SPI Review Part 3

What is a characteristic of read magnification in image processing?

• Rescans and acquires new data

• Reads old data

• Increases line density

• Improves spatial resolution

Answer explanation

Read magnification utilizes existing data to enhance the image display without rescanning. This means it reads old data, making it the correct choice, while other options imply new data acquisition or improvements that don't apply.

Which type of magnification can improve temporal resolution if the region of interest is shallower?

• Read magnification

• Write magnification

• Both read and write magnification

• Neither read nor write magnification

Answer explanation

Write magnification enhances temporal resolution by focusing on a shallower region, allowing for faster image acquisition and improved detail in dynamic studies, unlike read magnification which does not affect temporal aspects.

In write magnification, what happens if the pixel size is unchanged?

• Number of pixels decreases

• Number of pixels increases

• Spatial resolution decreases

• Temporal resolution remains unchanged

Answer explanation

In write magnification, if the pixel size remains unchanged, the number of pixels increases to maintain detail, leading to higher pixel density. Thus, the correct answer is that the number of pixels increases.

What is the appearance of speckle in tissues?

• Smooth and uniform

• Grainy or granular

• Bright and clear

• Dark and shadowy

Answer explanation

Speckle in tissues appears grainy or granular due to the interference patterns created by scattered ultrasound waves. This texture is characteristic of the echogenicity of the tissue, distinguishing it from smooth or clear appearances.

What causes speckle in imaging artifacts?

• Reflection of light

• Refraction of sound

• Interference effects of scattered sound

• Absorption of heat

Answer explanation

Speckle in imaging artifacts is primarily caused by interference effects of scattered sound. This phenomenon occurs when sound waves scatter off small particles, creating a pattern of constructive and destructive interference.

What is the effect of speckle on image quality?

• Enhances image contrast

• Reduces image contrast and spatial resolution

• Improves diagnostic accuracy

• Increases image brightness

Answer explanation

Speckle reduces image contrast and spatial resolution by introducing noise, which can obscure fine details and make it harder to distinguish between different structures in the image.

What is clutter in Doppler artifact?

• Strong reflections from blood cells

• Weak reflections from anatomic structures

• Strong reflections from anatomic structures

• Weak reflections from blood cells

Answer explanation

Clutter in Doppler artifact refers to strong reflections from anatomic structures, which can obscure the true Doppler signals from blood flow. This is why the correct answer is 'Strong reflections from anatomic structures'.

What is the purpose of fill-in interpolation in imaging?

• To remove noise

• To fill in gaps between lines

• To enhance color

• To increase brightness

Answer explanation

Fill-in interpolation is used in imaging to fill in gaps between lines, ensuring a smoother and more complete image. This process helps maintain visual continuity and enhances the overall quality of the image.

What does interpolation improve in images?

• Color accuracy

• Image detail (spatial resolution)

• Image brightness

• Image contrast

Answer explanation

Interpolation enhances image detail (spatial resolution) by estimating pixel values in between existing pixels, resulting in smoother and more defined images. It does not primarily affect color accuracy, brightness, or contrast.

Diagram showing fill-in interpolation with sector-shaped image and circular structure

• Fill-in interpolation with sector-shaped image

• Circular structure with fill-in interpolation

• Sector-shaped image with circular interpolation

• Diagram showing fill-in interpolation with sector-shaped image and circular structure

Answer explanation

The correct choice, 'Diagram showing fill-in interpolation with sector-shaped image and circular structure', accurately describes the visual elements presented in the question, encompassing both the fill-in interpolation and the sector-shaped image.