There are two basic reasons. First, sound waves do not travel through air. The bladder moves the bowel out of the way and is an acoustic window for visualization. The second reason is that it improves the ability to see structures that may be low in the pelvis.
"No matter where you are, no matter who you are, you deserve quality care. At Premier, we are dedicated to providing high quality diagnostics when you need it, where you want it, at a cost that makes sense."
Bill McCurdy - CEO and Founder, Premier Ultrasound Services - Avon, MA