Radiography Flashcards
What are the 5 basic radiograph densities from decreasing order
- Gas
- Fat
- Fluid/Soft Tissue
- Bone
- Metal
List some Abnormal Border Effacement examples
- What must all radiographs legally have on them?
- What does this include?
- When does it have to be put on the radiograph?
- What types are there?
- What else is required on x-rays?
- If putting in for a scheme what else is required?
- ID label
- Clinics Name, Date, Patients Name and Number, Owners Name
- At time of exposure or before processing
- Lead Number types, Radiopaque Tape, Light Flasher systems, Digital
- Must also have Left/Right Markers
- Microchip / Tattoo
- Pedigree Name
- What happens to Developer Solution as time passes?
- How often should the Developer Solution be changed?
- Time (oxidation) plus usage (Liberation H+) –> Decreased activity –> Decreased speed of film and decreased contrast of the image.
- Solution should be changed every 4 to 6 weeks Dependant on usage.
What happens if the temperature of the Developer Solution is:-
- Below 16 Degrees
- Above 25 Degrees?
- Too low <16C - Activity too low, underdevelopment regardless of time
- Too Hot >25C - Developer Fog, Emulsion damage
Pre Exposure Button
Explain Step One of Xray Production
Press the Pre-Exposure, activates the current through the filimant, heating the atoms in the wire, giving energy to the atoms which shoot out to make an electron cloud. Cloud size depends on the mA. The focusing cup charges giving it a negative charege so the cloud doesnt disperse.
Misuse will cause Cathode Damage getting thinner and breaks.
How do we get depth perception with Radiographs?
Always take a minimum of 2 radiographs (Orthogonal Views) 90 degrees to each other.
What are some factors which affect radiographic detail
- Tissue composition
- Contrast
- Radiographic Density
- Scatter radiation
- Screen Film Combinations
- Motion
- Processing
- Radiographic Technique
Scatter radiation in the x-ray room would be most significant for which of the following procedures. (1.5 marks)
Select one:
a. a ventrodorsal view of the pelvis of a dog.
b. a thorax radiograph of a cat.
c. a lateral radiograph of the shoulder region of a horse.
d. a lateral radiograph of the fetlock region of a horse.
e. radiograph using a high mAs and low kV technique of any anatomy
c. a lateral radiograph of the shoulder region of a horse.
Explain the difference between Digital Radiography (DR)
Indirect Detection Vs Direct Detection
Indirect Detection - Flat panel detectors
Utilizes a screen
○ Interacts with x-rays to produce light
○ Rows and columns of detector elements
(replace analog film)
Flat panel detects light produced (indirect
detection) for image formation
○ Light creates a charge build up in each element
○ Each element is individually read out
○ Read out is in the form of an electronic signal
Direct Detection - Flat panel detectors
One less step in image formation
○ Light is not produced
○ Electrons released after x-ray strikes a
photoconductor (Selenium)
○ Electrons collected by detector elements
Image formation
○ Charge collected by each element
Read out similar to an indirect panel
What is a Latent Image and how is it created?
What are the different types of Detectors?
Where and how are these Detectors worn?
- Film Badges
- Plastic with filters and xray sensitive film
- Thermoluminescent Dosimetry
- Absorbs energy of exposure and stores
- released as light on heating
- more sensitive than film badges 0.1mSv
- Luxel Badges / Optically Stimulated Luminescence (OSL)
- Aliminum Oxide Film
- Stores Dose - Emssions released by laser beam
- Records 0.01 mSv
- Worn at waist or Chest hight, Correct side to be facing forwards, worn below lead aprons, changed regularly, reports kept and available.
What is Beam Filtration?
How much does it Filter?
What is the legal requirement?
- It is a piece of aliminium that is placed in the beam to absorb low energy xrays, this increases the average beam energy to the patient.
- 3mm Aliminium Reduces patient dose bu up to 80%
- 2.5mm Aliminium for >70kV
Which of the following is the most accurate method of monitoring personal radiation dose?
Select one:
a. Wearing a film badge.
b. Using sonar pulsation dosimetry devices.
c. Using a thermoluminescence dosimeter.
d. Using a Laser Luminescence dosimeter.
e. Using an optically stimulated luminescence dosimeter.
e. Using an optically stimulated luminescence dosimeter.
Explain FFD and OFD
- If I have radiographic film that has opaque and milky areas after post processingwhat may have happened?
- What would happen to this film over time?
- Poor Fixing
- It will discolour to brown
What are the 3 Digital Imaging Networking and Display systems required in a practice?
- Picture Archiving and Communications System (PACS) - Storage and transfer.
- Medical Information Systems
- Hospital Information System (HIS) - Patient Info, Billing
- Radiology Information Systems (RIS) - Ordering rediographs (or Ultrasound, MRI, CT etc), Imaging Reports
X-Ray production Step 2b
What is Screen Speed?
If I wanted a High Definition xray would screen speed would I use?
What are teh four phases of Film Processing?
- Developing
- Fixing
- Washing
- Drying
What computer manipulations can you do with post processing? And what does it mean?
- Window
- How many shades of grey
- Level
- The central value for the shades of grey
- Pan
- Moving the image
- Magnify
- **Reversible alterations to the image.
What is Film Latitude?
What is the relation between wide latitude and High Contrast?
If I want a good detail radiograph what film speed do I use and why?
What is the rule for thin body parts regarding film speed?
Slow Film speed as it has smaller crystels so detail is better however it needs higher exposure to get good radiographic density.
Slow film speed for thin body parts, however when tissue thickness becomes too great and it is necessary to use a grid a faster screen is used to reduce exposure to personal
How do you tell if a dribble mark is from poor washing or poor Drying on your Developed Radiograph?
Drying marks are colourless where washing marks are yellow
What is the Code of Practice relevant for Veterinary medicine regarding Radiation Safety?
- Radiation Protection Series Publication no. 17
- Code of Practice and Safety guide for radiation Protection in Veterinary Medicine 2009
What is the purpose of wearing gloves while taking a radiograph?
To protect the wearer from scatter radiation, ands with gloves on should still not be in the primary beam. Gloves must be worn within 1m of the primary beam.
No Hands gloved or otherwise should be in the primary beam.
Select the following result on magnification, if the object-film distance is
decreased.
• Select one:
a. Increase
b. Stay the same
c. Change only if the focal spot has been changed
d. Decrease
Decrease
- Poor Radiographic Density has 2 differentials what are they?
- How do you differentiate between the two
- Underexposed and UnderDeveloped
- If anatomy is not seen that is underexposed
What is Border Effacement?
Give some normal examples of this
- Silhouette Sign (Masking)
- Dont confuse with (Summation)
- Structures of the same opacity are in physical contact
- Loss of individual margins
- structures merge and appear as one
- Normal Examples
- Liver and Diaphragm
- Bladder and urine
- Coronary vessels, myocardum and chamber lumen
What are some signs of poor radiographic density?
The Background should be Black if its grey its poor.
If you can see your fingers through the black its Poor
If the image area is too pale this is also poor density
If I have anatomy clipping what has happened and what system have I used?
Over Exposed with Digital Imaging
If the radiograph looks very grainy (white spots all over what could this be?
Old Intensifying Screen, needs replacing
- What does the Fixer do?
What is the structure of Film?
How do Film types vary?
Silver Halide crystals within emulsion (AgBr)
Single vs Double
Speed
Detail
Contrast and Latitude