磁共振多技术扫描与超声心动图检测心肌活性的比较  

Evaluation of myocardial viability by multiple MR techniques: a comparison with low-dose dobutamine stress echocardiography

作　　者：朱海云[1] 田建明[1] 王莉[1] 曾浩[1] 黄盛东[2] 徐静[3] 

机构地区：[1]第二军医大学长海医院放射科,上海200433 [2]长海医院胸心外科 [3]长海医院超声诊断科

出　　处：《第二军医大学学报》2005年第7期739-742,共4页Academic Journal of Second Military Medical University

基　　金：国家自然科学基金(30270419).

摘　　要：目的: 评估磁共振多技术扫描和小剂量多巴酚丁胺负荷超声心动图(LDDSE)检测心肌活性的价值.方法: 建立猪慢性心肌缺血模型25只,分别于模型制作前和制作后1～2个月进行磁共振多技术联合应用扫描及LDDSE检查,判断心肌缺血区和坏死区的大小,并与病理结果对照评估各种方法的敏感性、特异性.结果: 共有20只动物顺利完成所有检查,静息时MRI电影扫描共有16个节段(5.00%)运动丧失,9个节段(2.81%)运动减弱;负荷后电影扫描共有16个节段(5.00%)运动丧失为坏死心肌;负荷前后室壁运动计分指数(WMSI)有统计学差异(P<0.01);心肌灌注扫描见53个节段(16.56%)缺血;心肌活性扫描见23个节段(7.19%)坏死.静息时超声心动图检查共有16个节段(5.00%)运动丧失,13个节段(4.06%)运动减弱;负荷后共有16个节段(5.00%)运动丧失为坏死心肌,1个节段(0.31%)运动减弱,负荷前后WSMI有统计学差异(P<0.01).TTC染色见24个节段(7.50%)为无红染的苍白色梗死区.以TTC染色结果为金标准,MRI活性扫描、MRI电影、LDDSE检出无活性心肌的敏感性、特异性、准确性分别为95.80%、100%、99.70%;66.70%、100%、97.50%;66.70%、100%、97.50%. 结论: MRI心脏检查可结合形态、功能及灌注多种方法检测心肌活性,清晰显示心肌梗死的位置、程度,并可对左室室壁运动进行直观显示;LDDSE可通过评价异常心肌节段的收缩功能间接判断心肌损伤及其性质,其准确性较高且方法简便,但不能直接检测心肌灌注情况和心肌梗死的透壁程度.Objective: To assess the value of multiple MR techniques and low-dose dobutamine stress echocardiography (LDDSE) in detecting myocardial viability. Methods: The animal model of chronic myocardial ischemia was established in 25 pigs. MR and LDDSE were performed before and 1 or 2 months after surgery. The sizes of myocardial ischemia and necrosis were measured and compared with those of the pathological results. The sensitivity and specificity of both methods were calculated. Results: Examinations were successfully conducted in 20 of 25 pigs. Sixteen (5.00%) akinetic segments and 9 (2.81%) hypokinetic segments were detected by Cine MRI at rest. During dobutamine infusion, 16 (5.00%) akinetic segments were detected. Perfusion was abnormal in 53 (16.56%) segments, and delayed hyperenhancement was observed in 23 (7.19%) segments. Sixteen (5.00%) akinetic segments and 13 (4.06%) hypokinetic segments were detected by echocardiography at rest. During dobutamine infusion, 16 (5.00%) akinetic segments and 1 (0.31%) hypokinetic segments were detected. Twenty four (7.50%) segments of pale necrosis were detected by Triphenyl tetrazolium chloride (TTC). Compared with TTC results, the sensitivity, specificity and accuracy of contrast-enhanced MRI, cine MRI, and low-dose dobutamine stress echocardiography in detection of non-viable myocardium were 95.80%, 100%, 99.70%; 66.70%, 100%, 97.5%; and 66.70%, 100%, 97.50%, respectively. Conclusion: Cardiac MRI can detect the viable myocardium, delineate the location and the degree of myocardic necrosis, and demonstrate the wall motion of left ventricle. Low-dose dobutamine stress echocardiography can detect myocardial impairment indirectly by assessing contraction function of abnormal myocardial segments, but can not directly detect myocardial perfusion and extent of infarction.

关 键 词：磁共振成像 超声心动描计术 心肌 

分 类 号：R445[医药卫生—影像医学与核医学] R541[医药卫生—诊断学]