Olivo, A;
Hagen, CK;
Millard, TP;
Vittoria, F;
Diemoz, PC;
Endrizzi, M;
(2014)
Simultaneous implementation of low dose and high sensitivity capabilities in differential phase contrast and dark-field imaging with laboratory x-ray sources.
Proceedings of SPIE
, 9033
, Article 90330E. 10.1117/12.2042345.
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Abstract
We present a development of the laboratory-based implementation of edge-illumination (EI) x-ray phase contrast imaging (XPCI) that simultaneously enables low-dose and high sensitivity. Lab-based EI-XPCI simplifies the set-up with respect to other methods, as it only requires two optical elements, the large pitch of which relaxes the alignment requirements. Albeit in the past it was erroneously assumed that this would reduce the sensitivity, we demonstrate quantitatively that this is not the case. We discuss a system where the pre-sample mask open fraction is smaller than 50%, and a large fraction of the created beamlets hits the apertures in the detector mask. This ensures that the majority of photons traversing the sample are detected i.e. used for image formation, optimizing dose delivery. We show that the sensitivity depends on the dimension of the part of each beamlet hitting the detector apertures, optimized in the system design. We also show that the aperture pitch does not influence the sensitivity. Compared to previous implementations, we only reduced the beamlet fraction hitting the absorbing septa on the detector mask, not the one falling inside the apertures: the same number of x-rays per second is thus detected, i.e. the dose is reduced, but not at the expense of exposure time. We also present an extension of our phase-retrieval algorithm enabling the extraction of ultra-small-angle scattering by means of only one additional frame, with all three frames acquired within dose limits imposed by e.g. clinical mammography, and easy adaptation to lab-based phase-contrast x-ray microscopy implementations.
| Type: | Article |
|---|---|
| Title: | Simultaneous implementation of low dose and high sensitivity capabilities in differential phase contrast and dark-field imaging with laboratory x-ray sources |
| Event: | Medical Imaging 2014: Physics of Medical Imaging |
| Location: | San Diego, California, US |
| Dates: | 2014-02-15 - 2014-02-20 |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1117/12.2042345 |
| Publisher version: | http://dx.doi.org/10.1117/12.2042345 |
| Language: | English |
| Additional information: | Copyright 2014 Society of Photo-Optical Instrumentation Engineers. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited. Simultaneous implementation of low dose and high sensitivity capabilities in differential phase contrast and dark-field imaging with laboratory x-ray sources ", Proc. SPIE 9033, Medical Imaging 2014: Physics of Medical Imaging, 90330E (March 19, 2014); doi:10.1117/12.2042345 |
| Keywords: | Edge illumination, Coded apertures, Phase contrast, X-ray imaging, Phase sensitivity, Dark field imaging |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science > Dept of Med Phys and Biomedical Eng |
| URI: | https://discovery.ucl.ac.uk/id/eprint/1427169 |
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