A representative in vivo temperature recording during manual pullback. The flip angle is increased to 90°; SAR, 3.96 W/kg to exaggerate heating. A temperature baseline is obtained before scanning begins. Scanning generates a small temperature rise. After a further interval, the guidewire is withdrawn from the aortic arch during bSSFP MRI. Noteworthy heating was observed just as the guidewire tip entered the tip of the vascular introducer sheath at an insertion length of 14 cm.