Isotopic cisternography is a nuclear medicine exam that takes a kind of radiography with contrast of the brain and spine that allows to evaluate and diagnose changes in the flow of cerebrospinal fluid, caused by fistulas that allow the passage of this fluid to other parts of the body.
This test is performed after an injection of a substance that is a radiopharmaceutical, such as 99m Tc or In11, through a lumbar puncture, which allows this substance to pass through the entire column until it reaches the brain. In the case of a fistula, magnetic resonance or computed tomography images will also show the presence of this substance in other body structures.
What is Cisternography for
Cerebral cisternography serves to determine the diagnosis of CSF fistula, which is a small 'hole' in the tissue that lines the central nervous system composed of the brain and spinal cord, allowing the passage of cerebrospinal fluid to other parts of the body.
The great disadvantage of this exam is that it requires several brain images made in several sessions, and it may be necessary to do it in a few days in a row for a correct diagnosis. In some cases when the patient is very agitated, it is necessary to administer tranquilizers before the examination.
How is this exam done
Cisternography is an exam that requires many brain imaging sessions, which must be taken for two or three days straight. Therefore, hospitalization of the patient and often sedation may be necessary.
To perform the brain cisternography exam, you need:
- Apply anesthetic to the injection site and take a sample of the liquid from the spine that will be mixed with the contrast; An injection with the contrast should be administered at the end of the patient's spine and cover the nostrils with cotton; The patient should remain lying down for a few hours with the feet slightly higher than the rest of the body; then radiographic images of the chest and head are taken after 30 minutes, and then repeated after 4, 6, 12, and 18 hours after the application of the substance. Sometimes it may be necessary to repeat the exam after a few days.
It is necessary to rest for 24 hours after the examination, and the result will show the presence of CSF fistula, or not.
Contraindications
Cerebral cisternography is contraindicated in cases of increased intracranial pressure in pregnant women because of the risk that radiation poses to the fetus.
Where to do it
Isotopic cisternography can be performed in nuclear medicine clinics or hospitals.
