To develop a method for noninvasive T2-based thermometry that enables estimation of the in vivo temperature in adipose tissues at both 1.5T and 3T field strengths.Materials and Methods:
A total of 27 apparent T2-temperature measurement sets were performed on 13 human abdominal adipose tissue samples using an inversion prepared dual-echo single-slice sequence for apparent T2 estimation. The measurements were performed on Ingenia 1.5T and 3.0T scanners and Achieva 1.5T and 3.0T scanners. The apparent T2-values were measured at 4°C temperature intervals during heating from 21 to 45°C and cooling to 21°C. A two-parameter exponential fit was used to estimate the apparent T2 to temperature dependency on a scanner-to-scanner basis.Results:
In the temperature range evaluated (21–45°C), the apparent T2 relaxation times increased from an average of ˜100 msec to 190 msec at 1.5T and an average of ˜130 msec to 220 msec at 3T. The measured T2-relaxation times followed the calibration curve with a median absolute error of 0.37°C and maximum error of 1.7°C in 12 of the 13 samples, with the outlier having a notably different appearance upon visual inspection prior to measurement.Conclusion:
Changes in apparent T2 relaxation time has the potential to be used for accurately estimating local temperature within in vivo subcutaneous fat. J. Magn. Reson. Imaging 2016;43:1171–1178.