PET imaging of human brown adipose tissue with TSPO tracer [11C]PBR28


Ran C. PET imaging of human brown adipose tissue with TSPO tracer [11C]PBR28. Molecular Imaging & Biology. 2018;20 (2) :188-193.


Purpose: Brown adipose tissue (BAT) in adult humans has been recently re-discovered and intensively investigated as a new potential therapeutic target for obesity and type 2 diabetes (T2D). However, reliable assessment of BAT mass in vivo represents a considerable challenge. The purpose of this study is to demonstrate for the first time that human BAT depots can be imaged with a TSPO-specific PET tracer [11C]PBR28 under thermoneutral conditions.

Procedures: In this retrospective study, we analyzed the images of three healthy volunteers who underwent PET/MR imaging after injection of 14mCi of [11C]PBR28 at room temperature. Thirty-minute static PET images were reconstructed from the data obtained 60-90 minutes after the injection of the tracer .

Results: [11C]PBR28 uptake in the neck/supraclavicular regions was identified, which was parallel to the known distribution pattern of human BAT depots. These areas co-localized with the areas of hyperintensity and corresponded to fat on T1 weighted  MR images. Standardized uptake value (SUV) was used to quantify [11C]PBR28 signal in BAT depots. The average (± SD) SUV(mean) and SUVmax for BAT depots was 2.13 (±0.33) and 3.19 (±0.34) respectively, while the average SUV(mean) for muscle and subcutaneous adipose tissue was 0.79 (±0.1) and 0.18 (±0.04) respectively.

Conclusions: In this brief article, we provide the first evidence suggesting that [11C]PBR28, a widely available TSPO-specific PET tracer, can be used for imaging human BAT mass under thermoneutral conditions.


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Last updated on 02/28/2019