title: Spiral CT of pulmonary nodules: interobserver variation in assessment of lesion size.
abstract: The aim of this study was to assess interobserver variability in size determination of pulmonary nodules at spiral CT. Twenty-three patients with known pulmonary nodules (diameter 2-40 mm, mean diameter 7 mm) underwent spiral chest CT (collimation 5 mm, pitch 1). Images were reconstructed at 3- and 5-mm intervals (RI). Hard copies were analyzed by two radiologists who recorded every nodule with regard to location, diagnostic confidence ("definite," "probable") and nodule size in increments of 1 mm with specific attention to correct classification into one of three size classes (< or = 5 mm, 6-10 mm, > 10 mm). Interobserver variability was determined with Pearson's correlation coefficient and kappa measure. Of a total of 286 nodules, 103 nodules were found accordingly by both readers at 3 mm RI, and 96 at 5 mm RI. There was a good correlation of measurements (in millimeters) between both readers (Pearson's correlation coefficient: 0.89-0.95). Interobserver variability in categories was good at both reconstruction intervals (kappa: 0.61 at 3 mm, 0.74 at 5 mm RI) and very good (0.81) at 5 mm RI when uncertain nodules were excluded. Spiral CT allows reproducible size determination of pulmonary nodules as shown by good interobserver agreement in exact size measurement and categorization into three size classes.
authors.affiliation: Department of Clinical Radiology, University of Muenster, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Wormanns
authors.forename: S
authors.initials: S
authors.lastname: Diederich
authors.forename: M G
authors.initials: MG
authors.lastname: Lentschig
authors.forename: F
authors.initials: F
authors.lastname: Winter
authors.forename: W
authors.initials: W
authors.lastname: Heindel
mesh_terms: D002138:Calibration; D002921:Cicatrix / Q000000981:diagnostic imaging; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008171:Lung Diseases / Q000000981:diagnostic imaging; D008175:Lung Neoplasms / Q000000981:diagnostic imaging; D015588:Observer Variation; D015203:Reproducibility of Results; D003074:Solitary Pulmonary Nodule / Q000145:classification / Q000000981:diagnostic imaging*; D013223:Statistics as Topic; D014057:Tomography, X-Ray Computed / Q000379:methods*