Figure 4

Temperature distribution on guidewire during MR scan. A heating profile is obtained by moving temperature sensors within (red) and on the surface of (blue)the guidewire. The probes begin beyond the guidewire distal tip. Segment A-B indicates a 30 second baseline recording; MRI begins at B; a relative steady-state is achieved at C, when probe pullback begins. Temperature peaks correspond to physical landmarks including: D, the distal end of the solenoid coil; E, the guidewire “hotspot;” F, the proximal end of the solenoid coil; G, the inner rod-hypotube junction point; H, gel phantom entry point; H-I, air; I, hypotube-MMCX connector solder point.