SonoHSG/SIS
While performing a transvaginal ultrasound the uterus is distended with saline, allowing the most optimal view of the endometrial cavity and fallopian tubes (saline-infusion ultrasound). Air can then be injected into the tubes to determine if they are open (sonoHSG or HyCoSy).
HSG
The uterus is distended with contrast solution while an x-ray of the pelvis is being performed. This is the best non-invasive test to confirm tubal occlusion, but is sometimes unnecessary if tubal patency has already been confirmed.
