How Does an Ultrasound Work?

Nov 27, 2021 | Uncategorized

What is an ultrasound?

An ultrasound scan, sometimes called a sonogram, is a procedure that uses high-frequency sound waves to create an image of part of the inside of the body. No x-rays or any type of ionising radiation is involved, therefore it’s considered safer than other types of imaging- hence why we use ultrasound during pregnancy.

How does an ultrasound work?

An ultrasound works via a small device called an ultrasound probe, which gives off high-frequency sound waves. You can’t hear the sound waves, but when they bounce off different parts of the body, they create “echoes” that are picked up by the probe and turned into a moving image which is displayed on a monitor while the scan is carried out.

The shape and intensity of the echoes depend on how the area absorbs the sound waves. For example, most waves pass through a fluid-filled cyst and send back very few or faint echoes, which look black on the display screen. On the other hand, waves will bounce off a solid tumour, creating a pattern of echoes that the computer will interpret as a lighter-coloured image. Air and bone also reflect sound waves.

3 main categories of ultrasounds:

  • An external ultrasound scan- the probe is moved over the skin
  • An internal ultrasound scan- the probe is inserted into the body
  • An endoscopic ultrasound scan- the probe is attached to a long, thin, flexible tube (an endoscope) and passed further into the body

Uses of ultrasound scans:

Ultrasounds have a variety of uses, despite being most often associated with pregnancy. It can be ordered to investigate pain, swelling, or other symptoms.

  • Assessment of jugular venous pressure (JVP)
  • Pregnancy
  • Venepuncture
  • Focussed assessment for screening in trauma (FAST)
  • Lumbar puncture
  • Thoracentesis
  • Paracentesis
  • Evaluation of abdominal organs
  • Biopsy

Common types of ultrasound scans:

  • Abdominal scans – may be used to investigate abdominal pain, nausea, vomiting, abnormal sounds and lumps. Structures to be examined may include the gallbladder, bile ducts, liver, pancreas, spleen, kidneys and large blood vessels. Structures that contain air (such as the stomach and bowels) can’t be examined easily by ultrasound because air prevents the transfer of the sound waves.
  • Pelvic scans – may be performed if a woman is suffering pelvic pain or has abnormal periods, fibroids, cysts or other conditions associated with the female reproductive system.
  • Pregnancy scans – used to check for foetal abnormalities (such as spina bifida), check the age and position of a foetus and monitor foetal growth and development. Undergoing an ultrasound scan is now considered routine for pregnant women.
  • Musculoskeletal scans -used to check regions like a shoulder, hip or elbow.
  • Breast scans – to further investigate an abnormality picked up by physical examination or mammogram.
  • Eye scan– to check its internal structures. 
  • Doppler ultrasound– a special type of ultrasound used to detect the speed and direction of blood flow in certain regions of the body e.g. neck arteries and leg veins.

Why book a private ultrasound scan?

Many of our clients choose to book an ultrasound scan with us after having been referred for a scan in the NHS by their GP, but are unwilling to wait for a scan appointment within the NHS- which can take many weeks. Going privately bypasses this, allowing quicker, more convenient appointments, meaning faster results. We offer flexible and convenient appointments, with clinics running during the day, evening and weekends. 





No referral? No worry - book now for direct access to our ultrasound service.

We support both self-pay and insured patients. If you are self-funding, you can request to book a scan online within minutes. If you are insured, please contact our team to discuss your imaging request and arrange an appointment.