Ultrasound for Children Ultrasound, or sonography, is a safe, painless procedure that uses high-frequency sound waves reflecting off body structures to create a picture. No radiation is used with this technique. Ultrasound is often used to scan the abdomen and blood vessels. What can I expect? Your child will usually lie down for the procedure. A clear, water-based gel is applied to the skin and a hand-held probe is moved over the target area. He or she may be asked to change position so that other areas can be examined. FAQs How will it feel? The gel may feel cold and wet. The only other sensation is from the probe touching the skin, but some pressure may be used. How should I prepare my child? No preparation is needed, except for pelvic scans. Before pelvic scans, your child will be asked to drink 16-24 ounces of water and not empty his or her bladder until after the scan. A full bladder helps to show different structures in the pelvis. In some cases, your child will be asked to fast before the exam.