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So this is a 65-year-old male who presents with

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right upper quadrant pain, got an ultrasound

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that showed no significant abnormality.

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This is followed by a CAT scan

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that I'll show you over here.

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And you can scroll through the CAT scan.

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Just on the first scroll, don't see anything

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that jumps out at me as this is abnormal.

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Um, we can notice a few things, uh,

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that may become pertinent to the case.

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Firstly, the gallbladder has been resected.

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The liver looks a little, looks steatotic to me, and

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other than that, looks pretty okay, and I remember

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reading this case, and just right before I was about to

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close it, and not seeing any major abnormality, I just

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noticed that there was something in the right side of

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the abdomen that, that was not supposed to be there.

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And so, just sort of windowing it a little

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bit, you can see it right over there.

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When you window in almost like liver

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windows and zoom up on it, you can see that

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there's just sort of this extra nodule here.

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You see the fat very nicely here, very nicely here.

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That should be contiguous, but instead there's this

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sort of nodule that's sort of jutting out over there,

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and the patient's been having right-sided pain.

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And so that certainly became important

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to, to figure out what that was.

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An indeterminate finding in

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and of itself on the CT scan.

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So for that, we got an MRI.

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So let's go ahead and see what the MRI looks like.

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I'll start off by looking at the T2

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axial non-fat saturated image, and we're

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just going to sort of hone in on that

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abnormality that we picked up on the CT scan.

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Now we can see it right over here.

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Let's zoom up on it a little bit more.

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And so the first thing, we'll note

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that indeed it was a real finding.

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There's something in that location.

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It's causing a little bit of mass effect upon the

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liver, and just on its imaging appearance here,

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it looks like it's pretty well circumscribed,

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has a few T2 hypointense fill-in defects.

1:55

Thanks.

1:55

Now some hyperintense signal within it.

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Let's look at it on the T2 fat-saturated image.

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I think that'll be better for us to sort

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of understand its internal contents.

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On the fat-saturated image, you can actually see that

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there is a rind of fluid that's surrounding this.

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So there's some sort of irritation and inflammatory

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change associated with this and as we scroll

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downwards, you can actually see this lesion

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pretty well circumscribed, has all these small,

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small T2 hypointense fill-in defects as

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well as some hyperintense content within it.

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We look at it on the T1 axial pre-contrast image fat

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saturated again, I'm going to zoom up right where we

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need to look. We can see the finding here. Not much to

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really see except that it looks pretty intermediate

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in its intensity when you compare it to some

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of the muscles in that location. And the post-contrast

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image though, you can see that there is definitely rim

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enhancement associated with this surrounding the liver.

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There's also some areas of hyperemia and some

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definite rim enhancement associated with this finding.

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And so if you were to look at this, you may still

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call it indeterminate given the rim enhancement,

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you may be worried about an abscess, but sort of

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putting things together with some of the other

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findings we've noted in this patient, we note that

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the patient is post cholecystectomy,

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and one of the more common complications that can

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occur post cholecystectomy, and particularly with

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laparoscopic cholecystectomy, is this entity of dropped

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gallstones, and it turns out that this is quite common.

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In fact, I see it quite, quite often

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in our cases, and in the literature,

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they report an incidence of up to 20%.

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And with dropped gallstones, uh, you know, it's

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basically due to inadvertent spillage of gallstones

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into the peritoneal cavity during the surgery.

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Most patients will have no symptoms.

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You don't need to worry about it.

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The small subset of patients who do have symptoms

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will have them because of complications such

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as abscess or superinfection that can form.

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Sometimes fistulas can form, and there's

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some chronic infection associated with them.

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And what you'll end up seeing is essentially

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nodules within the peritoneal cavity.

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Now, they like to occur at certain locations.

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I often see them, uh, in Morrison's

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pouch or, and, or the, uh, peritoneal

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recess really in this location over here.

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They can certainly creep behind the liver over here.

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I've seen them certainly in the gallbladder

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fossa itself, but I've seen them everywhere.

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You can see them in the laparoscopic port sites

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itself, um, in the paracolic gutter as well.

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And you see them as nodules.

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Now, if they're calcified, uh,

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it becomes easier to see them.

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Describe them as potential dropped gallstones,

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but as you may know, most gallstones will not have

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enough calcium for them to appear radiopaque on

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CT images, and so oftentimes you'll see it as just

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these sort of soft tissue nodules. However, if you

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get the MRI, they'll look like what gallstones look

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like. They'll have that T2 hypointense appearance

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if they're cholesterol stones. They'll also be

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T1 hypointense if they're pigmented stones.

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They'll be T1 hyperintense. And, uh, if there is

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superimposed infection, they'll have sort of a

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rim around it, which enhances, uh, compatible with

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an abscess with some surrounding edema and fluid.

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And so this instance was, um, a case of a

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gentleman who had dropped gallstones post

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cholecystectomy and, uh, had a small abscess that

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was associated with it that was resulting in

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him having bouts of right upper quadrant pain.