Division of Imaging Sciences, The Rayne Institute, St. Thomas' Hospital, King's College London, London, UK.
Circulation. 2011 Jul 26;124(4):416-24. doi: 10.1161/CIRCULATIONAHA.110.965442. Epub 2011 Jul 11.
Persistent intracoronary thrombus after plaque rupture is associated with an increased risk of subsequent myocardial infarction and mortality. Coronary thrombus is usually visualized invasively by x-ray coronary angiography. Non-contrast-enhanced T1-weighted magnetic resonance (MR) imaging has been useful for direct imaging of carotid thrombus and intraplaque hemorrhage by taking advantage of the short T1 of methemoglobin present in acute thrombus and intraplaque hemorrhage. The aim of this study was to investigate the use of non-contrast-enhanced MR for direct thrombus imaging (MRDTI) in patients with acute myocardial infarction.
Eighteen patients (14 men; age, 61±9 years) underwent MRDTI within 24 to 72 hours of presenting with an acute coronary syndrome before invasive x-ray coronary angiography; MRDTI was performed with a T1-weighted, 3-dimensional, inversion-recovery black-blood gradient-echo sequence without contrast administration. Ten patients were found to have intracoronary thrombus on x-ray coronary angiography (left anterior descending, 4; left circumflex, 2; right coronary artery, 4; and right coronary artery-posterior descending artery, 1), and 8 had no visible thrombus. We found that MRDTI correctly identified thrombus in 9 of 10 patients (sensitivity, 91%; posterior descending artery thrombus not detected) and correctly classified the control group in 7 of 8 patients without thrombus formation (specificity, 88%). The contrast-to-noise ratio was significantly greater in coronary segments containing thrombus (n=10) compared with those without visible thrombus (n=131; mean contrast-to-noise ratio, 15.9 versus 2.6; P<0.001).
Use of MRDTI allows selective visualization of coronary thrombus in a patient population with a high probability of intracoronary thrombosis.
斑块破裂后持续的冠状动脉内血栓与随后心肌梗死和死亡率的增加相关。冠状动脉内血栓通常通过 X 射线冠状动脉造影进行有创性可视化。非对比增强 T1 加权磁共振（MR）成像通过利用急性血栓和斑块内出血中存在的正铁血红蛋白的短 T1 已经有助于颈动脉血栓和斑块内出血的直接成像。本研究的目的是探讨在急性心肌梗死患者中使用非对比增强 MR 进行直接血栓成像（MRDTI）的方法。
18 名患者（14 名男性；年龄 61±9 岁）在急性冠状动脉综合征发作后 24 至 72 小时内行侵入性 X 射线冠状动脉造影前进行了 MRDTI；MRDTI 采用 T1 加权、3 维、反转恢复黑血梯度回波序列，无需造影剂。10 名患者在 X 射线冠状动脉造影中发现冠状动脉内血栓（前降支 4 例；左旋支 2 例；右冠状动脉 4 例；右冠状动脉-后降支 1 例），8 名患者无可见血栓。我们发现，MRDTI 在 10 例患者中有 9 例正确识别血栓（敏感性为 91%；未检测到后降支血栓），在 8 例无血栓形成的对照组中有 7 例正确分类（特异性为 88%）。含血栓的冠状动脉节段（n=10）的对比噪声比明显大于无可见血栓的冠状动脉节段（n=131；平均对比噪声比，15.9 比 2.6；P<0.001）。
MRDTI 的使用可选择性地显示高概率存在冠状动脉内血栓的患者群体中的冠状动脉血栓。
