Exam 2 Flashcards
To double the density of a film by using mA’s, what do you do
Increase the mAs by 100%
Of the choices below which is true about a reciprocating grid
It is thicker than a stationary grid
When converting from a grid with a low ratio to a grid with a high ratio which of the following would be best to do to maintain good film quality
Increase the mA’s
What is recommended for spinal radiograpy in the usual chiropractic offic
A focus grid
What does using a high kV technique have
Produces more scatter
The preferred focused grid range for spinal radiography is
40’ to 72’
If a film has an overall darkened gray appearance but visible structures the probable cause of the problem would be which of the following
Exposure to the film scatter
The term “optimal kV” refers to which of the following
The lowest possible mAs with acceptable contrast on the film
How many lines per inch are recommended for stationary grid
100-103
Diminished penetration at the periphery of a grid is termed
Grid cut off
If a film is said to be “burned out” what would it look like
Too dark
Which choice below is the main reason why a fixed kV technique is preferred
Contrast is consistent
Remnant radiation refers to which of the following
Scattered rays that leave the patient and reach the grid, primary rays that leave the pateint and reach the grid
Which of the following would produce the least amount of grid lines
A moving grid
Exceeding the optimal kV range while maintaining good density will yield a film that has which of the following
A long scale contrast
As a general rule if you are going to xray an elderly patient you should do which of the following to your established radiographic technique
Decrease it
What would increase patient exposure
High kV technique
About how much increase in the mas is required when going from a non grid technique to using a technique with a 12:1 grid
5 times
If you took a 14 by 17 lateral lumbar film and saw the l5-s1 area was too light which of the following would be best
Take a spot 8x10 lateral and incrrease the mas by 60% and increase the kV
If you saw a blood vessel on end (axillary) on a chest film it would probably look like which of the four natural body desnities
Metal
If you saw 2 structures with paralleling tracks of calcification overlying the particular pillars diverging at the superior and closer at the interior what would you be looking at
The thyroid cartilage
If you took a-p lumbar on a thin patient using 85 kV at 100 mA with the exposure time of 1/2 seconds and film all structures was too likght what would be best
Increase the mAs by doubling it
What is true of reciprocating grid
It is thicker than a stationary grid
If you decided not to use a grid for AP lumbar film and adjusted the radiographic technique to maintain a good density what would be the outcome
The film would be very gray
To double density of film with kVp you should apply what rule
15%
If you compared 2 radiographics of a cervical spine with one having been taken at 40 and the other at 72 with the appropriate change in rad technique what would you find
On the 72 film the image will be smaller and clearer
Wich of the following could be a problem if your xray tube was laterally shifted from the center of the film
Shape distortion
What is the primary purpose of a grid
To reduce scatter radiation to film
What increases compton’s radiation
Higher kVp
What is the term used when comparing the height of the absorbing strips to width of interspacing material of a grid
Grid ratio
What is the recommended optimal kV range for an a-p lumbar film
80-90
When shopping for a grid which interspacing material would you want because its best for xraying spine
Aluminum
What best describes back scattr
Scatter directed toward the tube
If you wanted to alter your contrast so that a radiograph had more gray tones what would you increase
K
V
Which effect does using a reciprocating grid have that stationary grids dones
It blurs out the grid lines
Of the following which would produce film with the most visible grainy
High kvp/low mas fild
In which direction do grid lines run
In the long axis of the patient
Which radiograph technique would cause most absorption of xrays in patients body
10mas with 140 kv
What is most common cause of blurry image in practice
Patient motion
Which grid ratio is recommended for spinal filming
10:1
Contrast between stuctures of diffrent subject densities is due to which of the following
Differential abosrption
All other factors being equal which rad technique would demonstrate most film grain
100 kv with 200 ma for 1/8 of a second
The ____ is the main function of ma’s
Film density
Which of the following rad projections routinely uses an air gap technique
Lateral cervicals
A film with a darkened overalll gray appearance could be caused by which of the follwing
Exposure of the film to scatter
What would result in an increase in the amount of xrays passing through a patient without interaction that would produce secondary radiation
Higher kv
What rad projection should routinely use compensating filtration
Ap thoracic, lateral thoracic and full spine
10 day rule refers to what
10 days after onset of menses is the safest time for xray female
An accurate collimator should not allow more than ____ percent of SID light outside of exposure field
4
What is most effective in reducing secondary radiation
Filtration
Too high of a kV will have what effect on the film
Quantum mottle
Which step should you take when xraying an elderly female
Decrease mas by 30-50%
Rays that exit the patient and hit the film are termed what
Remnant rays
How much increase in mas is needed to maintain the same density when reducing the xray field form 14x17 to 8x10
60%
Which is not true about xray beam
More peripheral parts of the beam cause less distortion
A film exposed to secondary radiation will ahve which of the following appearances
It grays the film making dark
What would be most likely to decrease amount of scattered radiation to a film
An increase in patient sizing/ma’s
When xraying an elderly obese patient which of the following would be helpful in obtaining the best quality film
Using a lower kv in the optimal range
What would cause a decrease in subject density
Disuse atophy
If you increasee the mas and reduce the kv from a given radiographic technique what would be the outcome
It would have more contrast
To decrease the density of a previous film by 1/2 what would you do
Decreease ma’s by 50%
If film is too dark it is said to bewhat
Overexposed
What rad techniqe would have the shortest scale of contrast
60 kv with 100 ma for 2 seconds
How many kv would be needed to make slightest visible change in density on radiograph using single phase unit
4
What effect would adding 100% more mas to a radiographic technique have
Double the density of the film
What best describes what you should expect if you retake an AP lumbar with 15% decrease in kV and leave the ma’s constant
The density of the film would be reduced by 1/2
What is the recommended optimal kv range for ap thoracic film
75-85
What refers to an attenuation of part of the beam by the grid
Grid cut off
A film that is lighter on one side than the other most likley indicates what
Grid cut off
