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________ is the degree of geometric sharpness of the structural lines recorded on an image
- Definition
- Sharpness
- Resolution
Recorded Detail
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_______ 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
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Recorded Detail Vs. Visibility of Detail
- ________ is a geometric property that is not affected by the photographic properties of IR exposure & contrast
Recorded Detail
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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
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The spatial resolution of a digital imaging system is dependent on:
____
____
____
- Matrix size
- Pixel size
- Grayscale bit depth
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Spacial resolution measures for digital imaging systems:
______
______
______
______
- Point spread function
- Spacial frequency
- Modulation transfer function (MTF)
- Noise
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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
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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
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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
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______
- 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.
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Factors that Affect Recorded Detail
- Controlling factors
____
____
____
- Beam Geometry (SID, OID & Focal Spot Size)
- Image Receptor (digital systems)
- Motion (voluntary, involuntary & equipment)
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____: 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
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The size of the focal spot is controlled by the ____________
Line focus principle
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As focal spot size is increased, penumbra ____ & detail ____
As focal spot size is decreased, penumbra ____ & detail _____
- Increases, decreases
- decreases, increases
-
The relationship between SID & detail is ___:
— As SID is increased, penumbra/size distortion (magnification) ____ & detail ____
- Direct
- Decreases, Increases
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