Computed tomography angiography (CTA) is a useful approach for diagnosing vascular diseases. In this paper, we proposed a reconstruction algorithm for dual-source spiral CT with variable pitch. The projection data are collected by the double-source double-multislice spiral CT (DSDMS-CT). However, the pitch of the DSDMS-CT is variable other than being constant. We have developed a new formula performing interpolation along Z-axis for dual-source spiral CT with variable pitch. The dual-source spiral CT with variable pitch can chase contrast bolus more flexibly and more effectively. The simulation results show the correctness and efficiency of the proposed algorithm.
Algorithms ; Coronary Angiography ; methods ; Humans ; Tomography, Spiral Computed ; instrumentation ; methods

OBJECTIVETo evaluate the value of double source multidetector computed tomography (MDCT) in visualization of cardiac veins in patients with chronic heart failure.

METHODSThirty-five patients with chronic heart failure (aged 65.4 ± 8.8, 21 males and 14 females) were enrolled in the study. In Group A, MDCT and retrograde coronary venography (RCV) were performed consecutively; in Group B anterograde visualization of the coronary venous and RCV were performed.

RESULTSCoronary sinus, GCV and MCV of all individuals were identified in MDCT. LVPV was observed in 65% patients of Group A, and 66.7% patients of Group B. The correlation coefficient between MDCT and RCV was 0.944, and that between CVG and RCV was 0.42.

CONCLUSIONNon-invasive evaluation of cardiac veins with double source CT is feasible and may be used in cardiac resynchronization therapy.

Aged ; Coronary Angiography ; methods ; Female ; Humans ; Male ; Middle Aged ; Phlebography ; methods ; Tomography, Spiral Computed ; methods

Coronary Angiography ; methods ; Coronary Artery Disease ; diagnosis ; Humans ; Tomography, X-Ray Computed ; methods

OBJECTIVES: To explore the application value of postmortem computed tomography （CT） angiography on diagnosis of coronary atherosclerotic stenosis degree. METHODS: Based on the previous experimental results, the postmortem CT angiography device of human isolated heart was improved. Different coronary atherosclerotic stenosis degree of sudden death cases was selected. Before the cardiac anatomy, hearts were removed out completely and CT angiography was performed immediately. The CT angiography results were compared with histopathological findings. Meanwhile, the advantages and disadvantages of the angiography device before and after improvement were compared. RESULTS: The improved angiography device of isolated heart could get better imaging results. The postmortem CT angiography results had high consistency with the histopathological findings on diagnosis of coronary atherosclerotic stenosis degree. And the coronary artery lesions could be revealed more objectively and vividly by 3D reconstruction technology. However, CT angiography could only be used to examine the pathological changes of blood vessels, which might have some limitations on the diagnosis of cause of death. CONCLUSIONS Postmortem CT angiography can be used as an additional method for the conventional autopsy in the cases of coronary atherosclerosis.
Autopsy ; Computed Tomography Angiography/methods* ; Coronary Angiography ; Coronary Artery Disease/diagnostic imaging* ; Coronary Stenosis ; Heart ; Humans ; Middle Aged ; Predictive Value of Tests ; Tomography, X-Ray Computed

OBJECTIVETo explore the scan technique and image quality of coronary angiography with dual source computed tomography (CT) without oral metoprolol preparation.

METHODSPlain and enhanced dual source CT coronary angiography without oral metoprolol preparation was prospectively performed in 600 patients. Calcium scoring with plain scan images as well as multi-planar reconstruction (MPR), maximum intensity projection (MIP), and volume rendering technique (VRT) reconstruction with enhanced scan images were performed in all cases. The scan technique and post-reconstruction experience was summarized. The image quality was classified as 1 to 4 points, and coronary segments classified according to the American Heart Association standards were evaluated.

RESULTSThe average calcium score of the 600 cases was 213.6 +/- 298.7 (0-3,216.5). The average heart rate of the enhanced scan was 82.1 +/- 16.2 (47-139) bpm. The post-reconstruction methods with which coronary segments could be shown as best as possible consisted of single phase reconstruction method, two or more phases supplemented method, and electrocardiogram editing method. Altogether 8,457 coronary segments were evaluated, among which 97.2% were evaluated as point 1, 1.7% point 2, 0.5% point 3, and 0.6% point 4. The coronary segments in 261 cases were completely normal, while 360 segments were diagnosed with < 50% stenosis and 625 segments with > or = 50% stenosis.

CONCLUSIONSExcellent coronary artery image can be obtained with dual source CT in patients with any heart rate without oral metoprolol preparation. Heart rate is not a major source of the artifact, coronary segments can be well shown with single or multiple-phase reconstruction method.

Adult ; Coronary Angiography ; Female ; Heart Rate ; Humans ; Male ; Middle Aged ; Tomography, X-Ray Computed ; methods

The emergence of multi-slice spiral computed tomography (MSCT) has a significant influence on cardiovascular imaging. As a noninvasive technique, MSCT is considered suitable for the evaluation of coronary artery stenosis, quantitative and qualitative assessment of plaque, analysis of cardiac function and myocardial perfusion imaging, and determination of the patency of stents or bypass grafts. Recent studies has shown that noninvasive coronary artery imaging with MSCT is a feasible screening test for suspected coronary artery diseases and a valuable follow-up tool for patients who have undergone interventional or surgical therapeutic procedures.
Coronary Angiography ; methods ; Coronary Artery Disease ; diagnostic imaging ; Coronary Stenosis ; diagnostic imaging ; Humans ; Tomography, Spiral Computed

Objective To evaluate the value of third-generation dual-source CT scanner in application of high-pitch aorta CT angiography(CTA). Methods Totally 59 patients clinically indicated for whole aorta angiography were divided into 2 groups using a simple random method:in group 1 there were 28 patients who underwent the examination on a third-generation dual-source CT device,with a collimation of 2×192×0.6 mm and a rotation time of 0.25 s;in group 2 there were 31 patients who underwent the examination on a second generation dual-source CT device,with a collimation of 2×128×0.6 mm and a rotation time of 0.28 s. Both groups were given the examination operated in dual-source high-pitch ECG-gating mode with a pitch of 3.0,a tube voltage of 100 kV,and automated tube current modulation using a reference tube current of 288 mA. A contrast material bolus of 45 ml with a flow of 4.5 ml/s followed by a 50 ml saline chaser in 5.0 ml/s was used. CTA scan was automatically started using a bolus tracking technique at the level of the original part of aorta after a trigger threshold of 100 HU was reached. The start delay was set to 6 s in both groups. Effective dose(ED),signal to noise ratio (SNR),contrast to noise ratio (CNR),and subjective diagnostic quality of both groups were evaluated. Results The mean ED were 19.44% lower (t=-3.989,P=0.000) in group 1 [(3.15±0.86)mSv] than in group 2 [(3.91±0.60)mSv]. These two groups showed no significant differences in SNR or CNR (all P >0.05). The subjective diagnostic quality values also showed no significant difference between two groups [(1.39±0.50)scores vs. (1.45±0.51)scores;W=814.5,P=0.651].Conclusion Compared with the second-generation dual-source CT scanner,the third-generation dual-source CT scanner in whole aorta CTA can remarkably reduce the radiation dose without affecting image quality.
Aorta ; diagnostic imaging ; Computed Tomography Angiography ; methods ; Humans ; Radiation Dosage ; Retrospective Studies ; Signal-To-Noise Ratio

With 2mm-thick CT scanning during the rapid infusion of contrast material(TICT), cerebral aneurysms arising from the circle of Willis and adjacent vessels can be directly visualized. Twenty-five patients who had cerebral aneurysm confirmed by surgery were examined with TIGT and digital subtraction angiography. The authors examined TIGT prospectively to assess the detection rate of the cerebal aneurysms and to evaluate the clinical usefulness of TIGT. The detection rates of aneurysms by TIGT and digital subtraction angiography were 68% and 84%, respectively. TIGT is a rapid, safe and reliable method in the evaluation of patients with suspected cerebral aneurysm, permitting direct visualization of the aneurysm.
Aneurysm ; Angiography, Digital Subtraction ; Circle of Willis ; Humans ; Intracranial Aneurysm* ; Methods ; Prospective Studies ; Tomography, X-Ray Computed

OBJECTIVETo explore the diagnostic feasibility of noninvasive assessment of coronary atherosclerotic plaques with MSCT in comparison with IVUS.

METHODSContrast-enhanced MSCT angiography (Sensation 64, Siemens Medical Solutions) was performed before percutaneous coronary intervention (PCI), and three-vessel IVUS (Boston Scientific, Natick, MA) was performed during procedure in 12 patients with stable angina pectoris. Complete investigation was digitally stored, and assessed offline with EchoPlaque (Indec Systems, Mountain View, CA). The comparison of MSCT with IVUS was performed based on segment at plaque site (American Heart Association 15-segment model).

RESULTSA total of 88 segments in 31 vessels (left anterior descending: 12, left circumflex: 10, and right coronary artery: 9) were investigated by both IVUS and MSCT. Among 68 assessable segments (54 proximal-middle segments and 14 distal segments) by MSCT (20 segments were excluded for poor image quality: 16 for severe calcification, 2 for motion artifact, 2 for poor opacification), MSCT correctly detected 47 of the 51 segments with plaques (sensitivity: 92%), and correctly evaluated 16 of 17 segments without plaques (specificity: 94%). Concerning plaque quantification, MSCT correlated well with IVUS in grading whether the vessel obstruction was less or more than 50% (simple kappa: 0.63, 95% CI: from 0.47 to 0.78). Plaque area by MSCT also correlated with that by IVUS (r = 0.53, P < 0.01), but overestimated plaque area [(9.09 +/- 3.89) mm(2) vs. (6.80 +/- 2.81) mm(2), P < 0.01]. In addition, 30 of 43 hypoechoic compositions were detected as low-density compositions by MSCT with average CT number as 67.39 HU.

CONCLUSIONSIn segments without severe calcification, contrast-enhanced 64-slice CT angiography could detect plaques in coronary artery with high accuracy. Plaque area quantification by MSCT correlated with that of IVUS though with limited accuracy.

Coronary Angiography ; Coronary Artery Disease ; diagnostic imaging ; Humans ; Tomography, X-Ray Computed ; methods ; Ultrasonography, Interventional

OBJECTIVETo compare the image quality and radiation dose of prospectively electrocardiogram (ECG) -triggered spiral and sequential acquisition for coronary computed tomographic angiography by dual-source computed tomography.

METHODSSixty patients with suspected or known coronary artery disease were randomly divided into two groups. Group A underwent prospective ECG-triggering spiral scan and Group B underwent prospective ECG-triggering sequential scan. Both the image quality and radiation dose of the two groups were compared.

RESULTSThere was no significant difference in age and body mass index of the two groups. The average image quality score was 1.12 ± 0.38 in group A and 1.14 ± 0.38 in group B (Z=-0.291,P=0.771) . The rates of diagnostic coronary segments for two groups were 98.87% and 99.56% respectively (X2=0.59,P=0.443) . The mean radiation dose of group A was significantly lower than that of group B [ (1.31 ± 0.30) mSv vs. (3.36 ± 0.93) mSv; t=11.47, P=0.000] .

CONCLUSIONCompared with the prospective ECG-triggered sequential acquisition, the prospective ECG - triggered spiral scan for coronary computed tomographic angiography can remarkably reduce radiation dose without impairing image quality in patients with a low and stable heart rate (≤ 70 bpm) .

Aged ; Coronary Angiography ; methods ; Coronary Artery Disease ; diagnostic imaging ; Female ; Humans ; Male ; Middle Aged ; Radiation Dosage ; Tomography, Spiral Computed ; methods ; Tomography, X-Ray Computed ; methods