title: Feasibility of Quantification of Intracranial Aneurysm Pulsation with 4D CTA with Manual and Computer-Aided Post-Processing.
abstract: OBJECTIVE
  The analysis of the pulsation of unruptured intracranial aneurysms might improve the assessment of their stability and risk of rupture. Pulsations can easily be concealed due to the small movements of the aneurysm wall, making post-processing highly demanding. We hypothesized that the quantification of aneurysm pulsation is technically feasible and can be improved by computer-aided post-processing.
  
  
  METHODS
  Images of 14 cerebral aneurysms were acquired with an ECG-triggered 4D CTA. Aneurysms were post-processed manually and computer-aided on a 3D model. Volume curves and random noise-curves were compared with the arterial pulse wave and volume curves were compared between both post-processing modalities.
  
  
  RESULTS
  The aneurysm volume curves showed higher similarity with the pulse wave than the random curves (Hausdorff-distances 0.12 vs 0.25, p<0.01). Both post-processing methods did not differ in intra- (r = 0.45 vs r = 0.54, p>0.05) and inter-observer (r = 0.45 vs r = 0.54, p>0.05) reliability. Time needed for segmentation was significantly reduced in the computer-aided group (3.9 ± 1.8 min vs 20.8 ± 7.8 min, p<0.01).
  
  
  CONCLUSIONS
  Our results show pulsatile changes in a subset of the studied aneurysms with the final prove of underlying volume changes remaining unsettled. Semi-automatic post-processing significantly reduces post-processing time but cannot yet replace manual segmentation.
authors.affiliation: Department of Diagnostic and Interventional Neuroradiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Till
authors.initials: T
authors.lastname: Illies
authors.affiliation: Information Technology and Image Processing, University of Applied Sciences, Wedel, Germany.
authors.forename: Dennis
authors.initials: D
authors.lastname: Saering
authors.affiliation: Department of Neurosurgery, Osaka University Graduate School of Medicine, Osaka, Japan.
authors.forename: Manabu
authors.initials: M
authors.lastname: Kinoshita
authors.affiliation: Department of Neurosurgery, Osaka University Graduate School of Medicine, Osaka, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Fujinaka
authors.affiliation: Department of Diagnostic and Interventional Neuroradiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Maxim
authors.initials: M
authors.lastname: Bester
authors.affiliation: Department of Diagnostic and Interventional Neuroradiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Jens
authors.initials: J
authors.lastname: Fiehler
authors.affiliation: Department of Radiology, Osaka University Graduate School of Medicine, Osaka, Japan.
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Tomiyama
authors.affiliation: Department of Radiology, Osaka University Graduate School of Medicine, Osaka, Japan.
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Watanabe
mesh_terms: D017542:Aneurysm, Ruptured / Q000000981:diagnostic imaging; D001331:Automation; D004562:Electrocardiography; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D002532:Intracranial Aneurysm / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D013997:Time Factors