Use of Ultrasounography in Obstetrics and Gynaecology

Question 1

Pros and cons of abdominal ultrasound scan

Answer 1

In an obstetrics scan, due to the presence of liquor, a full bladder will not be required

Question 2

Pros and cons of vaginal (rectal) ultrasound

Answer 2

In virgins, do rectal ultrasound instead

Question 3

Abdominal ultrasound orientation: What are the three planes of the body?

Answer 3

• Coronal plane: separates front and back of the body
• Sagittal (longitudinal) plane: separates L and R side of body
• Transverse (axial) plane: separates upper and lower halves of the body

Question 4

What plane is this?

Answer 4

Coronal plane of foetal spine

Question 5

What plane is this?

Answer 5

Sagittal plane of fetal spine

Question 6

What are some terminology for orientation towards the patient’s head vs patient’s feet in longitudinal scan?

Answer 6

Question 7

On a transverse scan, patient’s R side is shown on the __________ of the screen

Answer 7

Question 8

What structures/features are assessed in a gyanecological ultrasound examination?

Answer 8

• Uterus – size, position, endometrium, myometrium and outline, e.g. endometrial polyps, fibroids, adenomyosis
• Ovaries – any abnormality, e.g. ovarian cyst
• Any adnexal mass, e.g. paratubal cyst, hydrosalpinx
• Any free fluid (ascites or haemoperitoneum)

Question 9

What is seen here?

Answer 9

Normal uterus in the sagittal plane

Question 10

What is seen here?

Answer 10

Endometrial polyp inside intrauterine cavity (saline sonogram)

Question 11

What is seen here?

Answer 11

Intramural fibroid in posterior uterine wall

Question 12

What is seen here?

Answer 12

Normal ovaries with small follicles inside it

Question 13

What is seen here?

Answer 13

Hypoechoic lesion represents endometriotic cyst

Question 14

Particular care should be taken to reduce the risk of thermal hazard whn exposing the following to diagnostic ultrasound:

Answer 14

1. Embryo less than 8 weeks after conception
2. Head, brain or spine of any foetus or neonate
3. Eye (in a subject of any age)

Question 15

Brief overview of the guidelines for the safe use of diagnostic U/S equipment

Answer 15

Question 16

Important things to take note of in early pregnancy scan - 1st trimester

Answer 16

TVS is usually done
* Checking pregnancy location (normal intrauterine vs ectopic)
* Confirming viability
* Assessment of other pelvic organs (ovary / uterus)

– Detecting multiple pregnancy
– Dating
– Nuchal translucency scan

Question 17

What is seen here?

Answer 17

At adnexal area, there is an extrauterine sac with a CRL (ectopic pregnancy)

Question 18

What is CRL?

Answer 18

Whenever we see an intrauterine sac with a foetal pole, we try to measure the CRL [can date pregnancy]

Question 20

What is seen in the L and R image?

Answer 20

L: twins
R: triplets

One baby = singleton

Question 21

Answer 21

Lambda sign: DC/DA twin
T sign: MC pair (monochorionic/diamniotic pair)

Question 22

What does nuchal translucency facilitate?

Answer 22

Nuchal translucency scan facilitates first trimester Down screening

Question 23

What is an Anomaly (structural) scan?

Answer 23

Question 24

What is the use of USG in 3rd trimester?

Answer 24

• Growth scan - screening
• Women with risk factors for growth restriction / difficulty with monitoring by

P/E
** Previous baby with IUGR
** Big fibroids
** Maternal obesity
** Single umbilical artery

Question 25

What do we need to do if placenta previa is noticed on anomaly scan?

Answer 25

Question 26

How can we tell whether baby is OA or OP in intrapartum ultrasound?

Answer 26

OA = baby is facing mummy’s back

OP = can see orbits

Question 27

What can we determine when head is identified?

Answer 27

Fetal presentation: part of the baby that is overlying the maternal pelvis (cephalic, face, brow, breech, shoulder, complex)

Fetal lie: Relationship between the longitudinal axis of the baby to the longitudinal axis of the mother (longitudinal, transverse, oblique)

Question 28

CVD exam with USG

Answer 28