Abstract：Objective: To explore imaging features of synovial chondromatosis correlated with pathology, and evaluate the value of different imaging examinations. Methods: The imaging data of 18 cases of pathologically confirmed synovial chondromatosis, who underwent the preoperative plain film, CT and MR plain-scan and enhanced-scan were analysed retrospectively. Amonge these cases, 11 males, 7 females, 30～78 years old, average age was 41.5 years old. One case was elbow joint, one case was shoulder joint, five cases were hip joint, eight cases were knee joint, two cases were ankle joint, one case was temporomandibular joint. Results: On X-ray, typical feature of synovial chondromatosis was free bodies in the joint space and soft tissue, which showed the “concentric lamina” sign, particularly in the cases of Milgram Ⅱ and Ⅲ stage. CT images showed much more free bodies and thickened hyperdense synovium. MR images clearly showed thickened synovium, free bodies, joint effusion and joint degenerative lesions, free bodies displayed two kinds of appearance, cartilaginous body and bony body with ring enhancement after using contrast material. For the Milgram Ⅰ stage cases, CT and MR showed the thickening synovium without positive features on plain film. CT and MR were superior to X-ray in showing the number and position of free body and synovial lesions especially on showing the cartilaginous free bodies. Conclusion: Synovial chondromatosis have characteristic radiological features with different imaging examinations, particularly CT and MR images provide much more information about free body and synovial lesions, are superior in the diagnosis of Milgram Ⅰ stage cases.
2009, Vol. 20 
