Some radiopaque agents, such as iohexol, iopamidol, and metrizamide are given by injection into the spinal canal. X-rays are then used to help diagnose problems or diseases in the head, spinal canal, and nervous system. The doses of radiopaque agents will be different for different patients and depend on the type of test. The strength of the solution is determined by how much iodine it contains. Different tests will require a different strength and amount of solution depending on the age of the patient, the contrast needed, and the x-ray equipment used.
Radiopaque agents are to be used only by or under the direct supervision of a doctor.
In deciding to use a diagnostic test, any risks of the test must be weighed against the good it will do. This is a decision you and your doctor will make. Also, test results may be affected by other things. Also tell your doctor if you are allergic to any other substance, such as sulfites or other preservatives. Studies have not been done in humans with most of the radiopaque agents.