Dunn Terence Sean, Patel Pratik, Abazid Bassem, Nagaraj Hosakote M, Desai Ravi V, Gupta Himanshu, Lloyd Steven G
Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama.
Lehigh Valley Health Network, Allentown, Pennsylvania.
Echocardiography. 2019 Jun;36(6):1181-1190. doi: 10.1111/echo.14358. Epub 2019 May 13.
Phase-contrast cardiovascular magnetic resonance (PC-CMR) quantification of intracardiac shunt (measuring the pulmonary to systemic flow ratio, Qp/Qs) is typically determined by measuring flow through planes perpendicular the pulmonary trunk (PA) and ascending aorta (Ao). This method is subject to error from presence of background velocity offsets and requires two scan acquisitions. We evaluated an alternate PC-CMR technique for quantifying Qp/Qs using a single modified plane that encompasses both the PA and Ao.
In 53 patients evaluated for intracardiac shunting, PC-CMR measurement in the individual Ao and PA planes and also in a single-acquisition plane was obtained and Qp/Qs calculated by each method. Bland-Altman analysis was performed to evaluate the agreement between the two methods.
The 95% confidence limits of agreement ranged from -0.52 to +0.34 indicating good agreement between the two methods. There was excellent agreement on the clinically relevant threshold value of Qp/Qs ratio of 1.5 (representing criteria for surgical correction of shunt).
Qp/Qs determined from the single-acquisition approach agrees well with that of the individual PA and Ao method and offers potential improved accuracy (due to background velocity offset).
心脏内分流的相位对比心血管磁共振成像（PC-CMR）定量分析（测量肺循环与体循环血流量比值，即Qp/Qs）通常通过测量垂直于肺动脉干（PA）和升主动脉（Ao）平面的血流来确定。该方法易受背景速度偏移的影响而产生误差，且需要两次扫描采集。我们评估了一种替代的PC-CMR技术，该技术使用一个包含PA和Ao的单一改良平面来定量分析Qp/Qs。
对53例接受心脏内分流评估的患者，分别在单独的Ao和PA平面以及单一采集平面进行PC-CMR测量，并通过每种方法计算Qp/Qs。采用Bland-Altman分析评估两种方法之间的一致性。
一致性的95%置信限为-0.52至+0.34，表明两种方法之间具有良好的一致性。在临床相关的Qp/Qs比值阈值1.5（代表分流手术矫正标准）方面，两种方法具有极好的一致性。
通过单一采集方法确定的Qp/Qs与单独的PA和Ao方法的结果高度一致，并且（由于背景速度偏移）可能具有更高的准确性。
