title: Long term follow-up for small pure ground-glass nodules: implications of determining an optimum follow-up period and high-resolution CT findings to predict the growth of nodules.
abstract: OBJECTIVE
  To identify the optimum follow-up period for pure ground-glass nodules (GGN) measuring less than 15 mm in diameter, and to evaluate whether the initial HRCT findings can be used as predictors for the progression of pure GGN.
  
  
  METHODS
  A total of 150 pure GGNs present in 111 patients were evaluated. The series of HRCT images for each GGN at the time of the initial detection, 2 years after detection, and at the final follow-up were evaluated. The HRCT findings of GGN were compared between the "increasing nodule" and "non-increasing nodule" groups.
  
  
  RESULTS
  Most (87.3%) pure GGN did not increase whereas some nodules (12.7%) eventually increased after long-term follow-up (mean 66.0 ± 25.0 months). Six (31.6%) out of the 19 increasing nodules were regarded as stable at the 2 year follow-up examination. Some morphological findings on initial HRCT, including a size greater than 10 mm (p = 0.001), lobulated margins (p = 0.015), and a bubble-like appearance (p = 0.002), were significantly associated with the growth of pure GGNs.
  
  
  CONCLUSIONS
  More than 2 years of follow-up are necessary to detect the growth of pure GGNs. Some characteristic findings indicated a high likelihood of future growth of the GGN.
authors.affiliation: Department of Radiology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505, Japan. tshotaro@yamaguchi-u.ac.jp
authors.forename: Shotaro
authors.initials: S
authors.lastname: Takahashi
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Tanaka
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Okimoto
authors.forename: Toshiki
authors.initials: T
authors.lastname: Tanaka
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Ueda
authors.forename: Tsuneo
authors.initials: T
authors.lastname: Matsumoto
authors.forename: Kazuto
authors.initials: K
authors.lastname: Ashizawa
authors.forename: Yoshie
authors.initials: Y
authors.lastname: Kunihiro
authors.forename: Shoji
authors.initials: S
authors.lastname: Kido
authors.forename: Naofumi
authors.initials: N
authors.lastname: Matsunaga
mesh_terms: 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; D011237:Predictive Value of Tests; D011857:Radiographic Image Interpretation, Computer-Assisted; D012189:Retrospective Studies; D003074:Solitary Pulmonary Nodule / Q000000981:diagnostic imaging* / Q000473:pathology; D018709:Statistics, Nonparametric; D014057:Tomography, X-Ray Computed / Q000379:methods*