Gynecologic ultrasonography: refers to female pelvic ultrasonography. Female pelvic ultrasonography has its own indications. There are 4 routes of examination: transabdominal, transvaginal, transrectal and perineal. The first 2 routes are commonly used in clinical practice. For unmarried women, the transrectal route is required if the pelvic structures are not well visualized via the abdominal wall, and the perineal route can be used for lesions in the vulva or lower vagina. In some patients, a combination of transabdominal and transvaginal routes is required. The diagnostic accuracy of ultrasonography depends on the operator’s technique, clinical experience and basic knowledge of anatomy.