The use of thermal imaging of brown adipose tissue in the supraclavicular region as a repeatable technique to quantify its function in humans

Abstract

Brown adipose tissue (BAT) is able to rapidly generate large amounts of heat through non-shivering thermogenesis and is mainly located in the supraclavicular region. Its precise role in human energy balance remains an area of intense debate due, in part, to a lack of non-invasive and repeatable methods for assessing its function. We, therefore, aimed to establish the feasibility of thermal imaging in order to assess the potential activation of BAT within these depots. Thermal imaging was undertaken in children aged 4–13 years whilst in a relaxed “steady-state”, seated in an upright posture, with arms adducted and with head, neck and shoulders unclothed and 1.0 m away from the camera (FLIR b60: Sweden) fixed on a tripod. Images were then taken over a 5 minute control that was followed by a 5 minute study period when the subject had placed their hands or feet into cool water. In each child, temperature of the region co-locating with BAT was consistent under resting conditions throughout the control period (e.g. mean 34.64, sem 0.08oC). Placement of hands or feet into cool water resulted in repeatable and rapid increases in BAT temperature (e.g. Hands: 0.99 ΔToC). In conclusion, BAT thermogenesis is rapidly activated in the child, a response that can be readily quantified by thermal imaging. This non-invasive technique may be used to establish the role of environmental influences on BAT function on a population wide basis.