The use of the diffusion-weighted MRI in the diagnostics of the solid renal neoplasms

Summary. Renal cell carcinoma (RCC) is the most common primary tumor of the kidney and is found in 3% of all malignancies and in 90% of cases of the renal malignant neoplasms. Among various histological subtypes clear cell RCC (ccRCC) is the most common which appears in 70–80% of pathological conclusions. In recent years, magnetic resonance imaging (MRI) is increasingly attracting the attention of clinicians as a method of choice for the diagnosis and staging of the RCC, due to several advantages over computed tomography. The purpose of the study was to assess the information content of MRI using diffusion-weighted imaging modality in the diagnostics of the solid renal tumors. The study involved 62 adult patients with pathologically verified kidney tumors: 37 patients with ccRCC, 13 patients with angiomyolipoma, 12 patients with oncocytoma; and 15 healthy volunteers. All patients underwent renal MRI which included diffusion-weighted imaging with subsequent apparent diffusion coefficient (ADC) measurement. We observed significant difference in mean ADC value of the normal renal parenchyma and ccRCC 3.36±0.41•10mm/s vs. 2.11±0.25•10mm/s, respectively (р<0,05). Additionally, statistically reliable difference in ADC values in patients with high and low ccRCC grades, angiomyolipoma and oncocytoma was obtained.