What happens during an ultrasound scan

Most ultrasound scans last between 15 and 45 minutes.Theyusually take place ina hospital radiologydepartment andare performed either by a radiologist or a sonographer.

They can also be carried out in community locations such as GP practices and may be performed by other healthcare professionals, such as midwives or physiotherapists who have been specially trained in ultrasound.

There are different kinds of ultrasound scans, depending on which part of the body is being scanned and why. The three main types are:

• external ultrasound scan the probe is moved over the skin
• internal ultrasoundscan the probe is inserted into the body
• endoscopic ultrasound scan the probe is attached to along, thin, flexible tube (an Endoscopy ) and passed further into the body

These techniques aredescribed below.

External ultrasound scan

An external ultrasound scan is most often used to examine your heart or an unborn baby in your womb. It can also be used to examine the liver, kidneys and other organs in the tummy and pelvis, as well as other organs or tissues that can be assessed through the skin, such as muscles and joints.

A small handheld probe is placed onto your skin, and moved over the part of the body being examined.

A lubricating gel is put onto your skin to allow the probe to move smoothly. This also ensures there is continuous contact between the probe and the skin.

You should not feel anything other than the sensor and gel on your skin (which is often cold). If you are having a scan of your womb or pelvic area, you may have afull bladder that causes you a little discomfort. There will be a toilet nearby to empty your bladder once the scan is complete.

Internal or transvaginal ultrasound scan

An internal examination allows a doctor to look more closely inside the body at organssuch as the prostate gland, ovaries or womb.

A 'transvaginal' ultrasound means 'through the vagina'.

During the procedure, you'll be asked to either lie on your back, or on your side with your knees drawn up towards your chest.

A smallultrasound probe with a sterile cover, not muchwider than a finger,isthen gently passed into the vagina or rectum, and images are transmitted to a monitor.

Internal examinations may cause some discomfort, but don'tusually cause any pain andshouldn't take very long.

Endoscopic ultrasound scan

During an endoscopic ultrasound scan,anendoscope is inserted into your body, usually through your mouth, to examine areas such as your stomach or gullet (oesophagus).

You'll usually be asked to lie on your side as the endoscope is carefully pushed down towards your stomach.

The endoscope has a light and an ultrasound device on the end. Once it has been inserted into the body, sound waves are used to create images in the same way as an external ultrasound.

You'll usually be given a sedative to keep you calm and local anaesthetic spray to numb your throat, as an endoscopic ultrasound scan can be uncomfortable andmay make you feel sick.You may also be given a mouth guard to keep your mouth open and protect your teeth, in case you bite the endoscope.