Endometriosis is a chronic condition in which tissue resembling the endometrium grows outside the uterus, most commonly on the ovaries, fallopian tubes, and pelvic peritoneum. This displaced tissue responds to menstrual hormones, bleeding with each cycle and causing inflammation, scarring, and pain. Transvaginal ultrasound can reliably detect endometriomas on the ovaries and, in experienced hands, can identify deep infiltrating endometriosis affecting structures like the rectovaginal septum, uterosacral ligaments, and bladder. While laparoscopy remains the gold standard for definitive diagnosis, ultrasound has become increasingly valuable as a non-invasive tool for mapping the extent of endometriosis before surgery and for monitoring the condition over time.
Sonography Term