Blood flow distribution in cerebral arteries

Area of Science:

• Neuroimaging
• Vascular Biology
• Medical Physics

Background:

• High-resolution phase-contrast MRI enables detailed assessment of blood flow in cerebral arteries.
• Understanding the distribution of total cerebral blood flow (tCBF) is crucial for diagnosing vascular conditions.

Purpose of the Study:

• To describe the distribution of tCBF within the cerebral vascular tree.
• To investigate the influence of age, sex, and anatomical variations on cerebral blood flow.
• To establish reference values for cerebral blood flow parameters.

Main Methods:

• Phase-contrast MRI was used to measure blood flow rate (BFR) in 21 intra- and extracerebral arteries in healthy young and elderly individuals.
• Total cerebral blood flow was calculated from internal carotid and vertebral artery flow.
• Mean cerebral perfusion was determined by normalizing tCBF to brain volume.

Main Results:

• Carotid and vertebral arteries supplied 72% and 28% of tCBF, respectively, independent of age, sex, or brain volume.
• Specific distributions were quantified for major cerebral arteries, including the middle cerebral artery (21%) and anterior cerebral artery (12%).
• Blood flow rate in cerebral arteries decreased with age, while mean cerebral perfusion was higher in women.

Conclusions:

• The study presents a novel method for mapping cerebral vascular tree flow profiles with established reference values.
• Findings highlight age-related changes and sex differences in cerebral blood flow.
• This method can aid in evaluating collateral flow systems and understanding cerebral hemodynamics.