Pediatric Radiology

, Volume 29, Issue 1, pp 68–72

Observer reliability in grading nephrocalcinosis on ultrasound examinations in children

  • P. T. Dick
  • Bruce M. Shuckett
  • Betty Tang
  • Alan Daneman
  • Sang Whay Kooh

DOI: 10.1007/s002470050539

Cite this article as:
Dick, P., Shuckett, B., Tang, B. et al. Pediatric Radiology (1999) 29: 68. doi:10.1007/s002470050539

Abstract

Background. Nephrocalcinosis is often associated with a variety of hypercalcemic conditions. Diagnostic ultrasound is often used for assessing nephrocalcinosis in children, but its reliability has not been proven. Objective. To determine the reliability of expert interpretation of sonographic films with a grading scale of severity for nephrocalcinosis. Materials and methods. Fifty-eight ultrasonographic films of 30 children with Williams syndrome and other conditions know to be associated with nephrocalcinosis were assessed. We used a blinded randomized design to assess intra- and interobserver reliability. Results. Grades I, II, and III nephrocalcinosis were noted in 13 %, 19 %, and 27 % of the examinations, respectively. The weighted kappa coefficient was 0.80 (standard error 0.12; 95 % confidence interval 0.68–0.92) for intraobserver agreement and 0.76 (standard error 0.13; 95 % confidence interval 0.63 to 0.89) for interobserver agreement. Reliability in assessing change from one examination to the next, with independently graded films, was fair with an unweighted kappa coefficient of 0.68 (95 % confidence interval 0.38–0.96) and 0.51 (95 % confidence interval 0.21–0.80) for intra- and interobserver reliability, respectively. Conclusion. The severity of nephrocalcinosis can be reliably interpreted with an ultrasonography grading scale.

Copyright information

© Springer-Verlag Berlin Heidelberg 1999

Authors and Affiliations

  • P. T. Dick
    • 1
  • Bruce M. Shuckett
    • 3
  • Betty Tang
    • 2
  • Alan Daneman
    • 3
  • Sang Whay Kooh
    • 2
  1. 1.Paediatric Research Outcomes Team, Division of Paediatric Medicine, The Hospital for Sick Children, University of Toronto 555 University Avenue, Toronto, Ontario M5G 1X8, CanadaCA
  2. 2.Division of Endocrinology, Department of Paediatrics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, CanadaCA
  3. 3.Department of Diagnostic Imaging, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, CanadaCA