Interesting ImagesFDG Uptake in Brown Adipose Tissue Activated by a β3-Adrenergic Receptor Agonist Prescribed for Overactive BladderOkuyama, Chio MD, PhD∗; Kikuchi, Ryutaro MD, PhD†; Ikeuchi, Takashi MD, PhD‡Author Information From the ∗Division of PET Imaging, Shiga Medical Center Research Institute Departments of †Thoracic Surgery ‡Diagnostic Radiology, Shiga General Hospital, Moriyama, Japan. Received for publication January 31, 2020; revision accepted March 20, 2020. Conflicts of interest and sources of funding: none declared. Correspondence to: Chio Okuyama, MD, PhD, Division of PET Imaging, Shiga Medical Center Research Institute, 5-4-30, Moriyama-cho, Moriyama-City, Shiga, 524-8524, Japan. E-mail: email@example.com. Clinical Nuclear Medicine: August 2020 - Volume 45 - Issue 8 - p 628-631 doi: 10.1097/RLU.0000000000003078 Buy Metrics Abstract Brown adipose tissue (BAT), which produces energy and is known to play a role as a hibernating gland, is sometimes visualized on 18F-FDG PET in children or in slender young adults in a cold environment. Because BAT is activated by catecholamines, FDG uptake in BAT is also observed in patients with pheochromocytoma or paraganglioma. We present the case of an elderly woman with remarkable FDG uptake in BAT. Activation of BAT by a β3-adrenergic receptor agonist (mirabegron) prescribed for overactive bladder was suspected as the cause of the marked visualization of BAT in this patient. Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.