Figure 2

In vitro temperature measurement at the tip of an insulated nitinol rod. Cartesian imaging (flip angle = 45°, TE/TR =1.27/2.54 ms) generated 37.2°C of heating (a) and spiral imaging (flip angle = 10°, TE/TR = 0.86/10 ms) generated 0.47°C of heating (b) during 1 minute of continuous scanning.