title: Predictive value of one-dimensional mean computed tomography value of ground-glass opacity on high-resolution images for the possibility of future change.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the relationship between clinical and radiological findings and the progression of ground-glass opacity (GGO) and to identify risk factors that predict the outcome of pure GGO lesions.
  
  
  METHODS
  A retrospective study was conducted on 63 nodules of pure GGO. Clinical characteristics, the largest diameter, shape, and marginal characteristics, and one-dimensional mean computed tomography (m-CT) value of the GGO lesions were evaluated. During follow-up, 12 GGO lesions increased in size, and 17 appeared as solid portion. These 29 lesions were classified as growth group, and the remaining 34 lesions as stable group.
  
  
  RESULTS
  The m-CT values were -634.9 ± 15.3 and -712.1 ± 14.1 HU for the growth and stable groups, respectively. The growth group was strongly associated with high m-CT values (p = 0.0007) and a history of lung cancer (p = 0.0389), whereas association with smoking habits and the shape of the GGO nodules was marginal. The m-CT values and a history of lung cancer were independent predictors for future changes in GGO lesions (p = 0.0023 and p = 0.0129, respectively). Sixteen of 18 lesions (88.9%) in patients without a history of lung cancer and with low m-CT values showed no nodule changes.
  
  
  CONCLUSIONS
  The m-CT value of GGO lesions is a risk factor associated with their future change. The interval of follow-up CT scanning or treatment policy should be determined considering the m-CT value.
authors.affiliation: Departments of *Surgery and †Radiology, Fukui Prefectural Hospital, Fukui, Japan.
authors.forename: Masaya
authors.initials: M
authors.lastname: Tamura
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Shimizu
authors.forename: Toru
authors.initials: T
authors.lastname: Yamamoto
authors.forename: Jun
authors.initials: J
authors.lastname: Yoshikawa
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Hashizume
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging* / Q000473:pathology*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*