Herment A, Mousseaux E, Jolivet O, DeCesare A, Frouin F, Todd-Pokropek A, Bittoun J
INSERM U.494 CHU Pitié, Paris, France.
Magn Reson Med. 2000 Jul;44(1):122-8. doi: 10.1002/1522-2594(200007)44:1<122::aid-mrm18>3.0.co;2-c.
We improved the three-point phase-contrast method by regularization of MR velocity data after acquisition of a low velocity-to-noise ratio (VNR) velocity image and a high VNR aliased velocity image. The phase unwrapping algorithm is based on the assumed correlation of the velocity of adjacent flow voxels on the low VNR and the unaliased high VNR images. We used Fourier encoding with eight velocity-encoding gradient steps to obtain reference velocity images of the aorta from five subjects (274 images) and compared them with the phase-contrast and three-point phase-contrast images with and without regularization. The VNR of the regularized velocity image was improved by 9.1 dB and the VNR of the three-point phase-contrast velocity image was improved by 0.7 dB with respect to the low first moment velocity image. Corresponding improvements of 9 dB and 3.7 dB were obtained for the estimations of instantaneous flow rate. Magn Reson Med 44:122-128, 2000.
我们通过在采集低速度噪声比（VNR）速度图像和高VNR混叠速度图像后对磁共振速度数据进行正则化，改进了三点相位对比法。相位解缠算法基于低VNR图像和无混叠高VNR图像上相邻流动体素速度的假定相关性。我们使用具有八个速度编码梯度步长的傅里叶编码，从五名受试者获取主动脉的参考速度图像（274幅图像），并将其与有和没有正则化的相位对比图像及三点相位对比图像进行比较。相对于低一阶矩速度图像，正则化速度图像的VNR提高了9.1 dB，三点相位对比速度图像的VNR提高了0.7 dB。在瞬时流速估计方面分别获得了9 dB和3.7 dB的相应改善。《磁共振医学》44:122 - 128，2000年。
