Interactive real-time RF control for MRI transmit channels

Abstract

Cardiac catheterization is one of the heavily researched areas of the real-time interventional studies in Magnetic Resonance Imaging (MRI), where elongated conductive wires are prone to excessive radiofrequency (RF) heating and tracking of the devices might be challenging. Previous studies have proposed several techniques for heating reduction at the conductive wire tip and device visualization, using multiple transmit channels but the software platform for real-time RF control of multiple transmit channels has been missing for interventional procedures. In this study, we are presenting a software framework capable of interactive real-time RF control of MRI transmit channels and reception of dynamic images from MR image reconstruction computer. The software consists of three main programs running on three di erent operating systems (Linux, Windows and VxWorks) that communicate with each other over TCP/IP connection. Besides socket programming, multi-threading/multi-tasking is implemented for each platform along with the synchronization semaphores. The graphical user interface end is developed with Qt. Siemens' work-in-progress tip-tracking pulse sequence (BEAT IRTTT) source code is modi ed to serve as the other end in our software system. The interactive real-time experiments are conducted on a copper sulfate phantom including a conductive wire. Dual-port body coil which is a product of Siemens is used as the transmit antenna and each port is driven independently. Results have shown the feasibility of the real-time RF control in the MRI, with an e ective total update latency of two frames on the dynamic image-series. We believe this framework will contribute to real-time interventional procedures in terms of RF safety and catheter tracking.