Imaging
Ultrasound Scan
An ultrasound scan uses high-frequency sound waves to create live images of inside the body. It is safe and painless, and is well known for scans during pregnancy.
Quick answer
Ultrasound Scan: what it is and what the results mean
Ultrasound uses sound waves, sent from a small handheld probe, that bounce back to build real-time images on a screen. It uses no radiation.
- Why it is done: Ultrasound is used to monitor pregnancy, examine organs such as the liver, gallbladder, kidneys and heart, look at blood flow in vessels, and guide procedures like biopsies.
- Understanding results: The person doing the scan (a sonographer or doctor) often sees results in real time, and a report goes to your doctor.
What it is
Ultrasound uses sound waves, sent from a small handheld probe, that bounce back to build real-time images on a screen. It uses no radiation.
Why it is done
Ultrasound is used to monitor pregnancy, examine organs such as the liver, gallbladder, kidneys and heart, look at blood flow in vessels, and guide procedures like biopsies.
What to expect
A gel is applied to the skin and a probe is moved over the area. It is painless and usually takes 15–45 minutes. Some scans (such as of the pelvis) may need a full bladder or an internal probe.
Understanding the results
The person doing the scan (a sonographer or doctor) often sees results in real time, and a report goes to your doctor. Ultrasound is excellent for many soft tissues and moving structures like the heart.
Good to know
Risks and limitations
Ultrasound is very safe with no known harmful effects, which is why it is used in pregnancy. It cannot see through bone or gas well, so it is not suitable for every part of the body.
Education and reference only. This explains the test in general terms and is not medical advice. Always follow the specific instructions from the team arranging your test, and discuss your results with your clinician.
Answers
Ultrasound Scan: frequently asked questions
Is ultrasound safe in pregnancy?
Yes. Ultrasound uses sound waves, not radiation, and has an excellent safety record, which is why it is the standard way to monitor pregnancy.
What can an ultrasound show?
It can show organs like the liver, gallbladder and kidneys, a developing baby, the heart in motion, and blood flow in vessels.
Related tests
Other imaging investigations
Sources
Where this is drawn from
- NHS — Tests and treatments
- NICE — diagnostic guidance
- Royal College of Radiologists / relevant professional body
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