Lecture notes
Radiology Notes - Dental Surgery BDS
- Module
- Dentistry
- Institution
- Cardiff University (CF)
A complete set of notes on all radiology teaching from the Dental Surgery BDS course at Cardiff University. All 5 years are covered.
[Show more]
Seller
FollowContent preview
Electromagnetic (EM) Radiation● Electric & magnetic fields - at 90 degrees to each other at a point
● Strength varies in alternating manor
● Properties: propagated in straight lines, can travel thr vacuum, variety of uses
● Inverse square law: intensity (l) of a beam of EM radiation at a given point, is total energy per
second flowing past the point when normalised to a unit area
Conventional Radiology
● Dark room processing for 5 mins
● Developing: reduction of silver ions at latent image centres to metallic silver (black)
● Fixation: removes silver bromide from emulsion & hardens gelatin
● Safelighting test: turn off all lights including safelight, prepare film & place coin on top, turn on
safelight for 3-4m, remove coin & process film. No visible image indicates correct safelighting.
Image of coin & fogged background indicates incorrect safelighting
Features of X-Ray Tube
● Aluminium paper: filters out low energy photons
● Tungsten filament: provides parallel beam of electrons to anode
● Copper anode: high thermal conductivity, target made of tungsten
● Oil: disperses heat
● Glass envelope: electrical insulator & holds vacuum
● Space cone: projects x-ray into parallel beam
X-Ray Equipment Features
● Adequate aluminium filtration
● High kV
● Constant potential
● Rectangular collimation
● Long focus to skin distance
● Accurate timer
● Adequate warning signals
● Safety checks every 3yr
, X-Ray Set Variables
● mA & time (mAs): determines quality of x-ray photons, affects degree of blackening of film (optical
density)
● kV: determines quality of x-ray beam & penetrating power of photons, affects film contrast
● Image receptors: film packets (direct action film), film cassettes (indirect action film)
● Processing: manual, automatic, self-developing
Cross Section Through Film
● Supercoat: thin transparent protective layer
● Emulsion: mixture of silver halide crystals which are sensitised if exposed to radiation
● Adhesive layer: attaches emulsion to base, composed of gelatine & solvent of the base
● Polyester base: flexible, withstands heat moisture & chemical exposure, supports emulsion
Cross Section Through Cassette
Cross Section of Intensifying Screen
Latent Image Formation
● Invisible image produced on film emulsion → converted to visible image on
processing
● X-ray photon interacts w silver iodide crystal → electrons released & used to form
latent image
Dangers Related to X-Rays
Somatic deterministic effects/certainty effects
● e.g. tissue reactions
● Effect that will definitely happen w high doses of radiation
● Severity of effect = proportional to dose received
● Threshold ‘safe’ dose
Stochastic effects
● e.g. cancer development, heritable disease
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller cassiejoevans. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for £4.49. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
60834 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy revision notes and other study material for 14 years now