This lecture is the continuation of previous transabdominal technique. In this lecture types of probes are explained briefly. Transducer Manipulation Techniques are explained as well. An idea of acoustic window is given and few TAUS pelvis images are displayed.

1. GYNAECOLOGICAL
ULTRASOUND
Lecture 2: Transabdominal Scanning Technique (part 2)
IQRA SAEED
Lecturer MIT

2. CONTENTS
Transducer
Types
Manipulations
TAUS for pelvis
Image display of TAUS
Acoustic window

3. TRANSDUCER
• A transducer is a device that converts electrical energy into mechanical energy
(sound waves) and back again, based on piezoelectric effect.
• It consists of five main components:
1. Crystal/ceramic element with piezoelectric properties usually lead zirconate
titanate (single/multiple)
2. Positive and ground electrodes
3. Damping block
4. Matching layer
5. Housing

6. TYPES OF TRANSDUCERS
• Linear Transducers : piezoelectric crystal arrangement is linear, shape of the beam
is rectangular, near field resolution is good. Footprint, frequency and applications
of this transducer depend on whether it is being used for 2D imaging or 3D
imaging.
For 2D imaging: wide footprint + 2.5-12MHz
Various applications e.g. vascular, breast, thyroid, tendons, intraoperative.
For 3D imaging: wide footprint + 7.5-11MHz
Various applications e.g. vascular, breast, thyroid.

7. • Convex Transducers: piezoelectric crystal arrangement is curvilinear, beam shape
is convex, good for in depth examinations, image resolution decreases as depth
increases. Footprint, frequency, applications depend on 2D/3D imaging.
For 2D imaging: wide footprint + 2.5-7.5MHz
Various applications e.g. abdominal examinations, transvaginal examinations, rectal
examinations
For 3D imaging: wide FOV, 3.5-6.5MHz
Abdominal examinations + subtype-microconvex transducers for neonatal and
paediatric examinations.

8. • Phased Array Transducers: Small footprint + low frequency i.e. 2-7.5MHz, beam
shape is triangular, near field resolution is poor.
Various applications e.g. cardiac, abdominal, brain

11. https://www.startradiology.com/the-basics/ultrasound-technique/index.html

12. • Pencil Transducers ( for Doppler studies - 2 to 8MHz)
• Endocavitary Transducers (Endovaginal, endorectal, 3.5-11.5MHz)
• Transesophageal Transducers (to scan heart through esophagus – 3 to 10MHz)

14. TRANSDUCER MANIPULATIONS

15. https://www.pocus101.com/ultrasound-machine-basics-knobology-probes-and-
modes/

16. • Sliding involves moving the entire probe in a specific direction to find a better
imaging window. This is usually used to find the best window, move to different
areas of the body, or to follow a specific structure (such as a vessel).
• Tilting the ultrasound probe involves moving the transducer from side to side
along the short axis of the probe. It is commonly also called “Fanning” as well.
Tilting will allow visualization of multiple cross-sectional images of a structure of
interest. You can apply this technique to structures such as the heart, kidney,
bladder, vessels, etc.

17. • Rotating the ultrasound probe involves turning the transducer in a clockwise or
counterclockwise direction along its central axis. Rotation is most commonly used
switch between the long and short axis of a specific structure such as a vessel, the
heart, the kidney, etc.
• Rocking the ultrasound probe involves “rocking” the ultrasound probe either
towards or away from the probe indicator along the long-axis. Rocking allows you
to help center the area of interest. This is also referred to as “in-plane” motion
because the image is kept in-plane throughout the manipulation.

18. • Compression with the ultrasound probe involves putting downward pressure on
the probe to evaluate the compressibility of a structure or organ of interest. The
most common use is to evaluate for deep vein thrombosis, differentiate between
artery versus vein, and evaluation for appendicitis (non-compressible).

19. TAUS FOR PELVIS AND ACOUSTIC
WINDOW
• TAUS is performed in patients who are not sexually active to visualize the pelvic
viscera.
• The TA examination is performed with the probe placed over anterior abdominal
wall at the level of pelvis.
• A distended urinary bladder aids in visualization of pelvic structures at TA
ultrasound window due to better sound transmission properties of water inside of
it. Full UB serves as an acoustic

20. • What is acoustic window? It is basically a location from which probe makes its scan.
The probe can be turned and/or angled in different directions yielding a different
view, but all of the views are from the same acoustic window or perspective.
Ultrasound gel also serves as an acoustic window.
• Distended bladder also displaces the bowel loops away from the field of view which
hinders scanning due to gassy shadows.

21. Clinical indications for pelvic examination include:
1. Anomalies
2. Inflammatory conditions
3. Neoplastic conditions
4. Other i.e. pregnancy/cysts/calcifications

22. IMAGE DISPLAY OF TAUS

24. • For TVS: empty bladder is required.