Ultrasound Evaluation of Ovarian Cysts

Before the Ultrasound era, any persistent pelvic mass felt on a physical examination had to be removed surgically, because that was the only way of excluding malignancy.  Today, we can make a fairly confident diagnosis of benign ovarian cysts on the basis on an ultrasound image.

Ovarian cysts can be quite painful…or not. Many cysts that would have most certainly remained undetected before the advent of transvaginal ultrasound (TVS) are now found incidentally at an ultrasound examination of women without symptoms of a mass.  Cysts come in all sizes but are fairly consistent in their ultrasound characteristics.  They are fluid-filled masses with a very thin, smooth wall and they do not “attenuate” the ultrasound beam.  In other words, they transmit the sound right through the cyst.  There are no solid components or projections in a cyst.  That said, there are some subcategories of ovarian cysts.  A simple cyst is that which is previously described above.  A cyst with internal “debris’ may be a hemorrhagic cyst (one that has bled into itself) or an endometrioma. Both can be quite painful regardless of size.  Your doctor can better distinguish a hemorrhagic cyst vs. an endometrioma based on clinical symptoms correlated with ultrasound findings.  Some small, simple cysts are actually not true cysts at all.  They are functional follicles, which enlarge during the first half of a menstrual cycle, release an egg and then slowly decrease in size until menstruation occurs.  These rarely cause pain but may occasionally be felt by your practitioner on a physical exam.

A pelvic sonogram for diagnosing a cyst is an easy and uncomplicated test.  You should come for your exam well hydrated but with an empty bladder unless otherwise instructed.  You may eat and drink before the exam, but we will ask you to avoid just prior to the exam.  The first part of the exam involves a transvaginal approach.  The covered ultrasound probe is passed to you for insertion. The sonographer will then direct the probe to examine your uterus, lining (endometrium) and then the ovaries.

The resolution and detail using the TVS approach is exceptional.  However, the trade-off for detail is the fact that the ultrasound beam can only “see” so far into the lower pelvis.  To complete an exam, the TVS probe is removed and a standard transabdominal approach follows.  This involves using a water soluble gel placed on the abdomen as a couplant to provide the smooth action of gliding the transducer over the skin.  This approach gives a more overall view of the pelvis.  Free fluid as the result of a ruptured ovarian cyst in addition to any nodes or lymphadenopathy may be seen up to the umbilicus.  The beauty of the dual approach is the fact that women no longer have to endure the agony of drinking 24-36 ounces of fluid and “holding” their bladder prior to an exam.  Fortunately, those days of ultrasound torture are a thing of the past.

Karen Dressel, RDMS, Sonographer and Fertility Coordinator