Anne G Egekvist1,2, Axel Forman1,2, Mads Riiskjaer1,2, Ulrik S Kesmodel3,4, Mie Mathiasen1,2, Mikkel Seyer-Hansen1,2. 1. Department of Clinical Medicine, Aarhus University, Aarhus, Denmark. 2. Department of Obstetrics and Gynecology, Aarhus University Hospital, Aarhus, Denmark. 3. Department of Obstetrics and Gynecology, Herlev and Gentofte University Hospital, Herlev, Denmark. 4. Institute for Clinical Medicine, University of Copenhagen, Copenhagen, Denmark.
Abstract
INTRODUCTION: The aim of the study was to assess the intra- and interobserver variability of two- and three-dimensional rectosigmoid nodule size measurements by transvaginal sonography in patients with rectosigmoid endometriosis. MATERIAL AND METHODS: Intra- and interobserver variability was assessed in 10 and 30 patients, respectively. Measurements in two dimensions were performed in real-time during the scan, and three-dimensional measurements of volume were done on a computer. Differences within and between observers were expressed in absolute units (mm) and percentage (%) of average nodule size. Coefficient of repeatability and Bland-Altman plots with limits of agreement were used to evaluate the intra- and interobserver variability. RESULTS: Intra- and interobserver variability in two-dimensional sonography ranged from 11 to 14 mm (46-51%) for length, 3 to 6 mm (32-57%) for depth and 5 to 9 mm (33-58%) for width of the nodule. Results of three-dimensional sonography, with assessment of nodule volume, showed intra- and interobserver variability 0.4 to 2.5 times the average nodule size. CONCLUSIONS: Measurements of rectosigmoid endometriosis nodule size with two- and three- dimensional transvaginal sonography were associated with large intra- and interobserver variability. These techniques should therefore be used with caution in clinical control and research of nodule growth.
INTRODUCTION: The aim of the study was to assess the intra- and interobserver variability of two- and three-dimensional rectosigmoid nodule size measurements by transvaginal sonography in patients with rectosigmoid endometriosis. MATERIAL AND METHODS: Intra- and interobserver variability was assessed in 10 and 30 patients, respectively. Measurements in two dimensions were performed in real-time during the scan, and three-dimensional measurements of volume were done on a computer. Differences within and between observers were expressed in absolute units (mm) and percentage (%) of average nodule size. Coefficient of repeatability and Bland-Altman plots with limits of agreement were used to evaluate the intra- and interobserver variability. RESULTS: Intra- and interobserver variability in two-dimensional sonography ranged from 11 to 14 mm (46-51%) for length, 3 to 6 mm (32-57%) for depth and 5 to 9 mm (33-58%) for width of the nodule. Results of three-dimensional sonography, with assessment of nodule volume, showed intra- and interobserver variability 0.4 to 2.5 times the average nodule size. CONCLUSIONS: Measurements of rectosigmoid endometriosis nodule size with two- and three- dimensional transvaginal sonography were associated with large intra- and interobserver variability. These techniques should therefore be used with caution in clinical control and research of nodule growth.