Title: High Performance Brain Imaging with Dedicated Head-Only MRI Systems
Speaker: Thomas Foo, PhD
The Department of Medical Imaging is pleased to have Thomas Foo, PhD, presenting at our Grand Rounds on Monday, October 29th, in the College of Medicine, Room 3117, at 12:00 pm.
Dr. Foo is Chief Scientist in the Biology and Physics Technology 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 has been at GE Global Research, first leading the MRI Laboratory, and then transitioning to the role of a Chief Scientist.
He received his AB in Physics and Mathematics from Kenyon College (Gambier, OH) in 1984, and his MSc and PhD in Medical Physics from the University of Wisconsin-Madison in 1990. His areas of research include fast imaging, cardiac and vascular imaging, high performance MR systems development, and image-guided therapy.
At GE Healthcare, he led the development of the cardiac MR product as well as expanding applications in cardiovascular MRI. At GE Global Research he leads efforts developing novel high-performance, dedicated neuroimaging MRI systems, including highly efficient head gradient coils that exceed the performance of any existing clinical MRI scanner. In addition, he also has an active program in developing combined MR-ultrasound systems for image-guided intervention and therapy.
He currently holds 81 issued U.S. patents and has authored or co-authored over 110 book-chapters and peer-reviewed journal papers. He is also a GE Coolidge Fellow, was recognized as a Fellow of the International Society of Magnetic Resonance in Medicine, and a Fellow of the American Institute for Medical and Biological Engineering.
Abstract: Brain imaging has been limited to using whole-body 3.0T 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 maximum gradient amplitude. Moreover, whole-body 3.0T MRI systems require extensive infrastructure modifications to support the installation of 5-7 tons of mass, cryo-venting, and up to 60 m2of room space. This limits accessibility to advanced technology for brain imaging as there are structural costs as well as monetary impacts to placing 3.0T scanners in locations closer to patients.
We have developed a lightweight, very low-cryogen 3T MRI platform for imaging the head and also extremities that has gradient and imaging performance that exceeds any comparable clinical 3.0T system. The Compact 3.0T scanner has a two-thirds smaller footprint and does not require cryo-venting, simplifying installation. In addition, the asymmetrical head gradient coil that was developed for this project raised the peripheral nerve stimulation (PNS) threshold for this system, allowing the safe use of gradient slew rates 3.5x faster than that achievable with whole-body MRI systems. The result is a high performance (80 mT/m, 700 T/m/s) compact MRI system that is <2,100 kg, and can be installed in a 24 m2room. The substantially faster Compact 3.0T 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. Further improvement has been shown to extend the gradient technology to achieve 200 mT/m and 500 T/m/s using the same power for imaging brain circuits.
College of Medicine, Room 3117