Use of Ultrasounography in Obstetrics and Gynaecology Flashcards
Pros and cons of abdominal ultrasound scan
In an obstetrics scan, due to the presence of liquor, a full bladder will not be required
Pros and cons of vaginal (rectal) ultrasound
In virgins, do rectal ultrasound instead
Abdominal ultrasound orientation: What are the three planes of the body?
- 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
What plane is this?
Coronal plane of foetal spine
What plane is this?
Sagittal plane of fetal spine
What are some terminology for orientation towards the patient’s head vs patient’s feet in longitudinal scan?
On a transverse scan, patient’s R side is shown on the __________ of the screen
What structures/features are assessed in a gyanecological ultrasound examination?
- 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)
What is seen here?
Normal uterus in the sagittal plane
What is seen here?
Endometrial polyp inside intrauterine cavity (saline sonogram)
What is seen here?
Intramural fibroid in posterior uterine wall
What is seen here?
Normal ovaries with small follicles inside it
What is seen here?
Hypoechoic lesion represents endometriotic cyst
Particular care should be taken to reduce the risk of thermal hazard whn exposing the following to diagnostic ultrasound:
- Embryo less than 8 weeks after conception
- Head, brain or spine of any foetus or neonate
- Eye (in a subject of any age)
Brief overview of the guidelines for the safe use of diagnostic U/S equipment
Important things to take note of in early pregnancy scan - 1st trimester
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
What is seen here?
At adnexal area, there is an extrauterine sac with a CRL (ectopic pregnancy)
What is CRL?
Whenever we see an intrauterine sac with a foetal pole, we try to measure the CRL [can date pregnancy]
What is seen in the L and R image?
L: twins
R: triplets
One baby = singleton
Lambda sign: DC/DA twin
T sign: MC pair (monochorionic/diamniotic pair)
What does nuchal translucency facilitate?
Nuchal translucency scan facilitates first trimester Down screening
What is an Anomaly (structural) scan?
What is the use of USG in 3rd trimester?
- 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
What do we need to do if placenta previa is noticed on anomaly scan?
How can we tell whether baby is OA or OP in intrapartum ultrasound?
OA = baby is facing mummy’s back
OP = can see orbits
What can we determine when head is identified?
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)
CVD exam with USG
