Exposure Mid-term

• The spatial resolution of flat-panel receptors is genrally superior to that of CR

  True
• Exit radiaiton is converted to visible light with the direct conversion detector

  False
• The quality of the CR latent image will remain the same for up to

  hours after exposure

  False
• The value of a pixel represents

  a single brightness level on a monitor
• Bit depth= n ^ 2

  False
• In a digital image ( fixed FOV ) , as the matrix size increases:

  image quality increases and the quantitiy of pixels increases
• A larger bit depth :

  increases the numbe rof shades of gray
• A decrease in pixel pitch would cause the spatial resolution to :

  increase
• Pixel bit depth is determined by the

  ADC
• In the CR reader unit, the IP is scanned with a(n) :


  helium neon laser beam
• The variation in anatomic details imaged s white to black brightness levels that can be defined by the unit of line pairs per millimeter best describes :

  spatial frequency
• The CR phosphor layer is composed of :

  barium flourhalide with europium
• What is divided into square DELs

  TFT array
• The percentage of x-rays that have reached the dtector and have been captured in the DELs is known as the :

  fill factor
• The DQE is :

  indirectly proportional to spatial frequency and directly proportional to the MTF
• The emission of light when stimulated by a high-intensity laser beam is know as :

  photostimulable luminences
• The product of total air kaerma and the area of the x-ray beam at entrance of the patient best describes :

  KAP
• When an IR has a wider dynamic range , it has a _____________ pixel depth

  larger
• The range of exposures that produce optical densities within the straight-line region of the sensitometric curve best describes :

  esposure latitude
• The pixel spacing or distanc emeasured from the center of a pixel to an adjacent pixel known as the ;

  pixel pitch
• If the variable matrix is increase for a fixed FOV, spatial resolution

  increases
• _______________- the SNR will improve image quality

  increasing
• Which is another term for Quantum Noise ?

  Quantum Mottle
• Indirect Converison Detectors use which materials to convert exit radiaiton to visible light ?

  Gadolinium Oxysulfide and Cesium Iodide
• Turbid scintillator phosphor give higher spatial reoslution by reducing the spread of visible light

  false
• Which type of imahing plate would be mechanically fed into a plate - reading machine, for imaging processing ?

  CR
• Pixels are measured in :

  microns
• A method of describing the contrast resolution compared with the amount of noise apparent in a digital image is know as :

  contrast-to -noise ratio
• Compared to film0based image receptors, digital image receptors have a ______ dynamic range

  wide
• What doe sSNR stand for ?

  signal to noise raito
• What can improve spatial resolution ?

  increase pixel density and decrease pixel pitch
• The higher the DQE of a system , the radiaiton exposure required to produce a quality image is :

  decrease
• When a matric is fixed , increasing the FOV will result in _______ pixels .

  larger
• DR IR's in comparison to CR IR's , are :

  more expensive
• Which of the following is true about the indirect converiosn DR system s?

  x-rays are converted to light , then electrical charges
• The CR latent image consist of :

  electron strapped in the phosphor layer
• If a fixed matrix is used , and the FOV decreases, what happens with the quantity of the pixels in the matrix ?

  no change
• The measure of imaging system's ability to display the contrast of anatomic objects varying in size is known as the :

  modulation transfer function
• A method of describing the strength of the radiation exposure compared with the amount of noise apparent in the digital image is known as the :

  signal to noise ratio
• In the term Air Kerma , KERMA is an acronym . What does KERMA stand for ?

  kinetic energy released in matter