Will a CT scan be accurate if done without a contrast?

Question

Hello doctor,

I am having pain in the right lower abdomen for 10 days. The ultrasound had shown mild inflammation of the appendix. Doctor then suggested a CECT whole abdomen. However, in the past, I have had difficulty keeping down the contrast they ask to drink. So the doctor advised CT Scan with IV contrast only and left out the drinking contrast part. The result of the CT scan came normal showing no Appendicitis. My query is, can the CT scan be done without drinking the contrast? Will it be accurate? Is IV only CT scan without the drink reliable? Is it surprising that USG showed mild appendicitis, but the CT scan did not? Please advise.

Answer 1

Hello,

Welcome to icliniq.com.

The appendix is a tubular structure measuring less than 5 mm in normal people. When there is appendicitis, the appendix enlarges to 8 to 10 mm or more in diameter. Ultrasound scan has an accuracy of 50 percent for appendicitis in most patients. You have been found with a likely 9 mm appendix before some days. The CT scan was done before a week. It is possible that the inflammation of appendix decreased in a week and so the CT scan finding with only IV contrast showed near-normal appendix and no features of inflammation surrounding it.

An oral and IV contrast CT is always better to look for appendix related problems. There is no need to drink lots of oral contrast at a time, and you can drink in a few sips every few minutes for two hours to help the contrast reach the appendix area. I do this for my patients, and there are fewer chances of confusion in diagnosis of appendicitis. In your case, there is a possibility that the inflammation of appendicitis decreased in the interval between ultrasound and CT scans.