3.0T MRI相位对比法评价法乐四联症根治术后肺动脉血流动力学的信息

A phase contrast magnetic resonance imaging study of hemodynamics of pulmonary artery in patients with repaired tetralogy of Fallot at 3.0 tesla

目的评价3.0TPC-MRI定量测量法乐四联症(TOF)术后随访患者肺动脉返流的准确性,并分析不同手术方式对肺动脉返流的影响。材料与方法共42例(男26例,女16例,年龄10～51岁,平均年龄18.7岁)TOF根治术患者在1个月内先后进行了肺动脉血流的超声心动图及3.0T心脏MRI检查,计算PC-MRI测量得到的肺动脉返流分数(PRF)、肺动脉平均反向血流量(ANF)。采用Spearman等级相关分析PC-MRI与超声心动图测量肺动脉返流严重程度的关联程度。采用Mann-WhtineyU检验分析右室流出道补片组与跨瓣环补片组PRF及ANF的差异。结果超声心动图显示轻度肺动脉返流10例(23.8%),中度32例(76.2%);MRI显示轻度、中度、重度肺动脉返流分别为10例(23.8%),8例(19.0%)及24例(57.1%),PC-MRI与超声心动图结果具有明显正相关性(rs=0.606,P<0.01)。右室流出道补片组及跨瓣环补片组PRF中位数分别为7.96%、48.60%,ANF中位数分别为5.45ml/每个心动周期(beat)、45.70ml/beat,与右室流出道补片组相比,跨瓣环补片组的PRF更高(U=52.000,P=0.001),ANF更多(U=55.000,P=0.002)。结论 3.0TPC-MRI测量肺动脉返流严重程度与超声心动图有很好相关性,同时可提供定量测量信息。3.0TPC-MRI能准确反映右室流出道补片及跨瓣环补片手术所致肺动脉血流动力学差异。

Objective： To compare pulmonary reguigitation （PR） measured by 3.0 T PC-MRI with data provided by echocardiography and evaluate the relationship between PR and different operation method. Materials and methods： We studied 42 patients （16 female, 26 male, mean age 18.7 years, range 10--51 years） with surgical correction of TOF who performed cardiac magnetic resonance imaging and echocardiography within a month. The pulmonary regurgitation fraction （PRF） and average negative flow （ANF） were calculated during one cardiac cycle. Spearman rank correlation analysis was performed for comparison of measurement results. For comparison PRF and ANF between RVOT patch and transannular patch, Mann- Whtiney U test was employed. Results： By echocardiography criteria,mild PR was present in 10 cases, moderate PR in 32 cases.while PC-MRI showed mild PR in 10 cases（23.8%）, moderete PR in 8 cases（19.0%） and severe PR in 24 cases （57.1%） respectively. The different categories （mild,moderate and severe） of PR measured by PC-MRI had a positive liner correlation with the results measured by echocardiography （rs=0.606, P〈0.001）. Patients with a transannular patch had a significantly higher PRF and ANF than patients with RVOT patch （U=52.000, P=0.001, U=55.000, P=0.002）. Conclusion： The PRF measured by 3.0 T PC-MRI has well correlation with that measured by echocardiography, and PC-MRI can provide adequate quantitative information to estimate PRF. 3.0 T PC-MRI can accurately reflect the difference of pulmonary blood flow causing by RVOT patch and transannular patch.