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This case is a patient who presents with right upper

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quadrant abdominal pain and in fact it's the same patient

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who had the autosomal dominant polycystic liver disease.

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And so we're going to evaluate it.

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Starting off with our T2-weighted images, and again, we

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see multiple liver cysts scattered throughout the liver,

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more than 10, certainly more than 10, perhaps even more

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than 20 liver cysts, and they all look about the same.

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We're going to focus on that large

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lesion, the right hepatic lobe over here.

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So this lesion over here looks a little bit

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different than the other cysts that we see.

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Certainly, there's a component of it, along its, uh,

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superior aspect that remains T2 hyperintense.

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Over here, along its posterior aspect, there's a

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lot more heterogeneous content, content that is

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relatively hypointense on the T2-weighted images.

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So this looks a little bit different

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than what we saw previously.

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So we're going to have to evaluate

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it using our remaining sequences.

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Next up is the T1 in and out of phase images.

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Here we have the out-of-phase image, here

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we have the in-phase image, and we can

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see this lesion over here once again.

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And, uh, doesn't lose signal in the out-of-phase

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image, so it contains no fat, doesn't lose signal

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in the in-phase image, so it contains no content

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that can result in increased susceptibility.

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We again see that, uh, the superior aspect of it

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looks different than the inferior aspect of it.

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This is relatively bright on the T1-weighted images,

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this is relatively dark on the T1-weighted images,

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and that sort of appearance can also be seen on the

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in-phase images, so that appears consistent across

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the out-of-phase images and the in-phase images.

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Next up, we're going to look at the T1 pre-contrast

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image performed with fat saturation, and on this image,

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again, we can see the liver lesion right over here,

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um, superior aspect of it is T1 hyperintense, the

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inferior aspect of it is T1 hypointense, and when we

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see hyperintense content on these pre-contrast imaging

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sequences, we We're really thinking about potentially

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hemorrhagic or proteinaceous debris, uh, within it.

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Now there's other things that can cause this sort of signal,

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but commonly these are the things that are going to do it.

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So we have to go to our post-contrast imaging sequences

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to see whether there's any internal enhancement.

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Now here we have the T1 post-contrast sequence performed

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in the arterial phase, and if we look at this lesion

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over here, there's a few things that become problematic

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if we were just to look at the arterial phase image.

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So here we have the T1 fat-saturated post

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contrast image performed in the arterial phase.

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And if we were to look at this liver lesion over

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here, there are a few things that become problematic

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if we were to just use these sets of images.

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So again, we can see the liver lesion

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over here, pretty well defined.

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It looks like internally, it's not completely avascular.

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Compare this liver lesion in question to

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say, something that looks completely cystic.

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Look how dark this lesion is.

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It looks completely avascular.

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Well, here it looks like it has a little bit of gray signal.

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That could suggest that there is internal enhancement.

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So how do we resolve this issue?

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Is this really enhancement or is this sort of

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gray signal that we see particularly on superior

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aspect just the T1 hyperintense content that

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was already present on the pre-contrast images?

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Well, for that, we need to look at our subtraction images.

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So here we have a T1 post-contrast

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image performed with subtraction.

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So all you're really seeing here is

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content that contains the contrast agent.

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If we scroll down to our liver lesion again,

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we can see that it is completely avascular.

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It looks like any of the other

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cysts that we see in this patient.

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has undergone internal hemorrhage and we talked

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about some of the complications with these

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cysts, one of which is undergoing hemorrhage.

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It can cause abdominal pain and if you sort of

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look at this, uh, case systematically, you can make

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that assessment without going down the wrong track

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of calling this potentially something malignant.