Malignant versus benign mediastinal lesions: quantitative assessment with diffusion weighted MR imaging.

Abstract

We aimed to evaluate the performance of diffusion-weighted magnetic resonance imaging in differentiating malignant from benign mediastinal lesions. Fifty-three mediastinal lesions were examined with T1- and T2-weighted (W) conventional images. Then, two diffusion-weighted images were obtained with b = 0 and 1000 s/mm² values and apparent diffusion coefficients (ADC) were calculated. The statistical significance of differences between measurements was tested using the Student-t test. The mean ADC of malignant lesions was significantly lower than that of the benign masses (p < 0.001). The cut-off value of ≤ 1.39 × 10(-3) mm²/s indicated a malignant lesion with a sensitivity of 95% and specificity of 87%. Diffusion-weighted imaging may be helpful in differentiating benign from malignant mediastinal masses.