Large-angle x-ray scatter in Talbot-Lau interferometry for breast imaging
Department of Radiology
Biological and Chemical Physics | Investigative Techniques | Medical Biophysics | Radiology
Monte Carlo simulations were used to investigate large-angle x-ray scatter at design energy of 25 keV during small field of view (9.6 cm x 5 cm) differential phase contrast imaging of the breast using Talbot-Lau interferometry. Homogenous, adipose and fibroglandular breasts of uniform thickness ranging from 2 to 8 cm encompassing the field of view were modeled. Theoretically determined transmission efficiencies of the gratings were used to validate the Monte Carlo simulations, followed by simulations to determine the x-ray scatter reaching the detector. The recorded x-ray scatter was classified into x-ray photons that underwent at least one Compton interaction (incoherent scatter) and Rayleigh interaction alone (coherent scatter) for further analysis. Monte Carlo based estimates of transmission efficiencies showed good correspondence [Formula: see text] with theoretical estimates. Scatter-to-primary ratio increased with increasing breast thickness, ranging from 0.11 to 0.22 for 2-8 cm thick adipose breasts and from 0.12 to 0.28 for 2-8 cm thick fibroglandular breasts. The analyzer grating reduced incoherent scatter by ~18% for 2 cm thick adipose breast and by ~35% for 8 cm thick fibroglandular breast. Coherent scatter was the dominant contributor to the total scatter. Coherent-to-incoherent scatter ratio ranged from 2.2 to 3.1 for 2-8 cm thick adipose breasts and from 2.7 to 3.4 for 2-8 cm thick fibroglandular breasts.
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Citation: Phys Med Biol. 2014 Nov 7;59(21):6387-400. doi: 10.1088/0031-9155/59/21/6387. Epub 2014 Oct 8. Link to article on publisher's site
Vedantham, Srinivasan; Shi, Linxi; and Karellas, Andrew, "Large-angle x-ray scatter in Talbot-Lau interferometry for breast imaging" (2014). Radiology Publications and Presentations. 79.