Drs. Hu and Smith contributed equally to this work.
Identification of brown adipose tissue in mice with fat–water IDEAL-MRI†
Article first published online: 23 APR 2010
Copyright © 2010 Wiley-Liss, Inc.
Journal of Magnetic Resonance Imaging
Volume 31, Issue 5, pages 1195–1202, May 2010
How to Cite
Hu, H. H., Smith, D. L., Nayak, K. S., Goran, M. I. and Nagy, T. R. (2010), Identification of brown adipose tissue in mice with fat–water IDEAL-MRI. J. Magn. Reson. Imaging, 31: 1195–1202. doi: 10.1002/jmri.22162
- Issue published online: 23 APR 2010
- Article first published online: 23 APR 2010
- Manuscript Accepted: 9 FEB 2010
- Manuscript Received: 5 NOV 2009
- NCI Centers for Transdisciplinary Research on Energetics and Cancer (TREC). Grant Number: U54CA116848
- NIDDK. Grant Numbers: R21 DK 081173, P30DK56336, P60DK079626, T32DK062710
- brown adipose tissue;
- white adipose tissue;
- fat fraction;
To investigate the feasibility of using IDEAL (Iterative Decomposition with Echo Asymmetry and Least squares estimation) fat–water imaging and the resultant fat fraction metric in detecting brown adipose tissue (BAT) in mice, and in differentiating BAT from white adipose tissue (WAT).
Materials and Methods:
Excised WAT and BAT samples and whole-mice carcasses were imaged with a rapid three-dimensional fat–water IDEAL-SPGR sequence on a 3 Tesla scanner using a single-channel wrist coil. An isotropic voxel size of 0.6 mm was used. Excised samples were also scanned with single-voxel proton spectroscopy. Fat fraction images from IDEAL were reconstructed online using research software, and regions of WAT and BAT were quantified.
A broad fat fraction range for BAT was observed (40–80%), in comparison to a tighter and higher WAT range of 90–93%, in both excised tissue samples and in situ. Using the fat fraction metric, the interscapular BAT depot in each carcass could be clearly identified, as well as peri-renal and inguinal depots that exhibited a mixed BAT and WAT phenotype appearance.
Due to BAT's multi-locular fat distribution and extensive mitochondrial, cytoplasm, and vascular supply, its fat content is significantly less than that of WAT. We have demonstrated that the fat fraction metric from IDEAL-MRI is a sensitive and quantitative approach to noninvasively characterize BAT. J. Magn. Reson. Imaging 2010;31:1195–1202. © 2010 Wiley-Liss, Inc.