The rim nephrogram in renovascular compromise

Abstract

The nephrogram is a sensitive indicator of renovascular compromise. An infrequently reported but characteristic nephrographic abnormality is the cortical rim nephrogram. This "rim sign" refers to a thin nephrographic rim outlining a kidney with an otherwise faint nephrogram. We report 2 patients with this nephrographic appearance due to acute renal artery insult. The rim nephrogram is a reliable sign of underperfusion of the kidney. It is dependent on collateral capsular vessels supplying the outer renal cortex. Underperfusion can be due to a primary renal artery problem or secondary to compromise of renal artery perfusion because of elevated interstitial or tubular pressure in the kidney. The sign has not been described with systemic circulatory problems.

Chemotherapy-related complications in the kidneys and collecting system: an imaging perspective

“…5a, b ). Sometimes the “rim sign” is present, which is a higher-attenuation subcapsular rim surrounding lower-attenuation infarcted renal parenchyma representing subcapsular perfusion through collateral flow [ 23 , 24 ]. However, as the “rim sign” is a universal and highly specific indicator of renovascular compromise, it can also be present in acute tubular necrosis and renal vein thrombosis.…”

Allergic Interstitial Nephritis Manifesting as a Striated Nephrogram

“…Segmental absence may be due to renal space-occupying processes, hemodynamic changes in peripheral branches of the renal artery, or small vessel disease such as vasculitides [ 7 , 8 ]. In the setting of renovascular compromise, the rim pattern represents preserved subcapsular perfusion by collateral flow [ 9 , 10 ]. Temporal delay in the progression of the nephrogram may be attributed to a unilateral decrease in renal blood flow [ 11 ].…”