title: Reliability of semiautomatic centerline analysis versus manual aortic measurement techniques for TEVAR among non-experts.
abstract: OBJECTIVE
  The study aimed to test whether reliability and inter-observer variability of preoperative measurements for thoracic endovascular aortic repair (TEVAR) among non-experts are improved by semiautomatic centerline analysis compared with manual assessment.
  
  
  METHODS
  Preoperative computed tomography (CT) angiographies of 30 patients with thoracic aortic disease (mean age 66.8 ± 11.6 years, 23 men) were retrospectively analysed in randomised order by one blinded vascular expert (reference standard) and three blinded non-expert readers. Aortic diameters were measured at four positions relevant to TEVAR using three measurement techniques (manual axial slices, manual multiplanar reformations (MPRs) and semiautomatic centerline analysis). Length measurements were performed using centerline analysis. Reliability was calculated as absolute measurement deviation (AMD) from reference standard and inter-observer variability as coefficient of variance (CV) among non-expert readers.
  
  
  RESULTS
  For axial, MPR and centerline techniques, mean AMD was 7.3 ± 7.7%, 6.7 ± 4.5% and 4.7 ± 4.8% and mean CV was 5.2 ± 4.2%, 5.8 ± 4.8% and 3.9 ± 5.4%. Both AMD and CV were significantly lower for centerline analysis compared with axial technique (p = 0.001/0.042) and MPR (p = 0.009/0.003). AMD and CV for length measurements by centerline analysis were 3.2 ± 2.8% and 2.6 ± 2.4%, respectively. Centerline analysis was significantly faster than MPR (p < 0.001).
  
  
  CONCLUSIONS
  Semiautomatic centerline analysis provides the most reliable and least variable diameter and length measurements among non-experts in candidates for TEVAR.
authors.affiliation: University Hospital Heidelberg, Department of Diagnostic and Interventional Radiology, Im Neuenheimer Feld 110, 69120 Heidelberg, Germany. fabian.rengier@web.de
authors.forename: F
authors.initials: F
authors.lastname: Rengier
authors.forename: T F
authors.initials: TF
authors.lastname: Weber
authors.forename: S
authors.initials: S
authors.lastname: Partovi
authors.forename: M
authors.initials: M
authors.lastname: Müller-Eschner
authors.forename: D
authors.initials: D
authors.lastname: Böckler
authors.forename: H-U
authors.initials: HU
authors.lastname: Kauczor
authors.forename: H
authors.initials: H
authors.lastname: von Tengg-Kobligk
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000792:Angiography; D001011:Aorta; D001013:Aorta, Thoracic / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D001018:Aortic Diseases / Q000000981:diagnostic imaging* / Q000601:surgery*; D001837:Body Weights and Measures; D057510:Endovascular Procedures / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D015203:Reproducibility of Results; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed