Using High-Field Magnetic Resonance Imaging to Estimate Distensibility of the Middle Cerebral Artery

Background: Although cerebral arterial stiffness may be an important marker for cerebrovascular health, there is not yet a measurement that accurately reflects the distensibility of major intracranial arteries. Herein, we aim to noninvasively measure distension of the human middle cerebral artery (MCA). Methods: Ten healthy volunteers (age: 30.3 10.8 years) underwent ultra-high-field (7-tesla) MRI scanning. Time-of-flight angiography and phase-contrast flow imaging were used to locate the M1 segment of the MCA and to determine the occurrence of systole and diastole. High-resolution cross-sectional cardiac triggered T-2-weighted images of the M1 segment of the MCA were acquired in systole and diastole. Results:The average distension of the MCA area from diastole to systole was 2.58% (range: 0.08%-6.48%). There was no significant correlation between MCA distension and the pulsatility index, calculated from the phase-contrast flow velocity profiles. Conclusion: These results lead to the first noninvasive image-based estimation of distensibility of the MCA (approx. 5.8 x 10(-4) mm Hg-1) and demonstrate that ultra-high-field MRI could be a promising tool for investigating distensibility of intracranial arteries in relation to cerebrovascular pathology. (C) 2016 The Author(s) Published by S. Karger AG, Basel