Table 1:

Comparison of the temperature changes measured using FO sensor and MRT, and the corresponding SAR values calculated from these. The SAR values calculated from the MRT measurements were averaged over ROIs placed 2 mm from the tip of the FO sensors, rather than averaged over 10 g of phantom material. The SAR_10g predicted by the 7T system and displayed on the console was 19.9 W/kg.

FO Sensor / ROI number	FiberOptic sensor measurement		MR Thermometry measurement		Difference in dT/dt (FO sensor vs. MRT)
	dT/dt [°C/min]	SAR [W/kg]	dT/dt [°C/min]	SAR [W/kg]	°C/min [95% CI]
1	0.237	14.22	0.252	15.12	−0.015 [−0.045, 0.016]
2	0.118	7.08	0.164	9.84	−0.046 [−0.056, −0.036]
3	0.020	1.20	0.039	2.34	−0.019 [−0.035, −0.003]
4	0.229	13.74	0.227	13.62	0.002 [−0.007, 0.011]