MR心肌首过灌注成像评估肥厚型心肌病心肌缺血

MR first-pass myocardial perfusion imaging in evaluation of myocardial ischemia in hypertrophic cardiomyopathy

目的采用MR心肌首过灌注成像评估肥厚型心肌病(HCM)心肌缺血情况。方法选取20例HCM患者(HCM组)和10名健康志愿者(对照组)行CMR检查(包括左心室短轴电影、心肌首过灌注成像和延迟增强扫描),测量舒张末期心肌厚度(EDTH),绘制左心室基底部、中部及心尖部的血池-信号强度心肌灌注曲线,获得各节段达峰时间(t_(peak))、心肌信号强度最大上升斜率(Slope_(max))、峰值信号强度(SI_(peak))等。根据EDTH,将HCM组各心肌节段分为非肥厚亚组和肥厚亚组,肥厚亚组又分为轻度肥厚(15~19mm)、中度肥厚(20~24mm)和重度肥厚(25~29mm)节段3个水平,采用单因素方差分析比较所有组别t_(peak)、Slope_(max)、SI_(peak)的总体差异,对HCM各亚组及各水平的t_(peak)、Slope_(max)、SI_(peak)行两两检验。结果对照组与HCM非肥厚亚组的Slope_(max)、t_(peak)差异均无统计学意义(P均>0.05)。HCM非肥厚亚组与HCM肥厚亚组Slope_(max)、t_(peak)差异均有统计学意义(P均<0.05)。HCM肥厚亚组中,轻度肥厚水平Slope_(max)明显高于中度和重度肥厚(P均<0.05),中度肥厚水平t_(peak)高于轻度肥厚(P<0.05);中度与重度肥厚间Slope_(max)、t_(peak)及轻度、中度和重度肥厚间SI_(peak)差异均无统计学意义(P均>0.05)。结论 MR心肌首过灌注成像可反映HCM不同肥厚节段的心肌缺血情况,有助于对HCM患者进行风险分层、制定治疗计划和预后评估。

Objective To evaluate the myocardial ischemia in hypertrophic cardiomyopathy （HCM） patients with MR first-pass myocardial perfusion imaging. Methods Totally 20 patients with HCM （HCM group） and 10 healthy volunteers （control group） underwent cardiac MR scanning, including left ventricle short axial cine, first-pass myocardial perfusion imaging and delayed enhanced imaging. Then the left ventricular end-diastolic wall thickness （EDTH） was measured. The blood pool-signal strength curves of the near, middle and far segments of left ventricle were drawn, and then time to peak （tpoak）, maximal upslope of time-intensity curve （S1opemax）, peak signal intensity （SIpeak） were measured. According to EDTH, different segments of HCM were divided into non-hypertrophic subgroup and hypertrophic subgroup, and patients in hypertrophic subgroup were further divided as slightly （15-19 ram）, moderately （20-24 ram） and severely hypertrophic level （25-29 mm）. One-way ANOVA analysis was used to analyze the differences of tpeak, Slope SIpeak among groups, as well as every two subgroups and levels. Results The differences of Slopemax, tpeak between control group and non-hypertrophic group were riot statistically significant （ both P 〉0. 05 ）. The differences of Slope^x and tp^k between non- hypertrophic group and hypertrophic group were statistically significant （both P〈0.05）. In hypertrophic subgroup, Slopemax of slightly hypertrophic level was higher than that of moderately and severely hypertrophic level （both P〈 0.05）, and tpeak of moderately hypertrophic level was higher than that of slightly hypertrophic level （P〈0. 05）. However, Slopemax and tpeak between moderately and severely hypertrophic level, SIpeak between every two levels were not significantly different （all P〉0.05）. Conclusion MR first-pass myocardial perfusion imaging can reflect myocardial ischemia of different hypertrophic segments of HCM, contributing to risk stratification, therapy planning and prognosis evaluation of HCM patients.