Design and Construction of a Low-Cost, Low-Field MRI System for MR Signal Acquisition

Low-field Magnetic Resonance Imaging (MRI) offers a cost-effective pathway to accessible medical scanning in resource-limited settings. This thesis presents the design, optimisation, and construction of a small-scale low-field MRI system for signal acquisition by making use of permanent magnets and locally sourced components. A Halbach cylinder was employed to generate the static magnetic field B0. A parallel genetic algorithm with an island model enabled efficient optimisation, yielding a simulated field strength of 50.2mT and a homogeneity of 128.73 ppmpp over a 60mm spherical volume. Manufacturing feasibility was addressed via tolerance analysis and additive manufacturing, resulting in a magnet assembly achieving an experimental field strength of 49.5mT and homogeneity of 7535 ppmpp. The system includes a complete radiofrequency chain with a solenoidal coil, software-defined radio, amplification and switching components. Spin-echo signals were successfully generated and detected with a signal-to-noise ratio of 14.39, confirming the viability of magnetic resonance signal acquisition at low field for this system. This work establishes a reproducible framework for low-field MRI development in low- and middle-income countries, providing a foundation for portable imaging, pre-clinical applications, and accessible diagnostic technology.

Grantor dc:publisher

Stellenbosch : Stellenbosch University

Year dc:date.issued

2026

Author dc:creator

• Machtelinckx, Timon

Advisors dc:contributor.advisor

• Du Plessis, Stefan
• Swart, Wayne

Language dc:language.iso

en

Repository record dc:identifier.uri

https://scholar.sun.ac.za/handle/10019.1/136275

OAI identifier oai:identifier

oai:scholar.sun.ac.za:10019.1/136275