| Popis: |
Cone-beam CT (CBCT) is a prevalent tool for image-guided radiation therapy (IGRT). It can be used for patient positioning and dose calculation, which are needed at the early and later stages of each fraction of treatment, respectively. The requirement of image quality on patient positioning is less demanding than that on dose calculation. This work introduces a two-pass data acquisition approach for CBCT imaging in IGRT, with the first pass being left-handed helix and the second pass being right-handed helix. The first scan alone produces images for patient positioning, whereas the two scans together are used to produce quality improved images for dose calculation. We refer to this two-pass data acquisition geometry as the double-helix trajectory. We propose a dedicated image reconstruction algorithm for the double-helix trajectory and demonstrate the algorithm via computer simulations. |
