直接 T2 定量评估急性缺血性损伤中的心肌水肿。

Direct T2 quantification of myocardial edema in acute ischemic injury.

机构信息

The Ohio State University, Columbus, Ohio 43210, USA.

出版信息

JACC Cardiovasc Imaging. 2011 Mar;4(3):269-78. doi: 10.1016/j.jcmg.2010.09.023.

DOI:10.1016/j.jcmg.2010.09.023

PMID:21414575

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC4282779/

Abstract

OBJECTIVES

To evaluate the utility of rapid, quantitative T2 mapping compared with conventional T2-weighted imaging in patients presenting with various forms of acute myocardial infarction.

BACKGROUND

T2-weighted cardiac magnetic resonance (CMR) identifies myocardial edema before the onset of irreversible ischemic injury and has shown value in risk-stratifying patients with chest pain. Clinical acceptance of T2-weighted CMR has, however, been limited by well-known technical problems associated with existing techniques. T2 quantification has recently been shown to overcome these problems; we hypothesized that T2 measurement in infarcted myocardium versus remote regions versus zones of microvascular obstruction in acute myocardial infarction patients could help reduce uncertainty in interpretation of T2-weighted images.

METHODS

T2 values using a novel mapping technique were prospectively recorded in 16 myocardial segments in 27 patients admitted with acute myocardial infarction. Regional T2 values were averaged in the infarct zone and remote myocardium, both defined by a reviewer blinded to the results of T2 mapping. Myocardial T2 was also measured in a group of 21 healthy volunteers.

RESULTS

T2 of the infarct zone was 69 ± 6 ms compared with 56 ± 3.4 ms for remote myocardium (p < 0.0001). No difference in T2 was observed between remote myocardium and myocardium of healthy volunteers (56 ± 3.4 ms and 55.5 ± 2.3 ms, respectively, p = NS). T2 mapping allowed for the detection of edematous myocardium in 26 of 27 patients; by comparison, segmented breath-hold T2-weighted short tau inversion recovery images were negative in 7 and uninterpretable in another 2 due to breathing artifacts. Within the infarct zone, areas of microvascular obstruction were characterized by a lower T2 value (59 ± 6 ms) compared with areas with no microvascular obstruction (71.6 ± 10 ms, p < 0.0001). T2 mapping provided consistent high-quality results in patients unable to breath-hold and in those with irregular heart rhythms, in whom short tau inversion recovery often yielded inadequate imaging.

CONCLUSIONS

Quantitative T2 mapping reliably identifies myocardial edema without the limitations encountered by T2-weighted short tau inversion recovery imaging, and may therefore be clinically more robust in showing acute ischemic injury.

摘要

目的

评估快速定量 T2 映射与常规 T2 加权成像在各种形式的急性心肌梗死患者中的应用价值。

背景

T2 加权心脏磁共振（CMR）可在不可逆性缺血损伤发生前识别心肌水肿，并且在胸痛患者的风险分层中具有价值。然而，T2 加权 CMR 的临床应用受到与现有技术相关的众所周知的技术问题的限制。最近的研究表明，T2 定量可以克服这些问题；我们假设在急性心肌梗死患者中测量梗死心肌与远隔心肌以及微血管阻塞区域的 T2 值可以帮助减少对 T2 加权图像解释的不确定性。

方法

前瞻性记录了 27 例急性心肌梗死患者 16 个心肌节段的 T2 值，使用一种新的映射技术。在不知道 T2 映射结果的情况下，由一名审阅者对梗死区和远隔心肌的 T2 值进行了平均。还对 21 名健康志愿者进行了心肌 T2 测量。

结果

梗死区的 T2 值为 69 ± 6 ms，远隔心肌为 56 ± 3.4 ms（p < 0.0001）。远隔心肌与健康志愿者的心肌 T2 值无差异（分别为 56 ± 3.4 ms 和 55.5 ± 2.3 ms，p = NS）。T2 映射可在 27 例患者中的 26 例中检测到水肿性心肌；相比之下，分段屏气 T2 加权短 tau 反转恢复图像在 7 例中为阴性，在另 2 例中因呼吸伪影而无法解释。在梗死区，微血管阻塞区的 T2 值较低（59 ± 6 ms），而无微血管阻塞区的 T2 值较高（71.6 ± 10 ms，p < 0.0001）。T2 映射可在无法屏气和心律不齐的患者中提供一致的高质量结果，在这些患者中，短 tau 反转恢复成像通常无法提供足够的图像。