Ultrasound imaging is also called ultrasound scanning or sonography. It involves exposing part of the body to high-frequency sound waves to produce pictures of the internal organs of the body. Some organs are situated deep inside the abdominal or pelvic cavity. Ovaries, for example, are not easily palpable. An ultrasound of the ovaries helps in accurate diagnosis of ovarian problems. Ultrasound exams do not use ionizing radiation as in x-rays. The ultrasound images are captured in real-time and can show the structure and movement of the body's internal organs, as well as blood flowing through blood vessels. This type of imaging is noninvasive and helps physicians diagnose and treat medical conditions.
The primary indications for a pelvic ultrasound are pelvic masses, pelvic pain, and abnormal bleeding. Views of the pelvis are obtained trans-abdominally through a full urinary bladder and trans-vaginally through an empty urinary bladder.
There is a considerable range of normal ovarian size between birth and two years of age because of the presence of cysts and follicles, which is normal and the follicles are normally less than 5 mm in diameter. The ovaries increase in size up to puberty and a multicystic appearance is fairly common. After menarche, the ovaries become ovoid in shape and the normal ovarian volume is 5 ml to 15 ml. Ovaries decrease in size after menopause. Due to their small size and lack of follicles, postmenopausal ovaries are difficult to visualize.
Ovarian cysts are common in all age groups. Typical benign cysts are completely anechoic, have thin walls, no septations, and no solid elements. Hemorrhagic cysts have a more complex appearance with internal septations and a retractile clot. If a lesion has questionable appearance, or is larger than 3 cm, serial scans are necessary. Typically, most ovarian cysts show resolution. A variety of non-ovarian tumors and other abnormalities can be mistaken for solid ovarian masses. The diagnosis of an ovarian abnormality depends upon patient's age, time since last menstrual period, hormonal status, symptoms, prior surgery, and physical examination findings. Functional cysts and benign tumors are more common in women of reproductive age. Malignant lesions are more common in postmenopausal women. However, ultrasound of ovaries is of limited value as the only method of detection of early stages of ovarian cancer and needs to be combined with serum cancer marker tests such as CA125.
The benefits of ultrasound can be listed as:
- Most ultrasound scanning is noninvasive and painless.
- Widely available and less expensive than other imaging methods.
- Ultrasound imaging uses no ionizing radiation.
- Ultrasound scanning gives a clear picture of soft tissues that do not show up well on x-ray images.
- Ultrasound may be repeated as often as is necessary.
- Ultrasound is the preferred for monitoring pregnancy and fetus.
- Ultrasound helps identify and evaluate a variety of genitor-urinary disorders in both sexes without even the minimal risks associated with x-rays.