Limits for Axial Motion in Cone Beam Computed Tomography

ABSTRACT Computed Tomography (CT) is a technique that allows the non‐destructive evaluation of internal structures of objects, producing cross‐sectional images. In many situations, it is necessary to explore objects with dimensions larger than the tomographic arrangement. To overcome this situation, it is possible to move the elements of the tomographic array and increase the field of view. One strategy with this objective is scanning with axial movement. To reduce exploration times, axial displacements should be as large as possible, ensuring that all the information necessary to reconstruct the volume with all its characteristics is obtained. This work analyzes the limits applicable to axial movement and its relationship with the geometry of the tomographic array. An analytical expression that measures the values of the axial displacement was obtained. The mathematical expression was validated using synthetic data and real images. The results obtained verify the validity of the proposed expression. In test data sets, it was verified that the use of an axial displacement smaller than the calculated limit ensures the reconstruction of the volume, preserving all its information. Using axial displacements larger than the calculated limit results in missing sections of the volume that are not fully captured.