Radiation Protection Procedures & Policies

These flashcards cover key vocabulary and concepts related to radiation protection, procedures, and policies to aid in exam preparation.

Cardinal Principles of Radiation Protection

Time, Distance, Shielding.

Scatter Radiation

The greatest source of occupational radiation exposure to the radiographer.

NCRP Report #116

States that personnel should stand at least 2 meters from the x-ray tube and the patient.

Time

Keep the time of exposure to radiation as short as possible.

Distance

Maintain as large a distance as possible between the source of radiation and the exposed person.

Shielding

Insert shielding material between the radiation source and the exposed person.

Dose Intensity

Directly related to the duration of exposure.

Inverse Square Law

Describes the relationship between distance and x-ray beam intensity.

HVL – Half Value Layer

Thickness of absorbing material needed to reduce x-ray intensity to half its original value.

TVL – Tenth Value Layer

Thickness of material that reduces radiation intensity to one tenth of its original value.

Isoexposure Curves

Represent positions in the room of equal exposure from the radiation source.

NCRP Report #102

Requires only necessary personnel in the diagnostic x-ray room during exposure.

Lead Apron Thickness

Must be 0.5mm if x-ray machine operated above 100 kVp.

Exposure Cord Requirements

Must extend at least 6 feet from mobile machines.

Mechanical Device

1st choice for holding the plate or restraining the patient.

Preventive Positioning

The radiographer should never stand in the primary beam.

Pregnancy Monitoring

Recommends wearing a second personal exposure monitor at waist level.

Structural Barrier

Consists of materials that absorb primary radiation.

Primary Barrier Height

Must be 7 feet high or 2.1 meters.

Ceiling Barrier

Never considered a primary barrier in diagnostic radiography.

Secondary Barriers

Designed to shield areas from secondary/scatter radiation.

Lead Thickness for Secondary Barriers

Consists of 0.8mm of lead thickness and 2.1 meters tall.

Control Booth Design

Extends at least 2.1 meters upward from the floor.

Control Booth Window

Typically consists of 1.5mm lead equivalent clear lead-acrylic.

Air Kerma

Absorbed dose in air from the x-ray beam passage.

Workload (W)

Specified in mAS or mA-min per week.

Use Factor (U)

Represents the portion of beam-on time directed at primary barriers.

Occupancy Factor (O)

Determines the occupancy situation of areas around the x-ray unit.

Controlled Area Max Dose

Maximum permitted equivalent dose of 1000 µSv or 1 mSv.

Uncontrolled Area Max Dose

Maximum permitted equivalent dose of 20 µSv.

Distance Measurement (D)

Average distance from the x-ray tube to each wall or barrier.

Energy Measurement (E)

Maximum kVp the x-ray unit is capable of.

Radiation Area Sign Criteria

Must be visible where exposure rate exceeds 0.05mSv in 1 hour at 30 cm.

Scatter Radiation Characteristics

More intense backscatter than forward scatter at diagnostic levels.

Patient Restraint Protocol

Preferred to use equipment for holding patients.

Radiation Protection Policies

Guidelines ensuring safety during exposure to radiation.

Protective Shielding Material

Based on the type and thickness of the shield used.

Exposure Cord Functionality

Required for safe operation and distance from the x-ray source.

Patient Proximity Rules

Aprons and gloves are required when closer than 2 meters.

Radiation Safety Procedures

Designed to minimize exposure to personnel.

Safety Measures for Radiographers

Includes continuous review and adherence to safety protocols.

Impact of Beam Energy

Higher energy beams require different shielding thickness.

Lead Absorption Properties

High density and atomic number make lead effective for shielding.

Scatter Radiation Definition

Radiation deflected from its original path.

Room Layout Considerations

Important for safety and radiation management.

Control Booth Specifications

Designated area for personnel during x-ray procedures.

Safety Cut-off for X-ray Machines

Mechanism to prevent unnecessary exposures.

Exposure Monitoring for Technologists

Key for managing radiation dose for workers.

Barrier Overlap Requirement

Secondary barriers must overlap primary barriers by 1.27cm.