HSG vs HSC vs H2O sono...What is the difference?

Medical terminology can really give patients fits and no where is this more apparent than in the distinctions between hysterosalpingogram (HSG), hysteroscopy (HSC) and hysterosonogram (H2O sono or water sono). In fact, these three tests are very different although similar information can be gleaned from them depending upon the clinical situation. Taking an accurate medical history is so very important. We ask our patients to recount specific details of complicated medical testing and yet, personally I can’t usually remember what I had for lunch yesterday (actually I can because I have been on the Special K diet since 1/1/07!). Memory is not perfect and that is why retrieving medical records is so important. When patients are moving away from Washington DC, which happens about every 4 years or so, I always make sure that they take a complete set of records with them.

So today’s “Question of the Day” from 100 Questions and Answers about Infertility, the book that more of you faithful readers need to review on Amazon.com (hint, hint and remember my Mother always said “if you can’t say anything nice, then don’t say anything at all), tries to shed some light on this confusing trio of tests.

12. What is a hysteroscopy, and do I need one? Is it the same as a water sonogram or a hysterosalpingogram?

A hysteroscopy is an outpatient surgical procedure that is performed either to diagnose or to treat a problem within the uterine cavity. During hysteroscopy, the physician inserts a small fiber-optic telescope through the cervix and into the uterus. Either gas or liquid can be used to distend the uterus and allow the physician to directly visualize the uterine cavity. The physician may also introduce small instruments into the uterus to cut scar tissue or remove polyps or fibroids. Although diagnostic hysteroscopy can be performed in the physician’s office under local anesthesia, operative hysteroscopy requires anesthesia because of the cramping that occurs during uterine manipulation. Complications of hysteroscopy are rare but may include infection, bleeding, uterine perforation, damage to adjacent structures, and even death.

A water sonogram (hysterosonogram) is a specialized ultrasound examination performed using a transvaginal ultrasound probe. A small catheter is placed within the uterine cavity, and sterile saline is then introduced into the cavity during the sonogram to allow the physician to visualize any uterine polyps or fibroids. Usually, this kind of examination does not provide any information about the status of the fallopian tubes. Nevertheless, hysterosonograms are helpful in identifying the presence of an endometrialpolyp seen on routine sonogram or the location of a fibroid (see Figure below). They have limited benefit in evaluating uterine scar tissue and are only diagnostic (not therapeutic).

A hysterosalpingogram (HSG) is similar to a hysterosonogram in that fluid is introduced into the uterine cavity—but that is where the similarity ends. During an HSG (see Figure below), a radioopaque dye is first introduced into the uterus; x-rays are then taken of the area. The HSG can be used to diagnose polyps and fibroids and is superior to hysterosonogram in evaluating the presence of uterine scar tissue. This type of imaging also provides information on the status of the fallopian tubes, unlike either a hysteroscopy or a hysterosonogram. Because it employs traditional x-rays, an HSG is usually performed at a hospital’s radiology department or at a radiologist’s office, as few REs have this equipment in their offices.