RT 217 - Management of Patient Radiation Dose during Diagnostic X-Ray Procedures

When verbal and nonverbal messages are understood as intended, communication between the radiographer and the patient is _________

effective

good communication:

reduce anxiety and stress

enhances professional image

increase the chance of successful examination

Patient protection during a diagnostic x-ray procedure should begin with _______________

clear, concise instructions

If a patient ____________ during a radiographic exposure, the radiographic image will be blurred

moves

these can eliminate or at least minimize patient motion

immobilization

motion reduction techniques

types of patient motion:

voluntary

involuntary

what is motion controlled by will?

voluntary motion

lack of voluntary motion control may be attributed to:

patient age

breathing problems

anxiety

discomfort

excitability

fear

mental instability

To eliminate voluntary patient movement during radiography, the radiographer must?

gain the cooperation of patient or immobilize

caused by muscle groups such as those associated with the digestive organs or the heart, cannot be willfully controlled

involuntary motion

Other clinical manifestations also cause involuntary motion. These include:

chills

tremors

muscle spasms

pain

active withdrawal

these can compensate for involuntary motion:

decrease exposure time

increase mAs

The potential for radiation exposure to a patient's radiosensitive organs or tissues requires ______________ and/or ____________ to reduce or eliminate a radiation dose that would otherwise cause biologic damage

intelligent patient positioning

personal shielding

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

lens of the eye

breasts

thyroid gland

reproductive organs

___________________ are used on patients during diagnostic x-ray procedures to protect the reproductive organs from exposure to the useful beam when these organs are in or within approximately ____________ of a properly collimated beam.

gonadal shielding

5 cm

_____________________ of the radiographic beam must always be the first step in gonadal protection

adequate and precise collimation

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

female reproductive organs

three times

For __________, the use of a _____________ placed over the reproductive organs reduces exposure by approximately ___________

female patients

flat contact shield

50%

Primary beam exposure for male patients may be reduced as much as _________________ when the gonads are also covered with a contact shield

90% - 95%

When a gonadal shield is employed, it must be positioned ____________ over the patient's reproductive organs

directly

________________ on the patient can be used to guide placement of a testicular or ovarian shield.

external anatomic landmarks

for a male patient in the ______________ position, the ________________ can serve as a guide for shield placement over the testes

supine

symphysis pubis

For safeguarding the ovaries of a female patient, the shield should be located approximately _____________ to each palpable anterior superior iliac spine

2.5cm (1 inch) medial

types of gonadal shielding:

flat contact shields

shadow shields

shaped contact shields

clear lead shields

These shields can be sited directly over the patient's reproductive organs.

flat contact shields

flat contact shields are most effective when used as protective devices for patients having ___________________ or ___________ radiographs while in a recumbent position

AP or PA

Flat contact shields are made of lead strips or lead-impregnated materials _____________ thick

1mm

shadow shields are made up of?

radiopaque material

Suspended from above the radiographic beam-defining system, these shields hang above the area of clinical interest to cast a shadow in the primary beam over the patient's reproductive organs.

shadow shields

The ____________ functions as a shadow shield that is intended to shelter the breast and gonads

clear lead filter

The ________________ casts the shadow of the shield over the anatomy.

beam-defining light

__________________ containing 1 mm of lead, are contoured to enclose the male reproductive organs

shaped contact shields

Disposable or washable ___________________ function as carriers for these shields

athletic supporters or jockey-style briefs

The cup-like shape of the shield permits it to be placed comfortably over the scrotum and penis whether the patient is in a recumbent or a nonrecumbent position

shaped contact shields

clear lead shields are impregnated with approximately ___________________

30% lead by weight

an example in clear lead shields is _____________________, along with the clear lead gonad and breast shields, a lightweight, fully transparent, clear lead filter is also incorporated so as to provide uniform density throughout the spinal canal

full spinal scoliosis examination

selection of appropriate technical exposure factors:

mass per unit volume of tissue

effective atomic numbers

type of IR

SID

type and quantity of filtration

type of x-ray generator

Neglecting to use standardized technique charts necessitates estimating the technical exposure factors, which may result in:

poor quality

repeat examinations

unnecessary exposure

are all essential to producing quality diagnostic images consistently while minimizing patient radiation exposure:

adequate kvp

well-calibrated AEC

_____________ and __________________ reduces patient radiation exposure significantly while yielding satisfactory image quality

increase kvp by 15%

decrease mAs

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

air gap technique

air gap technique works by using an increased ______________

OID

If magnification is not desired, a complementary increase in _______________ may be made.

SID

To perform an air gap technique, the image receptor is placed _________________ from the patient, and the xray tube is placed approximately __________________ away from the image receptor.

10 - 15 cm (4-6 inches)

300-366 cm (10 - 12 feet)

In high-kVp radiography that employs kVp settings of __________ or above, air gap techniques are, for the most part, not as effective

90 kVp

In general, when x-rays are scattered through greater angles, such as occurs for radiographs produced at less than 90 kVp, ________________ are more useful.

air gap technique

is any image that must be performed more than once because of human or mechanical error during the production of the initial image

repeat image

The radiographer should, from the beginning of the examination:

correctly position patient

select appropriate technical factors

benefit of a repeat analysis program:

provides valuable information for process improvement

helps minimize patient exposure

improves performance

Improving the overall performance of the department includes:

increasing awareness

more careful

reasons for unacceptable images:

patient mispositioning

wrong centering of beam

patient motion

incorrect collimation

presence of external foreign bodies

postprocessing artifacts

Some traditional radiographic examinations are very often performed casually in the absence of ________________

definite medical indications

In general, the amount of radiation received by a patient from diagnostic imaging procedures may be presented in three ways:

entrance skin exposure (ESE)

bone marrow dose

gonadal dose

is used in radiation safety terminology to refer to the dose to the epidermis, the most superficial layer of the skin

skin dose

The primary function of the ______________ is to protect underlying tissues and structures

epidermis

___________________ may be converted to patient skin dose by using well-documented multiplicative factors.

entrance skin exposure

_______________ are the sensing devices most often used to determine skin dose directly.

thermoluminescent dosimeters (TLDs)

the sensing material in the TLD

lithium fluoride

___________________ is used to assess the impact of gonadal dose.

genetically significant dose

is the equivalent dose (EqD) 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

genetically significant dose

According to the ___________________, the estimated GSD for the population of the United States is approximately __________________

US public health service

0.20 mSv

_____________________ 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

Because ______________ may be responsible for inducing leukemia, the dose to this organ becomes very significant.

irradiation of bone marrow

Bone marrow dose may also be described in terms of a quantity called the ________________

mean marrow dose

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

fluoroscopically guided positioning

The _____________________ recognizes that the routine use of fluoroscopy to ensure proper positioning for radiography prior to making an exposure is an unethical practice that increases patient dose unnecessarily and should never be used in place of appropriate skills required of the competent radiologic technologist.

american society of radiologic technologists (ASRT)

The _______________ recommendation states that abdominal examinations should be performed during the ____________________ to minimize the possibility of irradiating an embryo

NCRP

first few days after the onset of menses

for possibility of pregnancy, a shield is also recommended if the ovaries and uterus are ___________________ from any edge of the field

less than 5 cm

If the physician believes it is in the best interest of a pregnant or potentially pregnant patient to undergo a radiologic examination, the examination can be accomplished by consciously selecting the _______________ that will still yield a diagnostically useful image for the examination and by ___________________ to include only the anatomic area of interest.

smallest technical factors

precisely collimating

____________: The risk of a radiation-induced leukemia in children after a substantial dose of ionizing radiation is approximately two times that of adults

1978

is frequently a problem in diagnostic pediatric radiography

patient motion

how do you solve pediatric patient motion?

use short exposure times

use immobilization techniques

_________________ reduces the radiation field size to the dimensions of the image receptor, but because many pediatric patients are significantly smaller than the image receptor, further manual adjustment of collimation is often necessary

automatic collimation system

as of _________, over _________________ RTs have taken the pledge (image gently campaign)

2015, 35,000

GOAL: To change long-established practice by raising awareness about methods for lowering radiation dose during pediatric medical imaging examinations

image gently campaign

GOAL: This campaign promotes lowering the amount of radiation used in medically necessary imaging procedures and eliminating unnecessary procedures in adult medical imaging.

image wisely campaign

as of ____________, over ____________ RTs have taken the pledge (image wisely campaign)

2015, 47000 RTs

imaging procedures should be explained in ____________________

simple terms

__________________ are available to immobilize either the whole body or the individual body part to be radiographed

restraining devices

________________ must be available for each x-ray unit to help provide a uniform selection of technical exposure factors

standardized technique charts

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

air gap technique

_________________ is the easiest quantity to obtain and the most widely used

ESE (entrance skin exposure)

Use a ________________ to protect the breasts of female patients

PA projection