Sex differences in cerebral pulsatility and damping: A 4D flow MRI study.

Area of Science:

• Cerebrovascular physiology
• Medical imaging
• Gerontology

Background:

• Cerebral pulsatility is a key indicator of cerebrovascular health.
• Limited understanding exists regarding age-related sex differences in cerebral pulsatility and damping across cerebral arteries.

Purpose of the Study:

• To investigate sex differences in cerebral pulsatility and damping throughout the adult lifespan.
• To explore age-related changes in these hemodynamic parameters within specific cerebral arteries.

Main Methods:

• Utilized 4D flow MRI to measure cerebral hemodynamics in internal carotid arteries (ICAs), middle cerebral arteries (MCAs), and basilar artery.
• Calculated cerebral pulsatility index (PI) and damping factor (DF) in 164 participants across three age groups (young, middle-aged, older).

Main Results:

• Young females showed lower PI than males in ICAs; middle-aged females had lower PI in the right ICA.
• Older females exhibited greater PI than males in the right ICA and right MCA.
• Cerebral damping factor (DF) between the right ICA and MCA was lower in young females than in young males.

Conclusions:

• Females demonstrate more pronounced age-related increases in cerebral pulsatility compared to males, especially in anterior circulation arteries.
• Damping differences were not sex-specific in proximal anterior circulation arteries, indicating potentially different underlying mechanisms.
• Findings highlight sex-specific trends in cerebral pulsatility with aging, warranting further mechanistic investigation.