Module 11 - Facilities and Equipment Requirements

Question 1

What is the primary goal when designing an X-ray facility?

Answer 1

To minimize radiation exposure to workers, patients, and the public.

Question 2

What are the three main stages of X-ray facility design?

Answer 2

Facility plan preparation, room layout planning, and shielding requirement determination.

Question 3

What is the annual dose limit for radiation workers in controlled areas?

Answer 3

20 mSv.

Question 4

What is the annual dose limit for the public in uncontrolled areas?

Answer 4

1 mSv.

Question 5

What is the dose constraint for sensitive populations in uncontrolled areas (e.g., pediatric wards)?

Answer 5

0.3 mSv/year.

Question 6

What must radiology rooms accessed from public areas include?

Answer 6

Self-closing doors and radiation warning signs.

Question 7

What is the purpose of primary protective barriers?

Answer 7

To shield from the direct X-ray beam.

Question 8

What is the purpose of secondary protective barriers?

Answer 8

To shield from scatter and leakage radiation.

Question 9

Which factor measures how often the X-ray beam is directed at a barrier?

Answer 9

Use factor (U).

Question 10

What does the occupancy factor (T) represent?

Answer 10

The fraction of time a space is occupied during X-ray use.

Question 11

What is considered a primary barrier in a radiographic room?

Answer 11

The wall behind the upright bucky and the floor beneath the table.

Question 12

Should the X-ray tube ever be directed at the control booth?

Answer 12

No.

Question 13

What document outlines regulatory limits for X-ray shielding calculations?

Answer 13

NCRP Report 147 (or Report 49).

Question 14

What is the regulation that governs medical X-ray equipment in Canada?

Answer 14

The Radiation Emitting Devices Act.

Question 15

What must all X-ray operators and involved personnel use?

Answer 15

Protective devices and personal dosimeters.

Question 16

What must be done if a radiation worker declares pregnancy?

Answer 16

Limit fetal dose to 4 mSv for the remainder of pregnancy.

Question 17

How long must dosimetry records be kept?

Answer 17

For the lifetime of the facility.

Question 18

What does the beam-limiting device ensure?

Answer 18

Field size doesn’t exceed 5 × 5 cm at 100 cm FID.

Question 19

What does the automatic exposure control (AEC) do?

Answer 19

Regulates exposure to maintain consistent image quality.

Question 20

What must all digital display devices undergo before clinical use?

Answer 20

Daily quality checks.

Question 21

What is the purpose of PACS in a digital imaging system?

Answer 21

To store, retrieve, and manage diagnostic images efficiently.

Question 22

What does a radiation protection survey assess?

Answer 22

Whether exposure levels are within regulatory limits.

Question 23

When must a radiation protection survey be conducted?

Answer 23

Upon installation, after modifications, and periodically.

Question 24

What must be done before disposing of X-ray equipment?

Answer 24

Perform a final survey and remove radiation-producing parts.

Question 25

What is the maximum leakage radiation allowed from an X-ray tube housing at 1 meter?

Answer 25

1.0 mGy/hour.

Question 26

What are the three steps in planning a medical X-ray facility?

Answer 26

Prepare facility plans, consider room design/layout, and determine shielding requirements.

Question 27

What must a facility plan include for shielding assessment?

Answer 27

Room dimensions, equipment location, control booth, adjacent room use and occupancy, image processing areas, barrier types, materials, and door/window positions.

Question 28

What is the difference between controlled and uncontrolled areas?

Answer 28

Controlled areas are for radiation workers (limit: 20 mSv/year); uncontrolled areas are for the general public (limit: 1 mSv/year).

Question 29

What constraint dose applies in uncontrolled areas with sensitive populations?

Answer 29

0.3 mSv/year (e.g., pediatric or obstetric wards).

Question 30

What features must a diagnostic room with stationary equipment accessed by the public have?

Answer 30

A self-closing door and warning signs with the X-ray symbol and 'Unauthorized Entry Prohibited.'

Question 31

Why should the X-ray beam be directed only toward shielded areas?

Answer 31

To prevent radiation exposure to adjacent rooms or areas.

Question 32

What is the purpose of a control booth in X-ray room design?

Answer 32

To shield the operator, ensuring occupational exposure is ≤ 0.4 mSv/week.

Question 33

What makes shielding 'primary' vs 'secondary'?

Answer 33

Primary barriers intercept the direct beam; secondary barriers protect against scatter and leakage.

Question 34

What three factors are used in shielding calculations?

Answer 34

Workload (W), Occupancy factor (T), and Use factor (U).

Question 35

How is workload (W) defined in shielding design?

Answer 35

As the total mA·min per week; based on patient volume and X-ray procedures.

Question 36

What does the occupancy factor (T) represent?

Answer 36

The proportion of time an area is occupied during X-ray operations.

Question 37

What does a use factor (U) of 1 mean?

Answer 37

The X-ray beam is directed at the surface for 100% of the workload.

Question 38

Why are shielding barriers made continuous and structurally sound?

Answer 38

To prevent radiation leaks; lead shielding must be supported to avoid 'creeping.'

Question 39

What law governs X-ray equipment in Canada?

Answer 39

The Radiation Emitting Devices Act.

Question 40

What must be done before each X-ray exposure?

Answer 40

Ensure non-essential persons exit the room and the operator uses protective devices.

Question 41

Who must wear personal dosimeters?

Answer 41

Declared radiation workers and anyone likely to receive over 1 mSv/year.

Question 42

What happens if a radiation worker declares pregnancy?

Answer 42

Their dose must be limited to 4 mSv for the remainder of the pregnancy.

Question 43

Can equipment be left on and unattended?

Answer 43

No—machines energized and ready to emit radiation must not be left unattended.

Question 44

What is radiation output reproducibility?

Answer 44

Radiation output must vary less than 5% across 10 exposures under identical conditions.

Question 45

What is the limit for current-time product per exposure?

Answer 45

600 mAs for tube voltage ≥ 50 kVp.

Question 46

What does the AEC (automatic exposure control) do?

Answer 46

Regulates exposure based on patient size and composition to maintain consistent image density.

Question 47

What is the acceptable variation in AEC exposure for digital systems?

Answer 47

Ratio of highest to lowest data values ≤ 1.2 or within manufacturer specs.

Question 48

What does beam limiting equipment do?

Answer 48

Allows adjustment of field size; minimum field must be ≤ 5 cm × 5 cm at 100 cm FID.

Question 49

How close must light and X-ray fields align?

Answer 49

Within 2% of the source-to-image distance.

Question 50

What is the minimum focal spot-to-skin distance in fluoroscopy?

Answer 50

30 cm (mobile), 38 cm (stationary), 20 cm (special applications).

Question 51

What is the maximum air kerma rate in fluoroscopy?

Answer 51

150 mGy/min with AIC and high-level control active.

Question 52

What is the purpose of a last image hold?

Answer 52

Displays the last captured fluoroscopic image to avoid unnecessary re-exposure.

Question 53

How often should CR imaging plates and cassettes be cleaned?

Answer 53

Regularly, at least monthly, and inspected for damage or contamination.

Question 54

What must be done before using digital display devices?

Answer 54

Daily performance checks for distortion, luminance, and resolution.

Question 55

What is the purpose of PACS in radiology?

Answer 55

To archive, retrieve, and manage diagnostic images efficiently.

Question 56

When should radiation protection surveys be conducted?

Answer 56

At initial installation, after modifications, and periodically during use.

Question 57

Who should perform shielding calculations and surveys?

Answer 57

Qualified personnel trained in structural shielding design, like a medical physicist.

Question 58

What must be done before disposing of X-ray equipment?

Answer 58

Disable radiation-producing parts, conduct a final survey, and document the process.

Question 59

What documentation is required during X-ray equipment disposal?

Answer 59

A record of removal, transfer, or destruction, and radiation survey results.