Zhang Qinwei, Coolen Bram F, Versluis Maarten J, Strijkers Gustav J, Nederveen Aart J
Department of Radiology, Academic Medical Center, Amsterdam, the Netherlands.
Department of Biomedical Engineering and Physics, Academic Medical Center, Amsterdam, the Netherlands.
NMR Biomed. 2017 Jul;30(7). doi: 10.1002/nbm.3719. Epub 2017 Mar 13.
In this study, we present a new three-dimensional (3D), diffusion-prepared turbo spin echo sequence based on a stimulated-echo read-out (DPsti-TSE) enabling high-resolution and undistorted diffusion-weighted imaging (DWI). A dephasing gradient in the diffusion preparation module and rephasing gradients in the turbo spin echo module create stimulated echoes, which prevent signal loss caused by eddy currents. Near to perfect agreement of apparent diffusion coefficient (ADC) values between DPsti-TSE and diffusion-weighted echo planar imaging (DW-EPI) was demonstrated in both phantom transient signal experiments and phantom imaging experiments. High-resolution and undistorted DPsti-TSE was demonstrated in vivo in prostate and carotid vessel wall. 3D whole-prostate DWI was achieved with four b values in only 6 min. Undistorted ADC maps of the prostate peripheral zone were obtained at low and high imaging resolutions with no change in mean ADC values [(1.60 ± 0.10) × 10 versus (1.60 ± 0.02) × 10 mm /s]. High-resolution 3D DWI of the carotid vessel wall was achieved in 12 min, with consistent ADC values [(1.40 ± 0.23) × 10 mm /s] across different subjects, as well as slice locations through the imaging volume. This study shows that DPsti-TSE can serve as a robust 3D diffusion-weighted sequence and is an attractive alternative to the traditional two-dimensional DW-EPI approaches.
在本研究中,我们提出了一种基于受激回波读出的新型三维(3D)扩散准备快速自旋回波序列(DPsti-TSE),可实现高分辨率且无失真的扩散加权成像(DWI)。扩散准备模块中的去相位梯度和快速自旋回波模块中的重相位梯度产生受激回波,可防止涡流导致的信号损失。在体模瞬态信号实验和体模成像实验中均证明,DPsti-TSE与扩散加权回波平面成像(DW-EPI)之间的表观扩散系数(ADC)值几乎完全一致。在前列腺和颈动脉壁的体内成像中证明了DPsti-TSE具有高分辨率且无失真的特点。仅需6分钟即可使用四个b值实现三维全前列腺DWI。在低分辨率和高分辨率成像下均获得了前列腺外周带的无失真ADC图,平均ADC值无变化[(1.60±0.10)×10与(1.60±0.02)×10 毫米²/秒]。在12分钟内实现了颈动脉壁的高分辨率三维DWI,不同受试者以及成像体积内不同切片位置的ADC值一致[(1.40±0.23)×10 毫米²/秒]。本研究表明,DPsti-TSE可作为一种强大的三维扩散加权序列,是传统二维DW-EPI方法的一个有吸引力的替代方案。