title: Geometry-constraint-scan imaging for in-line phase contrast micro-CT.
abstract: X-ray phase contrast computed tomography (CT) uses the phase shift that x-rays undergo when passing through matter, rather than their attenuation, as the imaging signal and may provide better image quality in soft-tissue and biomedical materials with low atomic number. Here a geometry-constraint-scan imaging technique for in-line phase contrast micro-CT is reported. It consists of two circular-trajectory scans with x-ray detector at different positions, the phase projection extraction method with the Fresnel free-propagation theory and the filter back-projection reconstruction algorithm. This method removes the contact-detector scan and the pure phase object assumption in classical in-line phase contrast Micro-CT. Consequently it relaxes the experimental conditions and improves the image contrast. This work comprises a numerical study of this technique and its experimental verification using a biomedical composite dataset measured at an x-ray tube source Micro-CT setup. The numerical and experimental results demonstrate the validity of the presented method. It will be of interest for a wide range of in-line phase contrast Micro-CT applications in biology and medicine.
authors.affiliation: Research Center of Digital Radiation Imaging and Biomedical Imaging, Beijing University of Aeronautics and Astronautics, Beijing 100191, People's Republic of China.
authors.forename: Jian
authors.initials: J
authors.lastname: Fu
authors.affiliation: Research Center of Digital Radiation Imaging and Biomedical Imaging, Beijing University of Aeronautics and Astronautics, Beijing 100191, People's Republic of China.
authors.forename: Guangyuan
authors.initials: G
authors.lastname: Yu
authors.affiliation: Research Center of Digital Radiation Imaging and Biomedical Imaging, Beijing University of Aeronautics and Astronautics, Beijing 100191, People's Republic of China.
authors.forename: Dekai
authors.initials: D
authors.lastname: Fan
mesh_terms: D000465:Algorithms; D019047:Phantoms, Imaging; D011856:Radiographic Image Enhancement / Q000379:methods*; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000295:instrumentation / Q000379:methods*; D014961:X-Ray Diffraction / Q000295:instrumentation / Q000379:methods*
keywords: X-ray in-line phase contrast imaging; geometry-constraint scanning mode; micro computed tomography; reconstruction algorithm