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.
In the MR Biophysics track, students will take the following courses in the first two years of entering the program:
Instrumentation: Magnetic Resonance Imaging
Nuclear Magnetic Resonance
Magnetic Resonance Imaging
Functional MRI Contrast Mechanisms and Applications
Functional MRI Journal Club
During a student's first two years, each semester consists of one course in biophysics, one in neuroscience, and one in a related area to compliment his or her strengths and interests. This allows students to gain experience in both technical and applied areas. Since students are supported as described below, their time is not occupied by teaching requirements, and they will get involved with a research area under the direction of a faculty member. Students typically coauthor several refereed journal publications prior to graduation. Directed studies and research courses are available to students, as are classes at two area universities: Marquette University and the University of Wisconsin-Milwaukee. An oral dissertation proposal defense, in addition to a written comprehensive qualifying exam, is expected to be completed by the end of the third year or at the beginning of the student's fourth year in the program. A final dissertation defense is expected to occur by the fifth year of study.