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Sample records for artery image quality

  1. Contrast-enhanced magnetic resonance angiography in carotid artery disease: does automated image registration improve image quality?

    International Nuclear Information System (INIS)

    Menke, Jan; Larsen, Joerg

    2009-01-01

    Contrast-enhanced magnetic resonance angiography (MRA) is a noninvasive imaging alternative to digital subtraction angiography (DSA) for patients with carotid artery disease. In DSA, image quality can be improved by shifting the mask image if the patient has moved during angiography. This study investigated whether such image registration may also help to improve the image quality of carotid MRA. Data from 370 carotid MRA examinations of patients likely to have carotid artery disease were prospectively collected. The standard nonregistered MRAs were compared to automatically linear, affine and warp registered MRA by using three image quality parameters: the vessel detection probability (VDP) in maximum intensity projection (MIP) images, contrast-to-noise ratio (CNR) in MIP images, and contrast-to-noise ratio in three-dimensional image volumes. A body shift of less than 1 mm occurred in 96.2% of cases. Analysis of variance revealed no significant influence of image registration and body shift on image quality (p > 0.05). In conclusion, standard contrast-enhanced carotid MRA usually requires no image registration to improve image quality and is generally robust against any naturally occurring body shift. (orig.)

  2. 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)

  3. 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)

  4. CT angiography of intracranial arterial vessels: impact of tube voltage and contrast media concentration on image quality

    International Nuclear Information System (INIS)

    Ramgren, Birgitta; Holtaas, Stig; Siemund, Roger; Dept. of Radiology, Lund Univ., Lund

    2012-01-01

    Background Computed tomography angiography (CTA) of intracranial arteries has high demands on image quality. Important parameters influencing vessel enhancement are injection rate, concentration of contrast media and tube voltage. Purpose To evaluate the impact of an increase of contrast media concentration from 300 to 400 mg iodine/mL (mgI/mL) and the effect of a decrease of tube voltage from 120 to 90 kVp on vessel attenuation and image quality in CT angiography of intracranial arteries. Material and Methods Sixty-three patients were included into three protocol groups: Group I, 300 mgI/mL 120 kVp; Group II, 400 mgI/mL 120 kVp; Group III, 400 mgI/mL 90 kVp. Hounsfield units (HU) were measured in the internal carotid artery (ICA) and the M1 and M2 segments of the middle cerebral artery. Image quality grading was performed regarding M1 and M2 segments, volume rendering and general image impression. Results The difference in mean HU in ICA concerning the effect of contrast media concentration was statistically significant (P = 0.03) in favor of higher concentration. The difference in ICA enhancement due to the effect of tube voltage was statistically significant (P < 0.01) in favor of lower tube voltage. The increase of contrast medium concentration raised the mean enhancement in ICA with 18% and the decrease of tube voltage raised the mean enhancement with 37%. Image quality grading showed a trend towards improved grading for higher contrast concentration and lower tube voltage. Statistically significant better grading was found for the combined effect of both measures except for general impression (P 0.01-0.05). Conclusion The uses of highly concentrated contrast media and low tube voltage are easily performed measures to improve image quality in CTA of intracranial vessel

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

    International Nuclear Information System (INIS)

    Ferencik, Maros; Nomura, Cesar H.; Maurovich-Horvat, Pal; Hoffmann, Udo; Pena, Antonio J.; Cury, Ricardo C.; Abbara, Suhny; Nieman, Koen; Fatima, Umaima; Achenbach, Stephan; Brady, Thomas J.

    2006-01-01

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

  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. Improving the image quality of contrast-enhanced MR angiography by automated image registration: A prospective study in peripheral arterial disease of the lower extremities

    International Nuclear Information System (INIS)

    Menke, Jan

    2010-01-01

    Objective: If a patient has moved during digital subtraction angiography (DSA), manual pixel shift can improve the image quality. This study investigated whether such image registration can also improve the quality of contrast-enhanced magnetic resonance angiography (MRA) in patients with peripheral arterial disease of the lower extremities. Materials and methods: 404 leg MRAs of patients likely to have peripheral artery disease were included in this prospective study. The standard non-registered MRAs were compared to automatically linear, affine and warp registered MRAs by four image quality parameters, including the vessel detection probability (VDP) in maximum intensity projection (MIP) images and contrast-to-noise ratios (CNR). The different registration types were compared by analysis of variance. Results: All studied image quality parameters showed similar trends. Generally, registration improved the leg MRA quality significantly (P < 0.05). The 12% of lower legs with a body shift of 1 mm or more showed the highest gain in image quality when using linear registration instead of no registration, with an average VDP gain of 20-49%. Warp registration improved the image quality slightly further. Conclusion: Automated image registration can improve the MRA image quality especially in the lower legs, which is comparable to the effect of pixel shift in DSA.

  8. Comparison of coronary artery calcium screening image quality between C-150 and e-Speed electron beam scanners.

    Science.gov (United States)

    Budoff, Matthew J; Shinbane, Jerold S; Oudiz, Ronald J; Child, Janis; Carson, Sivi; Chau, Alex; Tseng, Philip; Gao, Yanlin; Mao, Songshou

    2005-03-01

    The newest generation of electron beam tomographic scanner (e-Speed) has increased spatial and temporal resolution compared with the C-150 XP scanner. The aim of this study was to evaluate coronary artery calcium screening image quality between the e-Speed and C-150 scanners (GE Imatron, San Francisco, CA). Studies from 41 patients (14 women and 27 men) who underwent serial coronary artery calcium screening with the C-150 (first study) and the e-Speed (second study) were analyzed. Individual computed tomography (CT) slices were assessed for coronary artery motion artifacts, and CT Hounsfield units (HU) and noise values (CT HU standard deviation) at 16 discrete cardiac sites were measured and averaged. With the e-Speed scanner, there were significant decreases in right coronary artery motion artifacts compared with the C-150 scanner (0.3% versus 1.8%, P Image quality is significantly improved with use of the e-Speed scanner, due to its improved temporal and spatial resolution, compared with the C-150 scanner.

  9. Image quality of mean temporal arterial and mean temporal portal venous phase images calculated from low dose dynamic volume perfusion CT datasets in patients with hepatocellular carcinoma and pancreatic cancer

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    Wang, X. [Radiology Department, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing (China); Henzler, T., E-mail: thomas.henzler@medma.uni-heidelberg.de [Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University (Germany); Gawlitza, J.; Diehl, S. [Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University (Germany); Wilhelm, T. [Department of Surgery, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University (Germany); Schoenberg, S.O. [Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University (Germany); Jin, Z.Y.; Xue, H.D. [Radiology Department, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing (China); Smakic, A. [Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University (Germany)

    2016-11-15

    Purpose: Dynamic volume perfusion CT (dVPCT) provides valuable information on tissue perfusion in patients with hepatocellular carcinoma (HCC) and pancreatic cancer. However, currently dVPCT is often performed in addition to conventional CT acquisitions due to the limited morphologic image quality of dose optimized dVPCT protocols. The aim of this study was to prospectively compare objective and subjective image quality, lesion detectability and radiation dose between mean temporal arterial (mTA) and mean temporal portal venous (mTPV) images calculated from low dose dynamic volume perfusion CT (dVPCT) datasets with linearly blended 120-kVp arterial and portal venous datasets in patients with HCC and pancreatic cancer. Materials and methods: All patients gave written informed consent for this institutional review board–approved HIPAA compliant study. 27 consecutive patients (18 men, 9 women, mean age, 69.1 years ± 9.4) with histologically proven HCC or suspected pancreatic cancer were prospectively enrolled. The study CT protocol included a dVPCT protocol performed with 70 or 80 kVp tube voltage (18 spiral acquisitions, 71.2 s total acquisition times) and standard dual-energy (90/150 kVpSn) arterial and portal venous acquisition performed 25 min after the dVPCT. The mTA and mTPV images were manually reconstructed from the 3 to 5 best visually selected single arterial and 3 to 5 best single portal venous phases dVPCT dataset. The linearly blended 120-kVp images were calculated from dual-energy CT (DECT) raw data. Image noise, SNR, and CNR of the liver, abdominal aorta (AA) and main portal vein (PV) were compared between the mTA/mTPV and the linearly blended 120-kVp dual-energy arterial and portal venous datasets, respectively. Subjective image quality was evaluated by two radiologists regarding subjective image noise, sharpness and overall diagnostic image quality using a 5-point Likert Scale. In addition, liver lesion detectability was performed for each liver

  10. Image quality of mean temporal arterial and mean temporal portal venous phase images calculated from low dose dynamic volume perfusion CT datasets in patients with hepatocellular carcinoma and pancreatic cancer

    International Nuclear Information System (INIS)

    Wang, X.; Henzler, T.; Gawlitza, J.; Diehl, S.; Wilhelm, T.; Schoenberg, S.O.; Jin, Z.Y.; Xue, H.D.; Smakic, A.

    2016-01-01

    Purpose: Dynamic volume perfusion CT (dVPCT) provides valuable information on tissue perfusion in patients with hepatocellular carcinoma (HCC) and pancreatic cancer. However, currently dVPCT is often performed in addition to conventional CT acquisitions due to the limited morphologic image quality of dose optimized dVPCT protocols. The aim of this study was to prospectively compare objective and subjective image quality, lesion detectability and radiation dose between mean temporal arterial (mTA) and mean temporal portal venous (mTPV) images calculated from low dose dynamic volume perfusion CT (dVPCT) datasets with linearly blended 120-kVp arterial and portal venous datasets in patients with HCC and pancreatic cancer. Materials and methods: All patients gave written informed consent for this institutional review board–approved HIPAA compliant study. 27 consecutive patients (18 men, 9 women, mean age, 69.1 years ± 9.4) with histologically proven HCC or suspected pancreatic cancer were prospectively enrolled. The study CT protocol included a dVPCT protocol performed with 70 or 80 kVp tube voltage (18 spiral acquisitions, 71.2 s total acquisition times) and standard dual-energy (90/150 kVpSn) arterial and portal venous acquisition performed 25 min after the dVPCT. The mTA and mTPV images were manually reconstructed from the 3 to 5 best visually selected single arterial and 3 to 5 best single portal venous phases dVPCT dataset. The linearly blended 120-kVp images were calculated from dual-energy CT (DECT) raw data. Image noise, SNR, and CNR of the liver, abdominal aorta (AA) and main portal vein (PV) were compared between the mTA/mTPV and the linearly blended 120-kVp dual-energy arterial and portal venous datasets, respectively. Subjective image quality was evaluated by two radiologists regarding subjective image noise, sharpness and overall diagnostic image quality using a 5-point Likert Scale. In addition, liver lesion detectability was performed for each liver

  11. Evaluation of temporal windows for coronary artery bypass graft imaging with 64-slice CT

    International Nuclear Information System (INIS)

    Desbiolles, Lotus; Leschka, Sebastian; Scheffel, Hans; Husmann, Lars; Garzoli, Elisabeth; Marincek, Borut; Alkadhi, Hatem; Plass, Andre; Gaemperli, Oliver; Kaufmann, Philipp A.

    2007-01-01

    Temporal windows providing the best image quality of different segments and types of coronary artery bypass grafts (CABGs) with 64-slice computed tomography (CT) were evaluated in an experimental set-up. Sixty-four-slice CT with a rotation time of 330 ms was performed in 25 patients (four female; mean age 59.9 years). A total of 84 CABGs (62 individual and 22 sequential grafts) were evaluated, including 28 internal mammary artery (33.3%), one radial artery with sequential grafting (2.4%), and 54 saphenous vein grafts (64.3%). Ten data sets were reconstructed in 10% increments of the RR-interval. Each graft was separated into segments (proximal and distal anastomosis, and body), and CABG types were grouped according to target arteries. Two readers independently assessed image quality of each CABG segment in each temporal window. Diagnostic image quality was found with good inter-observer agreement (kappa=0.62) in 98.5% (202/205) of all graft segments. Image quality was significantly better for saphenous vein grafts versus arterial grafts (P<0.001) and for distal anastomosis to the right coronary compared with other target coronary arteries (P<0.05). Overall, best image quality was found at 60%. Image quality of proximal segments did not significantly vary with the temporal window, whereas for all other segments image quality was significantly better at 60% compared with other temporal windows (P<0.05). Sixty-four-slice CT provides best image quality of various segments and types of CABG at 60% of the RR-interval. (orig.)

  12. Suitable Image Intensity Normalization for Arterial Visualization

    Directory of Open Access Journals (Sweden)

    Yara Omran

    2012-12-01

    Full Text Available Ultrasonic imaging is a widely used non-invasivemedical imaging procedure since it is economical, comparativelysafe, portable and adaptable. However, one of its main weaknessesis the poor quality of images, which makes the enhancementof image quality an important issue in order to have a moreaccurate diagnose of the disease, or for the transformation of theimage through telemedicine channel and in many other imageprocessing tasks [1]. The purpose of this paper is to automaticallyenhance the image quality after the automatic detection of theartery wall. This step is essential before subsequent measurementsof arterial parameters [9]. This was performed automaticallyby applying linear normalization, where results showedthat normalization of ultra sound images is an important step inenhancing the image quality for later processing. In comparisonwith other methods, our method is automatic. The evaluationof image quality was done mathematically by comparing pixelintensities of images before and after enhancement, in additionto a visual evaluation.

  13. Troubleshooting arterial-phase MR images of gadoxetate disodium-enhanced liver

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    Huh, Ji Mi; Kim, So Yeon; Lee, Seung Soo; Kim, Kyoung Won [Dept. of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Yeh, Benjamin M.; Wang, Z. Jane [Dept. of Radiologyand Biomedical Imaging, University of California San Francisco, San Francisco (United States); Wu, En Haw [Dept. of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Linkou and Chang Gung University College of Medicine, Taoyuan (China); Zhao, Li Qin [Beijing Friendship Hospital, Capital Medical University, Beijing (China); Chang, Wei Chou [Tri-Service General Hospital and National Defense Medical Center, Taipei (China)

    2015-12-15

    Gadoxetate disodium is a widely used magnetic resonance (MR) contrast agent for liver MR imaging, and it provides both dynamic and hepatobiliary phase images. However, acquiring optimal arterial phase images at liver MR using gadoxetate disodium is more challenging than using conventional extracellular MR contrast agent because of the small volume administered, the gadolinium content of the agent, and the common occurrence of transient severe motion. In this article, we identify the challenges in obtaining high-quality arterial-phase images of gadoxetate disodium-enhanced liver MR imaging and present strategies for optimizing arterial-phase imaging based on the thorough review of recent research in this field.

  14. Troubleshooting arterial-phase MR images of gadoxetate disodium-enhanced liver

    International Nuclear Information System (INIS)

    Huh, Ji Mi; Kim, So Yeon; Lee, Seung Soo; Kim, Kyoung Won; Yeh, Benjamin M.; Wang, Z. Jane; Wu, En Haw; Zhao, Li Qin; Chang, Wei Chou

    2015-01-01

    Gadoxetate disodium is a widely used magnetic resonance (MR) contrast agent for liver MR imaging, and it provides both dynamic and hepatobiliary phase images. However, acquiring optimal arterial phase images at liver MR using gadoxetate disodium is more challenging than using conventional extracellular MR contrast agent because of the small volume administered, the gadolinium content of the agent, and the common occurrence of transient severe motion. In this article, we identify the challenges in obtaining high-quality arterial-phase images of gadoxetate disodium-enhanced liver MR imaging and present strategies for optimizing arterial-phase imaging based on the thorough review of recent research in this field

  15. Optimized imaging quality and radiation dose for coronary artery angiography using 128-slice, dual-source Flash Spiral CT under the natural heart rate

    International Nuclear Information System (INIS)

    Xue Yuejun; Qian Nong; Shao Yanhui; Pan Changjie; Rong Weiliang; Xu Yiqun; Tao Zhiwei

    2011-01-01

    Objective: To compare the quality and radiation doses of coronary artery angiography under the natural heart rate condition between Flash spiral heart mode and prospective electrocardiogram- triggering sequence mode using dual-source, in order to choose personalized low doses of coronary artery scanning mode. Methods: Sixty patients who underwent coronary angiography (CTA) on a 128-slice, dual- source CT scanner were divided into 2 group i.e, group A (27 cases) and group B (33 cases). Flash spiral heart scan mode was employed for group A. Inclusion criteria included: heart rate 75 bpm), date acquisition was set at 30%-50% of the R-R interval. (3) At the arrhythmias, premature beat, fibrillation atrial, date acquisition was set at 20%-90% of the R-R interval. In both groups, patients with a BMI ≥ 25.0 kg/m 2 were examined with a tube voltage of 120 kV, while the other patients with a BMI 2 were examined with a tube voltage of 100 kV. The BMI was (24.6±1.0) kg/m 2 in group A, while that was (24.6±0.9) kg/m 2 in group B. In both groups, all images were transferred to the workstation for further processing and analysis. The imaging quality of coronary artery segments and the radiation dose were compared with t test. Results: A total of 336 coronary artery segments were evaluated in group A and 412 segments were evaluated in group B. The imaging quality of coronary artery segments were scored. Excellent or good was achieved in 98.2% (330 of 336) artery segments in group A, and that was 98.1% (404 of 412) in group B. There was no statistical difference in imaging quality between the two groups (t=0.513, P=0.608). The average effective dose was (0.74±0.29) mSv in group A, whereas that was (3.67± 1.37) mSv in group B. There was a significant difference between the two groups (t=-10.858, P= 0.000). Conclusions: The personalized low doses coronary artery scanning mode can substantially reduce radiation damage while preserving good imaging quality. (authors)

  16. Intraoperative echocardiographic imaging of coronary arteries and graft anastomoses during coronary artery bypass grafting without cardiopulmonary bypass.

    Science.gov (United States)

    Suematsu, Y; Takamoto, S; Ohtsuka, T

    2001-12-01

    No accepted approach exists for the intraoperative evaluation of the quality of coronary arteries and the technical adequacy of graft anastomoses during coronary artery bypass grafting without cardiopulmonary bypass. We assessed the accuracy of high-frequency epicardial echocardiography and power Doppler imaging in evaluating coronary arteries during coronary artery bypass grafting without cardiopulmonary bypass. To validate measurements of coronary arteries and graft anastomoses by high-frequency epicardial echocardiography and power Doppler imaging, we compared luminal diameters determined by these methods with diameters determined histologically in a study of off-pump coronary artery bypass grafting in 20 dogs. Technical errors were deliberately created in 10 grafts (stenosis group). The results of these animal validation studies showed that the maximum luminal diameters of coronary arteries and graft anastomoses measured by high-frequency epicardial echocardiography (HEE) and power Doppler imaging (PDI) correlated well with the histologic measurements: HEE = 1.027 x Histologic measurements + 0.005 (P anastomoses were examined intraoperatively by high-frequency epicardial echocardiography and power Doppler imaging, and luminal diameters determined by power Doppler imaging were compared with those determined by postoperative coronary angiography. The results demonstrated that graft anastomosis by power Doppler imaging correlated well with the angiographic measurements: PDI = 1.018 x Angiographic measurements - 0.106 (P anastomoses and can detect technical errors and inadequacies during coronary artery bypass grafting without cardiopulmonary bypass.

  17. Analysis of main influence factors on coronary artery image quality with 64-multidetector row helical CT using a pulsating cardiac phantom

    International Nuclear Information System (INIS)

    Liu Bin; Zhao Hong; Wu Xingwang; Zhang Jiawen; Yu Yongqiang; Liao Jingmin

    2006-01-01

    Objective: To explore the main influence factors (heart rate, rotation speed, and reconstruction algorithm) on the image quality of coronary artery with 40 mm VCT (64-detector row helical CT) using a pulsating cardiac phantom. Methods: An adjustable pulsating cardiac phantom (GE) containing predetermined simulated coronary arteries was scanned using a 40 mm VCT (GE LightSpeed CT) with cardiac pulsating rates of 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, and 115 beats per minute (bpm). The variable rotation speeds technique of 0.35 s, 0.40 s, and 0.45 s were used, respectively. The raw data were reconstructed using both one-sector and multi-sector reconstruction algorithm at optimal window of the R-R interval. The image quality score (IQS) was evaluated by two radiologists according to the same evaluation standard of reformated image. The correlation between heart rate (HR), roation speed, reconstruction algorithm, and IQS were analyzed. The IQS as independent variable and the HR, rotation speed, reconstruction algorithm as dependent variables were analyzed by multiple linear regression analysis. Results: The heart rate and the reconstruction algorithm had significant influence on IQS. The rotation speed (0.35s, 0.40 s, and 0.45 s) didn't have significant influence on IQS. There was linear regression relationship between heart rate, reconstruction algorithm and IQS (P<0.01). The equation of multiple regression was IQS=5.154-0.046 x (HR) + 0.500 x (reconstruction algorithm). The multi-sector reconstruction algorithm improved the image quality than one-sector did. Conclusion: The main influence factors on the image quality of coronary artery can be evaluated with 40 mm VCT using a pulsating cardiac phantom. It plays an important role in clinical research and application. (authors)

  18. Imaging the vertebral artery

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    Tay, Keng Yeow; U-King-Im, Jean Marie; Trivedi, Rikin A.; Higgins, Nicholas J.; Cross, Justin J.; Antoun, Nagui M. [Addenbrooke' s Hospital and University of Cambridge, Department of Radiology, Cambridge (United Kingdom); Davies, John R.; Weissberg, Peter L. [Addenbrooke' s Hospital and University of Cambridge, Division of Cardiovascular Medicine, Cambridge (United Kingdom); Gillard, Jonathan H. [Addenbrooke' s Hospital and University of Cambridge, Department of Radiology, Cambridge (United Kingdom); Addenbrooke' s Hospitald, University Department of Radiology, Cambridge (United Kingdom)

    2005-07-01

    Although conventional intraarterial digital subtraction angiography remains the gold standard method for imaging the vertebral artery, noninvasive modalities such as ultrasound, multislice computed tomographic angiography and magnetic resonance angiography are constantly improving and are playing an increasingly important role in diagnosing vertebral artery pathology in clinical practice. This paper reviews the current state of vertebral artery imaging from an evidence-based perspective. Normal anatomy, normal variants and a number of pathological entities such as vertebral atherosclerosis, arterial dissection, arteriovenous fistula, subclavian steal syndrome and vertebrobasilar dolichoectasia are discussed. (orig.)

  19. Imaging the vertebral artery

    International Nuclear Information System (INIS)

    Tay, Keng Yeow; U-King-Im, Jean Marie; Trivedi, Rikin A.; Higgins, Nicholas J.; Cross, Justin J.; Antoun, Nagui M.; Davies, John R.; Weissberg, Peter L.; Gillard, Jonathan H.

    2005-01-01

    Although conventional intraarterial digital subtraction angiography remains the gold standard method for imaging the vertebral artery, noninvasive modalities such as ultrasound, multislice computed tomographic angiography and magnetic resonance angiography are constantly improving and are playing an increasingly important role in diagnosing vertebral artery pathology in clinical practice. This paper reviews the current state of vertebral artery imaging from an evidence-based perspective. Normal anatomy, normal variants and a number of pathological entities such as vertebral atherosclerosis, arterial dissection, arteriovenous fistula, subclavian steal syndrome and vertebrobasilar dolichoectasia are discussed. (orig.)

  20. 16-slice multi-detector row CT coronary angiography: image quality and optimization of the image reconstruction window

    International Nuclear Information System (INIS)

    Kim, Yoo Kyung; Shim, Sung Shine; Lim, Soo Mee; Hwang, Ji Young; Kim, Yoon Kyung

    2005-01-01

    The purpose of this experiment is to investigate the image quality of CT coronary angiography using a 16-slice multi-detector row CT and to determine the optimal image reconstruction window. CT coronary angiography was obtained in 36 nonsymptomatic volunteers using a 16-slice multi-detector row CT (SOMATOM Sensation, Siemens Medical System). The mean heart rates were 70 beats per minute (bpm) or less in 18 persons and more than 70 bpm in 18 persons. Eleven data sets were obtained for each patient (reconstructed at 30%-80% of the cardiac cycle with an increment of 5%). Image quality of the eight coronary segments [left main coronary artery (LM), proximal and middle segments of left anterior descending artery (p-LAD, m-LAN) and left circumflex coronary artery (p-LCx, m-LCx) and proximal, middle and distal segments of right coronary artery (p-RCA, m-RCA, d-RCA)] was assessed. The optimal reconstruction windows in the cardiac cycle for the best image quality were 60-70% for the segments of the LM, LAD, and LC arteries in two groups (bpm 70) and 55-65% (bpm 70) for the segments of the RCA. On the best dataset for each coronary segment, the following diagnostic image quality was achieved in the two groups: LM: 100%, 83%; p-LAD: 100%, 88% m-LAD: 100%, 72%; p-LCx: 100%, 72%; m-LCx: 100%, 72%; p-RCA: 94%, 72%; m-RCA: 61%, 50%; d-RCA: 100%, 80%. The 16 slice multi-detector row CT scan provided visualization of the coronary arteries with high resolution. Especially in the group with a mean heart rate of 70 bpm or less, all the coronary segments except the RCA showed diagnostic image quality. Optimal image quality was achieved with a 60-70% trigger delay for all coronary arterial segments, but the best images of RCA were achieved in the earlier cardiac phase in the patients with a mean heart rate of more than 70 bpm

  1. Dual-source computed tomography in patients with acute chest pain: feasibility and image quality

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    Schertler, Thomas; Scheffel, Hans; Frauenfelder, Thomas; Desbiolles, Lotus; Leschka, Sebastian; Stolzmann, Paul; Marincek, Borut; Alkadhi, Hatem [University Hospital Zurich, Department of Medical Radiology, Institute of Diagnostic Radiology, Zurich (Switzerland); Seifert, Burkhardt [University of Zurich, Department of Biostatistics, Zurich (Switzerland); Flohr, Thomas G. [Computed Tomography CTE PA, Siemens Medical Solutions, Forchheim (Germany)

    2007-12-15

    The aim of this study was to determine the feasibility and image quality of dual-source computed tomography angiography (DSCTA) in patients with acute chest pain for the assessment of the lung, thoracic aorta, and for pulmonary and coronary arteries. Sixty consecutive patients (32 female, 28 male, mean age 58.1{+-}16.3 years) with acute chest pain underwent contrast-enhanced electrocardiography-gated DSCTA without prior beta-blocker administration. Vessel attenuation of different thoracic vascular territories was measured, and image quality was semi-quantitatively analyzed by two independent readers. Image quality of the thoracic aorta was diagnostic in all 60 patients, image quality of pulmonary arteries was diagnostic in 59, and image quality of coronary arteries was diagnostic in 58 patients. Pairwise intraindividual comparisons of attenuation values were small and ranged between 1{+-}6 HU comparing right and left coronary artery and 56{+-}9 HU comparing the pulmonary trunk and left ventricle. Mean attenuation was 291{+-}65 HU in the ascending aorta, 334{+-}93 HU in the pulmonary trunk, and 285{+-}66 HU and 268{+-}67 HU in the right and left coronary artery, respectively. DSCTA is feasible and provides diagnostic image quality of the thoracic aorta, pulmonary and coronary arteries in patients with acute chest pain. (orig.)

  2. Dual-source computed tomography in patients with acute chest pain: feasibility and image quality

    International Nuclear Information System (INIS)

    Schertler, Thomas; Scheffel, Hans; Frauenfelder, Thomas; Desbiolles, Lotus; Leschka, Sebastian; Stolzmann, Paul; Marincek, Borut; Alkadhi, Hatem; Seifert, Burkhardt; Flohr, Thomas G.

    2007-01-01

    The aim of this study was to determine the feasibility and image quality of dual-source computed tomography angiography (DSCTA) in patients with acute chest pain for the assessment of the lung, thoracic aorta, and for pulmonary and coronary arteries. Sixty consecutive patients (32 female, 28 male, mean age 58.1±16.3 years) with acute chest pain underwent contrast-enhanced electrocardiography-gated DSCTA without prior beta-blocker administration. Vessel attenuation of different thoracic vascular territories was measured, and image quality was semi-quantitatively analyzed by two independent readers. Image quality of the thoracic aorta was diagnostic in all 60 patients, image quality of pulmonary arteries was diagnostic in 59, and image quality of coronary arteries was diagnostic in 58 patients. Pairwise intraindividual comparisons of attenuation values were small and ranged between 1±6 HU comparing right and left coronary artery and 56±9 HU comparing the pulmonary trunk and left ventricle. Mean attenuation was 291±65 HU in the ascending aorta, 334±93 HU in the pulmonary trunk, and 285±66 HU and 268±67 HU in the right and left coronary artery, respectively. DSCTA is feasible and provides diagnostic image quality of the thoracic aorta, pulmonary and coronary arteries in patients with acute chest pain. (orig.)

  3. A quality score for coronary artery tree extraction results

    Science.gov (United States)

    Cao, Qing; Broersen, Alexander; Kitslaar, Pieter H.; Lelieveldt, Boudewijn P. F.; Dijkstra, Jouke

    2018-02-01

    Coronary artery trees (CATs) are often extracted to aid the fully automatic analysis of coronary artery disease on coronary computed tomography angiography (CCTA) images. Automatically extracted CATs often miss some arteries or include wrong extractions which require manual corrections before performing successive steps. For analyzing a large number of datasets, a manual quality check of the extraction results is time-consuming. This paper presents a method to automatically calculate quality scores for extracted CATs in terms of clinical significance of the extracted arteries and the completeness of the extracted CAT. Both right dominant (RD) and left dominant (LD) anatomical statistical models are generated and exploited in developing the quality score. To automatically determine which model should be used, a dominance type detection method is also designed. Experiments are performed on the automatically extracted and manually refined CATs from 42 datasets to evaluate the proposed quality score. In 39 (92.9%) cases, the proposed method is able to measure the quality of the manually refined CATs with higher scores than the automatically extracted CATs. In a 100-point scale system, the average scores for automatically and manually refined CATs are 82.0 (+/-15.8) and 88.9 (+/-5.4) respectively. The proposed quality score will assist the automatic processing of the CAT extractions for large cohorts which contain both RD and LD cases. To the best of our knowledge, this is the first time that a general quality score for an extracted CAT is presented.

  4. Assessment of coronary artery disease with nicorandil stress magnetic resonance imaging

    International Nuclear Information System (INIS)

    Kawase, Yoshio; Nichimoto, Masaki; Hato, Katsunori; Okajima, Kazue; Yoshikawa, Junichi

    2004-01-01

    Although dipyridamole and adenosine have been used as vasodilator agents, we believe they are inadequate for vasodilator perfusion magnetic resonance imaging, due to adverse effects (flushing, warmth, headaches, and arrhythmia). Nicorandil, a potassium channel opener, has been reported to increase coronary blood flow and it was associated with fewer adverse effects than adenosine or dipiridamole. We set out to investigate whether the coronary artery stenosis could be assessed by nicorandil stress perfusion magnetic resonance imaging. First-pass contrast-enhanced magnetic resonance images of the left ventricle acquired from 50 patients at rest and during intravenous administration of nicorandil using multi-slice turbo field echo with multi shot echo-planar-imaging. Coronary angiography was performed within 1 week. There was no adverse effects during nicorandil stress in any patients. The overall sensitivity and specificity of magnetic resonance imaging in identifying patients with significant stenosis of at least one coronary artery were 93.9% (31 of 33 patients) and 94.1% (16 of 17 patients), respectively. The sensitivity of magnetic resonance imaging for detecting significant stenosis in the left anterior descending artery was 87.5%; the sensitivity in the left circumflex artery was 80%; the sensitivity in the right coronary artery was 92.3%. Similar sensitivities were observed for all 3 vascular regions, indicating that all myocardial segments were visualized with similar image quality. The present study shows that nicorandil stress perfusion magnetic resonance imaging is a safe, feasible technique for assessing coronary artery stenosis severity in a totally-noninvasive manner. (authors)

  5. Myocardial imaging by direct injection of thallium-201 into coronary artery

    International Nuclear Information System (INIS)

    Sugihara, Hiroki; Inagaki, Suetsugu; Kubota, Yasushi

    1988-01-01

    Myocardial perfusion images were evaluated by direct injection of Thallium (Tl)-201 into coronary artery. Approximately 0.5 - 1 mCi of Tl-201 were instilled into the right coronary artery and/or the left coronary artery after coronary arteriography. Three images were obtained in the anterior, left anterior oblique and left lateral projections. Myocardial perfusion images of single photon emission computed tomography were also acquired in some patients. An image of supreme quality could be obtained in spite of small dose of Tl-201 since there was a lack of interference from background activity. Myocardial perfusion images corresponded to areas which were supplied by left or right coronary artery respectively. And the regional myocardial blood flow distribution of a coronary artery bypass graft could be revealed by instilling Tl-201 into the graft. Further, contribution of collateral channels to myocardial perfusion was showed. Not only left ventricle but also right ventricle was clearly visualized by injection of Tl-201 into right coronary artery. But in a case with arrhythmogenic right ventricular dysplasia, there was an area of decreased tracer uptake in the apex of the right ventricle which was identified as the site of dysplasia by electrophysiologic study. We conclude that direct injection of Tl-201 into coronary artery is an useful method to clarify the correlation between coronary anatomical findings and coronary perfusion and contribution of collaterals to myocardial perfusion, and also to detect the right ventricular myopathic site. (author)

  6. Improving quality of arterial spin labeling MR imaging at 3 Tesla with a 32-channel coil and parallel imaging.

    Science.gov (United States)

    Ferré, Jean-Christophe; Petr, Jan; Bannier, Elise; Barillot, Christian; Gauvrit, Jean-Yves

    2012-05-01

    To compare 12-channel and 32-channel phased-array coils and to determine the optimal parallel imaging (PI) technique and factor for brain perfusion imaging using Pulsed Arterial Spin labeling (PASL) at 3 Tesla (T). Twenty-seven healthy volunteers underwent 10 different PASL perfusion PICORE Q2TIPS scans at 3T using 12-channel and 32-channel coils without PI and with GRAPPA or mSENSE using factor 2. PI with factor 3 and 4 were used only with the 32-channel coil. Visual quality was assessed using four parameters. Quantitative analyses were performed using temporal noise, contrast-to-noise and signal-to-noise ratios (CNR, SNR). Compared with 12-channel acquisition, the scores for 32-channel acquisition were significantly higher for overall visual quality, lower for noise and higher for SNR and CNR. With the 32-channel coil, artifact compromise achieved the best score with PI factor 2. Noise increased, SNR and CNR decreased with PI factor. However mSENSE 2 scores were not always significantly different from acquisition without PI. For PASL at 3T, the 32-channel coil at 3T provided better quality than the 12-channel coil. With the 32-channel coil, mSENSE 2 seemed to offer the best compromise for decreasing artifacts without significantly reducing SNR, CNR. Copyright © 2012 Wiley Periodicals, Inc.

  7. Imaging in acute basilar artery thrombosis

    Energy Technology Data Exchange (ETDEWEB)

    Castillo, M. (Dept. of Radiology, Univ. of North Carolina School of Medicine, Chapel Hill, NC (United States)); Falcone, S. (Dept. of Radiology, Univ. of Miami School of Medicine, Miami, FL (United States)); Naidich, T.P. (Dept. of Radiology, Univ. of Miami School of Medicine, Miami, FL (United States)); Bowen, B. (Dept. of Radiology, Univ. of Miami School of Medicine, Miami, FL (United States)); Quencer, R.M. (Dept. of Radiology, Univ. of Miami School of Medicine, Miami, FL (United States))

    1994-08-01

    The aim of this study was to review the imaging features in acute (< 24 h) basilar artery thrombosis. CT and MR studies in 11 patients with clinical diagnosis of acute basilar artery thrombosis were retrospectively reviewed. MR angiography was obtained in 4 patients. Correlation with clinical symptoms was performed. Multiple cranial nerve palsies and hemiparesis were the most common clinical symptoms at presentation. CT revealed hyperdense basilar arteries (n = 7) and hypodensities in the posterior circulation territory (n = 8). In one instance, the infarction was hemorrhagic. MR imaging showed absence of flow void within the basilar in 6 patients and MRA (using both PC and TOF techniques) confirmed absence of blood flow in 4 basilar arteries. One week after presentation, 5 patients died. Autopsy was obtained in 1 case and confirmed the diagnosis of basilar artery thrombosis. Basilar artery thrombosis has fairly typical imaging features by both CT and MR. MRA may be used to confirm the diagnosis. Prompt recognition may lead to early thrombolytic treatment and may improve survival. (orig.)

  8. Magnetic resonance imaging of popliteal artery pathologies

    International Nuclear Information System (INIS)

    Holden, Andrew; Merrilees, Stephen; Mitchell, Nicola; Hill, Andrew

    2008-01-01

    This paper illustrates examples of popliteal artery pathologies imaged with contrast enhanced magnetic resonance angiography (CE-MRA) and magnetic resonance imaging (MRI) at a single tertiary referral centre. Popliteal artery pathologies were identified in 1710 patients referred over a 6-year period with symptoms suggesting lower limb arterial occlusive disease. Common pathologies such as atherosclerotic occlusive disease, thromboemboli and aneurysm disease are discussed as well as unusual pathologies such as cystic adventitial disease, mycotic aneurysm and arterial entrapment. The combination of CE-MRA and the excellent soft tissue resolution of MRI allow detailed evaluation of arterial and peri-arterial pathologies, and facilitate appropriate management decisions

  9. Magnetic resonance imaging of popliteal artery pathologies

    Energy Technology Data Exchange (ETDEWEB)

    Holden, Andrew [Department of Radiology, Auckland City Hospital, Park Road, Grafton, Auckland 9 (New Zealand)], E-mail: andrewh@adhb.govt.nz; Merrilees, Stephen [Department of Radiology, Auckland City Hospital, Park Road, Grafton, Auckland 9 (New Zealand)], E-mail: smerrilees@adhb.govt.nz; Mitchell, Nicola [Department of Radiology, Auckland City Hospital, Park Road, Grafton, Auckland 9 (New Zealand)], E-mail: nmit010@ec.auckland.ac.nz; Hill, Andrew [Department of Vascular Surgery, Auckland City Hospital, Park Road, Grafton, Auckland 9 (New Zealand)], E-mail: ahill@adhb.govt.nz

    2008-07-15

    This paper illustrates examples of popliteal artery pathologies imaged with contrast enhanced magnetic resonance angiography (CE-MRA) and magnetic resonance imaging (MRI) at a single tertiary referral centre. Popliteal artery pathologies were identified in 1710 patients referred over a 6-year period with symptoms suggesting lower limb arterial occlusive disease. Common pathologies such as atherosclerotic occlusive disease, thromboemboli and aneurysm disease are discussed as well as unusual pathologies such as cystic adventitial disease, mycotic aneurysm and arterial entrapment. The combination of CE-MRA and the excellent soft tissue resolution of MRI allow detailed evaluation of arterial and peri-arterial pathologies, and facilitate appropriate management decisions.

  10. MR imaging of persistent primitive trigeminal artery

    International Nuclear Information System (INIS)

    Ashikaga, Ryuichiro; Araki, Yutaka; Ono, Yukihiko; Ishida, Osamu; Mabuchi, Nobuhisa.

    1997-01-01

    The persistent trigeminal artery is the most common anomaly of the primitive carotid-vertebrobasilar anastomoses. We reviewed MR images and MR angiographies of 11 patients with primitive trigeminal artery. In 8 of the 11 cases, PTA were identified with conventional long TR spin-echo images. In 8 of 11 cases, a hypoplastic basilar trunk associated with PTA was seen on both MR images and MR angiographies. In 7 of 11 cases, a hypoplasia or agenesis of the ipsilateral posterior communicating artery was seen on MR angiographies. (author)

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

    International Nuclear Information System (INIS)

    Xie Hongbo; Li Xiangmin; Peng Zhenpeng; Zhou Xuhui; Yan Chaogui; Li Ziping

    2010-01-01

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

  12. Intra-arterial high signals on arterial spin labeling perfusion images predict the occluded internal carotid artery segment

    International Nuclear Information System (INIS)

    Sogabe, Shu; Satomi, Junichiro; Tada, Yoshiteru; Kanematsu, Yasuhisa; Kuwayama, Kazuyuki; Yagi, Kenji; Yoshioka, Shotaro; Mizobuchi, Yoshifumi; Mure, Hideo; Yamaguchi, Izumi; Kitazato, Keiko T.; Nagahiro, Shinji; Abe, Takashi; Harada, Masafumi; Yamamoto, Nobuaki; Kaji, Ryuji

    2017-01-01

    Arterial spin labeling (ASL) involves perfusion imaging using the inverted magnetization of arterial water. If the arterial arrival times are longer than the post-labeling delay, labeled spins are visible on ASL images as bright, high intra-arterial signals (IASs); such signals were found within occluded vessels of patients with acute ischemic stroke. The identification of the occluded segment in the internal carotid artery (ICA) is crucial for endovascular treatment. We tested our hypothesis that high IASs on ASL images can predict the occluded segment. Our study included 13 patients with acute ICA occlusion who had undergone angiographic and ASL studies within 48 h of onset. We retrospectively identified the high IAS on ASL images and angiograms and recorded the occluded segment and the number of high IAS-positive slices on ASL images. The ICA segments were classified as cervical (C1), petrous (C2), cavernous (C3), and supraclinoid (C4). Of seven patients with intracranial ICA occlusion, five demonstrated high IASs at C1-C2, suggesting that high IASs could identify stagnant flow proximal to the occluded segment. Among six patients with extracranial ICA occlusion, five presented with high IASs at C3-C4, suggesting that signals could identify the collateral flow via the ophthalmic artery. None had high IASs at C1-C2. The mean number of high IAS-positive slices was significantly higher in patients with intra- than extracranial ICA occlusion. High IASs on ASL images can identify slow stagnant and collateral flow through the ophthalmic artery in patients with acute ICA occlusion and help to predict the occlusion site. (orig.)

  13. Intra-arterial high signals on arterial spin labeling perfusion images predict the occluded internal carotid artery segment

    Energy Technology Data Exchange (ETDEWEB)

    Sogabe, Shu; Satomi, Junichiro; Tada, Yoshiteru; Kanematsu, Yasuhisa; Kuwayama, Kazuyuki; Yagi, Kenji; Yoshioka, Shotaro; Mizobuchi, Yoshifumi; Mure, Hideo; Yamaguchi, Izumi; Kitazato, Keiko T.; Nagahiro, Shinji [Tokushima University Graduate School, Department of Neurosurgery, Tokushima (Japan); Abe, Takashi; Harada, Masafumi [Tokushima University Graduate School, Department of Radiology, Tokushima (Japan); Yamamoto, Nobuaki; Kaji, Ryuji [Tokushima University Graduate School, Department of Clinical Neurosciences, Institute of Biomedical Biosciences, Tokushima (Japan)

    2017-06-15

    Arterial spin labeling (ASL) involves perfusion imaging using the inverted magnetization of arterial water. If the arterial arrival times are longer than the post-labeling delay, labeled spins are visible on ASL images as bright, high intra-arterial signals (IASs); such signals were found within occluded vessels of patients with acute ischemic stroke. The identification of the occluded segment in the internal carotid artery (ICA) is crucial for endovascular treatment. We tested our hypothesis that high IASs on ASL images can predict the occluded segment. Our study included 13 patients with acute ICA occlusion who had undergone angiographic and ASL studies within 48 h of onset. We retrospectively identified the high IAS on ASL images and angiograms and recorded the occluded segment and the number of high IAS-positive slices on ASL images. The ICA segments were classified as cervical (C1), petrous (C2), cavernous (C3), and supraclinoid (C4). Of seven patients with intracranial ICA occlusion, five demonstrated high IASs at C1-C2, suggesting that high IASs could identify stagnant flow proximal to the occluded segment. Among six patients with extracranial ICA occlusion, five presented with high IASs at C3-C4, suggesting that signals could identify the collateral flow via the ophthalmic artery. None had high IASs at C1-C2. The mean number of high IAS-positive slices was significantly higher in patients with intra- than extracranial ICA occlusion. High IASs on ASL images can identify slow stagnant and collateral flow through the ophthalmic artery in patients with acute ICA occlusion and help to predict the occlusion site. (orig.)

  14. Non-contrast-enhanced hepatic MR angiography: Do two-dimensional parallel imaging and short tau inversion recovery methods shorten acquisition time without image quality deterioration?

    Energy Technology Data Exchange (ETDEWEB)

    Shimada, Kotaro, E-mail: kotaro@kuhp.kyoto-u.ac.jp [Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University, Graduate School of Medicine, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507 (Japan); Isoda, Hiroyoshi, E-mail: sayuki@kuhp.kyoto-u.ac.jp [Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University, Graduate School of Medicine, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507 (Japan); Okada, Tomohisa, E-mail: tomokada@kuhp.kyoto-u.ac.jp [Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University, Graduate School of Medicine, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507 (Japan); Kamae, Toshikazu, E-mail: toshi13@kuhp.kyoto-u.ac.jp [Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University, Graduate School of Medicine, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507 (Japan); Arizono, Shigeki, E-mail: arizono@kuhp.kyoto-u.ac.jp [Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University, Graduate School of Medicine, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507 (Japan); Hirokawa, Yuusuke, E-mail: yuusuke@kuhp.kyoto-u.ac.jp [Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University, Graduate School of Medicine, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507 (Japan); Shibata, Toshiya, E-mail: ksj@kuhp.kyoto-u.ac.jp [Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University, Graduate School of Medicine, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507 (Japan); Togashi, Kaori, E-mail: ktogashi@kuhp.kyoto-u.ac.jp [Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University, Graduate School of Medicine, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507 (Japan)

    2011-01-15

    Objective: To study whether shortening the acquisition time for selective hepatic artery visualization is feasible without image quality deterioration by adopting two-dimensional (2D) parallel imaging (PI) and short tau inversion recovery (STIR) methods. Materials and methods: Twenty-four healthy volunteers were enrolled. 3D true steady-state free-precession imaging with a time spatial labeling inversion pulse was conducted using 1D or 2D-PI and fat suppression by chemical shift selective (CHESS) or STIR methods. Three groups of different scan conditions were assigned and compared: group A (1D-PI factor 2 and CHESS), group B (2D-PI factor 2 x 2 and CHESS), and group C (2D-PI factor 2 x 2 and STIR). The artery-to-liver contrast was quantified, and the quality of artery visualization and overall image quality were scored. Results: The mean scan time was 9.5 {+-} 1.0 min (mean {+-} standard deviation), 5.9 {+-} 0.8 min, and 5.8 {+-} 0.5 min in groups A, B, and C, respectively, and was significantly shorter in groups B and C than in group A (P < 0.01). The artery-to-liver contrast was significantly better in group C than in groups A and B (P < 0.01). The scores for artery visualization and overall image quality were worse in group B than in groups A and C. The differences were statistically significant (P < 0.05) regarding the arterial branches of segments 4 and 8. Between group A and group C, which had similar scores, there were no statistically significant differences. Conclusion: Shortening the acquisition time for selective hepatic artery visualization was feasible without deterioration of the image quality by the combination of 2D-PI and STIR methods. It will facilitate using non-contrast-enhanced MRA in clinical practice.

  15. Non-contrast-enhanced hepatic MR angiography: Do two-dimensional parallel imaging and short tau inversion recovery methods shorten acquisition time without image quality deterioration?

    International Nuclear Information System (INIS)

    Shimada, Kotaro; Isoda, Hiroyoshi; Okada, Tomohisa; Kamae, Toshikazu; Arizono, Shigeki; Hirokawa, Yuusuke; Shibata, Toshiya; Togashi, Kaori

    2011-01-01

    Objective: To study whether shortening the acquisition time for selective hepatic artery visualization is feasible without image quality deterioration by adopting two-dimensional (2D) parallel imaging (PI) and short tau inversion recovery (STIR) methods. Materials and methods: Twenty-four healthy volunteers were enrolled. 3D true steady-state free-precession imaging with a time spatial labeling inversion pulse was conducted using 1D or 2D-PI and fat suppression by chemical shift selective (CHESS) or STIR methods. Three groups of different scan conditions were assigned and compared: group A (1D-PI factor 2 and CHESS), group B (2D-PI factor 2 x 2 and CHESS), and group C (2D-PI factor 2 x 2 and STIR). The artery-to-liver contrast was quantified, and the quality of artery visualization and overall image quality were scored. Results: The mean scan time was 9.5 ± 1.0 min (mean ± standard deviation), 5.9 ± 0.8 min, and 5.8 ± 0.5 min in groups A, B, and C, respectively, and was significantly shorter in groups B and C than in group A (P < 0.01). The artery-to-liver contrast was significantly better in group C than in groups A and B (P < 0.01). The scores for artery visualization and overall image quality were worse in group B than in groups A and C. The differences were statistically significant (P < 0.05) regarding the arterial branches of segments 4 and 8. Between group A and group C, which had similar scores, there were no statistically significant differences. Conclusion: Shortening the acquisition time for selective hepatic artery visualization was feasible without deterioration of the image quality by the combination of 2D-PI and STIR methods. It will facilitate using non-contrast-enhanced MRA in clinical practice.

  16. Interleaving cerebral CT perfusion with neck CT angiography. Pt. II. Clinical implementation and image quality

    Energy Technology Data Exchange (ETDEWEB)

    Oei, Marcel T.H.; Meijer, Frederick J.A.; Woude, Willem-Jan van der; Smit, Ewoud J.; Ginneken, Bram van; Manniesing, Rashindra; Prokop, Mathias [Radboud University Medical Centre, Department of Radiology and Nuclear Medicine, P.O. Box 9101, Nijmegen (Netherlands)

    2017-06-15

    Feasibility evaluation of the One-Step Stroke Protocol, which is an interleaved cerebral computed tomography perfusion (CTP) and neck volumetric computed tomography angiography (vCTA) scanning technique using wide-detector computed tomography, and to assess the image quality of vCTA. Twenty patients with suspicion of acute ischaemic stroke were prospectively scanned and evaluated with a head and neck CTA and with the One-Step Stroke Protocol. Arterial enhancement and contrast-to-noise ratio (CNR) in the carotid arteries was assessed. Three observers scored artefacts and image quality of the cervical arteries. The total z-coverage was evaluated. Mean enhancement in the carotid bifurcation was rated higher in the vCTA (595 ± 164 HU) than CTA (441 ± 117 HU). CNR was rated higher in vCTA. Image quality scores showed no significant difference in the region of the carotid bifurcation between vCTA and CTA. Lower neck image quality scores were slightly lower for vCTA due to artefacts, although not rated as diagnostically relevant. In ten patients, the origin of the left common carotid artery was missed by 1.6 ± 0.8 cm. Mean patient height was 1.8 ± 0.09 m. Carotid bifurcation and origin of vertebral arteries were covered in all patients. The One-Step Stroke Protocol is feasible with good diagnostic image quality of vCTA, although full z-coverage is limited in tall patients. (orig.)

  17. Multislice CT imaging of anomalous coronary arteries

    International Nuclear Information System (INIS)

    Shi Heshui; Aschoff, Andrik J.; Brambs, Hans-Juergen; Hoffmann, Martin H.K.

    2004-01-01

    The purpose of the present study was to evaluate the role of 16 multislice computed tomography (MSCT) to identify the origin of anomalous coronary arteries and to confirm their anatomic course in relation to the great vessels. Accuracy of coronary artery disease (CAD) detection was a secondary aim and was tested with conventional angiograms (CA) serving as standard of reference. Two hundred and forty-two consecutive patients referred for noninvasive coronary CT imaging were reviewed for the study. Sixteen patients (6.6%) with anomalous coronary arteries were detected and included as the study group. MSCT and CA images were analyzed in a blinded fashion for accuracy of anomalous artery origin and path detection. Results were compared in a secondary consensus evaluation. Accuracy ratios to detect CAD with MSCT in all vessels were calculated. Coronary anomalies for all 16 patients were correctly displayed on MSCT. CA alone achieved correct identification of the abnormality in only 53% (P=0.016). Sensitivity and specificity of MSCT to detect significantly stenosed vessels was 90 and 92%. 16-MSCT is accurate to delineate abnormally branching coronary arteries and allows sufficiently accurate detection of obstructive coronary artery disease in distal branches. It should therefore be considered as a prime non-invasive imaging tool for suspected coronary anomalies. (orig.)

  18. The optimal monochromatic spectral computed tomographic imaging plus adaptive statistical iterative reconstruction algorithm can improve the superior mesenteric vessel image quality

    Energy Technology Data Exchange (ETDEWEB)

    Yin, Xiao-Ping; Zuo, Zi-Wei; Xu, Ying-Jin; Wang, Jia-Ning [CT/MRI room, Affiliated Hospital of Hebei University, Baoding, Hebei, 071000 (China); Liu, Huai-Jun, E-mail: hebeiliu@outlook.com [Department of Medical Imaging, The Second Hospital of Hebei Medical University, Shijiazhuang, Hebei, 050000 (China); Liang, Guang-Lu [CT/MRI room, Affiliated Hospital of Hebei University, Baoding, Hebei, 071000 (China); Gao, Bu-Lang, E-mail: browngao@163.com [Department of Medical Research, Shijiazhuang First Hospital, Shijiazhuang, Hebei, 050011 (China)

    2017-04-15

    Objective: To investigate the effect of the optimal monochromatic spectral computed tomography (CT) plus adaptive statistical iterative reconstruction on the improvement of the image quality of the superior mesenteric artery and vein. Materials and methods: The gemstone spectral CT angiographic data of 25 patients were reconstructed in the following three groups: 70 KeV, the optimal monochromatic imaging, and the optimal monochromatic plus 40%iterative reconstruction mode. The CT value, image noises (IN), background CT value and noises, contrast-to-noise ratio (CNR), signal-to-noise ratio (SNR) and image scores of the vessels and surrounding tissues were analyzed. Results: In the 70 KeV, the optimal monochromatic and the optimal monochromatic images plus 40% iterative reconstruction group, the mean scores of image quality were 3.86, 4.24 and 4.25 for the superior mesenteric artery and 3.46, 3.78 and 3.81 for the superior mesenteric vein, respectively. The image quality scores for the optimal monochromatic and the optimal monochromatic plus 40% iterative reconstruction groups were significantly greater than for the 70 KeV group (P < 0.05). The vascular CT value, image noise, background noise, CNR and SNR were significantly (P < 0.001) greater in the optimal monochromatic and the optimal monochromatic images plus 40% iterative reconstruction group than in the 70 KeV group. The optimal monochromatic plus 40% iterative reconstruction group had significantly (P < 0.05) lower image and background noise but higher CNR and SNR than the other two groups. Conclusion: The optimal monochromatic imaging combined with 40% iterative reconstruction using low-contrast agent dosage and low injection rate can significantly improve the image quality of the superior mesenteric artery and vein.

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

    International Nuclear Information System (INIS)

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

    2008-01-01

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

  20. A comparative analysis of double inversion recovery TFE and TSE sequences on carotid artery wall imaging

    International Nuclear Information System (INIS)

    Chen Jun; Di Yujin; Bu Chunqing; Zhang Yanfeng; Li Shuhua

    2012-01-01

    Objective: To analyze the characteristics of double inversion recovery (DIR) turbo field echo (TFE) and turbo spin echo (TSE) sequences and explore the value of double inversion recovery TFE sequence on carotid artery wall imaging. Patients and methods: 56 patients (32 males and 24 females, aged 31–76 years with a mean age of 53 years) were performed with DIR TFE and DIR TSE T1 weighted imaging (T1WI) sequences on carotid artery bifurcations. Image quality acquired by different techniques were evaluated and scored by two physicians. Whether there is significant difference is determined by SPSS 11.0 software. Paired-samples t test was used for statistics. Results: There was no significant difference in the image quality scores between two sequences (t = 0.880, P = 0.383 > 0.05). Conclusions: DIR TFE sequence has short scanning time and high spatial resolution. DIR TFE sequence can be used as the preferred sequence for screening carotid atherosclerotic plaque compared with DIR TSE sequence.

  1. 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

  2. Multi-Detector Computed Tomography Imaging Techniques in Arterial Injuries

    Directory of Open Access Journals (Sweden)

    Cameron Adler

    2018-04-01

    Full Text Available Cross-sectional imaging has become a critical aspect in the evaluation of arterial injuries. In particular, angiography using computed tomography (CT is the imaging of choice. A variety of techniques and options are available when evaluating for arterial injuries. Techniques involve contrast bolus, various phases of contrast enhancement, multiplanar reconstruction, volume rendering, and maximum intensity projection. After the images are rendered, a variety of features may be seen that diagnose the injury. This article provides a general overview of the techniques, important findings, and pitfalls in cross sectional imaging of arterial imaging, particularly in relation to computed tomography. In addition, the future directions of computed tomography, including a few techniques in the process of development, is also discussed.

  3. Intravascular ultrasound for iliac artery imaging. Clinical review

    DEFF Research Database (Denmark)

    Vogt, K G; Schroeder, T V

    2001-01-01

    IVUS is able to produce trans-sectional images of the iliac arteries at a high resolution. The three layered appearance of the arterial wall can be visualized. In the atherosclerotic diseased artery calcified plaques can be discerned from non-calcified plaques, and the distribution of the plaque...

  4. Intra-arterial digital subtraction angiography of the carotid arteries

    International Nuclear Information System (INIS)

    Nakstad, P.; Bakke, S.J.; Kjartansson, O.; Nyhus, S.

    1986-01-01

    A cross-over test in intra-arterial digital subtraction angiography (IADSA) of the carotid arteries was performed in 50 patients to evaluate image quality and side-effects with iohexol and metrizoate injected at concentrations of 100 mg I/ml by hand. The image quality was excellent or good in all cases. Although the severity and the frequency of side-effects were higher with metrizoate, both contrast media were suitable for IADSA at this low concentration. No complications were seen. It was assumed that the risk with IADSA was less than that of conventional-selectivity and with small amounts of contrast media, as in this study. (orig.)

  5. 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)

  6. Image quality on dual-source computed-tomographic coronary angiography

    International Nuclear Information System (INIS)

    Rixe, Johannes; Rolf, Andreas; Conradi, Guido; Elsaesser, Albrecht; Moellmann, Helge; Nef, Holger M.; Hamm, Christian W.; Dill, Thorsten; Bachmann, Georg

    2008-01-01

    Multi-detector CT reliably permits visualization of coronary arteries, but due to the occurrence of motion artefacts at heart rates >65 bpm caused by a temporal resolution of 165 ms, its utilisation has so far been limited to patients with a preferably low heart rate. We investigated the assessment of image quality on computed tomography of coronary arteries in a large series of patients without additional heart rate control using dual-source computed tomography (DSCT). DSCT (Siemens Somatom Definition, 83-ms temporal resolution) was performed in 165 consecutive patients (mean age 64±11.4 years) after injection of 60-80 ml of contrast. Data sets were reconstructed in 5% intervals of the cardiac cycle and evaluated by two readers in consensus concerning evaluability of the coronary arteries and presence of motion and beam-hardening artefacts using the AHA 16-segment coronary model. Mean heart rate during CT was 65±10.5 bpm; visualisation without artefacts was possible in 98.7% of 2,541 coronary segments. Only two segments were considered unevaluable due to cardiac motion; 30 segments were unassessable due to poor signal-to-noise ratio or coronary calcifications (both n=15). Data reconstruction at 65-70% of the cardiac cycle provided for the best image quality. For heart rates >85 bpm, a systolic reconstruction at 45% revealed satisfactory results. Compared with earlier CT generations, DSCT provides for non-invasive coronary angiography with diagnostic image quality even at heart rates >65 bpm and thus may broaden the spectrum of patients that can be investigated non-invasively. (orig.)

  7. Imaging and embolization of hepatocellular carcinoma supplied by gonadal artery

    International Nuclear Information System (INIS)

    Wu Hongping; Wang Junjie; Lu Yang; You Kaizhi

    2010-01-01

    Objective: To evaluate radiology and embolization for hepatocellular carcinoma supplied by gonadal artery. Methods: The medical records of 3 patients with hepatocellular carcinoma supplied by gonadal artery from August 2002 to September 2008 were reviewed. The demography, gonadal artery location, modus operandi, imaging features of liver cancer and prognosis were retrospectively analyzed. Results: Anatomic variation of gonadal artery occurred with the gonadal artery arising from the upper abdominal aorta in 1 patient and from the middle suprarenal artery in 2 patients. The blood supply of the hepatocellular carcinoma derived from the gonadal artery in all 3 patients. No complications occurred in the 6-month follow-up after embolization. Conclusion: Hepatocellular carcinoma may be supplied by gonadal artery with anomalous origin. This anatomic variant can be readily demonstrated by imaging to guide embolization. (authors)

  8. Dual energy CT of peripheral arteries: Effect of automatic bone and plaque removal on image quality and grading of stenoses

    International Nuclear Information System (INIS)

    Meyer, B.C.; Werncke, T.; Hopfenmueller, W.; Raatschen, H.J.; Wolf, K.-J.; Albrecht, T.

    2008-01-01

    Purpose: To evaluate the effect of automatic bone and plaque removal on image quality and grading of steno-occlusive lesions in patients undergoing dual energy CT angiography (CTA) of lower extremity. Materials and methods: Dual energy (DE) runoff CTA was performed in 50 patients using the following parameters: collimation 2 x 32 x 0.6; tube potentials, 80 kV and 140 kV; reconstructed slice thickness 1 mm. 100 mL iomeprol 400 and 50 mL saline were injected at 4 mL/s. Separate datasets were calculated for each of the two tubes and used to generate automatically bone-subtracted images (ABS) as well as bone and plaque subtracted images (ABPS). Residual bone in the ABS dataset was removed manually (=ABS-B dataset). In addition, a weighted average dataset from both dual energy acquisitions resembling a routine 120 kV CT acquisition was used for standard manual bone subtraction (MBS). Operator time for bone removal was measured. Effectiveness of bone subtraction and presence of vessel erosions was assessed by two readers in consensus. Stenosis grading in plaque subtracted and unsubtracted images was assessed and correlated. Results: Residual bone fragments (ribs: 46%, patella: 25%, spine: 4%, pelvis: 2%, tibia 2% of patients) were only observed with ABS. The time needed to manually remove these residual bones was 2.1 ± 1.1 min and was significantly lower than the duration of manual bone removal (6.8 ± 2.0 min, p < 0.0001, paired t-test). A total of 1159 arteries were analyzed. Compromising vessel erosions were observed less frequently in the ABS-B dataset (10.6%) than in the MBS dataset (15.2%, p < 0.001, wilcoxon's signed rank test). A total of 817 steno-occlusive lesions were assessed. While the agreement of grading of steno-occlusive lesions was good at the levels of the aorta and the pelvic arteries (κ = 0.70 in both, Cohen's kappa statistics), it was moderate at the level of the thigh arteries (κ = 0.57) and poor at the level of the calf (κ = 0.16). Conclusion

  9. 3D Image Fusion to Localise Intercostal Arteries During TEVAR

    Directory of Open Access Journals (Sweden)

    G. Koutouzi

    Full Text Available Purpose: Preservation of intercostal arteries during thoracic aortic procedures reduces the risk of post-operative paraparesis. The origins of the intercostal arteries are visible on pre-operative computed tomography angiography (CTA, but rarely on intra-operative angiography. The purpose of this report is to suggest an image fusion technique for intra-operative localisation of the intercostal arteries during thoracic endovascular repair (TEVAR. Technique: The ostia of the intercostal arteries are identified and manually marked with rings on the pre-operative CTA. The optimal distal landing site in the descending aorta is determined and marked, allowing enough length for an adequate seal and attachment without covering more intercostal arteries than necessary. After 3D/3D fusion of the pre-operative CTA with an intra-operative cone-beam CT (CBCT, the markings are overlaid on the live fluoroscopy screen for guidance. The accuracy of the overlay is confirmed with digital subtraction angiography (DSA and the overlay is adjusted when needed. Stent graft deployment is guided by the markings. The initial experience of this technique in seven patients is presented. Results: 3D image fusion was feasible in all cases. Follow-up CTA after 1 month revealed that all intercostal arteries planned for preservation, were patent. None of the patients developed signs of spinal cord ischaemia. Conclusion: 3D image fusion can be used to localise the intercostal arteries during TEVAR. This may preserve some intercostal arteries and reduce the risk of post-operative spinal cord ischaemia. Keywords: TEVAR, Intercostal artery, Spinal cord ischaemia, 3D image fusion, Image guidance, Cone-beam CT

  10. Effective imaging of carotid artery dissection

    International Nuclear Information System (INIS)

    Obradovis, G.

    1997-01-01

    Angiography has been the gold standard in the diagnosis of arterial dissection for many years. With recent advances in techniques, particularly in MRI it may be worthy to re-evaluate the imaging methods available in obtaining the most information to maxims the patients' level of management. Assessing the imaging methods used in four patients with clinically suspected carotid artery dissection may reveal the most appropriate clinical pathway in managing these types of patients. In today's economic environment, we are striving for the most cost-effective imaging methods combined with the least invasive and safest. We must also review the cost benefit analysis of CT, angiography (DSA), Doppler Ultrasound and MRI/MRA. It is not within the scope of this paper to argue the merits of each imaging method, but purely to present some of the benefits in using non-invasive techniques if the clinical indications warrant them and they are available. (author)

  11. Interesting images: Multiple coronary artery aneurysms.

    Science.gov (United States)

    Howard, Jonathon M; Viswanath, Omar; Armas, Alfredo; Santana, Orlando; Rosen, Gerald P

    2017-01-01

    We present the case of a 65-year-old male who presented with stable angina and dyspnea on exertion. His initial workup yielded a positive treadmill stress test for reversible apical ischemia, and transthoracic echocardiogram demonstrated impaired systolic function. Cardiac catheterization was then performed, revealing severe atherosclerotic disease including multiple coronary artery aneurysms. As a result, the patient was advised to and subsequently underwent a coronary artery bypass graft. This case highlights the presence of multiple coronary artery aneurysms and the ability to appreciate these pathologic findings on multiple imaging modalities, including coronary angiogram, transesophageal echocardiography, and direct visualization through the surgical field.

  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. Correlative magnetic resonance imaging in the evaluation of aortic and pulmonary artery abnormalities

    Energy Technology Data Exchange (ETDEWEB)

    Risius, B.; O' Donnell, J.K.; Geisinger, M.A.; Zelch, M.G.; George, C.R.; Graor, R.A.; Moodie, D.S.

    1985-05-01

    Magnetic resonance imaging (MRI) yields excellent quality images of the cardiovascular system utilizing the inherent natural contrast between flowing blood and the surrounding anatomic structures. To evaluate the clinical usefulness of MRI in the noninvasive diagnosis of large vessel disorders, the authors have performed MRI on 40 pts with either aortic or pulmonary artery abnormalities (18 thoracic or abdominal aortic aneurysms, 8 aorto-occlusive disease, 6 dissecting aneurysms, 4 Marfan's syndrome, 2 pulmonary artery aneurysms 1 pulmonary artery occlusion, 1 aortic coarctation). Images were obtained in the transverse, coronal and sagital body planes utilizing a 0.6T superconductive magnet. Cardiac and/or respiratory gating was employed in most cases. Correlation was made for all studies with conventional or digital subtraction angiography, computed tomography, and/or ultrasound. The diagnostic information obtained by MRI equaled or exceeded that obtained by other imaging techniques except for the few cases where cardiac arrhythmias precluded adequate gated acquisition. All aneurysms and their relationships to adjacent structures were readily demonstrated as were the presence or absence of mural thrombi and dissecting intimal flaps. Angiographically demonstrated atherosclerotic plaques and luminal stenoses were seen by MRI in all patients without arrhythmias. The authors concluded that MRI is a powerful noninvasive diagnostic aid in the delineation of large vessel disorders, especially where knowledge of anatomic interrelationships can guide surgical or other interventional planning.

  14. MR angiography of the pelvic and lower leg arteries: starting with time-resolved imaging of the lower leg is recommended

    International Nuclear Information System (INIS)

    Schmitt, R.; Christopoulos, G.; Brunner, S.; Froehner, S.; Dobritz, M.; Fellner, F.

    2001-01-01

    58 patients suffering from peripheral arterial vascular disease were examined using contrast-enhanced MR angiography with the intention of optimizing the visualization of lower leg arteries. Different from the customary acquisition order, were first the arteries of the lower legs depicted with three time-resolved phases. Afterwards, the iliacal and femoral vessels were imaged by applying the floating-table technique in two steps. In all cases, the lower leg arteries were depicted without overlying veins. By injecting the contrast agent in two phases, imaging quality of the iliofemoral arteries was not significantly reduced. - In conclusion, we would recommend the hybrid technique of peripheral contrast-enhanced MRA with primarily starting the acquisition of the lower legs in cases of foot infections or ulcerations where the transit time is reduced bi- or unilaterally. (orig.) [de

  15. Protocol and quality assurance for carotid imaging in 100,000 participants of UK Biobank: development and assessment.

    Science.gov (United States)

    Coffey, Sean; Lewandowski, Adam J; Garratt, Steve; Meijer, Rudy; Lynum, Steven; Bedi, Ram; Paterson, James; Yaqub, Mohammad; Noble, J Alison; Neubauer, Stefan; Petersen, Steffen E; Allen, Naomi; Sudlow, Cathie; Collins, Rory; Matthews, Paul M; Leeson, Paul

    2017-11-01

    Background Ultrasound imaging is able to quantify carotid arterial wall structure for the assessment of cerebral and cardiovascular disease risks. We describe a protocol and quality assurance process to enable carotid imaging at large scale that has been developed for the UK Biobank Imaging Enhancement Study of 100,000 individuals. Design An imaging protocol was developed to allow measurement of carotid intima-media thickness from the far wall of both common carotid arteries. Six quality assurance criteria were defined and a web-based interface (Intelligent Ultrasound) was developed to facilitate rapid assessment of images against each criterion. Results and conclusions Excellent inter and intra-observer agreements were obtained for image quality evaluations on a test dataset from 100 individuals. The image quality criteria then were applied in the UK Biobank Imaging Enhancement Study. Data from 2560 participants were evaluated. Feedback of results to the imaging team led to improvement in quality assurance, with quality assurance failures falling from 16.2% in the first two-month period examined to 6.4% in the last. Eighty per cent had all carotid intima-media thickness images graded as of acceptable quality, with at least one image acceptable for 98% of participants. Carotid intima-media thickness measures showed expected associations with increasing age and gender. Carotid imaging can be performed consistently, with semi-automated quality assurance of all scans, in a limited timeframe within a large scale multimodality imaging assessment. Routine feedback of quality control metrics to operators can improve the quality of the data collection.

  16. Additional value of B-flow imaging in arterial wall calcifications.

    Science.gov (United States)

    D'Abate, Fabrizio; de Bruin, Jorg L

    2018-02-01

    The accuracy of color Doppler ultrasonography (CDU) is hampered by the presence of arterial wall calcifications. B-flow imaging may overcome these limitations. We present a case of a severely calcified stenosis of the right common femoral artery (CFA) diagnosed with the aid of B-flow imaging. Both the CT angiography scan and CDU were limited by the presence of diffuse dense arterial calcifications. B-flow imaging showed a >75% stenosis of the CFA. B-flow imaging appears to improve the accuracy of CDU in the presence of calcified stenosis of the CFA. It is of clinical relevance to improve the duplex sonographic accuracy, ideally reducing the need for other imaging modalities prior to surgery. © 2017 Wiley Periodicals, Inc. J Clin Ultrasound 46:136-139, 2018. © 2017 Wiley Periodicals, Inc.

  17. Impact of a New Adaptive Statistical Iterative Reconstruction (ASIR)-V Algorithm on Image Quality in Coronary Computed Tomography Angiography.

    Science.gov (United States)

    Pontone, Gianluca; Muscogiuri, Giuseppe; Andreini, Daniele; Guaricci, Andrea I; Guglielmo, Marco; Baggiano, Andrea; Fazzari, Fabio; Mushtaq, Saima; Conte, Edoardo; Annoni, Andrea; Formenti, Alberto; Mancini, Elisabetta; Verdecchia, Massimo; Campari, Alessandro; Martini, Chiara; Gatti, Marco; Fusini, Laura; Bonfanti, Lorenzo; Consiglio, Elisa; Rabbat, Mark G; Bartorelli, Antonio L; Pepi, Mauro

    2018-03-27

    A new postprocessing algorithm named adaptive statistical iterative reconstruction (ASIR)-V has been recently introduced. The aim of this article was to analyze the impact of ASIR-V algorithm on signal, noise, and image quality of coronary computed tomography angiography. Fifty consecutive patients underwent clinically indicated coronary computed tomography angiography (Revolution CT; GE Healthcare, Milwaukee, WI). Images were reconstructed using filtered back projection and ASIR-V 0%, and a combination of filtered back projection and ASIR-V 20%-80% and ASIR-V 100%. Image noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were calculated for left main coronary artery (LM), left anterior descending artery (LAD), left circumflex artery (LCX), and right coronary artery (RCA) and were compared between the different postprocessing algorithms used. Similarly a four-point Likert image quality score of coronary segments was graded for each dataset and compared. A cutoff value of P ASIR-V 0%, ASIR-V 100% demonstrated a significant reduction of image noise in all coronaries (P ASIR-V 0%, SNR was significantly higher with ASIR-V 60% in LM (P ASIR-V 0%, CNR for ASIR-V ≥60% was significantly improved in LM (P ASIR-V ≥80%. ASIR-V 60% had significantly better Likert image quality scores compared to ASIR-V 0% in segment-, vessel-, and patient-based analyses (P ASIR-V 60% provides the optimal balance between image noise, SNR, CNR, and image quality. Copyright © 2018 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

  18. Dual-source CT coronary imaging in heart transplant recipients: image quality and optimal reconstruction interval

    International Nuclear Information System (INIS)

    Bastarrika, Gorka; Arraiza, Maria; Pueyo, Jesus C.; Cecco, Carlo N. de; Ubilla, Matias; Mastrobuoni, Stefano; Rabago, Gregorio

    2008-01-01

    The image quality and optimal reconstruction interval for coronary arteries in heart transplant recipients undergoing non-invasive dual-source computed tomography (DSCT) coronary angiography was evaluated. Twenty consecutive heart transplant recipients who underwent DSCT coronary angiography were included (19 male, one female; mean age 63.1±10.7 years). Data sets were reconstructed in 5% steps from 30% to 80% of the R-R interval. Two blinded independent observers assessed the image quality of each coronary segments using a five-point scale (from 0 = not evaluative to 4=excellent quality). A total of 289 coronary segments in 20 heart transplant recipients were evaluated. Mean heart rate during the scan was 89.1±10.4 bpm. At the best reconstruction interval, diagnostic image quality (score ≥2) was obtained in 93.4% of the coronary segments (270/289) with a mean image quality score of 3.04± 0.63. Systolic reconstruction intervals provided better image quality scores than diastolic reconstruction intervals (overall mean quality scores obtained with the systolic and diastolic reconstructions 3.03±1.06 and 2.73±1.11, respectively; P<0.001). Different systolic reconstruction intervals (35%, 40%, 45% of RR interval) did not yield to significant differences in image quality scores for the coronary segments (P=0.74). Reconstructions obtained at the systolic phase of the cardiac cycle allowed excellent diagnostic image quality coronary angiograms in heart transplant recipients undergoing DSCT coronary angiography. (orig.)

  19. Reducing radiation dose without compromising image quality in preoperative perforator flap imaging with CTA using ASIR technology.

    Science.gov (United States)

    Niumsawatt, Vachara; Debrotwir, Andrew N; Rozen, Warren Matthew

    2014-01-01

    Computed tomographic angiography (CTA) has become a mainstay in preoperative perforator flap planning in the modern era of reconstructive surgery. However, the increased use of CTA does raise the concern of radiation exposure to patients. Several techniques have been developed to decrease radiation dosage without compromising image quality, with varying results. The most recent advance is in the improvement of image reconstruction using an adaptive statistical iterative reconstruction (ASIR) algorithm. We sought to evaluate the image quality of ASIR in preoperative deep inferior epigastric perforator (DIEP) flap surgery, through a direct comparison with conventional filtered back projection (FBP) images. A prospective review of 60 consecutive ASIR and 60 consecutive FBP CTA images using similar protocol (except for radiation dosage) was undertaken, analyzed by 2 independent reviewers. In both groups, we were able to accurately identify axial arteries and their perforators. Subjective analysis of image quality demonstrated no statistically significant difference between techniques. ASIR can thus be used for preoperative imaging with similar image quality to FBP, but with a 60% reduction in radiation delivery to patients.

  20. Imaging experimental coronary artery thrombosis with indium-111 platelets

    International Nuclear Information System (INIS)

    Riba, A.L.; Thakur, M.L.; Gottschalk, A.; Zaret, B.L.

    1979-01-01

    The ability of cardiac scintigraphy with indium-111 ( 111 In)-labeled platelets to detect coronary artery thrombosis (CAT) was assessed in a canine model. Cardiac imaging and tissue distribution studies were performed shortly after administering 111 In-labeled platelets to 12 dogs (group 1) with acute CAT. Four dogs (group 2) with acute CAT were studied 2 and 22 hours after administering 111 In platelets. In addition, four dogs (group 3) with 24-hour-old CAT were similarly evaluated. In all group 1 animals, in vivo imaging 1 to 2 hours after 111 In platelet administration revealed intense uptake in the region of thrombus-containing left anterior descending arteries that was readily discernible from background blood pool activity. Sequential imaging of the four group 2 animals over a 22-hour period revealed no change in the scintigraphic pattern of the thrombosed arteries. In contrast, 111 In platelet imaging in the four group 3 animals with 24-hour-old CAT failed to reveal enhanced activity within the region of the thrombus-containing coronary artery. In the 12 group 1 animals, the CAT accumulated 69 +- 10 (mean +- SEM) times greater activity than present in blood and 651 +- 135 times greater activity than normal left ventricular myocardium. There was 24 +- 7 times greater 111 In activity in the damaged left anterior descending arteries compared with normal circumflex arteries. Similar uptake ratios were seen in group 2 animals. The 24-hour old thrombi from group 3 animals showed no enhanced 111 In uptake. This study demonstrates that experimental acute CAT can be detected readily with 111 In platelet cardiac scintigraphy

  1. Detection of renal arteries with fast spin-echo magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Tello, R.; Mitchell, P.J.; Witte, D.J.; Thomson, K.R. [University of Melbourne, Parkville, VIC (Australia). Department of Radiology

    1998-08-01

    With the increasing use of non-invasive imaging with MR and volumetric CT to evaluate renal arteries, the ability to accurately detect the number and state of native renal arteries becomes critical if conventional angiography is to be supplanted in these settings. The present study evaluated the utility of a fast spin-echo (FSE) T2-weighted sequence to detect the number and course of renal arteries and their ostia compared to conventional angiography. Ten patients underwent conventional catheter angiography either for renal artery stenosis evaluation or as potential renal donors. Each patient then had an MR study of the renal arteries and kidneys with FSE MR (TR = 4000 ms, TE = 102 ms, eight- echo train length, 5-mm-thick interleaved 128 phase encodes, superior and inferior saturation pulses, number of excitations (NEX) = 4, on a 1.5-T superconducting magnet). Images were reviewed by two `blinded` radiologists and renal arteries were counted and their ostia were evaluated. Results were compared with angiography and inter- and intra-observer statistics were calculated. All 10 patients underwent MR successfully, nine for renal artery stenosis (RAS) evaluation and one was a renal donor. A total of 24 renal arteries were imaged in 19 kidneys. Fast spin-echo MR is 95% accurate (95%CI: 88-100%) in detection of renal arteries, with no statistical difference between FSE MR and catheter angiography (McNemar P = 0.0). Inter- and intra-observer statistics demonstrate good-to-excellent agreement in renal artery detection (kappa: 0.63-0.90). In one case of RAS evaluation an incidental adrenal mass was detected as the aetiology of the patient`s hypertension. Fast spin-echo MR can be a useful adjunct as part of the imaging for renal arteries with MRI. Copyright (1998) Blackwell Science Pty Ltd 16 refs., 1 fig.

  2. Detection of renal arteries with fast spin-echo magnetic resonance imaging

    International Nuclear Information System (INIS)

    Tello, R.; Mitchell, P.J.; Witte, D.J.; Thomson, K.R.

    1998-01-01

    With the increasing use of non-invasive imaging with MR and volumetric CT to evaluate renal arteries, the ability to accurately detect the number and state of native renal arteries becomes critical if conventional angiography is to be supplanted in these settings. The present study evaluated the utility of a fast spin-echo (FSE) T2-weighted sequence to detect the number and course of renal arteries and their ostia compared to conventional angiography. Ten patients underwent conventional catheter angiography either for renal artery stenosis evaluation or as potential renal donors. Each patient then had an MR study of the renal arteries and kidneys with FSE MR (TR = 4000 ms, TE = 102 ms, eight- echo train length, 5-mm-thick interleaved 128 phase encodes, superior and inferior saturation pulses, number of excitations (NEX) = 4, on a 1.5-T superconducting magnet. Images were reviewed by two 'blinded' radiologists and renal arteries were counted and their ostia were evaluated. Results were compared with angiography and inter- and intra-observer statistics were calculated. All 10 patients underwent MR successfully, nine for renal artery stenosis (RAS) evaluation and one was a renal donor. A total of 24 renal arteries were imaged in 19 kidneys. Fast spin-echo MR is 95% accurate (95%CI: 88-100%) in detection of renal arteries, with no statistical difference between FSE MR and catheter angiography (McNemar P = 0.0). Inter- and intra-observer statistics demonstrate good-to-excellent agreement in renal artery detection (kappa: 0.63-0.90). In one case of RAS evaluation an incidental adrenal mass was detected as the aetiology of the patient's hypertension. Fast spin-echo MR can be a useful adjunct as part of the imaging for renal arteries with MRI. Copyright (1998) Blackwell Science Pty Ltd

  3. Adaptation of the Maracas algorithm for carotid artery segmentation and stenosis quantification on CT images

    International Nuclear Information System (INIS)

    Maria A Zuluaga; Maciej Orkisz; Edgar J F Delgado; Vincent Dore; Alfredo Morales Pinzon; Marcela Hernandez Hoyos

    2010-01-01

    This paper describes the adaptations of Maracas algorithm to the segmentation and quantification of vascular structures in CTA images of the carotid artery. The maracas algorithm, which is based on an elastic model and on a multi-scale Eigen-analysis of the inertia matrix, was originally designed to segment a single artery in MRA images. The modifications are primarily aimed at addressing the specificities of CT images and the bifurcations. The algorithms implemented in this new version are classified into two levels. 1. The low-level processing (filtering of noise and directional artifacts, enhancement and pre-segmentation) to improve the quality of the image and to pre-segment it. These techniques are based on a priori information about noise, artifacts and typical gray levels ranges of lumen, background and calcifications. 2. The high-level processing to extract the centerline of the artery, to segment the lumen and to quantify the stenosis. At this level, we apply a priori knowledge of shape and anatomy of vascular structures. The method was evaluated on 31 datasets from the carotid lumen segmentation and stenosis grading grand challenge 2009. The segmentation results obtained an average of 80:4% dice similarity score, compared to reference segmentation, and the mean stenosis quantification error was 14.4%.

  4. Multidetector CT of the coronary imaging: assessment of image quality and accuracy in detecting stenoses

    International Nuclear Information System (INIS)

    Huang Meiping; Liu Qishun; Liu Hui; Liang Changhong; Zhang Shaobin

    2006-01-01

    Objective: To evaluate the image quality of 64-multi detector computed tomography (MDCT) and the clinical accuracy in detecting coronary artery lesions. Methods: One hundred and five patients were studied by MDCT. The results were compared with invasive coronary angiography (ICA). Patients were excluded for atrial fibrillation, but not for high heart rate, coronary calcification, or obesity. MDCT was analyzed with regard to image quality and presence of coronary artery lesions. Results: The data evaluation of the image quality was based on a total of 1365 segments (13 coronary segments for each patient), of which 1144 segments were considered to have diagnostic image quality, but 221 segments (16.2%) could not be sufficiently evaluated because of severe calcifications (153 segments) and motion artifacts (68 segments). The median calcium score [Agatston score equivalent (ASE)] was 154 (range 0--1983). 87 of the 105 patients had an ASE of less than 1,000 [median 105 (range 0-994)], and 18 patients had an ASE greater than 1000 [median 1477 (range 1115-1983)]. For detecting lesions with 50% or greater narrowing (without any exclusion criteria), the overall sensitivity, specificity, positive predictive value, and negative predictive value were 85.7%, 97.9%, 93.0%, and 95.5%, respectively. When limiting the number of patients to those with a calcium score of less than 1000 ASE, the threshold- corrected sensitivity for lesions with 50% or greater narrowing was 96.0%; specificity, 98.9%; positive predictive value, 95.3%; and negative predictive value, 99.0%. Conclusion: Our results indicate high quantitative and qualitative diagnostic accuracy of 64-slice MSCT in comparison to QCA in a broad spectrum of patients. (authors)

  5. Optimal temporal windows and dose-reducing strategy for coronary artery bypass graft imaging with 256-slice CT

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Kun-Mu [Department of Radiology, Shin Kong Wu Ho-Su Memorial Hospital, 95 Wen Chang Road, Shih Lin District, Taipei 111, Taiwan. (China); Lee, Yi-Wei [Department of Radiology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan (China); Department of Biomedical Imaging and Radiological Sciences, National Yang Ming University, Taipei, Taiwan (China); Guan, Yu-Xiang [Department of Biomedical Imaging and Radiological Sciences, National Yang Ming University, Taipei, Taiwan (China); Chen, Liang-Kuang [Department of Radiology, Shin Kong Wu Ho-Su Memorial Hospital, 95 Wen Chang Road, Shih Lin District, Taipei 111, Taiwan. (China); School of Medicine, Fu Jen Catholic University, Taipei, Taiwan (China); Law, Wei-Yip, E-mail: m002325@ms.skh.org.tw [Department of Radiology, Shin Kong Wu Ho-Su Memorial Hospital, 95 Wen Chang Road, Shih Lin District, Taipei 111, Taiwan. (China); Su, Chen-Tau, E-mail: m005531@ms.skh.org.tw [Department of Radiology, Shin Kong Wu Ho-Su Memorial Hospital, 95 Wen Chang Road, Shih Lin District, Taipei 111, Taiwan. (China); School of Medicine, Fu Jen Catholic University, Taipei, Taiwan (China)

    2013-12-11

    Objective: To determine the optimal image reconstruction windows in the assessment of coronary artery bypass grafts (CABGs) with 256-slice computed tomography (CT), and to assess their associated optimal pulsing windows for electrocardiogram-triggered tube current modulation (ETCM). Methods: We recruited 18 patients (three female; mean age 68.9 years) having mean heart rate (HR) of 66.3 beats per minute (bpm) and a heart rate variability of 1.3 bpm for this study. A total of 36 CABGs with 168 segments were evaluated, including 12 internal mammary artery (33.3%) and 24 saphenous vein grafts (66.7%). We reconstructed 20 data sets in 5%-step through 0–95% of the R–R interval. The image quality of CABGs was assessed by a 5-point scale (1=excellent to 5=non-diagnostic) for each segment (proximal anastomosis, proximal, middle, distal course of graft body, and distal anastomosis). Two reviewers discriminated optimal reconstruction intervals for each CABG segment in each temporal window. Optimal windows for ETCM were also evaluated. Results: The determined optimal systolic and diastolic reconstruction intervals could be divided into 2 groups with threshold HR=68. The determined best reconstruction intervals for low heart rate (HR<68) and high heart rate (HR>68) were 76.0±2.5% and 45.0±0% respectively. Average image quality scores were 1.7±0.6 with good inter-observer agreement (Kappa=0.79). Image quality was significantly better for saphenous vein grafts versus arterial grafts (P<0.001). The recommended windows of ETCM for low HR, high HR and all HR groups were 40–50%, 71–81% and 40–96% of R-R interval, respectively. The corresponding dose savings were about 60.8%, 58.7% and 22.7% in that order. Conclusions: We determined optimal reconstruction intervals and ETCM windows representing a good compromise between radiation and image quality for following bypass surgery using a 256-slice CT.

  6. 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

  7. MR imaging and MR angiography in popliteal artery entrapment syndrome

    International Nuclear Information System (INIS)

    Atilla, S.; Akpek, S.; Yuecel, C.; Tali, E.T.; Isik, S.; Ilgit, E.T.

    1998-01-01

    Popliteal artery entrapment (PAE) syndrome is an uncommon congenital anomaly seen in young adults causing ischemic symptoms in the lower extremities. It is the result of various types of anomalous relationships between the popliteal artery and the neighboring muscular structures. The purpose of this study was to define the role of MR imaging combined with MR angiography in the diagnosis of PAE cases. Four cases with segmental occlusion and medial displacement of popliteal artery in digital subtraction angiography (DSA) examinations were diagnosed as PAE syndrome by MR imaging and MR angiography. The DSA and MRA images are compared. All of the cases showed various degrees of abnormal intercondylar insertion of the medial head of the gastrocnemius muscle. The MR images showed detailed anatomy of the region revealing the cause of the arterial entrapment. Subclassification of the cases were done and fat tissue filling the normal localization of the muscle was evaluated. The DSA and MRA images demonstrated the length and localization of the occluded segment and collateral vascular developments equally. It is concluded that angiographic evaluation alone in PAE syndrome might result in overlooking the underlying cause of the arterial occlusion, which in turn leads to unsuccessful therapy procedures such as balloon angioplasty. Magnetic resonance imaging combined with MR angiography demonstrates both the vascular anatomy and the variations in the muscular structures in the popliteal fossa successfully, and this combination seems to be the most effective way of evaluating young adults with ischemic symptoms suggesting PAE syndrome. (orig.)

  8. Evaluation of virtual monoenergetic imaging algorithms for dual-energy carotid and intracerebral CT angiography: Effects on image quality, artefacts and diagnostic performance for the detection of stenosis.

    Science.gov (United States)

    Leithner, Doris; Mahmoudi, Scherwin; Wichmann, Julian L; Martin, Simon S; Lenga, Lukas; Albrecht, Moritz H; Booz, Christian; Arendt, Christophe T; Beeres, Martin; D'Angelo, Tommaso; Bodelle, Boris; Vogl, Thomas J; Scholtz, Jan-Erik

    2018-02-01

    To investigate the impact of traditional (VMI) and noise-optimized virtual monoenergetic imaging (VMI+) algorithms on quantitative and qualitative image quality, and the assessment of stenosis in carotid and intracranial dual-energy CTA (DE-CTA). DE-CTA studies of 40 patients performed on a third-generation 192-slice dual-source CT scanner were included in this retrospective study. 120-kVp image-equivalent linearly-blended, VMI and VMI+ series were reconstructed. Quantitative analysis included evaluation of contrast-to-noise ratios (CNR) of the aorta, common carotid artery, internal carotid artery, middle cerebral artery, and basilar artery. VMI and VMI+ with highest CNR, and linearly-blended series were rated qualitatively. Three radiologists assessed artefacts and suitability for evaluation at shoulder height, carotid bifurcation, siphon, and intracranial using 5-point Likert scales. Detection and grading of stenosis were performed at carotid bifurcation and siphon. Highest CNR values were observed for 40-keV VMI+ compared to 65-keV VMI and linearly-blended images (P evaluation at shoulder and bifurcation height. Suitability was significantly higher in VMI+ and VMI compared to linearly-blended images for intracranial and ICA assessment (P performance. 40-keV VMI+ showed improved quantitative image quality compared to 65-keV VMI and linearly-blended series in supraaortic DE-CTA. VMI and VMI+ provided increased suitability for carotid and intracranial artery evaluation with excellent assessment of stenosis, but did not translate into increased diagnostic performance. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Imaging popliteal artery disease in young adults with claudication: self-assessment module.

    Science.gov (United States)

    Chew, Felix S; Bui-Mansfield, Liem T

    2007-09-01

    The educational objectives of this self-assessment module on imaging popliteal artery disease in young adults with intermittent claudication are for the participant to exercise, self-assess, and improve his or her knowledge of the imaging and clinical features of popliteal artery entrapment syndrome, cystic adventitial disease,and masses associated with popliteal artery obstruction.

  10. Evaluation of Image Quality in Low Tube-Voltage Chest CT Scan

    International Nuclear Information System (INIS)

    Kim, Hyun Ju; Cho, Jae Hwan; Park, Cheol Soo

    2010-01-01

    The patients who visited this department for pulmonary disease and need CT scans for Follow-up to observe change of CT value, evaluation of image quality and decrease of radiation dose as change of kVp. Subjects were the patients of 20 persons visited this department for pulmonary disease and Somatom Sensation 16(Semens, Enlarge, Germany) was used. Measurement of CT value as change of kVp was done by setting up ROI diameter of 1cm at the height of thyroid, aortic arch, right pulmonary artery in arterial phase image using 100 kVp, measuring 3 times, and recorded the average. CT value of phantom was measured by scanning phantoms which means contrast media diluted by normal saline by various ratio with tube voltage of 80 kVp, 100 kVp, 120 kVp, 140 kVp and recorded the average of 3 CT values of center of phantom image. In analysing radiation dose, CTDIVOL values of the latest arterial phase image of 120 kVp and as this research set that of 100 kVp were analyzed comparatively. 2 observers graded quality of chest images by 5 degrees (Unacceptable, Suboptimal, Adequate, Good, Excellent). CT value of chest image increased at 100 kVp by 14.06%∼27.26% in each ROI than 120 kVp. CT value of phantom increased as tube voltage lowered at various concentration of contrast media. CTDIVOL decreased at 100 kVp(5.00 mGy) by 36% than 120 kVp(7.80 mGy) in radiation dose analysis. here were 0 Unacceptable, 1 Suboptimal, 3 Adequate, 10 Good, 6 Excellent in totally 20 persons. Chest CT scanning with low kilo-voltage for patients who need CT scan repeatedly can bring images valuable for diagnose, and decrease radiation dose against patients

  11. Imaging of Dual Ophthalmic Arteries: Identification of the Central Retinal Artery

    Directory of Open Access Journals (Sweden)

    Louise Louw

    2014-01-01

    Full Text Available Identification of the origin of the central retinal artery (CRA is imperative in tailoring angiographic studies to resolve a given clinical problem. A case with dual ophthalmic arteries (OAs, characterized by different origins and distinct branching patterns, is documented for training purposes. Pre-clinical diagnosis of a 9-year-old child who presented with a sharp wire in the left-side eyeball was primarily corneal laceration. For imaging, a selected six-vessel angiographic study with the transfemoral approach was performed. Embolization was not required and the wire could be successfully removed. Right-side OA anatomy was normal, while left-side dual OAs with external carotid artery (ECA and internal carotid artery (ICA origins were seen. The case presented with a left-side meningo-ophthalmic artery (M-OA anomaly via the ECA, marked by a middle meningeal artery (MMA (origin: Maxillary artery; course: Through foramen spinosum with normal branches (i.e. anterior and posterior branches, and an OA variant (course: Through superior orbital fissure with a distinct orbital branching pattern. A smaller OA (origin: ICA; course: Through optic foramen with a distinct ocular branching pattern presented with the central retinal artery (CRA. The presence of the dual OAs and the M-OA anomaly can be explained by disturbed evolutionary changes of the primitive OA and stapedial artery during development. The surgical interventionist must be aware of dual OAs and M-OA anomalies with branching pattern variations on retinal supply, because of dangerous extracranial-intracranial anastomotic connections. It is of clinical significance that the origin of the CRA from the ICA or ECA must be determined to avoid complications to the vision.

  12. Imaging arterial cells, atherosclerosis, and restenosis by multimodal nonlinear optical microscopy

    Science.gov (United States)

    Wang, Han-Wei; Simianu, Vlad; Locker, Matthew J.; Sturek, Michael; Cheng, Ji-Xin

    2008-02-01

    By integrating sum-frequency generation (SFG), and two-photon excitation fluorescence (TPEF) on a coherent anti-Stokes Raman scattering (CARS) microscope platform, multimodal nonlinear optical (NLO) imaging of arteries and atherosclerotic lesions was demonstrated. CARS signals arising from CH II-rich membranes allowed visualization of endothelial cells and smooth muscle cells in a carotid artery. Additionally, CARS microscopy allowed vibrational imaging of elastin and collagen fibrils which are rich in CH II bonds in their cross-linking residues. The extracellular matrix organization was further confirmed by TPEF signals arising from elastin's autofluorescence and SFG signals arising from collagen fibrils' non-centrosymmetric structure. The system is capable of identifying different atherosclerotic lesion stages with sub-cellular resolution. The stages of atherosclerosis, such as macrophage infiltration, lipid-laden foam cell accumulation, extracellular lipid distribution, fibrous tissue deposition, plaque establishment, and formation of other complicated lesions could be viewed by our multimodal CARS microscope. Collagen percentages in the region adjacent to coronary artery stents were resolved. High correlation between NLO and histology imaging evidenced the validity of the NLO imaging. The capability of imaging significant components of an arterial wall and distinctive stages of atherosclerosis in a label-free manner suggests the potential application of multimodal nonlinear optical microscopy to monitor the onset and progression of arterial diseases.

  13. Joint segmentation of lumen and outer wall from femoral artery MR images: Towards 3D imaging measurements of peripheral arterial disease.

    Science.gov (United States)

    Ukwatta, Eranga; Yuan, Jing; Qiu, Wu; Rajchl, Martin; Chiu, Bernard; Fenster, Aaron

    2015-12-01

    Three-dimensional (3D) measurements of peripheral arterial disease (PAD) plaque burden extracted from fast black-blood magnetic resonance (MR) images have shown to be more predictive of clinical outcomes than PAD stenosis measurements. To this end, accurate segmentation of the femoral artery lumen and outer wall is required for generating volumetric measurements of PAD plaque burden. Here, we propose a semi-automated algorithm to jointly segment the femoral artery lumen and outer wall surfaces from 3D black-blood MR images, which are reoriented and reconstructed along the medial axis of the femoral artery to obtain improved spatial coherence between slices of the long, thin femoral artery and to reduce computation time. The developed segmentation algorithm enforces two priors in a global optimization manner: the spatial consistency between the adjacent 2D slices and the anatomical region order between the femoral artery lumen and outer wall surfaces. The formulated combinatorial optimization problem for segmentation is solved globally and exactly by means of convex relaxation using a coupled continuous max-flow (CCMF) model, which is a dual formulation to the convex relaxed optimization problem. In addition, the CCMF model directly derives an efficient duality-based algorithm based on the modern multiplier augmented optimization scheme, which has been implemented on a GPU for fast computation. The computed segmentations from the developed algorithm were compared to manual delineations from experts using 20 black-blood MR images. The developed algorithm yielded both high accuracy (Dice similarity coefficients ≥ 87% for both the lumen and outer wall surfaces) and high reproducibility (intra-class correlation coefficient of 0.95 for generating vessel wall area), while outperforming the state-of-the-art method in terms of computational time by a factor of ≈ 20. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. 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)

  15. Assessment of arterially hyper-enhancing liver lesions using virtual monoenergetic images from spectral detector CT: phantom and patient experience.

    Science.gov (United States)

    Große Hokamp, N; Höink, A J; Doerner, J; Jordan, D W; Pahn, G; Persigehl, T; Maintz, D; Haneder, S

    2017-11-28

    To investigate a benefit from virtual monoenergetic reconstructions (VMIs) for assessment of arterially hyper-enhancing liver lesions in phantom and patients and to compare hybrid-iterative and spectral image reconstructions of conventional images (CI-IR and CI-SR). All imaging was performed on a SDCT (Philips Healthcare, Best, The Netherlands). Images of a non-anthropomorphic phantom with a lesion-mimicking insert (containing iodine in water solution) and arterial-phase images from contrast-enhanced patient examinations were evaluated. VMIs (40-200 keV, 10 keV increment), CI-IR, and CI-SR were reconstructed using different strengths of image denoising. ROIs were placed in lesions, liver/matrix, muscle; signal-to-noise, contrast-to-noise, and lesion-to-liver ratios (SNR, CNR, and LLR) were calculated. Qualitatively, 40, 70, and 110 keV and CI images were assessed by two radiologists on five-point Likert scales regarding overall image quality, lesion assessment, and noise. In phantoms, SNR was increased threefold by VMI 40keV compared with CI-IR/SR (5.8 ± 1.1 vs. 18.8 ± 2.2, p ≤ 0.001), while no difference was found between CI-IR and CI-SR (p = 1). Denoising was capable of noise reduction by 40%. In total, 20 patients exhibiting 51 liver lesions were assessed. Attenuation was the highest in VMI 40keV , while image noise was comparable to CI-IR resulting in a threefold increase of CNR/LLR (CI-IR 1.3 ± 0.8/4.4 ± 2.0, VMI 40keV : 3.8 ± 2.7/14.2 ± 7.5, p ≤ 0.001). Subjective lesion delineation was the best in VMI 40keV image (p ≤ 0.01), which also provided the lowest perceptible noise and the best overall image quality. VMIs improve assessment of arterially hyper-enhancing liver lesions since they increase lesion contrast while maintaining low image noise throughout the entire keV spectrum. These data suggest that to consider VMI screening after arterially hyper-enhancing liver lesions.

  16. High-definition computed tomography for coronary artery stents imaging: Initial evaluation of the optimal reconstruction algorithm.

    Science.gov (United States)

    Cui, Xiaoming; Li, Tao; Li, Xin; Zhou, Weihua

    2015-05-01

    The aim of this study was to evaluate the in vivo performance of four image reconstruction algorithms in a high-definition CT (HDCT) scanner with improved spatial resolution for the evaluation of coronary artery stents and intrastent lumina. Thirty-nine consecutive patients with a total of 71 implanted coronary stents underwent coronary CT angiography (CCTA) on a HDCT (Discovery CT 750 HD; GE Healthcare) with the high-resolution scanning mode. Four different reconstruction algorithms (HD-stand, HD-detail; HD-stand-plus; HD-detail-plus) were applied to reconstruct the stented coronary arteries. Image quality for stent characterization was assessed. Image noise and intrastent luminal diameter were measured. The relationship between the measurement of inner stent diameter (ISD) and the true stent diameter (TSD) and stent type were analysed. The stent-dedicated kernel (HD-detail) offered the highest percentage (53.5%) of good image quality for stent characterization and the highest ratio (68.0±8.4%) of visible stent lumen/true stent lumen for luminal diameter measurement at the expense of an increased overall image noise. The Pearson correlation coefficient between the ISD and TSD measurement and spearman correlation coefficient between the ISD measurement and stent type were 0.83 and 0.48, respectively. Compared with standard reconstruction algorithms, high-definition CT imaging technique with dedicated high-resolution reconstruction algorithm provides more accurate stent characterization and intrastent luminal diameter measurement. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  17. Imaging diagnosis of congenital heart disease with single coronary artery

    International Nuclear Information System (INIS)

    Zhu Ming; Li Yuhua; Zhong Yumin; Sun Aimin

    2003-01-01

    Objective: To report 56 cases of congenital heart disease with congenital single coronary artery and to evaluate the imaging diagnostic techniques. Methods: All 56 patients with congenital single coronary artery underwent angiocardiography. Contrast enhancement magnetic resonance angiography (CE MRA) was performed in 4 cases. 48 cases were confirmed by operation. Results: In these 56 cases, single left coronary artery was found in 44 cases and single right coronary artery was found in 12. Conclusion: Congenital heart disease with congenital single coronary artery is not rare and correct diagnosis is very important for surgery

  18. Visualization of coronary arteries in patients after childhood Kawasaki syndrome: value of multidetector CT and MR imaging in comparison to conventional coronary catheterization

    International Nuclear Information System (INIS)

    Arnold, Raoul; Ley, Sebastian; Ley-Zaporozhan, Julia; Kauczor, Hans-Ulrich; Eichhorn, Joachim; Ulmer, Herbert; Schenk, Jens-Peter

    2007-01-01

    After childhood Kawasaki syndrome (KS) the coronary arteries undergo a lifelong dynamic pathological change, and follow-up coronary artery imaging is essential. At present, conventional coronary catheterization (CCC) and angiography is still regarded as the gold standard. Less-invasive methods such as multidetector CT angiography (MDCT-A) and MRI have been used sporadically. To compare the diagnostic quality of MDCT-A and MRI with that of CCC for coronary imaging in a group of patients with coronary artery pathology after childhood KS. A total of 16 patients (aged 5-27 years) underwent CCC and 16-row MDCT-A and 14 patients MRI (1.5 T). There was 100% agreement between MDCT-A and CCC in the detection of coronary aneurysms and stenoses. MDCT-A was superior for the visualization of calcified lesions. MRI and CCC showed 93% agreement for the detection of aneurysms. Visualization of coronary artery stenoses was difficult using MRI - one stenosis was missed. MDCT-A has excellent correlation with CCC regarding all changes affecting the coronary arteries in the follow-up of childhood KS. In comparison to MDCT-A and CCC, MRI is less precise in the detection of stenotic lesions. Due to its high image quality and ease of performance MDCT-A should be the primary diagnostic modality in patients following childhood KS. (orig.)

  19. Triple Arterial Phase MR Imaging with Gadoxetic Acid Using a Combination of Contrast Enhanced Time Robust Angiography, Keyhole, and Viewsharing Techniques and Two-Dimensional Parallel Imaging in Comparison with Conventional Single Arterial Phase

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Jeong Hee [Department of Radiology, Seoul National University Hospital, Seoul 03080 (Korea, Republic of); Department of Radiology, Seoul National University College of Medicine, Seoul 03087 (Korea, Republic of); Lee, Jeong Min [Department of Radiology, Seoul National University Hospital, Seoul 03080 (Korea, Republic of); Department of Radiology, Seoul National University College of Medicine, Seoul 03087 (Korea, Republic of); Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul 03087 (Korea, Republic of); Yu, Mi Hye [Department of Radiology, Konkuk University Medical Center, Seoul 05030 (Korea, Republic of); Kim, Eun Ju [Philips Healthcare Korea, Seoul 04342 (Korea, Republic of); Han, Joon Koo [Department of Radiology, Seoul National University Hospital, Seoul 03080 (Korea, Republic of); Department of Radiology, Seoul National University College of Medicine, Seoul 03087 (Korea, Republic of); Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul 03087 (Korea, Republic of)

    2016-11-01

    To determine whether triple arterial phase acquisition via a combination of Contrast Enhanced Time Robust Angiography, keyhole, temporal viewsharing and parallel imaging can improve arterial phase acquisition with higher spatial resolution than single arterial phase gadoxetic-acid enhanced magnetic resonance imaging (MRI). Informed consent was waived for this retrospective study by our Institutional Review Board. In 752 consecutive patients who underwent gadoxetic acid-enhanced liver MRI, either single (n = 587) or triple (n = 165) arterial phases was obtained in a single breath-hold under MR fluoroscopy guidance. Arterial phase timing was assessed, and the degree of motion was rated on a four-point scale. The percentage of patients achieving the late arterial phase without significant motion was compared between the two methods using the χ{sup 2} test. The late arterial phase was captured at least once in 96.4% (159/165) of the triple arterial phase group and in 84.2% (494/587) of the single arterial phase group (p < 0.001). Significant motion artifacts (score ≤ 2) were observed in 13.3% (22/165), 1.2% (2/165), 4.8% (8/165) on 1st, 2nd, and 3rd scans of triple arterial phase acquisitions and 6.0% (35/587) of single phase acquisitions. Thus, the late arterial phase without significant motion artifacts was captured in 96.4% (159/165) of the triple arterial phase group and in 79.9% (469/587) of the single arterial phase group (p < 0.001). Triple arterial phase imaging may reliably provide adequate arterial phase imaging for gadoxetic acid-enhanced liver MRI.

  20. Triple arterial phase MR imaging with gadoxetic acid using a combination of contrast enhanced time robust angiography, keyhole, and viewsharing techniques and two-dimensional parallel imaging in comparison with conventional single arterial phase

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Jeong Hee; Lee, Jeong Min; Han, Joon Koo [Dept. of Radiology, Seoul National University Hospital, Seoul (Korea, Republic of); Yu, Mi Hye [Dept. of Radiology, Konkuk University Medical Center, Seoul (Korea, Republic of); Kim, Eun Ju [Philips Healthcare Korea, Seoul (Korea, Republic of)

    2016-07-15

    To determine whether triple arterial phase acquisition via a combination of Contrast Enhanced Time Robust Angiography, keyhole, temporal viewsharing and parallel imaging can improve arterial phase acquisition with higher spatial resolution than single arterial phase gadoxetic-acid enhanced magnetic resonance imaging (MRI). Informed consent was waived for this retrospective study by our Institutional Review Board. In 752 consecutive patients who underwent gadoxetic acid-enhanced liver MRI, either single (n = 587) or triple (n = 165) arterial phases was obtained in a single breath-hold under MR fluoroscopy guidance. Arterial phase timing was assessed, and the degree of motion was rated on a four-point scale. The percentage of patients achieving the late arterial phase without significant motion was compared between the two methods using the χ2 test. The late arterial phase was captured at least once in 96.4% (159/165) of the triple arterial phase group and in 84.2% (494/587) of the single arterial phase group (p < 0.001). Significant motion artifacts (score ≤ 2) were observed in 13.3% (22/165), 1.2% (2/165), 4.8% (8/165) on 1st, 2nd, and 3rd scans of triple arterial phase acquisitions and 6.0% (35/587) of single phase acquisitions. Thus, the late arterial phase without significant motion artifacts was captured in 96.4% (159/165) of the triple arterial phase group and in 79.9% (469/587) of the single arterial phase group (p < 0.001). Triple arterial phase imaging may reliably provide adequate arterial phase imaging for gadoxetic acid-enhanced liver MRI.

  1. Analysis of the Sensitivity and Specificity of Noninvasive Imaging Tests for the Diagnosis of Renal Artery Stenosis

    International Nuclear Information System (INIS)

    Borelli, Flavio Antonio de Oliveira; Pinto, Ibraim M. F.; Amodeo, Celso; Smanio, Paola E. P.; Kambara, Antonio M.; Petisco, Ana Claudia G.; Moreira, Samuel M.; Paiva, Ricardo Calil; Lopes, Hugo Belotti; Sousa, Amanda G. M. R.

    2013-01-01

    Aging and atherosclerosis are related to renovascular hypertension in elderly individuals. Regardless of comorbidities, renal artery stenosis is itself an important cause of cardiovascular morbidity and mortality. To define the sensitivity, specificity, positive predictive value, and negative predictive value of noninvasive imaging tests used in the diagnosis of renal artery stenosis. In a group of 61 patients recruited, 122 arteries were analized, thus permitting the definition of sensitivity, specificity, and the relative contribution of each imaging study performed (Doppler, scintigraphy and computed tomographic angiography in comparison to renal arteriography). The mean age was 65.43 years (standard deviation: 8.7). Of the variables related to the study population that were compared to arteriography, two correlated with renal artery stenosis, renal dysfunction and triglycerides. The median glomerular filtration rate was 52.8 mL/min/m 2 . Doppler showed sensitivity of 82.90%, specificity of 70%, a positive predictive value of 85% and negative predictive value of 66.70%. For tomography, sensitivity was 66.70%, specificity 80%, positive predictive value 87.50% and negative predictive value 55.20%. With these findings, we could identify the imaging tests that best detected stenosis. Tomography and Doppler showed good quality and efficacy in the diagnosis of renal artery stenosis, with Doppler having the advantage of not requiring the use of contrast medium for the assessment of a disease that is common in diabetics and is associated with renal dysfunction and severe left ventricular dysfunction

  2. Analysis of the Sensitivity and Specificity of Noninvasive Imaging Tests for the Diagnosis of Renal Artery Stenosis

    Energy Technology Data Exchange (ETDEWEB)

    Borelli, Flavio Antonio de Oliveira, E-mail: fborelli@cardiol.br; Pinto, Ibraim M. F.; Amodeo, Celso; Smanio, Paola E. P.; Kambara, Antonio M.; Petisco, Ana Claudia G.; Moreira, Samuel M.; Paiva, Ricardo Calil; Lopes, Hugo Belotti; Sousa, Amanda G. M. R. [Instituto Dante Pazzanese de Cardiologia, São Paulo, SP (Brazil)

    2013-11-15

    Aging and atherosclerosis are related to renovascular hypertension in elderly individuals. Regardless of comorbidities, renal artery stenosis is itself an important cause of cardiovascular morbidity and mortality. To define the sensitivity, specificity, positive predictive value, and negative predictive value of noninvasive imaging tests used in the diagnosis of renal artery stenosis. In a group of 61 patients recruited, 122 arteries were analized, thus permitting the definition of sensitivity, specificity, and the relative contribution of each imaging study performed (Doppler, scintigraphy and computed tomographic angiography in comparison to renal arteriography). The mean age was 65.43 years (standard deviation: 8.7). Of the variables related to the study population that were compared to arteriography, two correlated with renal artery stenosis, renal dysfunction and triglycerides. The median glomerular filtration rate was 52.8 mL/min/m{sup 2}. Doppler showed sensitivity of 82.90%, specificity of 70%, a positive predictive value of 85% and negative predictive value of 66.70%. For tomography, sensitivity was 66.70%, specificity 80%, positive predictive value 87.50% and negative predictive value 55.20%. With these findings, we could identify the imaging tests that best detected stenosis. Tomography and Doppler showed good quality and efficacy in the diagnosis of renal artery stenosis, with Doppler having the advantage of not requiring the use of contrast medium for the assessment of a disease that is common in diabetics and is associated with renal dysfunction and severe left ventricular dysfunction.

  3. Evaluation of coronary artery bypass grafts with magnetic resonance imaging

    International Nuclear Information System (INIS)

    Okamura, Yoshitaka; Yamada, Yasuyuki; Mochizuki, Yoshihiko; Iida, Hiroshi; Mori, Hideaki; Sugita, You-ichi; Shimada, Kou-ichirou

    1997-01-01

    Currently, the efficacy of magnetic resonance imaging (MRI) for evaluating coronary artery disease has been reported. In this study, we have evaluated the usefulness and the problems of MRI for evaluating the patency of coronary artery bypass grafts. Thirty-five patients who received coronary artery bypass grafting (CABG) were evaluated by using MRI for determining the graft patency compared with conventional coronary angiography. There were 30 men and 5 women. The mean age was 61.2 years (range 45 to 75). The 35 patients had a total of 92 grafts (28 internal thoracic artery, 7 gastroepiploic artery and 57 saphenous vein grafts). Magnetic resonance coronary angiogram (MRCA) was performed with SIGNA HORIZON 1.5 T (GE Inc.) by using 2D-FASTCARD sequence. All patients underwent imaging in the transverse and coronal planes, most had imaging in the sagittal plane, and a few had in the oblique plane. By using MRCA, 82 of 90 grafts were diagnosed correctly as patent, and 1 of 2 grafts were diagnosed correctly as occluded. Thirty-four of 40 LAD grafts (85%), 20 of 22 RCA grafts (91%) and 29 of 30 Cx grafts (97%) were correctly evaluated. The efficacy of MRCA for evaluating the patency of coronary artery bypass grafts was recognized. But the sternal wire (stainless steel) and hemoclip interfere with the interpretation and reduce the sensitivity. Higher sensitivity may be obtained by changing the material of the sternal wires and hemoclips at coronary surgery. (author)

  4. 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.

  5. 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

  6. Effectiveness of thin-slice axial images of multidetector row CT for visualization of bronchial artery before bronchial arterial embolization

    International Nuclear Information System (INIS)

    Shida, Yoshitaka; Hasuo, Kanehiro; Aibe, Hitoshi; Kubo, Yuko; Terashima, Kotaro; Kinjo, Maya; Kamano, H.; Yoshida, Atsuko

    2008-01-01

    We assessed the ability of visualization of bronchial artery (BA) by using thin-slice axial images of 4-detector multidetector row CT in 65 patients with hemoptysis. In all patients, the origins of BA were well identified with observation of consecutive axial images with 1 mm thickness by paging method and bronchial arterial embolization (BAE) was performed successfully. Thin-slice axial images were considered to be useful to recognize BA and to perform BAE in patients with hemoptysis. (author)

  7. Intravital live cell triggered imaging system reveals monocyte patrolling and macrophage migration in atherosclerotic arteries

    Science.gov (United States)

    McArdle, Sara; Chodaczek, Grzegorz; Ray, Nilanjan; Ley, Klaus

    2015-02-01

    Intravital multiphoton imaging of arteries is technically challenging because the artery expands with every heartbeat, causing severe motion artifacts. To study leukocyte activity in atherosclerosis, we developed the intravital live cell triggered imaging system (ILTIS). This system implements cardiac triggered acquisition as well as frame selection and image registration algorithms to produce stable movies of myeloid cell movement in atherosclerotic arteries in live mice. To minimize tissue damage, no mechanical stabilization is used and the artery is allowed to expand freely. ILTIS performs multicolor high frame-rate two-dimensional imaging and full-thickness three-dimensional imaging of beating arteries in live mice. The external carotid artery and its branches (superior thyroid and ascending pharyngeal arteries) were developed as a surgically accessible and reliable model of atherosclerosis. We use ILTIS to demonstrate Cx3cr1GFP monocytes patrolling the lumen of atherosclerotic arteries. Additionally, we developed a new reporter mouse (Apoe-/-Cx3cr1GFP/+Cd11cYFP) to image GFP+ and GFP+YFP+ macrophages "dancing on the spot" and YFP+ macrophages migrating within intimal plaque. ILTIS will be helpful to answer pertinent open questions in the field, including monocyte recruitment and transmigration, macrophage and dendritic cell activity, and motion of other immune cells.

  8. Sub-piexl methods for improving vector quality in echo PIV flow, imaging technology.

    Science.gov (United States)

    Niu, Lili; Wang, Jing; Qian, Ming; Zheng, Hairong

    2009-01-01

    Developments of many cardiovascular problems have been shown to have a close relationship with arterial flow conditions. An ultrasound-based particle image velocimetry technique(Echo PIV) was recently developed to measure multi-component velocity vectors and local shear rates in arteries and opaque fluid flows by identifying and tracking flow tracers (ultrasound contrast microbubbles) within these flow fields. To improve the measurement accuracy, sub-pixel calculation method was adopted in this paper to maximize the ultrasound RF signal and B mode image correlation accuracy and increase the image spatial resolution. This algorithm is employed in processing both computer-generated particle image patterns and the B-mode images of microbubbles in rotating flows obtained by a high frame rate (up to 1000 frames per second) ultrasound imaging system. The results show the correlation of particle patterns and individual flow vector quality are improved and the overall flow mappings are also improved significantly. This would help the Echo PIV system to provide better multi-component velocity accuracy.

  9. Diffusion-weighted MR imaging of kidneys in renal artery stenosis

    International Nuclear Information System (INIS)

    Yildirim, Erkan; Kirbas, Ismail; Teksam, Mehmet; Karadeli, Elif; Gullu, Hakan; Ozer, Ismail

    2008-01-01

    Objective: The purpose of our study was to evaluate perfusion and diffusion of kidneys in renal artery stenosis (RAS) and any correlation between stenosis and ADC values and whether this imaging modality may be a noninvasive complementary assessment technique to MR angiography before interventional procedures. Materials and methods: Twenty consecutive patients suspected of having renal artery stenosis were evaluated with renal MR angiography to exclude stenosis and were then included in the study. Transverse DW multisection echo-planar MR imaging was performed. In the transverse ADC map, rectangular regions of interest were placed in the cortex on 3 parts (upper, middle, and lower poles) in each kidney. ADCs of the kidneys were calculated separately for the low, average, and high b-values to enable differentiation of the relative influence of the perfusion fraction and true diffusion. The ADC values of 39 kidneys (13 with renal artery stenosis and 26 normal renal arteries) were compared, and the relationship between stenosis degree and ADC values was calculated. Results: RAS was detected in 11 of 20 (55%) patients with MRA. Thirteen of 39 kidneys demonstrated RAS, and 26 were normal. The ADC low (1.9 ± 0.2 versus 2.1 ± 0.2; P = .020), ADC average (1.7 ± 0.2 versus 1.9 ± 0.1; P = .006), and ADC high (1.8 ± 0.2 versus 2.0 ± 0.1; P = .012) values were significantly lower in patients with kidneys with arterial stenosis than that in patients with kidneys with normal arteries. Statistical analysis revealed that stenosis degree correlated strongly with ADC low (r = -.819; P = .001), ADC average (r = -.754; P = .003), and ADC high (r = -.788; P = .001). The ADC low , ADC average , and ADC high values were significantly lower in patients with kidneys with arterial stenosis than that in patients with kidneys with normal arteries. Conclusion: We think that DW MR imaging of kidneys with RAS can help determine the functional status of a renal artery stenosis

  10. Spiral CT angiography (SCTA) study of celiac artery and superior mesenteric artery

    International Nuclear Information System (INIS)

    Yuan Zhenguo; Zhou Cunsheng; Xu Zuodong; Shi Hao; Wang Tao

    1999-01-01

    Objective: To study the visualization capability and scanning technique of SCTA in celiac artery, superior mesenteric artery (SMA) and other branches. Methods: Thirty patients, with normal abdominal SCTA results, were given small injection test dose after plain scan. The abdominal aorta parallel to the body of pancreas was chosen as target vessel, the peak-time plus 2 seconds as the best delay scan time. Iodine contrast medium 90∼110 ml was injected into antecubital vein at the speed of 3.5 ml/s, then scan from cranial to caudal was performed. Pitch 1.0 and slice thickness 3.2 mm were selected as the scan parameters. Maximum intensity projection (MaxIP) was employed in all patients and shaded surface display (SSD) in 23 cases. Results: The display rate using MaxIP and SSD of celiac artery, splenic artery, common hepatic artery, proper hepatic artery and SMA were all 100%, the gastroduodenal artery 100% and 91%, the left gastric artery 83% and 87%, respectively. Conclusions: SCTA as a minimally invasive examination is a valuable method to detect and diagnose disease or variations of celiac artery, its branches and SMA. Spiral scanning technique and image processing have a decisive effect on the image quality

  11. Thallium-201 myocardial imaging in young adults with anomalous left coronary artery arising from the pulmonary artery

    International Nuclear Information System (INIS)

    Moodie, D.S.; Cook, S.A.; Gill, C.C.; Napoli, C.A.

    1980-01-01

    Anomalous origin of the left coronary artery from the pulmonary artery (Bland-Garland-White syndrome) may produce myocardial ischemia, infarction, and frequently death in infancy. Some patients, however, develop satisfactory coronary artery collaterals and are relatively asymptomatic into adulthood. Very little is known about their myocardial perfusion patterns. We studied three young adults with this condition using stress thallium-201 myocardial imaging. Electrocardiograms in two patients demonstrated old arterolateral myocardial infarctions. Preoperative stress exercise tests were positive in all three patients. Marked perfusion abnormalities were found in the proximal anterolateral wall in all patients, and one patient also had a posterolateral defect. Postoperatively, all stress tests returned to normal. Thallium imaging demonstrated improvement in ischemic areas, but old scars persisted

  12. High-definition computed tomography for coronary artery stents imaging: Initial evaluation of the optimal reconstruction algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Cui, Xiaoming, E-mail: mmayzy2008@126.com; Li, Tao, E-mail: litaofeivip@163.com; Li, Xin, E-mail: lx0803@sina.com.cn; Zhou, Weihua, E-mail: wangxue0606@gmail.com

    2015-05-15

    Highlights: • High-resolution scan mode is appropriate for imaging coronary stent. • HD-detail reconstruction algorithm is stent-dedicated kernel. • The intrastent lumen visibility also depends on stent diameter and material. - Abstract: Objective: The aim of this study was to evaluate the in vivo performance of four image reconstruction algorithms in a high-definition CT (HDCT) scanner with improved spatial resolution for the evaluation of coronary artery stents and intrastent lumina. Materials and methods: Thirty-nine consecutive patients with a total of 71 implanted coronary stents underwent coronary CT angiography (CCTA) on a HDCT (Discovery CT 750 HD; GE Healthcare) with the high-resolution scanning mode. Four different reconstruction algorithms (HD-stand, HD-detail; HD-stand-plus; HD-detail-plus) were applied to reconstruct the stented coronary arteries. Image quality for stent characterization was assessed. Image noise and intrastent luminal diameter were measured. The relationship between the measurement of inner stent diameter (ISD) and the true stent diameter (TSD) and stent type were analysed. Results: The stent-dedicated kernel (HD-detail) offered the highest percentage (53.5%) of good image quality for stent characterization and the highest ratio (68.0 ± 8.4%) of visible stent lumen/true stent lumen for luminal diameter measurement at the expense of an increased overall image noise. The Pearson correlation coefficient between the ISD and TSD measurement and spearman correlation coefficient between the ISD measurement and stent type were 0.83 and 0.48, respectively. Conclusions: Compared with standard reconstruction algorithms, high-definition CT imaging technique with dedicated high-resolution reconstruction algorithm provides more accurate stent characterization and intrastent luminal diameter measurement.

  13. Detecting culprit vessel of coronary artery disease with SPECT 99Tcm-MIBI myocardial imaging

    International Nuclear Information System (INIS)

    Luan Zhaosheng; Zhou Wen; Peng Yong; Su Yuwen; Tian Jianhe; Gai lue; Sun Zhijun

    2002-01-01

    Objective: To assess the value of detecting culprit vessel of coronary artery disease (CAD) with SPECT 99 Tc m -MIBI myocardial imaging. Methods: Forty-six patients with CAD were studied. Every patients had multiple-vessel lesion showed by coronary arteriography and was treated by revascularization as percutaneous transluminal angioplasty (PTCA), coronary artery bypass graft (CABG) or laser holing. Exercise (EX), rest (RE) and intravenous infusion of nitroglycerine (NTG) SPECT 99 Tc m -MIBI myocardial imagings were performed before revascularization. Exercise and rest images revealed the myocardial ischemia. NTG images revealed myocardial viability. Culprit vessels were detected according to the defects showed by above mentioned images. The veracity of detected culprit vessels was tested with the outcome of the reperfusion therapy. Results: In this group, the coronary arteriography revealed 107 lesioned coronary arteries. Myocardial imaging detected 46 culprit vessels including 23 left anterior descending (LAD), 19 left circumflex coronary artery (LCX) and 4 right coronary artery (RCA). All 46 culprit vessels underwent revascularization and had nice outcome. The veracity of 99 Tc m -MIBI myocardial imaging detected culprit vessels was high according to patients' outcome. Conclusion: Exercise, rest and NTG 99 Tc m -MIBI myocardial imaging is a great method for detecting culprit vessels in multivessel coronary disease

  14. Thallium-201 myocardial imaging in the detection of coronary artery disease

    International Nuclear Information System (INIS)

    McKillop, J.H.; Murray, R.G.; Turner, J.G.; Gray, H.W.; Bessent, R.G.; Lorimer, A.R.; Greig, W.R.

    1978-01-01

    Thallium-201 myocardial imaging can detect abnormalities of myocardial perfusion. Visual interpretation of the images is complicated by some inhomogeneity of tracer uptake normally present. Using a quantitative approach we have established the regional variation of Thallium-201 uptake present in 23 normal controls and applied the same technique to 49 patients who had undergone selective coronary arteriography with left ventriculography because of chest pain. Half of the patients with significant coronary artery disease had abnormal rest Thallium-201 images, usually corresponding to areas of abnormal wall motion at ventriculography. Stress Thallium-201 images were abnormal in over 90% of patients with coronary artery disease. The stress image abnormalities and the arteriographic lesions correlated well in most patients with single and double vessel disease but in triple vessel disease the correspondence between the two studies was poor. Two of a group of patients with normal coronary arteriograms had abnormal Thallium-201 images due to other myocardial pathology. Our technique was highly sensitive in the non-invasive detection of significant coronary artery disease in a group of patients with chest pain. A small number of positive studies were also encountered due to other myocardial disorders. (author)

  15. All-optical extravascular laser-ultrasound and photoacoustic imaging of calcified atherosclerotic plaque in excised carotid artery

    Directory of Open Access Journals (Sweden)

    Jami L. Johnson

    2018-03-01

    Full Text Available Photoacoustic (PA imaging may be advantageous as a safe, non-invasive imaging modality to image the carotid artery. However, calcification that accompanies atherosclerotic plaque is difficult to detect with PA due to the non-distinct optical absorption spectrum of hydroxyapatite. We propose reflection-mode all-optical laser-ultrasound (LUS imaging to obtain high-resolution, non-contact, non-ionizing images of the carotid artery wall and calcification. All-optical LUS allows for flexible acquisition geometry and user-dependent data acquisition for high repeatability. We apply all-optical techniques to image an excised human carotid artery. Internal layers of the artery wall, enlargement of the vessel, and calcification are observed with higher resolution and reduced artifacts with nonconfocal LUS compared to confocal LUS. Validation with histology and X-ray computed tomography (CT demonstrates the potential for LUS as a method for non-invasive imaging in the carotid artery. Keywords: Atherosclerosis, Photoacoustic imaging, Laser-ultrasound, Calcification, Reverse-time migration

  16. Influence of adaptive statistical iterative reconstruction algorithm on image quality in coronary computed tomography angiography.

    Science.gov (United States)

    Precht, Helle; Thygesen, Jesper; Gerke, Oke; Egstrup, Kenneth; Waaler, Dag; Lambrechtsen, Jess

    2016-12-01

    Coronary computed tomography angiography (CCTA) requires high spatial and temporal resolution, increased low contrast resolution for the assessment of coronary artery stenosis, plaque detection, and/or non-coronary pathology. Therefore, new reconstruction algorithms, particularly iterative reconstruction (IR) techniques, have been developed in an attempt to improve image quality with no cost in radiation exposure. To evaluate whether adaptive statistical iterative reconstruction (ASIR) enhances perceived image quality in CCTA compared to filtered back projection (FBP). Thirty patients underwent CCTA due to suspected coronary artery disease. Images were reconstructed using FBP, 30% ASIR, and 60% ASIR. Ninety image sets were evaluated by five observers using the subjective visual grading analysis (VGA) and assessed by proportional odds modeling. Objective quality assessment (contrast, noise, and the contrast-to-noise ratio [CNR]) was analyzed with linear mixed effects modeling on log-transformed data. The need for ethical approval was waived by the local ethics committee as the study only involved anonymously collected clinical data. VGA showed significant improvements in sharpness by comparing FBP with ASIR, resulting in odds ratios of 1.54 for 30% ASIR and 1.89 for 60% ASIR ( P  = 0.004). The objective measures showed significant differences between FBP and 60% ASIR ( P  < 0.0001) for noise, with an estimated ratio of 0.82, and for CNR, with an estimated ratio of 1.26. ASIR improved the subjective image quality of parameter sharpness and, objectively, reduced noise and increased CNR.

  17. Angiographic imaging of the branching of the popliteal artery into the arteries of the lower leg

    International Nuclear Information System (INIS)

    Prayer, L.; Karnel, F.; Schurawitzki, H.

    1990-01-01

    For the anatomic analysis of the branching of the popliteal artery into the lower leg arteries, 414 intra-arterial DSA images of the lower extremity (obtained in 223 patients) were available. In 90.1% of the material examined, a 'normal' branching was found. If one leg of a patient showed 'normal' branching, there was a probability of 6.9% to find a different branching of the artery in the other leg. In 9.9% of the examined legs deviations from standard branching were observed. If there was a deviation from standard observed in one leg, the probability of finding a variant of branching in the other leg as well was 4.4%. (orig./MG) [de

  18. Impact of organ-specific dose reduction on the image quality of head and neck CT angiography

    International Nuclear Information System (INIS)

    Schimmoeller, L.; Lanzman, R.S.; Heusch, P.; Dietrich, S.; Miese, F.; Aissa, J.; Heusner, T.A.; Antoch, G.; Kroepil, P.

    2013-01-01

    Organ-specific dose reduction (OSDR) algorithms can reduce radiation on radiosensitive organs up to 59 %. This study evaluates the influence of a new OSDR algorithm on image quality of head and neck computed tomographic angiography (CTA) in clinical routine. Sixty-two consecutive patients (68 ± 13 years) were randomised into two groups and imaged using 128-row multidetector CT. Group A (n = 31) underwent conventional CTA and group B (n = 31) CTA with a novel OSDR algorithm. Subjective and objective image quality were statistically compared. Subjective image quality was rated on a five-point scale. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated with region-of-interest measurements. The SNR of the common carotid artery and middle cerebral artery was 53.6 ± 22.7 and 43.3 ± 15.3 (group A) versus 54.1 ± 20.5 and 46.2 ± 14.6 (group B). The CNR was 40.0 ± 19.3 and 29.7 ± 12.0 (group A) compared with 40.7 ± 16.8 and 32.9 ± 10.9 (group B), respectively. Subjective image quality was excellent in both groups (mean score 4.4 ± 0.7 versus 4.4 ± 0.6). Differences between the two groups were not significant. The novel OSDR algorithm does not compromise image quality of head and neck CTA. Its application can be recommended for CTA in clinical routine to protect the thyroid gland and ocular lenses from unnecessary high radiation. (orig.)

  19. Renal artery stenosis: comparative assessment by unenhanced renal artery mra versus contrast-enhanced MRA

    International Nuclear Information System (INIS)

    Khoo, Michael M.Y.; Deeab, Dhafer; Gedroyc, Wladyslaw M.W.; Dick, Elizabeth A.; Duncan, Neil; Taube, David

    2011-01-01

    To evaluate steady-state free precession (SSFP) non-contrast-enhanced MR angiography (Unenhanced-MRA) versus conventional contrast-enhanced MR angiography (CE-MRA) in the detection of renal artery stenosis (RAS). Retrospective analysis of 70 consecutive patients referred for suspected RAS, examined by SSFP Unenhanced-MRA and CE-MRA. Image quality, quality of visible renal arterial segments, presence and grade of RAS were evaluated. The Unenhanced-MRA were compared against reference standard CE-MRA results. 149 renal arteries were assessed with 21 haemodynamically significant stenoses (≥50% stenosis) demonstrated by CE-MRA. Combined sensitivity and specificity for RAS detection by Unenhanced-MRA was 72.8% and 97.8% respectively. There is substantial correlation for RAS detection between Unenhanced-MRA and CE-MRA with kappa values of between 0.64 and 0.74. There was excellent inter-observer correlation for RAS on Unenhanced-MRA (kappa values 0.82-1.0). Our study has shown Unenhanced-MRA to be a viable alternative to CE-MRA, yielding images equal in quality without the requirement for gadolinium contrast agents. The sensitivity and specificity for the detection of haemodynamically significant stenoses are comparable to CE-MRA. Potentially, Unenhanced-MRA could be used as an initial investigation to avoid performing CE-MRA in patients with normal renal arteries, however we suggest that its real value will lie in being complementary to CE-MRA. (orig.)

  20. Brachial artery approach for outpatient arteriography

    International Nuclear Information System (INIS)

    You, Jai Kyung; Park, Sung Il; Lee, Do Yun; Won, Jae Hwan

    1999-01-01

    To evaluate the diagnostic usefulness of brachial approach arteriography for outpatients, with particular regard to safety and image quality. The angiographic findings and follow-up medical records of 131 brachial approach arteriographies in 121 outpatients were retrospectively analysed. 5 F pigtail catheters were used in 125 cases and 5-F OCU-A catheters were used in three cases of renal arteriography, and three of upper extremity arteriography without catheter. Except for three cases of brachial artery puncture failure, all procedures were performed successfully. One hundred and fifteen of 119 lower extremity arteriographies were visualized down to the level of the tibioperoneal artery. The non-visualized cases were three in which there was multiple obstruction at the distal common iliac artery and one with insufficient contrast amount due to renal failure In four cases there were complications : two involved arterial thrombosis, one was an intramuscular hematoma, and one an A-V fistula. For outpatients, brachial approach arteriography can replace the femoral approach. Its image quality is excellent, there are time-cost benefits, and the rate of complications is relatively low

  1. Multidetector-row CT angiography of hepatic artery: comparison with conventional angiography

    International Nuclear Information System (INIS)

    Kim, Jin Woong; Jeong, Yong Yeon; Yoon, Woong; Kim, Jae Kyu; Park, Jin Gyoon; Seo, Jeong Jin; Kang, Heoung Keun

    2003-01-01

    To determine the usefulness of three-dimensional CT angiography using multidetector-row CT (MD-CT) for delineating the arterial anatomy of the liver. Hepatic arterial three-dimensional CT angiography was performed using MDCT (lightspeed Qx/I; GE medical systems, milwaukee, Wis., U.S.A.) in 45 patients with HCC undergoing conventional angiography for transcatheter hepatic arterial chemoembolization. The scanning parameters during the early arterial phase were 2.5 mm slice thickness, 7.5 mm rotation of table speed, and a pitch of 3. Images were obtained by one radiologist using maximum intensity projection from axial CT images obtained during the early arterial phase. Two radiologists blinded to the findings of conventional angiography independently evaluated the hepatic arterial anatomy and the quality of the images obtained. Compared with conventional angiography, reader A correctly evaluated the hepatic arterial anatomy depicted at three-dimensional CT angiography. Reader B's evaluation was correct in 40 of 45 patients. Interobserver agreement was good (kappa value, 0.73), and both readers assessed the quality of three-dimensional CT angiography as excellent. Three-dimensional CT angiography using MDCT was accurate for delineating the arterial anatomy of the liver, and interobserver agreement was good. The modality may provide, prior to conventional angiography, valuable information regrading a patient's hepatic arterial anatomy

  2. Segmental hepatic artery at hepatic hilar area. Analysis by 3 dimensional integrated image of artery, portal vein and bile duct

    Energy Technology Data Exchange (ETDEWEB)

    Sakai, Hisamune; Okuda, Kouji; Yoshida, Jun; Kinoshita, Hisafumi; Aoyagi, Shigeaki [Kurume Univ., School of Medicine, Kurume, Fukuoka (Japan)

    2006-11-15

    Multiple individual variations in running and bifurcation of the hepatic artery, biliary duct and portal vein are known in hepatic hilar area. This paper describes the examination of such arterial variations by integrating the 3D images of those vessels obtained by multidetector-row CT (MDCT). Subjects are findings from 64 patients with cholangiocarcinoma, hepatocarcinoma or cholelithiasis. MDCT dynamic scanning, and percutaneous transhepatic biliary drainage-CT and/or drip infusion cholangiography-CT with the intravenous iopamidol and/or iotroxate megulumin, were done with GE LightSpeed Ultra 16 slice type equipment to compose the 3D images. Arterial variants of the bifurcation in the right and left lobe were found to be 18 cases/62 (29%) and 13/64 (20%), respectively. The left artery running at right side of portal venous umbilical region was seen in 9/64 (14%) and right artery running ''northward'', in 9/62 (14%). Previous realization of such individual 3D arterial variations as above is necessary for the precise microsurgery of the hilar area to preserve the essential vessel. (T.I.)

  3. Segmental hepatic artery at hepatic hilar area. Analysis by 3 dimensional integrated image of artery, portal vein and bile duct

    International Nuclear Information System (INIS)

    Sakai, Hisamune; Okuda, Kouji; Yoshida, Jun; Kinoshita, Hisafumi; Aoyagi, Shigeaki

    2006-01-01

    Multiple individual variations in running and bifurcation of the hepatic artery, biliary duct and portal vein are known in hepatic hilar area. This paper describes the examination of such arterial variations by integrating the 3D images of those vessels obtained by multidetector-row CT (MDCT). Subjects are findings from 64 patients with cholangiocarcinoma, hepatocarcinoma or cholelithiasis. MDCT dynamic scanning, and percutaneous transhepatic biliary drainage-CT and/or drip infusion cholangiography-CT with the intravenous iopamidol and/or iotroxate megulumin, were done with GE LightSpeed Ultra 16 slice type equipment to compose the 3D images. Arterial variants of the bifurcation in the right and left lobe were found to be 18 cases/62 (29%) and 13/64 (20%), respectively. The left artery running at right side of portal venous umbilical region was seen in 9/64 (14%) and right artery running ''northward'', in 9/62 (14%). Previous realization of such individual 3D arterial variations as above is necessary for the precise microsurgery of the hilar area to preserve the essential vessel. (T.I.)

  4. 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.)

  5. Bilateral, Mirror-imaged, Postero-inferior Cerebellar Artery Aneurysms: Report of a Rare Case

    Directory of Open Access Journals (Sweden)

    G R Sharma

    2011-06-01

    Full Text Available A 60-year-old right-handed lady presented with the features of subarachnoid haemorrhage. The CT angiogram showed a pair of very rare bilateral, mirror-imaged distal postero-inferior cerebellar artery aneurysms. Both aneurysms were clipped via the midline posterior fossa craniectomy under general anaesthesia. The literatures is reviewed on the incidence, presentation, management and outcome of bilateral distal posterior-inferior cerebellar artery aneurysms. Keywords: bilateral mirror image, distal postero-inferior cerebellar artery aneurysms, posterior fossa craniectomy, microsurgical clipping

  6. National variation in preoperative imaging, carotid duplex ultrasound criteria, and threshold for surgery for asymptomatic carotid artery stenosis.

    Science.gov (United States)

    Arous, Edward J; Simons, Jessica P; Flahive, Julie M; Beck, Adam W; Stone, David H; Hoel, Andrew W; Messina, Louis M; Schanzer, Andres

    2015-10-01

    Carotid endarterectomy (CEA) for asymptomatic carotid artery stenosis is among the most common procedures performed in the United States. However, consensus is lacking regarding optimal preoperative imaging, carotid duplex ultrasound criteria, and ultimately, the threshold for surgery. We sought to characterize national variation in preoperative imaging, carotid duplex ultrasound criteria, and threshold for surgery for asymptomatic CEA. The Society for Vascular Surgery Vascular Quality Initiative (VQI) database was used to identify all CEA procedures performed for asymptomatic carotid artery stenosis between 2003 and 2014. VQI currently captures 100% of CEA procedures performed at >300 centers by >2000 physicians nationwide. Three analyses were performed to quantify the variation in (1) preoperative imaging, (2) carotid duplex ultrasound criteria, and (3) threshold for surgery. Of 35,695 CEA procedures in 33,488 patients, the study cohort was limited to 19,610 CEA procedures (55%) performed for asymptomatic disease. The preoperative imaging modality used before CEA varied widely, with 57% of patients receiving a single preoperative imaging study (duplex ultrasound imaging, 46%; computed tomography angiography, 7.5%; magnetic resonance angiography, 2.0%; cerebral angiography, 1.3%) and 43% of patients receiving multiple preoperative imaging studies. Of the 16,452 asymptomatic patients (89%) who underwent preoperative duplex ultrasound imaging, there was significant variability between centers in the degree of stenosis (50%-69%, 70%-79%, 80%-99%) designated for a given peak systolic velocity, end diastolic velocity, and internal carotid artery-to-common carotid artery ratio. Although 68% of CEA procedures in asymptomatic patients were performed for an 80% to 99% stenosis, 26% were performed for a 70% to 79% stenosis, and 4.1% were performed for a 50% to 69% stenosis. At the surgeon level, the range in the percentage of CEA procedures performed for a duplex ultrasound

  7. Excretory urogramm with angiotomography: Imaging of the renal arteries by excretory urogramm

    International Nuclear Information System (INIS)

    Binder, G.

    1982-01-01

    Excretory urography permits imaging of the renal arteries up to the intrarenal ramification if the contrast medium is injected as a bolus and the time of circulation between arm vein and abdominal aorta is determined with sufficient accuracy. Imaging of the vessel phase is done using simultaneous tomography. In the experimental part of the paper phantom tests are carried through to establish the contrast medium concentration to be expected in the renal arteries by means of microdensitometry. With the aid of 100 computerized tomograms of the abdomen the layer thickness required was determined to 4.5 cm; further phantom tests provided the necessary layer distances to image renal arteries that do not run in parallel to the plain of the film. The circulation time between arm vein and abdominal aorta was measured in 180 patients using the radioisotope method. It ranges between 9 and 22 seconds. Comparisons with the Decholin-method were made. 739 renal arteries were seen during the evaluation of 343 excretory urographies with angiotomograms, in 83 per cent of the cases these arteries were presented entirely. Provided perfect execution, simultaneous tomography is a very informative method. For 212 patients the side-effects of the bolar contrast medium injection were recorded. The importance of excretory urography with combined angiotomography for the diagnosis of arterial hypertension is discussed. (orig.) [de

  8. Influence of adaptive statistical iterative reconstruction algorithm on image quality in coronary computed tomography angiography

    Directory of Open Access Journals (Sweden)

    Helle Precht

    2016-12-01

    Full Text Available Background Coronary computed tomography angiography (CCTA requires high spatial and temporal resolution, increased low contrast resolution for the assessment of coronary artery stenosis, plaque detection, and/or non-coronary pathology. Therefore, new reconstruction algorithms, particularly iterative reconstruction (IR techniques, have been developed in an attempt to improve image quality with no cost in radiation exposure. Purpose To evaluate whether adaptive statistical iterative reconstruction (ASIR enhances perceived image quality in CCTA compared to filtered back projection (FBP. Material and Methods Thirty patients underwent CCTA due to suspected coronary artery disease. Images were reconstructed using FBP, 30% ASIR, and 60% ASIR. Ninety image sets were evaluated by five observers using the subjective visual grading analysis (VGA and assessed by proportional odds modeling. Objective quality assessment (contrast, noise, and the contrast-to-noise ratio [CNR] was analyzed with linear mixed effects modeling on log-transformed data. The need for ethical approval was waived by the local ethics committee as the study only involved anonymously collected clinical data. Results VGA showed significant improvements in sharpness by comparing FBP with ASIR, resulting in odds ratios of 1.54 for 30% ASIR and 1.89 for 60% ASIR (P = 0.004. The objective measures showed significant differences between FBP and 60% ASIR (P < 0.0001 for noise, with an estimated ratio of 0.82, and for CNR, with an estimated ratio of 1.26. Conclusion ASIR improved the subjective image quality of parameter sharpness and, objectively, reduced noise and increased CNR.

  9. Arterial Transit Time-corrected Renal Blood Flow Measurement with Pulsed Continuous Arterial Spin Labeling MR Imaging.

    Science.gov (United States)

    Shimizu, Kazuhiro; Kosaka, Nobuyuki; Fujiwara, Yasuhiro; Matsuda, Tsuyoshi; Yamamoto, Tatsuya; Tsuchida, Tatsuro; Tsuchiyama, Katsuki; Oyama, Nobuyuki; Kimura, Hirohiko

    2017-01-10

    The importance of arterial transit time (ATT) correction for arterial spin labeling MRI has been well debated in neuroimaging, but it has not been well evaluated in renal imaging. The purpose of this study was to evaluate the feasibility of pulsed continuous arterial spin labeling (pcASL) MRI with multiple post-labeling delay (PLD) acquisition for measuring ATT-corrected renal blood flow (ATC-RBF). A total of 14 volunteers were categorized into younger (n = 8; mean age, 27.0 years) and older groups (n = 6; 64.8 years). Images of pcASL were obtained at three different PLDs (0.5, 1.0, and 1.5 s), and ATC-RBF and ATT were calculated using a single-compartment model. To validate ATC-RBF, a comparative study of effective renal plasma flow (ERPF) measured by 99m Tc-MAG3 scintigraphy was performed. ATC-RBF was corrected by kidney volume (ATC-cRBF) for comparison with ERPF. The younger group showed significantly higher ATC-RBF (157.68 ± 38.37 mL/min/100 g) and shorter ATT (961.33 ± 260.87 ms) than the older group (117.42 ± 24.03 mL/min/100 g and 1227.94 ± 226.51 ms, respectively; P renal ASL-MRI as debated in brain imaging.

  10. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  12. Coronary artery anomalies in adults: imaging at dual source CT coronary angiography

    International Nuclear Information System (INIS)

    Laspas, Fotios; Roussakis, Arkadios; Mourmouris, Christos; Kritikos, Nikolaos; Efthimiadou, Roxani; Andreou, John

    2013-01-01

    Congenital abnormalities of the coronary arteries have an incidence of 1%, and most of these are benign. However, a small number are associated with myocardial ischaemia and sudden death. Various imaging modalities are available for coronary artery assessment. Recently, multi-detector CT has emerged as an accurate diagnostic tool for defining coronary artery anomalies. The purpose of this pictorial essay is to review the dual source CT appearance of congenital anomalies of the coronary arteries in adults.

  13. Superselective pseudo-continuous arterial spin labeling angiography

    Energy Technology Data Exchange (ETDEWEB)

    Jensen-Kondering, Ulf [Department of Radiology and Neuroradiology, University Medical Center Schleswig-Holstein, Kiel (Germany); Lindner, Thomas, E-mail: thomas.lindner@uksh.de [Department of Radiology and Neuroradiology, University Medical Center Schleswig-Holstein, Kiel (Germany); Osch, Matthias J.P. van [C. J. Gorter Center for High Field MRI, Department of Radiology, Leiden University Medical Center, Leiden (Netherlands); Rohr, Axel; Jansen, Olav [Department of Radiology and Neuroradiology, University Medical Center Schleswig-Holstein, Kiel (Germany); Helle, Michael [Department of Radiology and Neuroradiology, University Medical Center Schleswig-Holstein, Kiel (Germany); Now with Philips GmbH Innovative Technologies, Research Laboratories, Hamburg (Germany)

    2015-09-15

    Highlights: • Superselective arterial spin labeling was capable of acquiring angiograms of individually selected arteries. • Image quality was similar compared with a routinely used time-of-flight angiography. • Superselective arterial spin labeling was utilized in patients with arterio-venous malformations and made it possible to visualize individual feeding vessels in a complete non-invasive way - Abstract: Purpose: To evaluate the utility of a novel non-contrast enhanced, vessel-selective magnetic resonance angiography (MRA) approach based on superselective pseudo-continuous arterial spin labeling (ASL) for the morphologic assessment of intracranial arteries when compared to a clinically used time-of-flight (TOF) MRA. Materials and methods: Three sets of selective ASL angiographies (right and left internal carotid artery, basilar artery) as well as one TOF data set were obtained from each of the five volunteers included in this study on a clinical 1.5T system. The depiction of arterial segments as well as their delineation was evaluated and independently analyzed by two radiologists. Additionally, the ASL angiography approach was performed in two patients suffering from arterio-venous malformations (AVM) in order to illustrate potential applications in a clinical setting. Results: In both angiography techniques, intracranial arteries and their segments (distal branches up to A5 segments of the anterior cerebral arteries, M8 segments of the middle cerebral arteries, and P5 segments of the posterior cerebral arteries) were continuously depicted with excellent inter-reader agreement (κ > 0.81). In AVM patients, reconstructed images of the TOF angiography presented similar information about the size and shape of the AVM as did superselective ASL angiography. In addition, the acquired ASL angiograms of selected vessels allowed assessing the blood supply of individually labeled arteries to the AVM which could also be confirmed by digital subtraction angiography

  14. Superselective pseudo-continuous arterial spin labeling angiography

    International Nuclear Information System (INIS)

    Jensen-Kondering, Ulf; Lindner, Thomas; Osch, Matthias J.P. van; Rohr, Axel; Jansen, Olav; Helle, Michael

    2015-01-01

    Highlights: • Superselective arterial spin labeling was capable of acquiring angiograms of individually selected arteries. • Image quality was similar compared with a routinely used time-of-flight angiography. • Superselective arterial spin labeling was utilized in patients with arterio-venous malformations and made it possible to visualize individual feeding vessels in a complete non-invasive way - Abstract: Purpose: To evaluate the utility of a novel non-contrast enhanced, vessel-selective magnetic resonance angiography (MRA) approach based on superselective pseudo-continuous arterial spin labeling (ASL) for the morphologic assessment of intracranial arteries when compared to a clinically used time-of-flight (TOF) MRA. Materials and methods: Three sets of selective ASL angiographies (right and left internal carotid artery, basilar artery) as well as one TOF data set were obtained from each of the five volunteers included in this study on a clinical 1.5T system. The depiction of arterial segments as well as their delineation was evaluated and independently analyzed by two radiologists. Additionally, the ASL angiography approach was performed in two patients suffering from arterio-venous malformations (AVM) in order to illustrate potential applications in a clinical setting. Results: In both angiography techniques, intracranial arteries and their segments (distal branches up to A5 segments of the anterior cerebral arteries, M8 segments of the middle cerebral arteries, and P5 segments of the posterior cerebral arteries) were continuously depicted with excellent inter-reader agreement (κ > 0.81). In AVM patients, reconstructed images of the TOF angiography presented similar information about the size and shape of the AVM as did superselective ASL angiography. In addition, the acquired ASL angiograms of selected vessels allowed assessing the blood supply of individually labeled arteries to the AVM which could also be confirmed by digital subtraction angiography

  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. Label-free imaging of arterial cells and extracellular matrix using a multimodal CARS microscope

    Science.gov (United States)

    Wang, Han-Wei; Le, Thuc T.; Cheng, Ji-Xin

    2008-04-01

    A multimodal nonlinear optical imaging system that integrates coherent anti-Stokes Raman scattering (CARS), sum-frequency generation (SFG), and two-photon excitation fluorescence (TPEF) on the same platform was developed and applied to visualize single cells and extracellular matrix in fresh carotid arteries. CARS signals arising from CH 2-rich membranes allowed visualization of endothelial cells and smooth muscle cells of the arterial wall. Additionally, CARS microscopy allowed vibrational imaging of elastin and collagen fibrils which are also rich in CH 2 bonds. The extracellular matrix organization was further confirmed by TPEF signals arising from elastin's autofluorescence and SFG signals arising from collagen fibrils' non-centrosymmetric structure. Label-free imaging of significant components of arterial tissues suggests the potential application of multimodal nonlinear optical microscopy to monitor onset and progression of arterial diseases.

  17. MRI quality control: six imagers studied using eleven unified image quality parameters

    International Nuclear Information System (INIS)

    Ihalainen, T.; Sipilae, O.; Savolainen, S.

    2004-01-01

    Quality control of the magnetic resonance imagers of different vendors in the clinical environment is non-harmonised, and comparing the performance is difficult. The purpose of this study was to develop and apply a harmonised long-term quality control protocol for the six imagers in our organisation in order to assure that they fulfil the same basic image quality requirements. The same Eurospin phantom set and identical imaging parameters were used with each imager. Values of 11 comparable parameters describing the image quality were measured. Automatic image analysis software was developed to objectively analyse the images. The results proved that the imagers were operating at a performance level adequate for clinical imaging. Some deficiencies were detected in image uniformity and geometry. The automated analysis of the Eurospin phantom images was successful. The measurements were successfully repeated after 2 weeks on one imager and after half a year on all imagers. As an objective way of examining the image quality, this kind of comparable and objective quality control of different imagers is considered as an essential step towards harmonisation of the clinical MRI studies through a large hospital organisation. (orig.)

  18. 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.)

  19. Imaging Food Quality

    DEFF Research Database (Denmark)

    Møller, Flemming

    Imaging and spectroscopy have long been established methods for food quality control both in the laboratories and online. An ever increasing number of analytical techniques are being developed into imaging methods and existing imaging methods to contain spectral information. Images and especially...... spectral images contain large amounts of data which should be analysed appropriately by techniques combining structure and spectral information. This dissertation deals with how different types of food quality can be measured by imaging techniques, analysed with appropriate image analysis techniques...... and finally use the image data to predict or visualise food quality. A range of different food quality parameters was addressed, i.e. water distribution in bread throughout storage, time series analysis of chocolate milk stability, yoghurt glossiness, graininess and dullness and finally structure and meat...

  20. Comparably improved health-related quality of life after total arterial revascularization versus conventional coronary surgery--Copenhagen arterial revascularization randomized patency and outcome trial

    DEFF Research Database (Denmark)

    Damgaard, Sune; Lund, Jens T; Lilleør, Nikolaj B

    2011-01-01

    OBJECTIVE: We compared health-related quality of life up to 11 months after coronary artery bypass grafting using total arterial revascularization versus conventional coronary surgery. METHODS: In this randomized single-center trial, 161 patients underwent total arterial revascularization using.......01). For total arterial revascularization, there were also not statistically significant improvements for 'physical component summary' (P=0.09), 'bodily pain' (P=0.07) and 'vitality' (P=0.08). CONCLUSION: Health-related quality of life up to 1 year after total arterial revascularization is equal or slightly...... of the general Danish population. On all scales of the SF-36, there was statistically significant improvement at 3 and 11 months in both groups. For 'social functioning', the improvement following total arterial revascularization was significantly higher than following conventional revascularization (P=0...

  1. Normal myocardial perfusion imaging in the presence of significant coronary artery stenosis

    International Nuclear Information System (INIS)

    Tian Yueqin; He Zuoxiang; Fang Wei; Yang Minfu; Shen Rui

    2007-01-01

    Objective: The aim of this study was to investigate the factors which might result in normal myocardial perfusion imaging in the presence of significant coronary artery stenosis. Methods: One hundred and thirty-three patients [mean age of (59±10) years, 98 men, 35 women] who underwent coronary angiography and myocardial perfusion SPECT were retrospectively analyzed. Results: Forty-six (35%) patients performed adequate bicycle exercise testing and achieved more than 85% of their predicted maximal heart rates; while 87 (65%) patients did not. Eighty-four (63%) patients had single coronary stenosis, 31(23%) two-vessel and 17(13%) three-vessel diseases. The difference in stenosis severity among the vessels in 13 (76%) cases with three-vessel diseases was not more than 20%. There were totally 202 coronary artery stenosis: 93 (46%) in left anterior descending coronary artery (LAD), 52 (26%) left circumflex coronary artery (LCX), 52(26% ) right coronary artery (RCA) and 5 (2%) left main coronary artery (LM) disease. Eighty-six(43%) vessels had 50%-70% stenosis, 100 (49%) >70%-90% and 16(8% )more than 90%. Conclusion: Normal myocardial perfusion imaging with significant coronary artery stenosis can probably due to inadequate exercise, single vessel disease and mild to moderate stenotic lesion. (authors)

  2. Imaging of Small Animal Peripheral Artery Disease Models: Recent Advancements and Translational Potential

    Directory of Open Access Journals (Sweden)

    Jenny B. Lin

    2015-05-01

    Full Text Available Peripheral artery disease (PAD is a broad disorder encompassing multiple forms of arterial disease outside of the heart. As such, PAD development is a multifactorial process with a variety of manifestations. For example, aneurysms are pathological expansions of an artery that can lead to rupture, while ischemic atherosclerosis reduces blood flow, increasing the risk of claudication, poor wound healing, limb amputation, and stroke. Current PAD treatment is often ineffective or associated with serious risks, largely because these disorders are commonly undiagnosed or misdiagnosed. Active areas of research are focused on detecting and characterizing deleterious arterial changes at early stages using non-invasive imaging strategies, such as ultrasound, as well as emerging technologies like photoacoustic imaging. Earlier disease detection and characterization could improve interventional strategies, leading to better prognosis in PAD patients. While rodents are being used to investigate PAD pathophysiology, imaging of these animal models has been underutilized. This review focuses on structural and molecular information and disease progression revealed by recent imaging efforts of aortic, cerebral, and peripheral vascular disease models in mice, rats, and rabbits. Effective translation to humans involves better understanding of underlying PAD pathophysiology to develop novel therapeutics and apply non-invasive imaging techniques in the clinic.

  3. Different Imaging Strategies in Patients With Possible Basilar Artery Occlusion: Cost-Effectiveness Analysis.

    Science.gov (United States)

    Beyer, Sebastian E; Hunink, Myriam G; Schöberl, Florian; von Baumgarten, Louisa; Petersen, Steffen E; Dichgans, Martin; Janssen, Hendrik; Ertl-Wagner, Birgit; Reiser, Maximilian F; Sommer, Wieland H

    2015-07-01

    This study evaluated the cost-effectiveness of different noninvasive imaging strategies in patients with possible basilar artery occlusion. A Markov decision analytic model was used to evaluate long-term outcomes resulting from strategies using computed tomographic angiography (CTA), magnetic resonance imaging, nonenhanced CT, or duplex ultrasound with intravenous (IV) thrombolysis being administered after positive findings. The analysis was performed from the societal perspective based on US recommendations. Input parameters were derived from the literature. Costs were obtained from United States costing sources and published literature. Outcomes were lifetime costs, quality-adjusted life-years (QALYs), incremental cost-effectiveness ratios, and net monetary benefits, with a willingness-to-pay threshold of $80,000 per QALY. The strategy with the highest net monetary benefit was considered the most cost-effective. Extensive deterministic and probabilistic sensitivity analyses were performed to explore the effect of varying parameter values. In the reference case analysis, CTA dominated all other imaging strategies. CTA yielded 0.02 QALYs more than magnetic resonance imaging and 0.04 QALYs more than duplex ultrasound followed by CTA. At a willingness-to-pay threshold of $80,000 per QALY, CTA yielded the highest net monetary benefits. The probability that CTA is cost-effective was 96% at a willingness-to-pay threshold of $80,000/QALY. Sensitivity analyses showed that duplex ultrasound was cost-effective only for a prior probability of ≤0.02 and that these results were only minimally influenced by duplex ultrasound sensitivity and specificity. Nonenhanced CT and magnetic resonance imaging never became the most cost-effective strategy. Our results suggest that CTA in patients with possible basilar artery occlusion is cost-effective. © 2015 The Authors.

  4. Measurement of brain perfusion in newborns: Pulsed arterial spin labeling (PASL) versus pseudo-continuous arterial spin labeling (pCASL)

    Science.gov (United States)

    Boudes, Elodie; Gilbert, Guillaume; Leppert, Ilana Ruth; Tan, Xianming; Pike, G. Bruce; Saint-Martin, Christine; Wintermark, Pia

    2014-01-01

    Background Arterial spin labeling (ASL) perfusion-weighted imaging (PWI) by magnetic resonance imaging (MRI) has been shown to be useful for identifying asphyxiated newborns at risk of developing brain injury, whether or not therapeutic hypothermia was administered. However, this technique has been only rarely used in newborns until now, because of the challenges to obtain sufficient signal-to-noise ratio (SNR) and spatial resolution in newborns. Objective To compare two methods of ASL-PWI (i.e., single inversion-time pulsed arterial spin labeling [single TI PASL], and pseudo-continuous arterial spin labeling [pCASL]) to assess brain perfusion in asphyxiated newborns treated with therapeutic hypothermia and in healthy newborns. Design/methods We conducted a prospective cohort study of term asphyxiated newborns meeting the criteria for therapeutic hypothermia; four additional healthy term newborns were also included as controls. Each of the enrolled newborns was scanned at least once during the first month of life. Each MRI scan included conventional anatomical imaging, as well as PASL and pCASL PWI-MRI. Control and labeled images were registered separately to reduce the effect of motion artifacts. For each scan, the axial slice at the level of the basal ganglia was used for comparisons. Each scan was scored for its image quality. Quantification of whole-slice cerebral blood flow (CBF) was done afterwards using previously described formulas. Results A total number of 61 concomitant PASL and pCASL scans were obtained in nineteen asphyxiated newborns treated with therapeutic hypothermia and four healthy newborns. After discarding the scans with very poor image quality, 75% (46/61) remained for comparison between the two ASL methods. pCASL images presented a significantly superior image quality score compared to PASL images (p newborns. However, pCASL might be a better choice over PASL in newborns, as pCASL perfusion maps had a superior image quality that allowed a

  5. Automated classification and quantitative analysis of arterial and venous vessels in fundus images

    Science.gov (United States)

    Alam, Minhaj; Son, Taeyoon; Toslak, Devrim; Lim, Jennifer I.; Yao, Xincheng

    2018-02-01

    It is known that retinopathies may affect arteries and veins differently. Therefore, reliable differentiation of arteries and veins is essential for computer-aided analysis of fundus images. The purpose of this study is to validate one automated method for robust classification of arteries and veins (A-V) in digital fundus images. We combine optical density ratio (ODR) analysis and blood vessel tracking algorithm to classify arteries and veins. A matched filtering method is used to enhance retinal blood vessels. Bottom hat filtering and global thresholding are used to segment the vessel and skeleton individual blood vessels. The vessel tracking algorithm is used to locate the optic disk and to identify source nodes of blood vessels in optic disk area. Each node can be identified as vein or artery using ODR information. Using the source nodes as starting point, the whole vessel trace is then tracked and classified as vein or artery using vessel curvature and angle information. 50 color fundus images from diabetic retinopathy patients were used to test the algorithm. Sensitivity, specificity, and accuracy metrics were measured to assess the validity of the proposed classification method compared to ground truths created by two independent observers. The algorithm demonstrated 97.52% accuracy in identifying blood vessels as vein or artery. A quantitative analysis upon A-V classification showed that average A-V ratio of width for NPDR subjects with hypertension decreased significantly (43.13%).

  6. Social image quality

    Science.gov (United States)

    Qiu, Guoping; Kheiri, Ahmed

    2011-01-01

    Current subjective image quality assessments have been developed in the laboratory environments, under controlledconditions, and are dependent on the participation of limited numbers of observers. In this research, with the help of Web 2.0 and social media technology, a new method for building a subjective image quality metric has been developed where the observers are the Internet users. A website with a simple user interface that enables Internet users from anywhere at any time to vote for a better quality version of a pair of the same image has been constructed. Users' votes are recorded and used to rank the images according to their perceived visual qualities. We have developed three rank aggregation algorithms to process the recorded pair comparison data, the first uses a naive approach, the second employs a Condorcet method, and the third uses the Dykstra's extension of Bradley-Terry method. The website has been collecting data for about three months and has accumulated over 10,000 votes at the time of writing this paper. Results show that the Internet and its allied technologies such as crowdsourcing offer a promising new paradigm for image and video quality assessment where hundreds of thousands of Internet users can contribute to building more robust image quality metrics. We have made Internet user generated social image quality (SIQ) data of a public image database available online (http://www.hdri.cs.nott.ac.uk/siq/) to provide the image quality research community with a new source of ground truth data. The website continues to collect votes and will include more public image databases and will also be extended to include videos to collect social video quality (SVQ) data. All data will be public available on the website in due course.

  7. Coronary artery analysis: Computer-assisted selection of best-quality segments in multiple-phase coronary CT angiography

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Chuan, E-mail: chuan@umich.edu; Chan, Heang-Ping; Hadjiyski, Lubomir M.; Chughtai, Aamer; Wei, Jun; Kazerooni, Ella A. [Department of Radiology, The University of Michigan, Ann Arbor, Michigan 48109-0904 (United States)

    2016-10-15

    quality. The performance of our automated method was evaluated by comparing the automatically identified best-quality segments identified by the computer to those selected by the observers. Results: For the 20 test cases, 254 groups of corresponding vessel segments were identified after multiple phase registration and recursive matching. The AI-BQ segments agreed with the radiologist’s top 2 ranked segments in 78.3% of the 254 groups (Cohen’s kappa 0.60), and with the 4 nonradiologist observers in 76.8%, 84.3%, 83.9%, and 85.8% of the 254 groups. In addition, 89.4% of the AI-BQ segments agreed with at least two observers’ top 2 rankings, and 96.5% agreed with at least one observer’s top 2 rankings. In comparison, agreement between the four observers’ top ranked segment and the radiologist’s top 2 ranked segments were 79.9%, 80.7%, 82.3%, and 76.8%, respectively, with kappa values ranging from 0.56 to 0.68. Conclusions: The performance of our automated method for selecting the best-quality coronary segments from a multiple-phase cCTA acquisition was comparable to the selection made by human observers. This study demonstrates the potential usefulness of the automated method in clinical practice, enabling interpreting physicians to fully utilize the best available information in cCTA for diagnosis of coronary disease, without requiring manual search through the multiple phases and minimizing the variability in image phase selection for evaluation of coronary artery segments across the diversity of human readers with variations in expertise.

  8. Coronary artery analysis: Computer-assisted selection of best-quality segments in multiple-phase coronary CT angiography

    International Nuclear Information System (INIS)

    Zhou, Chuan; Chan, Heang-Ping; Hadjiyski, Lubomir M.; Chughtai, Aamer; Wei, Jun; Kazerooni, Ella A.

    2016-01-01

    quality. The performance of our automated method was evaluated by comparing the automatically identified best-quality segments identified by the computer to those selected by the observers. Results: For the 20 test cases, 254 groups of corresponding vessel segments were identified after multiple phase registration and recursive matching. The AI-BQ segments agreed with the radiologist’s top 2 ranked segments in 78.3% of the 254 groups (Cohen’s kappa 0.60), and with the 4 nonradiologist observers in 76.8%, 84.3%, 83.9%, and 85.8% of the 254 groups. In addition, 89.4% of the AI-BQ segments agreed with at least two observers’ top 2 rankings, and 96.5% agreed with at least one observer’s top 2 rankings. In comparison, agreement between the four observers’ top ranked segment and the radiologist’s top 2 ranked segments were 79.9%, 80.7%, 82.3%, and 76.8%, respectively, with kappa values ranging from 0.56 to 0.68. Conclusions: The performance of our automated method for selecting the best-quality coronary segments from a multiple-phase cCTA acquisition was comparable to the selection made by human observers. This study demonstrates the potential usefulness of the automated method in clinical practice, enabling interpreting physicians to fully utilize the best available information in cCTA for diagnosis of coronary disease, without requiring manual search through the multiple phases and minimizing the variability in image phase selection for evaluation of coronary artery segments across the diversity of human readers with variations in expertise.

  9. Imaging of Post-Traumatic Cardiac Rhabdomyolysis with Normal Coronary Arteries

    International Nuclear Information System (INIS)

    Filippo, M. de; Blasi, M. de; Paoli, G.; Sverzellati, N.; Beghi, C.; Ardissino, D.; Zompatori, M.

    2006-01-01

    Numerous cases of acute myocardial infarction (AMI) have been reported in the literature following closed chest injuries, due to post-traumatic dissection or thrombosis of a coronary artery. In the follow-up of AMI, wall thickness during diastole and systole provides important information on heart viability. Multidetector computed tomography (MDCT) is currently the only noninvasive instrumental investigation which provides an appreciable assessment of the coronary arteries, as well as heart wall thickness measurements. We describe and discuss the clinical and imaging findings, especially of MDCT, in a case of post-traumatic regional myocardial necrosis with normal coronary arteries

  10. Imaging of Post-Traumatic Cardiac Rhabdomyolysis with Normal Coronary Arteries

    Energy Technology Data Exchange (ETDEWEB)

    Filippo, M. de; Blasi, M. de; Paoli, G.; Sverzellati, N.; Beghi, C.; Ardissino, D.; Zompatori, M. [Univ. of Parma, Parma Hospital, Parma (Italy). Dept. of Clinical Sciences, Section of Radiological Sciences

    2006-11-15

    Numerous cases of acute myocardial infarction (AMI) have been reported in the literature following closed chest injuries, due to post-traumatic dissection or thrombosis of a coronary artery. In the follow-up of AMI, wall thickness during diastole and systole provides important information on heart viability. Multidetector computed tomography (MDCT) is currently the only noninvasive instrumental investigation which provides an appreciable assessment of the coronary arteries, as well as heart wall thickness measurements. We describe and discuss the clinical and imaging findings, especially of MDCT, in a case of post-traumatic regional myocardial necrosis with normal coronary arteries.

  11. Comparative imaging study in ultrasound, MRI, CT, and DSA using a multimodality renal artery phantom

    Energy Technology Data Exchange (ETDEWEB)

    King, Deirdre M.; Fagan, Andrew J.; Moran, Carmel M.; Browne, Jacinta E. [Medical Ultrasound Physics and Technology Group, School of Physics, Dublin Institute of Technology, Dublin 8 (Ireland); Centre for Advanced Medical Imaging (CAMI), St James' s Hospital, Dublin 8 (Ireland); Department of Medical Physics, University of Edinburgh, Edinburgh EH16 4TJ (United Kingdom); Medical Ultrasound Physics and Technology Group, School of Physics, Dublin Institute of Technology, Dublin 8 (Ireland)

    2011-02-15

    Purpose: A range of anatomically realistic multimodality renal artery phantoms consisting of vessels with varying degrees of stenosis was developed and evaluated using four imaging techniques currently used to detect renal artery stenosis (RAS). The spatial resolution required to visualize vascular geometry and the velocity detection performance required to adequately characterize blood flow in patients suffering from RAS are currently ill-defined, with the result that no one imaging modality has emerged as a gold standard technique for screening for this disease. Methods: The phantoms, which contained a range of stenosis values (0%, 30%, 50%, 70%, and 85%), were designed for use with ultrasound, magnetic resonance imaging, x-ray computed tomography, and x-ray digital subtraction angiography. The construction materials used were optimized with respect to their ultrasonic speed of sound and attenuation coefficient, MR relaxometry (T{sub 1},T{sub 2}) properties, and Hounsfield number/x-ray attenuation coefficient, with a design capable of tolerating high-pressure pulsatile flow. Fiducial targets, incorporated into the phantoms to allow for registration of images among modalities, were chosen to minimize geometric distortions. Results: High quality distortion-free images of the phantoms with good contrast between vessel lumen, fiducial markers, and background tissue to visualize all stenoses were obtained with each modality. Quantitative assessments of the grade of stenosis revealed significant discrepancies between modalities, with each underestimating the stenosis severity for the higher-stenosed phantoms (70% and 85%) by up to 14%, with the greatest discrepancy attributable to DSA. Conclusions: The design and construction of a range of anatomically realistic renal artery phantoms containing varying degrees of stenosis is described. Images obtained using the main four diagnostic techniques used to detect RAS were free from artifacts and exhibited adequate contrast

  12. Comparative imaging study in ultrasound, MRI, CT, and DSA using a multimodality renal artery phantom

    International Nuclear Information System (INIS)

    King, Deirdre M.; Fagan, Andrew J.; Moran, Carmel M.; Browne, Jacinta E.

    2011-01-01

    Purpose: A range of anatomically realistic multimodality renal artery phantoms consisting of vessels with varying degrees of stenosis was developed and evaluated using four imaging techniques currently used to detect renal artery stenosis (RAS). The spatial resolution required to visualize vascular geometry and the velocity detection performance required to adequately characterize blood flow in patients suffering from RAS are currently ill-defined, with the result that no one imaging modality has emerged as a gold standard technique for screening for this disease. Methods: The phantoms, which contained a range of stenosis values (0%, 30%, 50%, 70%, and 85%), were designed for use with ultrasound, magnetic resonance imaging, x-ray computed tomography, and x-ray digital subtraction angiography. The construction materials used were optimized with respect to their ultrasonic speed of sound and attenuation coefficient, MR relaxometry (T 1 ,T 2 ) properties, and Hounsfield number/x-ray attenuation coefficient, with a design capable of tolerating high-pressure pulsatile flow. Fiducial targets, incorporated into the phantoms to allow for registration of images among modalities, were chosen to minimize geometric distortions. Results: High quality distortion-free images of the phantoms with good contrast between vessel lumen, fiducial markers, and background tissue to visualize all stenoses were obtained with each modality. Quantitative assessments of the grade of stenosis revealed significant discrepancies between modalities, with each underestimating the stenosis severity for the higher-stenosed phantoms (70% and 85%) by up to 14%, with the greatest discrepancy attributable to DSA. Conclusions: The design and construction of a range of anatomically realistic renal artery phantoms containing varying degrees of stenosis is described. Images obtained using the main four diagnostic techniques used to detect RAS were free from artifacts and exhibited adequate contrast to allow

  13. Characteristics of a New X-Ray Imaging System for Interventional Procedures: Improved Image Quality and Reduced Radiation Dose.

    Science.gov (United States)

    Schernthaner, Ruediger E; Haroun, Reham R; Nguyen, Sonny; Duran, Rafael; Sohn, Jae Ho; Sahu, Sonia; Chapiro, Julius; Zhao, Yan; Radaelli, Alessandro; van der Bom, Imramsjah M; Mauti, Maria; Hong, Kelvin; Geschwind, Jean-François H; Lin, MingDe

    2018-03-01

    To compare image quality and radiation exposure between a new angiographic imaging system and the preceding generation system during uterine artery embolization (UAE). In this retrospective, IRB-approved two-arm study, 54 patients with symptomatic uterine fibroids were treated with UAE on two different angiographic imaging systems. The new system includes optimized acquisition parameters and real-time image processing algorithms. Air kerma (AK), dose area product (DAP) and acquisition time for digital fluoroscopy (DF) and digital subtraction angiography (DSA) were recorded. Body mass index was noted as well. DF image quality was assessed objectively by image noise measurements. DSA image quality was rated by two blinded, independent readers on a four-rank scale. Statistical differences were assessed with unpaired t tests and Wilcoxon rank-sum tests. There was no significant difference between the patients treated on the new (n = 36) and the old system (n = 18) regarding age (p = 0.10), BMI (p = 0.18), DF time (p = 0.35) and DSA time (p = 0.17). The new system significantly reduced the cumulative AK and DAP by 64 and 72%, respectively (median 0.58 Gy and 145.9 Gy*cm 2 vs. 1.62 Gy and 526.8 Gy*cm 2 , p < 0.01 for both). Specifically, DAP for DF and DSA decreased by 59% (75.3 vs. 181.9 Gy*cm 2 , p < 0.01) and 78% (67.6 vs. 312.2 Gy*cm 2 , p < 0.01), respectively. The new system achieved a significant decrease in DF image noise (p < 0.01) and a significantly better DSA image quality (p < 0.01). The new angiographic imaging system significantly improved image quality and reduced radiation exposure during UAE procedures.

  14. Coronary artery plaques: Cardiac CT with model-based and adaptive-statistical iterative reconstruction technique

    International Nuclear Information System (INIS)

    Scheffel, Hans; Stolzmann, Paul; Schlett, Christopher L.; Engel, Leif-Christopher; Major, Gyöngi Petra; Károlyi, Mihály; Do, Synho; Maurovich-Horvat, Pál; Hoffmann, Udo

    2012-01-01

    Objectives: To compare image quality of coronary artery plaque visualization at CT angiography with images reconstructed with filtered back projection (FBP), adaptive statistical iterative reconstruction (ASIR), and model based iterative reconstruction (MBIR) techniques. Methods: The coronary arteries of three ex vivo human hearts were imaged by CT and reconstructed with FBP, ASIR and MBIR. Coronary cross-sectional images were co-registered between the different reconstruction techniques and assessed for qualitative and quantitative image quality parameters. Readers were blinded to the reconstruction algorithm. Results: A total of 375 triplets of coronary cross-sectional images were co-registered. Using MBIR, 26% of the images were rated as having excellent overall image quality, which was significantly better as compared to ASIR and FBP (4% and 13%, respectively, all p < 0.001). Qualitative assessment of image noise demonstrated a noise reduction by using ASIR as compared to FBP (p < 0.01) and further noise reduction by using MBIR (p < 0.001). The contrast-to-noise-ratio (CNR) using MBIR was better as compared to ASIR and FBP (44 ± 19, 29 ± 15, 26 ± 9, respectively; all p < 0.001). Conclusions: Using MBIR improved image quality, reduced image noise and increased CNR as compared to the other available reconstruction techniques. This may further improve the visualization of coronary artery plaque and allow radiation reduction.

  15. Usefulness of 3D-CE renal artery MRA using parallel imaging with array spatial sensitivity encoding technique (ASSET)

    International Nuclear Information System (INIS)

    Shibasaki, Toshiro; Seno Masafumi; Takoi, Kunihiro; Sato, Hirofumi; Hino, Tsuyoshi

    2003-01-01

    In this study of 3D contrast enhanced MR angiography of the renal artery using the array spatial sensitivity encoding technique (ASSET), the acquisition time per 1 phase shortened fairly. And using the technique of spectral inversion at lipids (SPECIAL) together with ASSET, the quality of image was improved by emphasizing the contrast. The timing of acquisition was determined by the test injection. We started acquiring the MR angiography 2 seconds after the arrival of maximum enhancement of the test injection at the upper abdominal aorta near the renal artery. As a result parenchymal enhancement was not visible and depiction of the segmental artery was possible in 14 (82%) of 17 patients. At the present time we consider it better not to use the Fractional number of excitation (NEX) together with ASSET, as it may cause various artifacts. (author)

  16. Impaired left ventricular function has a detrimental effect on image quality in multi-detector row CT coronary angiography

    International Nuclear Information System (INIS)

    Manghat, N.E.; Morgan-Hughes, G.J.; Shaw, S.R.; Marshall, A.J.; Roobottom, C.A.

    2008-01-01

    Aim: To determine whether there is a relationship between left ventricular (LV) haemodynamic parameters, circulation times, and arterial contrast opacification that might affect the image quality of computed tomography (CT) coronary angiography. Methods: Thirty-six patients were included in the study: 18 with cardiomyopathy (CM) and LV dilatation of suspected ischaemic aetiology [age 57.9 ± 13.7 years, range 30-77 years; 14 male, four female; body mass index (BMI) = 27.7 ± 4.5, range 25.5-31.8] and 18 controls (age 62.3 ± 9.4 years, range 47-89 years; 10 male, eight female; BMI 27.8 ± 6.6; range 19.2-33.6). Coronary artery image quality was assessed using a three-point visual scale; contrast medium circulation times, aortic root contrast attenuation, and LV functional parameters were studied. Results: Visually reduced contrast opacification impaired image quality more often in the CM group than the control group (27.4 versus 5.1%). A total of 55.6% CM patients had a contrast transit time ranging from 30-75 s; the number of 'unassessable' segments increased with increasing transit time conforming to a fitted quadratic model (R 2 = 0.74). The relationship between LV ejection fraction and contrast attenuation may also conform to a quadratic model (R 2 = 0.71). Conclusion: LV haemodynamics influence coronary artery opacification using cardiac CT, and users imaging this subgroup must do so with the knowledge of this potential pitfall. The results indicate the need for further studies examining CT protocols in this clinical subgroup

  17. 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.)

  18. Classification of coronary artery tissues using optical coherence tomography imaging in Kawasaki disease

    Science.gov (United States)

    Abdolmanafi, Atefeh; Prasad, Arpan Suravi; Duong, Luc; Dahdah, Nagib

    2016-03-01

    Intravascular imaging modalities, such as Optical Coherence Tomography (OCT) allow nowadays improving diagnosis, treatment, follow-up, and even prevention of coronary artery disease in the adult. OCT has been recently used in children following Kawasaki disease (KD), the most prevalent acquired coronary artery disease during childhood with devastating complications. The assessment of coronary artery layers with OCT and early detection of coronary sequelae secondary to KD is a promising tool for preventing myocardial infarction in this population. More importantly, OCT is promising for tissue quantification of the inner vessel wall, including neo intima luminal myofibroblast proliferation, calcification, and fibrous scar deposits. The goal of this study is to classify the coronary artery layers of OCT imaging obtained from a series of KD patients. Our approach is focused on developing a robust Random Forest classifier built on the idea of randomly selecting a subset of features at each node and based on second- and higher-order statistical texture analysis which estimates the gray-level spatial distribution of images by specifying the local features of each pixel and extracting the statistics from their distribution. The average classification accuracy for intima and media are 76.36% and 73.72% respectively. Random forest classifier with texture analysis promises for classification of coronary artery tissue.

  19. In vivo MR perfusion imaging of renal artery stenosis

    International Nuclear Information System (INIS)

    Powers, T.; Lorenz, C.H.; Bain, R.; Holburn, G.; Price, R.R.

    1989-01-01

    Various techniques have been developed for noninvasive evaluation of renal blood flow. More important in the assessment of potential renal ischemia may be actual perfusion of the nephron mass. MR pulse sequences have been devised that allow perfusion imaging (PI) in a dog model of renal artery stenosis. Unilateral renal artery stenosis was created in mongrel dogs and quantitation of renal blood flow was obtained with radioactive microspheres. Perfusion imaging was performed on a 1.5-T system to obtain the apparent diffusion coefficient. During initial studies, it was found that the usual gradient factor used in brain PI was too high for renal studies; a factor of < 50 was found to be optimal. Additionally, respiratory gating with acquisition at end expiration was necessary to prevent renal motion. Recent studies have shown that PI reflects the asymmetry of flow in this model

  20. The evaluation of the radiation dose and image quality through the change of the tube voltage in cerebral CT angiography

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ji Won; Jung, Kang Kyo; Cho, Pyong Kon [Radiological Science, Catholic University of Daegu, Daegu (Korea, Republic of)

    2015-06-15

    To image diagnosis in neurovascular diseases using Multi-Detector Computed Tomography (MDCT), injected the same contrast material when inspecting Brain Computed Tomography Angiography (BCTA) to examine radiation dose and Image quality on changing Cerebral Artery CT number by tube voltage. Executed an examination with same condition[Beam Collimation 128 x 0.6 mm, Pitch 0.6, Rotation Time 0.5s, Slice Thickness 5.0 mm, Increment 5.0 mm, Delay Time 3.0 sec, Care Dose 4D (Demension ; D)] except for tube voltage on 50 call patients for BCTA and divided them into two groups (25 people for a group, group A: 80, group B: 120 kVp). From all the acquired images, set a ROI(Region of Interest) on four spots such as left cerebral artery, right cerebral artery, posterior cerebral artery and cerebral parenchyma to compare quantitative evaluation, qualitative evaluation and effective dose after measuring CT number value from Picture Archiving Communications System(PACS). Evaluating images with CT number acquired from BCTA examination, images with 80 kVp was 18 % higher in Signal to Noise Ratio and 19 % in Contrast to Noise Ratio than those with 120 kVp. It was seen that expose dose was decreased by over 50 % with tube voltage 80 kVp than with 120 kVp. Group A (25 patients) was examination with tube voltage 80 kVp while group B with 120 kVp to examine radiation dose and Image quality. It is considered effective to inspect with lower tube voltage than with conventional high kVp, which can reduce radiation dose without any affect on diagnosis.

  1. Hepatic artery perfusion imaging

    International Nuclear Information System (INIS)

    Thrall, J.H.; Gyves, J.W.; Ziessman, H.A.; Ensminger, W.D.

    1985-01-01

    Organ and region-selective intra-arterial chemotherapy have been used for more than two decades to treat malignant neoplasms in the extremities, head and neck region, pelvis, liver, and other areas. Substantial evidence of improved response to regional chemotherapy now exists, but there are stringent requirements for successful application of the regional technique. First, the chemotherapeutic agent employed must have appropriate pharmacokinetic and pharmacodynamic properties. Second, the drug must be reliably delivered to the tumor-bearing area. This typically requires an arteriographic assessment of the vascular supply of the tumor, followed by placement of a therapeutic catheter and confirmation that the ''watershed'' perfusion distribution from the catheter truly encompasses the tumor. Optimal catheter placement also minimizes perfusion of nontarget organs. Radionuclide perfusion imaging with technetium 99m-labeled particles, either microspheres or macroaggregates of albumin, has become the method of choice for making these assessments. Catheter placement itself is considered by many to represent a type of ''therapeutic'' intervention. However, once the catheter is in the hepatic artery the radionuclide perfusion technique can be used to assess adjunctive pharmacologic maneuvers designed to further exploit the regional approach to chemotherapy. This chapter presents the technetium Tc 99m macroaggregated albumin method for assessing catheter placement and the pharmacokinetic rationale for regional chemotherapy, and discusses two promising avenues for further intervention

  2. Three-dimensional imaging of the optic nerve using magnetic resonance angiography. Application to anterior communicating artery aneurysm and craniopharingioma

    International Nuclear Information System (INIS)

    Okuyama, Tohru; Fukuyama, Atsushi; Fukuyama, Koichi; Ikeno, Kunihiro; Araki, Hiroyuki; Okada, Kinya; Sohma, Noriko

    2005-01-01

    The purpose of this investigation was to analyze three-dimensional images of the optic nerve obtained by magnetic resonance angiography (MRA) in cases of anterior communicating artery aneurysm and craniopharingioma. Four ruptured anterior communicating artery aneurysms, five non-ruptured anterior communicating artery aneurysms and two craniopharingiomas were examined. The images were taken using MR/i Hispeed Plus 1.5 T Infinity version, and analyzed by Advantage Work station AW4.1. The routine MR imaging parameters are shown in Table. The imaging time was about 10 minutes. Analysis was made by reformation of images parallel to the optic nerve obtained from the original MRA images. The optic nerve and brain tumor were traced with paintbrush from one sheet to another of the reformed images after subtraction of the blood vessels around the anterior communicating artery in these reformed images, and then three-dimensional images were constructed. Three-dimensional images of the blood vessels were reconstructed from MIP (maximum intensity projection) images using the threshold method. The optic nerve and anterior communicating arterial aneurysm or brain tumor were both observed in the overlapped 3D-SSD (shaded surface display) images. The analysis time was about 15 minutes. Three-dimensional images of the optic nerve and anterior communicating artery aneurysm or brain tumor were able to be made in all cases. As a preoperative investigation for anterior communicating artery aneurysm or suprasellar brain tumor, we considered that three-dimensional imaging of the optic nerve is useful in the operative approach because the optic nerve acts as a merkmal for the anterior communicating aneurysm or brain tumor. (author)

  3. Digital image processing of arterial thrombi images, recorded by light transmission

    International Nuclear Information System (INIS)

    Nyssen, M.; Blockeel, E.; Bourgain, R.

    1985-01-01

    For several years, the formation and evolution of thrombi in small arteries of rats has been quantitatively studied at the Laboratory of Physiology and Physiopathology at the V.U.B. Global size parameters can be determined by projecting the image of a small arterial segment onto photosensitive cells. The transmitted light intensity is a measure for the thrombotic phenomenon. This unique method permitted extensive in vivo study of the platelet vessel wall interaction and local thrombosis. A development has emerged with the aim to improve the resolution of these measurements in order to get information on texture and form of the thrombotic mass at any stage of its evolution. In the particular situation studied, the dispersive properties of the flowing blood were found to be highly anisotropic. An explanation for this phenomenon could be given by considering the alignment of red blood cells in the blood flow. In order to explain the measured intensity profiles, the authors postulated alignment in the plane perpendicular to the flow as well. The theoretical predictions are in good agreement with the experimental values if we assume almost perfect alignment of the erythrocytes such that their short axes are pointing in the direction of the center of the artery. Conclusive evidence of the interaction between local flow properties and light transmission could be found by observing arteries with perturbated flow

  4. Comparison of high-resolution contrast-enhanced 3D MRA with digital subtraction angiography in the evaluation of hepatic arterial anatomy

    International Nuclear Information System (INIS)

    Matoba, M.; Tonami, H.; Kuginuki, M.; Yokota, H.; Takashima, S.; Yamamoto, I.

    2003-01-01

    AIM: To evaluate the validity of high-resolution contrast-enhanced three-dimensional magnetic resonance angiography (MRA) in defining hepatic arterial anatomy and to compare this with digital subtraction angiography (DSA). MATERIALS AND METHODS: MRA and DSA were performed in 30 patients. MRA was performed with breath-hold, gadolinium-enhanced, three-dimensional, fast low-angle shot sequence with a 512 pixel matrix. MRA was compared with DSA in terms of image quality and depiction of hepatic arterial anatomy. The agreement in image quality between MRA and DSA was determined with the kappa statistic. RESULTS: With respect to image quality, there was excellent or good correlation between MRA and DSA for the common hepatic artery (κ=0.85), proper hepatic artery (κ=0.72), gastroduodenal artery (κ=0.70), left hepatic artery (κ=0.49), left gastric artery (κ=0.50), splenic artery (κ=0.84), and superior mesenteric artery (κ=0.88). Poor correlation was found for the right hepatic artery (κ=0.18) and right gastric artery (κ=0.38). With regard to hepatic arterial anatomy, MRA correlated correctly with DSA in 28 of the 29 cases, i.e. 97% of patients. CONCLUSION: MRA is a useful technique for the evaluation of the hepatic artery, and for the vast majority of patients, MRA can replace intra-arterial DSA

  5. A fast analysis method for non-invasive imaging of blood flow in individual cerebral arteries using vessel-encoded arterial spin labelling angiography

    Science.gov (United States)

    Chappell, Michael A.; Okell, Thomas W.; Payne, Stephen J.; Jezzard, Peter; Woolrich, Mark W.

    2012-01-01

    Arterial spin labelling (ASL) MRI offers a non-invasive means to create blood-borne contrast in vivo for dynamic angiographic imaging. By spatial modulation of the ASL process it is possible to uniquely label individual arteries over a series of measurements, allowing each to be separately identified in the resulting angiographic images. This separation requires appropriate analysis for which a general Bayesian framework has previously been proposed. Here this framework is adapted for clinical dynamic angiographic imaging. This specifically addresses the issues of computational speed of the algorithm and the robustness required to deal with real patient data. An algorithm is proposed that can incorporate planning information about the arteries being imaged whilst adapting for subsequent patient movement. A fast maximum a posteriori solution is adopted and shown to be only marginally less accurate than Monte Carlo sampling under simulation. The final algorithm is demonstrated on in vivo data with analysis on a time scale of the order of 10 min, from both a healthy control and a patient with a vertebro-basilar occlusion. PMID:22322066

  6. Arterial hyperintensity on BLADE fluid-attenuated inversion recovery images (FLAIR) in hyperacute territorial infarction: comparison with conventional FLAIR

    Energy Technology Data Exchange (ETDEWEB)

    Kwag, Eujean; Lim, Soo Mee; Park, Ji Eun; Chae, In Hye [Ewha Womans University School of Medicine, Department of Radiology, Mokdong Hospital, Seoul (Korea, Republic of)

    2014-09-15

    To evaluate the utility of BLADE fluid-attenuated inversion recovery images (FLAIR) magnetic resonance (MR) imaging compared to conventional FLAIR for the detection of arterial hyperintensity (AH) in hyperacute territorial infarction. We retrospectively analysed MR images of patients with hyperacute (<6 h) territorial infarction over a 9-month study period. Special attention was paid to the presence or absence of AH in the frontal, parietal and temporal lobes and the number of AHs in the sylvian fissure. We also evaluated the presence of three kinds of artefacts on BLADE FLAIR and conventional FLAIR images. AH was seen in 41 (91 %) patients with conventional FLAIR and 45 (100 %) patients with BLADE FLAIR images. More instances of AH were detected in the frontal, parietal and temporal lobes and within the sylvian fissure using BLADE FLAIR. Motion artefacts, pulsation artefacts from the sigmoid sinus and incomplete cerebrospinal fluid (CSF) nulling that reduced image quality were observed more frequently on conventional FLAIR images than on BLADE FLAIR images. BLADE FLAIR sequences are more sensitive than conventional FLAIR for the detection of AH in hyperacute territorial infarctions and provide better image quality by reducing artefacts. They may be used in place of conventional FLAIR for patients with hyperacute stroke. (orig.)

  7. Renal cell carcinoma metastases to the pancreas - Value of arterial phase imaging at MDCT

    International Nuclear Information System (INIS)

    Corwin, Michael T.; Lamba, Ramit; McGahan, John P.; Wilson, Machelle

    2013-01-01

    Background: The pancreas is an increasingly recognized site of renal cell carcinoma metastases. It is important to determine the optimal MDCT protocol to best detect RCC metastases to the pancreas. Purpose: To compare the rate of detection of renal cell carcinoma metastases to the pancreas between arterial and portal venous phase MDCT. Material and Methods: A retrospective review of CTs of the abdomen yielded six patients with metastatic RCC to the pancreas. Five of six patients had pathologically proven clear cell RCC. Two blinded reviewers independently reported the number of pancreatic lesions seen in arterial and venous phases. Each lesion was graded as definite or possible. The number of lesions was determined by consensus review of both phases. Attenuation values were obtained for metastatic lesions and adjacent normal pancreas in both phases. Results: There were a total of 24 metastatic lesions to the pancreas. Reviewer 1 identified 20/24 (83.3%) lesions on the arterial phase images and 13/24 (54.2%) lesions on the venous phase. Seventeen of 20 (85.0%) arterial lesions were deemed definite and 9/13 (69.2%) venous lesions were definite. Reviewer 2 identified 19/24 (79.2%) lesions on the arterial phase and 14/24 (58.3%) on the venous phase. Seventeen of 19 (89.5%) arterial lesions were definite and 7/14 (50%) venous lesions were definite. Mean attenuation differential between lesion and pancreas was 114 HU and 39 HU for arterial and venous phases, respectively (P<0.0001). Conclusion: Detection of RCC metastases to the pancreas at MDCT is improved using arterial phase imaging compared to portal venous phase imaging

  8. High speed intravascular photoacoustic imaging of atherosclerotic arteries (Conference Presentation)

    Science.gov (United States)

    Piao, Zhonglie; Ma, Teng; Qu, Yueqiao; Li, Jiawen; Yu, Mingyue; He, Youmin; Shung, K. Kirk; Zhou, Qifa; Kim, Chang-Seok; Chen, Zhongping

    2016-02-01

    Cardiovascular disease is the leading cause of death in the industrialized nations. Accurate quantification of both the morphology and composition of lipid-rich vulnerable atherosclerotic plaque are essential for early detection and optimal treatment in clinics. In previous works, intravascular photoacoustic (IVPA) imaging for detection of lipid-rich plaque within coronary artery walls has been demonstrated in ex vivo, but the imaging speed is still limited. In order to increase the imaging speed, a high repetition rate laser is needed. In this work, we present a high speed integrated IVPA/US imaging system with a 500 Hz optical parametric oscillator laser at 1725 nm. A miniature catheter with 1.0 mm outer diameter was designed with a 200 μm multimode fiber and an ultrasound transducer with 45 MHz center frequency. The fiber was polished at 38 degree and enclosed in a glass capillary for total internal reflection. An optical/electrical rotary junction and pull-back mechanism was applied for rotating and linearly scanning the catheter to obtain three-dimensional imaging. Atherosclerotic rabbit abdominal aorta was imaged as two frame/second at 1725 nm. Furthermore, by wide tuning range of the laser wavelength from 1680 nm to 1770 nm, spectroscopic photoacoustic analysis of lipid-mimicking phantom and an human atherosclerotic artery was performed ex vivo. The results demonstrated that the developed IVPA/US imaging system is capable for high speed intravascular imaging for plaque detection.

  9. Carotid artery plaque imaging. Present status and new perspectives

    International Nuclear Information System (INIS)

    Hishikawa, Tomohito; Date, Isao; Iihara, Koji; Yamada, Naoaki; Ueda, Hatsue; Nagatsuka, Kazuyuki; Miyamoto, Susumu

    2010-01-01

    At present, the management of carotid artery (CA) stenosis depends largely on the degree of stenosis. CA plaque imaging is a modality, which assesses the nature of CA plaques objectively and less invasively, that has developed remarkably in recent years. The use of CA plaque imaging in the management of CA stenosis not only reveals the degree of stenosis but it can make the selection of treatment more appropriate by taking the plaque character into consideration. In this manuscript, we introduce ultrasound, intravascular ultrasound, angiography, magnetic resonance imaging (MRI), positron emission tomography (PET) and computed tomography (CT) and describe the present situation and new perspectives of CA plaque imaging. (author)

  10. Evaluation of life quality after arterial uterine embolization for leiomyoma

    International Nuclear Information System (INIS)

    Liu Zhaoyu; Shan Ming; Lu Zaiming; Zheng Jiahe; Zhang Jun; Sun Wei

    2007-01-01

    Objective: To evaluate the quality of life in women with uterine leiomyoma after treatment by uterine arterial embolization. Methodes: 118 patients of uterine leiomyoma were treated by uterine arterial embolization (UAE) from January 2003 to March 2005. The quality of life was measured by a fibroid specific symptom and HRQOL questionnaire pre-and post-embolization. Patients satisfaction was surveyed together with decrease of fibroids' mass measurement. Results: The decrease of fibroid size and uterine volume were 49.6% and 45.2% at 6 months after embolization with simultaneously obvious improvement of clinical symptoms. The scores of quality of life obviously improved in all follow-up subscales (P<0.001). No amenorrhea occurred during the period of observation with more than 60% of respondents acknowledging the positive improvement in fibroid-related symptoms though UAE; and 80% would probably or definitely take UAE as the first choice of treatment again. Conclusion: The treatment of symptomatic leiomyomas by UAE can improve the quality of life dramatically with a promising satisfaction. (authors)

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

    International Nuclear Information System (INIS)

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

    2009-01-01

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

  12. Vascular fluorscene casting and imaging cryomicrotomy for computerized three-dimensional renal arterial reconstruction

    NARCIS (Netherlands)

    Lagerveld, B.W.; Wee, ter R.; Rosette, de la J.J.M.C.H.; Spaan, J.A.; Wijkstra, H.

    2010-01-01

    OBJECTIVE To assess the combined use of a casting technique, cryomicrotomy imaging, and three-dimensional (3D) computer analysis as a method for visualizing and reconstructing the arterial vascular tree in a porcine renal model. MATERIAL AND METHODS The arterial branches of two porcine kidneys were

  13. Vascular fluorescence casting and imaging cryomicrotomy for computerized three-dimensional renal arterial reconstruction

    NARCIS (Netherlands)

    Lagerveld, Brunolf W.; ter Wee, Rene D.; de La Rosette, Jean J. M. C. H.; Spaan, Jos A. E.; Wijkstra, Hessel

    2007-01-01

    OBJECTIVES To assess the combined use of a casting technique, cryomicrotomy imaging, and three-dimensional (3D) computer analysis as a method for visualizing and reconstructing the arterial vascular tree in a porcine renal model. MATERIAL AND METHODS The arterial branches of two porcine kidneys were

  14. Coronary artery wall imaging in mice using osmium tetroxide and micro-computed tomography (micro-CT)

    International Nuclear Information System (INIS)

    Pai, Vinay M.; Kozlowski, Megan; Donahue, Danielle; Miller, Elishiah; Xiao, Xianghui; Chen, Marcus Y.; Yu, Zu-Xi; Connelly, Patricia; Jeffries, Kenneth; Wen, Han

    2012-01-01

    The high spatial resolution of micro-computed tomography (micro-CT) is ideal for 3D imaging of coronary arteries in intact mouse heart specimens. Previously, micro-CT of mouse heart specimens utilized intravascular contrast agents that hardened within the vessel lumen and allowed a vascular cast to be made. However, for mouse coronary artery disease models, it is highly desirable to image coronary artery walls and highlight plaques. For this purpose, we describe an ex vivo contrast-enhanced micro-CT imaging technique based on tissue staining with osmium tetroxide (OsO 4 ) solution. As a tissue-staining contrast agent, OsO 4 is retained in the vessel wall and surrounding tissue during the fixation process and cleared from the vessel lumens. Its high X-ray attenuation makes the artery wall visible in CT. Additionally, since OsO 4 preferentially binds to lipids, it highlights lipid deposition in the artery wall. We performed micro-CT of heart specimens of 5- to 25-week-old C57BL/6 wild-type mice and 5- to 13-week-old apolipoprotein E knockout (apoE -/- ) mice at 10 μm resolution. The results show that walls of coronary arteries as small as 45 μm in diameter are visible using a table-top micro-CT scanner. Similar image clarity was achieved with 1/2000th the scan time using a synchrotron CT scanner. In 13-week-old apoE mice, lipid-rich plaques are visible in the aorta. Our study shows that the combination of OsO 4 and micro-CT permits the visualization of the coronary artery wall in intact mouse hearts.

  15. Image quality of ct angiography using model-based iterative reconstruction in infants with congenital heart disease: Comparison with filtered back projection and hybrid iterative reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Jia, Qianjun, E-mail: jiaqianjun@126.com [Southern Medical University, Guangzhou, Guangdong (China); Department of Radiology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong (China); Department of Catheterization Lab, Guangdong Cardiovascular Institute, Guangdong Provincial Key Laboratory of South China Structural Heart Disease, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong (China); Zhuang, Jian, E-mail: zhuangjian5413@tom.com [Department of Cardiac Surgery, Guangdong Cardiovascular Institute, Guangdong Provincial Key Laboratory of South China Structural Heart Disease, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong (China); Jiang, Jun, E-mail: 81711587@qq.com [Department of Radiology, Shenzhen Second People’s Hospital, Shenzhen, Guangdong (China); Li, Jiahua, E-mail: 970872804@qq.com [Department of Catheterization Lab, Guangdong Cardiovascular Institute, Guangdong Provincial Key Laboratory of South China Structural Heart Disease, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong (China); Huang, Meiping, E-mail: huangmeiping_vip@163.com [Department of Catheterization Lab, Guangdong Cardiovascular Institute, Guangdong Provincial Key Laboratory of South China Structural Heart Disease, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong (China); Southern Medical University, Guangzhou, Guangdong (China); Liang, Changhong, E-mail: cjr.lchh@vip.163.com [Department of Radiology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong (China); Southern Medical University, Guangzhou, Guangdong (China)

    2017-01-15

    Purpose: To compare the image quality, rate of coronary artery visualization and diagnostic accuracy of 256-slice multi-detector computed tomography angiography (CTA) with prospective electrocardiographic (ECG) triggering at a tube voltage of 80 kVp between 3 reconstruction algorithms (filtered back projection (FBP), hybrid iterative reconstruction (iDose{sup 4}) and iterative model reconstruction (IMR)) in infants with congenital heart disease (CHD). Methods: Fifty-one infants with CHD who underwent cardiac CTA in our institution between December 2014 and March 2015 were included. The effective radiation doses were calculated. Imaging data were reconstructed using the FBP, iDose{sup 4} and IMR algorithms. Parameters of objective image quality (noise, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR)); subjective image quality (overall image quality, image noise and margin sharpness); coronary artery visibility; and diagnostic accuracy for the three algorithms were measured and compared. Results: The mean effective radiation dose was 0.61 ± 0.32 mSv. Compared to FBP and iDose{sup 4}, IMR yielded significantly lower noise (P < 0.01), higher SNR and CNR values (P < 0.01), and a greater subjective image quality score (P < 0.01). The total number of coronary segments visualized was significantly higher for both iDose{sup 4} and IMR than for FBP (P = 0.002 and P = 0.025, respectively), but there was no significant difference in this parameter between iDose{sup 4} and IMR (P = 0.397). There was no significant difference in the diagnostic accuracy between the FBP, iDose{sup 4} and IMR algorithms (χ{sup 2} = 0.343, P = 0.842). Conclusions: For infants with CHD undergoing cardiac CTA, the IMR reconstruction algorithm provided significantly increased objective and subjective image quality compared with the FBP and iDose{sup 4} algorithms. However, IMR did not improve the diagnostic accuracy or coronary artery visualization compared with iDose{sup 4}.

  16. Magnetic resonance angiography in infrapopliteal arterial disease: prospective comparison of 1.5 and 3 Tesla magnetic resonance imaging.

    Science.gov (United States)

    Diehm, Nicolas; Kickuth, Ralph; Baumgartner, Iris; Srivastav, Sudesh K; Gretener, Silvia; Husmann, Marc J; Jaccard, Yves; Do, Do Dai; Triller, Juergen; Bonel, Harald M

    2007-06-01

    To prospectively determine the accuracy of 1.5 Tesla (T) and 3 T magnetic resonance angiography (MRA) versus digital subtraction angiography (DSA) in the depiction of infrageniculate arteries in patients with symptomatic peripheral arterial disease. A prospective 1.5 T, 3 T MRA, and DSA comparison was used to evaluate 360 vessel segments in 10 patients (15 limbs) with chronic symptomatic peripheral arterial disease. Selective DSA was performed within 30 days before both MRAs. The accuracy of 1.5 T and 3 T MRA was compared with DSA as the standard of reference by consensus agreement of 2 experienced readers. Signal-to-noise ratios (SNR) and signal-difference-to-noise ratios (SDNRs) were quantified. No significant difference in overall image quality, sufficiency for diagnosis, depiction of arterial anatomy, motion artifacts, and venous overlap was found comparing 1.5 T with 3 T MRA (P > 0.05 by Wilcoxon signed rank and as by Cohen k test). Overall sensitivity of 1.5 and 3 T MRA for detection of significant arterial stenosis was 79% and 82%, and specificity was 87% and 87% for both modalities, respectively. Interobserver agreement was excellent k > 0.8, P < 0.05) for 1.5 T as well as for 3 T MRA. SNR and SDNR were significantly increased using the 3 T system (average increase: 36.5%, P < 0.032 by t test, and 38.5%, P < 0.037 respectively). Despite marked improvement of SDNR, 3 T MRA does not yet provide a significantly higher accuracy in diagnostic imaging of atherosclerotic lesions below the knee joint as compared with 1.5 T MRA.

  17. Imaging and management of atherosclerotic renal artery stenosis

    International Nuclear Information System (INIS)

    Sarkodieh, J.E.; Walden, S.H.; Low, D.

    2013-01-01

    Renal artery stenosis (RAS) causes chronic, progressive ischaemic nephropathy and is the most common cause of secondary hypertension. Radiology plays a large part in the diagnosis, with a variety of imaging techniques available. Each has relative advantages and disadvantages depending on each unique clinical setting. We discuss and illustrate the range of diagnostic methods and interventional techniques for diagnosis and management of RAS and review the current evidence base for endovascular therapy compared with optimal medical management. Knowledge of the relative merits of the various forms of imaging and treatment will guide decision making in the multidisciplinary setting

  18. Functional assessment of sequential coronary artery fistula and coronary artery stenosis with fractional flow reserve and stress adenosine myocardial perfusion imaging

    Directory of Open Access Journals (Sweden)

    Kuan Leong Yew

    2015-10-01

    Full Text Available Coronary artery fistula is an abnormal connection between one coronary artery to another coronary artery or cardiac chambers. The coronary artery fistula may cause significant shunting of blood and cause “pseudo-stenosis” or “steal phenomenon”. This will also accentuate pre-existing mild-moderate de novo coronary lesions with resultant greater pressure gradient difference across the lesions. Thus, fractional flow reserve can be a useful tool to guide intervention decision on the coronary artery fistula. There are very few published reports regarding the use of FFR to assess coronary artery fistula. In fact, there is no outcome data regarding the deferment of coronary artery fistula intervention when the FFR is not physiologically significant. This case highlighted the use of FFR to evaluate the functional significance of coronary fistula in the setting of ischemia evaluation and it was proven to be safe to defer intervention with good 3 year clinical outcome. Stress adenosine myocardial perfusion imaging correlated with the FFR result.

  19. Ligation of the internal maxillary artery for intractable epistaxis. 3D imaging of internal maxillary artery using helical CT scan

    International Nuclear Information System (INIS)

    Handa, Toru; Yazin, Koji; Hirakawa, Katsuhiro; Fukushima, Noriyuki; Takumida, Masaya; Hirata, Shitau; Iguchi, Tetsuhiko; Amano, Yoshiharu

    2001-01-01

    Sever posterior epistaxis is one of the serious clinical problems. Nasal bleeding usually occurs in the anterior septal region, where it can be seen easily and controlled with topical cautery or localized packing. When the bleeding occurs in the posterior nose, it becomes a more serious problem. Many methods have been used to control posterior epistaxis. Some of these are electrocautery, posterior nasal packing, vascular ligation and therapeutic percutaneous embolization. Between 1997 and 2000, nineteen patients were admitted to our hospital because of intractable epistaxis. There were 16 male and 3 female patients whose average age was 55 years. Ten of 19 patients were hypertensive, and none of these had undergoing treatment. Five of 19 patients received maxillary artery ligation. Clinical applications of 3D imaging of the internal maxillary artery using helical CT scan were done for 5 patients. These images were helpful for planning of ligation of the internal maxillary artery. (author)

  20. Ligation of the internal maxillary artery for intractable epistaxis. 3D imaging of internal maxillary artery using helical CT scan

    Energy Technology Data Exchange (ETDEWEB)

    Handa, Toru [Akitsu Prefectual Hospital, Hiroshima (Japan); Yazin, Koji; Hirakawa, Katsuhiro; Fukushima, Noriyuki; Takumida, Masaya; Hirata, Shitau; Iguchi, Tetsuhiko; Amano, Yoshiharu

    2001-03-01

    Sever posterior epistaxis is one of the serious clinical problems. Nasal bleeding usually occurs in the anterior septal region, where it can be seen easily and controlled with topical cautery or localized packing. When the bleeding occurs in the posterior nose, it becomes a more serious problem. Many methods have been used to control posterior epistaxis. Some of these are electrocautery, posterior nasal packing, vascular ligation and therapeutic percutaneous embolization. Between 1997 and 2000, nineteen patients were admitted to our hospital because of intractable epistaxis. There were 16 male and 3 female patients whose average age was 55 years. Ten of 19 patients were hypertensive, and none of these had undergoing treatment. Five of 19 patients received maxillary artery ligation. Clinical applications of 3D imaging of the internal maxillary artery using helical CT scan were done for 5 patients. These images were helpful for planning of ligation of the internal maxillary artery. (author)

  1. Diagnosis Of The Risk For Carotid Artery Stenos Based On Thermal Model In Infrared Images

    Directory of Open Access Journals (Sweden)

    Fatemeh Valipoori Goodarzi

    2017-02-01

    Full Text Available Background and purpose: Ischemic stroke is the third leading cause of death and a common cause of hospitalization in the United States of America and is also an important factor for Inability of patients and carotid stenos is one of the most important factors in creating it. Now, Imaging studies include: Angiography, MRI, CT scan and Doppler ultrasonography , are used to detect carotid artery stenos that is one of the most important causes of ischemic stroke. However, each method has unique advantages and disadvantages, that many of them will have a compromise between performance and accuracy versus easy usage and cost considerations. In contrast, in this paper, thermography is used as a non-invasive and cost effective to detect carotid artery Stenos and thus the risk of stroke. Materials and methods: This study is done on a series of thermal images obtained from the Clinical Center in California. In this imaging, the automatic detection of carotid artery stenos and thus Risk for stroke was done, based on: (1 the difference of average temperature between the right and left carotid arteries in the neck (2 The presence or absence of internal and external carotid arteries. Results: In this study, with the survey conducted by a specialist brain of patients had been previously, the accuracy of this work is confirmed. the techniques and points that are Experimental and  scientifically based  and obtained in this study, can help to doctors for Early detection of Artery disease, based on analysis of thermal images . Conclusion: The method presented in this paper is considered as a non-invasive and cost-effective method that automatically operates to detect the carotid arteries and prevent the Risk for stroke.

  2. Imaging of blunt arterial trauma of the upper extremity in children

    International Nuclear Information System (INIS)

    Hodina, M.; Gudinchet, F.; Schnyder, P.; Reinberg, O.

    2001-01-01

    We report four patients with blunt arterial trauma of the upper limb following unusual mechanisms of injury in two patients (one fell on the handlebars of his bicycle, the second was crushed by a moving lawn mower) and due to bicycle accidents in two further patients. The use of digital subtraction angiography (DSA) in all patients, together with colour Doppler imaging (CDI) in one patient, provided optimum preoperative identification and localisation of the arterial lesions. (orig.)

  3. Imaging of peripheral arteries by 16-row multidetector computed tomography angiography: A feasible tool?

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, Anuj [Department of Radiology, National Organ Transplant Program, Tripoli (Libyan Arab Jamahiriya)]. E-mail: dranujmish@yahoo.com; Bhaktarahalli, Jahnavi Narayanaswamy [Department of Clinical Pathology, Tripoli Medical Centre, Tripoli (Libyan Arab Jamahiriya); Ehtuish, Ehtuish F. [Department of Surgery, National Organ Transplant Program, Tripoli (Libyan Arab Jamahiriya)

    2007-03-15

    Objective: To evaluate the efficacy of multidetector (16-row) computed tomography (MDCT) in imaging the upper and lower limb arterial tree in trauma and peripheral arterial occlusive disease (PAOD). Methods: Thirty-three patients underwent MDCT angiography (MDCTA) of the upper or the lower limb on 16-row MDCT scanner between November, 2004 and July, 2005. The findings were compared with the surgical outcome in cases with trauma and suspected arterial injuries or color Doppler correlation was obtained for patients of PAOD. Results: MDCTA allowed a comprehensive diagnostic work-up in all trauma cases with suspected arterial injuries. In the 23 cases of PAOD, MDCT adequately demonstrated the presence of stenosis or occlusion, its degree and extent, the presence of collaterals and plaques. Conclusion: Our experience of CT angiography (CTA) with 16-row MDCT scanner has clearly demonstrated its efficacy as a promising, new, fast, accurate, safe and non-invasive imaging modality of choice in cases of trauma with suspected arterial injuries and as a useful screening modality in cases of PAOD for diagnosis and for grading.

  4. Imaging of peripheral arteries by 16-row multidetector computed tomography angiography: A feasible tool?

    International Nuclear Information System (INIS)

    Mishra, Anuj; Bhaktarahalli, Jahnavi Narayanaswamy; Ehtuish, Ehtuish F.

    2007-01-01

    Objective: To evaluate the efficacy of multidetector (16-row) computed tomography (MDCT) in imaging the upper and lower limb arterial tree in trauma and peripheral arterial occlusive disease (PAOD). Methods: Thirty-three patients underwent MDCT angiography (MDCTA) of the upper or the lower limb on 16-row MDCT scanner between November, 2004 and July, 2005. The findings were compared with the surgical outcome in cases with trauma and suspected arterial injuries or color Doppler correlation was obtained for patients of PAOD. Results: MDCTA allowed a comprehensive diagnostic work-up in all trauma cases with suspected arterial injuries. In the 23 cases of PAOD, MDCT adequately demonstrated the presence of stenosis or occlusion, its degree and extent, the presence of collaterals and plaques. Conclusion: Our experience of CT angiography (CTA) with 16-row MDCT scanner has clearly demonstrated its efficacy as a promising, new, fast, accurate, safe and non-invasive imaging modality of choice in cases of trauma with suspected arterial injuries and as a useful screening modality in cases of PAOD for diagnosis and for grading

  5. Image quality of low-dose CCTA in obese patients: impact of high-definition computed tomography and adaptive statistical iterative reconstruction.

    Science.gov (United States)

    Gebhard, Cathérine; Fuchs, Tobias A; Fiechter, Michael; Stehli, Julia; Stähli, Barbara E; Gaemperli, Oliver; Kaufmann, Philipp A

    2013-10-01

    The accuracy of coronary computed tomography angiography (CCTA) in obese persons is compromised by increased image noise. We investigated CCTA image quality acquired on a high-definition 64-slice CT scanner using modern adaptive statistical iterative reconstruction (ASIR). Seventy overweight and obese patients (24 males; mean age 57 years, mean body mass index 33 kg/m(2)) were studied with clinically-indicated contrast enhanced CCTA. Thirty-five patients underwent a standard definition protocol with filtered backprojection reconstruction (SD-FBP) while 35 patients matched for gender, age, body mass index and coronary artery calcifications underwent a novel high definition protocol with ASIR (HD-ASIR). Segment by segment image quality was assessed using a four-point scale (1 = excellent, 2 = good, 3 = moderate, 4 = non-diagnostic) and revealed better scores for HD-ASIR compared to SD-FBP (1.5 ± 0.43 vs. 1.8 ± 0.48; p ASIR as compared to 1.4 ± 0.4 mm for SD-FBP (p ASIR (388.3 ± 109.6 versus 350.6 ± 90.3 Hounsfield Units, HU; p ASIR vs. SD-ASIR respectively). Compared to a standard definition backprojection protocol (SD-FBP), a newer high definition scan protocol in combination with ASIR (HD-ASIR) incrementally improved image quality and visualization of distal coronary artery segments in overweight and obese individuals, without increasing image noise and radiation dose.

  6. Breath-hold imaging of the coronary arteries using Quiescent-Interval Slice-Selective (QISS) magnetic resonance angiography: pilot study at 1.5 Tesla and 3 Tesla.

    Science.gov (United States)

    Edelman, Robert R; Giri, S; Pursnani, A; Botelho, M P F; Li, W; Koktzoglou, I

    2015-11-23

    Coronary magnetic resonance angiography (MRA) is usually obtained with a free-breathing navigator-gated 3D acquisition. Our aim was to develop an alternative breath-hold approach that would allow the coronary arteries to be evaluated in a much shorter time and without risk of degradation by respiratory motion artifacts. For this purpose, we implemented a breath-hold, non-contrast-enhanced, quiescent-interval slice-selective (QISS) 2D technique. Sequence performance was compared at 1.5 and 3 Tesla using both radial and Cartesian k-space trajectories. The left coronary circulation was imaged in six healthy subjects and two patients with coronary artery disease. Breath-hold QISS was compared with T2-prepared 2D balanced steady-state free-precession (bSSFP) and free-breathing, navigator-gated 3D bSSFP. Approximately 10 2.1-mm thick slices were acquired in a single ~20-s breath-hold using two-shot QISS. QISS contrast-to-noise ratio (CNR) was 1.5-fold higher at 3 Tesla than at 1.5 Tesla. Cartesian QISS provided the best coronary-to-myocardium CNR, whereas radial QISS provided the sharpest coronary images. QISS image quality exceeded that of free-breathing 3D coronary MRA with few artifacts at either field strength. Compared with T2-prepared 2D bSSFP, multi-slice capability was not restricted by the specific absorption rate at 3 Tesla and pericardial fluid signal was better suppressed. In addition to depicting the coronary arteries, QISS could image intra-cardiac structures, pericardium, and the aortic root in arbitrary slice orientations. Breath-hold QISS is a simple, versatile, and time-efficient method for coronary MRA that provides excellent image quality at both 1.5 and 3 Tesla. Image quality exceeded that of free-breathing, navigator-gated 3D MRA in a much shorter scan time. QISS also allowed rapid multi-slice bright-blood, diastolic phase imaging of the heart, which may have complementary value to multi-phase cine imaging. We conclude that, with further clinical

  7. Carotid artery B-mode ultrasound image segmentation based on morphology, geometry and gradient direction

    Science.gov (United States)

    Sunarya, I. Made Gede; Yuniarno, Eko Mulyanto; Purnomo, Mauridhi Hery; Sardjono, Tri Arief; Sunu, Ismoyo; Purnama, I. Ketut Eddy

    2017-06-01

    Carotid Artery (CA) is one of the vital organs in the human body. CA features that can be used are position, size and volume. Position feature can used to determine the preliminary initialization of the tracking. Examination of the CA features can use Ultrasound. Ultrasound imaging can be operated dependently by an skilled operator, hence there could be some differences in the images result obtained by two or more different operators. This can affect the process of determining of CA. To reduce the level of subjectivity among operators, it can determine the position of the CA automatically. In this study, the proposed method is to segment CA in B-Mode Ultrasound Image based on morphology, geometry and gradient direction. This study consists of three steps, the data collection, preprocessing and artery segmentation. The data used in this study were taken directly by the researchers and taken from the Brno university's signal processing lab database. Each data set contains 100 carotid artery B-Mode ultrasound image. Artery is modeled using ellipse with center c, major axis a and minor axis b. The proposed method has a high value on each data set, 97% (data set 1), 73 % (data set 2), 87% (data set 3). This segmentation results will then be used in the process of tracking the CA.

  8. Imaging before and after uterine artery embolization

    International Nuclear Information System (INIS)

    Kroencke, T.J.

    2008-01-01

    Percutaneous catheter-based embolization treatment of symptomatic uterine fibroids has evolved into the most widely used alternative therapeutic approach to surgical treatment worldwide. Uterine artery embolization (UAE) induces infarction of leiomyomas, resulting in ischemic necrosis, hyaline degeneration, and size reduction with resolution of associated symptoms. Published experience suggests that UAE is an effective and reliable option for treating uterine fibroids with high patient satisfaction. Magnetic resonance imaging (MRI) is superior to ultrasonography for determining the site, size and number of fibroids, which is important for establishing the indication for UAE. Other potential advantages of MRI include the option of performing MR angiography (MRA) and obtaining contrast-enhanced images for monitoring the outcome of UAE and assessing possible complications after UAE. (orig.) [de

  9. Identification of arteries and veins in cerebral angiography fluoroscopic images

    Science.gov (United States)

    Andra Tache, Irina

    2017-11-01

    In the present study a new method for pixels tagging into arteries and veins classes from temporal cerebral angiography is presented. This need comes from the neurosurgeon who is evaluating the fluoroscopic angiography and the magnetic resonance images from the brain in order to locate the fistula of the patients who suffer from arterio-venous malformation. The method includes the elimination of the background pixels from a previous segmentation and the generation of the time intensity curves for each remaining pixel. The later undergo signal processing in order to extract the characteristic parameters needed for applying the k-means clustering algorithm. Some of the parameters are: the phase and the maximum amplitude extracted from the Fourier transform, the standard deviation and the mean value. The tagged classes are represented into images which then are re-classified by an expert into artery and vein pixels.

  10. Noncontrast magnetic resonance angiography of the hand: improved arterial conspicuity by multidirectional flow-sensitive dephasing magnetization preparation in 3D balanced steady-state free precession imaging.

    Science.gov (United States)

    Fan, Zhaoyang; Hodnett, Philip A; Davarpanah, Amir H; Scanlon, Timothy G; Sheehan, John J; Varga, John; Carr, James C; Li, Debiao

    2011-08-01

    : To develop a flow-sensitive dephasing (FSD) preparative scheme to facilitate multidirectional flow-signal suppression in 3-dimensional balanced steady-state free precession imaging and to validate the feasibility of the refined sequence for noncontrast magnetic resonance angiography (NC-MRA) of the hand. : A new FSD preparative scheme was developed that combines 2 conventional FSD modules. Studies using a flow phantom (gadolinium-doped water 15 cm/s) and the hands of 11 healthy volunteers (6 males and 5 females) were performed to compare the proposed FSD scheme with its conventional counterpart with respect to the signal suppression of multidirectional flow. In 9 of the 11 healthy subjects and 2 patients with suspected vasculitis and documented Raynaud phenomenon, respectively, 3-dimensional balanced steady-state free precession imaging coupled with the new FSD scheme was compared with spatial-resolution-matched (0.94 × 0.94 × 0.94 mm) contrast-enhanced magnetic resonance angiography (0.15 mmol/kg gadopentetate dimeglumine) in terms of overall image quality, venous contamination, motion degradation, and arterial conspicuity. : The proposed FSD scheme was able to suppress 2-dimensional flow signal in the flow phantom and hands and yielded significantly higher arterial conspicuity scores than the conventional scheme did on NC-MRA at the regions of common digitals and proper digitals. Compared with contrast-enhanced magnetic resonance angiography, the refined NC-MRA technique yielded comparable overall image quality and motion degradation, significantly less venous contamination, and significantly higher arterial conspicuity score at digital arteries. : The FSD-based NC-MRA technique is improved in the depiction of multidirectional flow by applying a 2-module FSD preparation, which enhances its potential to serve as an alternative magnetic resonance angiography technique for the assessment of hand vascular abnormalities.

  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. Comparison of image quality and portal vein visualization in IADSP using iopamidol, 76 % urografin, and 38 % urografin

    International Nuclear Information System (INIS)

    Shibata, Toshiya; Yamashita, Keiji; Konishi, Junji; Hayakawa, Katsumi; Hamanaka, Daizaburo; Okumura, Ryouji; Ishi, Yasushi.

    1988-01-01

    The image quality of intra-arterial digital subtraction portography (IADSP) was studied in 50 randomly assigned patients using one of three contrast agents: iopamidol, (IOP, 20 cases), 76 % Na-meglumine diatrzioate (76 % UG, 20 cases), and 38 % Na-meglumine diatrizoate (38 % UG, 10 cases). Sharpness and contrast of images, and portal vein visualization were evaluated in these groups. IOP provided better image quality and portal vein visualization than 76 % UG. There was no significant difference between them in terms of side effects, such as contrast medium-induced pain and feeling of warmth, or changes in physiological parameters like blood pressure and heart rate. When a low osmolar contrast agent like IOP passes through the mesentery capillary bed, the eflux of the contrast agent into the interstitial space and the influex of water into the capillary may be less, resulting in less dilution of the contrast agent in the superior mesenteric vein. This might explain the better image quality and portal vein visualization of IOP. (author)

  13. Image quality, radiation dose and diagnostic accuracy of 70 kVp whole brain volumetric CT perfusion imaging: a preliminary study

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Xiao Kun; Ni, Qian Qian; Zhou, Chang Sheng; Chen, Guo Zhong; Luo, Song; Zhang, Long Jiang; Lu, Guang Ming [Medical School of Nanjing University, Department of Medical Imaging, Jinling Hospital, Nanjing, Jiangsu (China); Schoepf, U.J. [Medical School of Nanjing University, Department of Medical Imaging, Jinling Hospital, Nanjing, Jiangsu (China); Medical University of South Carolina, Ashley River Tower, Division of Cardiovascular Imaging, Charleston, SC (United States); Fuller, Stephen R.; De Cecco, Carlo N. [Medical University of South Carolina, Ashley River Tower, Division of Cardiovascular Imaging, Charleston, SC (United States)

    2016-11-15

    To evaluate image quality and diagnostic accuracy for acute infarct detection and radiation dose of 70 kVp whole brain CT perfusion (CTP) and CT angiography (CTA) reconstructed from CTP source data. Patients were divided into three groups (n = 50 each): group A, 80 kVp, 21 scanning time points; groups B, 70 kVp, 21 scanning time points; group C, 70 kVp, 17 scanning time points. Objective and subjective image quality of CTP and CTA were compared. Diagnostic accuracy for detecting acute infarct and cerebral artery stenosis ≥ 50 % was calculated for CTP and CTA with diffusion weighted imaging and digital subtraction angiography as reference standards. Effective radiation dose was compared. There were no differences in any perfusion parameter value between three groups (P > 0.05). No difference was found in subjective image quality between three groups (P > 0.05). Diagnostic accuracy for detecting acute infarct and vascular stenosis showed no difference between three groups (P > 0.05). Compared with group A, radiation doses of groups B and C were decreased by 28 % and 37 % (both P < 0.001), respectively. Compared with 80 kVp protocol, 70 kVp brain CTP allows comparable vascular and perfusion assessment and lower radiation dose while maintaining high diagnostic accuracy in detecting acute infarct. (orig.)

  14. Comparison of Power Versus Manual Injection in Bolus Shape and Image Quality on Contrast-Enhanced Magnetic Resonance Angiography: An Experimental Study in a Swine Model.

    Science.gov (United States)

    Tsuboyama, Takahiro; Jost, Gregor; Pietsch, Hubertus; Tomiyama, Noriyuki

    2017-09-01

    The aim of this study was to compare power versus manual injection in bolus shape and image quality on contrast-enhanced magnetic resonance angiography (CE-MRA). Three types of CE-MRA (head-neck 3-dimensional [3D] MRA with a test-bolus technique, thoracic-abdominal 3D MRA with a bolus-tracking technique, and thoracic-abdominal time-resolved 4-dimensional [4D] MRA) were performed after power and manual injection of gadobutrol (0.1 mmol/kg) at 2 mL/s in 12 pigs (6 sets of power and manual injections for each type of CE-MRA). For the quantitative analysis, the signal-to-noise ratio was measured on ascending aorta, descending aorta, brachiocephalic trunk, common carotid artery, and external carotid artery on the 6 sets of head-neck 3D MRA, and on ascending aorta, descending aorta, brachiocephalic trunk, abdominal aorta, celiac trunk, and renal artery on the 6 sets of thoracic-abdominal 3D MRA. Bolus shapes were evaluated on the 6 sets each of test-bolus scans and 4D MRA. For the qualitative analysis, arterial enhancement, superimposition of nontargeted enhancement, and overall image quality were evaluated on 3D MRA. Visibility of bolus transition was assessed on 4D MRA. Intraindividual comparison between power and manual injection was made by paired t test, Wilcoxon rank sum test, and analysis of variance by ranks. Signal-to-noise ratio on 3D MRA was statistically higher with power injection than with manual injection (P < 0.001). Bolus shapes (test-bolus, 4D MRA) were represented by a characteristic standard bolus curve (sharp first-pass peak followed by a gentle recirculation peak) in all the 12 scans with power injection, but only in 1 of the 12 scans with manual injection. Standard deviations of time-to-peak enhancement were smaller in power injection than in manual injection. Qualitatively, although both injection methods achieved diagnostic quality on 3D MRA, power injection exhibited significantly higher image quality than manual injection (P = 0.001) due to

  15. Intra-Arterial MR Perfusion Imaging of Meningiomas: Comparison to Digital Subtraction Angiography and Intravenous MR Perfusion Imaging.

    Directory of Open Access Journals (Sweden)

    Mark A Lum

    Full Text Available To evaluate the ability of IA MR perfusion to characterize meningioma blood supply.Studies were performed in a suite comprised of an x-ray angiography unit and 1.5T MR scanner that permitted intraprocedural patient movement between the imaging modalities. Patients underwent intra-arterial (IA and intravenous (IV T2* dynamic susceptibility MR perfusion immediately prior to meningioma embolization. Regional tumor arterial supply was characterized by digital subtraction angiography and classified as external carotid artery (ECA dural, internal carotid artery (ICA dural, or pial. MR perfusion data regions of interest (ROIs were analyzed in regions with different vascular supply to extract peak height, full-width at half-maximum (FWHM, relative cerebral blood flow (rCBF, relative cerebral blood volume (rCBV, and mean transit time (MTT. Linear mixed modeling was used to identify perfusion curve parameter differences for each ROI for IA and IV MR imaging techniques. IA vs. IV perfusion parameters were also directly compared for each ROI using linear mixed modeling.18 ROIs were analyzed in 12 patients. Arterial supply was identified as ECA dural (n = 11, ICA dural (n = 4, or pial (n = 3. FWHM, rCBV, and rCBF showed statistically significant differences between ROIs for IA MR perfusion. Peak Height and FWHM showed statistically significant differences between ROIs for IV MR perfusion. RCBV and MTT were significantly lower for IA perfusion in the Dural ECA compared to IV perfusion. Relative CBF in IA MR was found to be significantly higher in the Dural ICA region and MTT significantly lower compared to IV perfusion.

  16. Detection of vessel wall calcifications in vertebral arteries using susceptibility weighted imaging

    Energy Technology Data Exchange (ETDEWEB)

    Adams, Lisa C.; Boeker, Sarah M.; Bender, Yvonne Y.; Fallenberg, Eva M.; Wagner, Moritz; Hamm, Bernd; Makowski, Marcus R. [Department of Radiology, Charite, Berlin (Germany); Liebig, Thomas [Department of Neuroradiology, Charite, Berlin (Germany)

    2017-09-15

    Calcification of the brain supplying arteries has been linked to an increased risk for cerebrovascular disease. The purpose of this study was to test the potential of susceptibility weighted MR imaging (SWMR) for the detection of vertebral artery calcifications, based on CT as a reference standard. Four hundred seventy-four patients, who had received head CT and 1.5 T MR scans with SWMR, including the distal vertebral artery, between January 2014 and December 2016, were retrospectively evaluated and 389 patients were included. Sensitivity and specificity for the detection of focal calcifications and intra- and interobserver agreement were calculated for SWMR and standard MRI, using CT as a standard of reference. The diameter of vertebral artery calcifications was used to assess correlations between imaging modalities. Furthermore, the degree of vessel stenosis was determined in 30 patients, who had received an additional angiography. On CT scans, 40 patients showed a total of 52 vertebral artery calcifications. While SWMR reached a sensitivity of 94% (95% CI 84-99%) and a specificity of 97% (95% CI 94-98%), standard MRI yielded a sensitivity of 33% (95% CI 20-46%), and a specificity of 93% (95% CI 90-96%). Linear regression analysis of size measurements confirmed a close correlation between SWMR and CT measurements (R {sup 2} = 0.74, p < 0.001). Compared to standard MRI (ICC = 0.52; CI 0.45-0.59), SWMR showed a higher interobserver agreement for calcification measurements (ICC = 0.84; CI 0.81-0.87). For detection of distal vertebral artery calcifications, SWMR demonstrates a performance comparable to CT and considerably higher than conventional MRI. (orig.)

  17. Radiation dose and image quality of X-ray volume imaging systems: cone-beam computed tomography, digital subtraction angiography and digital fluoroscopy.

    Science.gov (United States)

    Paul, Jijo; Jacobi, Volkmar; Farhang, Mohammad; Bazrafshan, Babak; Vogl, Thomas J; Mbalisike, Emmanuel C

    2013-06-01

    Radiation dose and image quality estimation of three X-ray volume imaging (XVI) systems. A total of 126 patients were examined using three XVI systems (groups 1-3) and their data were retrospectively analysed from 2007 to 2012. Each group consisted of 42 patients and each patient was examined using cone-beam computed tomography (CBCT), digital subtraction angiography (DSA) and digital fluoroscopy (DF). Dose parameters such as dose-area product (DAP), skin entry dose (SED) and image quality parameters such as Hounsfield unit (HU), noise, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were estimated and compared using appropriate statistical tests. Mean DAP and SED were lower in recent XVI than its previous counterparts in CBCT, DSA and DF. HU of all measured locations was non-significant between the groups except the hepatic artery. Noise showed significant difference among groups (P < 0.05). Regarding CNR and SNR, the recent XVI showed a higher and significant difference compared to its previous versions. Qualitatively, CBCT showed significance between versions unlike the DSA and DF which showed non-significance. A reduction of radiation dose was obtained for the recent-generation XVI system in CBCT, DSA and DF. Image noise was significantly lower; SNR and CNR were higher than in previous versions. The technological advancements and the reduction in the number of frames led to a significant dose reduction and improved image quality with the recent-generation XVI system. • X-ray volume imaging (XVI) systems are increasingly used for interventional radiological procedures. • More modern XVI systems use lower radiation doses compared with earlier counterparts. • Furthermore more modern XVI systems provide higher image quality. • Technological advances reduce radiation dose and improve image quality.

  18. Dual-source CT cardiac imaging: initial experience

    International Nuclear Information System (INIS)

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

    2006-01-01

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

  19. Feasibility of low-dose contrast medium high pitch CT angiography for the combined evaluation of coronary, head and neck arteries.

    Directory of Open Access Journals (Sweden)

    Zhiwei Wang

    Full Text Available PURPOSE: To evaluate the image quality and radiation dose of combined heart, head, and neck CT angiography (CTA using prospectively electrocardiography (ECG-triggered high-pitch spiral scan protocol, compared with single coronary CTA. MATERIALS AND METHODS: 151 consecutive patients were prospectively included and randomly divided into three groups. Group 1 (n = 47 underwent combined heart, neck, and head CTA using prospectively ECG-triggered high-pitch spiral (Flash scan protocol with a single-phase intravenous injection of iodinated contrast and saline flush; Group 2 (n = 51 underwent single coronary CTA with Flash scan protocol; and Group 3 (n = 53 underwent single coronary CTA with prospective sequence scan protocol. All patients were examined on a dual source CT (Definition FLASH. The image quality was determined for each CT study. RESULTS: Patients of scanning protocol Group 1, 2, and 3 showed no significant differences in age, sex, heart rates, and BMI. Evaluation of coronary artery image quality showed comparable results in the three scanning protocol groups on a per patient-based analysis. In group 1, image quality was found to be sufficient to be diagnostic in all arterial segments of carotid arteries. The mean dose-length product (DLP for group 1 was 256.3±24.5 mGy×cm and was significantly higher in comparison with group 2 (93.4±19.9 mGy×cm; p < 0.001. However, there was no significant difference of DLP between group 1 and group 3 (254.1±69.9 mGy×cm. CONCLUSIONS: The combined heart, neck, and head arteries scan using prospectively electrocardiography (ECG-triggered high-pitch spiral scan protocol in 1 single examination resulted in an excellent opacification of the aorta, the carotid arteries, and the coronary arteries and provided a good image quality with low radiation dose.

  20. Simultaneous PET/MR imaging in a human brain PET/MR system in 50 patients—Current state of image quality

    International Nuclear Information System (INIS)

    Schwenzer, N.F.; Stegger, L.; Bisdas, S.; Schraml, C.; Kolb, A.; Boss, A.; Müller, M.

    2012-01-01

    Objectives: The present work illustrates the current state of image quality and diagnostic accuracy in a new hybrid BrainPET/MR. Materials and methods: 50 patients with intracranial masses, head and upper neck tumors or neurodegenerative diseases were examined with a hybrid BrainPET/MR consisting of a conventional 3T MR system and an MR-compatible PET insert. Directly before PET/MR, all patients underwent a PET/CT examination with either [ 18 F]-FDG, [ 11 C]-methionine or [ 68 Ga]-DOTATOC. In addition to anatomical MR scans, functional sequences were performed including diffusion tensor imaging (DTI), arterial spin labeling (ASL) and proton-spectroscopy. Image quality score of MR imaging was evaluated using a 4-point-scale. PET data quality was assessed by evaluating FDG-uptake and tumor delineation with [ 11 C]-methionine and [ 68 Ga]-DOTATOC. FDG uptake quantification accuracy was evaluated by means of ROI analysis (right and left frontal and temporo-occipital lobes). The asymmetry indices and ratios between frontal and occipital ROIs were compared. Results: In 45/50 patients, PET/MR examination was successful. Visual analysis revealed a diagnostic image quality of anatomical MR imaging (mean quality score T2 FSE: 1.27 ± 0.54; FLAIR: 1.38 ± 0.61). ASL and proton-spectroscopy was possible in all cases. In DTI, dental artifacts lead to one non-diagnostic dataset (mean quality score DTI: 1.32 ± 0.69; ASL: 1.10 ± 0.31). PET datasets of PET/MR and PET/CT offered comparable tumor delineation with [ 11 C]-methionine; additional lesions were found in 2/8 [ 68 Ga]-DOTATOC-PET in the PET/MR. Mean asymmetry index revealed a high accordance between PET/MR and PET/CT (1.5 ± 2.2% vs. 0.9 ± 3.6%; mean ratio (frontal/parieto-occipital) 0.93 ± 0.08 vs. 0.96 ± 0.05), respectively. Conclusions: The hybrid BrainPET/MR allows for molecular, anatomical and functional imaging with uncompromised MR image quality and a high accordance of PET results between PET/MR and PET

  1. Simultaneous PET/MR imaging in a human brain PET/MR system in 50 patients-Current state of image quality

    Energy Technology Data Exchange (ETDEWEB)

    Schwenzer, N.F., E-mail: nina.schwenzer@med.uni-tuebingen.de [Department of Diagnostic and Interventional Radiology, Eberhard-Karls University Tuebingen, Tuebingen (Germany); Stegger, L., E-mail: stegger@gmx.net [Department of Nuclear Medicine and European Institute for Molecular Imaging, University of Muenster, Muenster (Germany); Bisdas, S., E-mail: sbisdas@gmail.com [Department of Diagnostic and Interventional Neuroradiology, Eberhard-Karls University Tuebingen, Tuebingen (Germany); Schraml, C., E-mail: christina.schraml@med.uni-tuebingen.de [Department of Diagnostic and Interventional Radiology, Eberhard-Karls University Tuebingen, Tuebingen (Germany); Kolb, A., E-mail: armin.kolb@med.uni-tuebingen.de [Laboratory for Preclinical Imaging and Imaging Technology of the Werner Siemens-Foundation, Department of Preclinical Imaging and Radiopharmacy, Eberhard-Karls University Tuebingen, Tuebingen (Germany); Boss, A., E-mail: Andreas.Boss@usz.ch [Department of Diagnostic and Interventional Radiology, Eberhard-Karls University Tuebingen, Tuebingen (Germany); Institute of Diagnostic and Interventional Radiology, University Hospital Zuerich, Zuerich (Switzerland); Mueller, M., E-mail: mark.mueller@med.uni-tuebingen.de [Department of Nuclear Medicine, Eberhard-Karls University Tuebingen, Tuebingen (Germany); and others

    2012-11-15

    Objectives: The present work illustrates the current state of image quality and diagnostic accuracy in a new hybrid BrainPET/MR. Materials and methods: 50 patients with intracranial masses, head and upper neck tumors or neurodegenerative diseases were examined with a hybrid BrainPET/MR consisting of a conventional 3T MR system and an MR-compatible PET insert. Directly before PET/MR, all patients underwent a PET/CT examination with either [{sup 18}F]-FDG, [{sup 11}C]-methionine or [{sup 68}Ga]-DOTATOC. In addition to anatomical MR scans, functional sequences were performed including diffusion tensor imaging (DTI), arterial spin labeling (ASL) and proton-spectroscopy. Image quality score of MR imaging was evaluated using a 4-point-scale. PET data quality was assessed by evaluating FDG-uptake and tumor delineation with [{sup 11}C]-methionine and [{sup 68}Ga]-DOTATOC. FDG uptake quantification accuracy was evaluated by means of ROI analysis (right and left frontal and temporo-occipital lobes). The asymmetry indices and ratios between frontal and occipital ROIs were compared. Results: In 45/50 patients, PET/MR examination was successful. Visual analysis revealed a diagnostic image quality of anatomical MR imaging (mean quality score T2 FSE: 1.27 {+-} 0.54; FLAIR: 1.38 {+-} 0.61). ASL and proton-spectroscopy was possible in all cases. In DTI, dental artifacts lead to one non-diagnostic dataset (mean quality score DTI: 1.32 {+-} 0.69; ASL: 1.10 {+-} 0.31). PET datasets of PET/MR and PET/CT offered comparable tumor delineation with [{sup 11}C]-methionine; additional lesions were found in 2/8 [{sup 68}Ga]-DOTATOC-PET in the PET/MR. Mean asymmetry index revealed a high accordance between PET/MR and PET/CT (1.5 {+-} 2.2% vs. 0.9 {+-} 3.6%; mean ratio (frontal/parieto-occipital) 0.93 {+-} 0.08 vs. 0.96 {+-} 0.05), respectively. Conclusions: The hybrid BrainPET/MR allows for molecular, anatomical and functional imaging with uncompromised MR image quality and a high accordance

  2. Topographic anatomy of paraclinoid carotid artery aneurysms: usefulness of MR angiographic source images

    International Nuclear Information System (INIS)

    Nagasawa, S.; Deguchi, J.; Arai, M.; Tanaka, H.; Kawanishi, M.; Ohta, T.

    1997-01-01

    We evaluated the usefulness of magnetic resonance angiography (MRA) for showing the topography of paraclinoid carotid artery aneurysms in 27 patients with 30 paraclinoid aneurysms undergoing conventional angiography, three-dimensional time-of-flight MRA and surgery. The anatomy shown on the axial MRA source images was consistent with that found at surgery. The neck of the aneurysm could always be identified on the source images, while it could not be analysed exactly on conventional angiography in 3 cases (10 %). The optic nerves, including those displaced by the aneurysm, were recognised in all patients. The anterior clinoid process was shown as a low-intensity rim or area contiguous with the cortical bone. The source images were of great value in understanding the topography of paraclinoid carotid artery aneurysms. (orig.). With 2 figs

  3. Ultrasound Image Quality Assessment: A framework for evaluation of clinical image quality

    DEFF Research Database (Denmark)

    Hemmsen, Martin Christian; Pedersen, Mads Møller; Nikolov, Svetoslav Ivanov

    2010-01-01

    Improvement of ultrasound images should be guided by their diagnostic value. Evaluation of clinical image quality is generally performed subjectively, because objective criteria have not yet been fully developed and accepted for the evaluation of clinical image quality. Based on recommendation 50...... information, which is fast enough to get sufficient number of scans under realistic operating conditions, so that statistical evaluation is valid and reliable....

  4. Imaging nuclear medicine techniques for diagnostic evaluation of arterial hypertension

    International Nuclear Information System (INIS)

    Eisenberg, B.M.; Linss, G.

    1989-01-01

    Arterial hypertension may be caused by a malfunction of organs and in turn may lead to secondary organic lesions. Modern diagnostic nuclear medicine is applied for function studies in order to detect or exclude secondary hypertension and functional or perfusion disturbances due to hypertension, or to assess and follow up hemodynamic conditions and cardiac functions prior to and during therapy. The article presents a survey of imaging diagnostic nuclear medicine techniques for the eamination of the heart, the brain, the kidneys and endocrine glands in patients with arterial hypertension, discussing the methods with a view to obtainable information, limits of detection, and indications. (orig.) [de

  5. Estimation of brachial artery volume flow by duplex ultrasound imaging predicts dialysis access maturation.

    Science.gov (United States)

    Ko, Sae Hee; Bandyk, Dennis F; Hodgkiss-Harlow, Kelley D; Barleben, Andrew; Lane, John

    2015-06-01

    This study validated duplex ultrasound measurement of brachial artery volume flow (VF) as predictor of dialysis access flow maturation and successful hemodialysis. Duplex ultrasound was used to image upper extremity dialysis access anatomy and estimate access VF within 1 to 2 weeks of the procedure. Correlation of brachial artery VF with dialysis access conduit VF was performed using a standardized duplex testing protocol in 75 patients. The hemodynamic data were used to develop brachial artery flow velocity criteria (peak systolic velocity and end-diastolic velocity) predictive of three VF categories: low (800 mL/min). Brachial artery VF was then measured in 148 patients after a primary (n = 86) or revised (n = 62) upper extremity dialysis access procedure, and the VF category correlated with access maturation or need for revision before hemodialysis usage. Access maturation was conferred when brachial artery VF was >600 mL/min and conduit imaging indicated successful cannulation based on anatomic criteria of conduit diameter >5 mm and skin depth 800 mL/min was predicted when the brachial artery lumen diameter was >4.5 mm, peak systolic velocity was >150 cm/s, and the diastolic-to-systolic velocity ratio was >0.4. Brachial artery velocity spectra indicating VF 800 mL/min. Duplex testing to estimate brachial artery VF and assess the conduit for ease of cannulation can be performed in 5 minutes during the initial postoperative vascular clinic evaluation. Estimation of brachial artery VF using the duplex ultrasound, termed the "Fast, 5-min Dialysis Duplex Scan," facilitates patient evaluation after new or revised upper extremity dialysis access procedures. Brachial artery VF correlates with access VF measurements and has the advantage of being easier to perform and applicable for forearm and also arm dialysis access. When brachial artery velocity spectra criteria confirm a VF >800 mL/min, flow maturation and successful hemodialysis are predicted if anatomic criteria

  6. Dual-energy CTA in patients with symptomatic peripheral arterial occlusive disease. Study of diagnostic accuracy and impeding factors

    Energy Technology Data Exchange (ETDEWEB)

    Klink, Thorsten [Wuerzburg Univ. (Germany). Inst. of Diagnostic and Interventional Radiology; Bern Univ. (Switzerland). Univ. Inst. of Diagnostic, Interventional, and Pediatric Radiology; Wilhelm, Theresa; Roth, Christine [Univ. Hospital Giessen and Marburg, Marburg (Germany). Dept. of Diagnostic and Interventional Radiology; Heverhagen, Johannes T. [Bern Univ. (Switzerland). Univ. Inst. of Diagnostic, Interventional, and Pediatric Radiology

    2017-05-15

    The purpose of this study was to assess the diagnostic performance of dual-energy CT angiography (DE-CTA) in patients with symptomatic peripheral artery occlusive disease (PAOD) and to identify factors that impede its diagnostic accuracy. Dual-source DE-CTA scans of the lower extremities of 94 patients were retrospectively compared to the diagnostic reference standard, digital subtraction angiography (DSA). Two independent observers assessed PAOD incidence, image quality, artifacts, and diagnostic accuracy of DE-CTA in 1014 arterial segments on axial, combined 80/140 kVp reconstructions and on 3 D maximum intensity projections (MIP) after automated bone and plaque removal. The impact of calcifications, image quality, and image artifacts on the diagnostic accuracy was evaluated using Fisher's exact test. Furthermore, interobserver agreement was analyzed. Two observers achieved sensitivities of 98.0% and 93.9%, respectively, and specificities of 75.0% and 66.7%, respectively, for detecting stenoses of >50% of the lower extremity arteries. Calcifications impeded specificity, e.g. from 81.2% to 46.2% for reader 1 (p<0.001). Specificity increased with higher image quality, e.g. from 70.0% to 76.4% for reader 1 (p<0.001). Artifacts decreased the specificity of reader 2 (p<0.001). The overall interobserver agreement ranged between moderate and substantial for stenosis detection and calcified plaques. Conclusion DE-CTA is accurate in the detection of arterial stenoses of >50% in symptomatic PAOD patients. Calcified atherosclerotic plaques, image quality, and artifacts may impede specificity.

  7. MRI in giant cell (temporal) arteritis; Magnetresonanztomografie der Arteriitis temporalis Horton

    Energy Technology Data Exchange (ETDEWEB)

    Bley, T.A.; Uhl, M.; Frydrychowicz, A.; Langer, M. [Uniklinik Freiburg (Germany). Roentgendiagnostik; Markl, M. [Uniklinik Freiburg (Germany). Roentgendiagnostik - Medizinische Physik

    2007-07-15

    Giant cell (temporal) arteritis is a diagnostic challenge. Blindness is a dreaded complication, especially if high-dose steroid treatment is delayed. With an optimized MR protocol, noninvasive diagnosis of giant cell arteritis is facilitated. Submillimeter in-plane resolution makes it possible to distinguish healthy segments from inflamed segments. The lumen and arterial wall can be depicted in high detail. Post-contrast high-resolution MRI visualizes the superficial cranial arteries bilaterally and simultaneously, allowing assessment of the cranial involvement pattern. In combination with MR angiography of the aortic arch and supra-aortic arteries, the extracranial involvement pattern can be demonstrated in a single comprehensive MR examination assessing the cranial, cervical and thoracic vasculature. Good diagnostic image quality can be achieved at 1.5 Tesla and at 3 Tesla. However, due to higher signal-to-noise ratios, image quality seems to be superior at 3 Tesla. Over the course of successful long-term treatment, MR signs of mural inflammation decrease significantly and eventually vanish entirely. In contrast to color-coded Duplex sonography, which is a comparatively cost-efficient imaging modality, acquisition of high-resolution MRI is almost independent of the investigator's expertise. Compared to positron emission tomography with 18F-fluoro-2-deoxy-D-glucose, which is a very sensitive whole-body screening tool for detecting extracranial involvement of large vessel vasculitis, MRI allows visualization and assessment of both the superficial cranial arteries in high detail and the extracranial large artery involvement in the same investigation. (orig.)

  8. Intravascular near-infrared fluorescence molecular imaging of atherosclerosis: toward coronary arterial visualization of biologically high-risk plaques

    Science.gov (United States)

    Calfon, Marcella A.; Vinegoni, Claudio; Ntziachristos, Vasilis; Jaffer, Farouc A.

    2010-01-01

    New imaging methods are urgently needed to identify high-risk atherosclerotic lesions prior to the onset of myocardial infarction, stroke, and ischemic limbs. Molecular imaging offers a new approach to visualize key biological features that characterize high-risk plaques associated with cardiovascular events. While substantial progress has been realized in clinical molecular imaging of plaques in larger arterial vessels (carotid, aorta, iliac), there remains a compelling, unmet need to develop molecular imaging strategies targeted to high-risk plaques in human coronary arteries. We present recent developments in intravascular near-IR fluorescence catheter-based strategies for in vivo detection of plaque inflammation in coronary-sized arteries. In particular, the biological, light transmission, imaging agent, and engineering principles that underlie a new intravascular near-IR fluorescence sensing method are discussed. Intravascular near-IR fluorescence catheters appear highly translatable to the cardiac catheterization laboratory, and thus may offer a new in vivo method to detect high-risk coronary plaques and to assess novel atherosclerosis biologics.

  9. 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

    To present the theory for image reconstruction of a high-pitch, high-temporal-resolution spiral scan mode for dual-source CT (DSCT) and evaluate its image quality and dose. With the use of two x-ray sources and two data acquisition systems, spiral CT exams having a nominal temporal resolution per image of up to one-quarter of the gantry rotation time can be acquired using pitch values up to 3.2. The scan field of view (SFOV) for this mode, however, is limited to the SFOV of the second detector as a maximum, depending on the pitch. Spatial and low contrast resolution, image uniformity and noise, CT number accuracy and linearity, and radiation dose were assessed using the ACR CT accreditation phantom, a 30 cm diameter cylindrical water phantom or a 32 cm diameter cylindrical PMMA CTDI phantom. Slice sensitivity profiles (SSPs) were measured for different nominal slice thicknesses, and an anthropomorphic phantom was used to assess image artifacts. Results were compared between single-source scans at pitch = 1.0 and dual-source scans at pitch = 3.2. In addition, image quality and temporal resolution of an ECG-triggered version of the DSCT high-pitch spiral scan mode were evaluated with a moving coronary artery phantom, and radiation dose was assessed in comparison with other existing cardiac scan techniques. No significant differences in quantitative measures of image quality were found between single-source scans at pitch = 1.0 and dual-source scans at pitch = 3.2 for spatial and low contrast resolution, CT number accuracy and linearity, SSPs, image uniformity, and noise. The pitch value (1.6 pitch 3.2) had only a minor impact on radiation dose and image noise when the effective tube current time product (mA s/pitch) was kept constant. However, while not severe, artifacts were found to be more prevalent for the dual-source pitch = 3.2 scan mode when structures varied markedly along the z axis, particularly for head scans. Images of the moving coronary artery phantom

  10. 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

    Purpose: To present the theory for image reconstruction of a high-pitch, high-temporal-resolution spiral scan mode for dual-source CT (DSCT) and evaluate its image quality and dose. Methods: With the use of two x-ray sources and two data acquisition systems, spiral CT exams having a nominal temporal resolution per image of up to one-quarter of the gantry rotation time can be acquired using pitch values up to 3.2. The scan field of view (SFOV) for this mode, however, is limited to the SFOV of the second detector as a maximum, depending on the pitch. Spatial and low contrast resolution, image uniformity and noise, CT number accuracy and linearity, and radiation dose were assessed using the ACR CT accreditation phantom, a 30 cm diameter cylindrical water phantom or a 32 cm diameter cylindrical PMMA CTDI phantom. Slice sensitivity profiles (SSPs) were measured for different nominal slice thicknesses, and an anthropomorphic phantom was used to assess image artifacts. Results were compared between single-source scans at pitch=1.0 and dual-source scans at pitch=3.2. In addition, image quality and temporal resolution of an ECG-triggered version of the DSCT high-pitch spiral scan mode were evaluated with a moving coronary artery phantom, and radiation dose was assessed in comparison with other existing cardiac scan techniques. Results: No significant differences in quantitative measures of image quality were found between single-source scans at pitch=1.0 and dual-source scans at pitch=3.2 for spatial and low contrast resolution, CT number accuracy and linearity, SSPs, image uniformity, and noise. The pitch value (1.6≤pitch≤3.2) had only a minor impact on radiation dose and image noise when the effective tube current time product (mA s/pitch) was kept constant. However, while not severe, artifacts were found to be more prevalent for the dual-source pitch=3.2 scan mode when structures varied markedly along the z axis, particularly for head scans. Images of the moving

  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

    Purpose: To present the theory for image reconstruction of a high-pitch, high-temporal-resolution spiral scan mode for dual-source CT (DSCT) and evaluate its image quality and dose. Methods: With the use of two x-ray sources and two data acquisition systems, spiral CT exams having a nominal temporal resolution per image of up to one-quarter of the gantry rotation time can be acquired using pitch values up to 3.2. The scan field of view (SFOV) for this mode, however, is limited to the SFOV of the second detector as a maximum, depending on the pitch. Spatial and low contrast resolution, image uniformity and noise, CT number accuracy and linearity, and radiation dose were assessed using the ACR CT accreditation phantom, a 30 cm diameter cylindrical water phantom or a 32 cm diameter cylindrical PMMA CTDI phantom. Slice sensitivity profiles (SSPs) were measured for different nominal slice thicknesses, and an anthropomorphic phantom was used to assess image artifacts. Results were compared between single-source scans at pitch=1.0 and dual-source scans at pitch=3.2. In addition, image quality and temporal resolution of an ECG-triggered version of the DSCT high-pitch spiral scan mode were evaluated with a moving coronary artery phantom, and radiation dose was assessed in comparison with other existing cardiac scan techniques. Results: No significant differences in quantitative measures of image quality were found between single-source scans at pitch=1.0 and dual-source scans at pitch=3.2 for spatial and low contrast resolution, CT number accuracy and linearity, SSPs, image uniformity, and noise. The pitch value (1.6{<=}pitch{<=}3.2) had only a minor impact on radiation dose and image noise when the effective tube current time product (mA s/pitch) was kept constant. However, while not severe, artifacts were found to be more prevalent for the dual-source pitch=3.2 scan mode when structures varied markedly along the z axis, particularly for head scans. Images of the moving

  12. Diagnostic accuracy of color Doppler flow imaging and Duplex US in peripheral arterial disease

    International Nuclear Information System (INIS)

    Karmel, M.I.; Polak, J.F.; Whittemore, A.D.; Mannick, J.A.; Donaldson, M.C.; O'Leary, D.H.

    1988-01-01

    Color Doppler flow imaging (5 MHz) and Duplex US were used in a prospective examination of 154 arterial segments in the lower extremities of 11 symptomatic patients. Each extremity was divided into seven arterial segments (common femoral, profunda femoral, proximal, middle, and distal superficial femoral, and proximal and distal popliteal arteries). Arterial maps were drawn for each patient and compared with the arteriograms. Seventeen significant stenoses and 18 complete occlusions were predicted and confirmed by means of arteriography. Four significant stenoses and four occlusions were predicted and not confirmed. One hundred nine normal arterial segments were correctly predicted. No significant stenoses or occlusions were missed. Prospective identification of the severity and location of disease can help to optimize both the angiographic approach and hospital services utilization

  13. Imaging features of isolated unilateral pulmonary artery agenesis presenting in adulthood: a review of four cases

    International Nuclear Information System (INIS)

    Griffin, N.; Mansfield, L.; Redmond, K.C.; Dusmet, M.; Goldstraw, P.; Mittal, T.K.; Padley, S.

    2007-01-01

    Aim: To highlight the variation in clinical manifestations, imaging and management of four cases of unilateral pulmonary artery agenesis presenting in adulthood. Method: Four patients with unilateral pulmonary artery agenesis were referred to our institution between 1995 and 2005. They underwent a series of investigations, including chest radiography, echocardiography, ventilation perfusion scintigraphy, angiography, computed tomography (CT) and magnetic resonance imaging (MRI). Results: Two of the four patients had absence of the right main pulmonary artery, whilst the remaining two patients had absence of the left main pulmonary artery. One patient showed a restrictive defect on pulmonary function tests. Two patients who had ventilation perfusion scintigraphy showed absent perfusion and reduced ventilation on the affected side. Angiography (where performed), CT and MRI confirmed the anatomy and the presence of multiple collaterals. Bronchiectasis was demonstrated on CT in two patients, with one also demonstrating a mosaic attenuation pattern. One patient had an incidental lung tumour on the side of the agenesis, which was diagnosed as a chondroid hamartoma on histology. Three of the four patients eventually underwent resection of the affected lung. Conclusion: Isolated unilateral pulmonary artery agenesis has a non-specific presentation. Awareness of this condition can lead to earlier diagnosis, with cross-sectional imaging making an important contribution

  14. Imaging features of isolated unilateral pulmonary artery agenesis presenting in adulthood: a review of four cases

    Energy Technology Data Exchange (ETDEWEB)

    Griffin, N. [Royal Brompton and Harefield NHS Trust, London (United Kingdom)]. E-mail: nyreegriffin@hotmail.com; Mansfield, L. [Royal Brompton and Harefield NHS Trust, London (United Kingdom); Redmond, K.C. [Royal Brompton and Harefield NHS Trust, London (United Kingdom); Dusmet, M. [Royal Brompton and Harefield NHS Trust, London (United Kingdom); Goldstraw, P. [Royal Brompton and Harefield NHS Trust, London (United Kingdom); Mittal, T.K. [Royal Brompton and Harefield NHS Trust, London (United Kingdom); Padley, S. [Royal Brompton and Harefield NHS Trust, London (United Kingdom)

    2007-03-15

    Aim: To highlight the variation in clinical manifestations, imaging and management of four cases of unilateral pulmonary artery agenesis presenting in adulthood. Method: Four patients with unilateral pulmonary artery agenesis were referred to our institution between 1995 and 2005. They underwent a series of investigations, including chest radiography, echocardiography, ventilation perfusion scintigraphy, angiography, computed tomography (CT) and magnetic resonance imaging (MRI). Results: Two of the four patients had absence of the right main pulmonary artery, whilst the remaining two patients had absence of the left main pulmonary artery. One patient showed a restrictive defect on pulmonary function tests. Two patients who had ventilation perfusion scintigraphy showed absent perfusion and reduced ventilation on the affected side. Angiography (where performed), CT and MRI confirmed the anatomy and the presence of multiple collaterals. Bronchiectasis was demonstrated on CT in two patients, with one also demonstrating a mosaic attenuation pattern. One patient had an incidental lung tumour on the side of the agenesis, which was diagnosed as a chondroid hamartoma on histology. Three of the four patients eventually underwent resection of the affected lung. Conclusion: Isolated unilateral pulmonary artery agenesis has a non-specific presentation. Awareness of this condition can lead to earlier diagnosis, with cross-sectional imaging making an important contribution.

  15. Craniocervical artery dissection: MR imaging and MR angiographic findings

    International Nuclear Information System (INIS)

    Oelerich, M.; Schuierer, G.; Stoegbauer, F.; Kurlemann, G.; Schul, C.

    1999-01-01

    Dissection of the carotid and vertebral arteries is a not so uncommon cause of stroke and has to be considered as a differential diagnosis especially in younger patients. Therapeutic and prognostic implications are different from those in extracranial atherosclerotic disease. Dissection results from hemorrhage into the vessel wall usually between the layers of the media. Digital subtraction angiography (DSA) depicts the resulting luminal compromise that may reveal some typical, but not specific, findings. The same is true for non-invasive angiographic techniques such as time-of-flight magnetic resonance angiography (MRA) and computed tomography angiography (CTA), which have shown accurate results compared with DSA. The main advantage of these techniques is the direct visualization of the vessel wall confirming the intramural hematoma. This is achieved best with MR imaging due to the high signal of blood degradation products on T1- and T2-weighted images. Therefore, MRI in combination with MRA is presently the method of choice for initial diagnosis and follow-up of craniocervical artery dissection (CCAD). In some questionable cases, CTA is a non-invasive alternative that is independent of flow phenomena. (orig.)

  16. Craniocervical artery dissection: MR imaging and MR angiographic findings

    Energy Technology Data Exchange (ETDEWEB)

    Oelerich, M.; Schuierer, G. [Institute of Clinical Radiology, University of Muenster (Germany); Stoegbauer, F. [Department of Neurology, University of Muenster (Germany); Kurlemann, G. [Department of Pediatric Neurology, University of Muenster (Germany); Schul, C. [Department of Neurosurgery, University of Muenster (Germany)

    1999-09-01

    Dissection of the carotid and vertebral arteries is a not so uncommon cause of stroke and has to be considered as a differential diagnosis especially in younger patients. Therapeutic and prognostic implications are different from those in extracranial atherosclerotic disease. Dissection results from hemorrhage into the vessel wall usually between the layers of the media. Digital subtraction angiography (DSA) depicts the resulting luminal compromise that may reveal some typical, but not specific, findings. The same is true for non-invasive angiographic techniques such as time-of-flight magnetic resonance angiography (MRA) and computed tomography angiography (CTA), which have shown accurate results compared with DSA. The main advantage of these techniques is the direct visualization of the vessel wall confirming the intramural hematoma. This is achieved best with MR imaging due to the high signal of blood degradation products on T1- and T2-weighted images. Therefore, MRI in combination with MRA is presently the method of choice for initial diagnosis and follow-up of craniocervical artery dissection (CCAD). In some questionable cases, CTA is a non-invasive alternative that is independent of flow phenomena. (orig.) With 6 figs., 2 tabs., 33 refs.

  17. A transmit/receive radiofrequency array for imaging the carotid arteries at 7 Tesla: coil design and first in vivo results.

    Science.gov (United States)

    Kraff, Oliver; Bitz, Andreas K; Breyer, Tobias; Kruszona, Stefan; Maderwald, Stefan; Brote, Irina; Gizewski, Elke R; Ladd, Mark E; Quick, Harald H

    2011-04-01

    To develop a transmit/receive radiofrequency (RF) array for magnetic resonance imaging (MRI) of the carotid arteries at 7 T. The prototype is characterized in numerical simulations and bench measurements, and the feasibility of plaque imaging at 7 T is demonstrated in first in vivo images. The RF phased array coil consists of 8 surface loop coils. To allow imaging of both sides of the neck, the RF array is divided into 2 coil clusters, each with 4 overlapping loop elements. For safety validation, numerical computations of the RF field distribution and the corresponding specific absorption rate were performed on the basis of a heterogeneous human body model. To validate the coil model, maps of the transmit B1(+) field were compared between simulation and measurement. In vivo images of a healthy volunteer and a patient (ulcerating plaque and a 50% stenosis of the right internal carotid artery) were acquired using a 3-dimensional FLASH sequence with a high isotropic spatial resolution of 0.54 mm as well as using pulse-triggered proton density (PD)/T2-weighted turbo spin echo sequences. Measurements of the S-parameters yielded a reflection and isolation of the coil elements of better than -18 and -13 dB, respectively. Measurements of the g-factor indicated good image quality for parallel imaging acceleration factors up to 2.4. A similar distribution and a very good match of the absolute values were found between the measured and simulated B1(+) transmit RF field for the validation of the coil model. In vivo images revealed good signal excitation of both sides of the neck and a high vessel-to-background image contrast for the noncontrast-enhanced 3-dimensional FLASH sequence. Imaging at 7 T could depict the extent of stenosis, and revealed the disruption and ulcer of the plaque. This study demonstrates that 2 four-channel transmit/receive RF arrays for each side of the neck is a suitable concept for in vivo MRI of the carotid arteries at 7 Tesla. Further studies are

  18. 3D DSA findings of uterine artery and its optimal projection position

    International Nuclear Information System (INIS)

    Lu Weifu; Zhang Aiwu; Zhou Chunze; Lu Dong; Xiao Jingkun; Wang Weiyu; Zhang Xingming; Zhang Zhengfeng; Hou Changlong

    2011-01-01

    Objective: to observe the origin site, anatomic features of uterine artery with 3D DSA and to discuss the optimal projection position in order to improve the success rate of super-selective catheterization of uterine artery. Methods: Prospective pelvic angiography was performed in 42 adult females (a total of 84 uterine arteries). 3D DSA was carried out with 206 ° rotation. 3D reconstruction of the obtained images was performed and the angiographic manifestations of the uterine artery were analyzed. The optimal projection position for the displaying of uterine artery was discussed. The quality of images obtained with the projection angle of 15 °-25 °, 25 °-35 ° and 35 °-45 ° was determined and the results were compared with each other. Results: The orifices of all 84 uterine arteries could be well demonstrated on 3D DSA images. The uterine artery was originated from the anterior trunk of internal iliac artery (n=58, 69%), from main stem of internal iliac artery (n=16, 19.1%), from internal pudenda artery (n=8, 9.5%) and from inferior gluteal artery (n=2, 2.4%). The best projection position to show the opening and route of the uterine artery was contralateral oblique view of 25-35 degrees (P<0.05). Conclusion: 3D DSA can clearly display the anatomy of the uterine artery, which is very helpful for the management of super-selective catheterization of uterine artery. The optimal projection position for uterine artery is contralateral oblique view of 25-35 degrees. (authors)

  19. [Image fusion of gated-SPECT and CT angiography in coronary artery disease. Importance of anatomic-functional correlation].

    Science.gov (United States)

    Nazarena Pizzi, M; Aguadé Bruix, S; Cuéllar Calabria, H; Aliaga, V; Candell Riera, J

    2010-01-01

    A 77-year old patient was admitted for acute coronary syndrome without ST elevation. His risk was stratified using the myocardial perfusion gated SPECT, mild inferior ischemia being observed. Thus, medical therapy was optimized and the patient was discharged. He continued with exertional dyspnea so a coronary CT angiography was performed. It revealed severe lesions in the proximal RCA. SPECT-CT fusion images correlated the myocardial perfusion defect with a posterior descending artery from the RCA, in a co-dominant coronary area. Subsequently, cardiac catheterism was indicated for his treatment. The current use of image fusion studies is limited to patients in whom it is difficult to attribute a perfusion defect to a specific coronary artery. In our patient, the fusion images helped to distinguish between the RCA and the circumflex artery as the culprit artery of ischemia. Copyright © 2010 Elsevier España, S.L. y SEMNIM. All rights reserved.

  20. Using a web-based image quality assurance reporting system to improve image quality.

    Science.gov (United States)

    Czuczman, Gregory J; Pomerantz, Stuart R; Alkasab, Tarik K; Huang, Ambrose J

    2013-08-01

    The purpose of this study is to show the impact of a web-based image quality assurance reporting system on the rates of three common image quality errors at our institution. A web-based image quality assurance reporting system was developed and used beginning in April 2009. Image quality endpoints were assessed immediately before deployment (period 1), approximately 18 months after deployment of a prototype reporting system (period 2), and approximately 12 months after deployment of a subsequent upgraded department-wide reporting system (period 3). A total of 3067 axillary shoulder radiographs were reviewed for correct orientation, 355 shoulder CT scans were reviewed for correct reformatting of coronal and sagittal images, and 346 sacral MRI scans were reviewed for correct acquisition plane of axial images. Error rates for each review period were calculated and compared using the Fisher exact test. Error rates of axillary shoulder radiograph orientation were 35.9%, 7.2%, and 10.0%, respectively, for the three review periods. The decrease in error rate between periods 1 and 2 was statistically significant (p < 0.0001). Error rates of shoulder CT reformats were 9.8%, 2.7%, and 5.8%, respectively, for the three review periods. The decrease in error rate between periods 1 and 2 was statistically significant (p = 0.03). Error rates for sacral MRI axial sequences were 96.5%, 32.5%, and 3.4%, respectively, for the three review periods. The decrease in error rates between periods 1 and 2 and between periods 2 and 3 was statistically significant (p < 0.0001). A web-based system for reporting image quality errors may be effective for improving image quality.

  1. Assessing the blood pressure waveform of the carotid artery using an ultrasound image processing method

    Energy Technology Data Exchange (ETDEWEB)

    Soleimani, Effat; Mokhtari-Dizaji, Manijhe [Dept. of Medical Physics, Tarbiat Modares University, Tehran (Iran, Islamic Republic of); Fatouraee, Nasser [Dept. of Medical Engineering, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Saben, Hazhir [Dept. Radiology, Imaging Center of Imam Khomaini Hospital, Tehran Medical Sciences University, Tehran (Iran, Islamic Republic of)

    2017-04-15

    The aim of this study was to introduce and implement a noninvasive method to derive the carotid artery pressure waveform directly by processing diagnostic sonograms of the carotid artery. Ultrasound image sequences of 20 healthy male subjects (age, 36±9 years) were recorded during three cardiac cycles. The internal diameter and blood velocity waveforms were extracted from consecutive sonograms over the cardiac cycles by using custom analysis programs written in MATLAB. Finally, the application of a mathematical equation resulted in time changes of the arterial pressure. The resulting pressures were calibrated using the mean and the diastolic pressure of the radial artery. A good correlation was found between the mean carotid blood pressure obtained from the ultrasound image processing and the mean radial blood pressure obtained using a standard digital sphygmomanometer (R=0.91). The mean absolute difference between the carotid calibrated pulse pressures and those measured clinically was -1.333±6.548 mm Hg. The results of this study suggest that consecutive sonograms of the carotid artery can be used for estimating a blood pressure waveform. We believe that our results promote a noninvasive technique for clinical applications that overcomes the reproducibility problems of common carotid artery tonometry with technical and anatomical causes.

  2. Assessing the blood pressure waveform of the carotid artery using an ultrasound image processing method

    International Nuclear Information System (INIS)

    Soleimani, Effat; Mokhtari-Dizaji, Manijhe; Fatouraee, Nasser; Saben, Hazhir

    2017-01-01

    The aim of this study was to introduce and implement a noninvasive method to derive the carotid artery pressure waveform directly by processing diagnostic sonograms of the carotid artery. Ultrasound image sequences of 20 healthy male subjects (age, 36±9 years) were recorded during three cardiac cycles. The internal diameter and blood velocity waveforms were extracted from consecutive sonograms over the cardiac cycles by using custom analysis programs written in MATLAB. Finally, the application of a mathematical equation resulted in time changes of the arterial pressure. The resulting pressures were calibrated using the mean and the diastolic pressure of the radial artery. A good correlation was found between the mean carotid blood pressure obtained from the ultrasound image processing and the mean radial blood pressure obtained using a standard digital sphygmomanometer (R=0.91). The mean absolute difference between the carotid calibrated pulse pressures and those measured clinically was -1.333±6.548 mm Hg. The results of this study suggest that consecutive sonograms of the carotid artery can be used for estimating a blood pressure waveform. We believe that our results promote a noninvasive technique for clinical applications that overcomes the reproducibility problems of common carotid artery tonometry with technical and anatomical causes

  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. Process perspective on image quality evaluation

    Science.gov (United States)

    Leisti, Tuomas; Halonen, Raisa; Kokkonen, Anna; Weckman, Hanna; Mettänen, Marja; Lensu, Lasse; Ritala, Risto; Oittinen, Pirkko; Nyman, Göte

    2008-01-01

    The psychological complexity of multivariate image quality evaluation makes it difficult to develop general image quality metrics. Quality evaluation includes several mental processes and ignoring these processes and the use of a few test images can lead to biased results. By using a qualitative/quantitative (Interpretation Based Quality, IBQ) methodology, we examined the process of pair-wise comparison in a setting, where the quality of the images printed by laser printer on different paper grades was evaluated. Test image consisted of a picture of a table covered with several objects. Three other images were also used, photographs of a woman, cityscape and countryside. In addition to the pair-wise comparisons, observers (N=10) were interviewed about the subjective quality attributes they used in making their quality decisions. An examination of the individual pair-wise comparisons revealed serious inconsistencies in observers' evaluations on the test image content, but not on other contexts. The qualitative analysis showed that this inconsistency was due to the observers' focus of attention. The lack of easily recognizable context in the test image may have contributed to this inconsistency. To obtain reliable knowledge of the effect of image context or attention on subjective image quality, a qualitative methodology is needed.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-06-15

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

  6. Feasibility of 320-row area detector CT coronary angiography using 40 mL of contrast material: assessment of image quality and diagnostic accuracy

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Rihyeon; Park, Eun-Ah; Lee, Whal; Chung, Jin Wook [Seoul National University Hospital, Department of Radiology, Seoul (Korea, Republic of)

    2016-11-15

    To assess the image quality and diagnostic accuracy of 320-row area detector CT (320-ADCT) coronary angiography using 40 mL of contrast material in comparison with 60-mL protocol. This retrospective study included 183 patients who underwent 320-ADCT coronary angiography using 40 mL of contrast and additional 183 sex- and body mass index-matched patients using 60 mL of contrast constituting the control group. Both groups used the same 5-mL/sec injection rate. Quantitative image quality measurements and diagnostic accuracies were calculated and compared. Mean attenuation and contrast-to-noise ratio (CNR) at the aorta and all coronary arteries were lower in the 40-mL group than in the 60-mL group (all, p < 0.05), except for the CNR at proximal coronary arteries at 100 kVp (p = 0.073). However, the proportion of coronary segments with vessel attenuation >250 HU was not different between groups (all, p > 0.05), except for distal coronary arteries at 80 kVp (p = 0.001). Furthermore, there were no differences in per-patient and per-segment diagnostic accuracies between the groups (all, p > 0.05). 320-ADCT coronary angiography using 40 mL of contrast showed image quality and diagnostic accuracy comparable to the 60-mL protocol, demonstrating the clinical feasibility of lowering the risk of contrast-induced nephropathy through contrast volume reduction. (orig.)

  7. Initial experience in perfusion MR imaging of intracranial major artery occlusion with echo-planar technique

    International Nuclear Information System (INIS)

    Tsuchiya, Kazuhiro; Mizutani, Yoshiyuki; Inaoka, Sayuki; Hachiya, Junichi

    1997-01-01

    The purpose of this study was to evaluate the usefulness of perfusion MR imaging using a single-shot echo-planar technique in occlusion of intracranial main arteries. Our patient group consisted of 16 patients with internal carotid artery occlusion (n=9), Moyamoya disease (n=4), and middle cerebral artery occlusion (n=3). We performed the echo-planar perfusion studies with a 1.5-T unit using a free-induction-decay-type echo-planar sequence. With a bolus injection of Gd-DTPA, 30 consecutive scans were obtained at 10 sections every 2 seconds. The data were analyzed in three ways: a time-intensity curves in the territory of the involved artery (n=16); semiquantitative flow map of each section representing signal changes due to passage of Gd-DTPA (n=15); and serial images at a selected section (n=7). The time intensity curves were abnormal in 13 patients. The peak of signal drop was delayed in all of them. Flow maps showed focal flow abnormalities in 11 patients, but they were apparently normal in 4 patients probably due to collateral flow. In serial images, delay in appearance and/or disappearance of Gd-DTPA was noted in 6 patients. In patients with occlusion of intracranial main arteries, MR single-shot echo-planar technique is of clinical use because it can provide information about hemodynamic changes in a short examination time, in multiple sections, and with good temporal resolution. (author)

  8. PLEIADES-HR IMAGE QUALITY COMMISSIONING

    Directory of Open Access Journals (Sweden)

    L. Lebègue

    2012-07-01

    Full Text Available PLEIADES is the highest resolution civilian earth observing system ever developed in Europe. This imagery program is conducted by the French National Space Agency, CNES. It operates since 2012 a first satellite PLEIADES-HR launched on 2011 December 17th, a second one should be launched by the end of the year. Each satellite is designed to provide optical 70 cm resolution coloured images to civilian and defence users. The Image Quality requirements were defined from users studies from the different spatial imaging applications, taking into account the trade-off between on-board technological complexity and ground processing capacity. The assessment of the image quality and the calibration operation have been performed by CNES Image Quality team during the 6 month commissioning phase that followed the satellite launch. These activities cover many topics gathered in two families : radiometric and geometric image quality. The new capabilities offered by PLEIADES-HR agility allowed to imagine new methods of image calibration and performance assessment. Starting from an overview of the satellite characteristics, this paper presents all the calibration operations that were conducted during the commissioning phase and also gives the main results for every image quality performance.

  9. Retinal image quality during accommodation.

    Science.gov (United States)

    López-Gil, Norberto; Martin, Jesson; Liu, Tao; Bradley, Arthur; Díaz-Muñoz, David; Thibos, Larry N

    2013-07-01

    We asked if retinal image quality is maximum during accommodation, or sub-optimal due to accommodative error, when subjects perform an acuity task. Subjects viewed a monochromatic (552 nm), high-contrast letter target placed at various viewing distances. Wavefront aberrations of the accommodating eye were measured near the endpoint of an acuity staircase paradigm. Refractive state, defined as the optimum target vergence for maximising retinal image quality, was computed by through-focus wavefront analysis to find the power of the virtual correcting lens that maximizes visual Strehl ratio. Despite changes in ocular aberrations and pupil size during binocular viewing, retinal image quality and visual acuity typically remain high for all target vergences. When accommodative errors lead to sub-optimal retinal image quality, acuity and measured image quality both decline. However, the effect of accommodation errors of on visual acuity are mitigated by pupillary constriction associated with accommodation and binocular convergence and also to binocular summation of dissimilar retinal image blur. Under monocular viewing conditions some subjects displayed significant accommodative lag that reduced visual performance, an effect that was exacerbated by pharmacological dilation of the pupil. Spurious measurement of accommodative error can be avoided when the image quality metric used to determine refractive state is compatible with the focusing criteria used by the visual system to control accommodation. Real focusing errors of the accommodating eye do not necessarily produce a reliably measurable loss of image quality or clinically significant loss of visual performance, probably because of increased depth-of-focus due to pupil constriction. When retinal image quality is close to maximum achievable (given the eye's higher-order aberrations), acuity is also near maximum. A combination of accommodative lag, reduced image quality, and reduced visual function may be a useful

  10. 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

  11. Quality of service and customer satisfaction on arterial streets : final report

    Science.gov (United States)

    2003-06-13

    This report presents the results of a qualitative study of driver perception of quality of service (QOS) on urban arterial streets. The purpose of the study was to identify the factors that are important to drivers of personal automobiles (non-commer...

  12. Prognostic utility of carotid ultrasound and cardiac SPECT imaging in coronary artery bypass patients

    International Nuclear Information System (INIS)

    Bosevski, M.; Peovska, I.; Maksimovic, J.; Vavlukis, M.; Meskovska, S.

    2006-01-01

    The aim of our study was to evaluate the role of myocardial perfusion imaging (MPI) and common carotid artery intima-media thickness (CCA IMT) in the prognosis of patients with coronary artery disease referred for coronary artery bypass surgery (CABG) in a newly made prognostic model. 63 patients (age 60.36 ± 8.28 years) with angiographically established coronary artery disease referred for CABG were evaluated for: age, smoking, family disposition, dyslipidaemia, arterial hypertension, obesity, diabetes mellitus, previous myocardial infarction and revascularization. Patients underwent nitrate enhanced Gated SPECT myocardial perfusion imaging, with 17-segment analysis for calculation of perfusion scores and viability index. Common carotid artery IMT was measured by B-mode ultrasound. Patients were followed for cardiovascular events 12 months after CABG. The obtained data reported mean values of left ventricular ejection fraction (LVEF) 46.2±14.4%, viability index 0.76± 0.55, SRS 17.76±13.81 and summed nitrate score 12.89 ±10.36. Ultrasound detected CCA IMT 0.90± 0.24 mm, with increased value in 67.2% and presence of carotid plaques in 27.1% of pts. We registered 14 events and 8.8% mortality rate. Multiple regression modelling showed bilateral carotid plaque presence as a predictor of total events. Viability index and CCA IMT have been found as independent death predictors. Myocardial perfusion viability index and CCA IMT are predictors, independently associated with prognosis of patients referred for CABG. (author)

  13. Resliced image space construction for coronary artery collagen fibers.

    Science.gov (United States)

    Luo, Tong; Chen, Huan; Kassab, Ghassan S

    2017-01-01

    Collagen fibers play an important role in the biomechanics of the blood vessel wall. The objective of this study was to determine the 3D microstructure of collagen fibers in the media and adventitia of coronary arteries. We present a novel optimal angle consistence algorithm to reform image slices in the visualization and analysis of 3D collagen images. 3D geometry was reconstructed from resliced image space where the 3D skeleton was extracted as the primary feature for accurate reconstruction of geometrical parameters. Collagen fibers (range 80-200) were reconstructed from the porcine coronary artery wall for the measurement of various morphological parameters. Collagen waviness and diameters were 1.37 ± 0.19 and 2.61 ± 0.89 μm, respectively. The biaxial distributions of orientation had two different peaks at 110.7 ± 25.2° and 18.4 ± 19.3°. Results for width, waviness, and orientation were found to be in good agreement with manual measurements. In addition to accurately measuring 2D features more efficiently than the manual approach, the present method produced 3D features that could not be measured in the 2D manual approach. These additional parameters included the tilt angle (5.10 ± 2.95°) and cross-sectional area (CSA; 5.98 ± 3.79 μm2) of collagen fibers. These 3D collagen reconstructions provide accurate and reliable microstructure for biomechanical modeling of vessel wall mechanics.

  14. Quality Control in Mammography: Image Quality and Patient Doses

    International Nuclear Information System (INIS)

    Ciraj Bjelac, O.; Arandjic, D.; Boris Loncar, B.; Kosutic, D.

    2008-01-01

    Mammography is method of choice for early detection of breast cancer. The purpose of this paper is preliminary evaluation the mammography practice in Serbia, in terms of both quality control indicators, i.e. image quality and patient doses. The survey demonstrated considerable variations in technical parameters that affect image quality and patients doses. Mean glandular doses ranged from 0.12 to 2.8 mGy, while reference optical density ranged from 1.2 to 2.8. Correlation between image contrast and mean glandular doses was demonstrated. Systematic implementation of quality control protocol should provide satisfactory performance of mammography units and maintain satisfactory image quality and keep patient doses as low as reasonably practicable. (author)

  15. A universal color image quality metric

    NARCIS (Netherlands)

    Toet, A.; Lucassen, M.P.

    2003-01-01

    We extend a recently introduced universal grayscale image quality index to a newly developed perceptually decorrelated color space. The resulting color image quality index quantifies the distortion of a processed color image relative to its original version. We evaluated the new color image quality

  16. Development of quality metrics for ambulatory pediatric cardiology: Transposition of the great arteries after arterial switch operation.

    Science.gov (United States)

    Baker-Smith, Carissa M; Carlson, Karina; Ettedgui, Jose; Tsuda, Takeshi; Jayakumar, K Anitha; Park, Matthew; Tede, Nikola; Uzark, Karen; Fleishman, Craig; Connuck, David; Likes, Maggie; Penny, Daniel J

    2018-01-01

    To develop quality metrics (QMs) for the ambulatory care of patients with transposition of the great arteries following arterial switch operation (TGA/ASO). Under the auspices of the American College of Cardiology Adult Congenital and Pediatric Cardiology (ACPC) Steering committee, the TGA/ASO team generated candidate QMs related to TGA/ASO ambulatory care. Candidate QMs were submitted to the ACPC Steering Committee and were reviewed for validity and feasibility using individual expert panel member scoring according to the RAND-UCLA methodology. QMs were then made available for review by the entire ACC ACPC during an "open comment period." Final approval of each QM was provided by a vote of the ACC ACPC Council. Patients with TGA who had undergone an ASO were included. Patients with complex transposition were excluded. Twelve candidate QMs were generated. Seven metrics passed the RAND-UCLA process. Four passed the "open comment period" and were ultimately approved by the Council. These included: (1) at least 1 echocardiogram performed during the first year of life reporting on the function, aortic dimension, degree of neoaortic valve insufficiency, the patency of the systemic and pulmonary outflows, the patency of the branch pulmonary arteries and coronary arteries, (2) neurodevelopmental (ND) assessment after ASO; (3) lipid profile by age 11 years; and (4) documentation of a transition of care plan to an adult congenital heart disease (CHD) provider by 18 years of age. Application of the RAND-UCLA methodology and linkage of this methodology to the ACPC approval process led to successful generation of 4 QMs relevant to the care of TGA/ASO pediatric patients in the ambulatory setting. These metrics have now been incorporated into the ACPC Quality Network providing guidance for the care of TGA/ASO patients across 30 CHD centers. © 2017 Wiley Periodicals, Inc.

  17. Imaging Arterial Fibres Using Diffusion Tensor Imaging—Feasibility Study and Preliminary Results

    Directory of Open Access Journals (Sweden)

    Kerskens Christian

    2010-01-01

    Full Text Available Abstract MR diffusion tensor imaging (DTI was used to analyze the fibrous structure of aortic tissue. A fresh porcine aorta was imaged at 7T using a spin echo sequence with the following parameters: matrix 128 128 pixel; slice thickness 0.5 mm; interslice spacing 0.1 mm; number of slices 16; echo time 20.3 s; field of view 28 mm 28 mm. Eigenvectors from the diffusion tensor images were calculated for the central image slice and the averaged tensors and the eigenvector corresponding to the largest eigenvalue showed two distinct angles corresponding to near and to the transverse plane of the aorta. Fibre tractography within the aortic volume imaged confirmed that fibre angles were oriented helically with lead angles of and . The findings correspond to current histological and microscopy data on the fibrous structure of aortic tissue, and therefore the eigenvector maps and fibre tractography appear to reflect the alignment of the fibers in the aorta. In view of current efforts to develop noninvasive diagnostic tools for cardiovascular diseases, DTI may offer a technique to assess the structural properties of arterial tissue and hence any changes or degradation in arterial tissue.

  18. Imaging of peripheral arteries by 16-slice computed tomography angiography: a valuable tool

    International Nuclear Information System (INIS)

    Mishra, A.; Ehtuish, Ehtuish F.

    2007-01-01

    To evaluate the efficacy of multidetector (16-row) computed tomography (MDCT) in imaging the upper and lower limb arterial tree in trauma and peripheral vascular disease. Thirty three patients underwent multislice computed tomography angiography (MSCTA) of the upper or the lower limb on multislice (16-slice) CT scanner between November 2004 and July 2005 in the Department of Radiology, National Organ Transplant Center, Tripoli, Libya. The findings were retrospectively compared with the surgical outcome in cases of trauma with suspected arterial injuries; or color Doppler correlation was obtained, for patients of peripheral vascular disease. Multislice computed tomography angiography allows a comprehensive diagnostic work-up in all trauma cases with suspected arterial injuries. In 23 cases of peripheral vascular diseases, MSCTA adequately demonstrated the presence of any stenosis or occlusion, its degree and extent, the presence of collaterals and distal reformation if any; the presence of plaques. Our experience of computed tomography angiography with 16-row MDCT scanner has clearly demonstrated its efficacy as a promising, new, fast, accurate, safe and non-invasive imaging modality of choice in cases of trauma with suspected arterial injuries; and as a useful screening modality in cases of peripheral vascular disease for diagnosis and for grading. (author)

  19. Effects of massage therapy on sleep quality after coronary artery bypass graft surgery.

    Science.gov (United States)

    Nerbass, Flavia Baggio; Feltrim, Maria Ignez Zanetti; Souza, Silvia Alves de; Ykeda, Daisy Satomi; Lorenzi-Filho, Geraldo

    2010-01-01

    Having poor sleep quality is common among patients following cardiopulmonary artery bypass graft surgery. Pain, stress, anxiety and poor sleep quality may be improved by massage therapy. This study evaluated whether massage therapy is an effective technique for improving sleep quality in patients following cardiopulmonary artery bypass graft surgery. Participants included cardiopulmonary artery bypass graft surgery patients who were randomized into a control group and a massage therapy group following discharge from the intensive care unit (Day 0), during the postoperative period. The control group and the massage therapy group comprised participants who were subjected to three nights without massage and three nights with massage therapy, respectively. The patients were evaluated on the following mornings (i.e., Day 1 to Day 3) using a visual analogue scale for pain in the chest, back and shoulders, in addition to fatigue and sleep. Participants kept a sleep diary during the study period. Fifty-seven cardiopulmonary artery bypass graft surgery patients were enrolled in the study during the preoperative period, 17 of whom were excluded due to postoperative complications. The remaining 40 participants (male: 67.5%, age: 61.9 years ± 8.9 years, body mass index: 27.2 kg/m² ± 3.7 kg/m²) were randomized into control (n = 20) and massage therapy (n = 20) groups. Pain in the chest, shoulders, and back decreased significantly in both groups from Day 1 to Day 3. The participants in the massage therapy group had fewer complaints of fatigue on Day 1 (p=0.006) and Day 2 (p=0.028) in addition, they reported a more effective sleep during all three days (p=0.019) when compared with the participants in the control group. Massage therapy is an effective technique for improving patient recovery from cardiopulmonary artery bypass graft surgery because it reduces fatigue and improves sleep.

  20. Carotid and vertebral artery dissections: clinical aspects, imaging features and endovascular treatment

    International Nuclear Information System (INIS)

    Flis, Christine M.; Jaeger, H.R.; Sidhu, Paul S.

    2007-01-01

    Extracranial arterial dissections are a recognised cause of stroke, particularly in young adults. Clinical diagnosis may be difficult, and the classical triad of symptoms is uncommon. Imaging plays a pivotal role in the diagnosis of extracranial arterial dissections, and this review provides a detailed discussion of the relative merits and limitations of currently available imaging modalities. Conventional arteriography has been the reference standard for demonstrating an intimal flap and double lumen, which are the hallmarks of a dissection, and for detecting complications such as stenosis, occlusion or pseudoaneurysm. Noninvasive vascular imaging methods, such as ultrasound (US), magnetic resonance angiography (MRA) and computed tomography angiography (CTA) are increasingly replacing conventional angiography for the diagnosis of carotid and vertebral dissections. Ultrasound provides dynamic and ''real-time'' information regarding blood flow. Source data of MRA and CTA and additional cross-sectional images can provide direct visualisation of the mural haematoma and information about the vessel lumen. Anticoagulation to prevent strokes is the mainstay of medical treatment, but randomised trials to define the optimal treatment regime are lacking. Surgery has a limited role in management of dissections, but endovascular procedures are gaining importance for treatment of complications and if medical management fails. (orig.)

  1. Traumatic injuries: imaging and intervention of large arterial trauma

    International Nuclear Information System (INIS)

    Schoder, Maria; Prokop, Mathias; Lammer, Johannes

    2002-01-01

    Traumatic vessel injury can cause bleeding, thrombosis, embolization, or malperfusion due to external compression and spasm. Non-traumatic causes of acute large arterial emergencies include rupture of an aneurysm and pseudoaneurysm, dissection, embolization, and thrombosis in hypercoagulability syndromes. Ultrasonography is, of course, the imaging modality of choice in emergency cases; however, in central vascular injuries, spiral CT with contrast enhancement is the imaging modality that provides the most information. Angiography may be necessary for detailed information and before intervention. Stent-grafts are used to close large vascular lacerations, ruptured aortic aneurysms, and the entry tear of dissections. Interventional radiology methods play a major role in managing vascular emergencies. (orig.)

  2. Coronary artery stent mimicking intracardiac thrombus on cardiac magnetic resonance imaging due to signal loss

    DEFF Research Database (Denmark)

    Qayyum, Abbas Ali; Vejlstrup, Niels Grove; Ahtarovski, Kiril Aleksov

    2012-01-01

    Since the introduction of percutaneous coronary intervention for coronary artery disease, thousands of patients have been treated with the implantation of coronary stents. Moreover, several of the patients with coronary stent undergo cardiac magnetic resonance (CMR) imaging every year. This case...... report is of a 77-year-old man who was previously treated with the implantation of a coronary stent in the left circumflex artery. He underwent CMR imaging, which revealed a process 14×21 mm in the left atrium. Cardiac contrast computed tomography did not demonstrate any cardiac pathology. While...... the signal loss on MRI associated with implanted metallic devices is known, we report a case where an implanted coronary stent in the left circumflex artery led to an intracardiac signal loss mimicking intracardiac thrombus/tumor....

  3. Imaging of carotid artery disease: from luminology to function?

    Energy Technology Data Exchange (ETDEWEB)

    Gillard, J.H. [University Department of Radiology, Addenbrooke' s Hospital, Cambridge (United Kingdom)

    2003-10-01

    There have been tremendous advances in our ability to image atheromatous disease, particularly in the carotid artery, which is accessible and large enough to image. The repertoire of methodology available is growing, giving anatomical information on luminal narrowing which is approaching the level at which conventional carotid angiography will become very uncommon as CT and contrast-enhanced MR angiographic techniques become the norm. More exciting is the tentative ability to perform functional plaque imaging addressing enhancement patterns and macrophage activity using MR or positron-emission tomography techniques. These techniques, once rigorously evaluated, may, in addition to complex mathematical modelling of plaque, eventually allow us to assess true plaque risk. Time will best judge whether we will be able to move from the use of simple luminology to assessment of plaque function. (orig.)

  4. Imaging of carotid artery disease: from luminology to function?

    International Nuclear Information System (INIS)

    Gillard, J.H.

    2003-01-01

    There have been tremendous advances in our ability to image atheromatous disease, particularly in the carotid artery, which is accessible and large enough to image. The repertoire of methodology available is growing, giving anatomical information on luminal narrowing which is approaching the level at which conventional carotid angiography will become very uncommon as CT and contrast-enhanced MR angiographic techniques become the norm. More exciting is the tentative ability to perform functional plaque imaging addressing enhancement patterns and macrophage activity using MR or positron-emission tomography techniques. These techniques, once rigorously evaluated, may, in addition to complex mathematical modelling of plaque, eventually allow us to assess true plaque risk. Time will best judge whether we will be able to move from the use of simple luminology to assessment of plaque function. (orig.)

  5. Clinical evaluation of 99Tcm-MIBI myocardial perfusion imaging for the detection of coronary artery disease in patients with metabolic syndrome

    International Nuclear Information System (INIS)

    Tian Yueqin; Wei Hongxing; Guo Xinhua; Guo Feng; He Zuoxiang

    2008-01-01

    Objective: Metabolic syndrome is a combination of medical disorders that consist of a collection of independent factors at risk of developing coronary artery disease. The purpose of this study was to evaluate the value of 99 Tc m -methoxyisobutylisonitrile (MIBI) myocardial perfusion imaging for the diagnosis of coronary artery disease in patients with metabolic syndrome. Methods: A total of 251 patients [mean age (59 ± 10) years, 179 men, 72 women] were included in this study. All patients underwent exercise and rest 99 Tc m -MIBI myocardial perfusion imaging and coronary angiography. Results: Of the 163 patients with significant coronary artery stenosis, 116 showed abnormal 99 Tc m -MIBI myocardial perfusion imaging; and among the 88 patients with normal coronary angiography, 82 showed normal myocardial perfusion imaging. The sensitivity, specificity and accuracy of 99 Tc m -MIBI myocardial perfusion imaging for coronary artery disease detection were 71% (116/163), 93% (82/88) and 79% (198/251), respectively. The positive and negative predictive values were 95% (116/122) and 64% (82/129), respectively. Conclusion: 99 Tc m -MIBI myocardial perfusion imaging has important clinical value for detecting coronary artery disease in patients with metabolic syndrome. (authors)

  6. High-Resolution 3 T MR Microscopy Imaging of Arterial Walls

    International Nuclear Information System (INIS)

    Sailer, Johannes; Rand, Thomas; Berg, Andreas; Sulzbacher, Irene; Peloschek, P.; Hoelzenbein, Thomas; Lammer, Johannes

    2006-01-01

    Purpose. To achieve a high spatial resolution in MR imaging that allows for clear visualization of anatomy and even histology and documentation of plaque morphology in in vitro samples from patients with advanced atherosclerosis. A further objective of our study was to evaluate whether T2-weighted high-resolution MR imaging can provide accurate classification of atherosclerotic plaque according to a modified American Heart Association classification. Methods. T2-weighted images of arteries were obtained in 13 in vitro specimens using a 3 T MR unit (Medspec 300 Avance/Bruker, Ettlingen, Germany) combined with a dedicated MR microscopy system. Measurement parameters were: T2-weighted sequences with TR 3.5 sec, TE 15-120 msec; field of view (FOV) 1.4 x 1.4; NEX 8; matrix 192; and slice thickness 600 μm. MR measurements were compared with corresponding histologic sections. Results. We achieved excellent spatial and contrast resolution in all specimens. We found high agreement between MR images and histology with regard to the morphology and extent of intimal proliferations in all but 2 specimens. We could differentiate fibrous caps and calcifications from lipid plaque components based on differences in signal intensity in order to differentiate hard and soft atheromatous plaques. Hard plaques with predominantly intimal calcifications were found in 7 specimens, and soft plaques with a cholesterol/lipid content in 5 cases. In all specimens, hemorrhage or thrombus formation, and fibrotic and hyalinized tissue could be detected on both MR imaging and histopathology. Conclusion. High-resolution, high-field MR imaging of arterial walls demonstrates the morphologic features, volume, and extent of intimal proliferations with high spatial and contrast resolution in in vitro specimens and can differentiate hard and soft plaques

  7. Noninvasive imaging of coronary arteries: current and future role of multidetector row computer tomography

    International Nuclear Information System (INIS)

    Nedevska, M.; Stoinova, V.

    2006-01-01

    Full text: This review will present the current and future role of cardiac computer tomography (CCT), and particular multidetector CCT, for imaging of atherosclerotic pathologic changes of the coronary arteries. Atherosclerosis and its cardio-vascular complications represent one of the major issues of public health in industrial countries. Different imaging modalities, including invasive coronarography, have been aimed to the diagnosis of the disease, when it provokes symptomatic decrease of the blood flow. In spite of development of surgical and percutaneous methods for coronary revascularization, coronary artery disease remains the major cause of death in North America and Europe. This demonstrates the need of novel, complementary diagnostic strategies, aimed to identify asymptomatic stages as the basis of pharmacological interventions. Noninvasive coronary angiography with multidetector CT allows both assessment of luminal stenosis and subclinical disease of arterial wall. Large trails are missing now to understand and present what will be the role of this technology in the comprehensive assessment of patients, suspected of having CAD. Based on experience and current potentials we will describe how tomographic coronary imaging may eventually supplement traditional angiographic techniques in understanding the patterns of atherosclerotic CAD development

  8. Improving the Grading Accuracy of Astrocytic Neoplasms Noninvasively by Combining Timing Information with Cerebral Blood Flow: A Multi-TI Arterial Spin-Labeling MR Imaging Study.

    Science.gov (United States)

    Yang, S; Zhao, B; Wang, G; Xiang, J; Xu, S; Liu, Y; Zhao, P; Pfeuffer, J; Qian, T

    2016-12-01

    Systematic and accurate glioma grading has clinical significance. We present the utility of multi-TI arterial spin-labeling imaging and provide the bolus arrival time maps for grading astrocytomas. Forty-three patients with astrocytomas (21 men; mean age, 51 years) were recruited. The classification abilities of conventional MR imaging features, normalized CBF value derived from multi-TI arterial spin-labeling imaging, normalized bolus arrival time, and normalized CBF derived from single-TI arterial spin-labeling were compared in patients with World Health Organization (WHO) grade II, III, and IV astrocytomas. The normalized CBF value derived from multi-TI arterial spin-labeling imaging was higher in patients with higher grade astrocytoma malignancies compared with patients with lower grade astrocytomas, while the normalized bolus arrival time showed the opposite tendency. The normalized CBF value derived from the multi-TI arterial spin-labeling imaging showed excellent performance with areas under the receiver operating characteristic curve of 0.813 (WHO II versus III), 0.964 (WHO II versus IV), 0.872 (WHO III versus IV), and 0.883 (low-grade-versus-high-grade gliomas). The normalized CBF value derived from single-TI arterial spin-labeling imaging could statistically differentiate the WHO II and IV groups (area under the receiver operating characteristic curve = 0.826). The normalized bolus arrival time effectively identified the WHO grades II and III with an area under the receiver operating characteristic curve of 0.836. Combining the normalized CBF value derived from multi-TI arterial spin-labeling imaging and normalized bolus arrival time improved the diagnostic accuracy from 65.10% to 72.10% compared with the normalized CBF value derived from multi-TI arterial spin-labeling imaging being applied independently. The combination of multi-TI arterial spin-labeling imaging and conventional MR imaging had the best performance, with a diagnostic accuracy of 81

  9. Neovascularization in Vertebral Artery Atheroma-A Dynamic Contrast-Enhanced Magnetic Resonance Imaging-Based Comparative Study in Patients with Symptomatic and Asymptomatic Carotid Artery Disease.

    Science.gov (United States)

    Usman, Ammara; Yuan, Jianmin; Patterson, Andrew J; Graves, Martin J; Varty, Kevin; Sadat, Umar; Gillard, Jonathan H

    2018-05-24

    Atherosclerosis is a systemic inflammatory disease intertwined with neovascularization. Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) enables the assessment of plaque neovascularization. This study aimed to explore the systemic nature of atherosclerosis by assessing difference in severity of neovascularization as quantified by DCE-MRI of vertebral arteries (VAs) between patients with symptomatic and asymptomatic carotid artery disease. Ten consecutive patients with asymptomatic VA stenosis and concomitant symptomatic carotid artery disease (group 1) and 10 consecutive patients with asymptomatic VA stenosis and concomitant asymptomatic carotid artery disease (group 2) underwent 3-dimensional DCE-MRI of their cervical segment of VAs. A previously validated pharmacokinetic modeling approach was used for DCE-MRI analysis. K trans was calculated in the adventitia and plaque as a measure of neovessel permeability. Both patient groups were comparable for demographics and comorbidities. Mean luminal stenosis was comparable for both groups (54.4% versus 52.27%, P = .32). Group 1 had higher adventitial K trans and plaque K trans (.08 ± .01 min -1 , .07 ± .01 min -1 ) compared with Group 2 (.06 ± .01 min -1 , .06 ± .01 min -1 ) (P = .004 and .03, respectively). Good correlation was present among the two image analysts (intraclass correlation coefficient = .78). Vertebral Artery atheroma of patients with symptomatic carotid artery disease had increased neovessel permeability compared with the patients with asymptomatic carotid artery disease. These findings are consistent with the hypothesis that atherosclerosis is a systemic inflammatory disease. The VA atherosclerosis is likely to have increased severity of neovascularization if another arterial territory is symptomatic in the same patient cohort. Copyright © 2018 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  10. Serial right ventricle 201Tl imaging after exercise: relation to anatomy of the right coronary artery

    International Nuclear Information System (INIS)

    Brown, K.A.; Boucher, C.A.; Okada, R.D.; Strauss, H.W.; McKusick, K.A.; Pohost, G.M.

    1982-01-01

    The relation of the appearance of the right ventricle on serium 201 Tl myocardial imaging to coronary artery anatomy was examined in 88 consecutive patients undergoing exercise 201 Tl testing and coronary angiography for the evaluation of chest pain. Transient defects in the right ventricle were found in 8 patients. All had high grade (greater than or equal to 90%) stenosis of the proximal right coronary artery. Nonvisualization of right ventricular (RV) activity occurred in 10 patients. Nine of the 10 (90%) had significant (greater than or equal to 50% stenosis) disease of the proximal right coronary artery and 7 (70%) had high grade stenosis. The right ventricle appeared normal in 70 patients. Twenty-nine (41%) of these patients had significant proximal right coronary artery disease. Right ventricular appearance was not affected by the presence or absence of disease of the left anterior descending or left circumflex artery or by the appearance of the left ventricle. Thus, with serial RV thallium-201 myocardial imaging after exercise, we found that (1) RV transient defects suggest the presence of high grade proximal right coronary artery stenosis, (2) non-visualization of RV activity also predicts significant proximal right coronary disease, and (3) the right ventricle frequently appears normal despite proximal right coronary artery disease and therefore this finding does not exclude such disease

  11. Image quality in mammography

    International Nuclear Information System (INIS)

    Haus, A.G.; Doi, K.; Metz, C.E.; Bernstein, J.

    1976-01-01

    In mammography, image quality is a function of the shape, size, and x-ray absorption properties of the anatomic part to be radiographed and of the lesion to be detected; it also depends on geometric unsharpness, and the resolution, characteristic curve and noise properties of the recording system. X-ray energy spectra, modulation transfer functions, Wiener spectra, characteristic and gradient curves, and radiographs of a breast phantom and of a resected breast specimen containing microcalcifications are used in a review of some current considerations of the factors, and the complex relationship among factors, that affect image quality in mammography. Image quality and patient radiation exposure in mammography are interrelated. An approach to the problem of evaluating the trade-off between diagnostic certainty and the cost or risk of performing a breast imaging procedure is discussed

  12. Right ventricle performances with echocardiography and 99mTc myocardial perfusion imaging in pulmonary arterial hypertension patients.

    Science.gov (United States)

    Liu, Jie; Fei, Lei; Huang, Guang-Qing; Shang, Xiao-Ke; Liu, Mei; Pei, Zhi-Jun; Zhang, Yong-Xue

    2018-05-01

    Right heart catheterization is commonly used to measure right ventricle hemodynamic parameters and is the gold standard for pulmonary arterial hypertension diagnosis; however, it is not suitable for patients' long-term follow-up. Non-invasive echocardiography and nuclear medicine have been applied to measure right ventricle anatomy and function, but the guidelines for the usefulness of clinical parameters remain to be established. The goal of this study is to identify reliable clinical parameters of right ventricle function in pulmonary arterial hypertension patients and analyze the relationship of these clinical parameters with the disease severity of pulmonary arterial hypertension. In this study, 23 normal subjects and 23 pulmonary arterial hypertension patients were recruited from January 2015 to March 2016. Pulmonary arterial hypertension patients were classified into moderate and severe pulmonary arterial hypertension groups according to their mean pulmonary arterial pressure levels. All the subjects were subjected to physical examination, chest X-ray, 12-lead electrocardiogram, right heart catheterization, two-dimensional echocardiography, and technetium 99m ( 99m Tc) myocardial perfusion imaging. Compared to normal subjects, the right heart catheterization indexes including right ventricle systolic pressure, right ventricle end diastolic pressure, pulmonary artery systolic pressure, pulmonary artery diastolic pressure, pulmonary vascular resistance, and right ventricle end systolic pressure increased in pulmonary arterial hypertension patients and were correlated with mean pulmonary arterial pressure levels. Echocardiography parameters, including tricuspid regurgitation peak velocity, tricuspid regurgitation pressure gradient, tricuspid annular plane systolic excursion and fractional area, right ventricle-myocardial performance index, were significantly associated with the mean pulmonary arterial pressure levels in pulmonary arterial hypertension patients

  13. Intravascular Ultrasound Imaging of Peripheral Arteries as an Adjunct to Balloon Angioplasty and Atherectomy

    International Nuclear Information System (INIS)

    Korogi, Yukunori; Hirai, Toshinori; Takahashi, Mutsumasa

    1996-01-01

    This article reviews many of the applications of intravascular ultrasound (US) imaging for peripheral arterial diseases. In vitro studies demonstrate an excellent correlation between ultrasound measurements of lumen and plaque crossectional area compared with histologic sections. In vivo clinical studies reveal the enhanced diagnostic capabilities of this technology compared with angiography. Intravascular US imaging can provide valuable information on the degree, eccentricity, and histologic type of stenosis before intervention, and on the morphological changes in the arterial wall and the extent of excision after intervention. Intravascular US may also serve as a superior index for gauging the diameter of balloon, stent, laser probe, and/or atherectomy catheter appropriate for a proposed intervention. Significant new insights into the mechanisms of balloon angioplasty and atherectomy have been established by intravascular US findings. Intravascular US imaging has been shown to be a more accurate method than angiography for determining the cross-sectional area of the arterial lumen, and for assessing severity of stenosis. Quantitative assessment of the luminal cross-sectional area after the balloon dilatation should be more accurate than angiography as intimal tears or dissections produced by the dilatation may not be accurately evaluated with angiography. At the present time, intravascular US is still a controversial imaging technique. Outcome studies are currently being organized to assess the clinical value and cost effectiveness of intravascular ultrasound in the context of these interventional procedures

  14. Anatomical Variations of Carotid Artery and Optic Nerve in Sphenoid Sinus Using Computerized Tomographic Imaging

    Directory of Open Access Journals (Sweden)

    Nikakhlagh

    2014-12-01

    Full Text Available Background Sphenoid sinus is surrounded by many vital vascular and nervous structures. In more than 20% of patients with chronic sinusitis, involvement of sphenoid sinus has been observed. Besides, sphenoid sinus is an appropriate route to access anterior and middle cranial fossa in surgery. Therefore, it is important to have an adequate knowledge about the contents of sphenoid sinus and its proximity for nasal endoscopy, sinus surgeries and neurosurgeries. Objectives The aim of this study was to study sphenoid sinus proximity with carotid artery and the optic nerve using computerized tomographic imaging. Materials and Methods In this prospective study, computerized tomographic images of sphenoid sinus of patients referred to Imam Khomeini and Apadana hospitals were studied. The images were studied regarding any bulging, as well as not having a bone covering in sphenoid sinus regarding internal carotid artery and optic nerve. Furthermore, unilateralness or bilateralness of their relationships was studied. Results Among 468 coronal and axial CT scan images of sphenoid sinus, 365 (78% showed post-sellar pneumatization and 103 (22% pre-sellar pneumatization. Regarding existence of internal septa, 346 (74% cases showed multiple septation, and the remaining images were reported to have a single septum. According to the reports of CT scan images, the existence of bulging as a result of internal carotid artery and uncovered artery were 4.22% and 5.8% in the right sinus, 4.9% and 5.4% in the left sinus, and 4.34% and 4.6% in both sinuses, respectively. According to the reports of CT scan images, existence of bulging as a result of optic nerve and uncovered nerve were 5.7% and 4.3% in the right sinus, 6% and 5.4% in the left sinus, and 12% and 3.2% in both sinuses, respectively. Conclusions Due to variability of sphenoid sinus pneumatization and the separator blade of the two sinus cavities, careful attention is required during sinus surgery to avoid

  15. Three-dimensional analysis and classification of arteries in the skin and subcutaneous adipofascial tissue by computer graphics imaging.

    Science.gov (United States)

    Nakajima, H; Minabe, T; Imanishi, N

    1998-09-01

    To develop new types of surgical flaps that utilize portions of the skin and subcutaneous tissue (e.g., a thin flap or an adipofascial flap), three-dimensional investigation of the vasculature in the skin and subcutaneous tissue has been anticipated. In the present study, total-body arterial injection and three-dimensional imaging of the arteries by computer graphics were performed. The full-thickness skin and subcutaneous adipofascial tissue samples, which were obtained from fresh human cadavers injected with radio-opaque medium, were divided into three distinct layers. Angiograms of each layer were introduced into a personal computer to construct three-dimensional images. On a computer monitor, each artery was shown color-coded according to the three portions: the deep adipofascial layer, superficial adipofascial layer, and dermis. Three-dimensional computerized images of each artery in the skin and subcutaneous tissue revealed the components of each vascular plexus and permitted their classification into six types. The distribution of types in the body correlated with the tissue mobility of each area. Clinically, appreciation of the three-dimensional structure of the arteries allowed the development of several new kinds of flaps.

  16. Value of magnetic resonance imaging for the noninvasive detection of stenosis in coronary artery bypass grafts and recipient coronary arteries

    NARCIS (Netherlands)

    Langerak, Susan E.; Vliegen, Hubert W.; Jukema, J. Wouter; Kunz, Patrik; Zwinderman, Aeilko H.; Lamb, Hildo J.; van der Wall, Ernst E.; de Roos, Albert

    2003-01-01

    BACKGROUND: Magnetic resonance imaging (MRI) is a potential noninvasive diagnostic tool to detect coronary artery bypass graft stenosis, but its value in clinical practice remains to be established. We investigated the value of MRI in detecting stenotic grafts, including recipient vessels. METHODS

  17. Relationship Between Carotid Artery Calcification Detected in Dental Panoramic Images and Hypertension and Myocardial Infarction

    International Nuclear Information System (INIS)

    Moshfeghi, Mahkameh; Taheri, Jamileh Beigom; Bahemmat, Nika; Evazzadeh, Mohammad Ebrahim; Hadian, Hoora

    2014-01-01

    Carotid artery calcification may be related to cerebrovascular accident, which may result in death or physical and mental disabilities in survivors. Our purpose is to study the association of carotid artery calcification (CAC) on dental panoramic radiographs and two risk factors of cerebrovascular accident (CVA) including hypertension and myocardial infarction (MI). Panoramic images of 200 patients that were all women above 50 years of age (a population suffering from vascular diseases) were investigated. All panoramic images were provided under similar conditions in terms of the type of panoramic radiograph equipment, type of applied films and the automatic film processor. Then, the patients answered questions about MI history and taking antihypertensive drugs. We also measured the blood pressure of patients in two separate surveys. Data analysis was performed by SPSS statistical program. We used Exact Fisher test and Chi-Square test at a significant level of less than 0.05 to study the effect of these variables on the occurrence of carotid artery calcification. Among 200 studied samples, 22 of the patients (11%) had carotid artery calcification on the dental panoramic radiograph. In total, 52 patients (26%) had hypertension and four people (2%) had a history of MI. Eleven individuals among patients suffering from hypertension (21.2%) and three individuals among patients with a history of MI (75%) demonstrated CAC on dental panoramic images . The relationship between CAC found on dental panoramic radiographs and two CVA risk factors--hypertension and MI-- was significant. Therefore, it seems that detection of CAC on panoramic images of dental patients must be considered by dentists

  18. DIfferential Subsampling with Cartesian Ordering (DISCO): a high spatio-temporal resolution Dixon imaging sequence for multiphasic contrast enhanced abdominal imaging.

    Science.gov (United States)

    Saranathan, Manojkumar; Rettmann, Dan W; Hargreaves, Brian A; Clarke, Sharon E; Vasanawala, Shreyas S

    2012-06-01

    To develop and evaluate a multiphasic contrast-enhanced MRI method called DIfferential Sub-sampling with Cartesian Ordering (DISCO) for abdominal imaging. A three-dimensional, variable density pseudo-random k-space segmentation scheme was developed and combined with a Dixon-based fat-water separation algorithm to generate high temporal resolution images with robust fat suppression and without compromise in spatial resolution or coverage. With institutional review board approval and informed consent, 11 consecutive patients referred for abdominal MRI at 3 Tesla (T) were imaged with both DISCO and a routine clinical three-dimensional SPGR-Dixon (LAVA FLEX) sequence. All images were graded by two radiologists using quality of fat suppression, severity of artifacts, and overall image quality as scoring criteria. For assessment of arterial phase capture efficiency, the number of temporal phases with angiographic phase and hepatic arterial phase was recorded. There were no significant differences in quality of fat suppression, artifact severity or overall image quality between DISCO and LAVA FLEX images (P > 0.05, Wilcoxon signed rank test). The angiographic and arterial phases were captured in all 11 patients scanned using the DISCO acquisition (mean number of phases were two and three, respectively). DISCO effectively captures the fast dynamics of abdominal pathology such as hyperenhancing hepatic lesions with a high spatio-temporal resolution. Typically, 1.1 × 1.5 × 3 mm spatial resolution over 60 slices was achieved with a temporal resolution of 4-5 s. Copyright © 2012 Wiley Periodicals, Inc.

  19. Imaging Arterial Fibres Using Diffusion Tensor Imaging—Feasibility Study and Preliminary Results

    Directory of Open Access Journals (Sweden)

    Ciaran K. Simms

    2010-01-01

    Full Text Available MR diffusion tensor imaging (DTI was used to analyze the fibrous structure of aortic tissue. A fresh porcine aorta was imaged at 7T using a spin echo sequence with the following parameters: matrix 128 × 128 pixel; slice thickness 0.5 mm; interslice spacing 0.1 mm; number of slices 16; echo time 20.3 s; field of view 28 mm × 28 mm. Eigenvectors from the diffusion tensor images were calculated for the central image slice and the averaged tensors and the eigenvector corresponding to the largest eigenvalue showed two distinct angles corresponding to near 0∘ and 180∘ to the transverse plane of the aorta. Fibre tractography within the aortic volume imaged confirmed that fibre angles were oriented helically with lead angles of 15±2.5∘ and 175±2.5∘. The findings correspond to current histological and microscopy data on the fibrous structure of aortic tissue, and therefore the eigenvector maps and fibre tractography appear to reflect the alignment of the fibers in the aorta. In view of current efforts to develop noninvasive diagnostic tools for cardiovascular diseases, DTI may offer a technique to assess the structural properties of arterial tissue and hence any changes or degradation in arterial tissue.

  20. Improving best-phase image quality in cardiac CT by motion correction with MAM optimization

    Energy Technology Data Exchange (ETDEWEB)

    Rohkohl, Christopher; Bruder, Herbert; Stierstorfer, Karl [Siemens AG, Healthcare Sector, Siemensstrasse 1, 91301 Forchheim (Germany); Flohr, Thomas [Siemens AG, Healthcare Sector, Siemensstrasse 1, 91301 Forchheim (Germany); Institute of Diagnostic Radiology, Eberhard Karls University, Hoppe-Seyler-Str. 3, 72076 Tuebingen (Germany)

    2013-03-15

    Purpose: Research in image reconstruction for cardiac CT aims at using motion correction algorithms to improve the image quality of the coronary arteries. The key to those algorithms is motion estimation, which is currently based on 3-D/3-D registration to align the structures of interest in images acquired in multiple heart phases. The need for an extended scan data range covering several heart phases is critical in terms of radiation dose to the patient and limits the clinical potential of the method. Furthermore, literature reports only slight quality improvements of the motion corrected images when compared to the most quiet phase (best-phase) that was actually used for motion estimation. In this paper a motion estimation algorithm is proposed which does not require an extended scan range but works with a short scan data interval, and which markedly improves the best-phase image quality. Methods: Motion estimation is based on the definition of motion artifact metrics (MAM) to quantify motion artifacts in a 3-D reconstructed image volume. The authors use two different MAMs, entropy, and positivity. By adjusting the motion field parameters, the MAM of the resulting motion-compensated reconstruction is optimized using a gradient descent procedure. In this way motion artifacts are minimized. For a fast and practical implementation, only analytical methods are used for motion estimation and compensation. Both the MAM-optimization and a 3-D/3-D registration-based motion estimation algorithm were investigated by means of a computer-simulated vessel with a cardiac motion profile. Image quality was evaluated using normalized cross-correlation (NCC) with the ground truth template and root-mean-square deviation (RMSD). Four coronary CT angiography patient cases were reconstructed to evaluate the clinical performance of the proposed method. Results: For the MAM-approach, the best-phase image quality could be improved for all investigated heart phases, with a maximum

  1. Improving best-phase image quality in cardiac CT by motion correction with MAM optimization

    International Nuclear Information System (INIS)

    Rohkohl, Christopher; Bruder, Herbert; Stierstorfer, Karl; Flohr, Thomas

    2013-01-01

    Purpose: Research in image reconstruction for cardiac CT aims at using motion correction algorithms to improve the image quality of the coronary arteries. The key to those algorithms is motion estimation, which is currently based on 3-D/3-D registration to align the structures of interest in images acquired in multiple heart phases. The need for an extended scan data range covering several heart phases is critical in terms of radiation dose to the patient and limits the clinical potential of the method. Furthermore, literature reports only slight quality improvements of the motion corrected images when compared to the most quiet phase (best-phase) that was actually used for motion estimation. In this paper a motion estimation algorithm is proposed which does not require an extended scan range but works with a short scan data interval, and which markedly improves the best-phase image quality. Methods: Motion estimation is based on the definition of motion artifact metrics (MAM) to quantify motion artifacts in a 3-D reconstructed image volume. The authors use two different MAMs, entropy, and positivity. By adjusting the motion field parameters, the MAM of the resulting motion-compensated reconstruction is optimized using a gradient descent procedure. In this way motion artifacts are minimized. For a fast and practical implementation, only analytical methods are used for motion estimation and compensation. Both the MAM-optimization and a 3-D/3-D registration-based motion estimation algorithm were investigated by means of a computer-simulated vessel with a cardiac motion profile. Image quality was evaluated using normalized cross-correlation (NCC) with the ground truth template and root-mean-square deviation (RMSD). Four coronary CT angiography patient cases were reconstructed to evaluate the clinical performance of the proposed method. Results: For the MAM-approach, the best-phase image quality could be improved for all investigated heart phases, with a maximum

  2. Fractal Dimension Analysis of MDCT Images for Quantifying the Morphological Changes of the Pulmonary Artery Tree in Patients with Pulmonary Hypertension

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Haitao; Li, Ning; Guo, Lijun; Gao, Fei; Liu, Cheng [Shandong University, Shandong Medical Imaging Research Institute, Shandong (Korea, Republic of)

    2011-06-15

    The aim of this study was to use fractal dimension (FD) analysis on multidetector CT (MDCT) images for quantifying the morphological changes of the pulmonary artery tree in patients with pulmonary hypertension (PH). Fourteen patients with PH and 17 patients without PH as controls were studied. All of the patients underwent contrast-enhanced helical CT and transthoracic echocardiography. The pulmonary artery trees were generated using post-processing software, and the FD and projected image area of the pulmonary artery trees were determined with Image J software in a personal computer. The FD, the projected image area and the pulmonary artery pressure (PAP) were statistically evaluated in the two groups. The FD, the projected image area and the PAP of the patients with PH were higher than those values of the patients without PH (p < 0.05, t-test). There was a high correlation of FD with the PAP (r = 0.82, p < 0.05, partial correlation analysis). There was a moderate correlation of FD with the projected image area (r = 0.49, p < 0.05, partial correlation analysis). There was a correlation of the PAP with the projected image area (r = 0.65, p < 0.05, Pearson correlation analysis). The FD of the pulmonary arteries in the PH patients was significantly higher than that of the controls. There is a high correlation of FD with the PAP.

  3. Fractal Dimension Analysis of MDCT Images for Quantifying the Morphological Changes of the Pulmonary Artery Tree in Patients with Pulmonary Hypertension

    International Nuclear Information System (INIS)

    Sun, Haitao; Li, Ning; Guo, Lijun; Gao, Fei; Liu, Cheng

    2011-01-01

    The aim of this study was to use fractal dimension (FD) analysis on multidetector CT (MDCT) images for quantifying the morphological changes of the pulmonary artery tree in patients with pulmonary hypertension (PH). Fourteen patients with PH and 17 patients without PH as controls were studied. All of the patients underwent contrast-enhanced helical CT and transthoracic echocardiography. The pulmonary artery trees were generated using post-processing software, and the FD and projected image area of the pulmonary artery trees were determined with Image J software in a personal computer. The FD, the projected image area and the pulmonary artery pressure (PAP) were statistically evaluated in the two groups. The FD, the projected image area and the PAP of the patients with PH were higher than those values of the patients without PH (p < 0.05, t-test). There was a high correlation of FD with the PAP (r = 0.82, p < 0.05, partial correlation analysis). There was a moderate correlation of FD with the projected image area (r = 0.49, p < 0.05, partial correlation analysis). There was a correlation of the PAP with the projected image area (r = 0.65, p < 0.05, Pearson correlation analysis). The FD of the pulmonary arteries in the PH patients was significantly higher than that of the controls. There is a high correlation of FD with the PAP.

  4. Follow-up CT and CT angiography after intracranial aneurysm clipping and coiling - improved image quality by iterative metal artifact reduction

    Energy Technology Data Exchange (ETDEWEB)

    Bier, Georg; Hempel, Johann-Martin; Oergel, Anja; Hauser, Till-Karsten; Ernemann, Ulrike; Hennersdorf, Florian [Eberhard Karls University Tuebingen, Department of Diagnostic and Interventional Neuroradiology, Tuebingen (Germany); Bongers, Malte Niklas [Eberhard Karls University Tuebingen, Department of Diagnostic and Interventional Radiology, Tuebingen (Germany)

    2017-07-15

    This paper aims to evaluate a new iterative metal artifact reduction algorithm for post-interventional evaluation of brain tissue and intracranial arteries. The data of 20 patients that underwent follow-up cranial CT and cranial CT angiography after clipping or coiling of an intracranial aneurysm was retrospectively analyzed. After the images were processed using a novel iterative metal artifact reduction algorithm, images with and without metal artifact reduction were qualitatively evaluated by two readers, using a five-point Likert scale. Moreover, artifact strength was quantitatively assessed in terms of CT attenuation and standard deviation alterations. The qualitative analysis yielded a significant increase in image quality (p = 0.0057) in iteratively processed images with substantial inter-observer agreement (k = 0.72), while the CTA image quality did not differ (p = 0.864) and even showed vessel contrast reduction in six cases (30%). The mean relative attenuation difference was 27% without metal artifact reduction vs. 11% for iterative metal artifact reduction images (p = 0.0003). The new iterative metal artifact reduction algorithm enhances non-enhanced CT image quality after clipping or coiling, but in CT-angiography images, the contrast of adjacent vessels can be compromised. (orig.)

  5. Follow-up CT and CT angiography after intracranial aneurysm clipping and coiling - improved image quality by iterative metal artifact reduction

    International Nuclear Information System (INIS)

    Bier, Georg; Hempel, Johann-Martin; Oergel, Anja; Hauser, Till-Karsten; Ernemann, Ulrike; Hennersdorf, Florian; Bongers, Malte Niklas

    2017-01-01

    This paper aims to evaluate a new iterative metal artifact reduction algorithm for post-interventional evaluation of brain tissue and intracranial arteries. The data of 20 patients that underwent follow-up cranial CT and cranial CT angiography after clipping or coiling of an intracranial aneurysm was retrospectively analyzed. After the images were processed using a novel iterative metal artifact reduction algorithm, images with and without metal artifact reduction were qualitatively evaluated by two readers, using a five-point Likert scale. Moreover, artifact strength was quantitatively assessed in terms of CT attenuation and standard deviation alterations. The qualitative analysis yielded a significant increase in image quality (p = 0.0057) in iteratively processed images with substantial inter-observer agreement (k = 0.72), while the CTA image quality did not differ (p = 0.864) and even showed vessel contrast reduction in six cases (30%). The mean relative attenuation difference was 27% without metal artifact reduction vs. 11% for iterative metal artifact reduction images (p = 0.0003). The new iterative metal artifact reduction algorithm enhances non-enhanced CT image quality after clipping or coiling, but in CT-angiography images, the contrast of adjacent vessels can be compromised. (orig.)

  6. Image Quality Assessment via Quality-aware Group Sparse Coding

    Directory of Open Access Journals (Sweden)

    Minglei Tong

    2014-12-01

    Full Text Available Image quality assessment has been attracting growing attention at an accelerated pace over the past decade, in the fields of image processing, vision and machine learning. In particular, general purpose blind image quality assessment is technically challenging and lots of state-of-the-art approaches have been developed to solve this problem, most under the supervised learning framework where the human scored samples are needed for training a regression model. In this paper, we propose an unsupervised learning approach that work without the human label. In the off-line stage, our method trains a dictionary covering different levels of image quality patch atoms across the training samples without knowing the human score, where each atom is associated with a quality score induced from the reference image; at the on-line stage, given each image patch, our method performs group sparse coding to encode the sample, such that the sample quality can be estimated from the few labeled atoms whose encoding coefficients are nonzero. Experimental results on the public dataset show the promising performance of our approach and future research direction is also discussed.

  7. Wall morphology, blood flow and wall shear stress: MR findings in patients with peripheral artery disease

    Energy Technology Data Exchange (ETDEWEB)

    Galizia, Mauricio S.; Barker, Alex; Collins, Jeremy; Carr, James [Northwestern University, Department of Radiology, Feinberg School of Medicine, Chicago, IL (United States); Liao, Yihua [Northwestern University' s Feinberg School of Medicine, Department of Preventive Medicine, Chicago, IL (United States); McDermott, Mary M. [Northwestern University' s Feinberg School of Medicine, Department of Preventive Medicine, Chicago, IL (United States); Northwestern University' s Feinberg School of Medicine, Department of Medicine, Chicago, IL (United States); Markl, Michael [Northwestern University, Department of Radiology, Feinberg School of Medicine, Chicago, IL (United States); Northwestern University, Department Biomedical Engineering, McCormick School of Engineering, Chicago, IL (United States)

    2014-04-15

    To investigate the influence of atherosclerotic plaques on femoral haemodynamics assessed by two-dimensional (2D) phase-contrast (PC) magnetic resonance imaging (MRI) with three-directional velocity encoding. During 1 year, patients with peripheral artery disease and an ankle brachial index <1.00 were enrolled. After institutional review board approval and written informed consent, 44 patients (age, 70 ± 12 years) underwent common femoral artery MRI. Patients with contra-indications for MRI were excluded. Sequences included 2D time-of-flight, proton-density, T1-weighted and T2-weighted MRI. Electrocardiogram (ECG)-gated 2D PC-MRI with 3D velocity encoding was acquired. A radiologist classified images in five categories. Blood flow, velocity and wall shear stress (WSS) along the vessel circumference were quantified from the PC-MRI data. The acquired images were of good quality for interpretation. There were no image quality problems related to poor ECG-gating or slice positioning. Velocities, oscillatory shear stress and total flow were similar between patients with normal arteries and wall thickening/plaque. Patients with plaques demonstrated regionally increased peak systolic WSS and enhanced WSS eccentricity. Combined multi-contrast morphological imaging of the peripheral arterial wall with PC-MRI with three-directional velocity encoding is a feasible technique. Further study is needed to determine whether flow is an appropriate marker for altered endothelial cell function, vascular remodelling and plaque progression. (orig.)

  8. Image quality analysis of digital mammographic equipments

    Energy Technology Data Exchange (ETDEWEB)

    Mayo, P.; Pascual, A.; Verdu, G. [Valencia Univ. Politecnica, Chemical and Nuclear Engineering Dept. (Spain); Rodenas, F. [Valencia Univ. Politecnica, Applied Mathematical Dept. (Spain); Campayo, J.M. [Valencia Univ. Hospital Clinico, Servicio de Radiofisica y Proteccion Radiologica (Spain); Villaescusa, J.I. [Hospital Clinico La Fe, Servicio de Proteccion Radiologica, Valencia (Spain)

    2006-07-01

    The image quality assessment of a radiographic phantom image is one of the fundamental points in a complete quality control programme. The good functioning result of all the process must be an image with an appropriate quality to carry out a suitable diagnostic. Nowadays, the digital radiographic equipments are replacing the traditional film-screen equipments and it is necessary to update the parameters to guarantee the quality of the process. Contrast-detail phantoms are applied to digital radiography to study the threshold contrast detail sensitivity at operation conditions of the equipment. The phantom that is studied in this work is C.D.M.A.M. 3.4, which facilitates the evaluation of image contrast and detail resolution. One of the most extended indexes to measure the image quality in an objective way is the Image Quality Figure (I.Q.F.). This parameter is useful to calculate the image quality taking into account the contrast and detail resolution of the image analysed. The contrast-detail curve is useful as a measure of the image quality too, because it is a graphical representation in which the hole thickness and diameter are plotted for each contrast-detail combination detected in the radiographic image of the phantom. It is useful for the comparison of the functioning of different radiographic image systems, for phantom images under the same exposition conditions. The aim of this work is to study the image quality of different images contrast-detail phantom C.D.M.A.M. 3.4, carrying out the automatic detection of the contrast-detail combination and to establish a parameter which characterize in an objective way the mammographic image quality. This is useful to compare images obtained at different digital mammographic equipments to study the functioning of the equipments. (authors)

  9. Image quality analysis of digital mammographic equipments

    International Nuclear Information System (INIS)

    Mayo, P.; Pascual, A.; Verdu, G.; Rodenas, F.; Campayo, J.M.; Villaescusa, J.I.

    2006-01-01

    The image quality assessment of a radiographic phantom image is one of the fundamental points in a complete quality control programme. The good functioning result of all the process must be an image with an appropriate quality to carry out a suitable diagnostic. Nowadays, the digital radiographic equipments are replacing the traditional film-screen equipments and it is necessary to update the parameters to guarantee the quality of the process. Contrast-detail phantoms are applied to digital radiography to study the threshold contrast detail sensitivity at operation conditions of the equipment. The phantom that is studied in this work is C.D.M.A.M. 3.4, which facilitates the evaluation of image contrast and detail resolution. One of the most extended indexes to measure the image quality in an objective way is the Image Quality Figure (I.Q.F.). This parameter is useful to calculate the image quality taking into account the contrast and detail resolution of the image analysed. The contrast-detail curve is useful as a measure of the image quality too, because it is a graphical representation in which the hole thickness and diameter are plotted for each contrast-detail combination detected in the radiographic image of the phantom. It is useful for the comparison of the functioning of different radiographic image systems, for phantom images under the same exposition conditions. The aim of this work is to study the image quality of different images contrast-detail phantom C.D.M.A.M. 3.4, carrying out the automatic detection of the contrast-detail combination and to establish a parameter which characterize in an objective way the mammographic image quality. This is useful to compare images obtained at different digital mammographic equipments to study the functioning of the equipments. (authors)

  10. Patient management after noninvasive cardiac imaging results from SPARC (Study of myocardial perfusion and coronary anatomy imaging roles in coronary artery disease).

    NARCIS (Netherlands)

    Hachamovitch, R.; Nutter, B.; Hlatky, M.A.; Shaw, L.J.; Ridner, M.L.; Dorbala, S.; Beanlands, R.S.; Chow, B.J.; Branscomb, E.; Chareonthaitawee, P.; Weigold, W.G.; Voros, S.; Abbara, S.; Yasuda, T.; Jacobs, J.E.; Lesser, J.; Berman, D.S.; Thomson, L.E.; Raman, S.; Heller, G.V.; Schussheim, A.; Brunken, R.; Williams, K.A.; Farkas, S.; Delbeke, D.; Schoepf, U.J.; Reichek, N.; Rabinowitz, S.; Sigman, S.R.; Patterson, R.; Corn, C.R.; White, R.; Kazerooni, E.; Corbett, J.; Bokhari, S.; Machac, J.; Guarneri, E.; Borges-Neto, S.; Millstine, J.W.; Caldwell, J.; Arrighi, J.; Hoffmann, U.; Budoff, M.; Lima, J.; Johnson, J.R.; Johnson, B.; Gaber, M.; Williams, J.A.; Foster, C.; Hainer, J.; Carli, M.F. Di

    2012-01-01

    OBJECTIVES: This study examined short-term cardiac catheterization rates and medication changes after cardiac imaging. BACKGROUND: Noninvasive cardiac imaging is widely used in coronary artery disease, but its effects on subsequent patient management are unclear. METHODS: We assessed the 90-day

  11. Clinical Feasibility of Free-Breathing Dynamic T1-Weighted Imaging With Gadoxetic Acid-Enhanced Liver Magnetic Resonance Imaging Using a Combination of Variable Density Sampling and Compressed Sensing.

    Science.gov (United States)

    Yoon, Jeong Hee; Yu, Mi Hye; Chang, Won; Park, Jin-Young; Nickel, Marcel Dominik; Son, Yohan; Kiefer, Berthold; Lee, Jeong Min

    2017-10-01

    The purpose of the study was to investigate the clinical feasibility of free-breathing dynamic T1-weighted imaging (T1WI) using Cartesian sampling, compressed sensing, and iterative reconstruction in gadoxetic acid-enhanced liver magnetic resonance imaging (MRI). This retrospective study was approved by our institutional review board, and the requirement for informed consent was waived. A total of 51 patients at high risk of breath-holding failure underwent dynamic T1WI in a free-breathing manner using volumetric interpolated breath-hold (BH) examination with compressed sensing reconstruction (CS-VIBE) and hard gating. Timing, motion artifacts, and image quality were evaluated by 4 radiologists on a 4-point scale. For patients with low image quality scores (XD]) reconstruction was additionally performed and reviewed in the same manner. In addition, in 68.6% (35/51) patients who had previously undergone liver MRI, image quality and motion artifacts on dynamic phases using CS-VIBE were compared with previous BH-T1WIs. In all patients, adequate arterial-phase timing was obtained at least once. Overall image quality of free-breathing T1WI was 3.30 ± 0.59 on precontrast and 2.68 ± 0.70, 2.93 ± 0.65, and 3.30 ± 0.49 on early arterial, late arterial, and portal venous phases, respectively. In 13 patients with lower than average image quality (XD-reconstructed CS-VIBE) significantly reduced motion artifacts (P XD reconstruction showed less motion artifacts and better image quality on precontrast, arterial, and portal venous phases (P < 0.0001-0.013). Volumetric interpolated breath-hold examination with compressed sensing has the potential to provide consistent, motion-corrected free-breathing dynamic T1WI for liver MRI in patients at high risk of breath-holding failure.

  12. Dynamic MR imaging of hepatoma treated by transcatheter arterial embolization therapy

    International Nuclear Information System (INIS)

    Yamashita, Y.; Yoshimatsu, S.; Sumi, M.; Harada, M.; Takahashi, M.

    1993-01-01

    The effect of transcatheter arterial chemo-embolization theory (TACE) for hepatoma was evaluated with dynamic MR imaging with Gd-DTPA in 37 patients (44 tumors). TACE was performed using Lipiodol/cis-platinum and gelatin sponge (or microspheres) as an embolic material. All patients were examined with dynamic CT and MR imaging before and after treatment. On conventional spin echo images, changes of signal intensity after treatment varied regardless of presence of Lipiodol. Dynamic MR imaging revealed changes of tumor vascularity before and after treatment. On histologic correlation, areas of persistent tumor enhancement on dynamic MR imaging corresponded to areas of viable tumor cells while areas of nonenhancement corresponded to areas of necrosis. Dynamic MR imaging was superior in contrast resolution and was not influenced by the presence of Lipiodol compared with dynamic CT, and therefore residual viable tumors were better defined by dynamic MR imaging. (orig.)

  13. Assessing product image quality for online shopping

    Science.gov (United States)

    Goswami, Anjan; Chung, Sung H.; Chittar, Naren; Islam, Atiq

    2012-01-01

    Assessing product-image quality is important in the context of online shopping. A high quality image that conveys more information about a product can boost the buyer's confidence and can get more attention. However, the notion of image quality for product-images is not the same as that in other domains. The perception of quality of product-images depends not only on various photographic quality features but also on various high level features such as clarity of the foreground or goodness of the background etc. In this paper, we define a notion of product-image quality based on various such features. We conduct a crowd-sourced experiment to collect user judgments on thousands of eBay's images. We formulate a multi-class classification problem for modeling image quality by classifying images into good, fair and poor quality based on the guided perceptual notions from the judges. We also conduct experiments with regression using average crowd-sourced human judgments as target. We compute a pseudo-regression score with expected average of predicted classes and also compute a score from the regression technique. We design many experiments with various sampling and voting schemes with crowd-sourced data and construct various experimental image quality models. Most of our models have reasonable accuracies (greater or equal to 70%) on test data set. We observe that our computed image quality score has a high (0.66) rank correlation with average votes from the crowd sourced human judgments.

  14. Three-dimensional segmentation of pulmonary artery volume from thoracic computed tomography imaging

    Science.gov (United States)

    Lindenmaier, Tamas J.; Sheikh, Khadija; Bluemke, Emma; Gyacskov, Igor; Mura, Marco; Licskai, Christopher; Mielniczuk, Lisa; Fenster, Aaron; Cunningham, Ian A.; Parraga, Grace

    2015-03-01

    Chronic obstructive pulmonary disease (COPD), is a major contributor to hospitalization and healthcare costs in North America. While the hallmark of COPD is airflow limitation, it is also associated with abnormalities of the cardiovascular system. Enlargement of the pulmonary artery (PA) is a morphological marker of pulmonary hypertension, and was previously shown to predict acute exacerbations using a one-dimensional diameter measurement of the main PA. We hypothesized that a three-dimensional (3D) quantification of PA size would be more sensitive than 1D methods and encompass morphological changes along the entire central pulmonary artery. Hence, we developed a 3D measurement of the main (MPA), left (LPA) and right (RPA) pulmonary arteries as well as total PA volume (TPAV) from thoracic CT images. This approach incorporates segmentation of pulmonary vessels in cross-section for the MPA, LPA and RPA to provide an estimate of their volumes. Three observers performed five repeated measurements for 15 ex-smokers with ≥10 pack-years, and randomly identified from a larger dataset of 199 patients. There was a strong agreement (r2=0.76) for PA volume and PA diameter measurements, which was used as a gold standard. Observer measurements were strongly correlated and coefficients of variation for observer 1 (MPA:2%, LPA:3%, RPA:2%, TPA:2%) were not significantly different from observer 2 and 3 results. In conclusion, we generated manual 3D pulmonary artery volume measurements from thoracic CT images that can be performed with high reproducibility. Future work will involve automation for implementation in clinical workflows.

  15. Avoiding pitfalls in diagnosing basilar artery occlusive disease: clinical and imaging clues - case report

    Directory of Open Access Journals (Sweden)

    Adriana Bastos Conforto

    Full Text Available CONTEXT: The aim of this paper was to report on the characteristics that aid in establishing the diagnosis of basilar artery occlusive disease (BAOD among patients with hemiparesis and few or minor symptoms of vertebrobasilar disease. CASE REPORT: This report describes two cases in a public university hospital in São Paulo, Brazil. We present clinical and imaging findings from two patients with hemiparesis and severe BAOD, but without clinically relevant carotid artery disease (CAD. One patient presented transient ischemic attacks consisting of spells of right hemiparesis that became progressively more frequent, up to twice a week. The neurological examination revealed slight right hemiparesis and right homonymous hemianopsia. Magnetic resonance imaging (MRI revealed pontine and occipital infarcts. Magnetic resonance angiography and digital subtraction angiography revealed severe basilar artery stenosis. The other patient presented sudden left-side hemiparesis and hypoesthesia. One year earlier, she had reported sudden onset of vertigo that, at that time, was attributed to peripheral vestibulopathy and was not further investigated. MRI showed a right-side pontine infarct and an old infarct in the right cerebellar hemisphere. Basilar artery occlusion was diagnosed. Both patients presented their symptoms while receiving aspirin, and became asymptomatic after treatment with warfarin. CONCLUSIONS: Misdiagnosing asymptomatic CAD as the cause of symptoms in BAOD can have disastrous consequences, such as unnecessary carotid endarterectomy and exposure to this surgical risk while failing to offer the best available treatment for BAOD. Clinical and imaging features provided important clues for diagnosis in the cases presented.

  16. Minimum training requirement in ultrasound imaging of peripheral arterial disease.

    Science.gov (United States)

    Eiberg, J P; Hansen, M A; Grønvall Rasmussen, J B; Schroeder, T V

    2008-09-01

    To demonstrate the minimum training requirement when performing ultrasound of peripheral arterial disease. Prospective and blinded comparative study. 100 limbs in 100 consecutive patients suffering from peripheral arterial disease, 74% suffering critical limb ischemia, were enrolled during a 9 months period. One physician with limited ultrasound experience performed all the ultrasound examinations of the arteries of the most symptomatic limb. Before enrolling any patients 15 duplex ultrasound examinations were performed supervised by an experienced vascular technologist. All patients had a digital subtraction arteriography performed by an experienced vascular radiologist, unaware of the ultrasound result. The number of insufficiently insonated segments (non-diagnostic segments) was significantly reduced during the study; from 9% among the initial 50 limbs to 2% among the last 50 limbs (Pultrasound and arteriography from the initial 50 patients (overall Kappa=0.66, (95%-CI: 0.60-0.72); supragenicular Kappa=0.73 (95%-CI: 0.64-0.82); infragenicular Kappa=0.61 (95%-CI: 0.54-0.69)) to the last 50 patients (overall Kappa=0.66 (95%-CI: 0.60-0.72), supragenicular Kappa=0.67 (95%-CI: 0.57-0.76); infragenicular Kappa=0.66 (95%-CI: 0.58-0.73)). The minimum training requirement in ultrasound imaging of peripheral arterial disease appears to be less than 50 ultrasound examinations (probably only 15 examinations) for the supragenicular segments and 100 examinations for the infragenicular segments.

  17. Improving image quality in portal venography with spectral CT imaging

    International Nuclear Information System (INIS)

    Zhao, Li-qin; He, Wen; Li, Jian-ying; Chen, Jiang-hong; Wang, Ke-yang; Tan, Li

    2012-01-01

    Objective: To investigate the effect of energy spectral CT on the image quality of CT portal venography in cirrhosis patients. Materials and methods: 30 portal hypertension patients underwent spectral CT examination using a single-tube, fast dual tube voltage switching technique. 101 sets of monochromatic images were generated from 40 keV to 140 keV. Image noise and contrast-to-noise ratio (CNR) for portal veins from the monochromatic images were measured. An optimal monochromatic image set was selected for obtaining the best CNR for portal veins. The image noise and CNR of the intra-hepatic portal vein and extra-hepatic main stem at the selected monochromatic level were compared with those from the conventional polychromatic images. Image quality was also assessed and compared. Results: The monochromatic images at 51 keV were found to provide the best CNR for both the intra-hepatic and extra-hepatic portal veins. At this energy level, the monochromatic images had about 100% higher CNR than the polychromatic images with a moderate 30% noise increase. The qualitative image quality assessment was also statistically higher with monochromatic images at 51 keV. Conclusion: Monochromatic images at 51 keV for CT portal venography could improve CNR for displaying hepatic portal veins and improve the overall image quality.

  18. Improving image quality in portal venography with spectral CT imaging

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Li-qin, E-mail: zhaolqzr@sohu.com [Department of Radiology, Beijing Friendship Hospital Affiliated to Capital Medical University, Beijing,100050 (China); He, Wen, E-mail: hewen1724@sina.com [Department of Radiology, Beijing Friendship Hospital Affiliated to Capital Medical University, Beijing,100050 (China); Li, Jian-ying, E-mail: jianying.li@med.ge.com [CT Advanced Application and Research, GE Healthcare, 100176 China (China); Chen, Jiang-hong, E-mail: chenjianghong1973@hotmail.com [Department of Radiology, Beijing Friendship Hospital Affiliated to Capital Medical University, Beijing,100050 (China); Wang, Ke-yang, E-mail: ke7ke@sina.com [Department of Radiology, Beijing Friendship Hospital Affiliated to Capital Medical University, Beijing,100050 (China); Tan, Li, E-mail: Litan@ge.com [CT product, GE Healthcare, 100176 China (China)

    2012-08-15

    Objective: To investigate the effect of energy spectral CT on the image quality of CT portal venography in cirrhosis patients. Materials and methods: 30 portal hypertension patients underwent spectral CT examination using a single-tube, fast dual tube voltage switching technique. 101 sets of monochromatic images were generated from 40 keV to 140 keV. Image noise and contrast-to-noise ratio (CNR) for portal veins from the monochromatic images were measured. An optimal monochromatic image set was selected for obtaining the best CNR for portal veins. The image noise and CNR of the intra-hepatic portal vein and extra-hepatic main stem at the selected monochromatic level were compared with those from the conventional polychromatic images. Image quality was also assessed and compared. Results: The monochromatic images at 51 keV were found to provide the best CNR for both the intra-hepatic and extra-hepatic portal veins. At this energy level, the monochromatic images had about 100% higher CNR than the polychromatic images with a moderate 30% noise increase. The qualitative image quality assessment was also statistically higher with monochromatic images at 51 keV. Conclusion: Monochromatic images at 51 keV for CT portal venography could improve CNR for displaying hepatic portal veins and improve the overall image quality.

  19. Hyperspectral Image Analysis of Food Quality

    DEFF Research Database (Denmark)

    Arngren, Morten

    inspection.Near-infrared spectroscopy can address these issues by offering a fast and objectiveanalysis of the food quality. A natural extension to these single spectrumNIR systems is to include image information such that each pixel holds a NIRspectrum. This augmented image information offers several......Assessing the quality of food is a vital step in any food processing line to ensurethe best food quality and maximum profit for the farmer and food manufacturer.Traditional quality evaluation methods are often destructive and labourintensive procedures relying on wet chemistry or subjective human...... extensions to the analysis offood quality. This dissertation is concerned with hyperspectral image analysisused to assess the quality of single grain kernels. The focus is to highlight thebenefits and challenges of using hyperspectral imaging for food quality presentedin two research directions. Initially...

  20. Evaluation of selective arterial embolization effect by chitosan micro-hydrogels in hindlimb sarcoma rodent models using various imaging modalities

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Tai Kyoung; Kwon, Jeong Il; Na, Kyung Sook [Chonbuk National University Medical School and Hospital, Jeonju (Korea, Republic of); and others

    2015-09-15

    Embolization is mainly used to reduce the size of locally advanced tumors. In this study, selective arterial catheterization with chitosan micro-hydrogels (CMH) into the femoral artery was performed and the therapeutic effect was validated using different imaging methods. Male SD rats (n = 18, 6 weeks old) were randomly assigned into three groups: Group 1 as control, Group 2 without any ligation of distal femoral artery, and Group 3 with temporary ligation of the distal femoral artery. RR1022 sarcoma cell lines were inoculated into thigh muscle. After 1 week, CMH was injected into the proximal femoral artery. Different imaging modalities were performed during a 3-week follow-up. The tumor size was significantly (P < 0.001) decreased in both Group 2 and Group 3 (P < 0.001) after selective arterial embolization therapy. 18F-FDG-PET/CT revealed decreased intensity of 18F-FDG uptake in tumors. The accumulation status of 125I-CMH near the tumor was verified by gamma camera. Appropriate selective arterial embolization therapy with CMH was.

  1. Imaging of vascular dynamics within the foot using dynamic diffuse optical tomography to diagnose peripheral arterial disease

    Science.gov (United States)

    Khalil, M. A.; Kim, H. K.; Hoi, J. W.; Kim, I.; Dayal, R.; Shrikande, G.; Hielscher, A. H.

    2013-03-01

    Peripheral Arterial Disease (PAD) is the narrowing of the functional area of the artery generally due to atherosclerosis. It affects between 8-12 million people in the United States and if untreated this can lead to ulceration, gangrene and ultimately amputation. The current diagnostic method for PAD is the ankle-brachial index (ABI). The ABI is a ratio of the patient's systolic blood pressure in the foot to that of the brachial artery in the arm, a ratio below 0.9 is indicative of affected vasculature. However, this method is ineffective in patients with calcified arteries (diabetic and end-stage renal failure patients), which falsely elevates the ABI recording resulting in a false negative reading. In this paper we present our results in a pilot study to deduce optical tomography's ability to detect poor blood perfusion in the foot. We performed an IRB approved 30 patient study, where we imaged the feet of the enrolled patients during a five stage dynamic imaging sequence. The patients were split up into three groups: 10 healthy subjects, 10 PAD patients and 10 PAD patients with diabetes and they were imaged while applying a pressure cuff to their thigh. Differences in the magnitude of blood pooling in the foot and rate at which the blood pools in the foot are all indicative of arterial disease.

  2. Liver Abscess Associated with Hepatic Artery Pseudoaneurysm with Arteriovenous Fistula: Imaging and Interventional Management

    International Nuclear Information System (INIS)

    Kang, M.; Bapuraj, J.R.; Khandelwal, N.; Kochhar, R.; Kalra, N.; Verma, G. R.

    2006-01-01

    Hepatic artery pseudoaneurysm is an infrequently encountered entity that is usually seen secondary to trauma or surgical procedures. The clinical presentation is often due to complications such as massive intrahepatic or intraperitoneal bleeding as a result of rupture of the pseudoaneurysm into the biliary tree or peritoneal cavity, respectively. Hepatic artery pseudoaneurysm, associated with a liver abscess, has very rarely been described in the literature. We present the imaging features of a case of liver abscess associated with a hepatic artery pseudoaneurysm and complicated by rupture and formation of an arteriovenous fistula. The case was successfully managed by percutaneous endovascular embolization. The association between a hepatic artery pseudoaneurysm and a liver abscess must not be overlooked, bearing in mind the potentially fatal associated complications which can be averted or treated by timely intervention

  3. Liver Abscess Associated with Hepatic Artery Pseudoaneurysm with Arteriovenous Fistula: Imaging and Interventional Management

    Energy Technology Data Exchange (ETDEWEB)

    Kang, M.; Bapuraj, J.R.; Khandelwal, N.; Kochhar, R.; Kalra, N.; Verma, G. R. [Postgraduate Inst. of Medical Education and Research, Chandigarh (India). Depts. of Radiodiagnosis and General Surgery

    2006-03-15

    Hepatic artery pseudoaneurysm is an infrequently encountered entity that is usually seen secondary to trauma or surgical procedures. The clinical presentation is often due to complications such as massive intrahepatic or intraperitoneal bleeding as a result of rupture of the pseudoaneurysm into the biliary tree or peritoneal cavity, respectively. Hepatic artery pseudoaneurysm, associated with a liver abscess, has very rarely been described in the literature. We present the imaging features of a case of liver abscess associated with a hepatic artery pseudoaneurysm and complicated by rupture and formation of an arteriovenous fistula. The case was successfully managed by percutaneous endovascular embolization. The association between a hepatic artery pseudoaneurysm and a liver abscess must not be overlooked, bearing in mind the potentially fatal associated complications which can be averted or treated by timely intervention.

  4. Effects of massage therapy on sleep quality after coronary artery bypass graft surgery

    Directory of Open Access Journals (Sweden)

    Flavia Baggio Nerbass

    2010-01-01

    Full Text Available INTRODUCTION: Having poor sleep quality is common among patients following cardiopulmonary artery bypass graft surgery. Pain, stress, anxiety and poor sleep quality may be improved by massage therapy. OBJECTIVE: This study evaluated whether massage therapy is an effective technique for improving sleep quality in patients following cardiopulmonary artery bypass graft surgery. METHOD: Participants included cardiopulmonary artery bypass graft surgery patients who were randomized into a control group and a massage therapy group following discharge from the intensive care unit (Day 0, during the postoperative period. The control group and the massage therapy group comprised participants who were subjected to three nights without massage and three nights with massage therapy, respectively. The patients were evaluated on the following mornings (i.e., Day 1 to Day 3 using a visual analogue scale for pain in the chest, back and shoulders, in addition to fatigue and sleep. Participants kept a sleep diary during the study period. RESULTS: Fifty-seven cardiopulmonary artery bypass graft surgery patients were enrolled in the study during the preoperative period, 17 of whom were excluded due to postoperative complications. The remaining 40 participants (male: 67.5%, age: 61.9 years ± 8.9 years, body mass index: 27.2 kg/m² ± 3.7 kg/m² were randomized into control (n = 20 and massage therapy (n = 20 groups. Pain in the chest, shoulders, and back decreased significantly in both groups from Day 1 to Day 3. The participants in the massage therapy group had fewer complaints of fatigue on Day 1 (p=0.006 and Day 2 (p=0.028 in addition, they reported a more effective sleep during all three days (p=0.019 when compared with the participants in the control group. CONCLUSION: Massage therapy is an effective technique for improving patient recovery from cardiopulmonary artery bypass graft surgery because it reduces fatigue and improves sleep.

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

    International Nuclear Information System (INIS)

    Rist, Carsten; Nikolaou, Konstantin; Wintersperger, Bernd J.; Reiser, Maximilian F.; Becker, Christoph R.; Flohr, Thomas

    2006-01-01

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

  6. Perspectives on Imaging the Left Main Coronary Artery Using Intravascular Ultrasound and Optical Coherence Tomography

    Directory of Open Access Journals (Sweden)

    Harry C Lowe

    2015-01-01

    Full Text Available Percutaneous Coronary Intervention (PCI for significant left main coronary artery (LMCA stenosis is increasingly being viewed as a viable alternative to Coronary Artery Bypass Grafting (CABG (1. This is leading to an expectation of increasing numbers of such procedures, with a consequent focus on both the ability to image both lesion severity, and assess more accurately the results of PCI. While there have been advances in physiologic assessment of left main severity using fractional flow reserve (FFR, imaging of the LMCA using Intravascular Ultrasound (IVUS and more recently Optical Coherence Tomography (OCT has the specific advantage of being able to provide detailed anatomical information both pre and post PCI, such that it is timely to review briefly the current status of these two imaging technologies in the context of LMCA intervention.

  7. Spatial relationship between intrahepatic artery and portal vein based on the fusion image of CT-arterial portography (CTAP) and CT-angiography (CTA): New classification for hepatic artery at hepatic hilum and the segmentation of right anterior section of the liver

    International Nuclear Information System (INIS)

    Ibukuro, Kenji; Takeguchi, Takaya; Fukuda, Hozumi; Abe, Shoko; Tobe, Kimiko; Tanaka, Rei; Tagawa, Kazumi

    2012-01-01

    Purpose: To clarify the variations of the intrahepatic artery and portal vein and to verify the proper segmentation for the right anterior section of the liver. Materials and methods: CT during arterial portography and CT angiography were performed on 64-slice multi detector row CT in 147 patients. All images were transferred to a workstation for analysis using multi-image-fusion mode. We investigated the spatial relationship between hepatic artery and portal vein in the right hemiliver and the segmentation of the right anterior hepatic artery and portal vein. Results: The spatial anatomy of right hepatic arteries and portal vein was (1) anterior and posterior hepatic artery run superior and inferior to anterior portal vein, respectively (47.6%), (2) one anterior hepatic artery runs superior to and another one runs inferior to anterior portal vein (15%), (3) anterior and posterior hepatic arteries run superior to anterior portal vein (11.6%), (4) anterior and posterior hepatic arteries run inferior to anterior portal vein (7.5%), and (5) one posterior hepatic artery runs superior to and another one runs inferior to anterior portal vein (6.8%). The combined anatomy of right anterior artery and portal vein with regard to segmentation was classified as (1) dorso-ventral (26.5%), (2) dorso-ventral and inferior (10.9%), (3) multiple (18.4%), and (4) superior and inferior segments (1.4%). Conclusion: There are various types of spatial anatomy of intrahepatic artery and portal vein. The hepatic arteries as well as portal veins of right anterior section of the liver could be divided into dorsal and ventral, not superior and inferior.

  8. Method for imaging pulmonary arterial hypoplasia

    International Nuclear Information System (INIS)

    Triantafillou, M.

    2000-01-01

    Full text: Pulmonary hypoplasia represents an incomplete development of the lung, resulting in the reduction of distended lung volume. This is associated with small or absent number of airway divisions, alveoli, arteries and veins. Unilateral pulmonary Hypoplasia is often asymptomatic and may be demonstrated as a hypodense lung on a chest X-ray. Computer Tomography (CT) scanning would show anatomical detail and proximal vessels. Magnetic Resonance Imaging (MRI) will show no more detail than which the CT scan has already demonstrated. It is, also, difficult to visualise collateral vessels from systemic and/or bronchial vessels on both these modalities. Pulmonary Angiography would give the definitive answer, but it is time consuming and has significant risks associated with the procedure. There are high costs associated with these modalities. Nuclear Medicine Ventilation/Perfusion (V/Q) scan performed on these patients would demonstrate diminished ventilation due to reduced lung volume and absence of perfusion to the hypoplastic lung. To date, we have performed V/Q lung scan on two children in our department. Both cases demonstrate diminished ventilation with no perfusion to the hypoplastic lung. Though the gold standard is Pulmonary Angiography, V/Q scanning is cost effective, less time consuming and a non invasive procedure that can be performed as an outpatient. It is accurate as it demonstrates absent lung perfusion, confirming the patient has pulmonary arterial hypoplasia. Copyright (2000) The Australian and New Zealand Society of Nuclear Medicine Inc

  9. Evaluation of high-pitch dual-source CT angiography for evaluation of coronary and carotid-cerebrovascular arteries

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Kai [Department of Radiology, Xuanwu Hospital, Capital Medical University, Beijing 100053 (China); Li, Kuncheng, E-mail: cjr.likuncheng@vip.163.com [Department of Radiology, Xuanwu Hospital, Capital Medical University, Beijing 100053 (China); Han, Ruijuan [Department of Cardiology, Chaoyang Hospital, Capital Medical University, Beijing 100020 (China); Li, Wenhuan; Chen, Nan; Yang, Qi; Du, Xiangying; Wang, Chen [Department of Radiology, Xuanwu Hospital, Capital Medical University, Beijing 100053 (China); Liu, Guorong; Li, Yuechun [Department of Neurology Baotou Central Hospital, Inner Mongolia, Baotou 014040 (China); Zhou, Maorong [Department of Radiology, Baotou Central Hospital, Inner Mongolia, Baotou 014040 (China); Li, Ligang; Heidrun, Endt [CT BM Clinic Marketing, Siemens Healthcare, Beijing 100102 (China)

    2015-03-15

    Objectives: To explore the feasibility and diagnostic accuracy of a combined one-step high-pitch dual-source computed tomography angiography (CTA) technique for evaluation of coronary and carotid-cerebrovascular arteries. Materials and methods: 85 symptomatic patients suspected of coronary artery and cerebrovascular disease referred for simultaneous coronary and carotid-cerebrovascular CTA were included. Additional invasive angiography of the coronary and cerebral arteries was performed within 30 days in 23 and 13 patients, respectively. The objective parameters of image quality, the mean CT attenuations, image noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were evaluated. The subjective image quality of vessels was also assessed by 2 independent radiologists blinded to the patients’ medical history and scan protocols. The diagnostic performance of CTA including sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for the detection or exclusion of significant artery stenosis was calculated using the chi-squared test of contingency and correlated with the results of invasive angiography representing the standard of reference. Results: Image quality was rated excellent (score 1) in 95.3% (1074/1127), good (score 2) in 3.3% (37/1127), adequate (score 3) in 1.0% (11/1127), and non-diagnostic (score 4) in 0.4% (5/1127) of coronary segments. Image quality of carotid and cerebral vessels was rated mostly excellent (score 1, 95.12% [78/82]; score 2, 3.66% [3/82]; score 3, 1.22% [1/82]). The sensitivity, specificity, PPV and NPV for the detection of coronary stenosis were 92.2% (81.1–97.7%), 95.2% (91.7–97.5%), 79.6% (67.1–89.1%) and 98.3% (95.8–99.5%), respectively. For the detection of carotid and cerebral artery stenosis, CTA demonstrated a sensitivity of 92.8% (80.5–98.4%), a specificity of 93.5% (88.3–96.8%), a PPV of 79.6% (65.6–89.7%) and a NPV of 97.9% (94.1–99.5%). The effective

  10. Unilateral dysgenesis of the internal carotid artery: spectrum of imaging findings

    International Nuclear Information System (INIS)

    De Mendonca, J.L.F.; Viana, S.L.; Freitas, F.M.O.; Matos, V.L.; Viana, M.A.C.B.; Silva, R.F.; Quaglia, L.A.N.; Guerra, J.G.

    2008-01-01

    Dysgenesis of the internal carotid artery (ICA) is a broad term comprising hypoplasia, aplasia and agenesis of the vessel. It is a rare anomaly, often clinically silent, that can be confidently diagnosed by means of noninvasive imaging methods. After a review of teaching files, 7 patients with unilateral carotid dysgenesis were found, 2 with agenesis of the ICA, 3 with carotid aplasia, and 2 with hypoplasia of the vessel. Computed tomography (CT) and magnetic resonance angiography (MRA) of the brain were performed in all patients, with a complete magnetic resonance of the brain in 3 of them, a CT angiography of the brain in one, and MRA of the cervical arteries in 3. The fetal pattern of arterial circulation was found in 3 patients with agenesis/aplasia of the ICA and the adult pattern was found in 2 patients, being the brain circulation of normal pattern in the patients with hypoplasia of the ICA. Two patients presented signs of reduced flow to the brain hemisphere ipsilateral to the carotid dysgenesis; one of them with an old homolateral brain infarction. Far from being just an anatomic curiosity, the dysgenesis of the ICA may have serious consequences if not recognized prior to endarterectomies, carotid ligation or transsphenoidal surgery. As much as one-third of these patients will have intracranial aneurysms as well. The imaging methods, instead being mutually exclusive, are complementary in the evaluation of carotid dysgenesis. (author)

  11. Extent of hypoattenuation on CT angiography source images in basilar artery occlusion: prognostic value in the Basilar Artery International Cooperation Study.

    Science.gov (United States)

    Puetz, Volker; Khomenko, Andrei; Hill, Michael D; Dzialowski, Imanuel; Michel, Patrik; Weimar, Christian; Wijman, Christine A C; Mattle, Heinrich P; Engelter, Stefan T; Muir, Keith W; Pfefferkorn, Thomas; Tanne, David; Szabo, Kristina; Kappelle, L Jaap; Algra, Ale; von Kummer, Ruediger; Demchuk, Andrew M; Schonewille, Wouter J

    2011-12-01

    The posterior circulation Acute Stroke Prognosis Early CT Score (pc-ASPECTS) quantifies the extent of early ischemic changes in the posterior circulation with a 10-point grading system. We hypothesized that pc-ASPECTS applied to CT angiography source images predicts functional outcome of patients in the Basilar Artery International Cooperation Study (BASICS). BASICS was a prospective, observational registry of consecutive patients with acute symptomatic basilar artery occlusion. Functional outcome was assessed at 1 month. We applied pc-ASPECTS to CT angiography source images of patients with CT angiography for confirmation of basilar artery occlusion. We calculated unadjusted and adjusted risk ratios (RRs) of pc-ASPECTS dichotomized at ≥8 versus <8. Primary outcome measure was favorable outcome (modified Rankin Scale scores 0-3). Secondary outcome measures were mortality and functional independence (modified Rankin Scale scores 0-2). Of 158 patients included, 78 patients had a CT angiography source images pc-ASPECTS≥8. Patients with a pc-ASPECTS≥8 more often had a favorable outcome than patients with a pc-ASPECTS<8 (crude RR, 1.7; 95% CI, 0.98-3.0). After adjustment for age, baseline National Institutes of Health Stroke Scale score, and thrombolysis, pc-ASPECTS≥8 was not related to favorable outcome (RR, 1.3; 95% CI, 0.8-2.2), but it was related to reduced mortality (RR, 0.7; 95% CI, 0.5-0.98) and functional independence (RR, 2.0; 95% CI, 1.1-3.8). In post hoc analysis, pc-ASPECTS dichotomized at ≥6 versus <6 predicted a favorable outcome (adjusted RR, 3.1; 95% CI, 1.2-7.5). pc-ASPECTS on CT angiography source images independently predicted death and functional independence at 1 month in the CT angiography subgroup of patients in the BASICS registry.

  12. Problems of detection method of coronary arterial stenosis on cineangiograms by computer image processing

    International Nuclear Information System (INIS)

    Sugahara, Tetsuo; Yanagihara, Yoshio; Sugimoto, Naozou; Uyama, Chikao; Maeda, Hirofumi.

    1988-01-01

    For the evaluation of the coronary arterial stenosis (CAS), the detection method of CAS were estimated on the coronary cineangiograms by computer image processing. For correlation of the accuracy of measurement of diameter on the image of resolution of 30 and 4 μm/pixel were measured the diameter on the vessel model images using sum of first and second differential method. The accuracy of measurement on resolution image of 30 and 4 μm/pixel on 3 mm diameter is 4.7 % and 2.3 %, respectively. Threshold method was used for the detection of the arterial wall on the subtraction images. For the detection of CAS, measurement method of the branch segment and determination method of the radius and normal vessel diameter were evaluated. A matter of special importance is determination method of the normal diameter. In view of the fact that this is a matter of great importance, it caused error to the measurement of prerent stenosis and stenotic length. This resulted that the detection of CAS was important not only the accuracy of measurement of the vessel diameter but also determination method of the normal diameter. (author)

  13. Image quality and dose differences caused by vendor-specific image processing of neonatal radiographs

    International Nuclear Information System (INIS)

    Sensakovic, William F.; O'Dell, M.C.; Letter, Haley; Kohler, Nathan; Rop, Baiywo; Cook, Jane; Logsdon, Gregory; Varich, Laura

    2016-01-01

    Image processing plays an important role in optimizing image quality and radiation dose in projection radiography. Unfortunately commercial algorithms are black boxes that are often left at or near vendor default settings rather than being optimized. We hypothesize that different commercial image-processing systems, when left at or near default settings, create significant differences in image quality. We further hypothesize that image-quality differences can be exploited to produce images of equivalent quality but lower radiation dose. We used a portable radiography system to acquire images on a neonatal chest phantom and recorded the entrance surface air kerma (ESAK). We applied two image-processing systems (Optima XR220amx, by GE Healthcare, Waukesha, WI; and MUSICA"2 by Agfa HealthCare, Mortsel, Belgium) to the images. Seven observers (attending pediatric radiologists and radiology residents) independently assessed image quality using two methods: rating and matching. Image-quality ratings were independently assessed by each observer on a 10-point scale. Matching consisted of each observer matching GE-processed images and Agfa-processed images with equivalent image quality. A total of 210 rating tasks and 42 matching tasks were performed and effective dose was estimated. Median Agfa-processed image-quality ratings were higher than GE-processed ratings. Non-diagnostic ratings were seen over a wider range of doses for GE-processed images than for Agfa-processed images. During matching tasks, observers matched image quality between GE-processed images and Agfa-processed images acquired at a lower effective dose (11 ± 9 μSv; P < 0.0001). Image-processing methods significantly impact perceived image quality. These image-quality differences can be exploited to alter protocols and produce images of equivalent image quality but lower doses. Those purchasing projection radiography systems or third-party image-processing software should be aware that image processing

  14. Usefulness of dynamic MR imaging for the evaluation of transcatheter arterial embolization for hepatocellular carcinoma

    International Nuclear Information System (INIS)

    Kyomasu, Yoshinori; Nakayama, Masafumi; Kawakami, Mutsumi; Mashima, Yasuoki; Ichinose, Akira; Endou, Kazuo; Chiba, Kazuo; Tanno, Munehiko; Yamada, Hideo

    1992-01-01

    Thirteen patients with hepatocellular carcinoma (HCC) were studied with dynamic MR imaging in addition to conventional T 1 - and T 2 -weighted and enhanced T 1 -weighted images before and after the treatment of HCC by transcatheter arterial embolization (TAE). Dynamic MR imaging was performed using GRASS (gradient recalled acquisition in the steady state) sequences. The imaging was started at 10 seconds after rapid injection of Gd-diethylenetriaminepentaacetic acid (Gd-DTPA) with 6s breath hold. Thereafter about 12 images were obtained during 6s breath-holding with 20 seconds intervals. On T 1 - and T 2 -weighted images, signal intensity at the tumor tended to increase during the early period after TAE and to decrease later. Intensities of the HCC, however, were heterogeneous. Differentiation among embolic area, necrosis, viable cells and recurrent area, was often difficult only by conventional images. Dynamic GRASS images could clearly demonstrate an embolic area as a region without contrast enhancement. While recurrent tumor could be diagnosed as an area with early enhancement at the arterial phase. Development of the collateral circulation and dominancy of tumor feeding vessels after TAE could also be deduced on dynamic MR images together with enhanced T 1 -weighted images. The dynamic MR imaging was concluded to be a potentially useful procedure for the clinical evaluation of HCC after TAE. (author)

  15. Studies on the clinical application of MR perfusion image using arterial spin labeling method

    International Nuclear Information System (INIS)

    Miyasaka, Kenji

    1999-01-01

    A new technique for imaging brain perfusion, arterial spin labeling method was applied in clinic. Brain perfusion was imaged by FAIR and EPISTAR both of which using arterial spin labeling (ASL) method. Suitable parameters for small contamination were examined using a imaging phantom. Then normal volunteers were examined for imaging timing. Suitable time between labeling pulse and imaging pulse for brain capillary and parenchyma was 1.0 sec. For clinical application study, total 48 patients with brain diseases were examined by FAIR and/or EPISTAR. A lesion/white matter signal intensity ratio was calculated in all clinical cases. Average of signal intensity ratio in infarction, tumor and arteriovenous malformation (AVM) were 0.8, 2.2 and 18.6 at FAIR, and 0.6, 2.2 and 12.8 at EPISTAR, respectively. Low perfusion diseases such as cerebral infarction have low signal intensity ratio and high perfusion diseases such as AVM have high signal intensity ratio in both FAIR and EPISTAR. Brain lesions were imaged similarly in FAIR and EPISTAR, and no remarkable difference was found between FAIR and EPISTAR. As a result of diagnostic trial by signal intensity ratio in operated tumor, hemorrhagic cases could be diagnosed by accuracies of 75% in FAIR and 100% in EPISTAR, respectively. (author)

  16. Quality of life in opium-addicted patients with coronary artery disease as measured with WHOQOL-BREF.

    Science.gov (United States)

    Najafi, Mahdi; Sheikhvatan, Mehrdad; Montazeri, Ali; Sheikhfathollahi, Mahmood

    2009-05-01

    Several factors can influence the quality of life in patients with coronary artery disease (CAD). The goal of this research was to measure quality of life in opium-addicted patients with CAD in order to assess the effect of CAD risk factors on their quality of life. The WHOQOL-BREF questionnaire was completed through interviews with 275 patients who underwent isolated coronary artery bypass surgery in Tehran Heart Centre between May and September 2006. No significant differences were found in the mean scores of the four domains of quality of life between the addicted and non-addicted patients. Furthermore, the evaluation of QOL in the groups with CAD risk factors showed that the mean QOL domains were statistically similar between opium addicted and non-opium addicted patients. In the addicted group, men had a higher psychological health score than women. A previous history of myocardial infarction reduced the psychological score in this group. Also, in the addicted patients with a history of diabetes mellitus, social functioning was better than that of the non-diabetics. The different domains of quality of life in our opium-addicted and non-addicted patients with CAD were similar; and among all the major risk factors for coronary artery disease, only female gender and a previous history of myocardial infarction could influence quality of life in the opium-addicted patients.

  17. Anatomic distribution of renal artery stenosis in children: implications for imaging.

    Science.gov (United States)

    Vo, Nghia J; Hammelman, Ben D; Racadio, Judy M; Strife, C Frederic; Johnson, Neil D; Racadio, John M

    2006-10-01

    Renal artery stenosis (RAS) causes significant hypertension in children. Frequently, pediatric RAS occurs with systemic disorders. In these cases, stenoses are often complex and/or include long segments. We believed that hypertensive children without comorbid conditions had a different lesion distribution and that the difference might have implications for imaging and treatment. To identify locations of RAS lesions in these hypertensive children without comorbid conditions. Patients who had renal angiography for hypertension from 1993 to 2005 were identified. Patients with systemic disorders, renovascular surgery, or normal angiograms were excluded. The angiograms of the remaining patients were reviewed for number, type, and location of stenoses. Eighty-seven patients underwent renal angiography for hypertension; 30 were excluded for comorbid conditions. Twenty-one of the remaining 57 patients had abnormal angiograms; 24 stenoses were identified in those patients. All were focal and distributed as follows: 6 (25%) main renal artery, 12 (50%) 2nd order branch, 3 (12.5%) 3rd order branch, and 3 (12.5%) accessory renal artery. Hypertensive children without comorbid conditions who have RAS usually have single, focal branch artery stenoses. This distribution supports angiography in these patients because of its superior sensitivity in detecting branch vessel disease and its therapeutic role in percutaneous transluminal renal angioplasty.

  18. Anatomic distribution of renal artery stenosis in children: implications for imaging

    Energy Technology Data Exchange (ETDEWEB)

    Vo, Nghia J.; Racadio, Judy M.; Johnson, Neil D. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Division of Pediatric Interventional Radiology, Cincinnati, OH (United States); Hammelman, Ben D. [University of Cincinnati College of Medicine, Cincinnati, OH (United States); Strife, C.F. [Cincinnati Children' s Hospital Medical Center, Department of Pediatrics, Division of Nephrology and Hypertension, Cincinnati, OH (United States); Racadio, John M. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Division of Pediatric Interventional Radiology, Cincinnati, OH (United States); Cincinnati Children' s Hospital, Department of Radiology, Cincinnati, OH (United States)

    2006-10-15

    Renal artery stenosis (RAS) causes significant hypertension in children. Frequently, pediatric RAS occurs with systemic disorders. In these cases, stenoses are often complex and/or include long segments. We believed that hypertensive children without comorbid conditions had a different lesion distribution and that the difference might have implications for imaging and treatment. To identify locations of RAS lesions in these hypertensive children without comorbid conditions. Patients who had renal angiography for hypertension from 1993 to 2005 were identified. Patients with systemic disorders, renovascular surgery, or normal angiograms were excluded. The angiograms of the remaining patients were reviewed for number, type, and location of stenoses. Eighty-seven patients underwent renal angiography for hypertension; 30 were excluded for comorbid conditions. Twenty-one of the remaining 57 patients had abnormal angiograms; 24 stenoses were identified in those patients. All were focal and distributed as follows: 6 (25%) main renal artery, 12 (50%) 2nd order branch, 3 (12.5%) 3rd order branch, and 3 (12.5%) accessory renal artery. Hypertensive children without comorbid conditions who have RAS usually have single, focal branch artery stenoses. This distribution supports angiography in these patients because of its superior sensitivity in detecting branch vessel disease and its therapeutic role in percutaneous transluminal renal angioplasty. (orig.)

  19. Anatomic distribution of renal artery stenosis in children: implications for imaging

    International Nuclear Information System (INIS)

    Vo, Nghia J.; Racadio, Judy M.; Johnson, Neil D.; Hammelman, Ben D.; Strife, C.F.; Racadio, John M.

    2006-01-01

    Renal artery stenosis (RAS) causes significant hypertension in children. Frequently, pediatric RAS occurs with systemic disorders. In these cases, stenoses are often complex and/or include long segments. We believed that hypertensive children without comorbid conditions had a different lesion distribution and that the difference might have implications for imaging and treatment. To identify locations of RAS lesions in these hypertensive children without comorbid conditions. Patients who had renal angiography for hypertension from 1993 to 2005 were identified. Patients with systemic disorders, renovascular surgery, or normal angiograms were excluded. The angiograms of the remaining patients were reviewed for number, type, and location of stenoses. Eighty-seven patients underwent renal angiography for hypertension; 30 were excluded for comorbid conditions. Twenty-one of the remaining 57 patients had abnormal angiograms; 24 stenoses were identified in those patients. All were focal and distributed as follows: 6 (25%) main renal artery, 12 (50%) 2nd order branch, 3 (12.5%) 3rd order branch, and 3 (12.5%) accessory renal artery. Hypertensive children without comorbid conditions who have RAS usually have single, focal branch artery stenoses. This distribution supports angiography in these patients because of its superior sensitivity in detecting branch vessel disease and its therapeutic role in percutaneous transluminal renal angioplasty. (orig.)

  20. Image quality dependence on image processing software in ...

    African Journals Online (AJOL)

    Image quality dependence on image processing software in computed radiography. ... Agfa CR readers use MUSICA software, and an upgrade with significantly different image ... Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT

  1. Automatic detection of the carotid artery boundary on cross-sectional MR image sequences using a circle model guided dynamic programming

    Directory of Open Access Journals (Sweden)

    Brambs Hans

    2011-04-01

    Full Text Available Abstract Background Systematic aerobe training has positive effects on the compliance of dedicated arterial walls. The adaptations of the arterial structure and function are associated with the blood flow-induced changes of the wall shear stress which induced vascular remodelling via nitric oxide delivered from the endothelial cell. In order to assess functional changes of the common carotid artery over time in these processes, a precise measurement technique is necessary. Before this study, a reliable, precise, and quick method to perform this work is not present. Methods We propose a fully automated algorithm to analyze the cross-sectional area of the carotid artery in MR image sequences. It contains two phases: (1 position detection of the carotid artery, (2 accurate boundary identification of the carotid artery. In the first phase, we use intensity, area size and shape as features to discriminate the carotid artery from other tissues and vessels. In the second phase, the directional gradient, Hough transform, and circle model guided dynamic programming are used to identify the boundary accurately. Results We test the system stability using contrast degraded images (contrast resolutions range from 50% to 90%. The unsigned error ranges from 2.86% ± 2.24% to 3.03% ± 2.40%. The test of noise degraded images (SNRs range from 16 to 20 dB shows the unsigned error ranging from 2.63% ± 2.06% to 3.12% ± 2.11%. The test of raw images has an unsigned error 2.56% ± 2.10% compared to the manual tracings. Conclusions We have proposed an automated system which is able to detect carotid artery cross sectional boundary in MRI sequences during heart cycles. The accuracy reaches 2.56% ± 2.10% compared to the manual tracings. The system is stable, reliable and results are reproducible.

  2. Assessment of arterial hypervascularity of hepatocellular carcinoma: comparison of contrast-enhanced US and gadoxetate disodium-enhanced MR imaging

    International Nuclear Information System (INIS)

    Sugimoto, Katsutoshi; Moriyasu, Fuminori; Taira, Junichi; Imai, Yasuharu; Shiraishi, Junji; Saito, Kazuhiro; Saguchi, Toru

    2012-01-01

    To compare contrast-enhanced (CE) ultrasound with gadoxetate disodium-enhanced magnetic resonance (MR) imaging in the assessment of arterial hypervascularity of hepatocellular carcinoma (HCC) and dysplastic nodule (DN), with CT during hepatic arteriography (CTHA) as the reference standard. This study included 54 consecutively diagnosed patients, with 57 histologically confirmed HCCs and 3 DNs (high-grade). All patients underwent CE ultrasound, gadoxetate disodium-enhanced MR imaging and CTHA. Two trained diagnostic radiologists interpreted the CTHA images and rated the degree of intratumoral arterial vascularity by consensus using a five-point confidence scale as the reference standard. In the observer study, the degrees of vascularity on CE ultrasound and gadoxetate disodium-enhanced MR images were qualitatively analysed by four independent readers using a five-point confidence scale. Diagnostic accuracy was analysed by receiver-operating characteristic (ROC) analysis. The diagnostic accuracies of the average area under the ROC curve (AUC) were significantly greater with CE ultrasound (average AUC: 0.94; 95% confidence interval [CI]: 0.88-1.00) than with gadoxetate disodium-enhanced MR imaging (average AUC 0.84, 95% CI 0.74-0.93, P = 0.0014). Contrast-enhanced ultrasound yields a significantly higher AUC value than gadoxetate disodium-enhanced MR imaging in the assessment of arterial hypervascularity of HCC and DN. Key Points circle Arterial hypervascularity is an important feature determining treatment options in hepatocellular carcinoma. circle It can be assessed by contrast-enhanced (CE) ultrasound or magnetic resonance (MR) imaging. circle CE ultrasound was more accurate than Gd-EOB-DTPA MRI in assessing intratumoral vascularity. circle Hypovascular hepatic nodules should be further investigated using CE ultrasound. (orig.)

  3. Image quality at synthetic brain magnetic resonance imaging in children

    Energy Technology Data Exchange (ETDEWEB)

    Lee, So Mi; Cho, Seung Hyun; Kim, Won Hwa; Kim, Hye Jung [Kyungpook National University Hospital, Department of Radiology, Daegu (Korea, Republic of); Choi, Young Hun; Cheon, Jung-Eun; Kim, In-One [Seoul National University College of Medicine, Department of Radiology and Institute of Radiation Medicine, Seoul (Korea, Republic of); Cho, Hyun-Hae [Ewha Womans University Mokdong Hospital, Department of Radiology, Seoul (Korea, Republic of); You, Sun-Kyoung [Chungnam National University Hospital, Department of Radiology, Daejeon (Korea, Republic of); Park, Sook-Hyun [Kyungpook National University Hospital, Department of Pediatrics, Daegu (Korea, Republic of); Hwang, Moon Jung [GE Healthcare, MR Applications and Workflow, Seoul (Korea, Republic of)

    2017-11-15

    The clinical application of the multi-echo, multi-delay technique of synthetic magnetic resonance imaging (MRI) generates multiple sequences in a single acquisition but has mainly been used in adults. To evaluate the image quality of synthetic brain MR in children compared with that of conventional images. Twenty-nine children (median age: 6 years, range: 0-16 years) underwent synthetic and conventional imaging. Synthetic (T2-weighted, T1-weighted and fluid-attenuated inversion recovery [FLAIR]) images with settings matching those of the conventional images were generated. The overall image quality, gray/white matter differentiation, lesion conspicuity and image degradations were rated on a 5-point scale. The relative contrasts were assessed quantitatively and acquisition times for the two imaging techniques were compared. Synthetic images were inferior due to more pronounced image degradations; however, there were no significant differences for T1- and T2-weighted images in children <2 years old. The quality of T1- and T2-weighted images were within the diagnostically acceptable range. FLAIR images showed greatly reduced quality. Gray/white matter differentiation was comparable or better in synthetic T1- and T2-weighted images, but poorer in FLAIR images. There was no effect on lesion conspicuity. Synthetic images had equal or greater relative contrast. Acquisition time was approximately two-thirds of that for conventional sequences. Synthetic T1- and T2-weighted images were diagnostically acceptable, but synthetic FLAIR images were not. Lesion conspicuity and gray/white matter differentiation were comparable to conventional MRI. (orig.)

  4. Balancing patient dose and image quality

    International Nuclear Information System (INIS)

    Martin, C.J.; Sutton, D.G.; Sharp, P.F.

    1999-01-01

    The formation of images in diagnostic radiology involves a complex interdependence of many factors. The ideal balance is to obtain an image which is adequate for the clinical purpose with the minimum radiation dose. Factors which affect radiation dose and image quality can be grouped under three headings; radiation quality, photon fluence and removal of scattered radiation. If optimal performance is to be achieved, it is necessary to understand how these factors influence image formation and affect radiation dose, and apply methodology for image quality and dose analysis at each stage in the development and use of X-ray equipment

  5. 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.)

  6. Reduction of radiation exposure and improvement of image quality with BMI-adapted prospective cardiac computed tomography and iterative reconstruction

    International Nuclear Information System (INIS)

    Hosch, Waldemar; Stiller, Wolfram; Mueller, Dirk; Gitsioudis, Gitsios; Welzel, Johanna; Dadrich, Monika; Buss, Sebastian J.; Giannitsis, Evangelos; Kauczor, Hans U.; Katus, Hugo A.; Korosoglou, Grigorios

    2012-01-01

    Purpose: To assess the impact of body mass index (BMI)-adapted protocols and iterative reconstruction algorithms (iDose) on patient radiation exposure and image quality in patients undergoing prospective ECG-triggered 256-slice coronary computed tomography angiography (CCTA). Methods: Image quality and radiation exposure were systematically analyzed in 100 patients. 60 Patients underwent prospective ECG-triggered CCTA using a non-tailored protocol and served as a ‘control’ group (Group 1: 120 kV, 200 mA s). 40 Consecutive patients with suspected coronary artery disease (CAD) underwent prospective CCTA, using BMI-adapted tube voltage and standard (Group 2: 100/120 kV, 100–200 mA s) versus reduced tube current (Group 3: 100/120 kV, 75–150 mA s). Iterative reconstructions were provided with different iDose levels and were compared to filtered back projection (FBP) reconstructions. Image quality was assessed in consensus of 2 experienced observers and using a 5-grade scale (1 = best to 5 = worse), and signal- and contrast-to-noise ratios (SNR and CNR) were quantified. Results: CCTA was performed without adverse events in all patients (n = 100, heart rate of 47–87 bpm and BMI of 19–38 kg/m 2 ). Patients examined using the non-tailored protocol in Group 1 had the highest radiation exposure (3.2 ± 0.4 mSv), followed by Group 2 (1.7 ± 0.7 mSv) and Group 3 (1.2 ± 0.6 mSv) (radiation savings of 47% and 63%, respectively, p < 0.001). Iterative reconstructions provided increased SNR and CNR, particularly when higher iDose level 5 was applied with Multi-Frequency reconstruction (iDose5 MFR) (14.1 ± 4.6 versus 21.2 ± 7.3 for SNR and 12.0 ± 4.2 versus 18.1 ± 6.6 for CNR, for FBP versus iDose5 MFR, respectively, p < 0.001). The combination of BMI adaptation with iterative reconstruction reduced radiation exposure and simultaneously improved image quality (subjective image quality of 1.4 ± 0.4 versus 1.9 ± 0.5 for Group 2 reconstructed using iDose5 MFR versus

  7. 256-slice CT coronary angiography in atrial fibrillation: The impact of mean heart rate and heart rate variability on image quality

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Liang-Kuang [Department of Radiology, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan (China); College of Medicine, Fu Jen Catholic University, Taipei, Taiwan (China); Hsu, Shih-Ming [Department of Biomedical Imaging and Radiological Science, China Medical University, Taichung, Taiwan (China); Mok, Greta S.P. [Department of Electrical and Electronics Engineering, Faculty of Science and Technology, University of Macau, Macau (China); Law, Wei-Yip; Lu, Kun-Mu [Department of Radiology, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan (China); Yang, Ching-Ching, E-mail: g39220003@yahoo.com.tw [Department of Radiological Technology, Tzu Chi College of Technology, 880, Sec.2, Chien-kuo Rd. Hualien 970, Taiwan (China); Wu, Tung-Hsin, E-mail: tung@ym.edu.tw [Department of Biomedical Imaging and Radiological Sciences, National Yang Ming University, 155 Li-Nong St., Sec. 2, Taipei 112, Taiwan (China)

    2011-08-21

    Objective: The aim of this study was to evaluate the image quality of 256-MDCT in atrial fibrillation and to compare the findings with those among patients in sinus rhythm. Materials: All reconstructed images were evaluated by two independent experienced readers blinded to patient information, heart rate, and ECG results to assess the diagnostic quality of images of the coronary artery segments using axial images, multi-planar reformations, maximum intensity projections, and volume rendering technique. Results: No statistical significance was detected in terms of the overall image quality between patients in sinus rhythm and with atrial fibrillation. Pearson's correlation analysis showed no significant association between image quality and mean heart rate no matter for patients in sinus rhythm or with atrial fibrillation. Similarly, there was no correlation between image quality and heart rate variability for either patients in sinus rhythm or with atrial fibrillation. Our results showed that the optimal reconstruction window depends on patient's HR, and the pattern for patients in atrial fibrillation is similar to that obtained from non-atrial fibrillation patients. Conclusion: This study shows the potential of using 256-MDCT coronary angiography in patients with atrial fibrillation. Our results suggest that when appropriate reconstruction timing window is applied, patients with atrial fibrillation do not have to be excluded from MDCT coronary angiographic examinations.

  8. 256-slice CT coronary angiography in atrial fibrillation: The impact of mean heart rate and heart rate variability on image quality

    International Nuclear Information System (INIS)

    Chen, Liang-Kuang; Hsu, Shih-Ming; Mok, Greta S.P.; Law, Wei-Yip; Lu, Kun-Mu; Yang, Ching-Ching; Wu, Tung-Hsin

    2011-01-01

    Objective: The aim of this study was to evaluate the image quality of 256-MDCT in atrial fibrillation and to compare the findings with those among patients in sinus rhythm. Materials: All reconstructed images were evaluated by two independent experienced readers blinded to patient information, heart rate, and ECG results to assess the diagnostic quality of images of the coronary artery segments using axial images, multi-planar reformations, maximum intensity projections, and volume rendering technique. Results: No statistical significance was detected in terms of the overall image quality between patients in sinus rhythm and with atrial fibrillation. Pearson's correlation analysis showed no significant association between image quality and mean heart rate no matter for patients in sinus rhythm or with atrial fibrillation. Similarly, there was no correlation between image quality and heart rate variability for either patients in sinus rhythm or with atrial fibrillation. Our results showed that the optimal reconstruction window depends on patient's HR, and the pattern for patients in atrial fibrillation is similar to that obtained from non-atrial fibrillation patients. Conclusion: This study shows the potential of using 256-MDCT coronary angiography in patients with atrial fibrillation. Our results suggest that when appropriate reconstruction timing window is applied, patients with atrial fibrillation do not have to be excluded from MDCT coronary angiographic examinations.

  9. Impact of metal artifact reduction software on image quality of gemstone spectral imaging dual-energy cerebral CT angiography after intracranial aneurysm clipping

    Energy Technology Data Exchange (ETDEWEB)

    Dunet, Vincent; Bernasconi, Martine; Hajdu, Steven David; Meuli, Reto Antoine; Zerlauth, Jean-Baptiste [Lausanne University Hospital, Department of Diagnostic and Interventional Radiology, Lausanne (Switzerland); Daniel, Roy Thomas [Lausanne University Hospital, Department of Neurosurgery, Lausanne (Switzerland)

    2017-09-15

    We aimed to assess the impact of metal artifact reduction software (MARs) on image quality of gemstone spectral imaging (GSI) dual-energy (DE) cerebral CT angiography (CTA) after intracranial aneurysm clipping. This retrospective study was approved by the institutional review board, which waived patient written consent. From January 2013 to September 2016, single source DE cerebral CTA were performed in 45 patients (mean age: 60 ± 9 years, male 9) after intracranial aneurysm clipping and reconstructed with and without MARs. Signal-to-noise (SNR), contrast-to-noise (CNR), and relative CNR (rCNR) ratios were calculated from attenuation values measured in the internal carotid artery (ICA) and middle cerebral artery (MCA). Volume of clip and artifacts and relative clip blurring reduction (rCBR) ratios were also measured at each energy level with/without MARs. Variables were compared between GSI and GSI-MARs using the paired Wilcoxon signed-rank test. MARs significantly reduced metal artifacts at all energy levels but 130 and 140 keV, regardless of clips' location and number. The optimal rCBR was obtained at 110 and 80 keV, respectively, on GSI and GSI-MARs images, with up to 96% rCNR increase on GSI-MARs images. The best compromise between metal artifact reduction and rCNR was obtained at 70-75 and 65-70 keV for GSI and GSI-MARs images, respectively, with up to 15% rCBR and rCNR increase on GSI-MARs images. MARs significantly reduces metal artifacts on DE cerebral CTA after intracranial aneurysm clipping regardless of clips' location and number. It may be used to reduce radiation dose while increasing CNR. (orig.)

  10. Diagnosis of vertebral artery dissection with basiparallel anatomical scanning magnetic resonance imaging

    International Nuclear Information System (INIS)

    Katsuno, Makoto; Kobayashi, Shiro

    2011-01-01

    There is no consensus regarding the optimal method for diagnosing the dissection of intracranial arteries. We have developed a rapid and accurate examination method to diagnose vertebral artery dissection in the acute stage of cerebral infarction. Twenty-two patients with severe headache and neck pain and/or symptoms of brain stem or cerebellar ischemia underwent magnetic resonance imaging (MRI) with a 1.5-T scanner. Our protocol generated 3 contrast-weighted scans (T2-weighted, diffusion-weighted, and basi-parallel anatomical scanning [BPAS]-MRI) and conventional angiographs within 3 hours of the onset of symptoms. Then, we retrospectively analyzed the findings to identify the most reliable imaging method for diagnosing vertebral artery dissection in the acute stage of cerebral infarction. Based on the symptoms and the findings of T2-weighted imaging and conventional angiography, the initial diagnosis was dissection in 17 patients, lacunar infarction in 3 patients, and atherothrombosis in 2 patients. After follow-up studies the diagnosis was changed in 7 patients. The diagnosis based on symptoms and the findings of T2-weighted MRI and BPAS-MRI was dissection in 13 patients, atherothrombosis in 6 patients, and lacunar infarction in 3 patients. In 3 patients the diagnosis was changed during the follow-up phase. The diagnostic accuracy rate was higher with T2-weighted MRI and BPAS-MRI than with T2-weighted MRI and conventional angiography. We suggest that when intracranial vascular dissection is suspected, both the inner and outer contours of vessels must be inspected and that BPAS-MRI should be performed instead of conventional angiography to establish the definite diagnosis. (author)

  11. Imaging of coronary artery stents using multislice computed tomography: in vitro evaluation

    International Nuclear Information System (INIS)

    Maintz, David; Juergens, Kai-Uwe; Heindel, Walter; Fischbach, Roman; Wichter, Thomas; Grude, Matthias

    2003-01-01

    The aim of this study was to evaluate imaging features of different coronary artery stents during multislice CT Angiography (MSCTA). Nineteen stents made of varying material (steel, nitinol, tantalum) and of varying stent design were implanted in plastic tubes with an inner diameter of 3 mm to simulate a coronary artery. The tubes were filled with iodinated contrast material diluted to 200 Hounsfield units (HU), closed at both ends and positioned in a plastic container filled with oil (-70 HU). The MSCT scans were obtained perpendicular to the stent axes (detector collimation 4 x 1 mm, table feed 2 mm/rotation, 300 mAs, 120 kV). Axial images and multiplanar reformations were evaluated regarding artifact size, lumen visibility, and intraluminal attenuation values. Artifacts characterized by artifactual thickening of the stent struts leading to apparent reduction in the lumen diameter and increased intraluminal attenuation values were observed in all cases. The stent lumen was totally obscured in the Wiktor stent, the Wallgraft stent, and the Nir Royal stent. Partial residual of the stent lumen could be visualized in all other utilized stent products (artificial lumen reductions ranged from 62% in the V-Flex stent to 94% in the Bx Velocity stent). Parts of the stent lumen can be visualized in most coronary artery stents; however, detectability of in-stent stenoses remains to be evaluated for each stent type. (orig.)

  12. Different Imaging Strategies in Patients with Possible Basilar Artery Occlusion: Cost-Effectiveness Analysis

    NARCIS (Netherlands)

    S.E. Beyer (Sebastian E.); M.G.M. Hunink (Myriam); F. Schöberl (Florian); L. von Baumgarten; S.E. Petersen (Steffen); C. Kubisch (Christian); H. Janssen (Hendrik); B. Ertl-Wagner (Birgit); M.F. Reiser (Maximilian F.); W.H. Sommer (Wieland H.)

    2015-01-01

    textabstractBackground and Purpose-This study evaluated the cost-effectiveness of different noninvasive imaging strategies in patients with possible basilar artery occlusion. Methods-A Markov decision analytic model was used to evaluate long-term outcomes resulting from strategies using computed

  13. Quality assurance: image production and film quality

    International Nuclear Information System (INIS)

    Abd Aziz Mhd Ramli

    2004-01-01

    The contents of this chapter are follows - Factors Affecting Image Quality and Patient Dose: Quality Control in Diagnostic Radiology, Mechanical Safety, Electrical Safety, Radiation Protection, Performance and Safety Standard, Calibration of QC Test Tools

  14. Blind image quality assessment based on aesthetic and statistical quality-aware features

    Science.gov (United States)

    Jenadeleh, Mohsen; Masaeli, Mohammad Masood; Moghaddam, Mohsen Ebrahimi

    2017-07-01

    The main goal of image quality assessment (IQA) methods is the emulation of human perceptual image quality judgments. Therefore, the correlation between objective scores of these methods with human perceptual scores is considered as their performance metric. Human judgment of the image quality implicitly includes many factors when assessing perceptual image qualities such as aesthetics, semantics, context, and various types of visual distortions. The main idea of this paper is to use a host of features that are commonly employed in image aesthetics assessment in order to improve blind image quality assessment (BIQA) methods accuracy. We propose an approach that enriches the features of BIQA methods by integrating a host of aesthetics image features with the features of natural image statistics derived from multiple domains. The proposed features have been used for augmenting five different state-of-the-art BIQA methods, which use statistical natural scene statistics features. Experiments were performed on seven benchmark image quality databases. The experimental results showed significant improvement of the accuracy of the methods.

  15. Image quality and dose differences caused by vendor-specific image processing of neonatal radiographs

    Energy Technology Data Exchange (ETDEWEB)

    Sensakovic, William F.; O' Dell, M.C.; Letter, Haley; Kohler, Nathan; Rop, Baiywo; Cook, Jane; Logsdon, Gregory; Varich, Laura [Florida Hospital, Imaging Administration, Orlando, FL (United States)

    2016-10-15

    Image processing plays an important role in optimizing image quality and radiation dose in projection radiography. Unfortunately commercial algorithms are black boxes that are often left at or near vendor default settings rather than being optimized. We hypothesize that different commercial image-processing systems, when left at or near default settings, create significant differences in image quality. We further hypothesize that image-quality differences can be exploited to produce images of equivalent quality but lower radiation dose. We used a portable radiography system to acquire images on a neonatal chest phantom and recorded the entrance surface air kerma (ESAK). We applied two image-processing systems (Optima XR220amx, by GE Healthcare, Waukesha, WI; and MUSICA{sup 2} by Agfa HealthCare, Mortsel, Belgium) to the images. Seven observers (attending pediatric radiologists and radiology residents) independently assessed image quality using two methods: rating and matching. Image-quality ratings were independently assessed by each observer on a 10-point scale. Matching consisted of each observer matching GE-processed images and Agfa-processed images with equivalent image quality. A total of 210 rating tasks and 42 matching tasks were performed and effective dose was estimated. Median Agfa-processed image-quality ratings were higher than GE-processed ratings. Non-diagnostic ratings were seen over a wider range of doses for GE-processed images than for Agfa-processed images. During matching tasks, observers matched image quality between GE-processed images and Agfa-processed images acquired at a lower effective dose (11 ± 9 μSv; P < 0.0001). Image-processing methods significantly impact perceived image quality. These image-quality differences can be exploited to alter protocols and produce images of equivalent image quality but lower doses. Those purchasing projection radiography systems or third-party image-processing software should be aware that image

  16. Image quality and dose differences caused by vendor-specific image processing of neonatal radiographs.

    Science.gov (United States)

    Sensakovic, William F; O'Dell, M Cody; Letter, Haley; Kohler, Nathan; Rop, Baiywo; Cook, Jane; Logsdon, Gregory; Varich, Laura

    2016-10-01

    Image processing plays an important role in optimizing image quality and radiation dose in projection radiography. Unfortunately commercial algorithms are black boxes that are often left at or near vendor default settings rather than being optimized. We hypothesize that different commercial image-processing systems, when left at or near default settings, create significant differences in image quality. We further hypothesize that image-quality differences can be exploited to produce images of equivalent quality but lower radiation dose. We used a portable radiography system to acquire images on a neonatal chest phantom and recorded the entrance surface air kerma (ESAK). We applied two image-processing systems (Optima XR220amx, by GE Healthcare, Waukesha, WI; and MUSICA(2) by Agfa HealthCare, Mortsel, Belgium) to the images. Seven observers (attending pediatric radiologists and radiology residents) independently assessed image quality using two methods: rating and matching. Image-quality ratings were independently assessed by each observer on a 10-point scale. Matching consisted of each observer matching GE-processed images and Agfa-processed images with equivalent image quality. A total of 210 rating tasks and 42 matching tasks were performed and effective dose was estimated. Median Agfa-processed image-quality ratings were higher than GE-processed ratings. Non-diagnostic ratings were seen over a wider range of doses for GE-processed images than for Agfa-processed images. During matching tasks, observers matched image quality between GE-processed images and Agfa-processed images acquired at a lower effective dose (11 ± 9 μSv; P < 0.0001). Image-processing methods significantly impact perceived image quality. These image-quality differences can be exploited to alter protocols and produce images of equivalent image quality but lower doses. Those purchasing projection radiography systems or third-party image-processing software should be aware that image

  17. Tradeoffs between image quality and dose

    International Nuclear Information System (INIS)

    Seibert, J.A.

    2004-01-01

    Image quality takes on different perspectives and meanings when associated with the concept of as low as reasonably achievable (ALARA), which is chiefly focused on radiation dose delivered as a result of a medical imaging procedure. ALARA is important because of the increased radiosensitivity of children to ionizing radiation and the desire to keep the radiation dose low. By the same token, however, image quality is also important because of the need to provide the necessary information in a radiograph in order to make an accurate diagnosis. Thus, there are tradeoffs to be considered between image quality and radiation dose, which is the main topic of this article. ALARA does not necessarily mean the lowest radiation dose, nor, when implemented, does it result in the least desirable radiographic images. With the recent widespread implementation of digital radiographic detectors and displays, a new level of flexibility and complexity confronts the technologist, physicist, and radiologist in optimizing the pediatric radiography exam. This is due to the separation of the acquisition, display, and archiving events that were previously combined by the screen-film detector, which allows for compensation for under- and overexposures, image processing, and on-line image manipulation. As explained in the article, different concepts must be introduced for a better understanding of the tradeoffs encountered when dealing with digital radiography and ALARA. In addition, there are many instances during the image acquisition/display/interpretation process in which image quality and associated dose can be compromised. This requires continuous diligence to quality control and feedback mechanisms to verify that the goals of image quality, dose and ALARA are achieved. (orig.)

  18. Optimization of Synthetic Aperture Image Quality

    DEFF Research Database (Denmark)

    Moshavegh, Ramin; Jensen, Jonas; Villagómez Hoyos, Carlos Armando

    2016-01-01

    Synthetic Aperture (SA) imaging produces high-quality images and velocity estimates of both slow and fast flow at high frame rates. However, grating lobe artifacts can appear both in transmission and reception. These affect the image quality and the frame rate. Therefore optimization of parameter...

  19. The pacing stress test: thallium-201 myocardial imaging after atrial pacing. Diagnostic value in detecting coronary artery disease compared with exercise testing

    International Nuclear Information System (INIS)

    Heller, G.V.; Aroesty, J.M.; Parker, J.A.; McKay, R.G.; Silverman, K.J.; Als, A.V.; Come, P.C.; Kolodny, G.M.; Grossman, W.

    1984-01-01

    Many patients suspected of having coronary artery disease are unable to undergo adequate exercise testing. An alternate stress, pacing tachycardia, has been shown to produce electrocardiographic changes that are as sensitive and specific as those observed during exercise testing. To compare thallium-201 imaging after atrial pacing stress with thallium imaging after exercise stress, 22 patients undergoing cardiac catheterization were studied with both standard exercise thallium imaging and pacing thallium imaging. Positive ischemic electrocardiographic changes (greater than 1 mm ST segment depression) were noted in 11 of 16 patients with coronary artery disease during exercise, and in 15 of the 16 patients during atrial pacing. One of six patients with normal or trivial coronary artery disease had a positive electrocardiogram with each test. Exercise thallium imaging was positive in 13 of 16 patients with coronary artery disease compared with 15 of 16 patients during atrial pacing. Three of six patients without coronary artery disease had a positive scan with exercise testing, and two of these same patients developed a positive scan with atrial pacing. Of those patients with coronary artery disease and an abnormal scan, 85% showed redistribution with exercise testing compared with 87% during atrial pacing. Segment by segment comparison of thallium imaging after either atrial pacing or exercise showed that there was a good correlation of the location and severity of the thallium defects (r . 0.83, p . 0.0001, Spearman rank correlation). It is concluded that the location and presence of both fixed and transient thallium defects after atrial pacing are closely correlated with the findings after exercise testing

  20. Image quality assessment using deep convolutional networks

    Science.gov (United States)

    Li, Yezhou; Ye, Xiang; Li, Yong

    2017-12-01

    This paper proposes a method of accurately assessing image quality without a reference image by using a deep convolutional neural network. Existing training based methods usually utilize a compact set of linear filters for learning features of images captured by different sensors to assess their quality. These methods may not be able to learn the semantic features that are intimately related with the features used in human subject assessment. Observing this drawback, this work proposes training a deep convolutional neural network (CNN) with labelled images for image quality assessment. The ReLU in the CNN allows non-linear transformations for extracting high-level image features, providing a more reliable assessment of image quality than linear filters. To enable the neural network to take images of any arbitrary size as input, the spatial pyramid pooling (SPP) is introduced connecting the top convolutional layer and the fully-connected layer. In addition, the SPP makes the CNN robust to object deformations to a certain extent. The proposed method taking an image as input carries out an end-to-end learning process, and outputs the quality of the image. It is tested on public datasets. Experimental results show that it outperforms existing methods by a large margin and can accurately assess the image quality on images taken by different sensors of varying sizes.

  1. The study of surgical image quality evaluation system by subjective quality factor method

    Science.gov (United States)

    Zhang, Jian J.; Xuan, Jason R.; Yang, Xirong; Yu, Honggang; Koullick, Edouard

    2016-03-01

    GreenLightTM procedure is an effective and economical way of treatment of benign prostate hyperplasia (BPH); there are almost a million of patients treated with GreenLightTM worldwide. During the surgical procedure, the surgeon or physician will rely on the monitoring video system to survey and confirm the surgical progress. There are a few obstructions that could greatly affect the image quality of the monitoring video, like laser glare by the tissue and body fluid, air bubbles and debris generated by tissue evaporation, and bleeding, just to name a few. In order to improve the physician's visual experience of a laser surgical procedure, the system performance parameter related to image quality needs to be well defined. However, since image quality is the integrated set of perceptions of the overall degree of excellence of an image, or in other words, image quality is the perceptually weighted combination of significant attributes (contrast, graininess …) of an image when considered in its marketplace or application, there is no standard definition on overall image or video quality especially for the no-reference case (without a standard chart as reference). In this study, Subjective Quality Factor (SQF) and acutance are used for no-reference image quality evaluation. Basic image quality parameters, like sharpness, color accuracy, size of obstruction and transmission of obstruction, are used as subparameter to define the rating scale for image quality evaluation or comparison. Sample image groups were evaluated by human observers according to the rating scale. Surveys of physician groups were also conducted with lab generated sample videos. The study shows that human subjective perception is a trustworthy way of image quality evaluation. More systematic investigation on the relationship between video quality and image quality of each frame will be conducted as a future study.

  2. Noncontrast-enhanced magnetic resonance renal angiography using a repetitive artery and venous labelling technique at 3 T: comparison with contrast-enhanced magnetic resonance angiography in subjects with normal renal function.

    Science.gov (United States)

    Park, Sung Yoon; Kim, Chan Kyo; Kim, EunJu; Park, Byung Kwan

    2015-02-01

    To investigate the feasibility of noncontrast-enhanced MR angiography (NC-MRA) using the repetitive artery and venous labelling (RAVEL) technique to evaluate renal arteries compared to contrast-enhanced MR angiography (CE-MRA). Twenty-five subjects with normal renal function underwent NC-MRA using a RAVEL technique and CE-MRA at 3 T. Two independent readers analysed the MRA images. Image quality, number of renal arteries, presence or absence of an early branching vessel, and diameter of the main renal arteries were evaluated. The overall image quality of NC-MRA was fair or greater in 88% of right and 92% of left renal arteries, while it was 96% in both sides with CE-MRA. On NC-MRA, the number of renal arteries in all subjects was perfectly predicted by both readers. Sensitivity and specificity for predicting early branching vessels were 82% and 100% for reader 1 and 82% and 95% for reader 2. Inter-modality agreement for comparing the diameters of main renal arteries was good or excellent at all segments for both readers. Inter-reader agreement was moderate or good at all segments except at the right distal segment on NC-MRA. NC-MRA with the RAVEL technique at 3 T may have comparable diagnostic feasibility for evaluating renal arteries compared to CE-MRA. • Accurate pre-treatment evaluation of renal artery anatomy helps clinical decision-making. • NC-MRA using RAVEL offers acceptable imaging quality for renal artery evaluation. • The 3 T RAVEL technique provides excellent diagnostic performance for renal artery evaluation. • The 3 T RAVEL technique may be an alternative to contrast-enhanced MRA.

  3. Daily marital interaction quality and carotid artery intima-medial thickness in healthy middle-aged adults.

    Science.gov (United States)

    Joseph, Nataria Tennille; Kamarck, Thomas W; Muldoon, Matthew F; Manuck, Stephen B

    2014-06-01

    To examine the association between marital interaction quality during daily life and subclinical cardiovascular disease (CVD). Studies have shown that marital status and quality of marriage are associated with cardiovascular health. However, little is known about the role of marital interaction quality during daily life in contributing to these effects. The sample consisted of 281 healthy, employed middle-aged adults who were married or living with a partner in a marital-like relationship (mean age = 42.0 years, 88% white, 52% men). Marital interaction quality was assessed using hourly real-time ecological momentary assessments for 4 days, with participants rating their current or recent partner interactions on positive and negative characteristics (e.g., agreeableness and conflict). Carotid artery intima-medial thickness (IMT) was assessed using ultrasound imaging. Adjusting for demographics, positive marital interaction was inversely associated with IMT (b = -0.02, F(1,275) = 9.18, p = .002), and negative marital interaction was positively associated with IMT (b = 0.02 F(1,275) = 10.29, p = .001). These associations were not accounted for by behavioral and biological CVD risk factors and were consistent across age, sex, race, and education. The associations were also independent of marital interaction frequency, nonmarital social interaction quality, and personality factors. Global reports of marital quality, in contrast, were not associated with IMT. Marital quality as measured during real-time interactions between partners was associated with subclinical CVD in healthy middle-aged adults. This study supports the use of real-time social interaction assessment for characterizing links between social relationships and cardiovascular health.

  4. Modified-BRISQUE as no reference image quality assessment for structural MR images.

    Science.gov (United States)

    Chow, Li Sze; Rajagopal, Heshalini

    2017-11-01

    An effective and practical Image Quality Assessment (IQA) model is needed to assess the image quality produced from any new hardware or software in MRI. A highly competitive No Reference - IQA (NR - IQA) model called Blind/Referenceless Image Spatial Quality Evaluator (BRISQUE) initially designed for natural images were modified to evaluate structural MR images. The BRISQUE model measures the image quality by using the locally normalized luminance coefficients, which were used to calculate the image features. The modified-BRISQUE model trained a new regression model using MR image features and Difference Mean Opinion Score (DMOS) from 775 MR images. Two types of benchmarks: objective and subjective assessments were used as performance evaluators for both original and modified-BRISQUE models. There was a high correlation between the modified-BRISQUE with both benchmarks, and they were higher than those for the original BRISQUE. There was a significant percentage improvement in their correlation values. The modified-BRISQUE was statistically better than the original BRISQUE. The modified-BRISQUE model can accurately measure the image quality of MR images. It is a practical NR-IQA model for MR images without using reference images. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Renal artery origins: best angiographic projection angles.

    Science.gov (United States)

    Verschuyl, E J; Kaatee, R; Beek, F J; Patel, N H; Fontaine, A B; Daly, C P; Coldwell, D M; Bush, W H; Mali, W P

    1997-10-01

    To determine the best projection angles for imaging the renal artery origins in profile. A mathematical model of the anatomy at the renal artery origins in the transverse plane was used to analyze the amount of aortic lumen that projects over the renal artery origins at various projection angles. Computed tomographic (CT) angiographic data about the location of 400 renal artery origins in 200 patients were statistically analyzed. In patients with an abdominal aortic diameter no larger than 3.0 cm, approximately 0.5 mm of the proximal part of the renal artery and origin may be hidden from view if there is a projection error of +/-10 degrees from the ideal image. A combination of anteroposterior and 20 degrees and 40 degrees left anterior oblique projections resulted in a 92% yield of images that adequately profiled the renal artery origins. Right anterior oblique projections resulted in the least useful images. An error in projection angle of +/-10 degrees is acceptable for angiographic imaging of the renal artery origins. Patients sex, site of interest (left or right artery), and local diameter of the abdominal aorta are important factors to consider.

  6. Preoperative evaluation of hepatic arterial and portal venous anatomy using the time resolved echo-shared MR angiographic technique in living liver donors

    International Nuclear Information System (INIS)

    Lee, Min Woo; Lee, Jeong Min; Lee, Jae Young; Kim, Se Hyung; Park, Eun-Ah; Han, Joon Koo; Choi, Jin-Young; Choi, Byung Ihn; Kim, Young Jun; Suh, Kyung-Suk

    2007-01-01

    The purpose of this study was to determine whether MR angiography utilizing the time resolved echo-shared angiographic technique (TREAT) can provide an effective assessment of the hepatic artery (HA) and portal vein (PV) in living donor candidates. MR angiography (MRA)was performed in 27 patients (23 men and 4 women; mean age, 31 years) by using TREAT. Two blinded radiologists evaluated HA anatomy, origin of segment IV feeding artery and PV anatomy in consensus. Qualitative evaluations of MRA images were performed using the following criteria: (a) overall image quality, (b) presence of artifacts, and (c) degree of venous contamination of the arterial phase. Using intraoperative findings as a standard of reference, the accuracy for the HA anatomy, origin of segment IV feeding artery and PV anatomy on TREAT-MRA were 93% (25/27), 85% (23/27), and 96% (26/27), respectively. Overall image qualities were as follows: excellent (n=22, 81%), good (n=4, 15%), and fair (n=1, 4%). Significant artifacts or venous contamination of the arterial phase images was not noted in any patient. TREAT-MRA can provide a complete evaluation of HA and PV anatomy during preoperative evaluation of living liver donors. Furthermore, it provides a more detailed anatomy of the HA without venous contamination. (orig.)

  7. Analysis of deep inferior epigastric perforator (DIEP) arteries by using MDCTA: Comparison between 2 post-processing techniques.

    Science.gov (United States)

    Saba, Luca; Atzeni, Matteo; Ribuffo, Diego; Mallarini, Giorgio; Suri, Jasjit S

    2012-08-01

    Our purpose was to compare two post-processing techniques, Maximum-Intensity-Projection (MIP) and Volume Rendering (VR) for the study of perforator arteries. Thirty patients who underwent Multi-Detector-Row CT Angiography (MDCTA) between February 2010 and May 2010 were retrospectively analyzed. For each patient and for each reconstruction method, the image quality was evaluated and the inter- and intra-observer agreement was calculated according to the Cohen statistics. The Hounsfield Unit (HU) value in the common femoral artery was quantified and the correlation (Pearson Statistic) between image quality and HU value was explored. The Pearson r between the right and left common femoral artery was excellent (r=0.955). The highest image quality score was obtained using MIP for both observers (total value 75, with a mean value 2.67 for observer 1 and total value of 79 and a mean value of 2.82 for observer 2). The highest agreement between the two observers was detected using the MIP protocol with a Cohen kappa value of 0.856. The ROC area under the curve (Az) for the VR is 0.786 (0.086 SD; p value=0.0009) whereas the ROC area under the curve (Az) for the MIP is 0.0928 (0.051 SD; p value=0.0001). MIP showed the optimal inter- and intra-observer agreement and the highest quality scores and therefore should be used as post-processing techniques in the analysis of perforating arteries. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  8. Anatomic characteristics and natural history of renal artery aneurysms during longitudinal imaging surveillance.

    Science.gov (United States)

    Wayne, Erik J; Edwards, Matthew S; Stafford, Jeanette M; Hansen, Kimberley J; Corriere, Matthew A

    2014-08-01

    Renal artery aneurysms (RAAs) are uncommon, and rates of growth and rupture are unknown. Limited evidence therefore exists to guide clinical management of RAAs, particularly small aneurysms that are asymptomatic. To further characterize the natural history of RAAs, we studied anatomic characteristics and changes in diameter during imaging surveillance. Patients evaluated for native RAAs at a single institution during a 5-year period (July 2008 to July 2013) were identified and analyzed retrospectively. Patients with two or more cross-sectional imaging studies (computed tomography or magnetic resonance imaging) more than 1 month apart were included. Demographic and clinical data were collected from medical records, and anatomic data (including aneurysm diameter, calcification, and location) were obtained from electronic images. Changes in RAA diameters over time were evaluated by plots and Wilcoxon signed rank tests. Sixty-eight RAAs in 55 patients were analyzed. Median follow-up was 19.4 months (interquartile range, 11.2-49.0 months). Mean age at presentation was 61.8 ± 9.8 years, and 73% of patients were women. Hypertension was prevalent among 73% of patients. Multiple RAAs were present in 18% of patients, and 24% also had arterial aneurysms of other splanchnic or iliac vessels. The majority of RAAs were calcified and located at the main renal artery bifurcation. Mean initial aneurysm diameter was 16.0 ± 6.4 mm. Median annualized growth rate was 0.06 mm (interquartile range, -0.07 to 0.33 mm; P = .11). No RAA ruptures or acute symptoms occurred during surveillance, and 10.3% of RAAs were repaired electively. Risk of short-term RAA growth or rupture was low. These findings suggest that annual (or less frequent) imaging surveillance is safe in the majority of patients and do not support pre-emptive repair of asymptomatic, small-diameter RAAs. Copyright © 2014 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.

  9. Exercise thallium-201 myocardial imaging in left main coronary artery disease: sensitive but not specific

    International Nuclear Information System (INIS)

    Rehn, T.; Griffith, L.S.; Achuff, S.C.; Bailey, I.K.; Bulkley, B.H.; Burow, R.; Pitt, B.; Becker, L.C.

    1981-01-01

    To determine the usefulness of thallium-201 scintigraphy for identifying left main coronary artery disease, the results of scintigraphy at rest and during exercise were compared in 24 patients with 50 percent or greater narrowing of the left main coronary artery and 80 patients with 50 percent or greater narrowing of one or more of the major coronary arteries but without left main coronary involvement. By segmental analysis of the scintigrams, perfusion defects were assigned to the left anterior descending, left circumflex or right coronary artery, singly or in combination, and the pattern of simultaneous left anterior descending and circumflex arterial defects was used to identify left main coronary artery disease. Of the 24 patients with left main coronary artery disease, 22 (92 percent) had abnormal exercise scintigrams. Despite this high sensitivity, the pattern of perfusion defects was not specific; the ''left main pattern'' was found in 3 patients (13 percent) with left main coronary artery disease but also in 3 (33 percent) of 9 patients with combined left anterior descending and left circumflex arterial disease, 4 (19 percent) of 21 patients with three vessel disease and 3 (6 percent) of 50 patients with one or two vessel disease but excluding the group with left anterior descending plus left circumflex arterial disease. The pattern of perfusion defects in the patients with left main coronary artery disease was determined by the location and severity of narrowings in the coronary arteries downstream from the left main arterial lesion. Concomitant lesions in other arteries were found in all patients with left main coronary disease (one vessel in 1 patient, two vessels in 7 patients and three vessels in 16). For this reason, it is unlikely that even with improvements in radiopharmaceutical agents and imaging techniques, myocardial perfusion scintigraphy will be sufficiently specific for definitive identification of left main coronary artery disease

  10. Comparison of exercise electrocardiography and quantitative thallium imaging for one-vessel coronary artery disease

    International Nuclear Information System (INIS)

    Kaul, S.; Kiess, M.; Liu, P.; Guiney, T.E.; Pohost, G.M.; Okada, R.D.; Boucher, C.A.

    1985-01-01

    The relative value of exercise electrocardiography and computer analyzed thallium-201 imaging was compared in 124 patients with 1-vessel coronary artery disease (CAD). Of these, 78 had left anterior descending (LAD), 32 right and 14 left circumflex (LC) CAD. In patients with no previous myocardial infarction (MI), thallium imaging was more sensitive than the electrocardiogram (78% vs 64%, p less than 0.01), but in patients with previous MI, sensitivity was similar. Further, thallium imaging was more sensitive only in LAD and LC disease. Redistribution was compared with ST-segment depression as a marker of ischemia. Only in patients with prior MI (76% vs 44%, p less than 0.01) and only in LC and right CAD did redistribution occur more often than ST depression. Thallium imaging was more accurate in localizing stenoses than the electrocardiogram (p less than 0.001), but did not always correctly predict coronary anatomy. Septal thallium defects were associated with LAD disease in 84%, inferior defects with right CAD in 40% and posterolateral lesion defects with LC CAD in 22%. The results indicate the overall superiority of thallium imaging in 1-vessel CAD compared with exercise electrocardiography; however, there is a wide spectrum of extent and location of perfusion defects associated with each coronary artery. Thallium imaging complements coronary angiography by demonstrating the functional impact of CAD on myocardial perfusion

  11. Quality assurance for image-guided radiotherapy

    International Nuclear Information System (INIS)

    Marinello, Ginette

    2008-01-01

    The topics discussed include, among others, the following: Quality assurance program; Image guided radiotherapy; Commissioning and quality assurance; Check of agreement between visual and displayed scales; quality controls: electronic portal imaging device (EPID), MV-kV and kV-kV, cone-beam CT (CBCT), patient doses. (P.A.)

  12. Automated registration of multispectral MR vessel wall images of the carotid artery

    Energy Technology Data Exchange (ETDEWEB)

    Klooster, R. van ' t; Staring, M.; Reiber, J. H. C.; Lelieveldt, B. P. F.; Geest, R. J. van der, E-mail: rvdgeest@lumc.nl [Department of Radiology, Division of Image Processing, Leiden University Medical Center, 2300 RC Leiden (Netherlands); Klein, S. [Department of Radiology and Department of Medical Informatics, Biomedical Imaging Group Rotterdam, Erasmus MC, Rotterdam 3015 GE (Netherlands); Kwee, R. M.; Kooi, M. E. [Department of Radiology, Cardiovascular Research Institute Maastricht, Maastricht University Medical Center, Maastricht 6202 AZ (Netherlands)

    2013-12-15

    Purpose: Atherosclerosis is the primary cause of heart disease and stroke. The detailed assessment of atherosclerosis of the carotid artery requires high resolution imaging of the vessel wall using multiple MR sequences with different contrast weightings. These images allow manual or automated classification of plaque components inside the vessel wall. Automated classification requires all sequences to be in alignment, which is hampered by patient motion. In clinical practice, correction of this motion is performed manually. Previous studies applied automated image registration to correct for motion using only nondeformable transformation models and did not perform a detailed quantitative validation. The purpose of this study is to develop an automated accurate 3D registration method, and to extensively validate this method on a large set of patient data. In addition, the authors quantified patient motion during scanning to investigate the need for correction. Methods: MR imaging studies (1.5T, dedicated carotid surface coil, Philips) from 55 TIA/stroke patients with ipsilateral <70% carotid artery stenosis were randomly selected from a larger cohort. Five MR pulse sequences were acquired around the carotid bifurcation, each containing nine transverse slices: T1-weighted turbo field echo, time of flight, T2-weighted turbo spin-echo, and pre- and postcontrast T1-weighted turbo spin-echo images (T1W TSE). The images were manually segmented by delineating the lumen contour in each vessel wall sequence and were manually aligned by applying throughplane and inplane translations to the images. To find the optimal automatic image registration method, different masks, choice of the fixed image, different types of the mutual information image similarity metric, and transformation models including 3D deformable transformation models, were evaluated. Evaluation of the automatic registration results was performed by comparing the lumen segmentations of the fixed image and

  13. Automated registration of multispectral MR vessel wall images of the carotid artery

    International Nuclear Information System (INIS)

    Klooster, R. van 't; Staring, M.; Reiber, J. H. C.; Lelieveldt, B. P. F.; Geest, R. J. van der; Klein, S.; Kwee, R. M.; Kooi, M. E.

    2013-01-01

    Purpose: Atherosclerosis is the primary cause of heart disease and stroke. The detailed assessment of atherosclerosis of the carotid artery requires high resolution imaging of the vessel wall using multiple MR sequences with different contrast weightings. These images allow manual or automated classification of plaque components inside the vessel wall. Automated classification requires all sequences to be in alignment, which is hampered by patient motion. In clinical practice, correction of this motion is performed manually. Previous studies applied automated image registration to correct for motion using only nondeformable transformation models and did not perform a detailed quantitative validation. The purpose of this study is to develop an automated accurate 3D registration method, and to extensively validate this method on a large set of patient data. In addition, the authors quantified patient motion during scanning to investigate the need for correction. Methods: MR imaging studies (1.5T, dedicated carotid surface coil, Philips) from 55 TIA/stroke patients with ipsilateral <70% carotid artery stenosis were randomly selected from a larger cohort. Five MR pulse sequences were acquired around the carotid bifurcation, each containing nine transverse slices: T1-weighted turbo field echo, time of flight, T2-weighted turbo spin-echo, and pre- and postcontrast T1-weighted turbo spin-echo images (T1W TSE). The images were manually segmented by delineating the lumen contour in each vessel wall sequence and were manually aligned by applying throughplane and inplane translations to the images. To find the optimal automatic image registration method, different masks, choice of the fixed image, different types of the mutual information image similarity metric, and transformation models including 3D deformable transformation models, were evaluated. Evaluation of the automatic registration results was performed by comparing the lumen segmentations of the fixed image and

  14. Evaluation of the renal venous system on late arterial and venous phase images with MDCT angiography in potential living laparoscopic renal donors

    International Nuclear Information System (INIS)

    Kawamoto, S.; Lawler, L.P.; Fishman, E.K.

    2005-01-01

    Objective: The objective of our study was to assess whether both renal arteries and renal veins can be evaluated using single-phase MDCT data sets alone to eliminate the need for both arterial and venous phase data sets. Materials and methods: One hundred consecutive potential living renal donors who underwent 4- MDCT were evaluated. CT was performed with 120 mL of IV contrast material at an injection rate of 3 mL/sec. Both late arterial and venous phase acquisitions were obtained at 25 and 55 sec from the start of IV contrast injection, respectively. The number of the right and left renal veins and its anatomic variations were assessed by two reviewers. Late arterial phase images were evaluated initially, and then venous phase images were analyzed to assess opacification of the renal vein and to see whether venous phase data sets changed or added information about the venous anatomy as seen on late arterial phase images. Results: The retroaortic left renal vein was found in two subjects, and the circumaortic left renal vein was detected in three subjects. The renal veins were adequately opacified on late arterial phase images in all subjects. There were six subjects who had a normal left renal vein with a small posterior branch coursing posterior to the aorta and draining into the inferior vena cava, which were difficult to differentiate from the lumbar vein or ascending lumbar vein; in three of these six subjects, the small posterior branch was opacified only on venous phase images. Conclusion: Late arterial phase images obtained at 25 sec after the start of contrast injection can reveal the renal vein anatomy except for a small posterior branch of the left renal vein difficult to differentiate from the lumbar or ascending lumbar vein, as seen in three subjects. The data suggest that venous phase imaging is not necessary for the evaluation of renal vein anatomy. (author)

  15. Evaluation of the renal venous system on late arterial and venous phase images with MDCT angiography in potential living laparoscopic renal donors

    Energy Technology Data Exchange (ETDEWEB)

    Kawamoto, S.; Lawler, L.P.; Fishman, E.K. [Johns Hopkins Hospital, Baltimore, MD (United States). The Russell H. Morgan Department of Radiology and Radiological Science

    2005-03-15

    Objective: The objective of our study was to assess whether both renal arteries and renal veins can be evaluated using single-phase MDCT data sets alone to eliminate the need for both arterial and venous phase data sets. Materials and methods: One hundred consecutive potential living renal donors who underwent 4- MDCT were evaluated. CT was performed with 120 mL of IV contrast material at an injection rate of 3 mL/sec. Both late arterial and venous phase acquisitions were obtained at 25 and 55 sec from the start of IV contrast injection, respectively. The number of the right and left renal veins and its anatomic variations were assessed by two reviewers. Late arterial phase images were evaluated initially, and then venous phase images were analyzed to assess opacification of the renal vein and to see whether venous phase data sets changed or added information about the venous anatomy as seen on late arterial phase images. Results: The retroaortic left renal vein was found in two subjects, and the circumaortic left renal vein was detected in three subjects. The renal veins were adequately opacified on late arterial phase images in all subjects. There were six subjects who had a normal left renal vein with a small posterior branch coursing posterior to the aorta and draining into the inferior vena cava, which were difficult to differentiate from the lumbar vein or ascending lumbar vein; in three of these six subjects, the small posterior branch was opacified only on venous phase images. Conclusion: Late arterial phase images obtained at 25 sec after the start of contrast injection can reveal the renal vein anatomy except for a small posterior branch of the left renal vein difficult to differentiate from the lumbar or ascending lumbar vein, as seen in three subjects. The data suggest that venous phase imaging is not necessary for the evaluation of renal vein anatomy. (author)

  16. Advanced image-based virtual monoenergetic dual-energy CT angiography of the abdomen: optimization of kiloelectron volt settings to improve image contrast

    International Nuclear Information System (INIS)

    Albrecht, Moritz H.; Scholtz, Jan-Erik; Huesers, Kristina; Beeres, Martin; Bucher, Andreas M.; Kaup, Moritz; Martin, Simon S.; Fischer, Sebastian; Bodelle, Boris; Bauer, Ralf W.; Lehnert, Thomas; Vogl, Thomas J.; Wichmann, Julian L.

    2016-01-01

    To compare quantitative image quality parameters in abdominal dual-energy computed tomography angiography (DE-CTA) using an advanced image-based (Mono+) reconstruction algorithm for virtual monoenergetic imaging and standard DE-CTA. Fifty-five patients (36 men; mean age, 64.2 ± 12.7 years) who underwent abdominal DE-CTA were retrospectively included. Mono + images were reconstructed at 40, 50, 60, 70, 80, 90 and 100 keV levels and as standard linearly blended M 0 .6 images (60 % 100 kV, 40 % 140 kV). The contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR) of the common hepatic (CHA), splenic (SA), superior mesenteric (SMA) and left renal arteries (LRA) were objectively measured. Mono+ DE-CTA series showed a statistically superior CNR for 40, 50, 60, 70 and 80 keV (P < 0.031) compared to M 0 .6 images for all investigated arteries except SMA at 80 keV (P = 0.08). CNR at 40 keV revealed a mean relative increase of 287.7 % compared to linearly blended images among all assessed arteries (P < 0.001). SNR of Mono+ images was consistently significantly higher at 40, 50, 60 and 70 keV compared to M 0 .6 for CHA and SA (P < 0.009). Compared to linearly blended images, Mono+ reconstructions at low keV levels of abdominal DE-CTA datasets significantly improve quantitative image quality. (orig.)

  17. Intracoronary imaging using attenuation-compensated optical coherence tomography allows better visualisation of coronary artery diseases

    Energy Technology Data Exchange (ETDEWEB)

    Foin, Nicolas, E-mail: nicolas.foin@gmail.com [International Centre for Circulatory Health, Imperial College London, W2 1LA London (United Kingdom); Mari, Jean Martial [University College London, London (United Kingdom); Nijjer, Sukhjinder; Sen, Sayan; Petraco, Ricardo [International Centre for Circulatory Health, Imperial College London, W2 1LA London (United Kingdom); Ghione, Matteo; Di Mario, Carlo [Biomedical Research Unit, Royal Brompton Hospital, London (United Kingdom); Davies, Justin E. [International Centre for Circulatory Health, Imperial College London, W2 1LA London (United Kingdom); Girard, Michaël J.A. [Department of Bioengineering, National University of Singapore (Singapore); Singapore Eye Research Institute (Singapore)

    2013-05-15

    Purpose: To allow an accurate diagnosis of coronary artery diseases by enhancing optical coherence tomography (OCT) images of atheromatous plaques using a novel automated attenuation compensation technique. Background: One of the major drawbacks of coronary OCT imaging is the rapid attenuation of the OCT signal, limiting penetration in tissue to only few millimetres. Visualisation of deeper anatomy is however critical for accurate assessment of plaque burden in-vivo. Methods: A compensation algorithm, previously developed to correct for light attenuation in soft tissues and to enhance contrast in ophthalmic OCT images, was applied to intracoronary plaque imaging using spectral-domain OCT. Results: Application of the compensation algorithm significantly increased tissue contrast in the vessel wall and atherosclerotic plaque boundaries. Contrast enhancement allows a better differentiation of plaque morphology, which is particularly important for the identification of lipid rich fibro atheromatous plaques and to guide decision on treatment strategy. Conclusion: The analysis of arterial vessel structure clinically captured with OCT is improved when used in conjunction with automated attenuation compensation. This approach may improve the OCT-based interpretation of coronary plaque morphology in clinical practice.

  18. Visceral angiography with intra-arterial DSA and a programmed 100 mm technique

    International Nuclear Information System (INIS)

    Triller, J.; Ackermann, B.; Jung, H.

    1988-01-01

    One hundred and seventy specially selected visceral angiograms were carried out of 96 patients using I-A DSA and 100 mm technique. 85.2% of the I-A DSA and 91.7% of the 100 mm images were of good quality. I-A DSA produced comparable or better quality than the 100 mm technique in 66% during the arterial phase, in 79% during the paranchymatous phase and in 70% during the venous phase. The 100 mm technique produced better quality in a third of the cases during the arterial phase and in a quarter of the cases during the parenchymal and venous phases. The indications for the 100 mm technique are failure of I-A DSA or the need for high spatial resolution. (orig.) [de

  19. Image quality and dose in computed tomography

    International Nuclear Information System (INIS)

    Jurik, A.G.; Jessen, K.A.; Hansen, J.

    1997-01-01

    Radiation exposure to the patient during CT is relatively high, and it is therefore important to optimize the dose so that it is as low as possible but still consistent with required diagnostic image quality. There is no established method for measuring diagnostic image quality; therefore, a set of image quality criteria which must be fulfilled for optimal image quality was defined for the retroperitoneal space and the mediastinum. The use of these criteria for assessment of image quality was tested based on 113 retroperitoneal and 68 mediastinal examinations performed in seven different CT units. All the criteria, except one, were found to be usable for measuring diagnostic image quality. The fulfilment of criteria was related to the radiation dose given in the different departments. By examination of the retroperitoneal space the effective dose varied between 5.1 and 20.0 mSv (milli Sievert), and there was a slight correlation between dose and high percent of ''yes'' score for the image quality criteria. For examination of the mediastinum the dose range was 4.4-26.5 mSv, and there was no significant increment of image quality at high doses. The great variation of dose at different CT units was due partly to differences regarding the examination procedure, especially the number of slices and the mAs (milli ampere second), but inherent dose variation between different scanners also played a part. (orig.). With 6 figs., 6 tabs

  20. Comparisons of carotid artery stenting and carotid endoarterectomy in terms of diffusion-weighted MR imaging

    International Nuclear Information System (INIS)

    Mitsuoka, Hiroshi; Shintani, Tsunehiro; Masuda, Mikio; Higashi, Shigeki

    2009-01-01

    The objective of this study was to compare two methods of treatment for carotid arterial stenosis, carotid endarterectomy (CEA) and carotid artery stenting (CAS), by means of diffusion-weighted MR imaging (DWI). Nineteen treatments in 18 cases during the 2007 academic year were included in this study. CAS was performed for 9 cases with 10 lesions (10 procedures), while 9 cases with 9 lesions (9 procedures) were treated by CEA. Patients were examined by a neurologist before and after the procedure, and had pre- and post-procedural DWI. No strokes or transient ischemic attacks (TIAs) were observed in these cases. New DWI lesions were found in 7 out of the 10 procedures of CAS imaged 24 hours postprocedure, (average: 2.0 lesions). No new lesions were detected on DWI of CEA cases (χ 2 =8.33, p=0.0039). Certain high-risk subsets may respond well to CAS with a very low incidence of clinically-evident neurologic events, but with significantly higher incidence of periprocedural micro-brain embolism. Currently, CEA should be the first choice of treatment for atherosclerotic carotid artery stenosis. (author)

  1. Prognostic value of gated 201Tl myocardial perfusion SPECT imaging in patients with coronary artery disease

    International Nuclear Information System (INIS)

    Li Zicheng; Chen Xiaoming; Xu Hao

    2006-01-01

    Objective: To study the prognostic value of gated 201 Tl myocardial perfusion SPECT imaging in patients with coronary artery disease and assessment of therapy strategy for the individual patient. Methods: Eighty-four patients underwent rest and exercise stress 201 Tl gated myocardial perfusion SPECT imaging and were followed up for (32.92 ± 16.77) months. Images were studied using 17 segments and 1 to 4 scoring. Global summed stress score (SSS), summed rest score (SRS) and summed difference score (SDS=SSS-SRS) were also calculated. Post-stress and rest ejection fraction (EF) were automatically measured. Results: Nine cardiac events occurred (3.90% per year). SSS, SDS, SRS and EF were the independent predictors of cardiac events (P 201 Tl myocardial perfusion SPECT imaging can provide prognostic assessment for the patients with coronary artery disease and guide in selection of therapeutic strategy. Among all of the indices SSS is the best predictors of cardiac events. (authors)

  2. Retinal image quality assessment based on image clarity and content

    Science.gov (United States)

    Abdel-Hamid, Lamiaa; El-Rafei, Ahmed; El-Ramly, Salwa; Michelson, Georg; Hornegger, Joachim

    2016-09-01

    Retinal image quality assessment (RIQA) is an essential step in automated screening systems to avoid misdiagnosis caused by processing poor quality retinal images. A no-reference transform-based RIQA algorithm is introduced that assesses images based on five clarity and content quality issues: sharpness, illumination, homogeneity, field definition, and content. Transform-based RIQA algorithms have the advantage of considering retinal structures while being computationally inexpensive. Wavelet-based features are proposed to evaluate the sharpness and overall illumination of the images. A retinal saturation channel is designed and used along with wavelet-based features for homogeneity assessment. The presented sharpness and illumination features are utilized to assure adequate field definition, whereas color information is used to exclude nonretinal images. Several publicly available datasets of varying quality grades are utilized to evaluate the feature sets resulting in area under the receiver operating characteristic curve above 0.99 for each of the individual feature sets. The overall quality is assessed by a classifier that uses the collective features as an input vector. The classification results show superior performance of the algorithm in comparison to other methods from literature. Moreover, the algorithm addresses efficiently and comprehensively various quality issues and is suitable for automatic screening systems.

  3. REMOTE SENSING IMAGE QUALITY ASSESSMENT EXPERIMENT WITH POST-PROCESSING

    Directory of Open Access Journals (Sweden)

    W. Jiang

    2018-04-01

    Full Text Available This paper briefly describes the post-processing influence assessment experiment, the experiment includes three steps: the physical simulation, image processing, and image quality assessment. The physical simulation models sampled imaging system in laboratory, the imaging system parameters are tested, the digital image serving as image processing input are produced by this imaging system with the same imaging system parameters. The gathered optical sampled images with the tested imaging parameters are processed by 3 digital image processes, including calibration pre-processing, lossy compression with different compression ratio and image post-processing with different core. Image quality assessment method used is just noticeable difference (JND subject assessment based on ISO20462, through subject assessment of the gathered and processing images, the influence of different imaging parameters and post-processing to image quality can be found. The six JND subject assessment experimental data can be validated each other. Main conclusions include: image post-processing can improve image quality; image post-processing can improve image quality even with lossy compression, image quality with higher compression ratio improves less than lower ratio; with our image post-processing method, image quality is better, when camera MTF being within a small range.

  4. Subjective matters: from image quality to image psychology

    Science.gov (United States)

    Fedorovskaya, Elena A.; De Ridder, Huib

    2013-03-01

    From the advent of digital imaging through several decades of studies, the human vision research community systematically focused on perceived image quality and digital artifacts due to resolution, compression, gamma, dynamic range, capture and reproduction noise, blur, etc., to help overcome existing technological challenges and shortcomings. Technological advances made digital images and digital multimedia nearly flawless in quality, and ubiquitous and pervasive in usage, provide us with the exciting but at the same time demanding possibility to turn to the domain of human experience including higher psychological functions, such as cognition, emotion, awareness, social interaction, consciousness and Self. In this paper we will outline the evolution of human centered multidisciplinary studies related to imaging and propose steps and potential foci of future research.

  5. The clinical application value of myocardial perfusion imaging in evaluating coronary artery myocardial bridge patients with symptoms

    International Nuclear Information System (INIS)

    Wang Yuetao; Fu Ning; Ding Xuemei; Lu Cunzhi; Zhu Feng; Wang Guanmin; Huang Yijie; Wang Linguang

    2008-01-01

    Objective: Myocardial bridge is a common inborn coronary artery anomaly, myocardial bridge may be associated with myocardial ischemia. Only a few patients with coronary artery myocardial bridge were evaluated with nuclear medicine techniques. The aim of this study was to investigate the role of nuclear cardiology with myocardial perfusion technique in symptomatic myocardial bridge patients. Methods Nineteen myocardial bridge patients with the symptoms of chest pain and chest distress were analyzed retrospectively. 99 Tc m -methoxyisobutylisonitrile (MIBI) myocardial perfusion images (both exercise and rest) were performed in all. Imaging results were compared with the results of movement electrocardiogram (ECG) and coronary arteriography. The t test or χ 2 test was used to statistically analyze the data with Stata 7.0 software. Results: Of the 19 patients, 18 patients had myocardial bridge locating at the left anterior descending artery, 1 patient at the left anterior descending and left circumflex artery, the mean angiographic systolic occlusion within the myocardial bridge was (65.4 ± 22.1)%. Of these 19 patients, Exercise-rest 99 Tc m -MIBI myocardial perfusion imaging defined positive myocardial ischemia in 10 and negative in 9 patients. Of the 10 patients with 99 Tc m -MIBI myocardial perfusion imaging defined myocardial ischemia, 8 had reversible radioactive defect of partial anterior wall and (or) apex, 1 had reversible defect of post lateral wall and post septal wall, and 1 had reversible defect of inferior wall. The positive predictive value of myocardial perfusion imaging was 52.6% (10/19), which was higher than movement ECG [21.1% (4/19), χ 2 = 4.07, P 99 Tc m -MIBI myocardial periusion imaging defined myocardial ischemia. Six cases with Grade II stenosis, two were 99 Tc m -MIBI myocardial perfusion imaging defined myocardial ischemia. Eight cases with Grade III stenosis, seven were 99 Tc m -MIBI myocardial perfusion imaging defined myocardial

  6. Effectiveness of Using Dual-source CT and the Upshot it creates on Both Heart Rate and Image Quality

    Directory of Open Access Journals (Sweden)

    Tuba Selçuk

    2016-06-01

    Full Text Available Background: Early detection of coronary artery disease (CAD is important because of the high morbidity and mortality rates. As invasive coronary angiography (ICA is an invasive procedure, an alternative diagnostic method; coronary computed tomography angiography (CTA, has become more widely used by the improvements in detector technology. Aims: In this study, we aimed to examine the accuracy and image quality of high-pitch 128-slice dual-source CTA taking the ICA as reference technique. We also aimed to compare the accuracy and image quality between different heart rate groups of >70 beates per minute (bpm and ≤70 bpm. Study Design: Retrospective cross-sectional study. Methods: Among 450 patients who underwent coronary CTA with the FLASH spiral technique, performed with a second generation dual-source computed tomography device with a pitch value of 3.2, 102 patients without stent and/or bypass surgery history and clinically suspected coronary artery disease who underwent ICA within 15 days were enrolled. Image quality was assessed by two independent radiologists using a 4-point scale (1=absence of any artifacts- 4=non-evaluable. A stenosis >50% was considered significant on a per-segment, per-vessel, and per-patient basis and ICA was considered the reference method. Radiation doses were determined using dose length product (DLP values detected by the computed tomography (CT device. In addition, patients were classified into two groups according to their heart rates as ≤70 bpm (73 patients and >70 bpm (29 patients. The relation between the diagnostic accuracy and heart rate groups were evaluated. Results: Overall, 1495 (98% coronary segments were diagnostic in 102 patients (32 male, 70 female, mean heart rate: 65 bpm. There was a significant correlation between image quality and mean heart rate in the right coronary artery (RCA segments. The effective radiation dose was 0.98±0.09 mili Sievert (mSv. On a per-patient basis, sensitivity

  7. Arterial spin-labeling perfusion imaging of childhood meningitis: a case series.

    Science.gov (United States)

    Wong, Alex Mun-Ching; Yeh, Chih-Hua; Liu, Ho-Ling; Lin, Kuang-Lin; Wang, Huei-Shyong; Toh, Cheng-Hong

    2016-03-01

    Conventional magnetic resonance imaging (MRI), which is mainly used to detect complications, is ineffective in determining the neurological status of patients with meningitis. Hemodynamic change in the brain may be more indicative of the neurological status but few imaging studies have verified this. Arterial spin-labeling (ASL) perfusion, a noninvasive MR method requiring no contrast agent injection, can be used to measure cerebral blood flow (CBF). We describe three pediatric patients with meningitis, who all showed regions of increased CBF on perfusion imaging. One patient, presenting with headache and conscious disturbance, had CBF changes in the frontal, temporal, and occipital regions. The other two patients, presenting with hallucinations, memory deficits, and seizures, had CBF changes in the frontal and temporal regions. ASL perfusion imaging may be helpful in assessing patients with meningitis, demonstrating CBF changes more strongly correlating with the neurological status, and detecting active brain abnormalities.

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

    Energy Technology Data Exchange (ETDEWEB)

    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)

  9. Proceedings of Joint International Symposium on the role of noninvasive imaging modalities in clinical decision making of coronary artery disease

    International Nuclear Information System (INIS)

    Mena, I.G.; Strauss, H.W.

    1986-01-01

    This report contains ten papers on the use of noninvasive imaging in clinical diagnosis and decision making. Topics include a cost analysis of magnetic resonance imaging in medical technology, diagnostic uses of MRI in chronic coronary artery disease, clinical applications of cine computed tomography, the use of PET as a clinical tool, and the use of echocardiography in coronary artery disease. Individual papers are processed separately for the data base

  10. Improving the Image Quality of Synthetic Transmit Aperture Ultrasound Images - Achieving Real-Time In-Vivo Imaging

    DEFF Research Database (Denmark)

    Gammelmark, Kim

    in-vivo experiments, showed, that TMS imaging can increase the SNR by as much as 17 dB compared to the traditional imaging techniques, which improves the in-vivo image quality to a highly competitive level. An in-vivo evaluation of convex array TMS imaging for abdominal imaging applications......-vivo imaging, and that the obtained image quality is highly competitive with the techniques applied in current medical ultrasound scanners. Hereby, the goals of the PhD have been successfully achieved.......Synthetic transmit aperture (STA) imaging has the potential to increase the image quality of medical ultrasound images beyond the levels obtained by conventional imaging techniques (linear, phased, and convex array imaging). Currently, however, in-vivo applications of STA imaging is limited...

  11. A hybrid image fusion system for endovascular interventions of peripheral artery disease.

    Science.gov (United States)

    Lalys, Florent; Favre, Ketty; Villena, Alexandre; Durrmann, Vincent; Colleaux, Mathieu; Lucas, Antoine; Kaladji, Adrien

    2018-03-16

    Interventional endovascular treatment has become the first line of management in the treatment of peripheral artery disease (PAD). However, contrast and radiation exposure continue to limit the feasibility of these procedures. This paper presents a novel hybrid image fusion system for endovascular intervention of PAD. We present two different roadmapping methods from intra- and pre-interventional imaging that can be used either simultaneously or independently, constituting the navigation system. The navigation system is decomposed into several steps that can be entirely integrated within the procedure workflow without modifying it to benefit from the roadmapping. First, a 2D panorama of the entire peripheral artery system is automatically created based on a sequence of stepping fluoroscopic images acquired during the intra-interventional diagnosis phase. During the interventional phase, the live image can be synchronized on the panorama to form the basis of the image fusion system. Two types of augmented information are then integrated. First, an angiography panorama is proposed to avoid contrast media re-injection. Information exploiting the pre-interventional computed tomography angiography (CTA) is also brought to the surgeon by means of semiautomatic 3D/2D registration on the 2D panorama. Each step of the workflow was independently validated. Experiments for both the 2D panorama creation and the synchronization processes showed very accurate results (errors of 1.24 and [Formula: see text] mm, respectively), similarly to the registration on the 3D CTA (errors of [Formula: see text] mm), with minimal user interaction and very low computation time. First results of an on-going clinical study highlighted its major clinical added value on intraoperative parameters. No image fusion system has been proposed yet for endovascular procedures of PAD in lower extremities. More globally, such a navigation system, combining image fusion from different 2D and 3D image

  12. Role of magnetic resonance imaging in patient selection for uterine artery embolization

    International Nuclear Information System (INIS)

    Cura, M.; Cura, A.; Bugnone, A.

    2006-01-01

    Uterine fibroids are common tumors of the female pelvis. Uterine artery embolization (UAE) is an effective treatment of symptomatic uterine leiomyoma in the appropriate candidates, reducing or eliminating leiomyoma-related symptoms of bleeding, bulk, and/or pain. Magnetic resonance imaging (MRI) can be used to assess women with symptoms potentially attributable to uterine leiomyomas, and help to determine who is an appropriate candidate for UAE. Because of soft tissue characterization, multiplanar imaging capabilities, and enhancement, MR imaging not only accurately detects and characterizes uterine leiomyomas but also may predict who will benefit from the embolization. MRI ability to detect coexistent uterine or pelvic pathology may change the diagnosis and treatment management of patients being evaluated for UAE

  13. Role of magnetic resonance imaging in patient selection for uterine artery embolization

    Energy Technology Data Exchange (ETDEWEB)

    Cura, M.; Cura, A.; Bugnone, A. [Univ. of Texas Health Science Center, San Antonio, TX (United States). Dept. of Radiology

    2006-12-15

    Uterine fibroids are common tumors of the female pelvis. Uterine artery embolization (UAE) is an effective treatment of symptomatic uterine leiomyoma in the appropriate candidates, reducing or eliminating leiomyoma-related symptoms of bleeding, bulk, and/or pain. Magnetic resonance imaging (MRI) can be used to assess women with symptoms potentially attributable to uterine leiomyomas, and help to determine who is an appropriate candidate for UAE. Because of soft tissue characterization, multiplanar imaging capabilities, and enhancement, MR imaging not only accurately detects and characterizes uterine leiomyomas but also may predict who will benefit from the embolization. MRI ability to detect coexistent uterine or pelvic pathology may change the diagnosis and treatment management of patients being evaluated for UAE.

  14. Technique for arterial-phase contrast-enhanced three-dimensional MR angiography of the carotid and vertebral arteries.

    Science.gov (United States)

    Isoda, H; Takehara, Y; Isogai, S; Takeda, H; Kaneko, M; Nozaki, A; Sun, Y; Foo, T K

    1998-08-01

    Our goal was to evaluate whether contrast-enhanced three-dimensional MR angiography using the MR Smartprep technique would enable us to obtain arterial-phase MR angiograms of the carotid and vertebral arteries. The study included 35 patients with suspected lesions of the neck in whom the MR Smartprep technique was used for MR angiography performed with a 1.5-T superconducting system. The tracker volume was placed primarily in the middle part of the right common carotid artery. The imaging volume was placed in a coronal direction to include the carotid and vertebral arteries from the aortic arch to the skull base. A centric phase-ordering scheme was used. Imaging times were 20 to 38 seconds for 14 patients and 11 to 16 seconds for 21 patients. By using a smaller tracker volume and an imaging time of less than 16 seconds, we were able to achieve a 100% successful triggering rate and to delineate selectively arterial-phase carotid and vertebral arteries with almost no venous contamination. Contract-enhanced 3-D MR angiography with the MR Smartprep technique was useful for showing arterial-phase carotid and vertebral arteries selectively.

  15. No-reference image quality assessment for horizontal-path imaging scenarios

    Science.gov (United States)

    Rios, Carlos; Gladysz, Szymon

    2013-05-01

    There exist several image-enhancement algorithms and tasks associated with imaging through turbulence that depend on defining the quality of an image. Examples include: "lucky imaging", choosing the width of the inverse filter for image reconstruction, or stopping iterative deconvolution. We collected a number of image quality metrics found in the literature. Particularly interesting are the blind, "no-reference" metrics. We discuss ways of evaluating the usefulness of these metrics, even when a fully objective comparison is impossible because of the lack of a reference image. Metrics are tested on simulated and real data. Field data comes from experiments performed by the NATO SET 165 research group over a 7 km distance in Dayton, Ohio.

  16. Predictors of image quality of coronary computed tomography in the acute care setting of patients with chest pain

    Energy Technology Data Exchange (ETDEWEB)

    Bamberg, Fabian; Abbara, Suhny; Schlett, Christopher L.; Cury, Ricardo C.; Truong, Quynh A.; Rogers, Ian S. [Cardiac MR PET CT Program, Department of Radiology and Division of Cardiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States); Nagurney, John T. [Department of Emergency Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States); Brady, Thomas J. [Cardiac MR PET CT Program, Department of Radiology and Division of Cardiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States); Hoffmann, Udo [Cardiac MR PET CT Program, Department of Radiology and Division of Cardiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States)], E-mail: uhoffmann@partners.org

    2010-04-15

    Objective: We aimed to determine predictors of image quality in consecutive patients who underwent coronary computed tomography (CT) for the evaluation of acute chest pain. Method and materials: We prospectively enrolled patients who presented with chest pain to the emergency department. All subjects underwent contrast-enhanced 64-slice coronary multi-detector CT. Two experienced readers determined overall image quality on a per-patient basis and the prevalence and characteristics of non-evaluable coronary segments on a per-segment basis. Results: Among 378 subjects (143 women, age: 52.9 {+-} 11.8 years), 345 (91%) had acceptable overall image quality, while 33 (9%) had poor image quality or were unreadable. In adjusted analysis, patients with diabetes, hypertension and a higher heart rate during the scan were more likely to have exams graded as poor or unreadable (odds ratio [OR]: 2.94, p = 0.02; OR: 2.62, p = 0.03; OR: 1.43, p = 0.02; respectively). Of 6253 coronary segments, 257 (4%) were non-evaluable, most due to severe calcification in combination with motion (35%). The presence of non-evaluable coronary segments was associated with age (OR: 1.08 annually, 95%-confidence interval [CI]: 1.05-1.12, p < 0.001), baseline heart rate (OR: 1.35 per 10 beats/min, 95%-CI: 1.11-1.67, p = 0.003), diabetes, hypertension, and history of coronary artery disease (OR: 4.43, 95%-CI: 1.93-10.17, p < 0.001; OR: 2.27, 95-CI: 1.01-4.73, p = 0.03; OR: 5.12, 95%-CI: 2.0-13.06, p < 0.001; respectively). Conclusion: Coronary CT permits acceptable image quality in more than 90% of patients with chest pain. Patients with multiple risk factors are more likely to have impaired image quality or non-evaluable coronary segments. These patients may require careful patient preparation and optimization of CT scanning protocols.

  17. Daily Marital Interaction Quality and Carotid Artery Intima Medial Thickness in Healthy Middle Aged Adults

    Science.gov (United States)

    Joseph, Nataria T.; Kamarck, Thomas W.; Muldoon, Matthew F.; Manuck, Stephen B.

    2014-01-01

    Objective To examine the association between marital interaction quality during daily life and subclinical cardiovascular disease (CVD). Studies have shown that marital status and quality of marriage are associated with cardiovascular health. However, little is known about the role of marital interaction quality during daily life in contributing to these effects. Methods The sample consisted of 281 healthy, employed middle-aged adults who were married or living with a partner in a marital-like relationship (mean age = 42.0 years, 88% white, 52% men). Marital interaction quality was assessed using hourly real-time Ecological Momentary Assessments (EMAs) for 4 days, with participants rating their current or recent partner interactions on positive and negative characteristics (e.g., agreeableness and conflict). Carotid artery intima medial thickness (IMT) was assessed using ultrasound imaging. Results Adjusting for demographics, positive marital interaction was inversely associated with IMT, [b = −.02 F(1, 275) = 9.18, p = .002], and negative marital interaction was positively associated with IMT, [b = .02 F(1, 275) = 10.29, p = .001]. These associations were not accounted for by behavioral and biological cardiovascular disease (CVD) risk factors and were consistent across age, sex, race, and education. The associations were also independent of marital interaction frequency, nonmarital social interaction quality, and personality factors. Global reports of marital quality, in contrast, were not associated with IMT. Conclusions Marital quality as measured during real-time interactions between partners was associated with subclinical cardiovascular disease in healthy middle-aged adults. This study supports the utility of real-time social interaction assessment for characterizing links between social relationships and cardiovascular health. PMID:24915293

  18. Application of computed tomography virtual noncontrast spectral imaging in evaluation of hepatic metastases: a preliminary study.

    Science.gov (United States)

    Tian, Shi-Feng; Liu, Ai-Lian; Liu, Jing-Hong; Sun, Mei-Yu; Wang, He-Qing; Liu, Yi-Jun

    2015-03-05

    The objective was to qualitatively and quantitatively evaluate hepatic metastases using computed tomography (CT) virtual noncontrast (VNC) spectral imaging in a retrospective analysis. Forty hepatic metastases patients underwent CT scans including the conventional true noncontrast (TNC) and the tri-phasic contrast-enhanced dual energy spectral scans in the hepatic arterial, portal venous, and equilibrium phases. The tri-phasic spectral CT images were used to obtain three groups of VNC images including in the arterial (VNCa), venous (VNCv), and equilibrium (VNCe) phase by the material decomposition process using water and iodine as a base material pair. The image quality and the contrast-to-noise ratio (CNR) of metastasis of the four groups were compared with ANOVA analysis. The metastasis detection rates with the four nonenhanced image groups were calculated and compared using the Chi-square test. There were no significant differences in image quality among TNC, VNCa and VNCv images (P > 0.05). The quality of VNCe images was significantly worse than that of other three groups (P 0.05). The metastasis detection rate of the four nonenhanced groups with no statistically significant difference (P > 0.05). The quality of VNCa and VNCv images is identical to that of TNC images, and the metastasis detection rate in VNC images is similar to that in TNC images. VNC images obtained from arterial phase show metastases more clearly. Thus, VNCa imaging may be a surrogate to TNC imaging in hepatic metastasis diagnosis.

  19. Application of Computed Tomography Virtual Noncontrast Spectral Imaging in Evaluation of Hepatic Metastases: A Preliminary Study

    Directory of Open Access Journals (Sweden)

    Shi-Feng Tian

    2015-01-01

    Full Text Available Objective: The objective was to qualitatively and quantitatively evaluate hepatic metastases using computed tomography (CT virtual noncontrast (VNC spectral imaging in a retrospective analysis. Methods: Forty hepatic metastases patients underwent CT scans including the conventional true noncontrast (TNC and the tri-phasic contrast-enhanced dual energy spectral scans in the hepatic arterial, portal venous, and equilibrium phases. The tri-phasic spectral CT images were used to obtain three groups of VNC images including in the arterial (VNCa, venous (VNCv, and equilibrium (VNCe phase by the material decomposition process using water and iodine as a base material pair. The image quality and the contrast-to-noise ratio (CNR of metastasis of the four groups were compared with ANOVA analysis. The metastasis detection rates with the four nonenhanced image groups were calculated and compared using the Chi-square test. Results: There were no significant differences in image quality among TNC, VNCa and VNCv images (P > 0.05. The quality of VNCe images was significantly worse than that of other three groups (P 0.05. The metastasis detection rate of the four nonenhanced groups with no statistically significant difference (P > 0.05. Conclusions: The quality of VNCa and VNCv images is identical to that of TNC images, and the metastasis detection rate in VNC images is similar to that in TNC images. VNC images obtained from arterial phase show metastases more clearly. Thus, VNCa imaging may be a surrogate to TNC imaging in hepatic metastasis diagnosis.

  20. The effect of image sharpness on quantitative eye movement data and on image quality evaluation while viewing natural images

    Science.gov (United States)

    Vuori, Tero; Olkkonen, Maria

    2006-01-01

    The aim of the study is to test both customer image quality rating (subjective image quality) and physical measurement of user behavior (eye movements tracking) to find customer satisfaction differences in imaging technologies. Methodological aim is to find out whether eye movements could be quantitatively used in image quality preference studies. In general, we want to map objective or physically measurable image quality to subjective evaluations and eye movement data. We conducted a series of image quality tests, in which the test subjects evaluated image quality while we recorded their eye movements. Results show that eye movement parameters consistently change according to the instructions given to the user, and according to physical image quality, e.g. saccade duration increased with increasing blur. Results indicate that eye movement tracking could be used to differentiate image quality evaluation strategies that the users have. Results also show that eye movements would help mapping between technological and subjective image quality. Furthermore, these results give some empirical emphasis to top-down perception processes in image quality perception and evaluation by showing differences between perceptual processes in situations when cognitive task varies.

  1. Quality of radiation field imaging

    International Nuclear Information System (INIS)

    Petr, I.

    1988-01-01

    The questions were studied of the quality of imaging the gamma radiation field and of the limits of the quality in directional detector scanning. A resolution angle was introduced to quantify the imaging quality, and its relation was sought with the detection effective half-angle of the directional detector. The resolution angle was defined for the simplest configuration of the radiation field consisting of two monoenergetic gamma beams in one plane. It was shown that the resolution angle decreases, i.e., resolution in imaging the radiation field is better, with the effective half-angle of the directional detector. It was also found that resolution of both gamma beams deteriorated when the beams were surrounded with an isotropic background field. If the beams are surrounded with a background field showing general distribution, the angle size will be affected not only by the properties of the detector but also by the distribution of the ambient radiation field and the method of its scanning. The method described can be applied in designing a directional detector necessary for imaging the presumed radiation field in the required quality. (Z.M.). 4 figs., 3 refs

  2. Quality assessment for online iris images

    CSIR Research Space (South Africa)

    Makinana, S

    2015-01-01

    Full Text Available Iris recognition systems have attracted much attention for their uniqueness, stability and reliability. However, performance of this system depends on quality of iris image. Therefore there is a need to select good quality images before features can...

  3. The usefulness of the ivy sign on fluid-attenuated intensity recovery images in improved brain hemodynamic changes after superficial temporal artery-middle cerebral artery anastomosis in adult patients with moyamoya disease.

    Science.gov (United States)

    Lee, Jung Keun; Yoon, Byul Hee; Chung, Seung Young; Park, Moon Sun; Kim, Seong Min; Lee, Do Sung

    2013-10-01

    MR perfusion and single photon emission computerized tomography (SPECT) are well known imaging studies to evaluate hemodynamic change between prior to and following superficial temporal artery (STA)-middle cerebral artery (MCA) anastomosis in moyamoya disease. But their side effects and invasiveness make discomfort to patients. We evaluated the ivy sign on MR fluid attenuated inversion recovery (FLAIR) images in adult patients with moyamoya disease and compared it with result of SPECT and MR perfusion images. We enrolled twelve patients (thirteen cases) who were diagnosed with moyamoya disease and underwent STA-MCA anastomosis at our medical institution during a period ranging from September of 2010 to December of 2012. The presence of the ivy sign on MR FLAIR images was classified as Negative (0), Minimal (1), and Positive (2). Regions were classified into four territories: the anterior cerebral artery (ACA), the anterior MCA, the posterior MCA and the posterior cerebral artery. Ivy signs on preoperative and postoperative MR FLAIR were improved (8 and 4 in the ACA regions, 13 and 4 in the anterior MCA regions and 19 and 9 in the posterior MCA regions). Like this result, the cerebrovascular reserve (CVR) on SPECT was significantly increased in the sum of CVR in same regions after STA-MCA anastomosis. After STA-MCA anastomosis, ivy signs were decreased in the cerebral hemisphere. As compared with conventional diagnostic modalities such as SPECT and MR perfusion images, the ivy sign on MR FLAIR is considered as a useful indicator in detecting brain hemodynamic changes between preoperatively and postoperatively in adult moyamoya patients.

  4. Coronary artery bypass grafts: assessment of graft patency and native coronary artery lesions using 16-slice MDCT

    Energy Technology Data Exchange (ETDEWEB)

    Stauder, Norbert I.; Drosch, Tanja; Claussen, Claus D.; Kopp, Andreas F. [Eberhard-Karls-University, Department of Diagnostic Radiology, Tuebingen (Germany); Kuettner, Axel [Friedrich-Alexander-University, Department of Diagnostic Radiology, Erlangen (Germany); Schroeder, Stephen; Beck, Torsten [Eberhard-Karls-University, Department of Internal Medicine, Division Cardiology, Tuebingen (Germany); Stauder, Heidrun [Eberhard-Karls-University, Department of Thoracic and Cardiovascular Surgery, Tuebingen (Germany); Blumenstock, Gunnar [Eberhard-Karls-University, Department of Medical Information Processing, Tuebingen (Germany)

    2006-11-15

    The objective of this study was to evaluate the accuracy of electrocardiography (ECG)-gated 16-slice multidetector-row computed tomography (MDCT) in detection of stenosis of bypass grafts and native coronary arteries in patients who have undergone coronary artery bypass grafting (CABG). ECG-gated contrast-enhanced MDCT using 12 x 0.75-mm collimation was performed in 20 patients with recurrent angina 4.75 years after undergoing CABG. A total of 50 grafts, 16 arterial and 34 venous, were examined. All graft and coronary segments were evaluated for stenosis in comparison with conventional coronary angiography (CCA). Among the 80 arterial graft segments, 62 could be assessed (77.5%). Sensitivity, specificity, and positive and negative predictive values for stenosis were 96.2%, 97.2%, 96.2%, and 97.2%, respectively. In a total of 180 venous graft segments, 167 could be assessed. Sensitivity, specificity, and positive and negative predictive values for stenosis were 98.5%, 93.9%, 91.8%, and 98.9%, respectively. MDCT could assess 179 of 260 native coronary artery segments (68.8%).Sensitivity, specificity, and positive and negative predictive values for stenosis were 92.1%, 76.9%, 87.5%, and 84.7%, respectively. Sixteen-slice MDCT provides excellent image quality and diagnostic accuracy in detection of graft and coronary artery lesions in patients with suspected graft dysfunction. (orig.)

  5. Estimation of coronary flow reserve by sestamibi imaging in patients with mild hypertension and normal coronary arteries

    International Nuclear Information System (INIS)

    Storto, G.; Gallicchio, R.; Maddalena, F.; Pellegrino, T.; Petretta, M.; Fiumara, G.; Cuocolo, A.

    2015-01-01

    Patients with hypertension may exhibit abnormal vasodilator capacity during pharmacological vasodilatation. We assessed coronary flow reserve (CFR) by sestamibi imaging in hypertensive patients with normal coronary vessels. Twenty-five patients with untreated mild essential hypertension and normal coronary vessels and 10 control subjects underwent dipyridamole-rest Tc-99m sestamibi imaging. Myocardial blood flow (MBF) was estimated by measuring first transit counts in pulmonary artery and myocardial counts from tomograhic images. CFR was expressed as the ratio of stress to rest MBF. Coronary vascular resistances (CVR) were computed as the ratio between mean arterial pressure and MBF. Estimated MBF at rest was not different in patients and controls (1.11±0.59 vs. 1.14±0.28 counts/pixel/s; P=0.87). Conversely, stress MBF was lower in patients than in controls (1.55±0.47 vs. 2.68±0.53 counts/pixel/s; P<0.001). Thus, CFR was reduced in patients compared to controls (1.61±0.58 vs. 2.43±0.62; P<0.001). Rest and stress CVR values were higher in patients (P<0.001), while stress-induced changes in CVR were not different (P=0.08) between patients (-51%) and controls (-62%). In the overall study population, a significant relation between CFR and stress-induced changes in CVR was observed (r=-0.86; P<0.001). Sestamibi imaging may detect impaired coronary vascular function in response to dipyridamole in patients with untreated mild essential hypertension and normal coronary arteries. A mild increase in arterial blood pressure does not affect baseline MBF, but impairs coronary reserve due to the amplified resting coronary resistances.

  6. Increased Frame Rate for Plane Wave Imaging Without Loss of Image Quality

    DEFF Research Database (Denmark)

    Jensen, Jonas; Stuart, Matthias Bo; Jensen, Jørgen Arendt

    2015-01-01

    Clinical applications of plane wave imaging necessitate the creation of high-quality images with the highest possible frame rate for improved blood flow tracking and anatomical imaging. However, linear array transducers create grating lobe artefacts, which degrade the image quality especially...... in the near field for λ-pitch transducers. Artefacts can only partly be suppressed by increasing the number of emissions, and this paper demonstrates how the frame rate can be increased without loss of image quality by using λ/2-pitch transducers. The number of emissions and steering angles are optimized...

  7. Digital subtraction angiography of lower limb arteries using and automatic table translation. Feasibility. Preliminary results

    International Nuclear Information System (INIS)

    Seka, R.; Amiel, M.; Boller, A.; Chapelon, C.; Clermont, A.; Revel, D.; Pinet, F.

    1988-01-01

    Digital subtraction angiography (DSA) as a method of evaluating lower limb arteries required examination of one limb at a time up to now. Moreover repeated injections of contrast material were necessary. This problem was mainly due to the relative small image intensifier field available and to the difficulty of repositionning the patient between mask and image acquisition. The preliminary results obtained with 24 patients studied on angiographic unit equipped with: a DSA system (DG 300-CGR) using 512x512 matrix size, an angiographic table (Angix M 200) allowing an automatic sequantial translation, a removable image intensifier using a 16 inch field below the table, are reported. Thus, all those characteristics allow DSA of lower limb arteries. Only one injection of contrast material (Ioxaglate: 80 ml at 8-10 ml/second) was used per procedure. This, usually, allows good quality examination of lower limb arteries [fr

  8. 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.)

  9. Feasibility Study of Ex Ovo Chick Chorioallantoic Artery Model for Investigating Pulsatile Variation of Arterial Geometry.

    Directory of Open Access Journals (Sweden)

    Kweon-Ho Nam

    Full Text Available Despite considerable research efforts on the relationship between arterial geometry and cardiovascular pathology, information is lacking on the pulsatile geometrical variation caused by arterial distensibility and cardiomotility because of the lack of suitable in vivo experimental models and the methodological difficulties in examining the arterial dynamics. We aimed to investigate the feasibility of using a chick embryo system as an experimental model for basic research on the pulsatile variation of arterial geometry. Optical microscope video images of various arterial shapes in chick chorioallantoic circulation were recorded from different locations and different embryo samples. The high optical transparency of the chorioallantoic membrane (CAM allowed clear observation of tiny vessels and their movements. Systolic and diastolic changes in arterial geometry were visualized by detecting the wall boundaries from binary images. Several to hundreds of microns of wall displacement variations were recognized during a pulsatile cycle. The spatial maps of the wall motion harmonics and magnitude ratio of harmonic components were obtained by analyzing the temporal brightness variation at each pixel in sequential grayscale images using spectral analysis techniques. The local variations in the spectral characteristics of the arterial wall motion were reflected well in the analysis results. In addition, mapping the phase angle of the fundamental frequency identified the regional variations in the wall motion directivity and phase shift. Regional variations in wall motion phase angle and fundamental-to-second harmonic ratio were remarkable near the bifurcation area. In summary, wall motion in various arterial geometry including straight, curved and bifurcated shapes was well observed in the CAM artery model, and their local and cyclic variations could be characterized by Fourier and wavelet transforms of the acquired video images. The CAM artery model with

  10. Image quality and radiation dose of low dose coronary CT angiography in obese patients: Sinogram affirmed iterative reconstruction versus filtered back projection

    International Nuclear Information System (INIS)

    Wang, Rui; Schoepf, U. Joseph; Wu, Runze; Reddy, Ryan P.; Zhang, Chuanchen; Yu, Wei; Liu, Yi; Zhang, Zhaoqi

    2012-01-01

    Purpose: To investigate the image quality and radiation dose of low radiation dose CT coronary angiography (CTCA) using sinogram affirmed iterative reconstruction (SAFIRE) compared with standard dose CTCA using filtered back-projection (FBP) in obese patients. Materials and methods: Seventy-eight consecutive obese patients were randomized into two groups and scanned using a prospectively ECG-triggered step-and-shot (SAS) CTCA protocol on a dual-source CT scanner. Thirty-nine patients (protocol A) were examined using a routine radiation dose protocol at 120 kV and images were reconstructed with FBP (protocol A). Thirty-nine patients (protocol B) were examined using a low dose protocol at 100 kV and images were reconstructed with SAFIRE. Two blinded observers independently assessed the image quality of each coronary segment using a 4-point scale (1 = non-diagnostic, 4 = excellent) and measured the objective parameters image noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR). Radiation dose was calculated. Results: The coronary artery image quality scores, image noise, SNR and CNR were not significantly different between protocols A and B (all p > 0.05), with image quality scores of 3.51 ± 0.70 versus 3.55 ± 0.47, respectively. The effective radiation dose was significantly lower in protocol B (4.41 ± 0.83 mSv) than that in protocol A (8.83 ± 1.74 mSv, p < 0.01). Conclusion: Compared with standard dose CTCA using FBP, low dose CTCA using SAFIRE can maintain diagnostic image quality with 50% reduction of radiation dose.

  11. Image quality and dose in mammographic images obtained in Mexico City hospitals

    International Nuclear Information System (INIS)

    Ruiz-Trejo, C.; Brandan, M.-E.; Verdejo, M.; Flores, A.; Guevara, M.; Martin, J.; Madero-Preciado, L.

    2001-01-01

    The performance of three mammographic systems in large Mexican hospitals has been evaluated, as well as the image quality and associated dose. Quality control tests include examination of X-ray equipment, darkroom conditions, film processor, and viewboxes. Systems referred to as '1', '2', and '3' passed 50%, 75% and 75% of these tests, respectively. Quality image is assessed using five images obtained under similar nominal conditions in each X-ray equipment. System 1 generates no image of acceptable quality, while equipment 2 and 3 produce one and two, respectively. The mean glandular dose for the best images obtained in each service with an accreditation phantom has been measured, and the values are 1.4 mGy, 1.6 mGy, and 1.0 mGy, respectively. (author)

  12. ASAP (Automatic Software for ASL Processing): A toolbox for processing Arterial Spin Labeling images.

    Science.gov (United States)

    Mato Abad, Virginia; García-Polo, Pablo; O'Daly, Owen; Hernández-Tamames, Juan Antonio; Zelaya, Fernando

    2016-04-01

    The method of Arterial Spin Labeling (ASL) has experienced a significant rise in its application to functional imaging, since it is the only technique capable of measuring blood perfusion in a truly non-invasive manner. Currently, there are no commercial packages for processing ASL data and there is no recognized standard for normalizing ASL data to a common frame of reference. This work describes a new Automated Software for ASL Processing (ASAP) that can automatically process several ASL datasets. ASAP includes functions for all stages of image pre-processing: quantification, skull-stripping, co-registration, partial volume correction and normalization. To assess the applicability and validity of the toolbox, this work shows its application in the study of hypoperfusion in a sample of healthy subjects at risk of progressing to Alzheimer's disease. ASAP requires limited user intervention, minimizing the possibility of random and systematic errors, and produces cerebral blood flow maps that are ready for statistical group analysis. The software is easy to operate and results in excellent quality of spatial normalization. The results found in this evaluation study are consistent with previous studies that find decreased perfusion in Alzheimer's patients in similar regions and demonstrate the applicability of ASAP. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. MISTICA: Minimum Spanning Tree-Based Coarse Image Alignment for Microscopy Image Sequences.

    Science.gov (United States)

    Ray, Nilanjan; McArdle, Sara; Ley, Klaus; Acton, Scott T

    2016-11-01

    Registration of an in vivo microscopy image sequence is necessary in many significant studies, including studies of atherosclerosis in large arteries and the heart. Significant cardiac and respiratory motion of the living subject, occasional spells of focal plane changes, drift in the field of view, and long image sequences are the principal roadblocks. The first step in such a registration process is the removal of translational and rotational motion. Next, a deformable registration can be performed. The focus of our study here is to remove the translation and/or rigid body motion that we refer to here as coarse alignment. The existing techniques for coarse alignment are unable to accommodate long sequences often consisting of periods of poor quality images (as quantified by a suitable perceptual measure). Many existing methods require the user to select an anchor image to which other images are registered. We propose a novel method for coarse image sequence alignment based on minimum weighted spanning trees (MISTICA) that overcomes these difficulties. The principal idea behind MISTICA is to reorder the images in shorter sequences, to demote nonconforming or poor quality images in the registration process, and to mitigate the error propagation. The anchor image is selected automatically making MISTICA completely automated. MISTICA is computationally efficient. It has a single tuning parameter that determines graph width, which can also be eliminated by the way of additional computation. MISTICA outperforms existing alignment methods when applied to microscopy image sequences of mouse arteries.

  14. High spatial resolution and high contrast visualization of brain arteries and veins. Impact of blood pool contrast agent and water-selective excitation imaging at 3T

    International Nuclear Information System (INIS)

    Spuentrup, E.; Jacobs, J.E.; Kleimann, J.F.

    2010-01-01

    Purpose: To investigate a blood pool contrast agent and water-selective excitation imaging at 3 T for high spatial and high contrast imaging of brain vessels including the veins. Methods and Results: 48 clinical patients (47 ± 18 years old) were included. Based on clinical findings, twenty-four patients received a single dose of standard extracellular Gadoterate-meglumine (Dotarem registered ) and 24 received the blood pool contrast agent Gadofosveset (Vasovist registered ). After finishing routine MR protocols, all patients were investigated with two high spatial resolution (0.15 mm 3 voxel size) gradient echo sequences in random order in the equilibrium phase (steady-state) as approved by the review board: A standard RF-spoiled gradient-echo sequence (HR-SS, TR/TE 5.1 / 2.3 msec, FA 30 ) and a fat-suppressed gradient-echo sequence with water-selective excitation (HR-FS, 1331 binominal-pulse, TR/TE 8.8 / 3.8 msec, FA 30 ). The images were subjectively assessed (image quality with vessel contrast, artifacts, depiction of lesions) by two investigators and contrast-to-noise ratios (CNR) were compared using the Student's t-test. The image quality and CNR in the HR-FS were significantly superior compared to the HR-SS for both contrast agents (p < 0.05). The CNR was also improved when using the blood pool agent but only to a minor extent while the subjective image quality was similar for both contrast agents. Conclusion: The utilized sequence with water-selective excitation improved image quality and CNR properties in high spatial resolution imaging of brain arteries and veins. The used blood pool contrast agent improved the CNR only to a minor extent over the extracellular contrast agent. (orig.)

  15. Imaging of Unilateral Meningo-ophthalmic Artery Anomaly in a Patient with Bilateral Nasopharyngeal Angiofibroma

    Directory of Open Access Journals (Sweden)

    Louise Louw

    2014-01-01

    Full Text Available A 12-year-old boy with epistaxis presented with a rare midline nasopharyngeal angiofibroma that extended lateral into the pterygoid and infratemporal fossae. Pre-operative angiography revealed bilateral prominent feeder arteries and two major anastomotic connections, and a rare left meningo-ophthalmic artery (M-OA anomaly that was the sole path of supply to the eye. A literature search using Pubmed and Medline was conducted. For imaging, a six-vessel study (i.e. external and internal carotid and vertebral arteries on both sides was selected. Embolization of prominent tumor feeder arteries was unsafe for tumor extirpation, but super-selective embolization of both sphenopalatine arteries was performed to control epistaxis. The M-OA anomaly that originated from the maxillary artery (MA was marked by an ophthalmic artery (OA variant with orbital and ocular divisions that coursed through the superior orbital fissure and optic foramen, respectively, each with distinct branching patterns, a middle meningeal artery (MMA with normal branches (i.e. anterior and posterior branches, and two branch variations (i.e. lacrimal and meningeal branches that originated from the anterior branch of the MMA. The lacrimal branch coursed through a cranio-orbital foramen, but the meningeal branch remained outside the orbit. The anatomy of the right OA was normal. The left M-OA anomaly was considered incidental and not tumor-related since the tumor was more prominent on the right side, and no intra-orbital infiltrations occurred. Of clinical significance is that proximal embolization of MA or MMA carries a high risk of visual impairment in cases where M-OA anomalies are the sole mode of supply to the eye.

  16. Is body weight the most appropriate criterion to select patients eligible for low-dose pulmonary CT angiography? Analysis of objective and subjective image quality at 80 kVp in 100 patients

    Energy Technology Data Exchange (ETDEWEB)

    Szucs-Farkas, Zsolt; Strautz, Tamara; Patak, Michael A.; Kurmann, Luzia; Vock, Peter; Schindera, Sebastian T. [University Hospital and University of Berne, Department of Diagnostic, Interventional and Paediatric Radiology, Berne (Switzerland)

    2009-08-15

    The objective of this retrospective study was to assess image quality with pulmonary CT angiography (CTA) using 80 kVp and to find anthropomorphic parameters other than body weight (BW) to serve as selection criteria for low-dose CTA. Attenuation in the pulmonary arteries, anteroposterior and lateral diameters, cross-sectional area and soft-tissue thickness of the chest were measured in 100 consecutive patients weighing less than 100 kg with 80 kVp pulmonary CTA. Body surface area (BSA) and contrast-to-noise ratios (CNR) were calculated. Three radiologists analyzed arterial enhancement, noise, and image quality. Image parameters between patients grouped by BW (group 1: 0-50 kg; groups 2-6: 51-100 kg, decadelly increasing) were compared. CNR was higher in patients weighing less than 60 kg than in the BW groups 71-99 kg (P between 0.025 and <0.001). Subjective ranking of enhancement (P=0.165-0.605), noise (P=0.063), and image quality (P=0.079) did not differ significantly across all patient groups. CNR correlated moderately strongly with weight (R=-0.585), BSA (R=-0.582), cross-sectional area (R=-0.544), and anteroposterior diameter of the chest (R=-0.457; P<0.001 all parameters). We conclude that 80 kVp pulmonary CTA permits diagnostic image quality in patients weighing up to 100 kg. Body weight is a suitable criterion to select patients for low-dose pulmonary CTA. (orig.)

  17. Decline in Health-Related Quality of Life 6 Months After Coronary Artery Bypass Graft Surgery

    DEFF Research Database (Denmark)

    El Baz, Noha; Pedersen, Susanne S.; van Dijk, Jitse P

    2013-01-01

    Although coronary artery bypass graft (CABG) is known to improve health-related quality of life (HRQoL), this improvement does not seem to be realized in all patients who had undergone CABG surgery....

  18. Smoking cessation has no influence on quality of life in patients with peripheral arterial disease 5 years post-vascular surgery

    DEFF Research Database (Denmark)

    Hoogwegt, M T; Hoeks, S E; Pedersen, Susanne S.

    2010-01-01

    Smoking is an important modifiable risk factor in patients with peripheral arterial disease (PAD). We investigated differences in quality of life (QoL) between patients who quitted smoking during follow-up and persistent smokers.......Smoking is an important modifiable risk factor in patients with peripheral arterial disease (PAD). We investigated differences in quality of life (QoL) between patients who quitted smoking during follow-up and persistent smokers....

  19. Objective and Subjective Assessment of Digital Pathology Image Quality

    Directory of Open Access Journals (Sweden)

    Prarthana Shrestha

    2015-03-01

    Full Text Available The quality of an image produced by the Whole Slide Imaging (WSI scanners is of critical importance for using the image in clinical diagnosis. Therefore, it is very important to monitor and ensure the quality of images. Since subjective image quality assessments by pathologists are very time-consuming, expensive and difficult to reproduce, we propose a method for objective assessment based on clinically relevant and perceptual image parameters: sharpness, contrast, brightness, uniform illumination and color separation; derived from a survey of pathologists. We developed techniques to quantify the parameters based on content-dependent absolute pixel performance and to manipulate the parameters in a predefined range resulting in images with content-independent relative quality measures. The method does not require a prior reference model. A subjective assessment of the image quality is performed involving 69 pathologists and 372 images (including 12 optimal quality images and their distorted versions per parameter at 6 different levels. To address the inter-reader variability, a representative rating is determined as a one-tailed 95% confidence interval of the mean rating. The results of the subjective assessment support the validity of the proposed objective image quality assessment method to model the readers’ perception of image quality. The subjective assessment also provides thresholds for determining the acceptable level of objective quality per parameter. The images for both the subjective and objective quality assessment are based on the HercepTestTM slides scanned by the Philips Ultra Fast Scanners, developed at Philips Digital Pathology Solutions. However, the method is applicable also to other types of slides and scanners.

  20. Clinical evaluation of myocardial perfusion imaging with 99mTc-CPI

    International Nuclear Information System (INIS)

    Liu Xiujie

    1988-01-01

    10 normal subjects and 55 cases of patients with heart diseases were studied with 99m Tc-CPI myocardial perfusion imaging. The 99m Tc-CPI myocarbial imaging is superior to 99m Tc-TBI, because the uptake of 99m Tc-CPI in both lung and liver is lower. The imaging quality of 99m Tc-CPI is nearly as good as that of 201 Tl. 16 patients had both 99m Tc-CPI myocardial imaging and coronary artery angiography. The sensitivity of 99m Tc-CPI myocardial imaging for detecting coronary artery disease (CAD) was 92%, whereas the sensitivity of ECG was 84.6%. 99m Tc-CPI myocardial tomography was obtained in 17 patients using Toshiba 90B SPECT system. The imaging quality of myocardial tomography using 99m Tc-CPI is very good and superior to planar imaging for detecting myocardial infarction

  1. STANDARDIZING QUALITY ASSESSMENT OF FUSED REMOTELY SENSED IMAGES

    Directory of Open Access Journals (Sweden)

    C. Pohl

    2017-09-01

    Full Text Available The multitude of available operational remote sensing satellites led to the development of many image fusion techniques to provide high spatial, spectral and temporal resolution images. The comparison of different techniques is necessary to obtain an optimized image for the different applications of remote sensing. There are two approaches in assessing image quality: 1. Quantitatively by visual interpretation and 2. Quantitatively using image quality indices. However an objective comparison is difficult due to the fact that a visual assessment is always subject and a quantitative assessment is done by different criteria. Depending on the criteria and indices the result varies. Therefore it is necessary to standardize both processes (qualitative and quantitative assessment in order to allow an objective image fusion quality evaluation. Various studies have been conducted at the University of Osnabrueck (UOS to establish a standardized process to objectively compare fused image quality. First established image fusion quality assessment protocols, i.e. Quality with No Reference (QNR and Khan's protocol, were compared on varies fusion experiments. Second the process of visual quality assessment was structured and standardized with the aim to provide an evaluation protocol. This manuscript reports on the results of the comparison and provides recommendations for future research.

  2. Standardizing Quality Assessment of Fused Remotely Sensed Images

    Science.gov (United States)

    Pohl, C.; Moellmann, J.; Fries, K.

    2017-09-01

    The multitude of available operational remote sensing satellites led to the development of many image fusion techniques to provide high spatial, spectral and temporal resolution images. The comparison of different techniques is necessary to obtain an optimized image for the different applications of remote sensing. There are two approaches in assessing image quality: 1. Quantitatively by visual interpretation and 2. Quantitatively using image quality indices. However an objective comparison is difficult due to the fact that a visual assessment is always subject and a quantitative assessment is done by different criteria. Depending on the criteria and indices the result varies. Therefore it is necessary to standardize both processes (qualitative and quantitative assessment) in order to allow an objective image fusion quality evaluation. Various studies have been conducted at the University of Osnabrueck (UOS) to establish a standardized process to objectively compare fused image quality. First established image fusion quality assessment protocols, i.e. Quality with No Reference (QNR) and Khan's protocol, were compared on varies fusion experiments. Second the process of visual quality assessment was structured and standardized with the aim to provide an evaluation protocol. This manuscript reports on the results of the comparison and provides recommendations for future research.

  3. Objective masurement of image quality in fluoroscopic x-ray equipment FluoroQuality

    CERN Document Server

    Tapiovaara, M

    2003-01-01

    The report describes FluoroQuality, a computer program that is developed in STUK and used for measuring the image quality in medical fluoroscopic equipment. The method is based on the statistical decision theory (SDT) and the main measurement result is given in terms of the accumulation rate of the signal-to-noise ratio squared (SNR sup 2 sub r sub a sub t sub e). In addition to this quantity several other quantities are measured. These quantities include the SNR of single image frames, the spatio-temporal noise power spectrum and the temporal lag. The measurement method can be used, for example, for specifying the image quality in fluoroscopic images, for optimising the image quality and dose rate in fluoroscopy and for quality control of fluoroscopic equipment. The theory behind the measurement method is reviewed and the measurement of the various quantities is explained. An example of using the method for optimising a specified fluoroscopic procedure is given. The User's Manual of the program is included a...

  4. Image quality evaluation of full reference algorithm

    Science.gov (United States)

    He, Nannan; Xie, Kai; Li, Tong; Ye, Yushan

    2018-03-01

    Image quality evaluation is a classic research topic, the goal is to design the algorithm, given the subjective feelings consistent with the evaluation value. This paper mainly introduces several typical reference methods of Mean Squared Error(MSE), Peak Signal to Noise Rate(PSNR), Structural Similarity Image Metric(SSIM) and feature similarity(FSIM) of objective evaluation methods. The different evaluation methods are tested by Matlab, and the advantages and disadvantages of these methods are obtained by analyzing and comparing them.MSE and PSNR are simple, but they are not considered to introduce HVS characteristics into image quality evaluation. The evaluation result is not ideal. SSIM has a good correlation and simple calculation ,because it is considered to the human visual effect into image quality evaluation,However the SSIM method is based on a hypothesis,The evaluation result is limited. The FSIM method can be used for test of gray image and color image test, and the result is better. Experimental results show that the new image quality evaluation algorithm based on FSIM is more accurate.

  5. No-reference visual quality assessment for image inpainting

    Science.gov (United States)

    Voronin, V. V.; Frantc, V. A.; Marchuk, V. I.; Sherstobitov, A. I.; Egiazarian, K.

    2015-03-01

    Inpainting has received a lot of attention in recent years and quality assessment is an important task to evaluate different image reconstruction approaches. In many cases inpainting methods introduce a blur in sharp transitions in image and image contours in the recovery of large areas with missing pixels and often fail to recover curvy boundary edges. Quantitative metrics of inpainting results currently do not exist and researchers use human comparisons to evaluate their methodologies and techniques. Most objective quality assessment methods rely on a reference image, which is often not available in inpainting applications. Usually researchers use subjective quality assessment by human observers. It is difficult and time consuming procedure. This paper focuses on a machine learning approach for no-reference visual quality assessment for image inpainting based on the human visual property. Our method is based on observation that Local Binary Patterns well describe local structural information of the image. We use a support vector regression learned on assessed by human images to predict perceived quality of inpainted images. We demonstrate how our predicted quality value correlates with qualitative opinion in a human observer study. Results are shown on a human-scored dataset for different inpainting methods.

  6. Clinical and imaging features associated with intracranial internal carotid artery calcifications in patients with ischemic stroke

    Energy Technology Data Exchange (ETDEWEB)

    Yilmaz, Arda [Mersin University, Department of Neurology, Faculty of Medicine, Mersin (Turkey); Akpinar, Erhan [Hacettepe University, Department of Radiology, Faculty of Medicine, Ankara (Turkey); Topcuoglu, Mehmet Akif; Arsava, Ethem Murat [Hacettepe University, Department of Neurology, Faculty of Medicine, Ankara (Turkey)

    2015-05-01

    Intracranial internal carotid artery calcifications (ICAC), a frequent finding on imaging studies, are predictive of future stroke risk in population-based studies. The clinical significance of this observation among ischemic stroke patients is however less clear. In this study, we analyzed ICAC burden in relation to vascular risk factor profile, stroke etiology, and extent of craniocervical vascular calcifications in a consecutive series of ischemic stroke patients. The burden of ICAC was determined both on non-contrast CT and CT-angiography source images by semiquantitative scoring algorithms. The distribution of vascular risk factors, etiologic stroke subtype, and calcification burden in other craniocervical arteries was assessed among patients with no ICAC, mild-moderate ICAC, and severe ICAC. Of 319 patients included into the study, 28 % had no ICAC, 35 % had mild-moderate ICAC, and 37 % had severe ICAC on CT angiography. Independent factors associated with ICAC burden in multivariate analysis included age (p < 0.001), diabetes mellitus (p = 0.006), and coronary artery disease (p < 0.001). Furthermore, a stroke etiology of large artery atherosclerosis or cardioaortic embolism was significantly related to higher ICAC burden (p = 0.006). Patients with severe ICAC were more likely to harbor calcifications in other vascular beds (p < 0.001). All of these findings persisted when analyses were repeated with CT-based ICAC burden assessments. ICAC burden reflects a continuum of atherosclerotic disease involving carotid arteries together with other craniocervical vascular beds. ICAC is significantly associated with stroke of large vessel or cardioembolic origin. This information might help the clinician in prioritizing etiologic work-up in the acute period. (orig.)

  7. High-quality compressive ghost imaging

    Science.gov (United States)

    Huang, Heyan; Zhou, Cheng; Tian, Tian; Liu, Dongqi; Song, Lijun

    2018-04-01

    We propose a high-quality compressive ghost imaging method based on projected Landweber regularization and guided filter, which effectively reduce the undersampling noise and improve the resolution. In our scheme, the original object is reconstructed by decomposing of regularization and denoising steps instead of solving a minimization problem in compressive reconstruction process. The simulation and experimental results show that our method can obtain high ghost imaging quality in terms of PSNR and visual observation.

  8. Pulmonary artery imaging under free-breathing using golden-angle radial bSSFP MRI: a proof of concept.

    Science.gov (United States)

    Fyrdahl, Alexander; Vargas Paris, Roberto; Nyrén, Sven; Holst, Karen; Ugander, Martin; Lindholm, Peter; Sigfridsson, Andreas

    2018-03-14

    To evaluate the feasibility of an improved motion and flow robust methodology for imaging the pulmonary vasculature using non-contrast-enhanced, free-breathing, golden-angle radial MRI. Healthy volunteers (n = 10, age 46 ± 11 years, 50% female) and patients (n = 2, ages 27 and 84, both female) were imaged at 1.5 T using a Cartesian and golden-angle radial 2D balanced SSFP pulse sequence. The acquisitions were made under free breathing without contrast agent enhancement. The radial acquisitions were reconstructed at 3 temporal footprints. All series were scored from 1 to 5 for perceived diagnostic quality, artifact level, and vessel sharpness in multiple anatomical locations. In addition, vessel sharpness and blood-to-blood clot contrast were measured. Quantitative measurements showed higher vessel sharpness for golden-angle radial (n = 76, 0.79 ± 0.11 versus 0.71 ± 0.16, p golden-angle radial in the 2 patients. At comparable temporal footprints, golden-angle radial was scored higher for diagnostic quality (mean ± SD, 2.3 ± 0.7 versus 2.2 ± 0.6, p < .01) and vessel sharpness (2.2 ± 0.8 versus 2.1 ± 0.5, p < .01), whereas the artifact level did not differ (3.0 ± 0.9 versus 3.0 ± 1.0, p = .80). The ability to retrospectively choose a temporal resolution and perform sliding-window reconstructions was demonstrated in patients. In pulmonary artery imaging, the motion and flow robustness of a radial trajectory does both improve image quality over Cartesian trajectory in healthy volunteers, and allows for flexible selection of temporal footprints and the ability to perform real-time sliding window reconstructions, which could potentially provide further diagnostic insight. © 2018 International Society for Magnetic Resonance in Medicine.

  9. The value of MDCT in diagnosis of splenic artery aneurysms

    International Nuclear Information System (INIS)

    Sun Cong; Liu Cheng; Wang Ximing; Wang Daoping

    2008-01-01

    Objective: To evaluate the clinical value of multiple detector computed tomography (MDCT) in the diagnosis and planning the treatment of splenic aneurysms. Methods: Eight cases with splenic artery aneurysms (SAA) were retrospectively reviewed. Sixty four-slice spiral CT scans were performed. Intravenous contrast material was injected at 4 ml/s, and arterial and venous phase images were obtained. Subsequently, arterial phase images were analyzed and made for CT angiography. The diagnosis was made by using axial and reconstructive images. All of the patients were also performed Doppler color echocardiography. Results: All patients showed splenic artery and splenic artery aneurysms clearly with CT arterial phase images. Among them, six patients had splenic artery aneurysms, one had giant splenic artery aneurysms (GSAA) and one had splenic artery pseudoaneurysms. Ultrasound examination only diagnosed six of them. Conclusion: MDCT is a noninvasive and valuable method in diagnosis of splenic artery aneurysms and has high value in determination of treatment plan

  10. The value of MDCT in diagnosis of splenic artery aneurysms

    Energy Technology Data Exchange (ETDEWEB)

    Sun Cong [Shandong University, Shandong Provincial Medical Imaging Institute, Road jing-wu No. 324, Jinan, Shandong 250021 (China)], E-mail: suncong03@163.com; Liu Cheng; Wang Ximing; Wang Daoping [Shandong University, Shandong Provincial Medical Imaging Institute, Road jing-wu No. 324, Jinan, Shandong 250021 (China)

    2008-03-15

    Objective: To evaluate the clinical value of multiple detector computed tomography (MDCT) in the diagnosis and planning the treatment of splenic aneurysms. Methods: Eight cases with splenic artery aneurysms (SAA) were retrospectively reviewed. Sixty four-slice spiral CT scans were performed. Intravenous contrast material was injected at 4 ml/s, and arterial and venous phase images were obtained. Subsequently, arterial phase images were analyzed and made for CT angiography. The diagnosis was made by using axial and reconstructive images. All of the patients were also performed Doppler color echocardiography. Results: All patients showed splenic artery and splenic artery aneurysms clearly with CT arterial phase images. Among them, six patients had splenic artery aneurysms, one had giant splenic artery aneurysms (GSAA) and one had splenic artery pseudoaneurysms. Ultrasound examination only diagnosed six of them. Conclusion: MDCT is a noninvasive and valuable method in diagnosis of splenic artery aneurysms and has high value in determination of treatment plan.

  11. Cerebral bone subtraction CT angiography using 80 kVp and sinogram-affirmed iterative reconstruction: contrast medium and radiation dose reduction with improvement of image quality

    Energy Technology Data Exchange (ETDEWEB)

    Nagayama, Yasunori [Kumamoto City Hospital, Department of Radiology, Kumamoto (Japan); Kumamoto University, Department of Diagnostic Radiology, Chuo-ku, Kumamoto (Japan); Nakaura, Takeshi; Oda, Seitaro; Kidoh, Masafumi; Utsunomiya, Daisuke; Yamashita, Yasuyuki [Kumamoto University, Department of Diagnostic Radiology, Chuo-ku, Kumamoto (Japan); Tsuji, Akinori; Urata, Joji; Furusawa, Mitsuhiro; Yuki, Hideaki; Hirarta, Kenichiro [Kumamoto City Hospital, Department of Radiology, Kumamoto (Japan)

    2017-02-15

    The purpose of this study was to evaluate the feasibility of a contrast medium (CM), radiation dose reduction protocol for cerebral bone-subtraction CT angiography (BSCTA) using 80-kVp and sinogram-affirmed iterative reconstruction (SAFIRE). Seventy-five patients who had undergone BSCTA under the 120- (n = 37) or the 80-kVp protocol (n = 38) were included. CM was 370 mgI/kg for the 120-kVp and 296 mgI/kg for the 80-kVp protocol; the 120- and the 80-kVp images were reconstructed with filtered back-projection (FBP) and SAFIRE, respectively. We compared effective dose (ED), CT attenuation, image noise, and contrast-to-noise ratio (CNR) of two protocols. We also scored arterial contrast, sharpness, depiction of small arteries, visibility near skull base/clip, and overall image quality on a four-point scale. ED was 62% lower at 80- than 120-kVp (0.59 ± 0.06 vs 1.56 ± 0.13 mSv, p < 0.01). CT attenuation of the internal carotid artery (ICA) and middle cerebral artery (MCA) was significantly higher on 80- than 120-kVp (ICA: 557.4 ± 105.7 vs 370.0 ± 59.3 Hounsfield units (HU), p < 0.01; MCA: 551.9 ± 107.9 vs 364.6 ± 62.2 HU, p < 0.01). The CNR was also significantly higher on 80- than 120-kVp (ICA: 46.2 ± 10.2 vs 36.9 ± 7.6, p < 0.01; MCA: 45.7 ± 10.0 vs 35.7 ± 9.0, p < 0.01). Visibility near skull base and clip was not significantly different (p = 0.45). The other subjective scores were higher with the 80- than the 120-kVp protocol (p < 0.05). The 80-kVp acquisition with SAFIRE yields better image quality for BSCTA and substantial reduction in the radiation and CM dose compared to the 120-kVp with FBP protocol. (orig.)

  12. Developing and validating a psychometric scale for image quality assessment

    International Nuclear Information System (INIS)

    Mraity, H.; England, A.; Hogg, P.

    2014-01-01

    Purpose: Using AP pelvis as a catalyst, this paper explains how a psychometric scale for image quality assessment can be created using Bandura's theory for self-efficacy. Background: Establishing an accurate diagnosis is highly dependent upon the quality of the radiographic image. Image quality, as a construct (i.e. set of attributes that makes up the image quality), continues to play an essential role in the field of diagnostic radiography. The process of assessing image quality can be facilitated by using criteria, such as the European Commission (EC) guidelines for quality criteria as published in 1996. However, with the advent of new technology (Computed Radiography and Digital Radiography), some of the EC criteria may no longer be suitable for assessing the visual quality of a digital radiographic image. Moreover, a lack of validated visual image quality scales in the literature can also lead to significant variations in image quality evaluation. Creating and validating visual image quality scales, using a robust methodology, could reduce variability and improve the validity and reliability of perceptual image quality evaluations

  13. Performance evaluation of no-reference image quality metrics for face biometric images

    Science.gov (United States)

    Liu, Xinwei; Pedersen, Marius; Charrier, Christophe; Bours, Patrick

    2018-03-01

    The accuracy of face recognition systems is significantly affected by the quality of face sample images. The recent established standardization proposed several important aspects for the assessment of face sample quality. There are many existing no-reference image quality metrics (IQMs) that are able to assess natural image quality by taking into account similar image-based quality attributes as introduced in the standardization. However, whether such metrics can assess face sample quality is rarely considered. We evaluate the performance of 13 selected no-reference IQMs on face biometrics. The experimental results show that several of them can assess face sample quality according to the system performance. We also analyze the strengths and weaknesses of different IQMs as well as why some of them failed to assess face sample quality. Retraining an original IQM by using face database can improve the performance of such a metric. In addition, the contribution of this paper can be used for the evaluation of IQMs on other biometric modalities; furthermore, it can be used for the development of multimodality biometric IQMs.

  14. Noncontrast-enhanced magnetic resonance renal angiography using a repetitive artery and venous labelling technique at 3 T: comparison with contrast-enhanced magnetic resonance angiography in subjects with normal renal function

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sung Yoon [Sungkyunkwan University School of Medicine, Department of Radiology and Center for Imaging Science, Samsung Medical Center, Seoul (Korea, Republic of); Severance Hospital, Yonsei University College of Medicine, Department of Radiology and Research Institute of Radiological Science, Seoul (Korea, Republic of); Kim, Chan Kyo; Park, Byung Kwan [Sungkyunkwan University School of Medicine, Department of Radiology and Center for Imaging Science, Samsung Medical Center, Seoul (Korea, Republic of); Kim, EunJu [Philips Healthcare Korea, Seoul (Korea, Republic of)

    2014-09-13

    To investigate the feasibility of noncontrast-enhanced MR angiography (NC-MRA) using the repetitive artery and venous labelling (RAVEL) technique to evaluate renal arteries compared to contrast-enhanced MR angiography (CE-MRA). Twenty-five subjects with normal renal function underwent NC-MRA using a RAVEL technique and CE-MRA at 3 T. Two independent readers analysed the MRA images. Image quality, number of renal arteries, presence or absence of an early branching vessel, and diameter of the main renal arteries were evaluated. The overall image quality of NC-MRA was fair or greater in 88 % of right and 92 % of left renal arteries, while it was 96 % in both sides with CE-MRA. On NC-MRA, the number of renal arteries in all subjects was perfectly predicted by both readers. Sensitivity and specificity for predicting early branching vessels were 82 % and 100 % for reader 1 and 82 % and 95 % for reader 2. Inter-modality agreement for comparing the diameters of main renal arteries was good or excellent at all segments for both readers. Inter-reader agreement was moderate or good at all segments except at the right distal segment on NC-MRA. NC-MRA with the RAVEL technique at 3 T may have comparable diagnostic feasibility for evaluating renal arteries compared to CE-MRA. (orig.)

  15. The influence of environment temperature on SEM image quality

    International Nuclear Information System (INIS)

    Chen, Li; Liu, Junshan

    2015-01-01

    As the structure dimension goes down to the nano-scale, it often requires a scanning electron microscope (SEM) to provide image magnification up to 100 000  ×. However, SEM images at such a high magnification usually suffer from high resolution value and low signal-to-noise ratio, which results in low quality of the SEM image. In this paper, the quality of the SEM image is improved by optimizing the environment temperature. The experimental results indicate that at 100 000  ×, the quality of the SEM image is influenced by the environment temperature, whereas at 50 000  × it is not. At 100 000  × the best SEM image quality can be achieved from the environment temperature ranging 292 from 294 K, and the SEM image quality evaluated by the double stimulus continuous quality scale method can increase from grade 1 to grade 5. It is expected that this image quality improving method can be used in routine measurements with ordinary SEMs to get high quality images by optimizing the environment temperature. (paper)

  16. Body Image and quality of life of senior citizens included in a cardiac rehabilitation program

    Directory of Open Access Journals (Sweden)

    Fernanda Vargas Amaral

    2013-12-01

    Full Text Available Most people who have to live with some kind of disease tend to adopt healthy habits and create new ways of seeing themselves. The aim of this study is to explore the relationship between the index of quality of life and self perception of patients included in a cardiovascular rehabilitation program in Florianopolis/Brazil. The sample consists of 24 subjects of 62 ± 1.3 years of age, who have coronary artery disease. The Minnesota Living With Heart Failure Questionnaire (MLHFQ was used to assess the quality of life, and to identify the degree of body image discontentment the Stunkard and Sorensen questionnaire (1993 was applied. Statistical analysis was made through statistics programs and the software SPSS 11.0. The degree of association between variables was studied with Kendall test. It was verified that the higher the BMI and the current body shape, the greatest the degree of body image dissatisfaction. The emotional symptoms also appear to be significantly correlated with a desire for a smaller body shape and with indicators of lower quality of life (r = 0474 = 0735, p major 0.05. The physical symptoms were also considerably associated with the emotional symptoms. These results suggest that the variables concerning the quality of life are meaningful to significant body image and satisfaction, which seems to correlate with fewer emotional problems and better facing of the disease. Cardiovascular Rehabilitation Programs that implement physical activity in daily habits proves to be a suitable tool for improving these ailments in this post-acute phase

  17. Corrections of arterial input function for dynamic H215O PET to assess perfusion of pelvic tumours: arterial blood sampling versus image extraction

    International Nuclear Information System (INIS)

    Luedemann, L; Sreenivasa, G; Michel, R; Rosner, C; Plotkin, M; Felix, R; Wust, P; Amthauer, H

    2006-01-01

    Assessment of perfusion with 15 O-labelled water (H 2 15 O) requires measurement of the arterial input function (AIF). The arterial time activity curve (TAC) measured using the peripheral sampling scheme requires corrections for delay and dispersion. In this study, parametrizations with and without arterial spillover correction for fitting of the tissue curve are evaluated. Additionally, a completely noninvasive method for generation of the AIF from a dynamic positron emission tomography (PET) acquisition is applied to assess perfusion of pelvic tumours. This method uses a volume of interest (VOI) to extract the TAC from the femoral artery. The VOI TAC is corrected for spillover using a separate tissue TAC and for recovery by determining the recovery coefficient on a coregistered CT data set. The techniques were applied in five patients with pelvic tumours who underwent a total of 11 examinations. Delay and dispersion correction of the blood TAC without arterial spillover correction yielded in seven examinations solutions inconsistent with physiology. Correction of arterial spillover increased the fitting accuracy and yielded consistent results in all patients. Generation of an AIF from PET image data was investigated as an alternative to arterial blood sampling and was shown to have an intrinsic potential to determine the AIF noninvasively and reproducibly. The AIF extracted from a VOI in a dynamic PET scan was similar in shape to the blood AIF but yielded significantly higher tissue perfusion values (mean of 104.0 ± 52.0%) and lower partition coefficients (-31.6 ± 24.2%). The perfusion values and partition coefficients determined with the VOI technique have to be corrected in order to compare the results with those of studies using a blood AIF

  18. Successful Magnetic Resonance Imaging-Guided Focused Ultrasound Surgery for Recurrent Uterine Fibroid Previously Treated with Uterine Artery Embolization

    Directory of Open Access Journals (Sweden)

    Sang-Wook Yoon

    2010-01-01

    Full Text Available A 45-year-old premenopausal woman was referred to our clinic due to recurring symptoms of uterine fibroids, nine years after a uterine artery embolization (UAE. At the time of screening, the patient presented with bilateral impairment and narrowing of the uterine arteries, which increased the risk of arterial perforation during repeated UAE procedures. The patient was subsequently referred for magnetic resonance imaging-guided focused ultrasound surgery (MRgFUS treatment. Following the treatment, the patient experienced a significant improvement in symptoms (symptom severity score was reduced from 47 to 12 by 1 year post-treatment. MR images at 3 months showed a 49% decrease in fibroid volume. There were no adverse events during the treatment or the follow-up period. This case suggests that MRgFUS can be an effective treatment option for patients with recurrent fibroids following previous UAE treatment.

  19. Intracranial arterial wall enhancement using gadolinium-enhanced 3D black-blood T1-weighted imaging

    Energy Technology Data Exchange (ETDEWEB)

    Takano, Koichi, E-mail: k-takano@fukuoka-u.ac.jp; Hida, Kosuke; Kuwabara, Yasuo; Yoshimitsu, Kengo

    2017-01-15

    Purpose: We investigated the enhancement of the intracranial arterial walls with gadolinium-enhanced, black-blood three-dimensional T1-weighted imaging (Gd-3DBB) by using an improved motion-sensitized driven-equilibrium (iMSDE)—prepared volumetric isotropic turbo spin-echo acquisition (VISTA). Methods: A total of 115 patients underwent FLAIR, 3D-TOF-MRA and Gd-3DBB with a 1.5-T scanner. The degree and distribution of the arterial wall enhancement on Gd-3DBB was assessed. The association of the degree of wall enhancement with brain infarction/ischemic lesions on FLAIR, luminal changes on 3D-TOF-MRA, and cardiovascular risk factors (CVRFs) was investigated by univariate and multiple logistic regression analyses. Results: Strong enhancement of the arterial walls was observed in 77 vertebral arteries (33.5%), 4 basilar arteries (3.5%), 31 supraclinoid internal carotid arteries (ICAs) (13.5%) and 8 middle cerebral arteries (3.5%). In addition, 221 intrapetrous ICAs (96.1%) showed strong enhancement. After adjusting for confounding factors, multivariate analyses showed that the patient age was independently associated with the strong wall enhancement of the arteries for both the posterior (OR, 1.088; 95% CI, 1.034–1.146) and the anterior circulation (OR, 1.098, 95% CI 1.029–1.172). In addition, the presence of the supratentorial brain infarctions was independently associated with the strong wall enhancement in the anterior circulation excluding the intrapetrous ICAs (OR, 4.097; 95% CI, 1.483–11.319). Conclusions: Although the arterial wall enhancement on the Gd-3DBB probably reflects normal aging, the enhancement in the anterior circulation might be related to brain infarctions. On the other hand, the intrapetrous ICA enhancement is considered a nonspecific finding and should not be mistaken for arterial pathologies such as atherosclerosis or arteritis.

  20. Intracranial arterial wall enhancement using gadolinium-enhanced 3D black-blood T1-weighted imaging

    International Nuclear Information System (INIS)

    Takano, Koichi; Hida, Kosuke; Kuwabara, Yasuo; Yoshimitsu, Kengo

    2017-01-01

    Purpose: We investigated the enhancement of the intracranial arterial walls with gadolinium-enhanced, black-blood three-dimensional T1-weighted imaging (Gd-3DBB) by using an improved motion-sensitized driven-equilibrium (iMSDE)—prepared volumetric isotropic turbo spin-echo acquisition (VISTA). Methods: A total of 115 patients underwent FLAIR, 3D-TOF-MRA and Gd-3DBB with a 1.5-T scanner. The degree and distribution of the arterial wall enhancement on Gd-3DBB was assessed. The association of the degree of wall enhancement with brain infarction/ischemic lesions on FLAIR, luminal changes on 3D-TOF-MRA, and cardiovascular risk factors (CVRFs) was investigated by univariate and multiple logistic regression analyses. Results: Strong enhancement of the arterial walls was observed in 77 vertebral arteries (33.5%), 4 basilar arteries (3.5%), 31 supraclinoid internal carotid arteries (ICAs) (13.5%) and 8 middle cerebral arteries (3.5%). In addition, 221 intrapetrous ICAs (96.1%) showed strong enhancement. After adjusting for confounding factors, multivariate analyses showed that the patient age was independently associated with the strong wall enhancement of the arteries for both the posterior (OR, 1.088; 95% CI, 1.034–1.146) and the anterior circulation (OR, 1.098, 95% CI 1.029–1.172). In addition, the presence of the supratentorial brain infarctions was independently associated with the strong wall enhancement in the anterior circulation excluding the intrapetrous ICAs (OR, 4.097; 95% CI, 1.483–11.319). Conclusions: Although the arterial wall enhancement on the Gd-3DBB probably reflects normal aging, the enhancement in the anterior circulation might be related to brain infarctions. On the other hand, the intrapetrous ICA enhancement is considered a nonspecific finding and should not be mistaken for arterial pathologies such as atherosclerosis or arteritis.

  1. ANALYSIS OF THE EFFECTS OF IMAGE QUALITY ON DIGITAL MAP GENERATION FROM SATELLITE IMAGES

    Directory of Open Access Journals (Sweden)

    H. Kim

    2012-07-01

    Full Text Available High resolution satellite images are widely used to produce and update a digital map since they became widely available. It is well known that the accuracy of digital map produced from satellite images is decided largely by the accuracy of geometric modelling. However digital maps are made by a series of photogrammetric workflow. Therefore the accuracy of digital maps are also affected by the quality of satellite images, such as image interpretability. For satellite images, parameters such as Modulation Transfer Function(MTF, Signal to Noise Ratio(SNR and Ground Sampling Distance(GSD are used to present images quality. Our previous research stressed that such quality parameters may not represent the quality of image products such as digital maps and that parameters for image interpretability such as Ground Resolved Distance(GRD and National Imagery Interpretability Rating Scale(NIIRS need to be considered. In this study, we analyzed the effects of the image quality on accuracy of digital maps produced by satellite images. QuickBird, IKONOS and KOMPSAT-2 imagery were used to analyze as they have similar GSDs. We measured various image quality parameters mentioned above from these images. Then we produced digital maps from the images using a digital photogrammetric workstation. We analyzed the accuracy of the digital maps in terms of their location accuracy and their level of details. Then we compared the correlation between various image quality parameters and the accuracy of digital maps. The results of this study showed that GRD and NIIRS were more critical for map production then GSD, MTF or SNR.

  2. Angiographic Assessment of the Right Hepatic Artery for Encasement by Hilar Cholangiocarcinoma: Comparison Between Antero-Posterior and Right Anterior Oblique Projections

    International Nuclear Information System (INIS)

    Furukawa, Hiroyoshi; Iwata, Ryoko; Moriyama, Noriyuki

    2001-01-01

    Purpose: To evaluate the usefulness of right anterior oblique (RAO) arteriography for evaluating encasement of the right hepatic artery (RHA) by hilar cholangiocarcinoma.Methods: Celiac arteriography was performed in both the antero-posterior (AP) and RAO projection in ten patients with cholangiocarcinoma. The lengths of the arteries between the bifurcation of the anterior and posterior branch of the liver and the following points were measured: (a) the bifurcation of the left and right hepatic artery (AP-LR), (b) the bifurcation of the proper hepatic artery and the gastroduodenal artery (AP-PG). Additionally, image quality in investigating the invasion of the RHA was evaluated.Results: On the AP images, the average lengths of AP-LR and AP-PG were 24.5 ± 5.1 mm and 30.0 ± 4.9 mm, respectively. On RAO images, the lengths were 28.2 ± 4.6 mm and 32.7 ± 4.8 mm, respectively. Every length was different between the two projections (p < 0.01). In 6 of 10 patients with hilar cholangiocarcinoma, images in RAO projections were superior to AP images for evaluation of encasement.Conclusion: We conclude that angiography obtained in the RAO projection yields images that are superior to those obtained in the conventional AP projection for assessment of RHA encasement

  3. Dual-Energy Computed Tomography Angiography of the Lower Extremity Runoff: Impact of Noise-Optimized Virtual Monochromatic Imaging on Image Quality and Diagnostic Accuracy.

    Science.gov (United States)

    Wichmann, Julian L; Gillott, Matthew R; De Cecco, Carlo N; Mangold, Stefanie; Varga-Szemes, Akos; Yamada, Ricardo; Otani, Katharina; Canstein, Christian; Fuller, Stephen R; Vogl, Thomas J; Todoran, Thomas M; Schoepf, U Joseph

    2016-02-01

    The aim of this study was to evaluate the impact of a noise-optimized virtual monochromatic imaging algorithm (VMI+) on image quality and diagnostic accuracy at dual-energy computed tomography angiography (CTA) of the lower extremity runoff. This retrospective Health Insurance Portability and Accountability Act-compliant study was approved by the local institutional review board. We evaluated dual-energy CTA studies of the lower extremity runoff in 48 patients (16 women; mean age, 63.3 ± 13.8 years) performed on a third-generation dual-source CT system. Images were reconstructed with standard linear blending (F_0.5), VMI+, and traditional monochromatic (VMI) algorithms at 40 to 120 keV in 10-keV intervals. Vascular attenuation and image noise in 18 artery segments were measured; signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. Five-point scales were used to subjectively evaluate vascular attenuation and image noise. In a subgroup of 21 patients who underwent additional invasive catheter angiography, diagnostic accuracy for the detection of significant stenosis (≥50% lumen restriction) of F_0.5, 50-keV VMI+, and 60-keV VMI data sets were assessed. Objective image quality metrics were highest in the 40- and 50-keV VMI+ series (SNR: 20.2 ± 10.7 and 19.0 ± 9.5, respectively; CNR: 18.5 ± 10.3 and 16.8 ± 9.1, respectively) and were significantly (all P traditional VMI technique and standard linear blending for evaluation of the lower extremity runoff using dual-energy CTA.

  4. Evaluation of coronary artery disease by functional imaging from equilibrium radionuclide ventriculography

    International Nuclear Information System (INIS)

    He Zuoxiang

    1992-01-01

    Functional imagings were performed in 10 normals, 9 subjects with Non coronary Artery disease (NCAD), 33 CAD patients with documented MI (CAD-WMI) and 20 without MI (CAD-NMI). The sensitivity of LVGEF, LVREF and phase analysis at rest for detecting CAD-WMI was 66.7%, 78.8%, 93.9% respectively. LVGEF, LVREF during exercise for assessing CAD-NMI had the sensitivity of 90%, 80%, respectively, while specificity 90%. Early LVEF decrease, > 10% LVEF decrease and abnormal response at > 7 sectors during exercise were observed in 2 patients with 3 vessel. In conclusion, functional imaging were very useful for detecting CAD and evaluating its extent

  5. Estimation of an image derived input function with MR-defined carotid arteries in FDG-PET human studies using a novel partial volume correction method

    DEFF Research Database (Denmark)

    Sari, Hasan; Erlandsson, Kjell; Law, Ian

    2017-01-01

    Kinetic analysis of18F-fluorodeoxyglucose positron emission tomography data requires an accurate knowledge the arterial input function. The gold standard method to measure the arterial input function requires collection of arterial blood samples and is an invasive method. Measuring an image deriv...... input function (p > 0.12 for grey matter and white matter). Hence, the presented image derived input function extraction method can be a practical alternative to noninvasively analyze dynamic18F-fluorodeoxyglucose data without the need for blood sampling....

  6. CT-angiography source images indicate less fatal outcome despite coma of patients in the Basilar Artery International Cooperation Study.

    Science.gov (United States)

    Pallesen, Lars P; Khomenko, Andrei; Dzialowski, Imanuel; Barlinn, Jessica; Barlinn, Kristian; Zerna, Charlotte; van der Hoeven, Erik Jrj; Algra, Ale; Kapelle, L Jaap; Michel, Patrik; Bodechtel, Ulf; Demchuk, Andrew M; Schonewille, Wouter; Puetz, Volker

    2017-02-01

    Background Coma is associated with poor outcome in patients with basilar artery occlusion. Aims We sought to assess whether the posterior circulation Acute Stroke Prognosis Early CT Score and the Pons-Midbrain Index applied to CT angiography source images predict the outcome of comatose patients in the Basilar Artery International Cooperation Study. Methods Basilar Artery International Cooperation Study was a prospective, observational registry of patients with acute basilar artery occlusion with 48 recruiting centers worldwide. We applied posterior circulation Acute Stroke Prognosis Early CT Score and Pons-Midbrain Index to CT angiography source images of Basilar Artery International Cooperation Study patients who presented with coma. We calculated adjusted risk ratios to assess the association of dichotomized posterior circulation Acute Stroke Prognosis Early CT Score (≥8 vs. International Cooperation Study registry, CT angiography source images were available for review in 158 patients. Among these, 78 patients (49%) presented with coma. Compared to non-comatose patients, comatose patients were more likely to die (risk ratios 2.34; CI 95% 1.56-3.52) and less likely to have a favourable outcome (risk ratios 0.44; CI 95% 0.24-0.80). Among comatose patients, a Pons-Midbrain Index < 3 was related to reduced mortality (adjusted RR 0.66; 95% CI 0.46-0.96), but not to favourable outcome (adjusted RR 1.19; 95% CI 0.39-3.62). Posterior circulation Acute Stroke Prognosis Early CT Score dichotomized at ≥ 8 vs. <8 was not significantly associated with death (adjusted RR 0.70; 95% CI 0.46-1.05). Conclusion In comatose patients with basilar artery occlusion, the extent of brainstem ischemia appears to be related to mortality but not to favourable outcome.

  7. Myocardial CT perfusion imaging and SPECT for the diagnosis of coronary artery disease

    DEFF Research Database (Denmark)

    George, Richard T; Mehra, Vishal C; Chen, Marcus Y

    2014-01-01

    %, respectively, for SPECT. CONCLUSION: The overall performance of myocardial CT perfusion imaging in the diagnosis of anatomic CAD (stenosis ≥50%), as demonstrated with the Az, was higher than that of SPECT and was driven in part by the higher sensitivity for left main and multivessel disease.......PURPOSE: To compare the diagnostic performance of myocardial computed tomographic (CT) perfusion imaging and single photon emission computed tomography (SPECT) perfusion imaging in the diagnosis of anatomically significant coronary artery disease (CAD) as depicted at invasive coronary angiography....... MATERIALS AND METHODS: This study was approved by the institutional review board. Written informed consent was obtained from all patients. Sixteen centers enrolled 381 patients from November 2009 to July 2011. Patients underwent rest and adenosine stress CT perfusion imaging and rest and either exercise...

  8. Arm exercise-thallium imaging testing for the detection of coronary artery disease

    International Nuclear Information System (INIS)

    Balady, G.J.; Weiner, D.A.; Rothendler, J.A.; Ryan, T.J.

    1987-01-01

    Patients with lower limb impairment are often unable to undergo a standard bicycle or treadmill test for the evaluation of coronary artery disease. To establish an alternative method of testing, 50 subjects (aged 56 +/- 10 years) performed arm ergometry testing in conjunction with myocardial thallium scintigraphy. All underwent coronary angiography; significant coronary artery disease (greater than or equal to 70% stenosis) in at least one vessel was present in 41 (82%) of the 50 patients. Thallium scintigraphy was found to have an 83% sensitivity and 78% specificity for detecting coronary disease, compared with a sensitivity and specificity of 54% (p less than 0.01) and 67% (p = NS), respectively, for exercise electrocardiography. In the subgroup of 23 patients who had no prior myocardial infarction or left bundle branch block and were not taking digitalis, thallium scintigraphy had a sensitivity of 80% versus 50% for exercise electrocardiography. Scintigraphy yielded a sensitivity of 84, 74 and 90% for one, two and three vessel disease, respectively. Noninvasive arm ergometry exercise-thallium imaging testing appears to be reliable and useful and should be considered in the evaluation of coronary artery disease in patients with lower limb impairment

  9. 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.)

  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. Comparison of virtual monoenergetic and polyenergetic images reconstructed from dual-layer detector CT angiography of the head and neck.

    Science.gov (United States)

    Neuhaus, Victor; Große Hokamp, Nils; Abdullayev, Nuran; Maus, Volker; Kabbasch, Christoph; Mpotsaris, Anastasios; Maintz, David; Borggrefe, Jan

    2018-03-01

    To compare the image quality of virtual monoenergetic images and polyenergetic images reconstructed from dual-layer detector CT angiography (DLCTA). Thirty patients who underwent DLCTA of the head and neck were retrospectively identified and polyenergetic as well as virtual monoenergetic images (40 to 120 keV) were reconstructed. Signals (± SD) of the cervical and cerebral vessels as well as lateral pterygoid muscle and the air surrounding the head were measured to calculate the CNR and SNR. In addition, subjective image quality was assessed using a 5-point Likert scale. Student's t-test and Wilcoxon test were used to determine statistical significance. Compared to polyenergetic images, although noise increased with lower keV, CNR (p 0.05) of the cervical, petrous and intracranial vessels were improved in virtual monoenergetic images at 40 keV and virtual monoenergetic images at 45 keV were also rated superior regarding vascular contrast, assessment of arteries close to the skull base and small arterial branches (p virtual monoenergetic images reconstructed from DLCTA at low keV ranging from 40 to 45 keV improve the objective and subjective image quality of extra- and intracranial vessels and facilitate assessment of vessels close to the skull base and of small arterial branches. • Virtual monoenergetic images greatly improve attenuation, while noise only slightly increases. • Virtual monoenergetic images show superior contrast-to-noise ratios compared to polyenergetic images. • Virtual monoenergetic images significantly improve image quality at low keV.

  12. Improving high resolution retinal image quality using speckle illumination HiLo imaging.

    Science.gov (United States)

    Zhou, Xiaolin; Bedggood, Phillip; Metha, Andrew

    2014-08-01

    Retinal image quality from flood illumination adaptive optics (AO) ophthalmoscopes is adversely affected by out-of-focus light scatter due to the lack of confocality. This effect is more pronounced in small eyes, such as that of rodents, because the requisite high optical power confers a large dioptric thickness to the retina. A recently-developed structured illumination microscopy (SIM) technique called HiLo imaging has been shown to reduce the effect of out-of-focus light scatter in flood illumination microscopes and produce pseudo-confocal images with significantly improved image quality. In this work, we adopted the HiLo technique to a flood AO ophthalmoscope and performed AO imaging in both (physical) model and live rat eyes. The improvement in image quality from HiLo imaging is shown both qualitatively and quantitatively by using spatial spectral analysis.

  13. Learning Receptive Fields and Quality Lookups for Blind Quality Assessment of Stereoscopic Images.

    Science.gov (United States)

    Shao, Feng; Lin, Weisi; Wang, Shanshan; Jiang, Gangyi; Yu, Mei; Dai, Qionghai

    2016-03-01

    Blind quality assessment of 3D images encounters more new challenges than its 2D counterparts. In this paper, we propose a blind quality assessment for stereoscopic images by learning the characteristics of receptive fields (RFs) from perspective of dictionary learning, and constructing quality lookups to replace human opinion scores without performance loss. The important feature of the proposed method is that we do not need a large set of samples of distorted stereoscopic images and the corresponding human opinion scores to learn a regression model. To be more specific, in the training phase, we learn local RFs (LRFs) and global RFs (GRFs) from the reference and distorted stereoscopic images, respectively, and construct their corresponding local quality lookups (LQLs) and global quality lookups (GQLs). In the testing phase, blind quality pooling can be easily achieved by searching optimal GRF and LRF indexes from the learnt LQLs and GQLs, and the quality score is obtained by combining the LRF and GRF indexes together. Experimental results on three publicly 3D image quality assessment databases demonstrate that in comparison with the existing methods, the devised algorithm achieves high consistent alignment with subjective assessment.

  14. Imaging and modeling of acute pressure-induced changes of collagen and elastin microarchitectures in pig and human resistance arteries.

    Science.gov (United States)

    Bloksgaard, Maria; Leurgans, Thomas M; Spronck, Bart; Heusinkveld, Maarten H G; Thorsted, Bjarne; Rosenstand, Kristoffer; Nissen, Inger; Hansen, Ulla M; Brewer, Jonathan R; Bagatolli, Luis A; Rasmussen, Lars M; Irmukhamedov, Akhmadjon; Reesink, Koen D; De Mey, Jo G R

    2017-07-01

    The impact of disease-related changes in the extracellular matrix (ECM) on the mechanical properties of human resistance arteries largely remains to be established. Resistance arteries from both pig and human parietal pericardium (PRA) display a different ECM microarchitecture compared with frequently used rodent mesenteric arteries. We hypothesized that the biaxial mechanics of PRA mirror pressure-induced changes in the ECM microarchitecture. This was tested using isolated pig PRA as a model system, integrating vital imaging, pressure myography, and mathematical modeling. Collagenase and elastase digestions were applied to evaluate the load-bearing roles of collagen and elastin, respectively. The incremental elastic modulus linearly related to the straightness of adventitial collagen fibers circumferentially and longitudinally (both R 2 ≥ 0.99), whereas there was a nonlinear relationship to the internal elastic lamina elastin fiber branching angles. Mathematical modeling suggested a collagen recruitment strain (means ± SE) of 1.1 ± 0.2 circumferentially and 0.20 ± 0.01 longitudinally, corresponding to a pressure of ~40 mmHg, a finding supported by the vital imaging. The integrated method was tested on human PRA to confirm its validity. These showed limited circumferential distensibility and elongation and a collagen recruitment strain of 0.8 ± 0.1 circumferentially and 0.06 ± 0.02 longitudinally, reached at a distending pressure below 20 mmHg. This was confirmed by vital imaging showing negligible microarchitectural changes of elastin and collagen upon pressurization. In conclusion, we show here, for the first time in resistance arteries, a quantitative relationship between pressure-induced changes in the extracellular matrix and the arterial wall mechanics. The strength of the integrated methods invites for future detailed studies of microvascular pathologies. NEW & NOTEWORTHY This is the first study to quantitatively relate pressure

  15. Image Quality in High-resolution and High-cadence Solar Imaging

    Science.gov (United States)

    Denker, C.; Dineva, E.; Balthasar, H.; Verma, M.; Kuckein, C.; Diercke, A.; González Manrique, S. J.

    2018-03-01

    Broad-band imaging and even imaging with a moderate bandpass (about 1 nm) provides a photon-rich environment, where frame selection (lucky imaging) becomes a helpful tool in image restoration, allowing us to perform a cost-benefit analysis on how to design observing sequences for imaging with high spatial resolution in combination with real-time correction provided by an adaptive optics (AO) system. This study presents high-cadence (160 Hz) G-band and blue continuum image sequences obtained with the High-resolution Fast Imager (HiFI) at the 1.5-meter GREGOR solar telescope, where the speckle-masking technique is used to restore images with nearly diffraction-limited resolution. The HiFI employs two synchronized large-format and high-cadence sCMOS detectors. The median filter gradient similarity (MFGS) image-quality metric is applied, among others, to AO-corrected image sequences of a pore and a small sunspot observed on 2017 June 4 and 5. A small region of interest, which was selected for fast-imaging performance, covered these contrast-rich features and their neighborhood, which were part of Active Region NOAA 12661. Modifications of the MFGS algorithm uncover the field- and structure-dependency of this image-quality metric. However, MFGS still remains a good choice for determining image quality without a priori knowledge, which is an important characteristic when classifying the huge number of high-resolution images contained in data archives. In addition, this investigation demonstrates that a fast cadence and millisecond exposure times are still insufficient to reach the coherence time of daytime seeing. Nonetheless, the analysis shows that data acquisition rates exceeding 50 Hz are required to capture a substantial fraction of the best seeing moments, significantly boosting the performance of post-facto image restoration.

  16. Cardiac magnetic resonance imaging in patients with chest pain, high troponin levels and absence of coronary artery obstruction

    International Nuclear Information System (INIS)

    Avegliano, G.P.; Costabel, J.P.; Kuschnir, P.; Thierer, J.; Alves de Lima, A.; Sanchez, G.; Ronderos, J.; Huguet, M.; Petit, M.; Frangi, A.A.

    2011-01-01

    The prevalence of myocardial infarction with angiographically normal coronary arteries is approximately 7-10%. The etiological diagnosis is sometimes difficult and is important in terms of clinical practice and prognosis. The goal of our study was to show a series of consecutive patients with an initial diagnosis of acute coronary syndrome with high troponin levels and absence of coronary artery obstruction in which cardiac magnetic resonance imaging (CMRI) gave a description of the myocardial lesion, orientating towards the etiological diagnosis. From January 2005 to December 2009, 720 consecutive patients with an initial diagnosis of acute coronary syndrome and elevated troponins were included; 64 of these patients did not present angiographically significant coronary artery stenosis. Within 72 ± 24 h after coronary angiography, these patients underwent CMRI using b-SSFP sequences for cine imaging in short-axis, 2-, 3- and 4- chamber views for the evaluation of segmental wall motion, with T2-weighted and delayed enhancement (DE) images of the myocardium with an 'inversion-recovery' sequence. The following diagnoses were made: myocarditis (39 patients); myocardial infarction (12 patients); Tako-Tsubo syndrome (8 patients); apical hypertrophic cardiomyopathy (2 patients); 3 patients remained without diagnosis. These findings demonstrate the usefulness of CMRI in the clinical scenario of patients with chest pain, inconclusive ECG findings and high troponin levels with angiographically normal coronary arteries. The presence and distribution pattern of DE make it possible to define the etiological diagnosis and interpret the physiopathological process. (authors) [es

  17. Automated image quality assessment for chest CT scans.

    Science.gov (United States)

    Reeves, Anthony P; Xie, Yiting; Liu, Shuang

    2018-02-01

    Medical image quality needs to be maintained at standards sufficient for effective clinical reading. Automated computer analytic methods may be applied to medical images for quality assessment. For chest CT scans in a lung cancer screening context, an automated quality assessment method is presented that characterizes image noise and image intensity calibration. This is achieved by image measurements in three automatically segmented homogeneous regions of the scan: external air, trachea lumen air, and descending aorta blood. Profiles of CT scanner behavior are also computed. The method has been evaluated on both phantom and real low-dose chest CT scans and results show that repeatable noise and calibration measures may be realized by automated computer algorithms. Noise and calibration profiles show relevant differences between different scanners and protocols. Automated image quality assessment may be useful for quality control for lung cancer screening and may enable performance improvements to automated computer analysis methods. © 2017 American Association of Physicists in Medicine.

  18. IMAGE QUALITY FORECASTING FOR SPACE OBJECTS

    Directory of Open Access Journals (Sweden)

    A. I. Altukhov

    2013-05-01

    Full Text Available The article deals with an approach to quality predicting of the space objects images, which can be used to plan optoelectronic systems of remote sensing satellites work programs. The proposed approach is based on evaluation of the optoelectronic equipment transfer properties and calculation of indexes images quality considering the influence of the orbital shooting conditions.

  19. Transesophageal echocardiography in the assessment of coronary arteries

    International Nuclear Information System (INIS)

    Adamek-Kosmider, A.; Kasprzak, J.; Kosmider, M.; Krzeminska-Pakula, M.

    1993-01-01

    The study was undertaken to assess the usefulness of TEE for evaluation of morphology and flow in coronary arteries. TEE (2D, spectral and color Doppler imaging) and coronary angiography were performed in 75 patients - 41 with valvular heart disease and 34 with ischemic heart disease. Proximal coronary artery stenosis was detected by coronarography in 11 pts (9-left main coronary artery, 2-right coronary artery). TEE visualization of proximal coronary arteries was possible in all pts. Echocardiographic features of artery stenosis were: the narrowing of the vessel in 2D image (9 pts), high flow velocity spectral Doppler (4 pts, mean 135 cm/s vs 55 cm/s in normal arteries) and mosaic, turbulent flow in color Doppler (10 pts). Sensitivity and specificity of TEE for coronary artery stenosis detection was respectively 81%/98% for 2D imaging and 90%/100% for color Doppler. TEE is a new, noninvasive and safe method for the evaluation of proximal coronary arteries. Detection of LMCA stenosis prior to atheterization may enhance the safety of coronary angiography. (author)

  20. Retinal artery occlusion during carotid artery stenting with distal embolic protection device.

    Science.gov (United States)

    Kohara, Kotaro; Ishikawa, Tatsuya; Kobayashi, Tomonori; Kawamata, Takakazu

    2018-01-01

    Retinal artery occlusion associated with carotid artery stenosis is well known. Although it can also occur at the time of carotid artery stenting, retinal artery occlusion via the collateral circulation of the external carotid artery is rare. We encountered two cases of retinal artery occlusion that were thought to be caused by an embolus from the external carotid artery during carotid artery stenting with a distal embolic protection device for the internal carotid artery. A 71-year-old man presented with central retinal artery occlusion after carotid artery stenting using the Carotid Guardwire PS and a 77-year-old man presented with branch retinal artery occlusion after carotid artery stenting using the FilterWire EZ. Because additional new cerebral ischaemic lesions were not detecte