Rad 122 unit 2

Sensitivity is

• is NOT important for lower patient radiation

  dose in digital image

• ability of the detector to detect

  and respond to very low levels of visible light or

  radiation

• refers to the pixel size of an image.

Which is Not true of the dynamic range?

• In clinical images if the detector does not have a large enough dynamic range the values in areas of very high signal, such as the lungs, will be saturated and structural differences in the lung tissue will be lost.

• The dynamic range must be chosen appropriately to reduce the size of each sampling bin, but without having saturation.  

• The range of the high and low values that are properly digitized is known as the dynamic range of the detector

• The ability of the detector to

  respond to a wide range of light intensity.

Answer explanation

All not high and low

Which detector properties: One of the fundamental physical variables related to image quality in radiography and refers to the efficiency of a detector in converting incident x-ray energy into an image signal.

• Detective Quantum Efficiency (DQE)

• Signal- to-Noise Ratio (SNR)

• Contrast-to- Noise Ratio (CNR)

• Sensitivity

What determines the distance between the midpoint of one pixel to the midpoint of an adjacent pixel?

• light spread

• sampling frequency

• FPD

• sensitivity

Increasing the sampling frequency results in a smaller sampling and pixel pitch, which improves the spatial resolution of the digital image.

• True

• False

When exposed to x-ray radiation exciting the phosphor, exciting the electrons to be trapped in the lattice until inevitably they are stimulated by the second round of illumination. Which property

• computed radiography plate

• sampling frequency

• flat panel

• phosphor layer 

A digital image typically does not show soft tissue but with spatial resolution it shows the edge of skin.

• True

• False