eprintid: 1542415 rev_number: 57 eprint_status: archive userid: 608 dir: disk0/01/54/24/15 datestamp: 2017-02-23 17:06:52 lastmod: 2021-10-04 01:55:15 status_changed: 2017-10-12 09:10:06 type: article metadata_visibility: show creators_name: Hagen, CK creators_name: Diemoz, PC creators_name: Olivo, A title: On the relative performance of edge illumination x-ray phase contrast CT and conventional, attenuation-based CT ispublished: pub divisions: UCL divisions: B04 divisions: C05 divisions: F42 abstract: Purpose This article is aimed at comparing edge illumination (EI) x-ray phase contrast computed tomography (PCT) and conventional (attenuation-based) computed tomography (CT), based on their respective contrast and noise transfer. Methods The noise in raw projections obtained with EI PCT is propagated through every step of the data processing, including phase retrieval and tomographic reconstruction, leading to a description of the noise in the reconstructed phase tomograms. This is compared to the noise in corresponding attenuation tomograms obtained with CT. Specifically, a formula is derived that allows evaluating the relative performance of both modalities on the basis of their contrast-to-noise ratio (CNR), for a variety of experimental parameters. Results The noise power spectra of phase tomograms are shifted towards lower spatial frequencies, leading to a fundamentally different noise texture. The relative performance of EI PCT and CT, in terms of their CNR, is linked to spatial resolution: the CNR in phase tomograms is generally superior to that in attenuation tomograms for higher spatial resolutions (tens to hundreds of μm), but inferior for lower spatial resolutions (hundreds of μm to mm). Conclusions These results imply that EI PCT could outperform CT in applications for which high spatial resolutions are key, i.e. small animal or specimen imaging. This article is protected by copyright. All rights reserved. date: 2017-02-25 date_type: published publisher: American Association of Physicists in Medicine official_url: http://dx.doi.org/10.1002/mp.12179 oa_status: green full_text_type: other language: eng primo: open primo_central: open_green article_type_text: Article verified: verified_manual elements_id: 1209996 doi: 10.1002/mp.12179 lyricists_name: Diemoz, Paul lyricists_name: Hagen, Charlotte lyricists_name: Olivo, Alessandro lyricists_id: PCDIE01 lyricists_id: CKHAG69 lyricists_id: AOLIV86 actors_name: Bracey, Alan actors_id: ABBRA90 actors_role: owner full_text_status: public publication: Medical Physics volume: 44 number: 5 pagerange: 1876-1885 issn: 0094-2405 citation: Hagen, CK; Diemoz, PC; Olivo, A; (2017) On the relative performance of edge illumination x-ray phase contrast CT and conventional, attenuation-based CT. Medical Physics , 44 (5) pp. 1876-1885. 10.1002/mp.12179 <https://doi.org/10.1002/mp.12179>. Green open access document_url: https://discovery.ucl.ac.uk/id/eprint/1542415/1/Hagen_et_al-2017-Medical_Physics.2-10.pdf