长管状骨骨梗死的影像学表现及比较分析

Imaging findings and analysis on long tubular bone infarction

目的探讨长管状骨骨梗死的影像学表现。方法对10例经手术、活检及临床随访证实的长管状骨骨梗死的X线平片、CT和MRI检查进行回顾性分析，同时进行比较。结果病变均发生在股骨下端、胫腓骨上端等长管状骨。早期X线片多为阴性，CT表现为骨质疏松或小的虫蚀状改变，MRI表现为T1WI等或等低信号，RWI呈等或略高信号，边缘围以低信号环，再外缘见等T1、长T2信号环。中晚期X线片上可见斑点状、争状钙化，排列成串或蜿蜒走行；CT断面图像主要表现为圆形或斑片状高密度钙化。MRI上成典型地图样改变，即病变中心等或稍长T1、T2信号改变，均匀或不均匀，边缘T1WI呈花边状低信号带，T2WI呈内层为高信号，外层为低信号的双层轨道样改变。结论：MRI发现早期骨梗死比X线片及CT要敏感，中晚期三者均有典型表现，MRI检查优于X线片、CT。

Objective To explore the imaging features of long tubular bone infarction. Methods The plain radiography, CT and MRI were performed in ten patients with bone infarctions that occurred long tubular bone were analyzed retrospectively and compared. These cases were confirmed by operation and pathological puncture biopsy and clinical follow- up visit. Results The infarction sites were distal femur and proximal tibia. In early stage, most of cases were negative in radiography, osteoporosis and tiny moth- eaten lytic bony lesions on CT scans, which presented as iso -/low - signal on T1WI and iso-/high- signal on T2WI in the center of the bone infarct and as low- signal ring in the verge ,and was separated from the normal bone marrow with linear T1low - signal and T2 high - signal. In the middle and later stages, the lesion was characterized by punctate sclerosis and tortuous calcification on plain film or CT scans. Which presented as iso -/low - signal on T1WI and iso -/high - signal on T2 WI in the center of the bone infarct, which as lace ＂like low signal on T1 WI and two layers signal zone which was low at out layer and high at inner layer on T2WI. Conclusions MRI is more sensitive than X - ray and CT to find the bone infarct in the early stages. In the middle and later stages, the lesion shows certain characteristic signs on plain film. CT or MRI. MRI