Cerebrovascular reactivity measurement using magnetic resonance imaging: a systematic review Link to paper on Frontiers in Physiology Authors Emilie Sleight, Michael S. Stringer, Ian Marshall, Joanna M. Wardlaw, & Michael J. Thrippleton Abstract Cerebrovascular reactivity (CVR) magnetic resonance imaging (MRI) probes cerebral haemodynamic changes in response to a vasodilatory stimulus. CVR closely relates to the health of the vasculature & is therefore a key parameter for studying cerebrovascular diseases such as stroke, small vessel disease & dementias. MRI allows in vivo measurement of CVR but several different methods have been presented in the literature, differing in pulse sequence, hardware requirements, stimulus & image processing technique. We systematically reviewed publications measuring CVR using MRI up to June 2020, identifying 235 relevant papers. We summarised the acquisition methods, experimental parameters, hardware & CVR quantification approaches used, clinical populations investigated, & corresponding summary CVR measures. CVR was investigated in many pathologies such as steno-occlusive diseases, dementia & small vessel disease & is generally lower in patients than in healthy controls. Blood oxygen level dependent (BOLD) acquisitions with fixed inspired CO2 gas or end-tidal CO2 forcing stimulus are the most commonly used methods. General linear modelling of the MRI signal with end-tidal CO2 as the regressor is the most frequently used method to compute CVR. Our survey of CVR measurement approaches & applications will help researchers to identify good practice & provide objective information to inform the development of future consensus recommendations. Keywords Arterial spin labelling MRI Blood oxygen-level dependent Cerebrovascular reactivity Hypercapnia (CO(2)) inhalation Magnetic resonance imaging Systematic review Related links Link to paper on Frontiers in Physiology Professor Joanna Wardlaw Dr Michael Stringer Professor Ian Marshall Dr Michael Thrippleton Brain & nervous system Small vessel disease Dementia Stroke What is a MR scan? Social media tags & titles Featured paper: Cerebrovascular reactivity measurement using magnetic resonance imaging: a systematic review @FrontPhysiol @EdinUniBrainSci Publication date 02 Mar, 2021