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about tubal spill, contrast should be used. It is necessary to have a ballooned catheter to block egress of fluid from the uterine lumen during injection. After sonohysterography has been performed, the saline should be removed prior to instillation of positive contrast.

Some investigators advocate the use of color Doppler sonography with saline instillation in order to best depict tubal patency (Nicolini et al. 1987; Pellerito et al. 1992; Kupesic and Kurjak 2000). This technique can also be used with contrast.

Microbubble contrast agents provide an echogenic contrast to document tubal patency and spillage. The safety of this contrast agent has been established in multiple studies, but its cost makes selected use necessary.

If there is pain during injection, this may be sign of tubal obstruction, either intrinsic or extrinsic from adhesions. Spasm may be present and may cause transitory lack of filling of the proximal portion of the tube.

2.2.2.1  Normal and Abnormal Anatomy

With the use of saline or contrast, the normal tubal lumen is easily identified as thin serpentine adnexal structures.

Hydrosalpinges appear as fusiform cystic structures on TVS. The contrast may dilute or bubbles may come out of suspension, making complete delineation difficult to recognize.

2.2.3\ Accuracy

Sonography has a reported accuracy of approximately 90–92% (Nicolini et al. 1987; Pellerito et al. 1992). Sonosalpingography, with infusion of saline into the endometrial canal, provides improved delineation of the endometrium and internal uterine morphology. Three-dimensional ultrasound with surfaceand transparent-mode reconstructions of the uterus has reported advantages over conventional two-dimensional scanning. In experienced hands, a sensitivity of 93% and a specificity of 100% have been achieved (Pellerito et al. 1992).

2.2.4\ Side Effects and Complications

The side effects and complications of Sono-HSG are for the most part the same as for conventional HSG.

Fig. 8  TVUS: unfavorable ultrasound image caused by a large fibroid

2.2.5\ Limitations of Sono-HSG

Sono-HSG shares limitations similar to those of conventional transvaginal ultrasound and can only help evaluate patent endometrial canals (Goldberg et al. 1997).

The major drawback of this modality is its operator dependency. Additional limitations include factors that contribute to an unfavorable ultrasound image, such as a large-body habitus and/or the presence of large fibroids (Fig. 8).

2.3\ Magnetic Resonance Imaging

2.3.1\ Indications

Magnetic resonance (MR) imaging is suitable for assessing female infertility, as infertility typically results from benign processes in women of reproductive age. The causes of female infertility include ovulatory disorders (i.e., pituitary adenoma and polycystic ovarian syndrome), disorders of the fallopian tubes (i.e., hydrosalpinx, and pelvic inflammatory disease), uterine disorders (i.e., müllerian duct anomaly, adenomyosis, and leiomyoma), and pelvic endometriosis. 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.

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MR imaging provides clear delineation of internal and external uterine anatomy in multiple imaging planes, although it is not able to assess tubal patency or subtle, peritubular adhesion. The excellent tissue contrast of MR imaging allows specific diagnosis for many gynecological diseases.

As laparoscopic surgery is frequently the modality of choice to treat patients suffering from infertility, an accurate preoperative diagnosis is especially important for planning appropriate surgical intervention.

2.3.2\ Technical Considerations

Patients are best imaged with a phased-array MR surface coil. Current standard imaging protocols for infertility evaluation include axial, sagittal, and coronal fast spin echo sequence images of the uterus, which can be supplemented by oblique views to obtain true coronal and axial images of the uterus. Large field-of-view images to look for associated renal anomalies should be obtained. Further imaging of the pelvis with a transverse T1-weighted sequence should be performed. Gd-enhanced MR imaging is important for diagnosis of complex adnexal masses and distinguishing them from malignant processes.

Some authors recommend that an antiperistaltic (1 unit of glucagon or 20 mg of scopolamine butylbromide) should be administered intramuscularly or intravenously before examination.

2.3.3\ Limitations

As drawbacks of MRI are its higher cost, limited availability, and longer scanning time than ultrasound, MR imaging is often used as a problem-­ solving modality when sonography findings are inconclusive (Nicolini et al. 1987; Javitt 1997).

2.3.4\ Normal MR Anatomy

in Reproductive-Age Women

Uterine zonal anatomy is best demonstrated on T2-weighted images (Fig. 9). 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 width of the endometrium and the

Fig. 9  Normal anatomy in reproductive-age women: sagittal T2W MR image clearly demonstrates uterine zonal anatomy with high signal intensity of the endometrium (E), low signal of junction zone (J), and intermediate signal of the myometrium (M). B (urinary bladder)

junctional zone varies through 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 transverse and anteroposterior dimensions (Fleischer and Kepple 1997).

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 with hypointense stroma and hyperintense follicles on T2-weighted images.

Normal fallopian tubes are not routinely imaged because of their small diameter and tortuous course.