title: Impact of contrast injection and stent-graft implantation on reproducibility of volume measurements in semiautomated segmentation of abdominal aortic aneurysm on computed tomography.
abstract: OBJECTIVE
  To assess the impact of contrast injection and stent-graft implantation on feasibility, accuracy, and reproducibility of abdominal aortic aneurysm (AAA) volume and maximal diameter (D-max) measurements using segmentation software.
  
  
  METHODS
  CT images of 80 subjects presenting AAA were divided into four equal groups: with or without contrast enhancement, and with or without stent-graft implantation. Semiautomated software was used to segment the aortic wall, once by an expert and twice by three readers. Volume and D-max reproducibility was estimated by intraclass correlation coefficients (ICC), and accuracy was estimated between the expert and the readers by mean relative errors.
  
  
  RESULTS
  All segmentations were technically successful. The mean AAA volume was 167.0 ± 82.8 mL and the mean D-max 55.0 ± 10.6 mm. Inter- and intraobserver ICCs for volume and D-max measurements were greater than 0.99. Mean relative errors between readers varied between -1.8 ± 4.6 and 0.0 ± 3.6 mL. Mean relative errors in volume and D-max measurements between readers showed no significant difference between the four groups (P ≥ 0.2).
  
  
  CONCLUSIONS
  The feasibility, accuracy, and reproducibility of AAA volume and D-max measurements using segmentation software were not affected by the absence of contrast injection or the presence of stent-graft.
  
  
  CONCLUSIONS
  • AAA volumetry by semiautomated segmentation is accurate on CT following endovascular repair. • AAA volumetry by semiautomated segmentation is accurate on unenhanced CT. • Standardization of the segmentation technique maximizes the reproducibility of volume measurements.
authors.affiliation: Department of Radiology, Centre Hospitalier Universitaire de Montréal (CHUM), Hôpital Notre-Dame, 1560 Sherbrooke Est, Montréal, Québec, Canada, H2L 4M1, florencemorinroy@gmail.com.
authors.forename: Florence
authors.initials: F
authors.lastname: Morin-Roy
authors.forename: Claude
authors.initials: C
authors.lastname: Kauffmann
authors.forename: An
authors.initials: A
authors.lastname: Tang
authors.forename: Sofiane
authors.initials: S
authors.lastname: Hadjadj
authors.forename: Olivier
authors.initials: O
authors.lastname: Thomas
authors.forename: Nicolas
authors.initials: N
authors.lastname: Piché
authors.forename: Stéphane
authors.initials: S
authors.lastname: Elkouri
authors.forename: Dan Yang
authors.initials: DY
authors.lastname: Yang
authors.forename: Éric
authors.initials: É
authors.lastname: Therasse
authors.forename: Gilles
authors.initials: G
authors.lastname: Soulez
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D017544:Aortic Aneurysm, Abdominal / Q000000981:diagnostic imaging* / Q000601:surgery; D001027:Aortography / Q000379:methods*; D019917:Blood Vessel Prosthesis Implantation; D003287:Contrast Media / Q000008:administration & dosage*; D003430:Cross-Sectional Studies; D005240:Feasibility Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000379:methods*; D012372:ROC Curve; D015203:Reproducibility of Results; D012189:Retrospective Studies; D015607:Stents
chemical_list: D003287:Contrast Media