Department of Cardiac and Vascular Diseases, Institute of Cardiology, Jagiellonian University Collegium Medicum, Krakow, Poland.
Kardiol Pol. 2009 Aug;67(8A):1013-8.
Contrast-enhanced magnetic resonance imaging (CE-MRI) can identify myocardial scarring following acute myocardial infarction (AMI).
To compare myocardial contrast echocardiography (MCE) and CE-MRI in detection of resting perfusion defect in patients with acute myocardial infarction.
Twenty four patients (21 men, 3 women, mean age 58.7 +/- 11.4 years) underwent primary percutaneous coronary angioplasty (PCI) for anterior AMI. All patients underwent MCE: segmental perfusion was estimated in real time before and immediately after PCI and on third day after PCI, using low mechanical index (0.3) after 0.3-0.5 ml bolus injections of intravenous OptisonTM. The MCE was scored semiquantitatively as: 1--homogenous contrast enhancement, 2--patchy contrast enhancement, 3--no contrast (non-viable myocardium). All patients underwent CE-MRI on a 1.5 T scanner (SONATA, Siemens) on the third day after PCI. Acquisition of short axis slices was performed before and 20 min after injection of Gd-DPTA (0.15 mmol/kg) with an inversion recovery TurboFLASH sequence (TE 1.1 ms, TR 700 ms, flip angle 300) in multiple breath-holds. The pattern of hyperenhancement representing MI (which intensity was more than 150% intensity of myocardium) was quantified by planimetry. The CE-MRI was scored according to the severity of myocardial scar as: 1--without scar, 2-- <50% of myocardial thickness, 3 - > 50% of myocardial thickness.
Myocardial perfusion was analysed using MCE and contrast-enhanced MRI in 362 segments. Agreement between MCE and CE-MRI for identification of viable versus necrotic myocardium on third day after PCI was 86% (kappa = 0.73). Thirteen (54%) patients showed transmural necrosis at CE-MRI while 11 (46%) showed non-transmural necrosis. Patients from the transmural necrosis group showed a higher creatine kinase peak (p = 0.0001), higher CK-MB (p = 0.00002) and higher troponine level (p = 0.008), and more impaired baseline regional contractile function (p = 0.045). All angiographic parameters were less favourable in this group before as well as after PCI than in patients with non-transmural necrosis.
Myocardial contrast echocardiography correlates very well with CE-MRI in the assessment of myocardial perfusion after PCI in AMI. Contrast-enhanced MRI is accurate technique for assessing the infarct zone. Identification by CE-MRI of transmural necrosis was associated with more impaired left ventricular function, non-reperfused MI, and presence of Q waves in ECG.
对比增强磁共振成像（CE-MRI）可识别急性心肌梗死（AMI）后的心肌瘢痕。
比较心肌声学造影（MCE）和 CE-MRI 在检测急性心肌梗死后静息灌注缺陷中的应用。
24 例患者（21 名男性，3 名女性，平均年龄 58.7±11.4 岁）因前壁 AMI 行直接经皮冠状动脉介入治疗（PCI）。所有患者均行 MCE：在直接 PCI 前、即刻和第 3 天行低机械指数（0.3）静脉注射 OptisonTM 0.3-0.5ml 后实时评估节段性灌注。MCE 半定量评分：1-均匀增强，2-斑片状增强，3-无增强（无活力心肌）。所有患者均在 PCI 后第 3 天行 1.5T 扫描仪（SONATA，西门子）行 CE-MRI。使用反转恢复 TurboFLASH 序列（TE 1.1ms，TR 700ms，翻转角 300）在多次屏气下在短轴切片上采集图像，在注射 Gd-DPTA（0.15mmol/kg）前和后 20min 进行。通过定量分析 MI 代表的高增强模式（强度超过心肌强度的 150%）。根据心肌瘢痕的严重程度对 CE-MRI 进行评分：1-无瘢痕，2-<50%心肌厚度，3->50%心肌厚度。
在 362 个节段中使用 MCE 和对比增强 MRI 分析心肌灌注。MCE 和 CE-MRI 在识别 PCI 后第 3 天存活与坏死心肌方面的一致性为 86%（kappa=0.73）。CE-MRI 显示 13 例（54%）患者存在透壁性坏死，11 例（46%）患者存在非透壁性坏死。透壁性坏死组患者的肌酸激酶峰值更高（p=0.0001），CK-MB 更高（p=0.00002），肌钙蛋白水平更高（p=0.008），基线节段收缩功能受损更严重（p=0.045）。与非透壁性坏死组相比，该组患者的所有血管造影参数在 PCI 前后均较差。
MCE 在评估 AMI 后 PCI 后的心肌灌注方面与 CE-MRI 相关性非常好。CE-MRI 是评估梗死区的准确技术。CE-MRI 识别透壁性坏死与左心室功能受损更严重、非再灌注性 MI 和心电图 Q 波有关。
