Roentgenology Flashcards
Discovered xray
Wilhelm Roentgen
Father of dental radiology
Edmund kells
First dental radiograph
Otto walkhoff
First dental xray unit
William rollins
Process by which certain unstable atoms/elements undergo spontaneous disintegration or decay in an effort to attain a more balanced nuclear state
Radioactivity
Use of ionizing radiation to produce a recorded image or photosensitive material
Radiography
Process of making atom an ION
Inonization
Emission of energy through space or a substance in the form of waves/particles
Radiation
fundamental unit of matter
Atom
attraction of electron to nucleus
Electrostatic force / Binding energy
electron that has high binding energy
K Shell
Electron that has low binding energy
Q Shell
High energy electromagnetic photons emitted from inside of nucleus
Gamma
High energy electromagnetic photons emitted from Outside of nucleus
Xrays
Distance between crest/peak of 1 wave to another
Wavelength
number of wavelength that pass a given patient in certain amount.
Frequency
Filters longer wavelength
ALUMINUM DISK
99% of your byproduct in your xray production is?
HEAT
component of xray machine that absorbs heat
Insulating oil
Restricts size, shape of xray
Lead collimator
Alters the voltage of electricity
Transformer
Controls voltage to filament
Step down transformer
Low voltage or step down transformer is controlled by
Milliamperage
Increase potential between cathode-anode
Step up transformer
Accelerate electrons and generate xrays in the xray tube
High voltage
High voltage or step up transformer is controlled by
kVp (kilovoltage peak)
dissipates heat during taking xray
Copper stem
Tungsten has a high atomic number, high melting point, high thermal conductivity because
It can withstand high amount of heat
Release of electrons when filaments are heated
Thermionic emission
Shape of an effective focal spot
RECTANGULAR
the smaller the focal spot size =
the sharper the image
Filters longer wavelength
Aluminum disk
Restricts the size, shape of xray
Lead collimator
Allows the exit of xray
Tubehead seal
Shape of collimator
RECTANGLE
also called general radiation, breaking radiation, it is the primary source of xray. Produced on sudden stopping/deceleration of high speed electron when they hit/close to target.
BREMSSTRAHLUNG
Produced when a high speed electron dislodges an inner shell electron
Characteristic Radiation
most common type of scatter radiation in dental xray, no scatter rad, has ionization.
Photoelectric.
Applied force to accelerate electron from cathode to anode
kVp
controls heating of filament
mA
Periapical size for Pedo
Intraoral sizes
0 (22x35)
Periapical size for all areas of adult
Intraoral size
2 (31x41mm)
film used for impacted tooth and presence of sialolithiasis
Occlusal radiograph
film used to detect interproximal caries
Bitewing radiograph
most important part of film
EMULSION
- because of silver halide crystals; forms image
the smaller the crystal size =
the sharper the image
“the slower the film, the smaller the crystals, the greater resolution”
most recommended fast films
letter: E/ekta speed
muscle of the floor of the mouth, what muscle should relax to get the radiograph of periapical xray of mandible.
Mylohyoid muscle
proper placement of paralleling technique in maxilla: Superior border at the?
Height of palatal vault.
Increased Object film distance is a result of
Magnification
Bisecting angle technique!
Angulation:
Incisor: Max: +40 Mand: -15
Canine: +45 , -20
PM: +30, -10
Molars: +20, -5
type of error Excessive angulation =
Foreshortened
type of error insufficient angulation =
Elongated
Most common type of error during xray
Elongation
Bitewing is used or to detect
Proximal Caries
Vertically oriented bitewing is used for the assessment of
Periodontitis
Same Lingual Opposite Buccal
Clark Shift
Downward Lingual Upward Buccal
Frank shift
Phosphor layer coat base which converts xray energy into visible light; decrease dose -> decreases image resolution -> decreases exposure time, intensify the light.
Intensifying screen
Highest point of skull
Vertex
View Used for sphenoid sinus, body of mandible, vertex and base of skull, fractures of zygomatic arch, palatal lesion.
Submentovertex View “Jughundle’s View”
view used to assess frontal sinus
Caldwell view
extraoral view best to evaluate sinuses in general. also for mid face fracture, zygomatic fracture.
Water’s view “Occipitomental Projection”
Evaluates growth and development of the face
Cephalometric “Lateral View”
Most table landmark/area from which to evaluate craniofacial growth
Anterior Cranial Base “Sella-Nasion Plane”
Most useful as diagnostic requiring broad coverage of the jaws.
Panoramic view
“Pantomography”
Best for the examinations of condyles and neck of the mandible
Towne’s View
Identify fractures of the condylar neck and ramus, superimposition of mastoid process, OPEN Mouth
Reverse towne’s view
Image upon exposure of xray
Latent image
image after processing of xray
radiographic image
Conversion of exposed silver halide crystals into metallic silver grain
Developing
developing composition that Softens the emulsion, accelerator, activator for developing, alkaline pH.
Sodium Carbonate
Slow reducing agent, Black tones.
Hydroquinone
Quick reducing agent, gray tones.
Elon
Dilutes the developer to slow/stop development process
RInsing
Removes undeveloped/unexposed silver halide crystals and hardens the film
Fixing
Preservative of developing, fixing and local anesthetic.
Sodium Sulfite
Composition of fixing solution that hardens emulsion
Potassium Alum
Ensure removal of all thiosulfate ions and silver thiosulfate complexes
Washing
Resists passage of xray, appears color white
Radiopaque
Allows passage of xray appears color black
Radiolucent
Least to most radiopaque
Sinus - bone - dentin - enamel - AMALGAM
Sinus - bone - dentin - enamel - AMALGAM is highly radiopaque
All composite are Radiopaque? True or false
False
- composite and calcium hydroxide is not always radiopaque.
a contaminated solution can be ____developed
Underdeveloped
a concentrated solution can be ____developed
Overdeveloped
errors: Insufficient angulation, appear too long
Elongation
errors: excessive angulation, appear too short
Foreshortening
Portion of film appear cleared w/ curved line, not aimed at the center.
Cone cutting.
Zigzagged patterns appear on the film, placed backward in mouth.
Herringbone
Part of cell that is sensitive to radiation
Nucleus or DNA
Papilla of the tongue that has no taste buds
Filiform papilla
Inflammation of oral mucosa
Mucositis
a condition in which bone has died due to radiation exposure, common in mandible because of less blood supply & common to take radiograph.
Osteoradionecrosis
ALARA principle meaning.
As low as reasonably achievable
white/yellow pseudomembrane
Desquamated epithelial layer
Radioresistant to radiosensitive
MUSCLE, THYROID GLAND, SKIN, SMALL LYMPHOCYTES
MUSCLE, THYROID GLAND, SKIN, SMALL LYMPHOCYTES
To do good is
Beneficence
Not to do harm is
Non-maleficence
ALARA
As low as reasonably achievable
the process that determines the quantity of radiation exposure or dose
Dosimetry
maximum permissible dose for occupational
0.05 sv/yr
maximum permissible dose for non occupational & occup. preg.
0.001 sv/yr
radiation quantity that measures the capacity/concentration of radiation to ionize the air
Exposure
Exposure to radiation is measured by
Roentgen (traditional unit)
Methods of personnel protection
Distance: _ ft. away
Position: __-___ degree angle to the beam
Shielding: Behind a protective barrier
6 ft
90-135 degree
the metal that is most resistant to penetration of ionizing radiation
Lead
- Lead apron (px protection)
the best kVp
60-80 kvp
Cross-sectional 3D-image for the assessment of BONY tissue
e.g TMJ, neck of condyle. etc
CT Scan
Assessment of the SOFT tissue using radiofrequency pulses & magnetic field
MRI
“Magnetic Resonance Imaging”
Radioactive iodine is given through IV with patient undergoing
CT Scan
Gadolinium is given through IV with patient undergoing
MRI
CBCT
Cone-beam computed tomography
(comfortable position: sitting position)
Assessment of areas of ACTIVE BONE METABOLISM, by injection of TECHNETIUM-99
Nuclear imaging
Image acquisition inaccurasies
Noise
Picture element, unit of information, smallest controllable element of a picture represented on the screen.
Pixel
Most commonly used digital imaging receptor, 1st image receptor used for intraoral imaging.
Charge-coupled device.
most useful radiograph for detecting caries/interproximal
Bitewing
Film size for children
0
Film size for adult
2
Cone at enamel and dentin with bases in contact with each. Most common caries, location.
Pit and Fissure
Cone with base at enamel & apex towards Pulp
Proximal Surface
Most common pattern for bone loss
Loss of height of alveolar bone with crest more apically placed from the CEJ
Horizontal bone loss or “Angular bone defect”
Best prognosis of vertical bone defect (Wall)
3 Wall
Worst prognosis of vertical bone defect (wall)
1 wall
Most common osseous/bone defect
2 wall “CRATER”
