Bart Van Rooijen, Presenter: Nothing to Disclose

Anouk A.J.J. Van Der Lans, Abstract Co-Author: Nothing to Disclose

Boudewijn Brans, Abstract Co-Author: Nothing to Disclose

Joachim Ernst Wildberger MD, PhD, Abstract Co-Author: Nothing to Disclose

Patrick Schrauwen, Abstract Co-Author: Nothing to Disclose

Wouter Van Marken Lichtenbelt, Abstract Co-Author: Nothing to Disclose

Walter H. Backes PhD, Abstract Co-Author: Nothing to Disclose

Brown adipose tissue (BAT) is involved in non-shivering thermogenesis (NST). Novel non-invasive imaging methods are required to monitor the pharmaceutical targeting of BAT as a potential treatment of obesity. FDG-PET combined with CT is so far the only non-invasive method to detect active BAT. The aim of this work was to investigate the use of MRI to determine the presence of active BAT. 

Eleven healthy young adults were included. The subjects underwent MRI and FDG-PET/CT imaging of the supra-clavicular/cervical fat depots containing BAT. Cooling was performed by wrapping the subjects in a water-perfused suit connected to temperature controlled water baths. Prior to the PET/CT, subjects were exposed to mild cold conditions during which maximum NST occurs. Subjects were injected with 74 MBq FDG as a tracer of metabolic activity. BAT activity was quantified by auto-contouring BAT with a set threshold. In the MRI water-fat (Dixon) imaging was performed under normal ambient conditions followed by dynamic T2* weighted imaging during which subjects were exposed to a repeated boxcar cooling paradigm to activate the BAT.  

Water-fat MRI showed that supra-clavicular/cervical fat depots had an average fat content of 65.2 ± 7.0 %. For the regions identified as active BAT on PET/CT, the fat content was 66.0 ± 9.3 %. The volume fraction of activated voxels in the depots as measured by fMRI correlated with the activity concentration of FDG uptake on the PET/CT (R=0.63, P<0.05).

Our results suggest (active) BAT cannot be identified based on the fat fraction of the supra-clavicular/cervical depots. The use of fMRI to measure the presence of active BAT is promising as the fraction of activating voxels correlated with FDG uptake on PET/CT.

Pharmaceutical targeting of BAT may be a potential strategy in the treatment of obesity and imaging methods are needed to monitor its response. 

Van Rooijen, B, Van Der Lans, A, Brans, B, Wildberger, J, Schrauwen, P, Van Marken Lichtenbelt, W, Backes, W, Imaging Cold Activated Brown Adipose Tissue Using Functional MRI and 18F-FDG PET CT.  Radiological Society of North America 2013 Scientific Assembly and Annual Meeting, December 1 - December 6, 2013 ,Chicago IL. http://archive.rsna.org/2013/13017181.html