Interactive Transcript
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So today, we're going to be talking about imaging of the female pelvis
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with a specific emphasis on MRI of endometriosis.
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So let me pull up the first case here.
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So endometriosis is defined as the presence of functional
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endometrial glands and stroma outside of the endometrial cavity.
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It's quite common affecting 10% of all reproductive age women
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and causes chronic pelvic pain,
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infertility, pain with intercourse and other symptoms.
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Laparoscopy is technically the gold standard for diagnosis,
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although MRI is increasingly used these days to make the diagnosis and to help
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particularly in the pre surgical planning phase.
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So just a quick overview of our protocol here at the Brigham.
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So this is a patient without endometriosis that I'm going to use to go over
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the protocol and to talk a little bit about the normal anatomy
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of the female pelvis.
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So our protocol calls for axial
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and sagittal T2 non-fat sat weighted images of the pelvis and also
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a coronal T2 non-fat sat image of the pelvis and including the abdomen,
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so that we can take a peek at the kidneys and the ureters on both sides.
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Your T2 non-fat sat images are going to be
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your workhorse images for evaluation of the female pelvis.
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Along with these, I think the next most
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important sequence are probably the T1 pres.
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So our protocol calls for axial,
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T1 pre with fat sat and sagittal T1 pre with fat sat.
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Other institutions will do these without fat saturation.
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It doesn't really matter. The important thing is that it's a T1 pre
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contrast image so that there's no confusion between something that is
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intrinsically T1 bright and something that's enhancing.
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We also get DWI and ADC images of the pelvis.
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These are important in the endometriosis setting in evaluating malignant
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degeneration of an endometrioma or for infection.
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DWI images are not super useful in the evaluation of plain endometriosis itself.
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And then finally, we get post contrast enhanced images.
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Our protocol calls for these to be done
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in the sagittal plane when we're imaging the female pelvis and then to get more
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delayed post contrast images in the axial and the coronal plane.
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And we also make subtraction images
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which can be very helpful, specifically when you're looking for enhancement within
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an endometrioma, which is itself intrinsically T1 bright.
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So, those are overviews of protocol consideration.
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So now to talk about this case a little bit.
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So, again, this is not a woman with endometriosis.
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This is a 64-year-old woman who had NMDA encephalitis and had an ovarian cystic
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lesion, that they wanted to further characterize with an MRI.
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But I'm starting with her case because her pelvic anatomy is pretty clean and it's
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a nice opportunity for us to discuss the compartmental approach to the female
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pelvis, which is how endometriosis is recommended to be dictated now.
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So last month, an abdominal radiology,
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which is the Society of Abdominal Radiology's journal,
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the majority of the issue was dedicated to MRI of endometriosis and the first
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article in that publication was an MRI lexicon, which goes through
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recommendations by the disease, it's focused panel about how exactly to...
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which words exactly to use to describe the locations, morphologies,
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and then important findings for endometriosis in each area of the pelvis.
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So they recommend breaking down the pelvis by compartment.
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So there's an anterior compartment,
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which is basically everything anterior to the uterus.
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The middle compartment,
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which is the uterus and vagina itself, and the posterior compartment.
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Going into a little bit more detail in the anterior compartment.
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We have the prevesical space,
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which is here. It's an extraperitoneal structure, does extend all the way up
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to the umbilicus and includes urachal remnant tissue.
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We have the bladder itself.
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We have the round ligaments,
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which are these paired ligaments here, extending from the kind of anterior corners
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of the uterus into the inguinal canals bilaterally.
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It is normal that we see these structures,
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although they should be nice and thin in T2 hypointense like these ones.
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The canal of Nuck is the specific name
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given to the round ligaments when they're in the inguinal canal and in the labia.
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The next part of the anterior compartment
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is the vesicouterine space, which is a potential space.
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Between the bladder and the uterus here, the vesicovaginal space,
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which is an extraperitoneal space between the bladder and the vagina here.
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And then finally, the distal ureters.
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Again, in the middle compartment, it includes the uterus, the vagina,
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the fallopian tubes and the ovaries themselves.
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And then the posterior compartment will include the rectouterine space,
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the rectocervical space, both of which are intraperitoneal
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the rectovaginal space, which is extraperitoneal.
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The uterus sacral ligaments, which are going to be difficult to see
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on this particular example, but we'll see well in a case later on in this hour.
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The rectosigmoid colon itself, and then the presacral space.
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So that kind of is an overview of the locations where we'll describe endometriosis.
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We'll go into the morphologies of endometriosis and cases now.
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