VALUE OF DIFFUSION – WEIGHTED AND CONTRAST ENHANCED MAGNETIC RESONANCE IMAGING IN DIFFERENTIATION OF RENAL MASSES

Abstract

AIM: to evaluate the role of contrast enhanced magnetic resonance imaging and the usefulness of diffusion weighted magnetic resonance imaging in differentiating benign from malignant renal masses and to assess the diffusion characteristics as well as ADC values of different renal masses. MATERIALS AND METHODS: Fifty patients with renal masses and normal contra-lateral kidneys (used as control) were enrolled in the study. DWI was performed with b values of 0 and 1000 s/ mm2. Results of the histopathological evaluation were compared with the DWI and CE-MRI results. Apparent diffusion coefficient (ADC) values were calculated for each b value. RESULTS: The mean ADC values of normal renal parenchyma with b= 0 and 1000 s/ mm2 values were (3.7 ± 0.27) x 10–3 and (2.8 ± 0.21) x 10–3 mm2/s, respectively. The mean ADC values of benign cystic renal lesions (n=18) with b= 0 and 1000 s/ mm2 values were (3.73 ± 0.44) x 10–3 and (3.09 ± 0.46) x 10–3 mm2/s, respectively. The mean ADC values of benign solid renal lesions (n=5) with b= 0 and 1000 s/ mm2 values were (1.53 ± 0.44) x 10–3 and (1.797 ± 0.46) x 10–3 mm2/s, respectively. The mean ADC values of malignant cystic renal lesions (n=4) with b= 0 and 1000 values were (3.09 ± 0.29) x 10–3 and (2.73 ± 0.10) x 10–3 mm2/s, respectively. The mean ADC values of malignant solid renal lesions (n=23) with b= 0 and 1000 values were (1.63 ± 0.29) x 10–3 and (1.16 ± 0.25) x 10–3 mm2/s, respectively. The sensitivity, and specificity of combined CE-MRI and DW imaging were 95.6 % and 96.3% respectively. We can differentiate malignant renal lesions from benign renal lesions using CE-MR imaging combined with DWI. CONCLUSIONS: Combined CE-MRI and DWI with quantitative ADC measurements can be useful in differentiating benign from malignant renal lesions. Using high b values (b=1000 s / mm2) had the best specificity and sensitivity.