Evaluation of diffusion-weighted imaging for the differential diagnosis of poorly contrast-enhanced and T2-prolonged bone masses: Initial experience

Abstract

Purpose: To determine whether quantitative diffusion-weighted imaging (DWI) is useful for characterizing poorly contrast-enhanced and T2-prolonged bone masses. Materials and Methods: We studied 20 bone masses that showed high signal intensity on T2-weighted images and poor enhancement on contrast-enhanced T1-weighted images. These included eight solitary bone cysts, five fibrous dysplasias, and seven chondrosarcomas. To analyze diffusion changes we calculated the apparent diffusion coefficient (ADC) for each lesion. Results: The ADC values of the two types of benign lesions and chondrosarcomas were not significantly different. However, the mean ADC value of solitary bone cysts (mean ±SD, 2.57 ± 0.13 × 10-3 mm 2/second) was significantly higher than that of fibrous dysplasias and chondrosarcomas (2.0 ± 0.21 × 10-3 mm 2/second and 2.29 ± 0.14 × 10-3 mm 2/second, respectively, P < 0.05). None of the lesions with ADC values lower than 2.0 × 10-3 mm2/second were chondrosarcomas. Conclusion: Although there was some overlapping in the ADC values of chondrosarcomas, solitary bone cyst, and fibrous dysplasia, quantitative DWI may aid in the differential diagnosis of poorly contrast-enhanced and T2-prolonged bone masses. © 2006 Wiley-Liss, Inc.