title: Measurement of localized ground-glass attenuation on thin-section computed tomography images: correlation with the progression of bronchioloalveolar carcinoma of the lung.
abstract: OBJECTIVE
  This study was to measure localized ground-glass attenuation (GGA) in the peripheral lung on thin-section computed tomography (CT) and to assess any relationship between the attenuation and lesion.
  
  
  METHODS
  Twenty-eight surgically resected tumors with localized GGA at thin-section CT were studied. The tumors were histologically diagnosed as 8 atypical adenomatous hyperplasia (AAH), 11 bronchioloalveolar carcinoma (BAC), and 9 BAC with fibrosis. We assumed three concentric circles, which were 0.8, 1.0, and 1.2 times the diameter of each tumor and measured the average CT values corresponding to inside each circle. We calculated a difference in CT value between 0.8 and 1.2 times the diameter of the tumor and defined as the contrast index.
  
  
  RESULTS
  The contrast index for tumors with AAH, BAC, and BAC with fibrosis were 19.8 +/- 8.3, 42.5 +/- 16.0 (P < 0.05 vs. group with AAH), and 111.4 +/- 32.6 (P < 0.0001 vs. Group with BAC), respectively. The contrast index became greater in the stepwise progression from AAH to BAC and from BAC to BAC with fibrosis.
  
  
  CONCLUSIONS
  The contrast index correlated histologic findings of the tumor growth in BAC. The contrast index may be a useful and objective measurement for determining surgical treatment for localized GGA in preoperative diagnosis.
authors.affiliation: Department of Radiology, Matsuyama Medical Center for Cancer and Cardiovascular Disease, Ehime, Japan. minagao@ehime.med.or.jp
authors.forename: Michinobu
authors.initials: M
authors.lastname: Nagao
authors.forename: Kenya
authors.initials: K
authors.lastname: Murase
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Yasuhara
authors.forename: Junpei
authors.initials: J
authors.lastname: Ikezoe
authors.forename: Kenji
authors.initials: K
authors.lastname: Eguchi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Mogami
authors.forename: Koichi
authors.initials: K
authors.lastname: Mandai
authors.forename: Masao
authors.initials: M
authors.lastname: Nakata
authors.forename: Yumi
authors.initials: Y
authors.lastname: Ooshiro
mesh_terms: D002282:Adenocarcinoma, Bronchiolo-Alveolar / Q000000981:diagnostic imaging* / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D018450:Disease Progression; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed