Counting cotton gauze that has been placed in a patient's nose after intrathecal radiopharmaceutical administration is most useful when which of the following conditions is suspected?

Counting cotton gauze that has been placed in a patient's nose after intrathecal radiopharmaceutical administration is particularly useful in the context of suspected rhinorrhea, which is the leakage of cerebrospinal fluid (CSF) from the nasal cavity. This condition can occur when there is a disruption in the barrier between the CSF space and the nasal passages, potentially due to trauma or surgical procedures involving the brain or spine.

When radiopharmaceuticals are administered intrathecally, they can be traced as they leak into the nasal cavity if rhinorrhea is present. By placing cotton gauze in the nose, healthcare providers can monitor for the presence of radioactive material, indicating that CSF is indeed leaking through the nose. This method allows for a non-invasive evaluation of a condition that can have significant clinical implications, as it may require further intervention or surgical repair.

In contrast, while conditions like otorrhea and hydrocephalus involve CSF, they do not typically present with nasal drainage, making gauze counting less relevant for those conditions. Additionally, while assessing CSF shunt patency might involve monitoring flow, it does not directly relate to gauze placed in the nasal cavity for leak detection. Thus, counting the cotton gauze