SFEBES2015 Oral Communications Diabetes and cardiometabolic complications (6 abstracts)
1Section of Investigative Medicine, Imperial College London, London, UK; 2Imanova Centre for Imaging Sciences, London, UK; 3Department of Computing, Imperial College London, London, UK; 4Department of Radiology, Imperial College NHS Healthcare Trust, London, UK.
Background: Obesity is a major medical health problem. Human brown adipose tissue (BAT) is potently activated by cold exposure and is a potential novel anti-obesity target. The current gold standard for measuring BAT activity in humans is 18F-FDG PET/CT. However it has two major limitations exposure to ionizing radiation and high cost. Since BAT is a thermogenic organ located in the supraclavicular and neck regions, we hypothesised that an increase in temperature in this region detected by thermal imaging as a potential novel method to detect BAT activity in humans.
Objective: To validate thermal imaging of human BAT activation vs the current gold standard 18F-FDG PET/CT.
Method: PET/CT scans and thermal images were collected from ten healthy young males (mean age 26±6 years) during cold exposure. PET/CT scans were classified as BAT positive (n=7) if there was increased signal intensity on the PET/CT scans or BAT negative (n=3) if this was absent, during cold exposure. Temperatures within the left supraclavicular region of the thermal images were analysed and overlaid against the PET/CT scans. A further sub-analysis of temperatures of skin directly overlying BAT as seen on PET/CT was carried out.
Results: The hottest 10% of temperatures in thermal images correspond to cold-activated BAT as seen on PET/CT in BAT positive subjects. Thermal imaging of the supraclavicular region detects a significant increase in temperature (0.31±0.08 °C, P<0.001) between baseline and end of cold exposure in BAT positive but not the BAT negative groups. Focussing on skin directly overlying BAT as seen on PET/CT detects a comparable increase in temperature (0.35±0.03 °C, P<0.001) between baseline and end of cold exposure.
Conclusion: Thermal imaging is a novel valid alternative to the current gold standard, 18F-FDG PET/CT to measure BAT activity in humans which is cost effective and does not expose subjects to ionising radiation.