Table 3.
Temperature Changes During MRI Sequence(3D‐GRE) Performed Using 7 T Field
| Spinal Implant | RF‐Radiation‐Induced Heating (7 T) 3D‐bGRE (15 min) | ||||||
|---|---|---|---|---|---|---|---|
| Material | Length (cm) | Weight (g) | Implant (Δ°C) | CTRL‐l (Δ°C) | Diff‐1 (°C) | CTRL‐2 (Δ°C) | Diff‐2 (°C) |
| Rod | |||||||
| Pure titanium | 5 | 5.5 | 0.7 | 0.4 | 0.3 | 0.5 | 0.2 |
| 10 | 10.8 | 0.7 | 0.8 | −0.1 | 0.5 | 0.2 | |
| 15 | 16.2 | 0.6 | 0.8 | −0.2 | 0.9 | −0.3 | |
| 20 | 21.6 | 0.7 | 0.7 | 0 | 0.8 | −0.1 | |
| 20, cross‐linked | 66.0 | 0.6 | 0.6 | 0 | 0.3 | 0.3 | |
| Titanium alloy | 5 | 5.3 | 1.0 | 0.6 | 0.4 | 0.5 | 0.5 |
| 10 | 10.6 | 0.7 | 0.7 | 0 | 0.8 | −0.1 | |
| 15 | 15.9 | 0.7 | 0.7 | 0 | 0.6 | 0.1 | |
| 20 | 21.1 | 0.6 | 0.8 | −0.2 | 0.7 | −0.1 | |
| 20, cross‐linked | 65.0 | 0.7 | 0.6 | 0.1 | 0.8 | −0.1 | |
| Cobalt–chrome | 5 | 9.9 | 1.0 | 0.9 | 0.1 | 0.5 | 0.5 |
| 10 | 19.9 | 0.7 | 0.4 | 0.3 | 0.8 | −0.1 | |
| 15 | 29.8 | 0.8 | 0.4 | 0.4 | 0.9 | −0.1 | |
| 20 | 39.9 | 0.8 | 0.5 | 0.3 | 0.5 | 0.3 | |
| 20, cross‐linked | 102.6 | 0.6 | 0.8 | −0.2 | 0.4 | 0.2 | |
| Range (median) | 5–20 (12.5) | 5.5–102.6 (19.9) | 0.6–1.0 (0.7) | 0.4–0.9 (0.7) | −0.2 to 0.4 (0) | 0.3–0.9 (0.6) | −0.3 to 0.5 (0.1) |
| Screw | |||||||
| Titanium alloy/cobalt–chrome | 5.8 | 12.1 | 0.7 | 0.8 | −0.1 | 0.8 | −0.1 |
| Cross‐linking bridge | |||||||
| Titanium alloy | 5.2 | 11.4 | 0.6 | 0.7 | −0.1 | 0.7 | −0.1 |
CTRL‐1, change in temperature 5 cm away from implant; CTRL‐2, change in temperature after implant removal; Diff‐1, difference of implant from CTRL‐1; Diff‐2, difference of implant from CTRL‐2; Implant, change in temperature of implant.