0:01

So the next step with acute appendicitis,

0:03

if the patients don't present quite as

0:05

early, they can develop an abscess itself.

0:08

So again, same process.

0:09

You follow that colon down until you

0:10

reach the cecum, the terminal ileum.

0:12

And in this patient, we have a

0:14

marked inflammatory process going

0:16

on in the right lower quadrant.

0:17

Here is her appendix right here.

0:19

Again, same as the other cases, thick

0:21

walled, hyper-enhancing, dilated,

0:24

marked inflammation surrounding it.

0:25

And again, it's a blind

0:26

ending tubular structure.

0:27

It does end.

0:28

It doesn't keep going such

0:29

as the terminal ileum.

0:31

But as you scroll down further,

0:33

you now see this fluid collection.

0:35

It has a well-defined enhancing wall.

0:38

If you put hounsfield units on it, it's

0:39

most likely going to be less than 20.

0:42

This isn't just simple ascites,

0:44

again, because it has a wall here.

0:45

It's loculated at this portion.

0:48

It's not free fluid.

0:50

And in her case, unfortunately, she

0:51

has a second collection a little

0:53

bit lower down in her pelvis.

0:54

Again, thick, enhancing walls,

0:56

mild inflammation, and a little

0:58

bit of gas in it as well.

0:59

These are consistent with abscesses.

1:02

So in general to tell an abscess from

1:04

free fluid, because you certainly can

1:05

get reactive free fluid in a case of

1:07

appendicitis, is that this has volume.

1:10

An abscess does.

1:11

It's going to push other

1:12

structures away from it.

1:14

It doesn't just have concave margins

1:16

and fill whatever space that it has.

1:19

Other things to keep in mind is that when

1:20

you have an abscess, generally they need

1:22

to be three centimeters or greater to

1:24

drain if they are in an amenable location.

1:26

In this particular patient, you

1:28

can see her collections reach up to

1:30

her peritoneal lining right here.

1:32

reaching towards her skin surface

1:34

with no bowel in the way to block the

1:35

potential drainage of the catheter.

1:38

Most surgeons, if they have an abscess, would

1:40

prefer to have a percutaneous tube placed

1:43

prior to having surgery to help them cool down.

1:47

So this is our same patient.

1:48

She's actually 11 years old,

1:50

coming in with acute appendicitis

1:51

with those two large abscesses.

1:54

So the surgeons asked before going to

1:56

the operating room to place percutaneous

1:58

drainage catheters into the abscesses.

2:01

This is her CT scan low dose prior to her

2:04

procedure for percutaneous drainage catheters.

2:06

You can see these bright spots right here

2:08

are the ureters, and that's because this

2:10

was only a few hours after her CT scan.

2:12

She was still excreting contrast.

2:14

In this case, it was actually really helpful

2:16

because we could use them as a marker to know

2:18

where her ureters were so that we wouldn't

2:21

put a catheter through them.

2:22

You do have a lot of streak artifact

2:24

from the contrast in her bladder.

2:26

In this case, we wanted to keep it there so

2:28

that we could see exactly where the bladder

2:30

was to differentiate it from an abscess.

2:32

So you can see here a low dose CT scan is

2:34

used to guide percutaneous drainage catheters.

2:37

And even lower doses are what were used when

2:39

we actually placed the catheters here.

2:41

So you can see in these fluoroscopic CT

2:43

images right here, when the needle goes into

2:45

the different collections, very low dose.

2:48

So you can get the minimal amount of

2:49

radiation to the patient that is necessary

2:52

to get these drainage catheters in place.

2:54

Here's one going into that deeper collection

2:56

as well.

2:58

And then we place a second catheter

2:59

at the more superior anterior location

3:02

to drain these as best as we could.