Transcript

Your patient comes into the emergency department with  right lower quadrant pain and an  elevated white blood cell count.  After your exam, you’re immediately worried about  appendicitis. Do you want to confirm with imaging? What should we order? What are the things we should be looking for?  Let’s learn to work up appendicitis like a radiologist.

First, what should we order? Guidelines recommend ordering a  CT abdomen and pelvis with IV contrast.   The IV contrast will better let us visualize the appendix and evaluate for common complications of appendicitis.   But do we need oral contrast?  No! Administering oral contrast will needlessly prolong imaging acquisition and not provide much additional information.

IV contrast by itself will do the  job.   We order our CT with IV contrast, and here are the images. Does this patient have appendicitis? Do they need a surgical consult? Let’s look at a normal appendix first. Here’s a nice normal appendix. It’s not dilated, it’s tubular, and it has nice dark surrounding fat.

Back to our patient. Notice that the appendix is slightly more dilated, and it’s surrounded by all this edema and the peri appendiceal fat. Pro tip, if you’re having trouble identifying edema around the appendix, compare the fat around the appendix with other normal fat in other parts of the abdomen. See the difference now?

We also have some reactive lymph nodes in the right lower quadrant, and even the porcecum looks swollen. It’s probably reactive to the adjacent appendicitis. All these findings are concerning for acute appendicitis. So what do we do now? Our patient has appendicitis, but do they need surgery? The management of acute appendicitis is complex, but there are certain imaging findings that make antibiotic therapy alone less likely to be successful.

One finding is if the appendix has become gangrenous and perforated, creating free air or an abscess like in this patient. Another finding is if the patient has an appendicolith, essentially a calcified mass of fecal material that’s obstructing the appendix. A fecal lift is a common cause of appendicitis, and worth looking for on every study.

A third finding is if the appendix is massively dilated, like over 13 millimeters in diameter. So let’s review. You’re concerned about appendicitis. What should we order? CT abdomen pelvis with IV contrast. No oral contrast necessary. What should we look for? A big dilated appendix with surrounding edema in the fat.

Don’t forget to compare the fat around the appendix with normal fat elsewhere in the abdomen. Key findings to identify for our surgical colleagues? a very dilated appendix, an obstructing appendicolith, or free air or signs of abscess formation. Now you can evaluate appendicitis like a radiologist.

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Appendicitis