Exam 3 Flashcards
what is the established MPD for occupational exposure?
5.0 rads/year
1/16 lead is equivalent to how many inches of concrete?
4
where should the exposure switch be located?
inside the booth
how long should radiation exposure records be kept?
indefinetly
why should you not use an extremity screen in an office that primarily takes spinal films?
extremity films might get mixed with spinal films and require retakes
what is problem with storing xray films flat rather that upright?
pressure marks
what effect does large crystals in the intensifying screen have?
more light is emitted
how often should you clean your screens?
3 months
what is bad about split and gradient screens?
they increase patient exposure
for general skeletal radiology what speed of rare earth screens is recommended?
400-600
a loss of film screen contact would most likely create what problem?
blurring of part of the image
silver is removed in which part of the processing stage?
fixing
how would the film appear if you reduced the developing time and maintained the temp?
it will be too light
if your developer is brow what would you expect?
it is oxidized
what is the first thing you would do if you were manually processing films?
check the developer temp
what is the most common processing artifact with automatic processing?
roller marks
of the steps in manual processing which takes the longest?
washing
what is the purpose of the squeegee rollers in automatic processing?
to remove fluids from film between solutions
how intense is a high intensity light?
75-100 watts
what is true about subject density?
it is said to be decreased when it is dark
what would you expect if you took a film and your FFD was shorter than your grid range?
you will see grid lines
federal guidelines state that you need to be _____ years old to take xrays
18
what should employees who are pregnant do to take xrays?
wear a lead apron when xraying patients
what color glow is preferred for the intensifying screen chrystals today?
blue-green
what number is given for a par speed screen?
100
what can be used to maximize light reaching the film from the screen chrystal?
a reflective layer
where are the latches to open the cassette?
the side
what would produce the most grain on a film?
fast speed screens
with intensifying screens what gives you better detail?
a single screen system
what will you do with your old outdated films?
sell them for their silver content
what is true of subject density?
it is said to be increased when it is light
why are renal shadows often seen on an AP lumbar film?
due to contrast between oil and water densities
what is true of manual processing?
fixing is twice as long as developing
small white specks on a processed film usually indicate what?
dirty intensifying screen
with usual manual processing equipment which tank contains acidic solution?
developer tank
what color safelight filter is needed for most rare earth screens?
red
what is a high intensity lamp used for?
to see overexposed areas better
if you want to see the SI joints and the L5 disc space without distortion on a frontal view which would be the best thing to do?
direct central ray AP with a cephalic tilt
what film/screen combination is used in most chiro offices?
DOUBLE EMULSION FILM WITH DOUBLE INTENSIFYING SCREEN
what is the proper arrangement of the five subject film densities from most to least dense?
heavy metal, metal, water, oil, air
what is the lead equivalent thickness required for the ceiling of a single story building in inches?
none
too high of a KV will have what effect on a film?
quantum mottle
black branching streaks randomly placed on the film is usually due to what?
static electricity
what type of film is used in chiro offices?
double emulsion
what advantage does a single screen cassette have?
increased image detail
what speed is preferred in general spinal radiography with a rare earth system?
400
100 speed screens is referred to as?
par
rare earth screens have what effect?
less radiation dose to the patient
what produces the most grain on a film?
using fast speed screens
with intensifying screens what gives the best detail?
a single screen system
how many 14x17 films should be processed in a week?
20-25
if the temp in your dryer is too hot what will happen?
the film will have water spots
the sheet of lead in a cassette serves what purpose?
to help prevent back scatter
using an extremity cassette will have which effect?
it will increase patient exposure
if your cassette was incompletely closed what would the film look like?
it would have a black strip at the edge
what exists on a film after you expose the patient but before you process it?
a latent image
which combination of screen light and film color is preferred?
green light and purple film
what is the usual recommended optimal developing temp for manual processing?
68 degrees
sensitometry is a way to do what?
to check consistency of processing
in what phase of processing does the latent image become the manifest image?
developing phase
densitometry and sensitometry are primarily used for what purpose?
to moniter processing function
a curtain effect from lack of fluids being removed in automatic processing is caused by what?
malfunction of the squeegee rollers
what are the needed thickness of lead for primary and secondary protective barriers for an xray facility?
1/16 (primary) and 1/32 (secondary)
