Diffusion-weighted MRI in the characterization of soft-tissue tumors

Purpose: To explore the potential of perfusion-corrected diffusion-weighted magnetic resonance imaging (MRI) in characterizing soft-tissue tumors. Materials and Methods: Diffusion-weighted MRI was performed in 23 histologically proven soft-tissue masses using a diffusion-weighted spin-echo sequence with diffusion gradient strengths yielding five b-values (0-701 seconds/mm(2)). True diffusion coefficients and perfusion fractions were estimated and compared with apparent diffusion coefficients (ADCs). Results: ADC values of all tumors, subcutaneous fat. and muscle were significantly higher than true diffusion coefficients, indicating a contribution of per-fusion to the ADC, True diffusion coefficients of malignant tumors (1.08 X 10(-3) mm(3)/second) were significantly lower than those of benign masses (1.71 X 10(-3) mm(2)/second), whereas ADC values between these groups were not significantly different. Conclusion: Perfusion-corrected diffusion-weighted MRI has potential in differentiating benign from malignant soft-tissue masses.