So what else is on our differential diagnosis?
We’re thinking about GI pathology and possibly GU pathology.
So in GI pathology, Meckel’s diverticulum is a possibility, epiploic appendagitis,
patients who have Crohn’s, or ulcerative colitis,
that can present with a flare, with similar kinds of symptoms,
intussusception is when the bowel telescopes on itself
and that can cause pain similar to this as well,
and then a volvulus which is when the bowel is twisted upon itself.
From a GU pathology perspective, ectopic pregnancy, PID,
pelvic inflammatory disease, pyelonephritis, ovarian torsion or a cyst,
or possibly testicular torsion as well, and then renal colic.
So there’s lots of different things that can present with pain
on the right side of the abdomen,
and I always tell women that we’re a little bit tricky
because in addition to having all of our intestinal structures,
we also have our ovaries and our uterus
that can sometimes cause pain that might mimic appendicitis.
So how do we go ahead and diagnose appendicitis?
So first and foremost, we can definitely send some lab tests,
and then we wanna start thinking about imaging.
So what are our imaging tests of choice?
We have a few options.
The first one that we can talk about is ultrasound.
The benefit of doing an ultrasound to evaluate for appendicitis
is that there is no ionizing radiation exposure
and this can oftentimes be performed rapidly,
and it’s generally a cheap imaging modality and pretty readily available.
Some of the downsides are that it’s lower specificity.
There’s some limitations.
This is very operator dependent depending on where you’re working,
the radiology text may feel very comfortable performing the study
or potentially, they may feel less comfortable performing it
and getting an accurate result.
An obese body habitus limits this as well
as well as pain because you’re pushing in that area,
so you can imagine if you’re having a lot of pain,
you don’t want someone to be repeatedly pushing over the area
that you’re having pain,
and also overlying bowel gas can limit the ability for this to be assessed.
What do you see on the image when it’s positive for appendicitis?
You see a noncompressible dilated appendix.
You could potentially see a fecalith which is like that appendicolith
that is stuck occluding the lumen of the appendix.
So here on this image, you could see that the appendix wall
which is that circular structure looks inflamed,
there’s some fluid around the appendix, and it’s not compressible.
So when you push down on it, that structure should normally collapse,
it should normally – that circle, black circle on the center should normally go away
but in this situation, that black circle is gonna stay there.
You’re not able to compress it or make it go away.
For pediatric patients, ultrasound is your imaging test of choice.
Ultrasound is better for the pediatric patients for a few reasons.
There’s a lower incidence of obesity in children
so oftentimes, you are able to get better images for those patients
and we also know that over a lifetime, radiation exposure can add up.
So by getting a CAT scan in a young child, sometimes it needs to be done
but we really wanna make sure that we’re being thoughtful
about whether or not there’s a better test
or a test that does not expose that individual to that amount of radiation,
so we definitely wanna balance those two things
and think about them when we’re thinking about the diagnosis.
But if you’re worried about appendicitis in a pediatric patient,
reach for the ultrasound first.
That’s gonna be your imaging modality of first choice.
Additionally, we can go ahead and get a CAT scan.
The benefits of a CAT scan is that it’s a great test of choice for non-pregnant patients
and it also has the greatest sensitivity and specificity.
The other thing that’s really good about getting a CAT scan
is that it can tell you if there’s other things present.
So we discussed the differential diagnosis and the fact that it’s really quite broad.
So your ultrasound can tell you if any of those other things are there.
It can tell you if there’s an abscess, if there’s diverticulitis,
if there’s any evidence of bowel wall thickening
that would make you think about colitis.
So it can definitely give you additional information.
So in addition to saying it’s appendicitis or it’s not appendicitis,
it can tell you other stuff too.
The big downside here is that radiation exposure.
Over a course of a lifetime, it can add up
and essentially there’s some evidence
that it can be associated with development of malignancies
and ideally, we’re gonna make sure that we’re thinking about radiation exposure
for patients when we’re thinking about the tests
that we’re ordering in the emergency department.
What do you see though on a CT scan that’s positive for appendicitis?
You see an enlarged appendiceal diameter,
so the appendix is bigger than it normally would be with thickening of the wall.
You can see the appendicolith,
you can see fat stranding around the appendix.
If it’s ruptured, you can see evidence of that.
Potentially, if it’s been going on for a problem, you may see an abscess.
So there’s lots of different things that can be seen.
Now, the diagnosis here can be challenged by low intra-abdominal fat,
so patients who don’t have a lot of fat in their abdominal cavity
or who are very skinny, this can be a little bit limited.
The last test that can sometimes help us out is MRI.
MRI can be helpful in pregnant women,
and this is nonionizing radiation exposure.
So while CT scan is ionizing radiation, MRI is nonionizing radiation.
The downsides here is that it’s costly, it’s an expensive test,
and there is sometimes lack of availability in the emergency department.
So generally, we reserve our MRI scanner
for patients in whom you’re worried about strokes
or in whom you’re worried about epidural abscess.
What do you see here on MRI?
You see an enlarged appendix,
wall thickening, signs of inflammation next to the appendix.
One thing that you wanna make sure you remember
if you’re obtaining this for a pregnant patient is that IV gadolinium
which is the contrast agent that’s used for MRI is toxic to the fetus
or harmful to the fetus.
So for patients who are pregnant and whom you are getting an MRI,
you wanna be sure to order that without IV gadolinium.