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Research Highlights
In this section, a small number of projects are highlighted to provide a sample
of the broad spectrum of research interests currently supported by the MR Research Laboratory.
Neuroimaging ResearchUnderstanding Face Processing in Autism
RESEARCHERS Dr. Elizabeth Aylward and Dr. Todd Richards, Department of Radiology, are working in conjunction with Dr. Geraldine Dawson, UW Autism Center, on several studies exploring the biological basis for social cognition disabilities found in autistic patients. Prior research has suggested that these disabilities may be first evident in the failure to appropriately respond to people’s faces, a very basic aspect of social cognition. In their research, fMRI and electroencephalography (EEG) are used to explore abnormalities in the regional distribution of the brain response to faces for autistic young adults. Several hypotheses are being tested by comparing brain processing during the viewing of human faces to viewing of non-face visual stimuli to look at selective impairment of social information processing in autism. These studies also examine the neural patterns associated with face recognition in autism and are being used to determine the relationship between neural indices of brain function and behavioral tests of neuropsychological function, social cognition and behavior. Brain Metabolic and Chemical Abnormalities: Origins of Psychiatric Disease
RESEARCHERS Imbalances in neurochemicals and brain metabolism are at the root of many neuropsychiatric diseases and disorders. Dr. Stephen Dager and Dr. Seth Friedman, Department of Radiology, have developed methodology that utilizes MR imaging and spectroscopy of multiple nuclei (hydrogen-1 H, phosphorus-31P and fluorine-19F) to study brain chemistry, brain metabolite regulation and brain pharmacokinetics in adults and children with a variety of psychiatric disorders. Their research also has extended to the study of the metabolic effects of caffeine and the mechanisms involved in acute mountain sickness and respiratory regulation. To carry out this research, these investigators use RF coils built in the MR Research Laboratory specifically for these applications (for example, a fluorine coil and a decoupled, dual-tuned phosphorus-proton coil) together with laboratory-designed pulse sequences such as Proton Echo-Planar Spectroscopic Imaging (PEPSI), which is used to quantitatively measure regional brain metabolite concentrations in selected areas of the brain. Using these MR spectroscopic techniques, Dr. Dager and colleagues are currently working on several areas of neuroimaging research: Bipolar DisorderThis project, in collaboration with imaging researchers at Harvard University, is aimed at elucidating the chemical mechanisms in the brain that underlie bipolar disorder. Recent experimental findings have suggested that there are alterations in glycolytic flux in unmedicated bipolar disorder patients. These researchers are also assessing treatment response to lithium and valproic acid, two medications commonly prescribed for the disorder. They have found that the effects of mood stabilizers on brain chemistry are variable among patients.
Panic DisorderThe focus of this study is the characterization of the cellular mechanisms that underlie the phenomenon of the panic attack. Physiological manipulation (hyperventilation) is being used to study acid-base regulation in panic disorder. Advanced data acquisition at high-magnetic field (3T) is employed to study the progression of pH and lactate changes. In addition, these researchers are evaluating the effect of treatment (medication or cognitive behavioral therapy) on modulating brain respiratory regulation.Early-Onset AutismThis is a several year longitudinal research project to better understand the neurochemical and morphological alterations associated with brain development and cognitive/behavioral abnormalities in young children with autism. Initial results from a study of children between three and nine years of age suggest the presence of autism-related abnormalities in brain development by age three. For this study, the researchers are imaging children as young as 18 months of age to elucidate the time course and nature of abnormal brain developmental processes associated with autism and idiopathic developmental delay.FMRI and Women’s Sexual Health
RESEARCHERS
MR Hardware Development / RF COIL Laboratory
RESEARCHERS
Dr. Cecil Hayes, a pioneer in RF coil physics, founded the RF Coil Laboratory in 1992. With the assistance of engineers Mark Mathis, and recently Tim Wilbur, the laboratory has produced numerous custom RF coils for research and clinical projects at the UW. These include coils for high resolution imaging of the temporal lobes of the brain, the brachial plexus, peripheral nerves, the wrist, the carotid arteries, the neck, the torso, the pelvis, the heart, and for fMRI brain studies. Special coils have also been produced for our research affiliates in Seattle; Children’s and Veteran’s Administration hospitals. Experimental coils supporting high field, 4.7T and 7T scanners at the UW are also designed and supported. Current projects include a neurovascular array funded under NIH grant, and carotid four and eight channel variants for research in the United States, Europe and Asia. All coils for human studies conform to US Food and Drug Administration (FDA) and Institutional Review Board (IRB) guidelines. Several inventions, patents and applications, and commercial interests have been realized as a result of these activities. In addition to RF coil design and construction, the laboratory scientists also develop mechanical and electronic accessories that are utilized for specific experiments in the high magnet field environment of the MRI scanners. Mechanical devices that provide comfort and restrict patient movement during scanning are of particular interest because patient motion is a major cause of reduced image quality. For functional MRI studies of brain activity, sound and video devices have been built and then integrated into custom high-resolution head coils. The RF lab also provides electronic and mechanical design support for the UW MR Research Laboratory and has built devices for physiologic monitoring, stimulus response, and temperature control in the magnetic environment. Additionally, the RF Coil Lab scientists design, build, modify, and maintain the electronic hardware for the MR Research Laboratory’s 4.7T and 7T MR systems. VASCULAR IMAGING LABORATORY
Chun Yuan, PhD, Radiology MRI is a powerful tool for in vivo studies of the pathophysiology of human atherosclerosis (AS) progression. In addition to allowing for the precise assessment of AS plaque burden, MR images can be used to classify cardiovascular AS disease according to established criteria and to identify critical plaque features. In vivo MR studies in humans improve scientific understanding of cardiovascular disease mechanisms and associated risk factors and result in improved identification of high-risk stroke and heart disease in individuals as well as more appropriate clinical intervention.
The Vascular Imaging Laboratory (VIL) is comprised of a multi-disciplinary group of researchers and clinicians who are dedicated to the development of innovative MRI techniques for the analysis of cardiovascular systems. These techniques include both new acquisition strategies for obtaining images of the heart and blood vessels and post-processing strategies for extracting quantitative measurements of their form and function. The Vascular Imaging Laboratory consists of the following groups:
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Human sexuality is currently on the forefront of women’s
health issues, as sexual dysfunction may have a serious impact
on relationships and overall emotional well-being across
different life stages. Dr. Kenneth Maravilla and colleagues are utilizing
fMRI techniques to evaluate the patterns of brain activation
associated with a sexually arousing stimulus in normal female
subjects. Initially, the project is focused on identifying key
patterns of brain response and comparing them across pre- and
post-menopausal groups. By identifying the patterns
associated with female arousal, the researchers will then be
able to characterize the differences in brain activation patterns
seen in patients with neuropsychological or physiologic
impairments. The short-term applications of this research
include comparing the fMRI activation patterns pre- and
post-therapy to evaluate treatment response to new pharmacologic
measures. Ideally, this project will ultimately help to
improve understanding of the interactions between cerebral
and physical arousal in women and to develop effective
treatments for women with sexual arousal difficulties.
The quality of an image and the accuracy of the quantitative
information it contains is limited by the degree to which the
desired signal intensity exceeds the random noise that is also
present. A radio frequency (RF) receiver coil picks up both
the MR signal, which is a weak oscillating magnet field from
the rotating hydrogen nuclei in the patient, and the noise,
which is due to the random motion of charged particles in the
imaging system. The RF receiver coil is basically a sophisticated
antenna that functions as the imaging detector and is
the critical element that conveys imaging information from
the patient to the scanner. As such, its performance largely
determines the signal-to-noise ratio (SNR) in the resulting
image. High SNR can be used to reduce the time needed to
acquire an image, to see smaller features of the anatomy
(improve resolution), or to distinguish subtle variations in
image contrast due to disease. The focus of the RF Coil
Laboratory is to design RF coils that maximize signal and
minimize noise picked up when imaging a subject. Often this
improved SNR is the key requirement for making a new
diagnostic or research procedure possible.
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