ANATOMY OF FEMALE REPRODUCTIVE TRACT ON USG

1. NORMAL AND ABNORMAL
RADIOLOGICAL FINDINGS OF
FEMALE GENITAL TRACT -
PART1
By -Dr SHUBHANKAR TYAGI

2. WHY THE NEED OF IMAGING ?
1. Evaluation of pelvic pain
2. Evaluation of pelvic masses
3. Evaluation of endocrine abnormalities, including polycystic
ovaries
4. Evaluation of dysmenorrhea (painful menses)
5. Evaluation of amenorrhea
6. Evaluation of abnormal bleeding
7. Evaluation of delayed menses
8. Follow-up of a previously detected abnormality
9. Evaluation, monitoring, and/or treatment of infertility patients
10. Evaluation in the presence of a limited clinical examination
of the pelvis.

3. 11. Evaluation for signs or symptoms of pelvic infection
12. Further characterization of a pelvic abnormality noted on
another imaging study
13. Evaluation of congenital uterine and lower genital tract
anomalies
14. Evaluation of excessive bleeding, pain, or signs of
infection after pelvic surgery, delivery, or abortion
15. Localization of an intrauterine contraceptive device
16. Screening for malignancy in high-risk patients
17. Evaluation of incontinence or pelvic organ prolapse
18. Guidance for interventional or surgical procedures; and
19. Preoperative and postoperative evaluation of pelvic

4. UTERUS

5. The anterior surface of the uterine fundus and body is
covered by peritoneum.
The peritoneal space anterior to the uterus is the
vesicouterine pouch, or anterior cul-de-sac. This space is
usually empty, but it may contain small bowel.
Posteriorly, the peritoneal reflection extends to the
posterior fornix of the vagina,
forming the rectouterine recess, or posterior cul-de-sac.
Laterally, the peritoneal reflection forms the broad
ligaments, which extend from the lateral aspect of the
uterus to the lateral pelvic side walls

6. The round ligaments arise from the uterine cornua
anterior to the fallopian tubes in the broad ligaments,
extend anterolaterally, and course through the inguinal
canals to insert into the fascia of the labia majora.
The cervix is located posterior to the bladder and opens
into the upper vagina through the external os.
The vagina is a fibromuscular canal that lies in the midline
and runs from the cervix to the vestibule of the external
genitalia.

8. The main blood supply to the uterus is through the uterine
artery , a branch of the internal iliac artery.
The uterine artery reaches the uterus through the cardinal
ligament and then divides into an ascending and a
descending branch.
The uterine artery gives off multiple branches to the uterus
as it courses between the layers of broad ligament, before
anastomosing with the uterine branch of the ovarian artery.
The uterine artery also gives off branches to the cervix,
vagina, fallopian tubes, and ovary.

9. Size, shape, and position of the uterus depend on age,
hormonal status, pregnancy, and the degree of the bladder
distention. In women of reproductive age, the uterus is 6 to
9 cm long .
After menopause the size of the uterus significantly
decreases.
When the uterus is anteverted, it is visualized posterior
and superior to the bladder, whereas the retroverted uterus
projects into the cul-de-sac.
The uterus is divided into the body and cervix. The cervix
is typically located in the midline with the uterine body
often deviating to one side of the pelvis. Although it is often
difficult to clearly distinguish the uterus from the cervix, the
two can be separated from one another by their
configurations because the uterus is somewhat triangular
in shape, whereas the cervix has a more rounded
appearance

10. NORMAL UTERINE RADIOLOGICAL FINGINGS

15. ENDOMETRIAL PHASES AND MEASUREMENT

22. CT ANATOMY OF FGT
The cervix
enhances to
a lesser
degree
compared
with the
uterus and
often appears
hypodense

24. Post menopausal uterus

25. The endometrium is often seen as a central hypodensity,
most commonly ovoid or triangular in shape, better
delineated on contrast-enhanced images. The lower
attenuation of the endometrium relative to the
myometrium is normal for premenopausal patients and
should not be mistaken for fluid. This appearance is likely
related to a less rich vascular supply of the endometrium
relative to the myometrium.

30. The size of the cervix, however, is variable, depending
on many factors, including hormonal status and
pregnancy. Younger patients can have a normal cervix
that is larger than 4 cm in diameter.
Similar to the uterus, the enhancement pattern of cervix
can be zonal, although the cervix typically enhances
more slowly compared with the uterus, and this finding
should not be misinterpreted as abnormal.
The cervix consists of two parts, the supravaginal and
pars vaginalis, a lower portion that protrudes into vaginal
canal

32. The ovaries are ovoid parenchymal structures that most
commonly contain soft tissue stroma with small cystic areas
that represent normal follicles.
Their appearance varies with age and hormonal status. In
women of childbearing age, the average ovarian volume is
9.8 cm 3 ; in postmenopausal women, 5.8 cm 3 ; and in the
premenarchal group, 3.0 cm 3 .
In menstruating women, the normal ovary can be identified
on CT in most instances .
Postmenopausal ovaries may be difficult to detect on CT
because of their small size and lack of cysts

36. On CT, the cervix and body of uterus appear as soft
tissue masses, only identifiable from each other by their
shape, i.e. cervix is round and uterus oval or triangular in
cross section. In women of reproductive age, the
endometrium exhibits hypodensity relative to the inner
myometrium during most phases of contrast
enhancement, a finding that might be mistaken as fluid
within the uterine cavity.

39. On MRI, three distinct uterine zones can be differentiated in
women of reproductive age on T2-weighted imaging. The
endometrium represents the central high signal intensity
portion of theuterus.
The middle low signal intensity layer is the junctional zone
and represents the inner myometrium. The thickness of
normal junctional zone is less than 8 mm. The outer medium
signal intensity represents the outer myometrium. Its signal
intensity depends on the phase of menstrual cycle, but it
usually exhibits intermediate signal intensity on T2-weighted
image.
The zonal anatomy is important to assess the depth of
myometrial invasion of endometrial carcinoma. On T1-
weighted images, uterus is seen as an organ with medium to
low signal intensity.

43. The endometrium is best measured on the midline sagittal
scan of the uterus. The measurement is taken as the
distance between the two interfaces formed by junction of
subendometrial halo and the more echogenic
endometrium. This is the double layer thickness.
The normal endometrial cavity is seen as a central
echogenic line as a result of specular reflection from the
interface between apposing surfaces of the endometrium.
It should be straight or smoothly curved.

45. The cervix is better visualized by transvaginal
sonography as a tubular structure of homogeneous
echogenicity.
The mucus within the endocervical canal usually
appears as an echogenic interface which may become
hypoechoic during the periovulatory period as the fluid
content increases.
Retention (nabothian) cysts of the cervix are commonly
seen during routine sonography. They may vary in size
from a few mm to 4 cm.
They may be single or multiple and usually diagnosed
incidentally, although they may be associated with
chronic cervicitis

48. MULLERIAN DUCT ANOMALIES