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. Difference b/w direct and indirect exposure sensor?
bisecting - packet is as close to tooth as possible - but not parallel -parallel - packet is parallel to tooth - further away
X-rays hit phosphor screen creating florescent light that exposes the film
The mental ridge
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

2. Size film used for BW on adults
Eyewear - mask - and gown
Filament
#2
Mandibular occlusal

3. What info should be recorded on the dental radiographic mount

4. What 2 unites are used to measure biologic effect and dose equivalent
Patient positioned too far to the left
Size of crystals - thickness of emulsion - radiosensitive dyes
Sv & Rem
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

5. What causes missing apices
Insufficient vertical angulation
Filters placed in PID after tubehead production
Sv & Rem
Patient positioning

6. Mand lateral/canine anatomy
Tori
X-rays hit phosphor screen creating florescent light that exposes the film
Zygoma will be radiopaque - max. sinus will be a large area of radiolucency
Failed safelight test - suggesting that the safelight conditions in the darkroom are fogging the film

7. According to principles of shadow casting - How should the film be placed in relation to the tooth?
#1
Invisible image (remains like this until film is processed)
Parallel
CCD (direct) - CMOS (direct) - PSP (indirect)

8. When interpreting radiographs - you notice a radiopaque extension or spur off the proximal surface of #30. What do you think this is?
Film placed backwards
The mental ridge
Failed safelight test - suggesting that the safelight conditions in the darkroom are fogging the film
Dentsply rinn - XCP - XCP-DS - flow dental RAPD

9. which anatomic feature is visible on a PANO - bu not on a PA
Size of crystals - thickness of emulsion - radiosensitive dyes
Ala-tragus line is parallel to the floor
Mand. foramen
Paralleling; meets more principles of shadow casting

10. What 3 types of cells are most radioresistant
Copper stem - tungsten target - radiator
Large blank space is due to reversed image error or chemical contamination - missing apices is due to inadequate VA
Nerve - brain - muscle
1/6th of a second

11. What causes film fogging
Increased focal spot size - decrease source-object distance - & increased object-film distance
Coulombs/kilogram(C/kg) & Roentgen (R)
Old or contaminated processing solutions -exposure to chemical fumes -faulty safelight -scatter radiation
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

12. What causes conecut
Rectangular collimations
The less the patient is exposed - the less the operator is exposed
1/4 as intense
Not centered on sensor

13. What is the area of the skull that is in focus on a pano

14. What is the earliest sign of radiation exposure
Overdevelopment -temp. too high -time too long -developer concentration too high -inadequate fixation -accidental exposure to light -improper safelighting
Quantum of energy
Erythema
Filament

15. How do you determine How often to take radiographs
Cracking of the emulsion caused by excessive temp diff. b/w any darkroom solutions
Air space and soft tissues
Soft cloth - non abrasive cleaner
Evidence based selection criteria

16. What causes clear film
Every 4 weeks
No exposure - or fixer before developer
Blue light sensitive films
Ionization

17. desired thickness of lead apron
Move farther from the radiation
Remove silver
.25 mm
Overdevelopment -temp. too high -time too long -developer concentration too high -inadequate fixation -accidental exposure to light -improper safelighting

18. What is the name for the part of the target that is struck by electrons
Patient positioned too far foward in the focal trough
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
Focal spot
MRI

19. What are the short term effects of radiation exposure
Erythema - vomitting - nausea - hemorrage - diarrhea - hair loss
Cancer - cateracts - embryologic defects - genetic mutations - low birth weight
Increase the area of radiation exposure
nasal septum - ant. nasal spine - nasal fossa - median palatine suture - incisive foramen

20. What type of film are calcium tungstate screens paired with
Clear/blue in the area of overlap b/c fixer will not remove all crystals
1/4 as intense
Blue light sensitive films
Zygoma will be radiopaque - max. sinus will be a large area of radiolucency

21. What is the x-ray at the center of the primary beam called
Time b/w exposure and 1st clinically observable symptoms
Central ray
Green light sensitive film (Kodak T-Mat)
take 14 radiographs -omit the BW -paralleling should be technique of choice -panoramic might be better than FMS

22. How often should developing solutions be changed
Nerve - brain - muscle
Occlusal
Every 4 weeks
WBC - RBC - immature reproductive cells

23. How far from the work surface must the safelight be mounted
Rapidly producing cells are more sensitive to radiation
Increase the area of radiation exposure
Enamel - dentin - and bone
4 feet

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

25. What is the latent period
Gently agitating the hanger up and down a few times
Blue tinted polyester acetate
Time b/w exposure and 1st clinically observable symptoms
Chin down

26. Explain PSP
Patient's dental arches; maxilla and mandile
Every 6 mths
Mental foramen - mental ridge - mand canal
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

27. What is the primary beam
Dentsply rinn - XCP - XCP-DS - flow dental RAPD
Original - undeflected - useful beam
20 seconds
Periodically examining cassettes and intensifying screens; extra oral cassettes should be checked for warping and light leaks

28. What are the 2 units used to measure exposure to radiation
Duplicate - which will go to the insurance comp.; office keeps best copy
Coulombs/kilogram(C/kg) & Roentgen (R)
Blue light sensitive films
The mental ridge

29. What Size film is 1 1/16 x 2 1/8
The emulsion side of the film is placed against the orginal radiograph with the nonemulsion side up
Excessive vertical angulation
No. 3
Gray & Rad

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

31. when should radiographs be taken on a pregnant patient
10 min (dbl the development time)
Only when necessary to help the dentist diagnose and treat oral diseases; elective xrays should be postponed until after delivery
Part that was fixed but not developed would be clear
Blank or clear (takes all of the crystals off)

32. What type of safelight filter is acceptable
GBX - 2
Lead
Overdevelopment -temp. too high -time too long -developer concentration too high -inadequate fixation -accidental exposure to light -improper safelighting
5 mSv or .5 REM

33. What causes a HERRINGBONE effect
Increase the area of radiation exposure
2.5 mm
Film placed backwards
Panoramic cape

34. 3 film holding devices used for bisecting
D - E - F
Part that was fixed but not developed would be clear
Dentsply rinn stabe - BAI - dental SUPA
Absorb scatter radiation and prevent fogging

35. How are stabe film holders sterilized b/w uses
Sterilize film holder devices or discard disposable image receptor holding devices
Gelatin and silver halide crystals
Failed safelight test - suggesting that the safelight conditions in the darkroom are fogging the film
Filament

36. Max molar anatomy
Vertical BW
Left molar PA
Max sinus - zygoma - max tuberosity - coranoid process
Cut exposure time by 1/3

37. How long are films fixed
Patient positioned too far to the left
Faster film = lower definition and detail
Stop taking xrays and evaluate all equipment and techniques to ensure safety
10 min (dbl the development time)

38. What is added filtration
Filters placed in PID after tubehead production
Depends on the needs of the patient - established after intraoral exam
Eyewear - mask - and gown
Beam is perpendicular to the imaginary line that bisects the angle formed by the long axis and the film

39. What does alara stand for
As low as reasonably achievable
Short-term dose
Mand occlusal
Filament

40. On a mandibular molar PA - Where is the mylohoid ridge located
Highest of the 2 ridges - about the level of the cervical 3rd - behind the 2nd and 3rd molars
Take FMS on all new patients; recall adults with no sig. med. history only require BW and PA - if indicated
All of the ant. teeth will appear blurred and narrowed in width
Excessive VA w/ PID positioned too steep enough away from zero degrees

41. How does packet placement differ b/w bisecting and paralleling
Insufficient or improper washing
Mand canal - external oblique ridge - beg. of ramus
bisecting - packet is as close to tooth as possible - but not parallel -parallel - packet is parallel to tooth - further away
2.5 mm

42. when viewing a PANO - you notice that the right TMJ is magnified - bu the left TMJ is normal. What caused this error
MRI
Patient positioned too far to the left
Patient's dental arches; maxilla and mandile
Clear/blue in the area of overlap b/c fixer will not remove all crystals

43. When using D speed film - you use 50 impulses of radiation. How many impulses would you use with E speed film?
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
Top of film delineated by a straight line then dark
As low as reasonably achievable
25

44. According to principles of shadow casting - preferred source-object distance
max molars have 3 roots - mand have 2 roots
White blood cells - red blood cells - immature reproductive cells - epithelial cells - connective tissue cells - bone cells - nerve cells - brain cells - muscle cells
X-rays that have been deflected from an object and have changed paths
As far as practical

45. total filtration required of x-ray machines that operate above 70 kVp
2.5 mm
Negative
Faster film = lower definition and detail
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

46. What is the annual MPD for pregnant dental assistant
Aluminum
5 mSv or .5 REM
Lateral cephalometric
Far object-image receptor distance

47. What is the best way to reduce exposure to patient
6 ft
Patient positioned too far to the left
Rectangular collimation
Insufficient vertical angulation

48. What radiographs are used to determine if a foreign object is located facially or lingually
Occlusal
B/c of its stability to produce a large volume of radiographs in a short amount of time
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
Check the processing chemical - particularly the developer

49. What is the maximum size of the x-ray beam at the patients face
2.75 inches
Parallel
Original - undeflected - useful beam
Filters placed in PID after tubehead production

50. using a 16 inch cone focal-film distance - the diameter of the beam measured at the patient's face should be no larger than
Part that was fixed but not developed would be clear
Overdevelopment -temp. too high -time too long -developer concentration too high -inadequate fixation -accidental exposure to light -improper safelighting
2.75 inch
7 1/2 or 15 watt