Non contrast CT of the abdomen is done without contrast given through the vein. This is a study that can be limited because iv contrast can help us make many diagnosis. We still get a look at the abdominal organs like the liver, pancreas, spleen, kidneys. We also get a look at the bowel. Depending on the diagnosis, the study may not be as good.
What are some conditions that can be diagnosed on non contrast CT?
Non contrast CT of the abdomen can be a good test for some conditions. Kidney stones are better seen on non contrast CT. Other conditions such as bleeding, perforated bowel, bowel obstruction, appendicitis are some of the conditions that can be diagnosed on a non contrast CT. There are others as well.
Why is a non contrast CT done if it’s not as good?
Non contrast CT of the abdomen is done because not all patients are able to get iv contrast. Patients who have severe allergies to contrast may not be able have it. Patients who have poor kidney function can not get iv contrast in many cases. There are also shortages of iv contrast which may prevent it from being used.
Some physicians order non contrast CT scans of the abdomen because they are looking for a diagnosis that does not require iv contrast. Many head CTs are done without iv contrast. Strokes, bleeds and some masses can be seen without iv contrast in the brain. Kidney stones are best diagnosed without iv contrast. There are other examples like bleeds and perforated bowel in the abdomen.
Oral contrast use in non contrast CT of the abdomen
Non contrast CT of the abdomen can be done with oral contrast. This is a contrast you drink. It outlines the bowel and helps it stand out from other structures. Bowel which is not highlighted can both hide abnormalities and mimic them.
What conditions are limited with non contrast CT?
Non contrast CT of the abdomen is limited when looking for abnormalities from trauma. This can be organ injury like bruising and lacerations. Some tumors and infections will not be seen without iv contrast. Saying what an abnormality is can also be difficult without iv contrast.
Why is iv contrast useful?
IV contrast helps us see abnormalities. It allows us to diagnose abnormalities of the blood vessels since they are highlighted. Diagnosis can be missed on a non contrast CT of the abdomen. Fortunately, we have more then one way of making diagnosis. There are alternate tests likes ultrasound and MRI which can be done.
Non contrast CT of the abdomen is therefore a useful test and can make many diagnosis. It is important to remember that the lack of iv contrast causes limitations. We may not see an abnormality or not know what it is without iv contrast. We may need to repeat the CT with iv contrast or perform an additional test.