Figure 1.

Three compartment model of an imaging voxel. Each voxel is constituted by water (blue) and fat (yellow) in different proportions. Within the water portion we identify an intracellular (IC) and an extracellular (EC) compartments. In our study we assume the extracellular sodium concentration (${\text{C}}_{\text{EC}}$) to be fixed to 140 mM, which simplifies the calculation of intracellular sodium concentration (${\text{C}}_{\text{IC}}$). TSC, total sodium concentration; ${\text{C}}_{\text{fat}}$, fat sodium concentration; ECV, extracellular volume fraction; ICV, intracellular volume fraction; WF, water fraction; ${\text{V}}_{\text{TOT}}$, total voxel volume.