Understanding Ultrasound

An ultrasound is an exam that uses high-frequency sound waves to produce a picture of the inside of your body including organs and vessels.

Ultrasound is also used during procedures such as biopsies of the liver, thyroid and prostate. US guidance is used for a thoracentesis, paracentesis and amniocentesis. No radiation or X-rays are used.


Many of the abdominal organs are better visualized if the patient has been NPO or has eaten a light breakfast. Gas and gastric contents can obscure the organs. Patients need to be NPO after midnight but may take their medications with a sip of water for the following ultrasound procedures:

  • Abdomen
  • Gallbladder
  • Liver biopsy

Invasive exams have drug holds regarding blood thinning medications. In certain instances anticoagulation must be reversed due to the urgency of the exam. This must be arranged with the radiologist and the ordering physician.

Coumadin Must Be Held for 3 Days for:

  • Paracentesis

Coumadin Must Be Held for 3 Days and ASA, Ticlid, Aggrenox, Pletal and Plavix Must Be Held for 7 Days for:

  • Thyroid biopsy
  • Thoracentesis
  • Liver biopsy

A full or partially full bladder is required for a pelvic US and a pregnancy US. These patients must be encouraged to drink extra fluids and not empty their bladder before the exam.

During the US

During a US, a registered sonographer will move a hand-held device over the skin after it has been coated with gel. The gel is used to help the sound waves travel more easily and produce a clearer image. Pictures appear on a video screen and measurements are recorded. With ultrasound as a guide, some invasive procedures are able to be performed.

Providing safe, quality patient care is our highest priority. To help ensure quality and safety, we ask that you do not bring young children with you to your appointments, as children are not allowed to accompany you during Imaging procedures. Staff is unable to monitor your child in your absence.

If you have any questions or concerns, please contact your provider.

Back to Imaging Patient Instructions

Dear Friends and Neighbors,

CentraCare care givers have been working around the clock for more than 20 months to care for you, your families and friends during COVID. We are committed to caring for every Minnesotan who needs us, and nothing will prevent us from doing so – even during these never-seen-before times.

The challenge of providing this level of care is that our hospital beds are often full. ERs in all of our hospitals are packed. And our clinical teams are exhausted. Early in the pandemic, our community stepped up in amazing ways to help us. We ask that you again join us in fighting this pandemic together.

How can you help?

  • Please get your COVID vaccines and booster shots. They are proven safe and effective in reducing COVID illness, keeping people out of the hospital, and preventing death.
  • If your situation is not an emergency, please use other care options, including:
  • If this is a medical emergency, call 9-1-1, or visit the ER.

Together, we can do this. Thank you for your support.

Ken Holmen, MD
President and CEO