TY - JOUR
IS - 5
SP - 1876
AV - public
VL - 44
Y1 - 2017/02/25/
EP - 1885
TI - On the relative performance of edge illumination x-ray phase contrast CT and conventional, attenuation-based CT
A1 - Hagen, CK
A1 - Diemoz, PC
A1 - Olivo, A
JF - Medical Physics
PB - American Association of Physicists in Medicine
UR - http://dx.doi.org/10.1002/mp.12179
SN - 0094-2405
N2 - 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 ?m), but inferior for lower spatial resolutions (hundreds of ?m 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.