title: Pulmonary nodules: effect of increased data sampling on detection with spiral CT and confidence in diagnosis.
abstract: OBJECTIVE
  To compare spiral computed tomography (CT) with interscan spacing of 4-5 mm versus 8-10 mm for detection rate and level of confidence in diagnosis of pulmonary nodules.
  
  
  METHODS
  Four radiologists (two junior and two senior faculty members) retrospectively reviewed 67 spiral CT studies with one to six nodules per study. Every second image was masked, which resulted in 8-mm sections every 8 or 10 mm; then all images reconstructed every 4 or 5 mm were reviewed. Lesions were classified as definite, probable, or possible.
  
  
  RESULTS
  Narrow interscan spacing yielded more lesions overall (583 vs 566, P < .025) and more definite lesions and fewer equivocal lesions (482 vs 431 and 101 vs 135, respectively; P < .055). The greatest effects were in the reduction of possible lesions (50 vs 88, P < .001) and in the reduction of false-positive diagnoses made by less experienced radiologists.
  
  
  CONCLUSIONS
  Increased reconstruction frequency of spiral CT volume data sets improves detection of pulmonary nodules and enhances confidence in the diagnosis.
authors.affiliation: Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Hospital, Baltimore, MD 21287, USA.
authors.forename: J A
authors.initials: JA
authors.lastname: Buckley
authors.forename: W W
authors.initials: WW
authors.lastname: Scott
authors.forename: S S
authors.initials: SS
authors.lastname: Siegelman
authors.forename: J E
authors.initials: JE
authors.lastname: Kuhlman
authors.forename: B A
authors.initials: BA
authors.lastname: Urban
authors.forename: D A
authors.initials: DA
authors.lastname: Bluemke
authors.forename: E K
authors.initials: EK
authors.lastname: Fishman
mesh_terms: D005189:False Positive Reactions; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012372:ROC Curve; D012189:Retrospective Studies; D003074:Solitary Pulmonary Nodule / Q000000981:diagnostic imaging* / Q000453:epidemiology; D014057:Tomography, X-Ray Computed / Q000379:methods*