Biological and Medical Physics
Pure and applied research in biophysics is carried out in many departments at the University of Virginia. Interdisciplinary collaborations, colloquia, and special lectures by faculty with common interests in biophysics contribute to the Biological Physics Program within the Department of Physics.
An important aspect of Prof. Cates’ research involves a new type of MRI in which a subject inhales a laser-polarized noble gas such as 3He or 129Xe which is subsequently imaged. Coinvented by Prof. Cates in the early 1990s, “hyperpolarized gas imaging” produces images of the gas space of the lungs of unprecedented resolution. Also, since Xe dissolves readily into the blood and various tissues in the body, there is potential to extend the technique to other organs. Many basic physics issues remain critical to the continuing development of hyperpolarized gas imaging.
Professor Williams designs, develops, and optimizes various medical imaging technologies. His lab is developing various types of detectors for use in mammography, including large area, high performance digital detectors which should have greater quantum efficiency and dynamic range than currently used standard screen-film systems; small, dedicated detectors for single breast imaging (scintimammography) for situations where using a full-size camera is impractical or impossible; and an integrated dual modality breast imaging system that combines the sensitivity of digital mammography with the specificity of scintimammography in a single, compact, upright unit. This detector development work is complemented by work to help evaluate the sensitivity, linearity, spatial resolution, noise properties, and detective quantum efficiency of early commerical digital breast imaging systems. In addition to their investigation of these clinical systems, Professor Williams’ lab is also developing a molecular imaging system for small animal research that permits simultaneous acquisition of high resolution functional (nuclear medicine) and structural (digital x-ray) images from mice and rats. The resulting fused image correlates the radiotracer distribution with morphological information provided by the x-ray data.