title: [Comparison of basic imaging properties for digital radiographic systems based on a direct conversion type of flat panel detector].
abstract: The purpose of this study was to evaluate the basic imaging properties of the two latest digital radiographic X-ray systems, namely, the DynaDirect Winscope 6000 (abbr. as System A, Toshiba Medical Systems) and the Sonialvision Safire Multi (abbr. as System B, Shimadzu Corp.). These systems were based on a direct-conversion flat panel detector (FPD) of amorphous selenium. The basic imaging properties of the two systems were evaluated by measuring characteristic curves, presampled modulation transfer functions (MTFs), and noise power spectra (NPS) using DICOM images to which no resampling was performed with a matrix size of 2048x2048. In addition, noise equivalent quanta (NEQ) and detective quantum efficiency (DQE) calculated from the result of the basic imaging properties were evaluated. The characteristic curves of the two systems showed quite high linearity. The MTFs of the two systems indicated high-resolution properties, as is well known to be an advantage of the direct conversion FPD system. However, the NPS of System A showed better performance than System B under the same exposures. Therefore, the DQE of System A was higher than that of System B at all spatial frequencies.
authors.affiliation: Center for Diagnostic Imaging, Kurume University Hospital, Japan.
authors.forename: Shinji
authors.initials: S
authors.lastname: Sakai
authors.forename: Reiji
authors.initials: R
authors.lastname: Katayama
authors.forename: Junji
authors.initials: J
authors.lastname: Morishita
authors.forename: Taro
authors.initials: T
authors.lastname: Sakaguchi
authors.forename: Seiji
authors.initials: S
authors.lastname: Ohkubo
authors.forename: Takashi
authors.initials: T
authors.lastname: Maeda
authors.forename: Naofumi
authors.initials: N
authors.lastname: Hayabuchi
mesh_terms: D004867:Equipment Design; D011856:Radiographic Image Enhancement / Q000295:instrumentation*; D012643:Selenium
chemical_list: D012643:Selenium