GUIDEWIRE ANTENNAS FOR MR FLUOROSCOPY

Before MRI can be used for guiding vascular interventions, the problem of dependably visualizing guidewires must be solved, ideally the posi tion and curvature of the tip of the guidewire should be visible to fa cilitate steering through the vascular system, In this paper, various antennas are described that can be incorporated into a guidewire tip, These antennas allow the guidewire to be visualized with high contrast , Computer simulation and experimental evidence are presented showing the value of adding a passive MR signal source, with a short T-1, inte rnal to the coil. The internal source increases the available signal, narrows the apparent width of the guidewire, and allows the use of fas t imaging sequences.