超声、磁共振及核素扫描对心肌早期缺血的比较研究  

A comparative study on early phase of myocardial ischemia by echocardiography MRI SPECT

作　　者：刘庆华[1] 田建明[1] 王莉[1] 张致峰[1] 赵宝珍[1] 王宝文[2] 郑建明[1] 曾浩[1] 徐激斌[1] 倪文[1] 张顺民[1] 龚志锦[1] 

机构地区：[1]第二军医大学长海医院,上海200433 [2]解放军59医院,云南开远661600

出　　处：《中国临床医学影像杂志》2005年第3期144-148,共5页Journal of China Clinic Medical Imaging

基　　金：上海市科学技术发展基金的资助(基金编号014119098)

摘　　要：目的:对超声、磁共振及核素扫描方法识别心肌早期缺血的价值进行比较,以利于上述影像学新技术的临床应用。方法:10头正常家猪,开胸通过Ameroid环套扎猪冠脉左回旋支(LCX),建立心肌缺血模型,于术前及术后2周、5周进行组织多普勒超声心动图、背向散射积分超声心动图、磁共振及核素扫描检查,并与病理结果对照。结果:10头猪中6头猪手术成功,病理结果显示心肌细胞变性为主,除心内膜下小灶性梗死外,无明显梗死灶。①超声检查:术后2周,左室后壁(心内膜、心外膜)的心肌运动速度(Vendo、Vepi)、收缩期及舒张期运动速度峰值跨壁梯度(MVGm+、MVGm-)均明显下降,术后5周Vendo、Vepi和MVGm+较术前下降,但术后5周与术后2周相比无明显差别。背向散射积分周期变异幅度(CVIB)、背向散射积分平均值(AII)术后2周、5周与术前相比无显著区别。②磁共振检查:术后2周、5周缺血区磁共振上表现为首过低信号,其范围术后5周均较2周时缩小。③201Tl心肌灌注成像缺血区负荷成像时呈放射性缺损,静息延迟显像再充填,5周时放射性缺损较2周减轻。结论:组织多普勒指标心内膜运动速度及速度跨壁梯度、磁共振灌注成像和201Tl负荷心肌灌注成像能早期识别心肌缺血,反映缺血后侧支循环的过程。Objectives To compare the value of echocardiography MRI and SPECT in differentiating the early phase of myocardial ischemia in order to investigate the clinical feasibility of these medical imaging techniques in diagnosing myocardial ischemia. Materials and Methods The LCXs of coronary arteries of 10 pigs were obstructed by Ameroid occlusions to make myocardial ischemia model. Echocardiography MRI and 201Tl SPECT were performed before operation and 2 weeks or 5 weeks after operation and compared with histopathologic examination. Results Operations were successfully completed in 6 of the 10 pigs. The histopathology examination mainly showed myocardium denaturation with a little necrosis. ①Echocardiography after 2 weeks of ischemia the Vendo Vepi MVG of the systolic stage and diastolic stage depressed significantly. Compared with those of pre-operation the Vendo Vepi MVG of the systolic stage were still lower at the 5th week but no significant difference were seen between the 2nd week and the 5th week. The IBS indexes AII and CVIB showed no differences between the pre-operation and post-operation. ②Hypoenhancement on first-pass MRI was occurred in ischemic zone the range of which reduced at the 5th week when compared with that at the 2nd week. ③Perfusion defects were demonstrated by dipyridamole thallium SPECT in the ischemia zone and disappeared on delayed phase. With the development of collateral circulation the perfusion defects were smaller at the 5th week than that at the 2nd week after operation. Conclusion The changes of endocardial velocity MVG MRI and 201Tl stress SPECT can reflect collateral circulation development and delineate early myocardium ischemia. It is uncertain whether CVIB and AII can distinguish the very early myocardial ischemia. Therefore it is necessory that further research work should be launched.

关 键 词：心肌缺血 超声检查 磁共振成像 放射性核素显像 

分 类 号：R542.2[医药卫生—心血管疾病] R445.1[医药卫生—内科学]