On the relevance of brown adipose tissue in children.

The visualization of brown adipose tissue (BAT) in pediatric patients undergoing positron emission tomography/computed tomography (PET/CT) examinations is dependent on multiple physiologic and technical factors, such as age, sexual maturity, fat accumulation, disease status, medications, plasma glucose concentration, radiotracer dosage, acquisition parameters, and season and temperature during examinations. Evidence also suggests that children with metabolically active BAT have significantly greater muscle volume than those without visualized BAT, and that in both boys and girls, the amount of BAT increases during puberty. Hence, concurrent with the gains in skeletal muscle during infancy and puberty, all infants and adolescents have large amounts of BAT. New magnetic resonance imaging (MRI) techniques that discern the cytological differences between brown and white adipose tissue will likely provide the platform to reliably measure BAT in healthy subjects and determine the relevance of this tissue in humans.