Value of diffusion-weighted magnetic resonance imaging in the characterization of small solid renal lesions

Abstract

Aim of the study Our aim was to assess the value of diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) measurement for the characterization of small solid renal lesions. Patients and methods We prospectively evaluated 30 patients (18 men and 12 women). Their age ranging from 18 to 65 years (mean age of 49.6±12.9). They were examined by conventional MRI and DWI with b factors of 0, 600 and 1000 s/mm2. Mean ADC values of the normal renal parenchyma, benign, malignant small solid renal lesions were calculated Results The mean ADC value of normal renal parenchyma was significantly higher that of benign and malignant lesions. No statistical significance noted between the mean ADC values of benign and malignant renal lesions (P value=0.5). Among malignant lesions, the mean ADC value was highest in the RCC lesions (1.4±0.22) and lowest in the lymphoma lesions (0.679±0.08) showing statistical significance (P value=0.0001). The mean ADC values of RCC and TCC showed no statistical significance, whereas there was statistical significance was noted between RCC and pyelonephritis (P value=0.0004) , RCC and Angiomyolipomas (P value=0.0001), lesions. Conclusion DWI is a fast sequence that can be easily added to a routine MR imaging protocol. DWI is notably valuable in lesion detection and evaluation when gadolinium contrast medium cannot be administered. However, due to the overlap of ADC values between benign and malignant lesions, it cannot be used as a single diagnostic tool and should be concurrently interpreted in conjunction with conventional MRI for optimal characterization of renal lesions.