ESTRO 2024 - Abstract Book

S3932

Physics - Image acquisition and processing

ESTRO 2024

Figure 2a presents the MTF for CBCT HR , CBCT SR , CBCT LR and CBCT BI , calculated using the cylindrical water phantom. For CBCT HR , the 10% MTF level was at 0.64 lp/mm, for CBCT SR at 0.62 lp/mm, for CBCT LR at 0.35 lp/mm and for CBCT BI at 0.51 lp/mm. Comparing the noise levels showed similar SDs for CBCT HR and CBCT SR with values of 35.5 HU and 35.9 HU respectively. For CBCT BI and CBCT LR a SD of 38.9 HU and 16.5 HU was observed. Figure 2b shows the 2D NPS for the various CBCTs, highlighting the increased noise level on CBCT BI , the reduced noise level on CBCT LR but showing comparable noise spectrums on CBCT SR and CBCT HR .