(A) Posterior dynamic Tc99m-MAG3 images reveal normal symmetric radiotracer flow and parenchymal extraction by both kidneys. Activity seen along the right side of the body is due to some persistent radiotracer at the injection site (arrow). (B) Dynamic images reveal normal radiotracer excretion and clearance from both kidneys, indicating normal function. However, abnormal radiotracer activity is seen outside the urinary tract, extending from the left side of the bladder along the left abdomen (arrow). This activity progresses along the left paracolic gutter and terminates superior to the spleen.

Differential Diagnosis

Tc99m-MAG3 activity outside the urinary system in a patient with a recent history of pelvic surgery is most compatible with a urinary leak.

•  Urinary leak: