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On the relative performance of edge illumination x‐ray phase‐contrast CT and conventional, attenuation‐based CT
Author(s) -
Hagen Charlotte Klara,
Diemoz Paul Claude,
Olivo Alessandro
Publication year - 2017
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1002/mp.12179
Subject(s) - tomography , attenuation , contrast to noise ratio , noise (video) , image resolution , iterative reconstruction , image noise , phase (matter) , contrast (vision) , optics , statistical noise , physics , image quality , nuclear medicine , computer science , artificial intelligence , medicine , image (mathematics) , quantum mechanics , machine learning
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 μ m), but inferior for lower spatial resolutions (hundreds of μ m to mm). Conclusion These results imply that EI PCT could outperform CT in applications for which high spatial resolutions are key, e.g., small animal or specimen imaging.