Integrated Magnetic Resonance Imaging Center
Leadership
Leadership
Location
Clinical Office Building
909 Walnut Street, PA 19107
The Jefferson Integrated Magnetic Resonance Imaging Center (JIMRIC) provides enterprise-wide clinical and research support for investigators involved in magnetic resonance (MR) imaging of the human brain and central nervous system (CNS), cardiac, and musculoskeletal systems. Our technical specialists provide advanced imaging consultation on MRI pulse sequence development, optimization and study protocol definition, as well as computational post-processing of MR data to create clear, useful images of relevant structures and functions.
The Center has a special interest in functional MRI (fMRI), which assesses the physiological activity of a given body-area. In the case of JIMRIC, the fMRI capacity is used to analyze neural activity, particularly in the white matter of the brain, which connects the major “processing” nodes of the cortex. Being able to have an accurate picture of an area’s functional connectivity is important in determining the location of an injury, as well as the course a neurosurgical intervention might take. When combined with a structural analysis of the brain or other organ system, fMRI offers a potent diagnostic capacity.
While imaging optimization and support of clinical activities is one arm of what we do, the development and implementation of functional imaging techniques as potential biomarkers for analyses of various pathologies is our expertise. Our experts support numerous departments across the University and Hospital, including: Radiology, Psychiatry, Psychology, Neuroscience, Neuro-Oncology, Neurology, OT/PT and Neurosurgery.
The Center is also a resource for researchers looking to develop new grants in the area of brain and spine disorders. The Center will collaborate with any departments aiming to build a robust MR imaging methodology into their research studies in testing their hypotheses, particularly in the investigation of the Central Nervous System non-invasively in humans.
Ongoing Research Projects
Our focus here is on the use of blood-oxygen-level dependent (BOLD) and diffusion-based imaging techniques for integration into the operating room as a functional roadmap for surgical planning. To accomplish this, we are developing image post-processing pipelines to facilitate the automated generation of results for areas such as motor/language mapping, in patients with brain tumors, Parkinson’s (deep brain stimulation) and epilepsy.
For years our interest has been focused on the characterization of pediatric SCI using reduced field of view DTI, which allows for the quantification of water diffusion in neurons and could serve as a potential biomarker for diagnosis. In addition we are also investigating Diffusion Kurtosis Imaging (DKI), Neurite Orientation Density Dispersion Imaging (NODDI), Magnetization transfer (MT), and Cord Atrophy using automated spinal cord sectional area measurements (SCCSA) of the human spinal cord. We have used these techniques to study the normal and injured pediatric spinal cord and are in the process of developing imaging biomarkers as an adjunct to current diagnostic methods in spinal cord injured patients. The laboratory is also working towards development of a pediatric spinal cord template and multispectral analysis of the cord. This template, essentially a composite or “average” of many MR images of the pediatric spine, will serve as a benchmark clinicians can use to diagnose SCI. We are also investigating the relationship between the integrity of the CNS and SCI patients’ clinical neurologic presentation and functional ability in adult spinal cord injured patients.
The PET-MR scanner in Villanova is among only a handful of such machines in the country and has the capacity to track function versus receptor occupancy for a variety of cognitive tasks. Our researchers are now using this device to study the mechanisms of two “integrative” approaches to managing stressful and traumatic events in cancer patients using advanced functional neuroimaging methods such as fMRI, resting state and diffusion tensor imaging (DTI).
Neuronal loss and dopamine depletion alters motor signal processing and propagation between the cortical motor areas, the basal ganglia and the thalamus, resulting in the motor manifestation of Parkinson’s disease (PD). Abnormal neural connections and activity within these circuits have been demonstrated in animal models of PD, as well as in humans suffering from movement disorders. We aim to better understand the changes in functional connectivity (FC) and anatomical connectivity (AC) that occur with disease progression, and are exploring how both FC and AC of cortico-basal-ganglia-thalamic circuits change in patients with advanced PD. Our findings to date have helped to translate our understanding of these networks from animal studies to human patients.
We believe that advanced MR imaging may reveal a useful imaging biomarker that can help to predict response to treatment in patients suffering from PD.
Blood Oxygen Level Dependent (BOLD) imaging forms the basis of functional magnetic resonance imaging (fMRI), which has great potential to identify distributed associative neural networks and reveal features of brain organization. While capable of representing brain regions synchronized by monosynaptic or polysynaptic connections, fMRI suffers from significant variability and artifacts induced by motion, patient physiology, and differences in the task being performed by the subject. Resting state fMRI (rs-fMRI) has grown in popularity over recent years because it obviates the need for specific task paradigms and has been shown to be comparable to task-based fMRI. Some may argue, however, that rs-fMRI still represents a task state – as patients are asked to passively rest or stare at a fixation point. As such, rs-fMRI is likely influenced not only by anatomical connections, but also by thought processes during this “resting task”. We ultimately do not have a clear understanding of the true resting state of the human brain. As a result, the test-retest reliability of rs-fMRI remains poor to moderate and the between-subject variation remains high. Both of these factors limit the utility of rs-fMRI for longitudinal research and in clinical applications.
Despite its potential, rs-fMRI of the brain has limited clinical utility because of its poor test-retest reliability and high between-subject variation. For these reasons, rs-fMRI must be interpreted carefully and rarely can be used decisively as a clinical tool. Its research applications are also impaired as comparisons across patients to evaluate neurological diseases as well as its ability to longitudinally follow disease progression in a single patient has been limited. We believe that this is largely attributable to the way in which rs-fMRI is currently acquired. Patients are often asked to passively rest or stare at a fixation point – but thought processes during this “resting task” cannot be controlled. Since induction and maintenance of general anesthesia generates a consistent mental state, virtually eliminates head motion, and increases our ability to control certain aspects of patient physiology, BOLD imaging and resultant rs-fMRI under these conditions is expected to be more consistent between subjects and within subjects with repeat testing. If we are able to understand the effects of volatile gaseous anesthetics (vGA) on rs-fMRI and demonstrate improved reproducibility in this setting, we will be able to significantly expand its indications for clinical neuroscience research. We expect that the pervasive use of vGA and rs-fMRI will make our findings readily generalizable, as long as protocols developed in our work are adhered to by other researchers. With a truly reliable means of measuring functional brain states, neuroscientists will be able to better understand pathophysiology, improve diagnosis, and to quantify the effect of treatment in neurological diseases such as epilepsy, Alzheimer’s disease, Parkinson’s Disease, or even with normal aging.