Ganguly Arundhuti, Wen Zhifei, Daniel Bruce L, Butts Kim, Kee Stephen T, Rieke Viola, Do Huy M, Pelc Norbert J, Fahrig Rebecca
Department of Radiology, Stanford University, Lucas MRS Center, 1201 Pasteur Dr., Stanford, CA 94305, USA.
Acad Radiol. 2005 Sep;12(9):1167-77. doi: 10.1016/j.acra.2005.03.076.
We have installed an improved X-ray/MR (XMR) truly hybrid system with higher imaging signal-to-noise ratio (SNR) and versatility than our first prototype. In our XMR design, a fixed anode X-ray fluoroscopy system is positioned between the two donut-shaped magnetic poles of a 0.5T GE Signa-SP magnet (SP-XMR). This paper describes the methods for increased compatibility between the upgraded x-ray and MR systems that have helped improve patient management.
A GE OEC 9800 system (GE OEC Salt Lake City, UT) was specially reconfigured for permitting X-ray fluoroscopy inside the interventional magnet. A higher power X-ray tube, a new permanent tube mounting system, automatic exposure control (AEC), remote controlled collimators, choice of multiple frame rates, DICOM image compatibility, magnetically shimmed X-ray detector, X-ray compatible MR coil, and better RF shielding are the highlights of the new system. A total of 23 clinical procedures have been conducted with SP-XMR guidance of which five were performed using the new system.
The 70% increased power for fluoroscopy, and a new 6 times higher power single frame imaging mode, has improved imaging capability. The choice of multiple imaging frame rates, AEC, and collimator control allow reduction in X-ray exposure to the patient. The DICOM formatting has permitted easy transfer of clinical images over the hospital PACS network. The increased MR compatibility of the detector and the X-ray transparent MR coil has enabled faster switching between X-ray and MR imaging modes.
The improvements introduced in our SP-XMR system have further streamlined X-ray/MR hybrid imaging. Additional clinical procedures could benefit from the new SP-XMR imaging.
我们已安装了一台经过改进的X射线/磁共振（XMR）真正混合型系统，其成像信噪比（SNR）和通用性均高于我们的首个原型系统。在我们的XMR设计中，一个固定阳极X射线荧光透视系统位于一台0.5T GE Signa-SP磁体（SP-XMR）的两个环形磁极之间。本文描述了增强升级后的X射线和MR系统之间兼容性的方法，这些方法有助于改善患者管理。
对一台GE OEC 9800系统（GE OEC，盐湖城，犹他州）进行了专门重新配置，以允许在介入磁体内进行X射线荧光透视。新系统的亮点包括更高功率的X射线管、新的永久管安装系统、自动曝光控制（AEC）、遥控准直器、多种帧率选择、DICOM图像兼容性、磁屏蔽X射线探测器、X射线兼容MR线圈以及更好的射频屏蔽。在SP-XMR引导下共进行了23例临床手术，其中5例使用了新系统。
荧光透视功率提高了70%，并且新增了一种功率高6倍的单帧成像模式，成像能力得到改善。多种成像帧率选择、AEC和准直器控制可减少患者接受的X射线照射。DICOM格式允许临床图像通过医院PACS网络轻松传输。探测器与X射线透明MR线圈的MR兼容性增强，使得能够在X射线和MR成像模式之间更快切换。
我们的SP-XMR系统所做的改进进一步简化了X射线/磁共振混合成像。更多临床手术可能会受益于新的SP-XMR成像。
