AbstractID: 7971 Title: Multienergy imaging with gas detector
A digital radiography system based on the MICROMEGAS gas microstrip detector has been used to reconstruct multiple energy images. The
prototype, acquired from Biospace Instruments, delivers a low patient dose as a result of high detection efficiency coupled with a collimation
geometry that rejects most of the diffused radiation. A fan-shaped X-ray beam sweeps across the subject and the image is reconstructed one line at a
time. We have estimated the Detection Quantum Efficiency and resolution performance of this system.
For the purpose of multienergy imaging, radiographs of the same subject at two or more average x-ray energies are acquired either by changing the
tube’s high voltage and/or using different filters. The images are then combined to extract different features such as the average Z of a tissue or to
separate bone and soft tissue images. This method allows us to see regions that would otherwise be obscured as well as to enhance the contrast of a
particular structure.
These preliminary results form part of a protocol for early detection of the diffuse calcifications in soft tissues and to evaluate bone density. In this
context, we compare the benefits of multienergy imaging over much simpler dual energy imaging. A full-scale system having two simultaneous
orthogonal detection systems will be installed shortly at our hospital.
Research supported by Biospace Instruments and the Canada Foundation for Innovation