title: Volumetric measurement of pulmonary nodules at low-dose chest CT: effect of reconstruction setting on measurement variability.
abstract: OBJECTIVE
  To assess volumetric measurement variability in pulmonary nodules detected at low-dose chest CT with three reconstruction settings.
  
  
  METHODS
  The volume of 200 solid pulmonary nodules was measured three times using commercially available semi-automated software of low-dose chest CT data-sets reconstructed with 1 mm section thickness and a soft kernel (A), 2 mm and a soft kernel (B), and 2 mm and a sharp kernel (C), respectively. Repeatability coefficients of the three measurements within each setting were calculated by the Bland and Altman method. A three-level model was applied to test the impact of reconstruction setting on the measured volume.
  
  
  RESULTS
  The repeatability coefficients were 8.9, 22.5 and 37.5% for settings A, B and C. Three-level analysis showed that settings A and C yielded a 1.29 times higher estimate of nodule volume compared with setting B (P = 0.03). The significant interaction among setting, nodule location and morphology demonstrated that the effect of the reconstruction setting was different for different types of nodules. Low-dose CT reconstructed with 1 mm section thickness and a soft kernel provided the most repeatable volume measurement.
  
  
  CONCLUSIONS
  A wide, nodule-type-dependent range of agreement between volume measurements with different reconstruction settings suggests strict consistency is required for serial CT studies.
authors.affiliation: Department of Radiology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9700 RB, Groningen, The Netherlands.
authors.forename: Ying
authors.initials: Y
authors.lastname: Wang
authors.forename: Geertruida H
authors.initials: GH
authors.lastname: de Bock
authors.forename: Rob J
authors.initials: RJ
authors.lastname: van Klaveren
authors.forename: Peter
authors.initials: P
authors.lastname: van Ooyen
authors.forename: Wim
authors.initials: W
authors.lastname: Tukker
authors.forename: Yingru
authors.initials: Y
authors.lastname: Zhao
authors.forename: Monique D
authors.initials: MD
authors.lastname: Dorrius
authors.forename: Rozemarijn Vliegenthart
authors.initials: RV
authors.lastname: Proença
authors.forename: Wendy J
authors.initials: WJ
authors.lastname: Post
authors.forename: Matthijs
authors.initials: M
authors.lastname: Oudkerk
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D011829:Radiation Dosage; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012984:Software; D003074:Solitary Pulmonary Nodule / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed / Q000379:methods*