Percent error in the apparent dose for MTP measurements at ±10% B1 error and R2 measurements at 10% error in the MAGIC gel dosimeter. The MTP data were acquired at MT power 7.92 (−10% error) and 9.68 (+10% error) μT and offset frequency 1375 Hz. The R2 data were calculated by simulation using data from figure 4. Corresponding data for the MAGIC-2 dosimeter show an expected percent error in apparent dose for R2 at 2 Gy to be approximately 217%, while the percent error for the MTP was an average of 96%. At 4 Gy, the percent error in R2 was approximately 109%, while the percent error for the MTP was an average of 54%. With a few exceptions, the data followed this trend for all offset frequencies investigated (1375, 1787, 2322 and 3018 Hz off-resonance).