title: Reliability and Reproducibility of Manual and Automated Volumetric Measurements of Periapical Lesions.
abstract: BACKGROUND
  The present study aimed to test the reliability and reproducibility of 2 methods: manual and automated segmentation (using a threshold-based region growing algorithm) for measuring the volume of periapical lesions.
  
  
  METHODS
  A total of 43 cone-beam computed tomographic scans (14 men and 29 women, mean age of 54.6 ± 8.5 years) were analyzed by 3 observers. Intraobserver reproducibility and interobserver reliability were assessed using the intraclass correlation coefficient. Parametric correlation between manual and automated volumetric measurements was performed. In addition, the Student t test was also used to compare the mean time required for manual and automated volumetric measurements.
  
  
  RESULTS
  Automated segmentation showed slightly higher intraclass correlation coefficient values for all observers. A strong significant correlation was found between manual and automated volumetric measurements performed by the 3 observers. A significant difference in the mean procedure time was also found between both methods (P = .001).
  
  
  CONCLUSIONS
  Within the limitations of this study, the present results suggest that automated segmentation with a region growing algorithm is faster and slightly more reliable to calculate the volume of periapical lesions.
authors.affiliation: Department of Stomatology, School of Dentistry, University of São Paulo, São Paulo, Brazil.
authors.forename: Eduardo Massaharu
authors.initials: EM
authors.lastname: Aoki
authors.affiliation: Department of Stomatology, School of Dentistry, University of São Paulo, São Paulo, Brazil.
authors.forename: Reinaldo
authors.initials: R
authors.lastname: Abdala-Júnior
authors.affiliation: Department of Stomatology, School of Dentistry, University of São Paulo, São Paulo, Brazil.
authors.forename: Jefferson Xavier
authors.initials: JX
authors.lastname: de Oliveira
authors.affiliation: Department of Stomatology, School of Dentistry, University of São Paulo, São Paulo, Brazil.
authors.forename: Emiko Saito
authors.initials: ES
authors.lastname: Arita
authors.affiliation: Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, Massachusetts; Harvard Medical School, Boston, Massachusetts. Electronic address: acortes@nmr.mgh.harvard.edu.
authors.forename: Arthur Rodriguez Gonzalez
authors.initials: AR
authors.lastname: Cortes
mesh_terms: D000465:Algorithms; D054893:Cone-Beam Computed Tomography / Q000379:methods*; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D010485:Periapical Periodontitis / Q000000981:diagnostic imaging* / Q000209:etiology; D015203:Reproducibility of Results; D012189:Retrospective Studies; D019553:Tooth, Nonvital / Q000000981:diagnostic imaging*
keywords: Cone-beam computed tomography; periapical lesions; region growing; segmentation; volumetric measurements