Multi-parametric magnetic resonance imaging characterization of orbital lesions: a triple blind study.

: Multi-parametric MRI used for preoperative assessment of orbital lesions does not routinely include DCE-MRI, since its accuracy in differential diagnosis of orbital mass is still under debate. Aim of this study is to characterize orbital lesions by multi-parametric MRI, analysing the incremental predictive value of DCE-MRI in differential diagnosis of orbital lesions.: In this prospective triple-blind study, 43 consecutive patients with unilateral orbital lesion underwent conventional multimodal MRI and DCE-MRI before biopsy in a tertiary referral centre. Pre-operative MRI examination including conventional unenhanced MRI protocol, DWI with ADC maps, static CE 3D-T1 w and dynamic CE T1 w sequences, was performed within 1 week from surgery (anterior/lateral orbitotomy depending on location of the lesion, to carry out incisional/excisional biopsy).: Comparison between conventional T1 w/T2 w, DWI, CE 3D-T1 w and DCE-MRI groups showed a statistically significant difference in scores distribution ( < .001). Statistically significant difference was found between conventional T1 w/T2 w and DWI ( < .005), as well as between DWI and CE 3D-T1 w ( < .001). Conversely, no significant difference was found between CE 3D-T1 w and DCE ( < .005).: This study confirmed the positive effect of DWI and CE 3D-T1 w on orbital lesions diagnosis when added to conventional T1 w/T2 w sequences, whereas no substantial impact on diagnostic performance was observed with the further addition of DCE-MRI. DCE does not strongly influence diagnostic performance and inter-rater agreement in characterizing orbital lesions; therefore, it should be recommended in selected patients whose assessment of flow dynamics is particularly useful for management.: US = ultrasonography; MRI = magnetic resonance imaging; CT = computed tomography; STIR = Short-TI Inversion Recovery; DWI = diffusion weighted imaging; DCE-MRI = dynamic contrast-enhanced MRI; SE = Spin-Echo; TSE = Turbo Spin-Echo; THRIVE = T1-weighted high resolution Isotropic Volume Examination (dynamic contrast-enhanced ultrafast spoiled gradient echo); ROI = regions of interest; IRR = inter-rater reliability; TIC = time-intensity curve.