title: Application of a novel metal artifact correction algorithm in flat-panel CT after coil embolization of brain aneurysms: intraindividual comparison.
abstract: OBJECTIVE
  To evaluate a novel algorithm for correcting beam hardening artifacts caused by metal implants in computed tomography performed on a C-arm angiography system equipped with a flat panel (FP-CT).
  
  
  METHODS
  16 datasets of cerebral FP-CT acquisitions after coil embolization of brain aneurysms in the context of acute subarachnoid hemorrhage have been reconstructed by applying a soft tissue kernel with and without a novel reconstruction filter for metal artifact correction. Image reading was performed in multiplanar reformations (MPR) in average mode on a dedicated radiological workplace in comparison to the preinterventional native multisection CT (MS-CT) scan serving as the anatomic gold standard. Two independent radiologists performed image scoring following a defined scale in direct comparison of the image data with and without artifact correction. For statistical analysis, a random intercept model was calculated.
  
  
  RESULTS
  The inter-rater agreement was very high (ICC = 86.3 %). The soft tissue image quality and visualization of the CSF spaces at the level of the implants was substantially improved. The additional metal artifact correction algorithm did not induce impairment of the subjective image quality in any other brain regions.
  
  
  CONCLUSIONS
  Adding metal artifact correction to FP-CT in an acute postinterventional setting helps to visualize the close vicinity of the aneurysm at a generally consistent image quality.
authors.affiliation: Dept. of Diagnostic and Interventional Neuroradiology, University Medical Center Hamburg Eppendorf, Hamburg. jbuhk@uke.de
authors.forename: J-H
authors.initials: JH
authors.lastname: Buhk
authors.forename: M
authors.initials: M
authors.lastname: Groth
authors.forename: S
authors.initials: S
authors.lastname: Sehner
authors.forename: J
authors.initials: J
authors.lastname: Fiehler
authors.forename: N O
authors.initials: NO
authors.lastname: Schmidt
authors.forename: U
authors.initials: U
authors.lastname: Grzyska
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D000465:Algorithms; D016477:Artifacts; D002533:Cerebral Angiography / Q000379:methods*; D004621:Embolization, Therapeutic / Q000379:methods*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D002532:Intracranial Aneurysm / Q000000981:diagnostic imaging* / Q000628:therapy*; D008297:Male; D008670:Metals; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000379:methods; D015588:Observer Variation; D019736:Prostheses and Implants; D012680:Sensitivity and Specificity; D013345:Subarachnoid Hemorrhage / Q000000981:diagnostic imaging* / Q000628:therapy*; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D008670:Metals