Is A Non Contrast CT Of The Abdomen Enough?

It depends on what your looking for, but in general no.  Non contrast means that no oral or IV contrast is given.   I’d say that the non contrast CT of the abdomen is fine for certain focused questions but not good enough as a general diagnostic test.  The non contrast CT is often ordered however, especially in the emergency setting because it is quick.  There is a chance that something will be missed with a non contrast CT of the abdomen.

Often times, you will not even know what you may be missing.  It will be tough to identify many abnormalities of organs.  Trauma to the organs in the abdomen will not be detected in some cases.  Masses of the organs will not be detected in some cases.  Bowel abnormalities may not be seen, especially if the bowel is clumped together.

Non contrast CT of the abdomen is best when looking for kidney stones or bleeds.  Many other abnormalities may be missed.  It can be limited when patients are very thin.  Everything will be compressed together and there will be no separation between structures.  This can lead to confusion and missed diagnosis.

Lack of oral and IV contrast can lead to missed cancer, traumatic changes to organs, infections and abscesses, and abnormalities of blood vessels.  Life threatening diagnosis can be missed.  It is therefore important for the ordering physician to understand this limitation.  There may sometimes only be the slightest clue to an abnormality in which case the radiologist may recommend a contrast study.

A non contrast CT may not be able to tell what an abnormality is.  Contrast is essential to fully say what an abnormality may be.  A mass in an organ can often not be accurately diagnosed without contrast.  Pus pockets or absences may be missed or misdiagnosed as a fluid filled bowel loop.  Bowel loops may be mistaken for masses without contrast.

A non contrast CT is therefore a limited test that may or may not detect an abnormality.  It may not allow the radiologist to say what an abnormality is.  A non contrast CT is only appropriate for focused questions.  Like if there is a kidney stone or bleed.  It may allow the radiologist to diagnose other abnormalities but this is not certain.  The best chance for a complete evaluation of your abdomen is with a CT with oral and IV contrast.