title: A novel reconstruction tool (syngo DynaCT Head Clear) in the post-processing of DynaCT images to reduce artefacts and improve image quality.
abstract: BACKGROUND
  Latest generations of flat detector (FD) neuroangiography systems are able to obtain CT-like images of the brain parenchyma. Owing to the geometry of the C-arm system, cone beam artifacts are common and reduce image quality, especially at the periphery of the field of view. An advanced reconstruction algorithm (syngo DynaCT Head Clear) tackles these artifacts by using a modified interpolation-based 3D correction algorithm to improve image quality.
  
  
  METHODS
  Eleven volumetric datasets from FD-CT scans were reconstructed with the standard algorithm as well as with the advanced algorithm. In a two-step data analysis process, two reviewers compared dedicated regions of the skull and brain in both reconstruction modes using a 5-point scale (1, much better; 5, much worse; advanced vs standard algorithm). Both reviewers were blinded to the reconstruction mode. In a second step, two additional observers independently evaluated image quality of the 3D data (non-comparative evaluation) in dedicated regions also using a 5-point scale (1, not diagnostically evaluable; 5, good quality, perfectly usable for diagnosis) for both reconstruction algorithms.
  
  
  RESULTS
  Both in the comparative evaluation of dedicated brain regions and in the independent analysis of the FD-CT datasets the observers rated a better image quality if the advanced algorithm was used. The improvement in image quality was statistically significant at both the supraganglionic (p=0.018) and the infratentorial (p=0.002) levels.
  
  
  CONCLUSIONS
  The advanced reconstruction algorithm reduces typical artifacts in FD-CT images and improves image quality at the periphery of the field of view.
authors.affiliation: Institute of Neuroradiology, Hospital of Goethe University, Frankfurt am Main, Germany.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Lescher
authors.affiliation: Institute of Neuroradiology, Hospital of Goethe University, Frankfurt am Main, Germany.
authors.forename: Christina
authors.initials: C
authors.lastname: Reh
authors.affiliation: Institute of Neuroradiology, Hospital of Goethe University, Frankfurt am Main, Germany.
authors.forename: Maya Christina
authors.initials: MC
authors.lastname: Hoelter
authors.affiliation: Institute of Neuroradiology, Hospital of Goethe University, Frankfurt am Main, Germany.
authors.forename: Katja
authors.initials: K
authors.lastname: Czeppan
authors.affiliation: Institute of Neuroradiology, Hospital of Goethe University, Frankfurt am Main, Germany.
authors.forename: Luciana
authors.initials: L
authors.lastname: Porto
authors.affiliation: Institute of Neuroradiology, Hospital of Goethe University, Frankfurt am Main, Germany.
authors.forename: Stella
authors.initials: S
authors.lastname: Blasel
authors.affiliation: Institute of Neuroradiology, Hospital of Goethe University, Frankfurt am Main, Germany.
authors.forename: Joachim
authors.initials: J
authors.lastname: Berkefeld
authors.affiliation: Institute of Neuroradiology, Hospital of Goethe University, Frankfurt am Main, Germany.
authors.forename: Marlies
authors.initials: M
authors.lastname: Wagner
keywords: Angiography; CT; Technology