Chapter 12: Management of Patient Radiation Dose During Diagnostic X-Ray Procedures Review

Which of the following can help reduce the likelihood of repeat images owing to motion and other patient-related errors?

1. Effective communication

2. Proper application of immobilization

3. Shortest possible exposure time

a. 1 only

b. 1 and 2 only

c. 2 and 3 only

d. 1, 2, and 3

d. 1, 2, and 3

Which of the following exposure factors would produce the HIGHEST patient dose, all other variables unchanged (e.g. field size, area of interest, SID, etc.)?

a. High kVp, low mAs, increased filtration

b. High kVp, low mAs, decreased filtration

c. Low kVp, high mAs, increased filtration

d. Low kVp, high mAs, decreased filtration

d. Low kVp, high mAs, decreased filtration

Filtration in the X-ray tube is intended to reduce radiation dose to the skin caused by?

a. Short wavelength x-ray photons

b. Long wavelength x-ray photons

c. Off-focus x-radiation

d. Line-focus x-ray radiation

b. Long wavelength x-ray photons

Holistic patient care begins with ______________?

a. Script

b. Effective communication

c. Quality control program

d. Referring physician

b. Effective communication

Patient exposure can be reduced by ____________? (Select 3)

a. Proper body or part immobilization

b. Use of fluoroscopy guided centering

c. Selecting high ratio grid

d. Use of gonadal shielding

e. Adequate filtration

f. Selection of low kVp and higher mAs technical factors

a. Proper body or part immobilization

d. Use of gonadal shielding

e. Adequate filtration

Involuntary motion may be caused by?

a. General anxiety

b. Mental instability

c. Fear of the exam

d. Tremors due to Parkinson's disease

d. Tremors due to Parkinson's disease

Gonadal shielding is required whenever the productive organs are within _________ of a properly collimated beam.

a. 5"

b. 5 cm

c. 1"

d. 1 cm

b. 5 cm

Dose reduction from the use of gonadal shielding for females is?

a. 90%

b. 50%

c. 5%

d. 100%

b. 50%

Dose reduction from the use of gonadal shielding for males is?

a. 90%-95%

b. 50%

c. 5%

d. 100%

a. 90%-95%

Which of the following projections will a young female receive a lower dose to her breast tissue during a chest x-ray study?

a. AP

b. AP decubitus

c. Lateral

d. PA

d. PA

Appropriate technical exposure factors are determined by considerations such as? (Select 3)

a. SID

b. Mass per unit volume of tissue

c. AEC

d. Use of specific are shielding

e. Effective atomic number of tissues involved

f. Use of lowest possible kVp for position and part

a. SID

b. Mass per unit volume of tissue

e. Effective atomic number of tissues involved

Which of the following examinations are considered to be UNNECESSARY radiologic procedures? (Select 3)

a. Chest x-ray fro pre-employment physical

b. Whole-body multi-slice spiral CT screening

c. Screening mammography

d. Colonoscopy

e. Chest x-ray on scheduled admission to the hospital

a. Chest x-ray fro pre-employment physical

b. Whole-body multi-slice spiral CT screening

e. Chest x-ray on scheduled admission to the hospital

Genetically Significant Dose (GSD) is a concept used to asses?

a. The number of humans childbearing age

b. The impact of gonadal dose

c. Bone marrow doses for various radiographic examinations

d. ESE as a consequence of fluoroscopically guided positioning

b. The impact of gonadal dose

The immobilizer chair for infants is called?

Pigg-O-Stat

What does the impact of using a grid have on patient dose?

a. No impact

b. Lower the dose

c. Slightly lower impact

d. Increases

d. Increases

Which of the following materials is commonly used in the tabletop of a radiographic examination table to make the tabletop as radiolucent as possible?

a. Carbon fiber material

b. Formica

c. Granite

d. Slate

a. Carbon fiber material

Which of the following is NOT an x-ray beam limitation device?

a. Cone

b. Collimator

c. Filter

d. Extension cylinder

c. Filter

What is the approximate estimated genetically significant dose (GSD) for the population of the United States?

a. 0.20mSv

b. 0.50mSV

c. 0.10mSv

d. 0.90mSv

a. 0.20mSv

How to compensate for involuntary motion?

- Short exposure time with an appropriate increase in mA and by using very-high-speed image receptors.

Effective communication between the radiographer and the patient does which of the following?

1. Alleviates the patient's uneasiness

2. Increases the likelihood for cooperation during the procedure

3. Makes possible successful completion of the imaging procedure

a. 1 only

b. 2 only

c. 3 only

d. 1, 2, and 3

d. 1, 2, and 3

According to the national Council of Radiation Protection and Measurements, the chance of malformations from fatal radiation exposure is significantly increased above control levels only at doses:

a. Greater than 25 cGy

b. Greater than 15 cGy

c. Less than 10 cGy

d. Less than 5 cGy

b. Greater than 15 cGy

Which of the following are most often used to asses skin doses?

a. Compensating filters

b. Filtration equivalent to 4-mm aluminum placed in the path of the x-ray beam

c. Radiographic grids

d. Thermoluminescent dosimeter

d. Thermoluminescent dosimeter

Ways to reduce patient exposure

1. Use of proper immobilization techniques

2. Beam limitation

3. Adequate filtration

What leads to blurred images?

Motion

What technical exposure factors should be use to reduce the amount of radiation received by the patient?

High kVp and lower mAs

Which of the following results in an INCREASE in the patient dose?

a. Use of the lowest possible kVp with the highest possible mAs for each examination.

b. Use of gonadal or specific area shielding.

c. Use of standardized technique charts, when automatic exposure control is not used.

d. Use of the highest practical kVp with the lowest possible mAs for each examination.

a. Use of the lowest possible kVp with the highest possible mAs for each examination.

What can be used as an alternative to the use of a grid?

Air gap technique

True or False? Children are much more vulnerable to late effects of radiation than are adults.

True

True or False? A developing embryo-fetus is especially sensitive to exposure from ionizing radiation.

True

Entrance skin exposure may be converted to patient _______________ by using well-documented multiplicative factors.

a. Gonadal dose

b. Skin dose

c. Bone marrow dose

d. Genetically significant dose

b. Skin dose

Shadow shields are made of:

a. Aluminum

b. Copper

c. Radiopaque material

d. Rubber

c. Radiopaque material

Flat contact shields are made of:

a. Aluminum strips or aluminum-impregnated materials 1mm thick.

b. Tin strips or tin-impregnated materials 2mm thick.

c. Lead strips or lead-impregnated materials 1mm thick.

d. Wood strips or wood-impregnated materials 2mm thick.

c. Lead strips or lead-impregnated materials 1mm thick.

Examples of immobilization devices

- Tape

- Straps

- Velcro

- Pigg-O-Stat

Voluntary motions

Breathing

Involuntary motions

- Heart beat

- Peristalsis

- Parkinson's dissease

- Tremors, chills

- Muscle spasms

- Pain

Shaped contact shield

Cup shaped radiopaque device that encloses the scrotum and penis to protect the male reproductive organs from exposure to ionizing radiation

Flat contact shield

flat piece of lead, like an apron

Clear shields

These are made of transparent lead-acrylic material impregnated with approximately 30% of lead by weight

Shadow shields

Suspended from above the radiographic beam-defining system, this device hangs over the area of clinical interest to cast a shadow in the primary beam over the patient's reproductive organs

Air gap technique

alternative procedure to the use of a radiographic grid for reducing scattered radiation during certain examinations.

Gonadal shielding

Devices used during diagnostic x-ray procedures to protect the reproductive organs from exposure to the useful beam when they are in or within approximately 5 cm of a properly collimated beam.

Double dose

What the patient's skin and possibly the gonads receive whenever a repeat examination occurs

Gonadal dose

Radiation exposure received by the male and female reproductive organs

effective communication

an interaction that produces a satisfying result through an exchange of information

spatial resolution

the recorded detail in the radiographic image

Quality control program

Standardization in the processing of digital images, which includes regular monitoring and maintenance of all processing and image display equipment in a facility.

Quantum noise, or mottle

A blotchy radiographic image that results when an insufficient quantity of x-ray photons reaches the image receptor

Entrance Skin Exposure (ESE)

Most frequently reported way to specify the amount of radiation received by a patient from a diagnostic imaging procedure.

Image Wisely

Campaign to promote lowering the amount of radiation used in medically necessary imaging procedures and eliminating unnecessary procedures in adult medical imaging

Genetically Significant Dose (GSD)

The equivalent dose to the reproductive organs that, if received by every human, would be expected to bring about an identical gross genetic injury to the total population, as does the sum of the actual doses received by exposed individual members of the population.

Image Gently

A campaign to change long-established practice by raising awareness about methods for lowering radiation dose during pediatric medical imaging examination

Fluoroscopically Guided Positioning (FGP)

the practice of using fluoroscopy to determine the exact location of the central ray before taking a radiographic exposure