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. 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?
Excessive vertical angulation
No exposure to x-rays - electrical failure - malfunction of x-ray machine - or processing errors
For every 30 films processed 6-8 oz should be taken out and replaced with fresh solution
1/3-1/2

2. What radiographs are used to determine if a foreign object is located facially or lingually
Cut exposure time by 1/3
Occlusal
Dentsply rinn - XCP - XCP-DS - flow dental RAPD
To distinguish b/w patient's right and left side

3. What is the best method of protecting the thyroid gland from radiation?
Reduce size and shape of beam
8-16 inches
Thyroid collar - lead and lead-equivalent sprons are availaable with or without an attached thyroid collar
Max. sinus - zygoma

4. 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?
Enamel - dentin - and bone
Patient positioned too far foward in the focal trough
Chronic low-level exposures/long term dose; causing cancer - cataracts - low birth weight - genetic mutations - and embryological defects
bisecting was used b/c of the distortion of the elongated root - the roots appeared long b/c the vertical angulation was inadequate

5. What 3 types of cells are most radioresistant
The most distal tooth should be captured in full as well as a few mm of bone level behind the most distal tooth
No. 2
Nerve - brain - muscle
DEHNR

6. What 2 unites are used to measure absorption
B/c of its stability to produce a large volume of radiographs in a short amount of time
Long-term dose
#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
Gray & Rad

7. How long are films fixed
KVp
10 min (dbl the development time)
#0
Not as sharp and detailed as the intraoral image

8. 3 film holding devices used for bisecting
Dentsply rinn stabe - BAI - dental SUPA
Gelatin and silver halide crystals
bisecting - packet is as close to tooth as possible - but not parallel -parallel - packet is parallel to tooth - further away
Stop taking xrays and evaluate all equipment and techniques to ensure safety

9. Max premolar anatomy
No. 3
Max. sinus - zygoma
KVp
Dentin - enamel - bone

10. What factors would decrease edge sharpness and increase magnification
Old or contaminated processing solutions -exposure to chemical fumes -faulty safelight -scatter radiation
X-rays that have gone thru an object and are now a newer weaker beam
Far object-image receptor distance
68 degrees F

11. which projection is used to view sinuses
As far as practical
Soft cloth - non abrasive cleaner
Document patient's refusal and have them sign
PANO

12. According to the principles of shadow casting - preferred object-film distance
As close as possible
KVp
5 mSv or .5 REM
Every 6 mths

13. after processing exposed dental film - you notice dark spots on the film. What caused this
Increase the area of radiation exposure
2.75 inch
No. 3
Premature contact with developer

14. How are x-rays formed in the tubehead
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
Density
50 mSv (5rem)
X-rays hit phosphor screen creating florescent light that exposes the film

15. What is secondary radiation
Positioning the arches too far foward
take 14 radiographs -omit the BW -paralleling should be technique of choice -panoramic might be better than FMS
Evidence based selection criteria
X-rays that have gone thru an object and are now a newer weaker beam

16. What looking at a PANO What causes a big smile
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
4 feet
Removes the unexposed silver halide crystals
Chin down

17. when viewing a duplicated radiograph - you notice that the duplicate is too dark. What should you do to duplicating time to lighten the film
Increase the exposure time
Excessive vertical angulation
Patient positioned too far to the left
No. 3

18. How is vertical angulation established with the bisecting technique
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
Beam is perpendicular to the imaginary line that bisects the angle formed by the long axis and the film
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
Reg. replenishment and changing out expired solutiong with fresh chemicals at reg. intervals; monitor strength of chemicals on a daily basis

19. What control factors effect contrast
Genial tubercles - lingual foramen
No exposure - or fixer before developer
KVp
5(n-18)

20. you change you kVp from 90 to 70 and leave all other factors the same. What is the result
Extra oral
Removes the unexposed silver halide crystals
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
Zygoma will be radiopaque - max. sinus will be a large area of radiolucency

21. if the kVp is increased from 75-90 - What must be done to achieve a radiograph of comparible density
For every 30 films processed 6-8 oz should be taken out and replaced with fresh solution
Perpendicular to the tooth and film
No exposure to x-rays - electrical failure - malfunction of x-ray machine - or processing errors
decrease mA & time

22. total filtration required of x-ray machines that operate above 70 kVp
Patient positioned too far foward in the focal trough
2.5 mm
Gray & Rad
Overdevelopment -temp. too high -time too long -developer concentration too high -inadequate fixation -accidental exposure to light -improper safelighting

23. How is vertical angulation established with the paralleling technique
Max sinus - zygoma - max tuberosity - coranoid process
The most distal tooth should be captured in full as well as a few mm of bone level behind the most distal tooth
Perpendicular to the film - parallel to the bite portion of the stabe
Periodically examining cassettes and intensifying screens; extra oral cassettes should be checked for warping and light leaks

24. you change from an 8 inch to an 16 inch focal film distance. How is the intensity of the beam affected
1/4 as intense
#1
Panoramic cape
nasal septum - ant. nasal spine - nasal fossa - median palatine suture - incisive foramen

25. 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?
8-16 inches
Failed safelight test - suggesting that the safelight conditions in the darkroom are fogging the film
Remove silver
Gently agitating the hanger up and down a few times

26. How can exposure to the operator be reduced
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
Move farther from the radiation
Maintain acidity & alkalinity & prevent oxidation -
Gently agitating the hanger up and down a few times

27. What would happen to a film that is placed in the fixer prior to development
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
Blank or clear (takes all of the crystals off)
Method should be compensated for bisecting or paralleling
As close as possible

28. What is the major use of cross sectional occlusal radiograph
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
Provides more info. about the location of tori - impacted and malpositioned teeth and the calcification of soft tissues
Rapidly producing cells are more sensitive to radiation
Erythema - vomitting - nausea - hemorrage - diarrhea - hair loss

29. What are common sources of background radiation
Eyewear - mask - and gown
No. 3
Oral piercings - earings - glasses - necklaces - facial piercings - hair pins - hearing aids - dentures - and retainers
Cosmic - naturally occuring radiation from earth - radiation for radioactive materials

30. Size film used for anterior PA's for patients with narrow arches
GBX - 2
Not centered on sensor
Mand. foramen
#1

31. 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
Ionization
No. 2
Soft cloth - non abrasive cleaner

32. What are the long term effects of radiation exposure
Failed safelight test - suggesting that the safelight conditions in the darkroom are fogging the film
Blue tinted polyester acetate
Cancer - cateracts - embryologic defects - genetic mutations - low birth weight
Excessive vertical angulation

33. A properly exposed film appears completely black. when was is exposed to white light
#2
Before fixing
Movement caused by the patient - slippage of the image receptor - or vibration of the tube head
Thyroid collar - lead and lead-equivalent sprons are availaable with or without an attached thyroid collar

34. How does kVp affect patient exposure
Higher kVp = low exposure
Cracking of the emulsion caused by excessive temp diff. b/w any darkroom solutions
.25 mm
Maintain acidity & alkalinity & prevent oxidation -

35. What is the best way to reduce exposure to patient
#2
PANO
Nasal fossa - max sinus
Rectangular collimation

36. What is the emulsion composed of?
Time b/w exposure and 1st clinically observable symptoms
Gelatin and silver halide crystals
Quantum of energy
Old or contaminated processing solutions -exposure to chemical fumes -faulty safelight -scatter radiation

37. 1/10th dosage of gen. public - What are photons
Quantum of energy
B/c of its stability to produce a large volume of radiographs in a short amount of time
Stop taking xrays and evaluate all equipment and techniques to ensure safety
Scatter/secondary radition

38. if the source-object distance is cut from 16 to 8 - What must be changed to compensate
Method should be compensated for bisecting or paralleling
Decrease kVp by 15 and double exposure time = 10 mA 60 impules 75 kVp
Lighter image - patient exposed to larger beam which will increase exposure
2.75 inches

39. What is the name for the part of the target that is struck by electrons
5(n-18)
Aka general radiation; stopping or slowing of the electrons of the cathode stream as they collide with the nuclei of the target atoms
Occlucal
Focal spot

40. What type of safelight filter is acceptable
Rectangular collimations
GBX - 2
Dentin - enamel - bone
Patient movement

41. What would cause a film to be too light
Before fixing
20 seconds
After 2-3 min of fixing if needed
underexposure-underdevelopment -depleted developer solution -excessive fixation (takes all crystals off)

42. 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?
Max sinus - zygoma - max tuberosity - coranoid process
Clear/blue in the area of overlap b/c fixer will not remove all crystals
As close as possible
take 14 radiographs -omit the BW -paralleling should be technique of choice -panoramic might be better than FMS

43. Proper patient positiong for paralleling

Warning: Invalid argument supplied for foreach() in /var/www/html/basicversity.com/show_quiz.php on line 183

44. 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
Lighter image - patient exposed to larger beam which will increase exposure
Failed safelight test - suggesting that the safelight conditions in the darkroom are fogging the film
PANO
Filtration and collimation

45. What 3 types of cells are most radiosensitive
WBC - RBC - immature reproductive cells
After 2-3 min of fixing if needed
Erythema - vomitting - nausea - hemorrage - diarrhea - hair loss
Premature contact w/ developing chemicals - Drops of developer or fixer that splash onto the work area and came in contact with the film.

46. What are automatic processors faster than manual processing?
Insufficient or improper washing
take 14 radiographs -omit the BW -paralleling should be technique of choice -panoramic might be better than FMS
Patient's name - date - and other pertinent info
B/c of its stability to produce a large volume of radiographs in a short amount of time

47. when should radiographs be taken on a pregnant patient
Only when necessary to help the dentist diagnose and treat oral diseases; elective xrays should be postponed until after delivery
Erythema - vomitting - nausea - hemorrage - diarrhea - hair loss
Take FMS on all new patients; recall adults with no sig. med. history only require BW and PA - if indicated
Provides more info. about the location of tori - impacted and malpositioned teeth and the calcification of soft tissues

48. When looking at radiographs that were taken several years ago - you notice a brownish stain which makes interpretation difficult. What caused this?
Insufficient or improper washing
CCD (direct) - CMOS (direct) - PSP (indirect)
No. 4
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

49. What anatomical structures appear radiolucent on a dental radiograph
Air space and soft tissues
Eyewear - mask - and gown
No. 4
Soft cloth - non abrasive cleaner

50. Film submerged totally in fixer but not in developer
Filtration and collimation
take 14 radiographs -omit the BW -paralleling should be technique of choice -panoramic might be better than FMS
Part that was fixed but not developed would be clear
Aluminum