Intra and interobserver reliability and agreement of semiquantitative vertebral fracture assessment on chest computed tomography

PLoS One. 2013 Aug 5;8(8):e71204. doi: 10.1371/journal.pone.0071204. Print 2013.

Abstract

Objectives: To evaluate the reliability of semiquantitative Vertebral Fracture Assessment (VFA) on chest Computed Tomography (CT).

Methods: Four observers performed VFA twice upon sagittal reconstructions of 50 routine clinical chest CTs. Intra- and interobserver agreement (absolute agreement or 95% Limits of Agreement) and reliability (Cohen's kappa or intraclass correlation coefficient(ICC)) were calculated for the visual VFA measures (fracture present, worst fracture grade, cumulative fracture grade on patient level) and for percentage height loss of each fractured vertebra compared to the adjacent vertebrae.

Results: Observers classified 24-38% patients as having at least one vertebral fracture, giving rise to kappa's of 0.73-0.84 (intraobserver) and 0.56-0.81 (interobserver). For worst fracture grade we found good intraobserver (76-88%) and interobserver (74-88%) agreement, and excellent reliability with square-weighted kappa's of 0.84-0.90 (intraobserver) and 0.84-0.94 (interobserver). For cumulative fracture grade the 95% Limits of Agreement were maximally ±1,99 (intraobserver) and ±2,69 (interobserver) and the reliability (ICC) varied from 0.84-0.94 (intraobserver) and 0.74-0.94 (interobserver). For percentage height-loss on a vertebral level the 95% Limits of Agreement were maximally ±11,75% (intraobserver) and ±12,53% (interobserver). The ICC was 0.59-0.90 (intraobserver) and 0.53-0-82 (interobserver). Further investigation is needed to evaluate the prognostic value of this approach.

Conclusion: In conclusion, these results demonstrate acceptable reproducibility of VFA on CT.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Female
  • Humans
  • Lumbar Vertebrae / diagnostic imaging
  • Lumbar Vertebrae / injuries
  • Male
  • Middle Aged
  • Observer Variation
  • Radiography, Thoracic* / statistics & numerical data
  • Reproducibility of Results
  • Spinal Fractures / diagnostic imaging*
  • Spinal Fractures / epidemiology
  • Thoracic Vertebrae / diagnostic imaging
  • Thoracic Vertebrae / injuries*
  • Tomography, X-Ray Computed / methods*
  • Tomography, X-Ray Computed / statistics & numerical data

Grants and funding

This work was supported by a program grant from The Netherlands Organization for Scientific Research-Medical Sciences (NOW-MW project no. 40-00812-98-07-005). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.