title: Are two-dimensional CT measurements of small noncalcified pulmonary nodules reliable?
abstract: OBJECTIVE
  To evaluate the intra- and interreader agreement of two-dimensional computed tomographic (CT) measurements of pulmonary nodules less than 2 cm in diameter.
  
  
  METHODS
  Three readers independently made three serial measurements of each of 54 pulmonary nodules measuring 3-18 mm that had been observed on standard-dose multisection CT images obtained in 24 patients who ranged in age from 36 to 81 years (mean age, 54.6 years). There were 14 women (58%), who ranged in age from 43 to 81 years (mean age, 58.9 years), and 10 men (42%), who ranged in age from 36 to 65 years (mean age, 48.5 years). The largest transverse cross-sectional diameter of each nodule was measured at picture archiving and communication system, or PACS, workstations by using high-spatial-resolution reconstructed CT images and identical window settings. Intra- and interreader agreement were determined by using methods described by Bland and Altman: the coefficient of repeatability for intrareader agreement, and methods derived from the 95% limits of agreement defined by Bland and Altman for interreader agreement.
  
  
  RESULTS
  The repeatability coefficients were 1.70, 1.32, and 1.51 mm for readers 1, 2, and 3, respectively. The 95% limits of agreement for the difference among readers were -1.73 and 1.73.
  
  
  CONCLUSIONS
  Two-dimensional CT measurements are not reliable in the evaluation of small noncalcified pulmonary nodules.
authors.affiliation: Department of Radiology, Assistance Publique des Hôpitaux de Paris/INSERM, Georges Pompidou European University Hospital, 20 Rue Leblanc, 75015 Paris, France. marie-pierre.revel@hop.egp.ap-hop-paris.fr
authors.forename: Marie-Pierre
authors.initials: MP
authors.lastname: Revel
authors.forename: Alvine
authors.initials: A
authors.lastname: Bissery
authors.forename: Marie
authors.initials: M
authors.lastname: Bienvenu
authors.forename: Laetitia
authors.initials: L
authors.lastname: Aycard
authors.forename: Catherine
authors.initials: C
authors.lastname: Lefort
authors.forename: Guy
authors.initials: G
authors.lastname: Frija
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008171:Lung Diseases / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed / Q000379:methods* / Q000706:statistics & numerical data