Open-Source Multinuclear Low-Field Preclinical MRI Scanner.

Abstract

Low-field MRI (B₀ ≤ 0.2 T) is emerging as a technology with the potential to revolutionize clinical diagnostics and patient monitoring. The reduction in magnetic field strength comes along with a decrease in the cost of the scanners and the infrastructure required for their operation. This, in turn, enables the development of compact, portable systems that extend imaging capabilities to locations and scenarios that were previously inaccessible. This democratization has empowered research groups worldwide to design and build their own scanners, resulting in a surge of new devices. However, the majority of low-field scanners are optimized for human studies, which limits their application in preclinical research and constrains the testing and development of contrast agents tailored for low-field regimes. In particular, hyperpolarized agents hold considerable promise for low-field MRI due to their capacity to enhance signal and provide metabolic imaging of living systems. This signal enhancement counteracts the inherently low signal-to-noise ratio of thermally polarized studies, which is the main limitation of low-field MRI. To exploit this potential, hyperpolarization studies frequently require the detection of X-nuclei, such as ¹³C and ¹⁵N, thereby emphasizing the need for versatile, multinuclear preclinical scanners. In this study, we present an open-source multinuclear low-field MRI scanner that has been specifically designed for hyperpolarized preclinical research. The device operates at 66 mT and allows the detection of ¹H, ²³Na, ¹³C, and ¹⁵N nuclei. Comprehensive documentation and complete CAD designs are provided to facilitate replication and adaptation by the research community. To illustrate the performance of the system, the results of the acquisition of NMR spectra from each nucleus are presented, as well as the first images obtained with the scanner. This platform aims to bridge the gap in preclinical low-field MRI, enabling rigorous in vivo testing of novel contrast agents and supporting broader innovation in the field.