Department ofRadiology,University of Geneva, 1211 Geneva, Switzerland and the Advanced Clinical Imaging Technology, CIBMS Siemens Suisse SA, 1015 Lausanne, Switzerland.
IEEE Trans Med Imaging. 2013 Aug;32(8):1515-25. doi: 10.1109/TMI.2013.2259249. Epub 2013 May 6.
Clinical use of the Stejskal-Tanner diffusion weighted images is hampered by the geometric distortions that result from the large residual 3-D eddy current field induced. In this work, we aimed to predict, using linear response theory, the residual 3-D eddy current field required for geometric distortion correction based on phantom eddy current field measurements. The predicted 3-D eddy current field induced by the diffusion-weighting gradients was able to reduce the root mean square error of the residual eddy current field to ~1 Hz. The model's performance was tested on diffusion weighted images of four normal volunteers, following distortion correction, the quality of the Stejskal-Tanner diffusion-weighted images was found to have comparable quality to image registration based corrections (FSL) at low b-values. Unlike registration techniques the correction was not hindered by low SNR at high b-values, and results in improved image quality relative to FSL. Characterization of the 3-D eddy current field with linear response theory enables the prediction of the 3-D eddy current field required to correct eddy current induced geometric distortions for a wide range of clinical and high b-value protocols.
临床应用 Stejskal-Tanner 扩散加权图像受到由大残余 3D 涡流场引起的几何变形的阻碍。在这项工作中，我们旨在使用线性响应理论预测基于体模涡流场测量的几何变形校正所需的残余 3D 涡流场。扩散加权梯度引起的预测 3D 涡流场能够将残余涡流场的均方根误差降低到约 1Hz。该模型在四名正常志愿者的扩散加权图像上进行了测试，在进行失真校正后，发现 Stejskal-Tanner 扩散加权图像的质量与基于图像配准的校正（FSL）相比，在低 b 值时具有相当的质量。与配准技术不同，校正不受高 b 值时低 SNR 的阻碍，并且相对于 FSL 可提高图像质量。线性响应理论对 3D 涡流场的特征描述，使得可以预测用于校正广泛的临床和高 b 值方案中由涡流引起的几何变形所需的 3D 涡流场。
