For marrow/fat content: I think you'll get best reproducible and accurate measure (especially with addition of phantom along side subject's ROI) using dual energy CT. Option is usually offered as a free software product by CT vendors to measure bone density in spine and hips. You'll just need to change ROI.

As you know, signal noise increases with morbid obesity, so you might want to increase slice thickness a little, boost mA dose a little, and limit number of slices to only areas of interest. I think if you choose femur, shield gonads and resulting "bad" dose will end up very small indeed.

Great question.

PET/CT is the "current" gold-standard for measuring Human BAT Volume and Activity. There are several limitations of PET/CT such as high cost and radiation exposure. Furthermore, the presence of brown fat can obscure the lesions (due to enhanced fluorodeoxyglucose uptake in brown fat). This leads to my first question. Can we reduce this uptake by drugs? Propranolol maybe?

Nowadays, I have noticed a growing interest in the iterative decomposition with echo asymmetry and least-squares estimation (IDEAL) MRI for differentiating white and brown adipose tissue. It is needless to say "More work is needed", preferably human trials.

What do you think about infrared thermography and incorporation of 18F-FBnTP as tracers?

Thanks,

Amit