{"id":{"repo_id":"stellenbosch","oai_identifier":"oai:scholar.sun.ac.za:10019.1/136275"},"canonical_url":"https://search.dev.ndltd.org/etd/stellenbosch/oai:scholar.sun.ac.za:10019.1/136275","repository":{"repo_id":"stellenbosch","name":"Stellenbosch University","base_url":"https://scholar.sun.ac.za/server/oai/request"},"display":{"title":"Design and Construction of a Low-Cost, Low-Field MRI System for MR Signal Acquisition","abstract":"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.","abstract_html":"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.","abstract_has_math":false,"creators":["Machtelinckx, Timon"],"institution":"Stellenbosch : Stellenbosch University","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":["Du Plessis, Stefan","Swart, Wayne"],"committee_chairs":[],"committee_members":[],"year":2026,"date_issued":"2026-03","date_published":"2026-03","updated_at":"2026-07-24T04:40:12Z","subjects":[],"languages":["en"],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://scholar.sun.ac.za/handle/10019.1/136275","outbound_label":"Repository record","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Du Plessis, Stefan","Swart, Wayne"]},{"key":"dc:contributor.other","label":"Dc Contributor Other","values":["Stellenbosch University. 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Design and Construction of a Low-Cost, Low-Field MRI System for MR Signal Acquisition. Unpublished masters thesis. Stellenbosch: Stellenbosch University [online]. Available: https://scholar.sun.ac.za/items/d2f3a468-c854-4dac-bd10-ddbe343fb84a"]},{"key":"dc:description.abstract","label":"Abstract","values":["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."]},{"key":"dc:title","label":"Title","values":["Design and Construction of a Low-Cost, Low-Field MRI System for MR Signal Acquisition"]}]}],"canonical_facts":{"dc:contributor.advisor":["Du Plessis, Stefan","Swart, Wayne"],"dc:contributor.other":["Stellenbosch University. Faculty of Engineering. Dept. of Mechanical and Mechatronic Engineering."],"dc:creator":["Machtelinckx, Timon"],"dc:date.accessioned":["2026-04-30T11:40:52Z"],"dc:date.available":["2026-04-30T11:40:52Z"],"dc:date.issued":["2026-03"],"dc:description":["Thesis (MEngSc)--Stellenbosch University, 2026.","Machtelinckx, TR. 2026. Design and Construction of a Low-Cost, Low-Field MRI System for MR Signal Acquisition. Unpublished masters thesis. Stellenbosch: Stellenbosch University [online]. 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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. 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