Abstract
Background: Brown adipose tissue (BAT) is identified in mammals as an adaptive thermogenic organ for modulation of energy expenditure and heat generation. Human BAT may be primarily composed of brown-in-white (BRITE) adipocytes and stimulation of BRITE may serve as a potential target for obesity interventions. Current imaging studies of BAT detection and characterization have been mainly limited to PET/CT. MRI is an emerging application for BAT characterization in healthy children. Objective: To exploit Dixon and diffusion-weighted MRI methods to characterize cervical-supraclavicular BAT/BRITE properties in normal-weight and obese children while accounting for pubertal status. Materials and methods: Twenty-eight healthy children (9–15 years old) with a normal or obese body mass index participated. MRI exams were performed to characterize supraclavicular adipose tissues by measuring tissue fat percentage, T2*, tissue water mobility, and microvasculature properties. We used multivariate linear regression models to compare tissue properties between normal-weight and obese groups while accounting for pubertal status. Results: MRI measurements of BAT/BRITE tissues in obese children showed higher fat percentage (P < 0.0001), higher T2* (P < 0.0001), and lower diffusion coefficient (P = 0.015) compared with normal-weight children. Pubertal status was a significant covariate for the T2* measurement, with higher T2* (P = 0.0087) in pubertal children compared to prepubertal children. Perfusion measurements varied by pubertal status. Compared to normal-weight children, obese prepubertal children had lower perfusion fraction (P = 0.003) and pseudo-perfusion coefficient (P = 0.048); however, obese pubertal children had higher perfusion fraction (P = 0.02) and pseudo-perfusion coefficient (P = 0.028). Conclusion: This study utilized chemical-shift Dixon MRI and diffusion-weighted MRI methods to characterize supraclavicular BAT/BRITE tissue properties. The multi-parametric evaluation revealed evidence of morphological differences in brown adipose tissues between obese and normal-weight children.
Original language | English (US) |
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Pages (from-to) | 1682-1689 |
Number of pages | 8 |
Journal | Pediatric radiology |
Volume | 45 |
Issue number | 11 |
DOIs | |
State | Published - Oct 26 2015 |
Externally published | Yes |
Keywords
- Brown adipose tissue
- Brown-in-white adipocytes
- Children
- Magnetic resonance imaging
- Obesity
ASJC Scopus subject areas
- Pediatrics, Perinatology, and Child Health
- Radiology Nuclear Medicine and imaging