Objective To observe imaging manifestations of postparaplegic myositis ossificans(PPMO).Methods A total of 14 patients with clinically diagnosed PPMO who underwent X-ray examination of the lesion sites were retrospectively collected,among them 9 cases underwent CT and 4 cases underwent MR examination.Imaging manifestations of PPMO lesions were analyzed and staged.Results Among 14 cases,PPMO lesions located in soft tissue around bilateral hip joint in 8 cases,in soft tissue around unilateral hip joint in 3 cases,in bilateral thigh in 2 cases and in bilateral calf in 1 case.Early stage PPMO was assessed in 4 cases,while middle stage in 3 and late stage PPMO in 7 cases.X-ray films showed early stage PPMO represented as swelled soft tissue,with cloud flocculent high density ossification shadows and blurred edges in 4 cases.In 3 cases of middle stage PPMO,X-ray films showed patchy,strip-like high density ossification shadow with uneven density and clear edges.Lesions in 7 cases of late stage PPMO presented as large flake,banded high-density ossification shadow consistent to the long axis of backbone and muscle with clear edges on X-ray films.One case of early stage PPMO was characterized by swelled soft tissue and high density ossification shadow on CT,while 2 cases of middle stage PPMO showed patchy high-density ossification shadow with uneven density and local eggshell-like changes,and the typical lesions had concentric circle appearance with clear edges.Six cases of late stage PPMO showed large lamellar,cord-like high-density ossification lesions with uneven and low internal densities,myeloid cavity changes and increased marginal density presented as cortical-like changes on CT.On MRI,1 case of early stage PPMO was characterized by swelled soft tissue with long T1 and long T2 signals,blurred edges and feathery changes.One case of middle stage PPMO showed equal or slightly low signal on T1WI,uneven high signal on T2WI,and the signal intensities were higher than the surrounding muscle with stratifications,while the surrounding soft tissue and adjacent bone marrow showed low T1WI and high T2WI edema signals.Two cases of late stage PPMO showed equal and low signals on T1WI,uneven high signals on T2WI,cortical changes presented as low signals on the margin,and edema signals were found in the surrounding soft tissue.Conclusion Imaging manifestations of PPMO had certain characteristics.