Sonohysterography, sonohysterography, or SIS (saline infusion sonogram) is a noninvasive technique that uses a slow infusion of sterile saline into the uterine cavity during ultrasound. This procedure allows the doctor to evaluate abnormalities of the endometrium (lining of the uterus). The gynecologic ultrasound test is used to evaluate patients with unexplained vaginal bleeding, infertility problems, fibroids, or other abnormalities seen on a baseline ultrasound.
A vaginal ultrasound is performed first. The doctor inserts a speculum into the vagina and cleanses the cervix with an iodine solution. A catheter (thin tube) is inserted into the uterus and ultrasound images are taken while saline is injected through the catheter.
The study of the endometrium and uterine cavity has greatly benefited from the contribution of transvaginal ultrasound, which is currently the first line examination in the examination of abnormal uterine bleeding, pelvic pain and infertility.
If this vaginal ultrasound allows a satisfactory study of the uterine cavity and surrounding myometrium, which in most cases is due to the natural contrast of the endometrium, interpretation of the uterine lining may be difficult and other tests may need to be performed.
Thus, hysteroscopy will be performed as a second intention. In fact, hysteroscopy allows direct visualization of the uterine cavity and the taking of samples of the endometrium for histological study. Known since 1981, hysterosonography has now gained some notoriety. The idea was suggested by the observation of small liquid sheets in menopausal women. The presence of this physiological fluid, in case of advanced menopause, allows a perfect study of the cavity.
Injection of a contrast agent into the uterine cavity under ultrasound control allows for distension and provision of artificial contrast that allows better visualization of the endometrium and endocavitary abnormalities. The significant number of these explorations has led to a multiplication of their prescriptions.
El Dr. Daniel García, gynecologist and obstetrician at Ginefem, explains in this video what type of ultrasound is hysterosonography.