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.
How ultrasound scans work
A small device called an ultrasound probe is used, which gives off high-frequency sound waves. You can’t hear these 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. This image is displayed on a monitor while the scan is carried out.
Preparing for an ultrasound scan
- Before having some types of ultrasound scan, you may be asked to follow certain instructions to help improve the quality of the images produced. For example, you may be advised to:
- Drink water and not go to the toilet until after the scan – this may be needed before a scan of your unborn baby or your pelvic area
- Avoid eating for several hours before the scan – this may be needed before a scan of your digestive system, including the liver and gallbladder
- Depending on the area of your body being examined, the hospital may ask you to remove some clothing and wear a hospital gown.
What happens during an ultrasound scan
Most ultrasound scans last between 15 and 45 minutes. They usually take place in a hospital radiology department and are performed either by a radiologist or a sonographer.
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 ultrasound scan– the probe is inserted into the body
- endoscopic ultrasound scan– the probe is attached to a long, thin, flexible tube (an endoscope) and passed further into the body
These techniques are described 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 a full 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 organs such 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 small ultrasound probe with a sterile cover, not much wider than a finger, is then gently passed into the vagina or rectum, and images are transmitted to a monitor. Internal examinations may cause some discomfort, but don’t usually cause any pain and shouldn’t take very long. .
Endoscopic ultrasound scan
During an endoscopic ultrasound scan, an endoscope 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 and may 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.
What is an ultrasound test used for?
It is used in many situations. The way the ultrasound bounces back from different tissues can help to determine the size, shape and consistency of organs, structures and abnormalities. So, it can:
- Help to monitor the growth of an unborn child and check for abnormalities. An ultrasound scan is routine for pregnant women.
- Detect abnormalities of heart structures such as the heart valves. This type of ultrasound scan is called echocardiography. See the separate leaflet called Echocardiogram for more details.
Help to diagnose problems of internal organs such as the:
- Thyroid gland
- Lymph nodes
For example, it can help to determine if an abnormal lump in one of these organs is a solid tumour or a fluid-filled cyst. Ultrasound also helps look for stones in the gallbladder or kidney.
Help determine the nature of breast lumps. Ultrasound is one of the tests used to establish if a lump is non-cancerous (benign) or breast cancer.
Help diagnose problems with muscles, tendons and joints. For example, ultrasound scans are used to help diagnose:
- Frozen shoulder
- Tennis elbow
- Morton’s neuroma
- Carpal tunnel syndrome
- Detect abnormal widening of blood vessels (aneurysms).
3D scans show still pictures of your baby in three dimensions. 4D scans show moving 3D images of your baby, with time being the fourth dimension.
It’s natural to be really excited by the prospect of your first scan. But some mums find the standard 2D scans disappointing when all they see is a grey, blurry outline. This is because the scan sees right through your baby, so the photos show her internal organs.
With 3D and 4D scans, you see your baby’s skin rather than her insides. You may see the shape of your baby’s mouth and nose, or be able to spot her yawning or sticking her tongue out.
3D and 4D scans are considered as safe as 2D scans, because the images are made up of sections of two-dimensional images converted into a picture. However, experts do not recommend having 3D or 4D scans purely for a souvenir photo or recording, because it means that you are exposing your baby to more ultrasound than is medically necessary. Some private ultrasounds can be as long as 45 minutes to an hour, which may be longer than recommended safety limits.
3D scanning can also be useful to look at the heart and other internal organs. As a result, some fetal medicine units do use 3D scans, but only when they’re medically necessary.
If you decide to have one, the best time to have a 3D or 4D scan is when you’re between 26 weeks and 30 weeks pregnant.
Before 26 weeks your baby has very little fat under her skin, so the bones of her face will show through. After 30 weeks, your baby’s head may go deep down in your pelvis, so you may not be able to see her face.
ULTRA SOUND FACILITIES
- Complete Abdomen
- Trans vaginal Pelvic Scan
- Follicular Study
- Dating Scan / First Trimester Scan
- Anomaly Sean with 3D /4D
- Growth Scan
- IUGR follow up
- USG Cranium
- USG Abdomen
- USG for pleural Effusion
High Resolution Ultrasound
- Breast Sean
- Superficial Swelling
- Obsteric Donnler
- Scrotal Doppler
- Caroid Doppler
- Renal Doppler
- Portal Doppler
- Arterial-Upper / Lower Limb
- Venous — UPPer / Lower Limb
- AV Fistula