Memis Omer Gokalp, Eryaman Yigitcan, Aytur Orhan, Atalar Ergin
Bilkent University, Department of Electrical and Electronics Engineering, Ankara, Turkey.
Magn Reson Med. 2008 Jan;59(1):165-73. doi: 10.1002/mrm.21462.
Conventional MRI instruments transmit received MRI signals through electrical cables. Although this design has proved to be effective over the years, we report a fiber-optic system that addresses the needs of recent developments in MRI technology. One of these technologies is phased array coils with a high number of elements, where total size of interconnections is a primary problem, and other problem is internal MRI coils, where there is a need for improvements in safety. The Miniature Fiber-Optic Transmission (FOT) System was developed to address these issues. The system consists of a receiver coil with active detuning, a low-noise preamplifier, and a laser diode connected to a photodetector with fiber-optic cabling. The overall noise figure of the system is lower than 1 dB. Total power consumption is 50 mW, and the device is switchable with another fiber-optic line, which can also control active detuning. A prototype device was tested in a GE 1.5 Tesla MRI scanner, and several images were acquired with a signal to noise ratio similar to coaxial cabling. We believe that this design will reduce the cabling problems of arrays and enable placement of internal coils into body cavities with no safety hazard to the patient, such as electrical shock or burns.
传统的磁共振成像（MRI）仪器通过电缆传输和接收MRI信号。尽管多年来这种设计已被证明是有效的，但我们报告了一种光纤系统，该系统满足了MRI技术最新发展的需求。这些技术之一是具有大量元件的相控阵线圈，其中互连的总体尺寸是一个主要问题，另一个问题是内部MRI线圈，需要在安全性方面进行改进。微型光纤传输（FOT）系统就是为解决这些问题而开发的。该系统由一个带有有源失谐的接收线圈、一个低噪声前置放大器以及一个通过光纤电缆连接到光电探测器的激光二极管组成。该系统的整体噪声系数低于1 dB。总功耗为50 mW，并且该设备可与另一条光纤线路切换，该线路还可以控制有源失谐。一个原型设备在通用电气1.5特斯拉MRI扫描仪中进行了测试，并采集了几张图像，其信噪比与同轴电缆相似。我们相信这种设计将减少阵列的布线问题，并能够将内部线圈放置在体腔内，而不会对患者造成电击或烧伤等安全危害。
