The aim of this paper is to study the pre-operative staging of renal tumours, comparing CT and MR, and the imaging criteria used, examining the diagnostic efficacy for each of them. Thirty-four tumours were obtained from 29 patients. All cases were studied with CT and MR. To measure diagnostic efficacy, both for each technique and the criteria used in 2 different readings, a diagnostic performance curve (DPC) is calculated. Neither CT nor MR show infiltration of renal capsule. With regard to perinephritic fat, fascia and adjacent organ invasion, both techniques lead to overstaging, mainly CT. When applying more conservative reading criteria, the results are much improved, specially in relation to CT, although results with MR continue to be more favourable. MR is better to study vascular invasion, providing no false results. Of 22 tumours undergoing surgery, first option was the correct staging in 14 tumour with CT and in 16 with MR. When selecting the best imaging technique to stage renal tumours, MR allows a better and simpler radiologic reading. Nevertheless, considering the high correlation between CT and MR, CT can be used more reliably in institutions where no easy access to a MR unit is available. Both CT and MR overstage renal tumours.
Adult Aged