Sonohysterogram (SHG)

Image of a small fibroid found during a sonohysterogram.

The sonohysterogram is different than a plain ultrasound. The water injected into the uterus appears black–no shades of gray. Notice how the arrow points to a small fibroid that appears “highlighted” by the surrounding water.

A sonohysterogram is a simple ultrasound exam with one twist—a catheter is placed into the uterine cavity to fill it with water or saline. The procedure is quite painless, though some women require a mild sedative. The advantage of a sonohysterogram over a standard ultrasound is that the water infused into the uterus appears “black” on ultrasound and therefore outlines any polyps, fibroids or possible cancers.

Only a small fraction of our patients require sonohysterograms for evaluating abnormal bleeding. It can however be a useful tool when trying to sort through an ultrasound that appears to show one or more abnormal growths.

When one or more abnormalities are found within the uterus, they are easily “highlighted” by the water. The sonohysterogram is excellent for determining if a polyp or fibroid is present though it may have difficulty distinguishing one from the other.

For instance, the trained eye would know that the growth on the left is a uterine polyp. However, the 3 growths on the right may be a mixture of fibroids and polyps. The only way to know for sure would be to view them directly with a hysteroscope, remove then and let the lab decide.