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 mounting dental radiographs - What is the best way to differentiate max and mand films?
max teeth are longer - max molars have 3 roots - mand molars have 2 roots - most roots curve toward the distal - occlusal plane is straight or curved slight towards distal
Movement caused by the patient - slippage of the image receptor - or vibration of the tube head
Cut exposure time by 1/3
Mandibular lateral/central

2. What causes film fogging
Periapical examination - paralleling technique
Thyroid collar - lead and lead-equivalent sprons are availaable with or without an attached thyroid collar
Max sinus - zygoma - max tuberosity - coranoid process
Old or contaminated processing solutions -exposure to chemical fumes -faulty safelight -scatter radiation

3. According to principles of shadow casting - How should the central beam be directed
50 mSv or 5 REM
Perpendicular to the tooth and film
8-16 inches
Lead

4. What controls the speed with which the electrons travel from the cathode to the anode
Mandibular lateral/central
Erythema - vomitting - nausea - hemorrage - diarrhea - hair loss
KVp
Faster film = lower definition and detail

5. What is the most likely cause of a film with very poor definition
Method should be compensated for bisecting or paralleling
Mandibular occlusal
Patient movement
Periapical examination - paralleling technique

6. What is the optimum processing temp.
Copper stem - tungsten target - radiator
68 degrees F
Dentsply rinn stabe - BAI - dental SUPA
Removes the unexposed silver halide crystals

7. What causes elongation
Insufficient vertical angulation
Not centered on sensor
#4
Paralleling; meets more principles of shadow casting

8. What would cause a film to be too dark
Overexposure -overdevelopment -developer is too strong -not enough fixation -exposure to white light -improper safelighting
Erythema - vomitting - nausea - hemorrage - diarrhea - hair loss
X-rays that have gone thru an object and are now a newer weaker beam
WBC - RBC - immature reproductive cells

9. What is the max. permissable fose for radiation workers in systeme interventional units
Negative
Reduces the exposed silver halide crystals to black metallic silver
Erythema - vomitting - nausea - hemorrage - diarrhea - hair loss
50 mSv (5rem)

10. What must be done to xray fixer priod to disposal
BW
Overexposure -overdevelopment -developer is too strong -not enough fixation -exposure to white light -improper safelighting
Remove silver
No exposure to x-rays - electrical failure - malfunction of x-ray machine - or processing errors

11. What are occlusal radiographs used to diagnose
Cathode - filament - focusing cup
Excessive vertical angulation
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
6 ft

12. using a 16 inch cone focal-film distance - the diameter of the beam measured at the patient's face should be no larger than
Max. sinus - zygoma
Dark film is from over exposure and improper packet placement for strange looking teeth and not being able to determine What film is
2.75 inch
Invisible image (remains like this until film is processed)

13. What causes missing crowns
Occlusal
Negative
Mandibular lateral/central
Excessive vertical angulation

14. According to the principles of shadow casting - preferred object-film distance
DEHNR
Failed safelight test - suggesting that the safelight conditions in the darkroom are fogging the film
Lead
As close as possible

15. How long does film stay in the developer
5 min
The mental ridge
X-rays hit phosphor screen creating florescent light that exposes the film
decrease mA & time

16. How far from the work surface must the safelight be mounted
Perpendicular to the tooth and film
Density
Ala-tragus line is parallel to the floor
4 feet

17. desired thickness of lead apron
Aka general radiation; stopping or slowing of the electrons of the cathode stream as they collide with the nuclei of the target atoms
.25 mm
No exposure to x-rays - electrical failure - malfunction of x-ray machine - or processing errors
Excessive vertical angulation

18. What type of projection is used to visualize the crestol alveolar bone on a patient with moderate to severe bone loss
25
particulate radiation: made of protons - neutrons - electrons and alpha and beta particles; has mass -electromagnetic radiation: made of photons; no mass
Faster film = lower definition and detail
Vertical BW

19. What is a large dose of radiation given over a short period of time
Short-term dose
KVp
Produced by internal barriers in tube head (ex: glass and insulating oils)
Rapidly producing cells are more sensitive to radiation

20. How often must you replenish the solutions in an automatic processor
Move farther from the radiation
8-16 inches
Mand occlusal
For every 30 films processed 6-8 oz should be taken out and replaced with fresh solution

21. What Size film is 2 1/4 x 3
Part that was fixed but not developed would be clear
No. 4
Absorb scatter radiation and prevent fogging
Overexposure -overdevelopment -developer is too strong -not enough fixation -exposure to white light -improper safelighting

22. What 3 types of cells are most radiosensitive
Clinical exam
GBX - 2
WBC - RBC - immature reproductive cells
Chin down

23. What radiograph is used to sHow contrast in soft tissues
Film placed backwards
underexposure-underdevelopment -depleted developer solution -excessive fixation (takes all crystals off)
CCD (direct) - CMOS (direct) - PSP (indirect)
MRI

24. Mand central anatomy
Dark film is from over exposure and improper packet placement for strange looking teeth and not being able to determine What film is
Excessive vertical angulation
Gray & Rad
Genial tubercles - lingual foramen

25. Explain PSP
Genial tubercles - lingual foramen
Insufficient or improper washing
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
Dentsply rinn stabe - BAI - dental SUPA

26. What is the purpose of the lead foil?
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
50 mSv or 5 REM
White blood cells - red blood cells - immature reproductive cells - epithelial cells - connective tissue cells - bone cells - nerve cells - brain cells - muscle cells
Absorb scatter radiation and prevent fogging

27. when manually processing dental film - you notice the temp. has gotten warmer as the day progressed. How should the developing time be changed?
Higher temp. increases film fog - so radiographer should consult a time-temp. development chart to adjust developing time appropriately; developing time will decrease
Patient's dental arches; maxilla and mandile
Highest of the 2 ridges - about the level of the cervical 3rd - behind the 2nd and 3rd molars
Tori

28. Size film used for BW on adults when only one film is taken on each side
#0
15 impulses
#3
Mandibular lateral/central

29. What is the maximum size of the x-ray beam at the patients face
Coulombs/kilogram(C/kg) & Roentgen (R)
The mental ridge
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
2.75 inches

30. you notice that the xrays you process are becoming successively lighter than the quality control film you compare it to. What should you do
PANO
#4
Check the processing chemical - particularly the developer
Erythema - vomitting - nausea - hemorrage - diarrhea - hair loss

31. 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. sinus - zygoma
Excessive VA w/ PID positioned too steep enough away from zero degrees
White blood cells - red blood cells - immature reproductive cells - epithelial cells - connective tissue cells - bone cells - nerve cells - brain cells - muscle cells

32. What is secondary radiation
Mandibular lateral/central
X-rays that have gone thru an object and are now a newer weaker beam
Periodically examining cassettes and intensifying screens; extra oral cassettes should be checked for warping and light leaks
nasal septum - ant. nasal spine - nasal fossa - median palatine suture - incisive foramen

33. How are x-rays formed in the tubehead
Chronic low-level exposures/long term dose; causing cancer - cataracts - low birth weight - genetic mutations - and embryological defects
#2
Occlucal
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

34. you change from an 8 inch to an 16 inch focal film distance. How is the intensity of the beam affected
Tori
1/4 as intense
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
Cosmic - naturally occuring radiation from earth - radiation for radioactive materials

35. 3 film holding devices used for bisecting
Perpendicular to the tooth and film
Gently agitating the hanger up and down a few times
1/3-1/2
Dentsply rinn stabe - BAI - dental SUPA

36. What is scatter radiation
2.75 inches
Increase the exposure time
X-rays that have been deflected from an object and have changed paths
Short

37. When mounting a FMS - you notice that one film is blank. another film is dark - the teeth look strange - and it is difficult to determine What film it is. What do you think happened?
Dentsply rinn - XCP - XCP-DS - flow dental RAPD
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
6 ft

38. When looking at radiographs that were taken several years ago - you notice a brownish stain which makes interpretation difficult. What caused this?
Parallel
No. 0
Insufficient or improper washing
Copper stem - radiator and air space

39. What is done to the primary beam to make is useful
2.5 mm
Soft cloth - non abrasive cleaner
Filtration and collimation
Higher temp. increases film fog - so radiographer should consult a time-temp. development chart to adjust developing time appropriately; developing time will decrease

40. How do you differentiate b/w max and mand molar when mounting
Genetic cells
max molars have 3 roots - mand have 2 roots
Maintain acidity & alkalinity & prevent oxidation -
Take FMS on all new patients; recall adults with no sig. med. history only require BW and PA - if indicated

41. What is the best method of protecting the thyroid gland from radiation?
Chronic low-level exposures/long term dose; causing cancer - cataracts - low birth weight - genetic mutations - and embryological defects
Thyroid collar - lead and lead-equivalent sprons are availaable with or without an attached thyroid collar
Short-term dose
Large blank space is due to reversed image error or chemical contamination - missing apices is due to inadequate VA

42. What causes overlapping
White blood cells - red blood cells - immature reproductive cells - epithelial cells - connective tissue cells - bone cells - nerve cells - brain cells - muscle cells
Incorrect horrizontal angulation
2.75 inches
Eyewear - mask - and gown

43. What radiographs are used to determine if a foreign object is located facially or lingually
bisecting - packet is as close to tooth as possible - but not parallel -parallel - packet is parallel to tooth - further away
Occlusal
Take FMS on all new patients; recall adults with no sig. med. history only require BW and PA - if indicated
1/5 exposure time for edentulous

44. What is the x-ray at the center of the primary beam called
Chin down
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
Decrease kVp by 15 and double exposure time = 10 mA 60 impules 75 kVp
Central ray

45. What type of film are rare earth screens paired with
5 mSv or .5 REM
Periapical
Green light sensitive film (Kodak T-Mat)
#2

46. 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
WBC - RBC - immature reproductive cells
20 seconds
Lateral cephalometric

47. which anatomical structures appear radiolucent
Soft tissue - air space
Clinical exam
Premature contact with developer
Decrease kVp by 15 and double exposure time = 10 mA 60 impules 75 kVp

48. According to principles of shadow casting - preferred source-object distance
KVp
As far as practical
Time b/w exposure and 1st clinically observable symptoms
Blank or clear (takes all of the crystals off)

49. What is formed when high speed electrons strike the target
Excessive VA w/ PID positioned too steep enough away from zero degrees
X-ray and heat
Part that was fixed but not developed would be clear
Mand. foramen

50. How long is the final rinse
Scatter/secondary radition
Increased focal spot size - decrease source-object distance - & increased object-film distance
20 min
Zygoma will be radiopaque - max. sinus will be a large area of radiolucency