| This research is part of a larger long-term effort to develop a minimally invasive and cost effective method to ablate solid tumors using interventional Magnetic Resonance Imaging (iMRI). Using real-time MRI guidance, an electrode is inserted into pathologic tissue and ablation occurs through radiofrequency (RF) alternating current. MRI is also utilized to evaluate the resulting lesion. For many tissue types, including muscle and liver, the characteristic lesion appearance is an ellipsoidal inner core surrounded by a hyper-intense outer margin. Understanding the relationship between the MR signal change following ablation and the cellular response can facilitate effective treatment of pathology while maximally preserving surrounding normal tissue. This study involves a detailed quantification and understanding of the MR signal as well as a histological description of tissue response. It also includes a careful means to correlate these measurements. Our quantitative approach relies on in vivo grayscale MR images as well as ex vivo color tissue sections and stained histology measurements from a rabbit thigh animal model. Analysis techniques include 3D registration, lesion geometry modeling, and deformable model segmentation techniques. Ultimately, this study will enable interventional radiologists to better predict and assay tissue response to RF ablation in terms of lesion geometry and cellular viability. |
