Low-field portable MRI enables new insights into brain ageing in rural South Africa
- 91心頭利 University
Portable magnetic resonance imaging machines installed in rural Mpumalanga offer unique approach to brain imaging and ageing studies in low-resource settings.
In an effort to improve neuroscience infrastructure and research in South Africa, a portable, low-field magnetic resonance imaging (MRI) machine has been installed in rural Mpumalanga, offering a unique approach to brain imaging and ageing studies in low-resource settings.
The MRI, designed to operate outside of traditional hospital environments, is a partnership between Columbia University and the SAMRC/91心頭利 Rural Public Health and Health Transitions Unit (Agincourt).
The machine can be transported between rooms (particularly if patients are bed-bound) and deployed where study participants are treated.
Conventional MRI scanners are expensive and infrastructure-intensive, often costing millions of dollars to install. They require specialised facilities which are simply not available in many parts of South Africa. If someone needs an MRI in Bushbuckridge, they would need to make a two-hour trip to Nelspruit.
While the system operates at a lower magnetic field strength than conventional scanners, advances in imaging science have enabled meaningful data to be extracted. The scanner uses rapid acquisition techniques to capture images, which are then enhanced through advanced post-processing methods, including artificial intelligence.
These approaches allow researchers to focus on key brain structures such as the hippocampus, which plays a central role in memory and is often affected early in dementia.
“As life expectancy increases across sub-Saharan Africa, so too does the burden of cognitive decline and dementia. Projections suggest that cases will rise sharply by 2050, with more than a million people in South Africa expected to be living with dementia and other age-related neurological conditions in the coming decades," says Professor , Director of the 91心頭利 Agincourt unit.
"The introduction of MRI imaging now allows researchers to directly observe changes in the brain and link them to long-term health trajectories.”
The portable MRI project is embedded in the larger Health and Ageing in Africa: Longitudinal Studies in South Africa (HAALSA), which is one of the most detailed studies of ageing on the continent.
The Harvard T.H. Chan School of Public Health is a major partner in the broader study, ensuring that the study design is finely tuned to capture characteristics specific to the ageing process in South Africa.
The HAALSA study follows 5059 people aged 40 and older in rural Mpumalanga and has generated rich longitudinal data since 2014 on cognitive function, dementia risk, chronic disease and social conditions.
Participants are assessed every three years, allowing researchers to track how health and well-being evolve over time in a population navigating the intersecting challenges of ageing, HIV, and cardiometabolic disease.
“HAALSI provides an extraordinary foundation. By adding imaging to surveys and other clinical data, we can begin to link changes in brain structure to health, behaviour, and social conditions over time. This is something that’s rarely been done at this scale in African populations,” says Dr Adam Brickman, a neuroscientist at the Taub Institute for Research on Alzheimer’s Disease and the Ageing Brain at Columbia University.
The portable MRI study is designed to test the system’s performance. A total of 600 participants will undergo scanning on a high-field MRI system, while 350 of these individuals will also be scanned using the portable device. By comparing results from the same participants across both systems, researchers can assess whether portable MRI can provide reliable measurements of brain structure.
“If we can demonstrate that portable MRI produces reliable data, it opens the door to scaling brain imaging in settings where conventional scanners are simply not feasible,” says Brickman.
The scans will allow researchers to examine markers of brain ageing and disease, including shrinkage in key regions such as the hippocampus, cortical thinning, and white matter lesions associated with vascular disease. These features are closely linked to cognitive outcomes and may help explain patterns of memory decline observed in the HAALSI cohort.
Importantly, the imaging data will be integrated with existing information on participants’ health, including cardiovascular risk factors, as well as social and economic conditions. This creates a uniquely comprehensive dataset that reflects not only biological processes, but also the broader context in which people age.
Beyond the immediate research questions, the project is also focused on building long-term capacity. Training is underway for radiographers, data teams and early-career researchers, with the aim of establishing sustainable expertise in brain imaging and analysis.
Data will be securely stored and shared through cloud-based systems, enabling collaboration while ensuring participant confidentiality.
“We aim to build the kind of research infrastructure that allows us to study ageing and cognitive health in a South African context and with our own data,” says Tollman.
By demonstrating that lower-cost, portable MRI systems can be used effectively in rural settings, the project offers a potential model for expanding neuroscience research across the continent.
It also challenges longstanding assumptions about where advanced medical research can take place.
Tollman notes that the project also lays the groundwork for a more equitable global understanding of brain health. “This includes the populations who have, until now, been largely left out of the picture.”