Fig. 6

Axial (a) and coronal (b) low resolution CT part of PET/CT. a On the axial view the internal auditory canal parts of CNVII and VIII (red arrow), as well as the labyrinthine (bluearrow) and tympanic parts (green arrow) of CN VII can be visualized. b On the coronal view,the styloid process (red arrow) can be used as a landmark to visualize the stylomastoid foramen,containing the stylomastoid part of CN VII (arrow heads). c–f A 62 year-old-female with rightsided hearing loss. Axial fused/non fused FDG PET/CT (c, d) and coronal Maximum Intensity projection (MIP) (e) images showing an intensely hypermetabolic right cerebellopontine angle lesion (CPA) lesion. Given patient history of hearing loss, this was consistent with vestibular schwannoma, rather than a meningioma. Axial contrast enhanced T1 WI MRI (f) showing the classic heterogeneously enhancing “ice cream cone” mass extending into the right internal auditory canal (IAC) (arrow), consistent with vestibular schwannoma, which was confirmed pathologically. g, h A 71-yearold female patient with history of worsening right sided hearing loss, unsteadiness, and neck pain. Axial unfused PET/CT images (g) and contrast enhanced T1 WI MRI (h) show a right CPA enhancing lesion with mild focal FDG activity (SUVmax 3.0) (green arrow), extending along the IAC, labyrinthine and tympanic segments of CN7 (red arrow) confirming that this is a facial nerve schwannoma rather than the more common vestibular nerve schwannoma