Background suppression using Hadamard RF pulses for endovascular therapy in magnetic resonance.

摘要

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.