Abstract
The aim of this study was to assess the volume and function of human brown adipose tissue (BAT) in vivo using MR imaging. Methods: BAT volumes under thermoneutral conditions in the cervical areas were assessed via water-fat contrast using the Dixon method and via water-saturation efficiency using fast spin-echo and T2-weighted images. The existence of cervical BAT was also assessed by 18F-FDG PET/CT scans in the same subjects. BAT functionality was assessed via functional MR imaging (fMRI) blood oxygenation level–dependent (BOLD) signal changes in response to a mild cold challenge. Results: Under thermoneutral conditions, we were able to distinguish BAT from white adipose tissue in the cervical and supraclavicular fat. BAT showed higher water-to-fat contrast and higher water-saturation efficiency in MR imaging scans. The location and volume of BAT assessed by MR imaging were comparable to the measurements by 18F-FDG PET/CT scans. During mild cold challenge, BOLD fMRI signal increased in BAT by 10.7% ± 1.8% (P < 0.01). Conclusion: We demonstrated the feasibility of using MR imaging and fMRI to assess BAT volume and BAT responses to mild cold stimulation in the cervical areas of human subjects.
Footnotes
↵* Contributed equally to this work.
Published online Jul. 18, 2013.
- © 2013 by the Society of Nuclear Medicine and Molecular Imaging, Inc.