A newer modality three-dimensional ultrasound (3D USG) technology, that has developed three decades ago, has been a great help in diagnosis of infertility patients. It was initially used in obstetrics; however, its success raised interest about its potential in gynecology. Studies so far demonstrated that 3D USG can be a useful and, in some areas, an indispensible tool in evaluation of the gynecology patient.
As in two-dimensional ultrasound (2D USG), transvaginal approach is preferred in gynecologic examination with 3D USG. The transducer is held still close to the area of interest, and a quick sweep at the desired angle is performed. Acquired data are used to obtain a volume. The electronically stored data are processed to display three orthogonal planes. These planes can be rotated or moved as desired, and can be united to form a single 3D image. Manipulation of the acquired volume data is possible to examine a specific structure, such as surface rendering for evaluating congenital uterine anomalies. Another option is to view the volume in slices, as in computerized tomography. This is called multi-slice imaging. The number of slices and the space between them are user-defined.
An outstanding property of 3D USG is its capability to obtain images in previously unavailable planes using 2D USG. Coronal plane can provide detailed information about uterus and adnexa, and it is especially helpful in diagnosing congenital uterine anomalies
Studies have reported 100 % specificity and sensitivity for 3D USG, and a concordance of 100 and 96 %, respectively, when compared with laparoscopy and concurrent hysteroscopy.Also it has been reported that 3D USG had higher concordance with laparoscopy than MRI.
Leiomyomas, the most common benign tumor in women, are relatively easily diagnosed by gynecologists. However, with 2D USG it can be a challenge to differentiate a submucosal leiomyoma from an intramural one, or to determine its relationship with the endometrial cavity. This is especially important in patients with fertility problems, recurrent pregnancy failures, and abnormal uterine bleeding. Likewise, distinguishing the borders and exact location of multiple leiomyomas can be difficult with 2D USG. 3D USG can precisely map the location of leiomyomas and depict their intramural and submucosal components. This information is very valuable when making clinical decision
Intrauterine adhesions are a well-known cause of infertility. HSG and 2D SIS are the two common methods used for its diagnosis, while hystereoscopy is the golden standard. The role of 3D USG in the diagnosis has not been investigated widely. A study comparing 3D USG and HSG reported 3D USG to have a sensitivity of 100 % and HSG 66.7 % for correctly diagnosing and grading intrauterine adhesions. It may seem that there is not much to improve on 2D USG for diagnosing benign gynecological diseases, considering it is a widely used, effective and established imaging modality in gynecology. However, research shows that 3D USG is better in defining and mapping uterine lesions, and it is more sensitive and specific than 2D USG for a number of conditions
Ultimately, ultrasonography improves the quality of care provided by the assisted reproductive technologies (ART) by facilitating rapid diagnosis and the visualization of changes in reproductive physiology required to direct therapy.
Ultrasonography has advanced our knowledge of the physiology of the female reproduction and has permitted remarkable therapeutic advances in the management of infertility. The portability and remarkable technological advances of the instrumentation have allowed clinicians to employ rapid access to a high resolution imaging modality in a noninvasive manner. Imaging is being used for diagnostic purposes and has been integral in abbreviating the interval required to make a diagnosis of the etiology of infertility. Therapeutic protocols for infertility rely on rapid, accurate ultrasound imaging to direct changes in medication dosages and to plan the time for insemination and IVF procedures. The outcome of fertility therapies also involves ultrasound imaging, so that clinical pregnancy and gestation number can be determined and the course of pregnancy can be surveyed. Ultrasonography has allowed us to understand folliculogenesis, ovulation, luteal function, uterine response, conception, and implantation, and to apply this knowledge to explain and explore normal reproduction, infertility, and contraceptive technologies. As the technology of ultrasonography continues to evolve, we anticipate this indispensible tool will continue to shape our knowledge and enhance our ability to care for women.