title: Assessment of vertebral artery stents using 16-slice multi-detector row CT angiography in vivo evaluation: comparison of a medium-smooth kernel and a sharp kernel.
abstract: OBJECTIVE
  To assess the lumen visibility of extracranial vertebral artery stents examined with 16-slice multi-detector row computed tomography (MDCT) angiography in vivo using a medium-smooth kernel (B30s) and a sharp kernel (B60s), and to compare these with digital subtraction angiography (DSA) after stent placement.
  
  
  METHODS
  Twenty stents from 20 patients (14 men, 6 women; mean age, 62.7+/-10.1 years) who underwent CT angiography (CTA) with 16-slice MDCT were retrospectively analyzed. In CT angiograms using a B30s and a B60s, the lumen diameters and CT attenuations of the stented vessels were measured three times by three observers, and artificial luminal narrowing (ALN) was calculated. To assess measurement reliability on CT angiograms, the intraclass correlation coefficient (ICC) was used. DSA served as the reference standard for the in-stent luminal measurements on CT angiography. The median interval between CT angiography and DSA was 1 day (range 1-10).
  
  
  RESULTS
  For interobserver reliability, intraclass correlation coefficients for the lumen diameters on CT angiograms with a B30s and a B60s were 0.90 and 0.96, respectively. The lumen diameters on CT angiograms using a B30s were consistently smaller than that on CT angiograms using a B60s (p<0.01). The mean ALN was 37+/-7% on CT angiograms using a B30s and 25+/-9% on CT angiograms using a B60s. The mean CT attenuation in in-stent lumen was 347+/-55HU on CT angiograms using a B30s and 295+/-46HU on CT angiograms using a B60s. The ALN and CT attenuation within the stented vessels between CT angiograms using a B30s and a B60s was significant (p<0.01).
  
  
  CONCLUSIONS
  16-slice MDCT using a sharp kernel allows good visualization of the stented vessels and is useful in the assessment of vertebral artery stent patency after stent placement.
authors: Department of Radiology, Holy Family Hospital, College of Medicine, The Catholic University of Korea, Wonmi-Gu, Bucheon, Gyeonggi, Republic of Korea.
authors: Won Jong
authors: WJ
authors: Yoo
authors: Yeon Soo
authors: YS
authors: Lim
authors: Kook Jin
authors: KJ
authors: Ahn
authors: Byung Gil
authors: BG
authors: Choi
authors: Ji Young
authors: JY
authors: Kim
authors: Sung Hoon
authors: SH
authors: Kim
mesh_terms: D000465:Algorithms; D000792:Angiography / Q000379:methods*; D001807:Blood Vessel Prosthesis; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011856:Radiographic Image Enhancement / Q000379:methods; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D015607:Stents; D014057:Tomography, X-Ray Computed / Q000379:methods*; D016896:Treatment Outcome; D014711:Vertebral Artery / Q000000981:diagnostic imaging / Q000601:surgery; D014715:Vertebrobasilar Insufficiency / Q000000981:diagnostic imaging* / Q000601:surgery*