Impact Factor:3.7

DOI Number:10.1002/jmri.25632

Journal:Journal of Magnetic Resonance Imaging

Abstract:Purpose: To develop a technique for the separation and quantification of brown adipose tissue (BAT) and white adipose tissue (WAT) using fat fraction and T2* intensity based on the Gaussian mixture model (GMM).
Materials and Methods: Chemical-shift water–fat and T2* images were acquired at the neck, supraclavicular, interscapular, and paravertebral regions in 24 volunteers (Obese: n512, female/male56/6, body mass index [BMI]531.36 2.3 kg/m2, age516.160.6; Normal weight: n512, female/male56/6, BMI521.262.4 kg/m2, age512.962.4) using a 3T scanner with the chemical-shift water–fat mDixon sequence. BAT and WAT were clustered based on the Gaussian mixture model using the expectation–maximization algorithm. Results and reproducibility were compared and assessed using independent t-tests and intraclass correlation coefficient.
Results: BAT in obese participants was predominately found at the supraclavicular region and in normal-weight participants it was more scattered and distributed in interscapular–supraclavicular, axillary, and spine regions. Absolute volume of BAT was higher in the obese group (Obese: 315.2mL [689.1], Normal weight: 248.5mL [686.4]), but BAT/WAT ratios were significantly higher (P50.029) in the normal group. T2* of BAT (P50.04) and volume of WAT (P < 0.001) were significantly lower in the normals. Within-group comparison between male and female indicated no significant differences were found in volume (P50.776 (normal), 0.501 [obese]), T2* (P50.908 [normal], 0.249 [obese]) and fat-fraction of BAT (P50.985 [normal], 0.108 [obese]). The intraclass correlation coefficient showed a good reproducibility in volume (BAT: 0.997, WAT: 0.948), T2* (BAT: 0.969, WAT: 0.983), and fat-fraction (BAT: 0.952, WAT: 0.517).
Conclusion: BAT identified by this method was in agreement with other studies in terms of location, fat-fraction value, and T2* intensity. The proposed GMM-based segmentation could be a useful nonradiation imaging method for assessment of adipose tissue, in particular for serial follow-up of volume changes after drug or lifestyle interventions for obesity.

Indexed by:Journal paper

Discipline:Medicine

Document Type:J

Volume:46

Issue:3

Page Number:758-768

Translation or Not:no

Date of Publication:2017-01-16

Included Journals:SCI

Publication links:https://onlinelibrary.wiley.com/doi/10.1002/jmri.25632