title: Validation of DynaCT in the morphological assessment of abdominal aortic aneurysm for endovascular repair.
abstract: OBJECTIVE
  To evaluate the feasibility of intraoperative 3-dimensional rotational angiography (DynaCT) as a single tool to assess suitability for endovascular aneurysm repair (EVAR) and for sizing the stent-graft.
  
  
  METHODS
  Twenty elective patients undergoing EVAR were prospectively recruited. All had preoperative multidetector computed tomography (CT) scans and intraoperative (pre-stent deployment) DynaCT scans. Images were read independently by 4 experienced endovascular practitioners. A total of 17 morphological variables, including aneurysm neck diameter and length, were measured from the CT and DynaCT images and compared. Bland-Altman plots examined intraclass correlation of continuous outcomes; kappa correlation coefficient assessed agreement of ordinal results.
  
  
  RESULTS
  The mean DynaCT radiation dose was 3751+/-835 microGym(2). The mean difference between DynaCT and multidetector CT in aneurysm neck diameter measurement was -1.5 mm (95% CI -4.9 to 1.9). Differences in left and right common iliac artery diameters were -1.9 mm (95% CI -6.3 to 2.4) and -2.1 mm (95% CI -6.9 to 2.7), respectively. For presence of neck thrombus, the group kappa statistic was 0.51 (p<0.0001); for neck calcification, the kappa was 0.07 (p = 0.29). Nine (45%) cases had incomplete information on DynaCT because external iliac arteries were not included in the scan.
  
  
  CONCLUSIONS
  DynaCT provides adequate preoperative imaging for morphological assessment of aortic anatomy. The greatest limitation is the evaluation of access vessels and underestimation of calcification. Due to current limited detector size, precise positioning is essential to attain all necessary sizing information using DynaCT.
authors.affiliation: St George's Vascular Institute, St George's Hospital, London, UK.
authors.forename: Ian M
authors.initials: IM
authors.lastname: Nordon
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Hinchliffe
authors.forename: Amir H
authors.initials: AH
authors.lastname: Malkawi
authors.forename: Jeremy
authors.initials: J
authors.lastname: Taylor
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Holt
authors.forename: Robert
authors.initials: R
authors.lastname: Morgan
authors.forename: Ian M
authors.initials: IM
authors.lastname: Loftus
authors.forename: Matt M
authors.initials: MM
authors.lastname: Thompson
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D017130:Angioplasty; D017544:Aortic Aneurysm, Abdominal / Q000000981:diagnostic imaging* / Q000628:therapy*; D001027:Aortography / Q000379:methods*; D019917:Blood Vessel Prosthesis Implantation; D015331:Cohort Studies; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D016343:Monitoring, Intraoperative; D015588:Observer Variation; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed