Penguins for exam 3 Flashcards
____ determines quality of the x-ray beam
kVP
Most exposure timers are ____ and are controlled by a ____
- Electronic
2. Microprocessor
____ is the process of converting AC to DC
Rectification
_____ controls screen film radiographic contrast
kVp
An increase in kVp will results in ____ Quantity, ___ Qauluty
Increase in both
An increase in mA will result in ____ Quantity , ___ Quality
- Increase Quantity
2. No change in Quality
An increase in Exposure time will ____ Quantity, ___ Quality
- Increase Quantity
2. No change Quality
An increase in mAs will ____ Quantity, ___ Quality
- Increase Quantity
2. No change Quality
An increase in Distance will ____ Quantity, ___ Quality
- Decrease Quantity
2. No change Quality
An increase in filtration will ____ Quantity, ___ Quality
- Decrease Quantity
2. Increase Quality
with constant exposure time ____ controls the x-ray quantity and therefore pt. radiation dose
mA
____ controls OD
mAs
Define QA
Quality management that focuses on the person rather than the process
Define QC
Subdivision of QM that focuses on the equipment function
Define noise
Grainy or uneven appearance of an image caused by insufficient number of xrays
Define resolution
Measure of the ability of the system to image 2 separate objects and visually distinguish one from the other
Define speed
Sensitivity of film to x-rays
Influences: Resolution and noise
Term for “Fidelity with which the anatomical structure that is being imaged is rendered on the radiograph
Image Quality
List the 3 characteristics of image quality
- Spatial resolution
- Contrast resolution
- Noise
____ is the random fluctuations in OD of the image
Noise
The relationship between OD and radiation exposure is called ____
Characteristic curve Ranges from (.25-2.5)
What are the geometric factors that affect image quality
- Magnification
- Distortion
- Focal Spot blur
Name the subject factors that affect image quality
- Subject contrast
- Pt. thickness
- Tissue mass density
- Effective atomic #
- Object shape
- kVp
