Transfer of radioisotope from CSF to nasal secretion

The physiological range of radioisotope (RI) transferred from the CSF to the nasal secretions was observed in 17 subjects without CSF rhinorrhea. A combination of RI cisternography and insertion of cotton pledgets in the nose was used in order to detect the RI transfer in the nasal secretion. The RI ratio was calculated, and those of the 17 subjects were less than 0.3. This is likely to be the normal physiological range of RI transfer.