Illustration showing what happens during hysterosonography

During hysterosonography (his-tur-o-suh-NOG-ruh-fee), you have a thin, flexible tube called a catheter placed in the uterus. Salt water, also called saline, is injected through the flexible tube into the hollow part of the uterus. An ultrasound probe transmits images of the inside of the uterus to a nearby monitor.