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. Size film used for occlusals on adults
Take FMS on all new patients; recall adults with no sig. med. history only require BW and PA - if indicated
#4
Time b/w exposure and 1st clinically observable symptoms
Periodically examining cassettes and intensifying screens; extra oral cassettes should be checked for warping and light leaks

2. 3 film holding devices used for bisecting
Dentsply rinn stabe - BAI - dental SUPA
Mandibular occlusal
On the back side of the tori
Dentsply rinn - XCP - XCP-DS - flow dental RAPD

3. What size bulb is used in safelight
Cut exposure time by 1/3
7 1/2 or 15 watt
Excessive vertical angulation
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

4. What quality control procedures should be performed on xray cassettes
Located on the tooth surface that contacts the adjacent tooth
Movement caused by the patient - slippage of the image receptor - or vibration of the tube head
Oral piercings - earings - glasses - necklaces - facial piercings - hair pins - hearing aids - dentures - and retainers
Periodically examining cassettes and intensifying screens; extra oral cassettes should be checked for warping and light leaks

5. What Size film is used to take a BW on a 3 yr. old
Large blank space is due to reversed image error or chemical contamination - missing apices is due to inadequate VA
Copper stem - tungsten target - radiator
#0
Top of film delineated by a straight line then dark

6. What is the optimum processing temp.
Copper stem - radiator and air space
68 degrees F
Patient movement
1.5 mm

7. your film badge report sHows that you have received a small amt. of radiation. What should you do
Remove silver
#2
Stop taking xrays and evaluate all equipment and techniques to ensure safety
1/3-1/2

8. What can be done to prevent air bubbles from being trapped on the surface of films during manual processing
10 min (dbl the development time)
B/c of its stability to produce a large volume of radiographs in a short amount of time
Gently agitating the hanger up and down a few times
Beam is perpendicular to the imaginary line that bisects the angle formed by the long axis and the film

9. What causes elongation
Film placed backwards
Parallel
Insufficient vertical angulation
Absorb long wavelengths / soft radiation

10. What are three types of image receptors used in digital radiography
CCD (direct) - CMOS (direct) - PSP (indirect)
Paralleling; meets more principles of shadow casting
Chin down
Move farther from the radiation

11. What is the max. permissable fose for radiation workers in systeme interventional units
50 mSv (5rem)
Cracking of the emulsion caused by excessive temp diff. b/w any darkroom solutions
Lighter image - patient exposed to larger beam which will increase exposure
Old or contaminated processing solutions -exposure to chemical fumes -faulty safelight -scatter radiation

12. How often must you replenish the solutions in an automatic processor
Parallel
Overdevelopment -temp. too high -time too long -developer concentration too high -inadequate fixation -accidental exposure to light -improper safelighting
Air space and soft tissues
For every 30 films processed 6-8 oz should be taken out and replaced with fresh solution

13. What is the ADA approved method of mounting dental radiographs
Old or contaminated processing solutions -exposure to chemical fumes -faulty safelight -scatter radiation
Filament
Labial
Doesn't matter

14. What is characteristic radiation
As far as practical
X-ray and heat
A form of radiation originating from an atom following removal of an electron or excitation of an atom
No exposure - or fixer before developer

15. What happens in the fixer
Removes the unexposed silver halide crystals
Blank or clear (takes all of the crystals off)
bisecting - packet is as close to tooth as possible - but not parallel -parallel - packet is parallel to tooth - further away
take 14 radiographs -omit the BW -paralleling should be technique of choice -panoramic might be better than FMS

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

17. What are the 2 units used to measure exposure to radiation
Higher kVp = low exposure
Coulombs/kilogram(C/kg) & Roentgen (R)
No. 0
bisecting was used b/c of the distortion of the elongated root - the roots appeared long b/c the vertical angulation was inadequate

18. What is the annual MPD for radiation workers
Lead
50 mSv or 5 REM
PANO
Erythema - vomitting - nausea - hemorrage - diarrhea - hair loss

19. How far from the work surface must the safelight be mounted
4 feet
Higher temp. increases film fog - so radiographer should consult a time-temp. development chart to adjust developing time appropriately; developing time will decrease
Absorb long wavelengths / soft radiation
X-rays hit phosphor screen creating florescent light that exposes the film

20. What should be done prior to ordering radiographs for a patient
Panoramic cape
No exposure - or fixer before developer
Ionization
Clinical exam

21. What control factors effect contrast
KVp
Short-term dose
As far as practical
Copper stem - radiator and air space

22. What radiographs are used to locate a salivary stone in the submandibular duct
WBC - RBC - immature reproductive cells
Mandibular occlusal
5(n-18)
Highest of the 2 ridges - about the level of the cervical 3rd - behind the 2nd and 3rd molars

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

24. What film is used to diagnose interproximal decay
#4
No. 4
Blue light sensitive films
BW

25. Mand central anatomy
15 impulses
The less the patient is exposed - the less the operator is exposed
Genial tubercles - lingual foramen
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

26. What parts of the x-ray machine are included in the cathode circuit
The emulsion side of the film is placed against the orginal radiograph with the nonemulsion side up
extraoral film
Cathode - filament - focusing cup
Zygoma will be radiopaque - max. sinus will be a large area of radiolucency

27. What type of angulation is used when taking radiographs of the mand. arch
Negative
Removes the unexposed silver halide crystals
Every 4 weeks
Overexposure -overdevelopment -developer is too strong -not enough fixation -exposure to white light -improper safelighting

28. What is the purpose of the lead foil?
Absorb scatter radiation and prevent fogging
Lateral cephalometric
Lighter image - patient exposed to larger beam which will increase exposure
Method should be compensated for bisecting or paralleling

29. What exposure would be useful in identifying salivary stones in the submandibular gland
Film badges
As low as reasonably achievable
Mand occlusal
1.5 mm

30. 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
Chin down
Left side
Increase the area of radiation exposure
Lighter image - patient exposed to larger beam which will increase exposure

31. What Size film is 7/8 x 1 3/8
Invisible image (remains like this until film is processed)
Depends on the needs of the patient - established after intraoral exam
Max. sinus - zygoma
No. 0

32. What is the primary beam
After 2-3 min of fixing if needed
Cancer - cateracts - embryologic defects - genetic mutations - low birth weight
Original - undeflected - useful beam
Method should be compensated for bisecting or paralleling

33. What is inherent filtration
Produced by internal barriers in tube head (ex: glass and insulating oils)
Patient's name - date - and other pertinent info
No. 1
6 ft

34. 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
Patient movement
No exposure to x-rays - electrical failure - malfunction of x-ray machine - or processing errors
bisecting was used b/c of the distortion of the elongated root - the roots appeared long b/c the vertical angulation was inadequate

35. You take a radiograph using 10 mA 30 impulses and 90 kVp - your dentist wants a radiograph with increased contrast and equal density. What settings would you use?
No. 3
Decrease kVp by 15 and double exposure time = 10 mA 60 impules 75 kVp
8-16 inches
20 seconds

36. What is the most likely cause of a film with very poor definition
Step-wedge or test film
Patient movement
Positioning the arches too far foward
Original - undeflected - useful beam

37. in which pericapical projection will the mental ridge be visible
Filtration and collimation
Extra oral
Mandibular lateral/central
max molars have 3 roots - mand have 2 roots

38. Proper patient positiong for paralleling

39. What part of the x-ray machine is responsible for providing the electrons
Cancer - cateracts - embryologic defects - genetic mutations - low birth weight
Part that was fixed but not developed would be clear
Labial
Filament

40. What is the purpose of a pano
D - E - F
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
decrease mA & time
Blue tinted polyester acetate

41. What causes missing crowns
Excessive vertical angulation
Not as sharp and detailed as the intraoral image
KVp
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

42. when taking a radiograph - you pulls the cone out about 6 inches from the patient's face. What is the result
Increase the area of radiation exposure
1/3-1/2
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
Size of crystals - thickness of emulsion - radiosensitive dyes

43. What can be done to increase the life span of processing solutions
Reg. replenishment and changing out expired solutiong with fresh chemicals at reg. intervals; monitor strength of chemicals on a daily basis
Excessive vertical angulation
Cancer - cateracts - embryologic defects - genetic mutations - low birth weight
Absorb long wavelengths / soft radiation

44. desired thickness of lead apron
Gelatin and silver halide crystals
2.75 inch
.25 mm
Decrease kVp by 15 and double exposure time = 10 mA 60 impules 75 kVp

45. What would cause a film to be too dark
Max. sinus - zygoma
Patient's name - date - and other pertinent info
Overexposure -overdevelopment -developer is too strong -not enough fixation -exposure to white light -improper safelighting
Roentgen

46. What is the most commonly used personnel monitoring devide for dental offices
Aluminum
Reduces the exposed silver halide crystals to black metallic silver
Film badges
To distinguish b/w patient's right and left side

47. What must be done to xray fixer priod to disposal
No exposure - or fixer before developer
Nasal fossa - max sinus
Remove silver
Filters placed in PID after tubehead production

48. What causes film fogging
Duplicate - which will go to the insurance comp.; office keeps best copy
Film badges
No exposure - or fixer before developer
Old or contaminated processing solutions -exposure to chemical fumes -faulty safelight -scatter radiation

49. when taking a paralleling radiograph of a patient with palatal tori - Where is the film places
50 mSv (5rem)
Green light sensitive film (Kodak T-Mat)
On the back side of the tori
No exposure - or fixer before developer

50. 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?
Filament
Premature contact with developer
Failed safelight test - suggesting that the safelight conditions in the darkroom are fogging the film
Increase the area of radiation exposure