磁共振小视野弥散加权成像技术在影像诊断中的研究进展

摘要

Diffusion-weighted imaging (DWI), as a kind of functional imaging technique, is an important complement to the conventional MRI in imaging diagnosis. However, the most common technique is full field of view diffusion weighted imaging (fFOV-DWI), which has some defects that cannot be ignored, such as poor image quality, low resolution of anatomical structure and serious artifact. With development of technology, reduced field of view diffusion weighted imaging (rFOV DWI) avoids the need to encode a large extent in the phase-encode direction, shortens the echo train and reduces off-resonance-induced artifacts in single-shot echo-planar imaging (ssEPI), resulting in significantly improved image quality. This review focuses on the theory and clinical research advances of rFOV DWI in the various organs for imaging diagnosis.%磁共振弥散加权成像作为一种功能成像已经成为常规磁共振成像诊断中的重要组成部分.然而在目前的临床应用中较为广泛使用的全视野弥散加权成像技术,其图像质量较差,解剖结构分辨率较低,容易产生比较严重的伪影,图像的变形和失真等问题.随着技术的进展,小视野弥散加权成像技术通过在相位编码方向上缩减视野大小等方法显著提高了图像质量及组织结构分辨能力,减轻图像伪影、变形、失真等情况,这对于体积较小、结构精细、解剖部位附近磁化率变化较大或易受不自主生理性运动影响的器官及部位尤为重要.作者对小视野弥散加权成像的成像原理及其在各器官中的研究进展进行综述.