Associations of Intracranial Artery Length and Branch Number on Time‐of‐Flight MRA With Cognitive Impairment in Hypertensive Older Males

Background Hypertension‐induced impairment of the cerebral artery network contributes to cognitive impairment. Characterizing the structure and function of cerebral arteries may facilitate the understanding of hypertension‐related pathological mechanisms and lead to the development of new indicators for cognitive impairment. Purpose To investigate the associations between morphological features of the intracranial arteries distal to the circle of Willis on time‐of‐flight MRA (TOF‐MRA) and cognitive performance in a hypertensive cohort. Study Type Prospective observational study. Population 189 hypertensive older males (mean age 64.9 ± 7.2 years). Field Strength/Sequence TOF‐MRA sequence with a 3D spoiled gradient echo readout and arterial spin labeling perfusion imaging sequence with a 3D stack‐of‐spirals fast spin echo readout at 3T. Assessment The intracranial arteries were segmented from TOF‐MRA and the total length of distal arteries (TLoDA) and number of arterial branches (NoB) were calculated. The mean gray matter cerebral blood flow (GM‐CBF) was extracted from arterial spin labeling perfusion imaging. The cognitive level was assessed with short‐term and long‐term delay‐recall auditory verbal learning test (AVLT) scores, and with montreal cognitive assessment. Statistical Tests Univariable and multivariable linear regression were used to analyze the associations between TLoDA, NoB, GM‐CBF and the cognitive assessment scores, with P < 0.05 indicating significance. Results TLoDA ( r = 0.314) and NoB ( r = 0.346) were significantly correlated with GM‐CBF. Multivariable linear regression analyses showed that TLoDA and NoB, but not GM‐CBF ( P = 0.272 and 0.141), were significantly associated with short‐term and long‐term delay‐recall AVLT scores. These associations remained significant after adjusting for GM‐CBF. Data Conclusion The TLoDA and NoB of distal intracranial arteries on TOF‐MRA are significantly associated with cognitive impairment in hypertensive subjects. Level of Evidence 2 Technical Efficacy Stage 3