TY - JOUR
T1 - Impact of physiological factors on longitudinal structural MRI measures of the brain
AU - Zahid, Uzma
AU - Hedges, Emily P.
AU - Dimitrov, Mihail
AU - Murray, Robin M.
AU - Barker, Gareth J.
AU - Kempton, Matthew J.
N1 - Funding Information:
U Zahid was supported by funding from The Lord Leverhulme Charitable Trust , M Kempton was supported a Medical Research Council Career Development Fellowship (grant MR/J008915/1 )
Publisher Copyright:
© 2022 The Author(s)
PY - 2022/4
Y1 - 2022/4
N2 - Longitudinal MRI is used in clinical research studies to examine illness progression, neurodevelopment, and the effect of medical interventions. Such studies typically report changes in brain volume of less than 5%. However, there is a concern that these findings could be obscured or confounded by small changes in brain volume estimates caused by physiological factors such as, dehydration, blood pressure, caffeine levels, and circadian rhythm. In this study, MRI scans using the ADNI-III protocol were acquired from 20 participants (11 female) at two time points (mean interval = 20.3 days). Hydration, systolic and diastolic blood pressure, caffeine intake, and time of day were recorded at both visits. Images were processed using FreeSurfer. Three a priori hypothesised brain regions (hippocampus, lateral ventricles, and total brain) were selected, and an exploratory analysis was conducted on FreeSurfer's auto-segmented brain regions. There was no significant effect of the physiological factors on changes in the hypothesised brain regions. We provide estimates for the maximum percentage change in regional brain volumes that could be expected to occur from normal variation in each of the physiological measures. In this study, normal variations in physiological parameters did not have a detectable effect on longitudinal changes in brain volume.
AB - Longitudinal MRI is used in clinical research studies to examine illness progression, neurodevelopment, and the effect of medical interventions. Such studies typically report changes in brain volume of less than 5%. However, there is a concern that these findings could be obscured or confounded by small changes in brain volume estimates caused by physiological factors such as, dehydration, blood pressure, caffeine levels, and circadian rhythm. In this study, MRI scans using the ADNI-III protocol were acquired from 20 participants (11 female) at two time points (mean interval = 20.3 days). Hydration, systolic and diastolic blood pressure, caffeine intake, and time of day were recorded at both visits. Images were processed using FreeSurfer. Three a priori hypothesised brain regions (hippocampus, lateral ventricles, and total brain) were selected, and an exploratory analysis was conducted on FreeSurfer's auto-segmented brain regions. There was no significant effect of the physiological factors on changes in the hypothesised brain regions. We provide estimates for the maximum percentage change in regional brain volumes that could be expected to occur from normal variation in each of the physiological measures. In this study, normal variations in physiological parameters did not have a detectable effect on longitudinal changes in brain volume.
KW - Caffeine
KW - Hippocampus
KW - Hydration
KW - Lateral ventricle
KW - Longitudinal
KW - MRI
UR - http://www.scopus.com/inward/record.url?scp=85124040145&partnerID=8YFLogxK
U2 - 10.1016/j.pscychresns.2022.111446
DO - 10.1016/j.pscychresns.2022.111446
M3 - Article
AN - SCOPUS:85124040145
SN - 0925-4927
VL - 321
JO - Psychiatry Research. Neuroimaging
JF - Psychiatry Research. Neuroimaging
M1 - 111446
ER -
