title: High resolution CT in differentiating minimally invasive component in early lung adenocarcinoma.
abstract: OBJECTIVE
  To analyze high-resolution computed tomography (HRCT) appearances of early lung adenocarcinoma and evaluate HRCT in the differentiation of minimally invasive component in early lung adenocarcinoma.
  
  
  METHODS
  HRCT appearances of 140 nodules (less than 2 cm in diameter) of early lung adenocarcinoma were reviewed retrospectively. All these nodules were proven by surgery and pathology including 60 nodules of minimally invasive adenocarcinoma (MIA) and 80 nodules of preinvasive lesion (PL). HRCT features of two groups of lung nodules, including shape, margin, pattern, diameter, diameter of solid component, vascular changes, air bronchogram, vacuole, pleural indentation and multiplicity were analyzed and compared using univariate logistic regression analysis. Attenuation values of pure ground-glass nodule, pure ground-glass component and solid component of mixed ground-glass nodule were compared by using unpaired t-test or Wilcoxon rank-sum test.
  
  
  RESULTS
  The statistically significant differences were found in shape, margin, pattern, diameter, diameter of solid component, pulmonary vein changes, air bronchogram and pleural indentation (Odds ratio [OR] = 3.115 [P = 0.001], OR = 3.754 [P = 0.011], OR = 9.815 [P = 0.000], OR = 1.306 [P = 0.000], OR = 1.361 [P = 0.031], OR= 6.971 [P = 0.000], OR = 6.167 [P=0.000], OR = 2.296 [P = 0.027], respectively). The statistically significant difference was also found in attenuation value of solid component (t = 3.702, P = 0.000). By multivariate logistic analysis, attenuation value of solid component was significantly associated with MIA (OR = 1.005, P = 0.032). MIA was more often a larger, lobulated or irregular, mixed ground-glass nodule with a solid component larger than 5 mm, and higher attenuation values. In addition, MIA often had an abnormality in pulmonary vein, air bronchogram and pleural indentation.
  
  
  CONCLUSIONS
  HRCT can demonstrate the morphological features of early lung adenocarcinoma and identify minimally invasive component.
authors.affiliation: Department of Radiology, Jinshan Hospital & Shanghai Medical College, Fudan University, Shanghai 201508, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Radiology, Jinshan Hospital & Shanghai Medical College, Fudan University, Shanghai 201508, China. Electronic address: dr.jinweiqiang@163.com.
authors.forename: Jin Wei
authors.initials: JW
authors.lastname: Qiang
authors.affiliation: Department of Radiology, Chest Hospital, Shanghai Jiaotong University, Shanghai 200030, China. Electronic address: yejianding@126.com.
authors.forename: Jian Ding
authors.initials: JD
authors.lastname: Ye
authors.affiliation: Department of Radiology, Chest Hospital, Shanghai Jiaotong University, Shanghai 200030, China.
authors.forename: Xiao Dan
authors.initials: XD
authors.lastname: Ye
authors.affiliation: Department of Pathology, Chest Hospital, Shanghai Jiaotong University, Shanghai 200030, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Zhang
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging* / Q000473:pathology*; D000077192:Adenocarcinoma of Lung; D000368:Aged; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D011857:Radiographic Image Interpretation, Computer-Assisted; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*
keywords: Adenocarcinoma in situ; Atypical adenomatous hyperplasia; High-resolution CT; Lung cancer; Minimally invasive adenocarcinoma; Preinvasive lesion