Ultra-low-field MRI as a tool for measuring brain development in at-risk children in LMICS: feasibility, validity and clinical relevance


Bradford, Layla ORCID: 0000-0002-5195-9081, Ringshaw, Jessica, Malaba, Thokozile, Bourke, Niall, Wedderburn, Catherine, Williams, Steven CR, Deoni, Sean, Reynolds, Helen ORCID: 0000-0001-7443-4520, Read, Jim, Read, Lucy et al (show 9 more authors) (2026) Ultra-low-field MRI as a tool for measuring brain development in at-risk children in LMICS: feasibility, validity and clinical relevance [Preprint]

Access the full-text of this item by clicking on the Open Access link.

Abstract

<h4>Background</h4> Children in low- and middle-income countries (LMICs) face an elevated risk of developmental delay, yet scalable neuroimaging tools to study early brain development in these contexts remain limited. Children who are HIV-exposed but uninfected (CHEU) represent a growing population with evidence of language and motor delays and altered brain development compared with children who are HIV-unexposed (CHU). Ultra-low-field (ULF) MRI offers a more affordable alternative to conventional high-field (HF) MRI, but its application in early childhood remains underexplored. <h4>Methods</h4> We compared brain volumes derived from ULF (64mT) and HF (3T) MRI in South African CHEU and CHU as part of the DolPHIN-2 PLUS study. Volumetric segmentation was performed using FreeSurfer v7.4.1 and SynthSeg on the Flywheel platform. Agreement between modalities was assessed using Pearson’s and Lin’s concordance correlation coefficients across global and subcortical regions. Associations between ULF-derived brain volumes and developmental outcomes, measured by the Bayley Scales of Infant Development, Third Edition, were evaluated using partial correlations adjusted for sex and age. <h4>Results</h4> Forty-five children (9 CHEU, 36 CHU; mean age 45.6 months) had paired ULF and HF scans of usable quality. Strong correlations were observed between ULF and HF volumes for global white and grey matter regions (r > 0.92) and larger subcortical grey matter structures such as the thalamus, caudate, and putamen (r = 0.86–0.89). Moderate-to-weak correlations were evident in smaller structures (hippocampus, pallidum, amygdala). ULF underestimated most grey matter volumes, and overestimated total white matter volume relative to HF. ULF-derived global and subcortical volumes were associated with receptive and expressive communication (r = 0.34–0.59, all p < 0.05). <h4>Conclusions</h4> ULF MRI produces brain volume estimates comparable to HF MRI and captures meaningful associations with early language development. These findings support ULF MRI as a feasible and scalable tool for studying neurodevelopment in vulnerable paediatric populations in LMICs.

Item Type: Preprint
Uncontrolled Keywords: 3213 Paediatrics, 32 Biomedical and Clinical Sciences, Neurosciences, Bioengineering, Behavioral and Social Science, Pediatric Research Initiative, Mental Health, Biomedical Imaging, Clinical Research
Divisions: Faculty of Health & Life Sciences
Faculty of Health & Life Sciences > Inst. Life Courses & Medical Sciences
Faculty of Health & Life Sciences > Inst. Life Courses & Medical Sciences > Inst. Life Courses & Medical Sciences (T&R staff)
Faculty of Health & Life Sciences > Inst. Life Courses & Medical Sciences > Women's & Children's Health
Faculty of Health & Life Sciences > Inst. Systems, Molec & Integrative Biology
Faculty of Health & Life Sciences > Inst. Systems, Molec & Integrative Biology > Inst. Systems, Molec & Integrative Biology (T&R Staff)
Faculty of Health & Life Sciences > Inst. Systems, Molec & Integrative Biology > SMIB Professional Services
Faculty of Health & Life Sciences > Inst. Systems, Molec & Integrative Biology > Pharmacology & Therapeutics
Depositing User: Symplectic Admin
Date Deposited: 13 Aug 2026 10:24
Last Modified: 23 Sep 2026 20:19
DOI: 10.64898/2026.06.02.26354785
Open Access URL: https://www.medrxiv.org/content/10.64898/2026.06.0...
Related Websites:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3199938
Disclaimer: The University of Liverpool is not responsible for content contained on other websites from links within repository metadata. Please contact us if you notice anything that appears incorrect or inappropriate.
Altmetric
CORE (COnnecting REpositories)