Radiating Hope: Radiology Department Blog


Ultrasounds and Bladders: What’s the Connection?

Ultrasounds and Bladders: What’s the Connection?

Ultrasound uses sound waves to take pictures of structures inside your child’s body. High-frequency sound waves are transmitted from the probe, also known as a transducer, into the body. The transducer collects the sounds that bounce back, and a computer then uses those sound waves to create an image.

“What is the gel used for?” is a frequently asked question. Clear gel allows for smooth movement of the transducer over the skin, but most importantly it eliminates air between the skin and the transducer for the best sound conduction. Air prevents sound transmission, which can interfere with the ultrasound image.


The importance of a full bladder for a pelvic ultrasound is to create a “window” for the beam to pass through. A full bladder can change the position of the uterus, making it easier to see. A full bladder also moves loops of bowel up and out of the way to make it easier to see other pelvic organs such as the ovaries.


The different drinking instructions for certain age groups are as follows: (*Please keep in mind, instructions may change over time as we adjust protocols to provide the most up-to-date care possible. For any questions please contact the Ultrasound Department and we will be sure to clarify every step of the way.)

  • Under 5 years: 8-12 ounces one hour prior to the test
  • 5-12 years: 12-16 ounces one hour prior to the test
  • 12-18 years: 18-24 ounces one hour prior to the test

It is important to note it usually takes at least one hour from the time your child finishes drinking to actually fill his or her bladder. This is why we ask your child to drink an hour out from his or her exam time.

Ultrasounds requiring a full bladder have no eating restrictions, so your child is able to eat as normal. We will continue to try new things and adapt to new procedures to ensure the most modern and top-quality care. No matter what we change through the years, images are always better with your help.

Contributed by Paula Bennett (RT-US) and edited by Tony Dandino (RT-MR).

Avatar photo

About the author: Tony Dandino

Tony is an MRI Technologist at Cincinnati Children’s. Tony has been in his role for several years and serves as a Charge Tech, Quality Improvement Coach and Safety Coach for the MRI department. Tony has always known he wanted to work with children and in the medical field. Working at Cincinnati Children's has been the best of both worlds. Every day is something new and Tony can never wait to start the next adventure.