title: Performance of PI-RADS version 1 versus version 2 regarding the relation with histopathological results.
abstract: OBJECTIVE
  Aim of this study was to compare the diagnostic performance of PI-RADS version 1 (v1) and version 2 (v2) in the detection of prostate cancer (PCa).
  
  
  METHODS
  Multiparametric MRIs (mpMRI) of 50 consecutive patients with biopsy proven PCa, which had originally been evaluated according to PIRADS v1, were now retrospectively re-evaluated, comparing PI-RADS v1 and v2. MpMRI data were evaluated in comparison with histopathological whole-mount step-section slides. MRI examinations included T2-weighted, diffusion-weighted, and dynamic contrast-enhanced MRI.
  
  
  RESULTS
  Overall PI-RADS v1 showed a significantly larger discriminative ability of tumor detection: PI-RADS v1 AUC 0.96 (95 % CI 0.94-0.98) and v2 AUC 0.90 (95 % CI 0.86-0.94). For peripheral zone lesions, PI-RADS v1 showed a significantly larger ability of PCa discrimination: v1 AUC 0.97 (95 % CI 0.95-0.99) and v2 AUC 0.92 (95 % CI 0.88-0.96). For transition zone lesions, PI-RADS v1 showed more discrimination: v1 AUC 0.96 (95 % CI 0.92-1.00) and v2 0.90 (95 % CI 0.83-0.97), but the difference was not significant. PI-RADS v2 resulted in significantly more false negative results (3 % in v1, 14 % in v2) and a comparable number of true positive results (82 % in v1, 80 % in v2).
  
  
  CONCLUSIONS
  PI-RADS v2 uses a simplified approach, but shows a lower diagnostic accuracy. This could lead to a higher rate of false negative results with the risk of missing tumors within low PI-RADS score levels. Therefore, its use cannot be recommended unconditionally, and further improvement should be considered.
authors: Department of Radiology, Medical University of Innsbruck, Anichstraße 35, 6020, Innsbruck, Austria.
authors: Thomas
authors: T
authors: Auer
authors: Department of Medical Statistics, Informatics, and Health Economics, Medical University of Innsbruck, Schöpfstraße 41/1, 6020, Innsbruck, Austria.
authors: Michael
authors: M
authors: Edlinger
authors: Department of Urology, Medical University of Innsbruck, Anichstraße 35, 6020, Innsbruck, Austria.
authors: Jasmin
authors: J
authors: Bektic
authors: Landeskrankenhaus Hall, Abteilung für Urologie und Andrologie, Milser Straße 10, 6060, Hall in Tirol, Austria.
authors: Udo
authors: U
authors: Nagele
authors: Klinik für Urologie und Urologische Onkologie, Medizinische Hochschule Hannover, Carl-Neuberg-Straße 1, 30625, Hannover, Germany.
authors: Thomas
authors: T
authors: Herrmann
authors: Department of Pathology, Medical University of Innsbruck, Anichstraße 35, 6020, Innsbruck, Austria.
authors: Georg
authors: G
authors: Schäfer
authors: Department of Radiology, Medical University of Innsbruck, Anichstraße 35, 6020, Innsbruck, Austria.
authors: Friedrich
authors: F
authors: Aigner
authors: Department of Radiology, Medical University of Innsbruck, Anichstraße 35, 6020, Innsbruck, Austria. daniel.junker@tirol-kliniken.at.
authors: Daniel
authors: D
authors: Junker
mesh_terms: D020823:ADP-Ribosylation Factor 1; D000368:Aged; D038524:Diffusion Magnetic Resonance Imaging; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D012189:Retrospective Studies
chemical_list: D020823:ADP-Ribosylation Factor 1
keywords: Multiparametric MRI; PI-RADS; Prostate cancer