Radiology and 2 Flashcards

mandibular periapical films
Terms Definitions
swallowing, eating
pertaining to
pertaining to
fingers; toes
stone, calculus
every evening
irrigation, washing
narrowing stricture
Atrioventricular, Arteriovenous
neutral, neither
Nasal Fossae
bursting forth (of)
union, together, joined
excessive, above normal
Hb or Hgb
instrument for recording
Arteriosclerotic Heart Disease
Full Mouth Series
Define hypoechoic
less echoes
to break, surgical fracture
forming an opening (mouth)
high-energy, ionizing electromagnetic radiation. x-rays have properties of both waves and particles.
Introduction of D-Speed Film
All encompassing definition for increased radiolucency of bone.Many etiologies
I & D
Incision & Drainage
Pterygoid Plates and Hamular Process
- multiple energy levels- Brehmsstrahlung radiation
You need high contrast for...
Computed Tomography
Advantages: earlier detection than plain filmGood for hard to see image areas (spine, pelvis, sternum)Findings are more specific and suggestive for osteomyelitis Increased marrow density Sclerosis, demineralization, periosteal reaction
Scurvy radiological features
OsteopeniaWidened mataphysisBeak like metaphyseal outgrowths (Pelken's spurs)Wimberger's signScorbutic zone
A. Coronoid Process of Mandible
B. Zygoma
C. Zygomatic Process
What % of gallstones are radiopaque?
Wilhelm Roentgen
Who discovered x-radiation?- Wilhelm Roentgen- Albert Einstein- Andre Ampere- Alessandro Volta- Malcolm X
How can you increase penetration without changing overall density or contrast?
atoms or elements undergo spontaneous decay to become more stable
2 categories of infection
Suppurative (pus) staphNon-Suppurative (TB)
Brodie's Abscess Formation
Localized, abortive form of supperative osteomyelitisLocalized pain that worsens at nightLesions may be sterileChronic osteomyelitisReactive sclerosis
Malgainge Fracture
Fracture through the ischopubic rami and sacro-iliac joint of the same side of the pelvis
What is density?
Amount of blackness on film
Intraoral Films
Films placed inside the
mouth for dental radiology
Mounted radiographs must be viewed in an established sequence to prevent errors in interpretation.
scattered radiation
- decreases contrast bcuz extra exposure increases darkness of all tissues, reducing difference in darkness- reduced by long, rectangular PIDs by minimizing tissue exposure
which of the following is most radiolucent?- pulp- amalgam- dentin- enamel- bone
electromagnetic radiation
propagation of wavelike energy without mass through space or matter. The energy is accompanied by oscillating electric and magnetic fields positioned at right angles to each other.
What is radiographic image?
exposed film is processed
Cathodes have a _____ charge and generate electrons which produce energy which are attracted to the ______charged _________
Pedo Bitewings:
Size 0 or size 1 film
Osteomyelitis findings on MRI
Decreased signal intensity on T1Increased signal intensity on T2
In post. oblique of SI, elevated knee should be _____
True or false.  Mammo uses high grid ratio
- vertical angle too large- apicies of teeth projected toward middle of sensor and crowns projected off sensor- projects zygomatic process over roots of maxillary molars- projects buccal sucps farther down than palatal cusps
Xray's are produced at what part of the x-ray tube
What does cicatrization mean?
produced by organizing scar tissue
- length of time electrons move across tube (exposure time) measured in...
as ___ increases, he number of photons increases, but there is not change in energy distribution of photons.
The science or study of radiation as used in medicine; a branch of medical science that deals with the use of x-rays, radioactive substances, and other forms of radiant energy in the diagnosis and treatment of disease
Disadvantages to automatic processing.
Higher initial cost. Periodic maintenence.
What are the ideal parameters for extremeties?
50-70 kVp
when a neutral atom acquires either a positive or negative charge
Free radical formation
x-ray interacts with tissue
§ Produces free radicals when photons interact with water
§ Free radicals are formed:
□ Hydrogen radical
□ Oxygen radical
□ Hydroxyl radical
□ Hydroperoxyl radical (HO2) (toxic to cell)
§ Reformation of these molecules can form:
□ Hydrogen peroxide (toxic to cell) H202
□ Water
Sacroiliac joints require special radiography positioning because_________
They are oddly obliqued angles.
The two parts of a grid are
Grid strips, interspace material
maxillary canine horizontal angulation
- horizontal angle perpendicular to facial surface of canine or embrasure btwn canine and lateral incisor- minimizes overlapping btwn canine and lateral incisor
What is a tension pneumothorax?
emergency!continue accumulaton of air in the pleural cavity
- high- low
___ kVp produces images with low subject contrast.___ kVp produces images with high subject contrast.
properties of x-rays
invisible and cannot be detected by any of the senses
no mass or weight
no electrical charge
travel at the speed of light travel in waves and have short wavelengths with a high frequency
 travel in straight lines and can be deflected/scattered
cannot be focused to a point and always diverge from a point
can penetrate liquids, solids and gases. The composition of the substance determines whether the ray passes through or is absorbed.
are absorbed by matter, amount depends on the structure and wavelength of ray
interacts with materials and causes ionization
 causes certain substances to fluoresce or emit radiation in longer waveslengths
can produce an image on photographic film
causes biological changes in living cells
What is radiographic contrast?
The difference between 2 adjacent densities. Describes the variations of density on the film. Controlled mostly by the KVP.
What are the common grid ratios in vet med?
How can you make the film have more contrast without changing the density?
What is electromagnetic radiation?
A method of transporting energy through space and is distinguished by wavelength, frequency and energy
Intensity and mA:
• Increase mA: increase amount of electrons = more energy = increase intensity of x-ray beam
The prominence of the greater trochanter is about the same level as the upper border of the _______, whereas the ________ is 1 1/2 to 2 inches below symphysis pubis.
symphysis pubis ; ischial tuberosity
What happens to patient dose with an increase in BF?
Patient dose increases
What are the advantages of intensifying screens?
Decreased exposure time, decreased patient and personnel exposure, increased tube life, increased flexibility in kVp setting, decreased focal spot size.
What is a PET scan?
positron emission tomography (a type of nuclear imaging)
greater thickness of tissue
which of the following factors will increase the absorption of x-rays in matter?- higher kVp setting- shorter exposure time- greater thickness of tissue- lower atomic number atoms in tissue
X-Ray Beam Perpendicularity
The central ray of the x-ray beam should be perpendicular with the long axis of the toothPerpendicular relationship of the central ray and object reduces geometric distortion
What 3 factors affect x-ray penetration?
Wavelength, subject composition and tissue thickness.
What are phosphors?
emit visible light in blue or green spectrum and UV
This process called Fluorescence (black light poster)
What areas of the body are particularly sensitive to damage by x-rays?
*Skin & intestinal epithelium
*lens of the eye
*blood forming organs
Linear Non-threshold Curve-
§ Indicates that a response is seen at any dose: no matter how small the amount of radiation received. Some biologic damage always occurs
§ This is the curve seen in dental radiography
What is union of acetabulum?
a temporary growth joint of each acetabulum that solidifies in mid teen years
Which grid ratio is not used as frequently and why?
16:1, high patient dose
When are expiration films appropriate?
to look for suspected foreign bodies, obstructed bronchi and pneumothorax
absorbs more x-rays, light
compared to the soft tissue of the gingiva, a gold crown ____ and appears ____ on the radiograph after processing.- absorbs more x-rays, light- absorbs more x-rays, dark- allows transmission of more x-rays, light- allows transmission of more x-rays, dark
Why do you recover silver?
It saves money. Allows legal disposal of corrosive processing chemicals. Conservation of precious metal.
How does scatter have an effect on the radiograph?
degree of detail
Who is credited with discovering x-rays and when?
William C. Roentgen in Nov 1895
Proper abduction of femur is visible on a radiograph during a unilateral frog leg projection by?
femoral neck seen in profile, superimposed by greater trochanter
Reduced scatter radiation results in ________ radiograph OD. 
Lower... In order to maintain optimum OD
Anterior wall/Floor of nasal fossa
- inferior aspect of opening of nasal fossa- appears as bilateral, densely radiopaque, uniformly thick lines extending laterally from midline subjacent to nasal fossae
What are the disadvantages of US?
usally takes 20-30 minutes and quality is dependent upon operator. Also, harder to interpret
too light
If you change from a 8" to a 16", how will the radiograph appear if the dentist does not change the exposure time when using the 16" PID?- too light- too dark- fogged- increased contrast
What needs to be included for identifying film?
Name of hospital or practice.The date.The name or number of patient.Owner's name.X-ray view or orientation.
What is potential energy?
something at rest ( a boulder about to roll down a hill)
What structures are shown an an AP pelvis?
Pelvic girdle, L5, sacrum, coccyx, femoral heads and neck, greater trochanters
How to use the image shift principle
1. make radiograph of area2. identify relation of unknown object to known structure (pulp space)3. make 2nd radiograph at different vertical/horizontal angle4. which image shifted more in opposite direction of tube head in 2nd radiograph?
List and describe the step-by-step procedures for film viewing.
1. Start with the maxillary teeth (the maxillary periapical films on the upper left side of the film mount).
2. Move hrizontally across to the left maxillary teeth (the maxillary periapical films on the upper right side of the mount).
3. Move down to the left mandibular teeth ( the mandibular periapical films on the lower right side of the mount).
4. Move horizontally across to the right mandibular teeth (the mandibular periapical films on the lower left side of the mount).
5. Move up to the bite-wing films. View bite-wings on the left side of the mount, and then move to the bite-wings on the right side of the mount.
What's an important factor about film identification?
It must be permanent and unalterable to be legal.
When looking at exposure of a film what order do we go in?
1. Density: too light/too dark
2. Penetrating: yes/no (bones over thickest/densest part)
3. Contrast: high/low (bones are good indicator)
Directly above the ischial spine is a deep notch termed the _______.  Below the ischial spine is a smaller notch termed the ______.
Greater sciatic notch ; lesser sciatic notch
What does the text mean by scatter absorption depends on the angle?
If angle of scattered x-ray great enough to intersect grid strips, it will be absorbed.  Too slight, x-ray goes to IR
What are the advantages of US?
1. safe - non ionizing energy2. can be employed in any plane required3. less expensive4. portable5. real time scanning6. interventional procedures
what land marks are visable from a maxillary cuspid periapical?
1. maxillary sinus (not always seen)- bilateral, radiolucent
2. outline of nasal cavity- bilateral, radiopaque
3. lateral fossa (canine fossa)- bilateral radiolucent
If you lower the exposure factors when using a double screen, you...
Dec. dose to patient
Dec. scatter and dose to us
Better detail
Dec. FS size
Less heat
Less chance for patient motion
What are the two types of x-rays that are responsible for the OD or ___________ on a film?
Contrast; Those that pass through the patient without interacting and those that are scattered in patient (compton)
what is the purpose of the position indicating device?
it's a lead lined cylinder that aims and shapes the x-ray beam. some times referred to as the cone.
What is the function of the Low Voltage Circuit?
Controls the current to and heating of the filament
- this leads to thermionic emission
Where is CR for AP unilateral hip projection?
Perp to IR, 1 or 2 inches distal to midfemoral neck.   Femoral neck located 1 to 2 inches medial and 3 to 4 inches distal to ASIS. 
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