An ultrasound scan is a medical test that uses high-frequency sound waves to capture live images from the inside of your body.
An ultrasound allows your doctor to see problems with organs, vessels, and tissues—without needing to make an incision.
Unlike other imaging techniques, ultrasound uses no radiation, so it is the preferred and safe method for viewing a developing fetus during pregnancy and other fetal congenital abnormalities.
Ultrasound is also known as sonography.An ultrasound is also a helpful way to guide surgeons’ movements during certain medical procedures, such as biopsies.

A vascular ultrasound (or Doppler ultrasound) is an exam that uses high-frequency sound waves to produce a picture or graph of blood as it flows through a blood vessel. It helps in diagnosis of:

• Blockages to blood flow (such as clots);
• Narrowing of vessels (which may be caused by plaque);
• Tumors and congenital malformation

Most people associate ultrasound scans with pregnancy. These scans can provide an expectant mother with the first view of her unborn child. However, the test has many other uses.
According to the Radiological Society of North America, your doctor may order an ultrasound if you are experiencing pain, swelling, or other symptoms that require an internal view of your organs (RSNA, 2012). An ultrasound can provide a view of the:

• Abdominal viscera (Liver, Gall bladder, Spleen, Pancreas, Kidneys and Urinary bladder
• Pelvic viscera (Prostate, Uterus and ovaries)
• Brain (in infants)
• Eyes (B-scan)
• Thyroid
• Testicles
• Blood vessels
• Small parts (breasts, muscles, joints and tendon)
• Ultrasound guided procedures (fine needle aspiration, trucut biopsy, drain placement etc)

• The steps you will take to prepare for an ultrasound will depend on the area or organ that is being examined.
• Your doctor may tell you to fast for 8 to 12 hours before your ultrasound, especially if your abdomen is being examined. Undigested food can block the sound waves, making it difficult for the doctors to get a clear picture.
• If you are having an ultrasound of any of the following:
  GALLBLADDER / ABDOMEN / AORTA / LIVER / PANCREAS / SPLEEN / KIDNEYS, Please do not eat or drink 8 – 12 hours prior to exam. You may be told to eat a fat-free meal the evening before your test and then to fast until the procedure. However, you can continue to drink water and take any medications as instructed.
• If you are having an ultrasound of the PROSTATE, PELVIS or a PREGNANCY ultrasound, please drink 4 – 6 glass of water, 1 hour before exam. *YOUR BLADDER MUST BE FULL FOR EXAM* Please drink waters only – no carbonated beverages. If you are more than 20 weeks pregnant, there is no preparation for your ultrasound. Do not urinate.
• If you are having an ultrasound of any Extremity, Thyroid, Breast, Testicles, Carotid, upper or lower limb vessels there is NO PREPARATION REQUIRED.
• Doppler study (except Visceral): No special preparations.
• Prostate (TRUS) Ultrasound: Four laxatives (for bowel preparation) one night before and two hours of fasting.
• It will take approximately 10 – 30 minutes per exam / procedure depending on diagnosis.
• Your arrival time will be 15 minutes before your appointment time so you can be registered before your exam.
• Be sure to tell your doctor about any prescription drugs, over-the-counter medications, and herbal supplements that you take before the exam.
• It is important to follow your doctor’s instructions and ask any questions you may have prior to the procedure.