Endometriosis is a condition where tissue similar to the lining inside the uterus grows outside of it, often causing pain and infertility. Hysterosalpingography (HSG) is a common imaging procedure used in fertility assessments. Many individuals undergoing fertility investigations or experiencing symptoms of endometriosis often wonder if an HSG test can detect it. This article clarifies HSG’s capabilities regarding endometriosis detection.
Understanding Hysterosalpingography
Hysterosalpingography (HSG) is a radiological procedure that uses X-rays and a special contrast dye to visualize the inside of the uterus and the fallopian tubes. During the procedure, a thin tube is inserted into the cervix, and a radio-opaque material is injected. X-ray images are then taken as the dye fills the uterine cavity and flows through the fallopian tubes.
HSG’s primary purpose is to assess the uterine cavity’s shape and structure and determine if fallopian tubes are open (patent). It identifies fallopian tube blockages, which can prevent sperm from reaching an egg or a fertilized egg from traveling to the uterus. HSG can also reveal uterine abnormalities like fibroids, polyps, or adhesions.
HSG’s Limitations in Detecting Endometriosis
An HSG does not directly visualize or diagnose endometriosis tissue. Endometriosis involves endometrial-like tissue growing outside the uterus, often on pelvic organs like ovaries, fallopian tubes, or the uterus’s outer surface. Since HSG is an X-ray of the uterine cavity and fallopian tubes, it cannot directly image these external endometrial growths.
While HSG cannot directly detect endometriosis, it may reveal indirect signs, especially in severe cases. These indirect signs include fallopian tube blockages, distorted tubal anatomy, or hydrosalpinx (fluid-filled, blocked fallopian tubes), which can result from extensive adhesions caused by endometriosis. However, these findings are not specific to endometriosis and can stem from other conditions like previous infections or surgeries. Therefore, an HSG showing such signs does not confirm an endometriosis diagnosis, and further investigation would be necessary.
Primary Methods for Diagnosing Endometriosis
As HSG is not a primary diagnostic tool for endometriosis, other methods identify the condition. The gold standard for definitively diagnosing endometriosis is surgical laparoscopy. During this minimally invasive procedure, a surgeon makes a small incision, usually near the navel, and inserts a laparoscope to directly visualize pelvic organs for endometriosis tissue. A biopsy of suspicious tissue can be taken during laparoscopy for laboratory confirmation.
Other diagnostic approaches can suggest endometriosis, though they are not definitive alone. These include a thorough symptom review, a physical pelvic exam for changes like nodules or cysts, and imaging techniques such as specialized ultrasound or MRI. While standard ultrasounds may not confirm endometriosis, they can detect associated cysts, known as endometriomas. MRI can provide detailed images of pelvic organs and is particularly useful for identifying deep infiltrating endometriosis or planning surgery.
HSG’s Role in Endometriosis-Related Infertility
Even though HSG cannot directly diagnose endometriosis, it plays a role in the broader infertility workup, especially for those with suspected endometriosis. Endometriosis can lead to tubal blockages or distortions in fallopian tubes due to inflammation and scar tissue (adhesions). HSG is highly effective at detecting these tubal issues, a common cause of infertility.
Therefore, HSG helps identify potential mechanical barriers to conception caused by endometriosis. If the test reveals blocked or damaged fallopian tubes, it indicates a specific problem contributing to infertility, guiding subsequent treatment decisions. While HSG does not diagnose endometriosis itself, it provides valuable information about fallopian tube patency, crucial for fertility assessment. In some cases, the contrast dye’s flushing action during an HSG may even have a therapeutic effect, potentially clearing minor tubal obstructions and improving pregnancy rates.