Ultrasound System Controls and Knobology Flashcards

Dynamic range in ultrasound imaging refers to the ratio of which two signal values?

Answer: Highest to lowest detectable echo amplitude

Dynamic range is the ratio of the largest to the smallest signal amplitude the system can display, measured in decibels.

Harmonic imaging reduces which type of artifact compared to fundamental imaging?

Answer: Near-field clutter and side lobe artifacts

Tissue harmonic imaging uses the second harmonic frequency generated within tissue, which reduces near-field clutter and side lobe artifacts.

The ensemble length (packet size) in color Doppler refers to:

Answer: The number of pulses per scan line used to produce color information

Ensemble length is the number of pulses fired along each color Doppler scan line; larger ensemble lengths improve velocity accuracy but reduce frame rate.

What is the primary effect of increasing transmit frequency on image quality?

Answer: Improved resolution but reduced penetration

Higher frequencies produce shorter wavelengths, improving spatial resolution, but are attenuated more rapidly, reducing depth penetration.

Which setting would a sonographer adjust to reduce aliasing in pulsed wave Doppler without switching to CW Doppler?

Answer: Increase PRF

Increasing PRF raises the Nyquist limit, allowing higher velocities to be measured before aliasing occurs.

Spatial compounding averages frames acquired from multiple steering angles primarily to:

Answer: Reduce speckle and improve tissue boundary definition

Spatial compounding averages overlapping frames from different angles, reducing speckle noise and improving contrast resolution at tissue interfaces.