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

Abstract

Purpose: Our 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 methods: A 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. Results: There 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). Conclusion: There 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.

Keywords

• DWI
• Renal
• Benign
• Malignant