Ch. 3 Flashcards
The device that receives the radiation leaving the patient is the
Image receptor
_____ results in the process of image formation, whereby the X-ray beam interacts with the anatomic tissue, and a portion of the beam passes through the part and strikes the image receptor.
Differential absorption
______ is the loss of some of the energy from the X-ray beam as it passes through the imaged tissue:
Attenuation
The photoelectric effect involves the removal (ejection) of an electron. This process of removing an electron from an atom is known as:
Ionization
When the X-ray photon travels completely through the part without any interaction, it is called:
Transmission
When the X-ray photon strikes an atom within the tissue being imaged and loses all of its energy to an
inner shell electron of that atom, the photon is said to have been
Absorbed
When the x-ray photon strikes an atom within the tissue being imaged and loses only part of its energy to an outer shell electron of that atom, the photon is said to have been
Scattered
The interaction between x-ray photons and tissue that results in the production of a secondary x-ray photon is the:
Photoelectric interaction
When the entering x-ray photon loses energy and changes its path of travel as a result of interacting with an atom, the interaction is known as the:
Compton effect
The probability of total photon absorption by the photoelectric effect depends on the:
the energy of the incoming X-ray photon and atomic number of the anatomic tissue
The outer shell electron that is ejected during the Compton interaction is also known as a:
secondary electron and Compton electron
The x-ray photon that is scattered as a result of the Compton effect CANNOT:
strike the image receptor and provide useful anatomic information.
Interactions of high-energy x-rays (energies beyond the diagnostic range) with tissue include:
pair production and photodisintegration
Interactions of low-energy x-rays (energies below the diagnostic range) with tissue include:
Coherent scattering
The x-ray beam that leaves the patient in the direction of the image receptor is often referred to as:
Remnant radiation (useful)
If scattered photons are absorbed within the anatomic tissue, they:
contribute to the radiation exposure of the patient and do not contribute any useful
information about the anatomic part of interest
The amount of x-ray beam attenuation is affected by the:
-thickness of the body part and anatomic number of the atoms in the tissue
-thickness of the body part and energy of the X-ray beam
-atomic number of the atoms in the tissue and energy of the x-ray beam
-All options are correct.
-thickness of the body part and anatomic number of the atoms in the tissue
-thickness of the body part and energy of the X-ray beam
-atomic number of the atoms in the tissue and energy of the x-ray beam
- ALL OPTIONS ARE CORRECT
A body tissue with an increased tissue density results in:
increased beam attenuation
An increased part thickness results in:
increased beam attenuation
Unwanted exposure to the IR due to scatter radiation is called:
fog
Following exposure, the ________
image occurs first on the image receptor.
latent (not yet processed)
What occurs at higher kilovoltage?
fewer photon interactions and more photons transmitted
Beam attenuation ______ with a higher energy x-ray beam.
decreases
Image qualities for the visibility of anatomic structures include.
brightness (mAs) and contrast (kVp)
Image qualities for the accuracy of structure lines include.
spatial resolution and distortion
Muscle tissue absorbs more radiation than fat tissue because muscle tissue has a:
higher tissue density
The amount of luminance of a display monitor is:
brightness
Increased brightness means:
lighter
The difference in the brightness levels is:
image contrast
An image that has excessive brightness is considered:
unacceptable
________ refers to the absorption characteristics of the anatomic tissue imaged and the quality of the x-ray beam.
Subject contrast
The number of shades of gray that can be displayed by a computer system is:
Grayscale
A radiographic image with a greater number of similar brightness levels with small differences between them is said to have
low contrast (hard to see)
The ability of an image receptor to distinguish between objects with similar subject contrast is:
Contrast resolution
The smallest object that can be detected in an image is the
Spatial resolution
The accuracy of the anatomic structural lines in the radiographic image displayed is determined by the:
spatial resolution
Radiographic misrepresentation of the size or shape of the anatomic structure being imaged is:
-magnification and elongation
-magnification and foreshortening
-elongation and foreshortening
All options are correct.
-magnification and elongation
-magnification and foreshortening
-elongation and foreshortening
All options are correct.
Size distortion is affected by:
SID and OID
As seen on the radiographic image, scatter radiation:
decreases the visibility of anatomic structures
What occurs when too few photons reach the IR?
-The visibility of quantum noise is increased.
-image brightness is insufficient
-Image quality may be poor.
-All options are correct.
-The visibility of quantum noise is increased.
-image brightness is insufficient
-Image quality may be poor.
-All options are correct.