title: Differentiating small (≤1 cm) focal liver lesions as metastases or cysts by means of computed tomography: a case-study to illustrate a fuzzy logic-based method to assess the impact of diagnostic confidence on radiological diagnosis.
abstract: OBJECTIVE
  To quantify the impact of diagnostic confidence on radiological diagnosis with a fuzzy logic-based method.
  
  
  METHODS
  Twenty-two oncologic patients with 20 cysts and 30 metastases ≤1 cm in size found at 64-row computed tomography were included. Two readers (R1/R2) expressed diagnoses as a subjective level of confidence P(d) in malignancy within the interval [0,1] rather than on a "crisp" basis (malignant/benign); confidence in benignancy was 1 - p(d). When cross-tabulating data according to the standard of reference, 2 × 2 table cells resulted from the aggregation between p(d)/1 - p(d) and final diagnosis. We then assessed (i) readers diagnostic performance on a fuzzy and crisp basis; (ii) the "divergence" δ(F, C) (%) as a measure of how confidence impacted on crisp diagnosis.
  
  
  RESULTS
  Diagnoses expressed with lower confidence increased fuzzy false positives compared to crisp ones (from 0 to 0.2 for R1; from 1 to 2.4 for R2). Crisp/fuzzy accuracy was 94.0%/93.6% (R1) and 94.0/91.6% (R2). δ(F, C) (%) was larger in the case of the less experienced reader (R2) (up to +7.95% for specificity). According to simulations, δ(F, C) (%) was negative/positive depending on the level of confidence in incorrect diagnoses.
  
  
  CONCLUSIONS
  Fuzzy evaluation shows a measurable effect of uncertainty on radiological diagnoses.
authors.affiliation: Institute of Diagnostic Radiology, University of Udine Az. Ospedaliero-Universitaria "S. Maria della Misericordia", Via Colugna No. 50, 33100 Udine, Italy.
authors.forename: Rossano
authors.identifier: 0000-0002-0904-5147
authors.initials: R
authors.lastname: Girometti
authors.affiliation: Department of Mathematics and Earth Sciences, University of Trieste, Via Valerio 12b, 34127 Trieste, Italy.
authors.forename: Francesco
authors.identifier: 0000-0002-1950-8838
authors.initials: F
authors.lastname: Fabris
authors.affiliation: Department of Mathematics and Earth Sciences, University of Trieste, Via Valerio 12b, 34127 Trieste, Italy.
authors.forename: Andrea
authors.identifier: 0000-0002-7048-1466
authors.initials: A
authors.lastname: Sgarro
authors.affiliation: Department of Emergency Medicine, Palmanova Hospital, Via Natisone 1, 33057 Palmanova, Italy.
authors.forename: Gloria
authors.initials: G
authors.lastname: Zanella
authors.affiliation: Institute of Diagnostic Radiology, University of Udine Az. Ospedaliero-Universitaria "S. Maria della Misericordia", Via Colugna No. 50, 33100 Udine, Italy.
authors.forename: Serena
authors.initials: S
authors.lastname: Pullini
authors.affiliation: Institute of Diagnostic Radiology, University of Udine Az. Ospedaliero-Universitaria "S. Maria della Misericordia", Via Colugna No. 50, 33100 Udine, Italy.
authors.forename: Lorenzo
authors.identifier: 0000-0003-4480-8872
authors.initials: L
authors.lastname: Cereser
authors.affiliation: Institute of Diagnostic Radiology, University of Udine Az. Ospedaliero-Universitaria "S. Maria della Misericordia", Via Colugna No. 50, 33100 Udine, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Como
authors.affiliation: Institute of Diagnostic Radiology, University of Udine Az. Ospedaliero-Universitaria "S. Maria della Misericordia", Via Colugna No. 50, 33100 Udine, Italy.
authors.forename: Chiara
authors.identifier: 0000-0001-5132-3115
authors.initials: C
authors.lastname: Zuiani
authors.affiliation: Institute of Diagnostic Radiology, University of Udine Az. Ospedaliero-Universitaria "S. Maria della Misericordia", Via Colugna No. 50, 33100 Udine, Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: Bazzocchi
mesh_terms: D000328:Adult; D000368:Aged; D000465:Algorithms; D003936:Diagnosis, Computer-Assisted / Q000379:methods; D005260:Female; D017143:Fuzzy Logic; D006801:Humans; D008099:Liver / Q000473:pathology; D008113:Liver Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging*; D008297:Male; D008490:Medical Informatics; D008875:Middle Aged; D009362:Neoplasm Metastasis; D011237:Predictive Value of Tests; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*