Radiography Flashcards
(62 cards)
1
Q
Radiation risks
A
Invisible
Latent
Painless
Cumulative
2
Q
ALARA
A
As low as reasonably achievable
Time
Shielding
Distance
3
Q
Somatic
Genetic
Carciogenic
A
Effects straight after (red, baldness, cataract formation, digestive upset, positive effect on tumour)
Effects gonads (mutations of DNA)
Induces cancer in tissue
4
Q
SOP
A
Standard operating procedure
Instruction to take an x-ray
5
Q
IRR, date
Categorises by? Based upon?
A
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
6
Q
RPS
Appointed?
Make sure?
A
Radiation protection supervisor
In practice
Following local rules and safety
7
Q
RPA
Appointed?
Role?
Need?
A
Radiation protection advisor Externally Set up local rules Allocate boundaries for controlled area Certificate of competence
8
Q
Health and safety executive
A
Government agency
Regulate and enforce h&s
9
Q
Service
A
Annually
10
Q
Local rules
A
Actions to be followed
11
Q
Controlled area Distance? Symbol? Primary beam Scatter
A
Where radiation exceeds a specified minimum 2m Trefoil Doubke brink 1mm 0.5mm
12
Q
Dosimeter
2 types?
Sent off?
Sorted by?
A
Cumulative
Film badge - small blue film, contains small metallic filters
Thermoluminescent - radiation sensitive lithium floride crystals
1-3 months
RPA
13
Q
Dose limits
Classified worker 18+
Classified worker 18-
Non-classified worker
A
Amount that is thought not to have any additional risk to the radiation experienced in life
20msv (30%)
6msv
1msv
14
Q
PPE
X-ray if cracked
A
Gown
Thyroid protector
Sleeves 0.25
Gloves 0.35
Black lines
15
Q
Form of Frequency... Wavelength.. Travel Frequency = Photos/quanta Excitation Ionization
A
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
16
Q
Atom is? Electron has same no as E + P = Ion Radioactive =
A
A basic unit involved in x-ray production Protons =neural atom Atomic no. Atom with a charge Unstable nucleus
17
Q
Plug Step down transformer Coiled filament Cathode Step up transformer Focusing cup Thermonic emission Glass envelope Anode Target area 1% 99%
A
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
18
Q
Target area
2 types?
A
Bremsstrahlung/continuous Breaking radiation Bend around nucleus Characteristic Hit Electron on inner shell and drops
19
Q
Focal spot
Actual and effective
Small filament
Larger filament
A
TA and patient
Fine focus
Broad focus (penumbra effect)
20
Q
Penumbra effect
Caused by?
Ideal focal spot?
Larger filament causes?
A
Focal spot
Pin point
Shadowing
21
Q
Aluminium window filter size
A
2.5mm
22
Q
Primary beam
Shouldn’t be larger than what?
Reducing scatter
A
Cassette Tight collimation Compression of larger areas of tissue Reduce kv (<70) Lead topped tables Rotate staff
23
Q
Reducing exposure risk Grids Placed? Made of? Used to? Used for tissue above? Main purpose
A
On top of cassette Aluminium outer shell, strips of lead, radiolucent interspace (aluminium) Filter scatter 10cm (15cm chest) Protect image
24
Q
Parallel grid Focused grid Pseudo-focused Crossed grids Potter bucky diaphragm
A
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
25
Volt
Ampere
Watt
Power needed to maintain 1 amp
Electrical current
1 watt to maintain 1 amp
26
Line voltage compensator
Fluctuations in mains electricity output
27
```
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
28
Milli amperage
Effects?
Ma + s tells us?
Timer
Quanitity
Total quantity of x-ray photos emitted
Higher ma = less exposure time (reduce blur)
29
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
```
30
Density
| Depends on
Degree of blackness
| Mas
31
10kv rule
| Affects?
10kv increase : halve MaS
| Contrast
32
Ma and time
Triangle
33
Film focal distance
Affects
Normal distance
Distance between tube head and cassette
Beam intensity (density)
FFD doubled x mas by 4
75cm
34
Grid factor
Disadvantage
Depends on?
Old mas x GF = new mas
Increase mas
Ratio, number of lines/cm, thickness of lines
35
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)
36
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
37
Latitude
Films ability to produce shades of grey
38
Speed
Sensitivity to light / radiation
39
Film is sensitve to
```
Light
Heat
Radiation
Moisture
Chemicals
Pressure
```
40
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
41
```
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
```
42
```
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
43
```
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)
44
Negative contrast media
Uses?
Low density
Gases?
Gas
Radiolucent (black)
Room air, o2, co2, nitrous oxide
45
Double contrast
Patient prep
Cystography
Gastrography
Starve for 12-24 hours
46
Urethrography
Retrograde
47
Angiography
Pheripheral artery vein
48
Angiocardiography
Congenial heart defect
49
Fistulography
Veins, blood vessels
50
Fluroscopy
Continous x-ray taking
51
```
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
52
```
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
53
Magnetic resonance imaging
Uses?
Emitted signals detected by
Used for?
Magnetism and radiowaves
Rf coil
Soft tissue and bone (nervous system + brain)
54
```
Kennel club info
Opaque positioning aid
Elbow?
Min age
Nomenclature
Positioning
```
```
Number, date, microchip no.
Sandbag
110° 45°
1yr
Primary beam entry to exit
```
55
```
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
```
56
Manual processing
Rinsing
Time?
10 seconds
57
```
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
```
58
Manual processing
Washing
If to quick goes
Time?
Yellow-brown
| 15-30
59
Automatic processing
Temp?
Doesn't have?
Warm up period?
28°
Stop bath /rinse stage
10-20 minutes
60
```
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
```
61
```
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
```
62
View radiographs
Use a?
Compared to
Teleradiology
Viewing box
Walnut
Transmission of digital images for referral
