UW Radiology

Imaging Research in Progress Lecture – Thomas Foo, Ph.D. – Abstract and Brief Biographical Statement

Biographical Statement

Thomas_Foo

Thomas Foo is Chief Scientist in the Diagnostics and Biomedical Technologies group at GE Global Research.  He has been with GE since 1989 when he joined the Applied Science Laboratory at GE Healthcare.  Since 2005, he as been at GE Global Research, leading the MRI Laboratory until 2011.  Tom received his A.B. in Physics and Mathematics from Kenyon College (Gambier, OH) in 1984, and his Ph.D. in Medical Physics from the University of Wisconsin-Madison in 1990. His areas of research include fast imaging, cardiac and vascular imaging, and high performance MR systems development.  While at GE Healthcare, he helped develop new acquisition techniques in fast gradient-recalled echo imaging, contrast-enhanced MR Angiography, coronary artery imaging, and the assessment of myocardial infarction.  He also led the cardiac technology development team until 2005 when he transitioned to GE Global Research where he leads an effort developing a novel high-performance, dedicated neuroimaging MRI systems, including novel and high performance head gradient systems that exceed the performance of any existing clinical MRI scanner. He currently holds 76 issued U.S. patents and has authored or co-authored over 100 book-chapters and peer-reviewed journal papers. He is also a GE Coolidge Fellow and was recognized as a Fellow of the International Society of Magnetic Resonance in Medicine.

 

 

 

 

 

 

 

Abstract

Brain imaging has been limited to using whole-body 3T MRI systems that have an upper limit of gradient performance due to peripheral nerve stimulation (PNS) and also a practical limit as to the peak power needed to drive gradient amplitude. Moreover, whole-body 3T MRI systems require extensive infrastructure modifications to support the installation of 5-7 tons of mass, cryo-venting, and up to 60 m2 of room space. This limits accessibility to advanced technology for brain imaging as there are structural costs as well as monetary impacts to placing 3T scanners in locations closer to patients.

Our approach to advancing brain imaging is to develop a lightweight, low-cryogen 3T MRI platform that is compact but yet has the gradient performance that exceeds any comparable clinical 3T system. The Compact 3T scanner that has been developed has a significantly smaller footprint and does not require cryo-venting, simplifying installation. In addition, the dedicated head gradient coil that was developed for this project allows the use of slew rates 3.5x faster than that achievable with whole-body MRI systems.  This is due to the much higher PNS threshold for the smaller gradient coil.  The result is a high performance (85 mT/m, 700 T/m/s) compact MRI system that is <2,100 kg, and can be installed in a 24 m2 room.  The substantially faster Compact 3T MRI system has vastly improved image quality for anatomical imaging as well as for diffusion and fMRI applications. The 700 T/m/s slew rate reduces sequence TR in gradient echo pulse sequences as well as the echo spacing in Fast Spin Echo and Echo Planar Imaging. With up to 50% reduction in echo spacing, spatial distortion, image blurring, and signal loss is substantially reduced, allowing for higher spatial resolution and higher image SNR.