Spinal contrast agent

There are various explanations, backed by animal studies, for this complication. When there is obstruction to the normal outflow of blood from the aorta, there is an increased risk that the contrast agent will be diverted into the spinal circulation. This effect can be aided by a gravitational factor if the examination is performed with the patient in the supine position. 

A volume that is routinely used for CTA of the entire aorta is sufficient for spinal artery imaging. Depending on scan time and venous access, the volume of contrast agent should be adjusted accordingly. To account for an additional scan delay after table movement, an appropriate amount of supplementary volume should be added. In the end, the technologist and the radiologist... 

Water-soluble contrast media (CM) are preferred because of effective mixing with CSF, plus the radiopaque is absorbed and effectively excreted in the urine, and does not have to be physically removed from the subarachnoid space after the procedure. Sodium methiodal, the first water-soluble agent used for myelography, produced neurotoxicity problems when exposed to the cells of the spinal cord and brain, thus limiting utility to the lumbar region and requiring the appHcation of spinal or general anesthesia. 

Great care must be taken when performing contrast injection into the subarachnoid space. Improper technique could lead to a dcva.stating infection or spinal injury, and the use of the wntng contra.st agent can also have devastating results such us convulsions and subsequent, seven arachnoid in-riummution. 

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