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. What type of x-rays have greater penetrating power - long or short wavelength?
Short
Located on the tooth surface that contacts the adjacent tooth
#2
Cathode - filament - focusing cup

2. What are occlusal radiographs used to diagnose
locate retained roots -locate unerrupted or impacted teeth -evaluate for diseases and lesions -locate foreign bodies -reveal presence of salivary stones (sialothiths) -aid in evaluating fractures -size and shape of tori -aid in examining patients wit
No exposure - or fixer before developer
Duplicate - which will go to the insurance comp.; office keeps best copy
15 impulses

3. What PPE should be worn when exposing radiographs
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
Soft cloth - non abrasive cleaner
On the back side of the tori
Eyewear - mask - and gown

4. desired thickness of lead apron
Invisible image (remains like this until film is processed)
25
.25 mm
No exposure - or fixer before developer

5. What is the purpose of collimation
Copper stem - tungsten target - radiator
Patient movement
All of the ant. teeth will appear blurred and narrowed in width
Reduce size and shape of beam

6. How long is the final rinse
Clear/blue in the area of overlap b/c fixer will not remove all crystals
Labial
20 min
1/3-1/2

7. which anatomic feature is visible on a PANO - bu not on a PA
Mand. foramen
Patient positioned too far foward in the focal trough
Shadow around the tooth
Soft tissue - air space

8. What is the purpose of the lead foil?
Absorb scatter radiation and prevent fogging
Cancer - cateracts - embryologic defects - genetic mutations - low birth weight
#1 or #2 - placed so the edge of the receptor lines up behind the distal of the canine before the eruption of the permanent 2nd molar; - after the eruption of the perm. 2nd molar - 2 posterior PA's should be taken per quadrant
Blue light sensitive films

9. What Size film is 7/8 x 1 3/8
No. 0
Scatter/secondary radition
Every 4 weeks
Before fixing

10. What is the optimum processing temp.
Cathode - filament - focusing cup
Left molar PA
68 degrees F
Ala-tragus line is parallel to the floor

11. How are stabe film holders sterilized b/w uses
Not as sharp and detailed as the intraoral image
bisecting was used b/c of the distortion of the elongated root - the roots appeared long b/c the vertical angulation was inadequate
Sterilize film holder devices or discard disposable image receptor holding devices
Increased focal spot size - decrease source-object distance - & increased object-film distance

12. What control factors effect the density of a radiograph
Top of film delineated by a straight line then dark
MA & time
Vertical BW
Rapidly producing cells are more sensitive to radiation

13. When viewing a periapical radiograph - you notice that the image of the tooth is extremely long and well defined; However the apices are missing. What technique was used to take the radiograph? What caused the roots to appear long?
Nasal fossa - max sinus
take 14 radiographs -omit the BW -paralleling should be technique of choice -panoramic might be better than FMS
Extra oral
bisecting was used b/c of the distortion of the elongated root - the roots appeared long b/c the vertical angulation was inadequate

14. What factors affect the sharpness of the radiographic image
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
max molars have 3 roots - mand have 2 roots
6 ft
Patient's dental arches; maxilla and mandile

15. Explain PSP
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
Thyroid collar - lead and lead-equivalent sprons are availaable with or without an attached thyroid collar
#3
#2

16. What would happen to a film that is placed in the fixer prior to development
Chronic low-level exposures/long term dose; causing cancer - cataracts - low birth weight - genetic mutations - and embryological defects
Blank or clear (takes all of the crystals off)
Rapidly producing cells are more sensitive to radiation
No. 4

17. What is the proper patient position for BW's?
Ala-tragus line is parallel to the floor
Excessive vertical angulation
DEHNR
Old or contaminated processing solutions -exposure to chemical fumes -faulty safelight -scatter radiation

18. What radiograph is used to sHow contrast in soft tissues
Erythema - vomitting - nausea - hemorrage - diarrhea - hair loss
Air space and soft tissues
Remove silver
MRI

19. What is penumbra
Shadow around the tooth
#1
No. 1
Original packaging -area sheilded from radiation -50-70 degrees F

20. you notice that the xrays you process are becoming successively lighter than the quality control film you compare it to. What should you do
Check the processing chemical - particularly the developer
20 seconds
Sterilize film holder devices or discard disposable image receptor holding devices
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

21. How often should an FMS be taken on an adult with no significant medical history
5(n-18)
Take FMS on all new patients; recall adults with no sig. med. history only require BW and PA - if indicated
detect pathological lesions -establish position of mental foramen -establish position of mand canal -determine quality & quantity of alveolar bone present
Tori

22. What radiographs are used to locate a salivary stone in the submandibular duct
Every 4 weeks
Enamel - dentin - and bone
Mandibular occlusal
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

23. What determines the speed of dental films?
Size of crystals - thickness of emulsion - radiosensitive dyes
Depends on the needs of the patient - established after intraoral exam
bisecting - packet is as close to tooth as possible - but not parallel -parallel - packet is parallel to tooth - further away
Nasal fossa - max sinus

24. How does the reproductive capacity of a cell correlate with radiosensitivity
Rapidly producing cells are more sensitive to radiation
Sv & Rem
20 seconds
B/c of its stability to produce a large volume of radiographs in a short amount of time

25. What is the earliest sign of radiation exposure
Sv & Rem
25
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
Erythema

26. When can the films be exposed to white light
5(n-18)
15 impulses
Excessive vertical angulation
After 2-3 min of fixing if needed

27. With What type film are intensifying screens used?
Labial
Sv & Rem
Beam is perpendicular to the imaginary line that bisects the angle formed by the long axis and the film
extraoral film

28. when processing - two films overlap in the developer - but not in the fixer. How would the films appear
MA & time
Clear/blue in the area of overlap b/c fixer will not remove all crystals
Mandibular lateral/central
2.75 inches

29. 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
Max. sinus - zygoma
Lighter image - patient exposed to larger beam which will increase exposure
Blue light sensitive films
Dentsply rinn - XCP - XCP-DS - flow dental RAPD

30. What is scatter radiation
take 14 radiographs -omit the BW -paralleling should be technique of choice -panoramic might be better than FMS
Periapical
X-rays that have been deflected from an object and have changed paths
10 min (dbl the development time)

31. What is the major use of topographical occlusal radiographs
extraoral film
Evidence based selection criteria
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
No. 4

32. 1/10th dosage of gen. public - What are photons
#3
Quantum of energy
Lateral cephalometric
Filament

33. What is the main source of radiation exposure to the operator
Coulombs/kilogram(C/kg) & Roentgen (R)
15 impulses
Left side
Scatter/secondary radition

34. What is the emulsion composed of?
10 min (dbl the development time)
Gelatin and silver halide crystals
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
Ionization

35. What is the major diff. b/w particulate and electromagnetic radiation
Film placed backwards
#2
particulate radiation: made of protons - neutrons - electrons and alpha and beta particles; has mass -electromagnetic radiation: made of photons; no mass
Sterilize film holder devices or discard disposable image receptor holding devices

36. According to principles of shadow casting - How should the film be placed in relation to the tooth?
Parallel
#2
Document patient's refusal and have them sign
Insufficient vertical angulation

37. How does exposure time differ b/w adults and children
Cut exposure time by 1/3
As close as possible
2.75 inches
Every 6 mths

38. You process a set of BW's in the automatic processor. three of the BW's are of good quality - but fourth is completely blank. What probably caused this?
Zygoma will be radiopaque - max. sinus will be a large area of radiolucency
20 seconds
No exposure to x-rays - electrical failure - malfunction of x-ray machine - or processing errors
5(n-18)

39. What 3 types of cells are most radiosensitive
MRI
decrease mA & time
WBC - RBC - immature reproductive cells
Patient's dental arches; maxilla and mandile

40. How can exposure to the operator be reduced
Size of crystals - thickness of emulsion - radiosensitive dyes
Time b/w exposure and 1st clinically observable symptoms
Move farther from the radiation
Old or contaminated processing solutions -exposure to chemical fumes -faulty safelight -scatter radiation

41. What are the 2 units used to measure exposure to radiation
Patient's name - date - and other pertinent info
Coulombs/kilogram(C/kg) & Roentgen (R)
B/c of its stability to produce a large volume of radiographs in a short amount of time
Long-term dose

42. What factors would decrease edge sharpness and increase magnification
Far object-image receptor distance
Located on the tooth surface that contacts the adjacent tooth
Move farther from the radiation
Max. sinus - zygoma

43. Max. centrals anatomy
After 2-3 min of fixing if needed
nasal septum - ant. nasal spine - nasal fossa - median palatine suture - incisive foramen
Panoramic cape
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

44. What are automatic processors faster than manual processing?
As close as possible
B/c of its stability to produce a large volume of radiographs in a short amount of time
bisecting - packet is as close to tooth as possible - but not parallel -parallel - packet is parallel to tooth - further away
7 1/2 or 15 watt

45. What radiographs are used to determine if a foreign object is located facially or lingually
detect pathological lesions -establish position of mental foramen -establish position of mand canal -determine quality & quantity of alveolar bone present
Occlusal
Negative
Highest of the 2 ridges - about the level of the cervical 3rd - behind the 2nd and 3rd molars

46. 3 film holding devices used for paralleling
Occlucal
Dentsply rinn - XCP - XCP-DS - flow dental RAPD
Quantum of energy
Only when necessary to help the dentist diagnose and treat oral diseases; elective xrays should be postponed until after delivery

47. How many impulses are in .25 seconds
Faster film = lower definition and detail
On the back side of the tori
15 impulses
25

48. How does packet placement differ b/w bisecting and paralleling
Ionization
bisecting - packet is as close to tooth as possible - but not parallel -parallel - packet is parallel to tooth - further away
Chronic low-level exposures/long term dose; causing cancer - cataracts - low birth weight - genetic mutations - and embryological defects
No. 3

49. who discovered x-rays
Rectangular collimation
Short-term dose
Overdevelopment -temp. too high -time too long -developer concentration too high -inadequate fixation -accidental exposure to light -improper safelighting
Roentgen

50. What is a large dose of radiation given over a short period of time
2.5 mm
Short-term dose
1.5 mm
Shadow around the tooth