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DOI: 10.1055/s-0044-1782396
A moveable 3-D printed Phantom Setup for Evaluation of Motion induced Artefacts in a Total-Body PET/CT
Ziel/Aim: Due to their whole-body coverage and high temporal resolution, total-body (TB) PET scanners are particularly prone to patient motion induced artefacts. Motion correction methods aim to reduce these artefacts, but lack a ground truth for validation, which we aim to provide with the phantom setup developed in this study.
Methodik/Methods: Two -non-fillable thus wall-less- spherical phantoms of 28- and 10 mm diameter (8 kBq/ml), the latter embedded in a cylindrical volume (2 kBq/ml), were created using F-18 infused tissue equivalent resin and a stereolithographic 3D printer. 600 s (static reference) and 300 s (motion sequences) scans were performed with the phantoms mounted on a motorized translational stage (Thorlabs MT S50-Z8) in the Biograph Vision Quadra TB PET/CT Scanner (Siemens Healthineers). Different motion scenarios were modelled with a stroke/velocity of 20 mm/2 mms-1 (S20), 10 mm/1 mms-1 (S10), 5 mm/2.4 mms-1 (S5, mimicking 14.2 breaths/min). Motion artefacts were assessed by the CRC of the 10 mm sphere and its background, FWTM of a line profile and activity concentration recovery for the 28 mm sphere. A data gating approach was used to preliminarily assess the suitability of the setup validating motion correction methods.
Ergebnisse/Results: The CRC for the static reference was 50.7% and was reduced by motion to 21.7% (S20), 36.7% (S10) and 42.8% (S5). Gating of the data improved the CRC to 45.1% (S20), 46.4% (S10) and 47.1% (S5). The FWTM of the line profiles increased from 30.6 mm (static reference) to 43.4 mm (S20), 35.2 mm (S10) and 32.5 mm (S5) and could be recovered for the gated data with values of 32.1 mm (S20), 31.6 mm (S10) and 30.7 mm (S5). Activity recovery for the gated data was improved from 75.8% to 84.7% (S20), from 91.9% to 98.9% (S10) and from 97.4% to 99.1% (S5).
Schlussfolgerungen/Conclusions: This preliminary evaluation demonstrated the suitability of the experimental setup to validate motion correction methods, which we aim to correlate with the analysis of motion-corrected patient data.
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Publication History
Article published online:
25 March 2024
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