title: Influence of different reconstruction parameters in the visualization of intracranial stents using C-arm flat panel CT angiography: experience in an animal model.
abstract: BACKGROUND
  C-arm flat panel computed tomography angiography (CA-CTA) is a relatively new imaging modality. Consequently, knowledge about postprocessing parameters and their influence on image quality is still limited, especially for the visualization of implanted microstents.
  
  
  OBJECTIVE
  To optimize reconstruction parameters by evaluating the influence of these different parameters for CA-CTA visualization of microstents in an animal model.
  
  
  METHODS
  Eleven microstents were implanted within the left common carotid artery of 11 New Zealand white rabbits. Both CA-CTA, using intra-venous delivery of contrast material, and conventional digital subtraction angiography (DSA) was performed. CA-CTA datasets were reconstructed using three different image characteristics (normal, sharp, smooth). Two experienced neuroradiologists evaluated the image quality and performed measurements of inner and outer stent diameters as well as measurements of the lumen area.
  
  
  RESULTS
  Stent deployment was performed successfully in all animals. Inter-observer correlation coefficient for all measurements was high (r = 0.87-0.92). Lumen area and inner stent diameter were significantly smaller in image characteristic "smooth" (P < 0.01) than in "sharp" and "normal". Outer stent diameter was larger in "smooth" than in "sharp" and "normal" (P < 0.01). Stent strut size was significantly wider using image characteristic "smooth". "Sharp" and "normal" compared best to DSA, with "sharp" providing the closest match to DSA measurements, with the trade-off of significantly more noise than in the "normal" reconstructions.
  
  
  CONCLUSIONS
  The use of different image characteristics in the postprocessing of CA-CTA datasets has an influence on the visualization of implanted stents. Image characteristic "sharp" and "normal" compared best to DSA.
authors.affiliation: Department of Neuroradiology, University of Erlangen-Nuremberg, Erlangen, Germany Sabine.Ott@uk-erlangen.de.
authors.forename: Sabine
authors.initials: S
authors.lastname: Ott
authors.affiliation: Department of Neuroradiology, University of Erlangen-Nuremberg, Erlangen, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Struffert
authors.affiliation: Department of Neuroradiology, University of Erlangen-Nuremberg, Erlangen, Germany.
authors.forename: Marc
authors.initials: M
authors.lastname: Saake
authors.affiliation: Department of Neuroradiology, University of Erlangen-Nuremberg, Erlangen, Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Gölitz
authors.affiliation: Department of Neuroradiology, University of Erlangen-Nuremberg, Erlangen, Germany.
authors.forename: Edyta
authors.initials: E
authors.lastname: Adamek
authors.affiliation: Department of Neuroradiology, University of Erlangen-Nuremberg, Erlangen, Germany.
authors.forename: Arnd
authors.initials: A
authors.lastname: Doerfler
mesh_terms: D015901:Angiography, Digital Subtraction / Q000379:methods; D000818:Animals; D017536:Carotid Artery, Common / Q000000981:diagnostic imaging*; D003287:Contrast Media; D007091:Image Processing, Computer-Assisted / Q000379:methods; D023421:Models, Animal; D015588:Observer Variation; D011817:Rabbits; D011856:Radiographic Image Enhancement / Q000379:methods*; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015607:Stents; D015898:Tomography Scanners, X-Ray Computed; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media
keywords: C-arm flat panel computed tomography angiography; Digital subtraction angiography; animal model; intracranial stent; stent visualization