Related Experiment Video
Updated: Mar 25, 2026
Four-Dimensional CT Analysis Using Sequential 3D-3D Registration
Published on: November 23, 2019
Comparison of 2D radiography and a semi-automatic CT-based 3D method for measuring change in dorsal angulation over
Albert Christersson1, Johan Nysjö2, Lars Berglund3
1Department of Orthopaedics, Uppsala University, S-751 85, Uppsala, Sweden. albert.christersson@akademiska.se.
Objective:
The aim of the present study was to compare the reliability and agreement between a computer tomography-based method (CT) and digitalised 2D radiographs (XR) when measuring change in dorsal angulation over time in distal radius fractures.
Materials And Methods:
Radiographs from 33 distal radius fractures treated with external fixation were retrospectively analysed. All fractures had been examined using both XR and CT at six times over 6 months postoperatively. The changes in dorsal angulation between the first reference images and the following examinations in every patient were calculated from 133 follow-up measurements by two assessors and repeated at two different time points. The measurements were analysed using Bland-Altman plots, comparing intra- and inter-observer agreement within and between XR and CT.
Results:
The mean differences in intra- and inter-observer measurements for XR, CT, and between XR and CT were close to zero, implying equal validity. The average intra- and inter-observer limits of agreement for XR, CT, and between XR and CT were ± 4.4°, ± 1.9° and ± 6.8° respectively.
Conclusions:
For scientific purpose, the reliability of XR seems unacceptably low when measuring changes in dorsal angulation in distal radius fractures, whereas the reliability for the semi-automatic CT-based method was higher and is therefore preferable when a more precise method is requested.
