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251 Cards in this Set
- Front
- Back
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What is the purpose of x-ray film that creates a radiograph?
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It provides a permanent record of x-ray image!
Newer tech provides video capture though! |
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X-ray film composed of silver halide crystals on plastic sheet interact and do what?
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They change to black when!
Ionizing radiation - x-rays Visible light Pressure Bending Moisture |
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In general X-ray film is very similar to handle like?
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Photography film!
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What basically happens when the x-ray hits the film?
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It creates a latent image!
The energy of the x-ray photon dislodges an electron and causes silver ions to join a silver atom. |
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What is film contrast?
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It's the difference in colors. Low contrast tends to be either all white or black while high contrast has grey range. ??? Check with Susan as PP is odd.
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Higher kVp does what to the x-ray film?
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It creates a low contrast latent picture. Black and White but little grey. ???? Check with Susan as PP is odd.
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What is fast x-ray film compared to slow x-ray film?
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Fast has large crystals that require less exposure but turn larger areas black quicker. While slow has very small crystals that require more x-rays to hit to get a proper image.
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So in general what is x-ray film speed based on?
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The size of the silver halide crystals!
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There are in general two types of x-ray films. What are they?
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They are:
- Non-screen film - Screen film |
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Non-screen film is?
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Sensitive to ionizing radiation and has fine details. Requires more exposure. Often used in dental.
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What is screen film?
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These crystals are also sensitive to fluorescent light! Less sensitive to direct ionization. Good part is it requires less exposure but unfortunately lose image definition.
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Screen film has several different color types. What are they?
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Blue sensitive flim - Responds to ultra-violet to blue light.
Green sensitive film - Responds to screens that emit 60% green and 25% blues. Rare earth phosphors! |
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With screen film there can be a crossover punch through effect. This is when there are two screens and what happens?
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The light goes through one side and bounces back giving it a second chance to hit the film.
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What are some common x-ray sizes?
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14 x 14
14 x 17 7 x 17 8 x 10 10 x 12 11 x 14 |
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What are intensifying screens used for?
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They are thin sheet of phosphor crystals which lies next to film within cassette. They decrease the amount of radiation required for a diagnostic radiograph. You can use less mAs (fast exposure)
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What are the 4 layers of a screen?
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Base
Reflecting Layer Phosphor Layer Protective Coating |
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What is the difference in seconds compared to screen film from non-screen film?
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0.1 second exposure compared to 3.4 seconds! Huge difference in x-ray exposure!
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What are intensifying screens made of? The phosphor layers? Two types!
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Calcium tungstate and barium lead sulfate - blue light emission!
Rare earth screens - green light emission! |
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What are film holders called?
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Cassettes
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What are some factors in cassette design?
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Must be rigid, don't bend.
Durable, to handle use! Light-proof! Transparent to x-rays at least on one side! |
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What does manual film processing require?
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A dark room! Just like old school photography!
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What type of light can you use in a dark room?
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A red light! It doesn't hit the spectrum the film uses!
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What does developer solution do during manual film development?
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It reduces the silver bromide crystals to black metallic silver!
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What is the ideal time for developer of film?
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5 minutes at 68 degress Fahrenheit!
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What happens if the temperature is to high when developing film?
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It causes reticulation, melting a layer of the film and creates a slipping effect!
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How long does the rinse bath take?
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It is 30 seconds in water!
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What does the fixer solution do in film processing?
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It converts undeveloped silver bromide crystals into a solution that is washed away! Hardens film!
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What is the minimum fixing time for film?
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Depends on film appearance. Goes from cloudy to clear! Also called clearing time! Wait until it is clear!
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If you are drying film what is important?
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You want a clean cabinet without dust or water!
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What are the benefits of automatic film processing?
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Compact size!
Fast! Consistent! Time and temperature controled! Produces dry radiograph immediately! |
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What is an important note in develping and x-ray films during disposal?
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They are hazardous waste and must follow strict guidelines!
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What are some main structures of the x-ray machine?
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Tube
Collimators Controls Grids Table Top |
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What are the structures inside the x-ray tube?
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Cathode
Anode Filament |
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If the anode rotates what type of x-ray machine is it?
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It's a non-moving table one.
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If the anode is static in place what type of x-ray machine is it most likely?
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A portable x-ray device.
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What does the collimator do?
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It limits the size of the primary beam. It also limits exposure of x-rays based on target area.
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What is a device capable of limiting radiation, as a long narrow tube in which strongly absorbing or reflecting walls permit only radiation traveling parallel to the tube axis to traverse the entire length?
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Collimator
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The aperture collimator target looks like?
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A circle!
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The cylinder collimator target looks like?
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A circle as well but has a long colomn.
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The cone collimator target looks like?
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Not used much but like the colomn but with a funnel like walls to the circle.
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The shutter collimator target looks like?
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Most used! It is a square that can be controlled with width and length. It normally on makes rectangles.
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If you have an x-ray film and the target from the collimator is outside the region of the film this is?
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Improper use and x-rays will hit something beyond. You want to focus the beam only on the x-ray film!
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What are the controls on the x-ray machine?
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kVp
mA Time Exposure Switch Lamp |
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What does mA stand for?
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Milliamperage!
Determines NUMBER of x-rays produced! |
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What does kVp stand for?
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Kilovoltage peak!
It's the maximum energy of the beam! It's related to the speed! |
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What should you remember with an x-ray machine foot pedal?
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It's easy to forget about it and step on it! You want to keep it in a place where people won't accidently hit it.
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What should you remember when you hit the exposure switch?
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There is often a delay as the anode spins or things heat up. It's not instant!
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What is the lamp inside the x-ray machien used for?
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It helps shine light and direct the target. It should line up pretty close to where the x-rays will hit. This is used with the collimator to define your target area!
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Sometimes the lamp will do what if it's been on for awhile?
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It may turn off before you can get things done. The x-ray machine limits heat build up and though the lamp isn't part of the x-ray device it creates heat and will be switched off automatically if creating to much.
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What is a grid on an x-ray machine table?
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It's a flat plate with a series of foil lead strips roughly 0.5 mm wide. This helps keep only x-rays in direct line hitting the film.
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What is the purpose of the grid on an x-ray table?
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To absorbe scatter and improve x-ray image quality!
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What's a high ratio grid and a low ratio grid numbers?
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16:1 is high ratio grid! Removes more scatter
8:1 is low ratio and has more space! |
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If you have a high ratio grid (16:1) what should you remember about exposure?
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It takes longer because only direct beams hit! You have to be centered perfectly!
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What is a bucky system?
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It's a moving grid table. This tries to blur the image and not let pass through. So there are no grid lines on radiograph image.
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What are two main types of grid designs?
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Linear and Crossed!
Crossed absorbs scatter in both directions but needs greater exposure! |
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What should you remember with a focused grid?
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The distance is always the same and the device basically doesn't move at all. A focused grid is angled and must be aligned properly or it won't work.
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What's another thing you might need to remember about the bucky system table when it moves?
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It makes noise and might startle the animal!
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What's another note on the bucky system in reference to exposure?
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More time as grid moves. It blocks beams so you have to expose longer to get image.
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What is located in one of the corners of the radiograph cassettes?
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The Film Identification Label. It's shielded and can be exposed in the dark room process with information.
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What is required on film labels?
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Must be permanent
Name & Location of Hospital Name of Veterinarian Name of Patient and Client Case Number Date |
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If you are using a dark room what should you do with the label?
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Fill out the index card information before you enter the dark room so you can simply place it in the labeler.
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What might be some of the problems with the labeler if it isn't working correctly?
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Bulb weak or blown
Weak or dead batteries Not plugged in |
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There are all sorts of markers used in radiographs. What is the most important concern in using markers with x-ray's?
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To place it in a proper location!
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What are some types of markers used in radiographs?
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R verses L (Right and Left)
Medial verses Lateral Mercury Bubble Markers (Indicate Direction) |
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Some markers on radiographs indicate time. What are they used for?
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Motility studies and myelograms.
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Some markers are used to indicate view! For example you may need to know ...
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V-D verses D-V!
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If you forgot to use a marker what should you use to mark on the film?
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Some form of permenant marker such as a sharpie or film pencil.
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When it comes to film storage what is important in keeping films concerning patients?
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Keep all the radiographs in a single patient folder. Don't mix radiographs with other patients or folders. It helps in keeping a history of the animal.
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Each patient should have a unique sequential identification number and this is put on the radiograph. What are some things to remember about this number?
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It is assigned to the patient with the first radiograph taken.
It should be recorded in the patients record. This number is used for the patients entire life. |
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What is a radiology log used for?
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Records exposures and use of machine!
Allows reference for technique and issues. Keeps account of who took films. |
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In the radiology log what information should be in it?
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Name of Patient
Veterinarian Name I.D. Number Date Tech taking films And views taken. (Ex: V-D) kVp and mAs Settings Film Type Grid System And number of films and exposures! |
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Radiographs are considered to be part of the permanent medical record and should be?
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They never leave the hospital!
Think of them as a legal document! They can be copied and may leave for special cases but place holders must be used and who checked them out. |
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If you get an improper image position what is the problem?
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You have to take it again and increase exposure!
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Toward the Head is?
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Cranial
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Toward the Tail is?
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Caudal
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Toward the Back is?
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Dorsal
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Toward the front (sternum)
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Ventral
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Away from the midline! (On the sides)
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Lateral
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Towards the middle of the animal? (Midline)
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Medial
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Towards the nose of the animal?
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Rostral
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Towards the palm of the animal?
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Palmar
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Towards the rear foot of the animal?
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Plantar
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Anterior in human anatomy is?
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Dorsal in Animal
(Top of Arm so to speak) |
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Posterior in human anatomy is?
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Palmar/Plantar in Animal
(Back of Arm so to speak) |
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Views are described in relation to x-ray beam. So a V-D indicates?
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The x-ray travels through the ventral first and exits the dorsal.
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If the x-ray is traveling from the chest of the dog out it's rear end what is it called?
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Craniocaudal
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If the x-ray is entering from the dorsal and exiting through the ventral what is it?
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Dorsoventral
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If the x-ray is entering from the side (lateral) what is it called?
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Lateral
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If the x-ray is an A-P of front limb and entering from the dorsal to the palmar what is it?
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Dorsopalmar
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If the x-ray is an A-P of the hind limb and entering from the dorsal to the plantar what is it?
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Dorsoplantar
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If the x-ray is entering from the ventral and exiting the dorsal what is it?
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Ventrodorsal
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A side view is basically a?
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Lateral View!
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What does V-D stand for?
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Ventrodorsal
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What does A-P stand for?
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Anteriopalmar/plantar
Dorsopalmar or Dorsoplantar |
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What does a Cr or Cd stand for?
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Craniocaudal
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What does a D-P stand for?
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Dorsopalmar or Dorsoplantar
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There is a special hip view radiograph that is done for the OFA (Orthopedic Foundation for Animals). What should I know about this x-ray?
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Animals must be two years to be certified.
Proper positioning is a must! (V-D) Fully extend rear legs! Rotate Stifles Internally so Patellae are centered. Needs to include entire pelvis and stifles |
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Which is one of the more complex structures to take a radiograph from?
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The Head!
It has: - Tympanic bullae - TMJ joint - Sinuses - Teeth |
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What is the term for a short muzzle?
(Typically Boxer, Chihuahua, Bulldog, Persian Cats) |
Brachycephalic
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What is the term for a moderate muzzle?
(Typically Labrador, Beagle) |
Mesaticephalic
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What is the term for a long muzzle?
(Typically Collie, Borzoi, Greyhound) |
Dolicocephalic
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The Brachycephailc head structure is difficult to get good radiographs of what?
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Nasal Structures!
Also Strange Dentition - Dental? |
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When looking at a radiograph of an immature animal that is very young and still growing what should I remember?
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They will have open physes from the growth plates! They may look like fractures but are normal.
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What is a Physeal line?
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Growth plate lines
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In older adult animals what is sometimes visible even though they are not young and not growing anymore?
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The Physeal lines may still be visible so look close if trying to figure out fractures.
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What are the multiple tissue densities that reside in the head that I should be aware of?
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Teeth
Bone Soft Tissue Air |
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In terms of thickness of bone the Nasal Turbinates are?
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Paper Thin
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In terms of thickness of bone the Occipital protuberance is?
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Very Thick
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What should I remember about the skin folds of certain animals?
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Skin folds alter the thickness of tissues!
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What are the two routine views of the skull?
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D-V
Lateral with Open Mouth! |
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Sometimes we take a shot of the skull from the skyline view! Why?
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It's a Frontal trying to get the sinuses and nasal turbinates.
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A skull photo with the animal on it's back and mouth tied open is a special view called?
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The Basilar!
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There are many positions where we have the skull photo taken and the mouth open! What are some of this shots called?
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Maxilla Lateral
Maxilla Lateral Oblique Maxilla V-D Open MOuth Maxilla D-V intra-oral Mandible Lateral Mandible Lateral Oblique Mandible V-D intra-oral |
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What views would you use to take a Temporomandibular joints (TMJ) and Tympanic bullae?
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D-V closed mouth
Basilar Lateral rostrocaudal oblique |
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If you are doing a vertebral column x-ray what do you need to remember?
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Disc spaces need to be perpendicular to table at 90 degrees. So use foam wedges and sand bags to align the spinal column.
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During a dymanic study with hyper flexation of the area what do you need to remember?
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Overzealous manipulation may worse or even cause neurological damage!
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When taking an x-ray of a shoulder joint at the lateral angle what should I remember?
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Be sure to avoid superimposition of thoracic structures onto the joint!
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What does Radiographic contrast depend upon?
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Subject Contrast
Inherent Film Contrast Scatter Film Fogging |
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Radiographic contrast depends on kVP! What would I use for high contrast?
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Low kVp has large steps between grays! (High Contrast)
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Radiographic contrast depends on kVp! What would I use for low contrast?
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High kVp has small steps between grays! (Low Contrast)
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The subjects contrast depends on three major factors. What are these three things to consider?
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Thickness
Density Atomic Number |
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Black marks on radiographs are caused by?
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Scratches
End of film black from light leaking into storage container. Crescents from bending film. Border black due to worn felt strip in cassette Static electricity |
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White marks on radiographs are caused by?
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Fingerprints or blotches from fixer.
Crescents from bending before exposure. Hair, debris on film or screen. Dirt or iodine on skin. Contrast media on cassette, patient or table. |
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Blurred images on radiographs are caused by?
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Patient Motion
Tube Motion Cassette Motion |
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A distorted image on radiographs is caused by?
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Central beam not perpendicular to cassette.
Central beam not aimed at center of cassette. Poor film screen contact due to debris or defective cassette. Magnification from too high object-film distance. |
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Heavy lines across a radiograph is caused by?
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Wrong film-focal distance.
Grid not perpendicular to central beam Grid not centered on central beam Heavy lines on both sides because grid is upside down! |
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Edges of film underexposed and white on radiograph is caused by?
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Cassette not centered on beam.
Bucky tray not positioned properly under table. |
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When you have a double exposure on a radiograph this is caused by?
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Reusing cassette
Machine Fired Twice |
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If you have foreign objects on a radiograph these are often caused by?
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Positioning aids.
Collars, Leasheas AVID chips Monitoring equipment Handler/operator body parts in shot |
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A yellow radiograph or yellow patches is caused by?
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Due to improper fixation process or film sticking together during fixation.
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If the lower half of the film is underdeveloped the reasons are likely?
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Temperature is too low at bottom of tnak.
Stir before use! |
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If there are streaks on the film?
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Dirty wash water!
Water dropping on film when drying Developer on hanger clips |
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If the film is sticky and or cloudy what caused it?
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Improper fixer time. Indadequate rinsing.
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If you have brittle radiographs it is caused by?
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Drying too long
Drying temperature is too high |
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Any reticulated pattern might be caused by?
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Improper solution temperature.
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If you have multiple dark spots on the film this is likely caused by?
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Developer on film prior to processing!
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If you have multiple white spots on the film this is likely caused by?
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Fixer on film prior to processing!
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With an automatic film developer if the film density is too high what might have caused this?
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Developer temperature too high
Light leaking into processor Transport speed too slow |
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With an automatic film developer if the film density is decreased what might have caused this?
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Developer temperature too low
Exhausted developer Transport speed to fast Under-replenishing (Tank empty, Air in line, pump malfunction) |
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With an automatic film developer if the film is scratched it is likely caused by?
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Guide shoes malfunctioning (2 inches apart)
Drying tubes touching film |
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With an automatic film developer if there are streaks on the film it is likely caused by?
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Rollers dry or crusted
Dirty wash water Dirty air tubes |
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With an automatic film developer if there are black makrs on the film what caused this?
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Pressure marks from rollers
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With an automatic film developer if there is damp or tacky films what caused this?
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Insufficient drying (time or temp)
Insufficient fixing Insufficient air venting Clogged air filter |
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With an automatic film developer if the film is overlapped what caused this?
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Film fed too quickly.
Roller tension too tight. |
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With an automatic film developer if the film is stained what caused this?
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Failure to wipe down rollers.
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With an automatic film developer if the film has algae and debris what has happened?
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The tanks have stagnated
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What is the purpose of radiation safety?
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Maximize diagnostic information while minimizing radiation exposure.
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What is the term used that is a measure of the quantity of ionization produced by x-rays (exposure)
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Roentgen
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What is the term used for a unit of absorbed dose of ionizing radiation?
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Rad
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REM stands for?
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Rad Equivalent Man
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What is the term used to account for differences in effects of different types of radiation?
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REM - Rad Equivalent Man
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What is the term used for damage caused by ionization of molecules within the cells?
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Radiation Injury
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What does LD50 (30) mean?
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It means a leathal dose such that fifty percent die within 30 days.
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Can certain animals survive radation exposure?
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To a degree. Different animals can handle different amounts of radiation.
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If you get hit by a 100,00 rads what basically happens?
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You have almost instant molecular death. Blasts your information apart basically.
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If you get hit by 10,000 rads what basically happens?
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Death in a few days. Lots of neurological damage!
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If you get hit by 900-10,000 rads what basically happens?
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Death in several days. Your body loses it's immune system and ability to function.
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If you get hit by 300-900 rads what basically happens?
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May or may not cause death.
Lots of problems though and likely unable to produce much red or white blood cells which leads to infections. |
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What parts of the body can handle radation exposure better?
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Extremity exposure is often more capable as there are no vital organs, except for the head of course.
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But just because extremities can handle radation better it still can cause Squamous Cell Carcinoma which is?
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Skin Cancer
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What are some other possible effects from radation exposure?
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Premature Aging
Lowered Immune System Chance of neoplasia |
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What is neoplasia?
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The growth of tumors.
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Who MUST be exluded from the radiograph x-ray area?
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Anyone under 18 years old!
Anyone who is pregnant! |
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What are generational effects from radiation exposure?
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Mutation! Higher radiation injury causes more mutation.
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What are film badges?
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They are devices that determine exposure! A film in a plastic cover with variable filters in badge.
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How are film badges handled and used?
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Worn on collar, lapel or pocket.
After set time interval sent to company for processing. Permanent record of exposure for each individual. |
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What does a pocket ionization chamber do?
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It responds to ionizing radiation, is pen shaped and can be recharged. Levels need to be recorded.
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What is the maximim permissible rem dosage per week?
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0.1 rem average weekly.
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What is the maximim permissible rem dosage per 13-week?
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3.0 rem maximum per 13-week dose
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What is the maximim permissible rem dosage per year?
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5.0 rem maximum yearly dose.
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What do you need to remember about the monitoring of radiation and your health over time?
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The numbers you are allowed also lowers as radiation effects increase! So as you age the number lowers!
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You want to always wear your dosimeter or monitoring device where?
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On the outside of the led apron!
You can also add a second underneat if you wish. |
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What happens at higher altitudes in relation to radiation?
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You receive more background radiation at higher altitutdes.
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Is background radiation taken into account for exposure?
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Yes it is! They are assuming you are being exposed to this as well.
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If possible who should be in the room where the x-ray is being taken?
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Only the patient if possible!
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Where should you be if you are in the room where the x-ray is being taken?
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Be as far away from the beam as possible!
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What is the minimum lead thickness for radiation protection aprons?
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0.5 mm
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If you are wearing gloves what should you remember about radiation safety?
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You want them fully covered. Even if the one edge is covered in an open mitten setting the beams will scatter and bounce around hitting the hand on the reverse and making the protection less useful.
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What must you use everytime for radiation safety? Something special, not simply the apron.
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The Thyroid Shield!
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There are other types of items that can help protect operators such as a?
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Mobile Lead Shield
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What is one of the main ways to limit radiation exposure from the x-ray machien itself?
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The Collimation aspect! Only target what you need!
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Proper technique minimizes repeat exposures! What should I remember about kVp and mAs?
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Higher kVp requires less mAs and less radiation exposure!
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How should I treat a lead aprons and equipment?
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They should not be folded or creased! They need to be hung up after every use and a good idea to test them for holes!
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What should you do every 4 to 6 months on your radiation safety equipment?
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Radiograph and test it!
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If the dosimeter reports excessive exposure what should you consider?
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Was it actual or did something happen?
Did it get hot, bend, laundered. Did more than one person use it. Was it left in the x-ray room. |
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What are the main key points to limit exposure to radiation while taking x-rays?
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Proper technique!
Proper positioning! Collimation! Protective Clothing Always! |
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What is one of the main things to remember about taking x-rays! Something related to carelessness?
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Don't sacrifice proper radiation safety for speed!
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What is the purpose of a technique chart?
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To prevent wasted time and film due to inappropriate exposure factors.
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Why will one technique chart not work for another machine?
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Because each machine is different, even if the same model. Might be older, different enviornment and so on.
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What are some factors that have NO affect on exposure factors for technique charts?
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Object - Film Distance
Focal Spot Size Cassette Size Collimation Direction of X-ray Beam |
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When creating a technique chart you want to do what?
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Standardize as many factors as possible!
Don't switch things around. if you use a bucky tray always use it and so on to build chart. You can adjust after the chart is made by a certain factor. |
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When creating a technique chart what settings should be set at what rates?
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Start at between 60-80 kVP!
Take a series of exposures with same kVp Only change the mAs |
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If I start a Technique chart with a 70 kVp through all levels and a 2.5 mAs, what will the other two mAs settings be?
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Double it each time!
5.0 10.0 |
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When creating a Technique chart I end up with overexposed radiographs, too dark! What should I do?
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Reduce kVp by 10
OR Decrease mAs by Half! |
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When creating a Technique chart I end up with underexposed, too light! What should I do?
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Increase kVp by 10
OR Increase mAs by Double! |
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If you are creating a technique chart and are unable to increase kVP why would this happen?
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Likely a portable that only goes so high!
Increase mAs! |
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When creating a technique chart, besides kVp and mAs, what other factor is important?
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The thickness of the subject! Try to find an average thickness subject!
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If you have a standard table and add a grid, what can you adjust in increments to get a good radiograph from the standard settings?
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2 kvp per cm (40-80 kvp)
3 kvp per cm (80-100 kvp) 4 kvp per cm (100+ kvp) |
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How do I obtain proper technique for other areas of the body when taking an X-ray from a technique chart based on the abdomen?
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Select
One column higher for extremities Two columns higher for skull/vertebrae Three columns higher for pelvis Five columns lower for thorax mAs stays same! |
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From a technique chart if I have a thin animal or young one, what should I do?
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Halve mAs
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From a technique chart if I have an Obese animal or one with a cast what should I do?
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Double mAs
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From a technique chart if I am taking a skull shot what should I do?
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Add 5-10 kvp
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On a technique chart what setting does not affect contrast?
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mAs
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On a technique chart what setting is directly proportional to film density?
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mAs and kVp
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On a technique chart what setting affects contrast?
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kVp
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On a technique chart higher kvp will yield what type of contrast?
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Long scale of contrast (small steps)
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On a technique chart lower kvp will yield what type of contrast?
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Short scale of contrast (large steps)
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What is a general rule of changing setting that will maintain the same film density?
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Double mAs and subtract 10 kVp
OR Halve mAs and add 10 kVp |
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If the radiograph is too light?
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Increase kVp by 10
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If the radiograph is too dark?
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Decrease kVp by 10
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What are some reasons related to the patient that might create a radiograph that is darker than an average patient?
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Less Dense!
Bone Diseases Pneumothorax Pneumoperitoneum Gas filled intestines/stomach Muscle wasting/emaciation |
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What are some reasons related to the patient that might create a radiograph that is lighter than an average patient?
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Pleural effusion
Pulmonary Edema Ascites Large Mases Cardiac Disease |
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What does Ultrasonography provide?
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Provides information about the organ architecture! How it looks! It's independent though of actual function of the organs, such that you can only see what things look like, not how they are working.
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What type of crystals are used in the probe?
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Piezoelectric Crystals!
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What frequency does the ultrasound crystals ocillate at?
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several million hertz per seconds! (MHz) range!
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How does the ultrasound wave work in the body?
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It interacts with the tissues and is reflected in different degrees. The echo is what is picked up and provides the image!
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What does air do to ultrasound?
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Scatters sound
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What does fluid do to ultrasound?
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Transmit sound with little attenuation or reflection creating distant enhancement! Can see further!
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What does minerals or metals do with ultrasound?
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Ultra reflective!
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What does bone do with ultrasound?
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Can not penetrate!
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What would cause an ultrasound acoustic shadow?
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Air/Gas
Mineral/Metal Bone |
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What would cause an ultrasound acoustic enhancement showing more or further?
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Fluid!
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Echogenicity is the what?
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The brightness of the ultrasound echos!
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What is the ultrasound term for black, reflects few if any echos such as fluid?
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Anechoic
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What is the ultrasound term for darker, reflects few echoes but some?
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Hypoechoic
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What is the ultrasound term for brighter, reflects many echoes, like bone, mineral, and metal?
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Hyperechoic
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What frequency is used for cats and small dogs in ultrasound? Can also be used in equine repro or tendons/ligaments?
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7.5 mhz
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What frequency is used for medium to large breed dogs or for equine repro scanning?
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5 mhz
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With a higher frequency probe you have better?
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Better resolution and detail but less penetration! The waves are closer together so harder to reflect back, wave is lost.
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With a lower frequency probe you have better?
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Better penetration but less detail! The wave is longer and is easier to reflect back over distance!
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What regions can you scan with ultrasound?
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Any region not obscured by gas or bone!
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A CT uses what technology?
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x-rays!
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What does Nuclear Scintigraphy provide?
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Hot spots! It goes to places where the blood carrying the nuclear isotope congregates! It tends to also be attracted to bone so gives a blurry outline!
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What isotope is used in Nuclear Scintigraphy?
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Technetium 99m - Emits gamma rays!
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What is some concerns with Nuclear Scintigraphy?
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Restrict contact with patient! Rads!
Minimize contamination of waste! |
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What are some uses for scintigraphy?
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Thyroid - Hyperthyroid in cats!
Musculoskeletal - Bone stress issues or disease! Liver Scintigraphy - Congential Portosystemic Shunt |
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What does MRI stand for?
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Magnetic Resonance Imaging!
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What does CT stand for?
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Computed Tomography!
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What would I use an MRI for instead of a CT?
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I would use an MRI for non-bone tissue imagining! It provides excellent soft tissue views of the body!
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What would I use a CT for instead of an MRI?
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Anything to deal with bone! CT is very good for bone structure issues because it uses x-ray.
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What is a major concern with MRI's and objects in a patients body?
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They can't be ferrous metals or anything that is affected by a magnet. The MRI is very powerful and can cause serious harm or death if a metal object is in the body that is magnetic!
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What is a safe metal that can be used with an MRI?
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Titanium!
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Who developed a classification for medical devices that can be used or not used with MRI machines?
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ASTM International which is the standard supported by the US Food and Drug Admin.
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What are the three categories for MRI device safety?
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MR-Safe - Good to go!
MR-Conditional - Good up to so many Teslas! MR-Unsafe - Keep away! Dangerous! |
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What do I need to be aware of even if the patient is safe and everything seems good to go for the MRI?
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All objects in the room or something that enters the room can turn into a moving missle if attracted by a magnetic force. It is important to respect the power of the magnet and keep the patient and oneself safe!
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If a radiography is said to have a low density what is the problem?
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It is to light! It doesn't have enough black!
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If a radiography is said to have a high density what is the problem?
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It is to dark! It doesn't have enough white in it!
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How many shots of an x-ray will you take to start a technique chart?
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3!
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If you are making a technique chart and want more grey scale what do you do?
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More kVp!
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If you are making a technique chart and want more black or white what do you do?
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More mAs!
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If I wanted to basically keep the same radiography but wanted more grey scale what would I do?
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I would up the kVp by 10 and lower the mAs by half! This keeps it the same but is fine tuning what you are looking at!
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