A line fiducial method for geometric calibration of cone-beam CT systems with diverse scan trajectories.

A line fiducial method for geometric calibration of cone-beam CT systems with diverse scan trajectories.
Phys Med Biol. 2017 Nov 08;:
Authors: Jacobson MW, Ketcha MD, Capostagno S, Martin A, Uneri A, Goerres J, De Silva T, Reaungamornrat S, Han R, Manbachi A, Stayman JW, Vogt S, Kleinszig G, Siewerdsen JH
Abstract
Modern cone-beam CT systems, especially C-arms, are capable of diverse source-detector orbits. However, geometric calibration of these systems using conventional configurations of spherical fiducials (BBs) may be challenged for novel source-detector orbits and system geometries. In part, this is because the BB configurations are designed with careful forethought regarding the intended orbit so that BB marker projections do not overlap in projection views. Examples include helical arrangements of BBs (Rougee et al Proc. SPIE 1897 161-9) such that markers do not overlap in projections acquired from a circular orbit and circular arrangements of BBs (Cho et al Med Phys 32 968-83). As a more general alternative, this work proposes a calibration method based on an array of line-shaped, radio-opaque wire segments. With this method, geometric parameter estimation is accomplished by relating the 3D line equations representing the wires to the 2D line equations of their projections. The use of line fiducials simplifies many challenges with fiducial recognition and extraction in an orbit-independent manner. For example, their projecti...

Source: Physics in Medicine and Biology - November 8, 2017 Category: Physics Authors: Jacobson MW, Ketcha MD, Capostagno S, Martin A, Uneri A, Goerres J, De Silva T, Reaungamornrat S, Han R, Manbachi A, Stayman JW, Vogt S, Kleinszig G, Siewerdsen JH Tags: Phys Med Biol Source Type: research