title: Assessment of PI-RADS v2 for the Detection of Prostate Cancer.
abstract: OBJECTIVE
  To evaluate the diagnostic performance and inter-reader reliability of the multiparametric magnetic resonance imaging (mpMRI) based prostate imaging reporting and data system (PI-RADS) version 1 and version 2 for the assessment of prostate cancer.
  
  
  METHODS
  A cohort of 82 patients underwent endorectal mpMRI at 1.5T. Patients had at least one lesion with a PI-RADS v1 assessment category of ≥3 and were selected for targeted in-bore MR-guided biopsy in a subsequent session. The results of the histopathological workup were used as reference standard. All lesions were retrospectively evaluated according to PI-RADS v2 by an experienced and unexperienced blinded reader. Diagnostic performance was compared by analyzing the area under the Receiver Operating Characteristics Curve (AUC). The weighted kappa method was used to calculate inter-reader reliability.
  
  
  RESULTS
  Targeted MR-guided biopsy was performed in 136 lesions and revealed 39 malignant lesions in 31 patients. AUC values increased for the experienced reader (PI-RADS v1 0.79; PI-RADS v2 0.83) and unexperienced reader (PI-RADS v1 0.70; PI-RADS v2 0.83). When excluding the cases of low grade cancer (Gleason score=3+3), AUC values increased further for the experienced reader (PI-RADS v1 0.88; PI-RADS v2 0.91) and unexperienced reader (PI-RADS v1 0.78; PI-RADS v2 0.90). Specificity at the selected threshold of a PI-RADS v1/v2 assessment category ≥4 improved for both readers. Inter-reader agreement increased from κ=0.55 in PI-RADS v1 to κ=0.68 in v2.
  
  
  CONCLUSIONS
  PI-RADS v2 improved diagnostic performance for the assessment of suspicious intraprostatic lesions identified in PI-RADS v1 for both readers and led to higher inter-reader reliability. These results suggest that PI-RADS v2 is a reliable and replicable reporting system for the assessment of prostate cancer.
authors.affiliation: Institute for Diagnostic and Interventional Radiology, University Hospital Jena, Erlanger Allee 101, 07747 Jena, Germany. Electronic address: Moritz.Kasel-Seibert@med.uni-jena.de.
authors.forename: Moritz
authors.initials: M
authors.lastname: Kasel-Seibert
authors.affiliation: Center for Clinical Studies, University Hospital Jena, Jahnstrasse 3, 07747 Jena, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Lehmann
authors.affiliation: Institute for Diagnostic and Interventional Radiology, University Hospital Jena, Erlanger Allee 101, 07747 Jena, Germany.
authors.forename: René
authors.initials: R
authors.lastname: Aschenbach
authors.affiliation: Institute for Diagnostic and Interventional Radiology, University Hospital Jena, Erlanger Allee 101, 07747 Jena, Germany.
authors.forename: Felix V
authors.initials: FV
authors.lastname: Guettler
authors.affiliation: Department of Pathology, University Hospital Jena, Ziegelmuehlenweg 1, 07743 Jena, Germany.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Abubrig
authors.affiliation: Department of Urology, University Hospital Jena, Lessingstraße 1, 07743 Jena, Germany.
authors.forename: Marc-Oliver
authors.initials: MO
authors.lastname: Grimm
authors.affiliation: Institute for Diagnostic and Interventional Radiology, University Hospital Jena, Erlanger Allee 101, 07747 Jena, Germany.
authors.forename: Ulf
authors.initials: U
authors.lastname: Teichgraeber
authors.affiliation: Institute for Diagnostic and Interventional Radiology, University Hospital Jena, Erlanger Allee 101, 07747 Jena, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Franiel
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy / Q000379:methods; D015331:Cohort Studies; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D015588:Observer Variation; D011467:Prostate / Q000473:pathology; D011471:Prostatic Neoplasms / Q000473:pathology*; D012372:ROC Curve; D011873:Radiology Information Systems; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
keywords: Biopsy; ESUR; MRI; Prostate cancer