In Carotid or Vertebral Angiography, which type of contrast is commonly used?

• A. Nonionic contrast
• B. Ionic high-osmolar contrast
• C. Gadolinium-based contrast
• D. Barium sulfate

Answer: (A)

In cerebral angiography the contrast is iodinated and chosen for intravascular use; the best option is a nonionic iodinated contrast because its lower osmolality reduces the risk of adverse reactions and nephrotoxicity compared with older ionic high-osmolar agents. This makes it safer and better tolerated when injecting into carotid or vertebral arteries.

Gadolinium-based contrast is used mainly for MRI, not for arterial angiography. Barium sulfate is a GI contrast and is not suitable for intravascular use; injecting it into arteries can cause serious embolic or inflammatory complications. Ionic high-osmolar contrast, while historically used, has higher osmolality and more side effects, making nonionic iodinated contrast the preferred choice for cerebrovascular procedures.