Reimaging the Female Pelvis with Ultrasound after CT: When and Why? - HD

Introduction

Hi, my name is Maitre Patel.
I'm the division chief of ultrasound at Mayo Clinic in Arizona.
And I'll be talking to you about re-imaging the female pelvis with ultrasound after CT.
When and why?

We all know that CT is commonly done prior to ultrasound for women in a variety of situations.
For women who present acutely with pain in the emergency room.
Some women are suspected of having bowel pathology or renal calculi, or a patient may have had an abdominal and pelvic CT for other reasons in which adnexal findings are identified.
And it's not uncommon, therefore, for an image to be similar to this one in which a mass or a cyst is found in the adnexa and either the radiologist recommends an ultrasound to further evaluate this cyst, or having mentioned the cyst in a report, the emergency room physician orders an ultrasound to better evaluate the uterus and ovaries as a potential source of symptoms.

And my objective in this talk is to clarify some terminology regarding re-imaging versus follow-up imaging.
Elaborate general principles regarding when re-imaging is and isn't useful, familiarize you with the CT appearances of variety of normal abnormal pelvic entities.
And then finally discuss in some depth pelvic congestion syndrome, ovarian torsion, and pelvic inflammatory disease.

Re-imaging vs. Follow-up Imaging

There is a difference between the terms re-imaging and follow-up imaging.
Re-imaging refers to when an ultrasound is performed immediately or within a few days of the CT.
The purpose of re-imaging is to further characterize a CT finding or a suspected clinical entity.
Follow-up imaging on the other hand, is when ultrasound is performed after some time interval.
And the purpose here is not only to evaluate the CT finding, but to establish the effect of time on that finding, either showing that with time the mass or cyst has involuted is stable or has enlarged.

When Not to Re-image with Ultrasound

Now, there are a variety of times when I believe we should not be re-imaging with ultrasound.
First, if all you're finding is normal gynecological structures on the CT ultrasound is unlikely to be of very much use.
I'm not going to be going over a variety of different normal appearances of gynecology on CT.
But radiologists should be familiar with these when they interpret CT of the pelvis.
What I would like to spend some time on is this concept where we should not be re-imaging with ultrasound when the diagnosis is either a non neoplastic cyst or a benign neoplasm, because in this setting, follow-up imaging is what would be required, not re-imaging, because the change in time, the change of the mass over time is the key observation to make.

Now this concept is pretty well known in terms of ultrasound imaging.
The Society of Radiologists in Ultrasound had a consensus panel in 2009 that established some guidelines for when simple cysts identified on ultrasound would need to be re-imaged or have follow-up imaging.
And in these guidelines, the main issue that is trying to be established is how likely the mass is to be a non neoplastic cyst.
If it's a simple incidental cyst and it's very likely to be a non neoplastic physiologic cyst follow-up would not be necessary.
On the other hand, if it's reasonably a non neoplastic cyst, but might be a benign neoplasm, follow-up ultrasound would be useful.
And finally, if it's unlikely to be a non neoplastic cyst, then we might pursue some other imaging.
And the rules that have been established on ultrasound are well articulated in the paper that came out from this panel.
But essentially a premenopausal patient who's less than three centimeters in size in terms of having an adnexal simple incidental cyst, really does not need any follow-up.
Likewise, even up to five centimeters premenopausal patients with simple cysts don't need to be followed after that.
The SRU consensus panel was to follow these at yearly basis in postmenopausal patients.
If it was certainly less than one centimeter in size and a simple incidental cyst follow-up would not be necessary.
And actually that threshold could be increased up to three centimeters depending on the practice preference.
'Cause essentially what we're trying to distinguish is non neoplastic cysts versus benign neoplasms.
So we're really not worried about malignancy when we're looking at simple cysts.

Guidelines for Simple Cysts on CT

Now, what rules should we be using on CT?
Well, this was recently articulated in a paper that was published in the Journal of American College of Radiology, so I would refer you to go look at that article, but we're gonna talk about it in brief.
And this is the algorithm that has been described that I will be going over really briefly in the next few slides.
First of all, recognize that on CT a benign appearing cyst as defined by this paper, is really a cyst that is fluid in attenuation.
So less than 20 Hounsfield units, unilocular, not septated, has an oval or round shape, a regular or imperceptible wall and no solid area.
And in order to make it into this evaluation has to be less than 10 centimeters.
If a cyst meets all of these criteria, it can be considered to be a benign appearing cyst on CT.
A probably benign cyst as used in this paper and as I'll discuss, is a cyst that meets all of these criteria accept for the fact that the margins might be angulated, the cyst may not actually be round or oval, but might be tubular in shape.
A portion of the cyst or mass is obscured and not imaged, either because of coverage issues, meaning that the scan didn't cover all of the mass or because of streak artifact from, for example, metal prosthesis of the hip that can obscure portions of a mass.
And finally, if there's reduced signal to noise due to low dose technique or lack of IV contrast, if any of these features or criteria are present in addition to these, then you would call it a probably benign cyst.

So without going into too much detail, essentially the criteria that were established based on the ACR incidental findings Committee two subcommittee that I chaired, basically shows that premenopausal patients who have benign appearing cysts really don't need follow-up imaging of those cysts with ultrasound.
If they're less than five centimeters in size, less than or equal to five centimeters in size, if it's a probably benign cyst, we would decrease that threshold to three centimeters over those thresholds.
We would either follow up image the patients if they're within a few centimeters above that, or if they're probably benign and over five centimeters we would get a re-imaging and that would be the recommendation in the early post menopause, meaning in patients who are 50 to 55 or within five years of their final menstrual period, those numbers change slightly.
And finally, in the late post menopause, we have even more strict criteria for when we would want to re-image the patient.
Again, the details of this are beyond the scope of this particular presentation, but I would encourage you to look at the paper from the JACR and familiarize yourself with what the recommendations would be for any particular type of benign appearing cyst or probably benign cyst.
That's an incidental finding on CT.

Examples of Cysts and Re-imaging Decisions

And so for some examples, here's a patient who has a 2.7 centimeter cyst and you can see that this cyst in the left adnexa is one that is less than five centimeters in size.
So even if you conclude on the basis of this image that this is a probably benign cyst and not a benign appearing cyst because you don't have enough signal to noise, it would be still be something that you would not wanna follow.
Here's another example of a benign appearing cyst in a patient who's premenopausal, less than five centimeters, it's a three and a half centimeter cyst, 3.7 centimeter cyst, would not need follow-up.
This benign appearing 3.8 centimeter cyst doesn't need follow-up if she's in her early post menopause for a few months.
And if this was a older patient it would be something that we would recommend re-imaging with ultrasound.
And in this case, a follow-up ultrasound was performed on this 58-year-old patient showing that it was a benign cyst.

And here is a 5.2 centimeter cyst and a post-menopausal patient regardless of whether she's in the early post-menopausal period or the late post-menopausal period, this would be something that we would wanna get a re-imaging with ultrasound to try to evaluate for wall nodules.
And here, there were none and this turned out to be a benign neoplasm.

It is important to recognize that masses on CT are not as well characterized as they are in ultrasound.
So once they get up to a certain size, and certainly if they don't have features of a benign appearing cyst or a probably benign cyst, as this mass does not, that re-imaging with ultrasound is gonna play an important role in further evaluation of those masses.
And so, for example, that mass here and this mass on the left do not exhibit on the CT the same level of detail that we can see on ultrasound.
And here are some examples of the ultrasound images showing you this wall nodularity on this neoplasm that turned out to be a borderline neoplasm for this patient, a borderline malignancy and the contralateral ovary also has a wall nodularity that isn't as well demonstrated on the CT.

Specific Diagnoses on CT

There are certain features of masses on CT that can be characteristic.
A corpus luteum has an enhancing margin and it can have some hyper density in the posterior part of the cyst that refers to layering hemorrhage.
Leaking corpus luteum can have the same granulate enhancing margin, but also have hyperdense material within the peritoneal cavity basically representing hemorrhage.
Here's another example of a hemorrhagic cyst where you can see that the wall is nice and thin and regular, and there's a hyperdense clot that's separate from the wall.
It does not have the same density as the wall and also has a flat margin.
So this is layering clot.
And here's another example of layering clot within a hemorrhagic cyst.

So a typical scenario in these patients is a patient who has sudden onset of right lower quadrant pain and the CT is performed showing a hyperdense material within the lower half or the posterior half of a otherwise benign appearing cyst with a thin margin.
And what I would like to emphasize in this lecture is that having identified something that looks like a hemorrhagic ovarian cyst on CT does not mean that you need to re-image with ultrasound to again show the same features of hemorrhage.
This image is just as diagnostic as this image for a suspected acute hemorrhagic cyst.
So that would be an example of a patient who might benefit from follow-up imaging but certainly doesn't need re-imaging.

Here's another example of a type of patient who does not need re-imaging or even follow-up imaging with ultrasound to establish a diagnosis.
In both of these two patients, a fatty mass is identified here in the right adnexa here in the left adnexa.
The identification of fat within these masses makes it virtually pathognomonic for a dermoid or a benign cystic teratoma and ultrasound is really not required in this patient.

A hydrosalpinx can have a characteristic appearance on CT in that it can have a waist in a tubular mass as we see in this very large hydrosalpinx.
And sometimes that is best seen on rolling through the images on CT.
So you can see here this hypodense area is actually a tubular structure, which is a hydrosalpinx.
And occasionally one has to scroll through the images to get a better sense as to the tubular configuration of these masses.
But once you've established that the tubular, they don't have any wall nodularity and that they are fluid in attenuation, you can make a diagnosis of hydrosalpinx based on the CT and really not require an ultrasound for further evaluation.

Ovarian cancers can have a characteristic look on CT where you have a solid mass oftentimes with some ascites and sometimes those ovarian cancers will have mesenteric metastases with lymph nodes or omental metastases, retroperitoneal lymphadenopathy as we see in this case.
And if that's the situation where you're seeing a mass that has septations, nodularity and metastases, certainly ultrasound is not gonna add much value to further evaluation of that mass.

So I think we've gone over the fact that we don't wanna re-image when we're really looking for follow-up imaging is the key.
We don't wanna re-image if we can make a specific diagnosis on CT.
Another time that we don't want to re-image with ultrasound is when the CT shows a lesion that's clearly myometrial in origin.
So for example, in this case, this is the uterus, the star is on the cervix and you can see that there are three well-defined and well circumscribed masses in the right aspect of the uterus in the myometrium and a heterogeneous area at the fundus of the uterus as we see here that it's not well circumscribed, but these are all myometrial lesions separate from the endometrial cavity.
Re-imaging in this sense doesn't really add much value.
Here are the re-imaging images performed on this patient and you can see that on this transverse images.
Yes, there's clearly asymmetry of the myometrium.
We don't happen to see the fibroids as well on the ultrasound.
Here on the longitudinal images, clearly the uterus is enlarged, but I would venture to say that there's no added value to these two ultrasounds as compared to the CT once a myometrial lesion has been established.

So for example, in this case where there's a little hyperdense mass in the posterior myometrium of this uterus, re-imaging with ultrasound to prove that there is a mass in the myometrium doesn't add a lot of value because this can be presumed to be a fibroid just as easily as it can be presumed to be a fibroid on this image.

Scenarios Where Ultrasound is Unlikely to Provide Useful Information

The other times that I think that re-imaging with ultrasound is not a good idea is when the ultrasound is really unlikely to provide any useful information.
And that seems straightforward enough.
There are three scenarios I'd like to briefly mention.
Actually two briefly and one more in depth as to when this may be the case.

Dilated Pelvic Veins Without Symptoms

The first that I'll mention briefly is when we see dilated left pelvic veins or even bilateral pelvic sidewall veins and the patient does not have any clinical features of pelvic congestion syndrome.
Now this is not uncommon.
Here's an example of a patient who has fairly large pelvic sidewall veins here in the left adnexa, but she has no symptoms.
In fact, this has been studied previously.
In this preliminary paper or early paper, 34 consecutive female renal donors were evaluated and almost 50% of these had dilated pelvic wall varices in this particular patient population.
Now that prevalence of this particular finding is not a consistent finding amongst all studies, but some percentage of women will have dilated veins in the pelvis, usually on the left.
And oftentimes in patients who are multiparous when the CT has the anatomic features of pelvic congestion syndrome, the next step is really a good clinical history, not ultrasound 'cause of the patient's asymptomatic.
It really adds no value to do an ultrasound to also show these dilated veins.

Suspected TOA on CT

Another time that I think re-imaging with ultrasound is unlikely to provide a lot of useful information is when you already suspect TOA as the diagnosis on CT.
So for example, here's a mass in the left adnexa of a patient who is clinically suspected to have inflammation.
Now in reviewing the mass and the images themselves, one really can't tell what's going on in this patient and you would have to have solid mass as part of the differential ectopic pregnancy as part of the differential.
And here the color images really don't help.
All they show is that this tissue in the left adnexa is very hyperemic.
Your diagnosis and your differential diagnosis would be large.
But if I were to tell you that the woman was premenopausal, had pain and fever, and in fact had clinical symptoms suspicious for pelvic inflammatory disease, did not have a positive pregnancy test, and the question posed to you was, does this patient have PID or TOA?
You would have no problem in diagnosing an inflammatory mass in the left adnexa based on the CT.
But this was in fact that patient's first study, her ultrasound was ordered to further characterize this collection.
And I would submit to you that with this sort of image on CT and that particular clinical history ultrasound as we see in this case, doesn't add a lot of value, we don't really get to know anything more about this heterogeneous presumed inflammatory process by re-imaging her with ultrasound at this time.
The fact that you may or may not choose to drain this collection isn't really based on what it looks like on ultrasound because even on ultrasound pus tends to look very solid.

So the CT findings of TOA and TOC tub ovarian complex and tub ovarian abscess are have been well described.
You will oftentimes see a hypodense dilated mass with septations a serpiginous configuration.
There'll be other evidence of inflammation such as fat stranding and thickened uterosacral ligaments.
And quite frankly, the ultrasound can be confusing in these cases.
It can appear solid.
The fat is not well seen, the fat stranding gas is not as well appreciated.
And differentiating the mass or the inflammatory phlegmon from the adjacent bowel can be very difficult to perceive.

So I don't wanna be misunderstood.
When I talk about this ultrasound clearly is the right first examination for PID and TOA 'cause ultrasound will show a lot of characteristic findings in such patients and ultrasound can clarify the extent of how much inflammation there is.
Recognize the TOC or tub ovarian complex refers to when ovarian tissue is still visible and TOA is used as a term when there's no longer any ovarian tissue that's detectable.

So for example, in this patient who had suspected inflammation in her pelvis and has an ovary that is still recognizable as an ovary, but starting to merge into a heterogeneous hyperemic paraovarian somewhat convoluted configuration structure, this is what one would term a tubo ovarian complex.
And in this patient who also has an ovary, as we can see with one to three small follicles and a dominant physiologic cyst, but whose ovary is now less well distinguished from the inflammation that's occurring in the paraovarian tissues in the mesosalpinx has what is becoming a TOA.

So ultrasound clearly can show these findings and ultrasound is the right first test to do in these patients.
But once a CT has been done and the diagnosis is fairly well established clinically, I don't believe that ultrasound adds any value.

Ovarian Torsion

The other clinical scenario where I think re-imaging with ultrasound adds no value is when ultrasound might delay treatment of ovarian torsion.
Now ovarian torsion occurs as a syndrome where patients have acute onset of pelvic pain.
This pain is typically relatively abrupt onset and not insidious and it's not getting better over time as compared to a physiologic cyst with hemorrhage.
That can be somewhat insidious then lead to an abrupt pain cycle that improves the inciting cause.
In adults is oftentimes a mass such as a cyst or a teratoma.
But in children you can have more commonly torsion without any inciting cause.
And yes, ultrasound is the test of choice in these patients, but recognize that sometimes CT is done by the emergency room or by the provider preceding the ultrasound evaluation.
So it behooves us to know what this looks like on CT.

The pathophysiology of ovarian torsion is such that it's the twisted tube and pedicle that leads to venous congestion and then leads to lymphatic congestion.
And that congestion limits the subsequent arterial inflow.
So the tube and the ovary are always dilated and enlarged in patients who have ovarian torsion.
The ovary is always congested, so it's no surprise.
Then on ultrasound we'll always see an enlarged ovary.
Sometimes with an eccentric mass it typically has a ground glass type of appearance where follicles have been pushed to the edge by the edema of the stroma.
And diminished flow is actually what you'd hope to see if you did an ultrasound because that means that the ovary is still potentially salvageable.
Literature has shown that if you're unable to show flow in the ovary that is suspected to be torsed on ultrasound, that it typically is an ovary that has gone on to necrosis, it will not be able to be salvaged at surgery.

And so here are four different examples that at first glance look quite different from each other.
But with I think a more global perspective look very similar.
Here's a mass cyst that has hemorrhage in it and the ovarian stroma is very edematous and it's pushed the follicles to the edge as we see here.
Here's another ovary that's congested and the follicles of this ovary pushed to the edge.
Another one here where there's a ground glass appearance, the stroma is very hazy in appearance and there's a follicle here that's pushed to the edge.
And finally this is a torsed ovary where we see some follicles.
We also see an eccentrically positioned cyst as we saw in this case.
That's on the edge of the mass comparison to the contralateral side is helpful.
So here this left ovary is torsed and enlarged over six centimeters in size, whereas the contralateral right ovary was only two to three centimeters in maximum diameter.
And here you can see that that torsed left ovary is about as big as the uterus in this particular patient.

Now the fact that we're seeing flow within this torsed ovary clearly does not mean that the ovary is not torsed.
Again, in this case, this is a patient who has a torsed ovary with a very ground glass or smudgy looking parenchyma with some follicles pushed to the edge.
The fact that we're able to get color flow signal and doppler signal within the ovary does not mean that we should not worry about torsion.
And so that's I think the biggest confusion about the role of ultrasound in diagnosing ovarian torsion.
The diagnosis is suspected and made based on the morphologic appearance of the ovary, not the doppler findings because the presence of flow doesn't exclude torsion and the absence of flow may not make the diagnosis of torsion if the ovary is not enlarged.

Here's a very good example of that.
Of the former point, this is a mass.
This is the ovary that's quite large, 7.6 centimeters in size.
It has a hemorrhagic cyst within it.
The parenchyma of the ovary is really rather edematous.
And the reason I know that is because typically when we have a hemorrhagic cyst that's that large in the ovary, the ovarian stroma draped around the hemorrhagic cyst is thin.
But in this case it's not thin.
It's actually much thicker than we'd expect and it's a little smudgy.
And if we look carefully at that, you'll see that there are some follicles in that tissue that have been pushed to the edge.
So we need to worry about torsion that's been incited by this large hemorrhagic cyst.
Here's the contralateral ovary for comparison.
And you would be even more concerned because here this right ovary is normal and this is, we are still imaging part of that ovary with the hemorrhagic cyst and you can see that it's much, much larger.
So the fact that we're able to find both arterial and venous flow within this tissue does not dissuade us from thinking that torsion might be the cause for this patient's pain and symptoms.
And if someone were to ask us are we concerned about torsion, the answer would be unequivocally yes, we are still quite concerned about torsion as a cause of symptoms in this pain in this patient.

So the CT findings of ovarian torsion are similar to that on ultrasound in that there typically is enlargement or there always is enlargement of the ovary.
It's sometimes displaced from its usual location.
There can be a mass, the ovary can be hyperdense on non-contrast images reflecting increased blood content and there can be surrounding fat inflammatory changes.
So if we look at that, for example, here is the left ovary in a patient which is normal, but the right ovary in this patient is normal.
The left ovary has been flopped over to the right of midline.
So this is a cyst, this is the ovary.
And the ovary itself is larger than we would want to expect to see compared to the other side.
And the tube and the tissues leading to the ovary are thickened.
These are all features of torsion of the ovary on CT.

So if the patient presents with pain and symptoms compatible with torsion, I would not advise that you take the extra effort to do ultrasound if that is going to delay the diagnosis.
So if she comes in at two in the afternoon and the ultrasound unit and is ready and the sonographer is ready to do the study or if you're prepared to do the study at that time, then by all means go ahead and do the ultrasound as they start getting the OR ready.
But if she's presenting to the ED at midnight and there isn't somebody in-house ready to do the ultrasound, then I would not delay the diagnosis based on the fact that you don't have an ultrasound.

In this particular case, she did go onto ultrasound and you can see that the ultrasound shows us findings that are very similar to the CT here.
The right ovary looks normal, the left ovary is enlarged, it has an eccentric cyst and this image on ultrasound matches exactly that what we see on CT.
So I guess the point that I'm trying to emphasize is that this makes us think about the possibility of torsion this image on ultrasound.
So should this, it's exactly the same image, just a different modality.
The fact that we're able to see blood flow both in the enlarged left ovary and the normal right ovary doesn't mean that this left ovary is not torsed.
And the reason I wanna emphasize this point is that there are lots of examples where even in the literature where the diagnosis of torsion should have been or maybe was suggested based on the CT, but ultrasounds were delayed and may have contributed to the fact that the ovary was no longer salvageable.

So for example, from this very nice article by Chow and colleagues in 2007, these are images showing that the left ovary and tube are thickened and abnormal in appearance and an ultrasound that was done later that day, quote unquote showed a necrotic ovary surgery.
Here's another example from that paper.
A right ovary that's enlarged with a thickened tube.
This should make us think about the possibility of torsion in the appropriate clinical setting and ultrasound done later that day shows features of torsion and it was a necrotic ovary surgery.
Now I don't know what later that day means in these two patients, but if there was a delay between the CT and the ultrasound in order to get the ultrasound, I think that that's a mistake and that these findings on CT in the right clinical setting should lead to intervention.

When to Re-image with Ultrasound

So we've talked about a number of times when re-imaging with ultrasound is really not indicated to when should we be re-imaging with ultrasound?
Well first and foremost I think I wanna emphasize that if the sonographic pattern of the ovary it is going to help you make a diagnosis because it's not a characteristic finding on CT a characteristic abnormality, then by all means we should be doing ultrasound.
And so yes indeed in torsion, if the CT and or the clinical picture is equivocal or doesn't support the diagnosis of torsion, then we should be doing ultrasound to further evaluate these patients.

So for example, this patient who had an enlarged right ovary with a cyst that's eccentric and with thickening of the tube leading to the cornual of the uterus was suspected to be torsed based on the CT, I'm sorry, but the clinical picture was not as compelling in this particular patient.
And so the clinicians asked us to do an ultrasound for this patient and in fact she did have partial torsion of that right ovary.
And here is the image showing the eccentric cyst with the smudgy heterogeneous parenchyma of the ovary in which we were able to find a little bit of blood flow in this patient who came to us with a question of torsion and had enlargement of the right adnexa as compared to the left.
But the tube is not particularly thickened in this patient.
And again, she did not have symptoms that were very classic for torsion.

This is the patient who should go on to imaging with ultrasound and in fact in her case she did not have torsion.
She had a small hemorrhagic corpus luteum with a relatively normal appearing ovary.
Otherwise.

The other time that I think that re-imaging with ultrasound is helpful is when we want to understand the involvement of the ovary when we identify something on CT, if we're not sure that in a mass in the adnexa identified on CT involves the ovary or not, then ultrasound is a great tool to use.

So for example, in this case, here's the uterus starred, here's the left ovary with the black arrow.
And this was the region of the right ovary, but it looked like it might be flipped in a different spot.
The tube was not particularly thickened.
Is this a patient with torsion or with some other entity?
Very hard to tell based on the set of images that are provided and the clinical history was also not compelling for torsion in her case.
We did an ultrasound and it showed that the ovary here is fairly normal in appearance with some follicles, but it's starting to be a little bit less well-defined as compared to the periovarian structures.
And this patient ended up having PID not TOA, I mean tub ovarian abscess probably tub ovarian complex in this case since we are able to see the ovary.

Here's another case where there's a mass in the left adnexa, this is the top of the uterus.
The uterus has been shoved over to the right a little bit and here's this large mass, it's emanating off the posterior wall of the uterus on this angled oblique reformation.
And you can see the uterus here with the white arrow.
Is this an ovarian mass or is this a uterine mass?
It's very hard to tell based on the CT.
So an ultrasound is the right test to do here.
We're able to see that this mass is hypoechoic as compared to the uterus.
And then on the transvaginal images we're able to see a normal ovary that was positioned near a bowel loop and this is the mass, this is a transverse image or coronal image on the endovaginal image, but shows that the ovary is separate from the mass and this turned out to be an exophytic fibroid here.

This patient has a left adnexal mass but it has had previous hysterectomy, has angulated margins.
A little bit unusual for an ovarian mass in that there are angled margins.
The ultrasound quite helpful to further establish that this is a peritoneal pseudocyst with the ovary trapped between fluid collections, distorted with a follicle here you can see.
But these collections with angulated margins were basically paraovarian embedded indenting the ovary itself, and this is a pseudocyst.

So I think that ultrasound re-imaging is a very useful thing to do when we don't quite understand the involvement of the ovary.
When an adnexal mass is identified on CT and especially in premenopausal women, ultrasound excels at identifying ovarian tissue and should not hesitate to do an ultrasound to further evaluate the ovary.

Conclusion

So in conclusion then, a woman presents and for whatever reason gets a CT of the pelvis and a lesion is identified or a mass or a cyst is identified in the pelvis.
I hope what I've been able to do through the course of this lecture is to give you a framework as to when you can ignore that as a normal finding, when you want to get follow-up with ultrasound, when you want to re-image with ultrasound and when you really just wanna treat the patient and manage her for what we suspect is going on without need for doing an ultrasound.
Thank you.