title: Routinely performed multiparametric magnetic resonance imaging helps to differentiate common subtypes of renal tumours.
abstract: OBJECTIVE
  To retrospectively evaluate the ability of multiparametric magnetic resonance (MR) imaging to differentiate renal tumours.
  
  
  METHODS
  MR images from 100 consecutive pathologically proven solid renal tumours without macroscopic fat [57 clear cell, 16 papillary and 7 chromophobe renal cell carcinomas (RCCs), 16 oncocytomas and 4 minimal fat angiomyolipomas (AMLs)] between 2009 and 2012 were evaluated. Two radiologists blinded to pathology results independently reviewed double-echo chemical shift, dynamic contrast-enhanced T1- and T2-weighted images and apparent diffusion coefficient (ADC) maps. Signal intensity index (SII), tumour-to-spleen SI ratio (TSR), ADC ratio, wash-in (WiI) and wash-out indices (WoI) between different phases were calculated.
  
  
  RESULTS
  There were significant differences between papillary RCCs and other renal tumours for arterial WiI (P < 0.001), initial WoI (P = 0.006) and ADC ratio (P < 0.001); between chromophobe RCCs and oncocytomas for TSR (P = 0.02), parenchymal WiI (P = 0.03), late WiI (P = 0.02), initial WoI (P = 0.03) and late WoI (P = 0.04); and between clear cell RCCs and oncocytomas for SII (P = 0.01) and parenchymal WiI (P = 0.01). Papillary RCCs were distinguished from other tumours (sensitivity 37.5 %, specificity 100 %) and oncocytomas from chromophobe RCCs (sensitivity 25 %, specificity 100 %) and clear cell RCCs (sensitivity 100 %, specificity 94.2 %).
  
  
  CONCLUSIONS
  MR imaging provides criteria able to accurately distinguish papillary RCCs from other tumours and oncocytomas from chromophobe and clear cell RCCs.
  
  
  CONCLUSIONS
  • Multiparametric MR parameters accurately distinguish papillary RCCs with high specificity (100 %). • Oncocytomas can be distinguished from chromophobe RCCs with high specificity (100 %). • Oncocytomas can be distinguished from clear cell RCCs with high specificity (94.2 %). • In oncocytomatosis, imaging follow-up with such parameters analysis could be promoted.
authors.affiliation: Department of Radiology, Pellegrin Hospital, Place Amélie Raba Léon, 33076, Bordeaux, France, francois.cornelis@chu-bordeaux.fr.
authors.forename: F
authors.initials: F
authors.lastname: Cornelis
authors.forename: E
authors.initials: E
authors.lastname: Tricaud
authors.forename: A S
authors.initials: AS
authors.lastname: Lasserre
authors.forename: F
authors.initials: F
authors.lastname: Petitpierre
authors.forename: J C
authors.initials: JC
authors.lastname: Bernhard
authors.forename: Y
authors.initials: Y
authors.lastname: Le Bras
authors.forename: M
authors.initials: M
authors.lastname: Yacoub
authors.forename: M
authors.initials: M
authors.lastname: Bouzgarrou
authors.forename: A
authors.initials: A
authors.lastname: Ravaud
authors.forename: N
authors.initials: N
authors.lastname: Grenier
mesh_terms: D018249:Adenoma, Oxyphilic / Q000175:diagnosis / Q000473:pathology*; D000328:Adult; D000369:Aged, 80 and over; D018207:Angiomyolipoma / Q000175:diagnosis / Q000473:pathology; D002292:Carcinoma, Renal Cell / Q000175:diagnosis / Q000473:pathology*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000145:classification / Q000175:diagnosis / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies