White-Wilson Medical Center

Imaging Services Imaging Services

What is an Ultrasound?

Ultrasound is a procedure that uses high-frequency sound waves to view internal organs and produce images of the human body. The human ear cannot hear the sound waves used in an ultrasound.

Ultrasound is:

  • Noninvasive, which means it does not penetrate the skin or body openings, and
  • Diagnostic, which means it is used to determine what disease or condition is present

The technical term for ultrasound imaging is sonography.

Ultrasound technology was originally developed as sonar to track submarines during World War I. It was first used medically in the 1950s and is considered very safe.

The original ultrasound scanners produced still images, but modern scanners produce moving pictures, which are easier to interpret.

How Do You Prepare For An Ultrasound Scan?

Wear loose comfortable clothing to your ultrasound appointment.

For a liver or gallbladder scan, the patient is usually asked to fast (take nothing by mouth) for several hours before the test.

For a scan in early pregnancy, the woman is usually asked to drink several glasses of water and not to pass urine for a few hours before the test. A full bladder helps to improve the view of the uterus by displacing nearby loops of intestine.

What Happens During An Ultrasound Procedure?

You will probably be asked to lie down on a bed or table for the scan. Clothing over the area to be scanned is removed, and a special warm oil or gel is applied to the skin. This is to achieve good contact as the transducer is passed back and forth.

Ultrasonic waves are inaudible and cause no sensation, though pressure from the transducer may be uncomfortable. The scan usually takes 15 to 60 minutes.

When a scan is performed in conjunction with a biopsy, a local anesthetic reduces or eliminates any discomfort.

Normal activities can be resumed immediately after the test.

Ultrasound is very safe and painless, so there is little risk.

Your ultrasound images will be analyzed by a radiologist, a physician who specializes in ultrasound and other radiology testing. The radiologist will send a signed report which includes an interpretation of the image to your primary physician. You may receive your results right after your scan. If not, you will receive information on the report through your primary care physician.

Frequently Asked Questions

Here are some frequently asked questions related to ultrasound:

Q: Is an ultrasound ordered for any condition other than pregnancy?

A: There are several reasons the doctor requests an abdominal ultrasound. These include:

  • Finding the cause of stomach pain
  • Looking for stones in the gallbladder or kidney
  • Diagnosing enlargement of an abdominal organ
  • Pyloric stenosis, one cause for vomiting in babies
  • Suspicion of appendicitis

Q: If ultrasound cannot penetrate bone, is an ultrasound of the head ever done?

A: While ultrasound is usually ineffective for organs encased in bone, like the brain, cranial ultrasound is sometimes performed on infants who still have a soft spot (called the anterior fontanelle) in their skulls. Some indications for cranial ultrasound include:

  • Screening for bleeding in the brain
  • Signs of infection
  • Cranial abnormalities

Q: Is ultrasound ever ordered for a hip?

A: Hip ultrasound is ordered when the diagnosis is dislocated or underdeveloped hips on babies.

Q: Why is kidney ultrasound ordered?

A: Ultrasound does not test kidney function. When kidney ultrasound is ordered, it is to take pictures of the kidneys, the urinary bladder or renal arteries in order to detect the following conditions or disorders:

  • Urinary tract infection
  • The cause for blood in the urine
  • High blood pressure
  • Back or abdominal pain
  • Known or suspected kidney stones
  • A family history of kidney disease

Q: Is ultrasound ever ordered for the spine?

A: A spinal ultrasound is usually ordered to take pictures of the spinal cord in a baby three or four months old or less. A baby is usually referred for spinal ultrasound because of a dimple, hair patch, or discoloration of the skin. The study is done to look for an abnormality of the spinal cord.

Q: What are the disadvantages of ultrasound?

A: The main disadvantage of ultrasound is the inability of the sound waves to penetrate bone and gas.

Ultrasound Patient Preparation

Click here for the instructions to prepare patients for an Ultrasound.

Fully Accredited By ACR

White-Wilson Medical Center is fully accredited by the American College of Radiology.