Prism-array lenses for energy filtering in medical X-ray imaging: Physics of Medical Imaging, Pts 1-3
2007 (English)In: Medical Imaging 2007: Physics of Medical Imaging, Pts 1-3 / [ed] Hsieh, J; Flynn, MJ, BELLINGHAM: SPIE-INT SOC OPTICAL ENGINEERING , 2007, Vol. 6510, U270-U281 p.Conference paper (Refereed)
Conventional energy filters for x-ray imaging are based on absorbing materials which attenuate low energy photons, sometimes combined with an absorption edge, thus also discriminating towards 'photons of higher energies. These filters are fairly inefficient, in particular for photons of higher energies, and other methods for achieving a narrower bandwidth have been proposed. Such methods include various types of monochromators, based on for instance mosaic crystals or refractive multi-prism x-ray lenses (MPL's). Prism-array lenses (PAL's) are similar to MPL's, but are shorter, have larger apertures, and higher transmission. A PAL consists of a number of small prisms arranged in columns perpendicular to the optical axis. The column height decreases along the optical axis so that the projection of lens material is approximately linear with a Resnel phase-plate pattern superimposed on it. The focusing effect is one dimensional, and the lens is chromatic. Hence, unwanted energies can be blocked by placing a slit in the image plane of a desired energy. We present the first experimental and theoretical results on an energy filter based on a silicon PAL. The study includes an evaluation of the spectral shaping properties of the filter as well as a quantification of the achievable increase in dose efficiency compared to standard methods. Previously, PAL's have been investigated with synchrotron radiation, but in this study a medical imaging setup, based on a regular x-ray tube, is considered.
Place, publisher, year, edition, pages
BELLINGHAM: SPIE-INT SOC OPTICAL ENGINEERING , 2007. Vol. 6510, U270-U281 p.
, PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE), ISSN 0277-786X ; 6510
x-ray imaging, energy filtering, x-ray optics, prism-array lens, mammography
IdentifiersURN: urn:nbn:se:kth:diva-39417DOI: 10.1117/12.713767ISI: 000247292100027ScopusID: 2-s2.0-35148851667ISBN: 978-0-8194-6628-0OAI: oai:DiVA.org:kth-39417DiVA: diva2:440528
Conference: Medical Imaging 2007 Conference. San Diego, CA. FEB 18-20, 2007