Ultrasound Resolutions Review

These flashcards cover key concepts related to ultrasound resolutions, including axial, lateral, temporal, and contrast resolutions, as well as factors that influence them.

What does axial resolution depend on?

Spatial pulse length (SPL).

What effect does a shorter SPL have?

Improves axial resolution.

What does lateral resolution depend on?

Depends on beam width.

What does a narrower beam do?

Improves lateral resolution.

Where does the best lateral resolution occur?

At the focus.

What does temporal resolution depend on?

Depends on frame rate.

What effect does a higher frame rate have?

Improves temporal resolution.

What does contrast resolution depend on?

Dynamic range/gray scale.

What does persistence do?

Improves contrast resolution but degrades temporal resolution.

What does elevational resolution depend on?

Depends on beam thickness.

What is needed for two reflectors along the beam to be distinguished?

Good axial resolution is needed.

What is needed for two reflectors side-by-side to be distinguished?

Good lateral resolution is needed.

What causes motion blur?

Poor temporal resolution.

What type of artifact does slice thickness affect?

Elevational resolution.

What resolutions are improved by increasing frequency?

Improves axial and lateral resolutions.

How does increasing depth affect frame rate?

Increasing depth decreases frame rate.

How does increasing sector width affect temporal resolution?

Increasing sector width decreases temporal resolution.

What effect does increasing focal zones have on frame rate?

Increasing focal zones decreases frame rate.

What is the trade-off for continuous wave (CW) Doppler?

CW Doppler has no aliasing but no range resolution.

What is the trade-off for pulsed wave (PW) Doppler?

PW Doppler has range resolution but can experience aliasing.

What is SPL in the context of ultrasound?

SPL stands for spatial pulse length.

How does smaller beam width affect resolution?

Smaller beam width improves lateral resolution.

What is one effect of improving frame rate?

Improving frame rate enhances temporal resolution.

What happens to dynamic range when persistence is used?

Dynamic range improves contrast but degrades temporal resolution.

What does axial resolution relate to?

Axial resolution relates to the ability to distinguish two reflectors along the beam.

What happens to temporal resolution when frame rate is reduced?

Temporal resolution decreases when frame rate is reduced.

What is improved by increasing the frequency of ultrasound?

Increasing frequency improves axial and lateral resolutions.

What happens to resolution with poor motion management?

Poor motion management can lead to motion blur in the images.

In ultrasound, what is the trade-off when using CW Doppler?

Using CW Doppler provides no aliasing but lacks depth information.

How do frame rates relate to temporal resolution?

Higher frame rates correlate to better temporal resolution.

What happens to the slice thickness artifact as beam thickness increases?

Increasing beam thickness worsens the slice thickness artifact.

What technical adjustments can improve axial resolution?

Shorter SPL can improve axial resolution.

How does focal depth affect ultrasound imaging?

Maximizing focal depth improves lateral resolution.

What occurs when two structures are close together axially?

Good axial resolution is necessary for distinction.

What is the impact of lowering the frequency on resolution?

Lowering frequency can degrade axial and lateral resolution.

What is one key feature of PW Doppler?

PW Doppler allows for range resolution but may have aliasing.

Differentiate between axial and lateral resolution. What does each depend on?

Axial resolution depends on SPL, while lateral resolution depends on beam width.

What is the importance of persistence in ultrasound imaging?

Persistence can improve image quality through better contrast.

What is a common issue with increasing sector width?

Increasing sector width can lead to decreased temporal resolution.

How does increasing frequency affect temporal resolution directly?

Increasing frequency does not directly affect temporal resolution.

What does elevational resolution impact in an ultrasound image?

Elevational resolution impacts the thickness of the slice being viewed.