ARDMS SPI Image Formation and Processing 4

Question 1

Tissue harmonic imaging improves image quality primarily by:

Accepted Answer

Using the second harmonic frequency generated within tissue to form the image

Answer

As sound propagates through tissue, nonlinear distortion generates harmonic frequencies; imaging at the second harmonic reduces near-field artifact and clutter because harmonics build up away from the transducer.

Question 2

Dynamic range in ultrasound refers to:

Accepted Answer

The ratio of the largest to smallest echo amplitudes the system can process and display

Answer

Dynamic range (expressed in dB) describes the span between the strongest and weakest signals that can be meaningfully represented, influencing the number of displayed gray levels.

Question 3

Increasing the dynamic range setting on the ultrasound unit will:

Accepted Answer

Display more gray shades, producing a softer-appearing image

Answer

A wider displayed dynamic range maps more levels of echo amplitude into the gray scale, resulting in more subtle gray-scale gradations and a lower-contrast appearance.

Question 4

Compound spatial imaging (multi-angle compounding) improves image quality by:

Accepted Answer

Averaging images acquired from several steering angles to reduce speckle and improve margin definition

Answer

By combining frames obtained at different steering angles, compound imaging reduces angle-dependent artifacts and averages out speckle, improving structural border visibility.

Question 5

Coded excitation in ultrasound systems is used primarily to:

Accepted Answer

Improve signal-to-noise ratio and penetration without increasing peak pressure

Answer

Coded excitation (e.g., chirp or Golay codes) spreads pulse energy over time and uses matched-filter compression on receive, boosting SNR and penetration at the same mechanical index.

ARDMS SPI - ARDMS Sonography Principles and Instrumentation Practice Test

ARDMS SPI - ARDMS Sonography Principles and Instrumentation Practice Test

ARDMS SPI Image Formation and Processing 4