Radiology Flashcards
what type of radiation are X-rays
properties of EM radiaiton
type of wave
EM - electromagnetic radiation
- no mass, charge, travels at light speed and can travel in vacuum
sine wave
3 factors that define an EM radiation as a specific type of radiation?
What happens to another factor when you alter one factor?
two types of x-rays
difference between them
atomic number meaning
mass number meaning
what force holds electrons to nucleus?
what is binding energy and what increases this
number of protons
number of protons and neutrons
electrostatic forces
= energy required to exceed electrostatic force, bigger nucleus/closer to nucleus
radiation: electrical fundimentals
Current:
- what is current
- what are the two types
- what is the name of the name of the process of changing between these two types
- relevance of this in an x-ray unit
voltage:
- what
transformers:
- what
- types
X-rays:
- effect of divergent x-ray beam on dosage when you increase the distance from the source
what are the 5 components of an x-ray tube?
x-ray tube:
Glass envelope function (3)
x-ray tube:
- cathode two parts
- For both:
- what
- function/how
- benefits
x-ray tube:
- anode two parts
- For both:
- what
- function/how
- benefits
x-ray tube:
tube head components (4)
- what each is and function
x-ray tube: collimator
- what
- function
- benefits
- how x ray beams are produced by cathode and anode?
- what is the focal spot and its effect if too large (specific name of effect)?
- problems with a small focal spot and fixes for this
- positive anode attracts electrons, travel from cathode picking up speed (kinetic energy) - this energy is changed into a lot of heat and few photons at target
2/3. see image
X-ray production: two products from production:
- process’ producing heat (2)
- TWO ways in which x-rays are produced
- how for each
- what produced for each?
- which most common
- for rarer one: 2 ways can happen?
3 ways x-rays can interact with matter
name for reduction in intensity of X-ray beam and what two interactions cause this
what is the normal kV of an x-ray unit for intra oral imaging?
what is the kV a measurement of?
what happens to image quality and patient dose if increase/ decrease kV
X-ray image production
- how get an image?
- two effects of factor allowing imaging
- how common both are and their effect on x-ray image
- which is worse for patient?
- Compton worse for patient as photoelectron effect required for image and Compton not, also allows for more reactions to occur in dif tissues. also may increase operator dose
What method is used to reduce scatter in tissue?
what effect does this have specifically on factors causing more scatter and effect on image and effect on patient/surroundings? (6)
Difference between photoelectric/Compton effects together and continuous/characteristic radiation interactions?
Effects of radiation:
- types of particles causing tissue damage caused by radiation? (3)
- what is biological damage dependent on? (3)
- how causes damage? (2)
- on DNA (2 ways)
- how easy to repair?
1.2.3. see image
- single / double stranded damage (alpha caused normally)
- single easier / double harder = mutations = change in cell function
Tissue radiosensitivity:
- 2 factors relative to radiosensitivity of tissue types
- exapmles of high, moderate and low sensitive tissues
- function and rate of division (> if lesser differentiated / stem cells)
- image
radiation: two main effects on body (broad terms)
- factors effecting both happening and when effect seen
- what both can cause
Pregnancy and radiation
- direct dose needed to cause harm
radiation: staff protection:
what are the safety rules when doing radiographs
- 1.5 meters away from source at all directions
- never be in direction of beam
- behind solid leadlined/multiple layers of plastarboard walls
radiation protection philosophy - 3 factors
methods to reduce patient dose? (4)
radiology: what is the absorbed dose measured in?
what is the equivalent dose and what is it measured in
- Gy (gray)
- absorbed dose multiplied by weighting factor dependent on radiation type / tissue type? = Sieverts (Sv)
current diagnostic reference levels for intraoral radiographs in examinations?
for the different types of sensors in adults and children
Digital radiographs:
- types (2)
- cross infection control for both
- positives and negatives of both
digital phosphor plates in digital radiology:
- plate sizes and uses
- how is the digital image produced?
digital radiology: solid state sensors:
- how sensor works to make an image?
- issues with increasing pixels
- types? (dont need to know)
4 how get digital image?
digital radiology:
- 2 formats that radiogrpahs can be stored in
- difference between these two types
- also what else can be stored with images
- benefits to these - best way to view a digital radiograph (env & monitor)
Difference = dicom used to format and transfer to any type of viewing etc. and pacs to store and manage images and data
Film radiology: make up of film (4) and components of main component (4)
and how get image from this?
stages on how to get visible image from invisible latent image in film radiology? (5)
different methods to get image? (3)
possible issues with developing in film radiology at 4 different stages?
- final image
- chemical stages
- fixing
- washing
difference between digital and film radiology and comparison (pros of digital and cons of digital compared to film)
film radiology: what is Film Speed
effect of intensifying screens
Amount of exposure needed for image, fast = loser dose but worse image as:
Larger crystals = faster but worse image
What are the different speed films called in film radiology and what are the fastest
D (slowest)
E and F (fastest) - F fastest but not in dental use much yet
taking of a cephalometry radiograph:
how standardised?
how can be used to see soft tissues also?
rule for distance between receptor and focal spot and why?
CBCT radiograph
- what
- why not indicated for cephalometry
oblique lateral radiograph
- what
- when indicated over intra/OPT (5)
- what issues indicate this type of radiograph (4)
types of OPT, how done and what used for (2)
90 degree = orthogonal
the 4 planes of the face relevant in radiology?
OPT radiographs
What OPT stands for
What are 4 possible issues you can have with an OPT image?
Solution to superimposition and all of these issues?
* name of issue superimposition causes
* which side of focal trough gives enlargement and which for shrinking
Ortho-pan-TOMOGRAPHY
OPT
- positves and negatives of use
- way to reduce patient dose
Radiographic localisation:
- what is this used for
- when does it have to be used and in what for? (4)
- how is it done (two types)
- name of second method
- what occurrence is used to our advantage
- two types of second method
- 5 combination of radiographs to do these - what is the new 3rd way of doing this
- what is the acronym to help understanding
What is the purpose of quality assessment in radiology and what factors is it in reference to (7 aspects)
quality assessment in radiology:
- what are the 3 checks for any receptor type
- signs of damage on the 3 different types of receptor?
- how often should digital receptors be checked
- when acceptable or unacceptable
- types of errors
who are the 3 groups to be protected in radiology?
- patient health
- staff health
- public health
When is extra oral radiograph indicated for?
