Diagnostic ultrasound, also known as sonography, is an imaging method that uses high-frequency sound waves to produce images of the inside of the body. It is used to help diagnose causes of pain, swelling, and infection, as well as examine a baby in utero.
Ultrasound is a safe and painless exam. It does not use radiation and captures images in real time, making this method an ideal choice for many diagnostics and guiding procedures. Conventional ultrasound displays the images in thin, flat sections of the body. Advancements in ultrasound technology include three-dimensional (3-D) ultrasound that formats the sound wave data into 3-D images, and more recently, 4D ultrasound, which generates images that are continuously updated, much like a movie.
When are ultrasounds used?
Ultrasound imaging is a non invasive test that helps physicians diagnose and treat many medical conditions, including but not limited to:
- Evaluate blood flow through arteries and veins
- Assess damage after heart attack
- View uterus and ovaries during pregnancy
- Monitor developing baby’s health
- Diagnose gallbladder disease
- Guide a needle for biopsy or nerve block
- Examine a lump in the breast
- Check for thyroid tumors
- Detect prostate problems
- Assess joint inflammation
What happens during an ultrasound?
Before your ultrasound begins, you may be asked to do the following:
- Remove any jewelry from the area being examined.
- Remove some or all of your clothing.
- Change into a gown.
You’ll be asked to lie on an examination table.
Gel is applied to your skin over the area being examined. It helps prevent air pockets, which can block the sound waves that create the images. This water-based gel is easy to remove from skin and, if needed, clothing.
A trained technician (sonographer) presses a small, hand-held device (transducer) against the area being studied and moves it as needed to capture the images. The transducer sends sound waves into your body, collects the ones that bounce back and sends them to a computer, which creates the images.
There are other, internal ultrasound exams as well.
- Transesophageal echocardiogram. A transducer, inserted into your esophagus, obtains heart images. It’s usually done while you are sedated.
- Transrectal ultrasound. This test creates images of the prostate by placing a special transducer into the rectum.
- Transvaginal ultrasound. A special transducer is gently inserted into the vagina to get a quick look at the uterus and ovaries.
Although ultrasound is usually painless, there may be mild discomfort as the sonographer guides the transducer over your body or when it is inserted.
When your exam is complete, a doctor trained to interpret imaging studies (radiologist) analyzes the images and sends a report to your doctor. Your doctor will share the results with you.
You should be able to return to normal activities immediately after an ultrasound.