Fig. 5
From: Orbital tumours and tumour-like lesions: exploring the armamentarium of multiparametric imaging
41-year-old woman with right-sided progressive vision loss and proptosis. a. Axial T2W image shows a moderately hpointense fusiform lesion originating from the optic nerve sheath encasing the optic nerve (arrow). b. Corresponding axial ADC map from RESOLVE DWI shows restricted diffusion (arrow). Note only minor image deformation. c. ADC map from standard EPI sequence also shows restricted lesion diffusivity (arrow); however, note major image deformation due to susceptibility artefacts. d. Axial contrast enhanced T1W image reveals strong fusiform enhancement along the optic nerve (“tram track sign”, arrow). There was no extension through the orbital apex intracranially. e. Coronal fat saturated T1W image displaying concentric enhancement of the tumour around the compressed optic nerve creating a characteristic “bull’s eye” appearance (arrow). Imaging findings are in keeping with an ONSM. f. DTI 3D tractography reconstruction of the optic nerves reveals normal fibres on the left (fibers are depicted in green due to their anterior- posterior course) and major fibre atrophy on the right (arrow)