Q. Will a CT scan be accurate if done without drinking a contrast?

Answered by
Dr. Vivek Chail
and medically reviewed by Dr.Nithila A
This is a premium question & answer published on Sep 27, 2019

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.



Welcome to

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.

Was this answer helpful?


Same symptoms doesn’t mean you have the same problem. Consult a doctor now!

Related Questions:
Could CT scan miss appendicitis?

It can get diagnosed by pelvic ultrasound ... Hi doctor, I was in an emergency last night because of 48 hours of pain that moved to my right lower abdomen ... However, the other causes of right ...   Read full

CT scan shows non-growing lung nodules with scars. What does it suggest?

.. found six years back would have manifested into multiple lesions by now if there were cancer and you are right in your thoughts. Usually, cancer nodules double in 30 to 180 days time and if the nodules did not change in six months then cancer is n...   Read full

CT scan shows bilateral cerebral atrophy with delusion in an older person. What should be done?

.. symptoms you have described, of paranoid ideation, suspiciousness, restlessness, decreased sleep are all indicative of a psychotic type of illness, most probably schizophrenia. It will require treatment from a psychiatrist with antipsychotic medic...   Read full

Also Read Answers From:

ideaComprehensive Medical Second Opinion.Submit your Case

Also Read

Sexual Problems and Depression
Depression is one of the commonest psychiatric problems in the general population. About 10 % of men and more than doubl...  Read more»
Holiday Season During the Pandemic
Most of us wonder if there is a way to celebrate the holiday season during the COVID-19 pandemic safely. Here are some i...  Read more»
Skin Care Tips To Win Over Winter
This article discusses a few tips to manage and protect your skin during winter.  Read more»

Ask your health query to a doctor online?

Ask a Radiologist Now

* guaranteed answer within 4 hours.

Disclaimer: No content published on this website is intended to be a substitute for professional medical diagnosis, advice or treatment by a trained physician. Seek advice from your physician or other qualified healthcare providers with questions you may have regarding your symptoms and medical condition for a complete medical diagnosis. Do not delay or disregard seeking professional medical advice because of something you have read on this website. Read our Editorial Process to know how we create content for health articles and queries.