Truly hybrid X-ray/MR imaging: toward a streamlined clinical system

• Published in: Academic radiology Vol. 12; no. 9; p. 1167
• Main Authors: Ganguly, Arundhuti, Wen, Zhifei, Daniel, Bruce L, Butts, Kim, Kee, Stephen T, Rieke, Viola, Do, Huy M, Pelc, Norbert J, Fahrig, Rebecca
• Format: Journal Article
• Language: English
• Published: United States 01.09.2005
• Subjects: Equipment Design; Fluoroscopy - instrumentation; Humans; Magnetic Resonance Imaging - instrumentation; Phantoms, Imaging; Radiography, Interventional - instrumentation
• ISSN: 1076-6332
• 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.