What is the purpose of the power injector pressure limit setting?

• A. Prevents catheter rupture
• B. Controls injection temperature
• C. Sets the delay before injection
• D. Determines total contrast volume

Answer: (A)

The main idea is safety: the pressure limit on a power injector is a built-in safeguard that caps how high the injection pressure can rise. In coronary angiography, the injector pushes contrast through a catheter at high flow, and any unexpected resistance—such as a kinked catheter, contact at a vessel wall, or partial occlusion—can cause the pressure to spike. If there were no limit, that high pressure could damage the catheter itself or injure the vessel. Setting a maximum pressure keeps the system from exceeding safe levels and automatically stops the injection before damage occurs.

This setting is not about warming the contrast, timing of the injection, or the total amount of contrast delivered. Temperature control, delay before injection, and total volume are governed by other parameters, so they wouldn’t explain why the pressure limit is used.