Impaired hemodynamic response in the ischemic brain assessed with BOLD fMRI

► BOLD response and CBF in neurological impairment free ischemic patients are assessed. ► Conventional analysis misses activation detected with HRF-model-free analysis. ► Analysis with single HRF leads to misinterpretation of activation area. ► Severity of ischemia is correlated with baseline CBF, ΔCBF, BOLD magnitude and delay. ► Ischemia severity can be assessed with neuronal activity as endogenous vasodilator.