Vaginal ultrasonography (synonyms: transvaginal ultrasonography, vaginal ultrasound, vaginal echography) is a diagnostic imaging procedure used in gynecology and obstetrics – to visualize the uterus (womb), ovaries (ovaries), uterine tuba (fallopian tubes), Douglas space (lat. Excavatio rectouterina or Excavatio rectogenitalis; this is a pocket-shaped protrusion of the peritoneum between the rectum (rectum) and uterus (uterus) that extends to the posterior vaginal vault), the urinary bladder and the urethra (urethra) – in which the ultrasound probe is inserted transvaginally (through the vagina).
Examination of the pelvic organs using vaginal ultrasonography is a standard diagnostic procedure for all gynecologic conditions, infertility diagnosis and treatment, and early pregnancy (1st trimester/third trimester).
Indications (areas of application)
- In the context of infertility diagnostics, vaginal ultrasonography is used, for example, in the diagnosis of PCO syndrome: polycystic ovaries are present if at least one ovary (ovary) has a volume of at least 10 ml (milliliters) on ultrasound and/or 12 follicles of two to nine milliliters each are present.
- In the context of follicle maturation therapy (oocyte maturation therapy), vaginal sonography is an indispensable method for monitoring treatment. In this process, the follicles (follicles) are measured regularly (folliculometry).
- Furthermore, vaginal sonography is indispensable in oocyte aspiration, the removal of eggs under vaginal sonographic view.
The procedure
The principle of vaginal ultrasonography is the emission of ultrasound waves via crystal elements in the ultrasound probe, which are reflected and scattered by the tissue structures of the organs to be examined. Due to the reflection from the tissue structures in the pelvis, the ultrasound waves are partially received by the crystal elements located in the ultrasound probe. Only specially shaped ultrasound heads are used for vaginal sonography.
To the procedure of vaginal sonography:
- The sonographic examination does not require any preparatory measures, except that the sonography should be performed when the bladder is empty. During vaginal ultrasound, the patient lies on the gynecological examination chair.
- The attending gynecologist covers the ultrasound probe with a condom-like rubber cover containing a special gel to prevent the formation of air spaces to reduce the impedance phenomenon. Impedance represents a phenomenon that is of concern in the propagation of all sound waves and describes the resistance that opposes the propagation of ultrasound waves. Possible air pockets between the ultrasound probe and the tissue surface increase the characteristic impedance, thus reducing the resolving power of the procedure and lowering the diagnostic significance.
- The use of the cover with the included contact gel, in addition to reducing the impedance phenomenon, also serves to improve hygiene.
Vaginal sonography is used to assess the uterus (womb), including the endometrium (endometrium), the fallopian tubes (tubes) and the ovaries (ovaries), including the follicles (follicles) located in them.
