Fig. 5
A 41-year-old male with nasopharyngeal squamous cell carcinoma. Axial CT (a), and PET (b) images show an iso/hyperdense hypermetbolic mass extending into the enlarged left pterygopalatine fossa (red arrow) and foramen ovale (red arrowhead), confirming perineural tumor spread along the maxillary (V2) and mandibular (V3) divisions of the trigeminal (CNV) nerve. Note the normal appearance of the right pterygopalatine fossa (green arrow) and foramen ovale (green arrowhead). Axial contrast-enhanced fat suppressed T1 SI MR (c, d) of the neck confirm extension of the enhancing soft tissue mass from the left cavernous sinus/Meckel’s cave region in to the left pterygopalatine fossa (red arrow). Coronal fused PET/CT (e) and contrast-enhanced fat suppressed T1 SI MR (f) confirming perineural extension of the tumor along V3, infiltrating the left cavernous sinus/ Meckel’s cave region (arrow) and widening the ipsilateral foramen ovale (arrowhead)