Ultrasound: What Is It, Why It Is Used, and What Are the Risks?

Ultrasound is a common medical imaging procedure that uses sound waves and echoes to create a picture of the inside of the body. Physicians use ultrasound to view organs and tissues, check for signs of disease, guide biopsies and surgeries, and assess the health of unborn babies.

Preparing for an Ultrasound

Depending on the type of ultrasound you are having, there may be different requirements for pre-exam preparation. If you are having an abdominal ultrasound, you may be asked to:

  • Drink four to six glasses of water one hour before the exam and hold your urine
  • Avoid eating or drinking 2 hours before your exam
  • Do not smoke for at least 4 hours prior to the exam
  • Take any medications with small sips of water
  • Wear lightweight, comfortable clothing
  • Take off jewelry and leave any valuables at home

Ultrasound Procedure

During the ultrasound exam, you will be positioned on the exam table and a clear gel will be applied to your chest, back, or abdomen. To capture images, the technologist will move the ultrasound transducer probe over your skin. You may be asked to change positions during the exam to get better images of the area being examined.

An abdominal ultrasound usually takes about 30 minutes. You will need to remain still during the exam to ensure good image quality so the radiologist can provide a good diagnosis.

Types of Ultrasound

There are several types of ultrasound, including:

  • Abdominal ultrasound: This exam uses sound waves to create images of organs and structures in the abdomen.
  • Obstetric ultrasound: Used to check the health of unborn babies, prenatal ultrasound creates images of a fetus in the uterus.
  • Pelvic ultrasound: This exam examines the female reproductive organs (uterus, cervix, and ovaries) and may be used to look for signs of fibroids.
  • Transvaginal ultrasound: This uses a transducer in the vagina to create images of the uterus, fallopian tubes, and ovaries.
  • Thyroid ultrasound: This procedure uses sound waves to create an image of the thyroid gland in the neck.

Risks of Ultrasound

Ultrasound is generally considered a safe procedure with no known risks. Sometimes, there may be minor discomfort if the ultrasound probe presses too hard on the abdomen, but this should resolve quickly.

Why Is Ultrasound Used?

Ultrasound is a useful tool for physicians to assess and diagnose many conditions. It can provide detailed information about organs and soft tissues, as well as blood flow. Ultrasound can be used to evaluate heart function and detect heart abnormalities, as well as diagnose certain types of cancer. It can also be used to examine the kidneys, liver, and gallbladder, and to diagnose gallstones or other abnormalities.

When Is Ultrasound Used?

Ultrasound may be used when other imaging procedures, such as X-rays or CT scans, are not suitable. Ultrasound does not use radiation, so it is often the preferred imaging procedure for pregnant women. Ultrasound is also used in some cases to guide biopsies or other invasive procedures.