Saline Infusion Sonography (SIS) is a minimally invasive ultrasound technique that provides pictures of the inside of the uterus. It is also known as sonohysterography and involves inserting a small amount of saline (salt solution) into the uterus to allow the lining of the uterus (endometrium) to be clearly seen on an ultrasound scan. SIS is used to diagnose uterine abnormalities such as fibroids, polyps, and adhesions, and to evaluate the endometrial cavity for abnormalities  such as endometrial cancer or hyperplasia. The procedure is generally  performed under local anesthesia and can be coordinated with the female partner’s egg retrieval. SIS is a safe test that uses sound waves and a computer to create images, and does not use radiation.