1School of Cancer Sciences, University of Birmingham, Birmingham, West Midlands, United Kingdom; 2National Physical Laboratory, Middlesex, Greater London, United Kingdom; 3School of Electronic, Electrical & Computer Engineering, University of Birmingham, Birmingham, West Midlands, United Kingdom; 4Birmingham Children's Hospital NHS Foundation Trust, Birmingham, West Midlands, United Kingdom; 5Imaging & Medical Physics, University Hospitals Birmingham NHS Foundation Trust, Birmingham, West Midlands, United Kingdom
MRS can be used as a non-invasive temperature probe by measuring the chemical shift difference between water and a reference metabolite. The water chemical shift is linearly dependent on temperature, however protein and ionic concentrations may effect this dependence. Water chemical shift calibrations using accurate temperature methods were used in this study to assess the effect of ionic strength and protein strength at 3T. A recent investigation of the effects of ionic strength and a protein concentration has been performed on a 1.5T clinical scanner, vescovo et al. Temperature calibration curves were sensitive to ionic and protein concentrations. Agreement of results with Vescovo et al for similar solutions were also observed.