Drapé J L, Pessis E, Sarazin L, Minoui A, Godefroy D, Chevrot A
Service de Radiologie B, Hôpital Cochin, Paris.
J Radiol. 1998 May;79(5):391-402.
Although plain films are fundamental for routine imaging of degenerative chondral lesions, MRI is a promising tool of investigation for the articular cartilage. Its modalities are still imprecise and debated, but, because of its noninvasiveness, it is destined to be preferred over arthroCT. The small size of the cartilage requires thin slices of less than 3-mm thick. The various features of normal cartilage images must be well known. They depend on acquisition parameters, zonal structure of the cartilage and numerous artifacts (partial volume average, chemical shift, magnetic susceptibility, truncation, "magic angle"). Fast SE images provide a good compromise between contrast and the signal-to-noise ratio. T2-weighted images take advantage of an arthrographic effect in case of joint effusion. 3D GE images allow a more accurate evaluation with 1-mm thick slices. In all sequences, adding of a fat-suppression presaturation increases contrast between the cartilage and the surrounding structures. The diagnostic accuracies of the different sequences and of MR arthrography are discussed. Quantitative measurements of cartilage thickness and volume remain the topic of clinical research.
尽管平片是退行性软骨损伤常规成像的基础，但MRI是用于关节软骨检查的一种很有前景的工具。其成像方式仍不精确且存在争议，不过，由于其无创性，注定会比关节CT更受青睐。软骨尺寸小，需要厚度小于3毫米的薄层扫描。必须熟知正常软骨图像的各种特征。它们取决于采集参数、软骨的分层结构以及众多伪影（部分容积平均、化学位移、磁化率、截断、“魔角”）。快速自旋回波图像在对比度和信噪比之间提供了良好的折中。在关节积液的情况下，T2加权图像利用了关节造影效应。三维梯度回波图像使用1毫米厚的层面可进行更准确的评估。在所有序列中，添加脂肪抑制预饱和可增加软骨与周围结构之间的对比度。文中讨论了不同序列及磁共振关节造影的诊断准确性。软骨厚度和体积的定量测量仍是临床研究的课题。
