Functional magnetic resonance imaging (fMRI) continues to play a critical role in understanding the human brain. Yet current fMRI technology is far less than ideal for studying brain function due to the unnatural environment and restricting space of the magnet bore. Furthermore, fMRI cannot be performed on subjects who have metallic implants in their body (e.g., the elderly, soldiers and veterans), or who are impaired by certain physical disabilities as occurs in a variety of neurological and vestibular disorders. Finally, due to its expense and infrastructure requirements, MRI's predominant accessibility to wealthier institutions has resulted in a highly biased subject sampling and a shortage of studies in non-western environments and cultures. The general methodology used to obtain MR images today is essentially the same as that used approximately 4 decades ago. One major drawback of such methodology is that the tolerated magnetic field variation over the brain is limited to a small fraction of the magnet's field, B0. To overcome these limitations, a new MRI methodology has been conceived called STEREO, which stands for steering resonance over the object. By generating images with spatiotemporal-encoding, STEREO allows the B0 field to vary by a large amount, and for the first time, makes it possible to use a smaller, inherently less homogeneous magnet. In this project, the unique capabilities of STEREO will be exploited to demonstrate the feasibility of a portable, remotely supportable, head-only MRI scanner to permit imaging brain function in all populations and environments worldwide. To achieve this goal, this project will develop the STEREO methodology, in combination with new multi-coil gradient technology and new MRI spectrometer technology, to produce human brain images in a highly non-uniform B0. This project will also undertake a feasibility study of a new 1.5 T, high temperature superconducting magnet operating at liquid nitrogen temperature (77 K), to free the requirements for often unavailable liquid helium and/or a stable power supply for cryo-cooling. The overall objective of this grant proposal is to demonstrate the feasibility of critical new methods and technology required for this revolutionary MRI system to become a reality. A multidisciplinary team of leading experts from multiple institutions and industry will meet monthly to report and discuss progress, provide guidance, identify problems and decide corrective courses of action. Based on the experience gained in the process, our new generation MRI system will be specified and designed by the end of this 3-year project. This system will be built and tested with our next round of funding. Making this system available to neuroscientists will open exciting new territories of investigation into the human brain and human behavior, in a wide range of conditions and populations of subjects worldwide.
In this project, a new way to image human brain activity is investigated. The imaging technology is a new type of magnetic resonance imaging (MRI) that works with a small, lightweight, and portable head-only magnet. The compactness and efficiency of this imaging system makes the study of human brain possible outside the unnatural laboratory environment and in subjects who previously were excluded from getting an MRI scan.