What is a diagnostic ultrasound?
A diagnostic ultrasound is a medical procedure that uses sound waves to "see" inside the body. Ultrasound can be used to study the heart or to check the health of an unborn baby. It is also used to help diagnose many medical conditions, such as cancer, gallbladder disease, blood clots and eye disorders.
How ultrasound works
A transducer, or small microphone-like device, is placed over the area being examined. Sound waves then pass through the skin from the transducer. The sound waves bounce off certain organs and tissues in the body creating "echoes." The echoes are reflected back through the transducer, which converts the echoes to electrical signals. These moving images are viewed on a TV monitor and can be recorded or photographed for further study.
Some special types of diagnostic ultrasound
- Doppler ultrasound — Doppler ultrasound can show movement inside the body - for example when blood flows or the heart beats.
- Echocardiography — this type of ultrasound is used to study the heart and its surrounding structures. The test can provide information about the heart's size, shape and function. It's often combined with Doppler ultrasound. Transvaginal and Transrectal Ultrasound — smaller, specially designed transducers are inserted into the vagina or rectum. In some cases, these tests provide better images than traditional ultrasound or other diagnostic methods.
Diagnostic ultrasound can be used to detect, diagnose or monitor:
- Heart problems — ultrasound exams can make it possible to detect clots within the heart, evaluate damage after a heart attack, diagnose heart defects or an enlarged heart, and heart and artery diseases.
- Abdominal disorders — ultrasound may be used to detect gallstones, or check for problems in the liver, kidneys, pancreas or spleen.
- Blood vessel problems — ultrasound studies of veins and arteries in the neck, leg and other parts of the body may show problems such as enlargements that could burst and cause internal bleeding or a narrowing of the main artery leading to the brain, which could lead to stroke.
- Eye disorders — the ultrasound transducer can be placed on the eyelid to detect swelling, bleeding or foreign objects in the eye.
- Cancer — ultrasound can locate lumps in organs or tissues, and can often show the difference between fluid-filled cysts and cancerous tumors. It can also help detect prostate cancer and monitor treatment.
- Pelvic disorders — ultrasound can help determine the cause of pain or bleeding in the reproductive organs of women.
- Other problems — ultrasound may be used when imaging the breasts, examining the thyroid gland in the neck and when inserting a needle to obtain fluid from the lungs.
There is no pain involved with the ultrasound exam. However, you may feel mild pressure from the transducer or some discomfort from lying or sitting in certain positions.