Radiation Protection aka Dose Reduction Mechanisms

Question 1

Goals for Oral and Maxillofacial
Radiology
(2)

Answer 1

1. Reduce radiation exposure
2. Maintain a high degree of diagnostic
   efficiency

Question 2

It’s a juggling act to:
(2)

Answer 2

●reduce a patient’s radiation exposure
●maintain a high degree of diagnostic efficiency

Question 3

Dose Reduction Mechanisms
(4)

Answer 3

X-ray Tube Head
Patient Protection
Operator Safety
Et cetera

Question 4

Guiding Principle of
Radiation Protection
Since the probability or severity of biological
damage increases as the radiation dose
increases, it is desirable to

Answer 4

avoid receiving even
the smallest dose of radiation unnecessarily.

Question 5

ALADA lowers exposure
(2)

Answer 5

to patients
of all office personnel

Question 6

Dose Reduction Mechanisms
X-ray Tube Head (Mandated)
(2)

Answer 6

1. Filtration
2. Collimation

Question 7

Filtration
(3)

Answer 7

• Selective passage of contents through a
  specified substance
• Selectively removes a greater proportion of
  low keV x-ray photons
• Increases mean energy of the beam

Question 8

Mandated Minimum Total Filtration
for X-ray Tubes
Operating kV: Aluminum Filtration (mm)
<50:
50 to 70:
>70:

Answer 8

0.5mm
1.5mm
2.5mm

Question 9

EXIT SIDE
BEAM COLLIMATION
(2)

Answer 9

• Maximum 2.75” diameter
• (Rectangular preferred)

Question 10

Dose Reduction Mechanisms
X-ray Tube Head Options
(4)

Answer 10

1. Rectangular
   collimator
2. High kV generator/
   transformer
3. Constant potential
   (DC) fully rectified
4. Increased focal length

Question 11

effective dose is reflective
of the

Answer 11

specific technique

Question 12

Increased of Long BID Benefits
(3)

Answer 12

1. 27% less head volume
2. reduced effective dose
3. sharper image

Question 13

Dose Reduction Mechanisms
Practice Options
(4)

Answer 13

1. Film speed
2. Lead (Pb) thyroid collar
3. Film-holding devices with beam alignment
   capability
4. Time-temperature quality control processing

Question 14

FILM SPEED
(4)

Answer 14

• “D” speed (Ultraspeed)
• “E” speed (Ektaspeed)
• “F” speed (Insight)
• digital receptors

Question 15

• digital receptors
  (3)

Answer 15

• Photostimulable phosphor plate (PSPP)
• Charge Coupled Device (CCD)
• Complimentary Metal Oxide Semiconductors (CMOS)

Question 16

PATIENT PROTECTION
(2)

Answer 16

• Lead apron
• Thyroid collar

Question 17

Operating Policy Regarding the Use of
Diagnostic Ionizing Radiation
(2)

Answer 17

• During an exposure taken with a wall-mounted x-
  ray unit, the operator shall stand behind a
  protective barrier.
• If a barrier is not present, the operator shall stand
  at least six feet from the patient and at an angle
  between 90° - 135° to the direction of the useful
  beam.

Question 18

NEVER
Stand in the …

Answer 18

primary beam

Question 19

POSITION AND DISTANCE
Stand at least
(2)

Answer 19

• 6 feet away and,
• 900 –1350 to the
  primary beam

Question 20

NEVER
Hold film or other receptors …

Answer 20

in a patient’s mouth

Question 21

Radiation monitoring devices are optional,
but…………….
* — will be worn by all full-time
operators of radiographic equipment while x-
ray exposures are being made.
* Annual occupational whole body exposure will
not exceed – mSv
* Operators who have declared a pregnancy will
not receive more than – mSv to the embryo
or fetus during the term of the pregnancy.

Answer 21

Dosimeter badges
50
5

Question 22

The NOMAD and NOMAD Pro are

Answer 22

self-contained, hand-held, portable
dental X-ray units.

Question 23

OMAD Use Violates current
radiology statutes
(2)

Answer 23

• “During each exposure, the operator
  shall stand at least 6 feet from the
  patient or behind a protective barrier.”
• “Neither the tube housing nor the
  position indicating device (cone, cylinder)
  shall be hand-held during exposure.”

Question 24

Exemption for licensed hand
held units
* A — (provided by the
manufacturer) must be permanently mounted to
the cone and used at all times during
radiographic exposure.
* Operators must wear a — that is evaluated monthly.
* All personnel must receive —

Answer 24

backscatter shield
personnel monitor
device
training in the safe
use of these X-ray systems, and records of the
training kept for review.

Question 25

Maximize the operator’s area of protection by doing the following:
(3)

Answer 25

• Place the backscatter shield at the end of the PID (closest to the patient).
• Align the PID close to the patient.
• Keep all body parts within the area of the shield’s protection.