title: Pulmonary adenocarcinomas with ground-glass attenuation on thin-section CT: quantification by three-dimensional image analyzing method.
abstract: OBJECTIVE
  The purpose of this study was to evaluate software designed to calculate whole tumor volumes and the ratio of the solid component to whole volume (%solid) in pulmonary nodules with ground-glass opacity in three dimensions.
  
  
  METHODS
  The study included 49 patients with histologically diagnosed adenocarcinomas smaller than 2 cm in diameter. The %solid was calculated both automatically using new software, and by manual measurement of the following four parameters by two observers: the ratio of the largest diameter (a) and the area (b) at the mediastinal window to those at the lung window, and the ratio of the largest diameter (c) and the area (d) of the solid component to those of the ground-glass component at the lung window. Agreement of intra- and inter-observer data by both Spearman's rank correlation test and Bland-Altman's method, and a comparison by Spearman's rank correlation test of the %solid in both Noguchi sub-classifications and vessel invasion in histologic specimens, between the software and manual methods, were assessed.
  
  
  RESULTS
  Of the 49 nodules, 48 were successfully measured and assessed. The agreement of the observers with the software was better (Bland-Altman's method; mean difference, -0.3%; 95% limits of agreement, -3.1 to 2.5%) than with the manual measurements (a: 5.3%, -17.6 to 28.3%; b: 8.3%, -10.6 to 26.9%; c: 10.7%, -17.6 to 39%; d: 6.4%, -22 to 34.8%). The correlation between %solid and the histological group was worse with the software (Spearman's rank correlation test; r=0.487, p<0.001) than with the manual method (a, r=0.534; b, r=0.557; c, r=0.552; d, r=0.545).
  
  
  CONCLUSIONS
  Although the software requires improvement in the calculation of %solid with volumetric analysis, this is a reproducible and promising quantitative method for determining the grades of malignancy of small lung cancers.
authors.affiliation: Department of Diagnostic and Interventional Radiology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0825, Japan. h-sumikawa@radiol.med.osaka-u.ac.jp
authors.forename: Hiromitsu
authors.initials: H
authors.lastname: Sumikawa
authors.forename: Takeshi
authors.initials: T
authors.lastname: Johkoh
authors.forename: Tomofumi
authors.initials: T
authors.lastname: Nagareda
authors.forename: Junko
authors.initials: J
authors.lastname: Sekiguchi
authors.forename: Kumiko
authors.initials: K
authors.lastname: Matsuo
authors.forename: Yuka
authors.initials: Y
authors.lastname: Fujita
authors.forename: Javzandulam
authors.initials: J
authors.lastname: Natsag
authors.forename: Atsuo
authors.initials: A
authors.lastname: Inoue
authors.forename: Naoki
authors.initials: N
authors.lastname: Mihara
authors.forename: Osamu
authors.initials: O
authors.lastname: Honda
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Tomiyama
authors.forename: Masato
authors.initials: M
authors.lastname: Minami
authors.forename: Meinoshin
authors.initials: M
authors.lastname: Okumura
authors.forename: Hironobu
authors.initials: H
authors.lastname: Nakamura
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging* / Q000473:pathology; D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D012372:ROC Curve; D014057:Tomography, X-Ray Computed / Q000379:methods*