title: Ultrasound measurement of aortic diameter in a national screening programme.
abstract: OBJECTIVE
  Currently there is no universally accepted standard for ultrasound measurement of abdominal aortic aneurysm (AAA). The aim was to investigate the reliability and reproducibility of inner to inner (ITI) versus outer to outer (OTO) ultrasound measurement of AAA diameter.
  
  
  METHODS
  A prospective study design was used to collect 60 random images of aorta (1.4-7.1 cm). Inner and outer wall diameter measurements were then performed by 13 qualified AAA screening technicians and 11 vascular sonographers.
  
  
  RESULTS
  The mean (range) diameter for all 60 aortas by ITI was 3.91 cm (1.39-6.80) and by OTO was 4.18 cm (1.63-7.09), a significant mean difference of 0.27 cm (95% CI: 0.23-0.32 cm). The reproducibility coefficients for differences between technicians were 0.30 cm (95% CI: 0.24-0.36) for ITI and 0.42 cm (95% CI: 0.35-0.49) for OTO indicating significantly better repeatability using ITI. Finally, 15 images were measured twice in random order by all screeners and sonographers. For AAAs > 5 cm, repeatability was significantly better with ITI than OTO (0.14 vs. 0.21; p = 0.016).
  
  
  CONCLUSIONS
  There was the expected difference in AAA diameter between the two methods (0.27 cm). However, ITI wall method was measurably more reproducible.
authors: Department of Vascular and Endovascular Surgery, Leicester Royal Infirmary, Leicester, UK. tim.hartshorne@uhl-tr.nhs.uk
authors: T C
authors: TC
authors: Hartshorne
authors: C N
authors: CN
authors: McCollum
authors: J J
authors: JJ
authors: Earnshaw
authors: J
authors: J
authors: Morris
authors: A
authors: A
authors: Nasim
mesh_terms: D017544:Aortic Aneurysm, Abdominal / Q000000981:diagnostic imaging*; D004739:England; D006801:Humans; D008403:Mass Screening / Q000379:methods*; D009313:National Health Programs; D015588:Observer Variation; D011237:Predictive Value of Tests; D011446:Prospective Studies; D015203:Reproducibility of Results; D014463:Ultrasonography