Approach to Acute and Chronic Pelvic Pain: The Role of Ultrasound - SD

Introduction

Hi, I'm Rochelle Andretti.

I am a professor of clinical radiology and associate professor of obstetric and gynecology at Vanderbilt University Medical Center.

And I'm going to be speaking today on an approach to acute and chronic pelvic pain.

I'd like to emphasize the importance of sonography as the imaging modality of choice for evaluation of suspected acute and chronic gynecologic etiologies of pelvic pain.

Then I'd like to illustrate the use of ultrasound when a non gynecological etiology of pain is suspected and as an effective substitute to CT for pregnant patients as well as patients in the reproductive age group in view of the lack of ionizing radiation.

I'd also like to illustrate the use of MRI as a problem solving tool when the ultrasound exam isn't adequate or in place of CT in pregnant patients with suspected appendicitis.

The Concern: Frequency of Pelvic Pain

So what is the concern? Well, the frequency, pelvic pain may account for up to 40% of gynecologic visits.

It's the most common reason for hysterectomies and it's a common reason for laparoscopy the most common reason in the UK and the second most in the United States.

Where Does Imaging Fit In?

So where does imaging fit in?

The diagnostic considerations are based on whether it's a GYN or OB cause or a gastrointestinal and genital urinary cause, or other causes that may be vascular or musculoskeletal.

According to the a CR appropriateness criteria on acute pelvic pain in the reproductive age group, the selection of imaging is determined by clinically suspected, differential diagnoses.

Following a careful evaluation, sonography is the modality of choice for a suspected gynecologic or obstetrical abnormality and CT more useful for a GI or GU abnormality.

Although MRI is definitely favored over CT in the pregnant patient, but ultrasound may be a reasonable alternative.

Why Is Sonography the Modality of Choice?

So why is sonography the modality of choice?

It's non-invasive radiation free cost-effective.

It gives high resolution anatomic detail of the uterus and a nexa.

And we try to use both sonographic techniques whenever possible since they're complimentary with transvaginal ultrasound whenever possible, when there's no contraindications due to its better resolution and transabdominal sonography providing more information when when structures are beyond the field of view of the probe.

So when we use sonography with abdominal compression, we can displace bowel, bring structures closer to the transducer, identify focal areas of tenderness, and also use what we call the sliding organ sign to separate structures.

Here on the cine clip you can see where the transducer is pushing, between two structures, an ectopic pregnancy and assist within the ovary, demonstrating that they slide by each other, consistent with separate structures.

So what is the role of doppler spectral in color or power Doppler imaging can be used to characterize vascularity in the ovaries, fallopian tubes, and uterus and narrow our differential considerations.

When we look at this article that was published by Harris, in 2000, in radiology, he addressed actually pelvic pain and a normal pelvic sonogram.

He looked at 86 non GRA patients without symptoms of infection, systemic illness or bleeding.

The majority of these patients had improvement or resolution of pain, 77% of them.

And he also found that further imaging was unlikely to yield positive results of 13 studies that were done in these patients.

Only one yielded a diagnosis.

So a normal ultrasound can be a powerful finding.

Role of CT in Pelvic Pain

So, how about pelvic pain and CT computed tomography is used more frequently when a GI or GU abnormality is likely, but gynecologic disease is being detected with increasing frequency because it's quick due to advances in technology leading to faster acquisition times as well as 24 hour accessibility.

Role of MRI in Acute Pelvic Pain

So what about acute pelvic pain?

And M-R-I-M-R-I is favored over CT for assessing the pregnant patient due to the lack of ionizing radiation, but its use may be hampered because of its lack of widespread availability, especially in the acute setting.

So MRI is also a problem solving tool following ultrasound for specific indications if further characterization of disorder is required or if the patient's pain fails to resolve and is becomes more chronic in nature.

Definitions of Pelvic Pain Types

So now some definitions.

First, acute pain, which is intense pain characterized by sudden onset.

Chronic pain is a non cyclic pain that lasts six months or longer, which is severe enough to cause functional disability or the need for medical care.

And then we have cyclic pain, which is pain associated with the menstrual cycle, usually referred to as dysmenorrhea.

Approach to Imaging in Pelvic Pain

So in our approach to imaging, the patient with pelvic pain, we will look at acute pelvic pain, chronic pelvic pain, and dysmenorrhea first acute pelvic pain with a patient presenting with acute pelvic pain.

There are often other signs and symptoms which include fever, nausea and vomiting, leukocytosis, abnormal vaginal bleeding.

And also at this time we need to determine the pregnancy status.

Should ectopic pregnancy be under consideration and is there concern for fetal exposure to ionizing radiation making ultrasound or MRI the initial imaging modality of choice?

So we check a serum beta HCG level, A negative level essentially excludes the diagnosis of an intrauterine or extrauterine pregnancy.

And if we have a positive beta HCG level, then we need to look at obstetrical causes of acute pelvic pain in the first trimester.

This would boil down to either a failed intrauterine pregnancy or an ectopic pregnancy.

But in today's talk we are going to mainly be discussing the gynecologic causes of acute pelvic pain, looking at problems mainly arising from the adnexa.

Most Common Gynecologic Causes of Acute Pelvic Pain

So the most common causes or functional ovarian cysts, pelvic inflammatory disease and ovarian torsion.

Non-Neoplastic Cysts

First non neoplastic cysts, which can be either simple or hemorrhagic.

A follicular cyst is the most common and abnormal follicular enlargement due to anovulation commonly associated with hemorrhage with rapid resorption.

The corpus lutetium, which is a normal structure that often enlarges with hemorrhage, corpus luteum cysts, which are corpus lutetia that enlarge usually during pregnancy associated with resolution by 14 weeks gestation.

And then the least common type, the thecal lutian cysts associated with trophoblastic disease, multiple gestations and usually are large and numerous and may persist for weeks after withdrawal of the stimulus.

So what causes the pain of an ovarian cyst?

It's large size, usually greater than about 25 to 30 millimeters hemorrhage, rupture or leakage.

The characteristic appearance of a hemorrhagic cyst with hemolysis and retraction of clot, a reticular network of stranding is demonstrated or we may see a fluid, fluid level between fluid components and congealed red blood cells that may give a concave margin.

These are the most specific findings and when seen, they may be considered diagnostic of hemorrhagic cysts.

Acute hemorrhage can also be hyper coic suggestive of a solid mass.

A diffuse pattern of low level echoes could also be seen more commonly associated with an endometrioma.

Then we may have internal echoes and septations and leakage of hemorrhagic fluid associated with peritoneal irritation.

Often we make the diagnosis by looking at the evolution of the cyst, which usually resolves.

Here we have a thick walled cyst with a homogeneous echo pattern and septations associated with echogenic fluid.

10 days later we see involution confirming the presence of a hemorrhagic cyst.

There's still a little bit of fluid leakage around it, but usually there is no change in the appearance of this cyst unless the patient is either undergone a normal menstrual cycle or the cyst has ruptured.

So we usually wait about one to two menstrual cycles or six to eight weeks to assess for resolution.

And then how does doppler help us?

We see peripheral color doppler signal, no central vascularity and low impedance arterial flow.

In this patient we see a characteristic hemorrhagic cyst with a reticular pattern with flow within its periphery, both arterial and venous.

These findings actually may be more helpful with a solid appearing cyst since the lack of internal flow can help us make the diagnosis of a cyst rather than a solid mass.

Pelvic Inflammatory Disease (PID)

Now let's move on to pelvic inflammatory disease.

This consists of inflammation of the endometrium, fallopian tubes, pelvic peritoneum and adjacent structures causing fever, leukocytosis, and cervical motion tenderness.

It's usually caused by an ascending infection by ceria gonorrhea, chlamydia, or super infecting organisms from the vagina.

Now usually referred to as bacterial vaginosis.

It's manifested by tubo ovarian complexes, peritonitis and abscess formation.

It's usually bilateral but maybe unilateral in patients with IUDs, although nowadays it's less commonly seen with IUDs due to the use of the marina and the progesterone effect, which blocks ascension of bacteria by increasing cervical mucus.

A netter drawing showing a characteristic tubo ovarian complex and an intraoperative photo also showing the uterus broad ligaments and the dilated fallopian tube with purulent material on its surface.

So let's look at the clinical diagnosis of PID.

No simple diagnostic test exists and the accuracy with which signs and symptoms predict the presence of PID has been evaluated using a laparoscopic gold standard.

And this has been looked at in a retrospective review by SIMS and colleagues in 2003.

The dataset included women who attended the Department of Obstetrics and Gynecology Lung University Hospital Sweden with suspected PID collected between 1960 and 1969.

All patients included in the study had an initial diagnosis based on the clinical presentation, a total of 623 patients were included in the analysis.

494 patients were laparoscopically confirmed as having PID and 129 were not.

They found that three variables significantly influenced the prediction of PID, which were the elevated sed rate fever and adnexal tenderness.

But together they correctly classified only 65% of women with laparoscopically diagnosed PID.

So this was a real problem.

So how can transvaginal sonography help us?

Actually transvaginal sonography can only detect complications of PID since early changes are often subtle, although color doppler may actually enhance our capabilities.

The problem is that there is difficulty visualizing the tubal wall without surrounding fluid, but with surrounding fluid.

Common findings include wall thickness of greater than five millimeters incomplete SEPTA thickening of endo cell pinal folds, which is considered the cogwheel sign.

There are also non-specific findings of fluid in the endometrial cavity and or cul-de-sac and ovarian enlargement often referred to as the polycystic ovary appearance with numerous small cysts displayed.

So in this patient with a normal appearing fallopian tube and ovary, when we use color doppler, we actually see a lot of color doppler flow within the tube, which helps us to make the diagnosis of saling another patient with a fluid distended fallopian tube with echogenic fluid.

Of course this could be either blood or purulent material, but using color doppler we see that there is flow within the wall which would be consistent with inflammation.

A third example of Sal Pitis with a markedly distended fallopian tube and flow within the wall.

This, patient could actually, be confused with a patient with a cyst in the ovary, but seeing an incomplete septum within the mass suggests that this is a fallopian tube rather than a septated cyst within the ovary.

So now we move on to a more severe form of PID, which is the tube ovarian complex.

This is progression of disease with exudation of pus from the distal fallopian tube so that an inflammatory mass, including the tube in adjacent ovary is formed, but the ovary is still visualized.

That's a separate structure.

So we see here the ovary and adjacent fallopian tube in these two transvaginal images, but the ovary can still be seen separate from the distended fallopian tube that contains echogenic fluid.

So then we move on to the tube ovarian abscess.

The most severe form of PID where the imaging definition consists of a complete breakdown of architecture so that separate structures are no longer demonstrated.

Here we have a mass in two views with a cystic area that has what looks like incomplete septa.

So this is suggestive of the fallopian tube, but we cannot separate this from the ovary.

And another example of a tube ovarian abscess also both with conglomerate masses of tube and ovary where the tube is suggested by the thickened endo cell pinal folds, which we refer to as the cogwheel sign.

There's also increased flow by color doppler surrounding this mass consistent with the inflammation surrounding the abscess.

So where does CT fit in in the diagnosis of PID?

Given the vague and nonspecific symptoms, CT is often the first imaging study performed.

What we see are thick walled fluid fill fallopian tubes, but it is often difficult to differentiate among apal pink's, TOC and TOA by ct.

And also this exposes patients to radi to ionizing radiation, which is problematic among young women.

So we see two slices of a CT exam, within this patient where there are thickened fallopian tubes that contain fluid and does MRI have a role in the diagnosis of PID according to UDA in an article published in 2002 MRI may be more accurate than transvaginal sonography if doppler is not used.

However, costs lack of access and limited data preclude its widespread use.

And here we have an example of MR and CT imaging of a tub ovarian abscess where we see a peripherally enhancing fluid collection.

Usually sexually transmitted disease initiated infection is not evaluated with mr.

Um, so there aren't very few very many examples around, but this was given to me by Dr. Susana Lee at Mass General Hospital.

And we we see is a CT enhancing appendix and mass and adjacent to it a tub ovarian abscess.

The anatomic detail is not well seen on ct.

Um, so an MRI was performed.

What we see on T two and T one fat sat images with MRI are fluid and inflammation within the mass, which is the hyperintense area centrally and peripherally on the MRI study.

And on the T one fat sat image, we see wall enhancement around the mass, which is the hyperintense enhanced area surrounding the mass on this uh, transverse T one image.

Ovarian Torsion

Okay, now moving to ovarian torsion.

The diagnosis of torsion is strongly considered with abrupt onset of severe unilateral pain.

It's most commonly seen with associated nausea and vomiting.

The pain may be constant or intermittent depending on whether it might be partial or intermittent torsion.

However, symptoms may be variable And the diagnosis of adnexal torsion has remained a clinical and imaging enigma due to the vague clinical presentation with abdominal pain being the only consistent symptom.

So the common denominator of ovarian torsion is the lar enlarged abnormal appearing ovary, usually due to benign ovarian tumors or cysts in up to 80%, which may act as a fulcrum to potentiate torsion due to increased ovarian volume or weight.

Also, ovarian hormone induction can lead to hyperstimulation with enlargement of follicles, leading to a fulcrum for torsion as well.

Another cause could be a hemorrhagic corpus lium of pregnancy or hypermobile ad nexa, a congenital problem usually seen only in the pediatric population.

So, a problem often encountered in evaluation of torsion, is a result of the vascularity to the ovary, which can be either from the uterine artery and vein or the ovarian artery vein, giving us a dual blood supply and meeting at the pampiniform plexus that feeds the ovary.

When we look at the pathophysiology of torsion, first lymphatic and venous drainage is compromised.

Then there's congestion and edema as we see here in this um, diagram.

And then loss of arterial profusion.

So we finally have an organ that looks like this in large black and ugly.

So complete and unalleviated torsion can progress rapidly to occlusion of the arterial circulation.

The organ may quickly become very dark black in color due to hemorrhage, necrosis and gangrenous changes.

So early intervention is key.

It decreases the incidence of complications and improves ovarian salvage rates.

And the use of pelvic sonography has enhanced our ability to determine when intervention is advisable.

Nevertheless, gynecologists often delay surgery because of misleading ultrasound findings only, to find a non-viable, tissue upon exploration.

So once again, the common denominator of the vast majority of cases of torsion is an enlarged ovary or ovarian complex.

So we see here an enlarged emus ovary and here the ovarian complex that consists of ovary with hemorrhagic cyst within the emus ovary, we may see irregular internal texture suggesting hemorrhage and edema peripherally placed follicles, and within this ovary homogeneous low level centrally consistent with edema.

So where does Doppler fit in as far as torsion?

We would assume that color and spectral doppler would prove to be an accurate tool for the evaluation of ovarian torsion, but in actuality, doppler findings vary depending on degree of torsion and its chronicity.

So the lack of arterial and venous signal should enable confident diagnosis.

But there are false positive diagnoses and this is usually due to technical problems such as depth of penetration, greater than beam capabilities or improper doppler or gray scale settings.

Here's an example of a patient with a parat tubal cyst, an enlarged edematous ovary and power doppler demonstrating no evidence of flow in the ovary.

And we're seeing, normal flow in the iliac artery and vein.

So we know that we are penetrating deep enough.

So this di diagnosis is likely accurate.

On the other side of the coin, ovarian color doppler signal has been frequently reported in cases of surgically proven torsion.

In a retrospective series of 39 patients with pathologically proven ovarian torsion performed at Vanderbilt Medical Center, 21 of these or 54% had documented ovarian arterial doppler signal only.

But what's more important is that 33% of these patients had documented ovarian venous and arterial signal.

So we will see arterial and venous flow in a large percentage of patients with surgically proven torsion.

Here's an example showing the enlarged emus ovary with, surgical proof of torsion and arterial and venous flow demonstrated within this mass.

A more specific vascular sign of torsion is the twisted pedicle sign, often referred to as the whirlpool sign, but this, sign is not very sensitive because the ovarian pedicle must be targeted in order to be demonstrated.

And this is not routinely imaged on our routine exams, but we are seeing flow, within a twisted pedicle on this image and also on the surgical path specimen, which is a diagnostic of ovarian torsion.

So how do we diagnose ovarian torsion with ultrasound?

The most consistent finding is the enlarged emus, ovary or ovarian complex Doppler findings may vary likely depending on degree and chronicity.

The lack of doppler flow enables fairly confident diagnosis.

But arterial and venous doppler signal has been routinely reported in up to a third of surgically proven cases of ovarian torsion.

And is there a role for CT or MRI Sonography is the initial exam of choice, but computed tomography is being used more frequently.

So it's important to be familiar with findings of torsion by ct and most of this is due to, trying to rule out appendicitis in the abdomen.

So the CT features include, well, here we have a large cyst which turned out to be a per ovarian cyst.

We see thickening of the fallopian tube around the ovary considered the target sign.

We may see deviation of the uterus toward the side of torsion and infiltration of adjacent fat as we see here By ct.

We may also see the twisted pedicle sign.

Here we have an ovarian mass with thickened emus, ovarian cortex and lack of contrast enhancement and the beat configuration of the engorged vessels are seen, which, suggests the twisted pedicle.

And is there a role for MRI?

This has not been established raw and colleagues have shown similar diagnostic findings with both MR and ct.

In a study published in 2002, an example of MRI of ovarian torsion, we can see here a normal appearing ovary with follicles on this T two weighted coronal image and an enlarged ovary adjacent to it showing a heterogeneous hyperintense pattern due to edema and hemorrhage centrally and peripherally placed follicles.

Non-Gynecologic Causes of Acute Pelvic Pain

So now we move to non gynecologic causes of acute pelvic pain.

These include, appendicitis, diverticulitis, intestinal obstruction, inflammatory bowel disease, and ureteral calculi.

All of these where imaging plays a role, common gastrointestinal and genital urinary causes where ultrasound plays a role include appendicitis, ureteral calculi and inflammatory bowel disease.

Although I place a question next to this since this is not routinely performed in the United States.

Appendicitis

So appendicitis is is the most common GI cause of pelvic pain in women.

It is a diffuse or per umbilical pain that migrates to the right lower quadrant CT with contrast is the imaging modality of choice to confirm the diagnosis in non-pregnant females with a very high sensitivity and specificity.

But ultrasound may be an effective substitute with a sensitivity varying from about 67 to a hundred percent, and specificity of 83 to 96%.

So the sensitivity is variable because of its user dependence.

So ultrasound with graded compression is the initial imaging test in the pregnant female but is often inconclusive due to the large uterus.

But MRI would be the next imaging modality due to the lack of ionizing radiation.

A blind ended thick walled tubular non-compressible.

A peristaltic structure is seen as we see here, at least a three millimeter single wall thickness is demonstrated and there's an intact echogenic submucosal layer in uncomplicated appendicitis as we see here.

There also may be surrounding echogenic fat.

Um, we may see increased vascularity within the wall of the inflamed appendix with complicated appendicitis.

There may be a different appearance with marked thickening of the mucosal layer as we see here.

That's strikingly echogenic echogenic periappendiceal fat and fluid surrounding this structure in the form of an abscess Ct.

Features of appendicitis included enlarged appendix greater than six millimeters as seen here on this coronal CT image with thickened enhancing of the wall and per seql fat stranding.

MR features of appendicitis are similar to ct but we use a negative oral contrast agent, that, demonstrates low signal in the bowel on this coronal T two weighted image.

And also in the normal appendix that we see right here in this, coronal view of the pelvis, using T two weighted.

In in T two weighted image, the enlarged emus appendix is demonstrated, that is very hyperintense without any gastro mark contrast within it.

So we have, a fluid filled inflamed appendix, and we can make uh, this diagnosis.

Ureteral Calculi

Moving on to the urinary tract, we can use ultrasound to look for ureteral calculi.

First with ureteral calculi, the patient presents with cost of vertebral angle pain that radiates to the groin rather than true pelvic pain.

It is best detected by non-contrast CT with a high sensitivity and specificity, but an alternative for evaluation of the distal ureter is transabdominal or transvaginal sonography, especially in pregnant females.

So on these transabdominal images we see hydronephrosis.

And then within the distal ureter we may often demonstrate an obstructing calculus and echogenic focus with associated shadowing another patient with hydronephrosis and echogenic foci seen within the distal ureter using transvaginal sonography which demonstrate posterior acoustic shadowing as well as a twinkle artifact, which is a new doppler finding that has been associated, although not very specific for calculi.

Inflammatory Bowel Disease

And then we come to inflammatory bowel disease, which is a systemic inflammatory problem that requires close monitoring to prevent disability.

Surveillance of the disease activity is necessary to determine when medical management is needed.

CT in the past has been the imaging modality of choice, but there is a lot of evidence now that questions the safety of giving frequent ionizing radiation.

MRI is effective and radiation free, but it is expensive and often inaccessible transvaginal sonography has been found to be highly effective for detecting inflammatory activity.

So here on this longitudinal scan, from a report in European radiology, we see a thickening of the muscularis within this loop of bowel with a large ulcer pointed out with the black arrow, causing focal interruption of the submucosa.

We can also, use ultrasound with contrast enhancement to look at activity of inflammation in inflammatory bowel disease.

On this cross-sectional image of a loop of thickened ileum in a patient with Crohn's disease, from a report in radiology by Wilson and Burns, we see enhancement of the wall of the bowel, which you can see the arrows are pointing to.

We also see enhancement, adjacent to the bowel within the, within the fat.

And this enhancement has been described in the literature as the comb sign, which also is suggestive of active disease.

Ovarian Vein Thrombosis

Then we move on to a vascular etiology of pelvic pain ovarian vein thrombosis.

This is most commonly seen in postpartum patients, although ultrasound is usually the initial imaging modality.

CT and MRI are known to perform better than ultrasound in this diagnosis.

And what we will see with CT or MRI is enhancement of the periphery of the vessel with a central non enhancing thrombus.

However, I'd like to just show you a case where the CT was actually not as diagnostic as the ultrasound since we are not completely within the venous phase when the slices were taken.

So we see the enhancing left ovarian vein, which is normal, but it's difficult to pick out the abnormal right ovarian vein since there is no evidence of enhancement even peripherally.

And the ovarian vein in the pelvis also is not enhancing.

So it's hard to differentiate it from the adjacent bowel.

However, by ultrasound we actually see a distended ovarian vein that contains thrombus with only peripheral power doppler flow within the vein.

Approach to Acute Pelvic Pain

So in our approach to pelvic pain when it comes to acute pain, first we need to decide whether we have an obstetrical or gynecologic cause of pain and of course then we will go to ultrasound, as our modality of choice and or whether we suspect a non gynecologic etiology of pain.

And then we need to determine whether we have a positive or negative beta HCG level.

'cause if we have a positive beta HCG level, then ultrasound or MRI are the modalities of choice with a negative beta HCG level.

CT does have a higher sensitivity when it comes to the etiologies of non gynecologic pelvic pain, but ultrasound may still be a reasonable alternative.

Chronic Pelvic Pain

Now I'd like to emphasize the importance of sonography, the imaging modality of choice for the evaluation of suspected chronic gynecologic etiologies of pelvic pain with gynecologic etiologies being the most common cause of chronic pelvic pain.

And also how we can use MRI as a problem solving tool for specific indications if further characterization of a disorder is required or if the patient's pain fails to resolve or is more chronic in nature.

So common etiologies with imaging findings in, chronic pain would be endometriosis, adenomyosis, pelvic varis, malpositioned, IUDs, and inflammatory bowel disease.

Endometriosis

So endometriosis is the most common benign gynecologic disorder.

It's a result of functional endometrial tissue outside of the uterine cavity and musculature.

And what we see are cysts or endometriomas plaques, implants, or nodules.

So here on this netter drawing, we can see how endometriosis can affect just about anywhere within the pelvis, including the ovary, uterine ligaments, pouch of Douglas, pelvic peritoneum, and even abdominal scars.

Symptoms of endometriosis include dysmenorrhea, dyspareunia and abnormal bleeding and the severity of pain may not correlate with the extent of disease.

First, let's talk about the role of ultrasound and diagnosis.

Historically, the most recognized and readily diagnosed appearance of disease has been the endometrioma.

However, confirmation must be obtained with time.

Also, presently there are multiple reports of visualized implants using targeted sonography.

So we may be able to use sonography for more than just looking for an endometrioma.

So What do we see though with a classic endometrioma?

We'll see single or multiple thick walled cystic masses with diffused low level homogeneous echoes as we see here.

And also we may see hyper coic foci along the wall of these cysts.

So more recently, ultrasound has found to be u be able to be used to evaluate implants found in dependent areas of the pelvis, including the cul-de-sac, the uterosacral ligaments, the bladder bowel wall, and rectovaginal septum.

So what we like to do is target areas where the patient complains of focal pain.

And by targeting these areas we will find these implants.

What we find are usually solid and hypoechoic areas in the bowel wall.

The implant takes the form of a nodular or fusiform swelling.

It may also be a rounded solid structure that we may see within the cervix.

An image from Radiographics very nicely depicting the fusiform area behind the uterus that we see here.

And along the anterior wall of the rectum, which is consistent with, a nodule of endometriosis At our institution, we've used this technique and have found, as we see here, a nodule, in a patient status post a supracervical hysterectomy at the junction of the cervix and the vagina with some peripheral color doppler flow, which proved to be a cervical implant of endometriosis.

Here is another example of an endometrioid implant in the posterior cul-de-sac.

Here we have a sagittal view of the uterus, a transverse view, and this small hypoechoic nodule adjacent to the fundus within the cul-de-sac that proved to be an endometrioid implant.

So what would is the role of MRI as a problem solving tool in the diagnosis of, endometriosis?

Well, with MRI, we can have immediate gratification.

We don't have to wait, to, to see if an endometrioma, will resolve.

MRI has high sensitivity and specificity in diagnosing deep and nodular endometriosis in addition to the cystic type as well.

However, plaque like lesions may go undetected until laparoscopy.

So how can we use MRI to make the diagnosis of cystic endometriosis?

We see T one increase signal and on the T two weighted images, we may see a characteristic shading, but we may also see heterogeneous or homogeneous increased signal.

So here on this transverse verse view of the pelvis, we see hyperintense signal within the mass on the coronal T two weighted view of the pelvis.

We see the T two weighted, image with shading of the mass.

In another case courtesy of Dr. Lee.

At MGH we have a transabdominal sonogram showing two cystic masses within the pelvis and on T one and T two weighted, MRI images, we can see that these cysts do different things with the different sequences.

When we look carefully, we see that the structure on the right on the T two weight, excuse me, T one weighted image Is hypo intense.

And on the T two weighted image is hyperintense consistent with a hemorrhagic cyst, whereas the two structures on the left side of the pelvis are hyperintense on a T one weighted image.

And on T two weighted images, the larger structure shows some shading but also some heterogeneity.

The smaller structure shows a high intensity signal again on the T two weighted images, but both are consistent with endometriomas.

So what about MRI and nodular endometriosis?

With nodular endometriosis we may see a T one intermediate signal, but we always will see foci of high intensity signal within the intermediate signal.

And on T two weighted images we see variable signal characteristics.

So on these two images, first a T one fat sat in the transverse plane, we see a fusiform highly hyperintense area, that's associated with the anterior rectal wall.

And on this sagittal T two weighted image, it once again looks hyperintense.

So this is consistent with the fusiform implant that we may see associated with the rectal wall.

Another example showing a transverse Mr T one fat sat weighted image of the pelvis.

Here we see uterus and adjacent to the uterus, a small implant which shows intermediate signal, but areas of hyperintense foci within it, consistent with an implant.

Adenomyosis

Now let's move on to another cause of chronic pelvic pain.

The tender uterus which may be related to adenomyosis or possibly pelvic congestion.

So adenomyosis is a very common gynecological condition characterized by the presence of ectopic endometrial glands and hyperplastic stroma.

In the myometrium it is estimated that is present in up to 30% of females and 70% of path specimens status post hysterectomy.

It is commonly incorrectly labeled as fibroids usually seen in the older reproductive age group ultrasound has a reported sensitivity of 80 to 87% and specificity of 94 to 98%.

Symptoms usually include uterine tenderness, dysmenorrhea and menorrhagia.

And the sonographic signs include a gular configuration of the uterus, abnormal myometrial echo texture, heterogeneous myometrial echo texture, often with associated linear shadowing, poor definition of the endometrial myometrial junction, pseudo widening of the endometrium, An elliptical myometrial abnormality.

But relative absence of a discreet mass and color doppler signal ba may be present or even increased within the area.

First, a globular configuration of the uterus.

On this sagittal transvaginal image on this cine clip we can see hypo coic areas corresponding to smooth muscle hypertrophy as well as echogenic heterotopic endometrial tissue.

We may see myometrial cysts corresponding to dilated glands or hemorrhagic foci.

Ectopic glands may be seen and they actually may be echogenic due to hemorrhage within the glands.

The process may be focal as we see here in the anterior myometrium or diffuse throughout the uterus.

We often see linear hypo colic shadowing as we see here.

And this is associated with smooth muscle hypertrophy.

On the pathological examination, the endometrial myometrial junction may be very poorly defined and we can see here on this image that the myometrium is very heterogeneous and it's very difficult to pick out exactly where the endometrium is.

It's most likely this very faint line so that we may not be able to determine the thickness of the endometrium, by transvaginal imaging.

And we may measure the endometrium a lot wider than it really is.

So the most accurate findings according to a fairly recent report by kepp cap, in 2007 are a gular enlarged uterus, sub endometrial linear hypo coic striations, which is considered the most specific feature and myometrial cysts.

So Let's talk about adenomyosis and fibroids since these two are often confused with adenomyosis.

There is a relative absence of a discrete mass, but an elliptical myometrial abnormality or adeno myoma may be seen but will not change the uterine or endometrial contour.

As we can see here, another case of elliptical myometrial abnormality within a, retroverted uterus seen by transvaginal sonography.

But once again, the uterine contour is unchanged as opposed to omas as we see here on this longitudinal and transverse view of the uterus.

There is a change in the contour of the uterus with this small oma.

So how can color doppler help us with omas?

We see peripheral vascularity usually, but vascularity with adenomyosis may be present or even increase throughout the area in question.

In fact, it may have what we call a stippled effect within the myometrium.

And optimized for low flow may be the most valuable technique for differentiation of the two processes.

So some pearls in the evaluation of fibroids and adenomyosis.

There's a high reported sensitivity and specificity distinguishing between the two.

The majority of patients with adenomyosis, however, also have fibroids according to a report by Bromley in jam in 2000.

The relationship between heterogeneity of the uterus and severe disease is there only when fibroids are not present.

According to a report by holka in a JR in 2002.

And according to a report by bza, in 2002, six out of 16 false negative studies in this series, were attributed to limited myometrial evaluation due to fibroids.

So we can see on this c clip some fibroids in the posterior myometrium, but it's very difficult to make out what's going on anteriorly where we do see some evidence of striations that would represent adenomyosis as well.

So adenomyosis may be easily overlooked when fibroids are present even though they are often seen concurrently.

So moving on to how MRI can help us as a problem solving tool in the evaluation of adenomyosis, it's highly accurate with a sensitivity and specificity, of 86 to a hundred percent and an overall accuracy of 85 to 90%.

But the accuracies of sonography and MRI are similar.

Sonography is usually the first study obtained in the patient with pelvic symptoms.

But MRI may give give additional information in those cases which are indeterminate by transvaginal sonography.

So the MR signs are best seen on T two weighted images.

We may see abnormal myometrial signal intensity, which are low signal intensity due to the hyperplastic smooth muscle and areas of high signal intensity due to the heterotopic glands.

So here we have on sagittal and transverse T two weighted images, the hypo intense smooth muscle with some areas that show hyperintense foci, which are the hyperplastic glands, but we may also see thickening of the junctional zone.

In this coronal view.

We can see here endometrium junctional zone, the area between the endometrium and the more normal myometrium, which is fairly hyperintense.

That is very thickened.

We may see linear striations of high signal intensity, but these striations are different than those seen on ultrasound in that these are associated with the endometrium and this may also be associated with a pseudo widening of the endometrium.

So we will see some fuzziness around the endometrium with these small linear striations projecting and a poor definition of the endometrial myometrial junction.

So in this example, a transverse and sagittal T two weighted, T two weighted images of the pelvis.

We see linear striations associated with the endometrium here and here.

And also this is causing a pseudo widening of the endometrium.

The, junctional zone is markedly thickened in this patient and we see heterotopic, hyperintense foci, which are the glands, within the myometrium.

Pelvic Congestion Syndrome

So moving on then to the other cause of uterine tenderness or pelvic congestion syndrome.

This is chronic pelvic pain that is associated with dilatation of pelvic veins and reduced venous return.

It is a dull chronic pain exacerbated by prolonged standing and relieved by lying down and elevating the legs.

Often, sonography is used in the initial assessment to rule out other pelvic etiologies with similar symptoms, but has also been shown to be a value in the diagnosis.

So we may see the presence of these tortuous dilated vessels, the venous plexes in the adnexa and with color doppler we may see that these dilated veins, the arcuate veins within the uterus may be seen crossing the myometrium.

Other sonographic signs include dilatation of ovarian veins from six to 10 millimeters in diameter with reverse coddle flow.

Polycystic like changes of the ovary or variable spectral doppler wave forms in the veins during the Valsalva maneuver.

As we can see, represented here, in this image from a JR, which shows a spectral doppler of an ovarian vein and with Val Salva at this arrow we see reversal of flow, but phonography remains the gold standard and the diagnosis can be made with an ovarian vein diameter greater than 10 millimeters demonstrating reflux.

Ovarian Remnant Syndrome

Other causes of chronic pelvic pain include first ovarian remnants syndrome and uncommon condition occurring after unilateral or bilateral ectomy with or without a hysterectomy.

So a fragment of ovarian tissue is left behind encased in adhesions becoming functional and or cystic, causing the patient chronic pelvic pain.

So we can see in these images the multi septated ovarian mass in a patient's status post hysterectomy with a rim of ovarian tissue seen on both the sagittal and transverse views using transvaginal sonography.

Malpositioned IUDs

Okay, we often see intrauterine contraceptive, devices in patients causing pelvic pain.

These are easily visualized by transvaginal sonography due to their increased echogenicity and marked attenuation of the sound beam.

An abnormal position may cause chronic pain.

So by transvaginal sonography we can confirm the position of the IUD in the uterus and when abnormally located may show that part of the IUD is embedded in the myometrium 3D ultrasound.

Using reconstructions in the coronal plane can be especially useful in improving our visualization of the entire IUD.

So we have a 3D reconstructed image, a surface rendered image showing a satisfactory IUD location with shaft in the main cavity and the two short arms within the uterine cornew.

Another image 3D reconstruction showing an unsatisfactory IUD location fairly low in the cavity with one of the short arms embedded in the myometrium on the left side.

And here's an example of how we can be misled by 2D.

Ultrasound A, the shaft of the IUD looks like it's in fairly good location within the endometrial cavity on this 2D sagittal image.

But when we do the 3D reconstruction, we can see that it is obviously displaced that is low in the cavity in an oblique position with the left short arm embedded within the myometrium.

Approach to Chronic Pelvic Pain

So in our approach to chronic pelvic pain, we have ultrasound as the modality of choice and then we have MRI as our problem solving tool.

Cyclic Pain or Dysmenorrhea

And finally we have cyclic pain or dysmenorrhea.

This is cyclic pain during menstruation.

It may be divided into primary or secondary dysmenorrhea, primary dysmenorrhea if there is no underlying pelvic pathology and no direct imaging findings.

But imaging may be useful, especially ultrasound to exclude other causes.

This is usually seen in the younger menstruating age group and the pain usually begins a few hours before or shortly after the onset of menses in my last uh, two to three days.

Secondary dysmenorrhea, is due to an underlying pelvic pathology And this, may prevent present with a more variable type of pelvic pain than the primary dysmenorrhea.

And then as far as causes of secondary dysmenorrhea, the majority of them we've already covered since they may also cause chronic pelvic pain that is non cyclic.

These would include endometriosis, adenomyosis, IUDs and pelvic congestion syndrome.

We also have some other less common causes of secondary dysmenorrhea that are, that have some interesting presentations.

First, the uterine anomaly, the uterus delphis, here with an obstructing vaginal septum as an example, we can see this drawing from radiographics showing the vertical septum attached to the wall of the vagina, which could definitely cause a significant obstruction from the outflow of menstruation of the right.

Uterine horn.

A patient with exactly this problem, demonstrating a hemato post by transabdominal imaging.

This is a 13-year-old, so transvaginal imaging was not performed.

And, evaluation of the problem by trans, excuse me, transabdominal imaging, is not extremely accurate.

So an MRI of the pelvis was performed in this patient, which shows very nicely the normal appearing left vagina, left cervix, and the hemato posts on the right.

I also have some examples of dysmenorrhea due to adhesions.

We have a patient here with a corneal hydrocele, pinks post endometrial ablation with endometrial ablation.

We have an adherent, cavity within the majority of the uterus, but the corneal areas, may not be ablated, distally and functioning endometrial tissue may still bleed causing these corneal collections, especially if there is distal tubal obstruction.

These collections will cause pain with menstruation.

Another example of adhesions causing a hemato post.

One, patient following a leap procedure and, a loop electrosurgical excision procedure that uses a thin low voltage electrified wire loop to cut out abnormal dysplastic tissue in patients, with cervical dysplasia.

And of course, this type of procedure can, result in cervical stenosis and distension of the patient's, cervix and endometrial cavity as well, with, menstruation.

So once again, our approach to, pelvic cyclic pain, we have primary dysmenorrhea and really no imaging findings, would be found here.

But ultrasound may be used to rule out other, etiologies.

And then we have secondary dysmenorrhea, which would be worked up similarly to chronic pelvic pain since most it has very similar etiologies with ultrasound being the modality of choice and MRI our problem solving tool.

Radiation Concerns and Emphasis on Ultrasound and MRI

So also before concluding, just some points to ponder regarding radiation, which, supports more, emphasis on the use of ultrasound and even MRI when appropriate rather than, modalities such as CT that use ionizing radiation.

First, a pelvic CT in a pregnant patient, delivers up to 2.5 rads increasing fetal radiation dose to approximately tenfold above background.

This dose is well below the estimated threshold risk for fetal malformations.

However, linear extrapolation from cancer rates observed in atomic bomb survivors suggests that a pelvic CT could increase the risk for developing cancer by 0.3%, or about one in 300 in a fetus in utero, one in 400 in a 10-year-old girl and one in a thousand in a 30-year-old woman.

So the use of ultrasound cannot be stressed enough.

Sonography is the initial imaging modality of choice for evaluation of suspected gynecologic etiologies of pelvic pain.

Sonography is also an effective substitute to CT for evaluation of non gynecologic causes in patients in the reproductive age group, especially pregnant patients.

And MRI should be used as a problem solving tool when ultrasound is, not adequate or in place of CT in pregnant patients with suspected appendicitis.

Overview of Approach to Pelvic Pain

So here is just an overview of the entire approach to pelvic pain where we have acute pelvic pain, which should be divided into GYN or OB cause versus, suspected non GYN, cause chronic pelvic pain and cyclic pain.

And thank you very much for your attention.