MRI Female Pelvis: Benign Diseases

Indications for Pelvic MR and Benign Entities

I have no disclosures to make,

so in general indications for pelvic MR and benign entities.

There are several of them, including uterine fibroids that are institution.

We do a lot of uterine artery embolization, evaluating for adenomyosis, looking for endometriosis, evaluating ovarian lesions, particularly dermoids and cystic lesions that are indeterminate, congenital entities, the Malian anomalies such as bi cornea, unit cornea or septic uterine, dynamic pelvic floor imaging, which I won't be able to get to.

Due to time constraints, maternal and fetal evaluation in pregnancy, and also evaluation of other pelvic abnormalities, fluid collection, cystic lesions of the urethra, vagina and perineum, lipomas, abscesses and fistula.

Uterine Fibroids

So I'm gonna start with this, one, very common entity that we encounter, and I'll just give you just, two seconds to look at and formulate your opinion.

It's a pretty straightforward appearance.

And this is a case of uterine fibroids.

Now, these are the most common tumors of the uterus occurring in 20 to 30% of women of reproductive age.

Now, these are benign neoplasms of smooth muscle, with varying amounts of interspersed connective tissue.

They may present with abnormal uterine bleeding.

They may present with pressure and adjacent organs, pain, infertility, or even a palpable mass.

Depending on their location, they're classified as submucosal, intramural, or subserosal.

And MR is by far the most accurate imaging technique for their detection and localization.

Ultrasound, as you know, is limited by the f small field of view, and particularly in large uterine fibroids.

It is not very helpful.

There's a very classic appearance to fibroids.

There are typically well circumscribed sharply marginated masses that are low signal intensity in T one and T two weighted images.

The best sequences in general are the T two weighted images, and we find that all three planes are helpful, especially when, when we want to assess the relationship of the fibroid with say, the endometrial cavity.

Now, more cellular fibroids may demonstrate higher T two signal and increased enhancement, and degenerative fibroids can have quite a varied appearance.

So again, this is the classic, MR appearance, multiple, T two hyperintense masses, that generally should enhance, although in several cases, if they are, degenerated, they may not.

Submucosal Fibroids

I'll talk a little bit about the subtypes, sub mucosal fibroids of those that project into the endometrial canal.

And while there are only 5% of fibroids, these are the most commonly symptomatic ones.

Patients may have dysmenorrhea menorrhagia and an increased incidence of infertility.

And a lot of the intracavitary myomas, especially if they have an acute angle with a uterine wall, may be safely resected hysteroscopically.

So here's one such case of a very classic, submucosal uterine fibroid.

Again, this patient was very successfully hysteroscopically, resected.

Here's another patient of a submucosal fibroid.

You see, this is a little bit more pedunculated extends, toward the cervical o and this also was, hysteroscopically resected.

The main differential would be that of an endometrial polyp.

And typically these are high, in T two signal.

In some cases, they may have what is, reported to be a central fibrous course, or there might be some central hyperintensity in T two, and they should generally similarly enhance the uterine fibroids, on our post gadolinium images.

Subserosal Fibroids

Now, subs, Rosa uterine fibroids are those that project beneath the ci.

Usually they're asymptomatic, but these can cause mass effect, depending on what organ they're touching upon.

These may be pocd, if large, they may be resect, resected laparoscopically.

They may actually present, with pain if they undergo torsion, and result in infarction.

And in some cases, they have to be differentiated from adnexal lesion.

So it's very important that we identify, the ovaries and make sure that they're separate from them.

Here's a couple of, cases of such subserosal fibroids.

You can see these internal areas of degeneration as, high T two signal, and you can also see this posterior, subserosal fibroid.

Here's an interesting case because this is a very large fibroid, and it's in a very, very smalltalk.

And the implication of this is that, this could be actually fairly easily resected, uterine art embolization.

Sometimes in the setting, when you have a very smalltalk of a large, subserosa fibroid may not be as effective.

One thing to look at if, to look at, at if, we're not certain if we're dealing with an adexo, mass or something that arises from the uterus, is to look for what's called the bridging vessel sign.

We look for vessels or flow voids, that extend between the actual uterus and the exophytic fibroid.

Types of Degeneration in Fibroids

Now, there are different types of degeneration of fibroids, including hylan or calcific degeneration.

This is very common.

This is actually, these are the cases that we often see in ct in older patients.

Hemorrhagic degeneration is uncommon, but it occurs, in pregnancy, due to rupture of inter of, small, small vessels.

And these, may have high T one signal, and there may be minimal or no enhancement cystic degeneration, as you would expect, you'll have very high T two signal and non no enhancement and fatty degeneration, into a lipo, into a lipo myoma, excuse me, is, quite unusual.

Just some cases to show you.

This is a, a patient of hemorrhagic degeneration.

You can see very high signal on the T one, image over here.

And you can see sort of this heterogeneous with areas of high signal on T two as well.

Here's another patient with a subserosal fibroid that has undergone degeneration.

This patient was symptomatic and had some pain, and you can see internal areas of central, necrosis and non enhancement and, change in the T two signal.

As you can see, the T two weighted image.

Treatment Options for Fibroids

Now, the treatment options for fibroids, there's several, potential options, medical treatment, such as Lupron, which will decrease estrogen.

It's really not a very practical treatment because there is a significant long term, possibility of developing severe osteoporosis.

So patients typically, should get either surgery or, interventional radiology, treatment.

Now in surgery, as you know, either the patients can have hysterectomy, they can have myomectomy or hysteroscopic resection or even endometrial ablation.

And, interventional radiology has to offer uterine artery embolization.

This, ladder, therapy is a useful alternative to major surgery or hormone therapy because it's sown a great improvement in clinical symptoms, significant reduction of tumor balkan volume, and it eliminates the need for major surgery.

So the pre-procedure MR is actually an excellent tool for candidate selection for the interventional radiologists, and that's because we can evaluate the uterine cavity very nicely.

We can evaluate the exact fibroid location and also what is important.

We can evaluate fibroid enhancement.

Now, if the fibroids are not baseline enhancing, as you would expect, these patients will not benefit from uterine artery embolization.

It's also great in assessing a response, and you can see this patient here on the baseline, pre UAE, almost all the fibroids were enhancing.

There was one that was degenerated and had a small area of non enhancement.

But you can see after therapy, you can see that all these fibroids, have, turned into like black holes and they're no longer enhancing.

Here's another, again, pre and post.

Again, this is the intended effect.

This is what we wanna see, heterogeneously enhancing fibroid pre, and as you can see here, in this specific case, it's non enhancing.

We can also assess complications of uterine artery embolization.

And this specific, patient, there was endometritis and actually this, flow void here, was gas.

And the clinical history also was very helpful in this specific instance.

And another thing that we have to look for is fibroid expulsion.

And this can occur with or without associated infection.

You can see the pre and post.

You can see that this, uterine fibroid is in the process of being expelled, or sloughed, from the, uterus.

And here's the corresponding post gadolinium image, where again, you can see the treated fibroid, which is, actually extending through the, cervix.

This fibroid expulsion is very unusual, with an incidence of, approximately 0.5%.

These patients typically pre, present with bleeding discharge tissue passage, but they may have fever if they're infected.

And management consists of clinical evaluation, Mr antibiotics, pain control, observation.

However, we have to be weary because if these are not passed within a few days, hysteroscopic assisted removal may be necessary because, again, these patients in some cases, can, progress into sepsis.

There are several risk factors, and as you can expect, submucosal lesions are more, more likely, to be expelled also, if they have extensive contact with endometrial surface, if they're undulated, if the patients were pretreated with Lupron, and if the patients have had cervical prolapse.

Adenomyosis

So here's the next entity, another very common entity that we can very nicely diagnose an mr.

As you can see here.

And this is a case of diffuse uterine adenomyosis.

This is when we have heterotopic endometrial glands and stroma and the myometrium, and there's adjacent myometrial hyperplasia.

This could be microscopic, focal or diffuse, and it's quite frequent, usually affecting premenopausal women.

Now, the, there's, certain overlap with, symptoms of patients with uterine fibroids in these patients.

This is actually a nice, schematic, that shows, what is going on.

There's heterotopic endometrial tissue and glands and associated hemorrhage within the myometrium.

Now, ultrasound is often but not always useful.

What we look for is a more globular, uterine shape.

We look for increased, course heterogeneous, myometrial architecture, as we can see in both these images here.

And also we can look for small cystic spaces, that can be seen in about half of the patients.

Mr, however, is a superior, particularly for cases of more mild or subtle adenomyosis.

And, what we look for is we look for the junctional zone.

So this is the normal sort of thin junctional zone that we see.

It's, T two hypo intense.

And the one hallmark, major hallmark of adenomyosis is thickening of this junctional zone.

You can see here it is quite thick.

It's reached 16 millimeters, and what we use, is a cutoff of 12 millimeters if above 12 millimeters.

We call it abnormal.

The eight to 12 millimeter zone has been considered by many to be sort of equivocal.

And under eight is typically, absolutely normal.

So here's another case, 24 millimeters for the junctional zone, another case of adenomyosis.

The other hallmark is these small T two bright foci, as you can see here.

And these are islands of heterotopic endometrial tissue, cystic dilatation of these heterotopic glands or areas of hemorrhage.

Here's another patient, again, a very exaggerated case with a significant, widening of the junctional zone and multiple such, T two bright foci.

And sometimes we can see tiny little, areas of, non enhancement or, or hyperintensity on our, post gadolinium images.

Now, adenomyosis, as I said, may be either focal or diffuse.

In this case, it's focal, involving the posterior aspect of the uterus.

Again, very classic imaging findings.

Here's another case of focal adenomyosis involving the anterior aspect of the uterus, and here's a case of diffuse adenomyosis as seen previously.

Another thing to remember is that adenomyosis may coexist with fibroids.

And in this specific case, you can very nicely see the difference between fibroids, the more nice roundly, T two hyperintense, well circumscribed lesions, and the more sort of ill-defined borders, contiguous with a junctional zone, classic imaging findings.

The T two hyperintense foci that we see with adenomyosis.

A couple of pitfalls.

There is physiologic thickening of the junctional zone that it can occur early in the menstrual cycle, and in some cases there can be focal myometrial contractions.

These can in some, rare cases simulate, adenomyosis.

Tube Ovarian Abscess

So I'm gonna proceed here with the next unknown case.

And this is typically not, something that we diagnose on Mr, but I just wanted to show you some images and just briefly overview this entity.

So you can see T two weighted images.

You can see sort of a thick, thick enhancing walls of this, lesion.

You can see a fluid, fluid level on these two, two weighted images.

So in this case, this is a patient with a tube ovarian abscess, and this is a complication of pelvic inflammatory disease, typically polymicrobial infections.

And what happens is there's tubal necrosis in abscess formation, which extends into the ovary.

Now, this classically is a clinical or ultrasound at the most diagnosis.

Sometimes we see these patients on CT overnight, patients presenting with pelvic, pain.

And if you see CT or MR, you should, see a complex enhancing cystic and nexel max with peral enhancement.

And very briefly, I'll show you an ultrasound, case, and you can see an inflammatory mass, which includes the ovary and the dilated fallopian tube.

You can have internal echoes indicating pus within this dilated fallopian tube.

And again, you should see extension of this process into the ovary.

There should be increased the flow from the significant inflammation that's associated with this process, as you can see here.

And this is more likely what we'll see in ct.

Again, sometimes for the emergency room, we'll get, these cases we'll see a complex, pelvic mass, including the ovary in the dilated tube.

It's got enhancing walls.

And, almost always the clinical history is of utmost importance.

Here's a nice case of side-by-side ultrasound and CT sewing up bilateral, tube ovarian abscesses, again, with a classic imaging findings.

Here is a CT again of another patient with bilateral tube bov abscesses.

The presence of gas, quite unusual, but highly, highly specific, and it's less likely to encounter that on mr.

So going through our Mr. Case, again, this was a complex mass with thickened walls.

We have the fluid, fluid levels from the pus within the lesion.

And, also very diagnosis is the, increase that marked, in lesional enhancement and para lesional enhancement, that you can see in this large complex, contiguous mass.

Very briefly. Also, a couple other cases of TOAs.

Again, same sort of concept.

You may have internal, echoes or not echoes.

In this case, you'll have internal signal, fluid, fluid level, and you can have, thickened significantly thickened walls.

And here just to add a case with diffusion weighted images, you can see actually very nicely restricted diffusion, restricted diffusion, on these, tube ovarian abscesses.

Dermoid Cyst

Okay, here's the next, unknown case, another sort of classic entity, that we may encounter.

And in this specific case, we have a T two weighted image, and we have a fat saturated, image, which is actually a post GA image.

But the diagnosis in this case, as you can see, the lesion follows, the same signal characteristics of fat.

So this is a dermoid cyst or mature cystic teratoma.

These are the most common VE neoplasms anywhere from 26 to 44% of ovarian tumors.

10% are bilateral, typically seen in young females, and typically they're unilateral.

And as you know, they can be filled with all kinds of, ugly components such as keratin, sebum, hair, teeth, skin, and cartilage.

Ultrasound appearance, is classic.

There's a so-called tip of the iceberg sign.

In some cases, there's a highly echogenic focus that stone called dermoid plug.

And in some cases, there could be a fat fluid level on ct, very, very easy diagnosis.

Fatty mass in the adnexa is pathognomonic on a mar.

It exploits the presence of fat in sebum and will follow fat signal in all sequences.

There'll be high signal on both T one and T two weighted images and fat saturated sequences should show signal drop.

And I'll show you very quickly some cases.

Again, the most important thing to see is it follows the signal characteristics of fat, in all, sequences, the same fat that we see in the anterior abdominal wall.

Here's that other case that I showed you previously.

There can be internal components, within these lesions.

And again, these are, if it's a predominantly fatty lesion, this is the diagnosis.

Finally, as we said, about 10% can be bilateral, as you can see in this, patient here.

Endometriosis

And here's the next unknown case.

This is another sort of, fairly frequent entity.

You can see a, high signal intensity mass on a fat saturated, image.

It's relatively low on the T two, weighted images.

So this is endometriosis.

So endometriosis refers to ectopic functional endometrial glands that are, located outside of the uterus.

And this can rage anywhere from microscopic implants to large cysts.

The so, called endometrioma can be seen in about 50%.

It's a very common entity, especially in, in females with pelvic pain seen in approximately 31% of females undergoing laparoscopy.

Often the patients who have debilitating symptoms, pelvic pain, dysmenorrhea, dyspareunia, and infertility, classic imaging appearance, low level echoes, within a, a non, no color flow within the lesion.

This is an easy diagnosis to make when we're dealing with an endometrioma.

However, an ultrasound, we really cannot see the extra variant implants well, and that's where MR has an important role.

So the endometrioma, which is the common manifestation, there are two classic findings, what's called T two shading, the low signal intensity and T two weighted images, and also the, bright, signal on fat suppressed grade and echo T one sequences.

And here, sort of a classic such case, you can see low signal intensity, the T two shading and the T two weighted image.

And you can see that this is a very, very bright, lesion on the fat saturated pre contrast.

T one, A couple of other cases, you can see again, same imaging findings, relatively low signal intensity in T two, high signal intensity in the pre contrast, T one fat saturated.

And here's yet another case, anterior, to the uterus.

Again, same, similar, imaging characteristics.

However, where Mars helpful is in identifying other sites of involvement.

You can see, from this nice, diagram, from a Radiographics article, an older Radiographics article.

You can see all the potential different sites, for endometriosis.

So it's a great modality, Mr is, and the advantages that we can detect nearly all sites of deep pelvic endometriosis.

And it can also offer the surgeon an accurate map of the extent of disease.

So this is what these little, implants may look on laparoscopically.

And these are the small T one bright foy.

And again, fat saturated pre contrast images is what we need to use.

Deep pelvic endometriosis that refers to involvement of the uterosacral ligaments, the pouch of Douglas vagina, bladder, and rectum.

And I'll show you some cases.

Here's a patient with uterosacral ligament involvement, and again, classic imaging findings of the hyperintense.

Focus on the fat saturated T one image.

Here's a little cul-de-sac implant.

And another patient you can see over here.

This is another patient with iscu recal, fossa involvement.

And there's some sort of scarring and fibrosis also occurring, that you can see much better in the sep other patients.

So in some cases, actually what we may end up seeing, it might not be very, very bright, and there might be a lot of, low signal and sort of a stellate scarring, stellate appearance, of this hyperintense mass.

And this is actually extensive fibrosis in a patient with longstanding endometriosis.

The implication is if the surgeon tries to go there, it's gonna be very hard for them to dissect through that area.

Other unusual, locations will include the bladder, as you can see with these, implants here.

The colon wall here is a case with a, a patient with a serosal implant upon the colon wall.

They can involve the fallopian tubes as well.

As you can see in this patient.

Here, you can have sort of classic, tubular shape, bilaterally.

This is involvement of the fallopian tubes.

And also you can see anterior abdominal wall implants, especially if there's been prior surgery.

Abdominal, well, endometriosis occurs in approximately almost 1% of patients that have had a C-section.

And patients almost always have a history of surgery.

Often they have a palpable mass, constant, pain actually may be, more likely than cyclical pain.

The classic cyclical pain that we see, with endometriosis, and there's a differential, of course, it could be a hematoma, an abscess, a desmoid, a sarcoma lymphoma.

But again, the signal and the pre contrast T one weighted images, should help.

Müllerian Anomalies

So I'm gonna use the last, 10 minutes to talk briefly about the different Malian anomalies.

These are congenital abnormalities of female, female genital tract overall incidents, about 4% of all women.

Um, but and of occur in a lot of women that have, pregnancy problems, especially late first and early second trimester miscarriages, imaging evaluation consists of HSG ultrasound and MR again is the most accurate modality because we have detailed depiction of anatomy.

Here's a list, the old a FS classification scheme, and we'll go through these different entities.

Unicornuate Uterus

So what's the diagnosis in this case here?

So this is, you can see sort of a single, horn.

It has almost a banana shape.

This is a case of a coronary uterus.

This is due to complete or almost complete arrest of the development of one of the paired malian ducts.

These patients have a low fertility rate, a high incidence of spontaneous abortion, premature birth, IUGR, and abnormal fetal lie.

Other complications would include dysmenorrhea, hem, myometrial, endometriosis, and ectopic pregnancies.

So the prognosis and management actually depends on the presence of a communicating, rudimentary horn, especially if this contains an endometrial lining.

If there is a rudimentary horn that becomes obstructed, this will typically cause complications.

And surgical resection of that horn and tube, will be indicated.

Now also, if there's a communicating, rudimentary horn surgery is indicated because pregnancy is unlikely to be viable.

If there's a non communicating rudimentary horn that we see without an endometrial lining, complications are unlikely.

End surgery is generally not, indicated.

So, these are just, some images from a JUM article, recently, nicely showing the different types.

So, in this specific case, you can see, there's a cavitary communicating rudimentary horn that occurs in about 10%.

In this, patient here, we have a cavitary, but non communicating rudimentary horn, 22% of patients have that.

In this case, here you can see there's a cavitary, but entirely non communicating horn.

And finally, this is just a single, solitary isolated unicorn.

It's, uterus. I'm sorry, this was a non cavitary.

Here. So, on imaging, these are typically well visualized in HSG, MR should identify the presence and degree and dilatation of a non communicating rudimentary horn.

And quite honestly, this can be quite hard in some cases.

Another thing to important, an important thing to remember in these patients is that 40% will have associated renal anomalies, most likely ipsilateral renal agenesis, but there could be other, dysplasias, horseshoe ectopic kidneys, so an HSG, single uterine horn fallopian tube.

And, on mr, typically you'll see an elevated curved uterus with a banana shape, and we have to look for that, rudimentary horn here.

In this patient, there's a non communicating rudimentary horn without an endometrial lining.

This patient here actually had a non communicating cavitary rudimentary horn with probable endometrial lining.

And again, it's kind of hard to see in single images that I have to provide here.

And this patient here, this patient had a communicating cavitary rudimentary horn with an endometrial lining, and this patient had recurrent, spontaneous abortions.

And finally, we have to include either like a coronal, haste or single shot fas echo sequence.

We have to look at the kidneys, because as I said, again, there are, associated renal anomalies in 40% of patients.

Septate Uterus

Okay, in this case here, which, anomaly are we dealing with?

We have, uterus here.

We see sort of the, this is the most important feature, to look at the fundal contour.

And you can see here it's, nearly flat.

So in this specific case, this is a case of a septic uterus, right?

So this is the most common uterine anomaly.

And this is due to partial or complete failure of resorption of the utero vaginal septum after the malian ducts fuse, these may be partial or complete, complete meaning that they extend to the, all the way to the external cervical o and then 5% the septum may actually extend into the superior vagina.

There's a high rate of reproductive failure, and spontaneous abortions can occur in up to 90%, and these can be successfully corrected hysteroscopically leading to up to 86%, live, birth rates.

The combined accuracy of transvaginal ultrasound and HSG is about 90% and of mr 100%.

So, on HSG, the uterine horn should not be as divergent.

Here you can see the, comparison between a bi coordinate uterus and a coordinate uterus.

You can see, again, not very divergent horns.

As was mentioned earlier, we have to use long and short axis views of the uterus.

We look for the fundal contour, which should be convex flat or minimally in indented.

The inter corneal distance, should be, relatively small under two to four centimeters.

And we really don't look at the signal intensity of the septum.

It's not really reliable in any kind of differentiation or, it really doesn't, help that much, the clinician either.

We describe it and we say how far it goes.

But, that's about the extent to which we go.

So again, this is another case. Flat, fundal contour.

You can see a little bit of the septum here.

Another case here with a slightly convex, fundal contour.

And again, the septum, we typically, if we see it, we'll describe it.

Typically they're more fibrous inferiorly and, more myometrial superiorly in composition.

Bicornuate Uterus

So here's the other companion malian anomaly.

You can see divergent uterine horns.

You can see the corresponding mr.

And this is a case of a bi coronary uterus.

This is when we have two uterine horns in one cervix, and it results from partial non fusion of the malaria and ducts.

Fewer complications in septate.

And treatment, actually in this case, requires open, surgery laparotomy.

There's two different types depending on whether the central bridging myometrium extends to the internal cervical loss, in which case it's a uterus, bico, uni cos, or the external, in which case it's a uterine uterus.

Bico bico, main findings, again, similar as to septate, these are the same numbers, basically as we talked about.

The septate main findings are an external fundal cleft that exceeds one centimeter, an increased inter corneal distance of over four centimeters, and an increased inter corneal angle of 1 0 5 or more.

As you can see here, widely divergent horns in an HSG, more likely to be dealing with a bico uterus.

You can see a couple of mr cases, again, widely divergent horns.

This is classic four bico, uterus.

And this is the case that I showed you in the beginning.

Here's another case, and I'm actually pointing, to the fact there are two separate distinct, services, and two widely divergent horns.

Uterus Didelphys

So this is the case of uterus delphis.

So this is due to failure of fusion of the mure inducts, and we have two entirely separate uterine horns.

In two services. Frequently a vaginal septum is present, and these, patients actually have the highest pregnancy rates of mu layer and anomalies.

Mr again, is great in depicting, detailed, anatomy.

Now, HSG, there's a pitfall because they have to see both services in candidate, both services.

As you can imagine. If they only see the one cervix, this might be considered to be a unicorn root, uterus.

So they have to see and cannulate both services if they're doing an HSG.

And again, on mr, we have to look very carefully for entirely separate uterine horns and entirely ser separate services.

Tamoxifen Changes

So, okay, very quickly, what would you consider here?

This is actually one case.

This patient here has a history of breast cancer.

Just show you another benign entity.

So this is just the case of tamoxifen changes within the endometrium.

You can see these, mildly hyperintense endometrium with multiple focal bright cystic foci, and you can see a lattice pattern of enhancement.

And also here you can see, again, the same sort of appearance is hyperintense foci with a lattice pattern of enhancement.

Tamoxifen changes occur because while, estrogen, acts, tamoxifen acts against estrogen in the breast, it is, partial estrogen, a agonist on the female genital tract.

And these patients have increased risk of endometrial, lesions.

Mostly benign proliferative endometrium, endometrial hyperplasia, polyps with cystic dilated glands, and in some cases malignant, and up to half of the patients, that are in breast cancer.

And Tamoxifen will develop endometrial lesion requiring biopsy within 36 months.

Thank you very much.