title: Optimal contrast material concentration for distinguishing among carotid artery lumen, carotid stent, and neck in cone-beam computed tomography during carotid angiography: basic and clinical studies.
abstract: OBJECTIVE
  To explore the optimal contrast material (CM) concentration for distinguishing CM, carotid stent (CS), and neck components in cone-beam computed tomography (CBCT) during carotid angiography (CBCT-CA).
  
  
  METHODS
  A neck phantom containing CS and contrast-filled imitation vessels of 9 mm diameter was scanned using CBCT. CM (300 mgI/ml) was used in concentrations of 100, 50, 33, 10, 5, and 1%. In a clinical study, 30 patients with a CS (Precise or Wallstent) underwent CBCT-CA with CM injected at a rate of 3 ml/s and a concentration of 10 or 20%.
  
  
  RESULTS
  In the basic study, CBCTA using 5% CM enabled clear distinction among the three components under windowing at 1500 width and 300 center, and showed the exact diameter of the imitation vessel. Pixel values of CM inside the Precise and the Wallstent were 622.2 ± 32.9 (mean ± SD) and 746.0 ± 27.9, respectively. In the clinical study using CM at concentrations of 10 and 20%, pixel values of CM inside the Wallstent were 632.3 ± 69.2 and 1024.5 ± 99.0, respectively.
  
  
  CONCLUSIONS
  Optimal CM concentration for distinguishing among the three components was 5% in the basic study; the optimal concentration was 10% in the clinical study.
authors.affiliation: Department of Radiology, Wakayama Medical University, 811-1 Kimiidera, Wakayama, Wakayama, 641-8510, Japan.
authors.forename: Seiki
authors.initials: S
authors.lastname: Hosokawa
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Kawai
authors.forename: Morio
authors.initials: M
authors.lastname: Sato
authors.forename: Hiroki
authors.initials: H
authors.lastname: Minamiguchi
authors.forename: Motoki
authors.initials: M
authors.lastname: Nakai
authors.forename: Tadayoshi
authors.initials: T
authors.lastname: Nishioku
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Sonomura
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Matsumoto
authors.forename: Osamu
authors.initials: O
authors.lastname: Masuo
authors.forename: Toru
authors.initials: T
authors.lastname: Itakura
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015901:Angiography, Digital Subtraction / Q000379:methods*; D016893:Carotid Stenosis / Q000000981:diagnostic imaging* / Q000628:therapy*; D054893:Cone-Beam Computed Tomography; D003287:Contrast Media / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019047:Phantoms, Imaging; D011857:Radiographic Image Interpretation, Computer-Assisted; D015607:Stents
chemical_list: D003287:Contrast Media