Phimosis revealed by contamination with radioactive urine on bone scintigraphy

Because more than 50% of the radiotracer for bone scintigraphy is excreted through the urinary system within 2 hours after injection, increased radioactivity is expected in the urine. The most common artifact on bone scintigraphs is attributed to contamination with radioactive urine. The artifactual activity usually overlies soft tissues but may overlie bony structures and mimic a bony lesion. The authors incidentally observed an artifact in the pelvic area on bone scintigraphy, which was attributed to phimosis of the penis contaminated with radioactive urine.