Ultrasound is the term used for high-frequency sound waves. Ultrasound examinations use these sound waves to produce an image onto a screen showing the inside of your body.
Ultrasounds are painless and do not involve radiation, which means they are very safe. The high-frequency sound waves ensure images show very high detail, capable of looking at the very tiniest parts of the body. Ultrasound can be carried out while there is movement, so it is excellent for the imaging of babies and children.
It is important that you read any instructions given to you in preparation for your ultrasound and wear clothing that will provide easy access to the area being imaged.
Specific Ultrasound Examinations:
Abdomen Ultrasound: You will usually need to fast (have nothing to eat or drink) for 8 hours before the examination. This ensures there is no food or fluid covering the area that is to be examined. It also ensures the gall bladder is expanded to provide a clearer image.
Breast Ultrasound: No preparation is required.
Female Pelvis Ultrasound: There are two ways to carry out this examination and the preparation will depend on which is used:
Internal – The best way to examine the pelvic organs in detail is to have a ‘closer’ look using a transvaginal ultrasound where the ultrasound transducer is inserted into the vagina. Transvaginal ultrasound is usually recommended for patients who are aged 18 years and older. If the examination is not urgent, it is best done between days 5 to 12 of your menstrual cycle.
External – This is done in situations where an internal pelvic ultrasound is not appropriate, including children, or anyone who has not had an internal examination by their doctor. The ultrasound transducer is placed on the top of the lower abdomen (stomach area). To ensure that the inside of the pelvis area is seen clearly on the screen, a full bladder is required. You will need to drink 750 mL of water 1 hour before the procedure. Do not go to the toilet after drinking the fluid.
Obstetric (pregnancy and childbirth related) ultrasound: Sometimes in early pregnancy (first 3 months), you may be asked to have a full bladder for the examination. The department will provide you with appropriate instructions.
Thyroid ultrasound: No preparation is required.
Testes ultrasound: No preparation is required.
Musculoskeletal (muscle, bone, and joint-related) ultrasound: No preparation is required.
Renal (kidney-related) ultrasound: You will need to drink 750 mL of water 1 hour before the ultrasound. Do not go to the toilet after drinking the fluid. Drinking the water will enlarge the bladder, enabling it and the surrounding internal areas to be examined.
Renal (kidney) arteries ultrasound: You will need to fast (have nothing to eat or drink) for 8 hours before the examination to ensure that the renal arteries are not covered by food or fluid.
Aorta or leg arteries ultrasound: You will need to fast (have nothing to eat or drink) for 8 hours before the examination to minimise bowel gas that may obscure the large arteries in your lower abdomen, which are examined as part of this test.