[Imaging characterization of renal masses. Image atlas].

The diagnostic study, analysis and characterization of renal masses and their behavior is one of the key elements for elaborating a surgical or therapeutic strategy, determining the prognosis, and for the follow-up of treatment efficacy in patients with benign or malignant disease. At present, computed tomography (CT) and magnetic resonance imaging (MRI) are the two most reliable, effective and efficient instruments in this context--offering sensitivity and specificity values in excess of 87%, with a diagnostic relaibility of over 90% in application to renal masses of a cystic or complex nature, with nonspecific or specific inflammatory characteristics, or of a primary or secondary neoplastic nature. The aim of this study is to present the principal CT and MRI parameters in relation to renal pathology of this kind, correlating them to the clinical, physiopathological and histopathological data with a view to affording architectural, density, signal intensity and biological behavior parametric information of help in understanding the changes occurring in the renal and retroperitoneal regions secondary to such pathologies.