16排CT对冠状动脉桥血管病变评估的临床应用价值

目的探讨16排计算机断层扫描技术对冠状动脉桥血管病变评估的临床应用价值。方法本研究共入选62例冠状动脉旁路移植术后患者,其中6例因心率控制不佳被排除。对其余56例共152条桥血管(其中内乳动脉桥48条,隐静脉桥104条)分别用16排CT造影(CTA)和常规冠状动脉造影(CAG)进行检查。CTA检查均通过回顾性心电图门控方法进行。患者平均心率(58±6)次/min。在CTA检查过程中以4ml/s速度静脉注入120ml的Visipaque320造影剂。冠状动脉桥血管的通畅和狭窄程度由两位有经验的医师来评估。结果在本研究中,CTA方法能显示所有冠状动脉桥血管;CTA还能显示所有桥血管近端吻合处以及71%的远端吻合处。并且,经CTA检查发现有29条桥血管发生闭塞,13条桥血管有显著狭窄病变。通过CAG检查比较CTA结果证实:在所有42条CTA检查发现闭塞或狭窄的冠状动脉桥血管中,CAG显示有34条桥血管有闭塞或狭窄;在所有110条CTA检查显示正常的冠状动脉桥血管中,CAG显示有108条桥血管正常,有8例假阳性和2例假阴性发生。CTA检查的敏感性94%,特异性95%;阳性预测值86%,阴性预测值99%。结论CTA可提供清晰的冠状动脉桥血管图像以及较高的诊断准确性。CTA可作为评估冠状动脉桥血管病变的一种无创检查方法。     

Initial experience with 64-slice cardiac CT: non-invasive visualization of coronary artery bypass grafts.

AIMS: The aim of this study was to evaluate the diagnostic accuracy in the assessment of coronary artery bypass grafts using 64-slice computed tomography (CT) technology. METHODS AND RESULTS: CT coronary angiography was performed for 96 bypasses in 31 patients with suspected coronary artery disease using a Siemens Sensation 64-slice CT-scanner and compared with invasive coronary angiography (ICA). Patients with an irregular or fast heart rate despite beta-blocker administration were not excluded from the study. All bypass grafts and 94% of the distal bypass anastomoses could be visualized by CT, non-evaluable distal arterial anastomoses were either due to clip material or calcification artefacts. Forty-two bypass graft occlusions and three significant stenoses were detected by CT and confirmed by ICA. Two venous grafts were missed and one arterial graft was not evaluable with ICA, but both were clearly depicted by multi-slice CT. One false negative and two false positive CT-findings resulted in a sensitivity of 97.8%, a specificity of 89.3%, a positive predictive value of 90%, and a negative predictive value of 97.7%. CONCLUSION: State-of-the-art 64-slice CT coronary angiography demonstrates high diagnostic accuracy in the assessment of arterial and venous bypass graft stenoses.     

Non-invasive assessment of coronary artery bypass grafts by computed tomography: comparison with conventional coronary angiography

INTRODUCTION AND OBJECTIVES: Although it has been demonstrated that the diagnostic accuracy of computed tomography in the non-invasive assessment of major epicardial coronary arteries is high, only a few studies have evaluated the technique's reliability in assessing coronary artery bypass grafts. The aim of this study was to determine the diagnostic accuracy of multidetector computed tomography in the assessment of coronary grafts. PATIENTS AND METHOD: We prospectively evaluated 117 coronary grafts in 38 patients who had undergone coronary artery bypass graft surgery and who had a clinical indication for angiographic graft assessment. All patients were in sinus rhythm and had a heart rate below 75 bpm. A 16-detector scanner was used for non-invasive assessment of the coronary grafts at a slice thickness of 1.2 mm. The diagnostic accuracy of computed tomography in the non-invasive assessment of significant lesions (i.e., occluded lesions or those with a stenosis greater than 50%) in coronary artery bypass grafts was evaluated by comparison with the results of conventional angiography. RESULTS: Of the 117 grafts evaluated, 99 (84.6%) were visualized by conventional angiography and 109 (93.2%) by computed tomography. Overall, 98 grafts were analyzed using both techniques. The sensitivity and specificity of computed tomography in detecting significant lesions were: 92% and 97.3%, respectively, for all grafts; 89.5% and 97.6%, respectively, for venous grafts; and 100% and 96.8%, respectively, for arterial grafts. CONCLUSIONS: The diagnostic accuracy of multidetector computed tomography in coronary artery bypass graft assessment was high.     

Evaluation of coronary artery bypass grafts using helical scan computed tomography

The patency of coronary artery bypass grafts was evaluated by helical computed tomographic (CT) scan. One hundred forty patients who received an enhanced chest CT scan and a coronary angiography after bypass surgery were studied before discharge at the Fukui Cardiovascular Center. Among them was a total of 398 grafts and 436 anastomoses. For the evaluation of 248 vein grafts, the CT scan showed a 99.5% correct positive ratio and an overall accuracy of 96.4%. In 122 internal thoracic arteries tested, an overall accuracy of 64.7% was obtained. In gastroepiploic artery tests the overall accuracy was 33.3% and in radial artery tests it was 45.5%. Thirty-seven venous sequential anastomoses in 34 grafts and 1 internal thoracic artery sequential anastomosis were also evaluated. In the venous sequential anastomosis, the CT scan showed a 73.0% of accuracy overall. This study showed that the helical CT scan was useful to evaluate graft patency following bypass surgery. Cathet. Cardiovasc. Intervent. 46:322–326, 1999. © 1999 Wiley-Liss, Inc.     

Comparison of multidetector 64-slice computed tomographic angiography to coronary angiography to assess the patency of coronary artery bypass grafts

This study prospectively evaluated the diagnostic accuracy of 64-slice computed tomographic angiography (CTA) in assessing the patency of coronary artery bypass grafts compared with invasive coronary angiography. In total 147 bypass grafts (100 venous grafts and 47 mammary artery grafts) were evaluated in 50 consecutive patients. Contrast-enhanced 64-slice CTA was performed and compared with invasive angiography. The computed tomographic angiographic scan protocol used 64- x 0.5-mm slice collimation and 0.33-second gantry rotation time during simultaneous electrocardiographic gating. Patients with a heart rate >65 beats/min received beta blockers. Overall 145 of 147 bypass grafts (98.6%) were detected by CTA; 2 nonvisualized grafts were occluded at the time of invasive angiography. Of the grafts visualized, 28 were totally occluded, 103 were patent, and 14 had significant stenoses that were confirmed by invasive angiography. Ninety-five percent (111 of 117) of patent grafts demonstrated good run-off distal to anastomoses but without an ability to accurately evaluate the presence of retrograde flow; 83% (97 of 117) of distal anastomoses were adequately evaluated, whereas the remaining 17% (20 of 117) were not well visualized due to vascular clips and/or calcification artifacts. Two grafts were not demonstrated by invasive angiography but were detected by CTA and found to be widely patent. In conclusion, multidetector 64-slice CTA is a valuable tool for direct visualization of coronary bypass grafts and assessment of their patency. Dysfunctional bypass grafts can be detected with high diagnostic accuracy.     

Assessment of coronary artery disease using coronary computed tomography angiography in patients with aortic valve stenosis referred for surgical aortic valve replacement

Background

In patients referred for aortic valve replacement (AVR) a pre-surgical assessment of coronary artery disease is mandatory to determine the possible need for additional coronary artery bypass grafting. The diagnostic accuracy of coronary computed tomography angiography (coronary CTA) was evaluated in patients with aortic valve stenosis referred for surgical AVR.

Methods

Between March 2008 and March 2010 a total of 181 consecutive patients were included. All patients underwent pre-surgical coronary CTA (64- or 320-detector CT scanner) and invasive coronary angiography (ICA). The analyses were performed blinded to each other.

Results

The mean ± SD age of the included patients was 71 ± 9 years and 59% were male. The prevalence of significant coronary artery stenosis > 70% by ICA was 36%. Average heart rate during coronary CTA was 65 ± 16 bpm. In a patient based analysis 94% of the patients (171/181) were considered fully evaluable. Coronary CTA had a sensitivity of 68%, a specificity of 91%, a positive predictive value of 81%, and a negative predictive value of 83%. Advanced age, obstructive lung disease, NYHA function class III/IV, and high Agatston score were found to be significantly associated with disagreement between ICA and coronary CTA in univariate analysis.

Conclusion

In patients with aortic valve stenosis referred for surgical AVR the diagnostic accuracy of coronary CTA to identify significant coronary artery disease is moderate. Coronary CTA may be used successfully in a subset of patients with low age, no chronic obstructive lung disease, NYHA function class < III and low coronary Agatston score.     

Routine intraoperative angiography improves the early patency of coronary grafts performed on the beating heart

OBJECTIVES: The techniques of performing coronary revascularization without cardiopulmonary bypass are rapidly evolving. However, concern remains regarding the accuracy of coronary artery anastomoses performed on the beating heart. This report reviews the use of intraoperative angiography in the critical appraisal of "off-pump" coronary artery bypass graft (CABG) surgery. PATIENTS: Intraoperative angiography was performed in 24 consecutive patients undergoing CABG surgery without cardiopulmonary bypass. In all, 24 left internal mammary artery (LIMA) grafts and 18 saphenous vein bypass grafts were assessed for patency, anastomosis quality, distal and proximal runoff, and correct placement. RESULTS: All of the saphenous vein-to-coronary artery anastomoses were widely patent, although two patients (8%) required revision of their LIMA grafts on the basis of angiographic findings. CONCLUSION: Intraoperative angiography permits the surgeon to immediately appraise the CABG and to revise, if necessary, any graft abnormality, thus potentially eliminating the need for early repeated surgery. The practice of routine intraoperative angiography is likely to improve the outcome of CABG surgery on the beating heart.     

Non-selective intra-arterial digital subtraction angiography for the assessment of coronary artery bypass grafts

Non-selective intra-arterial digital subtraction angiography (DSA) was performed immediately before selective coronary and bypass angiography in 33 consecutive symptomatic patients 48± 30 months after coronary surgery, for the assessment of 75 coronary bypass grafts. Forty ml of non-ionic, low-iodine content contrast medium (iohexol) were injected into the ascending aorta at 10–20 ml/sec through a 7 or 8 F femoral pigtail catheter.Electrocardiogram-triggered images were acquired on a Siemens Digitron II apparatus in multiple projections in 24 patients and in a single projection in 9 patients. The results of this technique were compared by two independent angiographers with those of selective graft angiography in the same patients. Patency was shown by DSA in 45 of 54 grafts confirmed to be open by selective angiography (sensitivity 83%). Of 21 occluded grafts, stumps were clearly visible at selective angiography in 18 and at DSA in 9 (sensitivity for graft stumns = 50%, p<0.01) Of 54 patent grafts with selective angiogranhy. the distal anastomosis could be visualized by DSA in 28 (52%), but the resolution was comparable to selective angiography in 20 grafts (37%) only. A non-significant difference in the sensitivity of DSA was observed between patent saphenous grafts to the left anterior descending coronary artery versus all other coronary arteries (95 vs 85%, respectively), while only 1 of 5 patent left internal mammary artery grafts to the left anterior descending coronary artery was visualized. In 16 of 50 grafts (32%) visualized in a second projection substantial additional diagnostic information was obtained. In conclusion, non-selective intra-arterial electrocardiogram-triggered DSA can visualize patent saphenous grafts with a high sensitivity and may be a useful screening tool for bypass grafts patency; false negatives, however, and poor visualization of distal anastomoses limit its routine clinical use.     

Assessment of the distal anastomosis of coronary artery bypass grafts with a 2D T2-weighted turbo spin echo sequence and correlation to conventional coronary angiography

OBJECTIVE: The aim of the study was to evaluate the patency of the distal anastomoses of coronary artery bypass grafts and to detect graft stenoses and occlusions with a magnetic resonance (MR) spin echo sequence. PATIENTS AND METHODS: One hundred and eighty-five patients with 481 distal anastomoses were examined with a 1.5 T MR scanner and coronary angiography. A 2-dimensional T2-weighted breath-hold half-Fourier acquisition single-shot turbo spin echo sequence (Haste) was performed. All images were evaluated independently by a radiologist and cardiologist and compared to the conventional coronary angiography. The observers were blinded to the coronary angiography findings, but informed in regard to the surgical graft anastomosis. RESULTS: With the Haste sequence, 76% of the distal anastomoses were recognized (368/481). Forty-five of 52 (87%) stenoses and all occlusions were identified. The sensitivity and specificity for the evaluation of the distal anastomosis with the spin echo sequence was 87% and 96%. Twenty-four percent of the distal anastomoses were not identified due to a poor image quality or motion artefacts. CONCLUSION: Using the Haste sequence, a reliable assessment of graft patency of the distal anastomosis is possible. Further improvements of the spatial resolution and the image quality are necessary to recommend this MR technique for routine clinical use.     

16排CT在评价胸痛患者冠状动脉病变中的应用价值

目的：探讨16排计算机断层扫描技术(CT)在评价胸痛疑似冠心病患者冠状动脉病变中的应用价值。方法：52例胸痛疑似冠心病患者人选,分别用16排CT造影方法(CTA)和常规冠状动脉造影方法(CAG)评价冠状动脉病变情况,并以CAG为标准计算CTA诊断冠状动脉病变的敏感度、特异度、阳性预测值(PPV)和阴性预测值(NPV)。结果：CTA能评价所有627个冠状动脉节段中的546个(87%)。在该546个冠状动脉节段中,CTA诊断冠状动脉病变的敏感度、特异度、PPV和NPV分别是94%、95%、82%和99%;CTA对冠状动脉左主干及其近中段病变的敏感度、特异度、PPV和NPV均高于冠状动脉远段和分支血管。结论：CTA能较准确地评价胸痛疑似冠心病患者冠状动脉(尤其是近、中段)的病变情况。     

Can 64-row computed tomography replace angiography after coronary bypass?

Multi-detector (64-row) computed tomography has become an alternative to coronary angiography to diagnose graft occlusion and stenosis after coronary artery bypass. We compared the power of evaluation of multi-detector computed tomography with that of conventional coronary angiography in 60 patients who underwent coronary artery bypass with 135 grafts and 210 graft anastomoses. The diagnostic power of multi-detector computed tomography for graft occlusion was: 100% (2/2) sensitivity, 98.5% (131/133) specificity, 50% (2/4) positive predictive value, and 100% (133/133) negative predictive value; there were no significant differences in rates of occlusion among the different types of graft. The diagnostic power of multi-detector computed tomography for stenosis of the graft anastomosis was: 100% (2/2) sensitivity, 95.1% (194/204) specificity, 16.6% (2/12) positive predictive value, and 100% (194/194) negative predictive value, with no significant differences among grafts. Multi-detector computed tomography permits evaluation of bypass grafts and is much less invasive for the patients.     

CT Coronary Angiography: 256-Slice and 320-Detector Row Scanners

Multidetector computed tomography (MDCT) has rapidly evolved from 4-detector row systems in 1998 to 256-slice and 320-detector row CT systems. With smaller detector element size and faster gantry rotation speed, spatial and temporal resolution of the 64-detector MDCT scanners have made coronary artery imaging a reliable clinical test. Wide-area coverage MDCT, such as the 256-slice and 320-detector row MDCT scanners, has enabled volumetric imaging of the entire heart free of stair-step artifacts at a single time point within one cardiac cycle. It is hoped that these improvements will be realized with greater diagnostic accuracy of CT coronary angiography. Such scanners hold promise in performing a rapid high quality “triple rule-out” test without high contrast load, improved myocardial perfusion imaging, and even four-dimensional CT subtraction angiography. These emerging technical advances and novel applications will continue to change the way we study coronary artery disease beyond detecting luminal stenosis.     

平板运动试验结合多层螺旋CT冠状动脉成像对冠心病的诊断价值

目的 探究平板运动试验（TET）结合多层螺旋CT（MSCT）对冠心病的诊断价值.方法 选择临床拟诊冠心病（CAD）的患者200例,2周内先后进行平板运动试验、多层螺旋CT冠状动脉成像及冠状动脉造影（CAG）检查.以冠状动脉造影为＂金标准＂,分析平板运动试验、多层螺旋CT冠状动脉成像及两者结合对冠心病检出率的有关指标.结果 平板运动试验、多层螺旋CT冠脉成像及两者结合诊断冠心病的敏感性、特异性、阳性预测值、阴性预测值、准确性分别为81.3%（74/81）、70.6%（77/109）、69.8%（74/106）、81.9%（77/94）和75.5%（151/200）;83.5%（76/91）、84.4%（92/109）、82.6%（76/92）,85.2%（82/108）和84.0%（168/200）;98.0%（53/57）,100%（143/143）、100%（53/53）、97.3%（143/147）和98.0%（196/200）.结论 平板运动试验结合多层螺旋CT冠状动脉成像能明确诊断或排除冠心病.     

Noninvasive angiography of coronary bypass grafts with cardio-CT in a cardiology practice

BACKGROUND: The role of coronary artery bypass surgery as a key foundation in the therapy of coronary artery disease remains unchanged: in Germany in 2001, 75,537 coronary bypass procedures were performed. However, the endurance of coronary bypass grafts is limited: after 3 years, 20-30% of the bypass grafts have occluded. The myocardial infarct rate significantly increases 8 years after bypass surgery. Since the clinical outcome of the patients is closely related to the patency rate of their bypass grafts, it would be important for the patients to have the patency rate of their bypass grafts assessed on time to detect any occluded bypass grafts before the majority of the grafts become occluded. Recently, multi-slice computed tomography (MSCT) offers an attractive tool for this purpose. This paper describes our first experiences with MSCT in our cardiology practice and regards whether this new method provides relevant information for a cardiology practice. PATIENTS AND METHODS: Studies were performed at the Heart Diagnostic Center in Munich with an Mx 8000 four-row spiral CT with an effective slice thickness of 1.3 mm, 120 kV at 300 mA and approximately 120 ml of contrast medium in double bolus technique. Image reconstruction was performed for 5 heart phases between 50% and 70% of the RR intervals. Thus, a total of over 1,500 slices were reconstructed. 74 patients without angina or proof of myocardial ischemia had noninvasive bypass angiography at a mean of 5 years after surgery. RESULTS: Of the total of 220 investigated bypass grafts, 132 were venous and 88 were arterial. 177 bypass grafts were classified as open, 42 as occluded; and one venous bypass graft was highly narrowed. Compared with cardiac catheterization, the sensitivity of the cardio-CT regarding the occlusion of a bypass graft was 100% with a specificity of 96%. The only "false positive" occlusion was a LIMA with a small lumen. CONCLUSIONS: Our results show that noninvasive bypass angiography with the ultrafast multi-slice CT (MSCT) provides relevant information for the practicing cardiologist. Noninvasive bypass angiography with a cardio-CT predominantly aims at asymptomatic patients without proof of myocardial ischemia ("bypass check") for the detection of asymptomatic occluded bypass grafts as early as possible. In patients with asymptomatic bypass occlusion, considering a coronary or bypass intervention for prognostic reasons is an option. It is important to note that in our study in a mean of 5 years after bypass surgery almost every third patient had an unexpected bypass graft occlusion.     

Intraarterial digital subtraction angiography for evaluation of internal mammary artery graft in coronary bypass surgery

Digital subtraction angiography (DSA) was performed to evaluate graft patency in 60 patients who had undergone coronary artery bypass grafting with the internal mammary artery (IMA). Sixty IMA grafts with 62 distal anastomoses, and 84 saphenous vein grafts with 85 distal anastomoses were evaluated by intraarterial DSA with an image frequency of 4 frames/sec. A No. 4 Fr. angiography catheter was introduced percutaneously into the left brachial artery and contrast medium was injected both into the subclavian artery for opacification of the IMA grafts and into the ascending aorta for opacification of aortocoronary saphenous vein grafts. Bypass grafts were defined as patent when grafts were opacified through their entire course, including anastomotic sites. Fifty-nine IMA grafts with 61 distal anastomoses (98%) and 76 saphenous vein grafts with 77 distal anastomoses (91%) were patent. The overall patency rate for total grafts was 94%. In 4 patients, DSA showed a "string sign" in the IMA graft which was patent but narrowed at its distal segment. In 5 patients, large first intercostal branches were opacified. Intraarterial DSA with the retrograde brachial approach is not difficult, and is an excellent low risk method of evaluating the patency of IMA and saphenous vein grafts. DSA provided information about functional patency as well as anatomical patency of the IMA graft.     

Three-dimensional computed tomography angiography of coronary artery bypass graft with electron beam tomography]

OBJECTIVES: Assessment of coronary artery bypass graft patency by three-dimensional reconstructed computed tomography angiography (3D-CTA) derived from electrocardiography-gated contrast-enhanced electron beam tomography (EBT) was evaluated. METHODS: Thirty-nine patients with 99 grafts (45 arterial grafts and 54 venous grafts) underwent 3D-CTA and selective coronary angiography within a 3-week interval. 3D-CTA images of the coronary bypass grafts were compared with the coronary angiography images used as the control. RESULTS: 3D-CTA defined 42 of 44 arterial grafts as patent (sensitivity: 95%), all 47 venous grafts as patent (sensitivity: 100%) and all 7 venous grafts as occlusive (specificity: 100%). The overall sensitivity and specificity were 98% and 88%, respectively. CONCLUSIONS: 3D-CTA is an useful noninvasive technique with adequate sensitivity and specificity to assess coronary artery bypass graft patency.     

A pictorial review of coronary artery bypass grafts at multidetector row CT

Multidetector row CT scanners with submillimeter spatial resolution and high temporal resolution are now available and are increasingly used for noninvasive assessment of vascular disease including coronary arteries and grafts. The entire heart and graft course can be scanned within a single breath-hold, and contrast-enhanced images are reconstructed through retrospective ECG gating. In this pictorial review, we describe the CT findings of the most commonly used coronary artery bypass grafts on both axial images and two-dimensional and three-dimensional images providing a correlation with conventional coronary angiography.     

Diagnostic accuracy of noninvasive coronary angiography with 320-detector row computed tomography

We sought to evaluate the diagnostic accuracy of noninvasive coronary angiography using 320-detector row computed tomography, which provides 16-cm craniocaudal coverage in 350 ms and can image the entire coronary tree in a single heartbeat, representing a significant advance from previous-generation scanners. We evaluated 63 consecutive patients who underwent 320-detector row computed tomography and invasive coronary angiography for the investigation of suspected coronary artery disease. Patients with known coronary artery disease were excluded. Computed tomographic (CT) studies were assessed by 2 independent observers blinded to results of invasive coronary angiography. A single observer unaware of CT results assessed invasive coronary angiographic images quantitatively. All available coronary segments were included in the analysis, regardless of size or image quality. Lesions with >50% diameter stenoses were considered significant. Mean heart rate was 63 ± 7 beats/min, with 6 patients (10%) in atrial fibrillation during image acquisition. Thirty-three patients (52%) and 70 of 973 segments (7%) had significant coronary stenoses on invasive coronary angiogram. Seventeen segments (2%) were nondiagnostic on computed tomogram and were assumed to contain significant stenoses on an "intention-to-diagnose" analysis. Sensitivity, specificity, and positive and negative predictive values of computed tomography for detecting significant stenoses were 94%, 87%, 88%, and 93%, respectively, by patient (n = 63), 89%, 95%, 82%, and 97%, respectively, by artery (n = 260), and 87%, 97%, 73%, and 99%, respectively, by segment (n = 973). In conclusion, noninvasive 320-detector row CT coronary angiography provides high diagnostic accuracy across all coronary segments, regardless of size, cardiac rhythm, or image quality.     

Percutaneous angioplasty of stenoses of bypass grafts or of bypass graft anastomotic sites

Forty patients who had stenoses of coronary artery bypass grafts or stenoses of the proximal or distal coronary insertion sites were treated with percutaneous transluminal angioplasty (PTA). PTA was successful in 78% of the patients. Mean stenoses were diminished from 86% to 34% in luminal diameter. One patient needed emergency coronary artery bypass grafting. There were no deaths associated with PTA. Follow-up angiography showed continued patency in asymptomatic patients, whereas in all but 1 patient with recurrent symptoms restenosis had developed at the PTA site. In 38% of patients restenosis developed after successful PTA; the highest restenosis rate was after PTA of aorta/graft anastomoses or proximal graft stenoses. In conclusion, PTA is a successful, low risk alternative to repeat coronary artery bypass grafting, although the restenosis rates at some PTA sites are high.     

64排螺旋CT冠脉成像在冠状动脉搭桥术后的应用研究

目的 探讨64排螺旋CT冠脉成像在冠状动脉搭桥术后的应用价值.方法 选取我科用64排螺旋CT进行搭桥术后血管扫描的患者42例进行综合分析.结果 冠状动脉搭桥术前CT血管造影成像（CTA）与术中选择性冠脉血管造影（SCA）相比差异无统计学意义（P＞0.05）.术后3个月与术后1年同时行CTA检查和多层螺旋CT血管造影（MSCTA）检查者,在血管成功显示方面差异无统计学意义（P＞0.05）.结论 64排螺旋CT冠状动脉CTA成像能准确显示冠状动脉的走行,以及是否有斑块形成、导致狭窄等,可以用于冠脉搭桥术后血管评价,作为随访的检查手段,是评价冠状动脉病变及桥血管的形态与功能的重要筛选方法.