title: CT angiography of various superficial femoral artery stents: an in vitro phantom study.
abstract: OBJECTIVE
  To evaluate CT reconstruction parameters to improve stent lumen visualization in vitro.
  
  
  METHODS
  12 latest superficial femoral artery (SFA) stents were placed in a vessel phantom (diameter 4.7 mm, intravascular attenuation 250 HU, extravascular density 50 HU). Stents were imaged with a 128-slice scanner (SOMATOM Definition Flash, Siemens, Germany) with standard parameters: 120 kV, 200 mAs, collimation 128mm × 0.6mm. Different reconstruction parameters were evaluated: B26f, B30f, B45f, B46f and B60f kernel; slice thickness of 0.6, 2.0 and 5.0mm. To measure visualization characteristics, stent lumen diameter and intraluminal attenuation were assessed.
  
  
  RESULTS
  Best stent lumen visualization could be obtained using the B46f kernel (p<0.001). The visible stent lumen ranged from 66.4% to 83.3% with a mean diameter of 77.7 ± 4.6%. Nitinol stents showed a significant improved lumen visibility compared to the cobalt-chromium stent (p = 0.02). The most realistic lumen attenuation was achieved using the B46f kernel with a mean attenuation of 259.3 ± 8.9 HU. The visible lumen diameter in protocols with 5mm slice thickness was significantly lower (70.0 ± 4.9%) compared to thinner slices (p<0.001).
  
  
  CONCLUSIONS
  CTA of SFA stents should be reconstructed with a slice thickness of 2.0mm and a B46f kernel to achieve best image quality and to become more sensitive to exclude instent restenosis.
authors.affiliation: Department of Diagnostic and Interventional Radiology, Eberhard-Karls-University, Hoppe-Seyler-Str. 3, 72076 Tübingen, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Kaempf
authors.forename: Dominik
authors.initials: D
authors.lastname: Ketelsen
authors.forename: Roland
authors.initials: R
authors.lastname: Syha
authors.forename: Sebastian
authors.initials: S
authors.lastname: Sixt
authors.forename: Stefanie
authors.initials: S
authors.lastname: Mangold
authors.forename: Christoph
authors.initials: C
authors.lastname: Thomas
authors.forename: Claus D
authors.initials: CD
authors.lastname: Claussen
authors.forename: Martin
authors.initials: M
authors.lastname: Heuschmid
authors.forename: Klaus
authors.initials: K
authors.lastname: Brechtel
mesh_terms: D000497:Alloys; D000792:Angiography / Q000379:methods*; D002858:Chromium Alloys; D003035:Cobalt; D005263:Femoral Artery / Q000000981:diagnostic imaging*; D006801:Humans; D066298:In Vitro Techniques; D019047:Phantoms, Imaging; D011857:Radiographic Image Interpretation, Computer-Assisted; D015607:Stents; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D000497:Alloys; D002858:Chromium Alloys; C013616:nitinol; D003035:Cobalt