There are two approaches of applications; Transabdominal ultrasound and Transvaginal technique
Transabdominal ultrasound is used for larger structures and areas. It requires filling of urinary bladder to create contrast which makes the definitions of uterus and ovaries clearer. Full bladder is inconvenient for the women if they have to wait for their turn. The women should take a liter or so of fluids and hold their urine for the ultrasound. They can come prepared from home or drink in the clinic. The abdomen is exposed and gel applied over the areas to be evaluated. Transabdominal curved sector probe is placed on the lower abdomen. Uterus is first located and examined in capital and coronal planes and its length and breadth measured. Structure of the uterus is examined and abnormalities of uterine walls and its cavity observed. Size and texture of ovaries is observed. Their abnormalities and that of surrounding areas if any are detected.
In modern practice women attending fertility clinics require Transvaginal Ultrasonography on every visit. It is used to evaluate fertility factors, follow ovulation and Ovum Aspiration in IVF. It is a necessity in early pregnancy too.
Transvaginal technique does not require filling of urinary bladder. Woman after exposing herself lies on her back, draws her knees up and spreads them apart. An appropriately shaped vaginal probe is gently introduced into the vagina and taken deep near the uterus and ovaries. Minute details of the interior of these structures are visualized. Special preparation is not required. Procedure is not painful. Slight discomfort is felt at the insertion of vaginal probe.
Transvaginal Sonography is an absolute necessity for fertility managements. It is the only method to observe ovarian follicle carrying the ovum. Follicle diameter (FD), its growth to maturity and rupture to release ovum are visualized. The proliferation of the uterine endometrium affected by ovarian hormones is also observed by TVS, so is change in its characteristics. TVS monitoring is necessary for fertility assessments as well as success of ovulation therapy. TVS observes:
- Ovarian follicle carrying the ovum.
- Follicle diameter (FD), its growth to maturity and rupture to release ovum are visualized.
- Texture and the thickness of the uterine endometrium. Proliferation of the uterine endometrium affected by ovarian hormones and its changing characteristics.
- FD of the largest follicle in either ovary and endometrial thickness is related to the day of ovarian cycle.