Calibration of Artis-Zeego C-arm cone beam computerized tomography angiography imaging system

Abstract. Artis-Zeego is an advanced interventional imaging system that can provide the three-dimensional (3-D) reconstruction of the coronary artery in real time. However, the mechanical accuracy will degenerate after long-time use. The inaccurate geometry will affect the spatial resolution of the 3-D reconstruction. We propose a calibration algorithm to tackle this problem. There are three steps of our algorithm. First, we propose a geometry estimation algorithm that is based on the classical helical phantom. Second, we transfer the geometry to the nominal C-arm coordinate system. Third, we propose the posteriori movement models at three imaging work positions. The contributions include three parts. First, the proposed geometry estimation algorithm is more robust and easier to implement than other algorithms that are based on the helical phantom. Second, the geometry parameters can be transferred to the nominal C-arm system. Therefore, the calibration work will be independent of the phantom placement. Third, the movement models can estimate and predict the geometries at any acquisition angle. The clinical experiments demonstrate that the proposed method can estimate and predict the acquisition geometry with accuracy. The acquisition trajectories can be modeled as a rigid motion at head and left work positions. The acquisition trajectory should be modeled as a rigid motion with a residual translation at Table30 work position.