Radionuclide cisternography is a nuclear medicine imaging technique that uses intrathecal 111In-DTPA (diethyletriaminepentaacetic acid; pentetate) to visualize the flow of cerebrospinal fluid (CSF).
There are a few indications 1:
localization of CSF leak, such as in CSF rhinorrhea
evaluation of hydrocephalus, especially communicating hydrocephalus with suspected normal pressure hydrocephalus
Imaging occurs at 2-6 hours after injection into the lumbar subarachnoid space and then delayed imaging is performed at 18-24 hours, sometimes even with additional images at 72 hours.
With normal CSF dynamics and an intrathecal radionuclide injection, activity should be visualized in the basal cisterns by 1 hour, frontal poles and Sylvian fissures by 6 hours, and cerebral convexities by 12 hours. However, radionuclide reflux into the ventricular system is abnormal as flow moves from the ventricular system.
These days, the test is uncommonly performed. For evaluation of normal pressure hydrocephalus, the cisternographic pattern is not predictive of response to surgical shunting 2. CT is usually able to identify a causative bony defect in the majority of patient 3.