Interactive Transcript
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Alright, so this is our second case of the day.
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This is a 34-year-old,
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a 30-year-old female. Sorry.
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With painful periods in pain during intercourse and difficulty conceiving.
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So when I approach a female pelvis,
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I always start with the T2 nonfat sat images.
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As I've said, these are our work course images.
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And I start by scrolling through the sagittal just to kind of get a lay of the land,
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particularly thinking about how all those compartments are relative
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to each other and the orientation of the uterus.
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Then I'll take a look,
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a quick look through the axials to get a better look at the adnexa bilaterally.
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So there are a couple abnormal findings that we can point out right off the bat.
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So, the first is that this patient has
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a fairly large cystic lesion in her left adnexa here.
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It's T2 hyperintense, has a T2 hypointense nodule
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down here at the back and a thin septation,
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which we'll have to take a look at again later.
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I'm going to kind of break from my normal search pattern
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and jump into this here so that we can make a couple of teaching
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points before we look at the rest of the case.
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So I'm going to pull up the axial
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T1 fat saturated image and we're going to look at the same structure.
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So here, we can see that it is very, very intrinsically T1 bright.
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This is a pre contrast image,
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so this cannot be accounted for by gadolinium.
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This is intrinsic T1 hyperintensity.
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It is more T1 hyperintense than it is T2 hyperintense.
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And if I can convince you, this T2 dark nodule back here
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corresponds to this little focus right here that is just a little bit
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T1 brighter than the rest of the T1 brightness.
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So this is a very classic appearance of an endometrioma,
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which is the most common manifestation of endometriosis
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and is defined as a thick walled
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cystic structure containing blood products of varying chronicity.
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These blood products are what account
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for the intrinsic T1 hyperintensity of the lesion.
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They're bilateral in 50% of cases.
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They can sometimes contain these thin septations.
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That's okay.
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They can be unilocular or multilocular
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because there are blood products in them,
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they can restrict defusion a little bit.
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The way that we differentiate
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endometriomas from hemorrhagic cysts are by the relative T2 and T1 signal.
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So hemorrhagic cysts
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will be more T2 hyperintense and less T1 hyperintense than endometrioma.
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Another pearl is that endometriomas tend to be more homogeneous on the
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T1 weighted images and more heterogeneous
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on the T2 weighted images.
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And hemorrhagic cyst will be the opposite.
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So they'll be more homogeneous on the T2 and more heterogeneous on the T1.
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Another way that we can differentiate is to get a follow up ultrasound.
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Hemorrhagic cyst will evolve
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in appearance or resolve in six weeks,
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whereas endometriomas will remain stable.
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So now that we've talked a little bit
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about endometriomas, can we get the first question up, please?
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Ashley?
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So what is the most specific sign of an endometrioma?
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Is it the T2 Dark Spot sign,
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T2 Shading, T1 Hyperintensity, or Bilaterality?
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All right.
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So people have answered that T1 hyperintensity
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is the most specific sign of an endometrioma.
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So the most specific sign is actually
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the T2 dark spot sign, which is what we see here.
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So the reason that T1 hyperintensity
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isn't specific is that we can also see T1 hyperintensity in hemorrhagic cysts.
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And so while it is sensitive for endometrioma, it's not specific.
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This T1 dark spot sign, which is basically extremely
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inspissated blood product, is 93% specific for an endometrioma.
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It's only 35% sensitive though, it's not often seen.
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But when you do see this dark spot, you're pretty darn sure you're looking
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at an endometrioma and not a hemorrhagic cyst
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or another type of lesion.
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T2 shading is another kind of common buzzword
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that we hear with endometriomas, that is the T2 dark signal.
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There's some misunderstanding out there
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that it needs to be kind of layering T2 hypointensity.
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That's not the case. It just has to be T2 dark,
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that is less specific than the T2 dark spot sign for endometriomas.
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So the second point about endometriosis is to make in this case is
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the presence of superficial endometriotic implants.
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So if you look really carefully on this T1 fat saturated image,
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we have our cervix here, and we can see along the back wall
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of the cervix these very, very subtle linear areas of T1 hyperintensity.
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These are our small superficial endometriotic implants.
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Superficial endometriosis is the second
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morphology of endometriosis after endometrioma.
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They are defined as raised areas of glandular tissue that are
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on the peritoneal surface but that do not invade more than 5 mm.
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So they're not seen very well by MRI because they don't really invade.
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And all we can see are these kind of very
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subtle linear and punctate areas of T1 hyperintensity.
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There won't be a T2 correlate to these findings.
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MR often underestimates the amount of superficial endometriosis in the pelvis.
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MR is much better for deep infiltrating endometriosis,
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which we'll talk a little bit more about soon.
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Yeah. So other findings that we can see
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in this case. So, on the sagittal T2,
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we can see that the uterus is retroflex.
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So uterine version, antiversion versus retroversion
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is defined as the angle of the uterine body,
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including the cervix.
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So the angle of the whole uterus relative to the angle of the vagina.
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Uterine flexion is defined as the angle of the uterine body
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relative to the cervix itself.
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So this uterus is both retroverted and retroflexed.
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And retroversion of the uterus isn't a normal finding.
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It's less common than antiversion, which is the most common lay of the uterus.
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But to see retroflection like this, it makes you think, is there something
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along the uterine serosa back here that is tethering and causing scarring
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down of the uterus and kind of infolding on itself.
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And if we look on the axial,
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we can see this linear area of T2 hypointensity that is kind of bridging
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the rectum to this endometrioma and to the uterus.
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This is a little bit of deep infiltrating endometriosis that's responsible
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for that tethering and for the appearance of the uterus.
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And we'll have a better look at deep
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infiltrating endometriosis on another case.
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As a bonus, this patient also has a septate uterus.
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You can see the uterine septa right here.
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We know that it's septate because this indentation is greater
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than a centimeter in length,
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but the uterine serosal contour at the fundus is maintained.
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She also later had an HSG for evaluation of her infertility.
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Have had the septum partially resected at that time.
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And what we can see is that she has patent tubes,
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but there are all these adhesions around the ovary that is causing the contrast
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that is spilled to be kind of loculated in the pelvis around the ovary as opposed
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to free spillage, which is what we see here on the right.
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Great. Okay. So I think those are all the main
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teaching point I wanted to make with this case.
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I'm going to move on to the third.
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