Abstract:Objective: To investigate the MR imaging features of dysplasia epiphysealis hemimelica(DEH). Materials and Methods: Clinical records and MR images of 7 cases with DEH confirmed by pathology were retrospectively reviewed, including 6 boys and 1 girl, with ages from 1~9 years old. The conventional MR sequences and 3D-VIBE sequence were performed. Results: ①Location: 5 of 7 cases involved the knees, and 2 cases involved the ankles. Two cases had involvement of single epiphysis, while 5 cases involved multiple epiphyses. Three involved epiphyses were in the medial parts of the limbs, and 2 cases in the lateral parts of the limbs, while 1 case involved both sides, and 1 case involved the central part. ②Complications: premature physeal closure were found in 3 cases, including 1 case with epiphyseal plate closure, dislocation of patella and tibia bending deformation simultaneously, 1 case with the genu valgum, and 1 case with the ankle inversion. ③MR imaging features: 1 or more osteochondral masses were seen around the joint in all cases, which had signal intensity similar to that of normal epiphysis. The osseous components of the osteochondral masses were continuous or separated from the epiphysis. The surface cartilage cap was isointensity in T1WI and hyperintensity in VIBE sequence. Conclusion: MRI can precisely reveal the DEH lesions, and clarify the relationship between the mass and the inherent epiphysis. MRI was essential in the diagnosis, evaluation and treatment of DEH.