From the Department of Radiology, Division of Musculoskeletal Imaging and Intervention (B.K.M.), and Department of Orthopedic Surgery (A.M.S.), University of Wisconsin-Madison, Clinical Science Center, 600 Highland Ave, E3/311, Madison, WI 53792; Department of Radiology, Division of Musculoskeletal Imaging, University of California, San Diego, La Jolla, Calif (B.K.H., E.Y.C.); and Radiology Services, Veterans Affairs San Diego Healthcare System (E.Y.C.).
Radiographics. 2022 Sep-Oct;42(5):1457-1473. doi: 10.1148/rg.220051. Epub 2022 Aug 19.
This review is intended to aid in the interpretation of damage to the articular cartilage at routine clinical MRI to improve clinical management. Relevant facets of the histologic and biochemical characteristics and clinical management of cartilage are discussed, as is MRI physics. Characterization of damage to the articular cartilage with MRI demands a detailed understanding of the normal and damaged appearance of the osteochondral unit in the context of different sequence parameters. Understanding the location of the subchondral bone plate is key to determining the depth of the cartilage lesion. Defining the bone plate at MRI is challenging because of the anisotropic fibrous organization of articular cartilage, which is susceptible to the "magic angle" phenomenon and chemical shift artifacts at the interface with the fat-containing medullary cavity. These artifacts may cause overestimation of the thickness of the subchondral bone plate and, therefore, overestimation of the depth of a cartilage lesion. In areas of normal cartilage morphology, isolated hyperintense and hypointense lesions often represent degeneration of cartilage at arthroscopy. Changes in the subchondral bone marrow at MRI also increase the likelihood that cartilage damage will be visualized at arthroscopy, even when a morphologic lesion cannot be resolved, and larger subchondral lesions are associated with higher grades at arthroscopy. The clinical significance of other secondary features of cartilage damage are also reviewed, including osteophytes, intra-articular bodies, and synovitis. Work of the U.S. Government published under an exclusive license with the RSNA.
这篇综述旨在帮助解读常规临床 MRI 中关节软骨损伤，以改善临床管理。讨论了软骨的组织学和生化特征及临床管理的相关方面，以及 MRI 物理学。MRI 对关节软骨损伤的特征描述需要详细了解不同序列参数下骨软骨单位的正常和损伤外观。了解软骨下骨板的位置是确定软骨病变深度的关键。由于关节软骨的各向异性纤维组织，在与富含脂肪的骨髓腔的界面处存在“魔术角”现象和化学位移伪影，因此在 MRI 上定义骨板具有挑战性。这些伪影可能导致软骨下骨板厚度的高估，从而导致软骨病变深度的高估。在正常软骨形态区域，孤立的高信号和低信号病变通常代表关节镜下的软骨退变。MRI 上的软骨下骨髓变化也增加了关节镜下观察到软骨损伤的可能性，即使不能解决形态学病变，并且较大的软骨下病变与关节镜下的较高等级相关。还回顾了软骨损伤的其他次要特征的临床意义，包括骨赘、关节内体和滑膜炎。美国政府的工作在与 RSNA 的专属许可下发布。
