Routinely performed multiparametric magnetic resonance imaging helps to differentiate common subtypes of renal tumours

Objectives 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