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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.