| Reliable visualization of catheter is essential during MR-guided endovascular procedures. In this work, I propose a reliable approach for passive catheter visualization. Passive catheter visualization depends on the optimal concentration of MR contrast agent (Gd-DTPA) and the background suppression. I determined the optimal concentration of Gd-DTPA to maximize signal from catheter via experiments. Further, I propose using Hadamard (HD) pulses to suppress background signal. The Hadamard pulses were evaluated through simulations and through in vitro experiments. For simulations, a heterogeneous tissue model that mimics real tissue was proposed. For in vitro experiments, the Hadamard pulses were implemented on the 3 T MR scanner. In simulations and experiments the HD method had improved catheter signal ratio compared to the unsuppressed images for realistic heterogeneous (p < 0.05) in vitro backgrounds. The findings of this work show that HD profiles can be considered as a robust and reliable approach in endovascular MR. |
