Hansen Esben Søvsø Szocska, Pedersen Steen Fjord, Pedersen Steen Bønløkke, Kjærgaard Uffe, Schmidt Nikolaj Hjort, Bøtker Hans Erik, Kim Won Yong
The MR Research Centre, Aarhus University Hospital Skejby, Aarhus N, Denmark; Danish Diabetes Academy, Odense, Denmark.
Department of Cardiothoracic and Vascular Surgery T , Aarhus University Hospital Skejby , Aarhus N , Denmark.
Open Heart. 2016 Apr 20;3(1):e000346. doi: 10.1136/openhrt-2015-000346. eCollection 2016.
Microvascular obstruction (MVO) and intramyocardial haemorrhage (IMH) are known complications of myocardial ischaemia-reperfusion injury. Whereas MVO is an established marker for a poor clinical outcome, the clinical significance of IMH remains less well defined. Cardiovascular MR (CMR) and T2 weighted short tau inversion recovery (T2-STIR) imaging have been used to detect IMH and to explore its clinical importance. IMH is typically identified within the area-at-risk as a hypointense signal core on T2-STIR images. Because MVO will also appear as a hypointense signal core, T2-STIR imaging may not be an optimal method for assessing IMH. In this study, we sought to investigate the ability of T2-STIR to discriminate between MVO with IMH in a porcine myocardial ischaemia-reperfusion model that expressed MVO with and without IMH.
MVO with and without IMH (defined from both macroscopic evaluation and T1 weighted CMR) was produced in 13 pigs by a 65-min balloon occlusion of the mid left anterior descending artery, followed by reperfusion. Eight days after injury, all pigs underwent CMR imaging and subsequently the hearts were assessed by gross pathology.
CMR identified MVO in all hearts. CMR and pathology showed that IMH was present in 6 of 13 (46%) infarcts. The sensitivity and specificity of T2-STIR hypointense signal core for identification of IMH was 100% and 29%, respectively. T2-values between hypointense signal core in the pigs with and without IMH were similar (60.4±3 ms vs 63.0±4 ms).
T2-STIR did not allow identification of IMH in areas with MVO in a porcine model of myocardial ischaemic/reperfusion injury in the subacute phase of a reperfused myocardial infarction.
微血管阻塞（MVO）和心肌内出血（IMH）是心肌缺血再灌注损伤的已知并发症。虽然MVO是临床预后不良的既定标志物，但IMH的临床意义仍不太明确。心血管磁共振（CMR）和T2加权短tau反转恢复（T2-STIR）成像已用于检测IMH并探讨其临床重要性。IMH通常在危险区域内被识别为T2-STIR图像上的低信号核心。由于MVO也会表现为低信号核心，因此T2-STIR成像可能不是评估IMH的最佳方法。在本研究中，我们试图在表达有或无IMH的MVO的猪心肌缺血再灌注模型中，研究T2-STIR区分MVO与IMH的能力。
通过对13头猪的左前降支中段进行65分钟的球囊闭塞，随后再灌注，产生有或无IMH的MVO（根据宏观评估和T1加权CMR定义）。损伤8天后，所有猪均接受CMR成像，随后对心脏进行大体病理学评估。
CMR在所有心脏中均识别出MVO。CMR和病理学显示，13个梗死灶中有6个（46%）存在IMH。T2-STIR低信号核心识别IMH的敏感性和特异性分别为100%和29%。有和无IMH的猪的低信号核心之间的T2值相似（60.4±3 ms对63.0±4 ms）。
在再灌注心肌梗死亚急性期的猪心肌缺血/再灌注损伤模型中，T2-STIR无法在存在MVO的区域识别IMH。
