Test your basic knowledge |

Radiology 2

Subjects : health-sciences, radiology

Instructions:

Answer 50 questions in 15 minutes.
If you are not ready to take this test, you can study here.
Match each statement with the correct term.
Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.

1. your film badge report sHows that you have received a small amt. of radiation. What should you do
1/6th of a second
Rectangular collimation and fast film speed
Top of film delineated by a straight line then dark
Stop taking xrays and evaluate all equipment and techniques to ensure safety

2. What are common sources of background radiation
Cosmic - naturally occuring radiation from earth - radiation for radioactive materials
Rectangular collimation
Film badges
Document patient's refusal and have them sign

3. which anatomical structures appear radiolucent
take 14 radiographs -omit the BW -paralleling should be technique of choice -panoramic might be better than FMS
Filters placed in PID after tubehead production
Soft tissue - air space
No. 4

4. How do you determine How often to take radiographs
Increase the area of radiation exposure
Gray & Rad
Evidence based selection criteria
Mand occlusal

5. Proper patient positioning for bisecting
Max arch ala-tragus parallel to floor - mand arch
Didn't push button completely
#2
max molars have 3 roots - mand have 2 roots

6. What is reticulation
The emulsion side of the film is placed against the orginal radiograph with the nonemulsion side up
Zygoma will be radiopaque - max. sinus will be a large area of radiolucency
Cracking of the emulsion caused by excessive temp diff. b/w any darkroom solutions
Patient positioned too far to the left

7. desired thickness of lead apron
Vertical BW
Increase the area of radiation exposure
Cracking of the emulsion caused by excessive temp diff. b/w any darkroom solutions
.25 mm

8. What causes film fogging
#4
Large blank space is due to reversed image error or chemical contamination - missing apices is due to inadequate VA
Old or contaminated processing solutions -exposure to chemical fumes -faulty safelight -scatter radiation
Mand. foramen

9. Max lat. canine anatomy
No. 1
20 min
Increased focal spot size - decrease source-object distance - & increased object-film distance
Nasal fossa - max sinus

10. What radiographs are used to determine if a foreign object is located facially or lingually
Occlusal
Old or contaminated processing solutions -exposure to chemical fumes -faulty safelight -scatter radiation
Patient positioned too far foward in the focal trough
After 2-3 min of fixing if needed

11. What is inherent filtration
The most distal tooth should be captured in full as well as a few mm of bone level behind the most distal tooth
Produced by internal barriers in tube head (ex: glass and insulating oils)
Duplicate - which will go to the insurance comp.; office keeps best copy
Occlucal

12. when mounting a film the dot is convex - On What side of the mouth would you find #32?
Left side
Direct - directly obtaining a digital image by exposing intraoral sensor to x-rays to provide an image that can be viewed on a computer - indirect - photostimuable phosphor plate sensor technology - obtaining a digital image in which an exposed phosp
#3
max molars have 3 roots - mand have 2 roots

13. when duplicating radiographs - What side of the duplicating film is in contact with the radiograph to be duplicated
Blank or clear (takes all of the crystals off)
Periodically examining cassettes and intensifying screens; extra oral cassettes should be checked for warping and light leaks
The emulsion side of the film is placed against the orginal radiograph with the nonemulsion side up
No. 4

14. How are x-rays formed in the tubehead
Excessive VA w/ PID positioned too steep enough away from zero degrees
turn on machine -adjust settings -press exposure button -filament heats up/thermoionic emmision -electron cloud is formed -electrons flow from cathode to anode -electrons strike target -energy is converted into x-rays and heat
Cosmic - naturally occuring radiation from earth - radiation for radioactive materials
Blue light sensitive films

15. What are the 2 units used to measure exposure to radiation
Clinical exam
Coulombs/kilogram(C/kg) & Roentgen (R)
Focal spot size - target-image receptor distance - object-image receptor distance - motion - screen thickness - screen-film contact - and crystal/pixel size of intraoral image receptors
Images conditions of the teeth and supporting structures when a larger area than a PA is needed; provides more info. than a PA about the alveolar crest and apical areas

16. When looking at radiographs that were taken several years ago - you notice a brownish stain which makes interpretation difficult. What caused this?
2.75 inches
Left side
Enamel - dentin - and bone
Insufficient or improper washing

17. What 3 types of cells are most radioresistant
Nerve - brain - muscle
Premature contact with developer
#2
Zygoma will be radiopaque - max. sinus will be a large area of radiolucency

18. What is the term to describe the overall blackness of a radiograph
Patient positioned too far to the left
Density
50 mSv or 5 REM
Chin down

19. Your dentist asks you to take a FMS on a 65 yr old edentulous patient. How many exposures will you take? which exposures are not necessary? What intraoral technique will you use? What might be better than a FMS?
take 14 radiographs -omit the BW -paralleling should be technique of choice -panoramic might be better than FMS
Size of crystals - thickness of emulsion - radiosensitive dyes
Excessive vertical angulation
DEHNR

20. What control factors effect the density of a radiograph
extraoral film
Overexposure -overdevelopment -developer is too strong -not enough fixation -exposure to white light -improper safelighting
Chronic low-level exposures/long term dose; causing cancer - cataracts - low birth weight - genetic mutations - and embryological defects
MA & time

21. 3 film holding devices used for paralleling
Movement caused by the patient - slippage of the image receptor - or vibration of the tube head
Gray & Rad
Dentsply rinn - XCP - XCP-DS - flow dental RAPD
Lateral cephalometric

22. What is the optimum processing temp.
Reduce size and shape of beam
B/c of its stability to produce a large volume of radiographs in a short amount of time
Green light sensitive film (Kodak T-Mat)
68 degrees F

23. What is the ADA approved method of mounting dental radiographs
Negative
Labial
Copper stem - tungsten target - radiator
Nerve - brain - muscle

24. With What type film are intensifying screens used?
Gelatin and silver halide crystals
Erythema
extraoral film
Cosmic - naturally occuring radiation from earth - radiation for radioactive materials

25. How often must you replenish the solutions in an automatic processor
extraoral film
Filtration and collimation
For every 30 films processed 6-8 oz should be taken out and replaced with fresh solution
Mand canal - external oblique ridge - beg. of ramus

26. When taking a radiograph - you pull the end of the PID away from the patients face about 6 inches. How will this affect the radiographic image and patient exposure
No. 4
Lighter image - patient exposed to larger beam which will increase exposure
Highest of the 2 ridges - about the level of the cervical 3rd - behind the 2nd and 3rd molars
Part that was fixed but not developed would be clear

27. What factors would decrease edge sharpness and increase magnification
BW
1/3-1/2
Far object-image receptor distance
Film placed backwards

28. What is the main source of radiation exposure to the operator
Focal spot
Scatter/secondary radition
bisecting was used b/c of the distortion of the elongated root - the roots appeared long b/c the vertical angulation was inadequate
Evidence based selection criteria

29. What causes overlapping
Incorrect horrizontal angulation
Increase the area of radiation exposure
Short-term dose
Check the processing chemical - particularly the developer

30. What is added filtration
Vertical BW
Left molar PA
Overexposure -overdevelopment -developer is too strong -not enough fixation -exposure to white light -improper safelighting
Filters placed in PID after tubehead production

31. What speed films are most commonly used?
D - E - F
Eyewear - mask - and gown
Every 6 mths
Film badges

32. Mand lateral/canine anatomy
Ionization
Tori
As close as possible
Vertical BW

33. Difference b/w direct and indirect exposure sensor?
Direct - directly obtaining a digital image by exposing intraoral sensor to x-rays to provide an image that can be viewed on a computer - indirect - photostimuable phosphor plate sensor technology - obtaining a digital image in which an exposed phosp
Reg. replenishment and changing out expired solutiong with fresh chemicals at reg. intervals; monitor strength of chemicals on a daily basis
Film badges
DEHNR

34. you change from an 8 inch to an 16 inch focal film distance. How is the intensity of the beam affected
X-rays that have been deflected from an object and have changed paths
particulate radiation: made of protons - neutrons - electrons and alpha and beta particles; has mass -electromagnetic radiation: made of photons; no mass
1/4 as intense
Only when necessary to help the dentist diagnose and treat oral diseases; elective xrays should be postponed until after delivery

35. What is formed when high speed electrons strike the target
X-ray and heat
No. 2
Stop taking xrays and evaluate all equipment and techniques to ensure safety
Before fixing

36. According to principles of shadow casting - preferred source-object distance
Zygoma will be radiopaque - max. sinus will be a large area of radiolucency
As far as practical
Panoramic cape
Short

37. What is the purpose of replenishing the developer solution
Filtration and collimation
The emulsion side of the film is placed against the orginal radiograph with the nonemulsion side up
Maintain acidity & alkalinity & prevent oxidation -
Insufficient vertical angulation

38. What is small doses of radiation given over a long period of time
Periapical examination - paralleling technique
Erythema
Long-term dose
Photostimuable Phosphor Plate aka storage phosphor system -indirect digital imaging -captures analog data then processed in a laser scanning device -light is then converted into electrical signal that the computer uses to create the digital image

39. which anatomic feature is visible on a PANO - bu not on a PA
MA & time
Old or contaminated processing solutions -exposure to chemical fumes -faulty safelight -scatter radiation
Mand. foramen
Scatter/secondary radition

40. when taking a paralleling radiograph of a patient with palatal tori - Where is the film places
Reduces the exposed silver halide crystals to black metallic silver
On the back side of the tori
Periapical examination - paralleling technique
Original - undeflected - useful beam

41. How often should an FMS be taken on an adult with no significant medical history
Take FMS on all new patients; recall adults with no sig. med. history only require BW and PA - if indicated
Evidence based selection criteria
Film placed backwards
On the back side of the tori

42. What determines the speed of dental films?
Ala-tragus line is parallel to the floor
Excessive vertical angulation
Size of crystals - thickness of emulsion - radiosensitive dyes
#2

43. in which pericapical projection will the mental ridge be visible
Decrease kVp by 15 and double exposure time = 10 mA 60 impules 75 kVp
The mental ridge
Overdevelopment -temp. too high -time too long -developer concentration too high -inadequate fixation -accidental exposure to light -improper safelighting
Mandibular lateral/central

44. What causes foreshortening
Excessive vertical angulation
invisible -travel in straight lines -no mass/weight -travel and speed of light -no charge -interact w/ matter causing ionization -can penetrate opaque tissues and structures -can effect photographic film emulsion -can effect biologic tissue
Dentin - enamel - bone
nasal septum - ant. nasal spine - nasal fossa - median palatine suture - incisive foramen

45. What causes clear film
No exposure - or fixer before developer
Insufficient vertical angulation
Reduce size and shape of beam
Not as sharp and detailed as the intraoral image

46. How are stabe film holders sterilized b/w uses
Sterilize film holder devices or discard disposable image receptor holding devices
Zygoma will be radiopaque - max. sinus will be a large area of radiolucency
Top of film delineated by a straight line then dark
Erythema

47. which dose of radiation is more biologically damaging
Chronic low-level exposures/long term dose; causing cancer - cataracts - low birth weight - genetic mutations - and embryological defects
Periapical
Erythema
Original packaging -area sheilded from radiation -50-70 degrees F

48. What is the purpose of a pano
Chronic low-level exposures/long term dose; causing cancer - cataracts - low birth weight - genetic mutations - and embryological defects
Filters placed in PID after tubehead production
Blue light sensitive films
Image the entire dentition - surrounding alveolar bone - sinuses - and the TMJ - examine large area of face and jaws - locate impacted teeth - retain root tips - evaluate trauma - lesions - and diseases - and assess growth and development

49. How does the reproductive capacity of a cell correlate with radiosensitivity
For every 30 films processed 6-8 oz should be taken out and replaced with fresh solution
Overexposure -overdevelopment -developer is too strong -not enough fixation -exposure to white light -improper safelighting
Not centered on sensor
Rapidly producing cells are more sensitive to radiation

50. What Size film is 7/8 x 1 3/8
Provides more info. about the location of tori - impacted and malpositioned teeth and the calcification of soft tissues
Nasal fossa - max sinus
No. 0
Rapidly producing cells are more sensitive to radiation