This study aims to quantify perfusion, assess arterial vasoconstriction, and confirm reversibility using 3T ASL-MRI and MRA in 10 patients with suspected RCVS. Acquiring these data at multiple time points during RCVS progression, the investigators will assess the relationship between vasoconstriction and downstream perfusion and determine the role of these imaging techniques in early and accurate diagnosis of RCVS. The investigators also aim to investigate whether early imaging abnormalities can predict RCVS complications and clinical outcomes.