title: [Investigation of vessel visibility in the iterative reconstruction method in coronary computed tomography angiography using simulated vessel phantom].
abstract: Iterative reconstruction methods can reduce the noise of computed tomography (CT) images, which are expected to contribute to the reduction of patient dose CT examinations. The purpose of this study was to investigate impact of an iterative reconstruction method (iDose(4), Philips Healthcare) on vessel visibility in coronary CT angiography (CTA) by using phantom studies. A simulated phantom was scanned by a CT system (iCT, Philips Healthcare), and the axial images were reconstructed by filtered back projection (FBP) and given a level of 1 to 7 (L1-L7) of the iterative reconstruction (IR). The vessel visibility was evaluated by a quantitative analysis using profiles across a 1.5-mm diameter simulated vessel as well as visual evaluation for multi planar reformation (MPR) images and volume rendering (VR) images in terms of the normalized-rank method with analysis of variance. The peak CT value of the profiles decreased with IR level and full width at half maximum of the profile also decreased with the IR level. For normalized-rank method, there was no statistical difference between FBP and L1 (20% dose reduction) for both MPR and VR images. The IR levels higher than L1 sacrificed the spatial resolution for the 1.5-mm simulated vessel, and their visual vessel visibilities were significantly inferior to that of the FBP.
authors.affiliation: Department of Radiology, Kouseikai Takai Hospital.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Inoue
authors.forename: Katsuhiro
authors.initials: K
authors.lastname: Ichikawa
authors.forename: Takanori
authors.initials: T
authors.lastname: Hara
authors.forename: Atsushi
authors.initials: A
authors.lastname: Urikura
authors.forename: Takashi
authors.initials: T
authors.lastname: Hoshino
authors.forename: Youhei
authors.initials: Y
authors.lastname: Miura
authors.forename: Syouichi
authors.initials: S
authors.lastname: Terakawa
authors.forename: Fumiaki
authors.initials: F
authors.lastname: Uto
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001808:Blood Vessels; D017023:Coronary Angiography / Q000379:methods*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D019047:Phantoms, Imaging; D011856:Radiographic Image Enhancement / Q000379:methods*; D012680:Sensitivity and Specificity