Table 1.

Nitinol guidewire heating in ASTM gel phantom

	Wire + Catheter		Wire 10 cm distal to catheter		Wire only
	Measured	Theoretical	Measured	Theoretical	Measured	Theoretical
Cartesian bSSFP (flip = 60°, TR = 2.54 ms)	50.39 °C	--	5.41 °C	--	5.90 °C	--
Cartesian bSSFP (flip = 45°, TR = 2.54 ms)	27.37 °C	28.34 °C	3.10 °C	3.05 °C	3.05 °C	3.32 °C
Cartesian GRE (flip = 20°, TR = 2.86 ms)	4.31 °C	4.97 °C	0.56 °C	0.53 °C	0.65 °C	0.58 °C
Cartesian GRE (flip = 10°, TR = 2.86 ms)	1.07 °C	1.24 °C	0.14 °C	0.13 °C	0.16 °C	0.15 °C
Spiral GRE (16 interleaves, flip = 10°, TR = 5.16 ms)	0.61 °C	0.70 °C	0.09 °C	0.08 °C	0.08 °C	0.08 °C
Spiral GRE (8 interleaves, flip = 10°, TR = 8.60 ms)	0.37 °C	0.44 °C	0.03 °C	0.05 °C	0.07 °C	0.05 °C

Temperature increase from baseline observed during 2 minutes of continuous imaging in an acrylic gel phantom. Temperature was measured at the tip of the nitinol guidewire (Nitrex, Covidien, Plymouth, MN) with the guidewire collocated with the catheter, with the guidewire extended 10 cm distal to catheter and with the wire alone. Theoretical predications, based on flip angle and TR (Eqn2), of the relative heating compared to Cartesian bSSFP (flip angle = 60°) are also displayed