| This research project is part of a larger, long-term effort to develop a minimally invasive and cost effective method to ablate solid tumors using interventional MRI (iMRI) to guide and monitor therapy. A low-field, open magnet system is used to guide an ablation probe into the tumor and to monitor tissue destruction during the ablation procedure. Ablation may be produced by heating tissue from a radio frequency (RF) or laser energy source at the probe tip. Not only does MR provide tumor visualization, it can reveal the thermal lesion in various acquisition sequences (T2-weighted and T1-weighted with gadolinium contrast agent) and measure temperature changes. Potentially, these measurements can be used during clinical ablation procedures to determine tumor cell death and to minimize damage to normal surrounding tissue of critical importance. This research addresses how well these MR measurements predict the actual tissue response. In this work, we addressed this issue using animal models. We developed experimental and computer techniques to accurately register and correlate MR images with macroscopic tissue and histology images showing tissue response. To ascertain cell death or injury, we used various histological techniques. Ultimately, our goal was to quantitatively predict cell damage and death using MR image acquisition and analysis methods, and a cell death model that accounts for the tissue response from the temperature history. With this research, we established an analysis paradigm suitable for many future studies of ablation techniques, localized drug release, and other iMRI-guided therapies. |
