Brown Fat on a PET Scan (image) Garvan Institute of Medical Research Share Print E-Mail Caption Brown fat is visible on a PET scan as red coloration around the collarbone. The scan detects a glucose tracer, which is visible in the most metabolically active organs. Credit Garvan Institute of Medical Research Usage Restrictions with attribution Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.