Diagnostic Ultrasound - Abdomen and Pelvis

Cervix
Anatomy: Pelvis
TRANSABDOMINAL ULTRASOUND OF CERVIX
Urinary bladder
External os
Ectocervix
Right lateral vaginal fornix
Left lateral vaginal fornix
Urinary bladder
Cervical stroma
Submucosal layer
Mucosa layer of cervix
Endocervical canal
Shadowing from edges of mucosal layer
Urinary bladder
Internal os
Lower uterine wall
(Top) Transverse transabdominal ultrasound shows the ectocervix at the level of external os. The lateral vaginal fornices are seen as
relatively hypoechoic areas on each side of the ectocervix. (Middle) Transverse transabdominal ultrasound of the mid endocervix shows
the mildly thickened and echogenic mucosal layer. Note that, during the menstrual cycle, the thickness and echogenicity of the mucosal
layer undergoes changes as the endometrium does. When thickened, it typically casts shadowing from its edges. (Bottom) Transverse
transabdominal ultrasound shows the upper cervix at the level of the internal os, which opens into the uterine cavity. Identification of
the internal os is clinically significant in pregnancy for placental site localization.
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