Radiography Flashcards
Radiation risks
Invisible
Latent
Painless
Cumulative
ALARA
As low as reasonably achievable
Time
Shielding
Distance
Somatic
Genetic
Carciogenic
Effects straight after (red, baldness, cataract formation, digestive upset, positive effect on tumour)
Effects gonads (mutations of DNA)
Induces cancer in tissue
SOP
Standard operating procedure
Instruction to take an x-ray
IRR, date
Categorises by? Based upon?
Ionising radiation regulations, 1999
Risk banding - based upon use and dangers associated
Notification - low dose
Registration - veterinary radiation and x-ray devices
Consent - nuclear sector, injecting radioactive isotopes
RPS
Appointed?
Make sure?
Radiation protection supervisor
In practice
Following local rules and safety
RPA
Appointed?
Role?
Need?
Radiation protection advisor Externally Set up local rules Allocate boundaries for controlled area Certificate of competence
Health and safety executive
Government agency
Regulate and enforce h&s
Service
Annually
Local rules
Actions to be followed
Controlled area Distance? Symbol? Primary beam Scatter
Where radiation exceeds a specified minimum 2m Trefoil Doubke brink 1mm 0.5mm
Dosimeter
2 types?
Sent off?
Sorted by?
Cumulative
Film badge - small blue film, contains small metallic filters
Thermoluminescent - radiation sensitive lithium floride crystals
1-3 months
RPA
Dose limits
Classified worker 18+
Classified worker 18-
Non-classified worker
Amount that is thought not to have any additional risk to the radiation experienced in life
20msv (30%)
6msv
1msv
PPE
X-ray if cracked
Gown
Thyroid protector
Sleeves 0.25
Gloves 0.35
Black lines
Form of Frequency... Wavelength.. Travel Frequency = Photos/quanta Excitation Ionization
Electromagnetic energy (gamma, x-ray, ultraviolet, vision, infared, microwave, radio)
High, short
Straight lines, same speed, diverging
Number of cycles /second
Individual particles
One orbit to another releasing photon
Frees an electron giving it kinetic energy
Atom is? Electron has same no as E + P = Ion Radioactive =
A basic unit involved in x-ray production Protons =neural atom Atomic no. Atom with a charge Unstable nucleus
Plug Step down transformer Coiled filament Cathode Step up transformer Focusing cup Thermonic emission Glass envelope Anode Target area 1% 99%
240v Lowers current In cathode, made of tungsten - charge V - kv (40-100) - charge, direct electrons to anode Cloud of electrons Vaccum \+ charge, copper Tungsten (high melting point, atomic no. And good mechanical properties) 3mm and 20°c. Photos Heat
Target area
2 types?
Bremsstrahlung/continuous Breaking radiation Bend around nucleus Characteristic Hit Electron on inner shell and drops
Focal spot
Actual and effective
Small filament
Larger filament
TA and patient
Fine focus
Broad focus (penumbra effect)
Penumbra effect
Caused by?
Ideal focal spot?
Larger filament causes?
Focal spot
Pin point
Shadowing
Aluminium window filter size
2.5mm
Primary beam
Shouldn’t be larger than what?
Reducing scatter
Cassette Tight collimation Compression of larger areas of tissue Reduce kv (<70) Lead topped tables Rotate staff
Reducing exposure risk Grids Placed? Made of? Used to? Used for tissue above? Main purpose
On top of cassette Aluminium outer shell, strips of lead, radiolucent interspace (aluminium) Filter scatter 10cm (15cm chest) Protect image
Parallel grid Focused grid Pseudo-focused Crossed grids Potter bucky diaphragm
Linear, parallel + vertical, reduce film quality (grid cut off)
Vertical and slope away, prevent grid cut off
Mixture of 1+2, parallel but tapered
Crossed parallel
Moving
Volt
Ampere
Watt
Power needed to maintain 1 amp
Electrical current
1 watt to maintain 1 amp
Line voltage compensator
Fluctuations in mains electricity output
Kilovoltage It? Effects? Flat film / lack contrast Soot and white wash / too high contrast
Sets potential difference
Quality and penetrating power (speed)
High kv
Low kv
Milli amperage
Effects?
Ma + s tells us?
Timer
Quanitity
Total quantity of x-ray photos emitted
Higher ma = less exposure time (reduce blur)
Contrast
Long /low contrast
Short/high contrast
Depends on?
Difference in densities between adjacent areas Lots of grey small black and white White on a black background Kv Type of film Film fogging Use of contrast medium Tissue density, shape
Density
Depends on
Degree of blackness
Mas
10kv rule
Affects?
10kv increase : halve MaS
Contrast
Ma and time
Triangle
Film focal distance
Affects
Normal distance
Distance between tube head and cassette
Beam intensity (density)
FFD doubled x mas by 4
75cm
Grid factor
Disadvantage
Depends on?
Old mas x GF = new mas
Increase mas
Ratio, number of lines/cm, thickness of lines
Films
What it does?
Make up?
Classification of film emulsion?
Record image produced by differential absorptions
Polyester base (supports emulsion, 0.18mm)
Substratum (sticky, prevents dye cross over)
Emulsion (suspension of light sensitive salts in a Gelatine binder)
Supercoat (protection, hardened gelatine)
Monochromatic (blue light emitting intensifting screens, red/amber)
Orthochromatic (blue/green, red)
Types of grain?
Grains are?
Globulin grain
Tabular grain
Individual crystals of light sensitive substance in gelatin
Fine grain - detail, low speed, longer exposure time
Large grain - grainy, faster
Most effective against green light
Latitude
Films ability to produce shades of grey
Speed
Sensitivity to light / radiation
Film is sensitve to
Light Heat Radiation Moisture Chemicals Pressure
Non screen film
Made of?
Used for?
Screen film
Without intensifying screen
Envelope in light proof paper
Thick emulsion layer
Dentals - higher contrast, slower speed
With intensifying screen
Intensifying screen Converts photons into? Blue intensifying screen Green Construction Dirty?
Fit casette, sandwich film 95% Light (15-20% more effective) (reduces exposure) Calcium tungstate Rare earth phosphorus Base (support) Reflective/absorption (reflect Flash) Substratum (cardboard base) Phosphor layer (crystals in polyurethane binder, create flash) Super coat (protect) Small white marks on film
Casette Contains? Close contact or result in Radiolucent front Use to clean Damage to phosphor layer
Film and screen
Blur
Antistatic cleaner weekly (branched black lines)
Unexposure white marks
Positive contrast media
Uses elements of
Insoluble barium sulphate
Is a?
Used for?
Bips
Water soluble iodine agents
Ionic
Osmotic pressure?
Causes?
Product?
Non-ionic
Osmotic pressure?
Product?High atomic number which increases absorption (radiopaque/white)
White chalky substance
GI studies (Insoluble/inert)
Barium impregnated polyethelene sphere
Higher
Hypotension, damage brain, heart kidneys
Conray - bladder
Lower
Omnipaque (iv, myelography, perforation)
Negative contrast media
Uses?
Low density
Gases?
Gas
Radiolucent (black)
Room air, o2, co2, nitrous oxide
Double contrast
Patient prep
Cystography
Gastrography
Starve for 12-24 hours
Urethrography
Retrograde
Angiography
Pheripheral artery vein
Angiocardiography
Congenial heart defect
Fistulography
Veins, blood vessels
Fluroscopy
Continous x-ray taking
Computerised tomography Uses? Tissue contrast is? Grey scale described as? Detect?
X-rays
Greater (fluid, solid tissue distinguished)
Hounsfield units (3000- - 1000)
Oesteolysis, brain images, spinal vertebrae, thoracix metastasis, fractures, guided biopsy
Gamma scintigraphy Uses? Governed by? 1 liscences for Requires? Used for? Radionuclide Radiopharmaceuticals Half life Isolate for
Radioactive isotopes (iv injection)
Radioactive substances act 1993
Use and disposal
Protocol for attire, local rules
Thyroid gland, bone, brain blood flow, kidney and liver function
Atom disintegrates emitting gamma radiation
Medicinal product
Time take for med to decay to half original value
24 hours
Magnetic resonance imaging
Uses?
Emitted signals detected by
Used for?
Magnetism and radiowaves
Rf coil
Soft tissue and bone (nervous system + brain)
Kennel club info Opaque positioning aid Elbow? Min age Nomenclature Positioning
Number, date, microchip no. Sandbag 110° 45° 1yr Primary beam entry to exit
Manual processing Development Main ingredient? Reduction Exposure time? Temperature Solution is ... and maintained by Restrainer reduces?
Phenidone/metol-hydroquinone Exposed silver bromide converted into grains of black metallic silver 3-5 minutes (dark if over) 20° Alkaline (buffer + accelerator) Fog
Manual processing
Rinsing
Time?
10 seconds
Manual processing Fixing Main ingredient? Ph? Clearing? Fixing time Temp Safely switched on after Tanning
Sodium/ammonium thiosulphate Acidic Dissolves unexposed silver halide crystals (milky white until complete) 20 minutes (double time of clearing 10) Not over 21° 30 seconds Hardens the film emulsion Buffer, preservative
Manual processing
Washing
If to quick goes
Time?
Yellow-brown
15-30
Automatic processing
Temp?
Doesn’t have?
Warm up period?
28°
Stop bath /rinse stage
10-20 minutes
Ultrasonography Doesn't penetrate? Right lateral? Coupling gel left on for Area of observation B-mode M-mode High frequency Low frequency Crystals in transducer know as? Transducer Linear array Sector scanner Phased array Echogenicity Anechoic Hypoechoic Hyperechoic
Bone Heart 5 minutes Acoustic window Brightness - normal Movement - motion of heart Better image, lower penetration Poor image, higher penetration Piezoelectric effect Rectangular image - larger animals Triangle - deep tissue Change in Brightness Black Dark Bright
Endoscopy Is a? Gastroduodenoscopy Colonscopy Tracheobroncoscopy Rhinoscopy Urethroscopy Otoscopy Tracheoscopy Vaginoscopy Urethrocystoscopy Laproscopy Thoracoscopy Arthroscopy Get sample with Tissue sample use Broncoscopy time
Optical device Left lateral, flexible Rigid, flexible Sternal, flexible Sternal, rigid Lateral, flexible, rigid Rigid Rigid Rigid Sternal, rigid, flexible Abdo, dorsal, lateral, both Dorsal, both Rigid Guarded brushes Biopsy punch 30-50 seconds to limit hypoxia
View radiographs
Use a?
Compared to
Teleradiology
Viewing box
Walnut
Transmission of digital images for referral
