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Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Compensatory increase in oxygen extraction fraction is associated with age-related cerebrovascular disease
AU - McFadden, J.
AU - Matthews, J.
AU - Scott, L.
AU - Herholz, K.
AU - Dickie, B.
AU - Haroon, H.
AU - Sparasci, O.
AU - Ahmed, S.
AU - Kyrtata, N.
AU - Parker, G.J.M.
AU - Emsley, H.C.A.
AU - Handley, J.
AU - Lohezic, M.
AU - Parkes, L.M.
PY - 2025/2/28
Y1 - 2025/2/28
N2 - Cerebrovascular disease is an important contributor to dementia with reductions in cerebral blood flow (CBF) potentially compromising oxygen supply. In early stages, reduced CBF may be associated with a compensatory increase in oxygen extraction fraction (OEF) to maintain the cerebral metabolic rate of oxygen consumption (CMRO2). We used a simultaneous PET-MRI protocol to measure OEF, CBF, CMRO2, and arterial transit time (ATT) in elderly people (n = 24, age 69.6 ± 5.3 years) with a range of vascular disease risk (QRisk 18.7 ± 10.8 %) and cognitive abilities (MoCA scores 26.7 ± 3.4) to determine if a) vascular disease risk (parameterised with QRisk2 score) is associated with altered CBF, ATT, OEF and CMRO2, b) if impaired blood supply and increasing transit times are associated with elevated OEF and c) if these physiological measures are associated with impaired cognition. ATT rose by 132 ms per 10 point increase in QRisk and there was a trend for reduced CBF. Compensatory increases in OEF occurred in association with modified ATT and CBF, preserving CMRO2. There was no regional variation to these relationships. Cognitive impairment was associated with prolonged ATT. These findings demonstrate the potential use of multi-delay time ASL and Quantitative Susceptibility Mapping for the early detection of cerebrovascular changes and provide evidence for compensatory increases in oxygen extraction in the presence of reduced blood flow. © 2025 The Authors
AB - Cerebrovascular disease is an important contributor to dementia with reductions in cerebral blood flow (CBF) potentially compromising oxygen supply. In early stages, reduced CBF may be associated with a compensatory increase in oxygen extraction fraction (OEF) to maintain the cerebral metabolic rate of oxygen consumption (CMRO2). We used a simultaneous PET-MRI protocol to measure OEF, CBF, CMRO2, and arterial transit time (ATT) in elderly people (n = 24, age 69.6 ± 5.3 years) with a range of vascular disease risk (QRisk 18.7 ± 10.8 %) and cognitive abilities (MoCA scores 26.7 ± 3.4) to determine if a) vascular disease risk (parameterised with QRisk2 score) is associated with altered CBF, ATT, OEF and CMRO2, b) if impaired blood supply and increasing transit times are associated with elevated OEF and c) if these physiological measures are associated with impaired cognition. ATT rose by 132 ms per 10 point increase in QRisk and there was a trend for reduced CBF. Compensatory increases in OEF occurred in association with modified ATT and CBF, preserving CMRO2. There was no regional variation to these relationships. Cognitive impairment was associated with prolonged ATT. These findings demonstrate the potential use of multi-delay time ASL and Quantitative Susceptibility Mapping for the early detection of cerebrovascular changes and provide evidence for compensatory increases in oxygen extraction in the presence of reduced blood flow. © 2025 The Authors
KW - CBF
KW - Cerebrovascular disease
KW - Cognitive impairment
KW - Multi-PLD ASL
KW - OEF
KW - QSM
KW - amyloid
KW - flutemetamol f 18
KW - adult
KW - age
KW - aged
KW - arterial transit time
KW - Article
KW - brain blood flow
KW - cerebral metabolic rate of oxygen
KW - cerebrovascular disease
KW - cognition
KW - cognitive defect
KW - controlled study
KW - disease association
KW - female
KW - fluid-attenuated inversion recovery imaging
KW - human
KW - major clinical study
KW - male
KW - Montreal cognitive assessment
KW - nuclear magnetic resonance imaging
KW - oxygen extraction fraction
KW - oxygen saturation
KW - oxygen supply
KW - physiological process
KW - positron emission tomography
KW - QRISK score
KW - risk assessment
KW - risk factor
KW - vascular disease
KW - vascularization
U2 - 10.1016/j.nicl.2025.103746
DO - 10.1016/j.nicl.2025.103746
M3 - Journal article
VL - 45
JO - NeuroImage: Clinical
JF - NeuroImage: Clinical
SN - 2213-1582
M1 - 103746
ER -