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. When interpreting radiographs - you notice a radiopaque extension or spur off the proximal surface of #30. What do you think this is?
Original packaging -area sheilded from radiation -50-70 degrees F
The mental ridge
Thyroid collar - lead and lead-equivalent sprons are availaable with or without an attached thyroid collar
25

2. According to principles of shadow casting - How should the central beam be directed
No. 4
Perpendicular to the tooth and film
Copper stem - radiator and air space
Decrease kVp by 15 and double exposure time = 10 mA 60 impules 75 kVp

3. What happens in the fixer
Paralleling; meets more principles of shadow casting
Patient's dental arches; maxilla and mandile
Release of electrons when a material such as tungsten is heated to incandescence - electrons are boiled off from the cathode filament in the x-ray tube when electric current is passed through it
Removes the unexposed silver halide crystals

4. How many impulses are in .25 seconds
#0
Increase the exposure time
15 impulses
Film placed backwards

5. What is added filtration
20 min
Dark film is from over exposure and improper packet placement for strange looking teeth and not being able to determine What film is
Filters placed in PID after tubehead production
No. 3

6. What is thermionic emission
Release of electrons when a material such as tungsten is heated to incandescence - electrons are boiled off from the cathode filament in the x-ray tube when electric current is passed through it
Nerve - brain - muscle
Mand. foramen
Rectangular collimation

7. What causes missing apices
Parallel
Copper stem - radiator and air space
Size of crystals - thickness of emulsion - radiosensitive dyes
Insufficient vertical angulation

8. if the source-object distance is cut from 16 to 8 - What must be changed to compensate
The less the patient is exposed - the less the operator is exposed
Method should be compensated for bisecting or paralleling
Genial tubercles - lingual foramen
Release of electrons when a material such as tungsten is heated to incandescence - electrons are boiled off from the cathode filament in the x-ray tube when electric current is passed through it

9. 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?
1/6th of a second
bisecting was used b/c of the distortion of the elongated root - the roots appeared long b/c the vertical angulation was inadequate
Failed safelight test - suggesting that the safelight conditions in the darkroom are fogging the film
Positioning the arches too far foward

10. which radiographic technique records the most accurate image of crowns - roots - and supporting structures in a selected area?
Roentgen
Top of film delineated by a straight line then dark
Periapical examination - paralleling technique
X-rays that have been deflected from an object and have changed paths

11. Max. centrals anatomy
Short-term dose
Extra oral
8-16 inches
nasal septum - ant. nasal spine - nasal fossa - median palatine suture - incisive foramen

12. What is the maximum size of the x-ray beam at the patients face
2.75 inches
Panoramic cape
take 14 radiographs -omit the BW -paralleling should be technique of choice -panoramic might be better than FMS
Overexposure -overdevelopment -developer is too strong -not enough fixation -exposure to white light -improper safelighting

13. when viewing a PANO - you notice that the right TMJ is magnified - bu the left TMJ is normal. What caused this error
4 feet
Dentsply rinn stabe - BAI - dental SUPA
Roentgen
Patient positioned too far to the left

14. Max lat. canine anatomy
Nasal fossa - max sinus
#4
Blank or clear (takes all of the crystals off)
Every 6 mths

15. What is the x-ray at the center of the primary beam called
Lighter image - patient exposed to larger beam which will increase exposure
Central ray
Dentsply rinn - XCP - XCP-DS - flow dental RAPD
25

16. How long is the final rinse
Mental foramen - mental ridge - mand canal
20 min
Vertical BW
White blood cells - red blood cells - immature reproductive cells - epithelial cells - connective tissue cells - bone cells - nerve cells - brain cells - muscle cells

17. What would cause a film to be too light
underexposure-underdevelopment -depleted developer solution -excessive fixation (takes all crystals off)
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
Nerve - brain - muscle
X-rays that have been deflected from an object and have changed paths

18. What happens in the developer
1/5 exposure time for edentulous
White blood cells - red blood cells - immature reproductive cells - epithelial cells - connective tissue cells - bone cells - nerve cells - brain cells - muscle cells
Take FMS on all new patients; recall adults with no sig. med. history only require BW and PA - if indicated
Reduces the exposed silver halide crystals to black metallic silver

19. What is used to clean the screens inside of a cassestte
MRI
Soft cloth - non abrasive cleaner
Maintain acidity & alkalinity & prevent oxidation -
2.75 inches

20. What causes teeth to appear very short and distorted
Top of film delineated by a straight line then dark
The mental ridge
Excessive VA w/ PID positioned too steep enough away from zero degrees
Ionization

21. 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?
No exposure to x-rays - electrical failure - malfunction of x-ray machine - or processing errors
The most distal tooth should be captured in full as well as a few mm of bone level behind the most distal tooth
5(n-18)
X-ray and heat

22. How are indirect exposure films exposed
X-rays hit phosphor screen creating florescent light that exposes the film
Stop taking xrays and evaluate all equipment and techniques to ensure safety
Insufficient vertical angulation
Scatter/secondary radition

23. What type film is faster - intraoral or extraoral
Remove silver
Insufficient or improper washing
Dark film is from over exposure and improper packet placement for strange looking teeth and not being able to determine What film is
Extra oral

24. In the darkroom - you unwrap a film and place a coin on top of the film for several minutes. when you process the film - you notice a slight - well-defined white circle on the film. What does this mean?
Failed safelight test - suggesting that the safelight conditions in the darkroom are fogging the film
Tori
No. 3
Mand occlusal

25. How often should developing solutions be changed
Every 4 weeks
Check the processing chemical - particularly the developer
Gently agitating the hanger up and down a few times
Rectangular collimation

26. How are x-rays formed in the tubehead
#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
1/3-1/2
Method should be compensated for bisecting or paralleling
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

27. What is the most likely cause of a film with very poor definition
Patient movement
Cut exposure time by 1/3
Time b/w exposure and 1st clinically observable symptoms
Large blank space is due to reversed image error or chemical contamination - missing apices is due to inadequate VA

28. Proper patient positioning for bisecting
Max arch ala-tragus parallel to floor - mand arch
Remove silver
2.5 mm
Air space and soft tissues

29. What anatomical structures appear radiolucent on a dental radiograph
All of the ant. teeth will appear blurred and narrowed in width
Air space and soft tissues
Filters placed in PID after tubehead production
Erythema

30. when viewing a radiograph - the tooth looks normal in size and shape; However - there is a large blank space at the incisal edge and the apices are missing. What caused this error
Large blank space is due to reversed image error or chemical contamination - missing apices is due to inadequate VA
Failed safelight test - suggesting that the safelight conditions in the darkroom are fogging the film
No. 0
8-16 inches

31. What is formed when high speed electrons strike the target
Move farther from the radiation
X-ray and heat
Lateral cephalometric
Negative

32. What are the 2 units used to measure exposure to radiation
10 min (dbl the development time)
KVp
Coulombs/kilogram(C/kg) & Roentgen (R)
The most distal tooth should be captured in full as well as a few mm of bone level behind the most distal tooth

33. What looking at a PANO What causes a big smile
Quantum of energy
#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
Film placed backwards
Chin down

34. Mand lateral/canine anatomy
Tori
1/6th of a second
Extra oral
Lead

35. Max premolar anatomy
White blood cells - red blood cells - immature reproductive cells - epithelial cells - connective tissue cells - bone cells - nerve cells - brain cells - muscle cells
Max. sinus - zygoma
All of the ant. teeth will appear blurred and narrowed in width
6 ft

36. You notice on a PANO that the ant. teeth appear narrow and out of focus. What caused this
5(n-18)
Patient positioned too far foward in the focal trough
Erythema - vomitting - nausea - hemorrage - diarrhea - hair loss
Cathode - filament - focusing cup

37. you notice that a radiograph taken several months ago is brown and spotted. What happened
Clinical exam
Increased focal spot size - decrease source-object distance - & increased object-film distance
Dentin - enamel - bone
Insufficient or improper washing

38. you change you kVp from 90 to 70 and leave all other factors the same. What is the result
Scatter/secondary radition
#2
Time b/w exposure and 1st clinically observable symptoms
The wave length will be shorter - the quality and energy of the beam will be higher and the contrast will be lowe. - the image will also have a higher density

39. Size film used for PA's on small children
Invisible image (remains like this until film is processed)
Panoramic cape
#0
Evidence based selection criteria

40. What types of cells must be effected in order for mutation to occur
Genetic cells
1/3-1/2
PANO
Beam is perpendicular to the imaginary line that bisects the angle formed by the long axis and the film

41. 3 film holding devices used for paralleling
Duplicate - which will go to the insurance comp.; office keeps best copy
Dentsply rinn - XCP - XCP-DS - flow dental RAPD
Short
Release of electrons when a material such as tungsten is heated to incandescence - electrons are boiled off from the cathode filament in the x-ray tube when electric current is passed through it

42. How much total filtration is required of x-ray machines that operate lower than 70 kVp
Remove silver
Soft tissue - air space
Tori
1.5 mm

43. What is the purpose of collimation
Duplicate - which will go to the insurance comp.; office keeps best copy
Dentin - enamel - bone
Mand occlusal
Reduce size and shape of beam

44. How far should the operator stand from the source of radiation
The mental ridge
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
Rectangular collimation and fast film speed
6 ft

45. What 2 unites are used to measure absorption
Long-term dose
Gray & Rad
KVp
Film placed backwards

46. What size bulb is used in safelight
7 1/2 or 15 watt
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
Patient positioned too far to the left
Reduce size and shape of beam

47. What are occlusal radiographs used to diagnose
1.5 mm
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
Excessive vertical angulation
Decrease kVp by 15 and double exposure time = 10 mA 60 impules 75 kVp

48. What is the earliest sign of radiation exposure
Erythema
Insufficient vertical angulation
2.5 mm
Doesn't matter

49. How long are films fixed
Cathode - filament - focusing cup
10 min (dbl the development time)
Vertical BW
Removes the unexposed silver halide crystals

50. you process four BW films. three of the films appear normal - but one is clear. What happened