What is Ultrasound?
Ultrasound (US) imaging, also called ultrasound scanning or sonography, is a method of “seeing” inside the human body through the use of high-frequency sound waves. The sound waves are recorded and displayed as a real-time visual image. No ionizing radiation is involved in ultrasound scanning.
In most ultrasound examinations, a transducer, a lightweight device which produces sound waves, is placed on the patient’s skin.
What are some common uses of Ultrasound scanning?
- During pregnancy to monitor the development of the embryo or foetus.
- Superficial organs e.g., breast, thyroid, joints (shoulder, ankle).
- Blood flow. Doppler ultrasound is a special technique used to examine the blood flow. Doppler images can help to see and evaluate blockages to blood flow, such as clots, and build-up of plaque inside the vessels.
- Biopsy. It can also be used to guide procedures such as needle biopsies, in which a needle is used to sample cells from an organ for laboratory testing.
How should I prepare for the procedure?
- You should wear comfortable, loose fittingclothing.
How is the procedure performed?
- You will lie on your back on an examination table.
- A clear gel is applied to your body in the area to be examined, to help the transducer make secure contact with the skin. The sound waves produced by the transducer cannot penetrate air, so the gel helps eliminate air pockets between the transducer and the skin. The gel is water soluble., safe and harmless and can be easily wiped off after the scan with a paper towel.
- The radiographer presses the transducer firmly against the skin and sweeps it back and forth to image the area of interest.
- When the examination is complete, the gel can be easily cleaned with the use of tissue and you may be asked to dress and wait while the ultrasound images are reviewed.
What will I experience during the procedure?
- Ultrasound imaging is painless, fast, and easy. The radiographer will spread some gel on your skin and then press the transducer firmly against your body, moving it until the desired images are captured.
- There is no pain.
- The examination usually takes about 30 minutes. If blood flow visualisation is required, this may take up to 60 minutes.
When can I expect results?
The radiologist will review the images and the report will be sent to our orthopaedic specialist, Dr. Kevin Yip who will then discuss the scan results with you.
What are the benefits versus risks?
- Ultrasound scanning is non-invasive (no needles or injections in most cases) and is usually painless.
- Ultrasound is widely available and easy to use.
- Ultrasound imaging uses no ionising radiation and is preferred image modality for diagnosis and monitoring of pregnant women and their unborn infants.
- Ultrasound provides real-time imaging, making it a good tool for guiding minimally invasive procedures such as needle biopsies.
- Ultrasound images can visualise structure and blood vessels.
- For standard diagnostic ultrasound there are no known harmful effects on human.