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First case here is a 78-year-old gentleman

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who has a history of colon cancer and a few

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indeterminate lesions seen on a CT scan.

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So let's open up the CT images

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and see what we're talking about.

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As we scroll downwards, we can see that there's

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about a five-centimeter lesion in the right hepatic lobe.

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This actually measures, uh, has houseful

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units that are compatible with a simple cyst.

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We're not too worried about that.

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However, on the same image, you can see that there is

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an additional lesion in the left hepatic lobe over here.

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And as we scroll downwards, an additional

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lesion in the left hepatic lobe, over here,

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that are indeterminate based on CT imaging.

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So it's possible that they're benign things

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that we don't need to worry about, but it's also

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possible they could be metastasis, which would

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drastically change the management for this patient.

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So, an MRI was ordered for further evaluation.

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So let's start looking at the MRI images for this patient.

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We'll start with our T2-weighted sequences.

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This is the single-shot spin echo sequence.

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This is the turbo spin echo sequence.

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And the lesion, the larger lesion, the left

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hepatic lobe, we can see right over here.

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And we notice that the T2 signal

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of this lesion is rather bright.

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So when I see the T2 signal,

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uh, of this variety in any liver lesion,

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I'm already not too worried about it.

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It's quite similar to CSF over here, and so

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that's something that I don't really worry about.

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However, we do need to look at the

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other sequences to evaluate it.

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The other liver lesion we can see up here, it's a little bit

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smaller, and it too has a T2 signal that's rather bright.

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So already looking at this, I'm not

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too worried about this liver lesion.

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However, as I had mentioned, I'm not using this particular

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sequence to evaluate the T2 content of any liver lesion.

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turbo spin echo sequence over here.

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And on that, indeed, while there is a little bit more

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motion over here, we can see that the larger lesion

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appears consistently bright, very similar to CSF over here.

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So we're going to go into this thinking

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that this is probably going to be something

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I don't need to worry about, like a cyst.

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And because of the motion, the smaller lesion

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is actually much more difficult to see.

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And so that sort of showcases the utility of

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obtaining these two sets of T2-weighted sequences.

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As we go through our systematic evaluation

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of these lesions, we're going to look next

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up at the T1 in and out of phase sequence.

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So we'll focus on the larger lesion, the left hepatic lobe,

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and we can see that the lesion is hypointense on the T1 in

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and out of phase sequences, and it looks similar on both.

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There's no evidence of signal dropout on the out of phase

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sequence to suggest that it contains fat, and no signal

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dropout on the in-phase sequence over here to suggest that

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it contains any product with increased susceptibility.

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We're then going to look at our final set of sequences,

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which is the T1 pre and post-contrast sequences.

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On the pre-contrast sequence, we can see that the lesion

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is hypointense with respect to the liver parenchyma.

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On the hepatic arterial phase sequence,

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we can see that there is not a lot of

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contrast enhancement within this lesion.

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Of course, we're going to have to evaluate

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this lesion on the remaining sequences.

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Here, on the portal venous phase, we can again see that

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there is no internal enhancement within this lesion.

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There may be a thin, thin rim of

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imperceptible rim enhancement surrounding it.

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But internally, this is avascular.

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And finally, on the equilibrium phase

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images, we can again see that there is no

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internal enhancement within this lesion.

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internal enhancement, imperceptible rim enhancement.

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This is compatible with a cyst.

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The other lesion in question was also a cyst.

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Cysts are ubiquitous in our patient population, seen in up

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to 15 percent of the population, probably more if you're

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looking at cases, more often seen in females than males.

3:46

Thanks.

3:46

Um, and they tend to be asymptomatic

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and incidental findings.

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If they get large, maybe, and if they're near

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the capsule, for example over here, they can

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stretch the capsule and cause a little bit of pain.

3:58

They can undergo internal hemorrhage, sometimes that

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can cause pain and maybe sometimes fever as well.

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But overall, these are relatively good lesions

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to have if there's ever a good lesion to have.

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Prognosis is very good.

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They may grow over time.

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And if they are asymptomatic.

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You can certainly resect them or undergo

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marsupialization where you sort of open

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up the cyst into the peritoneal cavity.