title: Evaluation of aortocoronary bypass stents with cardiac MDCT compared with conventional catheter angiography.
abstract: OBJECTIVE
  The objective of our study was to determine the accuracy of 16-MDCT for evaluation of stent patency and in-stent stenosis in venous coronary bypass grafts.
  
  
  METHODS
  Fourteen patients who had previous stent placements in stenosed venous coronary bypass grafts underwent contrast-enhanced MDCT of the heart (collimation, 16 x 0.75 mm; 120 kV; 550 mAs(eff)) and invasive coronary angiography. A total of 20 stents were evaluated: Vessel and stent diameters proximal to, distal to, and at various sites inside the stent were measured on both techniques, and Bland-Altman plots and correlations were calculated. Image noise and image quality were also assessed applying a Student's t test for data comparison of image noise.
  
  
  RESULTS
  All 20 bypass stents were correctly classified as patent. Vessel diameters outside the stent showed an excellent correlation (r = 0.90) and in-stent diameters showed a good correlation (r = 0.72), with lower values for MDCT due to blooming artifacts. All significant in-stent stenoses were correctly classified.
  
  
  CONCLUSIONS
  In patients suspected of bypass in-stent stenosis, 16-MDCT may be considered as a valuable alternative to conventional angiography for evaluating bypass patency and in-stent stenosis.
authors.affiliation: Department of Diagnostic Radiology, University Hospital (RWTH) Aachen, Pauwelsstrasse 30, 52057 Aachen, Germany. gmuehlen@rad.rwth-aachen.de
authors.forename: Georg
authors.initials: G
authors.lastname: Mühlenbruch
authors.forename: Andreas H
authors.initials: AH
authors.lastname: Mahnken
authors.forename: Marco
authors.initials: M
authors.lastname: Das
authors.forename: Rüdiger
authors.initials: R
authors.lastname: Blindt
authors.forename: Christian
authors.initials: C
authors.lastname: Hohl
authors.forename: Joachim E
authors.initials: JE
authors.lastname: Wildberger
authors.forename: Rolf W
authors.initials: RW
authors.lastname: Günther
authors.forename: Harald P
authors.initials: HP
authors.lastname: Kühl
authors.forename: Ralf
authors.initials: R
authors.lastname: Koos
mesh_terms: D001807:Blood Vessel Prosthesis / Q000009:adverse effects*; D006328:Cardiac Catheterization; D017023:Coronary Angiography; D001026:Coronary Artery Bypass / Q000009:adverse effects* / Q000295:instrumentation* / Q000379:methods; D005260:Female; D006083:Graft Occlusion, Vascular / Q000000981:diagnostic imaging* / Q000209:etiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D019919:Prosthesis Implantation / Q000009:adverse effects / Q000379:methods; D015607:Stents / Q000009:adverse effects*; D014057:Tomography, X-Ray Computed / Q000295:instrumentation / Q000379:methods*; D016896:Treatment Outcome