INFERTILITY is defined as the inability to conceive after 12 months of unprotected sexual intercourse. In the lives of couples, there are very few things that are as emotionally charged as this topic.

Imaging is crucial in the diagnostic workup of women for infertility. There are several causes for infertility and imaging evaluation should take place after a clinical assessment. This article will focus on the pelvic causes, which range from tubal and peritubal abnormalities to uterine, cervical and ovarian abnormalities.

Hysterosalpingography (HSG) is usually the initial test that primarily evaluates patency of the fallopian tubes. Uterine filling defects and contour abnormalities may also be seen at HSG, but often require further imaging with Saline Infusion Sonography (SIS), pelvic ultrasonography or pelvic magnetic resonance imaging (MRI).

Cervical abnormalities may be seen during attempts at catheterisation for HSGs or SISs. Ovarian abnormalities are often seen at ultrasound.

FALLOPIAN TUBE ABNORMALITIES

Fallopian tube abnormalities are the most common cause of female infertility, accounting for 30 to 40 per cent of cases. HSGs allow depiction of tubal patency, tubal occlusion, tubal irregularity, and peritubal disease.

The differential diagnosis of tubal occlusion includes tubal spasm, infection, and prior surgery. Rare causes of occlusion include granulomatous salpingitis due to tuberculosis, intraluminal endometriosis, parasitic infection, and congenital blockage of the fallopian tubes.

If a proximal tubal occlusion is confirmed at HSG, selective salpingography and recanalisation may be performed. Hydrosalpinx occurs from distal tubal occlusion. It is most commonly caused from pelvic inflammatory disease. Tubal microsurgery is often needed in this case.

Tubal irregularity is caused from inflammatory conditions and is associated with pelvic inflammatory disease, ectopic pregnancy (pregnancy outside the womb), and infertility. Patients with this condition are offered in vitro fertilisation.

Both endometriosis and pelvic inflammatory disease may lead to peritubal adhesions with resultant infertility. MRI is useful for further evaluation of women with peritubal adhesions.

ENDOMETRIOSIS

In this condition, elements that make up the lining of the womb (endometrial glands and stroma) are found outside the womb. Approximately 30 to 50 per cent of women with endometriosis are infertile and 20 per cent of infertile women have endometriosis.

Imaging tests for endometriosis include pelvic ultrasound and MRI. Endometriosis may take the form of either small implants or cysts that change in size and appearance during the menstrual cycle. They can cause an inflammatory reaction, which leads to fibrosis and scarring.

Endometriotic cysts or endometriomas result from repeated haemorrhage within an implant. Ultrasound is not very sensitive for detection of endometriotic implants, but may detect endometrioma. They usually occur within both ovaries. MRI imaging is more sensitive and specific than ultrasound for the detection of endometriosis, but laparoscopy remains the gold standard.

INTRAUTERINE FILLING DEFECTS

Intrauterine filling defects seen at HSG may be caused by air bubbles, intrauterine adhesions, submucosal fibroids, endometrial polyps, or blood clots. Obtaining oblique views during a HSG can help to identify mobile filling defects, such as air bubbles and clots, but in general a saline infusion sonogram is performed for more detailed evaluation.

UTERINE SYNECHIAE

Intrauterine adhesions may occur because of previous pregnancy, dilation and curettage, surgery or infection. They appear as bright bands that traverse the endometrial cavity on SIS.

ENDOMETRIAL POLYPS AND SUBMUCOSAL FIBROIDS

Endometrial polyps or submucosal fibroids can interfere with transfer and implantation of the egg. Saline Infusion Sonograms can identify the number and location of these lesions, thus providing guidance for their removal.

UTERINE CONTOUR ABNORMALITIES

Common causes of uterine contour abnormalities include adenomyosis, uterine fibroids, and mullerian duct abnormalities.

Adenomyosis is characterised by the presence of ectopic endometrial glands within the muscular wall of the uterus with surrounding smooth muscle enlargement. Adenomyosis may cause impaired uterine contractility, which hampers the transportation of sperm through the uterine cavity. Submucosal adenomyosis may also impair implantation of the egg.

There is a strong association between adenomyosis and endometriosis in younger women. HSG, pelvic MRI or ultrasound may detect adenomyosis.

Uterine fibroids are the most common pelvic mass lesion and the most common cause of uterine enlargement in non-pregnant women. They can be identified at HSG by uterine enlargement, endometrial distortion, or filling defect. They can even obstruct the fallopian tube. The most common type of imaging is the pelvic ultrasound, but MRI is very sensitive and specific for detection of fibroids.

Mullerian duct abnormalities refer to structural abnormalities of the uterus and/or vagina as a result of developmental or fusion abnormalities of the mullerian ducts. There are seven classes of abnormality ranging from absence of the uterus and proximal vagina to abnormally, shaped uterus and fallopian tubes related to exposure to a particular drug called diethylstilbestrol (DES) while in the womb.

Cervical stenosis is defined as cervical narrowing that prevents the insertion of a 2.5-mm-wide dilator. The condition may be congenital or secondary to infection or trauma. Risk factors include previous cone biopsy, cryotherapy, laser treatment, and biopsy for cervical dysplasia. Cervical stenosis may cause obstruction to menstrual flow, with resulting amenorrhea, dysmenorrhea and potential infertility, due to inability of the sperm to enter the upper genital tract. Cervical stenosis may also impair assisted fertility techniques.

At HSG, cervical stenosis may appear as narrowing of the endocervical canal or obliteration of the cervical os. Cervical dilation relieves this problem.

Secondary ovarian causes of infertility include polycystic ovarian syndrome (PCOS), endometriosis and ovarian cancer. PCOS affects eight per cent of women and may be one of the most common causes of female infertility. Clinically, these women have excess male pattern hair distribution, obesity and irregular or absent periods. Up to 80 per cent of women with PCOS will have ovarian changes, which include increased ovarian volumes (>10 mls), increased numbers of peripheral follicles (>12), and increased brightness of the central portion of the ovary. Twenty to 30 per cent of the normal population will have ovaries with this appearance; therefore, clinical findings of the syndrome as well as blood tests showing increased levels of leutenizing hormone are necessary to make the diagnosis.

CLEARING BLOCKED TUBES

I bet you didn’t know that your radiologist could clear your blocked tubes.

Selective salpingography, a diagnostic procedure in which a small catheter directly opacifies the fallopian tube through the uterine ostium, has been used for the past 30 years to distinguish spasm from true obstruction.

In fallopian tube recanalisation, a catheter and guide wire system is used to clear proximal tubal obstruction. The procedure is successfully completed in 71 to 92 per cent of patients, and pregnancy rates after procedure average 30 per cent. The combination of selective salpingography and tubal recanalisation is now the gold standard for management of proximal tubal occlusion and is available in Kingston and Montego Bay.

Not every patient is a candidate for this procedure and some patients will have to have laparoscopy and surgical repair. Consultation with your gynaecologist and radiologist will determine your suitability for this procedure.

Dr Duane Chambers is a consultant radiologist and founding partner of Imaging and Intervention Associates located at shops 58 and 59 Kingston Mall, 8 Ocean Boulevard. He may be contacted through the office numbers 618-4346 or 967-7748.