What is ultrasonography?
In ultrasonography, or ultrasound, high-frequency sound waves, inaudible to the human ear, are transmitted through body tissues. The echoes are recorded and transformed into video or photographic images.
Ultrasound images help in the diagnosis of a wide range of diseases and conditions. The idea for ultrasonography came from sonar technology, which makes use of sound waves to detect underwater objects.
Ultrasound is used to create images of soft tissue structures, such as the gall bladder, liver, heart, kidney, female reproductive organs -- and even of babies still in the womb. Ultrasound can also detect blockages in the blood vessels.
Ultrasound cannot be used to image bones because they are too dense to penetrate. In addition, the intestinal tract and normal lung tissue are not easily identified with ultrasound because air or gas interfere with the production of ultrasound images.
Ultrasound may be used with other diagnostic procedures or by itself.
What is examined during an abdominal ultrasound?
The liver, gall bladder, pancreas, aorta, spleen, biliary tree (bile and gallbladder ducts) or inferior vena cava (IVC -- the large vein that returns blood to the heart from parts of the body below the diaphragm) may be examined during an abdominal ultrasound.
What is examined during a renal ultrasound?
The kidneys are examined during a renal ultrasound to determine their size, shape and exact position.
On the day of the test
- Please do not bring valuables such as jewelry and credit cards.
- Your ultrasound test is performed by registered, specially trained technologists and interpreted by a board-certified radiologist.
- You may be asked to change into a hospital gown.
During the test
You will lie on a padded examining table. A warm, water-soluble gel is applied to the skin over the area to be examined. The gel does not harm your skin or stain your clothes. A probe is gently applied against the skin. You may be asked to hold your breath briefly several times.
There is virtually no discomfort during the test. If a full bladder is required for the test, you may feel some discomfort when the probe is applied.
The ultrasound takes about 40 minutes to complete.
Are there any side effects?
Studies have shown ultrasound is not hazardous. There are no harmful side effects. In addition, ultrasound does not use radiation, as x-ray tests do.
After the test
The gel will be wiped off your skin. The results of your ultrasound are usually available within 24 hours after your test, Monday through Friday.
Your physician will discuss the test results with you.
Before the abdominal ultrasound
- Do not eat or drink anything from midnight the night before the test until your test is completed.
Before the renal ultrasound
- Only drink clear liquids (tea, black coffee, strained juices and clear broth) from midnight the night before the test until your test is complete.
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This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. This document was last reviewed on: 1/20/2009...#4994