title: [Factors of image quality in spiral x-ray computed tomography].
abstract: In helical CT, there are 4 mains factors of quality: The in-plane spatial resolution that is the same in conventional CT; The spatial resolution on the Z axis, which is the slice thickness. The increase factor of the slice thickness between a conventional and a helical CT depends on the pitch and the reconstruction algorithm. The value of the increase factor can be easily calculated; The signal to noise ratio which depends on the collimation, the mA, the KV and the reconstruction algorithm. The signal to noise ratio is not depending on the table speed; The reconstruction interval which can be less than the slice thickness. Then the contrast of small lesion is improved and stair-step artifacts are reduced in 3D reformations.
authors.affiliation: Radiologie Est, CHU Lille.
authors.forename: O
authors.initials: O
authors.lastname: Ernst
authors.forename: L
authors.initials: L
authors.lastname: Gaillandre
authors.forename: D
authors.initials: D
authors.lastname: Mizrahi
authors.forename: G
authors.initials: G
authors.lastname: Sergent
authors.forename: P
authors.initials: P
authors.lastname: Bonvarlet
authors.forename: C
authors.initials: C
authors.lastname: L'Herminé
mesh_terms: D000465:Algorithms; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D011786:Quality Control; D011856:Radiographic Image Enhancement; D014057:Tomography, X-Ray Computed / Q000379:methods*
vernacular_title: Facteurs de qualité de l'image en scanner spiralé.