ESTRO 2023 - Abstract Book

S1371

Digital Posters

ESTRO 2023

Results The spatial resolution measured with the Catphan phantom results showed spatial resolution well within 0.45-0.60 lp/mm and overall uniformity above 98.3% for all protocols. Iterative reconstruction resulted in fewer image artefacts and noise (see Figure 1 f-g). HU variation due to the phantom was within 30 HU for most of the materials and 80 HU for cortical bone when comparing a large diameter phantom (40 cm diameter) against the 20 cm one. The effect of the eFoV on the HU is more pronounced, due to the necessary use of truncated data, with better agreement for lung and soft tissues. The geometrical accuracy of the eFoV reconstruction depends on the volume within the eFoV being of the order of a few millimetres for most of the regions. The effect of the metal artefact reduction is shown in Figure 2 where iCBCT MAR shows reduced artefacts when compared to the image without correction and image quality compatible with a CT acquisition.