Detecting Hot Fat in Cold Humans: “Take a Breath and Hold”
Date: November 18, 2022 12-1 PM Eastern time
Speakers: Rosa Tamara Branca, Ph.D.
Brown adipose tissue (BAT) is a fat tissue specialized for heat production and used by most mammals to defend core body temperature when they are exposed to cold. Thanks to its fat-burning capacity and its newly discovered role in body weight regulation and metabolism, BAT has recently become a target for the treatment of obesity and its associated metabolic disorders.
Because this tissue is morphologically and functionally different than White Adipose Tissue (WAT), a variety of clinical and preclinical imaging modalities, including PET/CT, SPECT/CT, MRI, NIRF and ultrasound have been exploited to differentiate BAT and WAT in vivo. While most of these techniques work relatively well in rodents, they often fail in humans, where this tissue is sparse and often structurally more like WAT.
In the past 8 years, we have been using the lipophilic gas xenon as contrast agent for MRI and CT to detect both BAT function and mass in rodents, non-human primates, and humans. In this talk, I will describe how these two techniques, MRI with hyperpolarized xenon gas and xenon-enhanced CT, often seen as competing techniques in the context of lung ventilation imaging, can provide complementary information on BAT thermogenic function and mass that cannot be obtained by other means. Finally, I will describe how the in-silico 3D XCAT models have been modified and used to enable optimization of the CT imaging protocol for quantification of human BAT mass.