Factors Affecting Image Quality Flashcards
1
Q
Factors affecting Image Quality:
A
- Noise
- Screen and Film Speed
- Magnification
- Shape Distribution
- Focal-spot Blur
- Subject Factors
2
Q
Noise
A
- Random fluctuation in the density
- Grainy appearance on a radiograph
3
Q
What are the different types of noise
A
- Film Graininess
- Structure Mottle
- Quantum Mottle
4
Q
Film Graininess
A
irregular clumping of silver halide crystals
5
Q
Structure mottle
A
physical imperfections of intensifying screens
6
Q
Quantum Mottle
A
- IR has been exposed to an uneven “shower” pf light photons from the device, which is due to the fact that the x-ray beam itself is uneven
- Short exposure times and fast screens (decreases x-rays/detail)
7
Q
Speed
A
- Increase in speed
- Increase in Noise
- Decrease in Radiographic Quality
8
Q
Geometric Factors refers to the _____________ of the image and the accuracy with which the true edges of the anatomy may be seen
A
recorded detail
9
Q
What are the different geometric factors?
A
- Magnification (size distortion)
- Shape distribution
- Blur
10
Q
Magnification (Size Distortion)
A
Misrepresentation of true size of the object
11
Q
Magnification is influenced by _______,_______, and _________
A
- SID: source to image distance
- SOD: source to object distance
- OID: object to image distance
12
Q
_________ or _________ in distances will result in magnification
A
- Variation
- changes
13
Q
Law of Magnification
A
Image size/Object size = SID/SOD
14
Q
Magnification factor:
A
MF=SID/SOD
15
Q
% of Magnification
A
(Image size-Object size/ Object size ) x 100
