Busy. Please wait.
or

show password
Forgot Password?

Don't have an account?  Sign up 
or

Username is available taken
show password

why


Make sure to remember your password. If you forget it there is no way for StudyStack to send you a reset link. You would need to create a new account.
We do not share your email address with others. It is only used to allow you to reset your password. For details read our Privacy Policy and Terms of Service.


Already a StudyStack user? Log In

Reset Password
Enter the associated with your account, and we'll email you a link to reset your password.
Don't know
Know
remaining cards
Save
0:01
To flip the current card, click it or press the Spacebar key.  To move the current card to one of the three colored boxes, click on the box.  You may also press the UP ARROW key to move the card to the "Know" box, the DOWN ARROW key to move the card to the "Don't know" box, or the RIGHT ARROW key to move the card to the Remaining box.  You may also click on the card displayed in any of the three boxes to bring that card back to the center.

Pass complete!

"Know" box contains:
Time elapsed:
Retries:
restart all cards
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.

  Normal Size     Small Size show me how

screen film rad

screen film radiology

QuestionAnswer
emulsion area on film that captures the latent image
single emulsion little notch to load the film correctly. you have better resolution but the disadvantage is that you use more technique
double emulsion
purpose of the base for film construction provides mechanical support
prior to W.W.1 film was highly what? flammable
what are the three types of film? 1. cellulous nitrate/ 2. cellulous tiracetate/ 3. polyester
1.cellulous nitrate highly flammable, was the emulsion base prior/ after W.W.1
2. cellulous triacetate safety film (inflammable 20s), emulsion base that teared like paper
3. polyester safety film (inflammable 60s-today), flexible, not breakable and not easily tearable
film construction/ good characteristics of base safety film, non tear, flexible, stabile, rigid, uniform lucency, blue tint vs clear base, archival quality
blue tint reduced eyestrain to radiology
clear base which we achieve by shuttering to reduce eyestrain
cross over double emulsion film. front and back images are not perfectly superimposed so they apear blurry. with thinner film construction this is not seen
adhesive layer holds the emulsion in place
gelatin glue like or sticky substance that holds the silver halide crystal
halide gives off light
what are the two types of silver halides silver bromide and silver iodide
silver halide crystals tabular grains- flat= more even dispersion
tabular grain absorb more photons, reduce crossover, and reduce Ag coating required
silver halide crystal lattace ionic bonds which permits free Ag & e- to drift, sensitivity specks (impurity)- gold silver sulfide. forms latent image
over coat, top coat, super coat hard protective gelatin, prevents soft emulsion from scratches, etc. antistatic
antistatic built into top coat
what are the three classifications of film? pancromatic, othrchromatic, and blue sensitive
panchromatic sensitive to all colors
orthochromatic sensitive to green film/red light spectrum
blue sensitive controlled by dyes
calcium tungstate = blue film
resolution ability to image an obj faithfully
resolution is better with what? smaller crystals or thinner emulsion
speed how fast responds to min. exp
what gives you a faster speed? larger crystals or thicker emulsion
fast systems gives you what? less MAs and less pt dose
what is a disadvantage of a fast speed? loss of recorded detail
contrast ability to image density differences which depends on crystal size
true or false do you get better contrast with thinner emulsion and smaller crystals? true
latitude range of exposures to produce a quality image which is indirectly related to contrast
with low contrast what increases? exposure
what decreases with high contrast? exposure
film handling/storage below 68 degrees. film is 8x more sensitive than non film. once opened 45 days and an unopened box for 18 months
what is film sensitive to pressure, heat, and radiation
if film is to cold or to dry what happens you have static
what happens if film is to hot fogging or film sticks together
added pressure can cause what on film unwanted density known as an artifact
what are the 4 possible states of film green film, clear film, black film, and diagnostic film
green film film prior to processing
clear film can be found in repeat bin
black film how you get rid of mistakes, pop open cassette etc
diagnostic film acual image that is on film
cassette housed to protect film and screen
what makes up the cassette tube side, back side and blocker
tube side made out of radiolucent material, which absorbs good x ray forming beam to penetrate in order to get an image
back side made out of radiopaque material, which absorbs backscatter from patient
blocker housed the patient information
what is the purpose of the cassette it is light tight and promotes good film/ screen contact
safe light white 20 watt bulb. most rooms used a red filter
is laser film sensitive to red light T or F true
blue sensitive film amber safelight filter w/ low wattage white bulb
panchromatic film red safelighter filter w/ low wattage white light bulb. turn off red safelight when processing laser film
screens purpose allows us to control small quantity mAs of xrays into larger quantity of light photons to expose film
what is the advantage of screens less pt dose and less wear and tear on equipment
disadvantages of screens loss of spatial resolution due to spread of light when it hits the surface of the film
construction of screen base, reflective layer, and phosphor
base/ purpose & characteristics polyester which sole purpose is to provide mechanical support. rigid, radiolucent, and chemically inert
reflective layer and purpose magnesium oxide & titanium. the reflective layer is a mirror that redirects the light
phosphor (active) layer material & purpose calcium tungstate which gives off blue light. purpose is to convert xray to light
luminescence gives off light
fluoresence stops immediately when energy stops
phosphoresce *afterglow or lag after light is off (glow)
photostimuable gives off light twice
isotropic propagation light is emitted equally from screen phosphor in all directions
rare earth green - pure rare earth
what are the rare earth phosphors gadolinium, lanthanum, and yttrium
what are phosphor characteristics a high DQE/ absorption efficiency and conversion efficiency
what is conversion efficiency x ray is converted to light
examples of phosphors calcium tungstate (blue light) rare earth (blue or green light)
construction of screen/protective coating surface to clean. gauze and baby oil was used to help decrease static
how are artifacts shown on screens as white marks
spatial resolution the ability to see small structures
recorded detail or resolving partner ability to accurately image an object. indirectly to screen speed.
to increase resolving power, you must increase mAs (use slower sytem)= increase in pt dose T or F true
spatial resolution depends upon phosphor crystal size, phosphor layer thickness, phosphor concentration, type of phosphor, reflective layer and yellow light absorbing dye
yellow light absorbing dye put into reflective layer.
with a slower system what is the disadvantage a higher pt dose
line pair bar phantom LP/mm (7-15)normal resolution
density the degree of blackening
line spread fuction used a microdensitometer to measure the film screen combos ability to accurately measure boundaries of images
MTF modulation transfer function- information lost between subject and IR caused by light diffusion
intensification factor exposure w/out screens amnd exposure w/ screens
film/screen contact use wire mesh to test which is used to rule out poor screen film contact. poor= area of blur on image
film/ screen contact causes broken hinges or latches. foreign matter, warped cassettes, bent frame, worn felt, and air trapping which is transitory
mottle- noise film graniness, screen structure mottle, and quantum mottle
film graniness clumping of the silver hylide crystals
screen structure mottle graininess cuased by clumping of the phosphurs
quantum mottle (more common) noise from random interaction of x rays w/ screen (more common w/ high speed systems
asymmetric screens tube side- slow for resolution and contrast (mediastinum) back side- high speed as less radiation hits for wide latitude/low contrast structures (lungs)
order of automatic film processing develop, fix, wash, dry
1. develop converts latent image into manifest image
2. fix chemicals remove unexposed silver hylide emulsion
3. wash washes off chemical
4. dry permanant image thst emerges from processor
the manifest image is only seen after processing T or F TRUE
control panel 92 degrees F/ wash 4-5 degrees lower
development conversion of latent image into black metallic image
reduction vs oxidation rduction- adding electrons to positive ions to reduce them to a stabile state. oxidation- the lost of free electrons by a chemical
most important relationship in development time- direct relationship to short underd temperature- 20 sec in developer @ 93 degrees F
chemicals in developer reducing agents phenidode- gray tones/contrast hydrquinone- black tones/density
synergism two medicines work better than seperate
activator agent sodium cabonate- swells emulsion/makes alkaline base ph
restrainer= starter/ potassium bromide- antifoggant
preservative sodium sulfite- prevents oxidation
hardener glutaraldehyde- hardens emulsion
solvent water- dissolves chemicals/maintains temperature
sequestering agent chelate- removes metallic impurities
fixer clears unexposed emulsion- silver recovery, metallic replacement, E lectrolytic. provides archival quality
oxidation loss of free electrons
fixer agent/ammonium thiosulfate (hypo) actual chemical that removes unexposed silver hylide cystals (emulsion)
activator acid based which stops development
preservative sodium sulfate, same as developer
solvent same as developer, water
hardener potassium alum, hardens the emulsion 90-93/ 20-22 sec in the fixer
developer alkaline based
activator acid based
buffer acetate maintains acid ph
sequestering boric acid/salt which removes aluminum ions
wash 3rd tank washes away chemicals
temp of wash 5-7 degrees lower to maintain temp
what happens if you forget to turn the water off you get overexposed or fogged film
if you smell ammonia what does it mean cross contamination
dryer dry image, manifest image
film feed tray metallic food tray
guide shoes if missalined or dirty may cause scratches
feeding film into processor 2- 8x10s LW all other film sizes CW
film is ran singularly every 14" to run the replenisher T or F true
transport system controls development and processing times, solution and rollers (rubberized)
rollers detector w/microswitch. entry - guide shoe artifacts and pi line artifacts
replenishment system 2 tanks 1 extra developer solution and 1 fixer solution
you do not want an over replenished system T or F true. an over replenished system = over developed and vice versa
processor maintenance is to be done every day, measuring developer temp, density, contrast on a film also for consistency
what are the three types of maintenance scheduled, preventative, and non-scheduled
steps in maintenance start up- turn on to warm up/run films to clear rollers. may have to turn on rollers shut down- some departments lift lids, may have to turn off water supply
what are three types of static artifacts tree stag- friction smudge- crown-
trouble shooting tips/ static from feed tray ground
underdevelopment = underexposure, which will decrease contrast
time and temp too low reset
exhausted chemicals clean and replace
under-replenishment reset rates
diluted developer clean and replace density light/loose contrast
over development time or temp too long- reset forgot restrainer - add over replenishment- reset rate. high density/loose contrast
dichroic stain yellowish stain from improper washing exhausted or oxidized developer or fixer insufficient rinse contaminated developer
green was not clear insuff fix or wash
brown insufficient washing hypo retention
deposits dirty filter water most likely metallic oxidized silver load in fixer
deposits/ white milky fixer - hardener, too much acidity , developer contamination
deposits/ black flaky marks due to dirty city water
if film comes from the processor wet dryer
if film comes from the processor wet and sticky lack of hardener in fixer
if film jams lack of hardener and improper aligned rollers or guide shoes
if scratches lack of hardener. improperly or dirty rollers or guide shoes. pi lines/ guide shoe marks
wire mesh test checks for warped cassettes
artifacts runs- fixer prob
frilling weak fixer or too hot of solutions
blisters gas bubbles in emulsion
reticulation non uniform processing
streaks water on semi-dried emulsion, air flow to high, poor squeegee
buckshot (puddies) water or semi dried emulsion
exposed film is 8x more sensitive than unexposed film T or F true
Created by: eckoultd1972