ROENT MIDTERM

Question 1

FILM PROCESSING REFERS TO A
SERIES OF STEPS THAT PRODUCE A
VISIBLE PERMANENT IMAGE ON A
RADIOGRAPH

Answer 1

DENTAL FILM PROCESSING

Question 2

Convert latent image on the film into
a visible image

To preserve the visible image so that
it is permanent and does not
disappear from the dental
radiograph

Answer 2

Aim of processing

Question 3

FILM PROCESSING

Answer 3

• DEVELOPING
• RINSING
• FIXING
• WASHING
• DRYING

Question 4

Main action of the developer is to
chemically reduce all the silver ions
in the exposed crystals of silver
bromide ( with a latent image) to
metallic silver

Answer 4

DEVELOPER SOLUTION

Question 5

• A continuous, gentle rinsing for 30
  seconds in water is necessary after
  developing

Purpose:
- To dilute the developer and slows
down the development processing
- To remove alkali activator thus
preventing neutralization of acid
fixer

Answer 5

RINSING

Question 6

• Used in the fixing process.

Purpose:
- To dissolve and remove the
underdeveloped silver halide crystals
causes the film to be dark and non
diagnostic
- To harden and shrink film emulsion
during the process

Answer 6

FIXING SOLUTION

Question 7

• Films are dried with the help of x-ray
  dryer in a dust free area.
• While drying, films should not touch
  each other to avoid sticking of the
  film

Answer 7

Drying

Question 7

• The objective of washing is to
  remove residual processing
  chemicals and silver salts from the
  radiograph

Answer 7

Washing the film

Question 8

Automatic Processor Advantages:

Answer 8

• Time saving
• Constant film quality is achieved,
  due to fixed processing cycles
• Need for dark room is eliminated
• Less floor space is required
• Chemicals can be replenished
  automatically by machine
• Large number of films can be
  processed continuously

Question 9

FUNCTION
Reducing agent

ACTION
Increases
reduction potential of crystals and brings
out contrast

Answer 9

HYDROQUINONE

Question 10

Automatic Processor Disadvantages:

Answer 10

• Equipment is relaLvely expensive
• Strict maintenance and regular
  change is required, dirty rollers
  produce marked films
• Films may get lost in the tank

Question 10

FUNCTION
Alkaline activator

ACTION
Softens emulsion to reach crystals

Answer 10

SODIUM
CARBONATE

Question 11

FUNCTION
Reducing agent

ACTION
Bring out gray shade

Answer 11

Elon
(monomethylparaaminophenol)

Question 11

FUNCTION
restrainer

ACTION
Prevent
developer from reducing unexposed crystals

Answer 11

Potassium bromide

Question 12

FUNCTION
preservative

ACTION
Prevents rapid oxidation of chemical

Answer 12

Sodium sulfite

Question 13

FUNCTION
solvent

ACTION
Medium for dissolving chemicals

Answer 13

Water

Question 13

FUNCTION
acidifier

ACTION
Neutralizes developer

Answer 13

Acetic or sulfuric acid

Question 14

FUNCTION
Clearing Agent

ACTION
Clears unexposed silver halide

Answer 14

Ammonium thiosulfate/ Na thiosulfate

Question 15

FUNCTION
hardener

ACTION
Shrinks and hardens emulsion

Answer 15

Aluminum chloride/sulfide k alum

Question 16

• A well planned dark room makes the
  processing easier, which should be at
  least 4x5 feet (1.2x1.5m).
• The room should be well venLlated
  to supply fresh air for the comfort of
  the individual working in the area.

Answer 16

DARK ROOM

Question 17

Characteristics for darkroom:

Answer 17

a. Convenient locaLon and adequate
size
b. Ample working space with adequate
storage
c. LighLng
d. Temperature and humidity
controlled
e. Darkroom plumbing
f. Miscellaneous

Question 18

• Two types of lighting are essential in
  darkroom

Answer 18

I. Room lighting (white
illumination)

II. Safe lighting

Question 20

General safety rules in darkroom

Answer 20

• Limit access to the darkroom. Only
  approved persons with safety
  training should be allowed to work
  in the room
• Keep the work area clean
• Wet and dry areas should be clearly
  separated
• Always segregate chemicals
• Do not store chemicals on the floor
• Do not eat, drink, or smoke in the
  darkroom
• Always wash hands with soap and
  warm water after working with
  chemicals

Question 21

WAYS OF REDUCING RADIATION EXPOSURE TO THE PATIENTS

Answer 21

- ALARA CONCEPT (As Low As Reasonably Achievable) - Digital radiography 80% dose reduction

Question 21

Safety measure for operator protection

Answer 21

- Only the operator and patient are permitted in the x-ray room. - Operator will stand in a safe place: - 6 feet away not in direct beam - behind an appropriate barrier - outside the room if you cannot get 6 feet away - Never hold the film or tubehead during exposure.

Question 21

TRAID OF RADIATION SAFETY

Answer 21

- TIME - DISTANCE - SHIELDING

Question 22

The exposure time is related to radiation exposure and exposure rate ( exposure per unit time) as follows: Exposure = exposure rate x time

Answer 22

TIME

Question 23

The exposure to the individual decrease inversely as the square of distance. This is known as the inverse square law, whish is stated mathematically as: I = 1/D2

Answer 23

DISTANCE

Question 23

A person standing twice as far from the x-ray machine will be receive one forth the radiation

Answer 23

Inverse square law

Question 24

Materials such as concrete, lead will attenuate radiation (reduce its intensity) when they are placed between the source of radiation and the exposed individual.

Answer 24

Shielding

Question 25

Types of Room shielding

Answer 25

a) X-ray equipment room shielding b) Patient waiting room shielding

Question 25

Includes all the radiation passing through the tube housing, other than the useful radiation.

Answer 25

Leakage radiation

Question 26

Type of radiation to be considered for effective shielding

Answer 26

- Useful beam - Leakage radiation - Scattered radiation

Question 26

Type of shielding

Answer 26

1. Xray tube shielding (source shielding) 2. Room shielding a) X-ray equipment room shielding b) Patient waiting room shielding c) Control room shielding 3. Personal shielding 4. Patient shielding

Question 26

Which has undergone a change in direction during passage through matter.

Answer 26

Scattered radiation

Question 27

Radiation passing through the tube aperture, previously called primary beam

Answer 27

Useful beam

Question 30

- X rays produced in the tube are scattered in all directions - The x ray tube housing is lined with thin sheets of lead to protect both patients and personnel from leakage

Answer 30

X-ray tube shielding (source shielding)

Question 30

The control room of an x-ray equipment is secondary protective barrier which has two important aspects: a) The wall and viewing window of the control booth should have lead equivalents of 1.5mm. b) The location of control booth, should not be located where the primary beam falls directly, and the radiation should be scattered twice before entering the booth.

Answer 30

Shielding of x-ray control room

Question 31

They are designed to protect individuals located outside the x-ray rooms from unwanted radiation. - 2mm lead ≅25 mm layer of high quality barium plaster ≅ 150 mm of concrete ≅ 225 mm of solid bricks

Answer 31

Room Shielding (Structural Shielding)

Question 32

Should be used as and when necessary which comprise of: - Lead Aprons - Eye glasses with side shields - Hand gloves - Thyroid shields

Answer 32

Shielding Apparel

Question 33

- Personnel should remain in the radiation environment only when necessary (step behind the control booth, or leave the room when practical) - The distance between the personnel and the patient should be maximized when practical.

Answer 33

Personnel Shielding

Question 34

- Aprons are shielding apparel recommended for use by radiation workers. - These aprons protect an individual only from secondary (scattered) radiation, not the primary beam.

Answer 34

Shielding Apparel Lead

Question 35

Care of the Lead Apparel It is important that lead aprons are not abused, such as by:

Answer 35

a) Dropping them on the floor b) Piling them in a heap c) Improperly draping them over the back of a chair

Question 36

- Radiation protection of the patient involves both technical and medical decisions. - The technical decisions related to the choice of the appropriate equipment and to the technique.

Answer 36

Patients Shielding

Question 37

- Patient waiting areas are provided outside the x-ray room. - Red Light and warning place card is provided at a conspicuous place outside the x-ray room

Answer 37

Patient Waiting Area

Question 38

- Dental personnel and patients are at increased risk for acquiring tuberculosis, herpes viruses, upper respiratory infections, and hepatitis strain A through E.

Answer 38

Infection control

Question 39

Key steps in Radiographic Infection Control Apply universal precautions:

Answer 39

- Wear gloves during radiographic procedures - Disinfect and cover x-ray machine, working surfaces, chair and apron. - Sterilize non disposable instruments Use barrier – protected film sensor or disposable container - Prevent contamination of processing equipment