Sodium MRI of Fish on 0.5T Clinical Scanner

Sodium (23Na) magnetic resonance imaging (MRI) provides information about intra- and intercellular processes useful for medical diagnostics, such as Huntington’s disease, diabetes, etc. 23Na MRI is also used for technological applications such as the analysis of salt content in food products and the assessment of their characteristics using relaxation measurements. Due to 3–4 order difference in the MRI sensitivity for proton and sodium detection, 23Na MRI is usually performed using high-field MRI scanners. Current study explores feasibility of 23Na MRI at the low field 0.5T clinical scanner using different fish species. Using the 3D gradient echo method with the parameters: repetition time = 44.7 ms, echo time = 12 ms, and flip angle = 75°, 23Na MRI of euthanized and thawed fish of different orders (according to biological classification) with an isotropic resolution of 6 mm were obtained. For the assignment of anatomical structures of fish, proton images with an isotropic resolution of 2 mm were also obtained, and combined 1H and 23Na images were constructed. The analysis of the obtained images, including anatomical aspects, has been carried out. Using 23Na nuclear magnetic resonance spectroscopy methods, the rate of sodium excretion was assessed for typical methods of fish conservation for their subsequent use as anatomical specimens and exhibits in museums and scientific laboratories. The results of this work can be used to assess the potential of low-field multinuclear MRI, in biology, and technological (non-medical) applications, particularly, in the analysis of food and the development of methods for preservation of living tissues.