conclusion: CT-RVEF and CT-RVCO measured on ECG-gated CT are significantly correlated, respectively, to mPAP and RHC-CO in this population with severe reduction of the right ventricular ejection fraction and could be useful for evaluating

  3. Prospectively Electrocardiogram-Gated High-Pitch Spiral Acquisition Mode Dual-Source CT Coronary Angiography in Patients with High Heart Rates: Comparison with Retrospective Electrocardiogram-Gated Spiral Acquisition Mode

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Kai; Ma, Rui; Wang, Li Jun [Dept. of Radiology, Baotou Central Hospital, Baotou (China); Li, Li Gang; Chen, Jiu Hong [CT BM Clinic Marketing, Siemens Healthcare, Beijing (China)

    2012-11-15

    To assess the image quality and effective radiation dose of prospectively electrocardiogram (ECG)-gated high-pitch spiral acquisition mode (flash mode) of dual-source CT (DSCT) coronary angiography (CTCA) in patients with high heart rates (HRs) as compared with retrospectively ECG-gated spiral acquisition mode. Two hundred and sixty-eight consecutive patients (132 female, mean age: 55 {+-} 11 years) with mean HR > 65 beats per minute (bpm) were prospectively included in this study. The patients were divided into two groups. Collection was performed in group A CTCA using flash mode setting at 20-30% of the R-R interval, and retrospectively ECG-gated spiral acquisition mode in group B. The image noise, contrast-to-noise ratio (CNR), image quality scores, effective radiation dose and influencing factors on image quality between the two groups were assessed. There were no significant differences in image quality scores and proportions of non-diagnostic coronary artery segments between two groups (image quality scores: 1.064 {+-} 0.306 [group A] vs. 1.084 {+-} 0.327 [group B], p = 0.063; proportion of non-diagnostic coronary artery segments: segment-based analysis 1.52% (group A) vs. 1.74% (group B), p = 0.345; patient-based analysis 7.5% (group A) vs. 6.7% (group B), p = 0.812). The estimated radiation dose was 1.0 {+-} 0.16 mSv in group A and 7.1 {+-} 1.05 mSv in group B (p = 0.001). In conclusion, in patients with HRs > 65 bpm without cardiac arrhythmia, the prospectively high-pitch spiral-acquisition mode with image-acquired timing set at 20-30% of the R-R interval provides a similar image quality and low rate of non-diagnostic coronary segments to the retrospectively ECG-gated low-pitch spiral acquisition mode, with significant reduction of radiation exposure.

  4. Prospectively Electrocardiogram-Gated High-Pitch Spiral Acquisition Mode Dual-Source CT Coronary Angiography in Patients with High Heart Rates: Comparison with Retrospective Electrocardiogram-Gated Spiral Acquisition Mode

    International Nuclear Information System (INIS)

    Sun, Kai; Ma, Rui; Wang, Li Jun; Li, Li Gang; Chen, Jiu Hong

    2012-01-01

    To assess the image quality and effective radiation dose of prospectively electrocardiogram (ECG)-gated high-pitch spiral acquisition mode (flash mode) of dual-source CT (DSCT) coronary angiography (CTCA) in patients with high heart rates (HRs) as compared with retrospectively ECG-gated spiral acquisition mode. Two hundred and sixty-eight consecutive patients (132 female, mean age: 55 ± 11 years) with mean HR > 65 beats per minute (bpm) were prospectively included in this study. The patients were divided into two groups. Collection was performed in group A CTCA using flash mode setting at 20-30% of the R-R interval, and retrospectively ECG-gated spiral acquisition mode in group B. The image noise, contrast-to-noise ratio (CNR), image quality scores, effective radiation dose and influencing factors on image quality between the two groups were assessed. There were no significant differences in image quality scores and proportions of non-diagnostic coronary artery segments between two groups (image quality scores: 1.064 ± 0.306 [group A] vs. 1.084 ± 0.327 [group B], p = 0.063; proportion of non-diagnostic coronary artery segments: segment-based analysis 1.52% (group A) vs. 1.74% (group B), p = 0.345; patient-based analysis 7.5% (group A) vs. 6.7% (group B), p = 0.812). The estimated radiation dose was 1.0 ± 0.16 mSv in group A and 7.1 ± 1.05 mSv in group B (p = 0.001). In conclusion, in patients with HRs > 65 bpm without cardiac arrhythmia, the prospectively high-pitch spiral-acquisition mode with image-acquired timing set at 20-30% of the R-R interval provides a similar image quality and low rate of non-diagnostic coronary segments to the retrospectively ECG-gated low-pitch spiral acquisition mode, with significant reduction of radiation exposure.

  5. Low dose prospective ECG-gated delayed enhanced dual-source computed tomography in reperfused acute myocardial infarction comparison with cardiac magnetic resonance

    International Nuclear Information System (INIS)

    Wang Rui; Zhang Zhaoqi; Xu Lei; Ma Qin; He Yi; Lu Dongxu; Yu Wei; Fan Zhanming

    2011-01-01

    Purpose: To determine whether prospective electrocardiogram (ECG)-gated delayed contrast-enhanced dual-source computed tomography (DCE-DSCT) can accurately delineate the extension of myocardial infarction (MI) compared with delayed enhanced cardiac MR (DE-MR). Material and methods: Eleven patients were examined using dual-source CT and cardiac MR in 2 weeks after a first reperfused MI. DCE-DSCT scan protocol was performed with prospective ECG-gating sequential scan model 7 min after contrast administration. In a 17-model, infarcted myocardium detected by DE-MR was categorized as transmural and subendocardial extension. Segment of infarcted location and graded transmurality were compared between DCE-MDCT and DE-MR. Results: In all eleven patients, diagnostic quality was obtained for depicting delayed enhanced myocardium. Agreement between DCE-DSCT and MR was good on myocardial segment based comparison (kappa = 0.85, p < 0.001), and on transmural and subendocardial infarction type comparison (kappa = 0.82, p < 0.001, kappa = 0.52, p < 0.001, respectively). CT value was higher on infarcted region than that of normal region (100.02 ± 9.57 HU vs. 72.63 ± 7.32 HU, p < 0.001). Radiation dose of prospectively ECG-gating protocol were 0.99 ± 0.08 mSv (0.82-1.19 mSv). Conclusions: Prospective ECG-gated DCE-DSCT can accurately assess the extension and the patterns of myocardial infarction with low radiation dose.

  6. Low dose prospective ECG-gated delayed enhanced dual-source computed tomography in reperfused acute myocardial infarction comparison with cardiac magnetic resonance

    Energy Technology Data Exchange (ETDEWEB)

    Wang Rui, E-mail: rui_wang1979@yahoo.cn [Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, 100029 Beijing (China); Zhang Zhaoqi, E-mail: zhaoqi5000@vip.sohu.com [Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, 100029 Beijing (China); Xu Lei, E-mail: leixu2001@hotmail.com [Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, 100029 Beijing (China); Ma Qin, E-mail: tel1367@gmail.com [Department of Emergency, Beijing Anzhen Hospital, Capital Medical University, 100029 Beijing (China); He Yi, E-mail: heyi139@sina.com [Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, 100029 Beijing (China); Lu Dongxu, E-mail: larry.hi@163.com [Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, 100029 Beijing (China); Yu Wei, E-mail: yuwei02@gmail.com [Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, 100029 Beijing (China); Fan Zhanming, E-mail: fanzm120@tom.com [Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, 100029 Beijing (China)

    2011-11-15

    Purpose: To determine whether prospective electrocardiogram (ECG)-gated delayed contrast-enhanced dual-source computed tomography (DCE-DSCT) can accurately delineate the extension of myocardial infarction (MI) compared with delayed enhanced cardiac MR (DE-MR). Material and methods: Eleven patients were examined using dual-source CT and cardiac MR in 2 weeks after a first reperfused MI. DCE-DSCT scan protocol was performed with prospective ECG-gating sequential scan model 7 min after contrast administration. In a 17-model, infarcted myocardium detected by DE-MR was categorized as transmural and subendocardial extension. Segment of infarcted location and graded transmurality were compared between DCE-MDCT and DE-MR. Results: In all eleven patients, diagnostic quality was obtained for depicting delayed enhanced myocardium. Agreement between DCE-DSCT and MR was good on myocardial segment based comparison (kappa = 0.85, p < 0.001), and on transmural and subendocardial infarction type comparison (kappa = 0.82, p < 0.001, kappa = 0.52, p < 0.001, respectively). CT value was higher on infarcted region than that of normal region (100.02 {+-} 9.57 HU vs. 72.63 {+-} 7.32 HU, p < 0.001). Radiation dose of prospectively ECG-gating protocol were 0.99 {+-} 0.08 mSv (0.82-1.19 mSv). Conclusions: Prospective ECG-gated DCE-DSCT can accurately assess the extension and the patterns of myocardial infarction with low radiation dose.

  7. Detection of Airway Anomalies in?Pediatric?Patients with Cardiovascular Anomalies with Low Dose Prospective ECG-Gated Dual-Source CT

    OpenAIRE

    Jiao, Hui; Xu, Zhuodong; Wu, Lebin; Cheng, Zhaoping; Ji, Xiaopeng; Zhong, Hai; Meng, Chen

    2013-01-01

    OBJECTIVES: To assess the feasibility of low-dose prospective ECG-gated dual-source CT (DSCT) in detecting airway anomalies in pediatric patients with cardiovascular anomalies compared with flexible tracheobronchoscopy (FTB). METHODS: 33 pediatrics with respiratory symptoms who had been revealed cardiovascular anomalies by transthoracic echocardiography underwent FTB and contrast material-enhanced prospective ECG-triggering CT were enrolled. The study was approved by our institution review bo...

  8. Comprehensive cardiovascular ECG-gated MDCT as a standard diagnostic tool in patients with acute chest pain

    International Nuclear Information System (INIS)

    Runza, G.; La Grutta, L.; Alaimo, V.; Evola, S.; Lo Re, F.; Bartolotta, T.V.; Cademartiri, F.; Midiri, M.

    2007-01-01

    Acute myocardial infarction, pulmonary embolism, and aortic dissection are diseases associated with acute chest pain and may lead to severe morbidity and mortality. These diseases may not be trivial to diagnose in the settings of emergency room. ECG-gated multi-detector computed tomography (MDCT), already established for the assessment of pulmonary embolism and aortic dissection, provides reliable information regarding the triage of patients with acute coronary syndrome in the emergency room. MDCT recently appeared to be logistically feasible and a promising comprehensive method for the evaluation of cardiac and non-cardiac chest pain in emergency department patients. The possibility to scan the entire thorax visualizing the thoracic aorta, the pulmonary arteries, and the coronary arteries could provide a new approach to the triage of acute chest pain. The inherent advantage of MDCT with cardiac state-of-the-art capabilities is the rapid investigation of the main sources of acute chest pain with a high negative predictive value. Recent studies also reports an advantage in terms of costs. With current evidence, the selection of patients with acute chest pain candidates to MDCT should remain restricted to avoid unjustified risk of ionizing radiation

  9. Comprehensive cardiovascular ECG-gated MDCT as a standard diagnostic tool in patients with acute chest pain

    Energy Technology Data Exchange (ETDEWEB)

    Runza, G. [Department of Radiology, University of Palermo (Italy)], E-mail: grunza@sirm.org; La Grutta, L.; Alaimo, V. [Department of Radiology, University of Palermo (Italy); Evola, S. [Department of Cardiology, University of Palermo (Italy); Lo Re, F.; Bartolotta, T.V. [Department of Radiology, University of Palermo (Italy); Cademartiri, F. [Department of Radiology and Cardiology, Erasmus Medical Center, Rotterdam (Netherlands); Department of Radiology and Cardiology, Cardiovascular CT Unit, University Hospital, Parma (Italy); Midiri, M. [Department of Radiology, University of Palermo (Italy)

    2007-10-15

    Acute myocardial infarction, pulmonary embolism, and aortic dissection are diseases associated with acute chest pain and may lead to severe morbidity and mortality. These diseases may not be trivial to diagnose in the settings of emergency room. ECG-gated multi-detector computed tomography (MDCT), already established for the assessment of pulmonary embolism and aortic dissection, provides reliable information regarding the triage of patients with acute coronary syndrome in the emergency room. MDCT recently appeared to be logistically feasible and a promising comprehensive method for the evaluation of cardiac and non-cardiac chest pain in emergency department patients. The possibility to scan the entire thorax visualizing the thoracic aorta, the pulmonary arteries, and the coronary arteries could provide a new approach to the triage of acute chest pain. The inherent advantage of MDCT with cardiac state-of-the-art capabilities is the rapid investigation of the main sources of acute chest pain with a high negative predictive value. Recent studies also reports an advantage in terms of costs. With current evidence, the selection of patients with acute chest pain candidates to MDCT should remain restricted to avoid unjustified risk of ionizing radiation.

  10. New approach for simplified and automated measurement of left ventricular ejection fraction by ECG gated blood pool scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Inagaki, Suetsugu; Adachi, Haruhiko; Sugihara, Hiroki; Katsume, Hiroshi; Ijichi, Hamao; Okamoto, Kunio; Hosoba, Minoru

    1984-12-01

    Background (BKG) correction is important but debatable in the measurement of Left ventricular ejection fraction (LVEF) with ECG gated blood pool scintigraphy. We devised a new simplified BKG processing (fixed BKG method) without BKG region-of-interest (ROI) assignment, and the accuracy and reproducibility were assessed in 25 patients with various heart diseases and 5 normal subjects by comparison with LVEF obtained by contrast levolgraphy (LVG-EF). Four additional protocols for LVEF measurement with BKG-ROI assignment were also assessed for reference. LVEF calculated using the fixed BKG ratio of 0.64 (BKG count rates were 64%) of end-diastolic count rates of LV) with ''Fixed'' LV-ROI was best correlated with LVG-EF (r = 0.936, p < 0.001) and most approximated (Fixed BKG ratio method EF: 61.1 +- 20.1, LVG-EF: 61.2 +- 20.4% (mean +- SD)) among other protocols. The wide availability of the fixed value of 0.64 was tested in various diseases, body size and end-diastolic volume by LVG, and the results were to be little influenced by them. Furthermore, fixed BKG method produced lower inter-and intra- observer variability than other protocols requiring BKG-ROI assignment, probably due to its simplified processing. In conclusion, fixed BKG ratio method simplifies the measurement of LVEF, and is feasible for automated processing and single probe system.

  11. Thin-section CT of lung without ECG gating: 64-detector row CT can markedly reduce cardiac motion artifact which can simulate lung lesions

    International Nuclear Information System (INIS)

    Yanagawa, Masahiro; Tomiyama, Noriyuki; Sumikawa, Hiromitsu; Inoue, Atsuo; Daimon, Tadahisa; Honda, Osamu; Mihara, Naoki; Johkoh, Takeshi; Nakamura, Hironobu

    2009-01-01

    Purpose: Motion artifacts, which can mimic thickened bronchial wall and the cystic appearance of bronchiectasis, constitute a potential pitfall in the diagnosis of interstitial or bronchial disease. Therefore, purpose of our study was to evaluate whether 64-detector row CT (64-MDCT) enables a reduction in respiratory or cardiac motion artifacts in the lung area on thin-section CT without ECG gating, and to examine the correlation between cardiac motion artifact and heart rate. Materials and methods: Thirty-two patients with suspected diffuse lung disease, who underwent both 8- and 64-MDCT (gantry rotation time, 0.5 and 0.4 s, respectively), were included. The heart rates of an additional 155 patients were measured (range, 48-126 beats per minute; mean, 76 beats per minute) immediately prior to 64-MDCT, and compared to the degree of cardiac motion artifact. Two independent observers evaluated the following artifacts on a monitor without the knowledge of relevant clinical information: (1) artifacts on 8- and 64-MDCT images with 1.25-mm thickness and those on 64-MDCT images with 0.625-mm thickness in 32 patients; and (2) artifacts on 64-MDCT images with 0.625-mm thickness in 155 patients. Results: Interobserver agreement was good in evaluating artifacts on 8-MDCT images with 1.25-mm thickness (weighted Kappa test, κ = 0.61-0.71), and fair or poor in the other evaluations (κ < 0.31). Two observers stated that cardiac motion artifacts were more significant on 8-MDCT than on 64-MDCT in all 32 patients. Statistically significant differences were found at various checkpoints only in comparing artifacts between 8- and 64-MDCT for 1.25-mm thickness (Wilcoxon's signed-rank test, p < 0.0017). Cardiac motion artifacts on 64-MDCT had no significant correlation with heart rate (Spearman's correlation coefficient by rank test). Conclusion: The high temporal resolution of 64-MDCT appears to reduce cardiac motion artifact that can affect thin-section scans of the lung parenchyma

  12. Thin-section CT of lung without ECG gating: 64-detector row CT can markedly reduce cardiac motion artifact which can simulate lung lesions

    Energy Technology Data Exchange (ETDEWEB)

    Yanagawa, Masahiro [Department of Radiology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita-city, Osaka 565-0871 (Japan)], E-mail: m-yanagawa@radiol.med.osaka-u.ac.jp; Tomiyama, Noriyuki; Sumikawa, Hiromitsu; Inoue, Atsuo [Department of Radiology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita-city, Osaka 565-0871 (Japan); Daimon, Tadahisa [Department of Radiology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita-city, Osaka 565-0871 (Japan); Department of Medicine, Division of Pulmonary Medicine, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498 (Japan); Honda, Osamu [Department of Radiology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita-city, Osaka 565-0871 (Japan); Mihara, Naoki [Department of Radiology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita-city, Osaka 565-0871 (Japan); Department of Radiology, Osaka Advanced Medical Imaging Center, 5-20-1 Momoyamadai, Suita-city, Osaka 565-0854 (Japan); Johkoh, Takeshi [Department of Radiology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita-city, Osaka 565-0871 (Japan); Department of Medical Physics, Osaka University Graduate School of Medicine, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita-city, Osaka 565-0871 (Japan); Nakamura, Hironobu [Department of Radiology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita-city, Osaka 565-0871 (Japan)

    2009-01-15

    Purpose: Motion artifacts, which can mimic thickened bronchial wall and the cystic appearance of bronchiectasis, constitute a potential pitfall in the diagnosis of interstitial or bronchial disease. Therefore, purpose of our study was to evaluate whether 64-detector row CT (64-MDCT) enables a reduction in respiratory or cardiac motion artifacts in the lung area on thin-section CT without ECG gating, and to examine the correlation between cardiac motion artifact and heart rate. Materials and methods: Thirty-two patients with suspected diffuse lung disease, who underwent both 8- and 64-MDCT (gantry rotation time, 0.5 and 0.4 s, respectively), were included. The heart rates of an additional 155 patients were measured (range, 48-126 beats per minute; mean, 76 beats per minute) immediately prior to 64-MDCT, and compared to the degree of cardiac motion artifact. Two independent observers evaluated the following artifacts on a monitor without the knowledge of relevant clinical information: (1) artifacts on 8- and 64-MDCT images with 1.25-mm thickness and those on 64-MDCT images with 0.625-mm thickness in 32 patients; and (2) artifacts on 64-MDCT images with 0.625-mm thickness in 155 patients. Results: Interobserver agreement was good in evaluating artifacts on 8-MDCT images with 1.25-mm thickness (weighted Kappa test, {kappa} = 0.61-0.71), and fair or poor in the other evaluations ({kappa} < 0.31). Two observers stated that cardiac motion artifacts were more significant on 8-MDCT than on 64-MDCT in all 32 patients. Statistically significant differences were found at various checkpoints only in comparing artifacts between 8- and 64-MDCT for 1.25-mm thickness (Wilcoxon's signed-rank test, p < 0.0017). Cardiac motion artifacts on 64-MDCT had no significant correlation with heart rate (Spearman's correlation coefficient by rank test). Conclusion: The high temporal resolution of 64-MDCT appears to reduce cardiac motion artifact that can affect thin-section scans of

  13. Quantification of left ventricular regional functions using ECG-gated myocardial perfusion SPECT. Validation of left ventricular systolic functions

    International Nuclear Information System (INIS)

    Yamamoto, Akira; Takahashi, Naoto; Iwahara, Shin-ichiro; Munakata, Kazuo; Hosoya, Tetsuo

    2006-01-01

    We have developed a program to quantify regional left ventricular (LV) function and wall motion synchrony using electrocardiogram (ECG)-gated myocardial perfusion SPECT (MPS). This preliminary study was undertaken to validate the use of this program for estimating regional LV systolic function. Patients were subjected to MPS by 99m Tc-sestamibi at rest. The study included 20 patients who were confirmed to have a low probability of coronary artery disease (LPG; low probability group), 19 heart disease patients who were examined by MPS and equilibrium radionuclide angiography (ERNA) (ERG; ERNA group), and 24 patients who were examined by MPS and 2-dimensional echocardiography (2DE) (2DEG; 2DE group). The values of the ejection fraction (EF) and peak ejection rate (PER) were estimated. The global functions evaluated by this program were compared with those obtained by ERNA in the ERG. For regional assessment, the reference values of the functional indices were obtained for 17 LV segments in LPG. The Z score, (reference average value of the segment-patient's value of the segment)/reference standard deviation of the segment, was used for the evaluation of regional functions; a score equal to or greater than 2 was defined as abnormal. Semiquantitative visual interpretation of 2DE was used as the standard to assess wall motion. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of these criteria and the relationship between 2DE grading and Z scoring were validated in 2DEG. The values of the global EF and PER evaluated by this program correlated with those determined by ERNA (r=0.76 and 0.58, respectively; p -10 ). The potential of this program to quantify the regional systolic function was validated. (author)

  14. Real-time QRS detection using integrated variance for ECG gated cardiac MRI

    Directory of Open Access Journals (Sweden)

    Schmidt Marcus

    2016-09-01

    Full Text Available During magnetic resonance imaging (MRI, a patient’s vital signs are required for different purposes. In cardiac MRI (CMR, an electrocardiogram (ECG of the patient is required for triggering the image acquisition process. However, a reliable QRS detection of an ECG signal acquired inside an MRI scanner is a challenging task due to the magnetohydrodynamic (MHD effect which interferes with the ECG. The aim of this work was to develop a reliable QRS detector usable inside the MRI which also fulfills the standards for medical devices (IEC 60601-2-27. Therefore, a novel real-time QRS detector based on integrated variance measurements is presented. The algorithm was trained on ANSI/AAMI EC13 test waveforms and was then applied to two databases with 12-lead ECG signals recorded inside and outside an MRI scanner. Reliable results for both databases were achieved for the ECG signals recorded inside (DBMRI: sensitivity Se = 99.94%, positive predictive value +P = 99.84% and outside (DBInCarT: Se = 99.29%, +P = 99.72% the MRI. Due to the accurate R-peak detection in real-time this can be used for monitoring and triggering in MRI exams.

  15. ECG-gated myocardial tomo-scintigraphy by rotating bilateral collimator. Clinical application and artificial defect

    Energy Technology Data Exchange (ETDEWEB)

    Komatani, Akio; Takahashi, Kazuei; Takanashi, Toshiyasu; Yamaguchi, Koichi [Yamagata Univ. (Japan)

    1985-01-01

    Tomo-scintigraphy of /sup 201/Tl-myocardium by rotating bilateral collimator was performed in synchronization with cardiac cycle. Ten frames per R-R interval were acquired with ECG pulse signal during 16 min and tomographic reconstruction of end-diastolic and end-systolic image was done. This method was very useful to estimate not only three dimensional distribution of Tl-201, but also wall motion and change of wall thickness during cardiac cycle. However, through its clinical application, artificial defect was frequently noticed at inferior-apical portion of the myocardium. In order to elucidate the cause of the artifact, influence of tilted projection and cardiac motion due to respiratory was also investigated. During inspiratory phase of patients in rest, increment of volume up to 40% and 15 mm of caudal deviation of the left ventricle were observed. Furthermore, periodic motion of the diaphragm interrupted emission of gamma ray from the myocardium. It is proved that main cause of the artifact was not tilting projection, but these influence of respiratory motion.

  16. Evaluation of regional wall motion in myocardial infarction using animation ECG gated cardiac computed tomography

    International Nuclear Information System (INIS)

    Shimizu, Takahiko; Hyodo, Haruo; Hayashi, Terumi; Yamamoto, Hideo; Yagi, Shigeru

    1984-01-01

    Regional wall motion of the left ventricle was evaluated in 21 patients with myocardial infarction using an animation system of gated cardiac computed tomographic (CT) images (animation gated CCT). The results obtained were compared with data by two-dimensional echocardiography (2-DE). 1. Evaluation of the asynergic area by animation gated CCT and 2-DE: Animation gated CCT detected the following specific regions with asynergy established by 2-DE; 10/10 cases (100%) at the anterior wall of the left ventricle, 14/14 cases (100%) at the interventricular septum, and 9/11 cases (81.8%) at the infero-posterior wall. In addition, one false positive case and one negative case were observed at the lateral wall and the apex, respectively. Of 37 instances with asynergic areas established by 2-DE, 21 cases or 89.2% were detected by animation gated CCT; the sensitivity was 91.9%. 2. Evaluation of severity of asynergy by animation gated CCT and 2-DE: The degree of asynergy evaluated by both methods was compared with each other, and the agreement was as follows: 10/10 cases (100%) at the left-ventricular anterior wall, 13/13 cases (100%) at the interventricular septum, and 7/9 cases (77.8%) at the infero-posterior wall. 3. Evaluation of the asynergic area by nonanimation gated CCT and 2-DE: Nonanimation gated CCT detected asynergic areas ascertained by 2-DE at the following areas; 8/10 cases (80%) at the left-ventricular anterior wall, 12/14 cases (85.7%) at the interventricular septum, and 4/11 cases (36.4%) at the infero-posterior wall. The difference between animation and nonanimation gated CCT was statistically significant (p<0.05). The severity of asynergy could not be evaluated by nonanimation gated CCT. (J.P.N.)

  17. Medical imaging, PACS, and imaging informatics: retrospective.

    Science.gov (United States)

    Huang, H K

    2014-01-01

    Historical reviews of PACS (picture archiving and communication system) and imaging informatics development from different points of view have been published in the past (Huang in Euro J Radiol 78:163-176, 2011; Lemke in Euro J Radiol 78:177-183, 2011; Inamura and Jong in Euro J Radiol 78:184-189, 2011). This retrospective attempts to look at the topic from a different angle by identifying certain basic medical imaging inventions in the 1960s and 1970s which had conceptually defined basic components of PACS guiding its course of development in the 1980s and 1990s, as well as subsequent imaging informatics research in the 2000s. In medical imaging, the emphasis was on the innovations at Georgetown University in Washington, DC, in the 1960s and 1970s. During the 1980s and 1990s, research and training support from US government agencies and public and private medical imaging manufacturers became available for training of young talents in biomedical physics and for developing the key components required for PACS development. In the 2000s, computer hardware and software as well as communication networks advanced by leaps and bounds, opening the door for medical imaging informatics to flourish. Because many key components required for the PACS operation were developed by the UCLA PACS Team and its collaborative partners in the 1980s, this presentation is centered on that aspect. During this period, substantial collaborative research efforts by many individual teams in the US and in Japan were highlighted. Credits are due particularly to the Pattern Recognition Laboratory at Georgetown University, and the computed radiography (CR) development at the Fuji Electric Corp. in collaboration with Stanford University in the 1970s; the Image Processing Laboratory at UCLA in the 1980s-1990s; as well as the early PACS development at the Hokkaido University, Sapporo, Japan, in the late 1970s, and film scanner and digital radiography developed by Konishiroku Photo Ind. Co. Ltd

  18. Cardiac MRI: evaluation of phonocardiogram-gated cine imaging for the assessment of global und regional left ventricular function in clinical routine

    International Nuclear Information System (INIS)

    Nassenstein, Kai; Schlosser, Thomas; Orzada, Stephan; Haering, Lars; Czylwik, Andreas; Zenge, Michael; Mueller, Edgar; Eberle, Holger; Bruder, Oliver; Ladd, Mark E.; Maderwald, Stefan

    2012-01-01

    To validate a phonocardiogram (PCG)-gated cine imaging approach for the assessment of left ventricular (LV) function. In this prospective study, cine MR imaging of the LV was performed twice in 79 patients by using retrospectively PCG- and retrospectively ECG-gated cine SSFP sequences at 1.5 T. End-diastolic volumes (EDV), end-systolic volumes (ESV), stroke volumes (SV), ejection fraction (EF), muscle mass (MM), as well as regional wall motion were assessed. Subgroup analyses were performed for patients with valvular defects and for patients with dysrhythmia. PCG-gated imaging was feasible in 75 (95%) patients, ECG-gating in all patients. Excellent correlations were observed for all volumetric parameters (r > 0.98 for all variables analysed). No significant differences were observed for EDV (-0.24 ± 3.14 mL, P = 0.5133), ESV (-0.04 ± 2.36 mL, P = 0.8951), SV (-0.20 ± 3.41 mL, P = 0.6083), EF (-0.16 ± 1.98%, P = 0.4910), or MM (0.31 ± 4.2 g, P = 0.7067) for the entire study cohort, nor for either of the subgroups. PCG- and ECG-gated cine imaging revealed similar results for regional wall motion analyses (115 vs. 119 segments with wall motion abnormalities, P = 0.3652). The present study demonstrates that PCG-gated cine imaging enables accurate assessment of global and regional LV function in the vast majority of patients in clinical routine. (orig.)

  19. Accurate estimation of global and regional cardiac function by retrospectively gated multidetector row computed tomography. Comparison with cine magnetic resonance imaging

    International Nuclear Information System (INIS)

    Belge, Benedicte; Pasquet, Agnes; Vanoverschelde, Jean-Louis J.; Coche, Emmanuel; Gerber, Bernhard L.

    2006-01-01

    Retrospective reconstruction of ECG-gated images at different parts of the cardiac cycle allows the assessment of cardiac function by multi-detector row CT (MDCT) at the time of non-invasive coronary imaging. We compared the accuracy of such measurements by MDCT to cine magnetic resonance (MR). Forty patients underwent the assessment of global and regional cardiac function by 16-slice MDCT and cine MR. Left ventricular (LV) end-diastolic and end-systolic volumes estimated by MDCT (134±51 and 67±56 ml) were similar to those by MR (137±57 and 70±60 ml, respectively; both P=NS) and strongly correlated (r=0.92 and r=0.95, respectively; both P<0.001). Consequently, LV ejection fractions by MDCT and MR were also similar (55±21 vs. 56±21%; P=NS) and highly correlated (r=0.95; P<0.001). Regional end-diastolic and end-systolic wall thicknesses by MDCT were highly correlated (r=0.84 and r=0.92, respectively; both P<0.001), but significantly lower than by MR (8.3±1.8 vs. 8.8±1.9 mm and 12.7±3.4 vs. 13.3±3.5 mm, respectively; both P<0.001). Values of regional wall thickening by MDCT and MR were similar (54±30 vs. 51±31%; P=NS) and also correlated well (r=0.91; P<0.001). Retrospectively gated MDCT can accurately estimate LV volumes, EF and regional LV wall thickening compared to cine MR. (orig.)

  20. 3D non-contrast-enhanced ECG-gated MR angiography of the lower extremities with dual-source radiofrequency transmission at 3.0 T: Intraindividual comparison with contrast-enhanced MR angiography in PAOD patients.

    Science.gov (United States)

    Rasper, Michael; Wildgruber, Moritz; Settles, Marcus; Eckstein, Hans-Henning; Zimmermann, Alexander; Reeps, Christian; Rummeny, Ernst J; Huber, Armin M

    2016-09-01

    To compare prospectively image quality and diagnostic confidence of flow-sensitive 3D turbo spin echo (TSE)-based non-contrast-enhanced MR angiography (NE-MRA) at 3.0 T using dual-source radiofrequency (RF) transmission with contrast-enhanced MRA (CE-MRA) in patients with peripheral arterial occlusive disease (PAOD). After consent was obtained, 35 patients (mean age 69.1 ± 10.6 years) with PAOD stage II-IV underwent NE-MRA followed by CE-MRA. Signal-to-noise ratio and contrast-to-noise ratio were calculated. Subjective image quality was independently assessed by two radiologists and stenosis scoring was performed in 875 arterial segments. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for stenosis classification were calculated using CE-MRA as a reference method. Diagnostic agreement with CE-MRA was evaluated with Cohen's kappa statistics. NE-MRA provided high objective and subjective image quality at all levels of the arterial tree. Sensitivity and specificity for the detection of relevant stenosis was 91 % and 89 %, respectively; the NPV was 96 % and the PPV 78 %. There was good concordance between CE-MRA and NE-MRA in stenosis scoring. 3D electrocardiography (ECG)-gated TSE NE-MRA with patient-adaptive dual-source RF transmission at 3.0 T is a promising alternative for PAOD patients with contraindications for gadolinium-based contrast agents. It offers high sensitivity and NPV values in the detection of clinically relevant arterial stenosis. • Flow-sensitive TSE NE-MRA is a promising technique for PAOD evaluation. • Diagnostic accuracy is comparable to contrast-enhanced MRA. • NE-MRA eliminates the risk of NSF in patients with renal insufficiency. • Costs arising from the use of contrast agents can be avoided.

  1. Magnetic resonance angiography (MRA) of the calf station at 3.0 T: intraindividual comparison of non-enhanced ECG-gated flow-dependent MRA, continuous table movement MRA and time-resolved MRA

    International Nuclear Information System (INIS)

    Haneder, Stefan; Attenberger, Ulrike I.; Riffel, Philipp; Henzler, Thomas; Schoenberg, Stefan O.; Michaely, Henrik J.

    2011-01-01

    To compare 3D non-enhanced ECG-gated inflow-dependent MRA (NE-MRA) vs. continuous table movement (CTM) MR-angiography and time-resolved TWIST-MRA in the calf station at 3.0 T in a clinical patient collective. 36 patients (27 male/9 female, 66.1 ± 14.4 years) with PAOD (stage II-IV) underwent during a single MRI: NE-MRA, contrast-enhanced CTM-MRA and TWIST-MRA with a single dose of a gadolinium-based contrast agent. The image quality (IQ) and the degree of stenoses were rated on a four-point scale. Positive (PPV) and negative predictive values (NPV), sensitivity (SS) and specificity (SP) for stenoses detection were calculated for NE-MRA vs. CTM-MRA and vs. TWIST-MRA. Values were obtained for overall graduation of wall changes and for severe stenoses (>70%). With NE-MRA 122/288 segments were not assessable. Compared with CTM-MRA and TWIST-MRA the IQ was significantly inferior (p < 0.0001 to p = 0.0426). CTM-MRA/TWIST-MRA detected stenoses in 44.9%/46.1% of the segments, NE-MRA in 53.5%. SS/NPV of the NE-MRA ranged from 97.8 to 100%. The SP and PPV ranged from 72.7 to 85.5% and 66.7 to 78.2%. Contrast-enhanced MRA techniques are superior to NE-MRA regarding IQ and correct identification of stenoses. If technically successful, NE-MRA is characterised by high NPV and overestimation of the degree of stenoses. (orig.)

  2. Blind retrospective motion correction of MR images.

    Science.gov (United States)

    Loktyushin, Alexander; Nickisch, Hannes; Pohmann, Rolf; Schölkopf, Bernhard

    2013-12-01

    Subject motion can severely degrade MR images. A retrospective motion correction algorithm, Gradient-based motion correction, which significantly reduces ghosting and blurring artifacts due to subject motion was proposed. The technique uses the raw data of standard imaging sequences; no sequence modifications or additional equipment such as tracking devices are required. Rigid motion is assumed. The approach iteratively searches for the motion trajectory yielding the sharpest image as measured by the entropy of spatial gradients. The vast space of motion parameters is efficiently explored by gradient-based optimization with a convergence guarantee. The method has been evaluated on both synthetic and real data in two and three dimensions using standard imaging techniques. MR images are consistently improved over different kinds of motion trajectories. Using a graphics processing unit implementation, computation times are in the order of a few minutes for a full three-dimensional volume. The presented technique can be an alternative or a complement to prospective motion correction methods and is able to improve images with strong motion artifacts from standard imaging sequences without requiring additional data. Copyright © 2013 Wiley Periodicals, Inc., a Wiley company.

  3. Evaluation by means of ECG-gated cardiac blood pool scintigraphy of global and regional left ventricular function at rest and during exercise in patients with coronary artery disease

    International Nuclear Information System (INIS)

    Sauer, E.; Sebening, H.; Lutilsky, L.; Dressler, H.; Hoer, G.; Pabst, H.W.; Bloemer, H.; Technische Univ. Muenchen

    1978-01-01

    ECG-gated cardiac blood pool scintigraphy permits a non-invasive determination of the end-diastolic and end-systolic ventricular volumens and of the ejection fraction as well as a qualitative description of regional ventricular wall motion at rest and during exercise. In 6 healthy persons a significant increase of the ejection fraction from 66 +- 7% at rest to 78 +- 3% during exercise (p [de

  4. Evaluation of left ventricular function in patients with atrial fibrillation by ECG gated blood pool scintigraphy. Using frame count normalization method

    Energy Technology Data Exchange (ETDEWEB)

    Akanabe, Hiroshi; Oshima, Motoo; Sakuma, Sadayuki

    1988-07-01

    The assumption necessary to perform ECG gated blood pool scintigraphy (EGBPS) are seemingly not valid for patients with atrial fibrillation (af), since they have wide variability in cardiac cycle length. The data were acquired in frame mode within the limits of mean heart rate of fix the first diastolic volume, and were calculated by frame count normalization (FCN) method to correct total counts in each frame. EGBPS were performed twelve patients with af, who were operated against valvular disease. The data acquired within mean heart rate +-10 % in frame mode were divided to 32 frames, and calculated total frame counts. With FCN method total frame counts from at 22nd to 32nd frame were multiplied to be equal to the average of total frame counts. FCN method could correct total frame counts at the latter frames. And there was good correlation between left ventricular ejection fraction calculated from scintigraphy and that from contrast cineangiography. Thus EGBPS with FCN method may be allow estimation of cardiac function even in subjects with af.

  5. Assessment of automatic quantification of myocardial perfusion and left ventricular function derived from ECG gated myocardial SPECT with {sup 99m}Tc-tetrofosmin in ischemic heart disease

    Energy Technology Data Exchange (ETDEWEB)

    Abe, Mitsunori; Habara, Hirokazu; Tatsuno, Hironari; Fukuda, Hiroshi; Hamada, Noriko; Kazatani, Yukio [Ehime Prefectural Central Hospital (Japan)

    1999-09-01

    Non-invasive assessment of ischemic heart disease (IHD) requires information of both myocardial perfusion and left ventricular (LV) function. Recently, automatic quantification of ECG-gated myocardial scintigraphy with {sup 99m}Tc-tetrofosmin (QGS) can provide both of them. QGS, coronary angiograms (CAG) and left venticulograms (LVG) were performed in 83 patients with severe IHD in same period. Significant stenosis of coronary artery in CAG were assessed by QGS. The sensitivity, specificity and accuracy of significant stenosis by QGS was excellent (85%, 93% and 88%). The LV end-distolic and end-systolic volumes (EDV and ESV), LV ejection fraction (EF) and regional LV wall motion determined by QGS were compared to LVG. There was a good correlation between the values obtained from QGS and LVG (EDV: r=0.86, ESV: r=0.94, EF: r=0.84, p<0.0001), but QGS tended to underestimate EDV and EF. High complete agreement of regional LV wall motion was gained with 427 (74.0%) out of total 581 segments. In conclusion, QGS data was considered to be useful for assessment of determine significant stenosis and LV function in severe IHD. (author)

  6. Influence of trigger type, tube voltage and heart rate on calcified plaque imaging in dual source cardiac computed tomography: phantom study

    International Nuclear Information System (INIS)

    Penzkofer, Tobias; Donandt, Eva; Isfort, Peter; Allmendinger, Thomas; Kuhl, Christiane K; Mahnken, Andreas H; Bruners, Philipp

    2014-01-01

    To investigate the impact of high pitch cardiac CT vs. retrospective ECG gated CT on the quantification of calcified vessel stenoses, with assessment of the influence of tube voltage, reconstruction kernel and heart rate. A 4D cardiac movement phantom equipped with three different plaque phantoms (12.5%, 25% and 50% stenosis at different calcification levels), was scanned with a 128-row dual source CT scanner, applying different trigger types (gated vs. prospectively triggered high pitch), tube voltages (100-120 kV) and heart rates (50–90 beats per minute, bpm). Images were reconstructed using different standard (B26f, B46f, B70f) and iterative (I26f, I70f) convolution kernels. Absolute and relative plaque sizes were measured and statistically compared. Radiation dose associated with the different methods (gated vs. high pitch, 100 kV vs. 120 kV) were compared. Compared to the known diameters of the phantom plaques and vessels both CT-examination techniques overestimated the degrees of stenoses. Using the high pitch CT-protocol plaques appeared larger (0.09 ± 0.31 mm, 2 ± 8 percent points, PP) in comparison to the ECG-gated CT-scans. Reducing tube voltage had a similar effect, resulting in higher grading of the same stenoses by 3 ± 8 PP. In turn, sharper convolution kernels lead to a lower grading of stenoses (differences of up to 5%). Pairwise comparison of B26f and I26f, B46f and B70f, and B70f and I70f showed differences of 0–1 ± 6–8 PP of the plaque depiction. Motion artifacts were present only at 90 bpm high pitch experiments. High-pitch protocols were associated with significantly lower radiation doses compared with the ECG-gated protocols (258.0 mGy vs. 2829.8 mGy CTDI vol , p ≤ 0.0001). Prospectively triggered high-pitch cardiac CT led to an overestimation of plaque diameter and degree of stenoses in a coronary phantom. This overestimation is only slight and probably negligible in a clinical situation. Even at higher heart rates high pitch CT

  7. Surveillance study for creating the national clinical database relating to ECG-gated myocardial perfusion SPECT of asymptomatic ischemic heart disease in patients with type-2 diabetes mellitus. J-ACCESS 2 study design

    International Nuclear Information System (INIS)

    Kusuoka, Hideo; Yamasaki, Yoshimitsu; Izumi, Tohru; Kashiwagi, Atsunori; Kawamori, Ryuzo; Shimamoto, Kazuaki; Yamada, Nobuhiro; Nishimura, Tsunehiko

    2008-01-01

    Diabetes mellitus is an independent risk factor for acute myocardial infarction. Thus, a surveillance study was conducted as part of studies to create a national database related to electrocardiogram (ECG)-gated myocardial perfusion single-photon emission computed tomography (SPECT) of ischemic heart disease. Single-photon emission computed tomography was conducted in patients with type 2 diabetes mellitus and their prognoses will be followed for 3 years, stratified by patients' clinical background and SPECT findings. A total of 513 patients from 50 institutions were enrolled in this study, 297 of whom were men (age 66.2±0.4 years, mean±standard error of the mean (SEM)) and 261 women (age 67.8±0.5 years). They have a history of retinopathy (25.3%), neuropathy (19.9%), cerebrovascular disorder, chronic obstructive pulmonary disease, and photocoagulation. Major risk factors for present disease were hypertension (82.3%) and hyperlipidemia (79.7%). In 244 patients (129 men and 115 women), body mass index (BMI) was 25 or more. Fifty-two of them (10.1%) underwent coronary angiography; of these, 26 (50.0%) had no coronary artery lesions with 75% or more stenosis, and only 1 (1.9%) had a left main trunk with 50% or more stenosis. An overwhelming majority of patients (94.3%) underwent SPECT imaging by a 1-day stress-followed-by-rest procedure. Stress procedure was exercise in most (70.8%) patients, followed by dipyridamole infusion in 14.6%, adenosine infusion in 6.6%, and adenosine triphosphate infusion in 5.7%. Endpoint of stress examination was most often fatigue in lower limbs (40.7%), followed by completion of pharmacological stress protocol (28.7%), and achievement of target heart rate (26.3%). The largest number of patients (198, 38.6%) received 99m Tc-tetrofosmin at an initial dosage of 200-300 MBq (mean 331±3 MBq) followed by a second dosage of 700-800 MBq (mean 748±8 MBq). Among them, 491 (95.7%) received some kind of therapeutic drug: hypoglycemic drugs were

  8. Influence of gating phase selection on the image quality of coronary arteries in multidetector row computed tomography

    International Nuclear Information System (INIS)

    Laskowska, K.; Marzec, M.; Serafin, Z.; Nawrocka, E.; Lasek, W.; WWisniewska-Szmyt, J.; Kubica, J.

    2005-01-01

    Motion artifacts caused by cardiac movement disturb the imaging of coronary arteries with multidetector-row spiral computed tomography. The aim of this study was to determine the phase of the heart rate which provides the best quality of coronary artery imaging in retrospective ECG-gated CT. Although 75% is usually the best reconstruction phase, the optimal phase should be established individually for the patient, artery, segment, and type of tomograph for the best imaging quality. Forty-five cardiac CT angiograms of 26 patients were retrospectively evaluated. The examinations were performed with a 4-detector-row tomograph. ECG-gated retrospective reconstructions were relatively delayed at 0%, 12.5%, 25%, 37.5%, 50%, 62.5%, 75%, and 87.5% of the cardiac cycle. Selected coronary arteries of the highest diagnostic quality were estimated in the eight phases of the cardiac cycle. Only arteries of very high image quality were selected for analysis: left coronary artery trunks (44 cases, incl. 37 stented), anterior interventricular branches (36, incl. 3 stented), circumflex branches (16), right coronary rtery branches (23), and posterior interventricular branches (4). The reconstruction phase had a statistically significant impact on the quality of imaging (p < 0.0003). Depending on the case, optimal imaging was noted in various phases, except in the 12.5 % phase. The 75% phase appeared to be the best of all those examined (p < 0.05), both in the group of arteries without stents (p < 0.0006) and in those stented (p < 0.05). In some cases of repeated examinations the best phases differed within the same patient. (author)

  9. Quantitative evaluation of renal dynamic scan with 99mTc-MAG3 assessment of interoposterior myocardial infarction using ECG gated SPECT with 99mTc-MIBI

    International Nuclear Information System (INIS)

    Cho, Keiichi; Kumita, Shinichiro; Mizumura, Sunao

    1997-01-01

    Simultaneous assessment of regional myocardial perfusion and local contraction ability of interoposterior myocardial infarction was examined by ECG gated SPECT. In thirteen cases of acute interoposterior myocardial infarction, the above-mentioned data were obtained by 180deg data acquisition method using L-shaped 2 detecting element type gamma camera. Mean and standard deviation of %Uptake and wall thickening (WT) in inferior wall were as follows: Infarction case; 57±9.2%/23±11.3%, normal case; 71±8.2%/61±10.2%. The significant depression (p<0.01/p<0.001) of both data were found in the infarction case. The both data in posterior wall were as follows: Infarction case; 55±10.7%/16±8.9%, normal case; 64±9.7%/41±15.0%. The significant depression (p<0.05/p<0.001) were also found in the infarction case. In both inferior wall and posterior wall, the AUC of ROC curve of WT was greater than that of %Uptake, and diagnostic ability of this method was favorable. The best sensitivity/specificity rate and the threshold were as follows: %Uptake of inferior wall 77/65, -0.5SD, WT of inferior wall 100/100, -2SD, %Uptake of posterior wall 62/82, -1SD, WT of posterior wall 85/88, -4SD. Accordingly, in diagnosis of interoposterior myocardial infarction, assessment of focus cardiac function, for example WT, is necessary as well as %Uptake. (K.H.)

  10. Assessment of left ventricular filling in various heart disease, especially in ischemic heart disease, by ECG-gated cardiac blood pool scintigraphy

    International Nuclear Information System (INIS)

    Nakagawa, Hiroaki

    1986-01-01

    Using ECG-gated cardiac blood pool scintigraphy (BPS), left ventricular (LV) diastolic function was evaluated in various heart disease, especially in ischemic heart disease (IHD). LV function indices (2 systolic and 9 diastolic) were obtained from LV time activity curve derived from BPS. Among various diastolic indices, peak filling rate (PFR) and 2 other indices were significantly influenced by heart rate (HR), so corrected values for HR were used for this study. Various degrees of disturbance in diastolic filling were found in many cases without systolic impairment. According to the mechanism responsible for diastolic impairment, LV time activity curve showed a characteristic pattern. In IHD, filling disturbance in early diastole was observed before the impairment of systolic contraction developed, so it was thought to be an early predictor of cardiac failure. In the scar region of myocardial infarction (MI), decrease in regional ejection fraction and asynchrony in wall motion were shown, and these resulted in marked deterioration of early diastolic filling. On the other hand in angina pectoris (AP), such systolic disorders were not shown in the ischemic region perfused by stenotic coronary artery, although the disturbance of regional filling was found. The exercise capacity in AP was more related to the impairment in diastolic function at resting state than in systolic function, and furthermore the reserve of diastolic function as well as of systolic function was shown to be an important determinant of exercise capacity in AP. As HR increased, increase of PFR and decrease in time to peak filling was found, which was thought to be a sort of compensation for the shortening diastolic time due to increase in HR during exercise. Such compensation was decreased in AP with reduced exercise capacity. (J.P.N.)

  11. CT imaging before transcatheter aortic valve implantation (TAVI) using variable helical pitch scanning and its diagnostic performance for coronary artery disease

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, Shunsuke; Yamada, Yoshitake; Hashimoto, Masahiro; Okamura, Teppei; Jinzaki, Masahiro [Keio University School of Medicine, Department of Diagnostic Radiology, Shinanomachi, Shinjuku-ku, Tokyo (Japan); Yamada, Minoru [Keio University School of Medicine, Research Park, Tokyo (Japan); Yashima, Fumiaki; Hayashida, Kentaro; Fukuda, Keiichi [Keio University School of Medicine, Department of Cardiology, Tokyo (Japan)

    2017-05-15

    To evaluate the effectiveness of CT before TAVI using variable helical pitch (VHP) scanning and its diagnostic performance for coronary artery disease (CAD). Sixty patients (84.4 ± 4.6 years) scheduled for TAVI underwent CT using VHP scanning with the contrast material (CM) volume calculated as scanning time x weight [kg] x 0.06 mL. Retrospective electrocardiography (ECG)-gated scanning was utilized to examine the thorax, and non-ECG-gated scanning of the abdomen immediately followed. We analyzed CT attenuation values of the coronary arteries, aorta, iliac and femoral arteries. The coronary CT angiography images were evaluated for the presence of stenosis (≥50 %); invasive coronary angiography served as a reference standard. The average attenuations of all of the arteries were greater than 400 HU. We could evaluate the peripheral access vessels and dimensions of the ascending aorta, aortic root, and aortic annulus in all patients. The average volume of CM was 38.7 ± 8.5 mL. On per-patient and vessel analysis, CT showed 91.7 % and 89.5 % sensitivity, and 91.3 % and 97.4 % negative predictive value (NPV). CT using VHP scanning with an average CM volume of 38.7 mL is useful before TAVI and had a high sensitivity and NPV in excluding obstructive CAD. (orig.)

  12. Quantitative analysis of arterial flow properties for detection of non-calcified plaques in ECG-gated coronary CT angiography

    Science.gov (United States)

    Wei, Jun; Zhou, Chuan; Chan, Heang-Ping; Chughtai, Aamer; Agarwal, Prachi; Kuriakose, Jean; Hadjiiski, Lubomir; Patel, Smita; Kazerooni, Ella

    2015-03-01

    We are developing a computer-aided detection system to assist radiologists in detection of non-calcified plaques (NCPs) in coronary CT angiograms (cCTA). In this study, we performed quantitative analysis of arterial flow properties in each vessel branch and extracted flow information to differentiate the presence and absence of stenosis in a vessel segment. Under rest conditions, blood flow in a single vessel branch was assumed to follow Poiseuille's law. For a uniform pressure distribution, two quantitative flow features, the normalized arterial compliance per unit length (Cu) and the normalized volumetric flow (Q) along the vessel centerline, were calculated based on the parabolic Poiseuille solution. The flow features were evaluated for a two-class classification task to differentiate NCP candidates obtained by prescreening as true NCPs and false positives (FPs) in cCTA. For evaluation, a data set of 83 cCTA scans was retrospectively collected from 83 patient files with IRB approval. A total of 118 NCPs were identified by experienced cardiothoracic radiologists. The correlation between the two flow features was 0.32. The discriminatory ability of the flow features evaluated as the area under the ROC curve (AUC) was 0.65 for Cu and 0.63 for Q in comparison with AUCs of 0.56-0.69 from our previous luminal features. With stepwise LDA feature selection, volumetric flow (Q) was selected in addition to three other luminal features. With FROC analysis, the test results indicated a reduction of the FP rates to 3.14, 1.98, and 1.32 FPs/scan at sensitivities of 90%, 80%, and 70%, respectively. The study indicated that quantitative blood flow analysis has the potential to provide useful features for the detection of NCPs in cCTA.

  13. Can ECG-gated MDCT be considered an obligatory step to plan and manage a new chest-pain unit?

    International Nuclear Information System (INIS)

    Runza, G.; Alaimo, V.; La Grutta, L.; Galia, M.; Basile, A.; Cademartiri, F.; Krestin, G.P.; Midiri, M.

    2007-01-01

    The recent improvements in multi-detector computed tomography technology and its application in cardiac field allow to consider this non-invasive imaging technique as a promising comprehensive method for detecting significant coronary stenoses in a chest-pain unit. The possibility to use the ECG-synchronisation acquisition protocol, normally limited to the cardiac volume, for the entire thoracic vascular system should have the remarkable potential to reduce invasive and non-invasive procedures actually used to investigate acute chest pain and the number of unnecessary hospital admissions without reducing appropriate admissions in patients with chest pain

  14. Magnetic resonance (MR) cine imaging of the human heart

    International Nuclear Information System (INIS)

    Waterton, J.C.

    1985-01-01

    A novel approach has been developed for MR cine imaging of the human heart by a modified ECG-gated 2DFT method. A pulse sequence has been devised to minimise the effects of saturation which can be anticipated in sequences that require rapid pulsing. Five frames are produced at the same anatomical level at predetermined intervals during the cardiac cycle. The total time taken to achieve this data is 8 minutes. Additional frames can be interleaved by repeating the sequence with an ECG-gated delay. The anatomical sections, which can be in any orthogonal plane, are then displayed as a cine loop. Cine display in the coronal plane has been used to examine 10 volunteers and 12 patients. In addition to the morphological feature displayed in single slice ECG-gated imaging, areas of dyskinesia can be detected and subjective estimates have been made of left ventricular function. (author)

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

    International Nuclear Information System (INIS)

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

    2004-01-01

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

  16. A correlative study of aortic valve rotation angle and thoracic aortic sizes using ECG gated CT angiography

    Energy Technology Data Exchange (ETDEWEB)

    Saremi, Farhood, E-mail: fsaremi@usc.edu; Cen, Steven; Tayari, Nazila; Alizadeh, Houman; Emami, Amir; Lin, Leah; Fleischman, Fernando

    2017-04-15

    Objective: Various degrees of aortic valve rotation may be seen in individuals with no history of congenital cardiovascular malformations, but its association with aortic sizes has not been studied. Methods: Gated computed tomographic (CT angiograms in 217 patients were studied (66.7 ± 15; 22–97 years old)). Aortic diameters were determined at 5 anatomic locations. The length of the aorta from sinus to left subclavian artery was measured. The angle of valve rotation was recorded by measuring the angle between a line connecting the midpoint of the non-coronary sinus to the anterior commissure and another line along the interatrial septum. Rotation angles were correlated with aortic measurements. Patients were separated into two groups based on aortic sizes and into three groups based on age. The threshold for aortic dilatation was set at maximum ascending aorta diameter ≥40 mm (≥21 mm body surface area [BSA] indexed). Results: No significant difference in rotation angles was seen between the three age groups or between genders. Rotation angles were significantly correlated with maximal, average, and BSA adjustment of the aortic root and ascending aortic measurements. The aortic root angles were significantly different between the dilated versus nondilated aortas. There was no significant association between the rotation angles and age, length of ascending aorta, or diameters of descending aorta. Multivariate adaptive regression splines showed 25° of aortic root rotation as the diagnostic cut off for ascending aorta dilation. Above the 25° rotation, every 10° of increasing rotation was associated with a 3.78 ± 0.87 mm increase in aortic diameter (p < 0.01) and a 1.73 ± 0.25 times increased risk for having a dilated aorta (p < 0.01). Conclusion: Rotation angles of the aortic valve may be an independent non-invasive imaging marker for dilatation of the ascending aorta. Patients with increased rotation angle of the aortic valve may have higher risk for

  17. Reliability analysis of visual ranking of coronary artery calcification on low-dose CT of the thorax for lung cancer screening: comparison with ECG-gated calcium scoring CT.

    Science.gov (United States)

    Kim, Yoon Kyung; Sung, Yon Mi; Cho, So Hyun; Park, Young Nam; Choi, Hye-Young

    2014-12-01

    Coronary artery calcification (CAC) is frequently detected on low-dose CT (LDCT) of the thorax. Concurrent assessment of CAC and lung cancer screening using LDCT is beneficial in terms of cost and radiation dose reduction. The aim of our study was to evaluate the reliability of visual ranking of positive CAC on LDCT compared to Agatston score (AS) on electrocardiogram (ECG)-gated calcium scoring CT. We studied 576 patients who were consecutively registered for health screening and undergoing both LDCT and ECG-gated calcium scoring CT. We excluded subjects with an AS of zero. The final study cohort included 117 patients with CAC (97 men; mean age, 53.4 ± 8.5). AS was used as the gold standard (mean score 166.0; range 0.4-3,719.3). Two board-certified radiologists and two radiology residents participated in an observer performance study. Visual ranking of CAC was performed according to four categories (1-10, 11-100, 101-400, and 401 or higher) for coronary artery disease risk stratification. Weighted kappa statistics were used to measure the degree of reliability on visual ranking of CAC on LDCT. The degree of reliability on visual ranking of CAC on LDCT compared to ECG-gated calcium scoring CT was excellent for board-certified radiologists and good for radiology residents. A high degree of association was observed with 71.6% of visual rankings in the same category as the Agatston category and 98.9% varying by no more than one category. Visual ranking of positive CAC on LDCT is reliable for predicting AS rank categorization.

  18. Exact monitoring of aortic diameters in Marfan patients without gadolinium contrast: intraindividual comparison of 2D SSFP imaging with 3D CE-MRA and echocardiography

    International Nuclear Information System (INIS)

    Veldhoen, Simon; Behzadi, Cyrus; Derlin, Thorsten; Henes, Frank Oliver; Adam, Gerhard; Bannas, Peter; Rybczinsky, Meike; Kodolitsch, Yskert von; Sheikhzadeh, Sara; Bley, Thorsten Alexander

    2015-01-01

    To assess whether ECG-gated non-contrast 2D steady-state free precession (SSFP) imaging allows for exact monitoring of aortic diameters in Marfan syndrome (MFS) patients using non-ECG-gated contrast-enhanced 3D magnetic resonance angiography (CE-MRA) and echocardiography for intraindividual comparison. Non-ECG-gated CE-MRA and ECG-gated non-contrast SSFP at 1.5 T were prospectively performed in 50 patients. Two readers measured aortic diameters on para-sagittal images identically aligned with the aortic arch at the sinuses of Valsalva, sinotubular junction, ascending/descending aorta and aortic arch. Image quality was assessed on a three-point scale. Aortic root diameters acquired by echocardiography were used as reference. Intra- and interobserver variances were smaller for SSFP at the sinuses of Valsalva (p = 0.002; p = 0.002) and sinotubular junction (p = 0.014; p = 0.043). Image quality was better in SSFP than in CE-MRA at the sinuses of Valsalva (p < 0.0001), sinotubular junction (p < 0.0001) and ascending aorta (p = 0.02). CE-MRA yielded higher diameters than SSFP at the sinuses of Valsalva (mean bias, 2.5 mm; p < 0.0001), and comparison with echocardiography confirmed a higher bias for CE-MRA (7.2 ± 3.4 mm vs. SSFP, 4.7 ± 2.6 mm). ECG-gated non-contrast 2D SSFP imaging provides superior image quality with higher validity compared to non-ECG-gated contrast-enhanced 3D imaging. Since CE-MRA requires contrast agents with potential adverse effects, non-contrast SSFP imaging is an appropriate alternative for exact and riskless aortic monitoring of MFS patients. (orig.)

  19. Exact monitoring of aortic diameters in Marfan patients without gadolinium contrast: intraindividual comparison of 2D SSFP imaging with 3D CE-MRA and echocardiography

    Energy Technology Data Exchange (ETDEWEB)

    Veldhoen, Simon [University Medical Center Wuerzburg, Department of Diagnostic and Interventional Radiology, Bavaria (Germany); University Medical Center Hamburg-Eppendorf, Department of Diagnostic and Interventional Radiology, Hamburg (Germany); Behzadi, Cyrus; Derlin, Thorsten; Henes, Frank Oliver; Adam, Gerhard; Bannas, Peter [University Medical Center Hamburg-Eppendorf, Department of Diagnostic and Interventional Radiology, Hamburg (Germany); Rybczinsky, Meike; Kodolitsch, Yskert von; Sheikhzadeh, Sara [University Medical Center Hamburg-Eppendorf, Department of General and Interventional Cardiology, Hamburg (Germany); Bley, Thorsten Alexander [University Medical Center Wuerzburg, Department of Diagnostic and Interventional Radiology, Bavaria (Germany)

    2014-10-15

    To assess whether ECG-gated non-contrast 2D steady-state free precession (SSFP) imaging allows for exact monitoring of aortic diameters in Marfan syndrome (MFS) patients using non-ECG-gated contrast-enhanced 3D magnetic resonance angiography (CE-MRA) and echocardiography for intraindividual comparison. Non-ECG-gated CE-MRA and ECG-gated non-contrast SSFP at 1.5 T were prospectively performed in 50 patients. Two readers measured aortic diameters on para-sagittal images identically aligned with the aortic arch at the sinuses of Valsalva, sinotubular junction, ascending/descending aorta and aortic arch. Image quality was assessed on a three-point scale. Aortic root diameters acquired by echocardiography were used as reference. Intra- and interobserver variances were smaller for SSFP at the sinuses of Valsalva (p = 0.002; p = 0.002) and sinotubular junction (p = 0.014; p = 0.043). Image quality was better in SSFP than in CE-MRA at the sinuses of Valsalva (p < 0.0001), sinotubular junction (p < 0.0001) and ascending aorta (p = 0.02). CE-MRA yielded higher diameters than SSFP at the sinuses of Valsalva (mean bias, 2.5 mm; p < 0.0001), and comparison with echocardiography confirmed a higher bias for CE-MRA (7.2 ± 3.4 mm vs. SSFP, 4.7 ± 2.6 mm). ECG-gated non-contrast 2D SSFP imaging provides superior image quality with higher validity compared to non-ECG-gated contrast-enhanced 3D imaging. Since CE-MRA requires contrast agents with potential adverse effects, non-contrast SSFP imaging is an appropriate alternative for exact and riskless aortic monitoring of MFS patients. (orig.)

  20. Partial flip angle spin-echo imaging to obtain T1 weighted images with electrocardiographic gating

    International Nuclear Information System (INIS)

    Kawamitsu, Hideaki; Sugimura, Kazuro; Kasai, Toshifumi; Kimino, Katsuji

    1993-01-01

    ECG-gated spin-echo (SE) imaging can reduce physiologic motion artifact. However, it does not provide strong T 1 -weighted images, because the repetition time (TR) depends on heart rate (HR). For odd-echo SE imaging, T 1 contrast can be maximized by using a smaller flip angle (FA) of initial excitation RF pulses. We investigated the usefulness of partial FA SE imaging in order to obtain more T 1 -dependent contrast with ECG gating and determined the optimal FA at each heart rate. In computer simulation and phantom study, the predicted image contrast and signal-to-noise ratio (SNR) obtained for each FA (0∼180deg) and each HR (55∼90 beats per minute (bpm)) were compared with those obtained with conventional T 1 -weighted SE imaging (TR=500 ms, TE=20 ms, FA=90deg). The optimal FA was decreased by reducing HR. The FA needed to obtain T 1 -dependent contrast identical to that with T 1 -weighted SE imaging was 43deg at a HR of 65 bpm, 53deg at 70 bpm, 60deg at 75 bpm. This predicted FA were in excellent agreement with that obtained with clinical evaluation. The predicted SNR was decreased by reducing FA. The SNR of partial FA SE imaging at HR of 65 bpm (FA=43deg) was 80% of that with conventional T 1 -weighted SE imaging. However, this imaging method presented no marked clinical problem. ECG-gated partial FA SE imaging provides better T 1 -dependent contrast than conventional ECG-gated SE imaging, especially for Gd-DTPA enhanced imaging. (author)

  1. A new method for measuring temporal resolution in electrocardiogram-gated reconstruction image with area-detector computed tomography

    International Nuclear Information System (INIS)

    Kaneko, Takeshi; Takagi, Masachika; Kato, Ryohei; Anno, Hirofumi; Kobayashi, Masanao; Yoshimi, Satoshi; Sanda, Yoshihiro; Katada, Kazuhiro

    2012-01-01

    The purpose of this study was to design and construct a phantom for using motion artifact in the electrocardiogram (ECG)-gated reconstruction image. In addition, the temporal resolution under various conditions was estimated. A stepping motor was used to move the phantom over an arc in a reciprocating manner. The program for controlling the stepping motor permitted the stationary period and the heart rate to be adjusted as desired. Images of the phantom were obtained using a 320-row area-detector computed tomography (ADCT) system under various conditions using the ECG-gated reconstruction method. For estimation, the reconstruction phase was continuously changed and the motion artifacts were quantitatively assessed. The temporal resolution was calculated from the number of motion-free images. Changes in the temporal resolution according to heart rate, rotation time, the number of reconstruction segments and acquisition position in z-axis were also investigated. The measured temporal resolution of ECG-gated half reconstruction is 180 ms, which is in good agreement with the nominal temporal resolution of 175 ms. The measured temporal resolution of ECG-gated segmental reconstruction is in good agreement with the nominal temporal resolution in most cases. The estimated temporal resolution improved to approach the nominal temporal resolution as the number of reconstruction segments was increased. Temporal resolution in changing acquisition position is equal. This study shows that we could design a new phantom for estimating temporal resolution. (author)

  2. Comparison of prospective electrocardiography-gating high-pitch mode and without electrocardiography-synchronization high-pitch mode acquisition for the image quality and radiation doses of the aortic using dual-source CT

    International Nuclear Information System (INIS)

    Li Jian; Huan Yi; Zhao Hongliang; Wang Ying; Liu Ying; Wei Mengqi; Shi Mingguo; Zheng Minwen

    2013-01-01

    Objective: To evaluate the application of prospective ECG-gating Flash spiral scan mode dual-source CT in aortography, and compare it's image quality and radiation dose with without ECG-synchronization high-pitch spiral scanning mode. Methods: Fifty consecutive patients (Group A) with suspected aortic dissection or after operations for the aortic dissection were scanned with prospective ECG-gated high-pitch scan and another 50 consecutive patients (Group B) were analyzed by non-ECG-gated high-pitch scan. Image quality of the aortic was assessed by two independent readers. Image noise was measured, radiation dose estimates were calculated. The imaging quality of the aortic and the radiation dose were compared with Mann-whitney U and t test. Results: The average image quality score [(1.18 ± 0.40) in group A and (1.23 ± 0.31) in group B] showed no significant difference between group A and group B (U = 1.20, P = 0.23). The mean radiation dose of group A was lower than that of group B [(1.49 ± 0.38) mSv in group A, (2.79 ± 0.54) mSv in group B, t = 13.677, P < 0.05]. Conclusion: Prospective ECG-gated dual source CT Flash spiral scanning with low radiation dose and good image quality in the aortic dissection with high value of clinical application. (authors)

  3. Pictorial review: Electron beam computed tomography and multislice spiral computed tomography for cardiac imaging

    International Nuclear Information System (INIS)

    Lembcke, Alexander; Hein, Patrick A.; Dohmen, Pascal M.; Klessen, Christian; Wiese, Till H.; Hoffmann, Udo; Hamm, Bernd; Enzweiler, Christian N.H.

    2006-01-01

    Electron beam computed tomography (EBCT) revolutionized cardiac imaging by combining a constant high temporal resolution with prospective ECG triggering. For years, EBCT was the primary technique for some non-invasive diagnostic cardiac procedures such as calcium scoring and non-invasive angiography of the coronary arteries. Multislice spiral computed tomography (MSCT) on the other hand significantly advanced cardiac imaging through high volume coverage, improved spatial resolution and retrospective ECG gating. This pictorial review will illustrate the basic differences between both modalities with special emphasis to their image quality. Several experimental and clinical examples demonstrate the strengths and limitations of both imaging modalities in an intraindividual comparison for a broad range of diagnostic applications such as coronary artery calcium scoring, coronary angiography including stent visualization as well as functional assessment of the cardiac ventricles and valves. In general, our examples indicate that EBCT suffers from a number of shortcomings such as limited spatial resolution and a low contrast-to-noise ratio. Thus, EBCT should now only be used in selected cases where a constant high temporal resolution is a crucial issue, such as dynamic (cine) imaging. Due to isotropic submillimeter spatial resolution and retrospective data selection MSCT seems to be the non-invasive method of choice for cardiac imaging in general, and for assessment of the coronary arteries in particular. However, technical developments are still needed to further improve the temporal resolution in MSCT and to reduce the substantial radiation exposure

  4. Incremental value of regional wall motion analysis immediately after exercise for the detection of single-vessel coronary artery disease. Study by separate acquisition, dual-isotope ECG-gated single-photon emission computed tomography

    International Nuclear Information System (INIS)

    Yoda, Shunichi; Sato, Yuichi; Matsumoto, Naoya; Tani, Shigemasa; Takayama, Tadateru; Uchiyama, Takahisa; Saito, Satoshi

    2005-01-01

    Although the detection of wall motion abnormalities gives incremental value to myocardial perfusion single-photon emission computed tomography (SPECT) in the diagnosis of extensive coronary artery disease (CAD) and high-grade single-vessel CAD, whether or not it is useful in the diagnosis of mild, single-vessel CAD has not been studied previously. Separate acquisition, dual isotope electrocardiogram (ECG)-gated SPECT was performed in 97 patients with a low likelihood of CAD (Group 1) and 46 patients with single-vessel CAD (Group 2). Mild CAD was defined by stenosis of 50-75% (Group 2a, n=22) and moderate to severe CAD was defined by stenosis ≥76% (Group 2b, n=24). Myocardial perfusion and wall motion were graded by a 5 point-scale, 20-segment model. The sensitivity of myocardial perfusion alone was 50% for Group 2a, 83% for Group 2b and 67% for Group 2 as a whole. The overall specificity was 90%. When the wall motion analysis was combined, the sensitivity was increased to 82% in Group 2a and 92% in Group 2b. The ability to detect a wall motion abnormality immediately after exercise gives incremental diagnostic value to myocardial perfusion SPECT in the identification of mild, single-vessel CAD. (author)

  5. Measurement of left ventricular ejection fraction from gated technetium-99m sestamibi myocardial images

    International Nuclear Information System (INIS)

    Boonyaprapa, S.; Ekmahachai, M.; Thanachaikun, N.; Jaiprasert, W.; Sukthomya, V.; Poramatikul, N.

    1995-01-01

    Sixty patients underwent SPET imaging with MIBI. Immediately after SPET acquisition ECG-gated 99m Tc-MIBI perfusion images were acquired using 24 planar images per R-R interval. A new method for measurement of LVEF from the ECG-gated 99m Tc-MIBI perfusion images was developed. To validate the method, LVEF derived from MIBI perfusion images was compared with that from conventional radionuclide ventriculography in all 60 patients. Forty patients had evidence of myocardial infarction and 20 had normal perfusion on MIBI imaging. There was no statistically significant difference between LVEF computed from 99m Tc-MIBI perfusion images and that from radionuclide ventriculography (r=0.7062, P 99m Tc-MIBI perfusion images can be obtained at the same time as assessment of myocardial perfusion and in the same orientation and metabolism of the myocardium, thereby permitting more accurate and realistic prognosis and diagnosis in patients with coronary artery disease. (orig.)

  6. The amount of viable and dyssynchronous myocardium is associated with response to cardiac resynchronization therapy: initial clinical results using multiparametric ECG-gated [{sup 18}F]FDG PET

    Energy Technology Data Exchange (ETDEWEB)

    Lehner, Sebastian; Uebleis, Christopher; Haug, Alexander; Bartenstein, Peter [University of Munich, Department of Nuclear Medicine, Munich (Germany); Schuessler, Franziska; Kaeaeb, Stefan; Estner, Heidi [University of Munich, Medical Department I, Munich (Germany); Van Kriekinge, Serge D.; Germano, Guido [UCLA, Cedars-Sinai Medical Center, Los Angeles and David Geffen School of Medicine, Los Angeles, CA (United States); Hacker, Marcus [Medical University of Vienna, Division of Nuclear Medicine, Department of Biomedical Imaging and Image-guided Theraphy, Vienna (Austria)

    2013-12-15

    There is still a significant amount of patients who do not sufficiently respond to cardiac resynchronization therapy (CRT). Previous studies demonstrated that the amount of dyssynchronous myocardium was predictive of response to CRT. Otherwise, non-response is frequently associated with high amounts of scar tissue. The combination of these parameters might yield a more accurate prediction of response. We hypothesized that the probability of a CRT response increases with the presence of high amounts of ''viable and dyssynchronous'' myocardium. A total of 19 patients (17 male, 61 {+-} 10 years) underwent ECG-gated [{sup 18}F]fluorodeoxyglucose (FDG) myocardial positron emission tomography (PET) before CRT device implantation and were followed for 6 months. Response to CRT was defined as clinical improvement of at least one New York Heart Association (NYHA) class in combination with left ventricular (LV) ejection fraction (EF) improvement of >5 %. Twelve responders (71 %) and seven non-responders (29 %) were identified. For each patient bullseye maps of FDG uptake and phase analysis were calculated (QPS/QGS 2012, Cedars-Sinai, Los Angeles, CA, USA) and fused. Amounts of myocardium representing ''viable and synchronous'', ''scar and synchronous'', viable and dyssynchronous or ''scar and dyssynchronous'' myocardium were quantified by planimetric measurements of the fused bullseye maps. Responders by definition showed significant decrease in NYHA class and significant increase of LVEF. Furthermore, a significantly higher amount of viable and dyssynchronous myocardium was found as compared to non-responders (21 {+-} 13 % vs 6 {+-} 5 %; p < 0.05). Combined assessment of myocardial viability and LV dyssynchrony is feasible using multiparametric [{sup 18}F]FDG PET and could improve conventional response prediction criteria for CRT. (orig.)

  7. Gated magnetic resonance imaging of congenital cardiac malformations

    International Nuclear Information System (INIS)

    Fletcher, B.D.; Jocobstein, M.D.; Nelson, A.D.; Riemenschneider, T.A.; Alfidi, R.J.

    1984-01-01

    Magnetic resonance (MR) images of a variety of cardiac malformations in 19 patients aged 1 week to 33 years were obtained using pulse plethysmographic- or ECG-gated spin echo pulse sequences. Coronal, axial, and sagittal images displaying intracardiac structures with excellent spatial and contrast resolution were acquired during systole or diastole. It is concluded that MR will be a valuable noninvasive method of diagnosing congenital heart disease

  8. A fundamental study of non-contrast enhanced MR angiography using ECG gated-3D fast spin echo at 3.0 T

    International Nuclear Information System (INIS)

    Nakato, Kengo; Hiai, Yasuhiro; Tomiguchi, Seiji

    2010-01-01

    Contrast-enhanced magnetic resonance angiography (CE-MRA) is frequently performed in body and extremity studies because of its superior ability to detect the vascular stenosis. However, nephrotoxicity of the contrast medium has been emphasized in recent years. Non-contrast MRA using the three-dimensional electrocardiogram-synchronized fast spin echo method (fresh blood imaging (FBI), non-contrast MRA of arteries and veins (NATIVE) and triggered acquisition non contrast enhancement MRA (TRANCE)) is recommended as a substitute for CE-MRA. There are a few reports in the literature that evaluate the detectability of vascular stenosis using non-contrast MRA on 3.0 T MRI. The purpose of this study was to evaluate the detectability of vascular stenosis using non-contrast MRA at 3.0 T with an original vascular phantom. The vascular phantom consisted of silicon tubes. 30% and 70% stenosis of luminal diameter were made. Each silicon tube connected a pump producing a pulsatile flow. A flowing material to was used in this study to show the similarity of the intensity to blood on MRI. MRA without a contrast medium (NATIVE sequence) were performed in the vascular phantom by changing the image matrix, static magnetic field strength and flow velocity. In addition, the NATIVE sequence was used with or without flow compensation. Vascular stenosis was quantitatively estimated by measurement of the signal intensities in non-contrast MRA images. MRA with NATIVE sequence demonstrated an accurate estimation of 30% vascular stenosis at slow flow velocity. However, 30% stenosis was overestimated in cases of high flow velocity. Estimation was improved by using a flow compensation sequence. 70% stenosis was overestimated on MRA with NATIVE sequence. Estimation of 70% stenosis was improved by using a flow compensation sequence. Accurate estimation of vascular stenosis in MRA with a NATIVE sequence is improved by using the flow compensation technique. MRA with NATIVE sequence is considered to

  9. Evaluation of image quality and radiation dose of thoracic and coronary dual-source CT in 110 infants with congenital heart disease

    International Nuclear Information System (INIS)

    Saad, Moez Ben; Rohnean, Adela; Sigal-Cinqualbre, Anne; Adler, Ghazal; Paul, Jean-Francois

    2009-01-01

    There are only a few reports on the diagnostic accuracy, and the technical and clinical feasibility, of multidetector CT (MDCT) in infants with congenital heart disease (CHD). To evaluate the image quality and radiation dose of DSCT in babies with CHD. From November 2006 to November 2007, 110 consecutive infants with CHD referred for pre- or postoperative CT evaluation were included. All these infants had a spiral angiothoracic DSCT scan after injection of 300 mg/ml iopromide at 0.5-1 ml/s with a power injector using a low-dose protocol (80 kVp and 10 mAs/kg). Of these infants, 34 also underwent an ECG-gated coronary CT scan for evaluation of the course of the coronary arteries. No serious adverse events were recorded. The mean dose-length product was 8±6 mGy.cm (effective dose 0.5±0.2 mSv) and 21±9 mGy.cm (effective dose 1.3±0.6 mSv) during the non-ECG-gated spiral acquisition and ECG-gated acquisition, respectively. Diagnostic quality images were achieved with the spiral acquisition in 89% of cases. Compared to the spiral mode, ECG-gated acquisition significantly improved the visualization of the coronary arteries, with a diagnostic rate of 91% and 84% for the left and right coronary arteries, respectively. DSCT together with iopromide at 300 mg/ml is a valuable tool for the routine clinical evaluation of infants with CHD. ECG-gated acquisition provides reliable visualization of the course of the coronary arteries. (orig.)

  10. Impact of endothelial dysfunction on left ventricular remodeling after successful primary coronary angioplasty for acute myocardial infarction. Analysis by quantitative ECG-gated SPECT

    International Nuclear Information System (INIS)

    Matsuo, Shinro; Nakae, Ichiro; Matsumoto, Tetsuya; Horie, Minoru

    2006-01-01

    We hypothesized that endothelial cell integrity in the risk area would influence left ventricular remodeling after acute myocardial infarction. Twenty patients (61±8 y.o.) with acute myocardial infarction underwent 99m Tc-tetrofosmin imaging in the sub-acute phase and three months after successful primary angioplasty due to myocardial infarction. All patients were administered angiotensin-converting enzyme inhibitor after revascularization. Cardiac scintigraphies with quantitative gated SPECT were performed at the sub-acute stage and again 3 months after revascularization to evaluate left ventricular (LV) remodeling. The left ventricular ejection fraction (EF) and end-systolic and end-diastolic volume (ESV, EDV) were determined using a quantitative gated SPECT (QGS) program. Three months after myocardial infarction, all patients underwent cardiac catheterization examination with coronary endothelial function testing. Bradykinin (BK) (0.2, 0.6, 2.0 μg/min) was administered via the left coronary artery in a stepwise manner. Coronary blood flow was evaluated by Doppler flow velocity measurement. Patients were divided into two groups by BK-response: a preserved endothelial function group (n=10) and endothelial dysfunction group (n=10). At baseline, both global function and LV systolic and diastolic volumes were similar in both groups. However, LV ejection fraction was significantly improved in the preserved-endothelial function group, compared with that in the endothelial dysfunction group (42±10% to 48±9%, versus 41±4% to 42±13%, p<0.05). LV volumes progressively increased in the endothelial dysfunction group compared to the preserved-endothelial function group (123±45 ml to 128±43 ml, versus 111±47 ml to 109±49 ml, p<0.05). In re-perfused acute myocardial infarction, endothelial function within the risk area plays an important role with left ventricular remodeling after myocardial infarction. (author)

  11. Effects of electrocardiogram gating on CT pulmonary angiography image quality

    International Nuclear Information System (INIS)

    Ardley, Nicholas D.; Lau, Ken K.; Troupis, John M.; Buchan, Kevin; Paul, Eldho

    2014-01-01

    Pulmonary embolism (PE) is the third most common cause of death from cardiovascular disease. Computed-tomographic pulmonary angiography (CTPA) is an accurate and safe test for diagnosing PE. The aim of this retrospective analysis was to evaluate the effects on image quality (IQ) of electrocardiogram (ECG) gating during CTPA. Fifty consecutive patients presenting for CTPA were included in the study. A single acquisition was performed, resulting in two reconstructions: one at 75% of the R–R interval and the other without ECG influence. IQ evaluation was undertaken by two radiologists, focusing on respiratory and cardiac motion, image noise, low-contrast resolution, vessel and lung clarity, contrast media opacification and artefacts. Various regions of the lungs and vasculature were evaluated, and IQ scores were statistically compared. For the ECG-tagged reconstructions, IQ was noted to be better overall with regard to vessel clarity (P<0.05) and cardiac motion (P<0.05), while lung clarity was better only in the left lower zone (P<0.05). IQ was better with regard to image noise (P<0.05) and low-contrast resolution (P<0.05) in the non-ECG-tagged reconstructions. No statistical IQ difference between the two types of reconstruction was noted with regard to respiratory motion, contrast media opacification or presence of artefacts. The two types of reconstruction provide complementary information for evaluating CTPA results.

  12. Clinical application of 16-slice spiral CT in reconstruction imaging of coronary artery for diagnosing coronary disense

    International Nuclear Information System (INIS)

    Mao Xinbo; Zhu Xinjin; Zeng Huiliang; Chen Xueguang

    2005-01-01

    Objective: An evaluation of the reconstructed imaging of coronary arteries with 16-slice spiral CT in diagnosis of coronary disease. Methods: The reconstructed images of coronary arteries obtained on a 16-slice spiral CT scanner were reviewed in 60 cases, on which the following techniques were applied: retrospective ECG-gating, Segment method with 75% R-R interval, volume rendering technique (VRT), maximum intensity projection (MIP), mulfiplanar reconstruction (MPR), curved planar reconstruction (CPR) and CT virtual endoscopy (CTVE). Results: In all 60 cases, different stages of CHD were revealed in 21 cases; none abnormality was found in 33; and images were in poor quality in 2 cases, which was available for diagnosis. There were 4 stents planted in 4 cases: soft plaque suspected in lcase, patent in 2 and occlude in 1. Conclusion: The reconstructed imaging of coronary arteries with 16-slice spiral CT is superior modality in evaluation of severe coronary stenosis, plaques, and the pantency of the intra-luminal stents, which is an efficient and non-invasive imaging in diagnosis of early-stage CHD and screening in high risk population. (authors)

  13. Retrospective

    Science.gov (United States)

    Brooks, David A.

    Charting a course toward an uncertain future is always a risky business, especially among shoals of fiscal restraint or national tragedy, and the prudent navigator is well advised to remember where he's been as he looks ahead. The ocean and space sciences are poised for grand joint adventures, but shrinking budgets and the lingering Challenger numbness are restrictive lee shores that must be considered when laying plans. To sharpen the focus on future choices, it may be helpful to glance in the geophysical rearview mirror and remember some of the challenges and opportunities of a different era.A quarter century is a long time, but many images from 25 years ago can still be recalled in crisp detail, like photographs in a scrapbook. In 1961, results from the International Geophysical Year (IGY) filled the pages of the Transactions of the American Geophysical Union, and the U.S. program of space exploration finally was underway with conviction. The Indian Ocean Expedition, conceived during the IGY, ushered in a new era of international oceanography. The TIROS III satellite beamed to earth fuzzy pictures of tropical storms and revealed the intricate writhings of the Gulf Stream. Forecasters and fluid dynamicists suddenly saw new horizons, and geophysical turbulence became a major topic at the IUGG Symposium in Marseilles, France. Papers with prescient themes were presented at the AGU Ocean Section meeting: June Pattullo (then at Oregon State College, Corvallis) on heat storage in the Pacific; Ferris Webster (then at Woods Hole Oceanographic Institution, Woods Hole, Mass.) on Gulf Stream meanders. Polar oceanography was well represented in AGU journals: Kenneth Hunkins (at what was then called the Lamont Geological Observatory, Palisades, N.Y.) described the Alpha Rise, discovered from a drifting Arctic ice island, and Edward Thiel (then at the University of Minnesota, Minneapolis) and his co-workers discussed open ocean tides, gravimetrically measured from Antarctic

  14. Validity of computational hemodynamics in human arteries based on 3D time-of-flight MR angiography and 2D electrocardiogram gated phase contrast images

    Science.gov (United States)

    Yu, Huidan (Whitney); Chen, Xi; Chen, Rou; Wang, Zhiqiang; Lin, Chen; Kralik, Stephen; Zhao, Ye

    2015-11-01

    In this work, we demonstrate the validity of 4-D patient-specific computational hemodynamics (PSCH) based on 3-D time-of-flight (TOF) MR angiography (MRA) and 2-D electrocardiogram (ECG) gated phase contrast (PC) images. The mesoscale lattice Boltzmann method (LBM) is employed to segment morphological arterial geometry from TOF MRA, to extract velocity profiles from ECG PC images, and to simulate fluid dynamics on a unified GPU accelerated computational platform. Two healthy volunteers are recruited to participate in the study. For each volunteer, a 3-D high resolution TOF MRA image and 10 2-D ECG gated PC images are acquired to provide the morphological geometry and the time-varying flow velocity profiles for necessary inputs of the PSCH. Validation results will be presented through comparisons of LBM vs. 4D Flow Software for flow rates and LBM simulation vs. MRA measurement for blood flow velocity maps. Indiana University Health (IUH) Values Fund.

  15. MDCT evaluation of aortic root and aortic valve prior to TAVI. What is the optimal imaging time point in the cardiac cycle?

    Energy Technology Data Exchange (ETDEWEB)

    Jurencak, Tomas; Turek, Jakub; Nijssen, Estelle C. [Maastricht University Medical Center, Department of Radiology, P. Debyelaan 25, P.O. Box 5800, AZ, Maastricht (Netherlands); Kietselaer, Bastiaan L.J.H. [Maastricht University Medical Center, Department of Radiology, P. Debyelaan 25, P.O. Box 5800, AZ, Maastricht (Netherlands); Maastricht University Medical Center, CARIM School for Cardiovascular Diseases, Maastricht (Netherlands); Maastricht University Medical Center, Department of Cardiology, Maastricht (Netherlands); Mihl, Casper; Kok, Madeleine; Wildberger, Joachim E.; Das, Marco [Maastricht University Medical Center, Department of Radiology, P. Debyelaan 25, P.O. Box 5800, AZ, Maastricht (Netherlands); Maastricht University Medical Center, CARIM School for Cardiovascular Diseases, Maastricht (Netherlands); Ommen, Vincent G.V.A. van [Maastricht University Medical Center, Department of Cardiology, Maastricht (Netherlands); Garsse, Leen A.F.M. van [Maastricht University Medical Center, Department of Cardiothoracic Surgery, Maastricht (Netherlands)

    2015-07-15

    To determine the optimal imaging time point for transcatheter aortic valve implantation (TAVI) therapy planning by comprehensive evaluation of the aortic root. Multidetector-row CT (MDCT) examination with retrospective ECG gating was retrospectively performed in 64 consecutive patients referred for pre-TAVI assessment. Eighteen different parameters of the aortic root were evaluated at 11 different time points in the cardiac cycle. Time points at which maximal (or minimal) sizes were determined, and dimension differences to other time points were evaluated. Theoretical prosthesis sizing based on different measurements was compared. Largest dimensions were found between 10 and 20 % of the cardiac cycle for annular short diameter (10 %); mean diameter (10 %); effective diameter and circumference-derived diameter (20 %); distance from the annulus to right coronary artery ostium (10 %); aortic root at the left coronary artery level (20 %); aortic root at the widest portion of coronary sinuses (20 %); and right leaflet length (20 %). Prosthesis size selection differed depending on the chosen measurements in 25-75 % of cases. Significant changes in anatomical structures of the aortic root during the cardiac cycle are crucial for TAVI planning. Imaging in systole is mandatory to obtain maximal dimensions. (orig.)

  16. Retrospective study of renal images on whole bone scanning

    International Nuclear Information System (INIS)

    Yanagisawa, Munetoshi; Machida, Toyohei; Miki, Makoto; Ohishi, Yukihiko; Ueda, Masataka

    1978-01-01

    One hundred and twenty-seven cases were surveyed by sup(99m)Tc-pyrophosphate at Jikei hospital. Renal images on whole-bone scanning were observed in all cases; 75% of all renal images were normal and 25% were abnormal. Thirteen percent of these abnormal images were symmetric and 87% were asymmetric. Four of the symmetric renal images were bilaterally bad. Three of the four bilaterally bad renal images involved prostate carcinomas with general metastases and the last involved serious bilateral hydronephrosis. The reason for the high percentage of asymmetric renal images was that the materials involved many urogenital cases. Asymmetric renal images other than the urogenital cases, were recognised in 8% of all cases. This percentage is consistent with Hattner's report. Unilateral abnormal renal images involved 8 hydronephrosis cases, 2 unilateral nonfunctioning kidneys and one malrotation kidney. Among the hydronephrosis cases, serious cases gave low uptake and mild cases gave high uptake. The reason for this phenomenon was, presumably, that there were differences in renal uptake, renal excretion and renal pelvic accumulation. In nine cases, one kidney was not visualized on whole-bone scanning, 8 of them involved nephrectomy and the remainining one unilateral nonfunctioning kidney. Six cases presented locally abnormal renal images on whole-bone scanning, three of them suffered renal cell carcinomas and the rest renal solitary cyst. Eighty-eight percent of the abnormal renal images agreed with IVP findings. The renal images of whole-bone scanning faithfully reflected the original renal lesion. Two cases of renal carcinoma and renal solitary cyst recognized on whole-bone scanning are presented, to indicate the usefulness of renal images on whole-bone scanning. (auth.)

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

    International Nuclear Information System (INIS)

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

    2007-01-01

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

  18. Submillimeter (Lambda < 1 mm) Continuum Imaging at CSO: A Retrospective

    Science.gov (United States)

    Dowell, C. Darren

    2009-01-01

    This contribution is submitted on behalf of all students, postdocs, and staff inspired and supported by Tom Phillips to build an instrument and then wait for low precipitable water vapor. Over the 20 plus years of its existence, the Caltech Submillimeter Observatory (CSO) has seen a succession of ever more powerful detectors to measure continuum emission in the shortest submillimeter bands available from Mauna Kea. These instruments have been trained on the nearest solar systems, the most distant galaxies, and objects in between. I show several images collected over the 5 plus year history of the SHARC II camera and anecdotal comparison with past work.

  19. Analysis and clinical usefullness of cardiac ECT images

    International Nuclear Information System (INIS)

    Hayashi, Makoto; Kagawa, Masaaki; Yamada, Yukinori

    1983-01-01

    We estimated basically and clinically myocardial ECT image and ECG gated cardiac blood-pool ECT image. ROC curve is used for the evaluation of the accuracy in diagnostic myocardial infarction. The accuracy in diagnostic of MI is superior in myocardial ECT image and ECT estimation is unnecessary skillfulness and experience. We can absene the whole defect of MI than planar image by using ECT. LVEDV between estimated volume and contrast volume is according to it and get one step for automatic analysis of cardiac volume. (author)

  20. Influence of retrospective sorting on image quality in respiratory correlated computed tomography

    International Nuclear Information System (INIS)

    Guckenberger, Matthias; Weininger, Markus; Wilbert, Juergen; Richter, Anne; Baier, Kurt; Krieger, Thomas; Polat, Buelent; Flentje, Michael

    2007-01-01

    Purpose: To evaluate the influence of retrospective sorting on image quality in four-dimensional respiratory correlated CT. Materials and methods: Twelve patients with intrapulmonary tumors were examined using a 24-slice CT-scanner in helical mode. Images were reconstructed after retrospective sorting based on five algorithms: amplitude-based sorting with definition of peak-exhalation and peak-inhalation separately/locally for all breathing cycles (LAS) and globally for the time of image acquisition (GAS). Drifts of the breathing signal were corrected in dc-GAS. In phase-based (PS) and cycle-based (CS) algorithm the projections were sorted relative to time. Motion artifacts were scored by a radiologist. The tumor volumes were measured using automatic image segmentation. Results: Averaged over all breathing phases, LAS and PS achieved significantly improved image quality and lowest tumor volume variability compared to GAS, dc-GAS and CS. Imaging redundancy of 5 s was not sufficient for GAS and dc-GAS: missing corresponding amplitude positions in one or several breathing cycles resulted in incomplete reconstruction of peak-ventilation images in 11/12 and 10/12 patients with GAS and dc-GAS, respectively. Limiting the analysis to mid-ventilation phases showed GAS and dc-GAS as the most reliable algorithms. Conclusions: LAS and PS are suggested as a compromise between image quality and radiation dose

  1. Time-resolved computed tomography of the liver: retrospective, multi-phase image reconstruction derived from volumetric perfusion imaging

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, Michael A.; Kartalis, Nikolaos; Aspelin, Peter; Albiin, Nils; Brismar, Torkel B. [Karolinska University Hospital, Division of Medical Imaging and Technology, Department of Clinical Science, Intervention and Technology (CLINTEC), Karolinska Institutet, Stockholm (Sweden); Leidner, Bertil; Svensson, Anders [Karolinska University Hospital, Division of Medical Imaging and Technology, Department of Clinical Science, Intervention and Technology (CLINTEC), Karolinska Institutet, Stockholm (Sweden); Karolinska University Hospital Huddinge, Department of Radiology, Stockholm (Sweden)

    2014-01-15

    To assess feasibility and image quality (IQ) of a new post-processing algorithm for retrospective extraction of an optimised multi-phase CT (time-resolved CT) of the liver from volumetric perfusion imaging. Sixteen patients underwent clinically indicated perfusion CT using 4D spiral mode of dual-source 128-slice CT. Three image sets were reconstructed: motion-corrected and noise-reduced (MCNR) images derived from 4D raw data; maximum and average intensity projections (time MIP/AVG) of the arterial/portal/portal-venous phases and all phases (total MIP/ AVG) derived from retrospective fusion of dedicated MCNR split series. Two readers assessed the IQ, detection rate and evaluation time; one reader assessed image noise and lesion-to-liver contrast. Time-resolved CT was feasible in all patients. Each post-processing step yielded a significant reduction of image noise and evaluation time, maintaining lesion-to-liver contrast. Time MIPs/AVGs showed the highest overall IQ without relevant motion artefacts and best depiction of arterial and portal/portal-venous phases respectively. Time MIPs demonstrated a significantly higher detection rate for arterialised liver lesions than total MIPs/AVGs and the raw data series. Time-resolved CT allows data from volumetric perfusion imaging to be condensed into an optimised multi-phase liver CT, yielding a superior IQ and higher detection rate for arterialised liver lesions than the raw data series. (orig.)

  2. Magnetic resonance imaging of the heart and great vessels

    International Nuclear Information System (INIS)

    Naitoh, Hiroaki; Nishimura, Tsunehiko; Takamiya, Makoto; Kozuka, Takahiro.

    1985-01-01

    About sixty subjects with normal heart or various cardiovascular diseases were examined with 0.35 or 1.5 T superconductive magnetic resonance imaging (MRI) system, and ECG-gated spin-echo multislice technique was used to evaluate cardiovascular anatomy. MRI accurately demonstrated ventricular wall thinning caused by myocardial infarction and asymmetric ventricular hypertrophy owing to cardiomyopathy. Rheumatic valvular thickening, congenital cardiac malformations, aortic aneurysm and dissection were also clearly demonstrated by gated MRI without the use of any contrast media. MRI was shown to be an excellent non-invasive imaging modality for evaluation of pathoanatomy of the heart and great vessels. (author)

  3. MR imaging of silicone breast implants: evaluation of prospective and retrospective interpretations and interobserver agreement.

    Science.gov (United States)

    Quinn, S F; Neubauer, N M; Sheley, R C; Demlow, T A; Szumowski, J

    1996-01-01

    MR imaging was used to evaluate the integrity of silicone breast implants in 54 women with 108 implants. MR images were interpreted by relatively inexperienced readers who tried to reproduce the experiences reported in the literature. The study examines the interobserver agreement using different diagnostic signs and the influence of experience on interpretation errors. Prospective and retrospective interpretations were compared with surgical findings at the time of explanation. Diagnostic indicators, including the linguine sign, the inverted tear drop sign, the C sign, water droplets mixed with silicone, and extracapsular globules of silicone, were evaluated for diagnostic efficacy and interobserver agreement. The prospective sensitivity and specificity were 87% and 78%, respectively. With the retrospective interpretations, the sensitivity and specificity increased to 93% and 92%, respectively. Most of the prospective false-positive interpretations were due to misinterpreting radial folds as signs of implant rupture. Six implants interpreted retrospectively as false positives had gross amounts of silicone around the implants at surgery but there were no obvious rents in the implant shells. There was fair to excellent interobserver agreement with the individual diagnostic signs except for extracapsular globules of silicone. All of the signs had specificities of greater than 90%. The sensitivities of the individual signs were less than the overall retrospective sensitivity. With experience, the sensitivity improved from 87% to 93% and the specificity improved from 78% to 92%. This study helps substantiate the use of diagnostic signs used by other authors to detect silicone loss from breast implants by MR imaging; however, questions remain as to the clinical role of MR imaging in evaluating implants for silicone loss.

  4. High-Definition Computed Tomography for Coronary Artery Stent Imaging: a Phantom Study

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Wen Jie; Chen, Ke Min; Pang, Li Fang; Zhang, Huang; Pan, Zi Lai [Rui Jin Hospital, Medical School, Shanghai Jiao Tong University, Shangha (China); Guo, Ying; Li, Jian Ying [Beijing Economic and Technology Development Area, Beijing (China)

    2012-01-15

    To assess the performance of a high-definition CT (HDCT) for imaging small caliber coronary stents ({<=} 3 mm) by comparing different scan modes of a conventional 64-row standard-definition CT (SDCT). A cardiac phantom with twelve stents (2.5 mm and 3.0 mm in diameter) was scanned by HDCT and SDCT. The scan modes were retrospective electrocardiography (ECG)-gated helical and prospective ECG-triggered axial with tube voltages of 120 kVp and 100 kVp, respectively. The inner stent diameters (ISD) and the in-stent attenuation value (AVin-stent) and the in-vessel extra-stent attenuation value (AVin-vessel) were measured by two observers. The artificial lumen narrowing (ALN = [ISD - ISDmeasured]/ISD) and artificial attenuation increase between in-stent and in-vessel (AAI = AVin-stent - AVin-vessel) were calculated. All data was analyzed by intraclass correlation and ANOVA-test. The correlation coefficient of ISD, AVin-vessel and AVin-stent between the two observers was good. The ALNs of HDCT were statistically lower than that of SDCT (30 {+-} 5.7% versus 35 {+-} 5.4%, p < 0.05). HDCT had statistically lower AAI values than SDCT (15.7 {+-} 81.4 HU versus 71.4 {+-} 90.5 HU, p < 0.05). The prospective axial dataset demonstrated smaller ALN than the retrospective helical dataset on both HDCT and SDCT (p < 0.05). Additionally, there were no differences in ALN between the 120 kVp and 100 kVp tube voltages on HDCT (p = 0.05). High-definition CT helps improve measurement accuracy for imaging coronary stents compared to SDCT. HDCT with 100 kVp and the prospective ECG-triggered axial technique, with a lower radiation dose than 120 kVp application, may be advantageous in evaluating coronary stents with smaller calibers ({<=} 3 mm).

  5. CT angiography for planning transcatheter aortic valve replacement using automated tube voltage selection: Image quality and radiation exposure

    Energy Technology Data Exchange (ETDEWEB)

    Mangold, Stefanie [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Diagnostic and Interventional Radiology, Eberhard-Karls University Tuebingen, Tuebingen (Germany); De Cecco, Carlo N. [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Schoepf, U. Joseph, E-mail: schoepf@musc.edu [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Division of Cardiology, Department of Medicine, Medical University of South Carolina, Charleston, SC (United States); Kuhlman, Taylor S.; Varga-Szemes, Akos [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Caruso, Damiano [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Radiological Sciences, Oncology and Pathology, University of Rome “Sapienza”, Rome (Italy); Duguay, Taylor M. [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Tesche, Christian [Department of Cardiology, Heart Centre Munich-Bogenhausen, Munich (Germany); Vogl, Thomas J. [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Frankfurt (Germany); Nikolaou, Konstantin [Department of Diagnostic and Interventional Radiology, Eberhard-Karls University Tuebingen, Tuebingen (Germany); and others

    2017-01-15

    Highlights: • TAVR-planning CT was performed with automated tube voltage selection. • Automated tube voltage selection enables individual tube voltage adaptation. • Image quality was diagnostic while radiation exposure was significantly decreased. - Abstract: Purpose: To assess image quality and accuracy of CT angiography (CTA) for transcatheter aortic valve replacement (TAVR) planning performed with 3rd generation dual-source CT (DSCT). Material and methods: We evaluated 125 patients who underwent TAVR-planning CTA on 3rd generation DSCT. A two-part protocol was performed including retrospectively ECG-gated coronary CTA (CCTA) and prospectively ECG-triggered aortoiliac CTA using 60 mL of contrast medium. Automated tube voltage selection and advanced iterative reconstruction were applied. Effective dose (ED), signal-to-noise (SNR) and contrast-to-noise ratios (CNR) were calculated. Five-point scales were used for subjective image quality analysis. In patients who underwent TAVR, sizing parameters were obtained. Results: Image quality was rated good to excellent in 97.6% of CCTA and 100% of aortoiliac CTAs. CTA studies at >100 kV showed decreased objective image quality compared to 70–100 kV (SNR, all p ≤ 0.0459; CNR, all p ≤ 0.0462). Mean ED increased continuously from 70 to >100 kV (CCTA: 4.5 ± 1.7 mSv–13.6 ± 2.9 mSv, all p ≤ 0.0233; aortoiliac CTA: 2.4 ± 0.9 mSv–6.8 ± 2.7 mSv, all p ≤ 0.0414). In 39 patients TAVR was performed and annulus diameter was within the recommended range in all patients. No severe cardiac or vascular complications were noted. Conclusion: 3rd generation DSCT provides diagnostic image quality in TAVR-planning CTA and facilitates reliable assessment of TAVR device and delivery option while reducing radiation dose.

  6. CT angiography for planning transcatheter aortic valve replacement using automated tube voltage selection: Image quality and radiation exposure

    International Nuclear Information System (INIS)

    Mangold, Stefanie; De Cecco, Carlo N.; Schoepf, U. Joseph; Kuhlman, Taylor S.; Varga-Szemes, Akos; Caruso, Damiano; Duguay, Taylor M.; Tesche, Christian; Vogl, Thomas J.; Nikolaou, Konstantin

    2017-01-01

    Highlights: • TAVR-planning CT was performed with automated tube voltage selection. • Automated tube voltage selection enables individual tube voltage adaptation. • Image quality was diagnostic while radiation exposure was significantly decreased. - Abstract: Purpose: To assess image quality and accuracy of CT angiography (CTA) for transcatheter aortic valve replacement (TAVR) planning performed with 3rd generation dual-source CT (DSCT). Material and methods: We evaluated 125 patients who underwent TAVR-planning CTA on 3rd generation DSCT. A two-part protocol was performed including retrospectively ECG-gated coronary CTA (CCTA) and prospectively ECG-triggered aortoiliac CTA using 60 mL of contrast medium. Automated tube voltage selection and advanced iterative reconstruction were applied. Effective dose (ED), signal-to-noise (SNR) and contrast-to-noise ratios (CNR) were calculated. Five-point scales were used for subjective image quality analysis. In patients who underwent TAVR, sizing parameters were obtained. Results: Image quality was rated good to excellent in 97.6% of CCTA and 100% of aortoiliac CTAs. CTA studies at >100 kV showed decreased objective image quality compared to 70–100 kV (SNR, all p ≤ 0.0459; CNR, all p ≤ 0.0462). Mean ED increased continuously from 70 to >100 kV (CCTA: 4.5 ± 1.7 mSv–13.6 ± 2.9 mSv, all p ≤ 0.0233; aortoiliac CTA: 2.4 ± 0.9 mSv–6.8 ± 2.7 mSv, all p ≤ 0.0414). In 39 patients TAVR was performed and annulus diameter was within the recommended range in all patients. No severe cardiac or vascular complications were noted. Conclusion: 3rd generation DSCT provides diagnostic image quality in TAVR-planning CTA and facilitates reliable assessment of TAVR device and delivery option while reducing radiation dose.

  7. The content of social media's shared images about Ebola: a retrospective study.

    Science.gov (United States)

    Seltzer, E K; Jean, N S; Kramer-Golinkoff, E; Asch, D A; Merchant, R M

    2015-09-01

    Social media have strongly influenced awareness and perceptions of public health emergencies, but a considerable amount of social media content is now carried through images, rather than just text. This study's objective is to explore how image-sharing platforms are used for information dissemination in public health emergencies. Retrospective review of images posted on two popular image-sharing platforms to characterize public discourse about Ebola. Using the keyword '#ebola' we identified a 1% sample of images posted on Instagram and Flickr across two sequential weeks in November 2014. Images from both platforms were independently coded by two reviewers and characterized by themes. We reviewed 1217 images posted on Instagram and Flickr and identified themes. Nine distinct themes were identified. These included: images of health care workers and professionals [308 (25%)], West Africa [75 (6%)], the Ebola virus [59 (5%)], and artistic renderings of Ebola [64 (5%)]. Also identified were images with accompanying embedded text related to Ebola and associated: facts [68 (6%)], fears [40 (3%)], politics [46 (4%)], and jokes [284 (23%)]. Several [273 (22%)] images were unrelated to Ebola or its sequelae. Instagram images were primarily coded as jokes [255 (42%)] or unrelated [219 (36%)], while Flickr images primarily depicted health care workers and other professionals [281 (46%)] providing care or other services for prevention or treatment. Image sharing platforms are being used for information exchange about public health crises, like Ebola. Use differs by platform and discerning these differences can help inform future uses for health care professionals and researchers seeking to assess public fears and misinformation or provide targeted education/awareness interventions. Copyright © 2015 The Royal Institute of Public Health. All rights reserved.

  8. Estimation of radiation exposure of retrospective gated and prospective triggered 128-slice triple-rule-out CT angiography

    International Nuclear Information System (INIS)

    Ketelsen, Dominik; Fenchel, Michael; Thomas, Christoph; Boehringer, Nadine; Tsiflikas, Ilias; Kaempf, Michael; Claussen, Claus D; Heuschmid, Martin; Buchgeister, Markus

    2011-01-01

    Background: CT has become an important role in the differential diagnosis of acute chest pain to exclude an aortic dissection, pulmonary embolism and acute coronary artery syndrome. However, the additional radiation exposure is a cause of concern and dose saving strategies should be applied, if possible. Purpose: To estimate effective dose of retrospective gated and prospective ECG-triggered triple-rule-out computed tomography angiography (TRO-CTA). Material and Methods: An Alderson-Rando-phantom equipped with thermoluminescent dosimeters was used for dose measurements. Exposure was performed on a 128-slice single source scanner. The following scan parameters were used (retrospective ECG-gated): 120 kV, 190 mAs/rot., collimation 128x0.6 mm, rotation time 0.3 s. Protocols with a simulated heart rate (HR) of 60 and 100 bpm were performed using the standard ECG-pulsing as well as MinDose. Additionally, a prospective triggered TRO-CTA was acquired (HR 60 bpm). Results: The estimated effective dose of retrospective ECG-gated TRO-CTA ranged from 7.4-13.4 mSv and from 10.1-17.5 mSv for men and women, respectively. Due to radiosensitive breast tissue, women received a significant increased effective dose of up to 64.7% ± 0.03% (p = 0.028) compared to men. MinDose reduces radiation exposure of up to 33.0% ± 6.5% in comparison to standard ECG-pulsing (p < 0.001). The effective dose increased significantly with lower heart rates (p < 0.001). Prospective ECG-triggered TRO-CTA showed an effective dose of 5.9 mSv and 8.2 mSv for men and women, respectively. Compared to retrospective ECG-gated TRO-CTA a significant dose reduction was observed (p < 0.001). Conclusion: Due to the significant different dose exposure, scan protocols should be specifically adapted in a patient- and problem-oriented manner

  9. Estimation of radiation exposure of retrospective gated and prospective triggered 128-slice triple-rule-out CT angiography

    Energy Technology Data Exchange (ETDEWEB)

    Ketelsen, Dominik; Fenchel, Michael; Thomas, Christoph; Boehringer, Nadine; Tsiflikas, Ilias; Kaempf, Michael; Claussen, Claus D; Heuschmid, Martin (Dept. of Diagnostic and Interventional Radiology, Univ. Hospital Tuebingen, Tuebingen (Germany)), email: dominik.ketelsen@med.uni-tuebingen.de; Buchgeister, Markus (Depts. of Radiotherapy and Radiooncology, Univ. Hospital Tuebingen, Tuebingen (Germany))

    2011-09-15

    Background: CT has become an important role in the differential diagnosis of acute chest pain to exclude an aortic dissection, pulmonary embolism and acute coronary artery syndrome. However, the additional radiation exposure is a cause of concern and dose saving strategies should be applied, if possible. Purpose: To estimate effective dose of retrospective gated and prospective ECG-triggered triple-rule-out computed tomography angiography (TRO-CTA). Material and Methods: An Alderson-Rando-phantom equipped with thermoluminescent dosimeters was used for dose measurements. Exposure was performed on a 128-slice single source scanner. The following scan parameters were used (retrospective ECG-gated): 120 kV, 190 mAs/rot., collimation 128x0.6 mm, rotation time 0.3 s. Protocols with a simulated heart rate (HR) of 60 and 100 bpm were performed using the standard ECG-pulsing as well as MinDose. Additionally, a prospective triggered TRO-CTA was acquired (HR 60 bpm). Results: The estimated effective dose of retrospective ECG-gated TRO-CTA ranged from 7.4-13.4 mSv and from 10.1-17.5 mSv for men and women, respectively. Due to radiosensitive breast tissue, women received a significant increased effective dose of up to 64.7% +- 0.03% (p = 0.028) compared to men. MinDose reduces radiation exposure of up to 33.0% +- 6.5% in comparison to standard ECG-pulsing (p < 0.001). The effective dose increased significantly with lower heart rates (p < 0.001). Prospective ECG-triggered TRO-CTA showed an effective dose of 5.9 mSv and 8.2 mSv for men and women, respectively. Compared to retrospective ECG-gated TRO-CTA a significant dose reduction was observed (p < 0.001). Conclusion: Due to the significant different dose exposure, scan protocols should be specifically adapted in a patient- and problem-oriented manner

  10. Segmentation-based retrospective shading correction in fluorescence microscopy E. coli images for quantitative analysis

    Science.gov (United States)

    Mai, Fei; Chang, Chunqi; Liu, Wenqing; Xu, Weichao; Hung, Yeung S.

    2009-10-01

    Due to the inherent imperfections in the imaging process, fluorescence microscopy images often suffer from spurious intensity variations, which is usually referred to as intensity inhomogeneity, intensity non uniformity, shading or bias field. In this paper, a retrospective shading correction method for fluorescence microscopy Escherichia coli (E. Coli) images is proposed based on segmentation result. Segmentation and shading correction are coupled together, so we iteratively correct the shading effects based on segmentation result and refine the segmentation by segmenting the image after shading correction. A fluorescence microscopy E. Coli image can be segmented (based on its intensity value) into two classes: the background and the cells, where the intensity variation within each class is close to zero if there is no shading. Therefore, we make use of this characteristics to correct the shading in each iteration. Shading is mathematically modeled as a multiplicative component and an additive noise component. The additive component is removed by a denoising process, and the multiplicative component is estimated using a fast algorithm to minimize the intra-class intensity variation. We tested our method on synthetic images and real fluorescence E.coli images. It works well not only for visual inspection, but also for numerical evaluation. Our proposed method should be useful for further quantitative analysis especially for protein expression value comparison.

  11. Retrospective correction of bias in diffusion tensor imaging arising from coil combination mode.

    Science.gov (United States)

    Sakaie, Ken; Lowe, Mark

    2017-04-01

    To quantify and retrospectively correct for systematic differences in diffusion tensor imaging (DTI) measurements due to differences in coil combination mode. Multi-channel coils are now standard among MRI systems. There are several options for combining signal from multiple coils during image reconstruction, including sum-of-squares (SOS) and adaptive combine (AC). This contribution examines the bias between SOS- and AC-derived measures of tissue microstructure and a strategy for limiting that bias. Five healthy subjects were scanned under an institutional review board-approved protocol. Each set of raw image data was reconstructed twice-once with SOS and once with AC. The diffusion tensor was calculated from SOS- and AC-derived data by two algorithms-standard log-linear least squares and an approach that accounts for the impact of coil combination on signal statistics. Systematic differences between SOS and AC in terms of tissue microstructure (axial diffusivity, radial diffusivity, mean diffusivity and fractional anisotropy) were evaluated on a voxel-by-voxel basis. SOS-based tissue microstructure values are systematically lower than AC-based measures throughout the brain in each subject when using the standard tensor calculation method. The difference between SOS and AC can be virtually eliminated by taking into account the signal statistics associated with coil combination. The impact of coil combination mode on diffusion tensor-based measures of tissue microstructure is statistically significant but can be corrected retrospectively. The ability to do so is expected to facilitate pooling of data among imaging protocols. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Diagnostic value of imaging in infective endocarditis: a systematic review.

    Science.gov (United States)

    Gomes, Anna; Glaudemans, Andor W J M; Touw, Daan J; van Melle, Joost P; Willems, Tineke P; Maass, Alexander H; Natour, Ehsan; Prakken, Niek H J; Borra, Ronald J H; van Geel, Peter Paul; Slart, Riemer H J A; van Assen, Sander; Sinha, Bhanu

    2017-01-01

    Sensitivity and specificity of the modified Duke criteria for native valve endocarditis are both suboptimal, at approximately 80%. Diagnostic accuracy for intracardiac prosthetic material-related infection is even lower. Non-invasive imaging modalities could potentially improve diagnosis of infective endocarditis; however, their diagnostic value is unclear. We did a systematic literature review to critically appraise the evidence for the diagnostic performance of these imaging modalities, according to PRISMA and GRADE criteria. We searched PubMed, Embase, and Cochrane databases. 31 studies were included that presented original data on the performance of electrocardiogram (ECG)-gated multidetector CT angiography (MDCTA), ECG-gated MRI, 18 F-fluorodeoxyglucose ( 18 F-FDG) PET/CT, and leucocyte scintigraphy in diagnosis of native valve endocarditis, intracardiac prosthetic material-related infection, and extracardiac foci in adults. We consistently found positive albeit weak evidence for the diagnostic benefit of 18 F-FDG PET/CT and MDCTA. We conclude that additional imaging techniques should be considered if infective endocarditis is suspected. We propose an evidence-based diagnostic work-up for infective endocarditis including these non-invasive techniques. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Four dimensional magnetic resonance imaging with retrospective k-space reordering: A feasibility study

    International Nuclear Information System (INIS)

    Liu, Yilin; Yin, Fang-Fang; Cai, Jing; Chen, Nan-kuei; Chu, Mei-Lan

    2015-01-01

    Purpose: Current four dimensional magnetic resonance imaging (4D-MRI) techniques lack sufficient temporal/spatial resolution and consistent tumor contrast. To overcome these limitations, this study presents the development and initial evaluation of a new strategy for 4D-MRI which is based on retrospective k-space reordering. Methods: We simulated a k-space reordered 4D-MRI on a 4D digital extended cardiac-torso (XCAT) human phantom. A 2D echo planar imaging MRI sequence [frame rate (F) = 0.448 Hz; image resolution (R) = 256 × 256; number of k-space segments (N KS ) = 4] with sequential image acquisition mode was assumed for the simulation. Image quality of the simulated “4D-MRI” acquired from the XCAT phantom was qualitatively evaluated, and tumor motion trajectories were compared to input signals. In particular, mean absolute amplitude differences (D) and cross correlation coefficients (CC) were calculated. Furthermore, to evaluate the data sufficient condition for the new 4D-MRI technique, a comprehensive simulation study was performed using 30 cancer patients’ respiratory profiles to study the relationships between data completeness (C p ) and a number of impacting factors: the number of repeated scans (N R ), number of slices (N S ), number of respiratory phase bins (N P ), N KS , F, R, and initial respiratory phase at image acquisition (P 0 ). As a proof-of-concept, we implemented the proposed k-space reordering 4D-MRI technique on a T2-weighted fast spin echo MR sequence and tested it on a healthy volunteer. Results: The simulated 4D-MRI acquired from the XCAT phantom matched closely to the original XCAT images. Tumor motion trajectories measured from the simulated 4D-MRI matched well with input signals (D = 0.83 and 0.83 mm, and CC = 0.998 and 0.992 in superior–inferior and anterior–posterior directions, respectively). The relationship between C p and N R was found best represented by an exponential function (C P =100(1−e −0.18N R ), when N S

  14. Image-guided Ommaya reservoir insertion for intraventricular chemotherapy: a retrospective series.

    Science.gov (United States)

    Lau, Jonathan C; Kosteniuk, Suzanne E; Macdonald, David R; Megyesi, Joseph F

    2018-03-01

    Ayub Ommaya proposed a surgical technique for subcutaneous reservoir and pump placement in 1963 to allow access to intraventricular cerebrospinal fluid (CSF). Currently, the most common indication for Ommaya reservoir insertion (ORI) in adults is for patients with hematologic or leptomeningeal disorders requiring repeated injection of chemotherapy into the CSF space. Historically, the intraventricular catheter has been inserted blindly based on anatomical landmarks. The purpose of this study was to examine short-term complication rates with ORI with image guidance (IG) and without image guidance (non-IG). We retrospectively evaluated all operative cases of ORI from 2000 to 2014 by the senior author. Patient demographic data, surgical outcomes, and peri-operative complications were collected. Accurate placement and early (30-day) morbidity or mortality were considered primary outcomes. Fifty-five consecutive patients underwent ORI by the senior author over the study period (43.5 ± 16.6 years; 40.0% female). Indications for placement included acute lymphoblastic leukemia, diffuse large B-cell lymphoma, and leptomeningeal carcinomatosis. There were seven (12.7%) total complications: three (37.5%) with no-IG versus four (8.5%) with IG. Catheter malpositions were significantly higher in the non-IG group at 37.5% compared to 2.1%. Catheters were also more likely to require multiple passes with non-IG at 25% compare to 0% with IG. There were no early infections in either group. We demonstrate improved accuracy and decreased complications using an image-guided approach compared with a traditional approach. Our results support routine use of intra-operative image guidance for proximal catheter insertion in elective ORI for intraventricular chemotherapy.

  15. Does improved access to diagnostic imaging results reduce hospital length of stay? A retrospective study

    Directory of Open Access Journals (Sweden)

    Hurlen Petter

    2010-09-01

    Full Text Available Abstract Background One year after the introduction of Information and Communication Technology (ICT to support diagnostic imaging at our hospital, clinicians had faster and better access to radiology reports and images; direct access to Computed Tomography (CT reports in the Electronic Medical Record (EMR was particularly popular. The objective of this study was to determine whether improvements in radiology reporting and clinical access to diagnostic imaging information one year after the ICT introduction were associated with a reduction in the length of patients' hospital stays (LOS. Methods Data describing hospital stays and diagnostic imaging were collected retrospectively from the EMR during periods of equal duration before and one year after the introduction of ICT. The post-ICT period was chosen because of the documented improvement in clinical access to radiology results during that period. The data set was randomly split into an exploratory part used to establish the hypotheses, and a confirmatory part. The data was used to compare the pre-ICT and post-ICT status, but also to compare differences between groups. Results There was no general reduction in LOS one year after ICT introduction. However, there was a 25% reduction for one group - patients with CT scans. This group was heterogeneous, covering 445 different primary discharge diagnoses. Analyses of subgroups were performed to reduce the impact of this divergence. Conclusion Our results did not indicate that improved access to radiology results reduced the patients' LOS. There was, however, a significant reduction in LOS for patients undergoing CT scans. Given the clinicians' interest in CT reports and the results of the subgroup analyses, it is likely that improved access to CT reports contributed to this reduction.

  16. Combined prospective and retrospective correction to reduce motion-induced image misalignment and geometric distortions in EPI.

    Science.gov (United States)

    Ooi, Melvyn B; Muraskin, Jordan; Zou, Xiaowei; Thomas, William J; Krueger, Sascha; Aksoy, Murat; Bammer, Roland; Brown, Truman R

    2013-03-01

    Despite rigid-body realignment to compensate for head motion during an echo-planar imaging time-series scan, nonrigid image deformations remain due to changes in the effective shim within the brain as the head moves through the B(0) field. The current work presents a combined prospective/retrospective solution to reduce both rigid and nonrigid components of this motion-related image misalignment. Prospective rigid-body correction, where the scan-plane orientation is dynamically updated to track with the subject's head, is performed using an active marker setup. Retrospective distortion correction is then applied to unwarp the remaining nonrigid image deformations caused by motion-induced field changes. Distortion correction relative to a reference time-frame does not require any additional field mapping scans or models, but rather uses the phase information from the echo-planar imaging time-series itself. This combined method is applied to compensate echo-planar imaging scans of volunteers performing in-plane and through-plane head motions, resulting in increased image stability beyond what either prospective or retrospective rigid-body correction alone can achieve. The combined method is also assessed in a blood oxygen level dependent functional MRI task, resulting in improved Z-score statistics. Copyright © 2012 Wiley Periodicals, Inc.

  17. Evaluation of three methods for retrospective correction of vignetting on medical microscopy images utilizing two open source software tools.

    Science.gov (United States)

    Babaloukas, Georgios; Tentolouris, Nicholas; Liatis, Stavros; Sklavounou, Alexandra; Perrea, Despoina

    2011-12-01

    Correction of vignetting on images obtained by a digital camera mounted on a microscope is essential before applying image analysis. The aim of this study is to evaluate three methods for retrospective correction of vignetting on medical microscopy images and compare them with a prospective correction method. One digital image from four different tissues was used and a vignetting effect was applied on each of these images. The resulted vignetted image was replicated four times and in each replica a different method for vignetting correction was applied with fiji and gimp software tools. The highest peak signal-to-noise ratio from the comparison of each method to the original image was obtained from the prospective method in all tissues. The morphological filtering method provided the highest peak signal-to-noise ratio value amongst the retrospective methods. The prospective method is suggested as the method of choice for correction of vignetting and if it is not applicable, then the morphological filtering may be suggested as the retrospective alternative method. © 2011 The Authors Journal of Microscopy © 2011 Royal Microscopical Society.

  18. The data recording and processing programs of the MB-9101 data processing and image representing system for special cardiologic examinations

    International Nuclear Information System (INIS)

    Billing, A.; Csernay, L.

    1982-01-01

    At present one of the most important areas of isotopic medical diagnostics is the heart. Using a scintillation gamma camera with computer aided data processing the modelling of a heart cycle from several hundred cycles through ECG gating becomes possible. The series of images produced in this way show the movement of the heart wall like a film. Thus the location and extent of the infarction can be determined. The equipment has been developed by Gamma Works, the program system has been prepared in the Isotope Laboratory of the Szeged Medical University. (author)

  19. Retrospective comparison of three-dimensional imaging sequences in the visualization of posterior fossa cranial nerves.

    Science.gov (United States)

    Ors, Suna; Inci, Ercan; Turkay, Rustu; Kokurcan, Atilla; Hocaoglu, Elif

    2017-12-01

    To compare efficancy of three-dimentional SPACE (sampling perfection with application-optimized contrasts using different flip-angle evolutions) and CISS (constructive interference in steady state) sequences in the imaging of the cisternal segments of cranial nerves V-XII. Temporal MRI scans from 50 patients (F:M ratio, 27:23; mean age, 44.5±15.9 years) admitted to our hospital with vertigo, tinnitus, and hearing loss were retrospectively analyzed. All patients had both CISS and SPACE sequences. Quantitative analysis of SPACE and CISS sequences was performed by measuring the ventricle-to-parenchyma contrast-to-noise ratio (CNR). Qualitative analysis of differences in visualization capability, image quality, and severity of artifacts was also conducted. A score ranging 'no artefact' to 'severe artefacts and unreadable' was used for the assessment of artifacts and from 'not visualized' to 'completely visualized' for the assesment of image quality, respectively. The distribution of variables was controlled by the Kolmogorov-Smirnov test. Samples t-test and McNemar's test were used to determine statistical significance. Rates of visualization of posterior fossa cranial nerves in cases of complete visualization were as follows: nerve V (100% for both sequences), nerve VI (94% in SPACE, 86% in CISS sequences), nerves VII-VIII (100% for both sequences), IX-XI nerve complex (96%, 88%); nerve XII (58%, 46%) (p<0.05). SPACE sequences showed fewer artifacts than CISS sequences (p<0.002). Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Self-gated fat-suppressed cardiac cine MRI.

    Science.gov (United States)

    Ingle, R Reeve; Santos, Juan M; Overall, William R; McConnell, Michael V; Hu, Bob S; Nishimura, Dwight G

    2015-05-01

    To develop a self-gated alternating repetition time balanced steady-state free precession (ATR-SSFP) pulse sequence for fat-suppressed cardiac cine imaging. Cardiac gating is computed retrospectively using acquired magnetic resonance self-gating data, enabling cine imaging without the need for electrocardiogram (ECG) gating. Modification of the slice-select rephasing gradients of an ATR-SSFP sequence enables the acquisition of a one-dimensional self-gating readout during the unused short repetition time (TR). Self-gating readouts are acquired during every TR of segmented, breath-held cardiac scans. A template-matching algorithm is designed to compute cardiac trigger points from the self-gating signals, and these trigger points are used for retrospective cine reconstruction. The proposed approach is compared with ECG-gated ATR-SSFP and balanced steady-state free precession in 10 volunteers and five patients. The difference of ECG and self-gating trigger times has a variability of 13 ± 11 ms (mean ± SD). Qualitative reviewer scoring and ranking indicate no statistically significant differences (P > 0.05) between self-gated and ECG-gated ATR-SSFP images. Quantitative blood-myocardial border sharpness is not significantly different among self-gated ATR-SSFP ( 0.61±0.15 mm -1), ECG-gated ATR-SSFP ( 0.61±0.15 mm -1), or conventional ECG-gated balanced steady-state free precession cine MRI ( 0.59±0.15 mm -1). The proposed self-gated ATR-SSFP sequence enables fat-suppressed cardiac cine imaging at 1.5 T without the need for ECG gating and without decreasing the imaging efficiency of ATR-SSFP. © 2014 Wiley Periodicals, Inc.

  1. Retrospective case series of the imaging findings of facial nerve hemangioma.

    Science.gov (United States)

    Yue, Yunlong; Jin, Yanfang; Yang, Bentao; Yuan, Hui; Li, Jiandong; Wang, Zhenchang

    2015-09-01

    The aim was to compare high-resolution computed tomography (HRCT) and thin-section magnetic resonance imaging (MRI) findings of facial nerve hemangioma. The HRCT and MRI characteristics of 17 facial nerve hemangiomas diagnosed between 2006 and 2013 were retrospectively analyzed. All patients included in the study suffered from a space-occupying lesion of soft tissues at the geniculate ganglion fossa. Affected nerve was compared for size and shape with the contralateral unaffected nerve. HRCT showed irregular expansion and broadening of the facial nerve canal, damage of the bone wall and destruction of adjacent bone, with "point"-like or "needle"-like calcifications in 14 cases. The average CT value was 320.9 ± 141.8 Hu. Fourteen patients had a widened labyrinthine segment; 6/17 had a tympanic segment widening; 2/17 had a greater superficial petrosal nerve canal involvement, and 2/17 had an affected internal auditory canal (IAC) segment. On MRI, all lesions were significantly enhanced due to high blood supply. Using 2D FSE T2WI, the lesion detection rate was 82.4 % (14/17). 3D fast imaging employing steady-state acquisition (3D FIESTA) revealed the lesions in all patients. HRCT showed that the average number of involved segments in the facial nerve canal was 2.41, while MRI revealed an average of 2.70 segments (P facial nerve hemangioma were typical, revealing irregular masses growing along the facial nerve canal, with calcifications and rich blood supply. Thin-section enhanced MRI was more accurate in lesion detection and assessment compared with HRCT.

  2. Pitfalls of CT for deep neck abscess imaging assessment: a retrospective review of 162 cases.

    Science.gov (United States)

    Chuang, S Y; Lin, H T; Wen, Y S; Hsu, F J

    2013-01-01

    To investigate the diagnostic value of contrast-enhanced computed tomography (CT) for the prediction of deep neck abscesses in different deep neck spaces and to evaluate the false-positive results. We retrospectively analysed the clinical charts, CT examinations, surgical findings, bacteriology, pathological examinations and complications of hospitalised patients with a diagnosis of deep neck abscess from 2004 to 2010. The positive predictive values (PPV) for the prediction of abscesses by CT scan in different deep neck spaces were calculated individually on the basis of surgical findings. A total of 162 patients were included in this study. All patients received both intravenous antibiotics and surgical drainage. The parapharyngeal space was the most commonly involved space. The overall PPV for the prediction of deep neck abscess with contrast-enhanced CT was 79.6%. The PPV was 91.3% when more than one deep neck space was involved but only 50.0% in patients with isolated retropharyngeal abscesses. In the false-positive group, cellulitis was the most common final result, followed by cystic degeneration of cervical metastases. Five specimens taken intra-operatively revealed malignancy and four of these were not infected. There are some limitations affecting the differentiation of abscesses and cellulitis, particularly in the retropharyngeal space. A central necrotic cervical metastatic lymph node may sometimes also mimic a simple pyogenic deep neck abscess on both clinical pictures and CT images. Routine biopsy of the tissue must be performed during surgical drainage.

  3. Imaging of spinal injury in abusive head trauma: a retrospective study

    International Nuclear Information System (INIS)

    Choudhary, Arabinda K.; Ishak, Ramsay; Zacharia, Thomas T.; Dias, Mark S.

    2014-01-01

    Spinal imaging has been a neglected part of abusive head trauma (AHT) imaging. As most of the radiographs and CT spine are negative in AHT in infants, the cervical spine is assumed to be normal. There is increasing evidence in the role of injury to brainstem and cervical cord in the pathogenesis of AHT. In addition, in courts of law, there is fierce debate about AHT, its mimics and other disparate nontraumatic diagnoses explaining the neuroradiological and skeletal findings. However, this discussion ignores the evidence and significance of spinal injury. We sought to study the cervical spine in an AHT cohort to understand the true prevalence of spinal injuries in AHT and contrast it with cohorts of accidental and nontraumatic groups to give the clinicians a robust diagnostic tool in evaluating AHT. The purpose of this study is to compare the relative incidence of spinal ligamentous and soft-tissue abnormalities on spinal MRI among three groups of children ages < 48 months: (1) those with AHT, (2) those with accidental trauma, and (3) those with nontraumatic conditions. This comparative study included 183 children who underwent spine MRI: 67 with AHT, 46 with accidental trauma and a clinical suspicion of spinal injury, and 70 with nontraumatic conditions. Clinical and radiographic findings were collected in all cases and were analyzed retrospectively to identify MRI evidence of traumatic spinal injuries. The incidence of spinal injuries among the three groups was compared. The incidence of spinal ligamentous injuries was calculated for those with and without radiographic evidence of hypoxic-ischemic encephalopathy. All comparisons were performed using Fisher exact test with P < 0.05 considered statistically significant. Cervical spine ligamentous injuries (predominantly the nuchal, atlanto-occipital and atlanto-axial ligaments) were present in 78% of the AHT group, 46% of the accidental trauma group and 1% of the nontraumatic group; all of these differences were

  4. Imaging of spinal injury in abusive head trauma: a retrospective study

    Energy Technology Data Exchange (ETDEWEB)

    Choudhary, Arabinda K. [Nemours A.I. DuPont Children Hospital, Department of Radiology, Wilmington, DE (United States); Ishak, Ramsay; Zacharia, Thomas T. [Hershey Medical Center, Department of Radiology, Hershey, PA (United States); Dias, Mark S. [Hershey Medical Center, Department of Neurosurgery, Hershey, PA (United States)

    2014-09-15

    Spinal imaging has been a neglected part of abusive head trauma (AHT) imaging. As most of the radiographs and CT spine are negative in AHT in infants, the cervical spine is assumed to be normal. There is increasing evidence in the role of injury to brainstem and cervical cord in the pathogenesis of AHT. In addition, in courts of law, there is fierce debate about AHT, its mimics and other disparate nontraumatic diagnoses explaining the neuroradiological and skeletal findings. However, this discussion ignores the evidence and significance of spinal injury. We sought to study the cervical spine in an AHT cohort to understand the true prevalence of spinal injuries in AHT and contrast it with cohorts of accidental and nontraumatic groups to give the clinicians a robust diagnostic tool in evaluating AHT. The purpose of this study is to compare the relative incidence of spinal ligamentous and soft-tissue abnormalities on spinal MRI among three groups of children ages < 48 months: (1) those with AHT, (2) those with accidental trauma, and (3) those with nontraumatic conditions. This comparative study included 183 children who underwent spine MRI: 67 with AHT, 46 with accidental trauma and a clinical suspicion of spinal injury, and 70 with nontraumatic conditions. Clinical and radiographic findings were collected in all cases and were analyzed retrospectively to identify MRI evidence of traumatic spinal injuries. The incidence of spinal injuries among the three groups was compared. The incidence of spinal ligamentous injuries was calculated for those with and without radiographic evidence of hypoxic-ischemic encephalopathy. All comparisons were performed using Fisher exact test with P < 0.05 considered statistically significant. Cervical spine ligamentous injuries (predominantly the nuchal, atlanto-occipital and atlanto-axial ligaments) were present in 78% of the AHT group, 46% of the accidental trauma group and 1% of the nontraumatic group; all of these differences were

  5. Reconstructions with identical filling (RIF) of the heart: a physiological approach to image reconstruction in coronary CT angiography

    International Nuclear Information System (INIS)

    Reinartz, S.D.; Diefenbach, B.S.; Kuhl, C.K.; Mahnken, A.H.; Allmendinger, T.

    2012-01-01

    To compare image quality in coronary artery computed tomography angiography (cCTA) using reconstructions with automated phase detection and Reconstructions computed with Identical Filling of the heart (RIF). Seventy-four patients underwent ECG-gated dual source CT (DSCT) between November 2009 and July 2010 for suspected coronary heart disease (n = 35), planning of transcatheter aortic valve replacement (n = 34) or evaluation of ventricular function (n = 5). Image data sets by the RIF formula and automated phase detection were computed and evaluated with the AHA 15-segment model and a 5-grade Likert scale (1: poor, 5: excellent quality). Subgroups regarding rhythm (sinus rhythm = SR; arrhythmia = ARR) and potential premedication were evaluated by a per-segment, per-vessel and per-patient analysis. RIF significantly improved image quality in 10 of 15 coronary segments (P < 0.05). More diagnostic segments were provided by RIF regarding the entire cohort (n = 693 vs. 590, P < 0.001) and all of the subgroups (e.g. ARR: n = 143 vs. 72, P < 0.001). In arrhythmic patients (n = 19), more diagnostic vessels (e.g. LAD: n = 10 vs. 3; P < 0.014) and complete data sets (n = 7 vs. 1; P < 0.001) were produced. RIF reconstruction is superior to automatic diastolic non-edited reconstructions, especially in arrhythmic patients. RIF theory provides a physiological approach for determining the optimal image reconstruction point in ECG-gated CT angiography. (orig.)

  6. Temporally resolved electrocardiogram-triggered diffusion-weighted imaging of the human kidney: correlation between intravoxel incoherent motion parameters and renal blood flow at different time points of the cardiac cycle.

    Science.gov (United States)

    Wittsack, Hans-Jörg; Lanzman, Rotem S; Quentin, Michael; Kuhlemann, Julia; Klasen, Janina; Pentang, Gael; Riegger, Caroline; Antoch, Gerald; Blondin, Dirk

    2012-04-01

    To evaluate the influence of pulsatile blood flow on apparent diffusion coefficients (ADC) and the fraction of pseudodiffusion (F(P)) in the human kidney. The kidneys of 6 healthy volunteers were examined by a 3-T magnetic resonance scanner. Electrocardiogram (ECG)-gated and respiratory-triggered diffusion-weighted imaging (DWI) and phase-contrast flow measurements were performed. Flow imaging of renal arteries was carried out to quantify the dependence of renal blood flow on the cardiac cycle. ECG-triggered DWI was acquired in the coronal plane with 16 b values in the range of 0 s/mm(2) and 750 s/mm(2) at the time of minimum (MIN) (20 milliseconds after R wave) and maximum renal blood flow (MAX) (197 ± 24 milliseconds after R wave). The diffusion coefficients were calculated using the monoexponential approach as well as the biexponential intravoxel incoherent motion model and correlated to phase-contrast flow measurements. Flow imaging showed pulsatile renal blood flow depending on the cardiac cycle. The mean flow velocity at MIN was 45 cm/s as compared with 61 cm/s at MAX. F(p) at MIN (0.29) was significantly lower than at MAX (0.40) (P = 0.001). Similarly, ADC(mono), derived from the monoexponential model, also showed a significant difference (P renal blood flow and F(p) (r = 0.85) as well as ADC(mono) (r = 0.67) was statistically significant. Temporally resolved ECG-gated DWI enables for the determination of the diffusion coefficients at different time points of the cardiac cycle. ADC(mono) and FP vary significantly among acquisitions at minimum (diastole) and maximum (systole) renal blood flow. Temporally resolved ECG-gated DWI might therefore serve as a novel technique for the assessment of pulsatility in the human kidney.

  7. Magnetic resonance imaging for cardiac tumors

    International Nuclear Information System (INIS)

    Niwa, Koichiro; Tashima, Kazuyuki; Okajima, Yoshitomo; Nakajima, Hiromichi; Terai, Masaru; Nakajima, Hironori; Harada, Tsutomu; Ishida, Yoshikazu.

    1988-01-01

    We performed magnetic resonance imaging (MRI) in 4 patients with cardiac tumor (1 with rhabdomyoma, 1 with left atrial myxoma, and 2 with tumor of the left ventricular wall) for morphological evaluation of the tumor. ECG-gated MRI was performed by the spin echo imaging technique using a superconducting MRI system operating at 0.5 tesla. Spatial extension of the tumor was clearly demonstrated in all the patients. Gadolinium-DTPA (Gd-DTPA), was used in the 2 patients with tumor of the left ventricular myocardium to enhance the contrast, and allowed clear visualization of the tumor. These findings show the usefulness of MRI and MRI with Gd-DTPA for morphological evaluation of cardiac tumor. (author)

  8. Influence of Respiratory Gating, Image Filtering, and Animal Positioning on High-Resolution Electrocardiography-Gated Murine Cardiac Single-Photon Emission Computed Tomography

    Directory of Open Access Journals (Sweden)

    Chao Wu

    2015-01-01

    Full Text Available Cardiac parameters obtained from single-photon emission computed tomographic (SPECT images can be affected by respiratory motion, image filtering, and animal positioning. We investigated the influence of these factors on ultra-high-resolution murine myocardial perfusion SPECT. Five mice were injected with 99m technetium (99mTc-tetrofosmin, and each was scanned in supine and prone positions in a U-SPECT-II scanner with respiratory and electrocardiographic (ECG gating. ECG-gated SPECT images were created without applying respiratory motion correction or with two different respiratory motion correction strategies. The images were filtered with a range of three-dimensional gaussian kernels, after which end-diastolic volumes (EDVs, end-systolic volumes (ESVs, and left ventricular ejection fractions were calculated. No significant differences in the measured cardiac parameters were detected when any strategy to reduce or correct for respiratory motion was applied, whereas big differences (> 5% in EDV and ESV were found with regard to different positioning of animals. A linear relationship (p < .001 was found between the EDV or ESV and the kernel size of the gaussian filter. In short, respiratory gating did not significantly affect the cardiac parameters of mice obtained with ultra-high-resolution SPECT, whereas the position of the animals and the image filters should be the same in a comparative study with multiple scans to avoid systematic differences in measured cardiac parameters.

  9. DIAGNOSTIC IMAGING IN A DIRECT-ACCESS SPORTS PHYSICAL THERAPY CLINIC: A 2-YEAR RETROSPECTIVE PRACTICE ANALYSIS.

    Science.gov (United States)

    Crowell, Michael S; Dedekam, Erik A; Johnson, Michael R; Dembowski, Scott C; Westrick, Richard B; Goss, Donald L

    2016-10-01

    While advanced diagnostic imaging is a large contributor to the growth in health care costs, direct-access to physical therapy is associated with decreased rates of diagnostic imaging. No study has systematically evaluated with evidence-based criteria the appropriateness of advanced diagnostic imaging, including magnetic resonance imaging (MRI), when ordered by physical therapists. The primary purpose of this study was to describe the appropriateness of magnetic resonance imaging (MRI) or magnetic resonance arthrogram (MRA) exams ordered by physical therapists in a direct-access sports physical therapy clinic. Retrospective observational study of practice. Greater than 80% of advanced diagnostic imaging orders would have an American College of Radiology (ACR) Appropriateness Criteria rating of greater than 6, indicating an imaging order that is usually appropriate. A 2-year retrospective analysis identified 108 MRI/MRA examination orders from four physical therapists. A board-certified radiologist determined the appropriateness of each order based on ACR appropriateness criteria. The principal investigator and co-investigator radiologist assessed agreement between the clinical diagnosis and MRI/surgical findings. Knee (31%) and shoulder (25%) injuries were the most common. Overall, 55% of injuries were acute. The mean ACR rating was 7.7; scores from six to nine have been considered appropriate orders and higher ratings are better. The percentage of orders complying with ACR appropriateness criteria was 83.2%. Physical therapist's clinical diagnosis was confirmed by MRI/MRA findings in 64.8% of cases and was confirmed by surgical findings in 90% of cases. Physical therapists providing musculoskeletal primary care in a direct-access sports physical therapy clinic appropriately ordered advanced diagnostic imaging in over 80% of cases. Future research should prospectively compare physical therapist appropriateness and utilization to other groups of providers and

  10. Diagnostic performance of state-of-the-art imaging techniques for morphological assessment of vascular abnormalities in patients with chronic thromboembolic pulmonary hypertension (CTEPH)

    Energy Technology Data Exchange (ETDEWEB)

    Ley, Sebastian [University Hospital Heidelberg, Department of Diagnostic and Interventional Radiology, Heidelberg (Germany); Ley-Zaporozhan, Julia [University Hospital Heidelberg, Department of Diagnostic and Interventional Radiology, Heidelberg (Germany); Johannes Gutenberg University, Department of Diagnostic and Interventional Radiology; Universitaetsmedizin, Mainz (Germany); Pitton, Michael B.; Schneider, Jens; Wirth, Gesine M.; Dueber, Christoph; Kreitner, Karl-Friedrich [Johannes Gutenberg University, Department of Diagnostic and Interventional Radiology; Universitaetsmedizin, Mainz (Germany); Mayer, Eckhard [Kerckhoff-Hospital Bad Nauheim, Department of Thoracic Surgery, Bad Nauheim (Germany)

    2012-03-15

    To determine the most comprehensive imaging technique for the assessment of pulmonary arteries in patients with chronic thromboembolic pulmonary hypertension (CTEPH). 24 patients with CTEPH were examined by ECG-gated multi-detector CT angiography (MD-CTA), contrast-enhanced MR angiography (ce-MRA) and selective digital subtraction angiography (DSA) within 3 days. Two readers in consensus separately evaluated each imaging technique (48 main, 144 lobar and 449 segmental arteries) for typical changes like complete obstructions, vessel cut-offs, intimal irregularities, incorporated thrombus formations, and bands and webs. A joint interpretation of all three techniques served as a reference standard. Based on image quality, there was no non-diagnostic examination by either imaging technique. DSA did not sufficiently display 1 main, 3 lobar and 4 segmental arteries. The pulmonary trunk was not assessable by DSA. One patient showed thrombotic material at this level only by MD-CTA and MRA. Sensitivity and specificity of MD-CTA regarding CTEPH-related changes at the main/lobar and at the segmental levels were 100%/100% and 100%/99%, of ce-MRA 83.1%/98.6% and 87.7%/98.1%, and of DSA 65.7%/100% and 75.8%/100%, respectively. ECG-gated MD-CTA proved the most adequate technique for assessment of the pulmonary arteries in the diagnostic work-up of CTEPH patients. (orig.)

  11. Three-dimensional MR imaging of congenital heart disease

    International Nuclear Information System (INIS)

    Laschinger, J.C.; Vannier, M.W.; Knapp, R.H.; Gutierrez, F.R.; Cox, J.L.

    1987-01-01

    Contiguous 5-mm thick ECG-gated MR images of the thorax were edited using surface reconstruction techniques to produce three-dimensional (3D) images of the heart and great vessels in four healthy individuals and 25 patients with congenital heart disease (aged 3 months-30 years). Anomalies studied include atrial and ventricular septal defects, aortic coarctation, AV canal defects, double outlet ventricles, hypoplastic left heart syndrome, and a wide spectrum of patients with tetralogy of Fallot. The results were correlated with echocardiographic and cineradiographic studies, and with surgical findings or pathologic specimens. Three-dimensional reconstructions accurately localized the dimensions and locations of all cardiac and great vessel anomalies and often displayed anatomic findings not diagnosed or visualized with other forms of diagnostic imaging

  12. MR imaging in tumor invasion of the chest wall

    International Nuclear Information System (INIS)

    Bittner, R.C.; Lang, P.; Schorner, W.; Sander, B.; Weiss, T.; Loddenkemper, R.; Kaiser, D.; Felix, R.

    1989-01-01

    The authors have used MR imaging to study 22 patients who had intrathoracic, pleura-related malignancies and whose CT findings had suggested chest wall invasion. ECG-gated T1- and T2-weighted spin-echo sequences were used in all patients. Additionally, in 10 patients an ungated, multisection, gradient-echo sequence was used, which was repeated after intravenous administration of Gd-DTPA in five patients. Surgery confirmed chest wall invasion in 19 patients. CT showed tumor invasion only in 14 of these 19 patients. MR imaging showed high-signal-intensity lesion within chest wall and pleura in T2-weighted and Gd-DTPA-enhanced T1-weighted images as the typical pattern of chest wall invasion in all 19 patients. Two of the three patients with pleural inflammation and without chest wall invasion had high-signal-intensity pleural lesions, but none of these lesions were within the chest wall

  13. Clinical use of digital retrospective image fusion of CT, MRI, FDG-PET and SPECT - fields of indications and results

    International Nuclear Information System (INIS)

    Lemke, A.J.; Niehues, S.M.; Amthauer, H.; Felix, R.; Rohlfing, T.; Hosten, N.

    2004-01-01

    Purpose: To evaluate the feasibility and the clinical benefits of retrospective digital image fusion (PET, SPECT, CT and MRI). Materials and methods: In a prospective study, a total of 273 image fusions were performed and evaluated. The underlying image acquisitions (CT, MRI, SPECT and PET) were performed in a way appropriate for the respective clinical question and anatomical region. Image fusion was executed with a software program developed during this study. The results of the image fusion procedure were evaluated in terms of technical feasibility, clinical objective, and therapeutic impact. Results: The most frequent combinations of modalities were CT/PET (n = 156) and MRI/PET (n = 59), followed by MRI/SPECT (n = 28), CT/SPECT (n = 22) and CT/MRI (n = 8). The clinical questions included following regions (more than one region per case possible): neurocranium (n = 42), neck (n = 13), lung and mediastinum (n = 24), abdomen (n = 181), and pelvis (n = 65). In 92.6% of all cases (n = 253), image fusion was technically successful. Image fusion was able to improve sensitivity and specificity of the single modality, or to add important diagnostic information. Image fusion was problematic in cases of different body positions between the two imaging modalities or different positions of mobile organs. In 37.9% of the cases, image fusion added clinically relevant information compared to the single modality. Conclusion: For clinical questions concerning liver, pancreas, rectum, neck, or neurocranium, image fusion is a reliable method suitable for routine clinical application. Organ motion still limits its feasibility and routine use in other areas (e.g., thorax). (orig.)

  14. Angle-independent measure of motion for image-based gating in 3D coronary angiography

    International Nuclear Information System (INIS)

    Lehmann, Glen C.; Holdsworth, David W.; Drangova, Maria

    2006-01-01

    compared to an ECG-based gating strategy in a porcine model. The image-based gating strategy selected 61 projection images, compared to 45 selected by the ECG-gating strategy. Qualitative comparison revealed that although both the SIC-based and ECG-gated reconstructions decreased motion artifact compared to reconstruction with no gating, the SIC-based gating technique increased the conspicuity of smaller vessels when compared to ECG gating in maximum intensity projections of the reconstructions and increased the sharpness of a vessel cross section in multi-planar reformats of the reconstruction

  15. Prospective Electrocardiogram-Gated Multidetector Row Computed Tomography Coronary Angiography. Analysis of Quality Image and Radiation Dose

    International Nuclear Information System (INIS)

    Carrascosa, P.; Capunay, C.; Deviggiano, A.; Tajer, C.D.; Vallejos, J.; Goldsmit, A.; Garcia, M.J.

    2009-01-01

    Multidetector row computed tomography coronary angiography (MDCT-CA) has become a useful diagnostic tool for the direct quantification of coronary stenosis, for identifying coronary anomalies and for the assessment of coronary artery bypass grafts. Despite its clinical value has been questioned due to the effective radiation dose (ERD) received by each patient, radiation exposure is similar to other studies. However, different strategies are permanently tested in order to reduce the ERD maintaining adequate and diagnostic image quality. Objectives: To determine the image quality and effective radiation dose (ERD) of prospective electrocardiogram-gated multidetector row computed tomography coronary angiography (PMDCTCA) (the x-ray beam is turned on for only a short portion of diastole) compared to retrospective ECG gating (RMDCTCA) (the x-ray beam is turned on throughout the cardiac cycle) and a preliminary approach of its diagnostic accuracy compared to digital invasive coronary angiography (CA). Material and Methods: Fifty consecutive patients with suspected coronary artery disease and sinus rhythm were evaluated with PMDCT-CA and compared to a control group who underwent RMDCTCA. Image quality was analyzed by two reviewers. Interobserver concordance and ERD were determined. The diagnostic accuracy of PMDCT-CA compared to CA to detect coronary artery stenosis > 50% was assessed in 30 patients. Results: There were no significant differences in the image quality between both groups. Agreement between the reviewers for segment image quality scores was k = 0.92. Mean ERD was 3.5 mSv for PMDCT-CA compared to 9.7 and 12.9 mSv for RMDCT-CA with and without tube current modulation, respectively. Individual analysis including all segments showed that the sensitivity, specificity, positive predictive value and negative predictive value of PMDCT-CA for the detection of coronary stenosis were 94.74%, 81.82%, 90% and 90%, respectively. Conclusion: Our initial experience

  16. A statistical method for retrospective cardiac and respiratory motion gating of interventional cardiac x-ray images

    Energy Technology Data Exchange (ETDEWEB)

    Panayiotou, Maria, E-mail: maria.panayiotou@kcl.ac.uk; King, Andrew P.; Housden, R. James; Ma, YingLiang; Rhode, Kawal S. [Division of Imaging Sciences and Biomedical Engineering, King' s College London, London SE1 7EH (United Kingdom); Cooklin, Michael; O' Neill, Mark; Gill, Jaswinder; Rinaldi, C. Aldo [Department of Cardiology, Guy' s and St. Thomas' Hospitals NHS Foundation Trust, London SE1 7EH (United Kingdom)

    2014-07-15

    Purpose: Image-guided cardiac interventions involve the use of fluoroscopic images to guide the insertion and movement of interventional devices. Cardiorespiratory gating can be useful for 3D reconstruction from multiple x-ray views and for reducing misalignments between 3D anatomical models overlaid onto fluoroscopy. Methods: The authors propose a novel and potentially clinically useful retrospective cardiorespiratory gating technique. The principal component analysis (PCA) statistical method is used in combination with other image processing operations to make our proposed masked-PCA technique suitable for cardiorespiratory gating. Unlike many previously proposed techniques, our technique is robust to varying image-content, thus it does not require specific catheters or any other optically opaque structures to be visible. Therefore, it works without any knowledge of catheter geometry. The authors demonstrate the application of our technique for the purposes of retrospective cardiorespiratory gating of normal and very low dose x-ray fluoroscopy images. Results: For normal dose x-ray images, the algorithm was validated using 28 clinical electrophysiology x-ray fluoroscopy sequences (2168 frames), from patients who underwent radiofrequency ablation (RFA) procedures for the treatment of atrial fibrillation and cardiac resynchronization therapy procedures for heart failure. The authors established end-systole, end-expiration, and end-inspiration success rates of 97.0%, 97.9%, and 97.0%, respectively. For very low dose applications, the technique was tested on ten x-ray sequences from the RFA procedures with added noise at signal to noise ratio (SNR) values of√(5)0, √(1)0, √(8), √(6), √(5), √(2), and √(1) to simulate the image quality of increasingly lower dose x-ray images. Even at the low SNR value of √(2), representing a dose reduction of more than 25 times, gating success rates of 89.1%, 88.8%, and 86.8% were established. Conclusions: The proposed

  17. Incorporating Colour Information for Computer-Aided Diagnosis of Melanoma from Dermoscopy Images: A Retrospective Survey and Critical Analysis

    Directory of Open Access Journals (Sweden)

    Ali Madooei

    2016-01-01

    Full Text Available Cutaneous melanoma is the most life-threatening form of skin cancer. Although advanced melanoma is often considered as incurable, if detected and excised early, the prognosis is promising. Today, clinicians use computer vision in an increasing number of applications to aid early detection of melanoma through dermatological image analysis (dermoscopy images, in particular. Colour assessment is essential for the clinical diagnosis of skin cancers. Due to this diagnostic importance, many studies have either focused on or employed colour features as a constituent part of their skin lesion analysis systems. These studies range from using low-level colour features, such as simple statistical measures of colours occurring in the lesion, to availing themselves of high-level semantic features such as the presence of blue-white veil, globules, or colour variegation in the lesion. This paper provides a retrospective survey and critical analysis of contributions in this research direction.

  18. Non-Invasive and Minimally Invasive Imaging Evaluation of CSF Rhinorrhoea – a Retrospective Study with Review of Literature

    International Nuclear Information System (INIS)

    Vimala, Leena Robinson; Jasper, Anitha; Irodi, Aparna

    2016-01-01

    Localization of a cerebrospinal fluid [CSF] fistula is a diagnostic challenge. The choice of an optimal imaging technique is necessary to locate the site of CSF leak which is required for surgical/endoscopic repair of the CSF fistula. Retrospective analysis of imaging was performed in 33 patients who presented with symptoms suggestive of CSF rhinorrhoea over a period of two years. Either a bone defect on high resolution CT [HRCT] or CSF column extending extracranially from the subarachnoid space with or without brain/ meningeal herniation on magnetic resonance [MR] cisternography was considered positive for CSF leak. The MR imaging technique included 1-mm heavily T2-weighted [TR 2000 ms; TE-200 ms] fast spin echo study in coronal and sagittal planes. HRCT sections involved 0.625 to 0.8-mm sections in the coronal plane, with or without axial planes, through the paranasal sinuses, reconstructed in a sharp algorithm and acquired with the patient in prone position. Imaging findings were compared with endoscopic findings, being the gold standard for the assessment of CSF rhinorrhea. A total of 25 patients had a combination of HRCT and MR cisternography. The sensitivity, specificity, positive predictive value [PPV] and negative predictive value [NPV] of both MR cisternography and HRCT together were 93%, 100%, 100% and 50% respectively. Two patients underwent only MR cisternography, 5 patients underwent only HRCT and one patient underwent HRCT, MR cisternography and CT cisternography. Though PPV was 100% in the groups with HRCT alone, MR cisternography alone and combined CT cisternography, HRCT and MR cisternography, the results were not statistically significant as the number of patients in those groups was lower. Combination of MR cisternography and HRCT appears to be complementary, accurate and non-invasive and should be considered as optimal imaging modality for pre-op imaging in the evaluation of CSF rhinorrhoea

  19. Morphometric MRI changes in intracranial hypertension due to cerebral venous thrombosis: a retrospective imaging study

    International Nuclear Information System (INIS)

    Dong, Cheng; Zheng, Ying-mei; Li, Xiao-li; Wang, He-xiang; Hao, Da-peng; Nie, Pei; Pang, Jing; Xu, Wen-jian

    2016-01-01

    Aim: To evaluate whether some magnetic resonance imaging (MRI) signs suggesting idiopathic intracranial hypertension (IIH) could also be found in intracranial hypertension (IH) due to cerebral venous thrombosis (CVT) and to assess their possible contribution to diagnosing this disorder. Materials and methods: Thirty-one patients with IH due to CVT were evaluated prospectively using MRI. A group of 33 age- and sex-matched healthy volunteers served as controls. The optic nerve and sheath, pituitary gland, and ventricles were assessed. The prevalence of each imaging feature was compared between the two groups. Results: Optic nerve sheath (ONS) dilatation and decreased pituitary gland height were the most valid signs suggesting IH in CVT patients: sensitivity 70.97% and 87.1%, respectively; specificity 96.97% and 72.73%, respectively; area under the curve 0.840 and 0.809, respectively. The MRI finding that showed the strongest association with IH in CVT patients was ONS dilatation (odds ratio 78.5). Conclusions: The combination of T1-weighted volumetric MRI and magnetic resonance venography could be helpful for diagnosing IH with CVT. Abnormalities of the ONS and the pituitary gland were reliable diagnostic signs for IH due to CVT. - Highlights: • We compared the prevalence of MRI imaging features between IH patients due to CVT and healthy volunteers. • Several MRI imaging features occur more frequently in IH patients due to CVT. • Abnormalities of the ONS and the pituitary gland were reliable diagnostic signs for IH due to CVT.

  20. Evaluation of right ventricular volumes measured by magnetic resonance imaging

    DEFF Research Database (Denmark)

    Møgelvang, J; Stubgaard, M; Thomsen, C

    1988-01-01

    stroke volume was calculated as the difference between end-diastolic and end-systolic volume and compared to left ventricular stroke volume and to stroke volume determined simultaneously by a classical indicator dilution technique. There was good agreement between right ventricular stroke volume......Right ventricular volumes were determined in 12 patients with different levels of right and left ventricular function by magnetic resonance imaging (MRI) using an ECG gated multisection technique in planes perpendicular to the diastolic position of the interventricular septum. Right ventricular...... determined by MRI and by the indicator dilution method and between right and left ventricular stroke volume determined by MRI. Thus, MRI gives reliable values not only for left ventricular volumes, but also for right ventricular volumes. By MRI it is possible to obtain volumes from both ventricles...

  1. Clinical and imaging characteristics of localized megalencephaly: a retrospective comparison of diffuse hemimegalencephaly and multilobar cortical dysplasia

    Energy Technology Data Exchange (ETDEWEB)

    Nakahashi, Masumi; Tsushima, Yoshito; Amanuma, Makoto; Endo, Keigo [Gunma University Graduate School of Medicine, Department of Diagnostic Radiology and Nuclear Medicine, Maebashi, Gunma (Japan); Sato, Noriko; Ota, Miho [National Center Hospital of Neurology and Psychiatry, Department of Radiology, Kodaira, Tokyo (Japan); Yagishita, Akira [Tokyo Metropolitan Neurological Hospital, Department of Neuroradiology, Kokubunji, Tokyo (Japan); Saito, Yoshiaki; Sugai, Kenji; Sasaki, Masayuki [National Center Hospital of Neurology and Psychiatry, Department of Child Neurology, Kodaira, Tokyo (Japan); Natsume, Jun [Nagoya University Graduate School of Medicine, Department of Pediatrics, Nagoya, Aichi (Japan)

    2009-12-15

    Hemimegalencephaly is a well-known congenital malformation. However, localized megalencephaly, which may be one of the subtypes of hemimegalencephaly, has not been separately investigated. In the present study, we attempted to characterize the clinical and magnetic resonance (MR) imaging features of localized megalencephaly in comparison with ordinary diffuse hemimegalencephaly and multilobar cortical dysplasia. MR findings for 43 patients with hemimegalencephaly and ten with multilobar cortical dysplasia, which is the differential diagnosis of localized megalencephaly, were retrospectively reviewed. Clinical findings such as the onset and severity of seizures and imaging findings including the affected area of the brain, structures outside of the hemisphere, and interval morphological changes were examined. Of the 43 patients, 11 showed signs of localized megalencephaly (25.6%). Localized megalencephaly was predominantly seen on the left side (72.7%) and had a tendency toward severe-grade seizures compared to multilobar cortical dysplasia. The frequencies of the extracerebral abnormalities in the diffuse hemimegalencephaly, localized megalencephaly, and multilobar cortical dysplasia groups were 84.4%, 36.4%, and 0.0%, respectively. There were three localized megalencephaly patients whose affected areas shrank and whose images were similar to those of multilobar cortical dysplasia. Localized megalencephaly accounts for one quarter of all hemimegalencephaly cases in this study. The incidence of extracerebral abnormalities in patients with localized hemimegalencephaly was almost half that of patients with diffuse hemimegalencephaly. Extracerebral abnormalities were absent in patients with multilobar cortical dysplasia. Associated extracerebral abnormalities may be a clue to differentiating localized megalencephaly from multilobar cortical dysplasia. (orig.)

  2. Experience with magnetic resonance imaging of human subjects with passive implants and tattoos at 7 T: a retrospective study.

    Science.gov (United States)

    Noureddine, Yacine; Bitz, Andreas K; Ladd, Mark E; Thürling, Markus; Ladd, Susanne C; Schaefers, Gregor; Kraff, Oliver

    2015-12-01

    Over the last decade, the number of clinical MRI studies at 7 T has increased dramatically. Since only limited information about the safety of implants/tattoos is available at 7 T, many centers either conservatively exclude all subjects with implants/tattoos or have started to perform dedicated tests for selected implants. This work presents our experience in imaging volunteers with implants/tattoos at 7 T over the last seven and a half years. 1796 questionnaires were analyzed retrospectively to identify subjects with implants/tattoos imaged at 7 T. For a total of 230 subjects, the type of local transmit/receive RF coil used for examination, imaging sequences, acquisition time, and the type of implants/tattoos and their location with respect to the field of view were documented. These subjects had undergone examination after careful consideration by an internal safety panel consisting of three experts in MR safety and physics. None of the subjects reported sensations of heat or force before, during, or after the examination. None expressed any discomfort related to implants/tattoos. Artifacts were reported in 52% of subjects with dental implants; all artifacts were restricted to the mouth area and did not affect image quality in the brain parenchyma. Our initial experience at 7 T indicates that a strict rejection of subjects with tattoos and/or implants is not justified. Imaging can be conditionally performed in carefully selected subjects after collection of substantial safety information and evaluation of the detailed exposure scenario (RF coil/type and position of implant). Among the assessed subjects with tattoos, no side effects from the exposure to 7 T MRI were reported.

  3. Retrospective analysis of cytopathology using gray level co-occurrence matrix algorithm for thyroid malignant nodules in the ultrasound imaging

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    Kim, Yeong Ju; Lee, Jin Soo [Dept. of Radiology, Inje University Haeundae Paik Hospital, Busan (Korea, Republic of); Kang, Se Sik; Kim, Chang Soo [Dept. of Radiological Science, College of Health Sciences, Catholic University of Pusan, Busan (Korea, Republic of)

    2017-06-15

    This study evaluated the applicability of computer-aided diagnosis by retrospective analysis of GLCM algorithm based on cytopathological diagnosis of normal and malignant nodules in thyroid ultrasound images. In the experiment, the recognition rate and ROC curve of thyroid malignant nodule were analyzed using 6 parameters of GLCM algorithm. Experimental results showed 97% energy, 93% contrast, 92% correlation, 92% homogeneity, 100% entropy and 100% variance. Statistical analysis showed that the area under the curve of each parameter was more than 0.947 (p = 0 .001) in t he ROC curve, which was s ignificant in the recognition of thyroid malignant nodules. In the GLCM, the cut-off value of each parameter can be used to predict the disease through analysis of quantitative computer-aided diagnosis.

  4. Paediatric parotid neoplasms: a 10 year retrospective imaging and pathology review of these rare tumours

    International Nuclear Information System (INIS)

    Mamlouk, M.D.; Rosbe, K.W.; Glastonbury, C.M.

    2015-01-01

    Aim: To determine the relative incidence of benign and malignant paediatric parotid gland tumours and whether particular presenting symptoms or imaging characteristics were more likely to predict malignancy. Materials and methods: Hospital records were reviewed for all patients <18 years with histopathology-proven parotid neoplasms over the 10 year period from 2003–2013. Infantile haemangiomas and patients with neurofibromatosis type I were excluded. The presenting clinical symptoms for each patient were recorded. All available CT and MRI examinations for these patients were evaluated for tumour imaging characteristics. Results: Seventeen patients (nine boys, eight girls; age range 2–17 years) were identified with neoplastic parotid masses; 11 tumours were malignant (65%) and six were benign (35%). The malignant tumours consisted of three acinic cell carcinomas, two mucoepidermoid carcinomas, one alveolar rhabdomyosarcoma, one poorly differentiated carcinoma, one low-grade adenocarcinoma, and three metastases (two melanoma, one orbital medulloepithelioma). The benign tumours consisted of five pleomorphic adenomas and one schwannoma. Presenting clinical symptoms were similar between benign and malignant tumours. Twelve MRI and six CT examinations were available for review with five patients undergoing both techniques. MRI features commonly identified with malignant tumours included: hypointense T2 signal, restricted diffusion, ill-defined borders, and focal necrosis. Only four of the six tumours imaged at CT were visualized, and of those, the margins were indeterminate in three patients. Conclusion: Paediatric parotid masses are more likely to be malignant than benign. Presenting clinical symptoms and CT are not helpful for distinguishing benign and malignant disease. MRI features such as T2 hypointensity, restricted diffusion, ill-defined borders, and focal necrosis, although not specific, should raise concern for malignancy. - Highlights: • Pediatric parotid

  5. Fetal cardiac cine imaging using highly accelerated dynamic MRI with retrospective motion correction and outlier rejection.

    Science.gov (United States)

    van Amerom, Joshua F P; Lloyd, David F A; Price, Anthony N; Kuklisova Murgasova, Maria; Aljabar, Paul; Malik, Shaihan J; Lohezic, Maelene; Rutherford, Mary A; Pushparajah, Kuberan; Razavi, Reza; Hajnal, Joseph V

    2018-01-01

    Development of a MRI acquisition and reconstruction strategy to depict fetal cardiac anatomy in the presence of maternal and fetal motion. The proposed strategy involves i) acquisition and reconstruction of highly accelerated dynamic MRI, followed by image-based ii) cardiac synchronization, iii) motion correction, iv) outlier rejection, and finally v) cardiac cine reconstruction. Postprocessing entirely was automated, aside from a user-defined region of interest delineating the fetal heart. The method was evaluated in 30 mid- to late gestational age singleton pregnancies scanned without maternal breath-hold. The combination of complementary acquisition/reconstruction and correction/rejection steps in the pipeline served to improve the quality of the reconstructed 2D cine images, resulting in increased visibility of small, dynamic anatomical features. Artifact-free cine images successfully were produced in 36 of 39 acquired data sets; prolonged general fetal movements precluded processing of the remaining three data sets. The proposed method shows promise as a motion-tolerant framework to enable further detail in MRI studies of the fetal heart and great vessels. Processing data in image-space allowed for spatial and temporal operations to be applied to the fetal heart in isolation, separate from extraneous changes elsewhere in the field of view. Magn Reson Med 79:327-338, 2018. © 2017 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. 2017 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine.

  6. Low-grade Glioma Surgery in Intraoperative Magnetic Resonance Imaging: Results of a Multicenter Retrospective Assessment of the German Study Group for Intraoperative Magnetic Resonance Imaging.

    Science.gov (United States)

    Coburger, Jan; Merkel, Andreas; Scherer, Moritz; Schwartz, Felix; Gessler, Florian; Roder, Constantin; Pala, Andrej; König, Ralph; Bullinger, Lars; Nagel, Gabriele; Jungk, Christine; Bisdas, Sotirios; Nabavi, Arya; Ganslandt, Oliver; Seifert, Volker; Tatagiba, Marcos; Senft, Christian; Mehdorn, Maximilian; Unterberg, Andreas W; Rössler, Karl; Wirtz, Christian Rainer

    2016-06-01

    The ideal treatment strategy for low-grade gliomas (LGGs) is a controversial topic. Additionally, only smaller single-center series dealing with the concept of intraoperative magnetic resonance imaging (iMRI) have been published. To investigate determinants for patient outcome and progression-free-survival (PFS) after iMRI-guided surgery for LGGs in a multicenter retrospective study initiated by the German Study Group for Intraoperative Magnetic Resonance Imaging. A retrospective consecutive assessment of patients treated for LGGs (World Health Organization grade II) with iMRI-guided resection at 6 neurosurgical centers was performed. Eloquent location, extent of resection, first-line adjuvant treatment, neurophysiological monitoring, awake brain surgery, intraoperative ultrasound, and field-strength of iMRI were analyzed, as well as progression-free survival (PFS), new permanent neurological deficits, and complications. Multivariate binary logistic and Cox regression models were calculated to evaluate determinants of PFS, gross total resection (GTR), and adjuvant treatment. A total of 288 patients met the inclusion criteria. On multivariate analysis, GTR significantly increased PFS (hazard ratio, 0.44; P surgery. Patients with accidentally left tumor remnants showed a similar prognosis compared with patients harboring only partially resectable tumors. Use of high-field iMRI was significantly associated with GTR. However, the field strength of iMRI did not affect PFS. EoR, extent of resectionFLAIR, fluid-attenuated inversion recoveryGTR, gross total resectionIDH1, isocitrate dehydrogenase 1iMRI, intraoperative magnetic resonance imagingLGG, low-grade gliomaMGMT, methylguanine-deoxyribonucleic acid methyltransferasenPND, new permanent neurological deficitOS, overall survivalPFS, progression-free survivalSTR, subtotal resectionWHO, World Health Organization.

  7. Automatic extraction of myocardial mass and volumes using parametric images from dynamic nongated PET

    DEFF Research Database (Denmark)

    Harms, Hendrik Johannes; Hansson, Nils Henrik Stubkjær; Tolbod, Lars Poulsen

    2016-01-01

    Dynamic cardiac positron emission tomography (PET) is used to quantify molecular processes in vivo. However, measurements of left-ventricular (LV) mass and volumes require electrocardiogram (ECG)-gated PET data. The aim of this study was to explore the feasibility of measuring LV geometry using non......-gated dynamic cardiac PET. METHODS: Thirty-five patients with aortic-valve stenosis and 10 healthy controls (HC) underwent a 27-min 11C-acetate PET/CT scan and cardiac magnetic resonance imaging (CMR). HC were scanned twice to assess repeatability. Parametric images of uptake rate K1 and the blood pool were......LV and WT only and an overestimation for LVEF at lower values. Intra- and inter-observer correlations were >0.95 for all PET measurements. PET repeatability accuracy in HC was comparable to CMR. CONCLUSION: LV mass and volumes are accurately and automatically generated from dynamic 11C-acetate PET without...

  8. The Effectiveness of Ultrasonography in Detecting Emergent Pediatric Pathologies and Requirement for Additional Imaging Techniques: A Retrospective Study

    Directory of Open Access Journals (Sweden)

    Betül Tiryaki Baştuğ

    2018-04-01

    Full Text Available Introduction: In emergency cases, ultrasonography is used in guiding resuscitation, to provide procedural guidance, and confirm a clinical diagnosis. In addition, it may prevent unnecessary exposure of the patient to ionizing radiation and risks caused by transporting the patient away from monitoring. This paper aimed to evaluate the effectiveness of ultrasonography in detecting emergent pediatric pathologies in a state hospital radiology unit, and to identify whether additional imaging techniques, such as computed tomography, were required. Methods: This study was designed as a retrospective investigation. A group of 536 patients were randomly selected from 1.401 pediatric patients who underwent ultrasonography for non-traumatic emergent pathologies between 2015 and 2016. Results: Of the 536 patients, 46 were diagnosed with appendicitis, 14 with pathologies of the urinary system, 1 with ileus, 29 with mesenteric lymphadenitis, 4 with intussusception, 3 with ovarian cyst rupture, 1 with ovarian torsion, and 32 with scrotal pathologies. Computed tomography was performed for 20 patients. Ureteral calculi and appendicitis were confirmed by computed tomography in 5 and 14 patients, respectively, after being identified as secondary findings by ultrasonography. In 1 patient, ileus was verified by computed tomography. The sensitivity of ultrasonography was determined to be 85.7%. Only 14% of patients were not given definite pathological diagnoses by ultrasonography alone. Subsequent computed tomography for verifying secondary findings detected by ultrasonography was essential in only 20 patients. Conclusion: Our results promote the use of ultrasonography as the initial imaging test for evaluating pediatric patients with suspected emergency pathologies.

  9. Value of image fusion using single photon emission computed tomography with integrated low dose computed tomography in comparison with a retrospective voxel-based method in neuroendocrine tumours

    International Nuclear Information System (INIS)

    Amthauer, H.; Denecke, T.; Ruf, J.; Gutberlet, M.; Felix, R.; Lemke, A.J.; Rohlfing, T.; Boehmig, M.; Ploeckinger, U.

    2005-01-01

    The objective was the evaluation of single photon emission computed tomography (SPECT) with integrated low dose computed tomography (CT) in comparison with a retrospective fusion of SPECT and high-resolution CT and a side-by-side analysis for lesion localisation in patients with neuroendocrine tumours. Twenty-seven patients were examined by multidetector CT. Additionally, as part of somatostatin receptor scintigraphy (SRS), an integrated SPECT-CT was performed. SPECT and CT data were fused using software with a registration algorithm based on normalised mutual information. The reliability of the topographic assignment of lesions in SPECT-CT, retrospective fusion and side-by-side analysis was evaluated by two blinded readers. Two patients were not enrolled in the final analysis because of misregistrations in the retrospective fusion. Eighty-seven foci were included in the analysis. For the anatomical assignment of foci, SPECT-CT and retrospective fusion revealed overall accuracies of 91 and 94% (side-by-side analysis 86%). The correct identification of foci as lymph node manifestations (n=25) was more accurate by retrospective fusion (88%) than from SPECT-CT images (76%) or by side-by-side analysis (60%). Both modalities of image fusion appear to be well suited for the localisation of SRS foci and are superior to side-by-side analysis of non-fused images especially concerning lymph node manifestations. (orig.)

  10. NP-59 SPECT/CT Imaging in Stage 1 Hypertensive and Atypical Primary Aldosteronism: A 5-Year Retrospective Analysis of Clinicolaboratory and Imaging Features

    Directory of Open Access Journals (Sweden)

    Yi-Chun Chen

    2013-01-01

    Full Text Available Objective. We retrospectively analyzed all primary aldosteronism (PA patients undergoing NP-59 SPECT/CT imaging with regard to their clinicolaboratory and imaging features, investigation, and outcomes. Material and Methods. 11 PA patients who presented to our hospital for NP-59 SPECT/CT imaging between April 2007 and March 2012 and managed here were analyzed. Results. Among 11 PA patients, eight (73% had stage 1 hypertension, three (27% stage 2 hypertension, four (36% normal plasma aldosterone concentration, nine (82% nonsuppressed plasma renin activity (PRA, six (55% normal aldosterone-renin-ratio (ARR, eight (73% serum potassium ≧3 mEq/L, seven (64% subclinical presentation, seven (64% negative confirmatory testing, and four (36% inconclusive results on CT scan and seven (64% on planar NP-59 scan. All 11 (100% patients had positive results on NP-59 SPECT/CT scan. Two (18% met typical triad and nine (82% atypical triad. Among nine atypical PA patients, three (33% had clinical presentation, six (67% subclinical presentation, six (67% negative confirmatory testing, and four (44% inconclusive results on CT scan and six (67% on planar NP-59 scan. All patients had improved outcomes. Significant differences between typical and atypical PA existed in PRA and ARR. Conclusions. NP-59 SPECT/CT may provide diagnostic potential in stage 1 hypertensive and atypical PA.

  11. Pleural space infections after image-guided percutaneous drainage of infected intraabdominal fluid collections: a retrospective single institution analysis.

    Science.gov (United States)

    Avella, Diego M; Toth, Jennifer W; Reed, Michael F; Gusani, Niraj J; Kimchi, Eric T; Mahraj, Rickeshvar P; Staveley-O'Carroll, Kevin F; Kaifi, Jussuf T

    2015-04-11

    Percutaneous drainage of infected intraabdominal fluid collections is preferred over surgical drainage due to lower morbidity and costs. However, it can be a challenging procedure and catheter insertion carries the potential to contaminate the pleural space from the abdomen. This retrospective analysis demonstrates the clinical and radiographic correlation between percutaneous drainage of infected intraabdominal collections and the development of iatrogenic pleural space infections. A retrospective single institution analysis of 550 consecutive percutaneous drainage procedures for intraabdominal fluid collections was performed over 24 months. Patient charts and imaging were reviewed with regard to pleural space infections that were attributed to percutaneous drain placements. Institutional review board approval was obtained for conduct of the study. 6/550 (1.1%) patients developed iatrogenic pleural space infections after percutaneous drainage of intraabdominal fluid collections. All 6 patients presented with respiratory symptoms and required pleural space drainage (either by needle aspiration or chest tube placement), 2 received intrapleural fibrinolytic therapy and 1 patient had to undergo surgical drainage. Pleural effusion cultures revealed same bacteria in both intraabdominal and pleural fluid in 3 (50%) cases. A video with a dynamic radiographic sequence demonstrating the contamination of the pleural space from percutaneous drainage of an infected intraabdominal collection is included. Iatrogenic pleural space infections after percutaneous drainage of intraabdominal fluid collections occur at a low incidence, but the pleural empyema can be progressive requiring prompt chest tube drainage, intrapleural fibrinolytic therapy or even surgery. Expertise in intraabdominal drain placements, awareness and early recognition of this complication is critical to minimize incidence, morbidity and mortality in these patients.

  12. Radiologically defining horizontal gaze using EOS imaging-a prospective study of healthy subjects and a retrospective audit.

    Science.gov (United States)

    Hey, Hwee Weng Dennis; Tan, Kimberly-Anne; Ho, Vivienne Chien-Lin; Azhar, Syifa Bte; Lim, Joel-Louis; Liu, Gabriel Ka-Po; Wong, Hee-Kit

    2018-06-01

    As sagittal alignment of the cervical spine is important for maintaining horizontal gaze, it is important to determine the former for surgical correction. However, horizontal gaze remains poorly-defined from a radiological point of view. The objective of this study was to establish radiological criteria to define horizontal gaze. This study was conducted at a tertiary health-care institution over a 1-month period. A prospective cohort of healthy patients was used to determine the best radiological criteria for defining horizontal gaze. A retrospective cohort of patients without rigid spinal deformities was used to audit the incidence of horizontal gaze. Two categories of radiological parameters for determining horizontal gaze were tested: (1) the vertical offset distances of key identifiable structures from the horizontal gaze axis and (2) imaginary lines convergent with the horizontal gaze axis. Sixty-seven healthy subjects underwent whole-body EOS radiographs taken in a directed standing posture. Horizontal gaze was radiologically defined using each parameter, as represented by their means, 95% confidence intervals (CIs), and associated 2 standard deviations (SDs). Subsequently, applying the radiological criteria, we conducted a retrospective audit of such radiographs (before the implementation of a strict radioimaging standardization). The mean age of our prospective cohort was 46.8 years, whereas that of our retrospective cohort was 37.2 years. Gender was evenly distributed across both cohorts. The four parameters with the lowest 95% CI and 2 SD were the distance offsets of the midpoint of the hard palate (A) and the base of the sella turcica (B), the horizontal convergents formed by the tangential line to the hard palate (C), and the line joining the center of the orbital orifice with the internal occipital protuberance (D). In the prospective cohort, good sensitivity (>98%) was attained when two or more parameters were used. Audit using Criterion B

  13. Intracranial incidental findings on brain MR images in a pediatric neurology practice: a retrospective study.

    Science.gov (United States)

    Gupta, Surya N; Belay, Brook

    2008-01-15

    Previous studies have addressed the prevalence of incidental findings largely in healthy adult and pediatric populations. Our study aims to elucidate the prevalence of incidental findings in a pediatric neurology practice. We reviewed the charts of 1618 patients seen at a pediatric neurology practice at a tertiary care center from September 2003 to December 2005 for clinical data and incidental intracranial findings on brain magnetic resonance imaging reports. Incidental findings were divided into two categories: normal or abnormal variants. Clinical and demographic data were assessed for associations with incidental findings. From 1618 charts reviewed, only 666 patients (41% of all patients) had brain MRIs ordered. One-hundred and seventy-one (171) patients (25.7% of all patients; 95% CI: 22.6, 29.0) had incidental findings. Of these, 113 (17.0%; 95% CI: 14.1, 19.8) were classified as normal-variants and 58 (8.7%; 95% CI: 6.6, 10.9) were classified as abnormal. The nature of incidental findings was not related to age group, sex or clinical diagnosis (p=0.29, p=0.31 and p=0.69 respectively). Two patients (0.3%; 95% CI: approximately 0.0, 0.7) required neurosurgical referral. We report a high prevalence of and a low rate of referrals for incidental findings in comparison to previous studies. The present study may help guide management decisions and discussions with patients and families. Future studies should attempt to address issues of associations between primary or secondary diagnoses and intracranial incidental findings in a controlled, prospective fashion.

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

    International Nuclear Information System (INIS)

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

    2008-01-01

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

  15. Preliminary application of 320-detector spiral CT with ECG editing for assessing coronary artery in-stent restenosis

    International Nuclear Information System (INIS)

    Li Zhiming; Tan Lilian; Li Shuxin; Fu Xi; He Weihong; Liu Ke; Huang Yong; Yu Lin

    2011-01-01

    Objective: To determine the value of 320-detector spiral CT with retrospective ECG gating and editing software for detecting coronary artery in-stent restenosis. Methods: CT scans of 14 patients with coronary artery stnets were retrospectively analyzed. The examinations were performed using a 320-detector spiral CT scanner and retrospective ECG gating combined with ECG editing software. The image quality of reconstructed coronary artery in-stents was compared before and after the editing of synchronously recorded ECG. The paired-sample t test was used for statistical analysis. Results: Before ECG editing, arrhythmia and in-stent artifact resulted in image blurring, missing arterial segments, significant stepladder artifacts or non-visualization of the interior of stents. Of 14 cases before ECG editing, in-stent restenosis was detected in 10 and patency in 3. The coronary artery stent and distal bifurcation were delineated in one patient. After ECG editing, the image quality of coronary artery stents was improved with detection of in-stent restenosis (4 cases) including the one case that not evaluable before ECG editing. The average image quality score before ECG editing (2.14±0.86) was significantly (P<0.001) lower than that after ECG editing (3.07±0.73). Conclusion: Retrospective ECG gating combined with ECG editing of 320-detector spiral CT can reduce the artifacts produced by arrhythmia or in-stent swings and improve the imaging quality of coronary artery stents. (authors)

  16. Extracardiac findings at cardiac MR imaging: a single-centre retrospective study over 14 years.

    Science.gov (United States)

    Sokolowski, Felix C; Karius, Philipp; Rodríguez, Alejandra; Lembcke, Alexander; Wagner, Moritz; Hamm, Bernd; Dewey, Marc

    2018-04-30

    To determine the prevalence and significance of extracardiac findings (ECF) in a large set of cardiac magnetic resonance (MR) imaging examinations. The institutional review board (IRB) of the Charité approved this retrospective, single-centre study. A total of 4376 cardiac MR imaging reports of 3553 patients (age 37.4 ± 20 years, 60.8 % male) examined from 2000 to 2014 were included. Findings with a recommendation for follow-up were considered "major ECF". To analyse the association of indication, age and gender with ECF, Poisson regression and computed incidence rate ratios (IRR) were evaluated. The overall prevalence of ECF was 34% (95% confidence interval [CI] 32.5-35.6%). Major ECF were present in 3.4% (95% CI 2.9-4.1%) while findings that changed patient management were found in 0.9% (95% CI 0.7-1.3%). In the cases of congenital heart disease, ECF prevalence was higher compared to myocarditis (IRR, 6.0; 95% CI 5.1-7.1%; p < 0.001), while the prevalence of major ECF was lower (IRR, 0.2; 95% CI 0.02-0.51%; p < 0.05). Older patient age was associated with more nonvascular ECF (p < 0.001). Female patients had the same probability of having an ECF as male patients (IRR, 1.04; 95% CI 0.95-1.1%; p = 0.43). ECF in cardiac MR imaging are present in about every third patient while relevant ECF that change patient management can be found in about one out of 100 patients. Our data suggest that it is important to involve well-trained radiologists in reading cardiac MR images, which often reveal ECF if congenital heart disease is the clinical indication. • Extracardiac findings are present in about every third patient. • Relevant ECF changing patient management are found in one out of 100 findings. • Chance of ECF is high in patients with CHD and vascular indications.

  17. Computed tomography compared to magnetic resonance imaging in occult or suspect hip fractures. A retrospective study in 44 patients

    Energy Technology Data Exchange (ETDEWEB)

    Collin, David; Goethlin, Jan H. [Sahlgrenska University Hospital, Department of Radiology, Moelndal (Sweden); Geijer, Mats [Lund University, Department of Medical Imaging and Physiology, Skaane University Hospital, Lund (Sweden)

    2016-11-15

    Computed tomography (CT) for evaluation of occult and suspect hip fractures has been proposed as a good second-line investigation. The diagnostic precision compared to magnetic resonance imaging (MRI) is unclear. To compare the diagnostic performance of CT and MRI in a retrospective study on patients with suspect and occult hip fractures. Forty-four elderly consecutive patients with low-energy trauma to the hip were identified where negative or suspect CT was followed by MRI. Primary reporting and review by two observers as well as the diagnostic performance of the two modalities were compared. Surgical treatment and clinical course were used as outcomes. Compared to the primary reports, the CT reviewers found fewer normal and no suspect cases. MRI changed the primary diagnoses in 27 cases, and in 14 and 15 cases, respectively, at review. There was no disagreement on MRI diagnoses. In our patient population, MRI was deemed a more reliable modality for hip fracture diagnosis in comparison to CT. For clinical decision making, MRI seems to have a higher accuracy than CT. A negative CT finding cannot completely rule out a hip fracture in patients where clinical findings of hip fracture persevere. (orig.)

  18. A radial sampling strategy for uniform k-space coverage with retrospective respiratory gating in 3D ultrashort-echo-time lung imaging.

    Science.gov (United States)

    Park, Jinil; Shin, Taehoon; Yoon, Soon Ho; Goo, Jin Mo; Park, Jang-Yeon

    2016-05-01

    The purpose of this work was to develop a 3D radial-sampling strategy which maintains uniform k-space sample density after retrospective respiratory gating, and demonstrate its feasibility in free-breathing ultrashort-echo-time lung MRI. A multi-shot, interleaved 3D radial sampling function was designed by segmenting a single-shot trajectory of projection views such that each interleaf samples k-space in an incoherent fashion. An optimal segmentation factor for the interleaved acquisition was derived based on an approximate model of respiratory patterns such that radial interleaves are evenly accepted during the retrospective gating. The optimality of the proposed sampling scheme was tested by numerical simulations and phantom experiments using human respiratory waveforms. Retrospectively, respiratory-gated, free-breathing lung MRI with the proposed sampling strategy was performed in healthy subjects. The simulation yielded the most uniform k-space sample density with the optimal segmentation factor, as evidenced by the smallest standard deviation of the number of neighboring samples as well as minimal side-lobe energy in the point spread function. The optimality of the proposed scheme was also confirmed by minimal image artifacts in phantom images. Human lung images showed that the proposed sampling scheme significantly reduced streak and ring artifacts compared with the conventional retrospective respiratory gating while suppressing motion-related blurring compared with full sampling without respiratory gating. In conclusion, the proposed 3D radial-sampling scheme can effectively suppress the image artifacts due to non-uniform k-space sample density in retrospectively respiratory-gated lung MRI by uniformly distributing gated radial views across the k-space. Copyright © 2016 John Wiley & Sons, Ltd.

  19. Comparison of 16-frame and 8-frame gated SPET imaging for determination of left ventricular volumes and ejection fraction

    International Nuclear Information System (INIS)

    Navare, Sachin M.; Liu, Yi-Hwa; Wackers, Frans J.T.

    2003-01-01

    Electrocardiographic (ECG) gated single-photon emission tomography (SPET) allows for simultaneous assessment of myocardial perfusion and left ventricular (LV) function. Presently 8-frame per cardiac cycle ECG gating of SPET images is standard. The aim of this study was to compare the effect of 8-frame and 16-frame gated SPET on measurements of LV volumes and to evaluate the effects of the presence of myocardial perfusion defects and of radiotracer dose administered on the calculation of LV volumes. A total of 86 patients underwent technetium-99m SPET myocardial perfusion imaging using 16-frame per cardiac cycle acquisition. Eight-frame gated SPET images were generated by summation of contiguous frames. Left ventricular end-diastolic volume (EDV), end-systolic volume (ESV) and ejection fraction (EF) were calculated from the 16-frame and 8-frame data sets. The patients were divided into groups according to the administered dose of the radiotracer and the size of the perfusion defect. Results. Sixteen frame per cardiac cycle acquisition resulted in significantly larger EDV (122±72 ml vs 115±68 ml, P<0.0001), smaller ESV (64±58.6 ml vs 67.6±59.5 ml, P<0.0001), and higher LVEF (55.3%±18% vs 49%±17.4%, P<0.0001) as compared to 8-frame SPET imaging. This effect was seen regardless of whether a high or a low dose was administered and whether or not significant perfusion defects were present. This study shows that EDV, ESV and LVEF determined by 16-frame gated SPET are significantly different from those determined by 8-frame gated SPET. The radiotracer dose and perfusion defects do not affect estimation of LV parameters by 16-frame gated SPET. (orig.)

  20. Differentiation of recently infarcted myocardium from chronic myocardial scar: the value of contrast-enhanced SSFP-based cine MR imaging

    International Nuclear Information System (INIS)

    Kim, Kyoung Ah; Seo, Joon Beom; Do, Kyoung Hyun; Heo, Jeong Nam; Lee, Young Kyung; Song, Jae Woo; Lee, Jin Seong; Song, Koun Sik; Lim, Tae Hwan

    2006-01-01

    The purpose of this study is to demonstrate whether the signal intensity (SI) of myocardial infarction (MI) on contrast enhanced (CE)-cine MRI is useful for differentiating recently infarcted myocardium from chronic scar. This study included 24 patients with acute MI (36-84) years, mean age: 57) and 19 patients with chronic MI (44-80) years, mean age: 64). The diagnosis of acute MI was based on the presence of typical symptoms, i.e. elevation of the cardiac enzymes and the absence of any remote infarction history. The diagnosis of chronic MI was based on a history of MI or coronary artery disease of more than one month duration and on the absence of any recent MI within the previous six months. Retrospectively, the ECG-gated breath-hold cine imaging was performed in the short axis plane using a segmented, balanced, turbo-field, echo-pulse sequence two minutes after the administration of Gd-DTPA at a dose of 0.2 mmol/kg body weight. Delayed contrast-enhanced MRI (DCE MRI) in the same plane was performed 10 to 15 minutes after contrast administration, and this was served as the gold standard of reference. The SI of the infarcted myocardium on the CE-cine MRI was compared with that of the normal myocardium on the same image. The area of abnormal SI on the CE-cine MRI was compared with the area of hyper enhancement on the DCE MRI. The area of high SI on the CE-cine MRI was detected in 23 of 24 patients with acute MI (10 with homogenous high SI, 13 high SI with subendocardial low SI, and one with iso SI). The area of high SI on the CE- cine MRI was larger than that seen on the DCE MRI (ρ < 0.05). In contrast, the areas of chronic MI were seen as iso-SI with thin subendocardial low SI on the CE-cine MR in all the chronic MI patients. The presence of high SI on both the CE-cine MRI and the DCE MRI is more sensitive (95.8%) for determining the age of a MI than the presence of myocardial thinning (66.7%). The study showed the different SI patterns between recently

  1. Improving diagnostic sensitivity of combined dermoscopy and reflectance confocal microscopy imaging through double reader concordance evaluation in telemedicine settings: A retrospective study of 1000 equivocal cases.

    Directory of Open Access Journals (Sweden)

    A M Witkowski

    Full Text Available Reflectance confocal microscopy (RCM is an imaging device that permits non-invasive visualization of cellular morphology and has been shown to improve diagnostic accuracy of dermoscopically equivocal cutaneous lesions. The application of double reader concordance evaluation of dermoscopy-RCM image sets in retrospective settings and its potential application to telemedicine evaluation has not been tested in a large study population.To improve diagnostic sensitivity of RCM image diagnosis using a double reader concordance evaluation approach; to reduce mismanagement of equivocal cutaneous lesions in retrospective consultation and telemedicine settings.1000 combined dermoscopy-RCM image sets were evaluated in blind by 10 readers with advanced training and internship in dermoscopy and RCM evaluation. We compared sensitivity and specificity of single reader evaluation versus double reader concordance evaluation as well as the effect of diagnostic confidence on lesion management in a retrospective setting.Single reader evaluation resulted in an overall sensitivity of 95.2% and specificity of 76.3%, with misdiagnosis of 8 melanomas, 4 basal cell carcinomas and 2 squamous cell carcinomas. Combined double reader evaluation resulted in an overall sensitivity of 98.3% and specificity of 65.5%, with misdiagnosis of 1 in-situ melanoma and 2 basal cell carcinomas.Evaluation of dermoscopy-RCM image sets of cutaneous lesions by single reader evaluation in retrospective settings is limited by sensitivity levels that may result in potential mismanagement of malignant lesions. Double reader blind concordance evaluation may improve the sensitivity of diagnosis and management safety. The use of a second check can be implemented in telemedicine settings where expert consultation and second opinions may be required.

  2. Contrast-enhanced spectral mammography (CESM) versus breast magnetic resonance imaging (MRI): A retrospective comparison in 66 breast lesions.

    Science.gov (United States)

    Li, L; Roth, R; Germaine, P; Ren, S; Lee, M; Hunter, K; Tinney, E; Liao, L

    2017-02-01

    The purpose of this study was to retrospectively compare the diagnostic performance of contrast-enhanced spectral mammography (CESM) with that of breast magnetic resonance imaging (BMRI) in breast cancer detection using parameters, including sensitivity, positive predictive value (PPV), lesion size, morphology, lesion and background enhancement, and examination time. A total of 48 women (mean age, 56years±10.6 [SD]) with breast lesions detected between October 2012 and March 2014 were included. Both CESM and BMRI were performed for each patient within 30 days. The enhancement intensity of lesions and breast background parenchyma was subjectively assessed for both modalities and was quantified for comparison. Statistical significance was analyzed using paired t-test for mean size of index lesions in all malignant breasts (an index lesion defined as the largest lesion in each breast), and a mean score of enhancement intensity for index lesions and breast background. PPV, sensitivity, and accuracy were calculated for both CESM and BMRI. The average duration time of CESM and MRI examinations was also compared. A total of 66 lesions were identified, including 62 malignant and 4 benign lesions. Both CESM and BMRI demonstrated a sensitivity of 100% for detection of breast cancer. There was no statistically significant difference between the mean size of index lesions (P=0.108). The enhancement intensity of breast background was significantly lower for CESM than for BMRI (P0.05). The average examination time for CESM was significantly shorter than that of BMRI (P<0.01). CESM has similar sensitivity than BMRI in breast cancer detection, with higher PPV and less background enhancement. CESM is associate with significantly shorter exam time thus a more accessible alternative to BMRI, and has the potential to play an important tool in breast cancer detection and staging. Copyright © 2016 Éditions françaises de radiologie. Published by Elsevier Masson SAS. All rights

  3. Adverse reactions following administration of contrast media for diagnostic imaging in anaesthetized dogs and cats: a retrospective study.

    Science.gov (United States)

    Scarabelli, Stefania; Cripps, Peter; Rioja, Eva; Alderson, Briony

    2016-09-01

    To evaluate incidences of adverse reaction after the administration of contrast media. Retrospective observational study. Animals included 356 dogs and 58 cats receiving non-ionic iodinated contrast agents, and 425 dogs and 49 cats receiving gadolinium-based contrast agents. Anaesthesia records of dogs and cats receiving intravenous (IV) gadobutrol for magnetic resonance imaging (MRI) or IV iohexol for computed tomography (CT) were reviewed. Changes in pulse rate, respiratory rate and mean arterial pressure at 5 minutes after administration of the contrast medium were evaluated. Changes of 10-20% were considered mild, those of >20% moderate, and reactions that required immediate treatment were considered severe. Associations of sex, age and weight with contrast reaction were investigated using logistic regression. Differences in the incidences of reactions to CT and MRI contrast media were examined with chi-squared tests. A p-value of  0.2). Of dogs receiving iohexol, 64 (18.0%) had mild, 65 (18.3%) had moderate and three (0.8%) had severe reactions. Of dogs receiving gadobutrol, 42 (9.9%) had mild, 87 (20.5%) had moderate and one (0.2%) had a severe reaction. When dogs receiving iohexol were compared with those receiving gadobutrol, the odds ratio of a moderate reaction was 2.0 (95% confidence interval 1.34-3.10; p = 0.001). These estimates did not change substantially after adjustment for age, weight and sex. Severe reactions to iohexol and gadobutrol are rare in dogs and cats; moderate reactions are more likely with iohexol than with gadobutrol. © 2015 Association of Veterinary Anaesthetists and the American College of Veterinary Anesthesia and Analgesia.

  4. Diagnostic imaging of dementia with Lewy bodies by susceptibility-weighted imaging of nigrosomes versus striatal dopamine transporter single-photon emission computed tomography: a retrospective observational study

    Energy Technology Data Exchange (ETDEWEB)

    Kamagata, Koji; Sato, Kanako; Suzuki, Michimasa; Hori, Masaaki; Kumamaru, Kanako K.; Aoki, Shigeki [Juntendo University Graduate School of Medicine, Department of Radiology, Bunkyo-ku, Tokyo (Japan); Nakatsuka, Tomoya; Inaoka, Tsutomu; Terada, Hitoshi [Toho University Sakura Medical Center, Department of Radiology, Sakura, Sakura (Japan); Sakakibara, Ryuji; Tsuyusaki, Yohei [Toho University Sakura Medical Center, Department of Neurology, Sakura, Sakura (Japan); Takamura, Tomohiro [University of Yamanashi, Department of Radiology, Chuo-shi, Yamanashi (Japan)

    2017-01-15

    The characteristics of dementia with Lewy bodies (DLB), Alzheimer's disease (AD) and amnestic mild cognitive impairment (a-MCI) overlap but require different treatments; therefore, it is important to differentiate these pathologies. Assessment of dopamine uptake in the striatum using dopamine transporter (DaT) single-photon emission computed tomography (SPECT) is the gold standard for diagnosing DLB; however, this modality is expensive, time consuming and involves radiation exposure. Degeneration of the substantia nigra nigrosome-1, which occurs in DLB, but not in AD/a-MCI, can be identified by 3T susceptibility-weighted imaging (SWI). Therefore, the aim of this retrospective observational study was to compare SWI with DaT-SPECT for differentiation of DLB from AD/a-MCI. SWI data were acquired for patients with clinically diagnosed DLB (n = 29), AD (n = 18), a-MCI (n = 13) and healthy controls (n = 26). Images were analysed for nigrosome-1 degeneration. Diagnostic accuracy was evaluated for DLB, AD and a-MCI compared with striatal dopamine uptake using DaT-SPECT. SWI achieved 90% diagnostic accuracy (93% sensitivity, 87% specificity) for the detection of nigrosome-1 degeneration in DLB and not in AD/a-MCI as compared with 88.3% accuracy (93% sensitivity, 84% specificity) using DaT-SPECT. SWI nigrosome-1 evaluation was useful in differentiating DLB from AD/a-MCI, with high accuracy. This less invasive and less expensive method is a potential alternative to DaT-SPECT for the diagnosis of DLB. (orig.)

  5. Chronic thromboembolic pulmonary hypertension (CTEPH). Potential role of multidetector-row CT (MD-CT) and MR imaging in the diagnosis and differential diagnosis of the disease

    Energy Technology Data Exchange (ETDEWEB)

    Wirth, G.; Brueggemann, K.; Bostel, T.; Dueber, C.; Kreitner, K.F. [Universitaetsmedizin Mainz (Germany). Dept. of Radiology; Mayer, E. [Kerckhoff Hospital, Bad Nauheim (Germany). Dept. of Thoracic Surgery

    2014-08-15

    Chronic thromboembolic pulmonary hypertension (CTEPH) can be defined as pulmonary hypertension (resting mean pulmonary arterial pressure of 25 mm Hg or more determined at right heart catheterization) with persistent pulmonary perfusion defects. It is a rare, but underdiagnosed disease with estimated incidences ranging from 0.5% to 3.8% of patients after an acute pulmonary embolism (PE), and in up to 10% of those with a history of recurrent PE. CTEPH is the only form of pulmonary hypertension that can be surgically treated leading to normalization of pulmonary hemodynamics and exercise capacity in the vast majority of patients. The challenges for imaging in patients with suspected CTEPH are fourfold: the imaging modality should have a high diagnostic accuracy with regard to the presence of CTEPH and allow for differential diagnosis. It should enable detection of patients suitable for PEA with great certainty, and allow for quantification of PH by measuring pulmonary hemodynamics (mPAP and PVR), and finally, it can be used for therapy monitoring. This overview tries to elucidate the potential role of ECG-gated multidetector CT pulmonary angiography (MD-CTPA) and MR imaging, and summarizes the most important results that have been achieved so far. Generally speaking, ECG-gated MD-CTPA is superior to MR in the assessment of parenchymal and vascular pathologies of the lung, and allows for the assessment of cardiac structures. The implementation of iodine maps as a surrogate for lung perfusion enables functional assessment of lung perfusion by CT. MR imaging is the reference standard for the assessment of right heart function and lung perfusion, the latter delineating typical wedge-shaped perfusion defects in patients with CTEPH. New developments show that with MR techniques, an estimation of hemodynamic parameters like mean pulmonary arterial pressure and pulmonary vascular resistance will be possible. CT and MR imaging should be considered as complementary

  6. Application of eigen value expansion to feature extraction from MRI images

    International Nuclear Information System (INIS)

    Kinosada, Yasutomi; Takeda, Kan; Nakagawa, Tsuyoshi

    1991-01-01

    The eigen value expansion technique was utilized for feature extraction of magnetic resonance (MR) images. The eigen value expansion is an orthonormal transformation method which decomposes a set of images into some statistically uncorrelated images. The technique was applied to MR images obtained with various imaging parameters at the same anatomical site. It generated one mean image and another set of images called bases for the images. Each basis corresponds to a feature in the images. A basis is, therefore, utilized for the feature extraction from MR images and a weighted sum of bases is also used for the feature enhancement. Furthermore, any MR image with specific feature can be obtained from a linear combination of the mean image and all of the bases. Images of hemorrhaged brain with a spin echo sequence and a series of cinematic cerebro spinal fluid flow images with ECG gated gradient refocused echo sequence were employed to estimate the ability of the feature extraction and the contrast enhancement. Results showed us that proposed application of an eigen value expansion technique to the feature extraction of MR images is good enough to clinical use and superior to other feature extraction methods such as producing a calculated MR image with a given TR and TE or the matched-filter method in processing speed and reproducibility of results. (author)

  7. Altered carotid plaque signal among different repetition times on T1-weighted magnetic resonance plaque imaging with self-navigated radial-scan technique

    Energy Technology Data Exchange (ETDEWEB)

    Narumi, Shinsuke; Ohba, Hideki; Mori, Kiyofumi; Ohura, Kazumasa; Ono, Ayumi; Terayama, Yasuo [Iwate Medical University, Department of Neurology and Gerontology, Morioka (Japan); Sasaki, Makoto [Iwate Medical University, Advanced Medical Research Center, Morioka (Japan); Ogasawara, Kuniaki [Iwate Medical University, Department of Neurosurgery, Morioka (Japan); Hitomi, Jiro [Iwate Medical University, Department of Anatomy, Morioka (Japan)

    2010-04-15

    Magnetic resonance (MR) plaque imaging for carotid arteries is usually performed by using an electrocardiograph (ECG)-gating technique to eliminate pulsation-related artifacts, which can affect the plaque signals because of varied repetition time (TR) among patients. Hence, we investigated whether differences in TR causes signal alterations of the carotid plaque by using a non-gated plaque imaging technique. We prospectively examined 19 patients with carotid stenosis by using a T1-weighted self-navigated radial-scan technique with TRs of 500, 700, and 900 ms. The signal intensity of the carotid plaque was measured, and the contrast ratio (CR) relative to the adjacent muscle was calculated. CRs of the carotid plaques were 1.39 {+-} 0.39, 1.29 {+-} 0.29, and 1.23 {+-} 0.24 with TRs of 500, 700, and 900 ms, respectively, and were significantly different. Among the plaques, those with a hyperintensity signal (CR > 1.5) and moderate-intensity signal (CR 1.2-1.5) at 500 ms showed a TR-dependent signal decrease (hyperintensity plaques, 1.82 {+-} 0.26; 1.61 {+-} 0.19; and 1.48 {+-} 0.17; moderate-intensity plaques, 1.33 {+-} 0.08; 1.26 {+-} 0.08; and 1.19 {+-} 0.07), while those with an isointensity signal (CR < 1.2) remained unchanged regardless of TR (0.96 {+-} 0.12, 0.96 {+-} 0.11, and 0.97 {+-} 0.13). The signal intensity of the carotid plaque on T1-weighted imaging significantly varies among different TRs and tends to decrease with longer TR. MR plaque imaging with short and constant TR settings that the ECG-gating method cannot realize would be preferable for evaluating plaque characteristics. (orig.)

  8. Multispecialty retrospective review of the clinical utility of pelvic magnetic resonance imaging in the setting of pelvic pain.

    Science.gov (United States)

    Moore, John R; Pathak, Ram A; Snowden, Caroline; Bolan, Candice W; Young, Paul R; Broderick, Gregory A

    2017-12-01

    Pelvic pain is a common complaint, and management of it is often difficult. We sought to evaluate the utility of magnetic resonance imaging (MRI) in the diagnosis of male pelvic pain. Though MRIs are commonly ordered to evaluate pelvic pain, there are very few studies obtaining the efficacy of pelvic MRI in determining a definitive diagnosis. The primary aim of our study was to evaluate the clinical utility of pelvic MRI for a diagnosis code that included pain. After receiving institutional review board approval, a retrospective study was performed of all pelvic MRIs completed at our institution from January 2, 2010 to December 31, 2014. These were further delineated into ordering providers by specialty and urology-specific International Classification of Diseases, Ninth Revision (ICD-9) code diagnoses (male pelvic pain, prostatitis, groin pain, scrotal pain, testicular pain, and penile pain). Clinical utility was defined as positive if MRI findings resulted in a change in management. Subanalysis was performed on patients with an ICD-9 co-diagnosis of previous oncologic concern. A total of 2,643 pelvic MRIs were ordered at our institution over a 5-year period. Of these, 597 pelvic MRIs (23%) were ordered for a diagnosis code that included pain (hip pain, rectal pain, joint pain, penile pain, scrotal pain, male pelvic pain and orchitis). Total utility for MRIs to find anatomic abnormalities potentially responsible for the present pain was 34% (205/597). When ordered by urologic providers, utility was 23%. Oncologists represented the highest positivity rate at 57%. Chronic pelvic pain is a multispecialty complaint that is difficult to treat. We were surprised to find the large number of both specialists and generalists invested in the management of pelvic pain. The increasing availability of MRI technology makes it a likely candidate to test for a clinically significant anatomic reason for pain. Though MRI is a test with minimal adverse effect and no increased risk

  9. Sixty-four-slice multidetector computed tomography for preoperative evaluation of left ventricular function and mass in patients with mitral regurgitation: comparison with magnetic resonance imaging and echocardiography

    International Nuclear Information System (INIS)

    Guo, Ying-kun; Yang, Zhi-gang; Ning, Gang; Rao, Li; Pen, Ying; Wu, Yang; Dong, Li; Zhang, Tai-ming; Zhang, Xiao-chun; Wang, Qi-ling

    2009-01-01

    Quantitative values of left ventricular (LV) function and muscle mass in patients with mitral regurgitation are independent predictors of cardiac morbidity and mortality. The aim of this study was to prospectively evaluate whether 64-MDCT can assess the LV function in patients with mitral regurgitation with high accuracy when compared with the MRI and echocardiography results. Fifty-one patients with mitral regurgitation underwent retrospectively ECG-gated 64-MDCT, echocardiography, and MRI for assessing the global ventricular function. End-diastolic and end-systolic volume, stroke volume, ejection fraction, and mass were measured on 64-MDCT and echocardiography, and compared with the results measured on MRI which served as the reference standard. Intertechnique agreement was tested by using Pearson's correlation and Bland-Altman analyses. No significant differences were revealed in calculated LV function and mass between the 64-MDCT and MRI (paired t test, p = 0.07-0.53). Pearson's correlation analysis showed the functional parameters and mass correlated closely between the 64-MDCT and MRI (r = 0.89-0.96, p < 0.001). When compared with MRI, echocardiography underestimated the volumetric parameters of LV (paired t test, p = 0.0003-0.004), but significantly overestimated the EF values (p = 0.003), and moderate correlations of functional parameters were obtained (r = 0.78, 0.60, 0.81, and 0.62, respectively). ECG-gated 64-MDCT allows for accurate and reliable assessment of LV function in patients with mitral regurgitation, whereas LV volumes measured by two-dimensional echocardiography were underestimated and the ejection fraction was overestimated when compared with those achieved by using MRI. (orig.)

  10. Clinical advantages of three dimensional cine cardiac images

    International Nuclear Information System (INIS)

    Kinosada, Yasutomi; Okuda, Yasuyuki; Nakagawa, Tsuyoshi; Itou, Takafumi; Hattori, Takao.

    1996-01-01

    We evaluated clinical advantages and the quantitativeness of computerized three-dimensional (3D) cinematic images of a human heart, which were produced with a set of magnetic resonance (MR) images by using the computer graphic technique. Many contiguous, multi-location and multi-phase short axis images were obtained with the ECG gated conventional and fast cardiac imaging sequences in normal volunteers and selected patients with myocardial infarction, hypertrophic cardiomyopathy, dilated cardiomyopathy and left ventricular dysfunction. Judging by visual impressions of the computerized 3D cinematic cardiac images, we could easily understand and evaluate the myocardial motions or the anatomic and volumetric changes of a heart according to the cardiac phases. These images were especially useful to compare the wall motion, the left ventricular ejection-fraction (LVEF), or other cardiac functions and conditions between before and after therapeutic procedures such as percutaneous transluminal coronary angioplasty for patients with myocardial infarction. A good correlation between the LVEF calculated from a set of computerized 3D cinematic images and the ultra sound examinations were found. The results of our study showed that computerized 3D cinematic cardiac images were clinically useful to understand the myocardial motions qualitatively and to evaluate cardiac functions such as the LVEF quantitatively. (author)

  11. Retrospective evaluation of positional movements of patients with prostate cancer submitted to IGRT (radiotherapy guided by image)

    International Nuclear Information System (INIS)

    Rocha, N.K.S.; Filipov, D.; Soboll, D.S.

    2017-01-01

    It is a retrospective study that analyzed positional fluctuations of 29 patients submitted to prostate radiotherapy, using IGRT. The minimum and maximum averages of the lateral, longitudinal and vertical displacements were calculated, obtaining a general average of the displacements that remained close to zero and one the most evident variation between the lateral and vertical axes

  12. The diagnosis accuracy and safety of 99Tcm-MIBI myocardial perfusion imaging-a retrospective multicenter study

    International Nuclear Information System (INIS)

    Wang Rongfu; Qiu Yanli; Wang Liqin

    2012-01-01

    Objective: To evaluate the diagnostic accuracy and safety of 99 Tc m -MIBI MPI by retrospectively analyzing data from this multicenter study. Methods: Participating centers included six hospitals: Peking University First Hospital, Beijing Fuwai Hospital of Chinese Academy of Medical Science and Peking Union Medical College, Anzhen Hospital of Capital Medical University, Beijing Hospital of Health Ministry, Beijing Tongren Hospital of Capital Medical University and Peking University People's Hospital. According to the inclusion and exclusion criteria, 500 subjects (335 male, 165 female, mean age (60.1 ±11.1) years) who underwent MPI between April 1998 and April 2006 were enrolled. All subjects were investigated with stress/rest MPI and CAG within 1 month. Stress test was performed with bicycle ergometry or with intravenous dipyridamole, adenosine or ATP. Perfusion defects on MPI were allocated to corresponding coronary arteries. During the stress and imaging period,any discomfort or symptoms were recorded. Coronary stenosis with ≥ 50% luminal narrowing was considered significant in CAG and taken as the gold standard. 99 Tc m -MIBI MPI results for the number of stenosed vessels, stenotic severity and coronary artery allocation were compared using χ 2 test. Results: There were 280 subjects that underwent exercise stress tests and the remaining 220 received pharmacological stress tests (117 adenosine, 32 dipyridamole, 71 ATP). Two hundred and forty-nine patients had significant coronary stenosis and 251 had normal CAG. Out of the 249 patients with positive CAG results, 101 had one-vessel, 66 had two-vessel and 82 had three-vessel disease. Significant stenosis of the LAD was present in 205 patients, 144 had RCA stenosis and 130 had stenosis of the LCX. The sensitivity,specificity, accuracy, positive predictive and negative predictive values of MPI for detection of coronary artery disease were 65.1% (162/249), 81.3% (204/251), 73.2% (366/500), 77.5% (162

  13. Evaluation of mitral regurgitation by cine magnetic resonance imaging

    International Nuclear Information System (INIS)

    Kobayashi, Shiro; Kishi, Naohiro; Kumai, Toshihiko

    1993-01-01

    Valvular regurgitation can be detected as a region of signal loss ('flow void') by cardiac cine magnetic resonance (MR) imaging. Cine MR images of 36 patients with mitral regurgitation caused by mitral valve prolapse (MVP) and non-MVP were evaluated and compared with color Doppler flow images. The direction, distance, area and timing of flow void were detected in all patients in several different planes at mitral level with a 0.5 Tesla superconducting magnet by an ECG-gated fast field echo technique. In 23 of the 36 patients contiguous multiple transaxial images were also obtained to calculate the volumes of flow void and the left atrium. The direction of flow void tended to deviate to the opposite side within the left atrium in MVP. The frame showing maximal area of flow void was demonstrated in mid-systole in 24 of the 36 patients (67%). The distance, area and volume of flow void were concordant with the grade from color Doppler flow images. The volumes of flow void and the left atrium correlated (n=19, r=0.74, p<0.05) in MVP. In conclusion, cine MR images in several different planes or contiguous multiple slices are useful in determining spatial orientation and the extent and timing of mitral regurgitation noninvasively. Furthermore, calculation of the volume of flow void enables the assessment of the semiquantitation of mitral regurgitation. (author)

  14. Retrospective Reconstruction of High Temporal Resolution Cine Images from Real-Time MRI using Iterative Motion Correction

    DEFF Research Database (Denmark)

    Hansen, Michael Schacht; Sørensen, Thomas Sangild; Arai, Andrew

    2012-01-01

    acquisitions in 10 (N = 10) subjects. Acceptable image quality was obtained in all motion-corrected reconstructions, and the resulting mean image quality score was (a) Cartesian real-time: 2.48, (b) Golden Angle real-time: 1.90 (1.00–2.50), (c) Cartesian motion correction: 3.92, (d) Radial motion correction: 4...... and motion correction based on nonrigid registration and can be applied to arbitrary k-space trajectories. The method is demonstrated with real-time Cartesian imaging and Golden Angle radial acquisitions, and the motion-corrected acquisitions are compared with raw real-time images and breath-hold cine...

  15. Renal volume assessed by magnetic resonance imaging volumetry correlates with renal function in living kidney donors pre- and postdonation: a retrospective cohort study.

    Science.gov (United States)

    Lange, Daniel; Helck, Andreas; Rominger, Axel; Crispin, Alexander; Meiser, Bruno; Werner, Jens; Fischereder, Michael; Stangl, Manfred; Habicht, Antje

    2018-07-01

    Renal function of potential living kidney donors is routinely assessed with scintigraphy. Kidney anatomy is evaluated by imaging techniques such as magnetic resonance imaging (MRI). We evaluated if a MRI-based renal volumetry is a good predictor of kidney function pre- and postdonation. We retrospectively analyzed the renal volume (RV) in a MRI of 100 living kidney donors. RV was correlated with the tubular excretion rate (TER) of MAG3-scintigraphy, a measured creatinine clearance (CrCl), and the estimated glomerular filtration rate (eGFR) by Cockcroft-Gault (CG), CKD-EPI, and modification of diet in renal disease (MDRD) formula pre- and postdonation during a follow-up of 3 years. RV correlated significantly with the TER (total: r = 0.6735, P volumetry might be an alternative technique for the evaluation of split renal function and prediction of renal function postdonation in living kidney donors. © 2018 Steunstichting ESOT.

  16. Coronary endothelial function assessment using self-gated cardiac cine MRI and k-t sparse SENSE.

    Science.gov (United States)

    Yerly, Jérôme; Ginami, Giulia; Nordio, Giovanna; Coristine, Andrew J; Coppo, Simone; Monney, Pierre; Stuber, Matthias

    2016-11-01

    Electrocardiogram (ECG)-gated cine MRI, paired with isometric handgrip exercise, can be used to accurately, reproducibly, and noninvasively measure coronary endothelial function (CEF). Obtaining a reliable ECG signal at higher field strengths, however, can be challenging due to rapid gradient switching and an increased heart rate under stress. To address these limitations, we present a self-gated cardiac cine MRI framework for CEF measurements that operates without ECG signal. Cross-sectional slices of the right coronary artery (RCA) were acquired using a two-dimensional golden angle radial trajectory. This sampling approach, combined with the k-t sparse SENSE algorithm, allows for the reconstruction of both real-time images for self-gating signal calculations and retrospectively reordered self-gated cine images. CEF measurements were quantitatively compared using both the self-gated and the standard ECG-gated approach. Self-gated cine images with high-quality, temporal, and spatial resolution were reconstructed for 18 healthy volunteers. CEF as measured in self-gated images was in good agreement (R 2  = 0.60) with that measured by its standard ECG-gated counterpart. High spatial and temporal resolution cross-sectional cine images of the RCA can be obtained without ECG signal. The coronary vasomotor response to handgrip exercise compares favorably with that obtained with the standard ECG-gated method. Magn Reson Med 76:1443-1454, 2015. © 2015 International Society for Magnetic Resonance in Medicine. © 2015 International Society for Magnetic Resonance in Medicine.

  17. Image quality and artefact generation post-cerebral aneurysm clipping using a 64-row multislice computer tomography angiography (MSCTA) technology: A retrospective study and review of the literature.

    Science.gov (United States)

    Zachenhofer, Iris; Cejna, Manfred; Schuster, Antonius; Donat, Markus; Roessler, Karl

    2010-06-01

    Computed tomography angiography (CTA) is a time and cost saving investigation for postoperative evaluation of clipped cerebral aneurysm patients. A retrospective study was conducted to analyse image quality and artefact generation due to implanted aneurysm clips using a new technology. MSCTA was performed pre- and postoperatively using a Philips Brilliance 64-detector-row CT scanner. Altogether, 32 clipping sites were analysed in 27 patients (11 female and 16 male, mean ages 52a, from 24 to 72 years). Clip number per aneurysm was 2.3 mean (from 1 to 4), 54 clips were made of titanium alloy and 5 of cobalt alloy. Altogether, image quality was rated 1.8 mean, using a scale from 1 (very good) to 5 (unserviceable) and clip artefacts were rated 2.4 mean, using a 5 point rating scale (1 no artefacts, 5 unserviceable due to artefacts). A significant loss of image quality and rise of artefacts was found when using cobalt alloy clips (1.4 versus 4.2 and 2.1 versus 4.0). In 72% of all investigations, an excellent image quality was found. Excluding the cobalt clip group, 85% of scans showed excellent image quality. Artefacts were absent or minimal (grade 1 or 2) in 69% of all investigations and in 81% in the pure titanium clip group. In 64-row MSCTA of good image quality with low artefacts, it was possible to detect small aneurysm remnants of 2mm size in individual patients. By using titanium alloy clips, in our study up to 85% of postoperative CTA images were of excellent quality with absent or minimal artefacts in 81% and seem adequate to detect small aneurysm remnants. Copyright 2010 Elsevier B.V. All rights reserved.

  18. Quantitative analysis of computed tomography images and early detection of cerebral edema for pediatric traumatic brain injury patients: retrospective study

    OpenAIRE

    Kim, Hakseung; Kim, Gwang-dong; Yoon, Byung C; Kim, Keewon; Kim, Byung-Jo; Choi, Young Hun; Czosnyka, Marek; Oh, Byung-Mo; Kim, Dong-Joo

    2014-01-01

    Background The purpose of this study was to identify whether the distribution of Hounsfield Unit (HU) values across the intracranial area in computed tomography (CT) images can be used as an effective diagnostic tool for determining the severity of cerebral edema in pediatric traumatic brain injury (TBI) patients. Methods CT images, medical records and radiology reports on 70 pediatric patients were collected. Based on radiology reports and the Marshall classification, the patients were group...

  19. A retrospective, semi-quantitative image quality analysis of cone beam computed tomography (CBCT) and MSCT in the diagnosis of distal radius fractures

    International Nuclear Information System (INIS)

    Lang, H.; Neubauer, J.; Fritz, B.; Spira, E.M.; Strube, J.; Langer, M.; Kotter, E.

    2016-01-01

    To compare image quality and diagnostic validity of CBCT and MSCT for distal radius fractures. 35 CBCT and 33 MSCT scans were retrospectively reviewed with a visual grading scale regarding the depiction of cortical bone, trabecular bone, articular surfaces, and soft tissue. The extent and type of artefacts was analyzed. Agreement on AO classification and measurement of cortical disruption and length of the fracture gap was determined. Fracture reduction was evaluated in post-treatment x-rays. Statistical analysis was performed with visual grading characteristics (VGC), chi square tests, and Kendall's coefficient of concordance. CBCT performed significantly worse for cortical bone, articular surfaces, and especially soft tissue. Trabecular bone showed no significant difference. Significantly more CBCT images showed artefacts. Physics-based artefacts were the most common. CBCT scans also showed motion artefacts. There was no significant difference in agreement on AO classification. The agreement on measurements was substantial for both modalities. Slightly more fractures that had undergone MSCT imaging showed adequate reduction. This initial study of an orthopaedic extremity CBCT scanner showed that the image quality of a CBCT scanner remains inferior for most structures at standard settings. Diagnostic validity of both modalities for distal radius fractures seems similar. (orig.)

  20. A retrospective, semi-quantitative image quality analysis of cone beam computed tomography (CBCT) and MSCT in the diagnosis of distal radius fractures

    Energy Technology Data Exchange (ETDEWEB)

    Lang, H.; Neubauer, J.; Fritz, B.; Spira, E.M.; Strube, J.; Langer, M.; Kotter, E. [University Medical Center Freiburg, Department of Radiology, Freiburg (Germany)

    2016-12-15

    To compare image quality and diagnostic validity of CBCT and MSCT for distal radius fractures. 35 CBCT and 33 MSCT scans were retrospectively reviewed with a visual grading scale regarding the depiction of cortical bone, trabecular bone, articular surfaces, and soft tissue. The extent and type of artefacts was analyzed. Agreement on AO classification and measurement of cortical disruption and length of the fracture gap was determined. Fracture reduction was evaluated in post-treatment x-rays. Statistical analysis was performed with visual grading characteristics (VGC), chi square tests, and Kendall's coefficient of concordance. CBCT performed significantly worse for cortical bone, articular surfaces, and especially soft tissue. Trabecular bone showed no significant difference. Significantly more CBCT images showed artefacts. Physics-based artefacts were the most common. CBCT scans also showed motion artefacts. There was no significant difference in agreement on AO classification. The agreement on measurements was substantial for both modalities. Slightly more fractures that had undergone MSCT imaging showed adequate reduction. This initial study of an orthopaedic extremity CBCT scanner showed that the image quality of a CBCT scanner remains inferior for most structures at standard settings. Diagnostic validity of both modalities for distal radius fractures seems similar. (orig.)

  1. Sonographic patterns of renal lymphoma in B-mode imaging and in contrast-enhanced ultrasound (CEUS)—A retrospective evaluation

    International Nuclear Information System (INIS)

    Trenker, C.; Neesse, A.; Görg, C.

    2015-01-01

    Introduction: Retrospective analysis of sonographic patterns of renal lymphoma in B-mode imaging and contrast-enhanced ultrasound (CEUS). Patients/methods: From January 2000 to June 2014, 27 patients with clinical or histologically confirmed renal lymphoma were examined with B-mode imaging, followed by CEUS in 8 cases. Results: In B-mode imaging renal lymphoma were hypoechoic in all 27 cases (100%). 9 patients (33.3%) had a bilateral, 18 (66.7%) patients had an unilateral lymphoma infiltration of the kidneys. 8 (29.6%) cases of small nodular, 5 (18.5%) cases of large nodular and 6 (22.2%) cases of perirenal lymphoma infiltration of the kidney were observed in B-mode imaging. Bulky-formation of renal lymphoma was detected in 6 (22.2%) patients and 2 (7.4%) patients had a diffuse lymphoma infiltration of the kidneys. In CEUS an arterial isoechoic enhancement was observed in 5 (62.5%)- and, an arterial hypoechoic enhancement was observed in 3 (37.5%) cases of renal lymphoma. A hypoechoic enhancement in the parenchymal phase was observed in 8 (100%) cases of renal lymphoma infiltration. Conclusion: In B-mode-imaging, nodular lymphoma infiltration of the kidneys is the most common of all renal lymphoma patterns in B-mode imaging. In CEUS, renal lymphoma presented an arterial iso- or hypoechoic enhancement, followed by a hypoechoic enhancement in the parenchymal phase. In regard to the differentiation of renal lymphoma to benign lesions of the kidney, CEUS may be helpful. However, the differentiation of renal lymphoma from other malignant lesions of the kidney like renal cell carcinoma is not feasible by CEUS

  2. Phase image characterization of ventricular contraction in left anterior hemiblock

    International Nuclear Information System (INIS)

    Ono, Akifumi; Mizuno, Haruyoshi; Tahara, Yorio; Ishikawa, Kyozo

    1991-01-01

    We investigated whether or not left anterior hemiblock is present in patients with left axis deviation using first-harmonic Fourier analysis of gated blood-pool images. Gated blood-pool images were taken in 50 patients without contraction abnormality. They included 14 normal subjects, 8 patients with right bundle branch block (RBBB), 20 with left axis deviation (LAD) and 8 with both RBBB and LAD (RBBB+LAD). ECG gated blood-pool scans were acquired in the anterior and 'best septal' left anterior oblique projections. First, the phase images were displayed cinematically as a continuous-loop movie. Next, for quantitative analysis of the phase image, the whole left ventricular and left ventricular high lateral regions of interest were drawn. The 'regional phase shift' (RPS) was then defined as {RPS=A-a} where 'A' is the mean value of the whole left ventricular phase angles and 'a' is that of phase angles in the high lateral region. The left ventricular phase changes and the RPSs in the RBBB and LAD groups were similar to those in the normal group. In the RBBB+LAD group, the latest phase changes occurred in the high anterolateral region. The RPSs of this group were significantly lower than those in the other 3 groups (p<0.01). These data suggest that left anterior hemiblock might coexist with RBBB in patients with RBBB+LAD, whereas left anterior hemiblock might not exist in the majority of patients with LAD alone. (author)

  3. Association between idiopathic intracranial hypertension and sigmoid sinus dehiscence/diverticulum with pulsatile tinnitus: a retrospective imaging study

    Energy Technology Data Exchange (ETDEWEB)

    Zhaohui, Liu; Qing, Li [Capital Medical University, Beijing Tongren Hospital, Department of Radiology, Beijing (China); Cheng, Dong; Xiao, Wang; Xiaoyi, Han; Pengfei, Zhao; Han, Lv; Zhenchang, Wang [Capital Medical University, Beijing Friendship Hospital, Department of Radiology, Beijing (China)

    2015-07-15

    The mechanism of occurrence of sigmoid sinus dehiscence/diverticulum (SSDD) in pulsatile tinnitus (PT) patients remains under debate. Its association with idiopathic intracranial hypertension (IIH) lacks evidence, which is important for therapeutic planning and improving the clinical outcome. This study aimed to evaluate the association between SSDD and IIH by comparing the prevalence of several established imaging features of IIH between PT patients with SSDD and healthy volunteers. Thirty-three unilateral PT patients with SSDD identified on CT images and 33 age- and sex-matched healthy volunteers underwent T1-weighted volumetric magnetic resonance imaging (MRI). The optic nerve, pituitary gland, transverse sinus, and ventricles were assessed. The prevalence of established IIH imaging features was compared between the two groups. Furthermore, the PT patients were divided into two subgroups: PT patients with dehiscence only and PT patients with diverticulum. The same statistical analysis was performed on each pathophysiologic entity respectively. The PT patients with SSDD showed a significantly higher prevalence of empty sella (P < 0.001), flattened posterior sclera (P = 0.001), vertical tortuosity of the optic nerve (P = 0.001), protrusion of the optic nerve (P = 0.006), transverse sinus stenosis (P = 0.011), and distension of the optic nerve sheath (P = 0.000). There were no significant differences between the PT and control groups in the maximum widths of the third and fourth ventricles and the lateral ventricle size. In contrast to controls, the imaging findings persisted in both of pathophysiologic entities, except for transverse sinus stenosis. Several IIH imaging features occur more frequently in PT patients with SSDD than in healthy individuals, which suggests a potential correlation between SSDD with PT and IIH. (orig.)

  4. Association between idiopathic intracranial hypertension and sigmoid sinus dehiscence/diverticulum with pulsatile tinnitus: a retrospective imaging study

    International Nuclear Information System (INIS)

    Zhaohui, Liu; Qing, Li; Cheng, Dong; Xiao, Wang; Xiaoyi, Han; Pengfei, Zhao; Han, Lv; Zhenchang, Wang

    2015-01-01

    The mechanism of occurrence of sigmoid sinus dehiscence/diverticulum (SSDD) in pulsatile tinnitus (PT) patients remains under debate. Its association with idiopathic intracranial hypertension (IIH) lacks evidence, which is important for therapeutic planning and improving the clinical outcome. This study aimed to evaluate the association between SSDD and IIH by comparing the prevalence of several established imaging features of IIH between PT patients with SSDD and healthy volunteers. Thirty-three unilateral PT patients with SSDD identified on CT images and 33 age- and sex-matched healthy volunteers underwent T1-weighted volumetric magnetic resonance imaging (MRI). The optic nerve, pituitary gland, transverse sinus, and ventricles were assessed. The prevalence of established IIH imaging features was compared between the two groups. Furthermore, the PT patients were divided into two subgroups: PT patients with dehiscence only and PT patients with diverticulum. The same statistical analysis was performed on each pathophysiologic entity respectively. The PT patients with SSDD showed a significantly higher prevalence of empty sella (P < 0.001), flattened posterior sclera (P = 0.001), vertical tortuosity of the optic nerve (P = 0.001), protrusion of the optic nerve (P = 0.006), transverse sinus stenosis (P = 0.011), and distension of the optic nerve sheath (P = 0.000). There were no significant differences between the PT and control groups in the maximum widths of the third and fourth ventricles and the lateral ventricle size. In contrast to controls, the imaging findings persisted in both of pathophysiologic entities, except for transverse sinus stenosis. Several IIH imaging features occur more frequently in PT patients with SSDD than in healthy individuals, which suggests a potential correlation between SSDD with PT and IIH. (orig.)

  5. Retrospective assessment of exposure to static magnetic fields during production and development of magnetic resonance imaging systems

    NARCIS (Netherlands)

    Bongers, Suzan|info:eu-repo/dai/nl/313874050; Christopher, Yvette|info:eu-repo/dai/nl/27590184X; Engels, Hans; Slottje, Pauline|info:eu-repo/dai/nl/299345351; Kromhout, Hans|info:eu-repo/dai/nl/074385224

    2014-01-01

    At present, the relationship between chronic exposure to static magnetic fields (SMF) and health effects is unclear. We developed a task-based deterministic model for estimating historical electromagnetic field exposure from the static B-field (B0) of magnetic resonance imaging (MRI) systems, for a

  6. The utilisation and diagnostic yield of radiological imaging in a specialist functional GI disorder clinic: an 11-year retrospective study.

    LENUS (Irish Health Repository)

    Breen, Micheal

    2014-07-25

    The term functional gastrointestinal disorders (FGID) describes various aggregations of chronic gastrointestinal (GI) symptoms not explained by identifiable organic pathology; accordingly, their diagnosis rests on symptom-based criteria and a process of exclusion. Evidence is lacking on the appropriate use of abdominal imaging studies (AIS) in FGIDs.

  7. Quantitative analysis of computed tomography images and early detection of cerebral edema for pediatric traumatic brain injury patients: retrospective study.

    Science.gov (United States)

    Kim, Hakseung; Kim, Gwang-dong; Yoon, Byung C; Kim, Keewon; Kim, Byung-Jo; Choi, Young Hun; Czosnyka, Marek; Oh, Byung-Mo; Kim, Dong-Joo

    2014-10-22

    The purpose of this study was to identify whether the distribution of Hounsfield Unit (HU) values across the intracranial area in computed tomography (CT) images can be used as an effective diagnostic tool for determining the severity of cerebral edema in pediatric traumatic brain injury (TBI) patients. CT images, medical records and radiology reports on 70 pediatric patients were collected. Based on radiology reports and the Marshall classification, the patients were grouped as mild edema patients (n=37) or severe edema patients (n=33). Automated quantitative analysis using unenhanced CT images was applied to eliminate artifacts and identify the difference in HU value distribution across the intracranial area between these groups. The proportion of pixels with HU=17 to 24 was highly correlated with the existence of severe cerebral edema (P<0.01). This proportion was also able to differentiate patients who developed delayed cerebral edema from mild TBI patients. A significant difference between deceased patients and surviving patients in terms of the HU distribution came from the proportion of pixels with HU=19 to HU=23 (P<0.01). The proportion of pixels with an HU value of 17 to 24 in the entire cerebral area of a non-enhanced CT image can be an effective basis for evaluating the severity of cerebral edema. Based on this result, we propose a novel approach for the early detection of severe cerebral edema.

  8. Original article The risk of muscle dysmorphia and the perception of change in retrospective, current and ideal self-image – preliminary study

    Directory of Open Access Journals (Sweden)

    Dorota Mącik

    2014-11-01

    Full Text Available Background A specific type of causes of extended training and gym exercises is muscle dysmorphia. People with this disorder think that their current appearance is not satisfactory, and the focus on the perceived defect is great. The perceived defect usually is connected with body and muscle mass and body shape. According to the conceptual model of dysmorphia proposed by Grieve (2007, the aim of the study was to verify the thesis that the risk of muscle dysmorphia is associated with the negative self-image generalized based on physical appearance. Participants and procedure Twelve women and 18 men, fulfilling the criteria of exercise addiction according to Pope, filled out the ACL scale, answering the questions concerning what kind of person they were before training, who they are now and what kind of person they would like to be. Also, they answered freely the questions concerning their feelings about training. Results A significant difference between perceived retrospective and current self-image was observed. The people examined became, in their opinion, more self-confident, more dominating and independent, and they described themselves in more positive categories. However, there still is relatively a lot of aggression and anxiety. The analysis of the ideal self-image indicates that the presented image performs – at least partly – the defence mechanism role. This is also confirmed by the analysis of the statements of the subjects examined, especially the question about the benefits resulting from the training. Conclusions The results confirm the role of the negative self-image in the risk of muscle dysmorphia. The exercises change self-assessment, but they do not solve the problems that were the reason for it. The characteristics of these problems in further research will facilitate therapy planning.

  9. Short-Term Results of Carotid Endarterectomy and Stenting After the Introduction of Carotid Magnetic Resonance Imaging: A Single-Institution Retrospective Study.

    Science.gov (United States)

    Fukumitsu, Ryu; Yoshida, Kazumichi; Kurosaki, Yoshitaka; Torihashi, Koichi; Sadamasa, Nobutake; Koyanagi, Masaomi; Narumi, Osamu; Sato, Tsukasa; Chin, Masaki; Handa, Akira; Yamagata, Sen; Miyamoto, Susumu

    2017-05-01

    Although carotid artery stenting (CAS) has been gaining popularity as an alternative to carotid endarterectomy (CEA), perioperative stroke rate following contemporary CAS remains significantly higher than stroke rate after CEA. The purpose of this study was to assess perioperative (within 30 days) therapeutic results in patients with carotid stenosis (CS) after introduction of preoperative carotid magnetic resonance imaging plaque evaluation in a single center performing both CEA and CAS. Based on prospectively collected data for patients with CS who were scheduled for carotid revascularization, retrospective analysis was conducted of 295 consecutive patients with CS. An intervention was selected after consideration of periprocedural risks for both CEA and CAS. Concerning risk factors for CAS, results of magnetic resonance imaging plaque evaluation were emphasized with a view toward reducing embolic complications. CAS was performed in 114 patients, and CEA was performed in 181 patients. Comparing baseline characteristics of the 295 patients, age, T1 signal intensity of plaque, symptomatic CS, urgent intervention, and diabetes mellitus differed significantly between CAS and CEA groups. Among patients who underwent CAS, new hyperintense lesions on diffusion-weighted imaging were confirmed in 47 patients. New hyperintense lesions on diffusion-weighted imaging were recognized in 21.4% of patients who underwent CEA (n = 39), significantly less frequent than in patients who underwent CAS. The overall short-term outcome of CEA and CAS is acceptable. Preoperative carotid magnetic resonance imaging evaluation of plaque might contribute to low rates of ischemic complications in CAS. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Clinical indications and radiation doses to the conceptus associated with CT imaging in pregnancy: a retrospective study

    Energy Technology Data Exchange (ETDEWEB)

    Woussen, S.; Vanbeckevoort, D.; Bosmans, H.; Oyen, R. [University Hospitals Leuven, Department of Radiology, Leuven (Belgium); Lopez-Rendon, X.; Zanca, F. [University Hospitals Leuven, Department of Imaging and Pathology, Leuven (Belgium)

    2016-04-15

    To perform an internal audit at a university hospital with the aim of evaluating the number, clinical indication and operating procedure of computed tomography (CT) performed on pregnant patients and of estimating the radiation doses to the conceptus. A retrospective review was conducted of all CT examinations performed in a single centre on pregnant patients between January 2008 and July 2013. The radiation doses to the conceptus were estimated. The results were compared with published data. The number of CT examinations during pregnancy increased from 3-4 per year in 2008-2011 to 11 per year in 2012. The mean estimated conceptus radiation dose was considered negligible for CT of the head and cervical spine, being less than 0.01 mGy, and for CT of the chest, less than 0.1 mGy. The estimated conceptus radiation dose from abdominopelvic CT was on average 28.7 mGy (range 6.7-60.5 mGy). The number of CT scans of pregnant patients increased threefold during the last few years. Most clinical indications and doses were in line with good clinical practice and literature; only in two cases the dose to the conceptus was higher than 50 mGy. (orig.)

  11. Current development of cardiac imaging with multidetector-row CT

    International Nuclear Information System (INIS)

    Becker, Christoph R.; Ohnesorge, Bernd M.; Schoepf, U. Joseph; Reiser, Maximilian F.

    2000-01-01

    Multidector-row CT (MDCT) with retrospective ECG gating allows scanning the entire heart with 1.25 mm slice thickness and 250 ms effective exposure time within 35 s investigation time. The resulting images allow for an accurate high-resolution assessment of morphological detail of both the coronary arteries and the cardiac chambers. Performing a contrast-enhanced MDCT angiography (MD-CTA) in addition to a non-enhanced scan for the detection and quantification of coronary calcifications may be indicated in patients with atypical chest pain and in young patients with high cardiovascular risk. This group of patients may show non-calcified plaques as the first sign of their coronary artery disease. As the proximal part of the coronary arteries is well displayed by MD-CTA it also helps to delineate the course in anomalous coronary vessels. Additional information is drawn from the preoperative use of MD-CTA do determine the distance of the left internal mammarian artery to the left anterior descending coronary artery prior to minimal invasive bypass grafting. Additional indications for MD-CTA are the non-invasive follow up after venous bypass grafting, PTCA, and coronary stent interventions. MD-CTA allows following the course of the coronary vessels to the level of third generation coronary segmental arteries. A definite diagnosis to rule out coronary artery disease can be reliably made in vessels with a diameter of 1.5 mm or greater. With MDCT a number of different atherosclerotic changes can be observed in diseased coronary arteries. Non-stenotic lesions may show tiny calcifications surrounded by large areas of irregularly distributed soft tissue. Calcifications in this type of atherosclerotic coronary artery wall changes appear as 'the tip of iceberg'. Heavy calcifications usually tend to be non-stenotic because of vessel remodelling resulting in a widening of the coronary vessel lumen. Therefore, heavy calcifications appear to act like an 'internal stent' for a

  12. SU-E-J-252: A Motion Algorithm to Extract Physical and Motion Parameters of a Mobile Target in Cone-Beam Computed Tomographic Imaging Retrospective to Image Reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Ali, I; Ahmad, S [University of Oklahoma Health Sciences, Oklahoma City, OK (United States); Alsbou, N [Department of Electrical and Computer Engineering, Ada, OH (United States)

    2014-06-01

    Purpose: A motion algorithm was developed to extract actual length, CT-numbers and motion amplitude of a mobile target imaged with cone-beam-CT (CBCT) retrospective to image-reconstruction. Methods: The motion model considered a mobile target moving with a sinusoidal motion and employed three measurable parameters: apparent length, CT number level and gradient of a mobile target obtained from CBCT images to extract information about the actual length and CT number value of the stationary target and motion amplitude. The algorithm was verified experimentally with a mobile phantom setup that has three targets with different sizes manufactured from homogenous tissue-equivalent gel material embedded into a thorax phantom. The phantom moved sinusoidal in one-direction using eight amplitudes (0–20mm) and a frequency of 15-cycles-per-minute. The model required imaging parameters such as slice thickness, imaging time. Results: This motion algorithm extracted three unknown parameters: length of the target, CT-number-level, motion amplitude for a mobile target retrospective to CBCT image reconstruction. The algorithm relates three unknown parameters to measurable apparent length, CT-number-level and gradient for well-defined mobile targets obtained from CBCT images. The motion model agreed with measured apparent lengths which were dependent on actual length of the target and motion amplitude. The cumulative CT-number for a mobile target was dependent on CT-number-level of the stationary target and motion amplitude. The gradient of the CT-distribution of mobile target is dependent on the stationary CT-number-level, actual target length along the direction of motion, and motion amplitude. Motion frequency and phase did not affect the elongation and CT-number distributions of mobile targets when imaging time included several motion cycles. Conclusion: The motion algorithm developed in this study has potential applications in diagnostic CT imaging and radiotherapy to extract

  13. Right Ventricular Ejection Fraction using ECG-Gated First Pass Cardioangiography

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Young Hee; Lee, Hae Giu; Lee, Sung Yong; Park, Suk Min; Chung, Soo Kyo; Yim, Jeong Ik; Bahk, Yong Whee; Shinn, Kyung Sub; Kim, Young Gyun; Kwon, Soon Seog [Catholic University College of Medicine, Seoul (Korea, Republic of)

    1993-03-15

    Radionuclide cardioangiography has been widely applied and has played major roles in moninvasive assessment of cardiac function. Three techniques, first-pass gated first and gated equilibrium methods have commonly been used to evaluate right ventricular ejection fraction which usually abnormal in the patients with cardiopulmonary disease. It has been known that the gated first pass method is most accurate method among the three techniques in assessment of fight ventricular ejection fraction. The radionuclide right ventricular ejection fraction values were determined in 13 normal subjects and in 15 patients with chronic obstructive pulmonary disease by the gated first pass method and compared with those of the first pass method because there has been no published data of fight ejection fraction by the gated first pass method were compared with the defects from the pulmonary function test performed in the patients with chronic obstructive pulmomary disease. The results were as follows; 1) The values of fight ventricular ejection fraction by the gated first pass method were 50.1 +- 6.1% in normal subjects and 38.5 +- 8.5 in the patients with chronic obstructive pulmonary disease. There was statistically significant difference between the right ventricular ejection fraction of each of the two groups (p<0.05) 2) The right ventricular ejection fraction by the gated first pass method was not linearly correlated ith FEV{sub 1}, VC. DLCO. and FVC as well as P{sub a}O2 and P{sub a}CO2 of the patients with chronic obstructive pulmonary disease. We concluded that right ventricular ejection fraction by the gated first pass method using radionuclide cardioangiography may be useful in clinical assessment of the right ventricular function.

  14. Reproducibility of ECG-gated Ultrasound Diameter Assessment of Small Abdominal Aortic Aneurysms

    DEFF Research Database (Denmark)

    Bredahl, K; Eldrup, N; Meyer, C

    2013-01-01

    No standardised ultrasound procedure to obtain reliable growth estimates for abdominal aortic aneurysms (AAA) is currently available. We investigated the feasibility and reproducibility of a novel approach controlling for a combination of vessel wall delineation and cardiac cycle variation....

  15. Limited value of interlaced ECG-gated radiography in the presence of a normal chest radiograph

    International Nuclear Information System (INIS)

    Chen, J.T.T.; Ravin, C.E.; Handel, D.

    1984-01-01

    Twenty-seven patients with normal posteroanterior and lateral chest radiographs, who were undergoing cardiac catheterization because of symptoms strongly suggesting coronary artery disease, also had posteroanterior and lateral interlaced electrocardiogram-gated radiographs made. In 14 patients, the interlaced radiography system underestimated (suggested hypokinesia) the wall motion, which was normal on cardiac catheterization. In two cases the system overestimated the wall motion, in two others it both under- and overestimated the motion, and in only nine cases was the correlation correct. These data suggest that the technique is of limited application, particularly in cases in which the routine chest radiographs are normal

  16. Magnetic resonance imaging findings of the proximal metacarpus in Quarter Horses used for cutting: Retrospective analysis of 32 horses 2009-2012.

    Science.gov (United States)

    Barrett, M F; Manchon, P T; Hersman, J; Kawcak, C E

    2018-03-01

    Injury to the proximal suspensory ligament is a common cause of lameness in cutting horses. Radiographic and ultrasonographic imaging of lesions responsible for lameness can provide ambiguous results. MRI provides the most comprehensive diagnostic imaging evaluation of lesions specifically affecting cutting horses. To describe the distribution and severity of bone and soft tissue lesions present in the proximal metacarpus of Quarter Horse cutting horses and to assess the impact of these lesions on return to competition. Retrospective case series. Retrospective analysis of 32 cutting horses referred for MRI of the proximal metacarpus between 2009 and 2012 with a 2-year follow-up period. MRI studies were evaluated by a board-certified veterinary radiologist; the severity of lesions was graded from 0 (absent) to 3 (severe). A total of 20 right and 24 left forelimbs (12 bilateral studies) of 32 horses were evaluated. The most common findings were: third metacarpal (McIII) sclerosis at the proximal suspensory ligament (PSL) origin (42/44), McIII resorption at the PSL origin (32/44), PSL dorsal margin fibre irregularity (30/44) and McIII bone contusion (22/39). Of the 30 horses, 22 horses successfully returned to competition, irrespective of severity of injury. Strong correlation exists between the degree of resorption in the palmar cortex of proximal McIII, degree of McIII sclerosis and severity of dorsal margin fibre irregularity. Statistical significance was limited by small study population. Further analysis of prognosis was limited by availability of comprehensive medical records. Cutting horses with proximal metacarpal pain have significant pathological change within the proximal suspensory ligament and its enthesis on the palmar cortex of McIII. Severity of lesions and degree of lameness at the time of diagnosis does not influence return to performance. Accurate diagnosis of proximal metacarpal lesions based on MRI offers clinicians the capacity to select

  17. a New Approach to Physiologic Triggering in Medical Imaging Using Multiple Heart Sounds Alone.

    Science.gov (United States)

    Groch, Mark Walter

    A new method for physiological synchronization of medical image acquisition using both the first and second heart sound has been developed. Heart sounds gating (HSG) circuitry has been developed which identifies, individually, both the first (S1) and second (S2) heart sounds from their timing relationship alone, and provides two synchronization points during the cardiac cycle. Identification of first and second heart sounds from their timing relationship alone and application to medical imaging has, heretofore, not been performed in radiology or nuclear medicine. The heart sounds are obtained as conditioned analog signals from a piezoelectric transducer microphone placed on the patient's chest. The timing relationships between the S1 to S2 pulses and the S2 to S1 pulses are determined using a logic scheme capable of distinguishing the S1 and S2 pulses from the heart sounds themselves, using their timing relationships, and the assumption that initially the S1-S2 interval will be shorter than the S2-S1 interval. Digital logic circuitry is utilized to continually track the timing intervals and extend the S1/S2 identification to heart rates up to 200 beats per minute (where the S1-S2 interval is not shorter than the S2-S1 interval). Clinically, first heart sound gating may be performed to assess the systolic ejection portion of the cardiac cycle, with S2 gating utilized for reproduction of the diastolic filling portion of the cycle. One application of HSG used for physiologic synchronization is in multigated blood pool (MGBP) imaging in nuclear medicine. Heart sounds gating has been applied to twenty patients who underwent analysis of ventricular function in Nuclear Medicine, and compared to conventional ECG gated MGBP. Left ventricular ejection fractions calculated from MGBP studies using a S1 and a S2 heart sound trigger correlated well with conventional ECG gated acquisitions in patients adequately gated by HSG and ECG. Heart sounds gating provided superior

  18. Magnetic resonance imaging for evaluation of congenital heart disease

    International Nuclear Information System (INIS)

    Niwa, Koichiro; Uchishiba, Mika; Tateno, Shigeru; Aotsuka, Hiroyuki; Nakatani, Hayao; Matsuo, Kozo; Fujiwara, Tadashi; Tashima, Kazuyuki.

    1992-01-01

    We applied the segmental analysis of cardiac MR images for evaluation of congenital heart diseases (CHD). One hundred and ninety-three patients with CHD, ranging in age from 20 days to 18 years old, were studied by MRI. This study compared the effectiveness of MRI with cardiac angiography and echocardiography for the evaluation of major diagnosis of CHD and all components of cardiovascular anatomy. ECG-gated MRI was performed by spin echo and gradient refocused imaging techniques operating at 0.5 tesla. In all the patients not only cardiovascular anatomies of CHD but all structures relevant to the identification of arrangement of organs were displayed. In diagnosing a total of 193 of major cardiac anomalies and 741 segments of the vein, the atrium, the ventricle and the great vessels by MRI and angiocardiogram and/or echocardiogram, descrepancies were found in 6 patients (3.1%), and only 18 segments (2.4%), respectively. For vascular and complex cardiac anatomies MRI was able to provide good anatomical details. Based on these findings, the segmental analysis of cardiac MR images was found useful for achieving a systematic diagnosis of CHD. (author)

  19. Evaluation of Blalock-Taussig shunts using magnetic resonance imaging

    International Nuclear Information System (INIS)

    Okajima, Yoshitomo; Tashima, Kazuyuki; Terai, Masaru; Niwa, Koichirou.

    1988-01-01

    Four patients aged 3 to 18 months (mean 13 months) with a total of five Blalock-Taussig shunts (BT shunts; two were original BT shunts and three were modified BT shunts using GOLASKI grafts) underwent evaluation by ECG-gated magnetic resonance imaging. There were two cases with pulmonary atresia with intact ventricular septum, one with double outlet right ventricle with pulmonary stenosis and one with tetralogy of Fallot with pulmonary atresia who underwent bilateral BT shunts. At the time of study, an auscultory shunt murmur was audible in all patients. The magnetic resonance images were obtained with a Picker International Vista MR with a superconducting magnet operating at 0.5 Tesla. A spin echo sequence (echo time 40 msec) was used. All patients were placed within a 30 cm head coil radio antenna and sedated with chloral hydrate or diazepam. Four of 5 shunts were imaged on both coronal sections and sagittal sections during enddiastole. And there was no signal within the grafts. When the velocity of blood flow is beyond the cutoff velocity, the signal intensity of flowing blood is near background level. So we judged these grafts were patient. Our results showed that MRI was a very useful noninvasive method for evaluation of BT shunts. (author)

  20. Evaluation of Blalock-Taussig shunts using magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Okajima, Yoshitomo; Tashima, Kazuyuki; Terai, Masaru; Niwa, Koichirou.

    1988-10-01

    Four patients aged 3 to 18 months (mean 13 months) with a total of five Blalock-Taussig shunts (BT shunts; two were original BT shunts and three were modified BT shunts using GOLASKI grafts) underwent evaluation by ECG-gated magnetic resonance imaging. There were two cases with pulmonary atresia with intact ventricular septum, one with double outlet right ventricle with pulmonary stenosis and one with tetralogy of Fallot with pulmonary atresia who underwent bilateral BT shunts. At the time of study, an auscultory shunt murmur was audible in all patients. The magnetic resonance images were obtained with a Picker International Vista MR with a superconducting magnet operating at 0.5 Tesla. A spin echo sequence (echo time 40 msec) was used. All patients were placed within a 30 cm head coil radio antenna and sedated with chloral hydrate or diazepam. Four of 5 shunts were imaged on both coronal sections and sagittal sections during enddiastole. And there was no signal within the grafts. When the velocity of blood flow is beyond the cutoff velocity, the signal intensity of flowing blood is near background level. So we judged these grafts were patient. Our results showed that MRI was a very useful noninvasive method for evaluation of BT shunts.

  1. SU-F-J-203: Retrospective Assessment of Delivered Proton Dose in Prostate Cancer Patients Based On Daily In-Room CT Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Stuetzer, K; Paessler, T [OncoRay - National Center for Radiation Research in Oncology, Medical Faculty and University Hospital Carl Gustav Carus, Technische Universitaet Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Valentini, C; Thiele, J; Hoelscher, T [Department of Radiation Oncology, University Hospital Carl Gustav Carus, Techenische Universitaet Dresden (Germany); Exner, F [OncoRay - National Center for Radiation Research in Oncology, Medical Faculty and University Hospital Carl Gustav Carus, Technische Universitaet Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); now with: University of Wuerzburg, Department of Radiation Oncology, Wuerzburg (Germany); Krause, M; Richter, C [OncoRay - National Center for Radiation Research in Oncology, Medical Faculty and University Hospital Carl Gustav Carus, Technische Universitaet Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Department of Radiation Oncology, University Hospital Carl Gustav Carus, Techenische Universitaet Dresden (Germany); Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology, Dresden (Germany); German Cancer Consortium (DKTK), Dresden, Germany and German Cancer Research Center (DKFZ), Heidelberg (Germany)

    2016-06-15

    Purpose: Retrospective calculation of the delivered proton dose in prostate cancer patients based on a unique dataset of daily CT images. Methods: Inter-fractional motion in prostate cancer patients treated at our proton facility is counteracted by water-filled endorectal ballon and bladder filling protocol. Typical plans (XiO, Elekta Instruments AB, Stockholm) for 74 Gy(RBE) sequential boost treatment in 37 fractions include two series of opposing lateral double-scattered proton beams covering the respective iCTV. Stability of fiducial markers and anatomy were checked in 12 patients by daily scheduled in-room control CT (cCT) after immobilization and positioning according to bony anatomy utilizing orthogonal X-ray. In RayStation 4.6 (RaySearch Laboritories AB, Stockholm), all cCTs are delineated retrospectively and the treatment plans were recalculated on the planning CT and the registered cCTs. All fraction doses were accumulated on the planning CT after deformable registration. Parameters of delivered dose to iCTV (D98%>95%, D2%<107%), bladder (V75Gy<15%, V70Gy<25%, V65Gy<30%), rectum (V70Gy<10%, V50Gy<40%) and femoral heads (V50Gy<5%) are compared to those in the treatment plan. Intra-therapy variation is represented in DVH bands. Results: No alarming differences were observed between planned and retrospectively accumulated dose: iCTV constraints were met, except for one patient (D98%=94.6% in non-boosted iCTV). Considered bladder and femoral head values were below the limits. Rectum V70Gy was slightly exceeded (<11.3%) in two patients. First intra-therapy variability analysis in 4 patients showed no timedependent parameter drift, revealed strongest variability for bladder dose. In some fractions, iCTV coverage (D98%) and rectum V70Gy was missed. Conclusion: Double scattered proton plans are accurately delivered to prostate cancer patients due to fractionation effects and the applied precise positioning and immobilization protocols. As a result of rare

  2. MR neurography (MRN) of the long thoracic nerve: retrospective review of clinical findings and imaging results at our institution over 4 years

    Energy Technology Data Exchange (ETDEWEB)

    Deshmukh, Swati [Northwestern University, Chicago, IL (United States); Fayad, Laura M. [The Johns Hopkins Medical Institutions, The Russell H. Morgan Department of Radiology and Radiological Science, Baltimore, MD (United States); The Johns Hopkins Medical Institutions, Department of Oncology, Baltimore, MD (United States); The Johns Hopkins Medical Institutions, Department of Orthopaedic Surgery, Baltimore, MD (United States); Ahlawat, Shivani [The Johns Hopkins Medical Institutions, The Russell H. Morgan Department of Radiology and Radiological Science, Baltimore, MD (United States)

    2017-11-15

    Long thoracic nerve (LTN) injury can result in ipsilateral serratus anterior palsy and scapular winging. Traditional means of evaluating patients with suspected LTN injury include physical examination and electrodiagnostic studies. The purpose of our study is to describe high-resolution magnetic resonance (MR) findings in patients with clinical suspicion of LTN neuropathy. In this HIPAA-compliant, IRB-approved, retrospective study, two radiologists reviewed MR imaging performed for long thoracic neuropathy. Clinical presentation, electrodiagnostic studies and MR imaging of 20 subjects [mean age 37 ± 13 years; 25% (5/20) female] were reviewed. Observers reviewed MR imaging for LTN signal intensity, size, course, presence or absence of mass and secondary findings [skeletal muscle denervation (serratus anterior, trapezius, rhomboid) and scapular winging]. Descriptive statistics were reported. Clinical indications included trauma (n = 5), hereditary neuropathy (n = 1), pain (n = 8), winged scapula (n = 6), brachial plexitis (n = 4) and mass (n = 1). Electrodiagnostic testing (n = 7) was positive for serratus anterior denervation in three subjects. Abnormal LTN signal intensity, size, course or mass was present in 0/20. Secondary findings included skeletal muscle denervation in the serratus anterior in 40% (8/20), trapezius in 20% (4/20) and rhomboid in 20% (4/20). In 5% (1/20), an osteochondroma simulated a winged scapula, and in 2/20 (10%) MR showed scapular winging. High-resolution MR imaging is limited in its ability to visualize the long thoracic nerve directly, but does reveal secondary signs that can confirm a clinical suspicion of LTN injury. (orig.)

  3. Image-guided automated needle biopsy of 106 thoracic lesions: a retrospective review of diagnostic accuracy and complication rates

    International Nuclear Information System (INIS)

    Connor, S.; Dyer, J.; Guest, P.

    2000-01-01

    We reviewed the diagnostic accuracy and complication rates of transthoracic needle biopsy (TNB) with an automated 18-gauge core biopsy needle and gun, using either fluoroscopic or CT guidance. One hundred six lesions were biopsied in 103 patients between 1992 and 1998. Hard-copy images, imaging reports, pathology reports and clinical notes were reviewed. In 3 patients it was not possible to establish the lesion as either malignant or benign from the available follow-up, so these were removed from the analysis of diagnostic accuracy. Adequate samples for histological diagnosis were obtained in 104 of 106 (98 %) biopsies. There were 75 of 85 (88 %) true-positive core biopsies for malignant lesions and a specific cell type was identified in 70 of 85 (82 %) cases. A specific histological diagnosis was obtained in 12 of 18 (66 %) biopsies. There was a 19 % rate of pneumothorax with only 2.4 % requiring drainage. Minor haemoptysis occurred in 3.8 % of procedures. The TNB technique with an automated core biopsy needle provides a high level of diagnostic accuracy, effectively distinguishes cell type in malignancy and provides a definite diagnosis in benign disease more frequently than fine needle aspiration (FNA). There is no increased complication rate compared with FNA. (orig.)

  4. Diagnosis of right-sided varicocele: A retrospective comparative study between clinical examination, Doppler findings, US imaging and vascular anatomy at phlebography

    International Nuclear Information System (INIS)

    Cariati, Maurizio; Pieri, Stefano; Agresti, Paolo; Cariati, Massimiliano; Candito, Davide Fabio; Damiani, Giovanni; Marzano, Domenico

    2012-01-01

    Historically varicocele is diagnosed almost exclusively on the left side. The introduction of new imaging techniques has allowed the identification and characterization of right varicocele. This study aims to compare the diagnostic accuracy of various imaging techniques to data obtained using phlebography in the diagnosis of right varicocele. Patients treated for isolated right varicocele between 1992 and 2010 were retrospectively identified. Data from clinical examination, Doppler-USS, Color-Doppler-USS and Retrograde Phlebography were collected for each patient. 133 out of 4305 patients (3.1%) presented with an isolated right varicocele. 34 of these patients (25.6%) presented with palpable right varicocele. Doppler-USS identified various degrees of type I right venous reflux in 90 patients (67.7%). Phlebography showed venous reflux in all the patients (133), although with variability in terms of internal spermatic vein anatomy. Right varicocele is characterized by predictable anatomic features. Identification and characterization of these features is useful in guiding percutaneous treatment, allowing to optimize radiological display and reducing failure rate

  5. Diagnosis of right-sided varicocele: A retrospective comparative study between clinical examination, Doppler findings, US imaging and vascular anatomy at phlebography

    Energy Technology Data Exchange (ETDEWEB)

    Cariati, Maurizio, E-mail: davide.candito@libero.it [U.O.C. Radiologia, A.O. San Carlo Borromeo, via Pio II 3, 20153 Milan (Italy); Pieri, Stefano, E-mail: stefano.pieri@scamilloforlanini.rm.it [U.O.C. Diagnostica per Immagini Cardioscienze, A.O. San Camillo - Forlanini, Piazza Carlo Forlanini 1, 00151 Rome (Italy); Agresti, Paolo, E-mail: paolo.agresti@scamilloforlanini.rm.it [U.O.C. Diagnostica per Immagini Cardioscienze, A.O. San Camillo - Forlanini, Piazza Carlo Forlanini 1, 00151 Rome (Italy); Cariati, Massimiliano, E-mail: massimiliano.cariati@kcl.ac.uk [Department of Academic Oncology, King' s College London, 3rd Floor Bermondsey Wing, Guy' s Hospital, Great Maze Pond, London SE1 9RT (United Kingdom); Candito, Davide Fabio, E-mail: davide.candito@yahoo.it [Scuola di Specializzazione in Radiodiagnostica, Facoltà di Medicina e Chirurgia, Università degli studi di Milano, via Festa del Perdono 7, 20122 Milan (Italy); Damiani, Giovanni, E-mail: damiani_giovanni@libero.it [Scuola di Specializzazione in Radiodiagnostica, Facoltà di Medicina e Chirurgia, Università degli studi di Milano, via Festa del Perdono 7, 20122 Milan (Italy); Marzano, Domenico, E-mail: domenico.marzano@scamilloforlanini.rm.it [U.O.C. Urologia, A.O. San Camillo - Forlanini, Piazza Carlo Forlanini 1, 00151 Rome (Italy)

    2012-09-15

    Historically varicocele is diagnosed almost exclusively on the left side. The introduction of new imaging techniques has allowed the identification and characterization of right varicocele. This study aims to compare the diagnostic accuracy of various imaging techniques to data obtained using phlebography in the diagnosis of right varicocele. Patients treated for isolated right varicocele between 1992 and 2010 were retrospectively identified. Data from clinical examination, Doppler-USS, Color-Doppler-USS and Retrograde Phlebography were collected for each patient. 133 out of 4305 patients (3.1%) presented with an isolated right varicocele. 34 of these patients (25.6%) presented with palpable right varicocele. Doppler-USS identified various degrees of type I right venous reflux in 90 patients (67.7%). Phlebography showed venous reflux in all the patients (133), although with variability in terms of internal spermatic vein anatomy. Right varicocele is characterized by predictable anatomic features. Identification and characterization of these features is useful in guiding percutaneous treatment, allowing to optimize radiological display and reducing failure rate.

  6. I-123-mIBG myocardial imaging for assessment of risk for a major cardiac event in heart failure patients: insights from a retrospective European multicenter study

    Energy Technology Data Exchange (ETDEWEB)

    Agostini, Denis [CHU Cote de Nacre, Caen (France); Verberne, Hein J. [Academic Medical Centre, Amsterdam (Netherlands); Burchert, Wolfgang [Ruhr University Bochum, Institute of Radiology, Nuclear Medicine and Molecular Imaging, Heart and Diabetes Center NRW, Bad Oeyenhausen (Germany); Knuuti, Juhani [Turku University Central Hospital, Turku (Finland); Povinec, Pavol [Comenius University School of Medicine, Bratislava (Slovakia); Sambuceti, Gianmario [University of Genova, Genova (Italy); Unlu, Mustafa [Gazi University, Ankara (Turkey); Estorch, Montserrat [Hospital Sant Pau, Barcelona (Spain); Banerjee, Gopa; Jacobson, Arnold F. [GE Healthcare, Princeton, NJ (United States)

    2008-03-15

    Single-center experiences have shown that myocardial meta-iodobenzylguanidine (mIBG) uptake has prognostic value in heart failure (HF) patients. To verify these observations using a rigorous clinical trial methodology, a retrospective review and prospective quantitative reanalysis was performed on a series of cardiac {sup 123}I-mIBG scans acquired during a 10-year period at six centers in Europe. {sup 123}I-mIBG scans obtained on 290 HF patients [(262 with left ventricular ejection fraction (LVEF) < 50%)] from 1993 to 2002 were reanalyzed using a standardized methodology to determine the heart-to-mediastinum ratio (H/M) on delayed planar images. All image results were verified by three independent reviewers. Major cardiac events [MCEs; cardiac death, cardiac transplant, potentially fatal arrhythmia (including implantable cardioverter-defibrillator discharge)] during 24-month follow-up were confirmed by an adjudication committee. MCEs occurred in 67 patients (26%): mean H/M ratio was 1.51 {+-} 0.30 for the MCE group and 1.97 {+-} 0.54 for the non-MCE group (p < 0.001). Two-year event-free survival using an optimum H/M ratio threshold of 1.75 was 62% for H/M ratio less than 1.75, 95% for H/M ratio greater than or equal to 1.75 (p < 0.0001). Logistic regression showed H/M ratio and LVEF as the only significant predictors of MCE. Using the lower and upper H/M quartiles of 1.45 and 2.17 as high- and very low-risk thresholds, 2-year event-free survival rates were 52% and 98%, respectively. Among patients with LVEF {<=} 35% and H/M {>=} 1.75 (n = 73), there were nine MCEs because of progressive HF and only one because of an arrhythmia. Application of a clinical trial methodology via the retrospective reanalysis of {sup 123}I-mIBG images confirms the previously reported prognostic value of this method in HF patients, including potential identification of a quantitative threshold for low risk for cardiac mortality and potentially fatal ventricular arrhythmias. (orig.)

  7. Transthoracic Doppler echocardiography to predict optimal tube pulsing window for coronary artery CT angiography

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Gang, E-mail: cjr.sungang@vip.163.com [Department of Medical Imaging, Jinan Military General Hospital, No. 25, Shifan Road, Jinan, Shandong Province 250031 (China); Li, Min, E-mail: limin22000@yahoo.com.cn [Department of Medical Imaging, Jinan Military General Hospital, No. 25, Shifan Road, Jinan, Shandong Province 250031 (China); Jiang, Xiang-sen, E-mail: jiangxiangsen123@126.com [Department of Medical Imaging, Jinan Military General Hospital, No. 25, Shifan Road, Jinan, Shandong Province 250031 (China); Li, Li, E-mail: leely1976@yahoo.com.cn [Department of Medical Imaging, Jinan Military General Hospital, No. 25, Shifan Road, Jinan, Shandong Province 250031 (China); Peng, Zhao-hui, E-mail: zhaohuipeng_R@163.com [Department of Medical Imaging, Jinan Military General Hospital, No. 25, Shifan Road, Jinan, Shandong Province 250031 (China); Mu, Nan-nan, E-mail: munannan22000@sohu.com [Department of Medical Imaging, Jinan Military General Hospital, No. 25, Shifan Road, Jinan, Shandong Province 250031 (China)

    2012-09-15

    Rationale and objective: To evaluate the feasibility of transthoracic Doppler echocardiography to determine the optimal pulsing windows for CT coronary angiography to narrow the pulsing windows further, especially in higher heart rate. Materials and methods: Doppler was performed on 135 patients before CT scanning. For Doppler, the intervals with minimal motion were evaluated during both systole and diastole integrating electrocardiogram (ECG) intervals. For CT scanning, the retrospective ECG-gating was applied and the optimal reconstruction intervals were determined. The accuracy of Doppler analysis to predict the optimal reconstruction intervals was tested. The predicted length of pulsing windows was compared between Doppler analysis and traditional prospective ECG-gating protocol (heart rate ≦ 65 bpm, 60–76%; 66–79 bpm, 30–77%; ≧80 bpm, 31–47%). Results: According to Doppler analysis, the mean length of intervals with minimal motion in systole was 106.4 ± 39.2 ms and 125.2 ± 92.0 ms in diastole. When the intervals with minimal motion during diastole > 90 ms, the optimal reconstruction intervals were located at diastole; otherwise, at systole (P < 0.001). The optimal reconstruction intervals in 93.8% (132/135) patients could be predicted accurately by Doppler analysis. If the optimal reconstruction intervals predicted by Doppler were applied as the exposure windows, the mean length of pulsing windows should has been 105.2 ± 69.4 ms (range: 26.9–510.3 ms), which was significantly shorter than that of traditional prospective ECG-gating protocol (232.0 ± 120.2 ms, range: 93.2–427.3 ms, P < 0.001). Conclusion: Doppler can help detecting the optimal pulsing windows accurately. Prospective ECG-gating incorporating Doppler analysis may narrow pulsing windows significantly while maintaining image quality.

  8. Transthoracic Doppler echocardiography to predict optimal tube pulsing window for coronary artery CT angiography

    International Nuclear Information System (INIS)

    Sun, Gang; Li, Min; Jiang, Xiang-sen; Li, Li; Peng, Zhao-hui; Mu, Nan-nan

    2012-01-01

    Rationale and objective: To evaluate the feasibility of transthoracic Doppler echocardiography to determine the optimal pulsing windows for CT coronary angiography to narrow the pulsing windows further, especially in higher heart rate. Materials and methods: Doppler was performed on 135 patients before CT scanning. For Doppler, the intervals with minimal motion were evaluated during both systole and diastole integrating electrocardiogram (ECG) intervals. For CT scanning, the retrospective ECG-gating was applied and the optimal reconstruction intervals were determined. The accuracy of Doppler analysis to predict the optimal reconstruction intervals was tested. The predicted length of pulsing windows was compared between Doppler analysis and traditional prospective ECG-gating protocol (heart rate ≦ 65 bpm, 60–76%; 66–79 bpm, 30–77%; ≧80 bpm, 31–47%). Results: According to Doppler analysis, the mean length of intervals with minimal motion in systole was 106.4 ± 39.2 ms and 125.2 ± 92.0 ms in diastole. When the intervals with minimal motion during diastole > 90 ms, the optimal reconstruction intervals were located at diastole; otherwise, at systole (P < 0.001). The optimal reconstruction intervals in 93.8% (132/135) patients could be predicted accurately by Doppler analysis. If the optimal reconstruction intervals predicted by Doppler were applied as the exposure windows, the mean length of pulsing windows should has been 105.2 ± 69.4 ms (range: 26.9–510.3 ms), which was significantly shorter than that of traditional prospective ECG-gating protocol (232.0 ± 120.2 ms, range: 93.2–427.3 ms, P < 0.001). Conclusion: Doppler can help detecting the optimal pulsing windows accurately. Prospective ECG-gating incorporating Doppler analysis may narrow pulsing windows significantly while maintaining image quality

  9. The utilisation and diagnostic yield of radiological imaging in a specialist functional GI disorder clinic: an 11-year retrospective study

    International Nuclear Information System (INIS)

    Breen, Micheal; O'Neill, Siobhan B.; O'Donovan, Joanne P.; McWilliams, Sebastian; Murphy, Kevin P.; Maher, Michael M.; Desmond, Alan N.; Shanahan, Fergus; Quigley, Eamonn M.

    2014-01-01

    The term functional gastrointestinal disorders (FGID) describes various aggregations of chronic gastrointestinal (GI) symptoms not explained by identifiable organic pathology; accordingly, their diagnosis rests on symptom-based criteria and a process of exclusion. Evidence is lacking on the appropriate use of abdominal imaging studies (AIS) in FGIDs. We investigated the utilisation of AIS (site, modality, diagnostic yield/significance) at a tertiary FGID clinic over an 11-year period. Of 1,621 patients, 507 (31 %; 67.5 % women, mean age 43.9 ± 17.37 years) referred from primary care had 997 AIS (1.7 per patient): ultrasonography (US) 36.1 %, fluoroscopy (FLS) 28.8 %, computed tomography (CT) 19.6 %, plain radiography (PR) 13.5 %, nuclear medicine (NM) 1 %. Of the 997 AIS, 55.6 % (554/997) were normal. Of the AIS with positive findings, 9.9 % (62/625) were deemed 'probably significant' and 14.7 % (92/625) 'significant'. Of the CT and FLS studies, 12.3 % and 13.6 %, respectively, yielded 'significant' abnormalities compared to 2.2 % of the US studies and 2.1 % of the PR studies. CT identified five of seven neoplasms, associated with male sex, increasing age and symptom onset after age 50 years. This study confirmed low use of AIS in tertiary FGID clinics and a high proportion of normal studies. Barium swallow/meal and CT were more likely to identify 'probably significant' or 'significant' findings, including neoplasms. (orig.)

  10. Effect of Clozapine vs Other Second-Generation Antipsychotics on Hospitalization and Seclusion: A Retrospective Mirror-Image Study in a Japanese Public Psychiatric Hospital.

    Science.gov (United States)

    Misawa, Fuminari; Suzuki, Takefumi; Fujii, Yasuo

    2017-12-01

    Clozapine has been regarded as the gold standard for patients with treatment-resistant schizophrenia, but a recent network meta-analysis has questioned its relative superiority over other second-generation antipsychotics (SGAs) such as olanzapine and risperidone. We conducted a retrospective mirror-image study of clozapine vs other SGAs to evaluate real-world effectiveness of clozapine in terms of the duration of hospitalization and seclusion, both of which represent a critical outcome. We included all patients who initiated clozapine at the Yamanashi Prefectural KITA Hospital and had continued to take any SGA(s) other than clozapine for at least 1 year before the initiation of clozapine. We obtained data on hospitalization and seclusion during 1 year of SGA treatment (SGA phase) and 1 year after the treatment was switched to clozapine (clozapine phase). The study included 35 patients (21 men, 31 with schizophrenia, 4 with schizoaffective disorder) with the average ± SD age of 37.3 ± 11.1 years. The results indicated that total hospitalization days did not differ significantly between SGA and clozapine treatment. However, total duration of seclusion was significantly shorter in the clozapine phase than in the SGA phase. Furthermore, the number of patients who were secluded at least once was significantly smaller in the clozapine phase than in the SGA phase. The results were essentially unchanged when outlier patients were excluded and only when patients taking olanzapine and/or risperidone during the SGA phase were considered. Although the findings from this retrospective analysis need to be further tested in prospective trials, they endorse the relative effectiveness of clozapine over other SGAs in the real world.

  11. The Role of Magnetic Resonance Imaging in the Investigation and Management of Invasive Lobular Carcinoma-A 3-Year Retrospective Study in Two District General Hospitals.

    Science.gov (United States)

    Derias, Mina; Subramanian, Ashok; Allan, Simon; Shah, Elizabeth; Teraifi, Hassan El; Howlett, David

    2016-07-01

    Invasive lobular carcinoma (ILC) accounts for 5-15% of breast cancers. In comparison to other types of breast cancer, ILC is more likely to be associated with multifocal and contralateral breast involvement as well as a tendency to a diffuse infiltrative growth pattern which can represent a diagnostic challenge. The National Institute of Clinical Excellence guidelines in 2009 recommended the use of magnetic resonance imaging (MRI) in the preoperative assessment of ILC. This study aims to assess compliance with the guidelines in two District General Hospitals and the utility of MRI in the investigation of ILC. All cases of ILC between 2011 and 2013 were retrospectively identified from the pathology database and their breast imaging findings, pathology report, and operative intervention were reviewed. A total of 126 patients were identified with ILC, of these 46 had MRI preoperatively (36.5%). MRI upgraded mammography/ultrasound diagnoses in 10 patients (21.7%). MRI showed multicentric unilateral disease in 17 patients (37.0%) occult on ultrasound/mammogram, with these patients undergoing mastectomy and 16/17 (94.1%) confirmed multifocality on pathology. MRI showed a contralateral lesion in 9 patients (19.6%), four (8.7%) of which were malignant and had bilateral surgery, and five (10.9%) were benign on further imaging/biopsy. MRI also downgraded three patients (6.5%) to unifocal disease with reported multifocal appearances on mammography/ultrasound, and these patients underwent breast-conserving surgery. MRI adds significant additional information to mammograms/ultrasound in ILC and should be undertaken in all such cases preoperatively assuming no contraindication. © 2016 Wiley Periodicals, Inc.

  12. Association between the extent of sigmoid sinus dehiscence and an occurrence of pulsatile tinnitus: a retrospective imaging study

    International Nuclear Information System (INIS)

    Dong, C.; Zhao, P.; Liu, Z.; Xu, W.; Lv, H.; Pang, S.; Wang, Z.

    2016-01-01

    Aim: To assess the extent of sigmoid sinus dehiscence (SSD) on high-resolution computed tomography venography (HRCTV) or high-resolution computed tomography (HRCT) images in pulsatile tinnitus (PT) and non-PT groups to determine whether there is an association between the extent of SSD and occurrence of PT. Materials and methods: Twenty-eight SSD patients with ipsilateral PT and 28 age- and gender-matched SSD patients without PT who underwent HRCTV or HRCT were enrolled in this study and categorised into two groups: “PT group” and “non-PT group”. The extent of SSD in each group was calculated and compared. Results: The largest transverse diameter and largest vertical diameter of SSD in the PT group were 6.21±1.7 and 6.15±2.19 mm, respectively. The largest transverse diameter and largest vertical diameter of SSD in the non-PT group were 3.06±1.38 and 2.51±1.03 mm, respectively. The extent of SSD was statistically different between the two groups (p<0.001; p<0.001). Conclusions: As a cause of PT, SSD can also occur in individuals without PT symptoms. Preliminary findings suggest that there may be a potential correlation between the extent of SSD and an occurrence of PT. - Highlights: • We compared the extent of sigmoid sinus dehiscence in pulsatile tinnitus and non-pulsatile tinnitus groups. • The sigmoid sinus dehiscence in the pulsatile tinnitus patients was larger than those in non-pulsatile tinnitus patients. • There may be a potential correlation between the extent of sigmoid sinus dehiscence and an occurrence of pulsatile tinnitus.

  13. The utilisation and diagnostic yield of radiological imaging in a specialist functional GI disorder clinic: an 11-year retrospective study

    Energy Technology Data Exchange (ETDEWEB)

    Breen, Micheal; O' Neill, Siobhan B.; O' Donovan, Joanne P.; McWilliams, Sebastian [Cork University Hospital, Department of Radiology, Cork (Ireland); Murphy, Kevin P.; Maher, Michael M. [Cork University Hospital, Department of Radiology, Cork (Ireland); University College Cork, Department of Radiology, Cork (Ireland); Desmond, Alan N. [Cork University Hospital, Department of Medicine, Cork (Ireland); Shanahan, Fergus; Quigley, Eamonn M. [Cork University Hospital, Department of Medicine, Cork (Ireland); University College Cork, Alimentary Pharmabiotic Center, Cork (Ireland)

    2014-12-15

    The term functional gastrointestinal disorders (FGID) describes various aggregations of chronic gastrointestinal (GI) symptoms not explained by identifiable organic pathology; accordingly, their diagnosis rests on symptom-based criteria and a process of exclusion. Evidence is lacking on the appropriate use of abdominal imaging studies (AIS) in FGIDs. We investigated the utilisation of AIS (site, modality, diagnostic yield/significance) at a tertiary FGID clinic over an 11-year period. Of 1,621 patients, 507 (31 %; 67.5 % women, mean age 43.9 ± 17.37 years) referred from primary care had 997 AIS (1.7 per patient): ultrasonography (US) 36.1 %, fluoroscopy (FLS) 28.8 %, computed tomography (CT) 19.6 %, plain radiography (PR) 13.5 %, nuclear medicine (NM) 1 %. Of the 997 AIS, 55.6 % (554/997) were normal. Of the AIS with positive findings, 9.9 % (62/625) were deemed 'probably significant' and 14.7 % (92/625) 'significant'. Of the CT and FLS studies, 12.3 % and 13.6 %, respectively, yielded 'significant' abnormalities compared to 2.2 % of the US studies and 2.1 % of the PR studies. CT identified five of seven neoplasms, associated with male sex, increasing age and symptom onset after age 50 years. This study confirmed low use of AIS in tertiary FGID clinics and a high proportion of normal studies. Barium swallow/meal and CT were more likely to identify 'probably significant' or 'significant' findings, including neoplasms. (orig.)

  14. Gated listmode acquisition with the QuadHIDAC animal PET to image mouse hearts

    International Nuclear Information System (INIS)

    Schaefers, K.P.; Lang, N.; Stegger, L.; Schober, O.; Schaefers, M.

    2006-01-01

    Purpose: the aim of this study was to develop ECG and respiratory gating in combination with listmode acquisition for the quadHIDAC small-animal PET scanner. Methods: ECG and respiratory gating was realized with the help of an external trigger device (BioVET) synchronized with the listmode acquisition. Listmode data of a mouse acquisition (injected with 6.5 MBq of 18 F-FDG) were sorted according to three different gating definitions: 12 cardiac gates, 8 respiratory gates and a combination of 8 cardiac and 8 respiratory gates. Images were reconstructed with filtered back-projection (ramp filter), and parameters like left ventricular wall thickness (WT), wall-to-wall separation (WS) and blood to myocardium activity ratios (BMR) were calculated. Results: cardiac gated images show improvement of all parameters (WT 2.6 mm, WS 4.1 mm, BRM 2.3) in diastole compared to ungated images (WT 3.0 mm, WS 3.4 mm, BMR 1.3). Respiratory gating had little effect on calculated parameters. Conclusion: ECG gating with the quadHIDAC can improve myocardial image quality in mice. This could have a major impact on the calculation of an image-derived input function for kinetic modelling. (orig.)

  15. Evaluation of blood signal in cardiac MR imaging using ''black-blood'' technique

    International Nuclear Information System (INIS)

    Nakanishi, Tadashi; Yamada, Takayuki; Tamura, Akihisa; Miyasaka, Kenji; Kohata, Minako; Ono, Chiaki; Kajima, Toshio; Ito, Katsuhide

    1999-01-01

    Degradation of image quality encountered in cardiac imaging has been attributed to flowing blood signal in the ventricular cavity. To solve this problem, a sequence in which a pair of selective and non-selective inversion pulse in used for a preparation pulse, has been proposed. However, even with this sequence we frequently observed the signal in the blood pool caused by blood itself rather than blood flow. In this article, we investigated the characteristics of those signals. Five healthy normal volunteers and 13 patients with ischemic heart disease were scanned with a 1.5-tesla MR imager. Breath-hold ECG gated fast spin echo with the pair of inversion pulses was performed to obtain cardiac images with T 2 contrast. Typical blood signal appeared as inhomogeneous high intense band adjacent to inner surface of left ventricular apex. At ventricular base, no such signal was encountered even at akinetic myocardium in patients with old myocardial infarction. This signal was observed in all volunteers and 39% of patients. Decrease of TR resulting from tachycardia tended to reduce the blood signal in the left ventricular cavity. Thicker slice section and selective inversion pulse tended to increase the blood signal. Recognition of the signal is essential to differentiate true myocardial infarcts from blood signal, although bright blood imaging like gradient echo or thinner section can partly be helpful. (author)

  16. New imaging characteristics for predicting postoperative neurologic status in patients with metastatic epidural spinal cord compression. A retrospective analysis of 81 cases.

    Science.gov (United States)

    Lei, Mingxing; Liu, Shubin; Yang, Shaoxing; Liu, Yaosheng; Wang, Cheng; Gao, Hongjun

    2017-06-01

    Several clinical features have been proposed for the prediction of postoperative functional outcome in patients with metastatic epidural spinal cord compression (MESCC). However, few articles address the relationship between preoperative imaging characteristics and the postoperative neurologic status. This study aims to analyze the postoperative functional outcome and to identify new imaging parameters for predicting postoperative neurologic status in patients with MESCC. This study is a retrospective consecutive case series of patients with MESCC who were treated surgically. We assessed 81 consecutive patients who were treated with decompressive surgery for MESCC between 2013 and 2015. Eight imaging characteristics were analyzed for postoperative motor status by logistic regression models. Neurologic function was assessed using the Frankel grade preoperatively and postoperatively. The following imaging characteristics were assessed for postoperative motor status: location of lesions in the spine, lamina involvement, retropulsion of the posterior wall, number of vertebrae involved, pedicle involvement, fracture of any involved vertebrae, T2 signal of the spinal cord at the compression site, and circumferential angle of spinal cord compression (CASCC). The postoperative neurologic outcome was better than the preoperative neurologic status (p<.01). In the entire group, 40.7% of the patients were non-ambulatory before the surgical procedure, whereas 77.8% of the patients could walk after surgery (p=.01). In the multivariate analysis, the location of the lesions (odds ratio [OR]: 3.89, 95% confidence interval [CI]: 1.19-12.77, p=.02) and CASCC (OR: 2.31, 95% CI: 1.44-3.71, p<.01) were significantly associated with postoperative neurologic outcome. A CASCC of more than 180° was associated with an increased OR that approached significance, and the larger the CASCC, the higher the risk of poor postoperative neurologic status. The postoperative neurologic status was

  17. MR imaging of acute myocardial infarction in pigs using Gd-DTPA-labeled dextran

    International Nuclear Information System (INIS)

    Wikstroem, M.; Martinussen, H.J.; Wikstroem, G.; Ericsson, A.; Nyman, R.; Waldenstroem, A.; Hemmingsson, A.

    1992-01-01

    Myocardial infarctions were induced in 12 pigs. In 6 pigs, dextran-(Gd-DTPA)15 (≅ 0.1 mmol Gd/kg b.w.) was injected i.v. 4 to 4.5 hours after coronary artery occlusion. ECG gated MR images were obtained repeatedly before (n=4) and after (n=6) contrast medium injection. Relaxation times in blood samples were measured repeatedly. The animals were scarificed 2 hours after contrast medium administration. The hearts were excised, reaxamined in the MR equipment and stained with triphenyltetrazolium chloride (TTC) in order to define areas of infarction. The remaining 6 pigs were sacrificed 6 hours after occlusion without administration of contrast medium. These hearts were only imaged ex vivo. In vivo, the infarctions could not be identified with or without dextran-(Gd-DTPA)15. Ex vivo, without contrast medium, the infarctions had an increased signal intensity, most pronounced in the T2-weighted images. Dextran-(Gd-DTPA)15 caused a prolonged, pronounced shortening of T1 und T2 in blood samples. The infarct demarcation improved in the T1-weighted images after injection of dextran-(Gd-DTPA)15, due to a moderate enhancement in normal myocardium and a stronger enhancement at the periphery of the infarctions, while the central parts of the infarctions were only weakly enhanced. (orig.)

  18. Magnetic resonance imaging in complete type endocardial cushion defect

    International Nuclear Information System (INIS)

    Li Kuncheng; Yang Xiaoping; Yao Xinyu; Yang Yunxia; Liu Yuqing; Pang Zhixian

    1999-01-01

    Objective: To evaluate the value and limitation of magnetic resonance imaging (MRI) in complete type endocardial cushion defect (ETECD). Methods: Eight patients (male 5, female 3) were scanned by MRI with ECG-gated spin echo (SE) and gradient echo (GE) cine techniques. The diagnosis of CTECD was made by X-ray plain film, echocardiography, X-ray right cardiac catheterization and angiocardiography, as well as MRI four patients were treated with operation. Results: Every chamber of the heart was enlarged, more serious in the right atrium and ventricle, with thickening of right ventricular wall on MRI in majority of cases. The endocardial cushion disappeared, so the four chambers of the heart were directly connected with each other, and presented a cross shape. Ventricular septal membrane defect and type I atrial septal defect were depicted also. The normal structure of mitral and tricuspid valves were not intact. There were 6 cases with pulmonary hypertension, 2 cases with Tetralogy of Fallot, 4 cases with right aorta arch and descending aorta, 1 patient with dextroverted heart and another with persistent left superior vena cava connected with coronary sinus. The cine MRI could directly depict the situation of left-right or right-left shunt at atrial and ventricular levels, and regurgitation from ventricles to atria, meanwhile the valves were depicted clearly. Conclusions: MRI can clearly demonstrate all anatomic deformation and complicated hemodynamic change of CTECD, as well as other coexistent deformations

  19. Usefulness of combination post-stress dysfunction and perfusion imaging in technetium-99m-tetrofosmin myocardial scintigraphy

    International Nuclear Information System (INIS)

    Yamazaki, Yoko; Imai, Kamon; Konaka, Ryohei; Nakajima, Takatomo; Goto, Sayaka; Horie, Toshinobu; Saito, Satoshi; Ozawa, Yukio; Kanmatsuse, Katsuo

    2001-01-01

    Myocardial perfusion imaging has lower sensitivity for the diagnosis of coronary artery disease in patients with three-vessel disease. The presence of post-stress dysfunction of the left ventricle, evaluated by electrocardiography (ECG) gated single photon emission computed tomography (SPECT) with a quantitative gated SPECT program, was investigated in patients with coronary artery disease, and also whether combining post-stress dysfunction and myocardial perfusion imaging improved the diagnosis of coronary artery disease. ECG gated technetium-99m-tetrofosmin SPECT was performed using a one day, stress and rest, protocol in 139 patients. SPECT and coronary angiography were performed within 1 month. The coronary artery disease group consisted of 89 patients: 43 with one-vessel disease (1VD), 28 with two-vessel disease (2VD), and 18 with three-vessel disease (3VD). The group with zero-vessel disease (0VD) consisted of 50 patients. According to post-stress and rest ejection fraction (EF) and end-systolic volume (ESV), post-stress dysfunction is defined as follows: rest EF - post-stress EF≥5% and post-stress ESV - rest ESV≥5ml. In the coronary artery disease group, post-stress ESV was larger than rest ESV (37.8±26.4, 34.0±24.2 ml, p<0.001), and post-stress EF was lower than rest EF (61.5±11.1%, 64.2±10.8%, p<0.001). In the 0VD group, ESV and EF were the same for post-stress and rest (25.7±20.8, 26.2±21.6 ml, NS; 70.4±9.5%, 70.0±9.6%, NS). Post-stress dysfunction was 6.0% in the 0VD group and 30.3% in the coronary artery disease group (p<0.001). Furthermore, post-stress dysfunction in the 2VD (35.7%) and 3VD (38.9%) groups was higher than that in the 0VD group (p<0.01, p<0.01). Sensitivity of coronary artery disease diagnosis by myocardial perfusion imaging was 75%. The combination of post-stress dysfunction and myocardial perfusion imaging improved sensitivity from 75% to 82% (p<0.05), but reduced the specificity from 92% to 86% (p=0.08). Post

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

    International Nuclear Information System (INIS)

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

    2012-01-01

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

  1. Evaluating coronary reperfusion during acute myocardial infarction in a canine model by gadolinium-DTPA-enhanced magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Tanabe, Kazuaki; Ishibashi, Yutaka; Shimada, Toshio (Shimane Medical Univ., Izumo (Japan)) (and others)

    1993-05-01

    In previous studies, magnetic resonance imaging (MRI) using contrast agents was found to be useful in distinguishing reperfused infarcts from nonreperfused infarcts. However, there have been only a few detailed studies using consecutive MR images for the assessment of myocardial reperfusion during an acute infarction and also no studies have been performed using a percutaneous transluminal coronary occlusion model (closed chest model). We induced acute myocardial infarction in dogs by occluding and then reperfusing the coronary artery with a balloon catheter. ECG-gated MR images were taken using the spin-echo technique before and after Gd-DTPA injection during both coronary artery occlusion and after reperfusion. We defined the intensity ratio (IR) as the signal intensity at the ischemic area divided by that at the nonischemic area on MR images and compared each image by the IR. Without Gd-DTPA, there was no difference between infarcted and normally perfused myocardium. Infarcted myocardium had a low signal intensity (IR=0.68[+-]0.14) soon after Gd-DTPA injection. This difference diminished with time. After reperfusion the infarcted myocardium had a high signal intensity (IR: 1.76[+-]0.34). We conclude that Gd-DTPA-enhanced MRI can distinguish reperfused from nonreperfused infarcts soon after Gd-DTPA administration. (author).

  2. Evaluating coronary reperfusion during acute myocardial infarction in a canine model by gadolinium-DTPA-enhanced magnetic resonance imaging

    International Nuclear Information System (INIS)

    Tanabe, Kazuaki; Ishibashi, Yutaka; Shimada, Toshio

    1993-01-01

    In previous studies, magnetic resonance imaging (MRI) using contrast agents was found to be useful in distinguishing reperfused infarcts from nonreperfused infarcts. However, there have been only a few detailed studies using consecutive MR images for the assessment of myocardial reperfusion during an acute infarction and also no studies have been performed using a percutaneous transluminal coronary occlusion model (closed chest model). We induced acute myocardial infarction in dogs by occluding and then reperfusing the coronary artery with a balloon catheter. ECG-gated MR images were taken using the spin-echo technique before and after Gd-DTPA injection during both coronary artery occlusion and after reperfusion. We defined the intensity ratio (IR) as the signal intensity at the ischemic area divided by that at the nonischemic area on MR images and compared each image by the IR. Without Gd-DTPA, there was no difference between infarcted and normally perfused myocardium. Infarcted myocardium had a low signal intensity (IR=0.68±0.14) soon after Gd-DTPA injection. This difference diminished with time. After reperfusion the infarcted myocardium had a high signal intensity (IR: 1.76±0.34). We conclude that Gd-DTPA-enhanced MRI can distinguish reperfused from nonreperfused infarcts soon after Gd-DTPA administration. (author)

  3. A study of intraluminal flow in patients with aortic disease by cine magnetic resonance imaging

    International Nuclear Information System (INIS)

    Ohnishi, Shusaku; Fukui, Sugao; Kusuoka, Hideo; Kitabatake, Akira; Kamada, Takenobu.

    1990-01-01

    To evaluate the usefulness of cine magnetic resonance (MR) imaging in the diagnosis of aortic disease, we applied cine MR sequences with conventional spin echo (SE) sequence to 15 patients with aortic aneurysm and 5 patients with aortic dissection. ECG gated multi slice SE images (single echo) were obtained in transverse plane and the planes along the long axis of aorta. TE of SE sequence ranged from 15 to 32 msec. Cine MR images were obtained in 17 frames, where TR ranged from 30 to 60 msec and TE from 10 to 22 msec. We got these results as follows. For aortic aneurysm, SE images showed aneurysmal dilatation in thoracic aorta in 9 cases, and in abdominal aorta in 6 cases. Cine MR images showed us the intraluminal flow with high signal intensity. We could differentiate the slow flow image from mural thrombus using SE and cine MR sequences in the same plane. We could evaluate the dynamic flow image within a cavity of aneurysm and in in-flow and out-flow portions of aorta by cine MR imaging. For aortic dissection, SE images delineated the intimal tear and two separated lumens in all cases. We could obtain flow images within true and false lumen by cine MR imaging. The signal intensity within true lumen was higher than that within false lumen. It seemed to be due to the difference of flow velocity and the turbulence within false lumen. Entry to false lumen was seen as the interruption of dissected intima on SE images. Cine MR images clearly depicted the blood flow communication between two lumens through the entry. In 3 of 5 cases the blood flow through the entry was seen in both directions, from true to false lumen in systole and inversely in diastole. Thus, cine MR imaging will add the useful hemodynamic information in the diagnosis of aortic disease by conventional MR imaging. (author)

  4. Changes in the phase and amplitude images in the rehabilitation phase after myocardial infarction

    International Nuclear Information System (INIS)

    Csernay, L.; Mester, J.; Vidakovich, T.; Rajtar, M.; Pavics, L.; Szasz, K.

    1984-01-01

    A studing involving patients with completed myocardial infarction, who underwent a 3-week exercise program at a cardiocirculatory rehabilitation center in Southern Hungary, is described. Infarctions were confirmed by the typical clinical and ECG signs and symptoms as well as by 201-T1 imaging at rest. Patients with normal 201-T1 activity distribution were excluded. Three ECG-gated equilibrium radionuclide studies were performed in each case: The first was done on the first day of rehabilitation (at a mean post-infarction interval of 1.5 months); the second study was scheduled 3 weeks after the first on completion of the exercise program and the last 9 weeks after the first (on an outpatient basis). From April 25, 1983 to September 9, 1983 a total of 25 patients were investigated. Of these, 9 had normal 201-T1 images. Of the remaining 16, 9 showed no significant changes of the phase and amplitude images. In 2 cases dyskinesia was found to have been replaced by akinesia, and in another 3 akinesia was replaced by hypokinesia. By contrast, 2 previously akinetic patients became dyskinetic. We expect to increase our patient material to at least 50 cases by the end of 1983 and would like to present our results, illustrating them by some typical examples. (Author)

  5. The role of scintigraphy and ultrasound in the imaging of neonatal hypothyroidism: 5-year retrospective review of single-centre experience

    International Nuclear Information System (INIS)

    De Silva, Ami; Jong, Ian; McLean, Glenda; Nandurkar, Dee; Bergman, Philip; Brown, Justin; Rodda, Christina

    2014-01-01

    Congenital hypothyroidism (CH), as indicated by an elevation of capillary thyroid-stimulating hormone (TSH) at newborn screening, is a preventable cause of mental retardation with varying aetiology; it can be transient or permanent. Radionuclide assessment is currently the gold standard for imaging CH. This study aimed to (i) review the different scintigraphic patterns and correlate them with TSH levels/patient outcomes, (ii) assess the role of sonography in neonates with apparent agenesis as indicated by scintigraphy and (iii) develop a diagnostic investigative algorithm. The technetium thyroid scans of 83 consecutive patients (49 females, average age 32 days) with CH scanned between 2005 and 2009 were retrospectively reviewed. Two nuclear medicine physicians blinded to the clinical details interpreted the scans in consensus. Scintigram appearances were categorised into five groups. Patients scintigraphically diagnosed with thyroid agenesis were evaluated with ultrasound. TSH values and scintigraphic and sonographic findings were correlated with patients' final diagnosis. Based on scintigraphy, 14, 13 and 19 patients out of 83 were assessed as having normal thyroid sites with normal, increased and decreased uptake, respectively. Twenty-two of 83 patients had no uptake, and 15 of 83 patients had ectopic uptake. Higher median TSH levels were seen in no-uptake and ectopic uptake subgroups. Eighteen of 22 patients with no uptake were evaluated with ultrasound. Three of the 18 patients had a normal thyroid gland, and three of 18 patients had a hypoplastic thyroid. Scintigram findings in patients with congenital hypothyroidism fall into five major categories, which have therapeutic implications (lifelong thyroxine in agenesis versus trial of stopping thyroxine in other subgroups). Sonographic demonstration of thyroid tissue in patients scintigraphically diagnosed with thyroid agenesis has major management implications.

  6. Characteristics of spondylotic myelopathy on 3D driven-equilibrium fast spin echo and 2D fast spin echo magnetic resonance imaging: a retrospective cross-sectional study.

    Science.gov (United States)

    Abdulhadi, Mike A; Perno, Joseph R; Melhem, Elias R; Nucifora, Paolo G P

    2014-01-01

    In patients with spinal stenosis, magnetic resonance imaging of the cervical spine can be improved by using 3D driven-equilibrium fast spin echo sequences to provide a high-resolution assessment of osseous and ligamentous structures. However, it is not yet clear whether 3D driven-equilibrium fast spin echo sequences adequately evaluate the spinal cord itself. As a result, they are generally supplemented by additional 2D fast spin echo sequences, adding time to the examination and potential discomfort to the patient. Here we investigate the hypothesis that in patients with spinal stenosis and spondylotic myelopathy, 3D driven-equilibrium fast spin echo sequences can characterize cord lesions equally well as 2D fast spin echo sequences. We performed a retrospective analysis of 30 adult patients with spondylotic myelopathy who had been examined with both 3D driven-equilibrium fast spin echo sequences and 2D fast spin echo sequences at the same scanning session. The two sequences were inspected separately for each patient, and visible cord lesions were manually traced. We found no significant differences between 3D driven-equilibrium fast spin echo and 2D fast spin echo sequences in the mean number, mean area, or mean transverse dimensions of spondylotic cord lesions. Nevertheless, the mean contrast-to-noise ratio of cord lesions was decreased on 3D driven-equilibrium fast spin echo sequences compared to 2D fast spin echo sequences. These findings suggest that 3D driven-equilibrium fast spin echo sequences do not need supplemental 2D fast spin echo sequences for the diagnosis of spondylotic myelopathy, but they may be less well suited for quantitative signal measurements in the spinal cord.

  7. Anatomical accuracy of lesion localization. Retrospective interactive rigid image registration between 18F-FDG-PET and X-ray CT

    International Nuclear Information System (INIS)

    Noemayr, A.; Roemer, W.; Kuwert, T.; Hothorn, T.; Pfahlberg, A.; Hornegger, J.; Bautz, W.

    2005-01-01

    The aim of this study was to evaluate the anatomical accuracy and reproducibility of retrospective interactive rigid image registration (RIR) between routinely archived X-ray computer tomography (CT) and positron emission tomography performed with 18 F-deoxyglucose (FDG-PET) in oncological patients. Methods: two observers registered PET and CT data obtained in 37 patients using a commercially available image fusion tool. RIR was performed separately for the thorax and the abdomen using physiological FDG uptake in several organs as a reference. One observer performed the procedure twice (01a and 01b), another person once (02). For 94 malignant lesions, clearly visible in CT and PET, the signed and absolute distances between their representation on PET and CT were measured in X-, Y-, and Z-direction with reference to a coordinate system centered in the CT representation of each lesion (X-, Y-, Z-distances). Results: the mean differences of the signed and absolute distances between 01a, 01b, and 02 did not exceed 3 mm in any dimension. The absolute X-, Y-, and Z-distances ranged between 0.57 ± 0.58 cm for 01a (X-direction) and 1.12 ± 1.28 cm for 02 (Z-direction). When averaging the absolute distances measured by 01a, 01b, and 02, the percentage of lesions misregistered by less than 1.5 cm was 91% for the X-, 88% for the Y-, and 77% for the Z-direction. The larger error of fusion determined for the remaining lesions was caused by non-rigid body transformations due to differences in breathing, arm position, or bowel movements between the two examinations. Mixed effects analysis of the signed and absolute X-, Y-, and Z-distances disclosed a significantly greater misalignment in the thorax than in the abdomen as well as axially than transaxially. Conclusion: the anatomical inaccuracy of RIR can be expected to be <1.5 cm for the majority of neoplastic foci. errors of alignment are bigger in the thorax and in Z-direction, due to non-rigid body transformations caused, e

  8. MR tractography; Visualization of structure of nerve fiber system from diffusion weighted images with maximum intensity projection method

    Energy Technology Data Exchange (ETDEWEB)

    Kinosada, Yasutomi; Okuda, Yasuyuki (Mie Univ., Tsu (Japan). School of Medicine); Ono, Mototsugu (and others)

    1993-02-01

    We developed a new noninvasive technique to visualize the anatomical structure of the nerve fiber system in vivo, and named this technique magnetic resonance (MR) tractography and the acquired image an MR tractogram. MR tractography has two steps. One is to obtain diffusion-weighted images sensitized along axes appropriate for depicting the intended nerve fibers with anisotropic water diffusion MR imaging. The other is to extract the anatomical structure of the nerve fiber system from a series of diffusion-weighted images by the maximum intensity projection method. To examine the clinical usefulness of the proposed technique, many contiguous, thin (3 mm) coronal two-dimensional sections of the brain were acquired sequentially in normal volunteers and selected patients with paralyses, on a 1.5 Tesla MR system (Signa, GE) with an ECG-gated Stejskal-Tanner pulse sequence. The structure of the nerve fiber system of normal volunteers was almost the same as the anatomy. The tractograms of patients with paralyses clearly showed the degeneration of nerve fibers and were correlated with clinical symptoms. MR tractography showed great promise for the study of neuroanatomy and neuroradiology. (author).

  9. Gadolinium-enhanced magnetic resonance imaging in acute myocardial infarction

    International Nuclear Information System (INIS)

    Dijkman, P.R.M. van; Wall, E.E. van der; Roos, A. de; Doornbos, J.; Laarse, A. van der; Voorthuisen, A.E. van; Bruschke, A.V.G.; Rossum, A.C. van

    1990-01-01

    To evaluate he usefulness of the paramagnetic contrast agent Gadolinium-DTPA (diethylenetriaminepentaacetic acid) in Magnetic Resonance. Imaging of acute myocardial infarction, we studied a total of 45 patients with a first acute myocardial infarction by ECG-gated magnetic resonance imaging before and after intravenous administration of 0.1 mmol/kg Gadolinium-DTPA. All patients received thrombolytic treatment by intravenous streptokinase. The magnetic resonance imaging studies were preformed after a meam of 88 h (range 15-241) after the acute onset of acute myocardial infarction. Five patients without evidence of cardiac disease served as controls. Spin-echo measurements (TE 30 ms) were made using a Philips Gyroscan (0.5 Tesla) or a Teslacon II (0.6 Tesla). The 45 patients were divided into four groups of patients. In Group I( patients) Gadolinium-DTPA improved the detection of myocardial infarction by Gadolinium-DTPA. In Group II (20 patients) the magnetic resonance imaging procedure was repeated every 10 min for up to 40 min following administration of Gadolinium-DTPA. Optimal contrast enhancement was obtained 20-25 min after Gadolinium-DTPA. In Group III (27 patients) signal intensities were significantly higher in the patients who underwent the magnetic resonance imaging study more than 72 h (mean 120) after the acute event, suggesting increased acculumation of Gadolinium-DTPA in a more advanced stage of the infarction process. In Group IV (45 patients) Gadolinium-DTPA was administered in an attempt to distinguish between reperfused and nonreperfused myocardial areas after thrombolytic treatment for acute myocardial infarction. The signal intensities did not differ, but reperfused areas showed a more homogeneous aspect whereas nonreperfused areas were visualized as a more heterogeneous contrast enhancement. It is concluded that magnetic resonance imaging using the contrast agent Gadolinium-DTPA significantly improves the detection of infarcted myocardial areas

  10. Feasibility of a semi-automated contrast-oriented algorithm for tumor segmentation in retrospectively gated PET images: phantom and clinical validation

    Science.gov (United States)

    Carles, Montserrat; Fechter, Tobias; Nemer, Ursula; Nanko, Norbert; Mix, Michael; Nestle, Ursula; Schaefer, Andrea

    2015-12-01

    PET/CT plays an important role in radiotherapy planning for lung tumors. Several segmentation algorithms have been proposed for PET tumor segmentation. However, most of them do not take into account respiratory motion and are not well validated. The aim of this work was to evaluate a semi-automated contrast-oriented algorithm (COA) for PET tumor segmentation adapted to retrospectively gated (4D) images. The evaluation involved a wide set of 4D-PET/CT acquisitions of dynamic experimental phantoms and lung cancer patients. In addition, segmentation accuracy of 4D-COA was compared with four other state-of-the-art algorithms. In phantom evaluation, the physical properties of the objects defined the gold standard. In clinical evaluation, the ground truth was estimated by the STAPLE (Simultaneous Truth and Performance Level Estimation) consensus of three manual PET contours by experts. Algorithm evaluation with phantoms resulted in: (i) no statistically significant diameter differences for different targets and movements (Δ φ =0.3+/- 1.6 mm); (ii) reproducibility for heterogeneous and irregular targets independent of user initial interaction and (iii) good segmentation agreement for irregular targets compared to manual CT delineation in terms of Dice Similarity Coefficient (DSC  =  0.66+/- 0.04 ), Positive Predictive Value (PPV  =  0.81+/- 0.06 ) and Sensitivity (Sen.  =  0.49+/- 0.05 ). In clinical evaluation, the segmented volume was in reasonable agreement with the consensus volume (difference in volume (%Vol)  =  40+/- 30 , DSC  =  0.71+/- 0.07 and PPV  =  0.90+/- 0.13 ). High accuracy in target tracking position (Δ ME) was obtained for experimental and clinical data (Δ ME{{}\\text{exp}}=0+/- 3 mm; Δ ME{{}\\text{clin}}=0.3+/- 1.4 mm). In the comparison with other lung segmentation methods, 4D-COA has shown the highest volume accuracy in both experimental and clinical data. In conclusion, the accuracy in volume

  11. Subcutaneous Tissue Thickness is an Independent Predictor of Image Noise in Cardiac CT

    International Nuclear Information System (INIS)

    Staniak, Henrique Lane; Sharovsky, Rodolfo; Pereira, Alexandre Costa; Castro, Cláudio Campi de; Benseñor, Isabela M.; Lotufo, Paulo A.; Bittencourt, Márcio Sommer

    2014-01-01

    Few data on the definition of simple robust parameters to predict image noise in cardiac computed tomography (CT) exist. To evaluate the value of a simple measure of subcutaneous tissue as a predictor of image noise in cardiac CT. 86 patients underwent prospective ECG-gated coronary computed tomographic angiography (CTA) and coronary calcium scoring (CAC) with 120 kV and 150 mA. The image quality was objectively measured by the image noise in the aorta in the cardiac CTA, and low noise was defined as noise < 30HU. The chest anteroposterior diameter and lateral width, the image noise in the aorta and the skin-sternum (SS) thickness were measured as predictors of cardiac CTA noise. The association of the predictors and image noise was performed by using Pearson correlation. The mean radiation dose was 3.5 ± 1.5 mSv. The mean image noise in CT was 36.3 ± 8.5 HU, and the mean image noise in non-contrast scan was 17.7 ± 4.4 HU. All predictors were independently associated with cardiac CTA noise. The best predictors were SS thickness, with a correlation of 0.70 (p < 0.001), and noise in the non-contrast images, with a correlation of 0.73 (p < 0.001). When evaluating the ability to predict low image noise, the areas under the ROC curve for the non-contrast noise and for the SS thickness were 0.837 and 0.864, respectively. Both SS thickness and CAC noise are simple accurate predictors of cardiac CTA image noise. Those parameters can be incorporated in standard CT protocols to adequately adjust radiation exposure

  12. Subcutaneous Tissue Thickness is an Independent Predictor of Image Noise in Cardiac CT

    Energy Technology Data Exchange (ETDEWEB)

    Staniak, Henrique Lane; Sharovsky, Rodolfo [Hospital Universitário - Universidade de São Paulo, São Paulo, SP (Brazil); Pereira, Alexandre Costa [Hospital das Clínicas - Universidade de São Paulo, São Paulo, SP (Brazil); Castro, Cláudio Campi de; Benseñor, Isabela M.; Lotufo, Paulo A. [Hospital Universitário - Universidade de São Paulo, São Paulo, SP (Brazil); Faculdade de Medicina - Universidade de São Paulo, São Paulo, SP (Brazil); Bittencourt, Márcio Sommer, E-mail: msbittencourt@mail.harvard.edu [Hospital Universitário - Universidade de São Paulo, São Paulo, SP (Brazil)

    2014-01-15

    Few data on the definition of simple robust parameters to predict image noise in cardiac computed tomography (CT) exist. To evaluate the value of a simple measure of subcutaneous tissue as a predictor of image noise in cardiac CT. 86 patients underwent prospective ECG-gated coronary computed tomographic angiography (CTA) and coronary calcium scoring (CAC) with 120 kV and 150 mA. The image quality was objectively measured by the image noise in the aorta in the cardiac CTA, and low noise was defined as noise < 30HU. The chest anteroposterior diameter and lateral width, the image noise in the aorta and the skin-sternum (SS) thickness were measured as predictors of cardiac CTA noise. The association of the predictors and image noise was performed by using Pearson correlation. The mean radiation dose was 3.5 ± 1.5 mSv. The mean image noise in CT was 36.3 ± 8.5 HU, and the mean image noise in non-contrast scan was 17.7 ± 4.4 HU. All predictors were independently associated with cardiac CTA noise. The best predictors were SS thickness, with a correlation of 0.70 (p < 0.001), and noise in the non-contrast images, with a correlation of 0.73 (p < 0.001). When evaluating the ability to predict low image noise, the areas under the ROC curve for the non-contrast noise and for the SS thickness were 0.837 and 0.864, respectively. Both SS thickness and CAC noise are simple accurate predictors of cardiac CTA image noise. Those parameters can be incorporated in standard CT protocols to adequately adjust radiation exposure.

  13. SU-E-J-150: Four-Dimensional Cone-Beam CT Algorithm by Extraction of Physical and Motion Parameter of Mobile Targets Retrospective to Image Reconstruction with Motion Modeling

    International Nuclear Information System (INIS)

    Ali, I; Ahmad, S; Alsbou, N

    2015-01-01

    Purpose: To develop 4D-cone-beam CT (CBCT) algorithm by motion modeling that extracts actual length, CT numbers level and motion amplitude of a mobile target retrospective to image reconstruction by motion modeling. Methods: The algorithm used three measurable parameters: apparent length and blurred CT number distribution of a mobile target obtained from CBCT images to determine actual length, CT-number value of the stationary target, and motion amplitude. The predictions of this algorithm were tested with mobile targets that with different well-known sizes made from tissue-equivalent gel which was inserted into a thorax phantom. The phantom moved sinusoidally in one-direction to simulate respiratory motion using eight amplitudes ranging 0–20mm. Results: Using this 4D-CBCT algorithm, three unknown parameters were extracted that include: length of the target, CT number level, speed or motion amplitude for the mobile targets retrospective to image reconstruction. The motion algorithms solved for the three unknown parameters using measurable apparent length, CT number level and gradient for a well-defined mobile target obtained from CBCT images. The motion model agreed with measured apparent lengths which were dependent on the actual target length and motion amplitude. The gradient of the CT number distribution of the mobile target is dependent on the stationary CT number level, actual target length and motion amplitude. Motion frequency and phase did not affect the elongation and CT number distribution of the mobile target and could not be determined. Conclusion: A 4D-CBCT motion algorithm was developed to extract three parameters that include actual length, CT number level and motion amplitude or speed of mobile targets directly from reconstructed CBCT images without prior knowledge of the stationary target parameters. This algorithm provides alternative to 4D-CBCT without requirement to motion tracking and sorting of the images into different breathing phases

  14. SU-E-J-150: Four-Dimensional Cone-Beam CT Algorithm by Extraction of Physical and Motion Parameter of Mobile Targets Retrospective to Image Reconstruction with Motion Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Ali, I; Ahmad, S [University of Oklahoma Health Sciences, Oklahoma City, OK (United States); Alsbou, N [Ohio Northern University, Ada, OH (United States)

    2015-06-15

    Purpose: To develop 4D-cone-beam CT (CBCT) algorithm by motion modeling that extracts actual length, CT numbers level and motion amplitude of a mobile target retrospective to image reconstruction by motion modeling. Methods: The algorithm used three measurable parameters: apparent length and blurred CT number distribution of a mobile target obtained from CBCT images to determine actual length, CT-number value of the stationary target, and motion amplitude. The predictions of this algorithm were tested with mobile targets that with different well-known sizes made from tissue-equivalent gel which was inserted into a thorax phantom. The phantom moved sinusoidally in one-direction to simulate respiratory motion using eight amplitudes ranging 0–20mm. Results: Using this 4D-CBCT algorithm, three unknown parameters were extracted that include: length of the target, CT number level, speed or motion amplitude for the mobile targets retrospective to image reconstruction. The motion algorithms solved for the three unknown parameters using measurable apparent length, CT number level and gradient for a well-defined mobile target obtained from CBCT images. The motion model agreed with measured apparent lengths which were dependent on the actual target length and motion amplitude. The gradient of the CT number distribution of the mobile target is dependent on the stationary CT number level, actual target length and motion amplitude. Motion frequency and phase did not affect the elongation and CT number distribution of the mobile target and could not be determined. Conclusion: A 4D-CBCT motion algorithm was developed to extract three parameters that include actual length, CT number level and motion amplitude or speed of mobile targets directly from reconstructed CBCT images without prior knowledge of the stationary target parameters. This algorithm provides alternative to 4D-CBCT without requirement to motion tracking and sorting of the images into different breathing phases

  15. Clinical use of digital retrospective image fusion of CT, MRI, FDG-PET and SPECT - fields of indications and results; Klinischer Einsatz der digitalen retrospektiven Bildfusion von CT, MRT, FDG-PET und SPECT - Anwendungsgebiete und Ergebnisse

    Energy Technology Data Exchange (ETDEWEB)

    Lemke, A.J.; Niehues, S.M.; Amthauer, H.; Felix, R. [Campus Virchow-Klinikum, Klinik fuer Strahlenheilkunde, Charite, Universitaetsmedizin Berlin (Germany); Rohlfing, T. [Dept. of Neurosurgery, Stanford Univ. (United States); Hosten, N. [Inst. fuer Diagnostische Radiologie, Ernst-Moritz-Arndt-Univ. Greifswald (Germany)

    2004-12-01

    Purpose: To evaluate the feasibility and the clinical benefits of retrospective digital image fusion (PET, SPECT, CT and MRI). Materials and methods: In a prospective study, a total of 273 image fusions were performed and evaluated. The underlying image acquisitions (CT, MRI, SPECT and PET) were performed in a way appropriate for the respective clinical question and anatomical region. Image fusion was executed with a software program developed during this study. The results of the image fusion procedure were evaluated in terms of technical feasibility, clinical objective, and therapeutic impact. Results: The most frequent combinations of modalities were CT/PET (n = 156) and MRI/PET (n = 59), followed by MRI/SPECT (n = 28), CT/SPECT (n = 22) and CT/MRI (n = 8). The clinical questions included following regions (more than one region per case possible): neurocranium (n = 42), neck (n = 13), lung and mediastinum (n = 24), abdomen (n = 181), and pelvis (n = 65). In 92.6% of all cases (n = 253), image fusion was technically successful. Image fusion was able to improve sensitivity and specificity of the single modality, or to add important diagnostic information. Image fusion was problematic in cases of different body positions between the two imaging modalities or different positions of mobile organs. In 37.9% of the cases, image fusion added clinically relevant information compared to the single modality. Conclusion: For clinical questions concerning liver, pancreas, rectum, neck, or neurocranium, image fusion is a reliable method suitable for routine clinical application. Organ motion still limits its feasibility and routine use in other areas (e.g., thorax). (orig.)

  16. Appearance of high signal intensity and gadolinium-DTPA contrast enhancement in hypertrophied myocardium by magnetic resonance imaging

    International Nuclear Information System (INIS)

    Nishimura, Tsunehiko; Yamada, Naoaki; Nagata, Seiki

    1989-01-01

    This study was undertaken to examine the potential role of magnetic resonance imaging (MRI) for evaluating myocardial tissue characterization in hypertrophic cardiomyopathy (HCM). ECG-gated MRI images were acquired in 32 HCM patients and 30 patients with hypertensive heart disease (HHD), using a 1.5 T superconducting magnet system. The thickened areas were depicted as high signal intensities in the septum of 12 HCM patients (38%) and the endocardium of 5 HHD patients (17%). Echocardiography revealed that MRI appearance of high signal intensity was associated with more thickened myocardial wall. For evaluable 16 patients receiving i.v. injection of Gd-DTPA in a dose of 0.1 mM/kg, enhancement effects were observed in 10 patients (63%). High signal intensity appearing in the hypertrophied myocardium, as well as contrast enhancement, may not be characteristic of HCM, but reflect the likelihood of myocardial degeneration associated with the hypertrophied myocardium. Although MRI may not be capable of differentiating tissue characterization in HCM from that in HHD, it may provide different information about tissue characterization in the hypertrophied myocardium from that obtained by other techniques. (N.K.)

  17. Noninvasive determination of myocardial blood flow, oxygen consumption and efficiency in normal humans by carbon-11 acetate positron emission tomography imaging

    International Nuclear Information System (INIS)

    Porenta, G.; Cherry, S.; Czernin, J.; Brunken, R.; Kuhle, W.; Hashimoto, T.; Schelbert, H.R.

    1999-01-01

    The aims of this study were: (1) to measure noninvasively and near simultaneously myocardial blood flow, oxygen consumption, and contractile function and (2) to analyze myocardial energy expenditure and efficiency at rest and during dobutamine stress in normal humans. Dynamic and gated carbon-11 acetate positron emission tomography (PET) imaging was performed in 11 normal subjects. The initial uptake of 11 C-acetate was measured to estimate myocardial blood flow. Oxygen consumption was derived from the monoexponential slope of the 11 C-clearance curve recorded during myocardial washout. ECG-gated systolic and diastolic images were acquired during the peak myocardial 11 C activity to measure left ventricular radius, myocardial wall thickness, and long axis length. Myocardial oxygen consumption and parameters of cardiac geometry were used to determine myocardial energetics and cardiac efficiency by tension-area area analysis. Myocardial blood flow averaged 0.8±0.06 ml min -1 g -1 at rest and 1.48±0.15 ml min -1 g -1 during dobutamine stress. Oxygen delivery and consumption were 151±13 and 88±15 μl O 2 min -1 g -1 at rest and increased to 291±31 and 216±31 μl O 2 min -1 g -1 , respectively, during pharmacological stress (P 11 C acetate imaging provides the unique capability to study noninvasively determinants of myocardial energy delivery, expenditure, and efficiency. (orig.)

  18. Analysis of the cardiac motion in myocardial infarction by the ECG-synchronized CT

    International Nuclear Information System (INIS)

    Watanabe, Shigeru; Shimizu, Masahiko; Yoshida, Hideo; Morooka, Nobuhiro; Shukuya, Masaki

    1981-01-01

    The cardiac motion in patients with myocardial infarction was analyzed by the ECG-synchronized computed tomography (CT). For ECG synchronization, the ECG gating method and the data sorting method were used. By the ECG gating method, the gated cardiac images during 0.1 msec intervals at end-diastolic and the end-systolic phases were obtained. By the data sorting method, phasic CT images were reconstructed retrospectively by selecting appropriate data from a series of consecutive scans taken with simultaneous continuous ECG recordings. Six normal subjects and eight patients with myocardial infarction were studied by the ECG gating method, and 14 normal subjects and 25 patients with myocardial infarction were studied by the data sorting method. The end-diastolic and the end-systolic pictures at mid left ventricular level were superimposed and the cardiac borders were traced for the analysis (Fig. 4). Then the cardiac cross-sectional areas at each cardiac phase (40 msec) were calculated, and a cardiac area curve was obtained by plotting them consecutively. The cross-sectional images were divided into right anterior, right posterior, left anterior and left posterior segments. Cardiac area curves of the each segment were also obtained for further analysis. From these curves, the changing ratio of cardiac areas (maximum area - minimum area/maximum area) and the maximum area velocity in systole and diastole were calculated. On the images and the cardiac area curves in myocardial infarction patients, abnormal myocardial movements such as partial akinesis, hypokinesis or paradoxical movement were apparent asd the area of abnormal motions corresponded well with the location of infarction determined by ECG, RI scanning and angiography. A decrease of the changing ratio and the velocity in the infarction area were shown (Fig. 6, 7) and the functional disturbances were suggested during not only systole but diastole also. (author)

  19. Enhancing ejection fraction measurement through 4D respiratory motion compensation in cardiac PET imaging

    Science.gov (United States)

    Tang, Jing; Wang, Xinhui; Gao, Xiangzhen; Segars, W. Paul; Lodge, Martin A.; Rahmim, Arman

    2017-06-01

    ECG gated cardiac PET imaging measures functional parameters such as left ventricle (LV) ejection fraction (EF), providing diagnostic and prognostic information for management of patients with coronary artery disease (CAD). Respiratory motion degrades spatial resolution and affects the accuracy in measuring the LV volumes for EF calculation. The goal of this study is to systematically investigate the effect of respiratory motion correction on the estimation of end-diastolic volume (EDV), end-systolic volume (ESV), and EF, especially on the separation of normal and abnormal EFs. We developed a respiratory motion incorporated 4D PET image reconstruction technique which uses all gated-frame data to acquire a motion-suppressed image. Using the standard XCAT phantom and two individual-specific volunteer XCAT phantoms, we simulated dual-gated myocardial perfusion imaging data for normally and abnormally beating hearts. With and without respiratory motion correction, we measured the EDV, ESV, and EF from the cardiac-gated reconstructed images. For all the phantoms, the estimated volumes increased and the biases significantly reduced with motion correction compared with those without. Furthermore, the improvement of ESV measurement in the abnormally beating heart led to better separation of normal and abnormal EFs. The simulation study demonstrated the significant effect of respiratory motion correction on cardiac imaging data with motion amplitude as small as 0.7 cm. The larger the motion amplitude the more improvement respiratory motion correction brought about on the EF measurement. Using data-driven respiratory gating, we also demonstrated the effect of respiratory motion correction on estimating the above functional parameters from list mode patient data. Respiratory motion correction has been shown to improve the accuracy of EF measurement in clinical cardiac PET imaging.

  20. Evaluation of an exposed-radiation dose on a dual-source cardiac computed tomography examination with a prospective electrocardiogram-gated fast dual spiral scan

    International Nuclear Information System (INIS)

    Matsubara, Kosuke; Koshida, Kichiro; Koshida, Haruka; Sakuta, Keita; Hayashi, Hiroyuki; Takata, Tadanori; Horii, Junsei; Kawai, Keiichi; Yamamoto, Tomoyuki

    2012-01-01

    We evaluated exposed-radiation doses on dual-source cardiac computed tomography (CT) examinations with prospective electrocardiogram (ECG)-gated fast dual spiral scans. After placing dosimeters at locations corresponding to each of the thoracic organs, prospective ECG-gated fast dual spirals and retrospective ECG-gated dual spiral scans were performed to measure the absorbed dose of each organ. In the prospective ECG-gated fast dual spiral scans, the average absorbed doses were 5.03 mGy for the breast, 9.96 mGy for the heart, 6.60 mGy for the lung, 6.48 mGy for the bone marrow, 9.73 mGy for the thymus, and 4.58 mGy for the skin. These values were about 5% of the absorbed doses for the retrospective ECG-gated dual spiral scan. However, the absorbed dose differed greatly at each scan, especially in the external organs such as the breast. For effective and safe use of the prospective ECG-gated fast dual spiral scan, it is necessary to understand these characteristics sufficiently. (author)

  1. Magnetic resonance imaging of athlete's heart: myocardial mass, left ventricular function, and cross-sectional area of the coronary arteries

    International Nuclear Information System (INIS)

    Zandrino, F.; Sardanelli, F.; Molinari, G.; Masperone, M.A.; Smeraldi, A.; Odaglia, G.

    2000-01-01

    To evaluate left ventricular myocardial mass and function as well as ostial coronary artery cross-sectional area in endurance athletes, an athlete group of 12 highly trained rowers and a control group of 12 sedentary healthy subjects underwent MR examination. An ECG-gated breath-hold cine gradient-echo sequence was used to calculate myocardial mass, end-diastolic and end-systolic volumes, stroke volume, and cardiac output, all related to body surface area, as well as ejection fraction. A 3D fat-saturated ECG- and respiratory-triggered navigator echo sequence was used to evaluate coronary arteries: left main (LM), left anterior descending (LAD), left circumflex (LCx), and right coronary artery (RCA). Cross-sectional area was calculated and divided for body surface area. Myocardial mass was found significantly larger in athlete group than in control group (p = 0.0078), the same being for end-diastolic volume (p = 0.0078), stroke volume (p = 0.0055), LM (p = 0.0066) and LAD (p = 0.0129). No significant difference was found for all the remaining parameters. Significant correlation with myocardial mass was found for LM (p < 0.001) and LAD (p = 0.0340), not for LCx and RCA. Magnetic resonance imaging is a useful tool in evaluating the myocardial hypertrophy and function of athlete's heart. Magnetic resonance angiography is a valuable noninvasive method to visualize the correlated cross-sectional area increase of the left coronary artery system. (orig.)

  2. Clinical evaluation of cardiovascular disease by gated-MRI (magnetic resonance imaging) in the operating field of 0.35 and 1.5 Tesla

    International Nuclear Information System (INIS)

    Nishimura, Tsunehiko; Naito, Hiroaki; Yamada, Yukinori; Kozuka, Takahiro

    1985-01-01

    To evaluate the clinical usefulness of magnetic resonance imaging (MRI) in the cardiovascular disease, 21 patients were examined using 0.35 and 1.5 Tesla superconductive type (Magnetom, Siemens). In our study, all patients were performed using ECG-gated MRI. Therefore, the cardiac chambers were discriminated clearly from the myocardial wall compared to non-gated MRI. Gated-MRI was performed in 6 normal persons in the operating field at 0.35 and 1.5 Tesla. The image of the latter showed superior than that of the former because of high S/N ratio. In myocardial infarction, infarct area was demonstrated as the wall thinning in 4 of 5 patients. Hypertrophic cardiomyopathy showed thickened left ventricle associated with its narrowed cavity in 7 patients. In the remaining such as congenital and valvular heart disease, global and regional cardiac morphology were assessed noninvasively by gated MRI. In addition, gated MRI was also applied to the diagnosis of peripheral vascular diseases. In dissecting aneurysm, double channels with an intimal flap in the aorta were clearly visualized. And in the aortitis syndrome, aortic dilatation and stenosis were also assessed noninvasively. In conclusion, gated MRI in diagnosing various abnormalities of cardiovascular disease was confirmed. (author)

  3. CT coronary angiography: Influence of different cardiac reconstruction intervals on image quality and diagnostic accuracy

    Energy Technology Data Exchange (ETDEWEB)

    Dewey, Marc [Department of Radiology, Charite Medical School, Humboldt-Universitaet zu Berlin (Germany)], E-mail: marc.dewey@charite.de; Teige, Florian [Department of Radiology, Charite Medical School, Humboldt-Universitaet zu Berlin (Germany); Rutsch, Wolfgang [Department of Cardiology, Charite Medical School, Humboldt-Universitaet zu Berlin (Germany)], E-mail: wolfgang.rutsch@charite.de; Schink, Tania [Department of Medical Biometry, Charite Medical School, Humboldt-Universitaet zu Berlin (Germany)], E-mail: peter.martus@charite.de; Hamm, Bernd [Department of Radiology, Charite Medical School, Humboldt-Universitaet zu Berlin (Germany)

    2008-07-15

    Purpose: To prospectively analyze image quality and diagnostic accuracy of different reconstruction intervals of coronary angiography using multislice computed tomography (MSCT). Materials and methods: For each of 47 patients, 10 ECG-gated MSCT reconstructions were generated throughout the RR interval from 0 to 90%, resulting in altogether 470 datasets. These datasets were randomly analyzed for image quality and accuracy and compared with conventional angiography. Statistical comparison of intervals was performed using nonparametric analysis for repeated measurements to account for clustering of arteries within patients. Results: Image reconstruction intervals centered at 80, 70, and 40% of the RR interval resulted (in that order) in the best overall image quality for all four main coronary vessels. Eighty percent reconstructions also yielded the highest diagnostic accuracy of all intervals. The combination of the three best intervals (80, 70, and 40%) significantly reduced the nondiagnostic rate as compared with 80% alone (p = 0.005). However, the optimal reconstruction interval combination achieved significantly improved specificities and nondiagnostic rates (p < 0.05). The optimal combination consisted of 1.7 {+-} 0.9 reconstruction intervals on average. In approximately half of the patients (49%, 23/47) a single reconstruction was optimal. In 18 (38%), 3 (6%), and 3 (6%) patients one, two, and three additional reconstruction intervals were required, respectively, to achieve optimal quality. In 28% of the patients the optimal combination consisted of reconstructions other than the three best intervals (80, 70, and 40%). Conclusion: Multiple image reconstruction intervals are essential to ensure high image quality and accuracy of CT coronary angiography.

  4. Incidence and Imaging Findings of Costal Cartilage Fractures in Patients with Blunt Chest Trauma: A Retrospective Review of 1461 Consecutive Whole-Body CT Examinations for Trauma.

    Science.gov (United States)

    Nummela, Mari T; Bensch, Frank V; Pyhältö, Tuomo T; Koskinen, Seppo K

    2018-02-01

    Purpose To assess the incidence of costal cartilage (CC) fractures in whole-body computed tomographic (CT) examinations for blunt trauma and to evaluate distribution of CC fractures, concomitant injuries, mechanism of injury, accuracy of reporting, and the effect on 30-day mortality. Materials and Methods Institutional review board approval was obtained for this retrospective study. All whole-body CT examinations for blunt trauma over 36 months were reviewed retrospectively and chest trauma CT studies were evaluated by a second reader. Of 1461 patients who underwent a whole-body CT examination, 39% (574 of 1461) had signs of thoracic injuries (men, 74.0% [425 of 574]; mean age, 46.6 years; women, 26.0% [149 of 574]; mean age, 48.9 years). χ 2 and odds ratios (ORs) with 95% confidence intervals (CIs) were calculated. Interobserver agreement was calculated by using Cohen kappa values. Results A total of 114 patients (men, 86.8% [99 of 114]; mean age, 48.6 years; women, 13.2% [15 of 114]; mean age, 45.1 years) had 221 CC fractures. The incidence was 7.8% (114 of 1461) in all whole-body CT examinations and 19.9% (114 of 574) in patients with thoracic trauma. Cartilage of rib 7 (21.3%, 47 of 221) was most commonly injured. Bilateral multiple consecutive rib fractures occurred in 36% (41 of 114) versus 14% (64 of 460) in other patients with chest trauma (OR, 3.48; 95% CI: 2.18, 5.53; P chest trauma with CC fractures (13%, 15 of 114) versus patients with chest trauma without CC fractures (4%, 18 of 460) (OR, 3.72; 95% CI: 1.81, 7.64; P = .0001), as well as aortic injuries (n = 4 vs n = 0; P = .0015; OR, unavailable). Kappa value for interobserver agreement in detecting CC fractures was 0.65 (substantial agreement). CC fractures were documented in 39.5% (45 of 114) of primary reports. The 30-day mortality of patients with CC fractures was 7.02% (eight of 114) versus 4.78% (22 of 460) of other patients with chest trauma (OR, 1.50; 95% CI: 0.65, 3.47; P = .3371). Conclusion

  5. Heterogeneity of pulmonary perfusion as a mechanistic image-based phenotype in emphysema susceptible smokers.

    Science.gov (United States)

    Alford, Sara K; van Beek, Edwin J R; McLennan, Geoffrey; Hoffman, Eric A

    2010-04-20

    Recent evidence suggests that endothelial dysfunction and pathology of pulmonary vascular responses may serve as a precursor to smoking-associated emphysema. Although it is known that emphysematous destruction leads to vasculature changes, less is known about early regional vascular dysfunction which may contribute to and precede emphysematous changes. We sought to test the hypothesis, via multidetector row CT (MDCT) perfusion imaging, that smokers showing early signs of emphysema susceptibility have a greater heterogeneity in regional perfusion parameters than emphysema-free smokers and persons who had never smoked (NS). Assuming that all smokers have a consistent inflammatory response, increased perfusion heterogeneity in emphysema-susceptible smokers would be consistent with the notion that these subjects may have the inability to block hypoxic vasoconstriction in patchy, small regions of inflammation. Dynamic ECG-gated MDCT perfusion scans with a central bolus injection of contrast were acquired in 17 NS, 12 smokers with normal CT imaging studies (SNI), and 12 smokers with subtle CT findings of centrilobular emphysema (SCE). All subjects had normal spirometry. Quantitative image analysis determined regional perfusion parameters, pulmonary blood flow (PBF), and mean transit time (MTT). Mean and coefficient of variation were calculated, and statistical differences were assessed with one-way ANOVA. MDCT-based MTT and PBF measurements demonstrate globally increased heterogeneity in SCE subjects compared with NS and SNI subjects but demonstrate similarity between NS and SNI subjects. These findings demonstrate a functional lung-imaging measure that provides a more mechanistically oriented phenotype that differentiates smokers with and without evidence of emphysema susceptibility.

  6. Differentiation of hypertensive heart disease with hypertrophy and hepertrophic cardiomyopathy using consecutive time-course images of Gd-DTPA enhanced MRI

    International Nuclear Information System (INIS)

    Ochiai, Kouichi; Isibashi, Yutaka; Shimada, Toshio; Tsukihashi, Hironori; Sato, Hidetoshi; Kitamura, Jun; Morioka, Shigefumi; Kawamitsu, Hideaki; Sugimura, Kazuro

    1996-01-01

    We used consecutive time-course Gd-DTPA contrast magnetic resonance images to differentiate hypertrophic cardiomyopathy (HCM) from hypertensive heart disease with hypertrophy (HHD). Seventeen patients with HCM, 6 patients with HHD and 5 normal subjects (control) were studied. ECG-gated MRI with 1.5T system was performed before and after intravenous injection of Gd-DTPA (0.1mmol/Kg) using spin echo sequence. Gd-DTPA enhanced MRI was repeated every 10 to 55 minutes. We measured signal intensity (SI) of midleft ventricular myocardium and skeletal muscle, and then calculated the ratio between myocardial SI and skeletal muscle SI. Myocardium was enhanced by Gd-DTPA in all patients. However, there was difference in the decay of enhancement effect by Gd-DTPA between HCM and HHD. The decay in HCM was more slowly than in both HHD and control. There was no difference in the decay between HHD and control. The difference in the decay between HCM and HHD became significant 25 minutes after Gd-DTPA injection and lasted until 55 minutes. We conclude that the time-course of the decay of enhancement effect by Gd-DTPA is helpful to differentiate HCM from HHD and the difference of the decay might reflect structural changes of myocardium. (author)

  7. Liver function assessment using 99mTc-GSA single-photon emission computed tomography (SPECT)/CT fusion imaging in hilar bile duct cancer: A retrospective study.

    Science.gov (United States)

    Sumiyoshi, Tatsuaki; Shima, Yasuo; Okabayashi, Takehiro; Kozuki, Akihito; Hata, Yasuhiro; Noda, Yoshihiro; Kouno, Michihiko; Miyagawa, Kazuyuki; Tokorodani, Ryotaro; Saisaka, Yuichi; Tokumaru, Teppei; Nakamura, Toshio; Morita, Sojiro

    2016-07-01

    The objective of this study was to determine the utility of Tc-99m-diethylenetriamine-penta-acetic acid-galactosyl human serum albumin ((99m)Tc-GSA) single-photon emission computed tomography (SPECT)/CT fusion imaging for posthepatectomy remnant liver function assessment in hilar bile duct cancer patients. Thirty hilar bile duct cancer patients who underwent major hepatectomy with extrahepatic bile duct resection were retrospectively analyzed. Indocyanine green plasma clearance rate (KICG) value and estimated KICG by (99m)Tc-GSA scintigraphy (KGSA) and volumetric and functional rates of future remnant liver by (99m)Tc-GSA SPECT/CT fusion imaging were used to evaluate preoperative whole liver function and posthepatectomy remnant liver function, respectively. Remnant (rem) KICG (= KICG × volumetric rate) and remKGSA (= KGSA × functional rate) were used to predict future remnant liver function; major hepatectomy was considered unsafe for values liver were significantly higher than volumetric rates (median: 0.54 vs 0.46; P liver failure and mortality did not occur in the patients for whom hepatectomy was considered unsafe based on remKICG. remKGSA showed a stronger correlation with postoperative prothrombin time activity than remKICG. (99m)Tc-GSA SPECT/CT fusion imaging enables accurate assessment of future remnant liver function and suitability for hepatectomy in hilar bile duct cancer patients. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Value of retrospective image fusion of 18F-FDG PET and MRI for preoperative staging of head and neck cancer: Comparison with PET/CT and contrast-enhanced neck MRI

    International Nuclear Information System (INIS)

    Kanda, Tomonori; Kitajima, Kazuhiro; Suenaga, Yuko; Konishi, Jyunya; Sasaki, Ryohei; Morimoto, Koichi; Saito, Miki; Otsuki, Naoki; Nibu, Ken-ichi; Sugimura, Kazuro

    2013-01-01

    Purpose: To assess the clinical value of retrospective image fusion of neck MRI and 18 F-fluorodeoxyglucose ( 18 F-FDG) PET for locoregional extension and nodal staging of neck cancer. Materials and methods: Thirty patients with carcinoma of the oral cavity or hypopharynx underwent PET/CT and contrast-enhanced neck MRI for initial staging before surgery including primary tumor resection and neck dissection. Diagnostic performance of PET/CT, MRI, and retrospective image fusion of PET and MRI (fused PET/MRI) for assessment of the extent of the primary tumor (T stage) and metastasis to regional lymph nodes (N stage) was evaluated. Results: Accuracy for T status was 87% for fused PET/MRI and 90% for MRI, thus proving significantly superior to PET/CT, which had an accuracy of 67% (p = 0.041 and p = 0.023, respectively). Accuracy for N status was 77% for both fused PET/MRI and PET/CT, being superior to MRI, which had an accuracy of 63%, although the difference was not significant (p = 0.13). On a per-level basis, the sensitivity, specificity and accuracy for detection of nodal metastasis were 77%, 96% and 93% for both fused PET/MRI and PET/CT, compared with 49%, 99% and 91% for MRI, respectively. The differences for sensitivity (p = 0.0026) and accuracy (p = 0.041) were significant. Conclusion: Fused PET/MRI combining the individual advantages of MRI and PET is a valuable technique for assessment of staging neck cancer

  9. Value of retrospective image fusion of {sup 18}F-FDG PET and MRI for preoperative staging of head and neck cancer: Comparison with PET/CT and contrast-enhanced neck MRI

    Energy Technology Data Exchange (ETDEWEB)

    Kanda, Tomonori [Department of Radiology, Kobe University Graduate School of Medicine, Kobe (Japan); Department of Radiology, Hyogo Cancer Center, Hyogo (Japan); Kitajima, Kazuhiro, E-mail: kitajima@med.kobe-u.ac.jp [Department of Radiology, Kobe University Graduate School of Medicine, Kobe (Japan); Suenaga, Yuko; Konishi, Jyunya [Department of Radiology, Kobe University Graduate School of Medicine, Kobe (Japan); Sasaki, Ryohei [Division of Radiation Oncology, Department of Radiology, Kobe University Graduate School of Medicine, Kobe (Japan); Morimoto, Koichi; Saito, Miki; Otsuki, Naoki; Nibu, Ken-ichi [Department of Otolaryngology-Head and Neck Surgery, Kobe University Graduate School of Medicine, Kobe (Japan); Sugimura, Kazuro [Department of Radiology, Kobe University Graduate School of Medicine, Kobe (Japan)

    2013-11-01

    Purpose: To assess the clinical value of retrospective image fusion of neck MRI and {sup 18}F-fluorodeoxyglucose ({sup 18}F-FDG) PET for locoregional extension and nodal staging of neck cancer. Materials and methods: Thirty patients with carcinoma of the oral cavity or hypopharynx underwent PET/CT and contrast-enhanced neck MRI for initial staging before surgery including primary tumor resection and neck dissection. Diagnostic performance of PET/CT, MRI, and retrospective image fusion of PET and MRI (fused PET/MRI) for assessment of the extent of the primary tumor (T stage) and metastasis to regional lymph nodes (N stage) was evaluated. Results: Accuracy for T status was 87% for fused PET/MRI and 90% for MRI, thus proving significantly superior to PET/CT, which had an accuracy of 67% (p = 0.041 and p = 0.023, respectively). Accuracy for N status was 77% for both fused PET/MRI and PET/CT, being superior to MRI, which had an accuracy of 63%, although the difference was not significant (p = 0.13). On a per-level basis, the sensitivity, specificity and accuracy for detection of nodal metastasis were 77%, 96% and 93% for both fused PET/MRI and PET/CT, compared with 49%, 99% and 91% for MRI, respectively. The differences for sensitivity (p = 0.0026) and accuracy (p = 0.041) were significant. Conclusion: Fused PET/MRI combining the individual advantages of MRI and PET is a valuable technique for assessment of staging neck cancer.

  10. Can follow-up controls improve the confidence of MR of the breast? A retrospective analysis of follow-up MR images of the breast

    International Nuclear Information System (INIS)

    Betsch, A.; Arndt, E.; Stern, W.; Claussen, C.D.; Mueller-Schimpfle, M.; Wallwiener, D.

    2001-01-01

    Purpose: To assess the change in diagnostic confidence between first and follow-up dynamic MR examination of the breast (MRM). Methods: The reports of a total of 175 MRM in 77 patients (mean age 50 years; 36-76) with 98 follow-up MRM were analyzed. All examinations were performed as a dynamic study (Gd-DTPA, 0.16 mmol/kg; 6-7 repetitive studies). The change in diagnostic confidence was retrospectively classified as follows: Controlled lesion vanished during follow-up (category I); diagnostic confidence increases during follow-up (II), more likely benign (IIa), more suspicious (IIb); no difference in diagnostic confidence (III). Long-term follow-up over an average of four years was obtained for 57 patients with category IIa/III findings. Results: In 98 follow-up examinations, only two lesions vanished (2%). In 77/98 cases a category IIa lesion was diagnosed, in 11 cases a category IIb lesion. In 8 cases (8%) there was no change in diagnostic confidence during follow-up. Lesions in category IIb underwent biopsy in 10/11 cases, in one case long-term follow-up proved a completely regredient inflammatory change. In 8/11 suspicious findings (IIb) a malignant tumor was detected. The mean time interval between first and follow-up MRM was 8 months for I-IIb lesions, and 4 months for category III lesions. In the longterm follow-up two patients with a category II a lesion developed a carcinoma in a different breast area after four and five years. Conclusion: MRM follow up increases the diagnostic confidence if the time interval is adequate (>4 months). A persistently or increasingly suspicious finding warrants biopsy. (orig.) [de

  11. Classification of atrophic mucosal patterns on Blue LASER Imaging for endoscopic diagnosis of Helicobacter pylori-related gastritis: A retrospective, observational study.

    Science.gov (United States)

    Nishikawa, Yoshiyuki; Ikeda, Yoshio; Murakami, Hidehiro; Hori, Shin-Ichiro; Hino, Kaori; Sasaki, Chise; Nishikawa, Megumi

    2018-01-01

    Atrophic gastritis can be classified according to characteristic mucosal patterns observed by Blue LASER Imaging (BLI) in a medium-range to distant view. To facilitate the endoscopic diagnosis of Helicobacter pylori (HP)-related gastritis, we investigated whether atrophic mucosal patterns correlated with HP infection based on the image interpretations of three endoscopists blinded to clinical features. This study included 441 patients diagnosed as having atrophic gastritis by upper gastrointestinal endoscopy at Nishikawa Gastrointestinal Clinic between April 1, 2015 and March 31, 2016. The presence/absence of HP infection was not taken into consideration. Endoscopy was performed using a Fujifilm EG-L580NW scope. Atrophic mucosal patterns observed by BLI were classified into Spotty, Cracked and Mottled. Image interpretation results were that 89, 122 and 228 patients had the Spotty, Cracked and Mottled patterns, respectively, and 2 patients an undetermined pattern. Further analyses were performed on 439 patients, excluding the 2 with undetermined patterns. The numbers of patients testing negative/positive for HP infection in the Spotty, Cracked and Mottled pattern groups were 12/77, 105/17, and 138/90, respectively. The specificity, positive predictive value and positive likelihood ratio for endoscopic diagnosis with positive HP infection based on the Spotty pattern were 95.3%, 86.5% and 8.9, respectively. In all patients with the Spotty pattern before HP eradication, the Cracked pattern was observed on subsequent post-eradication endoscopy. The Spotty pattern may represent the presence of HP infection, the Cracked pattern, a post-inflammatory change as seen after HP eradication, and the Mottled pattern, intestinal metaplasia.

  12. Multislice computed tomographic coronary angiography: experience in a UK centre

    International Nuclear Information System (INIS)

    Morgan-Hughes, G.J.; Marshall, A.J.; Roobottom, C.A.

    2003-01-01

    AIM: To evaluate the technique of coronary angiography with retrospectively electrocardiogram (ECG)-gated four-slice helical computed tomography (CT). MATERIALS AND METHODS: Within 1 month of undergoing routine day-case diagnostic coronary angiography, 30 consecutive patients also underwent retrospectively ECG-gated multislice CT coronary angiography. This enabled direct comparison of seven segments of proximal and mid-coronary artery for each patient by two blinded assessors. Each segment of coronary artery from the multislice CT image was evaluated initially for 'assessability' and those segments deemed assessable were subsequently investigated for the presence or absence of a significantly (n=70%) stenotic lesion. RESULTS: Overall 68% of proximal and mid-coronary artery segments were assessable. The sensitivity and specificity of four-slice CT coronary angiography in assessable segments for detecting the presence or absence (n=70%) of stenoses were 72 and 86%, respectively. These results correspond to a positive predictive value of 53% and a 93% negative predictive value. If the 32% of non-assessable segments are added into the calculation then the sensitivity and specificity fall to 49 and 66%, respectively. CONCLUSION: Although multislice CT coronary angiography is a promising technique, the overall assessability and diagnostic accuracy of four-slice CT acquisition is not sufficient to justify routine clinical use. Further, evaluation should investigate the benefit of the reduction in temporal and spatial resolution offered by 16 and 32 slice acquisition

  13. Sci-Fri PM: Radiation Therapy, Planning, Imaging, and Special Techniques - 08: Retrospective Dose Accumulation Workflow in Head and Neck Cancer Patients Using RayStation 4.5.2

    International Nuclear Information System (INIS)

    Wong, Olive; Chan, Biu; Moseley, Joanne; McNiven, Andrea; Lindsay, Patricia; Bissonnette, Jean-Pierre; Waldron, John; Giuliani, Meredith; Zhang, Beibei

    2016-01-01

    Purpose: We have developed a semi-automated dose accumulation workflow for Head and Neck Cancer (HNC) patients to evaluate volumetric and dosimetric changes that take place during radiotherapy. This work will be used to assess how dosimetric changes affect both toxicity and disease control, hence inform the feasibility and design of a prospective HNC adaptive trial. Methods: RayStation 4.5.2 features deformable image registration (DIR), where structures already defined on the planning CT image set can be deformably mapped onto cone-beam computed tomography (CBCT) images, accounting for daily treatment set-up shifts and changes in patient anatomy. The daily delivered dose can be calculated on each CBCT and mapped back to the planning CT to allow dose accumulation. The process is partially automated using Python scripts developed in collaboration with RaySearch. Results: To date we have performed dose accumulation on 18 HNC patients treated at our institution during 2013–2015 under REB approval. Our semi-automated process establishes clinical feasibility. Generally, dose accumulation for the entire treatment course of one case takes 60–120 minutes: importing all CBCTs requires 20–30 minutes as each patient has 30 to 40 treated fractions; image registration and dose accumulation require 60–90 minutes. This is in contrast to the process without automated scripts where dose accumulation alone would take 3–5 hours. Conclusions: We have developed a reliable workflow for retrospective dose tracking in HNC using RayStation. The process has been validated for HNC patients treated on both Elekta and Varian linacs with CBCTs acquired on XVI and OBI platforms respectively.

  14. Sci-Fri PM: Radiation Therapy, Planning, Imaging, and Special Techniques - 08: Retrospective Dose Accumulation Workflow in Head and Neck Cancer Patients Using RayStation 4.5.2

    Energy Technology Data Exchange (ETDEWEB)

    Wong, Olive; Chan, Biu; Moseley, Joanne; McNiven, Andrea; Lindsay, Patricia; Bissonnette, Jean-Pierre; Waldron, John; Giuliani, Meredith; Zhang, Beibei [Princess Margaret Cancer Centre-UHN (Canada)

    2016-08-15

    Purpose: We have developed a semi-automated dose accumulation workflow for Head and Neck Cancer (HNC) patients to evaluate volumetric and dosimetric changes that take place during radiotherapy. This work will be used to assess how dosimetric changes affect both toxicity and disease control, hence inform the feasibility and design of a prospective HNC adaptive trial. Methods: RayStation 4.5.2 features deformable image registration (DIR), where structures already defined on the planning CT image set can be deformably mapped onto cone-beam computed tomography (CBCT) images, accounting for daily treatment set-up shifts and changes in patient anatomy. The daily delivered dose can be calculated on each CBCT and mapped back to the planning CT to allow dose accumulation. The process is partially automated using Python scripts developed in collaboration with RaySearch. Results: To date we have performed dose accumulation on 18 HNC patients treated at our institution during 2013–2015 under REB approval. Our semi-automated process establishes clinical feasibility. Generally, dose accumulation for the entire treatment course of one case takes 60–120 minutes: importing all CBCTs requires 20–30 minutes as each patient has 30 to 40 treated fractions; image registration and dose accumulation require 60–90 minutes. This is in contrast to the process without automated scripts where dose accumulation alone would take 3–5 hours. Conclusions: We have developed a reliable workflow for retrospective dose tracking in HNC using RayStation. The process has been validated for HNC patients treated on both Elekta and Varian linacs with CBCTs acquired on XVI and OBI platforms respectively.

  15. Postoperative satisfaction and the patient's body image, life satisfaction, and self-esteem: a retrospective study comparing adolescent girls and boys after cosmetic surgery.

    Science.gov (United States)

    Kamburoğlu, Haldun O; Ozgür, Figen

    2007-01-01

    Cosmetic surgery procedures are more complex for adolescents than for adults because there are more factors affecting patient satisfaction, especially psychological factors. This study was designed to find answers to four main questions: (1) whether postoperative satisfaction rates differ statistically between males and females, (2) whether postoperative satisfaction correlates significantly with the self-esteem, body image, life satisfaction trilogy, (3) what the postoperative patient satisfaction and cosmetic procedure rates are among adolescents by years, and (4) whether a statistically significant relationship exists between postoperative satisfaction and a willingness of adolescents to undergo another cosmetic surgery. The study enrolled 86 of 165 patients who underwent surgery between January 2001 and June 2005. A simple poll consisting of 12 simple questions was used to collect data. No statistically significant difference was found in postoperative satisfaction rates between males and females. The findings show that postoperative satisfaction is significantly related to self-esteem, body image, and life satisfaction. The patient satisfaction rate was 93.83%, and there was no increase in adolescent cosmetic surgery rates over the years. Adolescents are good candidates for cosmetic surgery, but patients must be evaluated carefully. Any suspicion about a patient's psychological status must result in a psychiatric consultation.

  16. Retrospective assessment of macrophytic communities in southern Lake Garda (Italy from in situ and MIVIS (Multispectral Infrared and Visible Imaging Spectrometer data

    Directory of Open Access Journals (Sweden)

    Claudia Giardino

    2012-01-01

    Full Text Available In situ and hyperspectral MIVIS (Multispectral Infrared and Visible Imaging Spectrometer images acquired over a period of 13 years are used to assess changes in macrophyte colonization patterns in the coastal zones of the Sirmione Peninsula in the southern part of Lake Garda (Italy. In situ data (abundance, cover density and diversity of macrophyte communities and MIVIS-derived maps of colonized substrates are analyzed by considering the variability of the main hydrological and physicochemical variables in order to indicate the main factors that explain the spatiotemporal variability of macrophyte communities. The results show a considerable modification in terms of macrophyte structural complexity and colonized areas. Almost 98% of macrophyte meadows (in particular communities with a density of over 70% are lost and subsequently replaced by moderate to extremely rare communities with density from 10% to 40%. Well-established submerged macrophytes are replaced by de-structured communities characterized by moderate to scarce density: on average lower than 30%. The study indicates that macrophyte distribution along the littoral zone of the Sirmione Peninsula is certainly linked to water transparency and water level fluctuation. The results also indicate that the worsening of eutrophication may be associated with the gradual disappearance of macrophyte meadows, but may also be accelerated by herbivorous aquatic birds grazing there. Lastly, the increasing frequency and number of catamaran tours could be considered a threat for the stability of these valuable communities.

  17. Does successful rotator cuff repair improve muscle atrophy and fatty infiltration of the rotator cuff? A retrospective magnetic resonance imaging study performed shortly after surgery as a reference.

    Science.gov (United States)

    Hamano, Noritaka; Yamamoto, Atsushi; Shitara, Hitoshi; Ichinose, Tsuyoshi; Shimoyama, Daisuke; Sasaki, Tsuyoshi; Kobayashi, Tsutomu; Kakuta, Yohei; Osawa, Toshihisa; Takagishi, Kenji

    2017-06-01

    Muscle atrophy and fatty infiltration in the rotator cuff muscles are often observed in patients with chronic rotator cuff tears. The recovery from these conditions has not been clarified. Ninety-four patients were included in this study. The improvement in muscle atrophy and fatty infiltration in successfully repaired rotator cuff tears was evaluated by magnetic resonance imaging at 1 year and 2 years after surgery and was compared with muscle atrophy and fatty infiltration observed on magnetic resonance imaging at 2 weeks after surgery to discount any changes due to the medial retraction of the torn tendon. The patients' muscle strength was evaluated in abduction and external rotation. Muscle atrophy and fatty infiltration of the supraspinatus were significantly improved at 2 years after surgery in comparison to 2 weeks after surgery. The subjects' abduction and external rotation strength was also significantly improved at 2 years after surgery in comparison to the preoperative values. Patients whose occupation ratio was improved had a better abduction range of motion, stronger abduction strength, and higher Constant score. Patients whose fatty infiltration was improved had a better range of motion in flexion and abduction, whereas the improvements of muscle strength and the Constant score were similar in the group that showed an improvement of fatty infiltration and the group that did not. Muscle atrophy and fatty infiltration can improve after rotator cuff repair. The strengths of abduction and external rotation were also improved at 2 years after surgery. Copyright © 2016 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

  18. Imaging of the Coronary Venous System: Validation of Three-Dimensional Rotational Venous Angiography Against Dual-Source Computed Tomography

    International Nuclear Information System (INIS)

    Knackstedt, Christian; Muehlenbruch, Georg; Mischke, Karl; Bruners, Philipp; Schimpf, Thomas; Frechen, Dirk; Schummers, Georg; Mahnken, Andreas H.; Guenther, Rolf W.; Kelm, Malte; Schauerte, Patrick

    2008-01-01

    Information on the anatomy of the cardiac venous system (CVS) is increasingly important for cardiac resynchronization therapy or percutaneous transvenous mitral valve annuloplasty. Three-dimensional (3D) imaging can further improve the understanding of the relationship of cardiac structures. This study was performed to validate the accuracy of rotational coronary sinus angiography (CSA) displaying the 3D anatomy of the CVS compared to ECG-gated, contrast-enhanced, cardiac dual-source computed tomography (DSCT). Five domestic pigs (60 kg) underwent DSCT using a standardized examination protocol. Using a standard C-arm for fluoroscopy, a rotational CSA was obtained and 3D-image reconstructions performed. Side branches were identified using both methods and enumerated. Vessel visibility was estimated for each side branch and great cardiac vein/anterior interventricular vein. Also, vessel diameters were measured at distinct landmarks, i.e., side branching. The amount of contrast medium was determined and the effective radiation exposure of both methods was calculated. There was no significant difference regarding the vessel diameter of the great cardiac vein/anterior interventricular vein or its side branches. Also, estimation of vessel visibility was not different between the two imaging modalities. Estimated radiation exposure and amount of contrast medium were lower for rotational CSA. In conclusion, a 3D reconstruction of rotational CSA images is possible. All parts of the CVS are well depicted, allowing a 3D overview of the CVS anatomy. On-site 3D visualization might improve decision making during cardiac interventions. In contrast to DSCT, rotational CSA does not demonstrate the anatomy of the mitral annulus or the course of the left circumflex artery.

  19. Retrospective 70 y-spatial analysis of repeated vine mortality patterns using ancient aerial time series, Pléiades images and multi-source spatial and field data

    Science.gov (United States)

    Vaudour, E.; Leclercq, L.; Gilliot, J. M.; Chaignon, B.

    2017-06-01

    For any wine estate, there is a need to demarcate homogeneous within-vineyard zones ('terroirs') so as to manage grape production, which depends on vine biological condition. Until now, the studies performing digital zoning of terroirs have relied on recent spatial data and scant attention has been paid to ancient geoinformation likely to retrace past biological condition of vines and especially occurrence of vine mortality. Is vine mortality characterized by recurrent and specific patterns and if so, are these patterns related to terroir units and/or past landuse? This study aimed at performing a historical and spatial tracing of vine mortality patterns using a long time-series of aerial survey images (1947-2010), in combination with recent data: soil apparent electrical conductivity EM38 measurements, very high resolution Pléiades satellite images, and a detailed field survey. Within a 6 ha-estate in the Southern Rhone Valley, landuse and planting history were retraced and the map of missing vines frequency was constructed from the whole time series including a 2015-Pléiades panchromatic band. Within-field terroir units were obtained from a support vector machine classifier computed on the spectral bands and NDVI of Pléiades images, EM38 data and morphometric data. Repeated spatial patterns of missing vines were highlighted throughout several plantings, uprootings, and vine replacements, and appeared to match some within-field terroir units, being explained by their specific soil characteristics, vine/soil management choices and the past landuse of the 1940s. Missing vines frequency was spatially correlated with topsoil CaCO3 content, and negatively correlated with topsoil iron, clay, total N, organic C contents and NDVI. A retrospective spatio-temporal assessment of terroir therefore brings a renewed focus on some key parameters for maintaining a sustainable grape production.

  20. Targeting post-infarct inflammation by PET imaging: comparison of 68Ga-citrate and 68Ga-DOTATATE with 18F-FDG in a mouse model

    International Nuclear Information System (INIS)

    Thackeray, James T.; Bankstahl, Jens P.; Walte, Almut; Wittneben, Alexander; Bengel, Frank M.; Wang, Yong; Korf-Klingebiel, Mortimer; Wollert, Kai C.

    2015-01-01

    Imaging of inflammation early after myocardial infarction (MI) is a promising approach to the guidance of novel molecular interventions that support endogenous healing processes. 18 F-FDG PET has been used, but may be complicated by physiological myocyte uptake. We evaluated the potential of two alternative imaging targets: lactoferrin binding by 68 Ga-citrate and somatostatin receptor binding by 68 Ga-DOTATATE. C57Bl/6 mice underwent permanent coronary artery ligation. Serial PET imaging was performed 3 - 7 days after MI using 68 Ga-citrate, 68 Ga-DOTATATE, or 18 F-FDG with ketamine/xylazine suppression of myocyte glucose uptake. Myocardial perfusion was evaluated by 13 N-ammonia PET and cardiac geometry by contrast-enhanced ECG-gated CT. Mice exhibited a perfusion defect of 30 - 40 % (of the total left ventricle) with apical anterolateral wall akinesia and thinning on day 7 after MI. 18 F-FDG with ketamine/xylazine suppression demonstrated distinct uptake in the infarct region, as well as in the border zone and remote myocardium. The myocardial standardized uptake value in MI mice was significantly higher than in healthy mice under ketamine/xylazine anaesthesia (1.9 ± 0.4 vs. 1.0 ± 0.1). 68 Ga images exhibited high blood pool activity with no specific myocardial uptake up to 90 min after injection (tissue-to-blood contrast 0.9). 68 Ga-DOTATATE was rapidly cleared from the blood, but myocardial SUV was very low (0.10 ± 0.03). Neither 68 Ga nor 68 Ga-DOTATATE is a useful alternative to 18 F-FDG for PET imaging of myocardial inflammation after MI in mice. Among the three tested approaches, 18 F-FDG with ketamine/xylazine suppression of cardiomyocyte uptake remains the most practical imaging marker of post-infarct inflammation. (orig.)

  1. A retrospective comparison of outcome and toxicity of preoperative image-guided intensity-modulated radiotherapy versus conventional pelvic radiotherapy for locally advanced rectal carcinoma

    International Nuclear Information System (INIS)

    Huang, Chun-Ming; Huang, Ming-Yii; Tsai, Hsiang-Lin; Huang, Ching-Wen; Ma, Cheng-Jen; Lin, Chih-Hung; Huang, Chih-Jen; Wang, Jaw-Yuan

    2017-01-01

    The aim of the study was to compare clinical outcomes and toxicity between 3D conformal radiotherapy (3DCRT) and image-guided intensity-modulated radiotherapy (IG-IMRT) administered through helical tomotherapy in locally advanced rectal cancer (LARC) patients receiving preoperative chemoradiotherapy. We reviewed 144 patients with Stage II–III rectal cancer receiving preoperative fluoropyrimidine-based chemoradiotherapy followed by radical resection. Tumor responses following chemoradiotherapy were evaluated using the Dworak tumor regression grade (TRG). Of the 144 patients, 45 received IG-IMRT and 99 received 3DCRT. A significant reduction in Grade 3 or 4 acute gastrointestinal toxicity (IG-IMRT, 6.7%; 3DCRT, 15.1%; P = 0.039) was observed by IG-IMRT. The pathologic complete response (pCR) rate did not differ between the IG-IMRT and the 3DCRT group (17.8% vs 15.1%, P = 0.52). Patients in the IG-IMRT group had the trend of favorable tumor regressions (TRG 3 or 4) compared with those in the 3DCRT group (66.7% vs 43.5%, P = 0.071). The median follow-up was 53 months (range, 18–95 months) in the 3DCRT group and 43 months (range, 17–69 months) in the IG-IMRT group. Four-year overall, disease-free, and local failure–free survival rates of the IG-IMRT and 3DCRT groups were 81.6% and 67.9% (P = 0.12), 53.8% and 51.8% (P = 0.51), and 88% and 75.1% (P = 0.031), respectively. LARC patients treated with preoperative IG-IMRT achieved lower acute gastrointestinal adverse effects and a higher local control rate than those treated with 3DCRT, but there was no prominent difference in distant metastasis rate and overall survival between two treatment modalities.

  2. Triple rule-out CT in the emergency department: protocols and spectrum of imaging findings

    Energy Technology Data Exchange (ETDEWEB)

    Frauenfelder, Thomas; Appenzeller, Philippe; Karlo, Christoph; Scheffel, Hans; Desbiolles, Lotus; Stolzmann, Paul; Marincek, Borut; Alkadhi, Hatem; Schertler, Thomas [University Hospital Zurich, Department of Medical Radiology, Institute of Diagnostic Radiology, Zurich (Switzerland)

    2009-04-15

    Triage decisions in patients suffering from acute chest pain remain a challenge. The patient's history, initial cardiac enzyme levels, or initial electrocardiograms (ECG) often do not allow selecting the patients in whom further tests are needed. Numerous vascular and non-vascular chest problems, such as pulmonary embolism (PE), aortic dissection, or acute coronary syndrome, as well as pulmonary, pleural, or osseous lesions, must be taken into account. Nowadays, contrast-enhanced multi-detector-row computed tomography (CT) has replaced previous invasive diagnostic procedures and currently represents the imaging modality of choice when the clinical suspicion of PE or acute aortic syndrome is raised. At the same time, CT is capable of detecting a multitude of non-vascular causes of acute chest pain, such as pneumonia, pericarditis, or fractures. Recent technical advances in CT technology have also shown great advantages for non-invasive imaging of the coronary arteries. In patients with acute chest pain, the optimization of triage decisions and cost-effectiveness using cardiac CT in the emergency department have been repetitively demonstrated. Triple rule-out CT denominates an ECG-gated protocol that allows for the depiction of the pulmonary arteries, thoracic aorta, and coronary arteries within a single examination. This can be accomplished through the use of a dedicated contrast media administration regimen resulting in a simultaneous attenuation of the three vessel territories. This review is intended to demonstrate CT parameters and contrast media administration protocols for performing a triple rule-out CT and discusses radiation dose issues pertinent to the protocol. Typical life-threatening and non-life-threatening diseases causing acute chest pain are illustrated. (orig.)

  3. Diagnostic evaluation of ischemic heart disease by X-ray computed tomography and magnetic resonance imaging

    International Nuclear Information System (INIS)

    Masuda, Yoshiaki; Kobayashi, Shiro; Takasu, Junichiro; Sakakibara, Makoto; Imai, Hitoshi; Aoyagi, Yutaka; Morooka, Nobuhiro; Watanabe, Shigeru; Inagaki, Yoshiaki

    1987-01-01

    To assess the usefulness of X-ray computed tomography (CT) and magnetic resonance imaging (MRI) in detecting and evaluating ischemic heart disease, conventional and enhanced CT were performed for 180 patients (150 with transmural infarction, 12 with subendocardial infarction, and 18 with angina pectoris). MRI examinations were performed for 38 patients (31 with transmural infarction, three with subendocardial infarction, and four with angina pectoris). With enhanced CT, two findings in the myocardium were direct evidence of myocardial infarction: 1) filling defects on the early scans, and 2) late enhancement of the myocardium on the delayed scans. The former were observed mainly at the sites of recent anterior myocardial infarction and the latter were seen in about half of the patients with recent and remote anterior myocardial infarctions. However, these findings were inadequately imaged in patients with inferoposterior infarction and subendocardial infarction. Among 137 patients with transmural infarction, enhanced CT revealed left ventricular aneurysms in 51 (37 %) and ventricular thrombi in 26 (19 %). ECG-gated MRI apparatus having a superconducting magnetic operating at 0.25 Tesla was used, and data for this study were collected using the single-slice spin echo technique. In eight of nine patients with acute myocardial infarction, gated MRI demonstrated the infarcted myocardium as regions of high signal intensity relative to that of the adjacent normal myocardium. Such a difference in MRI signal intensity was scarcely recognized in the chronic stage of myocardial infarction, but the indirect findings of infarction, such as regional wall thinning, wall motion disturbances, left ventricular aneurysms, and ventricular thrombi were easily detected using MRI. No characteristic finding was obtained by CT or MRI in patients with angina pectoris. (author)

  4. Retrospective and comparative analysis of 99mTc-Sestamibi breast specific gamma imaging versus mammography, ultrasound, and magnetic resonance imaging for the detection of breast cancer in Chinese women

    International Nuclear Information System (INIS)

    Yu, Xiuyan; Hu, Guoming; Zhang, Zhigang; Qiu, Fuming; Shao, Xuan; Wang, Xiaochen; Zhan, Hongwei; Chen, Yiding; Deng, Yongchuan; Huang, Jian

    2016-01-01

    Diagnosing breast cancer during the early stage may be helpful for decreasing cancer-related mortality. In Western developed countries, mammographies have been the gold standard for breast cancer detection. However, Chinese women usually have denser and smaller-sized breasts compared to Caucasian women, which decreases the diagnostic accuracy of mammography. However, breast specific gamma imaging, a type of molecular functional breast imaging, has been used for the accurate diagnosis of breast cancer and is not influenced by breast density. Our objective was to analyze the breast specific gamma imaging (BSGI) diagnostic value for Chinese women. During a 2-year period, 357 women were diagnosed and treated at our oncology department and received BSGI in addition to mammography (MMG), ultrasound (US) and magnetic resonance imaging (MRI) for diagnostic assessment. We investigated the sensitivity and specificity of each method of detection and compared the biological profiles of the four imaging methods. A total of 357 women received a final surgical pathology diagnosis, with 168 malignant diseases (58.5 %) and 119 benign diseases (41.5 %). Of these, 166 underwent the four imaging tests preoperatively. The sensitivity of BSGI was 80.35 and 82.14 % by US, 75.6 % by MMG, and 94.06 % by MRI. Furthermore, the breast cancer diagnosis specificity of BSGI was high (83.19 % vs. 77.31 % vs. 66.39 % vs. 67.69 %, respectively). The BSGI diagnostic sensitivity for mammographic breast density in women was superior to mammography and more sensitive for non-luminal A subtypes (luminal A vs. non-luminal A, 68.63 % vs. 88.30 %). BSGI may help improve the ability to diagnose early stage breast cancer for Chinese women, particularly for ductal carcinoma in situ (DCIS), mammographic breast density and non-luminal A breast cancer

  5. Retrospective and comparative analysis of (99m)Tc-Sestamibi breast specific gamma imaging versus mammography, ultrasound, and magnetic resonance imaging for the detection of breast cancer in Chinese women.

    Science.gov (United States)

    Yu, Xiuyan; Hu, Guoming; Zhang, Zhigang; Qiu, Fuming; Shao, Xuan; Wang, Xiaochen; Zhan, Hongwei; Chen, Yiding; Deng, Yongchuan; Huang, Jian

    2016-07-11

    Diagnosing breast cancer during the early stage may be helpful for decreasing cancer-related mortality. In Western developed countries, mammographies have been the gold standard for breast cancer detection. However, Chinese women usually have denser and smaller-sized breasts compared to Caucasian women, which decreases the diagnostic accuracy of mammography. However, breast specific gamma imaging, a type of molecular functional breast imaging, has been used for the accurate diagnosis of breast cancer and is not influenced by breast density. Our objective was to analyze the breast specific gamma imaging (BSGI) diagnostic value for Chinese women. During a 2-year period, 357 women were diagnosed and treated at our oncology department and received BSGI in addition to mammography (MMG), ultrasound (US) and magnetic resonance imaging (MRI) for diagnostic assessment. We investigated the sensitivity and specificity of each method of detection and compared the biological profiles of the four imaging methods. A total of 357 women received a final surgical pathology diagnosis, with 168 malignant diseases (58.5 %) and 119 benign diseases (41.5 %). Of these, 166 underwent the four imaging tests preoperatively. The sensitivity of BSGI was 80.35 and 82.14 % by US, 75.6 % by MMG, and 94.06 % by MRI. Furthermore, the breast cancer diagnosis specificity of BSGI was high (83.19 % vs. 77.31 % vs. 66.39 % vs. 67.69 %, respectively). The BSGI diagnostic sensitivity for mammographic breast density in women was superior to mammography and more sensitive for non-luminal A subtypes (luminal A vs. non-luminal A, 68.63 % vs. 88.30 %). BSGI may help improve the ability to diagnose early stage breast cancer for Chinese women, particularly for ductal carcinoma in situ (DCIS), mammographic breast density and non-luminal A breast cancer.

  6. Multimodal imaging and detection approach to 18F-FDG-directed surgery for patients with known or suspected malignancies: a comprehensive description of the specific methodology utilized in a single-institution cumulative retrospective experience

    Directory of Open Access Journals (Sweden)

    Povoski Stephen P

    2011-11-01

    Full Text Available Abstract Background 18F-FDG PET/CT is widely utilized in the management of cancer patients. The aim of this paper was to comprehensively describe the specific methodology utilized in our single-institution cumulative retrospective experience with a multimodal imaging and detection approach to 18F-FDG-directed surgery for known/suspected malignancies. Methods From June 2005-June 2010, 145 patients were injected with 18F-FDG in anticipation of surgical exploration, biopsy, and possible resection of known/suspected malignancy. Each patient underwent one or more of the following: (1 same-day preoperative patient diagnostic PET/CT imaging, (2 intraoperative gamma probe assessment, (3 clinical PET/CT specimen scanning of whole surgically resected specimens (WSRS, research designated tissues (RDT, and/or sectioned research designated tissues (SRDT, (4 micro PET/CT specimen scanning of WSRS, RDT, and/or SRDT, (5 total radioactivity counting of each SRDT piece by an automatic gamma well counter, and (6 same-day postoperative patient diagnostic PET/CT imaging. Results Same-day 18F-FDG injection dose was 15.1 (± 3.5, 4.6-26.1 mCi. Fifty-five same-day preoperative patient diagnostic PET/CT scans were performed. One hundred forty-two patients were taken to surgery. Three of the same-day preoperative patient diagnostic PET/CT scans led to the cancellation of the anticipated surgical procedure. One hundred forty-one cases utilized intraoperative gamma probe assessment. Sixty-two same-day postoperative patient diagnostic PET/CT scans were performed. WSRS, RDT, and SRDT were scanned by clinical PET/CT imaging and micro PET/CT imaging in 109 and 32 cases, 33 and 22 cases, and 49 and 26 cases, respectively. Time from 18F-FDG injection to same-day preoperative patient diagnostic PET/CT scan, intraoperative gamma probe assessment, and same-day postoperative patient diagnostic PET/CT scan were 73 (± 9, 53-114, 286 (± 93, 176-532, and 516 (± 134, 178-853 minutes

  7. Retrospective single center study of the efficacy of large spot 532 nm laser for the treatment of facial capillary malformations in 44 patients with the use of three-dimensional image analysis.

    Science.gov (United States)

    Kwiek, Bartłomiej; Rożalski, Michał; Kowalewski, Cezary; Ambroziak, Marcin

    2017-10-01

    We wanted to asses the efficacy of large spot 532 nm laser for the treatment of facial capillary malformations with the use of three-dimensional (3D) image analysis. Retrospective single center study on previously non-treated patients with facial capillary malformations (CM) was performed. A total of 44 consecutive Caucasian patients aged 5-66 were included. Patients had 3D photography performed before and after and had at least one single session of treatment with 532 nm neodymium-doped yttrium aluminum garnet (Nd:YAG) laser with contact cooling, fluencies ranging from 8 to 11.5 J/cm 2 , pulse duration ranging from 5 to 9 milliseconds and spot size ranging from 5 to 10 mm. Objective analysis of percentage improvement based on 3D digital assessment of combined color and area improvement (global clearance effect [GCE]) were performed. Median maximal improvement achieved during the treatment (GCE max ) was 70.4%. Mean number of laser procedures required to achieve this improvement was 7.1 (ranging from 2 to 14)). Improvement of minimum 25% (GCE 25) was achieved by all patients, of minimum 50% (GCE 50) by 77.3%, of minimum 75% (GCE 75) by 38.6%, and of minimum 90% (GCE 90) by 13.64. Large spot 532 nm laser is highly effective in the treatment of facial CM. 3D color and area image analysis provides an objective method to compare different methods of facial CM treatment in future studies. Lasers Surg. Med. 49:743-749, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  8. Early Postoperative Magnetic Resonance Imaging in Detecting Radicular Pain After Lumbar Decompression Surgery: Retrospective Study of the Relationship Between Dural Sac Cross-sectional Area and Postoperative Radicular Pain.

    Science.gov (United States)

    Futatsugi, Toshimasa; Takahashi, Jun; Oba, Hiroki; Ikegami, Shota; Mogami, Yuji; Shibata, Syunichi; Ohji, Yoshihito; Tanikawa, Hirotaka; Kato, Hiroyuki

    2017-07-01

    A retrospective analysis. To evaluate the association between early postoperative dural sac cross-sectional area (DCSA) and radicular pain. The correlation between postoperative magnetic resonance imaging (MRI) findings and postoperative neurological symptoms after lumbar decompression surgery is controversial. This study included 115 patients who underwent lumbar decompression surgery followed by MRI within 7 days postoperatively. There were 46 patients with early postoperative radicular pain, regardless of whether the pain was mild or similar to that before surgery. The intervertebral level with the smallest DCSA was identified on MRI and compared preoperatively and postoperatively. Risk factors for postoperative radicular pain were determined using univariate and multivariate analyses. Subanalysis according to absence/presence of a residual suction drain also was performed. Multivariate regression analysis showed that smaller postoperative DCSA was significantly associated with early postoperative radicular pain (per -10 mm; odds ratio, 1.26). The best cutoff value for radicular pain was early postoperative DCSA of 67.7 mm. Even with a cutoff value of surgery. The best cutoff value for postoperative radicular pain was 67.7 mm. Absence of a suction drain at the time of early postoperative MRI was related to smaller DCSA.

  9. Image quality and diagnostic accuracy of unenhanced SSFP MR angiography compared with conventional contrast-enhanced MR angiography for the assessment of thoracic aortic diseases

    Energy Technology Data Exchange (ETDEWEB)

    Krishnam, Mayil S. [University of California, Cardiovascular and Thoracic Imaging, UCI Medical Center, Irvine, CA (United States); Tomasian, Anderanik; Malik, Sachin; Ruehm, Stefan G. [University of California at Los Angeles, Department of Radiological Sciences, Ronald Reagan Medical Center, Los Angeles, CA (United States); Desphande, Vibhas; Laub, Gerhard [Siemens Medical Solutions, Los Angeles, CA (United States)

    2010-06-15

    The purpose of this study was to determine the image quality and diagnostic accuracy of three-dimensional (3D) unenhanced steady state free precession (SSFP) magnetic resonance angiography (MRA) for the evaluation of thoracic aortic diseases. Fifty consecutive patients with known or suspected thoracic aortic disease underwent free-breathing ECG-gated unenhanced SSFP MRA with non-selective radiofrequency excitation and contrast-enhanced (CE) MRA of the thorax at 1.5 T. Two readers independently evaluated the two datasets for image quality in the aortic root, ascending aorta, aortic arch, descending aorta, and origins of supra-aortic arteries, and for abnormal findings. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were determined for both datasets. Sensitivity, specificity, and diagnostic accuracy of unenhanced SSFP MRA for the diagnosis of aortic abnormalities were determined. Abnormal aortic findings, including aneurysm (n = 47), coarctation (n = 14), dissection (n = 12), aortic graft (n = 6), intramural hematoma (n = 11), mural thrombus in the aortic arch (n = 1), and penetrating aortic ulcer (n = 9), were confidently detected on both datasets. Sensitivity, specificity, and diagnostic accuracy of SSFP MRA for the detection of aortic disease were 100% with CE-MRA serving as a reference standard. Image quality of the aortic root was significantly higher on SSFP MRA (P < 0.001) with no significant difference for other aortic segments (P > 0.05). SNR and CNR values were higher for all segments on SSFP MRA (P < 0.01). Our results suggest that free-breathing navigator-gated 3D SSFP MRA with non-selective radiofrequency excitation is a promising technique that provides high image quality and diagnostic accuracy for the assessment of thoracic aortic disease without the need for intravenous contrast material. (orig.)

  10. Image quality and diagnostic accuracy of unenhanced SSFP MR angiography compared with conventional contrast-enhanced MR angiography for the assessment of thoracic aortic diseases

    International Nuclear Information System (INIS)

    Krishnam, Mayil S.; Tomasian, Anderanik; Malik, Sachin; Ruehm, Stefan G.; Desphande, Vibhas; Laub, Gerhard

    2010-01-01

    The purpose of this study was to determine the image quality and diagnostic accuracy of three-dimensional (3D) unenhanced steady state free precession (SSFP) magnetic resonance angiography (MRA) for the evaluation of thoracic aortic diseases. Fifty consecutive patients with known or suspected thoracic aortic disease underwent free-breathing ECG-gated unenhanced SSFP MRA with non-selective radiofrequency excitation and contrast-enhanced (CE) MRA of the thorax at 1.5 T. Two readers independently evaluated the two datasets for image quality in the aortic root, ascending aorta, aortic arch, descending aorta, and origins of supra-aortic arteries, and for abnormal findings. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were determined for both datasets. Sensitivity, specificity, and diagnostic accuracy of unenhanced SSFP MRA for the diagnosis of aortic abnormalities were determined. Abnormal aortic findings, including aneurysm (n = 47), coarctation (n = 14), dissection (n = 12), aortic graft (n = 6), intramural hematoma (n = 11), mural thrombus in the aortic arch (n = 1), and penetrating aortic ulcer (n = 9), were confidently detected on both datasets. Sensitivity, specificity, and diagnostic accuracy of SSFP MRA for the detection of aortic disease were 100% with CE-MRA serving as a reference standard. Image quality of the aortic root was significantly higher on SSFP MRA (P 0.05). SNR and CNR values were higher for all segments on SSFP MRA (P < 0.01). Our results suggest that free-breathing navigator-gated 3D SSFP MRA with non-selective radiofrequency excitation is a promising technique that provides high image quality and diagnostic accuracy for the assessment of thoracic aortic disease without the need for intravenous contrast material. (orig.)

  11. Assessment of ejection fraction of the right and left ventricles in patients with acute myocardial infarction by magnetic resonance imaging

    International Nuclear Information System (INIS)

    Zhang, Youyi; Imai, Kamon; Araki, Yasushi; Nishino, Yukari; Saito, Satoshi; Ozawa, Yukio; Yasugi, Tadao

    1993-01-01

    Right and left ventricular function in acute myocardial infarction (AMI) was assessed by ECG-gated magnetic resonance imaging (MRI) in 64 patients and 8 volunteers. Five short axis images for intrinsic cardiac long-axis of the left ventricle were obtained at 9 msec and 309 msec after the R wave as end-diastole and end-systole. Right and left ventricular volumes were measured by Simpson's rule. The intraobserver variabilities in right and left ventricular ejection fraction (RVEF: r=0.94, LVEF: 0.89) were excellent. The interobserver variabilities in RVEF (r=0.61) and LVEF (r=0.77) were fair. LVEF, but not RVEF, was significantly reduced in patients with AMI. Among left ventricular dysfunction (LVEF≤40%) patients, 50% exhibited right ventricular dysfunction (RVEF≤40%). Among patients without left ventricular dysfunction, only 12% exhibited right ventricular dysfunction. In left ventricular and biventricular dysfunction compared with control, the left ventricular end-diastolic volume index increased (65±10 ml/m 2 , 68±12 ml/m 2 vs 54±8 ml/m 2 ), the end-systolic volume index increased (40±16 ml/m 2 , 43±7 ml/m 2 vs 18±1 ml/m 2 ), and the right ventricular end-diastolic volume index decreased (52±13 ml/m 2 , 53±20 ml/m 2 vs 65±8 ml/m 2 ). MRI can thus be used to assess ventricular systolic function. Since patients with left ventricular dysfunction revealed a high incidence of right ventricular dysfunction, an interaction between the left and right ventricles may occur in ventricular dysfunction. (author)

  12. Spin density projection-assisted R2 magnetic resonance imaging of the liver in the management of body iron stores in patients receiving multiple red blood cell transfusions: an audit and retrospective study in South Australia.

    Science.gov (United States)

    Brown, G C; Patton, W N; Tapp, H E; Taylor, D J; St Pierre, T G

    2012-09-01

    To assess the impact of non-invasive monitoring of liver iron concentration (LIC) on management of body iron stores in patients receiving multiple blood transfusions. A retrospective audit was conducted on clinical data from 40 consecutive subjects with haemolytic anaemias or ineffective haematopoiesis who had been monitored non-invasively for LIC over a period of at least 1 year. LIC was measured with spin density projection-assisted proton transverse relaxation rate-magnetic resonance imaging. Nineteen clinical decisions were explicitly documented in the case notes as being based on LIC results. Decisions comprised initiation of chelation therapy, increasing chelator dose, decreasing chelator dose and change of mode of delivery of deferioxamine from subcutaneous to intravenous. The geometrical mean LIC for the cohort dropped significantly (P= 0.008) from 6.8 mg Fe/g dry tissue at initial measurement to 4.8 mg Fe/g dry tissue at final measurement. The proportion of subjects with LIC in the range associated with greatly increased risk of cardiac disease and death (>15 mg Fe/g dry tissue) dropped significantly (P= 0.01) from 14 of 40 subjects at initial measurement to 5 of 40 subjects at final measurement. No significant changes in the geometrical mean of serum ferritin or the proportion of subjects with serum ferritin above 2500 or 1500 µg/L were observed. The data are consistent with previous observations that introduction of non-invasive monitoring of LIC can contribute to a decreased body iron burden through improved clinical decision making and improved feedback to patients and hence improved adherence to chelation therapy.

  13. Magnetic resonance imaging (MRI) of the cardiovascular system

    International Nuclear Information System (INIS)

    Yoshida, Shigeru

    1991-01-01

    Qualitative assessments of the hypertrophied myocardium were performed using spin-lattice relaxation time (T1) and spin-spin relaxation time (T2) obtained by magnetic resonance imaging (MRI) in 15 normotensive patients with asymmetric septal hypertrophy (ASH), 10 hypertensive patients with concentric hypertrophy (CH) and 5 normal subjects (N). The changes of these values were evaluated related to cardiac cycle, and their usefulness in differentiating diseases. The wall thickness and internal dimension of the left ventricle (LV) in 10 cases were obtained using echocardiography and MRI, and there was a good correlation coefficient in wall thickness (r=0.987) and in internal dimension (r=0.991). Left ventricular short-axis images were obtained using ECG-gated spin-echo sequence (Te=30, 80 msec) and using inversion recovery sequence. T1 and T2 images were calculated at endsystolic and diastolic cardiac phases. The regional wall thickness (WT) and T1 and T2 values were measured in the anterior septum, anterior wall, lateral wall, posterior wall and posterior septum. Myocardial T1 and T2 values were significantly decreased in systole (T1: 185.6±37.9 msec, T2: 24.4±6.3 msec) compared to those in diastole (T1: 249.2±56.7 msec, T2: 31.7±9.4 msec). In both ASH and CH groups, significant correlations were observed between diastolic T1 values and WT (ASH: r=0.80, CH: r=0.45), and between diastolic T2 values and WT (ASH: r=0.58, CH: r=0.60). In the regions where diastolic WT were more than 17 mm, T1 values in the ASH group (343.4±40.5 msec) were significantly higher than those of the CH group (247.3±21.4 msec), although the mean wall thickness values were similar in both groups. These results indicate that myocardial relaxation times are related to cardiac cycle, wall thickness and types of hypertrophy. The T1 and T2 values at diastolic cardiac phase might be useful for distinguishing hypertrophic cardiomyopathy from hypertrophy due to hypertension. (author)

  14. Clinical usefullness of ECG-triggered single photon emission comuter tomography of blood-pool

    International Nuclear Information System (INIS)

    Eilles, Chr.; Boerner, W.; Strauss, P.; Gerhards, W.; Reiners, Ch.

    1982-01-01

    ECT allows direct measurement of the volume of an organ and imaging without disturbing background-superposition. This makes ECT to an useful instrument for ECG-gated blood-pool imaging. Acquisition is made after the injection of 25 mCi Tc-99m HSA with a rotating Anger-Camera-System. ECG-gated imaging is done for each projection; herewith 50-70 cycles per projection are added according to the phase of the heart-cycle. Transversal-Sections of the heart are reconstructed with filtered-back-projection. For each slice a representative cycle, consisting of 10-16 frames, is computed. As shown by our group before a good quality of the reconstructed images can be obtained. Comparison is made with the results of the ECG-gated blood-pool-ECT, the results of the conventional blood-pool-studies and with the results of Laevo-Cardiography. (Author)

  15. Study of optimal exposure windows using 320-Detector rows dynamic volume CT

    Directory of Open Access Journals (Sweden)

    Gang Sun

    2010-12-01

    Full Text Available Gang Sun1, Min Li1, Li Li1, Guo-ying Li1, Zhi-wei Jing21Departments of Medical Imaging, 2Medical Statistics, Jinan Military General Hospital, Shandong Province, ChinaAbstract: The purpose of this study was to determine the optimal electrocardiographic (ECG pulsing windows and evaluate the effect on reduced dose and accuracy using 320-detector rows dynamic volume computed tomography (DVCT. A total of 170 patients were prospectively studied. The optimal reconstruction windows were analyzed in 76 patients scanned using retrospective ECG gating. Forty-seven patients were scanned by the predicted triggering windows. The optimal positions of exposure intervals according to different heart rates were evaluated. Optimal image quality, radiation dose, and diagnostic accuracy were then investigated by applying optimal triggering windows. The optimal ECG pulsing windows were determined as follows: when heart rate was <70 beats per minute, the exposure windows should be preset at 60%–80%; for a heart rate 70–90 beats per minute at 70%–90%; and for a heart rate ≥90 beats per minute at 30%–50%. The radiation dose for patients scanned with prospective ECG gating was significantly lower (5.9 versus 12.9 mSv, P < 0.001. However, because two or three heart beats were needed when heart rate was >70 beats per minute, the radiation dose increased with increasing heart rate for both retrospective and prospective ECG gating (r = 0.64, P < 0.001 and r = 0.59, P < 0.001, respectively. On the basis of a per segment analysis, overall sensitivity was 98.0% (49/50, specificity was 99.2% (602/607, the positive predictive value was 90.7% (49/54, and the negative predictive value was 99.8% (602/603. In conclusion, DVCT has the potential to provide high image quality across a wide range of heart rates using an optimized ECG pulsing window. However, it is recommended to control heart rate below 70 beats per minute, if possible, to decrease the radiation dose

  16. The retrospective gambler's fallacy

    Directory of Open Access Journals (Sweden)

    Daniel M. Oppenheimer

    2009-08-01

    Full Text Available The gambler's fallacy (Tune, 1964 refers to the belief that a streak is more likely to end than chance would dictate. In three studies, participants exhibited a extit{retrospective gambler's fallacy} (RGF in which an event that seems rare appears to come from a longer sequence than an event that seems more common. Study 1 demonstrates this bias for streaks, while Study 2 does so with single rare events and shows that the appearance of rarity is more important than actual rarity. Study 3 extends these findings from abstract gambling domains into real world domains to demonstrate the generalizability of the effects. The RGF follows from the law of small numbers (Tversky and Kahneman, 1971 and has many applications, from perceptions of the social world to philosophical debates about the existence of multiple universes.

  17. Imaging

    International Nuclear Information System (INIS)

    Kellum, C.D.; Fisher, L.M.; Tegtmeyer, C.J.

    1987-01-01

    This paper examines the advantages of the use of excretory urography for diagnosis. According to the authors, excretory urography remains the basic radiologic examination of the urinary tract and is the foundation for the evaluation of suspected urologic disease. Despite development of the newer diagnostic modalities such as isotope scanning, ultrasonography, CT, and magnetic resonsance imaging (MRI), excretory urography has maintained a prominent role in ruorradiology. Some indications have been altered and will continue to change with the newer imaging modalities, but the initial evaluation of suspected urinary tract structural abnormalities; hematuria, pyuria, and calculus disease is best performed with excretory urography. The examination is relatively inexpensive and simple to perform, with few contraindictions. Excretory urography, when properly performed, can provide valuable information about the renal parenchyma, pelvicalyceal system, ureters, and urinary bladder

  18. In vivo validation of cardiac output assessment in non-standard 3D echocardiographic images

    Energy Technology Data Exchange (ETDEWEB)

    Nillesen, M M; Lopata, R G P; Gerrits, I H; Thijssen, J M; De Korte, C L [Clinical Physics Laboratory-833, Department of Pediatrics, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands); De Boode, W P [Neonatology, Department of Pediatrics, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands); Huisman, H J [Department of Radiology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands); Kapusta, L [Pediatric Cardiology, Department of Pediatrics, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands)], E-mail: m.m.nillesen@cukz.umcn.nl

    2009-04-07

    Automatic segmentation of the endocardial surface in three-dimensional (3D) echocardiographic images is an important tool to assess left ventricular (LV) geometry and cardiac output (CO). The presence of speckle noise as well as the nonisotropic characteristics of the myocardium impose strong demands on the segmentation algorithm. In the analysis of normal heart geometries of standardized (apical) views, it is advantageous to incorporate a priori knowledge about the shape and appearance of the heart. In contrast, when analyzing abnormal heart geometries, for example in children with congenital malformations, this a priori knowledge about the shape and anatomy of the LV might induce erroneous segmentation results. This study describes a fully automated segmentation method for the analysis of non-standard echocardiographic images, without making strong assumptions on the shape and appearance of the heart. The method was validated in vivo in a piglet model. Real-time 3D echocardiographic image sequences of five piglets were acquired in radiofrequency (rf) format. These ECG-gated full volume images were acquired intra-operatively in a non-standard view. Cardiac blood flow was measured simultaneously by an ultrasound transit time flow probe positioned around the common pulmonary artery. Three-dimensional adaptive filtering using the characteristics of speckle was performed on the demodulated rf data to reduce the influence of speckle noise and to optimize the distinction between blood and myocardium. A gradient-based 3D deformable simplex mesh was then used to segment the endocardial surface. A gradient and a speed force were included as external forces of the model. To balance data fitting and mesh regularity, one fixed set of weighting parameters of internal, gradient and speed forces was used for all data sets. End-diastolic and end-systolic volumes were computed from the segmented endocardial surface. The cardiac output derived from this automatic segmentation was

  19. In vivo validation of cardiac output assessment in non-standard 3D echocardiographic images

    International Nuclear Information System (INIS)

    Nillesen, M M; Lopata, R G P; Gerrits, I H; Thijssen, J M; De Korte, C L; De Boode, W P; Huisman, H J; Kapusta, L

    2009-01-01

    Automatic segmentation of the endocardial surface in three-dimensional (3D) echocardiographic images is an important tool to assess left ventricular (LV) geometry and cardiac output (CO). The presence of speckle noise as well as the nonisotropic characteristics of the myocardium impose strong demands on the segmentation algorithm. In the analysis of normal heart geometries of standardized (apical) views, it is advantageous to incorporate a priori knowledge about the shape and appearance of the heart. In contrast, when analyzing abnormal heart geometries, for example in children with congenital malformations, this a priori knowledge about the shape and anatomy of the LV might induce erroneous segmentation results. This study describes a fully automated segmentation method for the analysis of non-standard echocardiographic images, without making strong assumptions on the shape and appearance of the heart. The method was validated in vivo in a piglet model. Real-time 3D echocardiographic image sequences of five piglets were acquired in radiofrequency (rf) format. These ECG-gated full volume images were acquired intra-operatively in a non-standard view. Cardiac blood flow was measured simultaneously by an ultrasound transit time flow probe positioned around the common pulmonary artery. Three-dimensional adaptive filtering using the characteristics of speckle was performed on the demodulated rf data to reduce the influence of speckle noise and to optimize the distinction between blood and myocardium. A gradient-based 3D deformable simplex mesh was then used to segment the endocardial surface. A gradient and a speed force were included as external forces of the model. To balance data fitting and mesh regularity, one fixed set of weighting parameters of internal, gradient and speed forces was used for all data sets. End-diastolic and end-systolic volumes were computed from the segmented endocardial surface. The cardiac output derived from this automatic segmentation was

  20. In vivo validation of cardiac output assessment in non-standard 3D echocardiographic images

    Science.gov (United States)

    Nillesen, M. M.; Lopata, R. G. P.; de Boode, W. P.; Gerrits, I. H.; Huisman, H. J.; Thijssen, J. M.; Kapusta, L.; de Korte, C. L.

    2009-04-01

    Automatic segmentation of the endocardial surface in three-dimensional (3D) echocardiographic images is an important tool to assess left ventricular (LV) geometry and cardiac output (CO). The presence of speckle noise as well as the nonisotropic characteristics of the myocardium impose strong demands on the segmentation algorithm. In the analysis of normal heart geometries of standardized (apical) views, it is advantageous to incorporate a priori knowledge about the shape and appearance of the heart. In contrast, when analyzing abnormal heart geometries, for example in children with congenital malformations, this a priori knowledge about the shape and anatomy of the LV might induce erroneous segmentation results. This study describes a fully automated segmentation method for the analysis of non-standard echocardiographic images, without making strong assumptions on the shape and appearance of the heart. The method was validated in vivo in a piglet model. Real-time 3D echocardiographic image sequences of five piglets were acquired in radiofrequency (rf) format. These ECG-gated full volume images were acquired intra-operatively in a non-standard view. Cardiac blood flow was measured simultaneously by an ultrasound transit time flow probe positioned around the common pulmonary artery. Three-dimensional adaptive filtering using the characteristics of speckle was performed on the demodulated rf data to reduce the influence of speckle noise and to optimize the distinction between blood and myocardium. A gradient-based 3D deformable simplex mesh was then used to segment the endocardial surface. A gradient and a speed force were included as external forces of the model. To balance data fitting and mesh regularity, one fixed set of weighting parameters of internal, gradient and speed forces was used for all data sets. End-diastolic and end-systolic volumes were computed from the segmented endocardial surface. The cardiac output derived from this automatic segmentation was

  1. A dynamic approach to identifying desired physiological phases for cardiac imaging using multislice spiral CT

    International Nuclear Information System (INIS)

    Vembar, M.; Garcia, M.J.; Heuscher, D.J.; Haberl, R.; Matthews, D.; Boehme, G.E.; Greenberg, N.L.

    2003-01-01

    In this investigation, we describe a quantitative technique to measure coronary motion, which can be correlated with cardiac image quality using multislice computed tomography (MSCT) scanners. MSCT scanners, with subsecond scanning, thin-slice imaging (sub-millimeter) and volume scanning capabilities have paved the way for new clinical applications like noninvasive cardiac imaging. ECG-gated spiral CT using MSCT scanners has made it possible to scan the entire heart in a single breath-hold. The continuous data acquisition makes it possible for multiple phases to be reconstructed from a cardiac cycle. We measure the position and three-dimensional velocities of well-known landmarks along the proximal, mid, and distal regions of the major coronary arteries [left main (LM), left anterior descending (LAD), right coronary artery (RCA), and left circumflex (LCX)] during the cardiac cycle. A dynamic model (called the 'delay algorithm') is described which enables us to capture the same physiological phase or 'state' of the anatomy during the cardiac cycle as the instantaneous heart rate varies during the spiral scan. The coronary arteries are reconstructed from data obtained during different physiological cardiac phases and we correlate image quality of different parts of the coronary anatomy with phases at which minimum velocities occur. The motion characteristics varied depending on the artery, with the highest motion being observed for RCA. The phases with the lowest mean velocities provided the best visualization. Though more than one phase of relative minimum velocity was observed for each artery, the most consistent image quality was observed during mid-diastole ('diastasis') of the cardiac cycle and was judged to be superior to other reconstructed phases in 92% of the cases. In the process, we also investigated correlation between cardiac arterial states and other measures of motion, such as the left ventricular volume during a cardiac cycle, which earlier has been

  2. Diagnostic accuracy of sub-mSv prospective ECG-triggering cardiac CT in young infant with complex congenital heart disease.

    Science.gov (United States)

    Gao, Wei; Zhong, Yu Min; Sun, Ai Min; Wang, Qian; Ouyang, Rong Zhen; Hu, Li Wei; Qiu, Han Sheng; Wang, Shi Yu; Li, Jian Ying

    2016-06-01

    To explore the clinical value and evaluate the diagnostic accuracy of sub-mSv low-dose prospective ECG-triggering cardiac CT (CCT) in young infants with complex congenital heart disease (CHD). A total of 102 consecutive infant patients (53 boys and 49 girls with mean age of 2.9 ± 2.4 m and weight less than 5 kg) with complex CHD were prospectively enrolled. Scans were performed on a 64-slice high definition CT scanner with low dose prospective ECG-triggering mode and reconstructed with 80 % adaptive statistical iterative reconstruction algorithm. All studies were performed during free breathing with sedation. The subjective image quality was evaluated by 5-point grading scale and interobserver variability was calculated. The objective image noise (standard deviation, SD) and contrast to noise ratio (CNR) was calculated. The effective radiation dose from the prospective ECG-triggering mode was recorded and compared with the virtual conventional retrospective ECG-gating mode. The detection rate for the origin of coronary artery was calculated. All patients also underwent echocardiography before CCT examination. 81 patients had surgery and their preoperative CCT and echocardiography findings were compared with the surgical results and sensitivity, specificity, positive and negative predictive values and accuracy were calculated for separate cardiovascular anomalies. Heart rates were 70-161 beats per minute (bpm) with mean value of 129.19 ± 14.52 bpm. The effective dose of 0.53 ± 0.15 mSv in the prospective ECG-triggering cardiac CT was lower than the calculated value in a conventional retrospective ECG-gating mode (2.00 ± 0.35 mSv) (p ECG-triggering CCT with sub-mSv effective dose provides excellent imaging quality and high diagnostic accuracy for young infants with complex CHD.

  3. Low-tube-voltage selection for triple-rule-out CTA: relation to patient size

    Energy Technology Data Exchange (ETDEWEB)

    Takx, Richard A.P. [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Krissak, Radko [Medical Faculty Mannheim - Heidelberg University, Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim (Germany); Hufeland Klinikum GmbH, Department of Diagnostic and Interventional Radiology, Bad Langensalza (Germany); Fink, Christian [Medical Faculty Mannheim - Heidelberg University, Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim (Germany); General Hospital Celle, Department of Radiology, Celle (Germany); Bachmann, Valentin; Henzler, Thomas; Meyer, Mathias; Schoenberg, Stefan O. [Medical Faculty Mannheim - Heidelberg University, Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim (Germany); Nance, John W. [Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); Apfaltrer, Paul [Medical Faculty Mannheim - Heidelberg University, Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim (Germany); Medical University of Vienna, Department of Biomedical Imaging and Image-guided Therapy, Vienna (Austria)

    2017-06-15

    To investigate the relationship between image quality and patient size at 100 kilovoltage (kV) compared to 120 kV ECG-gated Triple-Rule-Out CT angiography (TRO-CTA). We retrospectively included 73 patients (age 64 ± 14 years) who underwent retrospective ECG-gated chest CTA. 40 patients were scanned with 100 kV while 33 patients with 120 kV. Body mass index (BMI), patients' chest circumference (PC) and thoracic surface area (TSA) were recorded. Quantitative image quality was assessed as vascular attenuation in the ascending aorta (AA), pulmonary trunk (PA) and left coronary artery (LCA) and the signal-to-noise ratio (SNR) in the AA. There was no significant difference in BMI (26.0 ± 4.6 vs. 28.0 ± 6.7 kg/m{sup 2}), PC (103 ± 7 vs. 104 ± 10 cm{sup 2}) and TSA (92 ± 15 vs. 91 ± 19 cm{sup 2}) between 100 kV and 120 kV group. Mean vascular attenuation was significantly higher in the 100 kV compared to the 120 kV group (AA 438 vs. 354 HU, PA 460 vs. 349 HU, LCA 370 vs. 299 HU all p < 0.001). SNR was not significantly different, even after adjusting for patient size. Radiation dose was significantly lower in the 100 kV group (10.7 ± 4.1 vs. 20.7 ± 10.7 mSv; p < 0.001). 100 kV TRO-CTA is feasible in normal-to-overweight patients while maintaining image quality and achieving substantial dose reduction. (orig.)

  4. Assessment of coronary artery bypass graft patency by multidetector computed tomography and electron-beam tomography

    NARCIS (Netherlands)

    Piers, LH; Dorgelo, J; Tio, RA; Jessurun, GAJ; Oudkerk, M; Zijlstra, F

    This case report describes the use of retrospectively ECG-gated 16-slice multidetector computed tomography (MDCT) and electron-beam tomography (EBT) for assessing bypass graft patency in two patients with recurrent angina after coronary artery bypass graft surgery. The results of each tomographic

  5. Doses of Coronary Study in 64 Channel Multi-Detector Computed Tomography : Reduced Radiation Dose According to Varity of Examnination Protocols

    International Nuclear Information System (INIS)

    Kim, Moon Chan

    2009-01-01

    To compare radiation dose for coronary CT angiography (CTA) obtained with 6 examination protocols such as a retrospectively ECG gated helical scan, a prospectively ECG gated sequential scan, low kVp technique, and cardiac dose modulation technique. Coronary CTA was performed by using 6 current clinical protocols to evaluate effective dose and organ dose in primary beam area with anthropomorphic female phantom and glass dosimetric system in 64 channel multi-detector CT. After acquiring topograms of frontal and lateral projection with 80 kVp and 10 mA, main coronary scan was done with 0.35 sec tube rotation time, 40 mm collimation (0.625 mm x 64 ea), small scan field of view (32 cm diameter), 105 mm scan length. Heart beat rate of phantom was maintained 60 bpm in ECG gating. In constant mAs technique 120 kVp, 600 mA was used, and 100 kVp for low kVp technique. In a retrospectively ECG gated helical CT technique 0.22 pitch was used, peak mA (600 mA) was adopted in range of 40-80% of R-R interval and 120 mA (80% reduction) in others with cardiac dose modulation. And 210 mAs was used without cardiac dose modulation. In a prospectively ECG gated sequential CT technique data were acquired at 75% R-R interval (middle diastolic phase in cardiac cycle), and 120 msec additional padding of the tube-on time was used. For effective dose calculation region specific conversion factor of dose length product in thorax was used, which was recommended by EUR 16262. The mean effective dose for conventional coronary CTA without cardiac dose modulation in a retrospectively ECG gated helical scan was 17.8 mSv, and mean organ dose of heart was 103.8 mGy. With low kVp and cardiac dose modulation the mean effective dose showed 54.5% reduction, and heart dose showed 52.3% reduction, compared with that of conventional coronary CTA. And at the sequential scan(SnapShot pulse mode) under prospective ECG gating the mean effective dose was 4.9 mSv, this represents an 72.5% reduction compared with

  6. Automatic slice-alignment method in cardiac magnetic resonance imaging for evaluation of the right ventricle in patients with pulmonary hypertension

    Science.gov (United States)

    Yokoyama, Kenichi; Nitta, Shuhei; Kuhara, Shigehide; Ishimura, Rieko; Kariyasu, Toshiya; Imai, Masamichi; Nitatori, Toshiaki; Takeguchi, Tomoyuki; Shiodera, Taichiro

    2015-09-01

    We propose a new automatic slice-alignment method, which enables right ventricular scan planning in addition to the left ventricular scan planning developed in our previous work, to simplify right ventricular cardiac scan planning and assess its accuracy and the clinical acceptability of the acquired imaging planes in the evaluation of patients with pulmonary hypertension. Steady-state free precession (SSFP) sequences covering the whole heart in the end-diastolic phase with ECG gating were used to acquire 2D axial multislice images. To realize right ventricular scan planning, two morphological feature points are added to be detected and a total of eight morphological features of the heart were extracted from these series of images, and six left ventricular planes and four right ventricular planes were calculated simultaneously based on the extracted features. The subjects were 33 patients (25 with chronic thromboembolic pulmonary hypertension and 8 with idiopathic pulmonary arterial hypertension). The four right ventricular reference planes including right ventricular short-axis, 4-chamber, 2-chamber, and 3-chamber images were evaluated. The acceptability of the acquired imaging planes was visually evaluated using a 4-point scale, and the angular differences between the results obtained by this method and by conventional manual annotation were measured for each view. The average visual scores were 3.9±0.4 for short-axis images, 3.8±0.4 for 4-chamber images, 3.8±0.4 for 2-chamber images, and 3.5±0.6 for 3-chamber images. The average angular differences were 8.7±5.3, 8.3±4.9, 8.1±4.8, and 7.9±5.3 degrees, respectively. The processing time was less than 2.5 seconds in all subjects. The proposed method, which enables right ventricular scan planning in addition to the left ventricular scan planning developed in our previous work, can provide clinically acceptable planes in a short time and is useful because special proficiency in performing cardiac MR for

  7. Detecting Regional Myocardial Abnormalities in Patients With Wolff-Parkinson-White Syndrome With the Use of ECG-Gated Cardiac MDCT.

    Science.gov (United States)

    Lee, Hye-Jeong; Uhm, Jae-Sun; Joung, Boyoung; Hong, Yoo Jin; Hur, Jin; Choi, Byoung Wook; Kim, Young Jin

    2016-04-01

    Myocardial dyskinesia caused by the accessory pathway and related reversible heart failure have been well documented in echocardiographic studies of pediatric patients with Wolff-Parkinson-White (WPW) syndrome. However, the long-term effects of dyskinesia on the myocardium of adult patients have not been studied in depth. The goal of the present study was to evaluate regional myocardial abnormalities on cardiac CT examinations of adult patients with WPW syndrome. Of 74 patients with WPW syndrome who underwent cardiac CT from January 2006 through December 2013, 58 patients (mean [± SD] age, 52.2 ± 12.7 years), 36 (62.1%) of whom were men, were included in the study after the presence of combined cardiac disease was excluded. Two observers blindly evaluated myocardial thickness and attenuation on cardiac CT scans. On the basis of CT findings, patients were classified as having either normal or abnormal findings. We compared the two groups for other clinical findings, including observations from ECG, echocardiography, and electrophysiologic study. Of the 58 patients studied, 16 patients (27.6%) were found to have myocardial abnormalities (i.e., abnormal wall thinning with or without low attenuation). All abnormal findings corresponded with the location of the accessory pathway. Patients with abnormal findings had statistically significantly decreased left ventricular function, compared with patients with normal findings (p syndrome. These abnormal findings might reflect the long-term effects of dyskinesia, suggesting irreversible myocardial injury that ultimately causes left ventricular dysfunction.

  8. Impact of missing attenuation and scatter corrections on 99m Tc-MAA SPECT 3D dosimetry for liver radioembolization using the patient relative calibration methodology: A retrospective investigation on clinical images.

    Science.gov (United States)

    Botta, Francesca; Ferrari, Mahila; Chiesa, Carlo; Vitali, Sara; Guerriero, Francesco; Nile, Maria Chiara De; Mira, Marta; Lorenzon, Leda; Pacilio, Massimiliano; Cremonesi, Marta

    2018-04-01

    To investigate the clinical implication of performing pre-treatment dosimetry for 90 Y-microspheres liver radioembolization on 99m Tc-MAA SPECT images reconstructed without attenuation or scatter correction and quantified with the patient relative calibration methodology. Twenty-five patients treated with SIR-Spheres ® at Istituto Europeo di Oncologia and 31 patients treated with TheraSphere ® at Istituto Nazionale Tumori were considered. For each acquired 99m Tc-MAA SPECT, four reconstructions were performed: with attenuation and scatter correction (AC_SC), only attenuation (AC_NoSC), only scatter (NoAC_SC) and without corrections (NoAC_NoSC). Absorbed dose maps were calculated from the activity maps, quantified applying the patient relative calibration to the SPECT images. Whole Liver (WL) and Tumor (T) regions were drawn on CT images. Injected Liver (IL) region was defined including the voxels receiving absorbed dose >3.8 Gy/GBq. Whole Healthy Liver (WHL) and Healthy Injected Liver (HIL) regions were obtained as WHL = WL - T and HIL = IL - T. Average absorbed dose to WHL and HIL were calculated, and the injection activity was derived following each Institute's procedure. The values obtained from AC_NoSC, NoAC_SC and NoAC_NoSC images were compared to the reference value suggested by AC_SC images using Bland-Altman analysis and Wilcoxon paired test (5% significance threshold). Absorbed-dose maps were compared to the reference map (AC_SC) in global terms using the Voxel Normalized Mean Square Error (%VNMSE), and at voxel level by calculating for each voxel the normalized difference with the reference value. The uncertainty affecting absorbed dose at voxel level was accounted for in the comparison; to this purpose, the voxel counts fluctuation due to Poisson and reconstruction noise was estimated from SPECT images of a water phantom acquired and reconstructed as patient images. NoAC_SC images lead to activity prescriptions not significantly different from the

  9. Dual-source spiral CT with pitch up to 3.2 and 75 ms temporal resolution: Image reconstruction and assessment of image quality

    International Nuclear Information System (INIS)

    Flohr, Thomas G.; Leng Shuai; Yu Lifeng; Allmendinger, Thomas; Bruder, Herbert; Petersilka, Martin; Eusemann, Christian D.; Stierstorfer, Karl; Schmidt, Bernhard; McCollough, Cynthia H.

    2009-01-01

    coronary artery phantom acquired with the ECG-triggered high-pitch scan mode were visually free from motion artifacts at heart rates of 60 and 70 bpm. However, image quality started to deteriorate for higher heart rates. At equivalent image quality, the ECG-triggered high-pitch scan mode demonstrated lower radiation dose than other cardiac scan techniques on the same DSCT equipment (25% and 60% dose reduction compared to ECG-triggered sequential step-and-shoot and ECG-gated spiral with x-ray pulsing). Conclusions: A high-pitch (up to pitch=3.2), high-temporal-resolution (up to 75 ms) dual-source CT scan mode produced equivalent image quality relative to single-source scans using a more typical pitch value (pitch=1.0). The resultant reduction in the overall acquisition time may offer clinical advantage for cardiovascular, trauma, and pediatric CT applications. In addition, ECG-triggered high-pitch scanning may be useful as an alternative to ECG-triggered sequential scanning for patients with low to moderate heart rates up to 70 bpm, with the potential to scan the heart within one heart beat at reduced radiation dose.

  10. Dual-source spiral CT with pitch up to 3.2 and 75 ms temporal resolution: image reconstruction and assessment of image quality.

    Science.gov (United States)

    Flohr, Thomas G; Leng, Shuai; Yu, Lifeng; Aiimendinger, Thomas; Bruder, Herbert; Petersilka, Martin; Eusemann, Christian D; Stierstorfer, Karl; Schmidt, Bernhard; McCollough, Cynthia H

    2009-12-01

    acquired with the ECG-triggered high-pitch scan mode were visually free from motion artifacts at heart rates of 60 and 70 bpm. However, image quality started to deteriorate for higher heart rates. At equivalent image quality, the ECG-triggered high-pitch scan mode demonstrated lower radiation dose than other cardiac scan techniques on the same DSCT equipment (25% and 60% dose reduction compared to ECG-triggered sequential step-and-shoot and ECG-gated spiral with x-ray pulsing). A high-pitch (up to pitch = 3.2), high-temporal-resolution (up to 75 ms) dual-source CT scan mode produced equivalent image quality relative to single-source scans using a more typical pitch value (pitch = 1.0). The resultant reduction in the overall acquisition time may offer clinical advantage for cardiovascular, trauma, and pediatric CT applications. In addition, ECG-triggered high-pitch scanning may be useful as an alternative to ECG-triggered sequential scanning for patients with low to moderate heart rates up to 70 bpm, with the potential to scan the heart within one heart beat at reduced radiation dose.

  11. Dual-source spiral CT with pitch up to 3.2 and 75 ms temporal resolution: Image reconstruction and assessment of image quality

    Energy Technology Data Exchange (ETDEWEB)

    Flohr, Thomas G.; Leng Shuai; Yu Lifeng; Allmendinger, Thomas; Bruder, Herbert; Petersilka, Martin; Eusemann, Christian D.; Stierstorfer, Karl; Schmidt, Bernhard; McCollough, Cynthia H. [Siemens Healthcare, Computed Tomography, 91301 Forchheim, Germany and Department of Diagnostic Radiology, Eberhard-Karls-Universitaet, 72076 Tuebingen (Germany); Department of Radiology, Mayo Clinic, Rochester, Minnesota 55905 (United States); Siemens Healthcare, Computed Tomography, 91301 Forchheim (Germany); Department of Radiology, Mayo Clinic, Rochester, Minnesota 55905 (United States)

    2009-12-15

    coronary artery phantom acquired with the ECG-triggered high-pitch scan mode were visually free from motion artifacts at heart rates of 60 and 70 bpm. However, image quality started to deteriorate for higher heart rates. At equivalent image quality, the ECG-triggered high-pitch scan mode demonstrated lower radiation dose than other cardiac scan techniques on the same DSCT equipment (25% and 60% dose reduction compared to ECG-triggered sequential step-and-shoot and ECG-gated spiral with x-ray pulsing). Conclusions: A high-pitch (up to pitch=3.2), high-temporal-resolution (up to 75 ms) dual-source CT scan mode produced equivalent image quality relative to single-source scans using a more typical pitch value (pitch=1.0). The resultant reduction in the overall acquisition time may offer clinical advantage for cardiovascular, trauma, and pediatric CT applications. In addition, ECG-triggered high-pitch scanning may be useful as an alternative to ECG-triggered sequential scanning for patients with low to moderate heart rates up to 70 bpm, with the potential to scan the heart within one heart beat at reduced radiation dose.

  12. Retrospective quality control review of FDG scans in the imaging sub-study of PALETTE EORTC 62072/VEG110727: a randomized, double-blind, placebo-controlled phase III trial

    Energy Technology Data Exchange (ETDEWEB)

    Hristova, Ivalina [European Organization for Research and Treatment of Cancer Headquarters, Brussels (Belgium); Radboud University Medical Centre, Department of Nuclear Medicine, Nijmegen (Netherlands); Boellaard, Ronald [VU University Medical Centre, Department of Radiology and Nuclear Medicine, Amsterdam (Netherlands); Vogel, Wouter [The Netherlands Cancer Institute - Antoni van Leeuwenhoek, Department of Nuclear Medicine, Amsterdam (Netherlands); Mottaghy, Felix [Maastricht University, Department of Nuclear Medicine, Maastricht (Netherlands); Marreaud, Sandrine; Collette, Sandra [European Organization for Research and Treatment of Cancer Headquarters, Brussels (Belgium); Schoeffski, Patrick [University Hospitals Leuven, Department of General Medical Oncology, Leuven Cancer Institute, Department of Oncology, KU Leuven (Belgium); Sanfilippo, Roberta [Istituto Nazionale Tumori, Milano (Italy); Dewji, Raz [GlaxoSmithKline, Oncology R and D, Uxbridge (United Kingdom); Graaf, Winette van der [Radboud University Medical Centre, Department of Medical Oncology, Nijmegen (Netherlands); Oyen, Wim J.G. [Radboud University Medical Centre, Department of Nuclear Medicine, Nijmegen (Netherlands)

    2015-05-01

    {sup 18}F-Labelled fluorodeoxyglucose (FDG) can detect early changes in tumour metabolism and may be a useful quantitative imaging biomarker (QIB) for prediction of disease stabilization, response and duration of progression-free survival (PFS). Standardization of imaging procedures is a prerequisite, especially in multicentre clinical trials. In this study we reviewed the quality of FDG scans and compliance with the imaging guideline (IG) in a phase III clinical trial. Forty-four cancer patients were enrolled in an imaging sub-study of a randomized international multicentre trial. FDG scan had to be performed at baseline and 10-14 days after treatment start. The image transmittal forms (ITFs) and Digital Imaging and Communications in Medicine (DICOM) [1] standard headers were analysed for compliance with the IG. Mean liver standardized uptake values (LSUV{sub mean}) were measured as recommended by positron emission tomography (PET) Response Criteria in Solid Tumors 1.0 (PERCIST) [2]. Of 88 scans, 81 were received (44 patients); 36 were properly anonymized; 77/81 serum glucose values submitted, all but one within the IG. In 35/44 patients both scans were of sufficient visual quality. In 22/70 ITFs the reported UT differed by >1 min from the DICOM headers (max. difference 1 h 4 min). Based on the DICOM, UT compliance for both scans was 31.4 %. LSUV{sub mean} was fairly constant for the 11 patients with UT compliance: 2.30 ± 0.33 at baseline and 2.27 ± 0.48 at follow-up (FU). Variability substantially increased for the subjects with unacceptable UT (11 patients): 2.27 ± 1.04 at baseline and 2.18 ± 0.83 at FU. The high attrition number of patients due to low compliance with the IG compromised the quantitative assessment of the predictive value for early response monitoring. This emphasizes the need for better regulated procedures in imaging departments, which may be achieved by education of involved personnel or efforts towards regulations. LSUV{sub mean} could be

  13. Taking radionuclides to heart

    International Nuclear Information System (INIS)

    Kleynhans, P.H.T.; Lotter, M.G.; Van Aswegen, A.; Minnaar, P.C.; Iturralde, M.; Herbst, C.P.; Marx, D.

    1980-01-01

    Ischaemic heart disease is a main cause of death in South Africa. Non-invasive ECG gated radionuclide bloodpool imaging plays an increasingly useful role in the evalution of the function of the heart as a pump, and the extent of heart muscle perfusion defects is further pinpointed by invasive krypton-81m studies to improve patient management

  14. The Chameleon project in retrospective

    NARCIS (Netherlands)

    Smit, Gerardus Johannes Maria; Heysters, P.M.; Molenkamp, Egbert

    2004-01-01

    In this paper we describe in retrospective the main results of a four year project, called Chameleon. As part of this project we developed a coarse-grained reconfigurable core for DSP algorithms in wireless devices denoted MONTIUM. After presenting the main achievements within this project we

  15. Begg orthodontic therapy in retrospect

    NARCIS (Netherlands)

    Levin, Raymond Israel

    1975-01-01

    The purpose of the investigation described in this thesis was to study in retrospect a number of changes of the dentition, its occlusion and the facial skeleton which occurred in the treatment and posttreatment periods in a sample of 30 cases treated with the Begg fixed appliance techniques.

  16. Retrospect

    Science.gov (United States)

    Weaver, Anthony

    1971-01-01

    A collection of essays on education printed in The New Era during the 1920-1930 era and written by: Beatrice Ensor, A. S. Neill, G. Bernard Shaw, Adolphe Ferriere, C. G. Jung, Martin Buber, Alfred Adler, Harold Rugg, Ovide Decroly, and Paul Langevin. (SE)

  17. Delineation of upper urinary tract segments at MDCT urography in patients with extra-urinary mass lesions: retrospective comparison of standard and low-dose protocols for the excretory phase of imaging

    Energy Technology Data Exchange (ETDEWEB)

    Mueller-Lisse, Ulrike L. [University of Munich, Department of Urology, Munich (Germany); University of Munich Medical School, Department of Urology, Muenchen (Germany); Coppenrath, Eva M.; Meindl, Thomas; Degenhart, Christoph; Scherr, Michael K.; Reiser, Maximilian F.; Mueller-Lisse, Ullrich G. [University of Munich, Department of Radiology, Munich (Germany); Stief, Christian G. [University of Munich, Department of Urology, Munich (Germany)

    2011-02-15

    Excretory-phase CT urography (CTU) may replace excretory urography in patients without urinary tumors. However, radiation exposure is a concern. We retrospectively compared upper urinary tract (UUT) delineation in low-dose and standard CTU. CTU (1-2 phases, 120 KV, 4 x 2.5 mm, pitch 0.875, i.v. non-ionic contrast media, iodine 36 g) was obtained with standard (14 patients, n = 27 UUTs, average 175.6 mAs/slice, average delay 16.8 min) or low-dose (26 patients, n = 86 UUTs, 29 mAs/slice, average delay 19.6 min) protocols. UUT was segmented into intrarenal collecting system (IRCS), upper, middle, and lower ureter (UU,MU,LU). Two independent readers (R1,R2) graded UUT segments as 1-not delineated, 2-partially delineated, 3-completely delineated (noisy margins), 4-completely delineated (clear margins). Chi-square statistics were calculated for partial versus complete delineation and complete delineation (clear margins), respectively. Complete delineation of UUT was similar in standard and low-dose CTU (R1, p > 0.15; R2, p > 0.2). IRCS, UU, and MU clearly delineated similarly often in standard and low-dose CTU (R1, p > 0.25; R2, p > 0.1). LU clearly delineated more often in standard protocols (R1, 18/6 standard, 38/31 low-dose, p > 0.1; R2 18/6 standard, 21/48 low-dose, p < 0.05). Low-dose CTU sufficiently delineated course of UUT and may locate obstruction/dilation, but appears unlikely to find intraluminal LU lesions. (orig.)

  18. Assessment of left ventricular function using 201Tl electrocardiogram-gated myocardial single photon emission computed tomography

    International Nuclear Information System (INIS)

    Nishikubo, Naotsugu; Tamai, Hiroyuki

    2013-01-01

    Advances in computed tomography (CT) technology make it possible to obtain left ventricular wall motion using 3D reconstruction. In this study, we compared the images obtained from CT and 201 Tl electrocardiogram (ECG) gated single photon emission computed tomography (SPECT). In 20 patients with ischemic heart disease, we performed 201 Tl ECG gated SPECT (GE Healthcare Millennium VG) and ECG gated CT (Philips Medical Systems Brilliance iCT) to evaluate of left ventricular wall motion during the resting phase. In SPECT, left ventricular images were reconstructed using quantitative gated SPECT (QGS) software. In CT, the images were reconstructed using Virtual Place (AZE Software). The left ventricle was classified into five regions (anterior, lateral, inferior, septal, and apical). The amplitude of the wall motion was classified into five grades according to AHA classification. The values of the wall motion were separately checked by two radiographers. Assessment of left ventricular function myocardial wall movement using the three-dimensional movie display with ECG gated myocardial SPECT data was in agreement with the evaluation by cardiac CT inspection, and corresponded with wall motion in 88 of all 100 segments. SPECT analysis has the same quantity as that of obtained from CT for evaluation of left ventricular wall motion. (author)

  19. Assessment of left ventricular function by 201Tl FCG-gated myocardial SPECT

    International Nuclear Information System (INIS)

    Toba, Masahiro; Ishida, Yoshio; Fukuchi, Kazuki; Fukushima, Kazuhito; Katafuchi, Tetsurou; Hayashida, Kohei; Oka, Hisashi; Takamiya, Makoto

    1999-01-01

    We applied the QGS program for LV function analysis (described by Germano, 1995) to a 201 Tl SPECT study at rest, and estimated its accuracy. We performed 201 Tl ECG-gated myocardial SPECT in 25 patients with ischemic heart disease under an acquisition time used in the routine 99m Tc ECG-gated SPECT study. The quality of the gated images was visually assessed with a 4-point grading system. LVEDV, LVESV, LVEF determined by the QGS program were compared with those by Simpson's method on biplane LVG in 25 patients. Regional wall motion scores in 7 myocardial segments were assessed on the three-dimensional display created by the QGS program and the cine display of biplane LVG with a 5-point grading system. Wall motion scores obtained by the QGS program were compared with those by LVG. Although 72.0% of 201 Tl ECG-gated SPECT images were fair or poor in image quality, there were good correlations between the values obtained by the QGS program and LVG (LVEDV: r=0.82, LVESV: r=0.88, LVEF: r=0.89). In addition, wall motion scores by the QGS program were correspondent to those by LVG in 77.1% of all 175 myocardial segments. We conclude that the QGS program provides high accuracy in evaluating left ventricular function even from 201 Tl ECG-gated myocardial SPECT data. (author)

  20. Coronary computed tomography angiography using prospective electrocardiography-gated axial scans with 64-detector computed tomography. Evaluation of stair-step artifacts and padding time

    International Nuclear Information System (INIS)

    Kimura, Fumiko; Umezawa, Tatsuo; Asano, Tomonari; Chihara, Ruri; Nishi, Naoko; Nishimura, Shigeyoshi; Sakai, Fumikazu

    2010-01-01

    We compared stair-step artifacts and radiation dose between prospective electrocardiography (ECG)-gated coronary computed tomography angiography (prospective CCTA) and retrospective CCTA using 64-detector CT and determined the optimal padding time (PT) for prospective CCTA. We retrospectively evaluated 183 patients [mean heart rate (HR) <65 beats/min, maximum HR instability <5 beats/min] who had undergone CCTA. We scored stair-step artifacts from 1 (severe) to 5 (none) and evaluated the effective dose in 53 patients with retrospective CCTA and 130 with prospective CCTA (PT 200 ms, n=32; PT 50 ms, n=98). Mean artifact scores were 4.3 in both retrospective and prospective CCTAs. However, statistically more arteries scored <3 (nonassessable) on prospective CCTA (P<0.001). Mean scores for prospective CCTA with 200- and 50-ms PT were 4.1 and 4.3, respectively (no significant difference). The radiation dose of prospective CCTA was reduced by 59.1% to 80.7%. Prospective CCTA reduces the radiation dose and allows diagnostic imaging in most cases but shows more nonevaluable artifacts than retrospective CCTA. Use of 50-ms instead of 200-ms PT appears to maintain image quality in patients with a mean HR <65 beats/min and HR instability of <5 beats/min. (author)

  1. Targeting post-infarct inflammation by PET imaging: comparison of {sup 68}Ga-citrate and {sup 68}Ga-DOTATATE with {sup 18}F-FDG in a mouse model

    Energy Technology Data Exchange (ETDEWEB)

    Thackeray, James T. [Hannover Medical School, Department of Nuclear Medicine, Hannover (Germany); Hannover Medical School, Division of Molecular and Translational Cardiology, Department of Cardiology and Angiology, Hannover (Germany); Bankstahl, Jens P.; Walte, Almut; Wittneben, Alexander; Bengel, Frank M. [Hannover Medical School, Department of Nuclear Medicine, Hannover (Germany); Wang, Yong; Korf-Klingebiel, Mortimer; Wollert, Kai C. [Hannover Medical School, Division of Molecular and Translational Cardiology, Department of Cardiology and Angiology, Hannover (Germany)

    2014-08-12

    Imaging of inflammation early after myocardial infarction (MI) is a promising approach to the guidance of novel molecular interventions that support endogenous healing processes. {sup 18}F-FDG PET has been used, but may be complicated by physiological myocyte uptake. We evaluated the potential of two alternative imaging targets: lactoferrin binding by {sup 68}Ga-citrate and somatostatin receptor binding by {sup 68}Ga-DOTATATE. C57Bl/6 mice underwent permanent coronary artery ligation. Serial PET imaging was performed 3 - 7 days after MI using {sup 68}Ga-citrate, {sup 68}Ga-DOTATATE, or {sup 18}F-FDG with ketamine/xylazine suppression of myocyte glucose uptake. Myocardial perfusion was evaluated by {sup 13}N-ammonia PET and cardiac geometry by contrast-enhanced ECG-gated CT. Mice exhibited a perfusion defect of 30 - 40 % (of the total left ventricle) with apical anterolateral wall akinesia and thinning on day 7 after MI. {sup 18}F-FDG with ketamine/xylazine suppression demonstrated distinct uptake in the infarct region, as well as in the border zone and remote myocardium. The myocardial standardized uptake value in MI mice was significantly higher than in healthy mice under ketamine/xylazine anaesthesia (1.9 ± 0.4 vs. 1.0 ± 0.1). {sup 68}Ga images exhibited high blood pool activity with no specific myocardial uptake up to 90 min after injection (tissue-to-blood contrast 0.9). {sup 68}Ga-DOTATATE was rapidly cleared from the blood, but myocardial SUV was very low (0.10 ± 0.03). Neither {sup 68}Ga nor {sup 68}Ga-DOTATATE is a useful alternative to {sup 18}F-FDG for PET imaging of myocardial inflammation after MI in mice. Among the three tested approaches, {sup 18}F-FDG with ketamine/xylazine suppression of cardiomyocyte uptake remains the most practical imaging marker of post-infarct inflammation. (orig.)

  2. Retrospective dosimetry of Chernobyl liquidators

    International Nuclear Information System (INIS)

    Chumak, V.V.; Bakhanova, E.V.; Sholom, S.V.; Pasalskaya, L.F.; Bouville, A.; Krjuchkov, V.P.

    2000-01-01

    The numerous cohort of Chernobyl liquidators is a very attractive subject for epidemiological follow up due to high levels of exposure, age-gender distribution and availability of patients for medical examination. However, dosimetric information related to this population is incomplete, in many cases the quality of available dose records is doubtful and uncertainties of all dose values are not determined. Naive attempts to evaluate average doses on the basis of such factors as 'distance from the reactor' obviously fail due to large variation of tasks and workplace contamination. Therefore, prior to any sensible consideration of liquidators as a subject of epidemiological study, their doses should be evaluated (reevaluated) using the methods of retrospective dosimetry. Retrospective dosimetry in general got significant development over the last decade. However, most of the retrospective dosimetry techniques are time consuming, expensive and possess sensitivity threshold. Therefore, application of retrospective dosimetry for the needs of epidemiological follow up studies requires development of certain strategy. This strategy depends, of coarse, on the epidemiological design of the study, availability of resources and dosimetric information related to the time of clean up. One of the strategies of application of retrospective dosimetry may be demonstrated on the example of a cohort study with occasional nested case control consideration. In this case, the tools are needed for validation of existing dose records (of not always known quality), screening of the study cohort with express dosimetric method called to determine possible dose ranges, and 'state-of-the-art' assessment of individual doses for selected subjects (cases and controls). Verification of dose records involves analysis of the statistical regularities of dose distributions and detection of possible extraneous admixtures (presumably falsified dose records). This work is performed on impersonified data

  3. Thyroid carcinoma. A descriptive retrospective study

    International Nuclear Information System (INIS)

    Gonzalez, Carolina C.; Yaniskowski, Maria L.; Wyse, Eduardo P.; Giovannini, Andrea A.; Lopez, Monica B.; Wior, Myrian E.

    2006-01-01

    The thyroid carcinoma (TC) is not very frequent among all cancer. Its course is slow and is high potentially curable. Our aim was to analyse the characteristics in patients with TC. A retrospective analysis on 171 patients, with an average age of 41.1. (± 14.6), who asked for TC to our service between the years 2000-2004, was performed. From case histories it was evaluated: anamnesis, diagnostic image, histopathology and evolution. Tumours were grouped for size and TNM (tumor-nodule-metastasis) in stage (S). A simulated serum thyroglobulin level >2 ng/ml and positive image with 131 I or another nuclear marker were considered as positive for residual TC. In the totality of the analyzed patients 88% were female, 62% below 45 years old, and in 77% the thyroid function was normal. The fine needle aspiration (FNA) was diagnostic in 78%. Papillary thyroid carcinoma (PTC) in 96%. The 63% was SI; 14% SII; 19% SIII and 4% SIV. During follow-up, we observed that 90% of patients with Tg between 2 and 10 had evidence of residual TC, and 100% with Tg > 10 ng/ml, whereas 18% of those whose simulated Tg [es

  4. Ultrasound-guided identification of cardiac imaging windows.

    Science.gov (United States)

    Liu, Garry; Qi, Xiu-Ling; Robert, Normand; Dick, Alexander J; Wright, Graham A

    2012-06-01

    -ray gating windows were relatively weaker: R = 0.63 (p = 0.13) and R = 0.86 (p = 0.01). For IVS gating windows, the average estimated vessel blurs during single and multiple heartbeats were 0.5 and 0.66 mm, respectively. For x-ray gating windows, the corresponding values were 0.26 and 0.44 mm, respectively. In this study, the authors showed that IVS velocity can be used to identify periods of diastasis for coronary arteries. Despite variability in mid-diastolic rest positions over multiple steady rate heartbeats, vessel blurring of 0.5-1 mm was found to be achievable using the IVS gating technique. The authors envision this leading to a new cardiac gating system that, compared with conventional ECG gating, provides better resolution and shorter scan times for coronary MRA. © 2012 American Association of Physicists in Medicine.

  5. Risk factors for intervertebral instability assessed by temporal evaluation of the radiographs and reconstructed computed tomography images after L5-S1 single-level transforaminal interbody fusion: A retrospective study.

    Science.gov (United States)

    Kobayashi, Yoshiomi; Shinozaki, Yoshio; Takahashi, Yohei; Takaishi, Hironari; Ogawa, Jun

    2017-01-01

    Intervertebral instability risks following L5-S1 transforaminal lumbar interbody fusion (TLIF) and causes of bony bridge formation on computed tomography (CT) remain largely unknown. We evaluated the temporal changes on plain radiographs and reconstructed CT images from 178 patients who had undergone single-level L5-S1 TLIF between February 2011 and February 2015. We statistically analyzed temporal changes the L5-S1 angle on radiographs and intervertebral stability (IVS) at the last observation. Bony bridge formation between the L5-S1 vertebral bodies and the titanium cage subsidence were analyzed by using reconstructed CT. Preoperative L5-S1 angle in the non-IVS group was significantly greater than that in the IVS group. The cage subsidence was classified as follows: type A, both upper and lower endplates; type B, either endplate; or type C, no subsidence. Types B and C decreased over time, whereas type A increased after surgery. The bony bridges between vertebral bodies were found in 87.2% of patients, and 94.5% of all bony bridges were found only in the cage, not on the contralateral side. Our findings suggested that high preoperative L5-S1 angle increased the risk of intervertebral instability after TLIF. The L5-S1 angle decreased over time with increasing type A subsidence, and almost all bony bridges were found only in the cage. These results suggest that the vertebral bodies were stabilized because of cage subsidence, and final bony bridges were created. Methods to improve bony bridge creation are needed to obtain reliable L5-S1 intervertebral bone union. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Efficacy and safety of balloon pulmonary angioplasty for chronic thromboembolic pulmonary hypertension guided by cone-beam computed tomography and electrocardiogram-gated area detector computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Ogo, Takeshi, E-mail: ogo.takeshi.hp@mail.ncvc.go.jp [Division of Pulmonary Circulation, Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Centre, Osaka (Japan); Department of Advanced Mediccal Research for Pulmonary Hypertension, National Cerebral and Cardiovascular Centre, Osaka (Japan); Fukuda, Tetsuya [Department of Radiology, National Cerebral and Cardiovascular Centre, Osaka (Japan); Tsuji, Akihiro; Fukui, Shigefumi; Ueda, Jin [Division of Pulmonary Circulation, Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Centre, Osaka (Japan); Sanda, Yoshihiro [Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Centre, Osaka (Japan); Morita, Yoshiaki [Department of Radiology, National Cerebral and Cardiovascular Centre, Osaka (Japan); Asano, Ryotaro; Konagai, Nao [Division of Pulmonary Circulation, Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Centre, Osaka (Japan); Yasuda, Satoshi [Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Centre, Osaka (Japan)

    2017-04-15

    Highlights: • Recent advancement in CT enables distal CTEpH lesions to be visualized. • We investigated the efficacy and safety of BPA guided by CBCT or ECG-gated area detector CT. • BPA guided by CBCT or ECG-gated area detector CT is effective and safe in patients with CTEpH . • These new advanced CT techniques may be useful in pre-BPA target lesion assessment. - Abstract: Background: Chronic thromboembolic pulmonary hypertension (CTEPH) is a disease characterized by chronic obstructive thrombus and pulmonary hypertension. Balloon pulmonary angioplasty (BPA), an emerging alternative catheter-based treatment for inoperable patients with CTEPH, has not yet been standardised, especially for lesion assessment in distal pulmonary arteries. Recent advancement in computed tomography enables distal CTEPH lesions to be visualized. Methods: We retrospectively studied 80 consecutive patients with inoperable CTEPH who received BPA guided by cone-beam computed tomography (CT) (CBCT) or electrocardiogram (ECG)-gated area detector CT (ADCT) for target lesion assessment. We collected clinical and hemodynamic data, including procedural complications, before BPA and at 3 months and 1 year after BPA. Results: Three hundred eight-five BPA sessions (4.8 sessions/patient) were performed for the lesions of subsegmental arteries (1155 lesions), segmental arteries (738 lesions), and lobar arteries (4 lesions) identified by CBCT or ECG-gated ADCT. Significant improvements in the symptoms, 6-min walk distance, brain natriuretic peptide level, exercise capacity, and haemodynamics were observed 3 months and 1 year after BPA. No cases of death or cardiogenic shock with a low rate of severe wire perforation (0.3%) and severe reperfusion oedema (0.3%) were observed. Conclusions: BPA guided by CBCT or ECG-gated ADCT is effective and remarkably safe in patients with CTEPH . These new advanced CT techniques may be useful in pre-BPA target lesion assessment.

  7. Efficacy and safety of balloon pulmonary angioplasty for chronic thromboembolic pulmonary hypertension guided by cone-beam computed tomography and electrocardiogram-gated area detector computed tomography

    International Nuclear Information System (INIS)

    Ogo, Takeshi; Fukuda, Tetsuya; Tsuji, Akihiro; Fukui, Shigefumi; Ueda, Jin; Sanda, Yoshihiro; Morita, Yoshiaki; Asano, Ryotaro; Konagai, Nao; Yasuda, Satoshi

    2017-01-01

    Highlights: • Recent advancement in CT enables distal CTEpH lesions to be visualized. • We investigated the efficacy and safety of BPA guided by CBCT or ECG-gated area detector CT. • BPA guided by CBCT or ECG-gated area detector CT is effective and safe in patients with CTEpH . • These new advanced CT techniques may be useful in pre-BPA target lesion assessment. - Abstract: Background: Chronic thromboembolic pulmonary hypertension (CTEPH) is a disease characterized by chronic obstructive thrombus and pulmonary hypertension. Balloon pulmonary angioplasty (BPA), an emerging alternative catheter-based treatment for inoperable patients with CTEPH, has not yet been standardised, especially for lesion assessment in distal pulmonary arteries. Recent advancement in computed tomography enables distal CTEPH lesions to be visualized. Methods: We retrospectively studied 80 consecutive patients with inoperable CTEPH who received BPA guided by cone-beam computed tomography (CT) (CBCT) or electrocardiogram (ECG)-gated area detector CT (ADCT) for target lesion assessment. We collected clinical and hemodynamic data, including procedural complications, before BPA and at 3 months and 1 year after BPA. Results: Three hundred eight-five BPA sessions (4.8 sessions/patient) were performed for the lesions of subsegmental arteries (1155 lesions), segmental arteries (738 lesions), and lobar arteries (4 lesions) identified by CBCT or ECG-gated ADCT. Significant improvements in the symptoms, 6-min walk distance, brain natriuretic peptide level, exercise capacity, and haemodynamics were observed 3 months and 1 year after BPA. No cases of death or cardiogenic shock with a low rate of severe wire perforation (0.3%) and severe reperfusion oedema (0.3%) were observed. Conclusions: BPA guided by CBCT or ECG-gated ADCT is effective and remarkably safe in patients with CTEPH . These new advanced CT techniques may be useful in pre-BPA target lesion assessment.

  8. 99 mTc-MIBI washout as a complementary factor in the evaluation of idiopathic dilated cardiomyopathy (IDCM) using myocardial perfusion imaging.

    Science.gov (United States)

    Shiroodi, Mohammad Kazem; Shafiei, Babak; Baharfard, Nastaran; Gheidari, Mohammad Esmail; Nazari, Babak; Pirayesh, Elaheh; Kiasat, Ali; Hoseinzadeh, Samaneh; Hashemi, Abolghassem; Akbarzadeh, Mohammad Ali; Javadi, Hamid; Nabipour, Iraj; Assadi, Majid

    2012-01-01

    Rapid technetium-99 m methoxyisobutylisonitrile (99 mTc-MIBI) washout has been shown to occur in impaired myocardia. This study is based on the hypothesis that scintigraphy can be applied to calculate the myocardial 99 mTc-MIBI washout rate (WR) to diagnose and evaluate heart failure severity and other left ventricular functional parameters specifically in idiopathic dilated cardiomyopathy (IDCM) patients. Patients with IDCMP (n = 17; 52.65 ± 11.47 years) and normal subjects (n = 6; 49.67 ± 10.15 years) were intravenously administered 99 mTc-hexakis-2-methoxyisobutylisonitrile (99 mTc-MIBI). Next, early and delayed planar data were acquired (at 3.5-h intervals), and electrocardiogram (ECG)-gated myocardial perfusion single photon emission computed tomography (SPECT) was performed. The 99 mTc-MIBI WR was calculated using early and delayed planar images. Left ventricular functional parameters were also analyzed using quantitative gated SPECT (QGS) data. In target group, myocardial WRs (29.13 ± 6.68%) were significantly higher than those of control subjects (14.17 ± 3.31%; P 99 mTc-MIBI WR increased with the increasing severity of the NYHA functional class (23.16 ± 1.72% for class I, 30.25 ± 0.95% for class II, 32.60 ± 6.73% for class III, and 37.50 ± 7.77% for class IV; P = 0.02). The WR was positively correlated with the end-diastolic volume (EDV) index (r (2) = 0.216; β = 0.464; P = 0.02 [ml/m(2)], the end-systolic volume (ESV) index (r (2) = 0.234; β = 0.484; P = 0.01 [ml/m(2)]), the summed motion score (SMS) (r (2) = 0.544; β = 0.738; P = 0.00), and the summed thickening score (STS) (r (2) = 0.656; β = 0.810; P = 0.00); it was negatively correlated with the left ventricular ejection fraction (LVEF) (r (2) = 0.679; β = -0.824; P = 0.00). It can be concluded that 99 mTc-MIBI scintigraphy might be a valuable molecular imaging tool for the diagnosis and evaluation of myocardial damage or dysfunction severity.

  9. Evaluation of image quality and radiation dose at prospective ECG-triggered axial 256-slice multi-detector CT in infants with congenital heart disease

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Mei-ping; Liang, Chang-hong; Zhao, Zhen-jun; Liu, Hui; Li, Jing-lei; Zhang, Jin-e; Cui, Yan-hai; Yang, Lin; Liu, Qi-shun [Guangdong Academy of Medical Sciences, Guangdong General Hospital, Department of Radiology, Guangzhou (China); Ivanc, Thomas B.; Vembar, Mani [Philips Healthcare, CT Clinical Science, Highland Heights, OH (United States)

    2011-07-15

    There are a limited number of reports on the technical and clinical feasibility of prospective electrocardiogram (ECG)-gated multi-detector computed tomography (MDCT) in infants with congenital heart disease (CHD). To evaluate image quality and radiation dose at weight-based low-dose prospectively gated 256-slice MDCT angiography in infants with CHD. From November 2009 to February 2010, 64 consecutive infants with CHD referred for pre-operative or post-operative CT were included. All were scanned on a 256-slice MDCT system utilizing a low-dose protocol (80 kVp and 60-120 mAs depending on weight: 60 mAs for {<=}3 kg, 80 mAs for 3.1-6 kg, 100 mAs for 6.1-10 kg, 120 mAs for 10.1-15 kg). No serious adverse events were recorded. A total of 174 cardiac deformities, confirmed by surgery or heart catheterization, were studied. The sensitivity of MDCT for cardiac deformities was 97.1%; specificity, 99.4%; accuracy, 95.9%. The mean heart rate during scan was 136.7 {+-} 14.9/min (range, 91-160) with a corresponding heart rate variability of 2.8 {+-} 2.2/min (range, 0-8). Mean scan length was 115.3 {+-} 11.7 mm (range, 93.6-143.3). Mean volume CT dose index, mean dose-length product and effective dose were 2.1 {+-} 0.4 mGy (range, 1.5-2.8), 24.7 {+-} 5.9 mGy.cm (range, 14.7-35.8) and 1.6 {+-} 0.3 mSv (range, 1.1-2.5), respectively. Diagnostic-quality images were achieved in all cases. Satisfactory diagnostic quality for visualization of all/proximal/distal coronary artery segments was achieved in 88.4/98.8/80.0% of the scans. Low-dose prospectively gated axial 256-slice CT angiography is a valuable tool in the routine clinical evaluation of infants with CHD, providing a comprehensive three-dimensional evaluation of the cardiac anatomy, including the coronary arteries. (orig.)

  10. Gated single-photon emission tomography imaging protocol to evaluate myocardial stunning after exercise

    International Nuclear Information System (INIS)

    Hashimoto, Jun; Kubo, Atsushi; Iwasaki, Ryuichiro; Iwanaga, Shiro; Mitamura, Hideo; Ogawa, Satoshi; Kosuda, Shigeru

    1999-01-01

    This study was designed to apply ECG-gating to stress myocardial perfusion single-photon emission tomography (SPET) for the evaluation of myocardial stunning after exercise. Technetium-99m sestamibi was selected as the perfusion agent and a rest/exercise 1-day protocol was employed. Fourteen patients without coronary stenosis and 33 patients with coronary stenosis were enrolled in the study. We carried out three data acquisitions with ECG-gating: a 15-min data acquisition starting 30 min after the rest injection (AC1), a 5-min acquisition starting 5 min after the stress injection (AC2) and a 15-min acquisition starting 20 min after the stress injection (AC3). Calculation of left ventricular ejection fraction (LVEF) values was performed by means of automatic determination of the endocardial surface for all gating intervals in the cardiac cycle. Measured global EF values in 14 patients without coronary stenosis were 52.3%±7.6% (AC1), 60.6%±8.9% (AC2) and 55.6%±5.6% (AC3), and those in 11 patients with severe ischaemia were 53.6%±8.0% (AC1), 45.6%±12.1% (AC2) and 49.7%±10.7%. The magnitude of the depression of post-stress LVEF relative to the rest LVEF correlated with the severity of ischaemia (r=0.594, P=0.002), and segments manifesting post-stress functional depression were associated with ischaemic segments showing reversible perfusion defects. Stress myocardial perfusion SPET with ECG-gating is a feasible method for the evaluation of myocardial stunning as well as exercise-induced ischaemia. (orig.)

  11. Manifold learning based ECG-free free-breathing cardiac CINE MRI.

    Science.gov (United States)

    Usman, Muhammad; Atkinson, David; Kolbitsch, Christoph; Schaeffter, Tobias; Prieto, Claudia

    2015-06-01

    To present and validate a manifold learning (ML)-based method that can estimate both cardiac and respiratory navigator signals from electrocardiogram (ECG)-free free-breathing cardiac magnetic resonance imaging (MRI) data to achieve self-gated retrospective CINE reconstruction. In this work the use of the ML method is demonstrated for 2D cardiac CINE to achieve both cardiac and respiratory self-gating without the need of an external navigator or ECG signal. This is achieved by sequentially applying ML to two sets of retrospectively reconstructed real-time images with differing temporal resolutions. A 1D cardiac signal is estimated by applying ML to high temporal resolution real-time images reconstructed from the acquired data. Using the estimated cardiac signal, a 1D respiratory signal was obtained by applying the ML method to low temporal resolution images reconstructed from the same acquired data for each cardiac cycle. Data were acquired in five volunteers with a 2D golden angle radial trajectory in a balanced steady-state free precession (b-SSFP) acquisition. The accuracy of the estimated cardiac signal was calculated as the standard deviation of the temporal difference between the estimated signal and the recorded ECG. The correlation between the estimated respiratory signal and standard pencil beam navigator signal was evaluated. Gated CINE reconstructions (20 cardiac phases per cycle, temporal resolution ∼30 msec) using the estimated cardiac and respiratory signals were qualitatively compared against conventional ECG-gated breath-hold CINE acquisitions. Accurate cardiac signals were estimated with the proposed method, with an error standard deviation in comparison to ECG lower than 20 msec. Respiratory signals estimated with the proposed method achieved a mean cross-correlation of 94% with respect to standard pencil beam navigator signals. Good quality visual scores of 2.80 ± 0.45 (scores from 0, bad, to 4, excellent quality) were observed for the

  12. Image, Image, Image

    Science.gov (United States)

    Howell, Robert T.

    2004-01-01

    With all the talk today about accountability, budget cuts, and the closing of programs in public education, teachers cannot overlook the importance of image in the field of industrial technology. It is very easy for administrators to cut ITE (industrial technology education) programs to save school money--money they might shift to teaching the…

  13. Pituitary gigantism: a retrospective case series.

    Science.gov (United States)

    Creo, Ana L; Lteif, Aida N

    2016-05-01

    Pituitary gigantism (PG) is a rare pediatric disease with poorly defined long-term outcomes. Our aim is to describe the longitudinal clinical course in PG patients using a single-center, retrospective cohort study. Patients younger than 19 years diagnosed with PG were identified. Thirteen cases were confirmed based on histopathology of a GH secreting adenoma or hyperplasia and a height >2 SD for age and gender. Laboratory studies, initial pathology, and imaging were abstracted. Average age at diagnosis was 13 years with an average initial tumor size of 7.4×3.8 mm. Initial transsphenoidal surgery was curative in 3/12 patients. Four of the nine patients who failed the initial surgery required a repeat procedure. Octreotide successfully normalized GH levels in 1/6 patients with disease refractory to surgery (1/6). Two out of five patients received pegvisomant after failing octreotide but only one patient responded to treatment. Five patients were ultimately treated with radiosurgery or radiation patients were followed for an average of 10 years. PG is difficult to treat. In most patients, the initial transsphenoidal surgery failed to normalize GH levels. If the initial surgery was unsuccessful, repeat surgery was unlikely to control GH secretion. Treatment with octreotide or pegvisomant was successful in less than half the patients failing surgery. Radiosurgery was curative, but is not an optimal treatment for pediatric patients. Despite the small sample, our study suggests that the treatment outcome of pediatric PG may be different than adults.

  14. Brucellosis: a retrospective evaluation of 164 cases.

    Science.gov (United States)

    Kazak, Esra; Akalın, Halis; Yılmaz, Emel; Heper, Yasemin; Mıstık, Reşit; Sınırtaş, Melda; Özakın, Cüneyt; Göral, Güher; Helvacı, Safiye

    2016-11-01

    Brucellosis is a public health problem that is prevalent in several developing countries. The clinical and laboratory characteristics of 164 cases of brucellosis in Bursa, Turkey, were retrospectively evaluated. The ages of the 164 patients ranged from 15-85 years. All of the patients underwent the Rose Bengal test and 163 (99.4%) patients tested positive. 122 (74.4%) patients were diagnosed with acute brucellosis, 31 (18.9%) with subacute brucellosis and 11 (6.7%) with chronic brucellosis. Focal involvement was found in 101 (61.6%) patients. Although patients with focal involvement had a higher white blood cell count (p = 0.002), those without focal involvement had higher aspartate transaminase and alanine transaminase values, and lower platelet values (p = 0.005, 0.007 and 0.039, respectively). Spondylodiscitis was observed on imaging in 58 (66.7%) of the 87 patients who presented with back pain. Among the 118 patients who were examined within the first month of treatment, 79 (66.9%) responded to treatment. The relapse rate was 11.6% among all 164 patients. Brucellosis should be considered as a differential diagnosis among patients who present with fever, and joint or back pain. Focal involvement should be investigated in the presence of leucocytosis, and subacute or chronic forms of brucellosis. To identify cases of spondylodiscitis, radiography should be performed in patients who present with back pain. Copyright: © Singapore Medical Association

  15. Uncovering the problem-solving process: cued retrospective reporting versus concurrent and retrospective reporting.

    Science.gov (United States)

    van Gog, Tamara; Paas, Fred; van Merriënboer, Jeroen J G; Witte, Puk

    2005-12-01

    This study investigated the amounts of problem-solving process information ("action," "why," "how," and "metacognitive") elicited by means of concurrent, retrospective, and cued retrospective reporting. In a within-participants design, 26 participants completed electrical circuit troubleshooting tasks under different reporting conditions. The method of cued retrospective reporting used the original computer-based task and a superimposed record of the participant's eye fixations and mouse-keyboard operations as a cue for retrospection. Cued retrospective reporting (with the exception of why information) and concurrent reporting (with the exception of metacognitive information) resulted in a higher number of codes on the different types of information than did retrospective reporting.

  16. Comparison between retrospective gating and ECG triggering in magnetic resonance velocity mapping

    DEFF Research Database (Denmark)

    Søndergaard, L; Ståhlberg, F; Thomsen, C

    1993-01-01

    ECG-triggered cinematographic studies of the cardiovascular system are hampered by several technical restrictions such as the inability to image end-diastole, ghosting, varying signal intensity, and phase contributions from eddy currents. Retrospective gating may solve these problems, but involves...... of flow pulses. However, by reducing the time window retrospectively gated flow measurements were in good agreement with those that are ECG triggered. When fulfilling the demand of a narrow time window for interpolation, retrospective gating offers several advantages in MR velocity mapping....

  17. Hand infections: a retrospective analysis

    Directory of Open Access Journals (Sweden)

    Tolga Türker

    2014-09-01

    Full Text Available Purpose. Hand infections are common, usually resulting from an untreated injury. In this retrospective study, we report on hand infection cases needing surgical drainage in order to assess patient demographics, causation of infection, clinical course, and clinical management.Methods. Medical records of patients presenting with hand infections, excluding post-surgical infections, treated with incision and debridement over a one-year period were reviewed. Patient demographics; past medical history; infection site(s and causation; intervals between onset of infection, hospital admission, surgical intervention and days of hospitalization; gram stains and cultures; choice of antibiotics; complications; and outcomes were reviewed.Results. Most infections were caused by laceration and the most common site of infection was the palm or dorsum of the hand. Mean length of hospitalization was 6 days. Methicillin-resistant Staphylococcus aureus, beta-hemolytic Streptococcus and methicillin-susceptible Staphylococcus aureus were the most commonly cultured microorganisms. Cephalosporins, clindamycin, amoxicillin/clavulanate, penicillin, vancomycin, and trimethoprim/sulfamethoxazole were major antibiotic choices. Amputations and contracture were the primary complications.Conclusions. Surgery along with medical management were key to treatment and most soft tissue infections resolved without further complications. With prompt and appropriate care, most hand infection patients can achieve full resolution of their infection.

  18. Cancer cervix?: a retrospective study

    International Nuclear Information System (INIS)

    Hirapara, Pushpendra H.; Patidar, Arvindkumar; Walke, Rahul; Jakhar, Shankar Lal; Sharma, Neeti; Kumar, H.S.; Jain, Sandeep; Kalwar, Ashok; Bardia, M.R.

    2012-01-01

    Anemia is very commonly seen in most of the malignancies including cancer cervix. Anemia has long been reported to adversely affect the efficacy of radiation treatment in cervical cancer. At our center, carcinoma cervix accounts for approximately 8-10% of all malignancies. The objective of this study is to see the impact of anemia in the treatment of cancer cervix. In the present study, we collected data of treatment results of FIGO stage II and III cancer cervix patients retrospectively treated in years of 2009-10. We have tried to assess the outcome of results in patients whom haemoglobin (Hb) level < 10 gm/dl and e''10 gm/dl. Out of 200 patients of disease with baseline Hb less than 10 gm/dl, 80(40%) patients had residual disease after 4 weeks of completion of treatment. Out of 168 patients with baseline Hb more than 10 gm/dl, 42(25%) had residual disease (p-0.0012 i.e highly significant). Our study shows that there is a good disease control at local site in patients with higher pretreatment Hb level. Effect of pretreatment Hb on treatment outcome in terms of overall survival, disease free survival, and local relapse free survival along with effect on corrective measures should be studied in detail. (author)

  19. A retrospective of VAWT technology.

    Energy Technology Data Exchange (ETDEWEB)

    Ashwill, Thomas D.; Sutherland, Herbert J. (HJS Consulting, Albuquerque, NM); Berg, Dale E.

    2012-01-01

    The study of Vertical-Axis Wind Turbine (VAWT) technology at Sandia National Laboratories started in the 1970's and concluded in the 1990's. These studies concentrated on the Darrieus configurations because of their high inherent efficiency, but other configurations (e.g., the Savonius turbine) were also examined. The Sandia VAWT program culminated with the design of the 34-m 'Test Bed' Darrieus VAWT. This turbine was designed and built to test various VAWT design concepts and to provide the necessary databases to validate analytical design codes and