Sonogram machines emit sound waves, often known as ultrasound waves, which bounce off of organs, bones and muscles. The machines are able to calculate the distance between waves in order to generate a very accurate picture, which is displayed on a specialized computer screen.
In most cases, the waves are both sent and received from a wand-like instrument known as a transducer. A trained technologist will touch the wand to the skin above the area of interest. Jelly or lubricant is often applied first, both to help the wind glide and to amplify the sound waves to generate a clearer, more accurate picture. Most sonogram sessions result in pictures from many different angles, which technologists and physicians look at in sequence to get an idea of what is happening internally.
Patient prep is very important for certain sonogram exams. For example: before an abdominal sonogram, the patient must be fasting in order for us to visualize the gallbladder. When you eat foods that contain fat, your gallbladder contracts and therefore it is difficult to evaluate on sonogram.
Pelvic sonograms require the patient to have a full bladder. This is beneficial for many reasons-it provides a landmark for the ultrasound technologist. A full bladder pushes up on a woman’s uterus, thus enabling the uterus to be visualized. In the same token, a full bladder also pushes the prostate up in a male so the prostate can be visualized. Lastly, the fluid that the patient drinks helps to hydrate the tissues. Tissues that are hydrated make the sound waves pass thru the organs easier and help to create a more diagnostic image.