Fig. 2
a Sagittal steady state free precession (SSFP) MRI image of the brain showing the olfactory nerve anatomy: The fibers in the superior nasal mucosa (yellow fibers), ascend through the fenestrated cribriform plate of the ethmoid bone (green dashed line) to reach the anteriorcranial fossa and continue as the olfactory bulb (red arrow) and tract (green arrow) coursing atthe inferior surface of the ipsilateral frontal lobe. b–e A 38-year-old male presented with a 6month history of anosmia and episodic epiphoresis, nasal stuffiness. Coronal fused (a) andunfused (b) PET/CT images demonstrate a large aggressive hypermetabolic mass centered on thesuperior aspect of the nasal cavity, extending superiorly into the right anterior cranial fossa andcribriform plate of ethmoid bone, involving the expected location of the right olfactorynerve/bulb/track (arrow). Our differential diagnosis was olfactory neuroblastoma (Esthesioneuroblastoma), or sinonasal carcinoma/melanoma. Coronal contrast enhanced CT (c) demonstrate the enhancing mass extending into the anterior cranial fossa at the expected locationof CNI. Coronal short tau inversion recovery (STIR) (e) images confirm the intracranial extension (arrow) with involvement of the right olfactory nerve/bulb (red arrow). Note the normal left olfactory track (green arrowhead). Surgical pathology showed an olfactory neuroblastom