ARDMS SPI Transducer Construction and Function 2

Question 1

Which material property is most important for a transducer backing layer?

Accepted Answer

High acoustic impedance and high attenuation

Answer

The backing layer requires high acoustic impedance to load the crystal and high attenuation to absorb rearward-traveling energy and shorten pulse duration.

Question 2

A transducer's Q factor is defined as the ratio of the operating frequency to the:

Accepted Answer

Bandwidth

Answer

Q factor = operating (center) frequency divided by bandwidth; a low Q indicates wide bandwidth and good axial resolution.

Question 3

In a linear array transducer, electronic focusing in the elevation plane is achieved by:

Accepted Answer

A fixed acoustic lens

Answer

Elevation-plane focusing in a linear array is fixed and accomplished by a curved acoustic lens bonded to the transducer face.

Question 4

What is the primary purpose of the matching layer in a transducer?

Accepted Answer

Reduce acoustic impedance mismatch between crystal and tissue

Answer

The matching layer minimizes reflection at the crystal-tissue interface by presenting an intermediate acoustic impedance, maximizing energy transmission.

Question 5

Lateral resolution in a single-element focused transducer is BEST at the:

Accepted Answer

Focal zone

Answer

Lateral (azimuthal) resolution is best at the focal zone where the beam is narrowest.

ARDMS SPI - ARDMS Sonography Principles and Instrumentation Practice Test

ARDMS SPI - ARDMS Sonography Principles and Instrumentation Practice Test

ARDMS SPI Transducer Construction and Function 2