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Updated: May 13, 2026

Cortical Bone Assessment Using Ultrasonic Guided Waves: A Reproducibility Study in a Healthy Population
Published on: January 31, 2025
Interobserver variation of single-photon emission computed tomography bone scans in patients evaluated for unilateral
Luc H E Karssemakers1, Pieter G Raijmakers, Jitske W Nolte
1Department of Oral and Maxillofacial Surgery and Oral Pathology, VU University Medical Center, Amsterdam, The Netherlands. l.karssemakers@vumc.nl
Objective:
This study assessed the quantitative evaluation of the region of interest (ROI) by mean and maximum pixel counts of single-photon emission computed tomography (SPECT) scans in patients with clinical suspicion of unilateral condylar hyperactivity (UCH); the interobserver reliability and the correlation of condylar activity with patient age was determined.
Methods:
Two independent observers analyzed 67 bone SPECT scans. Maximum and mean activity values within an ROI on the mandibular condyle were analyzed; a cutoff value of 55% was used to determine the qualitative outcome.
Results:
Excellent interobserver agreement was seen for both maximum (kappa 1.0) and mean activity analysis (kappa 0.94). Maximum and mean condylar activities were strongly correlated (r > 0.98). Maximum and mean condylar activity of the normal condyle decreased significantly with increasing age.
Conclusions:
Maximum and mean condylar activity levels were highly correlated in patients with mandibular asymmetry. An excellent interobserver agreement was found with either maximum or mean condylar activity.
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