In Vivo Noninvasive 4D Pressure Difference Mapping in the Human Aorta: Phantom Comparison and Application in Healthy Volunteers and Patients
In Vivo Noninvasive 4D Pressure Difference Mapping in the Human Aorta: Phantom Comparison and Application in Healthy Volunteers and Patients
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DOI：
10.1002/mrm.22907
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发表时间：
2011-10-01
影响因子：
3.3
通讯作者：
Markl, Michael
中科院分区：
文献类型：
--
作者：
Bock, Jelena;Frydrychowicz, Alex;Markl, Michael
在这项工作中，我们提出了一个系统的幻影比较和临床应用的无创压力差映射在人体主动脉的基础上，时间分辨的三维相位对比数据。使用Navier-Stokes方程，基于MR三维速度矢量场（空间/时间分辨率类似于2.1 mm（3）/40 ms的流量敏感4D MRI）得出的压力梯度的积分和迭代细化计算相对压差。在使用狭窄体模进行体外研究后，系统评价了一组12名健康受试者和6名主动脉缩窄修复后患者胸主动脉的时间分辨3D压力梯度。体模研究的结果与预期值和标准方法（伯努利）一致。健康受试者的数据显示了良好的受试者间一致性，与文献的一致性良好。在患者中，压力波形显示峰值升高。狭窄处的压力梯度与多普勒超声的参考测量值进行比较。当使用连接狭窄近端和远端位置的所有可能路径的最大压差时，MRI结果显示与超声显著相关（r = 0.96，P < 0.05），但中度低估（14.7% +/- 15.5%）。本研究证明了所应用的方法从时间分辨3D相位对比MRI中获得额外定量信息（如压力梯度）的潜力。Magn Reson Med 66：1079-1088，2011. (C)2011 Wiley-Liss，Inc.
In this work, we present a systematic phantom comparison and clinical application of noninvasive pressure difference mapping in the human aorta based on time-resolved 3D phase contrast data. Relative pressure differences were calculated based on integration and iterative refinement of pressure gradients derived from MR-based three-directional velocity vector fields (flow-sensitive 4D MRI with spatial/temporal resolution similar to 2.1 mm(3)/40 ms) using the Navier-Stokes equation. After in vitro study using a stenosis phantom, time-resolved 3D pressure gradients were systematically evaluated in the thoracic aorta in a group of 12 healthy subjects and 6 patients after repair for aortic coarctation. Results from the phantom study showed good agreement with expected values and standard methods (Bernoulli). Data of healthy subjects showed good intersubject consistency and good agreement with the literature. In patients, pressure waveforms showed elevated peak values. Pressure gradients across the stenosis were compared with reference measurements from Doppler ultrasound. The MRI findings demonstrated a significant correlation (r = 0.96, P < 0.05) but moderate underestimation (14.7% +/- 15.5%) compared with ultrasound when the maximum pressure difference for all possible paths connecting proximal and distal locations of the stenosis were used. This study demonstrates the potential of the applied approach to derive additional quantitative information such as pressure gradients from time-resolved 3D phase contrast MRI. Magn Reson Med 66: 1079-1088, 2011. (C) 2011 Wiley-Liss, Inc.