title: A practical imaging classification for the non-invasive differentiation of renal cell carcinoma into its main subtypes.
abstract: Renal cell carcinoma (RCC) is a heterogeneous disease which encompasses various subtypes that exhibit differing biologic behavior and imaging findings. Non-invasive subtype differentiation by imaging facilitates prognostication and treatment selection. The aim of the study was to evaluate the performance of a diagnostic imaging key based on tumor morphology, T2 signal intensity on MRI, and tumor vascularity for differentiating RCC into its subtypes.
  
  
  
  Using a custom-designed diagnostic imaging key, three blinded fellowship-trained abdominal radiologists independently evaluated the cross-sectional imaging of 50 histologically proven RCCs and categorized these into subtypes in two sessions. The diagnostic performance of the imaging key was evaluated and compared to the baseline performance without the key.
  
  
  
  The 50 RCCs comprised 20 (40%) clear cell, 17 (34%) papillary, and 13 (26%) chromophobe tumors. All expert readers demonstrated an improvement in diagnostic accuracy by an average of 5.3% with the use of the key. The readers showed good to excellent diagnostic performance for clear cell RCC (area under the receiver operating curve, AUROC of 0.86-0.91) and papillary RCC (AUROC of 0.82-0.87), and fair performance with chromophobe RCC (AUROC of 0.67-0.77). The Reader-to-SOR (standard of reference) agreement increased from 0.53 (moderate) to 0.67 (good) with the use of the key.
  
  
  
  The diagnostic imaging key facilitates RCC subtype characterization and can be used as a decision support tool.
authors.affiliation: Department of Radiology and Diagnostic Imaging, University of Alberta Hospital, 2A2.41 Walter Mackenzie Center, 8440-112 Street, Edmonton, AB, T6G 2B7, Canada. brindley.cupido@gmail.com.
authors.forename: Brindley David
authors.initials: BD
authors.lastname: Cupido
authors.affiliation: Department of Radiology and Diagnostic Imaging, University of Alberta Hospital, 2A2.41 Walter Mackenzie Center, 8440-112 Street, Edmonton, AB, T6G 2B7, Canada.
authors.forename: Medica
authors.initials: M
authors.lastname: Sam
authors.affiliation: Department of Radiology and Diagnostic Imaging, University of Alberta Hospital, 2A2.41 Walter Mackenzie Center, 8440-112 Street, Edmonton, AB, T6G 2B7, Canada.
authors.forename: Sean David
authors.initials: SD
authors.lastname: Winters
authors.affiliation: Department of Radiology and Diagnostic Imaging, University of Alberta Hospital, 2A2.41 Walter Mackenzie Center, 8440-112 Street, Edmonton, AB, T6G 2B7, Canada.
authors.forename: Bilal
authors.initials: B
authors.lastname: Ahmed
authors.affiliation: Department of Radiology and Diagnostic Imaging, University of Alberta Hospital, 2A2.41 Walter Mackenzie Center, 8440-112 Street, Edmonton, AB, T6G 2B7, Canada.
authors.forename: Michael
authors.initials: M
authors.lastname: Seidler
authors.affiliation: Department of Radiology and Diagnostic Imaging, University of Alberta Hospital, 2A2.41 Walter Mackenzie Center, 8440-112 Street, Edmonton, AB, T6G 2B7, Canada.
authors.forename: Guan
authors.initials: G
authors.lastname: Huang
authors.affiliation: Department of Radiology and Diagnostic Imaging, University of Alberta Hospital, 2A2.41 Walter Mackenzie Center, 8440-112 Street, Edmonton, AB, T6G 2B7, Canada.
authors.forename: Gavin
authors.initials: G
authors.lastname: Low
mesh_terms: D000368:Aged; D002291:Carcinoma, Papillary / Q000000981:diagnostic imaging* / Q000473:pathology*; D002292:Carcinoma, Renal Cell / Q000000981:diagnostic imaging* / Q000473:pathology*; D003287:Contrast Media; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D021621:Imaging, Three-Dimensional; D007472:Iohexol; D007680:Kidney Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D009942:Organometallic Compounds; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media; D009942:Organometallic Compounds; C090600:gadobutrol; D007472:Iohexol
keywords: Carcinoma; Renal cell; Subtypes