Automatic correction of background phase offset in 4D-flow of great vessels and of the heart in MRI using a third-order surface model
Automatic correction of background phase offset in 4D-flow of great vessels and of the heart in MRI using a third-order surface model
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DOI：
10.1007/s10334-019-00765-z
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发表时间：
2019-12-01
影响因子：
2.3
通讯作者：
Mousseaux, Elie
中科院分区：
文献类型：
--
作者：
Craiem, Damian;Pascaner, Ariel F.;Mousseaux, Elie
目的评价一种自动校正心脏4D血流采集中速度偏移误差的方法。材料和方法速度偏移校正是在一个平面的平面计划，并比较体积的方法。自动检测静止区域。在体模中使用两个方向和两个编码速度（Venc）进行体外实验。一阶至三阶模型拟合三个速度分量的时间平均图像。体内实验包括志愿者中叠加到体模的真实感兴趣区。在15名志愿者中，比较了降主动脉近端和远端、肺动脉和升主动脉的血流量（Qs）。结果采用三阶模型校正后，偏移误差减小，残余体模速度低于0.6 cm/s，为Venc的0.4%。逐平面校正方法比体积方法更有效。通过志愿者与体模的叠加ROI的平均速度高度相关（r（2）= 0.96）。校正后，近端和远端降主动脉血流之间的显著差异从8.1 ml降至-1.4 ml（p <0.001），Qp/Qs从1.08 +/-0.09降至1.01 +/-0.05。讨论自动三阶模型校正了4D血流采集中的速度偏移误差，达到了临床应用的可接受水平。
Objective To evaluate an automatic correction method for velocity offset errors in cardiac 4D-flow acquisitions. Materials and methods Velocity offset correction was done in a plane-by-plane scheme and compared to a volumetric approach. Stationary regions were automatically detected. In vitro experiments were conducted in a phantom using two orientations and two encoding velocities (Venc). First- to third-order models were fit to the time-averaged images of the three velocity components. In vivo experiments included realistic ROIs in a volunteer superimposed to a phantom. In 15 volunteers, blood flow volume of the proximal and distal descending aorta, of the pulmonary artery (Qp) and the ascending aorta (Qs) was compared. Results Offset errors were reduced after correction with a third-order model, yielding residual phantom velocities below 0.6 cm/s and 0.4% of Venc. The plane-by-plane correction method was more effective than the volumetric approach. Mean velocities through superimposed ROIs of a volunteer vs phantom were highly correlated (r(2) = 0.96). The significant difference between proximal and distal descending aortic flows was decreased after correction from 8.1 to - 1.4 ml (p < 0.001) and Qp/Qs reduced from 1.08 +/- 0.09 to 1.01 +/- 0.05. Discussion An automatic third-order model corrected velocity offset errors in 4D-flow acquisitions, achieving acceptable levels for clinical applications.