Perirenal extravasation with blunt trauma from rupture of a calyceal fornix.

Perirenal extravasation of urine with an intact renal parenchyma and with dye visualized in the ureter was seen on an excretory urogram (IVP) and computed tomographic (CT) scan in two patients (bilateral in one) with multiple injuries following blunt trauma. Expectant management with no invasive procedures resulted in disappearance of the extravasation within 3 to 5 days. Traumatic rupture of a calyceal fornix is thought to be the cause of the extravasation similar to the perirenal extravasation seen with renal colic from a ureteral calculus.