电子束CT三维空间的实验性心肌梗死心脏与病理对照

COMPARISON OF ELECTRON BEAM CT TO PATHOLOGY WITH EXPERIMENTAL MYOCARDIAL ISCHEMIA

目的用电子束ＣＴ重建心肌梗死部位及形态的三维图像，探讨电子束ＣＴ诊断心肌梗死的准确性。方法结扎犬心冠状动脉左旋支及其分支，形成左心室侧壁梗死区。用电子束ＣＴ增强容积扫描方式，沿犬心长轴扫描得到犬心断面。利用区域扩充法对梗死心脏的梗死部位进行自动分割。采用表面重建法完成梗死犬心的三维重建。用硝基四唑对犬心病理切片进行染色，并分别计算肉眼与染色，以及ＣＴ诊断所观察到的梗死部位的体积。结果①清晰显示出了犬心的三维图像，并在三维图像上精确表示出了梗死的部位及形态；②电子束ＣＴ诊断心肌梗死，其体积小于硝基四唑得到的结果，大于肉眼观察到的结果。结论电子束ＣＴ心脏三维图像能够帮助医生更加准确地诊断心肌梗死的部位与大小；其反映的梗死区域包含坏死区、损伤区两部分。

URPOSE To reconstruct the threedimensional image of heart and the region of myocardial ischemia from twodimensional tomograph of electron beam CT (EBCT) and to assess the diagnostic accuracy of myocardial ischemia using EBCT.METHODS The left circumflex branch of coronary artery were occluded to form the ischemia in the left ventricular lateral wall in six dogs. The experimental dogs were put in suitable posture. A series of heart section were obtained by using the enhanced volume scanning method of EBCT along longitudinal axis of heart. The ischemic myocardium was recognized in program in areagrow method. Surface reconstruction was applied to constitute threedimensional image of whole heart. Dogs pathological section were stained with Nitro-BT in order to calculate the macroscopic and staining, as well as CT diagnostic volume of myocardial ischemia.RESULTS ① The reconstructed threedimensional image of heart was realistically displayed. The position and configuration of ischemic region was identified accurately and quantitatively. ② The volume of myocardial ischemia through CT diagnosis was less than that through staining, but was more than that through macroscopic examination.CONCLUSIONS The threedimesional reconstruction of myocardial ischemia can help physician to diagnose the focus of myocardial infarction more precisely than twodimensional image of EBCT. The infarct regions include necrotic and traumatic regions.