Usefulness of diffusion-weighted magnetic resonance imaging for the characterization of benign and malignant renal lesions

PurposeOur aim was to evaluate the diagnostic potential of diffusion-weighted magnetic resonance imaging (DW-MRI) and quantitative assessment of apparent diffusion coefficient (ADC) value for the characterization of renal lesions and differentiation into benign and malignant.Patients and methodsA total of 87 consecutive patients with 107 renal lesions were enrolled in this prospective study. MRI examinations including DWI with b factors of 0, 600 and 800 s/mm2 were performed at 1.5 T MRI unit. The mean ADC values of normal renal parenchyma, solid and cystic lesions were calculated.ResultsThere was statistical significance difference between ADC value of normal renal parenchyma with that of benign (n = 60, 56%) and malignant (n = 47, 44%) renal lesions (P value < 0.0001). ADC values differed significantly between solid (n = 74, 69.2%) and cystic lesions (n = 33, 30.8%) (P value < 0.0001). There was significant difference between ADC values of all benign (n = 60, 56%) and malignant renal lesions (n = 47, 44%) (P value < 0.0001) but not between benign solid (n = 27, 36.5%) and malignant solid renal lesions (n = 47, 63.5%) (P value = 0.784).ConclusionThere is overlap between the ADC values of benign and malignant lesions. The use of ADC value alone may lead to inaccurate assessment of renal lesions. Thus, DW-MRI should be interpreted in conjunction with conventional MRI sequences to allow for better characterization of renal lesions.