Ultrasound imaging is a non-invasive medical test that helps physicians diagnose and treat medical conditions. Ultrasound imaging, also called ultrasound scanning or sonography, involves exposing part of the body to high-frequency sound waves to produce pictures of the inside of the body. Ultrasound exams do not use radiation (as used in x-rays). Because ultrasound images are captured in real-time, they can show the structure and movement of the body's internal organs, as well as blood flowing through blood vessels.
A Doppler ultrasound study may be part of an ultrasound examination.
Doppler ultrasound is a special ultrasound technique that evaluates blood velocity as it flows through a blood vessel, including the body's major arteries and veins in the abdomen, arms, legs and neck.
Benefits of the procedure
Ultrasound examinations can help to diagnose a variety of conditions and to assess organ damage following illness.
Ultrasound is used to help physicians evaluate symptoms such as:
Ultrasound is a useful way of examining many of the body's internal organs, including but not limited to the:
- heart and blood vessels, including the abdominal aorta and its major branches
- uterus, ovaries, and unborn child (fetus) in pregnant patients
- thyroid and parathyroid glands
- scrotum (testicles)
Ultrasound is also used to:
- guide procedures such as needle biopsies, in which needles are used to extract sample cells from an abnormal area for laboratory testing.
- image the breasts and to guide biopsy of breast cancer
- diagnose a variety of heart conditions and to assess damage after a heart attack or diagnose for valvular heart disease.
- Doppler ultrasound images can help the physician to see and evaluate:
- blockages to blood flow (such as clots).
- narrowing of vessels (which may be caused by plaque).
- tumours and congenital malformation.
With the knowledge about the speed and volume of blood flow gained from a Doppler ultrasound image, the physician can often determine whether a patient is a good candidate for a procedure like angioplasty.
Before the procedure
You should wear comfortable, loose-fitting clothing for your ultrasound exam. You may need to remove all clothing and jewellery in the area to be examined.
You may be asked to wear a gown during the procedure.
Other preparation depends on the type of examination you will have. For some scans your doctor may instruct you not to eat or drink for as many as 12 hours before your appointment. For others you may be asked to drink up to six glasses of water two hours prior to your exam and avoid urinating so that your bladder is full when the scan begins For most ultrasound exams, the patient is positioned lying face-up on an examination table that can be tilted or moved.
A clear water-based gel is applied to the area of the body being studied to help the transducer make secure contact with the body and eliminate air pockets between the transducer and the skin. The ultrasound technologist or radiologist then presses the transducer firmly against the skin and sweeps it over the area of interest.
Doppler sonography is performed using the same transducer.
After the procedure
When the examination is complete, the patient may be asked to dress and wait while the ultrasound images are reviewed. However, the radiologist is often able to review the ultrasound images in real-time as they are acquired and the patient can be released immediately.