局限性骨化性肌炎的X线、CT表现

X-ray and CT findings of myositis ossificans circumscripta

目的:探讨局限性骨化性肌炎的X线平片和CT表现,提高影像诊断水平。方法:回顾性分析19例经病理或随访证实局限性骨化性肌炎患者的X线、CT表现,其中19例均行X线平片检查,13例行CT检查。结果:X线表现为软组织内条片状或分层状骨化影;CT表现:早期(急性水肿期)局部肌肉水肿,无明确骨化成分,受累骨可出现轻微骨膜增生,中期(增殖肿块期)表现为分层状"蛋壳"样骨化,病灶中心呈软组织密度,晚期(骨化修复期)病灶局限,边界清楚,周围肌肉水肿消失,影像学表现为离心性分布的骨化团块。结论:局限性骨化性肌炎早期影像学表现缺乏特征性,容易误诊,中晚期分层状"蛋壳"样骨化对本病诊断有重要价值。

Objective：To investigate the X-ray and CT findings of myositis ossificans circumscripta.Methods：The X-ray（n=19）and CT（n=13） findings of pathologically and follow-up proved myositis ossificans circumscripta in 19 patients were retrospectively analyzed.Results：The X-ray image showed the heterotopic bone with the appearance of lamella and strip in the soft tissue.CT showed that in earlier stage（acute edema stage）,there were the muscular edema and lightly peristeal reaction of the affected bone,but no heterotopic bone;In intermediate stage（proliferative neoplasm stage） the images showed calcified deposits in the margin of the leision with a appearance of eggshell and soft tissue density in the center of the leision.In advanced stage（ossific reparation stage） the lesion was localized and the margin became clear and the muscular edema had disappeared.Meanwhile,the images showed osseous mass with centrifugal distribution.Conclusion：The radiologic findings of myositis ossificans circumscripta are lack of distinctive appearance in earlier stage,which easily results in misdiagnosis.But,it is more useful to the diagnosis that the heterotopic bone with the appearance of lamella and eggshell in intermediate and advanced stage.