Department of Radiology, University of California San Francisco, Box 0628, L-307, 505 Parnassus Ave, San Francisco, CA 94143-0628, USA.
Radiographics. 2009 Oct;29(6):1797-810. doi: 10.1148/rg.296095521.
Diffusion-weighted magnetic resonance (MR) imaging allows the detection of focal solid and cystic lesions in the abdomen and pelvis and, if pitfalls are to be avoided, is most effectively used in conjunction with other imaging sequences. It is important to recognize that the strength of the diffusion sensitizing gradient (b value) can and should be adjusted to ensure optimal evaluation of the body region or organ being imaged, and that more than one b value is necessary for tissue characterization. The success of lesion detection and characterization largely depends on the extent of tissue cellularity because increased cellularity is associated with impeded diffusion, as indicated by a reduction in the apparent diffusion coefficient. It is also important to recognize that certain normal tissues such as the endometrium are highly cellular and as such demonstrate restricted diffusion, which should not be misinterpreted as disease. Impeded diffusion can also be seen in highly viscous cystic lesions such as abscesses. Diffusion-weighted imaging is an evolving technology with the potential to improve tissue characterization when findings are interpreted in conjunction with findings obtained with other conventional MR imaging sequences.
弥散加权磁共振（MR）成像可检测腹部和骨盆的局灶性实性和囊性病变，如果要避免陷阱，它与其他成像序列结合使用效果最佳。重要的是要认识到，扩散敏感梯度（b 值）的强度可以而且应该进行调整，以确保对正在成像的身体区域或器官进行最佳评估，并且需要多个 b 值来进行组织特征描述。病变检测和特征描述的成功在很大程度上取决于组织细胞密度，因为细胞密度增加与扩散受限有关，这表现为表观扩散系数降低。同样重要的是要认识到，某些正常组织（如子宫内膜）具有很高的细胞密度，因此表现出受限的扩散，这不应被误解为疾病。高度粘稠的囊性病变（如脓肿）也可观察到扩散受限。弥散加权成像技术是一种不断发展的技术，当与其他常规磁共振成像序列的结果结合使用时，有可能改善组织特征描述。
