SARS患者康复期早期骨缺血坏死的MRI征象

MRI features of early bone ischemia in recovered severe acute respiratory syndrome patients

目的 探讨SARS康复期患者骨坏死主要累及部位和早期MRI征象。方法 对 16例MRI检查有骨损害的SARS康复期病例进行MRI征象分析。结果 16例患者中 ,缺血坏死累及股骨头 11例、膝关节 9例、股骨 4例、胫骨 7例。“单线征”见于 10个髋关节、4个膝关节骨缺血坏死周围区 ;“双线征”见于 2个髋关节 ;“三线征”见于 6个髋关节、14个膝关节。结论 SARS康复期患者骨坏死最多累及髋关节和膝关节。早期骨坏死MRI特征性表现为周围区“三线征”或“单线征”环绕中央区的脂肪信号 ,或含脂肪信号的混杂信号。

Objective To analyze MRI features of early bone ischemia in recovered severe acute respiratory syndrome (SARS) patients. Methods MRI examinations of hip and knee were performed in 22 recovered severe acute respiratory syndrome patients, and 16 patients of osteonecrosis or bone marrow edema were detected. 3 of 16 cases underwent shoulder MRI examinations, four underwent ankle MRI examinations according to their symptoms. MRI features of osteonecrosis were analyzed and compared with CT. Results In 16 patients, avascular necrosis was found in 18 hips (11 patients) and 18 knees (9 patients). Osteo infarction was detected in six femora (4 patients) and 10 tibiae (7 patients). Bone marrow edema of bilateral femora was found in 3 cases with osteonecrosis. Bone marrow edema of pelvis, bilateral femora, and bilateral humeri was found in one case without osteonecrosis. ”Single line sign” of the peripheral zone was found in 10 hips and four knees. ”Double line sign” was found in 2 hips. ”Triple line sign” was found in six hips and 14 knees, corresponded to the blurred high density sclerosis line on CT in six knees (4 patients). Bone infarction was ”map shaped” lesions on MRI. Conclusion Avascular osteonecrosis of knee is as popular as of hip in recovered SARS patients. ”Triple line sign” or ”single line sign” of the peripheral zone surrounding central area of fat signal on MRI is a specific sign for early stage avascular osteonecrosis. Scan of T2WI with fat suppression is helpful to demonstrate ”line like sign”.