Less invasive surgical treatment is increasingly used because of less trauma, quicker recovery, and sometimes improved outcome. As the surgical exposure is reduced in these procedures, imaging has become increasingly important in the guidance of the procedure. While ultrasound and computed tomography can provide adequate visualization, MRI is the superior imaging modality due to its excellent soft tissue contrast. However, interventional MRI has been limited by the necessity of making each interventional device MR-safe. Since this process is frequently at odds with the functional design of the devices, the integration of magnetic resonance imaging as a common tool for intervention is severely limited. A MRI system designed to be"device-safe"would easily accommodate all the available interventional devices and eliminate one of the major bottlenecks of using MRI for the guidance of interventions. The aim of this application is to develop a robust commercial interventional MRI subsystem that will enable the application of this technology. Specifically, during Phase I of this proposal, HeartVista will demonstrate and test the feasibility of an RF-safe interventional MR interface subsystem that integrates into a commercial MR system. This subsystem will demonstrate a single transmit array element for providing safe localized excitation, a device transceiver interface demonstrating a low-power micro-coil excitation, and basic loopback control and real-time monitoring of RF safety. We expect to realize the basic infrastructure and functionality of this subsystem by the end of Phase I. Under previous NIH grant support through Stanford University and HeartVista Inc., we have established many of the systems needed for interventional MRI. These include high-fidelity real-time imaging, microcoil transceivers for real-time device tracking, and systems for parallel RF transmission. By the end of the Phase II period, we expect to provide 7 an advanced RF-safe interface to tightly monitor and control the RF deposition in the subject. 7 A state-of-the-art interventional imaging platform allowing control and data collection from a wide variety of interventional devices 7 a real-time imaging platform capable of orchestrating safety monitoring, device control, and simultaneous collection of real-time MR data. This proposal focuses on providing a"device-safe"MRI environment that will provide clinicians with the freedom to utilize the interventional devices that are most suited for the problem at hand.
Public Health Relevance: Less invasive surgical treatment is increasingly used because of less trauma, quicker recovery, and sometimes improved outcome. As the surgical exposure is reduced in these procedures, imaging has become increasingly important in the guidance of the procedure. While ultrasound and computed tomography can provide adequate visualization, MRI is the superior imaging modality due to its excellent soft tissue contrast. However, interventional MRI has been limited by the necessity of making each interventional device MR-safe. Since this process is frequently at odds with the functional design of the devices, the integration of magnetic resonance imaging as a common tool for intervention is severely limited. A MRI system designed to be"device-safe"would easily accommodate all the available interventional devices and eliminate one of the major bottlenecks of using MRI for the guidance of interventions. The aim of this application is to develop a robust commercial interventional MRI subsystem that will enable the application of this technology.
