title: CT angiography after carotid artery stenting: assessment of the utility of adaptive statistical iterative reconstruction and model-based iterative reconstruction.
abstract: BACKGROUND
  Follow-up CT angiography (CTA) is routinely performed for post-procedure management after carotid artery stenting (CAS). However, the stent lumen tends to be underestimated because of stent artifacts on CTA reconstructed with the filtered back projection (FBP) technique. We assessed the utility of new iterative reconstruction techniques, such as adaptive statistical iterative reconstruction (ASIR) and model-based iterative reconstruction (MBIR), for CTA after CAS in comparison with FBP.
  
  
  METHODS
  In a phantom study, we evaluated the differences among the three reconstruction techniques with regard to the relationship between the stent luminal diameter and the degree of underestimation of stent luminal diameter. In a clinical study, 34 patients who underwent follow-up CTA after CAS were included. We compared the stent luminal diameters among FBP, ASIR, and MBIR, and performed visual assessment of low attenuation area (LAA) in the stent lumen using a three-point scale.
  
  
  RESULTS
  In the phantom study, stent luminal diameter was increasingly underestimated as luminal diameter became smaller in all CTA images. Stent luminal diameter was larger with MBIR than with the other reconstruction techniques. Similarly, in the clinical study, stent luminal diameter was larger with MBIR than with the other reconstruction techniques. LAA detectability scores of MBIR were greater than or equal to those of FBP and ASIR in all cases.
  
  
  CONCLUSIONS
  MBIR improved the accuracy of assessment of stent luminal diameter and LAA detectability in the stent lumen when compared with FBP and ASIR. We conclude that MBIR is a useful reconstruction technique for CTA after CAS.
authors.affiliation: Division of Radiology, Department of Pathophysiological Therapeutic Science, Faculty of Medicine, Tottori University, 36-1 Nishi-cho, Yonago, 683-8504, Japan, keita98_1_7@hotmail.co.jp.
authors.forename: Keita
authors.initials: K
authors.lastname: Kuya
authors.forename: Yuki
authors.initials: Y
authors.lastname: Shinohara
authors.forename: Makoto
authors.initials: M
authors.lastname: Sakamoto
authors.forename: Naoki
authors.initials: N
authors.lastname: Iwata
authors.forename: Junichi
authors.initials: J
authors.lastname: Kishimoto
authors.forename: Shinya
authors.initials: S
authors.lastname: Fujii
authors.forename: Toshio
authors.initials: T
authors.lastname: Kaminou
authors.forename: Takashi
authors.initials: T
authors.lastname: Watanabe
authors.forename: Toshihide
authors.initials: T
authors.lastname: Ogawa
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000792:Angiography; D016477:Artifacts; D016893:Carotid Stenosis / Q000000981:diagnostic imaging* / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D019047:Phantoms, Imaging; D012189:Retrospective Studies; D015607:Stents; D014057:Tomography, X-Ray Computed