MR measurement of coronary blood flow and reserve in hypertrophic cardiomyopathy

本研究的目的是评价冠状动脉血流量每克心肌质量和血管舒张功能血流储备的整个左心室肥厚型心肌病（HCM）使用屏气速度编码电影（VEC）MR成像。29例HCM患者和9例健康志愿者进行了研究。在静脉注射潘生丁（0.56 mg/kg）之前和之后，使用垂直于冠状窦的倾斜成像平面获得快速VEC MR图像。将平均流速和血管横截面积的乘积积分以测量血流量。采集包含整个LV的屏气电影MR图像以量化LV质量。在基础状态下，HCM患者每克心肌质量的冠状动脉血流量为0.74±0.27 ml/min/B（p=NS）。应用潘生丁后，肥厚型心肌病患者冠脉血流量明显低于正常人（1.03±0.40 vs.2.14 ± 0.51ml/min/g，p<0.01），血流储备率明显低于正常人（1.72±0.49 vs.3.01 ±0.75，p<0.01）。总之，屏气VEC MR成像是一种无创技术，可用于评价药物应激后每克心肌质量的冠状动脉流量和HCM的血管扩张血流储备。

The purpose of this study was to evaluate coronary blood flow per gram of myocardial mass and vasodilator flow reserve for the entire left ventricle (LV) in hypertrophic cardiomyopathy (HCM) using breath-hold velocity encoded cine (VEC) MR imaging. Twenty-nine patients with HCM and 9 healthy volunteers were studied. Fast VEC MR images were obtained using an oblique imaging plane that was perpendicular to the coronary sinus before and after intravenous administration of dipyridamole (0.56 mg/kg). The products of mean velocity and cross-sectional area of the vessel were integrated to measure blood flow. Breath-hold cine MR images encompassing the entire LV were acquired to quantify LV mass. In the basal state, the coronary blood flow per gram of myocardial mass was 0.74±0.27 ml/min/b in patients with HCM (p=NS). After administration of dipyridamole, coronary blood flow in HCM increased to a level significantly less than that in healthy subjects (1.03±0.40 vs. 2.14±0.51 ml/min/g, p<0.01), resulting in severely depressed flow reserve ratio in HCM compared to normal subjects (1.72±0.49 vs 3.01±0.75, p<0.01). In conclusion, breath-hold VEC MR imaging is a noninvasive technique for evaluating coronary flow per gram of myocardial mass after pharmacological stress and vasodilator flow reserve with HCM.