DOI: 10.1148/rg.236025115
(Radiographics. 2003;23:1401-1421.)
© RSNA, 2003
MR Imaging of Disorders Associated with Female Infertility: Use in Diagnosis, Treatment, and Management1
Izumi Imaoka, MD,
Akihiko Wada, MD,
Michimasa Matsuo, MD,
Masumi Yoshida, MD,
Hajime Kitagaki, MD and
Kazuro Sugimura, MD
1 From the Departments of Radiology (I.I., A.W., M.M.) and Obstetrics and Gynecology (M.Y.), Tenri Hospital, 200 Mishima, Tenri, Nara 632-8552, Japan; the Department of Radiology, Shimane Medical University, Izumo, Japan (H.K.); and the Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Japan (K.S.). Presented as an education exhibit at the 2001 RSNA scientific assembly. Received July 1, 2002; revision requested August 22; final revision received May 9, 2003; accepted May 12. Address correspondence to I.I. (e-mail: iizumi@tenriyorozu-hp.or.jp).
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Abstract
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Magnetic resonance (MR) imaging has extended the usefulness of imaging in evaluation of pelvic disorders associated with female infertility. The causes of female infertility include ovulatory disorders (ie, pituitary adenoma and polycystic ovarian syndrome), disorders of the fallopian tubes (ie, hydrosalpinx and pelvic inflammatory disease), uterine disorders (ie, müllerian duct anomaly, adenomyosis, and leiomyoma), and pelvic endometriosis. Although laparoscopy, hysteroscopy, hysterosalpingography, and transvaginal ultrasonography are the most effective techniques for evaluation of pelvic disorders related to female infertility, MR imaging is used in a variety of clinical settings in diagnosis, treatment, and management. The applications of MR imaging include evaluation of the functioning uterus and ovaries, visualization of pituitary adenomas, differentiation of müllerian duct anomalies, and accurate noninvasive diagnosis of adenomyosis, leiomyoma, and endometriosis. In addition, MR imaging helps predict the outcome of conservative treatment for adenomyosis, leiomyoma, and endometriosis and may lead to selection of better treatment plans and management. Finally, MR imaging may serve as an adjunct to diagnostic laparoscopy and hysterosalpingography in patients with hydrosalpinx, peritubal adhesions, or pelvic adhesions related to endometriosis.
© RSNA, 2003
Index Terms: Endometriosis, 85.3192 • Fallopian tubes, abscess, 853.2174 • Fallopian tubes, stenosis or obstruction, 853.2172 • Fertility • Genitourinary system, 85.92 • Leiomyoma, 854.315 • Ovary, cysts, 852.3129 • Pituitary, neoplasms, 145.372 • Uterine neoplasms, 854.315 • Uterus, abnormalities, 854.1478
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LEARNING OBJECTIVES FOR TEST 2
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After reading this article and taking the test, the reader will be able to:
- Describe the clinical features of diseases associated with female infertility.
- Discuss the values of imaging modalities in diagnosis, treatment, and management of female infertility.
- Identify the MR imaging features of diseases associated with female infertility.
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Introduction
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Infertility is defined as 1 year of unprotected intercourse that does not result in pregnancy (1,2). In recent years, demand for infertility services and treatment of infertility have increased. Laparoscopy, hysteroscopy, and hysterosalpingography are the most effective techniques currently used to evaluate female pelvic disorders related to infertility. Although transvaginal ultrasonography (US) has been the foremost imaging modality for assessing the female genital tract, magnetic resonance (MR) imaging has also been used for over 10 years to evaluate problems associated with female infertility (3). For example, MR imaging is well known to provide accurate information for differentiation of congenital uterine anomalies and detection and localization of uterine leiomyomas (3,4).
One of the advantages of MR imaging is the nonuse of ionizing radiation, which is an important consideration in women of reproductive age. Another advantage is that MR imaging is less invasive and less observer dependent than the classic imaging techniques. Furthermore, recent advances in MR imaging with the phased-array coil have created further imaging possibilities, resulting in excellent spatial and tissue contrast resolution, multiplanar capability, and fast techniques. The disadvantages of MR imaging are relatively high cost and long examination time; it is contraindicated in patients with pacemakers, cochlear implants, and certain metallic objects.
In this article, we provide an overview of the capabilities and potential of MR imaging for diagnosis, treatment, and management of female infertility. Of the various causes of female infertility, ovulatory disorders (ie, pituitary tumor and polycystic ovarian syndrome), disorders of the fallopian tubes (ie, hydrosalpinx and pelvic inflammatory disease), uterine disorders (ie, müllerian duct anomaly, adenomyosis, and leiomyoma), and pelvic endometriosis are specifically discussed.
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MR Imaging Technique
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It is recommended that an antiperistaltic (eg, 1 U.S. Pharmacopeia unit of glucagon or 20 mg of scopolamine butylbromide) be administered intramuscularly or intravenously before examination.
MR imaging was performed with a 1.5-T unit (Vision and Symphony, Siemens Medical Systems, Erlangen, Germany; Signa, GE Medical Systems, Milwaukee, Wis) with a phased-array coil. T2-weighted fast spin-echo images (repetition time msec/echo time [effective] msec = 3,000–5,000/80–120, echo train length of eight to 16, two signals acquired) were obtained in the sagittal and axial planes. T2-weighted images provide the most detailed information about the uterine zonal anatomy (see the Normal Anatomy section for details). Images obtained in the coronal or perpendicular planes relative to the long uterine axis may be useful adjuncts for assessment of the uterine cavity.
T1-weighted spin-echo images (repetition time/echo time = 330–600/10–20, one to two signals acquired) were obtained in the axial or sagittal plane. T1-weighted images help characterize hemorrhage since extracellular methemoglobin causes T1 shortening. In addition, T1-weighted images obtained with a selective chemical fat-suppression technique are especially useful for detecting hemorrhagic adnexal masses (5–7) and should be obtained routinely in patients with infertility. There is no need to use intravenous contrast material (0.1 mmol/kg of gadolinium chelate) for routine infertility assessment. However, contrast material–enhanced studies are useful in selected cases, such as pelvic inflammatory disease, evaluation of vascularity in uterine leiomyoma, and detection of malignancy in an adnexal mass.
Other parameters included matrix size of 192–256 x 256–512, field of view appropriate to body habitus (22–26 cm), and 5–7-mm section thickness with an intersection gap of 20%.
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Normal Anatomy
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Reproductive-Age Women
Uterine zonal anatomy is exquisitely demonstrated on T2-weighted images (Fig 1). The endometrium has high signal intensity. The junctional zone, which corresponds to the innermost myometrium, appears as a band of low signal intensity. The peripheral myometrium has intermediate signal intensity that is higher than that of the striated muscle. The widths of the endometrium and junctional zone vary during the menstrual cycle; they are widest and most clearly visible in the late secretory phase. The uterine corpus is larger than the cervix throughout the reproductive-age period. In general, the corpus measures 6–8 cm in length by 5–6 cm in the transverse and anteroposterior dimensions (8).
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Figure 1. Normal uterus in a woman of reproductive age. Sagittal T2-weighted image of the uterus shows the endometrium (E), junctional zone (short arrows), and myometrium (M). It also shows the epithelium (arrowhead), fibrous stroma (long arrow), and peripheral myometrium (m) of the cervix.
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The cervix also shows zonal architecture on T2-weighted images. The central area of high signal intensity represents epithelium and mucus, the middle area of low signal intensity represents fibrous stroma, and the outer area of medium signal intensity represents peripheral myometrium. The vaginal wall has low signal intensity on T2-weighted images. The texture of the ovaries is clearly imaged in women of reproductive age, that is, the ovaries display hypointense stroma with hyperintense follicles on T2-weighted images. Normal fallopian tubes are not routinely imaged because of their small diameter and tortuous course.
On T1-weighted images, the normal pelvic musculature and viscera demonstrate homogeneous low to medium signal intensity.
Postmenopausal Women
After menopause, the uterine corpus becomes smaller and approximately equal in size to the cervix. It measures 4–6 cm in length by 3–5 cm in the transverse and anteroposterior dimensions (8). The zonal anatomy is indistinct when women are not receiving exogenous hormones (Fig 2). Although the cervix does not atrophy significantly, the peripheral myometrium is usually unclear. Ovaries may be undetected at MR imaging since they seldom have follicles.
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Figure 2. Postmenopausal uterus. Sagittal T2-weighted image shows a small uterine corpus that is almost the same size as the cervix (arrows). The zonal anatomy of the corpus is indistinct.
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When a woman of reproductive age has a small uterus with indistinct zonal anatomy or undetectable ovaries, as seen in postmenopausal women, the possibility of a disorder related to insufficient hormone secretion should be considered (Fig 3).
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Figure 3. Atrophic uterus in a 23-year-old woman with amenorrhea. She had been treated with carcinostatic agents for a brain tumor, and there was clinical suspicion that those medications caused ovarian failure and concomitant uterine atrophy. Sagittal T2-weighted image shows a small uterus, a finding suggestive of insufficient hormone secretion in a reproductive-age woman. Arrow = nabothian cyst. (Reprinted, with permission, from reference 50.)
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Ovulatory Dysfunction
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Disorders affecting ovulation account for 30%–40% of cases of female infertility (1). Measures of ovarian function include measurement of basal body temperature, endometrial biopsy, measurement of serum progesterone level, endocrine tests, and monitoring of follicle growth with US. Thus, the role of MR imaging is limited to assessment of whether a pituitary adenoma is present.
Pituitary Adenoma
Prolactin-producing hypophyseal adenoma (prolactinoma) is the most common functional pituitary adenoma. Its prevalence peaks in women between 20 and 30 years of age. Hyperprolactinemia can be a cause of infertility and is associated with diminished gonadotropin secretion, secondary amenorrhea, and galactorrhea. The patient should first be examined for drug-induced hyperprolactinemia before any infertility work-up is initiated. For example, antidepressants, cimetidine, dopamine antagonists, reserpine, sulpiride, verapamil, methyldopa, and estrogen therapy are known to interfere with prolactin secretion.
When a patient is suspected to have hyperprolactinemia not associated with drugs, MR imaging is the foremost and only imaging technique that can depict a pituitary microadenoma (
1 cm) (Fig 4). Most microadenomas have lower signal intensity than the normal pituitary gland on T1-weighted images. A convex outline of the pituitary gland or deviation of the pituitary stalk can also be detected. Dynamic study with intravenous bolus injection of contrast medium is the preferred technique for assessing microadenomas, as it allows excellent delineation between the tumor and the normal pituitary gland. In the dynamic study, the normal pituitary gland and stalk show strong enhancement in the early phase of dynamic imaging, whereas microadenomas show relatively weak enhancement (9,10).
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Figure 4a. Pituitary microadenoma. (a) Coronal T1-weighted image shows a pituitary gland that is not enlarged. (b) Coronal T1-weighted image obtained after intravenous bolus injection of contrast material shows a mass with decreased enhancement (arrow) in the pituitary gland.
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Figure 4b. Pituitary microadenoma. (a) Coronal T1-weighted image shows a pituitary gland that is not enlarged. (b) Coronal T1-weighted image obtained after intravenous bolus injection of contrast material shows a mass with decreased enhancement (arrow) in the pituitary gland.
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Macroadenomas (>1 cm) occupy the pituitary fossa and may cause visual abnormalities when they put pressure on the optic chiasm. Macroadenomas also tend to invade the cavernous sinus and erode the bony floor. The extent of the tumor can be determined by means of contrast-enhanced MR imaging (Fig 5).
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Figure 5a. Pituitary macroadenoma. Coronal unenhanced (a) and contrast-enhanced (b) T1-weighted images show a macroadenoma (arrowheads), which occupies the pituitary fossa and invades the left cavernous sinus (arrow).
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Figure 5b. Pituitary macroadenoma. Coronal unenhanced (a) and contrast-enhanced (b) T1-weighted images show a macroadenoma (arrowheads), which occupies the pituitary fossa and invades the left cavernous sinus (arrow).
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Polycystic Ovarian Syndrome
The diagnosis of polycystic ovarian syndrome is based on hormone imbalance and laboratory findings. Patients with this syndrome often demonstrate an abnormal ratio of luteinizing hormone to follicle-stimulating hormone. The clinical manifestations include hirsutism, anovulation, and infertility. At gross pathologic analysis, the morphologic findings in the ovaries consist of multiple small follicular cysts surrounded by thickened and luteinized theca.
Monitoring of follicle growth is usually performed with US, and the usefulness of MR imaging is not proved. On T2-weighted images, polycystic ovarian syndrome appears as multiple tiny, hyperintense peripheral cysts with hypointense central stroma (Fig 6) (11,12). However, MR imaging findings are nonspecific and serve only as supportive evidence of polycystic ovarian syndrome. Multiple tiny, hyperintense peripheral cysts have been seen in patients with anovulation, medication-stimulated ovulation, or vaginal agenesis (12).
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Figure 6. Polycystic ovarian syndrome. Axial T2-weighted image shows multiple tiny, hyperintense peripheral cysts (arrows) in the left ovary. The central stroma appears as a hypointense area (arrowhead). U = uterus. (Reprinted, with permission, from reference 50.)
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Disorders of the Fallopian Tubes
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Disorders of the fallopian tubes are a common cause of female infertility, accounting for 30%–40% of cases (1). Tubal disorders include damage to or obstruction of the fallopian tube and peritubal adhesions. Hysterosalpingography is the mainstay of evaluation of tubal patency, whereas laparoscopy is preferred for assessment of the peritubal environment. MR imaging aids in noninvasive assessment of tubal dilatation and peritubal disease. Dilated fallopian tubes manifest as fluid-filled ducts, which appear as retort-, sausage-, C-, or S-shaped cystic masses at MR imaging (Fig 7). Thin, longitudinally oriented folds along the interior of the tube represent incompletely effaced mucosal or submucosal plicae (13).
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Figure 7a. Hydrosalpinx. Axial T2-weighted (a) and contrast-enhanced fat-suppressed T1-weighted (b) images show a cystic mass of the left adnexa (arrow). The mass has a folded (arrowheads) and tortuous appearance. Therefore, it was diagnosed as a fluid-filled dilated fallopian tube.
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Figure 7b. Hydrosalpinx. Axial T2-weighted (a) and contrast-enhanced fat-suppressed T1-weighted (b) images show a cystic mass of the left adnexa (arrow). The mass has a folded (arrowheads) and tortuous appearance. Therefore, it was diagnosed as a fluid-filled dilated fallopian tube.
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Pelvic inflammatory disease is one of the most common causes of tubal or peritubal damage. The diagnosis is usually based on clinical or transvaginal US findings. MR imaging can also be helpful in assessment of pelvic inflammatory disease by showing tubo-ovarian abscesses, dilated fluid-filled tubes, and free pelvic fluid (Fig 8) (14). On T1-weighted images, a high-signal-intensity rim in the innermost portion of a tubo-ovarian abscess has been reported. This rim shows marked enhancement on postcontrast images and is believed to correspond to granulation tissue admixed with hemorrhage (15).
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Figure 8a. Tubo-ovarian abscess. Axial T2-weighted (a) and contrast-enhanced fat-suppressed T1-weighted (b) images show a tortuous mass of the right adnexa. The mass consists of an ovarian abscess (short arrow) and hydrosalpinx (arrowheads), which demonstrate marked perilesion enhancement. Adenomyosis is incidentally seen in the posterior myometrium (long arrow).
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Figure 8b. Tubo-ovarian abscess. Axial T2-weighted (a) and contrast-enhanced fat-suppressed T1-weighted (b) images show a tortuous mass of the right adnexa. The mass consists of an ovarian abscess (short arrow) and hydrosalpinx (arrowheads), which demonstrate marked perilesion enhancement. Adenomyosis is incidentally seen in the posterior myometrium (long arrow).
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Endometriosis also causes peritubal adhesions. As discussed later, transvaginal US is the preferred imaging technique for endometriosis and demonstrates high specificity, but MR imaging is more sensitive. Moreover, dilated fallopian tubes with high signal intensity on T1-weighted images, which correspond to hematosalpinx, reportedly correlate with one of the effects of endometriosis (Fig 9) (13). Nevertheless, MR imaging is as yet of little use in assessment of adhesions.
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Figure 9a. Hematosalpinx associated with endometriosis. Sagittal fat-suppressed T1-weighted (a) and T2-weighted (b) images show a dilated fallopian tube with a folded appearance (arrow). It has high signal intensity on both images and was diagnosed as a hematosalpinx. On the fat-suppressed T1-weighted image (a), a small endometrioma is seen as a tiny hyperintense lesion (arrowhead) on the surface of the hematosalpinx. B = bladder. (Reprinted, with permission, from reference 50.)
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Figure 9b. Hematosalpinx associated with endometriosis. Sagittal fat-suppressed T1-weighted (a) and T2-weighted (b) images show a dilated fallopian tube with a folded appearance (arrow). It has high signal intensity on both images and was diagnosed as a hematosalpinx. On the fat-suppressed T1-weighted image (a), a small endometrioma is seen as a tiny hyperintense lesion (arrowhead) on the surface of the hematosalpinx. B = bladder. (Reprinted, with permission, from reference 50.)
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Uterine Disorders
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Müllerian Duct Anomalies
If other causes of infertility are excluded, uterine anomalies may be suggested as a cause of infertility. On the other hand, unknown numbers of uterine anomalies may escape detection since reproductive ability is often unaffected or not noticeably affected (16).
Müllerian duct anomalies are classified according to the system established by the American Fertility Society (17) (Fig 10). MR imaging is useful for documenting uterine morphology. As mentioned earlier, coronal or perpendicular planes relative to the long uterine axis may provide useful information for assessment of the uterine cavity. The kidney should also be evaluated, since renal anomalies (ie, agenesis or ectopia) frequently accompany müllerian duct anomalies because of the close embryogenic relationship.
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Figure 10. American Fertility Society classification of müllerian duct anomalies. DES = diethylstilbestrol, * = uterus may be normal or take a variety of abnormal forms, ** = may have two distinct cervices. (Reprinted, with permission, from reference 17.)
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Class I: Hypoplasia or Agenesis.—
Failure of normal development of the müllerian ducts causes uterine agenesis or hypoplasia. Patients present with primary amenorrhea in adolescence. In these cases, disorders of sexual differentiation should be excluded (18,19). It is necessary to document whether a functioning uterine corpus and cervix are present. For instance, a functioning uterine corpus and cervix could predict future fertility, but a functioning corpus without a cervix requires hysterectomy to prevent endometriosis.
Mayer-Rokitansky-Küster-Hauser syndrome is a combined anomaly that belongs to this entity. The typical form of this syndrome is characterized by congenital absence of the uterus and upper vagina. The ovaries and fallopian tubes are usually normal. The atypical form of the syndrome includes associated abnormalities of the ovaries and fallopian tubes and renal anomalies (Fig 11) (20).
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Figure 11a. Mayer-Rokitansky-Küster-Hauser syndrome in a woman with primary amenorrhea. B = bladder. (a) Sagittal T2-weighted image shows uterine agenesis and absence of the vagina. (b) Coronal image obtained with true fast imaging with steady-state precession shows agenesis of the left kidney. Note the normal right ovary with follicles (arrow). Arrowheads = right kidney.
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Figure 11b. Mayer-Rokitansky-Küster-Hauser syndrome in a woman with primary amenorrhea. B = bladder. (a) Sagittal T2-weighted image shows uterine agenesis and absence of the vagina. (b) Coronal image obtained with true fast imaging with steady-state precession shows agenesis of the left kidney. Note the normal right ovary with follicles (arrow). Arrowheads = right kidney.
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Class II: Unicornuate.—
Agenesis of a unilateral müllerian duct causes a single, so-called banana-shaped uterus with a single fallopian tube. On T2-weighted images, normal zonal anatomy is observed in a small uterus (Fig 12).
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Figure 12a. Unicornuate uterus. Serial axial T2-weighted images (a obtained at a higher level than b) show a small uterus (arrow) with normal zonal anatomy. A rudimentary horn is not present. Arrowhead = right ovary.
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Figure 12b. Unicornuate uterus. Serial axial T2-weighted images (a obtained at a higher level than b) show a small uterus (arrow) with normal zonal anatomy. A rudimentary horn is not present. Arrowhead = right ovary.
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Some patients have a rudimentary horn on the contralateral side. When the rudimentary horn is noncommunicating, endometrial tissue expelled retrogradely through the fallopian tube during menstruation results in an increased frequency of endometriosis (21). This makes surgical resection of the horn necessary.
Spontaneous abortion and premature labor may occur in pregnancies with a unicornuate uterus, and the poorest fetal survival among all uterine anomalies has been reported (16).
Class III: Didelphus.—
Complete failure of fusion of the two müllerian ducts results in two complete uteri, each with its own cervix. T2-weighted images demonstrate two uterine horns or bodies with normal zonal anatomy (Fig 13). A longitudinal sagittal vaginal septum is usually, but not always, observed.
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Figure 13a. Uterus didelphys with an obstructed hemivagina. (a) Axial T2-weighted image shows two separate uteri and two cervices (arrows), all of which have normal zonal anatomy. Arrowheads = ovaries. (b) Coronal T2-weighted image shows a hematocele (H) due to obstruction of the right hemivagina. (c) Contrast-enhanced computed tomographic (CT) scan shows agenesis of the right kidney. Uterus didelphys with an obstructed hemivagina is termed Wunderlich syndrome and is usually associated with ipsilateral renal agenesis. (Reprinted, with permission, from reference 50.)
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Figure 13b. Uterus didelphys with an obstructed hemivagina. (a) Axial T2-weighted image shows two separate uteri and two cervices (arrows), all of which have normal zonal anatomy. Arrowheads = ovaries. (b) Coronal T2-weighted image shows a hematocele (H) due to obstruction of the right hemivagina. (c) Contrast-enhanced computed tomographic (CT) scan shows agenesis of the right kidney. Uterus didelphys with an obstructed hemivagina is termed Wunderlich syndrome and is usually associated with ipsilateral renal agenesis. (Reprinted, with permission, from reference 50.)
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Figure 13c. Uterus didelphys with an obstructed hemivagina. (a) Axial T2-weighted image shows two separate uteri and two cervices (arrows), all of which have normal zonal anatomy. Arrowheads = ovaries. (b) Coronal T2-weighted image shows a hematocele (H) due to obstruction of the right hemivagina. (c) Contrast-enhanced computed tomographic (CT) scan shows agenesis of the right kidney. Uterus didelphys with an obstructed hemivagina is termed Wunderlich syndrome and is usually associated with ipsilateral renal agenesis. (Reprinted, with permission, from reference 50.)
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Among all uterine anomalies, uterus didelphys is associated with the highest possibility of successful pregnancy, except for arcuate uterus (16).
Class IV: Bicornuate.—
Partial fusion of two müllerian ducts results in a bicornuate uterus with one cervix. The external uterine contour is concave or heart shaped, and the uterine horns are widely divergent. The MR imaging diagnostic criteria for bicornuate uterus are as follows: (a) divergent uterine horns with an intercornual distance exceeding 4 cm and (b) concavity of the fundal contour or an external fundal cleft more than 1 cm deep (Fig 14) (22).
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Figure 14. Bicornuate uterus. Axial T2-weighted image shows two endometrial cavities and one cervix. The external uterine contour is concave (short arrow) with a large intercornual distance (arrowheads). Long arrows = nabothian cysts.
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Class V: Septate.—
Septate uterus results from failure of resorption of a septum after complete fusion of the müllerian ducts. The septum may be a combination of both fibrous tissue and muscle. A fibrous septum is demonstrated as low signal intensity on T2-weighted images (Fig 15), whereas a septum composed of abundant muscular tissue shows intermediate signal intensity.
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Figure 15. Septate uterus. Axial T2-weighted image shows a normal external uterine contour (arrowheads). A thin fibrous septum is seen in the uterine cavity (arrow). (Reprinted, with permission, from reference 50.)
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The external uterine contour is normally convex, flat, or minimally indented by less than 1 cm (22), in contrast to that of a bicornuate uterus. T2-weighted images taken along a "true" coronal view of the uterine body and perpendicular to the long axis of the uterus provide exact images of the uterine contour and septum. This helps in differentiation of bicornuate from septate uterus.
Most patients evaluated for repeated abortions and found to have a uterine anomaly will have a septate uterus (16). Metroplasty is a surgical procedure used for treatment of this anomaly and may enhance fetal survival, with one report indicating that 95% of patients became pregnant, 73% carried to term, and 77% delivered a liveborn baby (23).
Class VI: Arcuate.
Arcuate uterus should be considered a normal variant, with a small indentation of the fundal endometrial canal and a normal external contour. It has no effect on fertility.
Class VII: Diethylstilbestrol Related.—
Diethylstilbestrol is a synthetic estrogen that was used to prevent miscarriage in the 1940s to 1970s (24). Exposure of the female fetus to diethylstilbestrol results in uterine anomalies including T-shaped uterus, irregular constrictions, and hypoplasia. At the site of constriction, localized thickening of the junctional zone is seen on T2-weighted images (22).
Diethylstilbestrol-related anomalies are associated with an increased rate of spontaneous abortions, preterm deliveries, and ectopic pregnancies.
Adenomyosis
Adenomyosis is not a common cause of infertility. The frequency of symptomatic adenomyosis peaks between the ages of 35 and 50 years, and it is most often found in parous women (25). However, nulligravid women are sometimes affected and experience infertility. The exact reasons for infertility in patients with adenomyosis remain unclear, although an enlarged uterus may be associated with reduced uterine or endometrial receptivity.
Both transvaginal US and MR imaging allow accurate, noninvasive diagnosis of adenomyosis. The relevant diagnostic US findings are (a) thickening and asymmetry of the anterior or posterior uterine walls and (b) a poorly defined area of decreased or increased echogenicity, heterogeneous echotexture, or a myometrial cyst. The MR imaging criteria include (a) a myometrial mass of low signal intensity with indistinct margins on both T1- and T2-weighted images and (b) diffuse or focal widening of the junctional zone on T2-weighted images. A junctional zone thickness of 12 mm or more optimizes the accuracy of MR imaging for this diagnosis (26). Punctate high-signal-intensity foci, which correspond to ectopic endometrium, are often demonstrated on T2-weighted images (Fig 16). One study found that MR imaging has higher sensitivity than transvaginal US (88% vs 53%) (26), whereas another found that MR imaging is as accurate as transvaginal US with a sensitivity of 86% and specificity of 89% (27).
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Figure 16. Adenomyosis. Sagittal T2-weighted image shows an enlarged uterus. An ill-defined myometrial lesion of decreased signal intensity is seen in the fundus, along with multiple small hyperintense foci (arrowheads). Arrows = nabothian cysts.
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Traditionally, hysterectomy has been the mainstay of treatment for adenomyosis. Medical therapy including gonadotropin-releasing hormone (GnRH) analog can be a conservative treatment option, which may provide symptomatic relief and preserve fertility. In patients with adenomyosis undergoing GnRH analog therapy, monitoring with MR imaging has demonstrated a significant decrease in junctional zone width and number of high-signal-intensity foci (28). The interface between adenomyosis and myometrium became more discrete with a concomitant reduction of the junctional zone in some cases (Fig 17). Diffuse adenomyosis with asymmetric widening of the junctional zone and punctate hyperintense foci tended to show this change, indicating the possibility of enucleating "shrunken adenomyosis" (28).
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Figure 17a. Adenomyosis treated with GnRH analog. (a) Sagittal T2-weighted image obtained before treatment shows adenomyosis in the posterior myometrium (arrows) with punctate hyperintense foci. (b) Sagittal T2-weighted image obtained after GnRH analog therapy shows that the lesion (arrows) is significantly smaller. The interface between the lesion and the myometrium is more discrete. (c) Sagittal T2-weighted image obtained 1 year after the end of treatment shows that the lesion (arrows) has returned to its pretherapy appearance.
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Figure 17b. Adenomyosis treated with GnRH analog. (a) Sagittal T2-weighted image obtained before treatment shows adenomyosis in the posterior myometrium (arrows) with punctate hyperintense foci. (b) Sagittal T2-weighted image obtained after GnRH analog therapy shows that the lesion (arrows) is significantly smaller. The interface between the lesion and the myometrium is more discrete. (c) Sagittal T2-weighted image obtained 1 year after the end of treatment shows that the lesion (arrows) has returned to its pretherapy appearance.
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Figure 17c. Adenomyosis treated with GnRH analog. (a) Sagittal T2-weighted image obtained before treatment shows adenomyosis in the posterior myometrium (arrows) with punctate hyperintense foci. (b) Sagittal T2-weighted image obtained after GnRH analog therapy shows that the lesion (arrows) is significantly smaller. The interface between the lesion and the myometrium is more discrete. (c) Sagittal T2-weighted image obtained 1 year after the end of treatment shows that the lesion (arrows) has returned to its pretherapy appearance.
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However, as with much of the treatment for uterine leiomyoma, the effect of medical therapy is not permanent because the disease course is reversed when treatment is discontinued. MR imaging clearly demonstrates the recurrent disease (Fig 17) (29).
Leiomyoma
Uterine leiomyoma, especially submucous leiomyoma, may be associated with pregnancy loss rather than infertility. Although leiomyoma is an infrequent cause of infertility, there may be some interference with sperm transport or implantation as a result of distortion, an increased surface area within the uterine cavity, or impingement by the leiomyoma on the endocervical canal or interstitial portion of the fallopian tube (30).
For identification of leiomyomas, transvaginal US can be a reliable method. A recent report states that transvaginal US is as effective as MR imaging for detection but that MR imaging outperforms transvaginal US in preoperative evaluation of location, number, and size of leiomyomas (31). Sonohysterography also clearly demonstrates the relationship between the endometrium and submucosal leiomyomas and thus serves as an important adjunct to transvaginal US (32). The diagnostic MR imaging finding for leiomyoma is a sharply marginated mass that typically has lower signal intensity than the myometrium on T2-weighted images (Fig 18). In addition, MR imaging is a highly accurate modality for differentiating leiomyomas from adenomyosis in cases of enlarged uterus, with a reported accuracy of 99% (33). Treatment options for leiomyoma include hysterectomy, myomectomy, medical hormonal therapy, and uterine artery embolization (UAE), whereas adenomyosis is usually treated with hysterectomy or medical hormonal therapy. For this reason, exact differentiation between leiomyoma and adenomyosis is important for patients who wish to preserve the uterus.
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Figure 18. Uterine leiomyomas. Sagittal T2-weighted image shows multiple uterine leiomyomas, including lesions with submucosal (M) and intramural (m) locations. Leiomyomas usually appear as sharply marginated hypointense masses on T2-weighted images, in contrast to adenomyosis (cf Fig 16). Arrows = nabothian cysts.
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At MR imaging, leiomyomas can demonstrate various signal intensities depending on the type of degeneration. Hyalinization is the most common type and is seen as low signal intensity on T2-weighted images. Edema is also a common histopathologic finding and shows high signal intensity on T2-weighted images with marked enhancement. Cystic degeneration appears as distinct, round areas of low signal intensity on T1-weighted images and high signal intensity on T2-weighted images and lacks enhancement (34,35). Myxoid degeneration appears as a cystic mass filled with gelatinous material and has high signal intensity on T2-weighted images. Myxoid stroma contributes to delayed enhancement. Red degeneration is a kind of hemorrhagic infarction; it appears as a peripheral rim of high signal intensity on T1-weighted images and of low signal intensity on T2-weighted images and completely lacks enhancement (35).
Myomectomy is a surgical procedure for patients who hope to preserve fertility. The reported rate of successful conception after myomectomy was 59.5% for patients with leiomyoma-associated infertility when there was no other apparent cause of infertility (36). A US study of uterine remodeling after myomectomy revealed a gradual decrease in uterine volume in the 6 months after the procedure, with the most remarkable change occurring in the initial 2–3 months (37). In an MR imaging study, the most remarkable uterine change occurred 1 month after myomectomy and consisted of a reduction in uterine volume and a proportionally normal zonal anatomy (38). Changes continued to be observed 6 months after the procedure. MR imaging also clearly demonstrated a postmyomectomy uterine scar, intramural hematoma, and disease recurrence (Fig 19) (38).
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Figure 19a. Uterine leiomyoma treated with myomectomy. (a) Sagittal T2-weighted image obtained before myomectomy shows a submucosal leiomyoma (arrow) in the anterior wall of the uterus. (b) Sagittal T2-weighted image obtained 6 months after myomectomy shows that the thickness of the myometrium has become normal. The transverse postoperative scar is seen as a low-signal-intensity line in the anterior myometrium (arrowhead).
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Figure 19b. Uterine leiomyoma treated with myomectomy. (a) Sagittal T2-weighted image obtained before myomectomy shows a submucosal leiomyoma (arrow) in the anterior wall of the uterus. (b) Sagittal T2-weighted image obtained 6 months after myomectomy shows that the thickness of the myometrium has become normal. The transverse postoperative scar is seen as a low-signal-intensity line in the anterior myometrium (arrowhead).
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UAE is gaining attention as a possible treatment for symptomatic leiomyoma. It is a relatively new method, and patients who wished to maintain fertility were usually excluded from the initial studies. It appears to be effective for improving menorrhagia, pelvic pain, and pelvic pressure in 96%–100% of patients (39,40). The average reduction in volume of the uterus and leiomyomas was 34%–55% after 3–4 months of UAE (40,41).
The MR imaging findings of leiomyomas after UAE are high signal intensity on T1-weighted images and homogeneous low signal intensity on T2-weighted images. It is thought that leiomyomas become infarcted shortly after UAE and that hemorrhagic necrosis and blood breakdown products are responsible for these signal intensity changes (42,43). At contrast-enhanced imaging, the vascularity of leiomyomas is seen to significantly diminish after UAE (41,43), although myometrial perfusion is maintained (Fig 20). In studies of UAE, 150–250-µm-diameter polyvinyl alcohol particles became lodged in arteries with a diameter of 1–2 mm, whereas arterioles were not blocked by the injected particles. Thus, the arterioles spared from the direct effect of the particles may supply the myometrium (41,44).
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Figure 20a. Uterine leiomyomas treated with UAE. (a-c) Sagittal T1-weighted (a), T2-weighted half-Fourier single-shot turbo spin-echo (b), and contrast-enhanced T1-weighted (c) images obtained before UAE show three uterine leiomyomas (arrows in b and c). (d-f) Corresponding images obtained 3 months after UAE show changes in the signal intensity of the leiomyomas. (d) T1-weighted image shows that the leiomyomas (arrows) now have high signal intensity. White circles = regions of interest for signal intensity measurement. (e) T2-weighted half-Fourier single-shot turbo spin-echo image shows a more discrete interface between the leiomyomas (arrows) and the myometrium. (f) Contrast-enhanced T1-weighted image shows significantly diminished vascularity in all three leiomyomas (arrows). Note that myometrial enhancement is maintained. (Case courtesy of Susan M. Ascher, MD, Georgetown University Hospital, Washington, DC.)
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Figure 20b. Uterine leiomyomas treated with UAE. (a-c) Sagittal T1-weighted (a), T2-weighted half-Fourier single-shot turbo spin-echo (b), and contrast-enhanced T1-weighted (c) images obtained before UAE show three uterine leiomyomas (arrows in b and c). (d-f) Corresponding images obtained 3 months after UAE show changes in the signal intensity of the leiomyomas. (d) T1-weighted image shows that the leiomyomas (arrows) now have high signal intensity. White circles = regions of interest for signal intensity measurement. (e) T2-weighted half-Fourier single-shot turbo spin-echo image shows a more discrete interface between the leiomyomas (arrows) and the myometrium. (f) Contrast-enhanced T1-weighted image shows significantly diminished vascularity in all three leiomyomas (arrows). Note that myometrial enhancement is maintained. (Case courtesy of Susan M. Ascher, MD, Georgetown University Hospital, Washington, DC.)
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Figure 20c. Uterine leiomyomas treated with UAE. (a-c) Sagittal T1-weighted (a), T2-weighted half-Fourier single-shot turbo spin-echo (b), and contrast-enhanced T1-weighted (c) images obtained before UAE show three uterine leiomyomas (arrows in b and c). (d-f) Corresponding images obtained 3 months after UAE show changes in the signal intensity of the leiomyomas. (d) T1-weighted image shows that the leiomyomas (arrows) now have high signal intensity. White circles = regions of interest for signal intensity measurement. (e) T2-weighted half-Fourier single-shot turbo spin-echo image shows a more discrete interface between the leiomyomas (arrows) and the myometrium. (f) Contrast-enhanced T1-weighted image shows significantly diminished vascularity in all three leiomyomas (arrows). Note that myometrial enhancement is maintained. (Case courtesy of Susan M. Ascher, MD, Georgetown University Hospital, Washington, DC.)
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Figure 20d. Uterine leiomyomas treated with UAE. (a-c) Sagittal T1-weighted (a), T2-weighted half-Fourier single-shot turbo spin-echo (b), and contrast-enhanced T1-weighted (c) images obtained before UAE show three uterine leiomyomas (arrows in b and c). (d-f) Corresponding images obtained 3 months after UAE show changes in the signal intensity of the leiomyomas. (d) T1-weighted image shows that the leiomyomas (arrows) now have high signal intensity. White circles = regions of interest for signal intensity measurement. (e) T2-weighted half-Fourier single-shot turbo spin-echo image shows a more discrete interface between the leiomyomas (arrows) and the myometrium. (f) Contrast-enhanced T1-weighted image shows significantly diminished vascularity in all three leiomyomas (arrows). Note that myometrial enhancement is maintained. (Case courtesy of Susan M. Ascher, MD, Georgetown University Hospital, Washington, DC.)
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Figure 20e. Uterine leiomyomas treated with UAE. (a-c) Sagittal T1-weighted (a), T2-weighted half-Fourier single-shot turbo spin-echo (b), and contrast-enhanced T1-weighted (c) images obtained before UAE show three uterine leiomyomas (arrows in b and c). (d-f) Corresponding images obtained 3 months after UAE show changes in the signal intensity of the leiomyomas. (d) T1-weighted image shows that the leiomyomas (arrows) now have high signal intensity. White circles = regions of interest for signal intensity measurement. (e) T2-weighted half-Fourier single-shot turbo spin-echo image shows a more discrete interface between the leiomyomas (arrows) and the myometrium. (f) Contrast-enhanced T1-weighted image shows significantly diminished vascularity in all three leiomyomas (arrows). Note that myometrial enhancement is maintained. (Case courtesy of Susan M. Ascher, MD, Georgetown University Hospital, Washington, DC.)
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Figure 20f. Uterine leiomyomas treated with UAE. (a-c) Sagittal T1-weighted (a), T2-weighted half-Fourier single-shot turbo spin-echo (b), and contrast-enhanced T1-weighted (c) images obtained before UAE show three uterine leiomyomas (arrows in b and c). (d-f) Corresponding images obtained 3 months after UAE show changes in the signal intensity of the leiomyomas. (d) T1-weighted image shows that the leiomyomas (arrows) now have high signal intensity. White circles = regions of interest for signal intensity measurement. (e) T2-weighted half-Fourier single-shot turbo spin-echo image shows a more discrete interface between the leiomyomas (arrows) and the myometrium. (f) Contrast-enhanced T1-weighted image shows significantly diminished vascularity in all three leiomyomas (arrows). Note that myometrial enhancement is maintained. (Case courtesy of Susan M. Ascher, MD, Georgetown University Hospital, Washington, DC.)
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Furthermore, MR imaging may be valuable for predicting the outcome of UAE. High signal intensity in a leiomyoma on T1-weighted images is a negative predictor of volume reduction (41,42). It is hypothesized that such leiomyomas have already undergone hemorrhagic degeneration and loss of vascular supply, so that they show a poor response to UAE (42). On the other hand, submucosal location of a leiomyoma is a positive predictor of volume reduction after UAE (Fig 21) (41).
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Figure 21a. Uterine leiomyomas treated with UAE. Sagittal T2-weighted half-Fourier single-shot turbo spin-echo images obtained before UAE (a) and 3 months after UAE (b) show multiple uterine leiomyomas. Both the uterus and the leiomyomas are smaller after UAE (b). The submucosal lesion (arrows) is especially diminished. (Case courtesy of Susan M. Ascher, MD.)
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Abstract
LEARNING OBJECTIVES FOR TEST...
