Physiologic uptake confined to the spleen, liver, and bone marrow (most intense in the spleen, as seen on posterior view) makes this most likely a labeled leukocyte exam. Lack of significant normal bowel excretion makes indium 111–oxine the likely radiolabel (over Tc99m-HMPAO). A small increased focus is seen in the anterior left upper quadrant (arrow).

Differential Diagnosis

•  Expected physiologic WBC accumulation surrounding gastrostomy tube tract: Given the history, this is the most likely etiology for the findings.

•  Abdominal infection: This is conceivable, although clinically important infections are typically more intense.

•  Physiologic intraluminal excretion in bowel: This does occur with Tc99m-HMPAO–labeled WBCs after 4 hours, but not with In111-oxine label. Also, this uptake would be more diffuse.

Essential Facts