陈旧性心肌梗死所致心功能不全患者的影像学诊断研究

An imaging diagnosis research on heart failure caused by old myocardial infarction

目的评价陈旧性心肌梗死所致心功能不全患者的影像学诊断临床价值。方法同时应用磁共振、心室造影及门控核素SPECT测量陈旧性心肌梗死所致心功能不全患者左室舒张末容积、左室收缩末容积和左室射血分数,比较几种检查对冠心病心功能不全患者左室容量测定及功能评价的优劣。应用双核素SPECT检查及心脏MR延迟增强显像分析左室存活心肌,比较分析磁共振检测的准确性。结果左室造影测得的左室舒张末容积和左室射血分数与磁共振检查结果不具相关性,左室造影所测指标高于MR;左室造影所测左室收缩末容积与磁共振相近,具有相关性,r=0.62,P=0.014。门控SPECT显像测得左室舒张末容积、左室收缩末容积与MR检查结果相近并具相关性,r值分别为0.65和0.66,P值分别为0.002和0.002。磁共振延迟增强显像与18F-FDG心肌代谢存活心肌显像具有较好的一致性。以18F-FDG心肌代谢显像为金标准,磁共振延迟增强显像敏感度68.3%,特异度92.5%。结论磁共振能够准确判断陈旧性心肌梗死患者左室容积、功能。磁共振对心梗后存活心肌的判断具有同18F-FDG核素SPECT相近的特异性,但敏感性仍有差距。

Objective to evaluate imaging diagnosis of heart failure induced by old myocardial infarction. Methods The LVEDV, LVESV and LVEF were measured by left ventriculography, gated SPECT and MR imaging in patients with heart failure induced by old myocardial infarction. The comparison of results obtained by those different methods was investigated. ^18F-FDG myocardial metabolism imaging and late contrast-enhanced MR imaging were employed to detect viable myocardium, and the accuracy of MR imaging was analyzed. Results The LVEDV and LVEF obtained by left ventriculography mismatched with those data obtained by MR imaging, with higher readings in ventriculography; the LVESV obtained by the above two methods were correlated closdy. The LVEDV, LVESV and LVEF obtained by gated SPECT had the results more closely related to those obtained by MR imaging. The result of late contrast-enhanced MR imaging was in agreement with ^18F-FDG myocardial metabolism imaging in assessment of myocardial viability, kappa value was 0. 446 （P〈0. 001）. Compared with ^18F-FDG myocardial metabolism imaging, which was taken as a gold standard, the sensitivity of late contrast-enhanced MR imaging was 68.3 % and the specificity was 92.5 %. Conclusions MR imaging can accurately detect left ventricular volume and function for patients with old myocardial infarction. As for the assessment of viable myocardium after myocardial infarction, MR imaging has specificity similar to ^18F-FDG SPECT but sensitivity inferior to ^18F-FDG SPECT.