Thermal Effects Associated with RF Exposures in Diagnostic MRI: Overview of Existing and Emerging Concepts of Protection

Table 2

Measured core temperature rise (measured at the tympanic membrane) in male volunteers as function of RF exposure at 1.5T (unpublished results, courtesy: dr Rob Kleihorst). The nominal target whole-body SAR was 4 W/kg (except for volunteer 11, where the target was 3 W/kg). Reported SAR levels are established by dosimetry, based on measured power distribution in the RF transmit chains.

Volunteer ID	Mass (kg)	Height (m)	SAR (W/kg)	Duration (s)	SA (J/kg)	(°C)	(°C)	Δ (°C)	Δ (°C)	Δ (°C)	Δ (°C)	Δ (°C)
1	76	1.76	4.24	660	2798	37.4	37.4	0.0	2.9	2.4	2.7	4.1
2	80	1.80	4.28	900	3852	36.9	37.6	0.7	1.4	1.6	2.2	3.0
3	82	1.82	4.31	900	3879	36.2	37.1	0.9	2.3	2.2	1.8	2.0
4	95	1.92	4.30	900	3870	36.5	37.4	0.9	3.7	2.7	3.3	5.7
5	90	1.70	4.24	900	3816	36.4	37.1	0.7	3.2	1.7	3.4	1.3
6	95	1.88	4.26	900	3834	36.8	37.7	0.9	4.3	2.7	4.3	2.6
7	106	1.91	4.15	900	3735	36.4	36.9	0.5	3.4	1.2	3.7	2.8
8	96	1.97	4.26	300	1278	36.9	37.0	0.1	1.8	1.2	1.9	1.3
9	74	1.82	4.20	300	1260	36.9	37.6	0.7	2.0	1.0	0.9	n.a.
10	79	1.86	4.30	900	3870	37.0	37.3	0.3	4.3	1.1	2.4	3.6
11	89	1.91	3.23	900	2907	36.0	36.6	0.6	4.3	1.8	2.4	2.8