Imaging Chap6 Flashcards
What are the four primary exposure technique factors?
kVp, mAs, distance, and filtration
What does kVp stand for in exposure technique factors?
kilovoltage peak
What does mAs stand for in exposure technique factors?
milliampere seconds
What is the purpose of using distance as an exposure technique factor?
To reduce patient dose by increasing the distance from the x-ray tube
How does filtration affect the quality of an x-ray image?
Filtration removes low-energy x-ray photons, resulting in a higher quality image
True or False: Increasing kVp will increase the penetration of the x-ray beam.
True
Fill in the blank: Increasing the _________ will decrease patient dose.
distance
Which exposure technique factor directly controls the amount of x-ray photons produced?
mAs
What is the relationship between mAs and image brightness?
Directly proportional
Why is it important to consider exposure technique factors when performing x-ray imaging?
To optimize image quality while minimizing patient dose
Radiation quantity is directly proportional to _____?
Milliamperage (mA)
If mA is increased, exposure time must:
Decrease
When kVp is increased, x-ray beam penetration ___
Increases
When kVp is decreased, subject contrast _________
Increases
What is the main reason to use a compensating filter?
To create an uniform exposure across varying tissue thickness
Using a high kVp and low mAs technique is recommended in digital imaging to
Prevent patient overexposure
What is the term for the overall blackness of a radiograph?
Density
_____ affects image brightness in digital radiography.
Post-processing
Increasing the focal spot size, _____ spatial resolution?
Decreases
______ is most responsible for image unsharpness
Focal spot size
The inverse square law states that the intensity of radiation is inversely proportional to:
The square of the distance from the source
If the SID is doubled, the intensity of the radiation reaching the image receptor ________.
Decreases by 1/4
_______ causes magnification
Increasing OID
_______ is used to adjust for changes iin SID while maintaining exposure to the IR
Direct square law
The main purpose of using a grid is to :
Reduce scatter
When is a grid used?
When the part is greater than 10 cm thick
Increasing collimation does what to scatter?
It decreases scatter
If an x-ray is taken using a 6:1 grid with 30 mA. What mAs would be needed if a 12:1 grid is used?
50 mAs
To compensate for increased collimation, the radiographer should:
Increase mAs
A hypersthenic patient will require __________ as compared to a sthenic patient
Increased kVp
How should the technique be adjusted for a wet plaster cast?
Increase the mAs by a factor of 3
How should the kVp be adjusted when imaging a pediatric patient under 6 years old?
Decrease the kVp by 15%
What is an example of an additive disease requiring an increase in kVp?
Pleural effusion
______ contrast agents increase the absorption of x-rays.
Positive
The 15% rule states that increasing the kVp by 15% is equivalent to:
Doubling the mAs
The air gap technique:
Reduces scatter
Increasing OID, ______ spatial resolution
Decreases
If the central ray is misaligned, what type of distortion will occur?
Shape distortion
What is the result of underexposure?
Quantum mottle
What happens to the exposure to the image receptor is the mAs is doubled?
It doubles
To reduce quantum noise, what should the radiographer do?
Increase mAs
_______ has the greatest affect on beam quality
KVp
Increasing mAs, ______ image contrast
Does not change
When adjusting technical factors for an asthenic patient, the radiographer should:
Decrease mAs
What is one condition that requires a decrease in kVp for proper exposure?
Osteoporosis
In the case of AEC, what determines the exposure time?
The detectors ability to measure radiation
What is the most important factor to control when trying to minimize motion blur?
Exposure time
The exposure indicator number on the digital image is used to determine:
The level of exposure received by the image receptor
When SID increases, spatial resolution ________
Increases
Decreasing SID, will _____
Increase magnification
The 15% rule is used to :
Maintain exposure while adjusting kVp
What is penumbra?
Unsharpness
The inverse square law affects ____
Density and intensity of the beam
What is the purpose of using a grid?
To reduce scatter and improve contrast
What effect does increasing grid ratio have on image contrast?
It increases contrast
If an x-ray is too light and needs more density, what adjustment should be made?
Increase the mAs
If an x-ray is too light and needs more density, what adjustment should be made?
Increase the mAs
What is the purpose of collimation?
To reduce scatter and improve contrast
What is a condition that would require a decrease in technical factors?
Emphysema
What is the appropriate technical factor adjustment for imaging a patient with a wet plaster cast?
Increase the mAs by 3
In pediatric imaging, what is the perferred method to reduce motion blur?
Using fast exposure times
How should exposure factors be adjusted for a patient with osteoporosis?
Decrease kVp
A radiograph of the abdomen shows a large amount of gas, which appears radiolucent. What adjustment should be made in technique?
Decrease kVp
A pediatric skull radiograph requires the same exposure factors as an adult starting at what age?
Six years
What should the radiographer do if an anatomic part has additive pathology such as edema?
Increase mAs
Tube filtration primarily affects which aspect of the x-ray beam?
Beam quality
In a high-frequency generator, how are exposure technique settings adjusted compared to a single-phase generator?
Decrease exposure factors
What effect does tube filtration have on patient dose?
Decreases pt dose
What is the purpose of compensating filtration?
To provide uniform exposure to areas with varying tissue thickness
As tissue thickness increases, beam attenuation ______
Increases
What effet does adding compensating filtration have on mAs
It increases mAs
Generators with higher efficiency, such as three-phase or high-frequency generators, typically require:
Lower exxposure factors
Increasing tube filtration results in:
Hardening of the beam
When using a single-phase generator, compared to a high-frequency generator, what adjustment should be made to exposure factors?
You should increase them
Why is tube filtration an important consideration in reducing patient dose?
It reduces low-energy photons that would be absorbed by the patient
. For a patient with severe emphysema, what change in technical factors is typically required?
Decrease kVp
When imaging a patient with a dry plaster cast, what adjustment should be made to the exposure technique?
Increase mAs by a factor of 2
For a patient with a large amount of ascites, which adjustment in technique is needed?
Increase mAs
How should the radiographer adjust the exposure technique for a patient with a pneumothorax
No change
When imaging a patient with pleural effusion, what adjustment should be made to the technique?
Increase kvp
Which pathological condition requires an increase in mAs to compensate for tissue attenuation?
Edema
What is the appropriate adjustment when imaging a patient with a destructive pathology such as advanced emphysema?
Decrease kvp
Increasing OID, _______ image magnification
Increases
What adjustment should be made to maintain exposure when SID is increased?
Increase mAs
Decreasing OID will increase _______
Spatial resolution
To maintain exposure to the image receptor when increasing OID, what must be done to mAs?
Increase mAs
In the event of excessive quantum noise in an image, what adjustment should be made?
Increase mAs
Increasing SID, does what to beam intensity?
Decreases it
To maintain exposure when kVp is increased by 15%, what should be done to mAs?
Decrease the mAs by half
Using a small focal spot size , _______ spatial resolution
Increases
Which of the following is a key consideration when imaging pediatric patients compared to adults?
Lowering kvp and mas is crucial
A pediatric skull radiograph requires a 15% decrease in kVp for children under the age of:
6 years
When imaging a child with a wet plaster cast, how should exposure factors be adjusted?
Increase mAs by a factor of 3
When imaging a pediatric chest x-ray, what is the recommended approach to reduce patient dose?
Using the lowest mAs possible for an adequate image
What should be considered when imaging a pediatric patient with scoliosis?
Using compensating filters
When using a higher grid ratio, what adjustment should be made to mAs to maintain image brightness?
It should be increased
Increasing kVp, _______ image contrast
Increases
When contrast media is used, what happens to the overall image contrast?
It increases
What is the effect of collimation on patient dose and image contrast?
Decreases patient dose and increases contrast
What adjustment should be made when imaging a body part with a destructive pathology like osteoporosis?
Decrease kVp
For a patient with a body part requiring positive contrast agents, how should technical factors be adjusted?
Kvp should be increased
