tests attempt 2
Card Set Information
tests attempt 2
In the fluorescent screens inside of your radiogrpahic cassette, which of the following forms of luminescense is the one desired in xray
What is the purpose of the oil that surrounds the glass envelope inside of the tube housing?
acts as an electrical insulator
Which of the variables in techniqe is the primary controller for making the image darker or lighter
To double the density of an image, increase kvp percent by_____?
You are forced to use a large OID, what two things can you do to get back some of the sharpness of detail?
increase SID, decrease your FSS
The lower the the Kvp the_______the contrast
As you clean up compton by using a collimator what is the efect on the scale of the contrast
the scale will get shorter
If you angle the xray tube against a parallel patient image, how will that affect the distortion on the image?
you will have shape distortion
What imaging term is defined as the degree of blackening of the image?
__________has nothing to do with sharpness of detail
Grids do two things to the image
improve contrast and decrease density
A penumbra is
the area of unsharpness around the edge of a radiographic image.
Sharpness of detail can be using what two types of crystals?
smaller and thinner crystals
To maximize your sharpness of detail,_____your OID and __________your FSS
In the line focus principle, the effective focal spot size must be ___________(smaller or larger) than the actual focal sport size to produce better detail
In order to maintain the same relative size of a radiographic image, if the OID is increase you should do what to the FSS and SID
decrease the FSS and increase the SID
A radiograph will a small number of widely, varying density values is said to possess
short scale, high contrast
radiographic contrast is defined as
the amount of difference between any two points
What is the effect of using air gap technique on both contrast and optical density
contrast will go up (high contrast), optical density will go down (get lighter)
The higher the grid ratio, the ________the contrast
What is the effect of adding a beam filter to both contrast and optical density
The film before it is developed is the
Which film processor solution is responsible for converting the latent into the manifest
What is the name for the situation where the xray beam passes through both layers of the films emulsion and how do you remedy this?
parallax, use a single emulsion film
Causes of safelight fog include
same light on that light sensitive filam and using a stronger than recommended wattage
The proper term for the image on a radiograph that can be seen after developement is known as the
When is the latent image formed?
when sensitive speck in film is activated
On an automatic film processor, to properly reclaim sliver that has been removed from a film, the reclaiming device must be connected to which processor tank?
The purpose of the developer in an xray film processor is to
convert exposed AgBr into black metallic silver
What is the biggest cause of automatic film processor jams and the film is said to be damp/sticky, what isn't working?
If a film ran through a processor w/o it first being exposed the film apperence will be
clear or light gray
In analog imaging the front part of the cassette must be made of a material that simultaneously produces two functions
be opaque to light and radiolucent to xrays
How can you decrease the amount of absorption of the xrays that a patient would get
According to the NCRP, a 35 yo radiographer can have a lifetime whole body dose limit of how many millirems?
What radiation QC procedure measures ten repetitive mas settings and states that the densities produced must be identical within the margin of 5%?
The higher the mas setting, the least radiation skin exposure to the patient
How may half values of xray beam filtraton must be added to the primary beam to reduce it's intensity too 25% of original?
What is the NCRP dose limit per month to the embryo-fetus once the pregnancy of an occupational worker has been diagnosed?
What radiation QC procedure measures identical mAs settings but using the differnt MA-time combinations all of which must be accurate within 10%?
The lower the kvp settings, the________the exposure
What is the NCRP required lead equivalency for all rdiation protection devices that are used to intercept scatter radiation?
What is the yearly dose limit for an occupational worker?
How accurate must the collimator field light coincide with the acutal xray field produced by the collimators themselves?
less than 2% of the SID
Compared to analog imaging, digital imaging uses this to reduce patient dosage
higher kvp settings
The NCRP dose limit for non occupationally exposed persons is _____ the established dosage for occupationally exposed worker
What is the smallest subdivision of an element that still has all of the chemical properties of that element
The atomic number of an atom is equal to the number of
the number of protons
What controls how many electrons are boiled off of the cathode and ultimately determine how many xrays are produced
The binding energy of an electron depends upon what two factors
the shell that the electron occupies and the number of protons
What is the smallest subdivision of a compound that still has the same chemical properties of that compound
What types of atoms will have the highest binding energies
atos with a high atomic number
What artificial radiation source provides the highest amount of your avage annual radiation exposure
medical and dental xrays
what is the name of the stream of electrons as they fly from the cathode over to the anode
Which worthless by product is produced 99% of the time when trying to make xrays
What is the average radiation (natural and manmade) dosage that everyone gets on an annual basis?
For imaging facilities that are trying to image thick bony structures a _______anode is preferred
What is a chemical disruption to the DNA molecule and is the most likely cause of late radiation effects?
point lesion/rung rekage
What is the most common interaction between xrays and fatty tissues?
What is NOT a reason for making the switch from analog to digital?
eliminate the need for repeat images
A CR plate should be processed_____after exposure
In computer languages, a single digit is called a
Optically stimulated dosiometers use a ___ to be stimulated
window width is to _________as window level is to______________
image contrast, brightness
In DR imaging, what device is often used to creat an almost scatter free xray beam and control the patients dosage
pre and post collimators
In DR imaging, if an image is considered to be photon deficient the image will appear:
Because visual clues are so scare with digital, what must you rely on to assure that your technical factors are following ALARA principles?
If you have an exposure field recognition error from overlapping collimation lines, what clue is seen on the image?
dark areas are visible outside the collimated field
The standard communication link that is required for all xray equipment so that all images can be combined together electronically for universal viewing is
This is the processing code that despite overexposures or underexposures makes digital images appear visually accpetable
After reading a CR image, to remove any residual image on a PSP plate, the plate must be exposed to
A miscalculation in your exposure indicator may occur if what happens?
exposure field recognition error, unexpected attenuators are found in the collimated field
To reduce noisy image on a digital image, you should
increase collimation, use a grid
due to the dynamic range of digital imagin, this is the biggest alara issue with CR and DR
To produce an image with the highest spatial resolution, the information on a PSP plate should be read with a
high sampling frequency
A dynamic range gives the radiographer:
a wide exposure latitude