Raya José G, Dietrich Olaf, Reiser Maximilian F, Baur-Melnyk Andrea
Department of Clinical Radiology-Grosshadern, Ludwig Maximilian University of Munich, Munich, Germany.
J Magn Reson Imaging. 2006 Dec;24(6):1207-20. doi: 10.1002/jmri.20748.
Diffusion-weighted imaging (DWI) is an MRI technique that is sensitive to random water movements at spatial scales far below typical MRI voxel dimensions. DWI is a valuable tool for the diagnoses of diseases that involve alterations in water mobility. In the spine, DWI has proven to be a highly useful method for the differential diagnosis of benign and malignant compression fractures. In these pathologies, the microscopic structure of bone marrow is altered in a very different ways, leading to different water mobility, which can be depicted by DWI. Most of the pulse sequences developed for MRI can be adapted for DWI. However, these DWI-adapted sequences are frequently affected by artifacts, mostly caused by physiological motion. Therefore, the introduction of additional correction techniques, or even the development of new sequences is necessary. The first part of this article describes the principles of DWI and the sequences used for DWI of the spine: spin echo (SE), turbo spin echo (TSE), single-shot echo planar imaging (EPI), and steady-state free precession (SSFP) sequences. In the second part, clinical applications of DWI of the spinal bone marrow are extensively discussed.
扩散加权成像（DWI）是一种磁共振成像（MRI）技术，对空间尺度远低于典型MRI体素尺寸的随机水分子运动敏感。DWI是诊断涉及水分子运动改变疾病的一种有价值的工具。在脊柱方面，DWI已被证明是鉴别诊断良性和恶性压缩性骨折的一种非常有用的方法。在这些病变中，骨髓的微观结构以非常不同的方式发生改变，导致水分子运动不同，而这可以通过DWI显示出来。大多数为MRI开发的脉冲序列都可适用于DWI。然而，这些适用于DWI的序列经常受到伪影的影响，这些伪影大多由生理运动引起。因此，有必要引入额外的校正技术，甚至开发新的序列。本文第一部分描述了DWI的原理以及用于脊柱DWI的序列：自旋回波（SE）、快速自旋回波（TSE）、单次激发回波平面成像（EPI）和稳态自由进动（SSFP）序列。第二部分广泛讨论了脊柱骨髓DWI的临床应用。
