On the Cutting Edge: UCSF and the Use of 7T MRI
The following was written by Sarah J. Nelson, Ph.D., Co-Chair of the Department of Bioengineering and Therapeutic Sciences, Director of the Center for Non-Invasive Imaging and Metabolomics and the Surbeck Laboratory of Advanced Imaging, and Margaret Hart Surbeck Distinguished Professor in the Department of Radiology and Biomedical Imaging
The San Francisco Veterans Affairs Medical Center is currently undergoing renovations to prepare for the addition of the 7T MRI, a state of the art imaging machine that will offer researchers a more in-depth look into the details of the brain. These researchers, led by Dr. Michael Weiner, director of the Center for Imaging of Neurodegenerative Diseases (CIND) at the San Francisco VA and professor of radiology, psychiatry, and neurology at UCSF, will be able to use this new, ultra-high resolution MRI to study and analyze biological markers that play a roll in the development of dementia, Alzheimer’s disease, post-traumatic stress disorder and other cognitive diseases and issues.
Ultra-high field MR is a rapidly developing area of advanced imaging research, with only approximately 35 7T (“T” standing for tesla) MRI machines installed throughout the world. This is not the first 7T MRI for the Department of Radiology and Biomedical Imaging at UCSF, where the focus for this powerful technology has been at the Surbeck Laboratory for Advanced Imaging, in the Institute for Quantitative Biosciences on the Mission Bay campus. The 7T whole body scanner, which was installed when the building opened in 2005, has facilitated the development of a cutting edge research program for characterizing and assessing the treatment response in human diseases. New technologies for making use of this system are being developed by Drs. Duan Xu, Xiaoliang Zhang, Dan Vigneron and Peder Larson, in conjunction with GE scientist Dr. Douglas Kelley.
The results of initial studies in patients with brain tumors, multiple sclerosis and osteoarthritis have highlighted the unique forms of contrast and high sensitivity provided by the system. One of the first applications is the use of susceptibility weighted imaging to visualize the evolution of radiation induced microbleeds in the brain. Dr. Janine Lupo and her colleagues in Neurological Surgery and Radiation Oncology, are applying the methods that she has developed to assess the relationship of radiation dose with abnormal cognitive function. This has major implications for defining treatment plans that will minimize the long term side effects of radiation in children and young adults with brain cancer.
Another application that takes advantage of high-resolution susceptibility weighted imaging technologies developed in the Surbeck Laboratory is the assessment of changes in brain morphology and vascular structures that are associated with neurological diseases. Dr. Roland Henry and colleagues in Neurology are using the 7T scanner to evaluate patients with Multiple Sclerosis, while Dr. Christopher Hess has worked with faculty in the Memory and Aging Center to obtain pilot data from patients with Alzheimer’s, Huntington’s and Prion diseases. Similar strategies are being applied by Dr. Pratik Mukherjee to evaluate the impact of traumatic brain injury (TBI) on brain structure and function.
The recent upgrade of the 7T scanner in the Surbeck Laboratory has provided Dr. Yan Li with the tools necessary to develop new metabolic imaging methods for detecting changes in biochemical function within the brain. These methods are being integrated with morphological, structural and metabolic imaging techniques in order to develop protocols for studying both neurological and psychiatric diseases. Drs. Tracy Luks and Angela Jakary are working with Dr. Stuart Eisendrath in evaluating mindfulness-based cognitive therapy (MCBT) for patients with depression, with Dr. Decartes Li to understand the effects of electroconvulsive therapy (ECT) and with Dr. Dan Mathalon to develop strategies to characterizing subjects at risk for schizophrenia.
The high sensitivity of the 7T scanner can also be applied to study changes in structural and functional properties in the musculoskeletal system. Drs. Sharmila Majumdar, Roland Krug and their colleagues have developed a number of novel imaging sequences that are being applied to evaluate changes in cartilage thickness, and degeneration of the extra cellular matrix that are associated with osteoarthritis. This heterogeneous and multifactorial disease affects a significant portion of the adult population is the second most common cause of permanent disability among subjects over the age of fifty. The increased sensitivity at 7T allows for improved spatial resolution for morphological images and for the more precise evaluation of biochemical changes that reflect changes in proteoglycans associated with degeneration. It is anticipated that the dramatic improvements in sensitivity afforded by this technology will facilitate detection of early signs of degeneration and evaluation of new therapeutic strategies.
These exciting developments, in conjunction with the applications that will be pursued using the 7T MRI being installed at the VA, will ensure that further life-saving research will be conducted at UCSF and will lead to new paradigms for clinical care.
For more information on MRI procedures in the Department of Radiology and Biomedical Imaging, please see here.