Weiss Steffen, Vernickel Peter, Schaeffter Tobias, Schulz Volkmar, Gleich Bernhard
Department of Technical Systems, Philips Research Laboratories, Hamburg, Germany.
Magn Reson Med. 2005 Jul;54(1):182-9. doi: 10.1002/mrm.20543.
A new concept is proposed to improve the safety of transmission lines with respect to heating during RF transmission. It is based on the integration of transformers into the transmission line. The concept was applied to an active tracking device. Miniature transformers were designed, and two types of tracking devices were built based on a standard line and a transformer line. Temperature measurements were performed for both devices during high specific absorption rate (SAR) scanning, and the suppression of RF heating to a physiologically non-relevant level was demonstrated for the transformer device. The transmission properties of the transformer line were examined in simulations and RF measurements. Active tracking with the transformer device performed robustly in the phantom. Because of the favorable signal transmission properties of the tested device, it is expected that the concept can be applied to the construction of clinical devices for tracking and intravascular imaging, which are RF-safe under clinical SAR conditions. Since the transformer line has a large bandwidth, the concept may also be applied for RF-safe transmission of non-MR signals.
提出了一个新的概念，以提高射频传输期间传输线在发热方面的安全性。它基于将变压器集成到传输线中。该概念应用于有源跟踪设备。设计了微型变压器，并基于标准线路和变压器线路构建了两种类型的跟踪设备。在高比吸收率（SAR）扫描期间对两种设备进行了温度测量，结果表明变压器设备能够将射频加热抑制到生理无关水平。在模拟和射频测量中研究了变压器线路的传输特性。变压器设备在体模中进行的有源跟踪表现稳健。由于测试设备具有良好的信号传输特性，预计该概念可应用于临床跟踪和血管内成像设备的构建，这些设备在临床SAR条件下是射频安全的。由于变压器线路具有较大带宽，该概念也可应用于非磁共振信号的射频安全传输。
