Fig. 4

Temperature increase observed in an acrylic gel phantom during 2 minutes of continuous scanning (scanning period indicated by vertical black lines). Temperature is measured at the tip of the nitinol guidewire for the guidewire and catheter co-located (a), guidewire extended 10 cm distal to catheter (b) and guidewire alone (c). Right-hand plots show reduced temperature scale (−0.2 °C to 1.2 °C ) to demonstrate subtle heating during GRE imaging