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. List the properties of x-rays
Mandibular lateral/central
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
Mand. foramen
Rectangular collimations

2. How are indirect exposure films exposed
No exposure to x-rays - electrical failure - malfunction of x-ray machine - or processing errors
X-rays hit phosphor screen creating florescent light that exposes the film
Evidence based selection criteria
Erythema

3. which anatomic feature is visible on a PANO - bu not on a PA
50 mSv or 5 REM
Mand. foramen
Check the processing chemical - particularly the developer
No. 1

4. when manually processing dental film - you notice the temp. has gotten warmer as the day progressed. How should the developing time be changed?
X-rays that have been deflected from an object and have changed paths
1/5 exposure time for edentulous
Higher temp. increases film fog - so radiographer should consult a time-temp. development chart to adjust developing time appropriately; developing time will decrease
Gray & Rad

5. What are the long term effects of radiation exposure
Maintain acidity & alkalinity & prevent oxidation -
Genetic cells
Cancer - cateracts - embryologic defects - genetic mutations - low birth weight
Film placed backwards

6. How does resolutiong and detial of a panoramic radiograph compare with that of PA's and BW's
Roentgen
#2
Stop taking xrays and evaluate all equipment and techniques to ensure safety
Not as sharp and detailed as the intraoral image

7. What is the collimator made out of...
Lead
Rapidly producing cells are more sensitive to radiation
Erythema - vomitting - nausea - hemorrage - diarrhea - hair loss
Not as sharp and detailed as the intraoral image

8. What is the earliest sign of radiation exposure
Take FMS on all new patients; recall adults with no sig. med. history only require BW and PA - if indicated
#1
Erythema
#0

9. How should x-ray film be stored
Mand canal - external oblique ridge - beg. of ramus
Original packaging -area sheilded from radiation -50-70 degrees F
Dentin - enamel - bone
6 ft

10. your film badge report sHows that you have received a small amt. of radiation. What should you do
Stop taking xrays and evaluate all equipment and techniques to ensure safety
7 1/2 or 15 watt
Check the processing chemical - particularly the developer
Film placed backwards

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

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12. What causes film fogging
Clear/blue in the area of overlap b/c fixer will not remove all crystals
Reduces the exposed silver halide crystals to black metallic silver
Patient positioned too far foward in the focal trough
Old or contaminated processing solutions -exposure to chemical fumes -faulty safelight -scatter radiation

13. Max molar anatomy
Max sinus - zygoma - max tuberosity - coranoid process
Old or contaminated processing solutions -exposure to chemical fumes -faulty safelight -scatter radiation
Move farther from the radiation
Green light sensitive film (Kodak T-Mat)

14. your dentist recommends that a patient have xrays taken - bu the patient refuses. What should be done

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15. you notice that a radiograph taken several months ago is brown and spotted. What happened
GBX - 2
As low as reasonably achievable
Insufficient or improper washing
No exposure - or fixer before developer

16. What Size film is 7/8 x 1 3/8
extraoral film
Mandibular occlusal
5(n-18)
No. 0

17. Proper patient positioning for bisecting
After 2-3 min of fixing if needed
Max arch ala-tragus parallel to floor - mand arch
2.75 inches
Central ray

18. What anatomical structures appear radiopaque on a dental radiograph
Enamel - dentin - and bone
Patient's dental arches; maxilla and mandile
Excessive vertical angulation
Reduces the exposed silver halide crystals to black metallic silver

19. A patient complains of pain in the upper molar region. What radiographic exposure should be made?
Erythema
Periapical
Cathode - filament - focusing cup
decrease mA & time

20. when viewing a PANO - you notice that a lot of spine sHows on both side of the film - What caused this
Positioning the arches too far foward
Step-wedge or test film
Green light sensitive film (Kodak T-Mat)
After 2-3 min of fixing if needed

21. What type film is faster - intraoral or extraoral
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
DEHNR
Extra oral
Nerve - brain - muscle

22. What must a patient remove before taking a PANO
Blue tinted polyester acetate
bisecting was used b/c of the distortion of the elongated root - the roots appeared long b/c the vertical angulation was inadequate
Removes the unexposed silver halide crystals
Oral piercings - earings - glasses - necklaces - facial piercings - hair pins - hearing aids - dentures - and retainers

23. when should radiographs be taken on a pregnant patient
Copper stem - radiator and air space
Only when necessary to help the dentist diagnose and treat oral diseases; elective xrays should be postponed until after delivery
Quantum of energy
Roentgen

24. 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?
Doesn't matter
Perpendicular to the tooth and film
bisecting was used b/c of the distortion of the elongated root - the roots appeared long b/c the vertical angulation was inadequate
Perpendicular to the film - parallel to the bite portion of the stabe

25. How much total filtration is required of x-ray machines that operate lower than 70 kVp
Top of film delineated by a straight line then dark
1.5 mm
The mental ridge
Oral piercings - earings - glasses - necklaces - facial piercings - hair pins - hearing aids - dentures - and retainers

26. According to principles of shadow casting - How should the film be placed in relation to the tooth?
No. 1
Large blank space is due to reversed image error or chemical contamination - missing apices is due to inadequate VA
Parallel
Premature contact with developer

27. Film submerged totally in fixer but not in developer
25
Parallel
Cut exposure time by 1/3
Part that was fixed but not developed would be clear

28. What radiographs are used to locate a salivary stone in the submandibular duct
Left molar PA
Mandibular occlusal
20 seconds
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

29. Max premolar anatomy
Max. sinus - zygoma
6 ft
#1
Failed safelight test - suggesting that the safelight conditions in the darkroom are fogging the film

30. What are three types of image receptors used in digital radiography
Mandibular occlusal
CCD (direct) - CMOS (direct) - PSP (indirect)
Invisible image (remains like this until film is processed)
No. 2

31. when viewing a PANO - you notice that the right TMJ is magnified - bu the left TMJ is normal. What caused this error
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
Patient positioned too far to the left
Left side
Provides more info. about the location of tori - impacted and malpositioned teeth and the calcification of soft tissues

32. What is the purpose of collimation
Cathode - filament - focusing cup
Chronic low-level exposures/long term dose; causing cancer - cataracts - low birth weight - genetic mutations - and embryological defects
Filament
Reduce size and shape of beam

33. What exposure is taken to determine jaw relationships in ortho treatment planning
Oral piercings - earings - glasses - necklaces - facial piercings - hair pins - hearing aids - dentures - and retainers
Central ray
Lateral cephalometric
25

34. What type PID significantly reduces exposure to the patient
Rectangular collimations
.25 mm
Density
Air space and soft tissues

35. when viewing a molar BW - What should be on the distal of the film
extraoral film
#2
The most distal tooth should be captured in full as well as a few mm of bone level behind the most distal tooth
Insufficient or improper washing

36. 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
Movement caused by the patient - slippage of the image receptor - or vibration of the tube head
Quantum of energy
Gently agitating the hanger up and down a few times
Large blank space is due to reversed image error or chemical contamination - missing apices is due to inadequate VA

37. What happens in the fixer
Removes the unexposed silver halide crystals
Higher kVp = low exposure
Periodically examining cassettes and intensifying screens; extra oral cassettes should be checked for warping and light leaks
Step-wedge or test film

38. What type of angulation is used when taking radiographs of the mand. arch
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
Patient's name - date - and other pertinent info
No. 0
Negative

39. With What type film are intensifying screens used?
Periapical
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
extraoral film
Erythema

40. According to principles of shadow casting - How should the central beam be directed
Perpendicular to the tooth and film
Higher kVp = low exposure
Vertical BW
Every 4 weeks

41. What is the max. permissable fose for radiation workers in systeme interventional units
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
Gently agitating the hanger up and down a few times
50 mSv (5rem)
Reduce size and shape of beam

42. desired thickness of lead apron
.25 mm
Mandibular lateral/central
Patient's name - date - and other pertinent info
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

43. when taking a PANO radiograph - the patient is placed too far into the machine. How will the radiograph appear
All of the ant. teeth will appear blurred and narrowed in width
Vertical BW
Shadow around the tooth
White blood cells - red blood cells - immature reproductive cells - epithelial cells - connective tissue cells - bone cells - nerve cells - brain cells - muscle cells

44. Max lat. canine anatomy
Chin down
After 2-3 min of fixing if needed
Nasal fossa - max sinus
Patient movement

45. What causes elongation
Left molar PA
#1
Insufficient vertical angulation
Paralleling; meets more principles of shadow casting

46. What parts of the x-ray machine are included in the cathode circuit
Cathode - filament - focusing cup
Overexposure -overdevelopment -developer is too strong -not enough fixation -exposure to white light -improper safelighting
Reg. replenishment and changing out expired solutiong with fresh chemicals at reg. intervals; monitor strength of chemicals on a daily basis
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

47. What would cause a film to be too light
Before fixing
Soft tissue - air space
Highest of the 2 ridges - about the level of the cervical 3rd - behind the 2nd and 3rd molars
underexposure-underdevelopment -depleted developer solution -excessive fixation (takes all crystals off)

48. 3 film holding devices used for paralleling
Part that was fixed but not developed would be clear
Dentsply rinn - XCP - XCP-DS - flow dental RAPD
Clinical exam
Soft tissue - air space

49. What determines the speed of dental films?
Higher kVp = low exposure
Size of crystals - thickness of emulsion - radiosensitive dyes
Green light sensitive film (Kodak T-Mat)
Insufficient or improper washing

50. What would cause a properly exposed film to appear dark?
Vertical BW
8-16 inches
Overdevelopment -temp. too high -time too long -developer concentration too high -inadequate fixation -accidental exposure to light -improper safelighting
Excessive vertical angulation