BS ISO 15708-3:2017 INTERNATIONAL ISO STANDARD 15708-3 First edition 2017-02 Non-destructive testing Radiation methods for computed tomography - Part 3: Operation and interpretation Essais non destructifs - Methodes par rayonnements pour la tomographie informatisée- Partie 3:Fonctionnement et interprétation Reference number IS0 15708-3:2017(E) iso @IS02017 BS ISO 15708-3:2017 IS0 15708-3:2017(E) Contents Page Foreword .iv 1 Scope. 2 Normative references. 3 Terms and definitions 4 Operational procedure 4.1 General 4.2 CT system set-up 4.2.1 General.: 4.2.2 Geometry 4.2.3 X-ray source 4.2.4 Detector 4.3 Reconstruction parameters 4.4 Visualization.. 4.5 Analysis and interpretation of CT images. 4.5.1 General... 4.5.2 Feature testing/defect testing 4.5.3 Dimensional testing. 5 Requirements foracceptableresults 5.1 Image quality parameters 5.1.1 Contrast 5.1,2 Noise. 5.1.3 Signal to noise ratio.. 5.1.4 Contrastto noiseratio, 5.1,5 Spatialresolution 10 5.2 Suitability of testing- 12 5.3 CT examination interpretation and acceptance criteria 12 5.4 Records and reports... 12 5.5 Artefacts.. 13 5.5.1 General 13 5.5.2 Beam hardening artefacts. 13 5.5.3 Edge artefacts 14 5.5.4 Scattered radiation. 15 5.5.5 Instabilities.. 15 5.5.6 Ring artefaets. 15 5.5.7 Centre of rotation error artefacts.. 16 5.5.8 Motion artefacts. 17 5.5.9 Artefacts due to an insufficient number of projections. 18 5.5.10 Cone beam artefacts.. 18 Annex A (informative) Spatial resolution measurement using line pair gauges. 19 Bibliography 23 @ IS0 2017 - All rights reserved ili BS ISO 15708-3:2017 IS0 15708-3:2017(E) Foreword Iso (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out throughIsotechnicalcommittees.Eachmemberbodyinterestedinasubjectforwhichatechnical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with IsO, also take part in the work. ISo collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. The procedures used to develop this document and those intended for its further maintenance are described inthe ISO/lEc Directives, Part 1. Inparticularthe different approval criteria needed for the different types of Iso documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see Wwwiso.org/directives). Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. Iso shall not be held responsible for identifying any or all such patent rights. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the ISo list of patent declarations received (see www.iso.org/patents). Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement, For an explanation on the meaning of isO specific terms and expressions related to conformity assessment, as well as information about IsO's adherence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following URL: wwwiso.org/iso/foreword.html This document was prepared by the European Committee for Standardization (CEN) (as EN 16016-3) and was adopted, under a special "fast-track procedure", by Technical Committee ISO/TC 135, Non- destructive testing, Subcommittee Sc 5, Radiographic testing, in parallel with its approval by the Iso member bodies. This first edition of IS0 15708-3 cancels and replaces ISQ 15708-2:2002, of which it forms the subject of a technical revision, It takes into consideration developments in computed tomography (CT) and computational power over the preceding decade. A list of all parts in the IS0