ZocdocAnswersCT scan with contrast cancelled after without contrast scan done. Why would that happen?

Question

CT scan with contrast cancelled after without contrast scan done. Why would that happen?

I had a CT scan today without contrast because of occasional severe right side flank pain. They were about to do a second scan with contrast when the radiologist said it wasn't necessary. Feeling nervous and not sure why they would stop the second scan... Any thoughts?

Answer

I encourage you to speak with your doctor about your concerns. CT contrast is helpful to look for certain things: intravenous contrast it helps delineate blood vessels and in the abdomen can help identify abscesses, lymph nodes, and oral contrast can help demarcate the bowel and get a sense of the thickness of the gut wall. For some types of scans you really need to give contrast to be able to see what you're looking for; for others you don't really need contrast for the scan to be useful. The reason it is important to know whether contrast is likely to help is that it comes with its own risks. IV contrast is toxic to the kidneys, and though we usually only give it to people who we think have strong enough kidneys that the drug won't hurt them, there's always a risk that the contrast will cause kidney damage and so we avoid giving it whenever possible. You would also have needed to get a second set of images with the contrast, and again, while the overall radiation risk is not that high, if it can be avoided we usually like to avoid giving people more radiation exposure than is necessary. So, without being there to discuss the case with your physicians, my guess is that the radiologist felt like they had gotten enough information from the scans they had and wanted to spare you unnecessary contrast and radiation exposure. If you are still having concerns I would definitely discuss your concerns with your doctor and go over the results of the scan with them.

This answer is for general informational purposes only and is not a substitute for professional medical advice.

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