Unit 8 - Spacial Resolution & Detail

  1. ________ is the degree of geometric sharpness of the structural lines recorded on an image
    - Definition
    - Sharpness
    - Resolution
    Recorded Detail
  2. _______ is a term applied to a digital image recorded as:
    - The ability of an imaging system to accurately display objects in 2 dimensions
    Spacial Resolution
  3. Recorded Detail Vs. Visibility of Detail

    - ________ is a geometric property that is not affected by the photographic properties of IR exposure & contrast
    Recorded Detail
  4. Assessing Recorded Detail
    - The recorded detail of an image can be assessed visually by evaluating the _____ of the anatomical structural lines.
    — Any image by size and/or shape will have ____ recorded detail 
    Recorded detail can also be assessed by using a resolution tool
    • Sharpness
    • decreased
  5. The spatial resolution of a digital imaging system is dependent on:
    ____
    ____
    ____
    • Matrix size
    • Pixel size
    • Grayscale bit depth
  6. Spacial resolution measures for digital imaging systems:
    ______
    ______
    ______
    ______
    • Point spread function 
    • Spacial frequency
    • Modulation transfer function (MTF)
    • Noise
  7. Point Spread Function
    - Expresses the ____ of an image
    - Determined by complex mathematical measurement of an image produced by a single point
    - Relates to _____ or blur
    • Boundary 
    • penumbra
  8. Spacial Frequency
    - Relates the number of ___ ___ in a given length
    - Determined by measuring the distance between pairs of lines from one another & then expressing them as cycles per unit of length (c/mm or c/cm)

    High frequency signal = _____ spacial resolution
    Low frequency signal = ______ spacial resolution
    • Line pairs
    • higher
    • lower
  9. Modular Transfer Function (MTF)
    ____ measures the accuracy of an image compared to the original object on a scale of __ to __.

    - Determined by mathematically calculating the % of object contrast recorded.
    —— MTF of __ = imaging system produces an image that appears exactly as the object
    —— MTF of __= no signal nor image
    MTF, 0 to 1

    • 1
    • 0
  10. ______
    - refers to background information received by the IR
    - If significantly less than the amount of information coming from the IR, computer processing algorithms filter it out
    - Rising noise levels degrade the image
    —— ____ Noise - insufficient amount of photons reaching the IR results in blotchy or mottled image.
    • Noise
    • Quantum noise
  11. Factors that Affect Recorded Detail
    - Controlling factors
    ____
    ____
    ____
    • Beam Geometry (SID, OID & Focal Spot Size)
    • Image Receptor (digital systems)
    • Motion (voluntary, involuntary & equipment)
  12. ____: distinct, sharp area seen within the center of an image

    ____: blurry, unsnarl area seen at the periphery (edges) of an image - negatively affects recorded detail
    • Umbra
    • Penumbra
  13. The size of the focal spot is controlled by the ____________
    Line focus principle
  14. As focal spot size is increased, penumbra ____ & detail ____
    As focal spot size is decreased, penumbra ____ & detail _____
    • Increases, decreases
    • decreases, increases
  15. The relationship between SID & detail is ___:
    — As SID is increased, penumbra/size distortion (magnification) ____ & detail ____
    • Direct
    • Decreases, Increases
Author
Marc817
ID
349321
Card Set
Unit 8 - Spacial Resolution & Detail
Description
Unit 8 - Spacial Resolution & Detail
Updated