Contrast-induced acute renal failure: persistent nephrogram as clue to early detection.

Renal failure from urographic contrast media is a serious potential hazard of excretory urography and is usually recognized by the clinician 24--48 hr after the procedure. The association of an abnormally increasing nephrogram with development of oliguric renal failure in children was described in 1969, but in 112 subsequent reported cases of contrast-induced renal failure, a persistent nephrographic pattern was described only once. With special attention to the abnormally persistent nephrogram, we were able to detect nine cases of contrast-induced renal failure after excretory urography. Two of these cases are discussed in detail and pertinent data on the other seven are presented.