Adult 1 Article 1 Basilar Artery 1 Carotid Artery, Internal 1 Cerebrovascular Circulation 1 Estrogens 1 Humans 1 Magnetic Resonance Angiography Menstrual Cycle 1 Neurovascular Coupling 1 Progesterone 1 Spin Labels 1 Young Adult 1 adult 1 arterial spin Labelling 1 arterial spin labeling 1 artery diameter 1 basilar artery 1 blood 1 blood sampling 1 brain blood flow 1 brain circulation 1 brain region 1 cerebral blood flow 1 clinical article 1 diagnostic imaging 1 estrogen 1 estrogen blood level 1 female 1 follicular phase 1