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Quantification of brown and white adipose tissue based on Gaussian mixture model using water–fat and T 2 * MRI in adolescents
Author(s) -
Hui Steve C.N.,
Ko Jacky K.L.,
Zhang Teng,
Shi Lin,
Yeung David K.W.,
Wang Defeng,
Chan Queenie,
Chu Winnie C.W.
Publication year - 2017
Publication title -
journal of magnetic resonance imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.563
H-Index - 160
eISSN - 1522-2586
pISSN - 1053-1807
DOI - 10.1002/jmri.25632
Subject(s) - intraclass correlation , medicine , adipose tissue , brown adipose tissue , reproducibility , obesity , nuclear medicine , repeatability , anatomy , zoology , biology , chemistry , chromatography
Purpose To develop a technique for the separation and quantification of brown adipose tissue (BAT) and white adipose tissue (WAT) using fat fraction andT 2 *intensity based on the Gaussian mixture model (GMM). Materials and Methods Chemical‐shift water–fat andT 2 *images were acquired at the neck, supraclavicular, interscapular, and paravertebral regions in 24 volunteers (Obese: n = 12, female/male = 6/6, body mass index [BMI] = 31.3 ± 2.3 kg/m 2 , age = 16.1 ± 0.6; Normal weight: n = 12, female/male = 6/6, BMI = 21.2 ± 2.4 kg/m 2 , age = 12.9 ± 2.4) 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: 315.2 mL [±89.1], Normal weight: 248.5 mL [±86.4]), but BAT/WAT ratios were significantly higher ( P = 0.029) in the normal group.T 2 *of BAT ( P = 0.04) 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 ( P = 0.776 (normal), 0.501 [obese]),T 2 *( P = 0.908 [normal], 0.249 [obese]) and fat‐fraction of BAT ( P = 0.985 [normal], 0.108 [obese]). The intraclass correlation coefficient showed a good reproducibility in volume (BAT: 0.997, WAT: 0.948),T 2 *(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, andT 2 *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. Level of Evidence: 2 Technical Efficacy: Stage 1 J. MAGN. RESON. IMAGING 2017;46:758–768