64层螺旋CT在评价冠状动脉桥血管中的价值

目的探讨64层螺旋CT在诊断冠状动脉桥血管的临床价值。方法对21例冠状动脉搭桥术的患者行64层螺旋CT心、胸部血管造影检查。对所有扫描原始数据行冠状、矢状MPR、曲面重建(CPR)以及VR、MIP重建。由两位有经验的放射科医生对所有图像进行观察,对桥血管狭窄进行诊断,并评价其狭窄程度。8例CT诊断桥血管重度狭窄(管腔狭窄>75%)或闭塞的患者同时行选择性血管造影检查。结果21例患者均可清晰地显示冠状动脉各主要分支,并能清晰地显示其斑块和管腔的狭窄。21例患者经螺旋CT心、胸部血管造影检查,可清晰显示52条桥血管,其中13条桥血管出现再狭窄(10条为大隐静脉桥血管,3条为乳内动脉桥血管),狭窄部位均位于桥血管吻合口处;重度狭窄7条,闭塞1条,此8条桥血管均与选择性血管的结果相吻合,CT评价冠状动脉桥血管重度狭窄的准确性为100%。结论64层螺旋CT心、胸血管造影检查不但能显示冠状动脉桥血管,而且能清晰地显示原始的冠状动脉及冠状动脉与桥血管的吻合口,是评价冠状动脉桥血管的一种有效的可靠的检查方法。     

多层螺旋CT在冠状动脉桥血管评价中的应用

目的:评价多层螺旋CT在冠状动脉搭桥术后随访的临床应用价值。方法:选择2001-12/2005-04在东南大学医学院附属扬州医院行桥血管多层螺旋CT检查的冠状动脉搭桥术后患者12例,其中1例相隔1年后复查,共13次扫描检查资料。所有患者应用美国通用电气公司的十六排八层螺旋CT机,采用snapshot冠状动脉成像方法进行检测,并进行CT图像重建后处理,重建出各主要血管及桥血管。分析桥血管和冠状动脉的通畅性,评价狭窄及狭窄程度。结果:13例次患者的22支桥血管多层螺旋CT均能很好显示,其中17支桥血管开通,5支桥血管未开通(完全闭塞)或有不同程度狭窄。13例次患者原供血血管均可见不同程度管壁钙化、管腔狭窄或闭塞。结论:多层螺旋CT可以全面地显示心脏的结构与功能、心肌的血流灌注和存活状态,直接无创显示冠状动脉,对于冠状动脉桥血管开通和狭窄的评价具有很好的价值。     

多层螺旋CT冠状动脉血管成像技术及临床应用

目的评价多层螺旋CT冠状动脉重建成像技术的临床应用。方法对56例患者进行心电门控16层螺旋CT（MSCT）增强扫描，所得数据行三维重建，其中15例与传统冠状动脉血管造影结果相对照。结果56例患者原始横断面图像及重建图像对近端冠状动脉均成功显示，显示率达100％；对中远段的显示，原始横断面图像优于重建图像。6例显示内支架7只；5例冠状动脉搭桥术后显示桥血管14条；15例MSCTA显示冠状动脉狭窄（〉50％）17处。经常规DSA检查发现18处。结论多层螺旋CT冠状动脉重建成像技术为有效可靠的冠心病影像学诊断方法，对病变血管腔狭窄、硬化斑块及内支架、桥血管情况的评价有一定价值。     

多层螺旋CT在冠状动脉桥血管评价中的应用

目的：评价多层螺旋CT在冠状动脉搭桥术后随访的临床应用价值.方法：选择2001-12/2005-04在东南大学医学院附属扬州医院行桥血管多层螺旋CT检查的冠状动脉搭桥术后患者12例,其中1例相隔1年后复查,共13次扫描检查资料.所有患者应用美国通用电气公司的十六排八层螺旋CT机,采用snapshot冠状动脉成像方法进行检测,并进行CT图像重建后处理,重建出各主要血管及桥血管.分析桥血管和冠状动脉的通畅性,评价狭窄及狭窄程度.结果：13例次患者的22支桥血管多层螺旋CT均能很好显示,其中17支桥血管开通,5支桥血管未开通（完全闭塞）或有不同程度狭窄.13例次患者原供血血管均可见不同程度管壁钙化、管腔狭窄或闭塞.结论：多层螺旋CT可以全面地显示心脏的结构与功能、心肌的血流灌注和存活状态,直接无创显示冠状动脉,对于冠状动脉桥血管开通和狭窄的评价具有很好的价值.     

64排螺旋CT在评价冠状动脉桥血管中的价值

目的：探讨64排螺旋CT对冠状动脉桥血管病变评估的临床应用价值。方法：对21例冠状动脉搭桥术后患者，共77条桥血管（其中内乳动脉桥20条，桡动脉桥1条，大隐静脉桥56条）行64排CT造影（CTA）。扫描时患者平均心率（60±5）次/min。扫描范围从内乳动脉起始部到膈下2cm。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。其中9例桥血管或吻合口远端冠状动脉狭窄（≥50%）或闭塞的患者同时接受了传统冠脉造影检查。结果：21例患者CTA均获得了成功。冠状动脉主干及主要分支，均可见不同程度的狭窄或闭塞。显示冠状动脉桥血管通畅62条。闭塞10条（其中内乳动脉桥2条，静脉桥8条），显示桥血管近端吻合处狭窄（≥50%）3条，远端吻合处狭窄（≥50%）2条。吻合口远侧冠状动脉再狭窄或闭塞6例。9例CAG结果与CTA完全吻合。CTA显示冠状动脉桥血管狭窄（≥50%）或闭塞的准确性达100%。结论：CTA可准确评价冠状动脉桥血管以及吻合口再狭窄的程度。CTA可直观显示桥血管近端吻合口的位置，可指导冠状动脉搭桥术后CAG入路。是评估冠状动脉桥血管病变的首选方法。     

16层CT冠状动脉成像与选择性冠状动脉造影的对比研究

目的:探讨16层CT对冠状动脉粥样硬化病变的显示情况及临床价值。方法:39例患者进行16层CT冠状动脉造影检查(疑似冠心病者31例,PTCA术后8例)及选择性冠状动脉造影。分析16层CT对冠状动脉各节段的显示情况。以管腔直径减小>50%为标准,判定冠状动脉狭窄。分析16层CT诊断冠状动脉狭窄的敏感性、特异性及符合率,及对病变性质的显示情况。结果:16层CT对冠状动脉的总体显示率为94.8%(333/351)。评价冠状动脉病变的总体敏感性为82.2%,特异性为94.7%,符合率为86.0%。16层CT显示钙化及非钙化斑块混合存在致血管狭窄21处,高估3处;中间密度斑块致狭窄8处,高估3处;软斑块3处,无显著狭窄。16层CT能清晰显示支架位置、形态及远端血流,1例再狭窄,1例闭塞,余通畅,其结果与选择性冠状动脉造影一致。另外,16层CT显示冠状动脉起源变异2例,前降支冠状动脉瘤1例,室壁瘤1例,房间隔缺损1例。结论:16层CT冠状动脉成像是一种颇具潜力的无创性检查方法,能够较为准确、全面的评价冠状动脉病变。     

64排螺旋CT在冠状动脉旁路移植患者术后随访中的应用价值

目的：探讨64排螺旋CT在冠状动脉旁路移植患者术后随访中的价值。方法：对52例接受冠状动脉旁路移植患者作螺旋CT检查,进行血管重建,对部分患者同期进行冠状动脉造影检查,结合临床症状对螺旋CT成像结果进行分析。结果：52例患者均成功完成了冠状动脉螺旋CT检查,共有187支桥血管成像,其中乳内动脉移植血管50支,静脉移植血管129支,桡动脉移植血管8支。50支乳内动脉移植血管中,6支有不同程度狭窄;129支静脉移植血管中,48支有不同程度狭窄;8支桡动脉桥中2支有不同程度狭窄。本组患者中有28例患者同期作了冠状动脉造影,共检出105支移植血管血管,造影结果与CT检查结果基本相符,螺旋CT检查假阳性率为4.4%,假阴性率为2.7%。检出有移植血管血管病变的27例患者中,22例有临床症状;另有3例有症状的患者,螺旋CT检查未发现有异常。结论：作为一种微创伤检查方法,64排螺旋CT是冠状动脉旁路移植患者术后随访的理想的方法。     

128层螺旋CT对冠状动脉搭桥术后桥血管病变的诊断研究

目的 探讨应用128层螺旋CT对冠状动脉旁路移植手术(CABG)术后桥血管病变的诊断价值.方法 对46例CABG术后(术后12～76个月)的患者行128层螺旋CT造影(MSCTA)检查,共检查133条桥血管,其中乳内动脉44条,大隐静脉89条.MSCTA检查后3～10d再行冠状动脉造影(CAG)检查,结果与MSCTA检查结果进行比较.结果 在133条桥血管中,MSCTA显示桥血管闭塞17条,桥血管狭窄(狭窄＞50％)20条.CAG结果显示桥血管闭塞17条,与MSCTA显示结果一致;桥血管狭窄(＞50％)有21条;与MSCTA检查结果比较,MSCTA检查结果假阳性1例,假阴性2例.计算MSCTA检查的敏感性为94.7％,特异性98.9％,阳性预测值97.3％,阴性预测值97.9％.结论 128层MSCTA检查可以比较准确地判断CABG术后桥血管的病变情况,是评价CABG术后桥血管病变的一种较好的无创伤检查方法.     

8层螺旋CT冠状动脉成像的价值

目的探讨8层螺旋CT对冠状动脉疾病的诊断价值。方法32例患者进行冠状动脉8层螺旋CT成像(CT an-giography,CTA)检查(PTCA术后8例,疑似冠心病者24例),同时对这些患者进行冠状动脉造影(coronary angiography,CAG)检查。以冠状动脉主要节段管腔直径减少>50%作为诊断冠心病的标准。结果8层螺旋CT对冠状动脉的总体显示率为88.2%,评价冠状动脉狭窄的敏感性64.7%,特异性为86.2%,显示钙化以及非钙化斑块混合存在导致血管狭窄19处,其中高估3处,可以显示冠状动脉内支架位置、形态以及远段血流,但难以准确显示支架内再狭窄和闭塞。结论8层螺旋CT对诊断冠状动脉疾病的意义有限。     

8层螺旋CT冠状动脉成像的价值

目的探讨8层螺旋CT对冠状动脉疾病的诊断价值。方法32例患者进行冠状动脉8层螺旋CT成像（CT angiography，CTA）检查（PTCA术后8例，疑似冠心病者24例），同时对这些患者进行冠状动脉造影（coronary angiography，CAG）检查。以冠状动脉主要节段管腔直径减少〉50％作为诊断冠心病的标准。结果8层螺旋CT对冠状动脉的总体显示率为88．2％，评价冠状动脉狭窄的敏感性64．7％，特异性为86．2％，显示钙化以及非钙化斑块混合存在导致血管狭窄19处，其中高估3处，可以显示冠状动脉内支架位置、形态以及远段血流，但难以准确显示支架内再狭窄和闭塞。结论8层螺旋CT对诊断冠状动脉疾病的意义有限。     

双源CT对冠状动脉桥血管的评价

【目的】评价双源螺旋CT对冠脉搭桥术后桥血管开通的诊断价值。【方法】对57例冠状动脉搭桥术后的患者行双源螺旋CT冠状动脉成像检查。【结果】所有141支桥血管均重建成功。其中内乳动脉桥39支,大隐静脉桥102支,通畅的桥血管102支（72．3％）,不同程度狭窄15支（10．63％）,完全闭塞24支（17．02％）。39支内乳动脉桥支33支通畅（84．62％）,102支大隐静脉桥支69支通畅（67．65％）,两种桥血管间相比较差异显著（P〈0．05）。【结论】双源螺旋CT是评价冠状动脉搭桥术后桥血管开通的有价值的无创检查方法。     

多层螺旋CT对冠状动脉桥血管的评价

目的评价16层螺旋CT对冠状动脉桥血管的显示能力。方法回顾性分析17例冠状动脉搭桥术(CABG)后患者的CT和选择性桥血管造影的资料,男15例,女2例,年龄51～78岁,平均(67±7)岁,术后6～85个月,平均(32±19)个月。共40支桥血管,原位乳内动脉13支,游离桡动脉11支,游离大隐静脉16支。由两位有丰富心血管影像诊断学经验的医生采用双盲法阅片,并取得一致结果。评价指标包括CT成像中桥血管的可评价性、有无闭塞或狭窄(管径缩小50%～99%)。结果所有40支桥血管均可评价,CT准确诊断5支桥血管闭塞和1支狭窄外,各有1例假阳性,其诊断桥血管闭塞与狭窄的敏感性、特异性达100%和97%,准确率分别为97.5%和97.1%。发生闭塞的血管与桥血管的类型和分布无关。结论16层螺旋CT是一种值得信赖的无创性随访研究桥血管通畅性的影像学方法。     

The statistical analysis of graft patency data in a clinical trial of antiplatelet agents following coronary artery bypass grafting

Because most coronary artery bypass patients receive more than one graft at surgery, it is most important to determine whether statistical analysis of graft patency should be performed on the premise that the multiple grafts within patients are dependent or independent experimental units. Veterans Administration Cooperative Study No. 207 was a multicenter clinical trial comparing four different antiplatelet regimens to placebo in the prevention of graft occlusion following coronary artery bypass grafting. Using the results from the 1-week postoperative angiograms from the Veterans Administration Cooperative Study No. 207, in which there were 3.2 distal anastomoses per patient, we have tested the hypothesis that grafts within patients tend to act dependently with respect to patency or occlusion by comparing the graft patency data to a binomial distribution (i.e., that distribution that would have been manifest if grafts were independent). Because the graft patency results in Study No. 207 significantly deviated from the binomial distribution (p = 0.0003), a more appropriate analysis for graft patency data was applied using a ratio estimate as applied to cluster sampling. The statistical methods used in 11 previous clinical trials of antithrombotic therapy after coronary artery bypass grafting were examined. Only one of the previous studies used such an analysis, and three additional reports attempted to correct for dependency of grafts within patients in their analyses using other statistical methods. In seven of the studies the investigators did not address the potential problem of a dependent relationship between multiple grafts within patients. We conclude that grafts within patients act as dependent experimental units and that the ratio estimate as applied to cluster sampling may be appropriately applied to these data.     

Assessment of coronary artery bypass graft patency by multidetector computed tomography and electron-beam tomography

This case report describes the use of retrospectively ECG-gated 16-slice multidetector computed tomography (MDCT) and electron-beam tomography (EBT) for assessing bypass graft patency in two patients with recurrent angina after coronary artery bypass graft surgery. The results of each tomographic modality were compared to the findings of traditional coronary angiography. In the first patient MDCT showed occlusion of the left internal mammary artery (LIMA) and saphenous vein graft after the second anastomosis. Coronary angiography confirmed these findings. In the second patient EBT showed patency of the LIMA and saphenous vein graft. After the first anastomosis of the saphenous vein graft, the connected vessel filled poorly. Coronary angiography confirmed both grafts to be patent, and detected an occlusion distal to the first anastomosis. These findings support the evidence that both MDCT and EBT are suitable techniques for establishing bypass graft patency by non-invasive means.     

多层螺旋CT血管成像评价冠状动脉血管旁路移植术

目的评价多层螺旋CT(MSCT)冠状动脉成像对冠状动脉桥血管的临床价值。方法28例患者的69条冠状动脉桥血管接受16层和64层螺旋CT冠状动脉成像。对桥血管成像进行影像质量评估,使用多元线性回归方法评估患者心率、心率波动幅度、呼吸运动以及不同CT扫描机对冠状动脉成像质量的影响。其中10位患者26条桥血管的CT血管成像结果与冠状动脉血管造影结果进行对比。结果呼吸运动伪影与冠状动脉桥血管成像质量呈负相关,相关系数为-0.838。64层CT扫描机的影像质量高于16层CT扫描机的影像质量。以CAG结果为参考标准,MSCT冠脉成像诊断桥血管及吻合口狭窄的特异性和敏感性分别为95.7%和92.3%。结论MSCT可以提供可靠的冠状动脉桥血管影像以及较高的诊断准确性。     

CT血管造影分析体外循环与非体外循环冠状动脉旁路移植后的桥血管通畅率

背景：近年来,非体外循环冠状动脉旁路移植后桥血管通畅率是否与传统的体外循环冠状动脉旁路移植相同存在争议。目的：探讨体外循环与非体外循环冠状动脉旁路移植后桥血管时间通畅率的差异性。方法：选取同一操作者行体外循环冠状动脉旁路移植患者100例,按其临床特征及桥血管病变危险因素匹配抽取非体外循环冠状动脉旁路移植患者137例。采用64排多螺旋CT血管造影分析冠脉搭桥后1个月,1年,2年,3年,4年的桥血管通畅情况。结果与结论：共对641条桥血管进行评价,两组中左侧乳内动脉桥血管时间通畅率均高于大隐静脉桥,两组左侧乳内动脉桥和大隐静脉桥血管时间通畅率比较差异均无显著性意义。说明非体外循环与体外循环冠状动脉旁路移植后患者桥血管时间通畅率相似,对于某些适当的患者来说,非体外循环冠状动脉旁路移植不失为一个良好的选择。     

THE LIMA SUCCESS STORY — WHITHER OTHER ARTERIAL GRAFTS — ARE VEIN GRAFTS OBSOLETE ?

SUMMARY The long-term benefit of myocardial revascularisation depends largely upon the continued patency of bypass grafts, but the long-term patency of vein grafts is poor. To improve the results of myocardial revascularisation, either measures to increase the patency of saphenous vein grafts or alternative conduits are required. Use of the left internal mammary artery as a graft is known to increase survival, and this has prompted wider use of other arterial grafts in the expectation that they will further enhance the long-term results of coronary artery bypass. This policy is based upon sound theory, but convincing evidence that it improves survival is lacking. Meanwhile, advances in the understanding of the pathology of vein graft occlusion have given rise to new methods of increasing vein graft patency. While these techniques are, as yet, only experimental, if translated into clinical practice, the places of arterial and venous grafts may require further assessment.     

Intraoperative application of power Doppler imaging: visualization of myocardial perfusion after anastomosis of left internal thoracic artery to left anterior descending coronary artery.

The purpose of this study was to determine the role of power Doppler imaging in assessing patency of coronary artery bypass graft (CABG) anastomosis. Twelve consecutive patients referred for CABG with the use of anastomosis of the internal thoracic artery to the left anterior descending coronary artery (LAD) were studied. A linear 6.5-MHz wide-band transducer was used during cardioplegic administration and reperfusion. Baseline power Doppler signals were obtained in the LAD in 11 patients, and post-CABG signals were obtained in 11 patients. In one patient the LAD was poorly visualized because of extensive calcification. In another patient the flow after bypass worsened and the graft was revised. Visualization of the LAD and internal thoracic artery grafts by epicardial intraoperative power Doppler imaging is feasible in almost all patients and allows rapid and simple intraoperative assessment of graft patency. In addition, myocardial perfusion is limited by heavily calcified coronaries.     

Repeat myocardial revascularization for uncontrollable angina after occlusion of prior aortocoronary bypass.

Twelve patients at Emory University Hospital have had repeat myocardial revascularization for recurrent, uncontrollable, disabling angina pectoris after previous coronary artery bypass grafts. The interval betweeen initial bypass procedure and reoperation ranged from six weeks to six years. The native coronary circulation remained unchanged in six, had developed additional proximal (left main) obstruction in four, and had advanced stenosis at the site of former anastomosis in three. Repeat revascularization consisted of new vein graft construction in eight and vein and internal mammary artery graft in four, with an average of 1.9 grafts per patient. There were no deaths. Seven of 12 patients (60%) are now asymptomatic and three of 12 (25%) are significantly improved. Patency of new grafts studied by elective repeat coronary angiography in six patients showed patency of all grafts to the left anterior descending artery and four of six grafts to other vessels. Analysis of the initial graft closures, method for selecting patients to undergo a second procedure, and operative technics believed important in safety of reoperation and avoidance of repeat early graft occlusion are presented.     

Composite arterial grafting

The success of coronary artery bypass grafting, the gold standard for the treatment of multivessel coronary artery disease, is limited by poor long-term vein-graft patency. By contrast, the left internal mammary artery has been demonstrated to have a superior graft patency rate and has provided excellent clinical results. This suggests that the use of arterial conduits for coronary artery bypass grafting may be beneficial for long-term results. Recently, there has been an upsurge in the use of arterial grafts for myocardial revascularization based on the clinical advantage of the use of the left internal mammary artery as a bypass conduit. Many retrospective studies have supported the safety and the effectiveness of arterial grafting, and it has become apparent that the free arterial graft can be used as a branched or a lengthened conduit to the in situ arterial graft by adopting one or more of the several composite grafting techniques. Arterial composite grafts with or without sequential grafting techniques appear an attractive strategy as increased number of distal coronary anastomoses can be performed, with a limited number of grafts, avoiding proximal aortic anastomoses. However, concerns regarding the total dependence of the coronary bypass flow on the flow of one in situ arterial graft and technical error, resulting in compromised flow in one or both limbs of the composite graft have prevented composite arterial grafting from being universally adopted. It is expected that in the near future a prospective, multi-institutional, randomized controlled trial, to compare the short- and long-term outcomes of exclusive arterial grafting using composite and conventional aortocoronary revascularization strategies, will be undertaken to validate the safety and efficacy of composite arterial grafting.