【作者】 凌志青；

【导师】 曾蒙苏； 钱菊英； 林江； 吴东；

【作者基本信息】 复旦大学 ， 影像医学与核医学， 2008， 博士

【摘要】 第一部分:64排螺旋CT冠脉成像技术参数研究目的:研究64排螺旋CT冠脉成像图像质量同技术因素之间关系。材料和方法:52例受检者(平均年龄62岁,女性19例)进行了64排螺旋CT冠脉成像检查。所有病例按心率分成3组:组1,心率＜70bpm,组2,80＞心率≥70bpm,组3,心率≥80bpm。64排螺旋CT使用64×0.625mm的准直以及350毫秒的机架旋转速度。每个病例于心脏RR间期的20—90%重建数据,间隔5%,共15个数据集。两位放射医师独立评估数据集中三大冠脉所有节段的各自成像质量。质量评价使用四级评分标准,其中3级和4级作为可接受图像质量。结果:总共52例病例中共有517个冠脉节段进行了评价。其中7(1.4%)个节段在所有15个时相的质量均未达到3级而判断为“不可评价”,428(83%)个节段最高得到4级评价。右冠中段相对其他节段有着明显较低质量评分,并在不同心率组中最易受心率变快影响。图像最佳的重建时相在低心率组中位于舒张中期(R-R间期的70—80%),在中等心率和高心率组中位于收缩末和舒张早期(R-R间期的40—50%)结论:64排螺旋CT冠脉成像具有较强的冠脉显示能力。在一个相当宽的心率范围内(55～102bpm),绝大多数冠脉节段(98.6%)的成像质量可以满足诊断要求。右冠中段仍是所有冠脉节段中的薄弱环节。最佳时相在心率小于70bpm时,绝大多数位于舒张中期;心率大于等于70bpm时,多数位于收缩末及舒张早期。第二部分:64排螺旋CT在冠心病诊断中的运用目的:64排螺旋CT冠脉成像和常规冠脉造影的对照研究,旨在评价其在冠心病诊断中的临床运用价值,同时与血管内超声就斑块的探查进行对照研究。材料和方法:51位临床诊断或怀疑冠心病患者(男性37例,女性14例,平均年龄63岁)先后进行了64排螺旋CT冠脉成像和常规冠脉造影。64排螺旋CT使用64×0.625mm的准直以及350毫秒的机架旋转速度。以冠脉节段≥50%狭窄作为标准,统计64排螺旋CT冠脉成像在检测血流动力学异常的明显狭窄的敏感性,特异性及诊断准确性,评价分每个冠脉节段,每支冠脉和每个病例分别进行。同时,10例病人的12支冠状动脉进行了血管内超声检查,其结果和CT进行对照研究,并就斑块面积和斑块负荷进行了相关性检验。结果:51例病人,50例顺利完成CT检查。1例病人因无法配合而排除于统计之外。常规造影总共显示的729个节段中,CT上707(97%)个节段能够满足诊断要求。常规冠脉造影共检出59(8%)个冠脉节段狭窄超过50%。在所有CT可评判的冠脉节段中,64排螺旋CT对于明显狭窄节段的诊断:敏感性92%,特异性96%,准确性96%,阳性预测值69%,阴性预测值99%。如以单支冠脉和患者为单位统计,敏感性、特异性分别为100%、88%和97%、88%。64排螺旋CT和血管内超声上的斑块测量数据的相关性检验,无论斑块面积还是斑块负荷,两种成像模式间侧值均具有明显相关性(r=0.8,0.7)。但斑块组织成分在CT上仍无法有效鉴别。结论:64排螺旋CT具有较好的诊断准确性,对明显狭窄的冠状动脉节段诊断敏感性92%,特异性96%,准确性96%。尽管64排CT在斑块面积和负荷测量上和血管内超声有着较好相关性,但对于斑块组成成分的检测仍存在困难。第三部分:64排螺旋CT对冠状动脉支架的显示目的:通过64排螺旋CT和常规冠脉造影影像资料的对照研究,评价64排螺旋CT对支架腔的显示情况。材料和方法:15例冠状动脉支架置入术后患者(男性12例,女性3例,21个支架)先后经历64排螺旋CT冠脉成像和常规冠脉造影检查。所有支架置入至少6个月。以常规造影作为金标准,支架腔再狭窄定义为支架腔狭窄程度和临近正常参照段相比＜50%,两位医师于CT上独立评价支架腔的显示情况以及有无再狭窄的发生,并进行敏感性,特异性的统计。同时就两位观察者间一致性进行检验。结果:在总共21个支架中,18(86%)个支架腔在64排冠脉成像上具有“可判断”能力。在这18个可判断节段中.64排螺旋CT正确检出2例再狭窄病例和1例闭塞病例,但有2例假阳性,经统计其敏感性100%,特异性87%,准确性89%。Kappa分析示两位观察者间具有较好的一致性(κ=0.72)。结论:作为一项非侵袭性检查技术,64排螺旋CT可以较好的判断支架腔的狭窄情况,有望常规运用于冠脉支架置入术后病人的长期随访。第四部分:多层螺旋CT在心肌桥诊断中的应用及优势目的:研究心电门控多层螺旋CT(MSCT)在心肌桥的诊断能力。材料和方法:对51例临床怀疑冠心病患者进行了MSCT、常规冠状动脉造影(CAG)以及血管内超声检查(共82支冠状动脉),分别统计MSCT对心肌桥检出的敏感性、特异性和准确性。观察者间一致性检验通过Cohen Kappa检验进行。结果:CAG及血管内超声共发现26例心肌桥,所有心肌桥均发生于左前降支中段附近。MSCT正确检出26例心肌桥中的25例,其敏感性88%,特异性96%,准确性94%,Kappa值为0.62。MSCT尚检出2例心肌桥,为侵袭性技术所漏诊。将侵袭性技术和MSCT综合结果作对照,则MSCT心肌桥检出的敏感性、特异性和准确性分别为89%、91%和90%。结论:MSCT作为一种无创性成像方法应用于心肌桥的诊断,方法可行,结果可靠。更多还原

【Abstract】 Part one:64-detector row CT coronary angiography:study on technique and image qualityObjective:To investigate technical aspects that influence the image quality at 64-detector row computed tomographic(64-MDCT) coronary angiography.Material and Methods:Coronary CT angiography was performed in 52 patients.Patients (mean age,62 years;nineteen women) were divided into three groups according to heart rates:group 1,＜70bpm;group 2,70 - 80bpm;group 3,≥80bpm.CT scans were obtained on a 64-MDCT scanner with a 64×0.625 mm collimation and 350-msec rotation time.A total of 15 data sets were reconstructed at 20-90%of the cardiac cycle in increments of 5%.Image quality of the coronary segments within three major coronary arteries was assessed by two radiologists independently with a four-step grading scale.Images assessed as grade 3 or 4 were considered to be of diagnostically acceptable quality.Results:A total of 517 segments were analyzed in 52 patients. Combining the scores for both reviewers,7 segments(1.4%) were judged unacceptable,428 segments(83%) were perfect.The middle segment of right coronary artery(RCA) had significant lower image quality and were more susceptible to the changes of heart rate.Best image quality was observed in group with a low heart rate for middiastolic reconstruction intervals(70- 80%of R-R interval) and in patients with a moderate or high heart rate for end-systolic or early-diastolic intervals (40～50%of R-R interval).Conclusion:64-MDCT has the potential to visualize 98.6%of cronary segments in patients with heart rates between 55 and 102 bpm.In patients with a heart rates＜70 bpm,the best results can be obtained with middiastolic intervals;in patients with a heart rates＞70bpm,the best image quality are achieved with end-systolic and early-diastolic intervals.Part two:The application of 64-MDCT in the diagnosis of CAD: Comparison with invasive techniquesObjective:The purpose of this study was to evaluate the potential clinical value of a 64-MDCT systems with that of invasive coronary angiography and intravascular ultrasound(IVUS)in the diagnosis of coronary artery disease.Material and Methods: Fifty-one consecutive patients(37man,14woman) aged 63 years±9 who were known or suspected of CAD underwent both coronary CT angiography and conventional coronary angiography.A CT system with acquisition of 64 slices per gantry rotation was used with a gantry rotation time of 350 milliseconds.Sensitivity,specificity,and diagnostic accuracy of 64-MDCT in the detection or exclusion of luminal stenosis greater than or equal to 50%were evaluated for each arterial segment,coronary vessel,and patient.In 10 patients,the results of CT were compare with IVUS in the detection of atherosclerotic plaque.Results:In 50 patients,MDCT was carried out without complications.One patient was excluded from the analysis due to the failure of scanning.Of 729 segment,707(97%) were judged evaluable by CT.QCA showed lesions with≥50%luminal narrowing in 8%(59/707) of the coronary segments. Sensitivity and specificity of 64-MDCT per segment were 92%and 96%.On a vessel-by-vessel and patients-by-patients basis,the sensitivity and specificity were 97%,88%and 100%,88%,respectively.Correlation of plaque areas and plaque burdens measured in MDCT and IVUS were relatively close(r=0.8,0.7).Conclusion: 64-MDCT is a reliable and accurate diagnostic tool in the detection of significant coronary stenosis with a sensitivity of 92%and a specificity of 96%.However,the potential of MDCT in detecting the component of plaques still was limited.Part three:Investigation of accuracy of 64-MDCT in the visualization of coronary stentObjective:To evaluate the accuracy of 64-MDCT correlation with that of conventional coronary angiography in the detection of in-stent lumen patency.Material and Methods:Fifteen consecutive patients(12man,3woman) with 21 stents delivered at least 6 months underwent both coronary CT angiography and conventional coronary angiography.Two independent blinded observers evaluated all stents for occlusion and restenosis(50%-99%luminal reduction).Conventional angiography was regarded as the standard of reference.Sensitivity,specificity,and diagnostic accuracy of 64-MDCT in the detection or exclusion of restenosis were evaluated.Results:Of 21 stents,18(86%) were considerd assessable.In the assessable segments,two restenoses and one occlusions were correctly detected by 64-MDCT,there was a sensitivity of 100%,a specificity of 87%and a accuracy of 89%,respectively.The K statistic demonstrated very good interobserver agreement( =0.72).Conclusion:64-MDCT allows noninvasive evaluation of stents,and may be a reliable tool in the follow-up of patients after coronary stent placement.Part four:The application and advantages of Multislice CT in the diagnosis of myocardial bridging.Objective:To investigate the ability of ECG-gated MSCT in the diagnosis of myocardial bridging.Materials and Methods:51 patients with suspected coronary artery disease underwent multi-detector row CT,conventional coronary angiography and intravascular ultrasonography(82 coronary arteries) as well.The sensitivity, specificity and accuracy of MSCT for the detection of myocardial bridging were determined.The interobserver agreement was also calculated by using Cohen’s Kappa test.Results:A total of 26 tunneled arteries exclusively located near the middle segment of LAD were found by CA and IVUS,however two myocardial bridges confirmed by MSCT were missed.Compared with these invasive methods,MSCT correctly detected 25 of 26 myocardial bridges with a sensitivity of 88%,specificity of 96%and accuracy of 94%.Kappa for overall interobserver variation was 0.62. With the results of invasive and non-invasive methods combined as the standard of reference,the overall sensitivity,specificity,and accuracy of MSCT in detecting MB were 89%,91%,and 90%,respectively.Conclusions:As a non-invasive imaging modality,MSCT may be feasible and reliable in the detection of myocardial bridging.更多还原