Hysterosalpingography (HSG) is a radiologic procedure that uses X-rays to create an image of the uterus and fallopian tubes in a person with female anatomy. It is used to diagnose the cause of infertility and can help identify structural abnormalities in the uterus, blockage of the fallopian tubes, scar tissue in the uterus, uterine fibroids, uterine tumors or polyps. The test is best performed between days 9 to 12 of the menstrual cycle (a week after menstruation but before ovulation). The procedure involves inserting a catheter into the cervix and filling the uterus with a contrast material that helps highlight the uterus and fallopian tubes on X-ray images. The radiologist interprets the images and reports if there is any blockage in the fallopian tubes or other structural abnormalities in the uterus.