Graduate Studies in Magnetic Resonance Biophysics
The Magnetic Resonance Biophysics track begins with faculty emphasis on teaching students the basic physics and mechanisms of MRI. Research directions that stem from these basics include:
- Creation of new, faster imaging techniques and hardware: Drs. James Hyde and Andrzej Jesmanowicz
- Understanding the precise interaction between basic neural events, their physiological consequences (e.g., blood oxygenation changes), and the nuclear magnetic resonance (NMR) signal: Drs. Kathleen Schmainda and Shi-Jiang Li
- Development of new mathematical and statistical models for Fourier image reconstruction and the precise quantification of activations in structure-function relationships
One emphasis of the program is on the development and application of faster imaging methods, with a principal application of mapping human brain function. This field is known as "fMRI," functional magnetic resonance imaging.
A second area of interest is quantitation of clinically relevant imaging parameters such as differential relaxation times in cancerous and normal brain tissues. Different relaxation times aid in the diagnoses of cancerous tissue.
A third emphasis is on 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, fMRI is imaging of the brain while it is functioning. For example, we ask our study subjects to perform functional-imaging tasks, or, more generally, we present stimuli to subjects and determine the structures or areas of the brain that are functioning. Functional MRI 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 is key to achieving these goals.
Facilities in the Department of Biophysics for fMRI research include a 3 Tesla GE short-bore Excite MRI system and a 3 Tesla GE long-bore Excite MRI system dedicated to research full time. Radio frequency and gradient coils can be designed and manufactured in the Biophysics electronics and machine shops. A 9.4 Tesla Bruker Biospec 94/30 USR In Vivo Spectroscopy Imaging System is housed in the Department of Biophysics for animal research. Computational facilities include several SGI workstations and a collection of Windows/Linux computers.
Magnetic Resonance Biophysics faculty are deeply involved in both the scientific application of MRI and scientific development of MRI technology.