Human brain perfusion simulations have been limited to less than five patient-specific cases. We propose a pipeline based on MRI to overcome this limitation. Computational geometry is adjusted using T1-weighted MRI, and the perfusion model parameters are tuned based on arterial spin labeling perfusion MRI. A cohort of 75 patients is used to demonstrate that the pipeline is suitable to generate virtual patients with statistically accurate and precise cerebral blood flow maps. Our findings encourage future studies on in silico clinical trials using similar virtual cohorts to improve ischaemic stroke interventions.