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

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

Quality Control (QC)

Obtained from ionization chamber measurements with the chamber situated just beneath a patient phantom slightly offset from the tabletop as part of routine medical physicist equipment surveys

Entrance exposure rate

The sensing devices most often used to determine skin dose directly are:

thermoluminescent dosimeters (TLDs)

What is something that a radiographer should ask a female patient of childbearing age about before the patient undergoes an x-ray examination?

the possibility of pregnancy

The group formed by the American Association of Physicists in Medicine (AAPM) whose purpose is for all stakeholders to educate the profession regarding the AAPM gonadal shielding positioning statement

CARES Committee

The campaign that promotes lowering the amount of radiation used in medically necessary imaging procedures and eliminating unnecessary procedures in adult medical imaging

Image Wisely campaign.

The recorded detail in the radiographic image is called:

spatial resolution.

An interaction that produces a satisfying result through an exchange of information is called:

effective communication

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

Image Gently campaign.

Patient care that considers the treatment of the whole person rather than just the area of interest

holistic patient care

Alternative procedure to the use in place of a radiographic grid for reducing scattered radiation during specific examinations using an increase in OID

air gap technique

Individual responsible for ordering a radiologic examination

referring physician

Nonverbal messages, that if understood as intended will promote effective communication between the radiographer and the patient

body language

Organization that issued a position statement in April 2019 indicating that patient gonadal shielding and fetal shielding during diagnostic imaging procedures should be discontinued as routine practice

American Association of Physicists in Medicine (AAPM)

Test to determine the degree of bone loss by measuring bone mineral density

Dual-energy X-ray absorptiometry (DEXA)

May be converted to patient dose by using well-documented multiplication factors

Entrance Skin Exposure (ESE)

A nonurgent x-ray procedures that can be booked at an appropriate time to meet patient needs and safety is called an:

elective x-ray exam

Radiation exposure received by the male and female reproductive organs is called:

gonadal dose

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

Fluoroscopy Guided Positioning (FGP)

A blotchy radiographic image that results when an insufficient quantum of x-ray photons reaches the image receptor is called:

quantum mottle

The equivalent dose to the reproductive organs that, if received by every human in a large population group, 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 is called:

Genetically Significant Dose(GSD)

Radiographic examinations performed in the absence of definite medical indications is called:

a nonessential radiologic exam

This is of great importance because it contains large numbers of stem, or precursor, blood cells that could be either depleted or, worse, even eliminated by substantial exposure to ionizing radiation

bone marrow

Can be used to protect the reproductive organs when they are not to be included in the area of interest

contact shield

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

1. Encourages reduction in anxiety and emotional stress

2. Enhances the professional image of the radiographer as a person who cares about the patient’s well-being

3. Increases the chance for successful completion of the examination

All 3

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

15cGy

When a lead shield is placed incorrectly within the collimated x-ray beam and automatic exposure control is used the lead shield may:

obscure anatomic information or interfere with the automatic exposure control system

The use of which of the following results in an increase in the patient dose?

a) The lowest possible kVp with the highest possible mAs for each examination

b) Removal of a grid

c) Standardized technique charts, when AEC is not used

d) The highest practicable kVp with the lowest possible mAs for each examination

a) The lowest possible kVp with the highest possible mAs for each examination.

Using appropriate technical exposure factors and an 8:1 ratio grid, an optimal quality cross-table lateral projection of the cervical spine was obtained. If another radiograph is obtained, using an air gap technique and technical exposure factors that are comparable to those used with the 8:1 ratio grid, the patient dose will be:

About the same

The skin and gonads of the patient receive a “double dose” of x-radiation whenever a _________ is necessary, as a consequence of human or mechanical error

repeat radiograph

Analysis of an imaging department’s repeat rate:

1. Provides valuable information for process improvement

2. Helps minimize patient exposure

3. Improve the overall performance of the department

All 3

Exposure of the fetus to radiation arising from diagnostic procedures:

a) Is not of concern because radiation from diagnostic procedures cannot cause any harm to an unborn fetus

b) Will result in the immediate need for the patient to have a therapeutic abortion because of fetal demise as a consequence of a diagnostic radiation exposure

c) Would definitely be a cause in all instances, by itself, for terminating a pregnancy

d) Would rarely be cause, by itself, for terminating a pregnancy

d) Would rarely be cause, by itself, for terminating a pregnancy

Inability of a patient to exercise control of voluntary motion may result as a consequence of:

1. Breathing problems or irregularities

2. Physical discomfort

3. Muscle spasms

1 and 2 only

What device is used to assess skin doses?

Thermoluminescent dosimeter (TLD)

Areas of the body that should be shielded from the useful beam whenever possible are the:

1. Lens of the eye

2. Breasts

3. Thyroid gland

All 3

Some clinical manifestations that can cause involuntary motion during a radiographic procedure include:

1. Chills

2. Tremors

3. Muscle spasms

4. Pain

All 4

If in the course of performing a specific radiographic procedure 75% of the active bone marrow were in the useful beam and received an average absorbed dose of 0.4 mGyt, the mean marrow dose would be how much?

0.3 mGyt

Which of the following are technical exposure factor considerations?

1. Patient mispositioning and incorrect collimation of the radiographic beam

2. Type of image receptor and source-to-image receptor distance used

3. Type of x-ray generator used and type and quantity of filtration employed

2 and 3 only

Before the start of a diagnostic radiographic procedure, the radiographer should thoroughly explain the procedure to the patient in simple terms that the patient can understand. If a patient has questions, how should the radiographer respond?

The radiographer must listen attentively to these questions and answer them truthfully in an appropriate tone of voice and in accordance with ethical guidelines.

To ensure a useful diagnostic image with minimal patient dose, scientifically correct technical exposure factors are chosen for each examination to ensure:

1. A high-quality image that has sufficient brightness to display anatomic structures

2. An appropriate level of subject contrast to differentiate amount anatomic structures

3. The maximum amount of spatial resolution and a minimum amount of distortion

All 3

If a radiographic procedure will cause pain, discomfort, or any strange sensations, the patient:

Must be fully informed before the procedure begins, but the radiographer should try not to overemphasize this aspect of the examination

If a flat contact shield is used during a typical fluoroscopic examination, to protect the patient’s reproductive organs when they are not included in the area of interest, the shield must be placed:

on top of the patient to cover the reproductive organs

When AEC is not used, neglecting to use standardized technique charts necessitates estimating the technical exposure factors, which may result in:

1. Poor-quality images

2. Repeat examinations

3. Additional and unnecessary exposure for the patient

All 3

ESE may be converted to patient ____________ by using well-documented multiplicative factors.

skin dose

Unwanted densities in the image that are not part of the patient’s anatomy and may negatively affect the ability of a radiologist to interpret the image correctly are called:

artifacts.

Studies of groups such as the atomic bomb survivors of Hiroshima have shown that damage to the newborn is unlikely for doses below:

0.2Gy

f a pregnant patient is inadvertently irradiated, which medical professional should determine fetal dose?

Medical physicist or radiation safety officer

Which of the following radiographic procedures are considered unnecessary?

1. Chest x-ray examination as part of a preemployment physical

2. Chest x-ray examination for mass screening for tuberculosis

3. Whole-body multislice spiral CT screening

All 3

True or False Patient exposure can be substantially reduced by using proper body or part immobilization and motion reduction techniques.

True

True or False Patients do not need to be given the opportunity to ask questions about their examination when they are having a routine x-ray examination.

False, patients should be encouraged to ask questions regarding their examination to ensure they understand the procedure and alleviate any concerns.

True or False In digital imaging, overexposure or underexposue can not be adjusted by computer to appear technically acceptable.

False, digital imaging allows for adjustment of exposure levels post-acquisition to achieve a technically acceptable image. (Automatic Rescaling)

True or False The AAPM statement indicating that patient gonadal shielding and fetal shielding during diagnostic imaging procedures should be discontinued as routine practice is based on research indicating that patient shielding may jeopardize the benefits of the radiologic examination.

True

True or False An air gap technique removes scatter radiation by using a decreased object-to-image receptor distance.

False; by using an increase in OID

True or False With CR or DR, it is necessary to develop a policy whereby the digital files that correspond to retaken images can be recovered for analysis since this would not happen automatically.

True

True or False During a diagnostic radiographic examination, the lens of the eye, breasts, and thyroid gland need not be selectively shielded from the primary beam.

False ; they should be shielded to minimize radiation exposure.

True or False Digital imaging significantly changed the cause of repeat images, shifting from positioning errors to exposure-related errors.

False; Digital imaging significantly changed the cause of repeat images from exposure-related to positioning errors

True or False Women older than 50 years are primarily affected by bone density loss, often resulting in pathologic fractures.

True

True or False No diagnostic procedures using ionizing radiation should be conducted unless its benefits outweighs its risk.

True

True or False Use of a lower kVp and a higher product of milliamperage and exposure time in seconds (mAs) reduces the patient dose.

False; a higher kVp and lower mAs combination reduces patient dose

True or False Skin dose is used in radiation safety terminology to refer to the dose to the epidermis, the most superficial layer of the skin.

True

True or False In digital imaging, the amount of exposure (related to the mAs setting) reaching the digital image directly affects the amount of brightness produced.

False; In digital imaging window leveling controls the brightness on the image

True or False The ESE dose levels set in regulations can be exceeded.

False; ESE dose levels should not be exceeded to ensure patient safety.

True or False The DEXA scan is an invasive x-ray procedure that can quantitively predict the risk of bone fracture(s).

False; DEXA scans are non-invasive and primarily used to measure bone density.

True or False Precise collimation is especially significant in pediatric studies because of the increased possibility of early tissue effects occurring in these young patients as compared to in older patients.

True

True or False Problems that occur in digital imaging (either CR or DR) tend to be systematic, which can affect the quality of every image and the degree of radiation exposure of every patient until the problems are identified and corrected.

True

True or False Words and actions of medical imaging personnel must demonstrate understanding and respect for human dignity and individuality.

True

True or False Inadequate or misinterpreted instructions may prevent the patient from being able to cooperate as needed.

True

True or False During a routine diagnostic examination, body or body part immobilization is of no value and therefore unnecessary.

False; proper immobilization is often essential to obtain clear images and minimize repeat exposures.

True or False Each encounter with a patient during a diagnostic x-ray procedure should begin with clear and concise instructions.

True

True or False Motion caused by muscle groups such as the digestive organs, or the heart is classified as voluntary motion.

False; this type of motion is classified as involuntary motion, as it is not under the patient's conscious control.

True or False As long as the part is adequately penetrated, decreasing kVp by 15% with a corresponding increase in mAs reduces patient exposure significantly while yielding satisfactory image quality.

False; while reducing kVp can lower patient exposure, it also requires a compensatory increase in mAs to maintain image quality, which may not always lead to reduced overall exposure.

True or False Because much evidence suggests that the developing embryo-fetus is very radiation sensitive, special care is taken in radiography to prevent unnecessary exposure of the abdominal area of pregnant women.

True

True or False GSD is the EqD to the reproductive organs that, if received by every human in as large population group, would be expected to bring about an identical gross genetic injury to that total population, as does the sum of the actual doses received by exposed individual members of the population.

True

Radiographers must limit the patient’s exposure to ionizing radiation by employing appropriate radiation ________ techniques and by using _________ devices and techniques that _________ radiation exposure.

reduction; protect; minimize

Holistic patient care must begin with _________ communication between the radiographer and the patient.

effective

When patients understand the procedure and their responsibilities, they can more fully __________.

cooperate

Repeat radiographic exposures sometimes can be attributed to _________ communication between the radiographer and the patient.

poor

____________ must be adjusted for patients’ specific conditions and history.

exposure techniques

As a consequence of their anatomic location, the __________ reproductive organs receive about three times more exposure during a given radiographic procedure involving the pelvic region than do the __________ reproductive organs.

female; male

The __________ of the epidermis varies from one anatomic location to another.

thickness

The American Society of Radiologic Technologists does not condone ____________________.

fluoroscopically guided positioning

For a DEXA scan two different ______________ x-ray beams are utilized.

low energy level

Use a PA projection to protect the ___________ of female patients

breasts

An _________ technique can be used as an alternative to the use of a mid-ratio grid (8:1).

air gap

When digital images are acquired, correct _____________ is essential to produce a high-quality diagnostic image.

post-processing

The radiographer is responsible for consulting an available _____________ technique chart before making each radiographic exposure to ensure an acceptable diagnostic image is acquired using exposure factors that yield minimal patient dose.

standardized

Adequate collimation of the radiographic beam to include only the area of __________ is essential.

interest

. According to the U.S. Public Health Service, the estimated GSD for the population of the United States is about ______ mSv

0.2

In general, ________ doses of ionizing radiation are sufficient to obtain useful images in pediatric imaging procedures than are necessary for adult imaging procedures.

smaller

Precise _____________ is especially significant in pediatric studies because of the increased possibility of late tissue effects occurring in these young patients as compared to in older patients.

collimation

Selection of appropriate technical exposure factors for each x-ray examination is essential to ensure a diagnostic image with _____________ patient dose.

minimal

Blind positioning, or positioning using the radiographer’s skills and the anatomic _____________ on the patient, without a repeat exposure, provides the patient with the lowest radiation dose.

landmarks

Occasionally it is permissible to obtain an _____________ image, when recommended by the radiologist for the purpose of obtaining additional diagnostic information.

additional

The concept of GSD implies that the genetic consequences of substantial absorbed doses of gonadal radiation received by a smaller number of individuals becomes significantly ________ when averaged over an entire population rather than applied to just a few of its members.

less

Bone marrow dose may also be described in terms of the _____________ dose.

mean marrow

In humans, radiation dose to bone marrow is of great importance because it may be responsible for inducing ___________.

leukemia

Diagnostic imaging procedures using ionizing radiation should not be conducted unless their _____________ outweighs their _____________.

benefits; risks

Whenever a female patient of childbearing age is to undergo an x-ray examination, it is essential that the radiographer carefully question the patient about the possibility of _____________. Part of this questioning involves asking the patient for the date of her last _____________ _____________.

pregnancy; menstrual period