ABSTRACT
PURPOSE: The aim of this study was to visualize the human olfactory transport pathway to the brain by performing imaging after nasal thallium-201 ((201)Tl) administration. PROCEDURES: Healthy volunteers were enrolled in this study after giving informed consent (five males, 35-51 years old). The subjects were nasally administered (201)TlCl into either the olfactory cleft. Twenty-four hours later, uptake of (201)Tl was detected by a single photon emission computed tomography (SPECT)/X-ray computed tomography hybrid system. For each subject, an MRI image was obtained and merged with the SPECT image. RESULTS: The peak of the (201)Tl uptake entered into the olfactory bulb in the anterior skull base through the cribriform lamina 24 h after nasal administration of (201)Tl. No participant had olfactory disturbance after treatment. CONCLUSIONS: Nasal (201)Tl administration was safely used to assess the direct pathway to the brain via the nose in healthy volunteers with normal olfactory threshold.
