What is ultrasound?

What is Ultrasound?

Ultrasound is an exam that uses sound waves to produce images. These images are obtained with a small ultrasound transducer (probe) that passes over the patient sending and receiving sound waves. Ultrasound does not use radiation to produce images and is a very safe procedure.


What is ultrasound used for?

Ultrasound can be used for a variety of studies because it does not use radiation or x-rays to produce images. Some of the most common uses include:

  • Pregnancy and fetal exams
  • Examine the body’s internal organs, including the heart, liver, gallbladder, spleen, pancreas, kidneys, bladder, uterus, testicles and ovaries
  • Blood flow measurements to check narrowing of blood vessels
  • Guide needle for biopsies including breast biopsies
  • Placement of catheters (small tubes) into blood vessels
  • Detect stones in the gallbladder, bile ducts, or kidneys


How to prepare for Ultrasound

While there is no special preparation needed for a CT Scan, there are a few things to bear in mind when preparing for your exam, including:

  • Bring a copy of your order for the procedure from your referring healthcare provider if given one, your insurance cards and photo identification
  • On the day of the exam, wear comfortable, loose-fitting clothing
  • Avoid metal zippers, hair pins, jewelry or clothing with snaps
  • Patients may take their usual medications prior to exam

Depending on the type of ultrasound needed, some special preparation may be required. This can include:

  • Female pelvis and pregnancy: Drink 4-6 glasses of water 1-2 hours before the examination. Do not pass urine for 2 hours before the test.
  • Aorta: Do not eat or drink 4 hours prior to the exam
  • Gallbladder: Do not eat or drink 6-8 hours prior to the exam
  • Liver, pancreas or spleen: Do not eat or drink 6-8 hours prior to the exam
  • Kidneys: Do not eat or drink 4 hours prior to the exam. One hour prior to the exam, please drink 24 ounces of water. Do not use the restroom until after the study
  • Breast: Please bring prior mammograms and ultrasounds


What to expect during an ultrasound

Ultrasounds typically take less than 30 minutes and are painless. Once you are positioned on the table, a special warm gel is applied to your skin. This gel improves the transmission of the sound waves between the body and the ultrasound probe. Ultrasonic waves make no noise and cause no sensation, although pressure from the transducer might be slightly uncomfortable.


Generally, the technologist can review the ultrasound images in real-time. However, you may also be asked to dress and wait while the ultrasound images are reviewed by one of our board-certified radiologists. 

In some ultrasound examinations, the probe is attached to a probe and inserted into a natural opening in the body. These exams include:

  • Transrectal ultrasound: The transducer is inserted into the rectum to view the prostate gland
  • Transvaginal ultrasound: The transducer is inserted into the vagina to view the uterus, ovaries and developing baby

When your ultrasound examination is done, you may resume your normal daily activities unless your healthcare provider instructs you otherwise. Your images will be sent to one of our board-certified radiologists for interpretation and a report will be sent to your provider.