Non-Invasive Monitoring Of Metabolite Levels Using Novel And Adapted MR Spectroscopy Techniques

Magnetic resonance imaging (MRI) and spectroscopy (MRS) provide non-invasive modalities to explore human morphology, function and metabolism. MRS methods are in widespread use in clinical research and to some degree in clinical applications. MRS methodology has been continuously extended for the last 30 years. All extensions employing novel MR pulse sequences (acquisition software), acquisition hardware capabilities of MRI scanners or post-processing methods have to be validated in theory, and in practice, where they are first tested in vitro and then in healthy subjects. The proposed project is based on a SNF project and a Horizon 2020 project of the sponsor-investigator, where multiple methodological extensions of MRS sequences are implemented for improved measurements of metabolite levels, characteristics and maps.

The intended study uses MRI-scanners which have a Conformité Européenne (CE) label for diagnostic use. The manufacturer of the MR scanner provides a "research-license mode" with the very same hardware; however, since the flexibility of this mode of operation makes a CE process prohibitively long and complex, no CE label was aimed at for the research-license mode.

The methodological developments within the proposed study aim at novel or improved sequences, which have the potential to observe previously undetectable metabolites and to evaluate metabolite changes as function of time-of-day or previous exercise. The sequences are applied in investigations of healthy adult subjects in everyday physiological situations to document the potential of the novel methods in terms of accuracy, precision, robustness. Without such investigations on healthy subjects the methodological advances cannot be verified in a valid situation and thus not ported to more specific research trials or clinical applications.

Inclusion criteria

• signed informed consent
• healthy (no neuronal or metabolic diseases as stated by the study participant)
• able to lie still in the MR scanner for at least one hour

Exclusion criteria

• <18 yrs of age
• pregnancy or current state of lactation
• active implants
• passive ferromagnetic implants
• passive non-ferromagnetic metallic implants > 4 cm inside a region covered by the active radio-frequency (RF) coils
• large tattoos inside a region covered by the active RF coils
• known or suspected non-compliance,
• under-weight (<35 kg body weight)