It is a diagnostic procedure in which saline solution is instilled in uterine cavity with the help of a fine catheter and free spillage of fluid in the abdominal cavity is detected with the help of transvaginal USG. It avoids the exposure to x ray radiation. The saline solution distends the uterus and neatly outlines the endometrial cavity which provides better delineation of uterine abnormalities like endometrial polyps/fibroids/scars etc.