Both Hysterosalpingography (HSG) and Hysterosonosalpingography (SHSG) are outpatient procedures used to evaluate tubal patency or obstruction in patients with infertility, as well as endocavitary uterine pathology.
HSG involves viewing the passage of an iodinated contrast dye through the uterus and tubes using several pelvic radiographs, while SHSG involves monitoring the passage of a gel-foam using pelvic ultrasound. Both are well tolerated, although referred pain is less with SHSG.
SHSG also has the advantage of avoiding the use of ionizing radiation and the risk of allergies to iodine, since a gel-foam composed of hydroxypropylcellulose and glycerol is used, and allergic reactions to it are rare. Compared to HSG, SHSG also allows concomitant visualization of the ovaries and myometrium.
In recent years the SHSG technique has improved with the introduction of new contrast media, 3D ultrasound, use of color Doppler and better ultrasound resolution. At present, it seems that SHSG can replace HSG as the first-line method in the study of infertility, one of its main advantages being the direct and dynamic examination of the fallopian tubes.