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. Materias 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 X 10(-3) mm(2)/second) was significantly higher than that of fibrous dysplasias and chondrosarcomas (2.0 +/- 0.21 X 10(-3) mm(2)/second and 2.29 +/- 0.14 x 10(-3) mm2 /second, respectively, P < 0.05). None of the lesions with ADC values lower than 2.0 X 10(-3) mm(2)/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.