The Imaging Features Of Chondroblastoma

Purpose To investigate the X-ray, CT and MRI features of chondroblastoma, and to discuss the correlation of different imaging features.Methods The imaging findings of 12 chondroblastomas proved by surgery and pathology were analyzed and compared to each other. We calculated the SSmax of the SI-T curves and Rrim-cen of the lesions.Results Benign lesions: all lesions involved the epiphyses of long bone. l.X-ray features: 7 lesions were lobular, and metaphyseal extension was depicted in 3 lesions. All lesions had low density, calcifications were observed in 5 of them. The rims were distinct and had scleroses with different degrees. All lesions were surrounded by areas of high density, 3 lesions had periosteal reactions. 2.CT features: the size of lesions ranged from 0.8cm × 0.8cm to 4.8cm × 4.0cm, and had lobules with different degrees. The rims were distinct and had scleroses with different degrees. The cortex of bone got thin, and 3 lesions had cortical erosion. The density of lesions was the same as the soft tissues, 9 had calcifications, 6 had areas of low density, and fluid-fluid level was demonstrated in 4 of them. Periosteal reaction was depicted in 2 patients. The lesions enhanced with different degrees. 3. MRI features: the lesions were hypointense on T1WI and heterogenous on T2WI with peripheral lobulation. 2 lesions had hyperintense areas on T1WI.3 lesions had fluid-fluid levels. 5 lesions had periosteal reactions, 6 had joint effusion. After intravenous administration of gadopentetate dimeglumine, ring-like enhancement was seen in 4 of 5 lesions, and 1 lesion showed homogeneous enhancement. There were enhancement in areas of edema within bone marrow and adjacent soft tissue and periosteal reaction. The lesions were hyperintense on DWI, especially for the intermediate areas both on T1WI and T2WI. The signal intensity of the upper parts of the fluid-fluid level was high, and the inferior parts was intermediate. The shape of the SI-T curves were alike, and the SSmax were 16.7% , 40%, 29.7%, 35% respectively。 The Rrim-cen were-0.058, -0.09, 0.110, -0.013 respectively. Malignant lesion: involved the iliac bone. There was an area of osteolytic destruction in the iliac bone and the its rim was unclear. It had the same density as soft tissue, but there was no distinct calcification. The cortical destruction and extraosseous soft tissue was depicted. It was intermediate on both T1WI and T2WI, and there were hyperintense areas on T1WI and T2WI.The density of the former was high on DWI, and the latter was lower.Conclusions The imaging features of the benign chondroblastoma are characteristic. They are osteolystic destruction in bone with peripheral sclerosis, their density are the same as the soft tissues,...