At the start of this track of the graduate program, the emphasis is on learning the basic physics and mechanisms of MRI. Research directions that open up from the basics include:
One emphasis is on the development and application of fast imaging methods. The principal application is to the mapping of human brain function. This field is known as FMRI: Functional Magnetic Resonance Imaging.
A second area is quantitation of clinically relevant imaging parameters such as differential relaxation times in cancerous and normal brain tissue. Different relaxation times aid in diagnoses of cancerous tissue.
Another emphasis is the development of more rigorous mathematical and statistical techniques for modeling and analyzing MRI and FMRI experiments. Fourier image reconstruction and computing of statistical activations are integral parts of MRI/FMRI.
In short, functional imaging is imaging the brain while it is functioning. We give functional imaging tasks to study participants perform or more generally present stimuli and determine the structures or areas of the brain which are functioning. FMRI does not directly measure neural activity in the brain. Instead, it measures the indirect consequences of locally increased neural activity: increased blood flow and increased blood oxygenation, both confined to the near region of the neural activation. These two physiological changes affect the NMR signal slightly (a few percent), since they change the microscopic distribution of the magnetic field in the brain. Designing improved hardware, experimental protocols, and post processing algorithms are key to achieving these goals.
Facilities for FMRI research include a 3 Tesla scanner dedicated to research, and a 1.5 Tesla scanner that is used for research about 1/2 time. RF and gradient coils can be designed and manufactured in the Biophysics electronics and machine shops. A 9.4 Tesla 40cm bore scanner will be arriving soon. Plans also include the acquisition of a new 3 Tesla scanner for neuroimaging development and studies. Computational facilities include several SGI workstations and a collection of Windows/Linux computers.
Magnetic Resonance Imaging track faculty are deeply involved in both scientific application of functional MRI and scientific development of functional MRI technology.