Periaqueductal gray (PAG) seed-based functional connectivity (FC) analyses between patients with SCD without chronic pain (NCP) and controls (CN).

Left: Images show the results of the two sample t-test pattern of CN (controls, blue) and SCD without chronic pain (patients with sickle cell disease and no chronic pain, orange) PAG FC, respectively. Color is coded based on z-score of the significance. Brain regions with warm color represent the positive connection and cold color represents the autocorrelation with PAG regions. Brain regions are numbered: (1) Left and right Cuneus/ left inferior occipital gyrus (brodmann area 18)/ left middle occipital gyrus/ left and right lingual gyrus, and (2) Left and right superior frontal gyrus. Right: In comparison to CN, NCP demonstrated increased connectivity only in the (1) Left and right Cuneus/ left inferior occipital gyrus (brodmann area 18)/ left middle occipital gyrus/ left and right lingual gyrus, and decreased connectivity of the (2) Left and right superior frontal gyrus (y-axis = z-score of the significance, x-axis = brain region of interest by number).