She Hoi Lam, Roest Arno A W, Calkoen Emmeline E, van den Boogaard Pieter J, van der Geest Rob J, Hazekamp Mark G, de Roos Albert, Westenberg Jos J M
Department of Radiology, Princess Margaret Hospital, Hong Kong, SAR.
Division of Pediatric Cardiology, Department of Pediatrics, Leiden University Medical Center, Leiden, The Netherlands.
Congenit Heart Dis. 2017 Jan;12(1):40-48. doi: 10.1111/chd.12397. Epub 2016 Jul 18.
To evaluate the inflow pattern and flow quantification in patients with functional univentricular heart after Fontan's operation using 4D flow magnetic resonance imaging (MRI) with streamline visualization when compared with the conventional 2D flow approach.
Seven patients with functional univentricular heart after Fontan's operation and twenty-three healthy controls underwent 4D flow MRI. In two orthogonal two-chamber planes, streamline visualization was applied, and inflow angles with peak inflow velocity (PIV) were measured. Transatrioventricular flow quantification was assessed using conventional 2D multiplanar reformation (MPR) and 4D MPR tracking the annulus and perpendicular to the streamline inflow at PIV, and they were validated with net forward aortic flow.
Inflow angles at PIV in the patient group demonstrated wide variation of angles and directions when compared with the control group (P < .01). The use of 4D flow MRI with streamlines visualization in quantification of the transatrioventricular flow had smaller limits of agreement (2.2 ± 4.1 mL; 95% limit of agreement -5.9-10.3 mL) when compared with the static plane assessment from 2DFlow MRI (-2.2 ± 18.5 mL; 95% limit of agreement agreement -38.5-34.1 mL). Stronger correlation was present in the 4D flow between the aortic and trans-atrioventricular flow (R correlation in 4D flow: 0.893; in 2D flow: 0.786).
Streamline visualization in 4D flow MRI confirmed variable atrioventricular inflow directions in patients with functional univentricular heart with previous Fontan's procedure. 4D flow aided generation of measurement planes according to the blood flood dynamics and has proven to be more accurate than the fixed plane 2D flow measurements when calculating flow quantifications.
采用带有流线可视化的四维血流磁共振成像（MRI），评估Fontan手术治疗后的功能性单心室心脏患者的血流流入模式和血流定量，并与传统二维血流方法进行比较。
7例Fontan手术治疗后的功能性单心室心脏患者和23名健康对照者接受了四维血流MRI检查。在两个相互垂直的双腔平面上应用流线可视化技术，并测量峰值流入速度（PIV）时的流入角度。采用传统二维多平面重建（MPR）和四维MPR跟踪瓣环并垂直于PIV处的流线流入来评估房室血流定量，并通过主动脉净前向血流进行验证。
与对照组相比，患者组PIV时的流入角度在角度和方向上表现出较大差异（P < 0.01）。与二维血流MRI的静态平面评估（-2.2±18.5 mL；95%一致性界限-38.5-34.1 mL）相比，在房室血流定量中使用带有流线可视化的四维血流MRI时一致性界限较小（2.2±4.1 mL；95%一致性界限-5.9-10.3 mL）。主动脉血流与房室血流之间的四维血流相关性更强（四维血流中的R相关性：0.893；二维血流中的R相关性：0.786）。
四维血流MRI中的流线可视化证实了既往接受Fontan手术的功能性单心室心脏患者的房室流入方向存在变化。四维血流根据血流动力学辅助生成测量平面，并且在计算血流定量时已证明比固定平面的二维血流测量更准确。
