Fig. 1.

[¹¹C]PBR28 PET signal elevations in the Pandemic group. (A) Mean images computed from 57 Pre-pandemic and 15 Pandemic subjects are displayed as maximum intensity projections. (B) Significant cluster from the Pandemic > Pre-Pandemic voxel-wise contrast is shown in a red–yellow color scale. There were no significant regions for the Pre-Pandemic > Pandemic contrast. (C) Visualization of mean [¹¹C]PBR28 SUVR extracted from sub-portions of the cluster statistically significant in A. IPS = Intraparietal Sulcus, PCUN = Precuneus, IC = Insular Cortex, SCC = Subcallosal Cortex, ACC = Anterior Cingulate Cortex, NAc = Nucleus Accumbens, SMA = Supplementary Motor Area, MFG = Middle Frontal Gyrus, HIPP = Hippocampus. Error bars denote 25th to 75th inter-quartile range. Triangles denote data from Scanner 1 and circles denote data from Scanner 2. (D) Case study of one subject scanned before- (September 2016) and during the pandemic (October 2020) in Scanner 1. Bar graph of mean [¹¹C]PBR28 SUVR are extracted from the cluster sub-portions in (C) and difference image (post-pre) are reported in red-yellow and cyan-blue color bars. E) Mean [¹¹C]PBR28 SUVR extracted from sub-clusters in (C) and sorted by scan date. The range of the color scale was set for each region independently to best illustrate the pandemic PET signal increase, for visualization purposes.