New Assistive devices for MR-guided microwave thermocoagulation of liver tumors

Rationale and Objectives. The purpose of this study was to develop and test new assistive devices to aid in the performance of safe, easy, and accurate microwave thermocoagulation therapy guided by magnetic resonance (MR) imaging. Materials and Methods. An open-configuration MR imager with an optical tracking system for image plane control and a microwave coagulator operating at 2.45 GHz were used. Liver tumors were percutaneously punctured under the guidance of MR images and ablated. Handpiece adapters were then prepared for the optical tracking system. An MR-compatible endoscopic system also was used. Navigation software was installed and customized. These devices were combined to provide near-real-time MR image-guided navigation during thermocoagulation therapy for liver tumors. Results. The handpiece adapters improved the flexibility of approaches for percutaneous puncture of tumors. The MR-compatible endoscope was used as a thoracoscope, and tumors just below the diaphragm were safely and easily punctured through the diaphragm. The customized navigation software displayed near-real-time MR images together with two reformatted images (on the same plane and on a perpendicular plane) from the registered high-resolution three-dimensional data. enabling, accurate MR imaging navigation. Conclusion. These new assistive devices made it easier to perform safe, easy, and accurate MR-guided thermocoagulation therapy of liver tumors.