Ultrasound is a safe, painless method for examining the internal organs that avoids the use of radiation. Instead, high-frequency sound waves are generated and the echoes that result from their bouncing off the soft tissue structures can be used to measure size, to detect structural abnormalities, to determine whether a lump is solid or fluid-filled or to monitor growth of the foetus during pregnancy.
 

This form of imaging has many uses:

• In obstetrics, to monitor growth of the baby and check that there are no abnormalities.

• In urology, for diagnosis of urinary bladder, scrotal, prostatic and kidney disease.

• To look for blockages of blood flow in blood vessels.

• To diagnose vascular aneurysms which are abnormal dilatations of blood vessels.

• To look for abnormalities of the heart valves or other heart structures (examination specifically of the heart by ultrasound is called echocardiography).

• To investigate the cause of jaundice (yellowing of the skin and whites of the eyes).

• To diagnose abnormalities of the liver, gallbladder (including gallstones), pancreas, thyroid gland, lymph nodes, ovaries or testicles and breast.

This is not an all-inclusive list and new uses for ultrasound continue to be found.

Ultrasound examination is a painless procedure that takes between 15 minutes and one hour to complete. Usually, a lubricating gel is used to help conduct the sound waves into the body. This will be applied to your skin by the person carrying out the examination then a probe will be held against your skin and moved over its surface. While the ultrasound scan is in progress, the images are displayed on a video monitor. Permanent copies of the examination results can be produced as still pictures or as a video recording. For some more specialised kinds of ultrasound examination the probe is inserted into the body. For example, the probe can be swallowed into the gullet (oesophagus) in order to obtain detailed pictures of the heart valves.

Large amounts of gas in the bowel can interfere with the images. Therefore, if you are having an ultrasound scan of your abdomen, you may be instructed to eat low-fiber foods for 24 to 36 hours before the examination. It may be scheduled at a time when the bowel is relatively gas-free, as is the case in the early morning before breakfast. Some examinations require a preparatory cleansing of the bowel (enema) and fasting for several hours before the appointment. Others require a full bladder. If any of these is necessary, this will be explained to you beforehand.

Pregnancy or pelvic examinations:

• You may eat normally.

• Your bladder must be full for this examination. Drink at least 32 ounces of liquid one hour prior to your examination. (four 8 oz. glasses)

• Please do not urinate until after your examination is completed. If you are very uncomfortable, please notify the staff when you arrive.

• Allow 45-50 minutes for the examination.

Abdominal Examinations:

• The evening before your examination, eat only fresh fruit, vegetables, gelatin, and clear liquids. Do NOT eat meat, fried foods, or dairy products.

• Do NOT eat or drink anything for 6 hours prior to appointment.

• Allow 45-60 minutes for the examination.

Examination of any other part of the body:

• No special preparation is required.

• Allow 45-60 minutes for the examination.

Most ultrasound examinations are carried out in the radiology (X-ray) department of a hospital and they may be conducted on either an in-patient or an out-patient basis. Occasionally, people, particularly children, may be given a sedative drug to help them lie still during the examination. Often you will be able to see the images of the scan on the video screen during the procedure. Afterwards, the lubricating gel will be wiped off your skin so that it doesn’t soil your clothes. If the test is carried out as an out-patient procedure, then you will be able to go home immediately afterwards, although if you have been given any kind of sedation then you will not be allowed to drive and will need someone to accompany you.

Ultrasound examination is completely painless and safe. It is not known to have any complications.