MEDRADSC 2AA3 - Lecture 4.3 - The Transducer

what material in an ultrasound transducer is used to send and receive ultrasound waves?

piezo-electric crystals

how are the crystals arranged in the transducer?

numerous small crystals arranged linearly across the face of the transducer which create a sound beam

what is required of the piezoelectric material in the ultrasound transducer?

to create mechanical deformations of materials when an electrical energy is applied to it

what is an example of a natural piezoelectric material?

quartz

what are the two common synthetic piezoelectric materials used in ultrasound?

lead zirconate titanate (PZT) and piezoelectric ceramics barium titanate (PCBT)

PZT and PCBT are also known as _____________.

piezoceramics

True or False: Piezoelectric ceramics and materials can be used in the autoclave for sterilization.

False

backing material

used to stop crystals from ringing once the drive voltage has ceased and prevents the crystals from resonating continuously

acoustic matching layers

designed to reduce reflection of sound waves and promote transmission into tissue

without matching layers, nearly _________% reflection would occur at this point in the transducer.

80-90

what are the main types of transducers in ultrasound?

linear, curved linear, phased array sector, linear phased, trapezoidal and intracavity

A patient is receiving a cardiac ultrasound in the imaging procedure, the technologist is most likely to use which type of array?

A. Linear

B. Curved Linear

C. Phased Array

C

A patient is receiving a thyroid ultrasound for a fine needle aspiration. Which type of transducer will the technologist use?

A. Curved linear

B. Trapezoidal

C. Intracavity

D. Linear

D

what type of anatomy are linear array transducers used for?

superficial anatomy, approximately 8cm deep at most

what are the frequency ranges for a linear transducer?

12-3 MHz, 18-5 MHz, decreased penetration, increased resolution

what type of anatomy are curved linear array transducers used for?

liver, gallbladder, pancreas, GI tract, pelvic organs and neonatal brain, provides a larger FOV

what are the frequency ranges for a curved linear transducer?

6-1 MHz, 9-3 MHz, 8-5 MHz, increased penetration

what are the two main types of intracavity transducers?

transvaginal and transrectal