Sugano N, Ohzono K, Nishii T, Sakai T, Haraguchi K, Yoshikawa H, Kubo T
Department of Orthopaedic Surgery, Osaka University Medical School, Suita, Kyoto, Japan.
Magn Reson Imaging. 2001 Jan;19(1):47-50. doi: 10.1016/s0730-725x(01)00221-1.
To diagnose rapidly destructive coxopathy (RDC) in its early stages and understand the pathomechanism of associated joint destruction, ten cases of RDC were followed by periodic MRI from onset of the disease. In the initial stage (stage 1) of RDC, when radiographs revealed slight narrowing of the joint space, a small subchondral area of low signal intensity was observed on T(1)-weighted images (T1WI) and inhomogeneous high intensity was observed on T(2)-weighted images (T2WI) in the antero-lateral portion of the femoral head. When radiographs showed obliteration of the joint space (stage 2), MRI revealed a diffuse area of low intensity on TIWI and high intensity on T2WI in the proximal femur, including the femoral neck and head, suggesting extensive bone marrow edema. The femoral head and acetabulum were aggressively destroyed (stage 3) in all cases 3 to 6 months after the diffuse abnormal pattern was observed on MRI. MRI in stage 3 cases showed low intensity areas on both T1WI and T2WI. RDC did not show the band-like pattern of low intensity on T1WI and high intensity on T2WI that typify MRI findings in cases of osteonecrosis. When joint space narrowing is observed radiographically, the diffuse abnormal pattern of low intensity on T1WI and high intensity on T2WI induced by a subchondral small lesion might be an early sign of RDC.
为了在早期快速诊断快速破坏性关节病（RDC）并了解相关关节破坏的发病机制，对10例RDC患者自疾病发作起进行定期MRI随访。在RDC的初始阶段（1期），当X线片显示关节间隙轻度变窄时，在T1加权像（T1WI）上观察到股骨头前外侧部分有小的软骨下低信号区，在T2加权像（T2WI）上观察到不均匀高信号。当X线片显示关节间隙消失（2期）时，MRI显示股骨近端包括股骨颈和股骨头在内的区域在T1WI上呈弥漫性低信号，在T2WI上呈高信号，提示广泛的骨髓水肿。在MRI上观察到弥漫性异常表现后3至6个月，所有病例的股骨头和髋臼均出现严重破坏（3期）。3期病例的MRI在T1WI和T2WI上均显示低信号区。RDC未表现出骨坏死病例典型的T1WI低信号带和T2WI高信号带模式。当X线片观察到关节间隙变窄时，由软骨下小病变引起的T1WI低信号和T2WI高信号的弥漫性异常表现可能是RDC的早期征象。
