title: Evaluation of differential phase contrast cone beam CT imaging system.
abstract: Grating-based differential phase contrast (DPC) imaging enables the use of a hospital-grade X-ray tube, but compromises the image quality due to insufficiently coherent illumination. In this research, a bench-top DPC cone beam CT (DPC-CBCT) was systematically evaluated and compared with the traditional attenuation-based CBCT in terms of contrast to noise ratio, noise property, and contrast resolution through phantom studies. In order to evaluate DPC-CBCT for soft tissue imaging, breast specimen and small animal studies were carried out. Phantom studies indicate that phase image has lower-frequency noise, higher CNR, and improved contrast resolution. However, phase image quality was degraded in soft tissue imaging due to coherence loss caused by small-angle scattering. Hence dark-field imaging was introduced to quantitatively investigate small-angle scattering caused by an object. Experimental results indicate that inhomogeneous objects affect phase contrast imaging, phase image is more sensitive to noise, and its performance is material dependent. Dark-field imaging could also be used to locate and reduce phase image noise and artifact caused by small-angle scattering.
authors.affiliation: Department of Electrical and Computer Engineering, University of Rochester, Rochester, NY, USA.
authors.forename: Jiangkun
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Physics and Astronomy, University of Rochester, Rochester, NY, USA.
authors.forename: Weixing
authors.initials: W
authors.lastname: Cai
authors.affiliation: Department of Electrical and Computer Engineering, University of Rochester, Rochester, NY, USA.|Department of Imaging Sciences, University of Rochester Medical Center, Rochester, NY, USA.
authors.forename: Ruola
authors.initials: R
authors.lastname: Ning
mesh_terms: D000273:Adipose Tissue / Q000000981:diagnostic imaging; D000818:Animals; D054893:Cone-Beam Computed Tomography / Q000379:methods*; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D051379:Mice; D008858:Microscopy, Phase-Contrast; D009132:Muscles / Q000000981:diagnostic imaging; D019047:Phantoms, Imaging; D059629:Signal-To-Noise Ratio; D013552:Swine
keywords: Cone beam CT; dark-field imaging; phase contrast imaging