MR imaging features of acute bilateral renal cortical necrosis

Bilateral renal cortical necrosis (BRCN) is an uncommon cause of acute rena l failure, Kidney biopsy, arteriography, and contrast-enhanced computed tom ography (CT) are usually used to diagnose BRCN, However, these methods can have potentially serious side effects. We report two cases in which magneti c resonance imaging (MRI) evidenced characteristic features of BRCN, which were confirmed by histological findings and arteriography and correlated wi th clinical evolution. In the first case report, the diagnosis of a massive and complete cortical necrosis variety was suggested on MRI that showed a thin rim of low signal intensity along border of kidneys. It was confirmed on kidney biopsy, and the renal function did not recover. The second case i s an incomplete form with cortical patchy areas of low signal intensity. In these two patients, MRI helped to establish an early diagnosis of BRCN wit h characteristic representative findings, without the potential nephrotoxic effects of iodinated contrast that has to be used in CT and arteriography. Kidney biopsy, besides the risks of complications, provides only a parcele d analysis of the renal tissue and therefore does not allow any conclusion as to the extension of cortical necrosis. MRI may be of great help for the diagnosis and follow-up of acute renal cortical necrosis. (C) 2000 by the N ational Kidney Foundation, Inc.