Assessment of olfactory nerve by SPECT-MRI image with nasal thallium-201 administration in patients with olfactory impairments in comparison to healthy volunteers

Shiga, Hideaki*; Taki, Junichi*; Washiyama, Koshin*; Yamamoto, Jumpei*; Kinase, Sakae   ; Okuda, Koichi*; Kinuya, Seigo*; Watanabe, Naoto*; Tonami, Hisao*; Koshida, Kichiro*; Amano, Ryohei*; Furukawa, Mitsuru*; Miwa, Takaki*

Current olfactory function tests are useful for the analysis of olfactory thresholds in olfaction-impaired patients. However, a decrease in olfactory thresholds has not been used as an index for olfactory nerve damage in patients. The authors assessed peripheral olfactory nerve viability by performing combined SPECT-CT after nasal administration of Tl-201 to determine whether olfactory nerve was damaged in patients with olfactory impairments in comparison to healthy volunteers. It was found that nasal Tl-201 migration to the olfactory bulb was significantly lower in the patients with head trauma, respiratory infection, and chronic rhinosinusitis than in healthy volunteers.