Clinical pearls: Etiologies of superscan appearance on Fluorine-18-Fludeoxyglucose positron emission tomography-computed tomography

Abstract

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.

Hot liver on 18F-FDG PET/CT imaging—a quandary for oncoradiologists in South Asia

“…Superscan 2 in 18 F-FDG PET/CT is described as sequestration of the radiopharmaceutical in an organ or an organ system with reduction or complete absence in the activity detected in those organs which are normally associated with significant physiologic uptake of 18 F-FDG. The organs showing normal physiological uptake are kidneys, collecting systems, brain, and heart.…”

“…Usually infective etiologies like hepatic tuberculosis, 3 Q fever hepatitis will cause increased uptake in the liver without significant suppression of the background physiological activity. 2 Metastases from lung cancer rarely cause superscan appearance. 4 Very rarely, even infective etiologies can cause superscan appearance, which is the situation in our case.…”