Cerebral oxygen extraction fraction (OEF) maps are critical to investigate salvageable tissue in ischemic stroke. We compare OEF maps obtained using quantitative susceptibility mapping plus quantitative blood oxygen level-dependent modeling (QSM+qBOLD=QQ) with the reference standard OEF maps obtained using 15O PET in 10 healthy adults. The whole brain and regional average OEF values were found to be substantially equivalent between the two methods, e.g. 32.8 ± 6.7 % on PET and 34.2 ± 2.6 % on QQ (p=0.002, TOST) for whole brain average. QQ estimates OEF maps from a single routine MRI sequence without burdensome gas inhalation or respiratory-control procedures.