Figure 1.

Brain temperature can be non-invasively derived from volumetric magnetic resonance spectroscopic imaging (MRSI) data by calculating the frequency difference between the temperature-sensitive water peak and one or more metabolite peaks that are temperature-insensitive (left^*). When using creatine as the reference, voxel-level brain temperature can be calculated according to the following equation: T_CRE = −102.61(Δ_H20−CRE) + 206.1°C, Δ_H20−CRE = chemical shift difference between the creatine and water resonances. Example T_CRE calculations are provided for a participant's single tissue slice (right). Representative spectra illustrate Δ_H20−CRE derivations, with plots depicting a water-suppressed metabolite spectrum (red line), with an overlay that indicates the location of the reference water signal (blue line). Spectral plots were created within the Metabolite Imaging and Data Analysis System (MIDAS) software package, and the figure was created using BioRender. ^*Adapted from Dehkharghani et al. (2015).