title: Interscan variation of semi-automated volumetry of subsolid pulmonary nodules.
abstract: BACKGROUND
  We aimed to test the interscan variation of semi-automatic volumetry of subsolid nodules (SSNs), as growth evaluation is important for SSN management.
  
  
  METHODS
  From a lung cancer screening trial all SSNs that were stable over at least 3 months were included (N = 44). SSNs were quantified on the baseline CT by two observers using semi-automatic volumetry software for effective diameter, volume, and mass. One observer also measured the SSNs on the second CT 3 months later. Interscan variation was evaluated using Bland-Altman plots. Observer agreement was calculated as intraclass correlation coefficient (ICC). Data are presented as mean (± standard deviation) or median and interquartile range (IQR). A Mann-Whitney U test was used for the analysis of the influence of adjustments on the measurements.
  
  
  RESULTS
  Semi-automatic measurements were feasible in all 44 SSNs. The interscan limits of agreement ranged from -12.0 % to 9.7 % for diameter, -35.4 % to 28.6 % for volume and -27.6 % to 30.8 % for mass. Agreement between observers was good with intraclass correlation coefficients of 0.978, 0.957, and 0.968 for diameter, volume, and mass, respectively.
  
  
  CONCLUSIONS
  Our data suggest that when using our software an increase in mass of 30 % can be regarded as significant growth.
  
  
  CONCLUSIONS
  • Recently, recommendations regarding subsolid nodules have stressed the importance of growth quantification. • Volumetric measurement of subsolid nodules is feasible with good interscan agreement. • Increase of mass of 30 % can be regarded as significant growth.
authors.affiliation: Department of Radiology, University Medical Center, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands.
authors.forename: Ernst Th
authors.initials: ET
authors.lastname: Scholten
authors.forename: Pim A
authors.initials: PA
authors.lastname: de Jong
authors.forename: Colin
authors.initials: C
authors.lastname: Jacobs
authors.forename: Bram
authors.initials: B
authors.lastname: van Ginneken
authors.forename: Sarah
authors.initials: S
authors.lastname: van Riel
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Willemink
authors.forename: Rozemarijn
authors.initials: R
authors.lastname: Vliegenthart
authors.forename: Matthijs
authors.initials: M
authors.lastname: Oudkerk
authors.forename: Harry J
authors.initials: HJ
authors.lastname: de Koning
authors.forename: Nanda
authors.initials: N
authors.lastname: Horeweg
authors.forename: Mathias
authors.initials: M
authors.lastname: Prokop
authors.forename: Willem P Th M
authors.initials: WP
authors.lastname: Mali
authors.forename: Hester A
authors.initials: HA
authors.lastname: Gietema
mesh_terms: D000368:Aged; D055088:Early Detection of Cancer; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D003074:Solitary Pulmonary Nodule / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed / Q000379:methods*