| Autor: |
Alloo SJ, Paganin DM, Morgan KS, Gureyev TE, Mayo SC, Mohammadi S, Lockie D, Menk RH, Arfelli F, Zanconati F, Tromba G, Pavlov KM |
| Jazyk: |
angličtina |
| Zdroj: |
Optics letters [Opt Lett] 2022 Apr 15; Vol. 47 (8), pp. 1945-1948. |
| DOI: |
10.1364/OL.445802 |
| Abstrakt: |
Propagation-based phase-contrast x-ray imaging (PB-PCXI) generates image contrast by utilizing sample-imposed phase-shifts. This has proven useful when imaging weakly attenuating samples, as conventional attenuation-based imaging does not always provide adequate contrast. We present a PB-PCXI algorithm capable of extracting the x-ray attenuation β and refraction δ, components of the complex refractive index of distinct materials within an unknown sample. The method involves curve fitting an error-function-based model to a phase-retrieved interface in a PB-PCXI tomographic reconstruction, which is obtained when Paganin-type phase retrieval is applied with incorrect values of δ and β. The fit parameters can then be used to calculate true δ and β values for composite materials. This approach requires no a priori sample information, making it broadly applicable. Our PB-PCXI reconstruction is single-distance, requiring only one exposure per tomographic angle, which is important for radiosensitive samples. We apply this approach to a breast-tissue sample, recovering the refraction component δ, with 0.6-2.4% accuracy compared with theoretical values. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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