1.5TMRI评估肺动脉高压患者右心功能及肺动脉血液动力学

The Assessment of Right Ventricular Function and Pulmonary Artery Hemodynamics in Patients with Pulmonary Hypertension by 1.5T MRI

背景与目的肺动脉高压(pulmonary hypertension,PH)患者肺动脉压力增高,右心功能逐渐下降,最终导致右心衰竭而死亡,因而准确、无创地监测PH患者右心功能及肺动脉血液动力学改变尤为重要。本研究旨在评价心脏MRI(cardiac magnetic resonance imaging,CMRI)在评估PH患者右心功能及肺动脉血液动力学中的价值。方法对25例PH患者及30例健康志愿者进行心脏电影MRI(cine-MRI)及相位对比法MRI(PC-MRI)扫描。对cine-MRI扫描图像进行后处理,计算获得右心室舒张末期容积(end-diastolicvolume,EDV)、收缩末期容积(end-systolic volume,ESV)、搏出量(stroke volume,SV)、射血分数(ejection fraction,EF)及心肌质量(myocardial mass,MM),以上数据除EF外均经体表面积(body surfacearea,BSA)校正。对PC-MRI扫描图像进行处理并计算获得主肺动脉(main pulmonary artery,MPA)峰值流速及其顺应性。采用两独立样本t检验分析两组参数有无差异,明显性标准为P<0.05。结果与对照组相比,PH组右心室EDV、ESV及MM指数均明显高于后者(P<0.01),EF明显低于后者(P<0.01),SV指数与对照组无明显差异(P>0.05),MPA峰值流速及顺应性均明显低于对照组(P<0.01)。结论 CMRI在PH患者右心功能及MPA血液动力学参数评估中具有重要意义。

Background and objective Pulmonary hypertension （PH） is characterized by rising pulmonary arterial pressure, decreasing right ventricular （RV） function, and ultimately, RV failure.Therefore, it is important to monitor RV function and pulmonary artery hemodynamics accurately and noninvasively. This study evaluates cardiac magnetic resonance imaging （CMRI） in assessing RV function and pulmonary artery hemodynamics in patients with PH. Methods Cine-MRI and phase-contrast MRI （PC-MRI） were performed in 25 PH patients and 30 healthy volunteers. Cine-MRI images were postprocessed on Report Card software and the following parameters were obtained： RV end-diastolic volume （EDV）, end-systolic volume （ESV）, stroke volume （SV）, ejection fraction （EF）, and myocardial mass （MM）. Except for EF, all of the above parameters were normalized to body surface area （BSA）. PC-MRI images were post-processed on Report Card software, peak velocity and distensibility of main pulmonary artery （MPA） could also be obtained. Student t test was employed for statistical assessment.Results Compared with controls, RV EDV, ESV and MM index in PH patients were significantly increased （P〈0.01）, EF was significantly impaired （P〈0.01）, peak velocity and distensibility of MPA were significantly lower （P〈0.01）. SV index between the two groups had no significant difference （P〉0.05）. Conclusion Cardiac MRI is of great value in the assessment of RV function and MPA hemodynamic parameters in patients with PH.