Table 1.

MR imaging and radiation specifications between HiRes Ultra cochlear implant and off-label usage on MRIdian

Condition	Advanced Bionic HiRes Ultra MR specification	ViewRay MRIdian Linac specification
Static B0 field	1.5 T	0.35 T
Maximum spatial gradient	20 T/m	7 T/m (static gradient outside covers) 18 mT/m (dynamic gradient field strength)
Max SAR	2.0 W/kg	1.2 W/kg
Max slew rate	200 T/m/sec per axis	160 T/m/sec per axis
Duration after implantation	4 weeks after implant	N/A
Radiation maximum energy	15 MV	6 MV
Radiation maximum dose	250 Gy	N/A

Abbreviations: MR = magnetic resonance; SAR = specific absorption rate.