1. ULTRASOUND IN OBSTETRICS & GYNECOLOGY
Hidayat Wijayanegara
Department of Obstetric & Gynecology
School Medicine Padjadjaran University /
Hasan Sadikin Hospital Bandung

2. Ultrasound examination :
Reveals vital information
Fetal anatomy
Fetal environment
Growth
Well being
No biological hazard
The first obstetrical application of USG imaging : Ian Donald (1958)

3. Ultrasound
Sound waves of frequencies higher than the hearing limit of the human ear are called ultrasonic waves
The limit is by convention 20 KHz
Medical practice frequencies between MHz are commonly used

4. Technology :
Sound waves reflecting back from the fetus or image structure  displayed on the ultrasound screen
Alternating current is applied to a transducer made of piezoelectric material  intermittent high frequency sound waves exceeding 20,000 cps are generated

5. Interface between structures of different tissue densities
The transducer emits a pulse of sound waves that passes through the layer of soft tissue 
Interface between structures of
different tissue densities
Some of the energy is reflected back
to the transducer
A small electrical voltage
Display on a screen
Bone is dense (echogenic)  white on the screen
Fluid (anechoic)  black
Soft tissues  varying shade of gray

6. The diagnostic ultrasound visualization method
1.Operator control 6. Visual information
2.Transducer drive 5. Electric information
3.Ultrasound pulses 4. Acoustic information
The diagnostic ultrasound visualization method
Operator
Instrument
Transducer
Tissue interaction

11. Transabdominal Scanning :
Performed with 3.5 – 7 MHz
Safety : no confirmed biological effects in mammalian tissue have been demonstrated in the frequency range of medical ultrasound (AIUM, 1991)

12. Choice of equipment : Transabdominal scanning Transvaginal scanning
Doppler and color flow imaging 3D 2D

13. Biophysical mechanism :
Are not fully understood
The effects of ultrasound on various biological entities may be due to one or a combination of any of the following :
1. Heating effects
2. Cavitational effects
3. Mechanical effects
Are associated only with high
average intensities and not
found in diagnostic equipment

14. Preparation of the patient
Ultrasound beam cannot penetrate gas
The interface created by gas  the sound beam totally reflected
Water  excellent transmission medium
The distension of bladder  displaces intestinal loop  acoustic window to the pelvic structure
Patient should be scanned with a full bladder
The full bladder technique offer :
1. It displaces the fetal head upwards
2. It allow visualization of the cervix

15. Coupling agents Scanning technique
A gel or an oil  eliminates the air interface between the transducer and the patient’s skin
Scanning technique
The patient is on your right
The machine is on your left
Work in dim lighting to help reflection on the screen

16. Indications for ultrasound examination
Gynecology : - Uterus, Ovaries, Adnexa
- Abnormal bleeding, pelvic pain & discomfort
- IUCD location and complications
- Pelvic mass reveals mass or enlargement of pelvic organ
- Evaluation of masses palpable
- Ovulation induction therapy
- Guidance for abscess drainage

17. Uses of ultrasound in gynecology
1. Determine the size and location of lesions
2. Characteristics of the lesion: cystic, complex or solid
3. Determine if mass is uterine or extrauterine
4. Evaluate the extent of pelvic inflammatory disease or endometriosis and follow-up
5. Follow the course of a simple cyst: regression, etc.
6. Locate the position of an intrauterine device
7. Detection of ascites
8. Radiation therapy planning

18. Obstetrics : Routine obstetrical ultrasound scan: 18-20 weeks
1st Trimester :
Confirm pregnancy, viability, gestational age
Rule out :
Ectopic pregnancy
Gestational trophoblastic disease
Foreign bodies
Large for dates – fibroid, uterine malformation, multiple gestation
Small for dates – missed abortion, blighted ova

19. Ovaries, rule out adnexal lesions, uterine position, rule out uterine anomalies
Undetermined etiology of vaginal bleeding
Suspected complications, i.e subchorionic hematome

20. 2nd and 3rd trimester :
Confirm viability, gestational age, fetal number
Evaluated fetal growth, anatomy, lie, position, follow up anomaly
Evaluate placenta, AFV, cord
Biophysical profile for fetal well being
Vaginal bleeding

21. Components of basic ultrasound examination according to Trimester pregnancy
1st trimester
Gestational sac location
Embryo identification
Crown rump length (CRL)
Fetal heart rate motion
Fetal number
Uterus & adnexal evaluation
2nd and 3rd trimester
Fetal number
Presentation
Fetal heart motion
Placental location
Amniotic fluid volume
Gestational age
Survey of fetal anatomy
Evaluation for maternal pelvic mass

22. Ultrasonic Landmark Occurence (weeks of gestation)
Gestational sac 5 – 6 weeks
Fetal embryonic pale 6 – 7 weeks
Detection of fetal life 7 – 8 weeks
Placenta 8 – 10 weeks
Loss of gestational sac 11 – 13 weeks
Fetal head 11 – 14 weeks
(Biparietal diameter)

23. Evaluation of ultrasound to determine gestational age
Crown Rump Length (CRL)
Biparietal diameter (BPD)
Femur Length (FL)
Head Circumference (HC)
Abdominal Circumference (AC)

24. Accuracy of ultrasound measurement for different gestational groups
Ultrasound parameter Accuracy
Gestational sac diameter days
Crown Rump Length days
BPD second trimester + 1 to 1.5 weeks
BPD third trimester + 2 to 4 weeks
FL second trimester + 1 to 1.5 weeks
FL third trimester + 3 to 3.5 weeks
Multiple parameter (2nd trimester) weeks
Multiple parameter (3rd trimester) weeks

25. Summary 1. Physics of ultrasound
The ultrasound used in clinical practice is limited to frequencies in the range of 1-10 cycles per second (1-10 MHz)
In Obstetrics : 3.5 MHz and 5 MHz
2.Ultrasound
Is produced when transmitted pulses of sound from the transducer cross body structures and reflect energy back to the transducer from the interfaces of organs

26. 3. Ultrasound in Obstetrics
Confirmation of an intrauterine pregnancies
Exclusion of an ectopic pregnancies
Assessment of an intrauterine pregnancies
Determination of gestational age :
Are uncertain of the date of conception
Resolving discrepancies between gestational age and uterine size :
Large for dates
Small for dates

27. Investigation of uterine bleeding
Visualization for high risk procedures
Amniocentesis
Chorionic villous sampling
Cordocentesis
Evaluation of fetal well-being
Distinguish congenital malformation
Biophysical profile
Doppler flow velocimetry
IUGR  60-80% of the time in cases where the umbilical artery waveforms are abnormal due to uteroplacental insufficiency

70. THANK YOU