Molecular Imaging of Brown Adipose Tissue Mass

Figure 1. BAT imaging with 11C-MRB and 18F-FDG under room and cold temperature in male subject. 18F-FDG and 11C-MRB are scaled from SUV 0 (black) to SUV 2 (white). 11C-MRB images are computed from the average of frames acquired between 40 to 60 min post-injection. Original data with permission from reference [54].

Figure 2. BAT imaging with TSPO PET tracer: 64Cu-Dis and 18F-F-DPA. (a) PET imaging with 64Cu-Dis in mouse under room temperature. (b) Representative coronal image under a cold exposure condition. (c) Quantitative analysis of (a,b). There was no significant difference in uptake between control and cold-treated groups (p = 0.359). (d) PET imaging with 18F-F-DPA in a mouse under room temperature. (e) Representative coronal image under a cold exposure condition. (f) Quantitative analysis of (d,e). There was no significant difference in uptake between control and cold treated groups (p = 0.356).

Figure 3. BAT imaging with TSPO PET tracer: 11C-PBR28. Representative images of a healthy volunteer who underwent PET/MRI using 11C-PBR28. The images were obtained 60–90 min after 14 m Ci of 11C-PBR28 injection. The supraclavicular BAT depots are indicated with arrows. Reproduced data with permission from reference [64].

Figure 4. BAT imaging with TSPO PET tracer 18F-F-DPA: (a) PET imaging with 18F-F-DPA in mouse under room temperature. (b) Representative coronal image under light anesthesia for 30 min before tracer injection. (c) Quantitative analysis of (a,b). There was a significant difference in uptake between the control and anesthesia treated groups.

Figure 5. Example of image registration and a reconstructed fat fraction map before and after cooling. The first column shows thermoneutral and post-cooling images (one slice from the first echo in the acquisition). In the second column, the overlay of the same images before (top) and after registration (bottom) is shown. The images are colored orange (thermoneutral) and blue (post-cooling) for better visualization of differences between the scans. The third column shows the thermoneutral and post-cooling fat fraction maps of the supraclavicular adipose depot, overlaid on the corresponding images. Lipid content in the supraclavicular region is color-mapped over a 30–100% fat fraction range. Reprinted with permission from reference [85]. Copyright © 2021 Abreu-Vieira, Sardjoe Mishre, Burakiewicz, Janssen, Nahon, van der Eijk, Riem, Boon, Dzyubachyk, Webb, Rensen and Kan.

Figure 6. BAT imaging with micellar SRFluor680. (A) Representative PET/CT with 18F-FDG in a single living SKH1 mouse. (B,C) Fluorescence/X-ray images of the same SKH1 mouse with micellar SRFluor680. (D) Effect of BAT metabolic activation on probe accumulation. Representative fluorescence images of the excised BAT are shown above each of the bars. Note: n.s. (not significant), ** (p < 0.01). Reproduced from reference [103] with permission from the Royal Society of Chemistry.