| This dissertation investigates the hypothesis that Magnetic Resonance Imaging (MRI) can provide useful morphologic and physiologic information for online guidance and monitoring of minimally invasive procedures. Several methods are pervasive in examining this hypothesis. First, all procedures are performed in standard cylindrical scanner architectures (i.e., 1.5 T MRI scanners), which provide the highest clinically-available field strengths (currently increasing to 3.0 T), the best field homogeneity, and the most advanced hardware designs. Second, local imaging coils, integrated with the interventional devices, were developed and applied to increase the signal-to-noise ratio within the tissue of interest. Third, the interventions are structured such that both standard and newly developed diagnostic imaging protocols can be used during the procedures.; In investigating this hypothesis, two application areas were explored: cardiovascular and prostate interventions. For MR-guided cardiovascular interventions, novel hardware---including a combined electrophysiology/MR-imaging catheter and an intravascular extended-sensitivity imaging antenna---were developed and applied in a series of animal studies. For MR-guided prostate interventions, systems for both transperineal and transrectal procedures were designed and applied. As part of two ongoing clinical protocols, these systems were used for MR-guided prostate biopsy, fiducial-marker placement, and high-dose-rate brachytherapy treatment. To date, ten patients with prostate cancer have been treated using the systems described and developed here. |
