Table 2.

Regions of normally high TSPO expression in human brain based on 43 normal subjects scanned using ¹¹C-PK11195 (PK) and 20 normal subjects scanned using ¹¹C-PBR28 (PBR). MNI coordinates of local maxima based on averaged scan data are provided

Region	MNI coordinates (x,y,z); peak signal value
	PK (BPnd)	PBR (SUVr)
midbrain collicular region*	5 –28 –5; 0.20	7 –27 –5; 1.68
pons	1 –32 –33; 0.27	1 –30 –37; 1.51
medulla	#	2 –43 –44; 1.59
thalami	12 –16 9; 0.33–12 –20 8; 0.28	13 –14 7; 1.63–8 –21 5; 1.63

^*Signal in this region included superior and inferior colliculi and cuneiform nuclei. Coordinates of peak TSPO PET signal specifically within the inferior colliculi region of interest were x = –4, y = –33, z = –8 (PK) and x = –4, y = –34, z = –9 (PBR.) #No distinct peak in medulla was discernible in the PK dataset, possibly due to lower scan resolution.