A Hybrid Approach to Reduce Cone-Beam Artifacts for a Circular Orbit Cone-Beam CT System

Common Image Artifacts in Cone Beam CT

Roi Cone-beam Ct on a Circular Orbit for Geometric Magnification Using Reprojection

We present an algorithm which allows us to investigate what is feasible when reconstructing a Region-Of-Interest (ROI) from transaxial truncated cone-beam projections obtained on a circular orbit in combination with information obtained at a different magnification level. We use the well-known fact that a rough estimate of the global properties of the Radon Transform is sufficient to obtain a r...

Analysis of Cone-Beam Artifacts in off-Centered Circular CT for Four Reconstruction Methods

Cone-beam (CB) acquisition is increasingly used for truly three-dimensional X-ray computerized tomography (CT). However, tomographic reconstruction from data collected along a circular trajectory with the popular Feldkamp algorithm is known to produce the so-called CB artifacts. These artifacts result from the incompleteness of the source trajectory and the resulting missing data in the Radon s...

Auto calibration of a cone-beam-CT.

PURPOSE This paper introduces a novel autocalibration method for cone-beam-CTs (CBCT) or flat-panel CTs, assuming a perfect rotation. The method is based on ellipse-fitting. Autocalibration refers to accurate recovery of the geometric alignment of a CBCT device from projection images alone, without any manual measurements. METHODS The authors use test objects containing small arbitrarily posi...

Respiratory correlated cone beam CT.

A cone beam computed tomography (CBCT) scanner integrated with a linear accelerator is a powerful tool for image guided radiotherapy. Respiratory motion, however, induces artifacts in CBCT, while the respiratory correlated procedures, developed to reduce motion artifacts in axial and helical CT are not suitable for such CBCT scanners. We have developed an alternative respiratory correlated proc...