Recommendations for the Three-Dimensional Computed Tomography of Musical Instruments and Other Cultural Artefacts funded by Nuremberg / Fürth 2018 Content Introductory Remarks ...................................................................................................... 6 Introduction ..................................................................................................................... 7 1 Three-Dimensional Computed Tomography ............................................................. 7 1.1 Medical 3D-CT .................................................................................................. 7 1.2 Industrial 3D-CT ................................................................................................ 8 2 Practical Advice ........................................................................................................ 9 Best Practice Guide ....................................................................................................... 10 3 Preliminary Considerations..................................................................................... 10 4 Measuring Planning................................................................................................ 10 4.1 Suitability of the Objects .................................................................................. 10 4.2 Scientific Question .......................................................................................... 10 4.3 Sub Volume Measuring (Volume of Interest: VOI) ........................................... 11 4.4 Conservation Aspects ..................................................................................... 12 4.5 Collecting of the Object Data Relevant to Measuring ...................................... 14 4.6 Assembly Planning .......................................................................................... 15 4.7 Mounting of the Object .................................................................................... 16 4.8 Transport......................................................................................................... 16 5 CT-Measuring ........................................................................................................ 16 5.1 Climate ............................................................................................................ 16 5.2 Set-Up ............................................................................................................. 17 5.3 Items to Be Scanned with the Object ............................................................... 17 5.4 Vertical Combination of CT Scans ................................................................... 18 5.5 Dosimetry ........................................................................................................ 18 5.6 Documentation ................................................................................................ 19 5.6.1 Check Lists .............................................................................................. 19 5.6.2 Photos ...................................................................................................... 19 5.7 Collecting Metadata ........................................................................................ 19 5.8 Data Processing .............................................................................................. 20 5.8.1 Data Format ............................................................................................. 20 5.8.2 Data Transport ......................................................................................... 20 5.8.3 Data Volume and Hardware ..................................................................... 20 5.8.4 Software ................................................................................................... 21 5.8.5 File Names, Structure of Folder and Archiving ......................................... 21 Recommendations For the Three-Dimensional Computed Tomography of Musical Instruments 6 Evaluation of Data .................................................................................................. 21 6.1 Assessment of Image Quality .......................................................................... 21 6.2 Answering the Scientific Question ................................................................... 22 6.3 Preparation of Tomograms .............................................................................. 22 Technical Guidelines ..................................................................................................... 23 7 The Choice of Technical Parameters ..................................................................... 23 7.1 The Communication Matrix ............................................................................. 24 7.1.1 X-Ray Energy, <> 225 keV ....................................................................... 26 7.1.2 Filtering of the Source .............................................................................. 27 7.1.3 Tube Current ............................................................................................ 27 7.1.4 Multi Energy Methods .............................................................................. 27 7.1.5 FlyBy or Stop&Go .................................................................................... 28 7.1.6 Trajectory Planning .................................................................................. 28 7.1.7 Image Processing Chain .......................................................................... 29 7.1.8 Integration Time ....................................................................................... 30 7.1.9 Measurement Time .................................................................................. 30 7.1.10 Data Volume ............................................................................................ 31 7.2 Further Considerations .................................................................................... 31 7.2.1 Number of Recorded Projections ............................................................. 31 7.2.2 On the Relevance of Communication ....................................................... 31 Metadata Model ............................................................................................................ 33 8 Introduction ............................................................................................................ 33 8.1 Metadata Structure .......................................................................................... 33 8.2 Setup of the Metadata Structure Based on the Workflow ................................ 33 8.3 Acquisition Areas within the Single Work Areas .............................................. 35 8.3.1 Work Area 1: Object Description .............................................................. 35 8.3.2 Work Area 2: Measurement ..................................................................... 36 8.3.3 Work Area 3: Reconstruction and Evaluation ........................................... 37 8.3.4 Overview of Work Areas ........................................................................... 37 9 The Acquisition Fields of the Work Areas in Detail ................................................. 39 9.1 Acquisition Fields of the Work Area „Object Description“ ................................. 40 9.1.1 Object Description - Identification ............................................................. 40 9.1.2 Definition of a Volume of Interest (VOI) .................................................... 41 9.1.3 X-Ray-Relevant Features – Entire Object or VOI ..................................... 41 9.1.4 Conservational Requirements .................................................................. 42 3 Recommendations For the Three-Dimensional Computed Tomography of Musical Instruments 9.1.5 Scientific Issue (per Object or VOI) .......................................................... 42 9.2 Acquisition Fields of the Work Area „Measurement“ ........................................ 43 9.2.1 Documentation of the Object Measurement ............................................. 43 9.2.2 Parameters of the Projection Data Set ..................................................... 44 9.2.3 Archiving of Projections ............................................................................ 46 9.2.4 Documentation of the Measurement Process ........................................... 46 9.3 Acquisition Fields of the Work Area „Reconstruction and Evaluation“ .............. 47 9.3.1 Reconstruction ......................................................................................... 47 9.3.2 Post-Processed Reconstruction ............................................................... 49 9.3.3 Evaluation and Visualization .................................................................... 50 9.4 Common Acquisition Fields ............................................................................. 51 9.4.1 CT-Facility ................................................................................................ 51 9.4.2 Test Specimen ......................................................................................... 53 9.4.3 Scientific Issue Keyword .......................................................................... 54 10 LIDO Specification .............................................................................................. 55 Appendices 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