Diffusion Weighted Imaging in Acute Ischemic Posterior Optic Neuropathy

Rhinocerebral Mucormycosis Axial DWI and ADC images show restricted diffusion involving the intraorbital segment of left optic nerve consistent with acute infarction and large left MCA territory infarct. 3 D TOF MRA showed diffuse narrowing of the intracranial left ICA with complete occlusion of left MCA and its cortical branches. Enhancing soft tissue was seen in the left maxillary and fronto-ethmoid sinuses with extension of inflammation in the retro orbital fat, bulky extraocular muscles suggesting sinus and orbital cellulitis.

Lymphoma Axial Diffusion weighted image and ADC map at the level of orbits. Diffusion restriction seen in posterior two third intraorbital and intracanalicular segments of the right optic nerve as well as in periorbital and orbital soft tissue of the medial aspect of left eye. Axial and coronal NCCT scan of the sphenoid sinus with bilateral orbits. Hyperdense soft tissue seen in the left hemi-sphenoid sinus, left pre and post septal soft tissues in the medial aspect of the left eye. Corresponding T2 weighted axial MRI and post-contrast T1 weighted sagittal and coronal images. Lobulated enhancing T2 hypointense soft tissue seen in the left orbital and left sphenoid sinus.

Rhinocerebral Mucormycosis

Axial DWI and ADC images showing restricted diffusion in the intraorbital segment of right optic nerve and right anterior temporal lobe consistent with acute infarction.

T2 weighted and post contrast T1 weighted FATSAT images show inflammatory changes in the right naso maxillary cavity, right cheek, temporalis muscle and masseteric spaces.The maxillary inflammation extends to the preseptal space, right retro-orbital fat with T2 hyperintense bulky and enhancing extra ocular muscles. The right optic nerve also appears hyperintense with mild enhancement.