Di Cesare E, Battisti S, Riva A, Corbacelli C, De Bernardinis G, Cicogna S, Masciocchi C
Dipartimento di Radiologia, ASL-Università L'Aquila, Via Vetoio 1, 67100, L'Aquila, Italy.
Radiol Med. 2009 Mar;114(2):216-28. doi: 10.1007/s11547-009-0366-x. Epub 2009 Mar 5.
The aim of this study was to evaluate the clinical utility of cardiac magnetic resonance imaging (MRI) with dobutamine stress in patients with atypical chest pain or equivocal electrocardiography (ECG) stress test, not suitable for stress echocardiography, using steady-state free-precession and parallel imaging technique.
Thirty-three patients (22 men, 11 women; mean age 62.4 years) underwent MRI with a 1.5-Tesla imager (General Electric, HD). We used an eight-channel phase-array dedicated coil. The MRI protocol included short-axis cine steady-state sequences with four-chamber parallel imaging of the left ventricle outflow tract at rest and after stress induction. Images were acquired 3 min after the intravenous injection of 5,10, 20, 30 or 40 microg/kg/min dobutamine. MRIs were analysed both at rest and at incremental dobutamine doses. Results were considered positive for coronary artery disease (CAD) if any new or worsening wall motion abnormality developed during the stress test. Twenty-two patients underwent coronary angiography; in the remaining ten, survival free from cardiovascular events over at least 9 months was considered as absence of disease.
One patient presented severe hypertension at rest and was excluded from our study. We analysed 960 segments and observed appearance or worsening of kinesis in 29 different segments in seven patients. Seven patients were considered positive for CAD on the basis of new or worsening wall motion abnormalities during dobutamine stress, yielding an overall sensitivity of 85% and a specificity of 100% in CAD detection.
Dobutamine stress cardiac MRI is an accurate method for assessing myocardial ischaemia in patients with CAD, and it could be useful as a noninvasive tool for excluding the disease. The increase in signal intensity and acquisition speed obtained by using steady-state free precession with parallel imaging proved useful in increasing test specificity with respect to previous similar studies.
本研究旨在评估对于不适合进行负荷超声心动图检查的非典型胸痛或心电图（ECG）负荷试验结果不明确的患者，采用稳态自由进动和并行成像技术进行多巴酚丁胺负荷心脏磁共振成像（MRI）的临床应用价值。
33例患者（22例男性，11例女性；平均年龄62.4岁）接受了使用1.5特斯拉成像仪（通用电气，HD）的MRI检查。我们使用了八通道相控阵专用线圈。MRI方案包括短轴电影稳态序列，在静息状态和负荷诱导后对左心室流出道进行四腔并行成像。在静脉注射5、10、20、30或40微克/千克/分钟多巴酚丁胺后3分钟采集图像。在静息状态和多巴酚丁胺剂量递增时均对MRI进行分析。如果在负荷试验期间出现任何新的或加重的室壁运动异常，则结果被视为冠状动脉疾病（CAD）阳性。22例患者接受了冠状动脉造影；其余10例患者中，至少9个月无心血管事件生存被视为无疾病。
1例患者在静息状态下出现严重高血压，被排除在我们的研究之外。我们分析了960个节段，在7例患者的29个不同节段中观察到运动出现或加重。7例患者基于多巴酚丁胺负荷期间新的或加重的室壁运动异常被视为CAD阳性，在CAD检测中总体敏感性为85%，特异性为100%。
多巴酚丁胺负荷心脏MRI是评估CAD患者心肌缺血的一种准确方法，并且可作为排除该疾病的无创工具。与以往类似研究相比，使用稳态自由进动和并行成像获得的信号强度增加和采集速度提高，被证明有助于提高检测特异性。
