Oral Presentation 23rd International Society of Magnetic Resonance Conference 2023

Recent years have seen an increasing interest in the development of biomedical applications of Portable NMR, driven by its portability, mobility and low cost compared to conventional MRI. We have recently reported [1] the results of the first-ever clinical trial of application of Portable NMR for quantification of Mammographic Density, an important breast cancer risk factor and biomarker of the success of failure of certain hormonal anticancer treatments. While this trial has further illustrated the great potential of Portable NMR as a clinical imaging modality, it has also identified the avenues of development required for transforming Portable NMR from an experimental technique into a robust and reliable clinical tool.

From the point of view of MR physics, a major difference between single-sided Portable NMR and conventional MRI is the lack of a true “90^o” RF pulse in the former, which is a consequence of the strong permanent magnetic field gradient. This has significant implications for the interpretation of quantitative measurements such as spin-relaxation or diffusion. We will discuss our latest findings concerning the measurement of biological tissue samples ex vivo and the implications of the inherent non-ideality of Portable NMR RF pulses for compositional imaging of tissues. We will also discuss our work on the development of phantoms emulating the composition of biological tissues, where the non-ideality of Portable NMR RF pulses has similarly produced some unexpected complications. The results demonstrate that even relatively simple Portable NMR pulse sequences can work in ways that differ from conventional MR. A more detailed understanding of these complexities is a prerequisite for the development of future clinical applications of Portable NMR.