X-ray imaging in medicine, industry, and security can be limited by low material contrast. Our lab's focus is to develop a higher-contrast imager that acquires multiple categories of x-ray information. Our current system acquires not only the conventional transmitted radiation, but also the signature of scattered radiation versus angle, out to about 10 degrees. At a basic level this is akin to combining bright field and dark-field imaging in microscopy. X-ray pencil beams are scanned over the object, the resulting radiation distributions are recorded, and point-by-point a stack of scatter images at different angles plus a transmitted image are built.
A particular medical application is to bone mineral assessment. Conventionally, bone mineral density is measured using dual-energy radiography, which makes two transmission images using very different x-ray spectra. We have recently implemented this on our SPSxi, and thus at each image location now have both conventional and scatter information on bone. The USRA project will be to advance the system, including design and implementation of a better calibration test object for bone measurements, better processing of the scatter data, and preliminary images of grocery store animal bones.
The project will involve experiments with x rays, data capture, and especially data correction and software development. Demonstrated ability to create new scripts in Python and Matlab would be good preparation. It will be a great opportunity to learn fundamentals of radiation physics and image capture while enhancing programming skills.
Supervisor: Prof. Paul Johns, johns
physics [dot] carleton [dot] ca (johns[at]physics[dot]carleton[dot]ca)