title: In Vitro Validation of an Artefact Suppression Algorithm in X-Ray Phase-Contrast Computed Tomography.
abstract: X-ray phase-contrast tomography can significantly increase the contrast-resolution of conventional attenuation-contrast imaging, especially for soft-tissue structures that have very similar attenuation. Just as in attenuation-based tomography, phase contrast tomography requires a linear dependence of aggregate beam direction on the incremental direction alteration caused by individual voxels along the path of the X-ray beam. Dense objects such as calcifications in biological specimens violate this condition. There are extensive beam deflection artefacts in the vicinity of such structures because they result in large distortion of wave front due to the large difference of refractive index; for such large changes in beam direction, the transmittance of the silicon analyzer crystal saturates and is no longer linearly dependent on the angle of refraction. This paper describes a method by which these effects can be overcome and excellent soft-tissue contrast of phase tomography can be preserved in the vicinity of such artefact-producing structures.
authors: Graduate School of Engineering, Gunma University, Kiryu, Gunma, Japan.
authors: Naoki
authors: N
authors: Sunaguchi
authors: Graduate School of Engineering and Science, Yamagata University, Yonezawa, Yamagata, Japan.
authors: Tetsuya
authors: T
authors: Yuasa
authors: Mercian Cleantec Corporation, Fujisawa, Kanagawa, Japan; MiZ Corporation, Kamakura, Kanagawa, Japan.
authors: Shin-Ichi
authors: S
authors: Hirano
authors: Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, United States of America.
authors: Rajiv
authors: R
authors: Gupta
authors: Research Institute for Science and Technology, Tokyo University of Science, Noda, Chiba, Japan.
authors: Masami
authors: M
authors: Ando
mesh_terms: D000465:Algorithms; D000818:Animals; D001169:Arthritis, Experimental / Q000000981:diagnostic imaging* / Q000473:pathology; D001172:Arthritis, Rheumatoid / Q000000981:diagnostic imaging / Q000473:pathology; D016477:Artifacts; D050197:Atherosclerosis / Q000000981:diagnostic imaging* / Q000473:pathology; D003331:Coronary Vessels / Q000000981:diagnostic imaging* / Q000473:pathology; D004195:Disease Models, Animal; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D058226:Plaque, Atherosclerotic / Q000000981:diagnostic imaging* / Q000473:pathology; D051381:Rats; D011917:Rats, Inbred Lew; D012031:Refractometry; D014057:Tomography, X-Ray Computed / Q000295:instrumentation / Q000379:methods*