【作者】 何次；

【导师】 廖明松；

【作者基本信息】 第三军医大学 ， 影像医学与核医学， 2009， 硕士

【摘要】 背景:冠状动脉硬化性心脏病(简称冠心病)是一种常见病、多发病。在我国发病率高达6.49%,并且呈上升趋势,其死亡率已超过癌症成为第一大致死原因。目前,CAG仍然是诊断冠状动脉血供情况的“金标准”,但这是一种有创性检查,并且检查费用较高、费时,限制了其在临床上的广泛应用。长期以来,人们一直在寻找无创或微创诊断冠脉血供的方法。MSCT和超声是两种发展较快的无创性检查,MSCT中的64层螺旋CT的空间分辨率达到0.4mm,时间分辨率达到0.37s,越来越接近CAG;ASMA-FAM技术也是近年来发展起来的一门新的超声技术,可以定量评价心脏室壁运动状态。为了探讨ASMA-FAM和64层螺旋CT对冠心病诊断的价值,我们设计了本课题。目的:探讨自动室壁分区运动分析、全方位M型超声心动图(ASMA-FAM)及64层螺旋CT(MSCT)在冠心病诊断中的价值,评价心律对64层螺旋CT冠状动脉成像质量的影响及心电编辑技术对心律不齐所致冠脉成像质量改变的控制。材料与方法:本研究分为两个部份,第一部份是ASMA-FAM、64层螺旋CT诊断冠心病与CAG的对照研究,第二部份是探讨心律对64层螺旋CT冠状动脉造影的影响和心电编辑软件对心律不齐引起的图像质量改变的控制。在第一部份的研究中,对临床诊断为冠心病并经CAG确诊的48例住院病人(男39例,女9例,年龄47~68,平均54.1±2.3岁)行ASMA-FAM和64层螺旋CT检查和对照研究。应用ASMA测量收缩期及舒张期自动室壁分区面积的变化率(FAC),以直方图及数据两种方式显示,以FAC<49%为具有临床诊断意义。FAM全方位分区测量划分室壁节段的运动幅度,按照美国超声心动图学会计分标准,内膜运动≥6mm为室壁运动正常,<6mm为室壁运动异常。64层螺旋CT采用回顾性心电门控技术对患者进行冠状动脉造影,用多平面重组(MPR)、最大密度投影(MIP)及容积重建(VR)技术对冠状动脉进行重组。MSCT及CAG均依照美国心脏病协会建议的树状结构模型把冠状动脉分为:左冠状动脉主干,左前降支的近、中、远段和对角支,左回旋支的近、远段和钝缘支,右冠状动脉的近、中、远段和后降支共12段。对管径≥1.5 mm的冠状动脉分支进行评价。以传统冠状动脉造影结果与ASMA-FAM、64层螺旋CT进行对照分析,分别计算ASMA-FAM、MSCT及并列试验诊断冠心病的敏感性、特异性、准确率、阳性预测值和阴性预测值。在第二部份的研究中,把112例患者(男性70例,女性42例,年龄40～89岁,平均63.4±2.8岁)按心率波动幅度分成四组:A组45例,心率波动为0～4次/分;B组32例,心率波动为5～9次/分;C组23例,心率波动为10～14次/分;D组12例,心率波动为≥15次/分。在回顾性心电门控技术下对冠状动脉进行常规扫描,用多平面重组(MPR)、最大密度投影(MIP)及容积重建(VR)技术来对冠状动脉进行重组。对各组重建图像依统一的5分制评分标准进行定量评分,比较组间差异。对其中26例患者由于心律不齐而图像质量较差进行了心电编辑,分析编辑前后图像质量差异。结果:第一部份研究中,传统导管法造影显示573个节段,其中有196段(34.2%)冠状动脉狭窄≥50%;48例共测量分析室壁运动768(16×48)个节段,ASMA显示372个节段(48.4%)收缩期室壁运动色彩变换呈无序状态且不完整,FAC<49%。FAM测量室壁运动幅度,386个节段(50.3%)存在运动幅度减弱<6mm;64层螺旋CT共显示523个节段,其中189个节段狭窄,与CAG相符的174个节段,CAG诊断狭窄而64层螺旋CT诊断正常的13个节段,MSCT诊断狭窄而CAG诊断正常的有15个节段。ASMA-FAM诊断冠心病的敏感性、特异性、准确率、阳性预测值、阴性预测值分别为83.3%,75.1%,78.8%,73.7%,84.2%;64层螺旋CT诊断冠心病的敏感性、特异性、准确率、阳性预测值、阴性预测值分别为93.0%,95.5%, 94.6%,92.1%, 96.1%;两者并联试验敏感性为97.4%,特异性为68.8%,准确率为81.9%,阳性预测值为72.5%,阴性预测值为97.0%。第二部份的研究中,112例患者共显示1116支血管,其中图像质量评分为4分的有686支(61.5%),图像质量为3分的有280支(25.1%),小于等于2分的有150支(13.4%),图像可评定为966支(86.6%)。RCA2受心律影响明显,随心率变化增大图像质量明显下降(P<0.001,r=-0.488)。对26例因心律不齐而影响诊断的患者进行了心电编辑,26例患者共观察了260个节段,其中编辑前97个节段(37.3%)图像质量小于等于2分而无法做出诊断,采用心电编辑技术对图像进行修正后,有71个节段(73.1%)图像质量明显改善,评分大于3分,仍有26个节段图像质量小于等于2分而无法做出诊断。结论:1.ASMA-FAM、MSCT是筛查冠心病的两种有效的无创性检查方法,两种方法联合应用诊断冠心病敏感性明显提高,在排除冠心病方面有更大优势。2.心律是64层螺旋CT成像重要影响因素之一,当心率波动≥15分/次时64层螺旋CT冠状动脉成像受影响严重;3.心电编辑技术对心律不齐所致64层螺旋CT冠脉造影成像质量改变有提升作用。更多还原

【Abstract】 Background:Conventional coronary angiography, which currently remains as the reference and gold standard of the diagnosis of coronary disease, is invasive, expensive and time consumptive. In current clinical practice, there is a need for a less-invasive modality that can help to assess the cardiovascular system of patients. Owing to ongoing technical refinements and intense scientific and clinical evaluations, multi-slice spiral computed tomography (MSCT) and automated segmental motion analysis and free angel mode (ASMA-FAM) of the heart have matured into a clinical application that is about to fulfill its promise to replace invasive cardiac catheterization in selected patient populations.The development of electrocardiographically(ECG) synchronized multi-slice spiral CT scanning and reconstruction techniques has yielded fast volume coverage and high spatial and temporal resolution as prerequisites for successful cardiac imaging; and ASMA-FAM can show the regional wall motion abnormality sensitively ,which can reflect the situation of heart. But CT coronary angiography is technically more challenging than other CT applications owing to the continuously moving heart, many factors can affect the quality of the images, and the cardiac rhythm is the key one of them.The study is about the application of ASMA-FAM and MSCT in patients with coronary heart disease.OBJECTIVE:To compare ASMA-FAM, MSCT with CAG in patients with coronary heart disease;and to evaluate the accuracy for the assessment of coronary heart disease with the two noninvasive diagnosis.To analyze cardiac rhythm during the scanning and its influence on image quality in coronary angiography with 64-slice spiral CT;and to study the ECG-editor enhancing the image qulity of MSCT. MEHODS:This study was divided into 2 parts; PartⅠwas about the comparative study of ASMA-FAM and MSCT to CAG, and partⅡwas about the influence of cardiac rhythm on image quality of 64-slice spiral CT in coronary angiography and the solution.In partⅠ,A retrospective study was undertaken in 48 cases(male 39 cases, female 9 cases, and mean age of 54.1±2.3) which were performed with ASMA-FAM、MSCT and CAG within 7 days. The regional wall motion (RWM)and the fraction of area changing(FAC) were measured with ASMA-FAM ;Images from MSCT were retrospectively reconstructed under different reformations: multi-planner reconstruction(MPR)、maximum intensity projection(MIP) and volume rendering (VR);All the post-process images were reviewed by two observers with 2 years working experience. Both the results from ASMA-FAM and MSCT are compared with the values of CAG, which served as the reference and gold standard. Sensitivity, specificity, accuracy, positive predictive value, and negative predictive value were calculated.In partⅡ, A retrospective study was undertaken in 112 cases (male 70 cases, female 42 cases, and mean age of 63.4±2.8)which had retrospectively ECG-gated 64-slice spiral CT scan in coronary angiography, and fluctuation of heart rate during the scanning was recorded. Maximum intensity projection (MIP), multi-planar reconstruction (MPR) and volume rendering (VR) were reconstructed .The 112 cases are divided into 4 groups according to the heart rate’s fluctuation. Group A 0～4bpm、Group B 5～9bpm、Group C 10～19bpm、Group D≥20bpm .The image qualities of brands or segments of coronary arteries (total 1118) were compared between different groups.RESULTS:In partⅠ, 768,523 and 573 segments among the 48 patients are shown with ASMA-FAM ,MSCT and CAG respectively, and 372(48.4%) are regional wall motion abnormality reflected by ASMA-FAM ; 523 coronary arteries were evaluated with 189(36.1%) lesions found by MSCT. Of them, 174 lesions were consisted with CAG, 15 lesions were falsely positive and 13 lesions were found by CAG not picked up by MSCT;And 196/573(34.2%) segments are stenoses shown by CAG. Sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of ASMA-FAM in diagnosis of coronary heart disease were 83.3%,75.1%, 78.8%, 73.7%, 84.2%;and those of MSCT were 93.0%,95.5%, 94.6%,92.1%, 96.1% respectively.In partⅡ,There is no significant difference between group A,B and C(P>0.001), but the difference between group D and A,B,C is very obvious(P<0.001), and the image quality in group D was significantly lower than those in group A,B and C in the display of RCA1,RCA3,PDA,LM,LAD1,LAD2,LAD3,LCX1 and LCX2.The image quality of RCA2 was significant different among different groups (P<0.001).CONCLUSION:ASMA-FAM and MSCT are available in the diagnosis of coronary heart disease as noninvasive methods; they have excellent sensitivity and specificity in detecting CHD, and also can give fairly accurate assessment of stenoses severity in most patients as compared to CAG. As alternative methods, they can be used for screening patients with coronary heart disease.The cardiac rhythm is an important factor on image quality of 64-slice spiral CT in coronary angiography. The image quality of coronary artery begins to be poor when the fluctuation of heart rate is greater than 15bpm,especially in RCA2.The ECG-editor can enhance the image qulity of MSCT.更多还原