ABSTRACT
Blood pressure (BP) changes with age are widespread, and systemic high blood pressure (HBP) is a significant contributor for strokes and cognitive impairment. A non-invasive methodology to quantify changes in cerebral vasculature using Magnetic Resonance Angiography (MRA) imaging and correlation of cerebrovascular changes to mean arterial pressure (MAP) is presented. MRA images and systemic BP measurements were obtained from patients (n = 15, M = 8, F = 7, Age = 49.2 ± 7.3 years) over 700 days (an initial visit and then a follow-up period of 2 years with a final visit). A novel segmentation algorithm was developed to delineate brain vasculature from surrounding tissue. Vascular probability distribution function (PDF) was calculated from segmentation data to correlate the temporal changes in cerebral vasculature to MAP calculated from systemic BP measurements. A 3D reconstruction of the cerebral vasculature was performed using a growing tree model. The segmentation algorithm had a 99.9% specificity and 99.7% sensitivity in identifying and delineating cerebral vasculature. The PDFs had a statistically significant correlation to MAP changes below the circle of Willis (p-value = 0.0007). The proposed methodology may be used to quantify changes in cerebral vasculature and cerebral perfusion pressure non-invasively through MRA image analysis, which may be a useful tool for clinicians to optimize medical management of HBP.
