When bone scan reveals appendicitis

Diagnosis of appendicitis in infants can be challenging. We report the imaging findings in a 4 year-old girl with a misleading history of fever and right hip pain. Hips X-ray was normal and ultrasound scan did not show any effusion in the right hip joint. Bone scan was performed to eliminate osteo-arthritis or early osteomyelitis. This examination showed no bone metabolism alteration, but demonstrated increased blood pooling in the right iliac fossa that turned out to be a ruptured appendix with abscess. Besides the identification on bone abnormalities, bone scan is able to demonstrate soft-tissue or visceral hyperemia that can reveal misleading differential diagnostics.