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

• Published in: PloS one 2013-02, Vol.8 (2), p.e57671-e57671
• Main Authors: Shiga, Hideaki, Taki, Junichi, Washiyama, Kohshin, Yamamoto, Junpei, Kinase, Sakae, Okuda, Koichi, Kinuya, Seigo, Watanabe, Naoto, Tonami, Hisao, Koshida, Kichiro, Amano, Ryohei, Furukawa, Mitsuru, Miwa, Takaki
• Format: Article
• Language: English
• Subjects: Administration, Intranasal; Adult; Aged; Biological Transport; Biology; Case-Control Studies; Chronic infection; Computed tomography; Correlation; Craniocerebral Trauma - complications; Female; Females; Head injuries; Hospitals; Humans; Infections; Intranasal administration; Magnetic Resonance Imaging; Male; Males; Medical imaging; Medical technology; Medicine; Middle Aged; Migration; NMR; Nuclear magnetic resonance; Object recognition; Odor recognition; Odor thresholds; Odors; Olfaction; Olfaction Disorders - diagnostic imaging; Olfaction Disorders - etiology; Olfaction Disorders - metabolism; Olfaction Disorders - physiopathology; Olfactometers; Olfactory bulb; Olfactory Bulb - diagnostic imaging; Olfactory Bulb - metabolism; Olfactory Bulb - pathology; Olfactory Bulb - physiopathology; Olfactory nerve; Olfactory Nerve - diagnostic imaging; Olfactory Nerve - metabolism; Olfactory Nerve - pathology; Olfactory Nerve - physiopathology; Otolaryngology; Patients; Respiratory tract; Respiratory tract diseases; Respiratory Tract Infections - complications; Rhinosinusitis; Science; Sensory Thresholds; Single photon emission computed tomography; Sinusitis - complications; Smell; Thallium; Thallium isotopes; Thallium Radioisotopes - administration & dosage; Thallium Radioisotopes - metabolism; Thallium-201; Thresholds; Tomography; Tomography, Emission-Computed, Single-Photon; Trauma
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0057671

The aim of this study was to assess whether migration of thallium-201 ((201)Tl) to the olfactory bulb were reduced in patients with olfactory impairments in comparison to healthy volunteers after nasal administration of (201)Tl. 10 healthy volunteers and 21 patients enrolled in the study (19 males and 12 females; 26-71 years old). The causes of olfactory dysfunction in the patients were head trauma (n = 7), upper respiratory tract infection (n = 7), and chronic rhinosinusitis (n = 7). (201)TlCl was administered unilaterally to the olfactory cleft, and SPECT-CT was conducted 24 h later. Separate MRI images were merged with the SPECT images. (201)Tl olfactory migration was also correlated with the volume of the olfactory bulb determined from MRI images, as well as with odor recognition thresholds measured by using T&T olfactometry. Nasal (201)Tl migration to the olfactory bulb was significantly lower in the olfactory-impaired patients than in healthy volunteers. The migration of (201)Tl to the olfactory bulb was significantly correlated with odor recognition thresholds obtained with T&T olfactometry and correlated with the volume of the olfactory bulb determined from MRI images when all subjects were included. Assessment of the (201)Tl migration to the olfactory bulb was the new method for the evaluation of the olfactory nerve connectivity in patients with impaired olfaction.