Renal neoplasms amenable to partial nephrectomy: MR imaging.

Abstract

To determine the magnetic resonance (MR) imaging characteristics of renal lesions in patients who undergo technically successful partial nephrectomy. Between February 1991 and September 1997, 38 patients (41 lesions) who underwent partial nephrectomy at a single institution were preoperatively evaluated with contrast material-enhanced, multiplanar, surface-coil MR imaging. Imaging findings that could affect the decision to perform partial nephrectomy were retrospectively evaluated: tumor size; tumor location; presence of pseudocapsule; suspected tumor invasion of renal sinus fat, renal collecting system, renal vein, or perinephric fat; and morphologic and physiologic status of the contralateral kidney. Correlation was made with surgical and pathologic findings. Thirty-three of 41 lesions (80%) were renal cell carcinomas, five were oncocytic neoplasms (12%), two were hemorrhagic cysts (5%), and one was an angiomyolipoma (2%). Twenty-four of 41 (59%) lesions had pseudocapsules. In most cases, the perinephric fat (n = 38 [93%]), the renal sinus fat (n = 31 [76%]), and the renal collecting system (n = 39 [95%]) were correctly interpreted as being uninvolved by tumor. Renal neoplasms amenable to partial nephrectomy can be identified and characterized with contrast-enhanced, multiplanar, surface-coil MR imaging.