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. How are indirect exposure films exposed
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
Focal spot
X-rays hit phosphor screen creating florescent light that exposes the film
Clear/blue in the area of overlap b/c fixer will not remove all crystals

2. According to principles of shadow casting - How should the central beam be directed
Premature contact with developer
Max sinus - zygoma - max tuberosity - coranoid process
Perpendicular to the tooth and film
Copper stem - radiator and air space

3. What are the long term effects of radiation exposure
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
All of the ant. teeth will appear blurred and narrowed in width
15 impulses
Cancer - cateracts - embryologic defects - genetic mutations - low birth weight

4. Explain PSP
Erythema
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
1/3-1/2
2.5 mm

5. What causes teeth to appear very short and distorted
Periapical examination - paralleling technique
Excessive VA w/ PID positioned too steep enough away from zero degrees
extraoral film
PANO

6. What is the earliest sign of radiation exposure
5(n-18)
Excessive vertical angulation
Erythema
Quantum of energy

7. 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?
#4
bisecting - packet is as close to tooth as possible - but not parallel -parallel - packet is parallel to tooth - further away
bisecting was used b/c of the distortion of the elongated root - the roots appeared long b/c the vertical angulation was inadequate
Invisible image (remains like this until film is processed)

8. What is thermionic emission
Step-wedge or test film
After 2-3 min of fixing if needed
Method should be compensated for bisecting or paralleling
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 processing - two films overlap in the developer - but not in the fixer. How would the films appear
Original - undeflected - useful beam
Ionization
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
Clear/blue in the area of overlap b/c fixer will not remove all crystals

10. How can exposure to the operator be reduced
Move farther from the radiation
10 min (dbl the development time)
Reduce size and shape of beam
Nerve - brain - muscle

11. How often must you replenish the solutions in an automatic processor
decrease mA & time
For every 30 films processed 6-8 oz should be taken out and replaced with fresh solution
#2
Filters placed in PID after tubehead production

12. How does film speed correlate with definition and detail?
15 impulses
Faster film = lower definition and detail
Dentsply rinn stabe - BAI - dental SUPA
5 min

13. What 3 types of cells are most radiosensitive
WBC - RBC - immature reproductive cells
nasal septum - ant. nasal spine - nasal fossa - median palatine suture - incisive foramen
#2
6 ft

14. When can the films be exposed to white light
After 2-3 min of fixing if needed
Every 4 weeks
Gently agitating the hanger up and down a few times
Patient positioned too far to the left

15. 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?
Quantum of energy
D - E - F
take 14 radiographs -omit the BW -paralleling should be technique of choice -panoramic might be better than FMS
Cut exposure time by 1/3

16. How does resolutiong and detial of a panoramic radiograph compare with that of PA's and BW's
Beam is perpendicular to the imaginary line that bisects the angle formed by the long axis and the film
Panoramic cape
Not as sharp and detailed as the intraoral image
Rapidly producing cells are more sensitive to radiation

17. How are stabe film holders sterilized b/w uses
1/4 as intense
CCD (direct) - CMOS (direct) - PSP (indirect)
Sterilize film holder devices or discard disposable image receptor holding devices
5(n-18)

18. What exposure would be useful in identifying salivary stones in the submandibular gland
Periodically examining cassettes and intensifying screens; extra oral cassettes should be checked for warping and light leaks
Part that was fixed but not developed would be clear
Mand occlusal
2.75 inch

19. What is the major diff. b/w particulate and electromagnetic radiation
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
Provides more info. about the location of tori - impacted and malpositioned teeth and the calcification of soft tissues
Air space and soft tissues
particulate radiation: made of protons - neutrons - electrons and alpha and beta particles; has mass -electromagnetic radiation: made of photons; no mass

20. Size film used for BW on adults
#2
Clinical exam
Filters placed in PID after tubehead production
Air space and soft tissues

21. What are automatic processors faster than manual processing?
extraoral film
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
Premature contact w/ developing chemicals - Drops of developer or fixer that splash onto the work area and came in contact with the film.

22. Max. centrals anatomy
Lead
nasal septum - ant. nasal spine - nasal fossa - median palatine suture - incisive foramen
8-16 inches
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. 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?
Filters placed in PID after tubehead production
.25 mm
Filament
Dark film is from over exposure and improper packet placement for strange looking teeth and not being able to determine What film is

24. What are occlusal radiographs used to diagnose
Old or contaminated processing solutions -exposure to chemical fumes -faulty safelight -scatter radiation
Cathode - filament - focusing cup
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
KVp

25. What would cause the radiographic image to be blurred
Gently agitating the hanger up and down a few times
Film badges
Movement caused by the patient - slippage of the image receptor - or vibration of the tube head
Cosmic - naturally occuring radiation from earth - radiation for radioactive materials

26. How does radiation effect cells
Focal spot
Do not suggest gagging - emphasize - use power of suggestions - apply distractiong techniques - give patient breathing instructions - reduce tactile stimuli - being exposures in the ant. region - place image receptor firmly and expertly - confuse the
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

27. What are three types of image receptors used in digital radiography
Take FMS on all new patients; recall adults with no sig. med. history only require BW and PA - if indicated
CCD (direct) - CMOS (direct) - PSP (indirect)
#0
Perpendicular to the film - parallel to the bite portion of the stabe

28. which radiographic technique records the most accurate image of crowns - roots - and supporting structures in a selected area?
2.75 inch
Short
Periapical examination - paralleling technique
As far as practical

29. What is the annual MPD for pregnant dental assistant
5 mSv or .5 REM
4 feet
Patient's name - date - and other pertinent info
Method should be compensated for bisecting or paralleling

30. How can you differentiate the zygoma from the max sinus in a max posterior PA
Roentgen
Aluminum
Erythema - vomitting - nausea - hemorrage - diarrhea - hair loss
Zygoma will be radiopaque - max. sinus will be a large area of radiolucency

31. What looking at manually processed films - you notice small black spots on the films. What caused those spots?
Tori
Premature contact w/ developing chemicals - Drops of developer or fixer that splash onto the work area and came in contact with the film.
Film badges
All of the ant. teeth will appear blurred and narrowed in width

32. What can be done to minimize gagging when taking radiographs
underexposure-underdevelopment -depleted developer solution -excessive fixation (takes all crystals off)
Chronic low-level exposures/long term dose; causing cancer - cataracts - low birth weight - genetic mutations - and embryological defects
Do not suggest gagging - emphasize - use power of suggestions - apply distractiong techniques - give patient breathing instructions - reduce tactile stimuli - being exposures in the ant. region - place image receptor firmly and expertly - confuse the
Extra oral

33. What Size film is used to take a BW on a 3 yr. old
#3
particulate radiation: made of protons - neutrons - electrons and alpha and beta particles; has mass -electromagnetic radiation: made of photons; no mass
#0
Lighter image - patient exposed to larger beam which will increase exposure

34. What is small doses of radiation given over a long period of time
Long-term dose
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
Absorb scatter radiation and prevent fogging
Original packaging -area sheilded from radiation -50-70 degrees F

35. when viewing a PANO - you notice that a lot of spine sHows on both side of the film - What caused this
Short-term dose
Lead
Positioning the arches too far foward
Filament

36. 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?
As low as reasonably achievable
15 impulses
Perpendicular to the tooth and film
Failed safelight test - suggesting that the safelight conditions in the darkroom are fogging the film

37. Size film used for anterior PA's for patients with narrow arches
For every 30 films processed 6-8 oz should be taken out and replaced with fresh solution
Clinical exam
#1
10 min (dbl the development time)

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?
No exposure to x-rays - electrical failure - malfunction of x-ray machine - or processing errors
Periapical examination - paralleling technique
Increase the exposure time
Genetic cells

39. What is the optimum processing temp.
1/6th of a second
X-rays that have gone thru an object and are now a newer weaker beam
68 degrees F
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

40. What is the major use of topographical occlusal radiographs
Excessive vertical angulation
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
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
1/6th of a second

41. What is reticulation
Cracking of the emulsion caused by excessive temp diff. b/w any darkroom solutions
Excessive VA w/ PID positioned too steep enough away from zero degrees
Increase the area of radiation exposure
Ionization

42. What is scatter radiation
1/5 exposure time for edentulous
#2
Chin down
X-rays that have been deflected from an object and have changed paths

43. What does alara stand for
Original - undeflected - useful beam
Overexposure -overdevelopment -developer is too strong -not enough fixation -exposure to white light -improper safelighting
As low as reasonably achievable
No exposure to x-rays - electrical failure - malfunction of x-ray machine - or processing errors

44. In which area of the tooth is interproximal caries often seen
Remove silver
Located on the tooth surface that contacts the adjacent tooth
Paralleling; meets more principles of shadow casting
Patient positioned too far foward in the focal trough

45. How long are films fixed
10 min (dbl the development time)
1/5 exposure time for edentulous
Mental foramen - mental ridge - mand canal
Mandibular occlusal

46. if the kVp is increased from 75-90 - What must be done to achieve a radiograph of comparible density
decrease mA & time
Parallel
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
Cosmic - naturally occuring radiation from earth - radiation for radioactive materials

47. What can be done to prevent air bubbles from being trapped on the surface of films during manual processing
Paralleling; meets more principles of shadow casting
Gently agitating the hanger up and down a few times
Periapical examination - paralleling technique
Periodically examining cassettes and intensifying screens; extra oral cassettes should be checked for warping and light leaks

48. What type PID significantly reduces exposure to the patient
4 feet
Patient positioning
Rectangular collimations
Insufficient vertical angulation

49. What would cause a film to be too light
Highest of the 2 ridges - about the level of the cervical 3rd - behind the 2nd and 3rd molars
Short-term dose
Shadow around the tooth
underexposure-underdevelopment -depleted developer solution -excessive fixation (takes all crystals off)

50. What controls the speed with which the electrons travel from the cathode to the anode
Labial
KVp
No. 3
Filament