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 dental pantomogram (DPT) show
Shows full dentition of the maxilla and mandible -allows to see present teeth and unerupted teeth in jaw - can be useful if patient has large bone lesion.
What is a panoramic
Full view of teeth
Patients left is on right of screen and vice versa
What is lateral cephalogram
Often used in orthodontics
Determine the relationship of mandible, maxilla and skull base
Can see angulation and development of skull Often used in orthodontics
How is the palmer notation charted?
Mouth divided into 4 quadrants
Teeth number 1-8 from central incisor
Letters and numbers system:
• Modification of Palmer
• LR3 to represent lower R canine
Should start from Upper R -> Upper [-> lower [ -> lower R
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
Y-shape of Ennis
Upside down Y of cortical bone
Where the floor of the nasal cavity meets the floor of the maxillary antrum
Bony margin at the edge of the two cavities
Floor of Maxillary antrum
periapical radgiorpah upper right lateral in cisor to 2nd molar can see partial Y of ennis
Floor of maxillary antrum - radiopaque - white, scallops around maxillary teeth - should be intact and antrum floor
Sinus septum - normal bony projection
Soft tissue shadow of the cheek-nasolabial fold
• Periapical of the UL quadrant
• Cheek-Nasolabial fold - shows where the cheek is fuller =more radiopaque area due to greater attenuation
Soft tissue-nose
Nose can be seen especially at a high angled periapical radiograph
Nose = white shadow and radiopaque area over the apices of the
central incisors.
In midline of maxillary you can see intermaxillary suture - neonatal
line.
Zygomata
White shadow at the posterior maxillary molar regions
Zygomatic buttress
Where zygoma contact maxilla
Radiopaque block of bone - zygoma
Pterygoid hamulus
Back of alveolar process at the end = maxillary tuberosity
Just posterior to the maxillary tuberosity= pterygoid hamulus
Coronoid process
Posterior maxillary region of the UR quadrant view.
Can see a bony finger - coronoid process of mandible.
Submandibular fossa and mylohyoid ridge
Cross section of left body of mandible
On the lingual surfaces ridge where the bone is thicker, mylohyoid
ridge.
Mylohyoid ridge is where the mylohyoid muscle attaches to the
mandible
Inferior to mylohyoid ridge = submandibular fossa - where the
submandibular gland sits.
Inferior alveolar canal
Running through centre inf. Alveolar canal - sensitivity to teeth in mandible - radiopaque lines = cortical margins or canal.
Mental foramen
where the Inferior alveolar canal exits the mandible
Radiolucent area
Between the 15 and 2nd premolars in mandible
Lingual Forman
Small foramen on lingual surface of mandible
Projects inferior to the central incisors
Small radiolucent area - should have a good corticated margin on the outside
Maxillary antrum
Should always see 4 white corticated lines: Antral floor, har palate, zygomatic buttress, posterior of antrum
Soft tissue shadows
Should see 4 structures: Pinna of ear (both sides), dorsum of tongue (usually tell patients to put to roof of mouth), soft palate and epiglottis
Direct restoration
Generally, radiopaque
Root canal treatment
Nerve and blood vessel is taken out and filled with restorative material - canal is now filled and appears more radiopaque
Crown
• Full coverage of restorative material
• Some can be entirely metal, or porcelain with a metal core (which appears radiopaque)
