Brown adipose tissue detected by PET/CT imaging is... : Nuclear Medicine Communications (original) (raw)

ORIGINAL ARTICLES

Brown adipose tissue detected by PET/CT imaging is associated with less central obesity

Green, Aileen L.a; Bagci, Ulasd; Hussein, Sarfarazd; Kelly, Patrick V.c; Muzaffar, Razia; Neuschwander-Tetri, Brent A.b; Osman, Medhat M.a

aDepartment of Radiology, Division of Nuclear Medicine, Saint Louis University

bDepartment of Internal Medicine, Division of Gastroenterology and Hepatology, Saint Louis University School of Medicine

cDepartment of Statistics, Doisy College of Health Sciences Research Administration, St Louis, Missouri

dDeparment of Electrical and Computer Science, Center for Research in Computer Vision, University of Central Florida, Orlando, Florida, USA

Correspondence to Medhat M. Osman, MD, PhD, Division of Nuclear Medicine & PET/CT, Saint Louis University Hospital, 2nd Floor, 3635 Vista Avenue, St Louis, MO 63110, USA Tel: +1 314 577 8047; fax: +1 314 268 5144; e-mail: [email protected]

Received October 10, 2016

Received in revised form March 30, 2017

Accepted April 21, 2017

Abstract

Purpose

This retrospective review was performed to determine whether patients with brown adipose tissue (BAT) detected by fluorine-18-fluorodeoxyglucose (18F-FDG) PET/computed tomography (CT) imaging have less central obesity than BMI-matched control patients without detectable BAT.

Patients and methods

Thirty-seven adult oncology patients with 18F-FDG BAT uptake were retrospectively identified from PET/CT studies from 2011 to 2013. The control cohort consisted of 74 adult oncology patients without detectable 18F-FDG BAT uptake matched for BMI/sex/season. Tissue fat content was estimated by CT density (Hounsfield units) with a subsequent noise removal step. Total fat and abdominal fat were calculated. An automated separation algorithm was utilized to determine the visceral fat and subcutaneous fat at the L4/L5 level. In addition, liver density was obtained from CT images. CT imaging was interpreted blinded to clinical information.

Results

There was no difference in total fat for the BAT cohort (34±15 l) compared with the controls (34±16 l) (_P_=0.96). The BAT cohort had lower abdominal fat to total fat ratio compared with the controls (0.28±0.05 vs. 0.31±0.08, respectively; _P_=0.01). The BAT cohort had a lower visceral fat/(visceral fat+subcutaneous fat) ratio compared with the controls (0.30±0.10 vs. 0.34±0.12, respectively; _P_=0.03). Patients with BAT had higher liver density, suggesting less liver fat, compared with the controls (51.3±7.5 vs. 47.1±7.0 HU, _P_=0.003).

Conclusion

The findings suggest that active BAT detected by 18F-FDG PET/CT is associated with less central obesity and liver fat. The presence of foci of BAT may be protective against features of the metabolic syndrome.