title: Interobserver variation of single-photon emission computed tomography bone scans in patients evaluated for unilateral condylar hyperactivity.
abstract: 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.
authors: Department of Oral and Maxillofacial Surgery and Oral Pathology, VU University Medical Center, Amsterdam, The Netherlands. l.karssemakers@vumc.nl
authors: Luc H E
authors: LH
authors: Karssemakers
authors: Pieter G
authors: PG
authors: Raijmakers
authors: Jitske W
authors: JW
authors: Nolte
authors: Dirk B
authors: DB
authors: Tuinzing
authors: Alfred G
authors: AG
authors: Becking
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002648:Child; D005146:Facial Asymmetry / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D006965:Hyperplasia; D007091:Image Processing, Computer-Assisted / Q000706:statistics & numerical data; D008297:Male; D008335:Mandibular Condyle / Q000000981:diagnostic imaging*; D015588:Observer Variation; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D013669:Technetium Tc 99m Medronate / Q000031:analogs & derivatives; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods / Q000706:statistics & numerical data*; D055815:Young Adult
chemical_list: D019275:Radiopharmaceuticals; C024226:technetium Tc 99m hydroxymethylene diphosphonate; D013669:Technetium Tc 99m Medronate