Hysterosalpingography (HSG) is a test used to assess the integrity of the uterus and fallopian tubes. For this, a contrast medium is injected into the vagina and different images of the pelvic cavity are taken through an X-ray machine.
On the other hand, there is an improved version of the conventional HSG that replaces the X-rays with ultrasound. In this way, the images are observed through a transvaginal ultrasound. This is known as hysterosalpingosonography (HSSG).