The cervix is the cylindrical lower portion of the uterus that projects into the vagina, serving as the passageway between the uterine cavity and the vaginal canal. It plays a critical role in pregnancy by remaining firmly closed to support the growing fetus and then dilating during labor to allow delivery. On transvaginal ultrasound, the cervix is clearly visualized and its length, diameter, and internal architecture can be assessed. Cervical evaluation is important in obstetric ultrasound for screening for preterm birth risk, monitoring cervical cerclage, and assessing cervical insufficiency, and in gynecologic ultrasound for evaluating cervical masses, polyps, and nabothian cysts.
Sonography Term