Objective:To evaluate radiography

CT

MRI

and DSA in the diagnosis of chondrosarcomas in pelvis.Methods:A retrospective review was conducted of 14 radiographs

14 CT scans

9 MR images and 6 DSA obtained in 14 patients with histologically proved chondrosarcoma.Results:The sites of tumor occurrence were ilium(4 cases)

sacrum(3 cases)

both ilium and sacrum(6 cases)

and ischium(1 case).Mean tumor size at diagnosis was 9.3 cm(range

3～16cm).Of the 14 cases

allmanifested osteolytic lesions associated with cortical destruction on radiography

CT scans and MR images.Intraosseous calcification suggestive of a cartilage tumor was present in 9 cases on radiographs and 14 cases on CT scans.An associated soft-tissue mass was identified in 11 cases on radiographs

14 cases on CT scans and 9 cases on MR images.Ten of 14 CT scans and 8 of 9 MR images were obtained after intravenous administration of contrast material.The tumors demonstrated heterogeneous enhancement on CT scans and MR images.Six cases of DSA showed abundant blood supply and above 2 feeding arteries.The surgery was done 2～3 days after embolism by spongia gelatinosa.Conclusions:Destruction of bone

soft-tissue mass and cartilage calcification are the characteristic imaging features of the chondrosarcoma.Each imaging modality has advantages and disadvantages.CT and MR images can reflect the pathology of the pelvic chondrosarcoma.Correct diagnosis before operation is useful to the surgeons.