评估再灌注急性心肌梗死中心肌内出血的 T1 加权心血管磁共振成像。

Assessment of intramyocardial hemorrhage by T1-weighted cardiovascular magnetic resonance in reperfused acute myocardial infarction.

机构信息

Department of Cardiothoracic and Vascular Surgery T, Aarhus University Hospital Skejby, Brendstrupsgaardsvej 100, Aarhus N DK-8200, Denmark.

出版信息

J Cardiovasc Magn Reson. 2012 Aug 30;14(1):59. doi: 10.1186/1532-429X-14-59.

BACKGROUND

Intramyocardialhemorrhage (IMH) reflects severe reperfusion injury in acute myocardial infarction. Non-invasive detection of IMH by cardiovascular magnetic resonance (CMR) may serve as a surrogate marker to evaluate the effect of preventive measures to reduce reperfusion injury and hence provide additional prognostic information. We sought to investigate whether IMH could be detected by CMR exploiting the T1 shortening effect of methemoglobin in an experimental model of acute myocardial infarction. The results were compared to T2-weighthed short tau inversion recovery (T2-STIR), and T2*-weighted(T2*W) sequences.

METHODS AND RESULTS

IMH was induced in ten 40 kg pigs by 50-min balloon occlusion of the mid LAD followed by reperfusion. Between 4-9 days (average 4.8) post-injury, the left ventricular myocardium was assessed by T1-weigthed Inversion Recovery(T1W-IR), T2-STIR, and T2W sequences. All CMR images were matched to histopathology and compared with the area of IMH. The difference between the size of the IMH area detected on T1W-IR images and pathology was -1.6 ± 11.3% (limits of agreement, -24%-21%), for the T2W images the difference was -0.1 ± 18.3% (limits of agreement, -36.8%-36.6%), and for T2-STIR the difference was 8.0 ± 15.5% (limits of agreement, -23%-39%). By T1W IR the diagnostic sensitivity of IMH was 90% and specificity 70%, for T2*W imaging the sensitivity was 70% and specificity 50%, and for T2-STIR sensitivity for imaging IMH was 50% and specificity 60%.

CONCLUSION

T1-weigthed non-contrast enhanced CMR detects IMH with high sensitivity and specificity and may become a diagnostic tool for detection of IMH in patients with myocardial infarction.

背景

心肌内出血（IMH）反映了急性心肌梗死时严重的再灌注损伤。心血管磁共振（CMR）通过非侵入性方法检测 IMH 可以作为评估预防措施减少再灌注损伤效果的替代标志物，从而提供额外的预后信息。我们旨在研究在急性心肌梗死的实验模型中，是否可以通过 CMR 利用高铁血红蛋白的 T1 缩短效应来检测 IMH。将结果与 T2 加权短 tau 反转恢复（T2-STIR）和 T2加权（T2W）序列进行比较。

方法和结果

通过 50 分钟的 LAD 中段球囊阻塞再灌注后，在 10 头 40 公斤猪中诱导 IMH。在损伤后 4-9 天（平均 4.8 天），通过 T1 加权反转恢复（T1W-IR）、T2-STIR 和 T2W 序列评估左心室心肌。所有 CMR 图像均与组织病理学相匹配，并与 IMH 面积进行比较。T1W-IR 图像上检测到的 IMH 面积与病理学之间的差异为-1.6±11.3%（一致性限，-24%-21%），T2W 图像的差异为-0.1±18.3%（一致性限，-36.8%-36.6%），而 T2-STIR 的差异为 8.0±15.5%（一致性限，-23%-39%）。通过 T1W IR，IMH 的诊断灵敏度为 90%，特异性为 70%，T2*W 成像的灵敏度为 70%，特异性为 50%，T2-STIR 成像的灵敏度为 50%，特异性为 60%。