Ultrasonography is the study of internal organs or blood vessels using high-frequency sound waves. The actual test is called an ultrasound scan or sonogram. Duplex ultrasonography uses Doppler technology to study blood cells moving through major veins and arteries. There are several types of ultrasound. Each is used in diagnosing specific parts of the body.
An ultrasound is a noninvasive, safe method of examining a patient's eyes, pelvic or abdominal organs, breast, heart, or arteries and veins. It is often used to diagnosis disease, locate the source of pain, or look for stones in the kidney or gallbladder. Ultrasound produces images in real time. Images appear on the screen instantly. It may also be used to guide doctors who are performing a needle biopsy to locate a mass. (Needle biopsies are often used to obtain a sample of breast tissue to test for cancer cells.) Duplex/Doppler ultrasound aids in diagnosing a blockage in or a malformation of the vessel. Different color flows aid in identifying problem areas in smaller vessels. Endoscopic ultrasound combines a visual endoscopic exam, during which a flexible tube called an endoscope is threaded down the throat, with an ultrasound test. The ultrasound probe is attached to the end of the endoscope. An endoscopic ultrasound is helpful in determining how deeply a tumor has grown into normal tissues or the gastrointestinal tract. During a transvaginal ultrasound, the ultrasound probe is inserted into the vagina to obtain better images of the ovaries and uterus. Color flow Doppler imaging, using a transvaginal probe, is being performed to detect abnormal blood flow patterns associated with ovarian cancer.
Ultrasound is considered safe with no known risks or precautions. The exam uses no radiation. Under nor mal circumstances the exam is normally painless. However, if the patient has a full bladder, pressure exerted during the exam may feel uncomfortable. An ultrasound conducted in conjunction with an invasive exam carries the same risks as the invasive exam.
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Author Info: Debra Wood R.N., The Gale Group Inc., Gale, Detroit, Gale Encyclopedia of Cancer, 2002 |