Intro to Radiology and Radiographic anatomy Flashcards
Define radiography
Techniques involved in producing radiographic images
Define radiology
Interpretation of medical imaging
Define radiation protection
Protection of patients and staff from hateful effects of ionising radiation
What is a radiograph?
• An image produced by transmission of X-rays through an object
• X-rays pass through the body to reach the image detector and cause blackening in the image
• Image created by different absorption of X-ray photons by different tissues o Two-dimensional image of a 3D object.
5 Features of X-rays
• High energy electromagnetic radiation
• Travel as wave packets called ‘photons’ o Invisible
• Attenuated by matter - Rays are either absorbed or scattered
• Ionizing radiation which can damage tissue - all radiographs must be “justified” i.e. the potential benefit must outweigh the risk.
Features of radio opaque areas in a radio graphic image?
White - rep dense structures w have attenuated the X-ray beam
Features of radiolucent areas in radiographic image
-black
-area where X-ray beam has passed thru object
What do the Grey shadows represent ?
X-ray beam stops to varying degreee
Density of radiographic appearance effected by:
Density affected by:
Type of material
Thickness of material
Shape of the object
Intensity of the X-ray beam
Position of object relative to the X-ray beam and receptor
Sensitivity and type of the image receptor.
Limitations of viewing a 2D image of a 3D object
o 1 view only o Superimposition
• Overlapping shadows of different parts of an object or a separate object
• Causes limitation of information on location and shape of the object.
• E.g. Braces - stops looking at crowns of teeth (caries is radiolucent)
o No Depth information
What is the image orientation of X-rays
• AlI X-rays are orientated the same
o Patients Left is on your Right, Patient’s Rights is on your Left
• Right bitewing:
• Molars = Left
•Premolars = Right
• Left bitewing:
• Molars = Right
• Premolars = Left
What does the dental anatomy look like on a radiographic image
Enamel - Very dense tissue - white
Dentine- less dense than enamel
Root Canal - soft tissue - radiolucent
PDL - Black lines (very easily penetrable)
White line - edge of bone (cortical bone - lamina dura)
Types of radiographs
Intraoral and extraoral
Where is image detector placed in intraoral radiograph
Image detector is placed inside patient mouth
Upper Occlusal - 65-degree angle; localisation to see on palatal or labial side of incisor teeth
Lower Occlusal - at a near 90 degree angle; localisation to see on lingual or buccal side of incisor teeth (In picture you can see a sublingual duct has a stone blocking it, something not visible on a panoramic view).
What do incisors look like on radiograph
Enamel thinner on incisor than molar cos less density
Incisors single root
Where is image detector placed in extraoral radiograph
outside patients mouth
What does incisive foremen look like
Inside patient mouth
Is the opening of the incisive canal which contains; the spheno-palatine artery and palatine nerve.
Radiolucent (dark area on radiograph)
due to it being a foramen; less bone, less dense > fewer x-rays are attenuated
What does the canine fossa look like
Where bone of maxilla is thinner, mesial to canine root
Bony depression
Radiolucent area due to thinner bone to attenuate x-ray beam
What does floor of nasal cavity look like?
Anterior teeth can be seen (crowns not localised)
Can see lateral incisor and some of first premolar
tooth
Can see a radiopaque white line (covered in red)
which is the floor of the nasal cavity
