sonohysterography

Sonohysterography, also known as saline infusion sonography (SIS), is a transvaginal ultrasound technique in which sterile saline is infused into the uterine cavity through a transcervical catheter to distend the cavity and improve visualization of the endometrium. Compared with standard transvaginal ultrasound, SIS enhances detection of intrauterine abnormalities and helps characterize the shape and contours of the cavity.

The procedure is typically performed on an outpatient basis and is often scheduled in the early proliferative phase of the menstrual cycle to reduce the risk of pregnancy and optimize visualization. A speculum examination is followed by sterile cannulation of the cervix and insertion of a small-bore catheter into the uterine cavity. Saline is infused under real-time ultrasound guidance to distend the cavity while imaging is performed. The exam is generally well tolerated and single-use sterile technique is standard.

Indications include abnormal uterine bleeding, infertility assessment, and evaluation of recurrent pregnancy loss. SIS is also used to detect intrauterine polyps, submucosal fibroids, and intrauterine adhesions, and to aid preoperative planning for hysteroscopic procedures or other intrauterine interventions, including during assisted reproductive technology cycles.

Advantages include improved visualization of intrauterine lesions, lower invasiveness, and lower cost than diagnostic hysteroscopy. Limitations include that SIS may miss some lesions and findings may still require confirmatory hysteroscopy. It does not assess tubal patency; for tubal evaluation, other tests are used.

Contraindications include pregnancy and active pelvic infection. Possible risks are mild cramping, transient vaginal bleeding, and, rarely, uterine perforation or infection, with these risks minimized by aseptic technique.