Clinical Pearls: Etiologies of Superscan Appearance on Fluorine-18-Fludeoxyglucose Positron Emission Tomography-Computed Tomography

The term “superscan” usually refers to a characteristic pattern on skeletal scintigraphy consisting of symmetrically intense and diffuse radiotracer uptake in the skeleton with absent or diminished visualization of the genitourinary system and soft tissues. Superscans and superscan-like appearances have also been described on fluorine-18-fludeoxyglucose positron emission tomography-computed tomography (18-F-FDG PET/CT). We review reported cases of 18-F-FDG PET/CT superscans and propose criteria for differentiating pathologic superscans from physiologic causes. Knowledge of the 18-F-FDG PET/CT superscan, its reported pathologic causes, its benign imitators, and its clinical implications is important to the nuclear medicine physician or radiologist specializing in the interpretation of nuclear studies to avoid several diagnostic pitfalls.