title: Evaluation of effectiveness of a computer system (CAD) in the identification of lung nodules with low-dose MSCT: scanning technique and preliminary results.
abstract: OBJECTIVE
  Evaluation of the effectiveness of computer-aided diagnosis (CAD) in the identification of pulmonary nodules.
  
  
  METHODS
  Two observers (A1, A2) with different levels of experience independently evaluated 20 chest MSCT studies with and without the aid of a CAD system (LungCheck, R2 Technology, Inc). The study parameters were as follows: 140 kVs, 40 mAs, collimation 4 x 1 mm, slice thickness 1.25 mm, reconstruction interval 1.0 mm. The observers analysed the images with and without CAD and evaluated: 1) nodule size (longer axis); 2) number and location of nodules; 3) reading time for each observer. The gold standard was represented by the evaluation of both readers in consensus with the aid of the CAD system.
  
  
  RESULTS
  Without CAD support the two readers identified 77 (A1) and 79 (A2) nodules and with CAD 81 (A1) and 82 (A2) nodules. Working in consensus the two observers identified 81 nodules without the aid of the CAD and 84 nodules with the aid of CAD. Total number of nodules identified by CAD was 104, 25 of which were false positive and 5 false negative. The average reading time with the aid of the CAD decreased by as much as 40% for both the observers.
  
  
  CONCLUSIONS
  The preliminary results of our study suggest that the CAD technique is an accurate automatic support tool in the identification of pulmonary nodules. It reduces reading time and automatically supplies the size, volume, density and number of nodules, thus being useful both in screening programmes and in the follow-up of cancer patients, in whom comparison of the images is particularly difficult.
authors.affiliation: Dipartimento di Scienze Radiologiche, Università degli Studi di Roma La Sapienza, Roma, Italy. francesco.fraioli@uniroma1.it
authors.forename: F
authors.initials: F
authors.lastname: Fraioli
authors.forename: C
authors.initials: C
authors.lastname: Catalano
authors.forename: M
authors.initials: M
authors.lastname: Almberger
authors.forename: L
authors.initials: L
authors.lastname: Bertoletti
authors.forename: V
authors.initials: V
authors.lastname: Cantisani
authors.forename: M
authors.initials: M
authors.lastname: Danti
authors.forename: F
authors.initials: F
authors.lastname: Pediconi
authors.forename: R
authors.initials: R
authors.lastname: Passariello
mesh_terms: D000328:Adult; D000368:Aged; D003936:Diagnosis, Computer-Assisted; D005260:Female; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D003074:Solitary Pulmonary Nodule / Q000000981:diagnostic imaging*; D036542:Tomography, Spiral Computed