The diagnostic performance of helical computed tomography (CT) is excellent. However, some artifacts have been reported, such as motion, beam hardening and scatter artifacts. We herein report a case of motion-induced artifact mimicking cervical dens fracture. A 60-year-old man was involved in a motorcycle accident that resulted in cervical spinal cord injury and quadri plegia. Reconstructed CT images of the cervical spine showed a dens fracture. We assessed axial CT in detail, and motion artifact was detected.

Spin-tag perfusion imaging is an MRI method that quantitatively measures cerebral blood flow. Compared with conventional perfusion techniques, advantages of this arterial spin-labeling (ASL) include repeatability and the avoidance of intravenous contrast administration. In the present study, we performed an analysis of 3T high-field MRI examinations utilizing ASL perfusion during migraine attacks. A 32-year-old male patient was studied in three situations: during migraine attack within 1 h post-onset, 30 min after oral administration of rizatriptan 10 mg, and attack-free period. Normalized ASL images acquired during migraine attack showed significant relative hypoperfusion in the bilateral median thalamic areas including hypothalamus and significant relative hyperperfusion in the frontal cortex compared to images acquired during the migraine-free state. When normalized ASL images acquired 30 min after treatment were compared with those acquired during the attack, relative improvement of perfusion in the bilateral median thalamic areas including hypothalamus was observed. Hypothalamus and its surrounding areas may participate in the pathogenesis in migraine attack.

Background

Studies in monkeys with intranasally instilled gold ultrafine particles (UFPs; < 100 nm) and in rats with inhaled carbon UFPs suggested that solid UFPs deposited in the nose travel along the olfactory nerve to the olfactory bulb.

Methods

To determine if olfactory translocation occurs for other solid metal UFPs and assess potential health effects, we exposed groups of rats to manganese (Mn) oxide UFPs (30 nm; ~ 500 μg/m3) with either both nostrils patent or the right nostril occluded. We analyzed Mn in lung, liver, olfactory bulb, and other brain regions, and we performed gene and protein analyses.

Results

After 12 days of exposure with both nostrils patent, Mn concentrations in the olfactory bulb increased 3.5-fold, whereas lung Mn concentrations doubled; there were also increases in striatum, frontal cortex, and cerebellum. Lung lavage analysis showed no indications of lung inflammation, whereas increases in olfactory bulb tumor necrosis factor-α mRNA (~ 8-fold) and protein (~ 30-fold) were found after 11 days of exposure and, to a lesser degree, in other brain regions with increased Mn levels. Macrophage inflammatory protein-2, glial fibrillary acidic protein, and neuronal cell adhesion molecule mRNA were also increased in olfactory bulb. With the right nostril occluded for a 2-day exposure, Mn accumulated only in the left olfactory bulb. Solubilization of the Mn oxide UFPs was < 1.5% per day.

Conclusions

We conclude that the olfactory neuronal pathway is efficient for translocating inhaled Mn oxide as solid UFPs to the central nervous system and that this can result in inflammatory changes. We suggest that despite differences between human and rodent olfactory systems, this pathway is relevant in humans.