Table 1.
IEC and FDA guidelines on SAR and heating in human MRI studies
| Limit | Whole-Body Average |
Heat Average |
Head, Trunk Local SAR |
Extremities Local |
|---|---|---|---|---|
| IEC (6-minute average) | ||||
| Normal (all patients) | 2 W/kg (0.5°C) | 3.2 W/kg | 10 W/kg | 20 W/kg |
| First level (supervised) | 4 W/kg (1°C) | 3.2 W/kg | 10 W/kg | 20 W/kg |
| Second level (IRB approval) | 4 W/kg (>1°C) | >3.2 W/kg | >10 W/kg | >20 W/kg |
| Localized heating limit | 39°C in 10 g | 38°C in 10 g | 40°C in 10 g | |
| FDA | 4 W/kg for 15 min |
3 W/kg for 10 min |
8 W/kg in 1g for 10 min |
12 W/kg in 1g for 5 min |