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WorksheetsIMAG 1118 Chapter 4 Image Formation and Radiographic Quality
Total questions: 93
Worksheet time: 47mins
What is the result of increased attenuation in dense structures?
Higher loss of energy; more absorption
Less energy lost; more transmission
No change in energy; constant absorption
Increased energy gain; less absorption
What is differential absorption?
Differential absorption is the process of reflecting electromagnetic radiation
What happens to energy transmission in less dense structures?
More energy is absorbed
Less energy is transmitted
More energy is transmitted
Energy remains constant
Which of the following describes attenutation?
Attenuation is the reduction in beam intensity as it interacts with anatomic tissue.
Attenuation is the complete loss of beam intensity during transmission.
Attenuation refers to the amplification of beam intensity over a specified distance.
Attenuation is the increase in beam intensity as it interacts with anatomic tissue.
Which of the following is a type of attenuation?
Reflection
Refraction
Absorption
Diffusion
How does decreased attenuation affect radiolucent structures?
Increases energy absorption
Decreases energy transmission
Increases energy transmission
No effect on energy transmission
What happens to photons as the primary x-ray beam interacts with an anatomic part?
They are absorbed, scattered, and transmitted.
They are only absorbed.
They are only scattered.
They are only transmitted.
What creates an image that structurally represents an anatomic part in x-ray imaging?
Differential absorption.
Uniform absorption of photons.
Complete transmission of photons.
Reflection of photons.
What happens to the energy of the incoming photon in the photoelectric effect?
It ejects an outer-shell electron
It is completely absorbed by the atom
It passes through without interaction
It excites the atom
What is created when an X-ray ionizes an atom in the photoelectric effect?
High-energy gamma ray
Low-energy secondary X-ray photon
Neutron
Proton
Which factors affect the probability of the photoelectric effect occurring?
Energy of the incoming X-ray photon
Energy of the incoming X-ray photon and tissue atomic number
Tissue atomic number
Quality of the X-ray beam
What happens to an incoming photon during Compton Scattering?
It gains energy and changes direction.
It loses some of its energy and changes direction.
It remains unchanged.
It is absorbed completely.
Compton Scattering can occur within which of the following energy ranges?
Only at high diagnostic energies.
Only at low diagnostic energies.
Within all diagnostic energies.
Only at medium diagnostic energies.
What factor is Compton Scattering dependent on?
Tissue atomic number
The energy of the incoming photon.
The speed of the incoming photon.
The mass of the incoming photon.
How does higher kVp affect the number of overall interactions in Compton Scattering?
It increases the number of overall interactions.
It has no effect on the number of interactions.
It reduces the number of overall interactions.
It doubles the number of interactions.
At what energy range do most photoelectric interactions occur?
10 – 80 keV
80 – 300 keV
5 – 50 keV
100 – 200 keV
Which type of electron is involved in photoelectric interactions?
Outer shell electron
Inner shell electron
Free electron
Valence electron
What happens to the inner shell electron during a photoelectric interaction?
It is absorbed
It is ejected
It remains in place
It changes energy levels
What is the effect of atomic number on photoelectric interactions?
Higher atomic numbers absorb less
Higher atomic numbers absorb more
Atomic number has no effect
Lower atomic numbers absorb more
At what energy range is there more Compton scattering?
10 – 80 keV
80 – 300 keV
5 – 50 keV
100 – 200 keV
Which type of electron is involved in Compton scattering?
Outer shell electron
Inner shell electron
Free electron
Valence electron
What happens to the x-ray during Compton scattering?
It is absorbed completely
It continues with decreased energy in a different direction
It remains unchanged
It increases in energy
How does atomic number affect Compton scattering?
Higher atomic numbers absorb more
Atomic number independent
Lower atomic numbers absorb more
Atomic number dependent
What happens to an incident photon during the photoelectric effect?
It is absorbed by an inner orbital electron.
It is scattered with less energy.
It passes through the atom without interaction.
It is absorbed by an outer orbital electron.
In the Compton effect, what happens to the ejected electron?
It leaves the atom with energy equal to the excess imparted by the photon.
It remains in the same orbital.
It gains energy and moves to a higher orbital.
It is absorbed back into the nucleus.
What is a key difference between the photoelectric effect and the Compton effect?
The photoelectric effect involves outer orbital electrons, while the Compton effect involves inner orbital electrons.
The photoelectric effect results in photon scattering, while the Compton effect results in photon absorption.
The photoelectric effect involves inner orbital electrons, while the Compton effect involves outer orbital electrons.
The photoelectric effect results in no change in photon energy, while the Compton effect results in increased photon energy.
Which of the following interactions with matter is responsible for patient dose?
Characteristic
Photoelectric
Compton
Bremsstrahlung
What happens to the energy of the x-ray during coherent (classical) scattering?
It increases
It decreases
It remains the same
It is absorbed completely
Which of the following interactions with matter is responsible for technologist dose?
Bremsstrahlung
Compton
Characteristic
Photoelectric
At what energy levels does coherent (classical) scattering typically occur?
High energy levels
Medium energy levels
Low energy levels
All energy levels
What causes the x-ray to change direction in coherent (classical) scattering?
Loss of energy
Higher energy state
Absorption by the atom
Emission of a new photon
What happens to X-rays when tissue thickness increases by 4 to 5 cm?
They are completely absorbed.
They are reduced by approximately 50%.
They pass through without any change.
They increase in intensity.
How does the type of tissue affect beam attenuation?
Tissues with a lower atomic number increase attenuation.
Tissues with a higher atomic number increase attenuation.
All tissues have the same effect on attenuation.
Tissues with a higher atomic number decrease attenuation.
What effect does increasing tissue density have on beam attenuation?
It decreases beam attenuation.
It has no effect on beam attenuation.
It increases beam attenuation.
It reverses beam attenuation.
How does higher kVp affect X-ray beam quality and attenuation?
It decreases the energy and increases attenuation.
It increases the energy and decreases attenuation.
It decreases the energy and decreases attenuation.
It increases the energy and increases attenuation.
What is exit/remnant radiation?
Radiation that leaves the patient
Radiation that enters the patient
Radiation that is absorbed by the patient
Radiation that is reflected by the patient
What is exit/remnant radiation composed of?
Only transmitted radiation
Only scattered radiation
Transmitted and scattered radiation
Absorbed and reflected radiation
What effect does scatter radiation have on an image?
Enhances image clarity
Creates unwanted fog on the image
Increases image brightness
Reduces image contrast
What is the characteristic of radiopaque tissues in relation to x-rays?
They absorb incoming x-rays and create light areas on the image.
They transmit incoming x-rays and create dark areas on the image.
They neither absorb nor transmit x-rays.
They only create shades of gray on the image.
How do radiolucent tissues appear on an x-ray image?
As light areas due to increased brightness.
As dark areas due to decreased brightness.
As completely transparent areas.
As uniformly gray areas.
What is the result of anatomic tissues that vary in absorption and transmission between radiopaque and radiolucent?
They create a uniform white image.
They create a range of dark and light areas/shades of gray.
They create a completely black image.
They create a completely transparent image.
What happens when remnant radiation interacts with the digital IR?
It is absorbed by the IR
It is converted to electric signal values
It is reflected back
It is stored as heat
What determines the strength/intensity of the signal value in an electronic data set?
The color of the IR
The speed of the radiation
The x-ray beam attenuation with varying anatomic tissues
The temperature of the environment
How is the electronic data set used to produce a visible image?
It is printed on paper
It is manually drawn by technicians
It is computer processed and displayed on a monitor
It is projected onto a wall
What does a quality radiograph accurately represent?
The color of the anatomic area
The anatomic area of interest
The size of the anatomic area
The density of the anatomic area
What are the two main factors that determine the quality of a radiograph?
Contrast and brightness
Visibility of anatomic structures and accuracy of structural lines
Size and shape of the anatomic area
Density and texture of the anatomic area
Which of the following factors is related to the visibility of anatomic structures in radiographic quality?
Spatial resolution
Brightness
Distortion
Sharpness
What aspect of radiographic quality is associated with the accuracy of structural lines?
Brightness
Contrast
Spatial resolution
Color
What is the definition of brightness?
The amount of luminance (light emission) of a display monitor
The color contrast of a display monitor
The resolution of a display monitor
The refresh rate of a display monitor
Why must a digital image have sufficient brightness?
To enhance the color saturation
To visualize the anatomic structures of interest
To increase the resolution
To reduce the file size
On what factor is the brightness of a digital image dependent?
The amount of radiation received by the IR
The color depth of the image
The file format of the image
The pixel density of the image
What does a wide dynamic range in digital imaging allow?
Detection of a narrow range of exposure intensities
Detection of a wide range of exposure intensities
Detection of only low exposure intensities
Detection of only high exposure intensities
What happens to an extremely overexposed image?
It can be processed properly
It cannot be processed properly
It becomes underexposed
It enhances image quality
What is the combined result of multiple factors such as anatomic structure, radiation quality, and image receptor characteristic?
Displayed Image Contrast
Image Resolution
Color Saturation
Pixel Density
Why must an image exhibit differences in brightness levels?
To enhance color
To differentiate among anatomic tissues
To increase resolution
To reduce noise
What causes the range of brightness levels displayed in an image?
The camera's lens quality
The tissues' differential absorption of the x-ray photons
The monitor's brightness setting
The image's color balance
What characterizes low subject contrast in anatomic tissues?
Tissues that absorb the beam completely
Tissues that reflect the beam
Tissues that attenuate the beam similarly
Tissues that do not interact with the beam
What is the characteristic of high subject contrast in anatomic tissues?
Tissues that absorb the beam completely
Tissues that attenuate the beam very differently
Tissues that reflect the beam
Tissues that do not interact with the beam
What is a characteristic of high contrast images?
Few shades of gray
Lots of shades of gray
Little differences among shades
High kVp
Which of the following is true about low contrast images?
Short scale
Increase contrast
Long scale
More black and white
In high contrast images, what is the relationship between the shades of gray?
Big differences between them
Little differences among them
Long scale
Decrease contrast
What is contrast resolution?
The ability to distinguish between different colors
The ability to distinguish between objects having similar subject contrast
The ability to enhance image brightness
The ability to store images in different formats
What does gray scale refer to in digital imaging?
The number of colors in an image
The number of different shades of gray that can be stored and displayed
The brightness level of an image
The contrast level of an image
Displayed image contrast is a product of which two factors?
Image brightness and color depth
Subject contrast and contrast resolution
Image size and resolution
Color contrast and image sharpness
What is the smallest object that can be detected in an image referred to as?
Spatial resolution
Image contrast
Color depth
Pixel density
Why must anatomic structures be displayed accurately and with the greatest amount of sharpness?
To enhance color accuracy
To ensure proper spatial resolution
To reduce file size
To improve image brightness
What determines the accuracy of the anatomic structural lines displayed in an image?
Image brightness
Spatial resolution
Color contrast
Pixel count
What is one method to minimize motion unsharpness in images?
Increase exposure time
Use the shortest exposure time possible
Decrease temporal resolution
Increase the distance from the subject
What is the responsibility of radiographers regarding motion in images?
To increase motion as much as possible
To decrease motion as much as possible
To maintain constant motion
To ignore motion effects
How does increasing time affect temporal resolution?
Decreases motion and decreases temporal resolution
Increases motion and increases temporal resolution
Decreases motion and increases temporal resolution
Increases motion and decreases temporal resolution
What is distortion?
Accurate representation of an object's size and shape
Misrepresentation of either the size or shape of an object
Enhancement of image quality
Reduction of image noise
Which of the following is a type of size distortion?
Elongation
Foreshortening
Minification
Distortion
Which of the following is a type of shape distortion?
Magnification
Elongation
Minification
Clarity
What is the effect of increasing the Source-to-Image Distance (SID) on magnification?
Increase magnification
Decrease magnification
No effect on magnification
Magnification becomes zero
How does decreasing the Object-to-Image Distance (OID) affect magnification?
Increases magnification
Decreases magnification
No effect on magnification
Magnification becomes zero
Which of the following statements is true about radiographic images?
They never have magnification
They always have some magnification
They have no distortion
They are always the same size as the object
What is shape distortion in imaging?
Accurate representation of an object's image
Misrepresentation of an object's image shape
Enhancement of an object's image
Reduction of an object's image size
Which of the following is a controlling factor for shape distortion?
Alignment of the light source
Misalignment of the tube, the part, or the IR
Color of the object
Size of the object
What does elongation in shape distortion refer to?
Objects that appear shorter than the true object
Objects that appear longer than the true object
Objects that appear wider than the true object
Objects that appear smaller than the true object
What does foreshortening in shape distortion refer to?
Objects that appear longer than the true object
Objects that appear wider than the true object
Objects that appear shorter than the true object
Objects that appear larger than the true object
What is the result of Compton interactions in medical imaging?
Enhanced image clarity
Unwanted exposure resulting in fog
Increased image contrast
Improved brightness
How does scatter affect the image contrast in medical imaging?
Increases image contrast
Decreases image contrast
Has no effect on image contrast
Enhances image details
What is one of the consequences of scatter in medical imaging?
Provides useful diagnostic information
Masks the desired brightness on the image
Enhances image sharpness
Reduces image noise
How is quantum noise displayed on an image?
Brightness fluctuations and graininess
Sharpness and clarity
Color variations
Increased contrast
What causes quantum noise in an image?
Too many x-ray photons reaching the image receptor
Too few x-ray photons reaching the image receptor
High resolution of the image
Excessive image processing
What is an image artifact?
A desired brightness level on an image
Any unwanted brightness level on an image not part of the patient's anatomy
A type of medical imaging technique
A tool used to enhance image quality
How can image artifacts affect medical images?
They enhance the overall quality of the image
They provide additional anatomical information
They may obscure anatomic information
They are used to highlight important areas
What is the responsibility of radiographers regarding image artifacts?
To add artifacts to images for better analysis
To remove all items possible that may cause artifacts
To ignore artifacts as they are not important
To use artifacts to diagnose conditions
Which of the following substances is NOT one of the five that need to be in anatomical physical contact for visualizing anatomy on radiographic images?
Air/gas
Fat
Water
Bone
What is the acceptable variability for kilovoltage accuracy in X-ray quality control?
+/- 2%
+/- 5%
+/- 10%
+/- 15%
How is kilovoltage accuracy measured in X-ray quality control?
With a digital timer
With a digital kVp meter
With a manual gauge
With a pressure sensor
What is the variability for exposure timer accuracy when the exposure time is less than 10 ms?
+/- 2%
+/- 5%
+/- 8%
+/- 10%
What is the variability for exposure timer accuracy when the exposure time is more than 10 ms?
+/- 2%
+/- 5%
+/- 8%
+/- 10%
