A case of intracranial hypotension with spontaneous cerebrospinal fluid (CSF) 
leak was reported. A Tc-99m diethyltriaminepentacetic acid radionuclide 
cisternography (RNC) showed the accumulation of radioactivity in the area of the 
subarachnoid space, the poor migration of the isotope over the convexities, and 
the early appearance of kidney and bladder activity. To localize the site of CSF 
leak, RNC will be the choice, and when the time comes, RNC will work well in the 
location of the leak.