Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Raemistrasse 100, 8091, Zurich, Switzerland.
Department of Diagnostic Imaging, University Children`s Hospital, University of Zurich, Zurich, Switzerland.
BMC Med Imaging. 2022 Sep 27;22(1):169. doi: 10.1186/s12880-022-00895-2.
To find the best level to measure aortic flow for quantification of aortic regurgitation (AR) in 4D flow CMR.
In 27 congenital heart disease patients with AR (67% male, 31 ± 16 years) two blinded observers measured antegrade, retrograde, net aortic flow volumes and regurgitant fractions at 6 levels in 4D flow: (1) below the aortic valve (AV), (2) at the AV, (3) at the aortic sinus, (4) at the sinotubular junction, (5) at the level of the pulmonary arteries (PA) and (6) below the brachiocephalic trunk. 2D phase contrast (2DPC) sequences were acquired at the level of PA. All patients received prior transthoracic echocardiography (TTE) with AR severity grading according to a recommended multiparametric approach.
After assigning 2DPC measurements into AR grading, agreement between TTE AR grading and 2DPC was good (κ = 0.88). In 4D flow, antegrade flow was similar between the six levels (p = 0.87). Net flow was higher at level 1-2 than at levels 3-6 (p < 0.05). Retrograde flow and regurgitant fraction at level 1-2 were lower compared to levels 3-6 (p < 0.05). Reproducibility (inter-reader agreement: ICC 0.993, 95% CI 0.986-0.99; intra-reader agreement: ICC 0.982, 95%CI 0.943-0.994) as well as measurement agreement between 4D flow and 2DPC (ICC 0.994; 95%CI 0.989 - 0.998) was best at the level of PA.
For estimating severity of AR in 4D flow, best reproducibility along with best agreement with 2DPC measurements can be expected at the level of PA. Measurements at AV or below AV might underestimate AR.
找到测量主动脉瓣反流（AR）的最佳主动脉瓣水平，以量化 4D 流中的 AR。
在 27 例 AR（67%男性，31±16 岁）的先天性心脏病患者中，两位盲法观察者在 4D 流中于 6 个水平测量顺行、逆行、净主动脉流量和反流分数：（1）主动脉瓣（AV）下方，（2）AV 处，（3）主动脉窦处，（4）窦管交界处，（5）肺动脉（PA）水平，（6）头臂干下方。在 PA 水平采集二维相位对比（2DPC）序列。所有患者均接受了经胸超声心动图（TTE）检查，根据推荐的多参数方法对 AR 严重程度进行分级。
根据推荐的多参数方法将 2DPC 测量值分配到 AR 分级后，TTE AR 分级与 2DPC 之间的一致性良好（κ=0.88）。在 4D 流中，六个水平之间的顺行流量相似（p=0.87）。水平 1-2 的净流量高于水平 3-6（p<0.05）。水平 1-2 的逆行流量和反流分数低于水平 3-6（p<0.05）。重复性（读者间一致性：ICC 0.993，95%CI 0.986-0.99；读者内一致性：ICC 0.982，95%CI 0.943-0.994）以及 4D 流与 2DPC 之间的测量一致性（ICC 0.994；95%CI 0.989-0.998）在 PA 水平最佳。
在 4D 流中估计 AR 的严重程度时，在 PA 水平可获得最佳的重复性和与 2DPC 测量的最佳一致性。AV 或其下方的测量值可能低估 AR。
