TY - GEN AV - restricted SP - 588 Y1 - 2024/10/03/ EP - 597 TI - Resolving Variable Respiratory Motion From Unsorted 4D Computed Tomography N1 - This version is the author accepted manuscript. For information on re-use, please refer to the publisher?s terms and conditions. UR - https://doi.org/10.1007/978-3-031-72378-0_55 PB - Springer, Cham SN - 0302-9743 N2 - 4D Computed Tomography (4DCT) is widely used for many clinical applications such as radiotherapy treatment planning, PET and ventilation imaging. However, common 4DCT methods reconstruct multiple breath cycles into a single, arbitrary breath cycle which can lead to various artefacts, impacting the downstream clinical applications. Surrogate driven motion models can estimate continuous variable motion across multiple cycles based on CT segments ?unsorted? from 4DCT, but it requires respiration surrogate signals with strong correlation to the internal motion, which are not always available. The method proposed in this study eliminates such dependency by adapting the hyper-gradient method to the optimization of surrogate signals as hyper-parameters, while achieving better or comparable performance, as demonstrated on digital phantom simulations and real patient data. Our method produces a high-quality motion-compensated image together with estimates of the motion, including breath-to-breath variability, throughout the image acquisition. Our method has the potential to improve downstream clinical applications, and also enables retrospective analysis of open access 4DCT dataset where no respiration signals are stored. Code is available at https://github.com/Yuliang-Huang/4DCT-irregular-motion. ID - discovery10203159 T3 - Lecture Notes in Computer Science, vol 15001 A1 - Huang, Yuliang A1 - Eiben, Bjoern A1 - Thielemans, Kris A1 - McClelland, Jamie R KW - 4DCT KW - Irregular breath KW - Motion model ER -