MRI characterization of brown adipose tissue in obese and normal-weight children

作者：Deng Jie^*; Schoeneman Samantha E; Zhang Huiyuan; Kwon Soyang; Rig**y Cynthia K; Shore Richard M; Josefson Jami L

来源：Pediatric Radiology, 2015, 45(11): 1682-1689.

DOI：10.1007/s00247-015-3391-z

• Brown adipose tissue
• Brown-in-white adipocytes
• Children
• Magnetic resonance imaging
• Obesity

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.
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.
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.
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).
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.

• 单位
  西北大学