For more than four decades, magnetic resonance imaging (MRI) has been using magnetic properties of hydrogen protons to provide images of anatomy, physiology and biochemistry of human body. Contrary to the early expectation of MRI, it did not evolve into a tool that would allow investigation into the causation of diseases and disorders. In 1998, construction of the 8 Tesla MRI scanner gave birth to ultra high field (UHF) technology which quickly was adopted by manufacturers who offered commercial 7 Tesla scanners. Today, more than 50 institutions around the world have installed UHF MRI scanners. Research on these scanners has proven that this powerful technology could finally offer sensitivity and specificity for various pathologies and provide insight to the inner working of complex physiological functions such as the human mind. To harness the great potential of UHF MRI, many different aspects of MR scanners needed to be re-examined and re-engineered. The science, engineering and safety of these new MR imagers were critical issues, which had to be developed in parallel to make them viable imagers of human subjects. In this presentation, an account will be given of some of the technical developments for UHF MRI technology such as RF coil design, susceptibility, safety, complex excitation and reconstruction schemes which were necessary to build such scanners. In addition, a closer look at the potentials of these scanners to go beyond imaging of body parts and become an organ-specific, tissue-specific, and ultimately a tool for cellular and molecular imaging. A brief discussion will also be made about UHF MRI applications and their associated perils and payoffs in the clinical settings. In this context, the new development which will primarily benefit UHF MRI like simultaneous multislice technology, compress sensing, parallel transmit and receive, and dynamic B0 shimming will be presented along with some of the studies of multiple sclerosis, stroke, and brain tumors at 8 Tesla.
BIOGRAPHY
Alayar Kangarlu began his undergraduate study in Physics at Sharif University of Technology in Tehran. He continued his education in the US and completed a BS degree in1981. He pursued his training by acquiring a masters degree and PhD in Physics in 1987. He moved to Ohio as an assistant professor of physics at the University of Dayton after which he moved to Ohio State University in 1995 where he began work in the MRI research group at the department of radiology. His group built an 8 Tesla whole body system in 1998, the highest field MRI scanner in the world. He published some seminal papers on many ultra high field topics such as safety, dielectric resonances, RF coils, and applications of 8T MRI to multiple sclerosis, stoke, and cancer. Dr Kangarlu was recruited by Columbia University and New York State Psychiatric Institute in 2004 where he has been since. At Columbia, he leads the MRI Physics group where he focuses on technical development of MRI in neuroscience and psychiatric disorders. He is currently pursuing development of MRS and fMRI techniques for understanding of brain networks to be used in etiology of depression and other psychiatric disorders.