Mobility-weighted Effective Extracellular Ion Concentration Imaging using MRI

Motivation: Extracellular fluid within the brain is complex electrolyte comprising various ions. Disturbances in the balance of electrolytes have been associated with various pathological disorders. Goal(s): The study aimed to provide quantitative visualization of mobility-weighted effective extracellular ion concentration at every pixel. Approach: Three phantom experiments were conducted using CTI, precisely controlling ion concentrations, mobilities and cell-alike phantom validation. Results: The measured values of ion concentrations in three phantoms were comparable to the intended values, demonstrating accuracy. The conductivity tensor imaging method could extract the contribution of ionic concentration and mobility in measured conductivity information. Impact: We proposed a method to derive the mobility-weighted effective extracellular ion concentration using conductivity tensor imaging (CTI). Ionizing radiation significantly alters the concentration of ions in tissues. Understanding cellular-level ion concentrations is critical for optimizing the effectiveness of radiation therapy.