Fig. 17

Intracranial spread of ROCM in a patient with bilateral ethmoid sinus disease (not shown). Coronal T1W image (a) reveals abnormal soft tissue within the left orbital apex (thick arrow). Note the normal fat signals in the contralateral orbital apex (dotted arrow). CE FS axial T1W images (b, c) demonstrate the soft tissue in the left orbital apex (thick arrow in b), non-enhancement of the left cavernous sinus (arrow head in c) suggesting thrombosis, and loss of flow void along the left carotid siphon (stepped arrow in c) representing occlusion. Axial CE FLAIR image (d) reveals leptomeningeal enhancement along the left middle cerebral artery sulcus (thin arrow). 3-D reconstruction of a Time-of-Flight MR angiogram (e) confirms the occlusion of the left internal carotid artery along with attenuated, irregular flow signals within the M1 segment of the middle cerebral artery (curved arrow), reformed via the circle of Willis, and reduced distal cortical arborisation. Diffusion weighted image (f) demonstrates scattered acute infarcts in the left middle cerebral artery territory. In summary, the diagnosis of ROCM with orbital apex involvement and intracranial spread (cavernous sinus thrombosis, leptomeningeal disease and MCR-related vasculitis) was suggested