Oxygen extraction fraction (OEF) and cerebral blood flow (CBF) in
moyamoya, sickle cell anemia (SCA), and age-matched control
participants. A two-sided Wilcoxon rank-sum test was performed to
test the primary hypothesis that OEF was elevated in moyamoya and
SCA participants compared to age-matched controls, and that CBF was
decreased in moyamoya participants compared to controls. (a) OEF is
elevated in moyamoya participants compared to age-matched controls
(P < 0.001). (b) Reduced mean gray matter CBF in moyamoya
participants relative to controls, but this reduction was not
significant, likely due to preserved posterior territory CBF in many
patients and regions of high ASL intravascular signal. (c) OEF is
elevated in SCA participants compared to age-matched controls
(P = 0.045). (d) CBF is elevated in SCA participants compared to
age-matched controls (P < 0.001). *P < 0.05, **P < 0.01. In
the moyamoya arm of the study, a sub-analysis was performed that
evaluated only females in both the control (n = 15) and moyamoya
(n = 17) groups. Trends were identical, and the OEF was elevated in
the moyamoya participants compared to the controls (P = 0.06), and
CBF was decreased in the moyamoya participants compared to controls
(P = 0.02).