心血管磁共振 T2 加权序列对急性心肌梗死后水肿心肌的诊断效能研究

Objectives: To investigate the diagnostic efficacy of cardiovascular magnetic resonance black blood and bright blood T2-weighted sequence on edematous myocardium in patients with acute myocardial infarction after reperfusion. Methods: Seventy-six patients with first acute myocardial infarction admitted to Xuanwu Hospital of Capital Medical University from September 2016 to December 2018 were included in this study. The CMR T2-STIR and T2p-SSFP images were collected and analyzed, and the diagnostic efficiency on identifying edema myocardium was evaluated using quantitative T2-MAP sequences as the gold standard. Image quality included image artifact recognition at patient level, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) comparison at slice level. Diagnostic efficacy included sensitivity, specificity, and accuracy in the identification of myocardial edema at segment level. Results: The mean age of 76 patients with first AMI was (57±11) years, including 66 males. All patients underwent CMR examination within one week after admission. At the patient level, the motor artifacts of T2-STIR and T2p-SSFP in black blood were 24 cases and 5 cases, and that of susceptibility artifacts were 17 cases and 2 cases, respectively. The difference was statistically significant (P<0.05). At the slice level, the SNR of remote myocardium and edematous myocardium in T2-STIR was twice higher than that in T2p-SSFP (P<0.05). The CNR of edematous myocardium to remote myocardium and blood pool in T2-STIR was more robust than that in T2p-SSFP, and the difference was statistically significant (P<0.05). At the segmental level, the sensitivity of T2-STIR was high (87.4% [83.3%, 90.8%]), and the specificity of T2p-SSFP was high (95.4% [89.5%, 98.5%]). The combination of T2-STIR and T2p-SSFP could significantly improve the sensitivity and accuracy of myocardial edema recognition, with a sensitivity of (93.7% [90.5%, 96.1%]) and a Youden index of 0.86. Conclusions: The high image quality of CMR T2-weighted sequence has practical clinical value on identifying edematous myocardium after acute myocardial infarction. The combination of black blood and bright blood T2 sequence can significantly improve the sensitivity and accuracy on identifying edematous myocardium after acute myocardial infarction.