What is an ultrasound scan?
An ultrasound scan is a medical procedure that uses high-frequency sound waves to create a picture of part of the inside of the body.
The ultrasound machine sends sound waves at the internal body structures such as heart, abdominal and pelvic organs, muscles and blood vessels. The reflected sounds (sometimes referred to as echoes) are recorded to create a picture that can be seen on a monitor.
Generally, an ultrasound is painless, does not use radiation, and is non-invasive. However, some ultrasounds use a special probe inserted into a person’s rectum, oesophagus or vagina.
An ultrasound scan is performed by a specially trained health professional (sonographer, radiologist or sonologist).
What types of ultrasound scans are used?
The most common types of ultrasound scans are:
- transvaginal ultrasound which examines the female pelvis, uterus, cervix, fallopian tubes, ovaries, kidney and bladder
- abdominal ultrasound which examines the abdomen and other organs, and is frequently used in pregnancy
- echocardiogram to examine the heart
- bone sonography to assist in the diagnosis of osteoporosis
- doppler ultrasound to monitor the blood flow in the major veins and arteries
- 3D ultrasound that shows a three-dimensional image of the inside of the body
- 4D ultrasound that creates a three-dimensional image in motion.
When is an ultrasound scan used?
Ultrasound scans can be used for screening, diagnosis or to assist with treatment. This type of scan can be used to:
- examine organs
- examine lumps to see if further testing is needed
- examine ligaments and tendons
- monitor blood flow
- help in treatment by guiding the doctor to the right site for a biopsy or injection.
How do I prepare for an ultrasound scan?
There are several things you can to help you prepare for an ultrasound scan and it will depend on the type of ultrasound scan you are having.
- Bring your referral letter to the appointment.
- If you have had any x-rays or ultrasound, CT or MRI scans in the past two years, bring the results with you to the appointment.
- Follow any instructions you received such as fasting or drinking a lot of water and not going to the toilet before the scan.
- Let the sonographer know if you are diabetic before your ultrasound.
- Wear clothing that will make it easy to access the area being scanned.
How is the ultrasound scan done?
For the ultrasound scan you are usually asked to lie down on a bed and the area being examined is exposed. The ultrasound is performed with a smooth hand-held device (transducer) which is attached to a computer.
A clear gel will be applied to your skin which helps the sound waves pass easily into the area under examination. The transducer will be placed onto this area and then moved across it with a rotating and sliding action so that the image can be projected onto the monitor.
An ultrasound scan usually takes 20 to 40 minutes but can last up to 60 minutes depending on the area being scanned.
What are the risks with an ultrasound scan?
An ultrasound scan is a very safe medical procedure and there are usually no side effects. Most people can return to their normal activities afterwards.
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