title: Defects of a mammography quality control phantom visualized by synchrotron radiation imaging.
abstract: Synchrotron radiation (SR) imaging of an RMI 156 mammography quality control phantom, serial number 156-15330, revealed some defects which degraded the visibility of calcification specks. SR imaging was performed at SPring-8, in Harima, Japan by using a monochromatic energy of 20 KeV with a field-of-view of 24 X 24 mm. Different kinds of images were obtained by changing sample-to-detector distances; absorption images and refraction-enhanced images. Specks were embedded in a wax matrix and were imaged as black in an absorption image. In a refraction-enhanced image, they were imaged as a black region with white margins. Foreign objects with opposite contrast were detected near, or overlapped with, some specks. As they were depicted as white in the absorption images and as white with a black margin in the refraction-enhanced image, it seemed that they had low X-ray attenuation and a low refraction index compared with the surrounding wax. They might presumably be air bubbles. Visibility of specks in an absorption image was seriously interfered with when those object(s) overlapped with specks. This kind of defect may cause a difficulty in meeting quality assurance specifications when a facility inadvertently purchases defective phantoms.
authors.affiliation: Department of Radiology, St. Marianna University School of Medicine, Kawasaki, Japan. keiko401@marianna-u.ac.jp
authors.forename: Keiko
authors.initials: K
authors.lastname: Imamura
authors.forename: Mamoru
authors.initials: M
authors.lastname: Fukuda
authors.forename: Norishige
authors.initials: N
authors.lastname: Ehara
authors.forename: Keiko
authors.initials: K
authors.lastname: Miyamoto
authors.forename: Yoshihide
authors.initials: Y
authors.lastname: Kanemaki
authors.forename: Keiji
authors.initials: K
authors.lastname: Umetani
authors.forename: Haruki
authors.initials: H
authors.lastname: Ogata
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Nakajima
mesh_terms: D016477:Artifacts; D001943:Breast Neoplasms / Q000000981:diagnostic imaging; D002114:Calcinosis / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D008327:Mammography / Q000295:instrumentation*; D019047:Phantoms, Imaging; D011786:Quality Control; D011856:Radiographic Image Enhancement / Q000295:instrumentation*; D017356:Synchrotrons