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

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 mm2/second) was significantly higher than that of fibrous dysplasias and chondrosarcomas (2.0 ± 0.21 × 10–3 mm2/second and 2.29 ± 0.14 × 10–3 mm2/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. J. Magn. Reson. Imaging 2006. © 2006 Wiley-Liss, Inc.