Imaging of Pelvic Pain: Pre- and Postmenopausal Women - SD

Introduction

I am Marcela Bon Les, a woman's imager. I have a private practice in Pittsburgh, Pennsylvania. Also, I have an appointment at the University of Pittsburgh as a clinical assistant professor.

I will be talking about imaging of pelvic pain in the pre and postmenopausal woman.

Overview of Pelvic Pain

Pelvic pain is one of the most frequent causes of outpatient visits. 25% of all referrals to gynecologists, 40% of all gynecological laparoscopic surgeries and 12% of hysterectomies are due to pelvic pain. The medical care cost is more than $2 billion per year to treat pelvic pain.

Pelvic pain is most frequently caused by variances, endometriosis and pelvic adhesions.

Initial Evaluation

The initial imaging modality after a good history and physical is pelvic ultrasound.

A good history should be obtained. The menstruating status, the type of pain, if it's severe, the location of the pain, if it's unilateral versus bilateral, the character of the pain, if it's intermittent, crampy, constant should be documented. The onset of pain, the duration of pain is important. Past history of similar episodes and of previous surgeries is also important information.

Associated gastrointestinal and genitourinary symptoms should be obtained.

A good physical exam should be done. Size and consistency and mobility of the uterus and ovaries should be documented. The type of pain during examination.

Laboratory assays that may be done in patients who present with pelvic pain are complete blood cell count. Erythrocyte sedimentation rate, vaginal swabs for chlamydia and gonorrhea, urinalysis with culture. And in the menstruating female pregnancy test with a beta human chorionic gonadotropin should be considered also possibly a CA 125.

However, the initial imaging study should always be an ultrasound.

Acute vs. Chronic Pelvic Pain

Acute pelvic pain is abrupt in onset and duration measured in hours or days, rarely last more than a month without a crisis resolution or cure. It's due to direct insult of tissue trauma that activates the neuroreceptors and neural pain fibers. The severity of the pain is directly proportional to the severity of the traumatic insult. It's thought to be a symptom, whereas chronic pain is viewed as a disease.

Chronic pelvic pain presents in the same location for at least six months. It may lead to years of disability suffering. Many medical procedures, it's associated with depression, and usually the patient is uncooperative and noncompliant.

The differential diagnosis for chronic pelvic pain include adhesions, endometriosis, adenomyosis, and infections, and neoplasms, which have uncertain relationship to the chronic pain. Chronic pain is probably multifactorial, therefore, it is difficult to diagnose and to treat.

Laparoscopy is a valuable tool in patients with chronic pain. It's performed in less than 50% of women and will confirm the clinical impression, establish a diagnosis, and it's also useful for therapy for removal of adhesions, aspiration of ovarian cysts, biopsy of intraperitoneal structures, avoiding exploratory laparotomy, and also it can be very helpful for a follow-up course of the disease.

Classification of Acute Pain

Acute pain can be divided as its origin from gynecologic origin or non gynecologic origin.

Gynecologic causes of acute pelvic pain may be ovarian, such as cyst, functional or hemorrhagic, endometriosis, pelvic inflammatory disease, torsion, neoplasm, malignant or benign, including dermoid cyst, adenomas and fibromas.

Gynecological causes arising from the uterus most commonly are due to fibroids, degenerative or torsion of a fibroid or from adenomyosis, cervical stenosis.

Extra ovarian causes of acute pelvic pain include ectopic pregnancy, ovarian hyperstimulation syndrome.

Non gynecological causes of acute pelvic pain may be from gastrointestinal origin such as appendicitis, diverticulitis, or inflammatory bowel disease. Urological causes include acute cystitis, ureteral, and urethral calculi.

Classification of Chronic Pain

Gynecologic chronic pain can also be due to gynecological and non gynecologic causes. The most common gynecologic causes of chronic pelvic pain include adenomyosis and endometriosis, adhesions, chronic pelvic pain, chronic pelvic inflammatory disease, pelvic floor myalgia, pelvic congestion, pelvic relaxation, retained ovarian syndrome, and uterine fibroids.

The non gynecologic causes of chronic pelvic pain may be due to abdominal wall factors, gastrointestinal origin, urologic, psychologic, neurogenic, or orthopedic in origin.

Studies on Pelvic Pain with Normal Ultrasound

A large amount of patients will present for pelvic pain. A large amount of patients that present for pelvic pain have a normal ultrasound. The outcome of these patients with pelvic pain and a normal transvaginal ultrasound is a high negative predictive value of 92%.

In a study by Harriss and his group evaluated 86 women, 77% of the pelvic pain improved or resolved in these women. The majority of these women, 86%, had acute or subacute pain, and approximately 50% had chronic pain. Only 10% required further imaging, one who had a CT a month later showed that the cause of the pain was due to diverticulitis. 33% underwent 19 surgical procedures, and that they found in these patients had endometriosis, pelvic varices, and adhesions.

Their conclusion was that women with pelvic pain and normal pelvic ultrasound will get better with or without surgical intervention and further imaging is unlikely to yield positive results.

A study by Kurjak and his group evaluated laparoscopically findings in patients with pelvic pain and 1,194 patients evaluated 355 had normal pelvis and normal pelvis. Another 264 had a pelvic inflammatory disease. The others had either ovarian pathology, pelvic adhesions, or pelvic congestion. Smaller amounts were due to uterine fibroids and endometriosis, uterine displacement, ectopic pregnancy.

Another study evaluated pelvic pain correlated with laparoscopic finding. Found that 18% of patients with abnormal pelvic exam had no abnormality at laparoscopic surgery. 63% patients with a normal pelvic exam had abnormal findings at laparoscopic surgery. The causes, the abnormalities seen in a laparoscopy were ovarian abnormalities, pelvic adhesions, pelvic inflammatory disease, and endometrioma.

Their conclusion was that there's not always a correlation between the presence of pelvic pain and abnormality of the pelvic organs.

Uterine Causes of Pelvic Pain

The most common causes of pelvic pain due to uterine abnormalities are fibroids, adenomyosis, pelvic inflammatory disease such as endometriosis, cervical stenosis, or cancer causing distension of the uterine cavity.

Fibroids

Fibroids or leiomyomas are composed of interlacing bundles of smooth muscles and connective tissue. They're the most common pelvic tumor. The incidence increases with age, 20% of women greater than 30 years of age will have fibroids. It's more common in the black population than in the white population.

Fibroids are usually multiple of various size and seen mostly in the body, in the fundus of the uterus. This is the indication for 30% of the hysterectomies in United States.

Classification of fibroids include intramural, submucosal and subserosal. Intramural are fibroids, which are confined within the myometrium. This is a nice drawing on the right from Dr. Netter's book. Submucosal fibroids are those that are projecting into the uterine cavity, and when the whole submucosal fibroid is within the endometrial cavity, it's referred as intracavitary fibroid. Cavitary fibroid.

Subserosal fibroids are those that are projecting from the peritoneal surface and when the whole fibroid is projected outside of the uterus with a pedicle, they're considered pedunculated fibroids.

Clinical presentation of fibroids are variable. They depend on the size, the number of tumors, age of patient, proximity of the tumor to the endometrial cavity, mobility of the fibroid. In the presence of degenerative process and infection, pain is usually due to degeneration, infarction and infection in the fibroid. Strong uterine contractions. Rotation of the fibroids within the pseudocapsule may interfere vessels and result in necrosis.

Torsion of pedicles may occur in the subserosal and submucosal fibroids and can cause infarction, degeneration, necrosis and potential infection. Five to 10% of the fibroids are submucosal. They encroach and distort the endometrium causing abnormal bleeding. These submucosal fibroids are prone to necrosis due to insufficient blood supply. They're also prone to infection, exposed position, predisposing to ascending infection, and also prone to degeneration, which is due to the torsion of the pedicle. All these can cause pain.

Intramural fibroids most commonly cause uterine enlargement. They can cause pain when they undergo degeneration and less likely get infected. Subserosal fibroids cause pressure on the adjacent pelvic organs or ligaments causing pain.

Leiomyomas are estrogen dependent, usually regress after menopause and increase in size with pregnancy. In postmenopausal woman, if a leiomyoma increases in size, it needs to be removed because of the fear that there may be sarcomatous changes.

The sonographic findings of leiomyoma is variable. They may present as a uterine enlargement mild. They may be mild to moderately echogenic mass causing nodularity of the contour. They may cause distortion of the endometrial echo or alter echo of the myometrium. They may present as a hypoechoic solid mass with poor posterior transmission or increased echogenicity, and that may be related to the fibrous component, or if it's associated with posterior acoustic shadowing, it may be due to calcifications within the fibroid. 25% of the fibroids will have calcifications. Some of them may be small, others may be a rim around the fibroid.

A hypoechoic pseudocapsule can occasionally be seen and occasionally cystic degeneration seen as irregular anechoic areas may be present.

Here is a transvaginal view sagittal projection of the uterus midline. We see the endometrial cavity and you see the endometrial mucosa being displaced by this heterogeneous mass, which has posterior acoustic shadowing.

Here is a transverse view of the same on the same patient, and you can see nicely a hypoechoic or heterogeneous mass with shadowing, displacing the endometrial cavity.

This is an image, a 3D acquisition, coronal image showing an intracavitary fibroid. We can see nicely the endometrial cavity surrounding the fibroid. 2D coronal view obtained from a 3D acquisition is very helpful in being able to identify the location of these submucosal or intracavity fibroids.

Here's another patient, longitudinal view of the uterus midsection, and we can see longitudinal and transverse. There's an echogenic mass in the fundus of the uterus, and this is a fibroid that probably has fibrous changes very echogenic.

Here's another case. It's an older case, but it shows how sometimes these fibroids can obliterate visualization of the endometrial cavity. And here you see all these echogenic masses with posterior acoustic shadowing and which prevents us from evaluating the endometrium.

Fluid within the endometrium can be very helpful and outline the submucosal fibroid. Here on your left, we have a transvaginal study with a small amount of fluid secondary to sonohysterogram that was done, and we see nicely a broad base hypoechoic mass, which is being outlined by this echogenic linear structure, which represents the endometrial lining. This is a submucosal fibroid.

MRI can be very helpful in these patients. There's probably no need to do an MRI in most of the cases because a diagnosis can be done with transvaginal ultrasound and sonohysterogram and the 2D coronal image that we can obtain with 3D acquisition. But in this case, you can see MRI view showing nicely a little fibroid displacing the endometrial cavity. And this is a nice way also to see the relationship between the fibroid and the endometrial cavity.

Here's another MRI coronal and sagittal view showing the uterus sagittal view of the uterus with the endometrial. And here was a mass, pedunculated fibroid, which this MRI image shows nicely the relationship of the fibroid to the uterus.

The management of symptomatic fibroids varies. It can be medical, hysterectomy, myomectomy, hysteroscopic procedures such as endometrial ablation, especially in submucosal fibroids that are causing bleeding or more recently, uterine artery embolization has been shown to be very helpful in patients who have symptomatic fibroids.

Uterine artery embolization causes 50 to 60% of these fibroids to reduce in size. It can relieve symptoms in 85 to 95% of patients. It causes shorter hospital days and a rapid recovery time.

And here we have another patient. On the left is a transabdominal study showing a longitudinal view of the uterus. Endometrial cavity is being displaced anteriorly by this heterogeneous, predominantly hypoechoic mass, transvaginal ultrasound. You can see the mass better that it's heterogeneous and this was a fibroid. This was a postmenopausal woman who had a fibroid. She returned six months later because the uterus had increased in size, and as you can see in this picture that that fibroid has almost doubled in size.

Any post-menopausal woman who presents with increasing in size of a fibroid needs to have it surgically removed. And the reason for that is because there's always the potential of uterine sarcoma.

Uterine sarcomas arise from the mesenchymal tissue, less than 2% of them arise from existing fibroids. 85% have irregular bleeding and 19% with pelvic pain and enlarging fibroid in a post-menopausal woman should be treated with suspicion. Usually the diagnosis is not done preoperatively since sonographic findings are very similar to benign fibroids, the extent of the disease in these patients is very important because it determines the prognosis. When a cancer is confined to the uterus, the five year survival can be up to 50%.

Here's another patient, a transabdominal study showing a very difficult to see the uterus and there was very heterogeneous with echogenic linear structures and shadowing. Here's a CT showing that a lot of this echogenic linear structures that were seen on transabdominal ultrasound that were actually gas within this mass. And what this was was a carcinosarcoma.

Adenomyosis

Adenomyosis another common disease of the uterus that can cause pain. It's more common than what we thought. We see it in 70 to 80% of parous women. 70% are symptomatic. Transvaginal ultrasound has pretty high sensitivity, specificity and accuracy. Sensitivity of 80 to 86%, specificity of 50 to 96% and accuracy of 68 to 86%.

Adenomyosis may present as two types, diffuse or focal. The focal is nodular and sometimes referred as adenomyomas. Patients who have adenomyosis present with uterine enlargement. Pelvic pain, dysmenorrhea, menorrhagia.

Adenomyosis is due to migration of glands from the basal layer of the endometrium into the myometrium. These ectopic glands are seen two to three millimeters below the endomyometrial junction, and they're often misdiagnosed as leiomyomas.

The sonographic findings of the diffuse adenomyosis is uterine enlargement with heterogeneous appearance of the myometrium. There is usually an asymmetry between the myometrial walls with the anterior wall being thicker than the posterior wall. Subendometrial tiny cysts or nodules may be seen in 50% of the cases, and this most likely reflects the cyclic functions of the endometrial glands.

The sonographic findings of the focal adenomyosis is ill-defined echogenic mass or an adenomyoma. Color and power doppler ultrasound demonstrate the penetrating vascular pattern within the mass, which helps to differentiate these from the fibroids. Fibroids are well-defined hypoechoic mass with vascularity in the periphery of the mass.

And here's a nice example of diffuse adenomyosis, transabdominal study longitudinal view. We see the endometrial cavity. You see that the uterus is markedly enlarged. The anterior myometrial wall is thicker than the posterior myometrial wall, very heterogeneous myometrium. And within the myometrium you can see these little cystic areas, which are probably glands and on color flow. You see how diffuse the vascularity enters the mass different than in fibroids in which the vascularity surrounds outlines. It's in the periphery of the mass.

Another patient, two views showing very thick anterior myometrium compared to the posterior myometrium. The endomyometrial junction is not seen here. This is typical of adenomyosis.

We know that MRI has a very high sensitivity and specificity for diagnosing adenomyosis. The diffuse form of adenomyosis is seen on MRI as a uterine enlargement with diffuse thickening of the endomyometrial junction. Normally, the endomyometrial junction's width is about eight millimeters. When it's wide greater than 12 millimeters, it usually represents diffuse adenomyosis. Endomyometrial junction of eight to 12 millimeters is sometimes associated with focal adenomyosis. Low signal on T2 weighted represents the hypertrophy of the smooth muscle surrounding islands of ectopic endometrial glands.

And here's a nice example of adenomyosis on this MRI. We can see that the myometrium is very heterogeneous. The anterior wall is much thicker than the posterior wall, and the endomyometrial junction is thick. Cannot see the anterior part of the endomyometrial junction.

Management for patients who are symptomatic with adenomyosis can be medical treatment, hysterectomy or also uterine artery embolization has shown to improve dysmenorrhea in these women.

Endometritis

Another cause of pain in women is pelvic inflammatory disease and endometritis in the uterus can be seen or identified, and it's usually associated in patients who already have pelvic inflammatory disease or after a D&C. Sonographic findings in the endometritis includes increased echogenicity. As you can see here in this transvaginal study shown in thickened endometrium. Or sometimes, occasionally we can see acoustic enhancement. Occasionally we can see fluid and the presence of gas can be seen in 21% of the patients and confirms the diagnosis.

Here you see two different patients with complex fluid collections. These two patients have endometritis on one on this patient. The complex fluid collection can mimic a pseudosac, which can be seen in ectopic pregnancies.

Another patient transabdominal study shows a longitudinal view of the uterus, a complex endometrial fluid collection. Within the fluid collection, we see this linear echogenic structure transvaginal better delineates the endometrium. We see nicely the os of the endometrium echogenic complex fluid collection within the endometrial and this curvilinear echogenic structure with shadowing consistent with gas. This confirms that this is endometritis.

Cervical Stenosis

Pain can also be due to cervical stenosis and cervical stenosis may be due to chronic cervical infection. Treatment of endocervicitis, or surgery to the cervix can cause cervical stenosis. The definition of cervical stenosis is the inability to pass a 2.5 millimeter or less probe to the canal.

This causes distension of the uterine cavity. Hematometra, pyometra, and all these may cause cramps. Suprapubic pain in the pre-menopausal woman. It may be the pain may also be associated with oligomenorrhea and amenorrhea and dysmenorrhea.

Cervical dilatation is usually the treatment that is done and can be done with ultrasound guidance.

And postmenopausal woman. Endometrial fluid collection may be due to carcinoma, endometrial or cervical, endometrial polyps, status post-radiation therapy. But the most common cause of endometrial fluid collection in the postmenopausal woman is probably exogenous estrogen administration due to some degree of cervical stenosis.

Here's a postmenopausal woman. Transvaginal ultrasound shows marked distension of the uterine cavity by fluid due to cervical stenosis in a hematometra or maybe due in a postmenopausal woman to reactivation of endometriosis. These women are usually taking hormone replacement therapy, and as you can see here on this transvaginal study, dilated standard endometrial cavity with homogeneous fluid, which was blood. And here again, you can see distension of the cervical canal with fluid, and these were two patients who had cervical stenosis secondary to because they were postmenopausal.

Cervical Cancer

So cervical cancer can also cause pain, can cause cervical cancer can also cause uterine endometrial cavity distension and pain. However, ultrasound is not very helpful in the diagnosis of cervical disease.

However, cervical cancer has decreased in the past decades because of the widespread screening with a PAP test. MRI actually has had the most impact on preoperative staging of cervical cancer.

Most common cause of cervical cancer is squamous cell. And usually cervical cancer spreads locally and through lymphatic invasion.

Here's a transvaginal study, retroverted uterus, sagittal view. We can see the endometrial nicely, the fundus of the uterus, and in the cervical area we see this irregular marginated heterogeneous mass. And here again, we see that the mass had a lot of vascularity. On this longitudinal view, we see nicely the cervical canal, but it almost can be seen that there is invasion into the myometrium. And this was a large cervical cancer.

Ovarian Causes of Pelvic Pain

Causes of pelvic pain due to ovarian origin depends if the patient is on the premenopausal woman. It's most likely due to functional cysts or hemorrhagic cyst can be due to endometriosis, pelvic inflammatory disease, torsion or tumor, most commonly benign such as dermoid can be malignant. In postmenopausal women, the most common cause of pain from an ovarian origin is cyst or tumor. And the most common tumor benign tumor would be a fibroma or malignant or in another common cause of ovarian tumors are malignant tumors.

Functional Cysts

Functional cysts in premenopausal seen in premenopausal women, these include follicular, corpus luteum and thecal lutein cysts. The follicular cyst occurs when a mature follicle fails to ovulate or involute and should not be diagnosed till it's greater than 2.5 centimeters. The corpus luteum cyst results from failure of absorption or excess bleeding into the corpus luteum. The thecal lutein cysts are the largest and they're associated with high levels of human chorionic gonadotropin. These are associated with gestational trophoblastic disease.

Hemorrhagic Cysts

Probably the most common cause of pelvic pain. The premenopausal woman is a hemorrhagic cyst. This is internal hemorrhage into functional cysts. These patients present with acute pelvic pain and they actually probably can tell you exactly when the pain occurred.

Sonographic, the findings depend on the amount and the time of hemorrhage relative to the ultrasound done. An acute hemorrhage, usually the hemorrhagic cyst will present as a hyperechoic mimicking a solid mass. The posterior wall will be smooth and many times it will have posterior acoustic enhancement. As the clot hemolyzes, the hemorrhagic cyst becomes more complex and a reticular pattern develops, which contains tiny little septations. No flow will be seen within the mass. Occasionally you'll see free fluid, and that's due to leakage or rupture of the hemorrhagic cysts.

And this is typical findings of hemorrhagic cysts. On the left, you can see a hemorrhagic cyst very homogeneous. We don't see very well the ovarian tissue surrounding it because it's so large. And here's another patient on your right, which has a typical reticular pattern. When you see this reticular pattern, it can be nothing else but a hemorrhagic cyst.

Cysts in Postmenopausal Women

Postmenopausal women can also present with cysts. They're seen in 17% of all asymptomatic women, 90% of less than three centimeters. The important thing here is 53% of these cysts will disappear totally with time. The rest will either decrease or increase in size, but there's really no relationship between the cyst, age, weight of the patient parity or hormone use, or the length of time for menopause.

What do you do with these cysts in post-menopausal females? Well, they're prevalent. They're usually seen in five to 8% in one study, and they're usually measured between 20 to 50 millimeters. But in the literature, it has been shown that the risk for malignancy is less than 1%. The only time that it's worrisome is if you do see within the cyst, small mural nodules. If no small mural nodules are seen, then you can follow this following this management.

If they're one to three centimeters, they do not need any follow up. You may wanna do a CA 125 level. If they're between three to five centimeters, you may follow them. Nobody knows exactly when you should do a follow up ultrasound probably in a year. You may also wanna do a CA 125 level. In these patients, if they're between five and 10 centimeters in diameter, they're usually still benign. They may be associated with a low malignant neoplasm. You may wanna consider laparoscopic removal if the patient is clinically stable.

Endometriosis

Endometriosis another very common cause of pelvic pain in the premenopausal woman. Endometriosis is functional endometrial tissue outside the uterine musculature implanted on the surface of other organs and response to the hormonal stimuli. It's most frequently seen in the ovary. Uterine ligaments may be seen in the pouch of Douglas, pelvic peritoneum, fallopian tubes less frequently in the bladder, cervix or vagina, but can also be seen in abdominal scars C after C-section.

Endometriosis occurs in women in the reproductive years between 25 years and 29 years. Seven to 10% of the population has endometriosis, and it's the cause of 20 to 50% of infertility in women. Tenfold increased risk of women with first degree relatives and the symptoms, the most common symptoms are pain and dysmenorrhea, dyspareunia, abnormal menstrual bleeding and infertility.

Pain is not correlated with the extent of the disease and imaging is very limited in these patients.

Here's a nice case of endometriosis, which is usually bilateral. This is a transverse view transabdominal the uterus and two bilateral hypoechoic masses. On transvaginal ultrasound, you can see better the morphology or the echogenicity of these masses. This was very hypoechoic homogeneous looks very similar to the hemorrhagic cyst I showed you prior.

Transvaginal ultrasound has a high sensitivity specificity for diagnosis endometriosis, and the reason is identification of an endometrioma, which is occasionally referred to as a chocolate cyst, may be seen. The ultrasound findings of an endometrioma are nonspecific. The mass may be cystic with diffuse low level echoes, as I showed you prior as seen in this image. It may be multilocular with thin septations and irregular walls. It may look just like a hemorrhagic cyst. However, hemorrhagic cysts usually have that reticular pattern free fluid and decrease in size over time. These may not change at all in time and usually you will not see that classical reticular pattern.

MRI can be used to diagnose endometriosis. And when would you use MRI? Well, when the ultrasound findings are equivocal or for diagnosis of superficial peritoneal implants, extra peritoneal lesions, lesions in the rectovaginal space, sacral ligaments. On MRI an endometrioma has a high signal T1 weighted and it loses this signal on T2 weighted referred as the shading sign. And this is due to the high protein in iron concentration from recurrent hemorrhage.

The sensitivity of MRI diagnosing endometriosis is 90 to 92% with a specificity of 91 to 98%.

Management of Ovarian Cystic Lesions

Well, what do you do with women premenopausal women with ovarian cystic lesions? Simple or minimally complicated cyst under five centimeters are usually physiologic and may need no follow up. Hemorrhage without vascular soft tissue component is usually a reliable indicator of benign lesion. However, if there's any question about the imaging features, you can recommend a follow up ultrasound, one or two menstrual cycles in one or two menstrual cycles. Usually you wanna do it in the early proliferative phase of the cycle, and if that doesn't help, you can always do a CT or MRI, especially in cases that you are questioning dermoid cyst.

What are the diagnostic goals for ovarian masses? It's important to discriminate between lesions that need to be further evaluated with imaging, a follow-up have surgery, and those that do not determine if the MRI CT exam or a follow-up ultrasound should be done for management decisions. If you do think that it's suspicious for a malignancy, then you may wanna refer the patient to a gynecological oncologist.

It's important to be able to determine if the mass that you're seeing is ovarian or extraovarian. Look for a rim of ovarian parenchyma, little follicle surrounding the mass to establish an intraovarian origin. Identify a separate ipsilateral ovary from the mass to establish that it's extraovarian in origin while scanning. Observe movement of the mass with respect to the ovary during manual compression or with a transducer.

Here is a ovarian cystic mass and we see in the periphery a few little follicles to confirm that it's within the ovary and nicely you can see here resistant waveform in this proliferative phase. Two other, another case of ovarian cyst. And you can see nicely that this the cyst is surrounded by ovarian tissue longitudinal transverse. You can see nicely the ovarian tissue and you see in the periphery. It's a lower resistant waveform probably due to the luteal phase of the cycle.

In premenopausal women who present with larger ovarian cyst, I mean greater than five centimeters, we perform transvaginal cyst aspiration. We use a transvaginal probe with a guide and insert a 20 gauge, 20 centimeter needle through the vaginal vault into the cyst aspirating the fluid. Patients usually get immediate relief from the pain. The procedure is not painful. Occasionally I will place a little lidocaine in the vaginal vault, but if there's no inflammation, there's probably no need for lidocaine.

Pelvic Inflammatory Disease (Ovarian Involvement)

Another cause of pain due to ovarian origin is pelvic inflammatory disease. Usually these ovaries are enlarged. They have decreased cortical medullary differentiation. The masses, when they do present as a mass, which are seen in 38.9% of the cases, they're usually non-specific masses are probably most likely due to ovarian abscess. And these can be cystic complex or solid. Sometimes these masses represent adhesions of the ovaries to the omentum and occasionally identification of gas can be seen and confirms the diagnosis.

Here's the beautiful Netter diagram showing fallopian tube and infection going into the ovary. Actually, the ovary is pretty resistant to infection and first sign you will see is endometritis. Then you will see since it's an ascending infection, the infection starts from the cervix up, the endometrium into the fallopian tubes and usually the ovaries are the last to be affected and they're pretty resistant as you can see here. But after continuous spillage of purulent fluid into the periovarian region, the ovary does get infected.

And you can see nicely on this transvaginal study, which correlates nicely with a Netter diagram, the dilated fallopian tube with complex or heterogeneous fluid within it and penetrating into the ovary infecting the ovary. In this case, we refer this to a tubo-ovarian complex and not quite a tubo-ovarian abscess.

Instead of a tubo-ovarian abscess, which we see in this case, in this case, transabdominal on your left and transvaginal on the right, we see posterior to the uterus. A complex mass seen better on the transvaginal much better. On this transvaginal study we see solid material within the mass, and this was a tubo-ovarian abscess, which can be drained.

And here's another patient, bilateral disease, which is common in pelvic inflammatory disease. This is a transabdominal transverse view of the uterus and shows bilateral adnexal masses. Transvaginal ultrasound in your right shows that the masses are very complex multiloculated. In this case, there was nothing to actually drain. This patient was treated with antibiotic treatment and after antibiotic therapy, she returned and her ovaries had resumed the normal size in morphology.

Tubo-ovarian abscess. When tubo-ovarian abscess are refractory to medical management, that means antibiotic treatment. They can be drained with ultrasound guidance either using transabdominal transvaginal transrectal approach. The approach really depends on the location of the abscess, an abscess high in the pelvis or anterior to the uterus. You may wanna do a transabdominal approach in those abscess in the cul-de-sac. You may wanna do a transvaginal or transrectal approach.

Ultrasound guided aspiration is very effective and safe and avoids laparoscopic and laparotomy. Transvaginal guided technique eliminates the risk of general anesthesia, surgical morbidity, and abdominal wall complications. It also avoids the loops of bowel urinary bladder uterus. Neurovascular structure therefore makes this procedure much more desirable.

Systemic antibiotics should be administered when this procedure is done. Occasionally, if you get non purulent collection, you may just wanna do an aspiration without placement of the catheter. If you do obtain purulent fluid. When you do aspirate these fluid collections, you may wanna place a catheter for at least three days, irrigating it every day with saline.

The curative rate is about 78% even in these patients with fluid. And here's the case. A patient presented with a complex, a large, complex mass, and we drained it using transvaginal guided transvaginal aspiration. And as you can see here on the right, we didn't completely, and usually you don't completely drain it completely, but enough that you can start treating the patient with antibiotics.

Here's another patient. This was a difficult case. It was difficult to see this abscess. We actually had seen it on CT and then when we did the transvaginal ultrasound, this correlated with what we had seen on CT and these echogenic areas within this solid looking mass was gas. And you can see here the needle coming in and draining this purulent fluid collection.

Post-menopausal women can also get tubo-ovarian abscesses. It's a rare condition. It's only seen in 1.7% of all the tubo-ovarian abscesses. Usually these women require surgery, and the diagnosis is not made preoperatively. And the cause of this is recurrent pelvic inflammatory disease. The responsible agent is usually E. coli or Neisseria. These patients require prolonged hospitalization and do get complications. So it's important in the postmenopausal woman if you suspect a tubo-ovarian abscess to do early and radical surgery.

Ovarian Tumors

Another cause of pelvic pain in predominantly in the premenopausal woman is ovarian tumors. The most common ovarian tumor in the premenopausal woman is a cystic teratoma or dermoid cyst. It consists of 15 to 25% of all the ovarian neoplasm. 10 to 50% are bilateral. They're composed of well differentiated derivatives of the three germ cell layers. Ectoderm, mesoderm endoderm.

In the reproductive age group, usually the patient's asymptomatic and it's seen doing a ultrasound or sometimes it's clinically palpated. Complications include torsion rupture. Malignant transformation is very uncommon seen in less than 2% of the patients.

The sonographic appearance of cystic teratoma or dermoid cysts are very variable. They can be from anechoic to hyperechoic. There's been a few classifications or sonographic mnemonic signs of dermoid. One is the dermoid plug, which is a cystic mass with an echogenic shadowing mural nodule. The mural nodule is due to hair, teeth or fat. The cystic component is sebum, which is liquid at body temperature.

Another mnemonic sonographic sign is tip of the iceberg. It's a very highly echogenic mass in the increased echogenicity is due to a mixture of hair and sebum and multiple tissue interfaces. And this produces ill-defined shadowing obliterating posterior, obliterating visualization of the posterior wall.

The dermoid mesh is another classical mnemonic sonographic presentation of a dermoid. And these are multiple linear echogenic interfaces floating within a cyst. Also, fat fluid or hair fluid levels can be seen.

Pitfalls are that many times dermoids can mimic bowel gas, acute hemorrhagic cysts and endometriomas and therefore you may need another imaging modality to confirm the diagnosis.

Here's a nice case of the tip of the iceberg sign. We see that there's a mass echogenic mass with shadowing and it's within an ovary. You see that the surrounding this mass is little follicles demonstrating that this is an ovarian mass. And another view tip of the iceberg, very echogenic mass and shadowing another dermoid. Here is longitudinal view of the uterus transabdominal study. And in the lower uterine segment, you could see to one side to the right that there's an ill-defined echogenic mass, difficult to outline.

Well, here's the mass better seen on in the right sagittal and transverse views. You can see the mass here and here, occasionally when it can be missed or diagnosed as a loop of bowel.

Another patient with a dermoid cyst. And here you can see this is a dermoid plug, a cystic mass with a mural nodule that's very echogenic and shadowing very sometimes very tough to differentiate this from the adjacent loops of bowel.

Another dermoid, complex cystic mass complex echogenic areas shadowing. This is due to sebum, the fluid typical of a dermoid fat within a mass fluid, fat fluid levels. Here's another one showing the typical fat fluid levels nicely seen on this transvaginal study. As you rotate the patient, the fluid changes position here within the mass you see these little echogenic nodules typical of a dermoid.

Occasionally you may need to do CT or MRI to confirm the diagnosis. And here nicely on T1 and T2 shows the typical MRI findings of a dermoid. Identification of fat diagnosis of dermoids is usually made by ultrasound, but if there's any questions a CT or MRI can be helpful to confirm the presence of fat.

If these dermoids are large, they may have laparoscopic surgery. Tiny dermoids are usually just followed with ultrasound because surgery can probably cause more damage to the ovary than the dermoid itself.

Another tumor that can be seen in the ovary can cause pain is a cystadenoma. These are benign tumors. They usually unilocular. They may have septations and they may even have solid components and complex fluid and can be sometimes mistaken for malignant tumors. And here on the right you can see cystic mass with septations. Typical of a cystadenoma in a postmenopausal woman.

Ovarian fibromas are benign ovarian tumors, the size can range from microscopic to very large. They're usually hard, flat, chalky white surfaces that have whorled appearance. They may have calcifications and they may be bilateral. The absence of fat helps differentiate them from the other solid tumors which are called thecomas.

They're very similar sonographic to uterine fibroids because they have variable attenuation. They usually present as a hypoechoic mass with posterior acoustic shadowing.

And here's a nice case of a fibroma. This is a transvaginal study transverse view of the uterus. Endometrium is seen here and separate from the uterus is a solid mass and the mass could be separated or shown that it's separate from the mass by pushing with a transvaginal probe between the mass and the uterus showing that there's definite a separation between both of them. This was an ovarian fibroma.

He was another patient, a different patient transabdominal site presented with acute pain and this is a transabdominal view sagittal projection showing a mass posterior to the uterus. Transvaginal shows that the mass had no flow and here an MRI was done and this was torsion of a fibroma. And here is the pathologic specimen.

Ovarian Torsion

Ovarian torsion that's due to partial or complete rotation of the ovarian pedicle resulting in compromised blood supply. It's usually seen in premenopausal woman and usually associated with a cyst or benign tumors such as a dermoid. The reason it's not usually associated with malignant tumors is because malignant tumors usually are invading or have a reaction to the adjacent tissue and therefore preventing from torsion to occur.

Predisposing factors for ovarian torsion include hypermobile elongated tube or a mesosalpinx tube spasm or exercise adhesions.

Torsion is either with just the includes only the ovary, the tube, or both. 67% of ovarian adnexal torsion includes both the ovary in the tube. It's the fifth most common gynecological or surgical emergency. And usually the patient presents with severe pain, intense localized. It occasionally may be intermittent and in those it's usually due to partial rotation. These patient also present with anorexia nausea and vomiting.

The sonographic ultrasound is usually the initial study in patients who present with ovarian torsion. It is important to correctly identify the absence of torsion to allow conservative treatment. It is also very important to make the diagnosis as soon as possible so that the right surgery can be done. Early diagnosis is crucial.

And now what is customary to do in premenopausal woman is to do untwist the vascular pedicle despite necrotic appearance of the ovary surgery. And two and four to six weeks later return to surgery after the hemorrhage and edema has resolved. In postmenopausal women who are less likely to get ovarian torsion. Usually this treatment is oophorectomy.

The sonographic findings of ovarian torsion include a large ovary, a large ovary, I mean 23 to 44 cubic centimeters. The ovary can be echogenic with multiple small cystic areas aligning in the periphery. Right ovary is more likely to be involved and you because they feel that the sigmoid on the left protects the left ovary.

You may see a coexisting cystic solid or complex mass in 73% of the cases. It's less commonly seen in patients who have pelvic inflammatory disease, endometriosis or malignant neoplasm. And this is due to the in these cases it's felt that these patients have adhesions, therefore renders the ovaries immobile to torsion.

The identification or absence of flow can help make the diagnosis. Occasionally we'll see free fluid and identification of the twisted vascular pedicle can be very helpful. Comparing with a contralateral side is crucial in making this diagnosis, even though that identification of absent flow in the ovary can help you make the diagnosis, that's only seen in less than 50% of the cases. And the reason is that the ovary has dual supply, dual arterial supply.

So you may see flow within the ovary and still have ovarian torsion. As you can see in this study that was done, absent arterial venous flow was seen in 40% of the patients, but you could see normal arterial and venous flow and 7% of the patients. So there's a whole variety of flow patterns that can be seen in the presence of adnexal torsion.

But even though that color doppler is highly variable in patients with torsion, the absence of arterial blood flow is still seen in a significant percent of patients. Normal flow is seen in 60% of patients where, and that's due to the dual arterial supply and probably that due to venous thrombosis occurs before arterial obstruction. Absence of reversal diastolic flow has been described in these patients most frequently.

What we will see is either decrease or absence of venous flow first, and this is felt to represent a collapse of the venous wall, which probably occurs before arterial compromise a color flow doppler in ovarian torsion, the presence of flow does not allow exclusion of torsion suggests that the ovary may be viable, especially the flow is seen centrally. Absence of flow in a twisted vascular pedicle may indicate that a not viable ovary.

CT may even help when ultrasound findings are ambiguous by showing non-specific lack of enhancement, midline mass and possibly gas within the mass deviation of the uterus to the side of the affected ovary is frequently seen associated with a thickened fallopian tube and obliteration of the planes.

And here's a case of an ovarian torsion on the left and normal ovary showing flow within the ovary on the right markedly enlarged ovary echogenic center. And you can see in the periphery multiple cystic areas in this torsed ovary. Very important to compare one side from the other.

Ovarian Cancer

Ovarian cancer is the most frequent cause of death from gynecological malignancy. United States. 20,700 new cases per year are seen with ovarian cancers. 16,000 women will die with this disease this year. One in 17 women will develop ovarian cancer, which is less frequent than in breast cancer, which is one in eight.

The problem is that usually by the time the patient presents the tumor is advanced. The symptoms become apparent when the tumor compresses or invades the adjacent structures. As ascites develops or there's metastasis, 70% of these women will present with advanced disease and therefore the five year survival rates in these women is 15 to 20% compared to stage one, which is up to 90%.

And here you can see on your left a transvaginal study showing a large, complex mass solid and cystic components. Doppler shows low resistant waveform, increased diastolic flow. In this post-menopausal woman with an adnexal mass post-menopausal woman should not have a low resistant waveform, increased diastolic flow in any adnexal mass.

Another patient, and this is to show that morphology is the most important thing. This woman presented with a complex adnexal mass. Postmenopausal woman had a the mass had a solid component that had flow, but the flow within it was a high resistant flow. But the morphology is more important than the waveform. This was cancer until proven otherwise and it was an ovarian carcinoma.

Metastasis to the ovaries can also present and it's seen in 10 to 30% of ovarian malignancy. Most are postmenopausal females. Most common is from adenocarcinoma of the endometrium, but metastasis can also come from the breast. Gastrointestinal tract, 30 to 40% present with bilateral adnexal masses and metastasis can also be due to lymphoma or leukemia.

And here's in a case of an enlarged ovary with in a postmenopausal woman, no mass was seen, just the ovary was enlarged and had low resistant waveform with increased diastolic flow. This is abnormal. This was metastasis due to an adenocarcinoma of the endometrium.

Echogenic free fluid in a premenopausal woman may be due to ruptured hemorrhagic cysts, pelvic inflammatory disease or ectopic pregnancy. However, in the postmenopausal woman, when you see echogenic free fluid, you have to worry about malignancy even though you may not see the primary.

Non-Gynecological Causes of Pelvic Pain

Pelvic pain can also be due to non gynecological abnormalities. And these can arise from the bladder, urethra, ureter, bowel or other.

Bladder Abnormalities

In the bladder pain, patient can present with pain due to cystitis or infection. A cystitis can be due to infectious cystitis, interstitial or radiation cystitis. These women can present with severe pelvic pain. The predisposing factors of infectious cystitis are various and here are two different patients with cystitis.

On your left you can see a distended bladder with echogenic material and some echogenic foci representing gas. This was infected fluid within the bladder on your right, another patient which shows a thickened bladder wall, diffusely, thickened bladder wall, cystic areas within the bladder wall. This was due to radiation cystitis.

Bladder diverticuli can also cause pain and that's due to they can cause the urinary stasis which goes to become infected and become painful. Usually what you see an ultrasound, a well-defined fluid filled masses which can vary in size and disappear when the patient voids. In this case on your right a magnified view shows nicely the pedicle between the diverticuli and the bladder wall.

Bladder tumors which are more common in men than women, but women can present with bladder tumors can present also with pain. And here's a case a transabdominal study. On your top left shows a polypoid mass protruding into the bladder and on transvaginal you see the wall even better, the mass outlined by the bladder, the urine and here on color flow, lots of flow seen centrally and low resistant waveform on color flow. And this was a bladder tumor in a postmenopausal woman who presented with bleeding.

In a premenopausal woman. This is not the images are not very nice but I love this case. And this is a bladder, transabdominal bladder and we saw that in the base of the bladder there was this mass, the very smooth mass protruding into the bladder. And this was endometriosis in a premenopausal woman.

Another patient with endometriosis that I had recently. And we follow, this is the bladder, the wall is thin, it should be two millimeters and then all of a sudden you see focal thickening in the wall of the bladder. The wall, this is a transvaginal study too. Wall of the bladder and this was endometriosis, another patient bladder. And these two echogenic curvilinear echogenic structure was shadowing within the bladder. Here's the uterus and here's the bladder transvaginal. Studies show these curvilinear echoes. These were bladder calculi. Patient presented with pain.

Urethral and Ureteral Abnormalities

Patients can present with abnormalities in the urethra that can cause pain and they can be due to calculi cyst that are calculi or stenosis also calculi and the ureter can cause pain. So it's very important when you finish a transvaginal ultrasound and you're pulling out the transvaginal probe to look at the urethra. Many times we'll find the cause for the patient's symptoms.

Here we can see this was a transperineal study and you see the curved line shows you the vagina anterior to the vagina. You see the bladder and the urethra within the urethra. There's a curvilinear echogenic structure and this was a calculus within the urethra.

Another patient transperineal study. This is the vagina, this is the urethra cyst within the urethra. Bladder is here.

Anterior urethral diverticuli result from abscess formation in the periurethral ducts which can become congested, obstructed, infected and can also cause pain. And here's a patient in the urethra, the wall of the urethra. She had the cystic structure with increased flow. You see lots of flow within this, the surrounding the periphery of the cystic structure. And this was also an urethral diverticuli that was infected.

Transabdominal study shows a little echogenic structure right next to the wall was shadowing. We did transvaginal and we saw a dilated urethra and the calcifications or calculus were able to be identified. A different patient. Transvaginal ultrasound showed a dilated ureter. And then in the distal ureter the wall was very thick and increased flow was seen within the wall of the distal ureter. You could see lots of flow.

We did not see a stone in this case. This patient was treated with antibiotics and came back 10 days later and the distal ureter was back to normal size. We feel that maybe she passed a stone and this was inflammation of the distal ureter due to the recent passage of a calculus.

Bowel Abnormalities

Abnormalities in the bowel can also present as with pelvic pain masses in the bowel. For example, carcinoma polyps, abscesses, diverticular appendiceal abscesses, dilated loops of bowel due to obstruction or wall thickening of the bowel due to inflammatory or metastatic disease.

Here on your left normal distended loops of bowel on your right thickened wall of this loop of bowel secondary to ulcerative colitis. This was picked up on a transvaginal ultrasound.

Another case picked up on ultrasound was distended loops of bowel. When we did a transvaginal study, we saw that there was a mass in the pelvis. We inserted water into the rectum and we saw that the water delineated the mass which was within the wall off the sigmoid. This was a sigmoid tumor which was diagnosed on the transvaginal study but because we had seen distended loops of bowel, this is in the right lower quadrant, it's hard to see but you see a tubular structure, thickened wall and then you see next to it a round mass, heterogeneous in appearance. And this is the appendiceal abscess right where the patient was having pain. Right lower quadrant.

These are two transvaginal studies longitudinal and transverse. Another patient with appendicitis. And you can see here the appendix wall is very thickened and within the appendix you can see this, it's seen appendicolith is seen as an echogenic foci and here thickened wall and an abscess adjacent to it.

This are two transvaginal studies. Another patient presented with pelvic pain, huge, large, complex mass echogenic fluids around it. This was a large ruptured appendiceal abscess.

Two other patients. This is another patient you can see thickened wall. This was in the left lower quadrant, very thick bowel. The bowel was very thickened. And then you see this big heterogeneous mass adjacent to one of the walls. This was a diverticular abscess.

Another patient sort of ill-defined mass. In the left lower quadrant you see these echogenic structures within it. This is gas and this was a diverticular abscess, which unless you look for it carefully, it could be easily missed.

You can see that the wall is diffusely thickened of this loop of bowel and this was metastatic disease to the loop of bowel.

This is another patient presented with you see a loop of bowel. It looks normal until all of a sudden you come to one point. There's some thickening, focal thickening of this loop bowel. This is in longitudinal and this is the transverse view of the loop bowel. A hypoechoic mass seen interior wall. When you ask the patient, she'll gives you a history that she recently had a polypectomy. So this most likely we thought was a hematoma secondary to the recent polypectomy. The patient was brought back a couple weeks later and this was no longer visualized.

Vascular Abnormalities

Pelvic varices which are dilated incompetent ovarian veins may also cause pelvic pain and it's not sure why it's thought that it may be due to venous stasis which produces congestion and pain. Treatment for pelvic congestion syndrome include hormonal ovarian suppression, psychotherapy or oophorectomy ligation of ovarian veins and embolization of ovarian veins.

And here we can see a transvaginal study showing the uterus and the tubular structure. This is a normal vessel seen in the adnexa. These are abnormal vessels. These are varices. You can see the uterus adjacent to the uterus. There's all these cystic structures when you put flow. They're all vessels. These are veins, dilated veins. They're abnormal in their pelvic varices which can also cause pain.

Another patient presented with pelvic pain and when we did color we saw that this iliac vessel had a clot in it. This patient also had an adnexal mass and she had pelvic thrombophlebitis.

Another patient with pelvic pain had a thrombus within the pelvic vein and she had also deep vein thrombosis of her lower extremity which extended into the pelvic veins.

Other Non-Gynecological Causes

Also, pain can be due to abnormalities in the lymph nodes in the pelvis either due to inflammation, metastatic disease or lymphoma. As you can see in this case an enlarged pelvic lymph node secondary to lymphoma.

Also pelvic pain can be due to structures such as a pelvic kidney here. This patient did not know she had a pelvic kidney. On this transvaginal study, another patient had a transplanted kidney which was hydronephrotic causing pain.

Conclusion

In conclusion, evaluation of pelvic pain should be initiated with a pelvic ultrasound transabdominal and transvaginal to exclude gynecological and certain non gynecological pathology. Most women with normal pelvic ultrasound will improve with or without surgical intervention and further imaging is unlikely to yield positive results. However, if the ultrasound is limited, MRI or CT of the pelvis may be helpful.