Journal of Vascular Surgery
Volume 45, Issue 2 , Pages 263-268, February 2007

Intraobserver and interobserver variability of 64-row computed tomography abdominal aortic aneurysm neck measurements

  • Nicolas Diehm, MD

      Affiliations

    • Division of Clinical and Interventional Angiology, Swiss Cardiovascular Center, Inselspital, University Hospital of Bern, Bern, Switzerland
    • ,
  • Ralph Kickuth, MD

      Affiliations

    • Institute of Diagnostic and Interventional Radiology, Swiss Cardiovascular Center, Inselspital, University Hospital of Bern, Bern, Switzerland
    • ,
  • Brigitta Gahl, MSc

      Affiliations

    • Department of Cardiovascular Surgery, Swiss Cardiovascular Center, Inselspital, University Hospital of Bern, Bern, Switzerland.
    • ,
  • Dai-Do Do, MD

      Affiliations

    • Division of Clinical and Interventional Angiology, Swiss Cardiovascular Center, Inselspital, University Hospital of Bern, Bern, Switzerland
    • ,
  • Jürg Schmidli, MD

      Affiliations

    • Department of Cardiovascular Surgery, Swiss Cardiovascular Center, Inselspital, University Hospital of Bern, Bern, Switzerland.
    • ,
  • Henning Rattunde, MD

      Affiliations

    • Institute of Diagnostic and Interventional Radiology, Swiss Cardiovascular Center, Inselspital, University Hospital of Bern, Bern, Switzerland
    • ,
  • Iris Baumgartner, MD

      Affiliations

    • Division of Clinical and Interventional Angiology, Swiss Cardiovascular Center, Inselspital, University Hospital of Bern, Bern, Switzerland
    • ,
  • Florian Dick, MD

      Affiliations

    • Department of Cardiovascular Surgery, Swiss Cardiovascular Center, Inselspital, University Hospital of Bern, Bern, Switzerland.
    • Corresponding Author InformationReprint requests: Florian Dick, MD, Department of Cardiovascular Surgery, Swiss Cardiovascular Center, Inselspital, University Hospital of Bern, Freiburgstrasse, 3010 Bern, Switzerland.

Received 2 September 2006; accepted 4 October 2006.

Background

Integrity of the abdominal aortic aneurysm (AAA) neck is crucial for the long-term success of endovascular AAA repair (EVAR). However, suitable tools for reliable assessment of changes in small aortic volumes are lacking. The purpose of this study was to assess the intraobserver and interobserver variability of software-enhanced 64-row computed tomographic angiography (CTA) AAA neck volume measurements in patients after EVAR.

Methods

A total of 25 consecutive patients successfully treated by EVAR underwent 64-row follow-up CTA in 1.5-mm collimation. Manual CTA measurements were performed twice by three blinded and independent readers in random order with at least a 4-week interval between readings. Maximum and minimum transverse aortic neck diameters were measured twice on two different levels within the proximal neck. Volumetry of the proximal aortic neck was performed by using dedicated software. Variability was calculated as 1.96 SD of the mean arithmetic difference according to Bland and Altman. Two-sided and paired t tests were used to compare measurements. P values <.05 were considered to indicate statistical significance.

Results

Intraobserver agreement was excellent for dedicated aneurysmal neck volumetry, with mean differences of less than 1 mL (P > .05), whereas it was poor for transverse aortic neck diameter measurements (P < .05). However, interobserver variability was statistically significant for both neck volumetry (P < .005) and neck diameter measurements (P < .015).

Conclusions

The reliability of dedicated AAA neck volumetry by using 64-row CTA is excellent for serial measurements by individual readers, but not between different readers. Therefore, studies should be performed with aortic neck volumetry by a single experienced reader.

 

 Competition of interest: none.

PII: S0741-5214(06)01848-9

doi:10.1016/j.jvs.2006.10.004

Journal of Vascular Surgery
Volume 45, Issue 2 , Pages 263-268, February 2007

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