(HyCoSy) Hysterosalpingo contrast sonography is used for evaluation of fallopian tube patency in patients with fertility problems who underwent transvaginal sonography. HyCoSy compared to more invasive techniques such as chromo-laparoscopy is rapidly becoming the screening test of choice to determine tubal patency.
Any body cavity that can be accessed can, in principle, be injected with vascular contrast. The contrast agent is instilled into the uterine cavity via a small Foley type catheter and, using transvaginal echography, the passage of the echogenic contrast along the tubes and into the adnexal peritoneum is tracked.
Hysterosalpingo contrast sonography does not offer the same anatomical and false negative results, e.g., because of tubal spasm, are possible so conventional X-ray salpingography is needed when tubal surgery is an option.

See also Endocavitary Echography, Transvaginal Sonography.