UTC Ultrasound Physics & Instrumentation

Question 1

What is the accepted average speed of sound in soft tissue used as the standard for ultrasound imaging calculations?

Accepted Answer

1,540 m/s

Answer

The accepted average speed of sound in soft tissue is 1,540 m/s, which is the standard value used by all ultrasound systems for depth calculations.

Question 2

The piezoelectric effect in ultrasound transducers refers to which property?

Accepted Answer

Conversion of electrical energy to mechanical vibrations and vice versa

Answer

The piezoelectric effect is the ability of certain crystals to convert electrical energy into mechanical vibrations (and vice versa), which is the fundamental operating principle of ultrasound transducers.

Question 3

Acoustic impedance (Z) is calculated using which two factors?

Accepted Answer

Density and propagation speed

Answer

Acoustic impedance Z = density (ρ) × propagation speed (c); differences in impedance at tissue interfaces determine how much sound is reflected versus transmitted.

Question 4

Which type of resolution describes the ability to distinguish two adjacent structures lying side by side perpendicular to the ultrasound beam?

Accepted Answer

Lateral resolution

Answer

Lateral resolution (also called azimuthal or transverse resolution) is the ability to distinguish two structures that are side by side in the direction perpendicular to the beam.

Question 5

What happens to the wavelength of an ultrasound wave when the frequency is increased while propagation speed remains constant?

Accepted Answer

Wavelength decreases proportionally

Answer

Since wavelength = velocity/frequency (λ = v/f), increasing frequency while velocity remains constant in tissue causes wavelength to decrease proportionally.

(UTC) Ultrasound Technologist Certification Practice Test

(UTC) Ultrasound Technologist Certification Practice Test

UTC Ultrasound Physics & Instrumentation