MR measurement of coronary blood flow and reserve in hypertrophic cardiomyopathy

本研究的目的是利用屏气速度编码电影（VEC）磁共振成像评估肥厚性心肌病（HCM）患者每克心肌质量的冠状动脉血流量和整个左心室（LV）的血管扩张剂血流储备。研究对象为29例HCM患者和9名健康志愿者。静脉注射双嘧达莫（0.56 mg/kg）前后，采用垂直于冠状窦的斜位显像面获得快速VEC MR图像。将血管的平均流速和横截面积的乘积综合起来测量血流。获得包括整个左室的屏气电影MR图像以量化左室质量。在基础状态下，HCM患者冠脉血流量为0.74±0.27 ml/min/b （p=NS）。给予双嘧达莫后，HCM冠状动脉血流明显低于健康组（1.03±0.40 vs 2.14±0.51 ml/min/g, p<0.01），血流储备比明显低于正常组（1.72±0.49 vs 3.01±0.75,p<0.01）。总之，憋气VEC磁共振成像是一种无创技术，用于评估药物应激和血管扩张剂血流储备后每克心肌块的冠状动脉流量。

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.