Deep brain stimulation temperature measurements
| Sequence | SAR (W/kg) | Temperature (°C) | ΔTmean (°C) | ΔTmax (°C) | P < .01 | ||
|---|---|---|---|---|---|---|---|
| Local | Whole Body | Baseline | Imaging | ||||
| Standardized sequence | |||||||
| FSE SS | 7.13 | 0.24 | 24.8 ± 0.1 | 30.5 ± 0.1 | 5.7 | 5.8 | * |
| FSE SS | 3.87 | 0.13 | 24.6 ± 0.2 | 28.2 ± 0.1 | 3.6 | 3.7 | * |
| FSE SS | 2.10 | 0.07 | 24.4 ± 0.1 | 26.1 ± 0.1 | 1.7 | 2.3 | * |
| FSE SS | 1.12 | 0.04 | 24.9 ± 0.1 | 25.8 ± 0.2 | 0.9 | 1.3 | * |
| FSE MS | 7.26 | 0.24 | 24.8 ± 0.1 | 31.3 ± 0.1 | 6.5 | 6.7 | * |
| FSE MS | 2.17 | 0.07 | 24.8 ± 0.1 | 26.6 ± 0.1 | 1.8 | 2.0 | * |
| FSE MS | 0.50 | 0.02 | 24.1 ± 0.1 | 24.2 ± 0.1 | 0.1 | 0.3 | |
| Clinical sequences | |||||||
| EPI | 0.14 | 0.00 | 23.7 ± 0.1 | 23.9 ± 0.1 | 0.2 | 0.3 | |
| MPRAGE | 0.36 | 0.01 | 23.3 ± 0.1 | 23.4 ± 0.1 | 0.1 | 0.2 | |
| QMT | 3.44 | 0.11 | 23.8 ± 0.1 | 24.8 ± 0.1 | 1.0 | 1.5 | * |
| MT MRA | 4.28 | 0.14 | 24.2 ± 0.1 | 25.8 ± 0.1 | 1.6 | 1.8 | * |
Note.—SAR indicates specific absorption rate; ΔTmean, mean temperature increase; ΔTmax, maximum observed temperature increase; FSE, fast spin-echo; SS, single section; MS, multisection; EPI, echo-planar imaging; MPRAGE, magnetization prepared rapid acquisition gradient-echo; QMT, quantitative magnetization transfer; MT MRA, magnetization transfer-suppressed MR angiography. Baseline temperature is the mean ± 1 SD of 12 consecutive measurements (1 min of data) at ambient conditions before the start of the MR imaging sequence. Imaging temperature is the mean ± 1 SD of 12 consecutive measurements (1 min of data) obtained during 10 to 15 min of continuous imaging, encompassing the time of the maximum observed temperature increase. For all measurements, the background reference temperature increase was <0.5°C.