title: Multiparametric magnetic resonance imaging of the prostate with computer-aided detection: experienced observer performance study.
abstract: OBJECTIVE
  To compare the performance of experienced readers in detecting prostate cancer (PCa) using likelihood maps generated by a CAD system with that of unassisted interpretation of multiparametric magnetic resonance imaging (mp-MRI).
  
  
  METHODS
  Three experienced radiologists reviewed mp-MRI prostate cases twice. First, readers observed CAD marks on a likelihood map and classified as positive those suspicious for cancer. After 6 weeks, radiologists interpreted mp-MRI examinations unassisted, using their favourite protocol. Sensitivity, specificity, reading time and interobserver variability were compared for the two reading paradigms.
  
  
  RESULTS
  The dataset comprised 89 subjects of whom 35 with at least one significant PCa. Sensitivity was 80.9% (95% CI 72.1-88.0%) and 87.6% (95% CI 79.8-93.2; p = 0.105) for unassisted and CAD paradigm respectively. Sensitivity was higher with CAD for lesions with GS > 6 (91.3% vs 81.2%; p = 0.046) or diameter ≥10 mm (95.0% vs 80.0%; p = 0.006). Specificity was not affected by CAD. The average reading time with CAD was significantly lower (220 s vs 60 s; p < 0.001).
  
  
  CONCLUSIONS
  Experienced readers using likelihood maps generated by a CAD scheme can detect more patients with ≥10 mm PCa lesions than unassisted MRI interpretation; overall reporting time is shorter. To gain more insight into CAD-human interaction, different reading paradigms should be investigated.
  
  
  CONCLUSIONS
  • With CAD, sensitivity increases in patients with prostate tumours ≥10 mm and/or GS > 6. • CAD significantly reduces reporting time of multiparametric MRI. • When using CAD, a marginal increase of inter-reader agreement was observed.
authors.affiliation: Department of Radiology at the Candiolo Cancer Institute, FPO, IRCCS, Strada Provinciale 142 km 3.95, 10060, Candiolo, Turin, Italy. valentina.giannini@ircc.it.
authors.forename: Valentina
authors.identifier: http://orcid.org/0000-0001-5052-8231
authors.initials: V
authors.lastname: Giannini
authors.affiliation: Department of Radiology at the Candiolo Cancer Institute, FPO, IRCCS, Strada Provinciale 142 km 3.95, 10060, Candiolo, Turin, Italy.
authors.forename: Simone
authors.initials: S
authors.lastname: Mazzetti
authors.affiliation: Department of Radiology at the Candiolo Cancer Institute, FPO, IRCCS, Strada Provinciale 142 km 3.95, 10060, Candiolo, Turin, Italy.
authors.forename: Enrico
authors.initials: E
authors.lastname: Armando
authors.affiliation: Department of Radiology at the Candiolo Cancer Institute, FPO, IRCCS, Strada Provinciale 142 km 3.95, 10060, Candiolo, Turin, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Carabalona
authors.affiliation: Department of Radiology at the Candiolo Cancer Institute, FPO, IRCCS, Strada Provinciale 142 km 3.95, 10060, Candiolo, Turin, Italy.
authors.forename: Filippo
authors.initials: F
authors.lastname: Russo
authors.affiliation: Department of Urology, San Giovanni Bosco Hospital, Turin, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Giacobbe
authors.affiliation: Department of Urology, University Campus Biomedico, Rome, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Muto
authors.affiliation: Department of Radiology at the Candiolo Cancer Institute, FPO, IRCCS, Strada Provinciale 142 km 3.95, 10060, Candiolo, Turin, Italy.|Department of Surgical Sciences, University of Torino, A.O.U. Città della Salute e della Scienza, Via Genova 3, 10126, Turin, Italy.
authors.forename: Daniele
authors.initials: D
authors.lastname: Regge
mesh_terms: D000368:Aged; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011467:Prostate / Q000000981:diagnostic imaging*; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
keywords: Computer-aided detection; Diagnostic performance; Magnetic resonance imaging; Observer study; Prostate cancer