MRS Thermometry of the Brain Using Calibration Results of Aqueous Metabolite Solutions

¹Dept. of Radiology, Uppsala University Hospital, Uppsala, Sweden; ²Dept. of Surgical Sciences, Anesthesiology and Intensive Care, Uppsala University Hospital, Uppsala, Sweden; ³Dept. of Clinical Sciences, Division of Thoracic Surgery, Lund University Hospital, Lund, Sweden; ⁴Dept. of Clinical Sciences, Division of Experimental Brain Research, Lund University Hospital, Lund, Sweden

Reliability of MRS brain temperature estimation is limited by accuracy of the calibration measurements of chemical shifts difference between water and metabolite lines. More accurate calibration data were obtained using NAA, glycerophosphocholine (GPC) and Cr aqueous solutions. Brain temperature of five healthy subjects was measured using Cho, Cr and NAA peaks. Volunteers mean brain and body (rectal) temperatures were 38.10.3 oC and 37.60.2oC, respectively. The fact that brain temperatures were 0.50.4 oC higher than body temperatures is in agreement with the literature. Calculations of the brain temperatures using Cho, Cr, and NAA references simultaneously improve reliability of the temperature estimations.