title: Pulmonary lesions detected in population-based CT screening for lung cancer: reliable findings of benign lesions.
abstract: OBJECTIVE
  To identify the characteristics of benign pulmonary lesions in order to reduce false-positive rates in screening computed tomography (CT) and in order to reduce frequency of follow-up high-resolution CT (HRCT).
  
  
  METHODS
  We evaluated 238 screening-detected benign lesions and 23 screening-detected lung cancers for 12 characteristics: spiculation, well-defined margin, concave margin, polygonal shape, notch/lobulation, solid component, ground-glass opacity (GGO), air bronchogram, cavity, bubble-like appearance, pleural indentation, and vascular convergence. We also measured the lesion diameters to set a threshold for benign lesions. We tested combinations of these characteristics to differentiate benign lesions from lung cancers.
  
  
  RESULTS
  By using certain combinations of the characteristics that showed statistically significant differences between benign lesions and lung cancers, benign lesions could be extracted without contamination by lung cancer in screening CT, when the combination included solid component as a positive finding. In HRCT, more than 80% of the benign lesions could be extracted without contamination by lung cancer when the combination included GGO as a negative finding.
  
  
  CONCLUSIONS
  It seems possible to reduce the frequency of follow-up HRCT to establish a diagnosis of benign lesions using certain combinations of the characteristics of benign nodules.
authors.affiliation: Department of Radiology, Ehime University School of Medicine, Shitsukawa, Japan.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Murakami
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Yasuhara
authors.forename: Shinji
authors.initials: S
authors.lastname: Yoshioka
authors.forename: Masahiko
authors.initials: M
authors.lastname: Uemura
authors.forename: Teruhito
authors.initials: T
authors.lastname: Mochizuki
authors.forename: Junpei
authors.initials: J
authors.lastname: Ikezoe
mesh_terms: D000368:Aged; D003937:Diagnosis, Differential; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D008171:Lung Diseases / Q000000981:diagnostic imaging / Q000453:epidemiology; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000453:epidemiology*; D008297:Male; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D015203:Reproducibility of Results; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods