A hydrosalpinx is a condition in which a fallopian tube becomes blocked, usually at its distal end, and fills with clear fluid. On transvaginal ultrasound, a hydrosalpinx appears as a tubular, anechoic or hypoechoic structure in the adnexa, often with a folded or C-shaped configuration. The walls may appear thin, and incomplete septations from folded walls can create a cogwheel appearance in cross-section. Hydrosalpinx is important clinically because it is a common cause of female infertility, as the blocked tube cannot capture and transport the egg. It can result from previous pelvic infection, endometriosis, or prior surgery, and its detection on ultrasound has important implications for fertility treatment planning.
Sonography Term