radiation protection ch. 12

holistic patient care must begin with effective communication between

the radiographer and the patient

what is defined as an interaction that produces a satisfying result through an exchange of communication

effective communication

effective communication can be accomplished through what

verbal messages, body language, clear and concise instructions

a benefit of effective communication: it alleviates the patient's

uneasiness

effective communication will increase the likelihood for ___________ and successful completion of the imaging procedure

cooperation

ways a radiographer can limit the patient's exposure to ionizing radiation

-appropriate radiation reduction techniques

-using protective devices

-use of proper immobilization

-motion reduction techniques

-beam limitation devices

-filtration of x ray beam

-use of gonadal shielding

-selection of suitable technical exposure factors

-elimination of repeat exposures

-use of appropriate digital image processing

when verbal or nonverbal messages are understood as intended, what is effective between the radiographer and the patient

communication

good communication encourages a reduction in

anxiety and emotional stress

good communication enhances enhances the professional image of the radiographer, as a person who cares about

the patient's well being

it is important to give effective communication for procedures that will cause

pain or discomfort

if the procedure might cause pain, discomfort, or any strange sensation, when must the radiographer inform the patient of this?

before the procedure begins

why should the radiographer try not to overemphasize the pain or discomfort of a procedure?

to prevent the patient from imagining more pain or discomfort than the procedure will cause

what can some repeat exposures result from

poor communication

what might prevent the patient from being able to cooperate

inadequate or misinterpreted instructions (if something happens unexpectedly, the patient may move at an inappropriate time)

what will happen if a patient moves during a radiographic exposure

the image will be blurred

why is a repeat image necessary for images with motion blur

they have little to no diagnostic value

what can minimize or eliminate patient motion

body or body part immobilization and the use of motion reduction techniques

what does a repeat image result in

additional radiation exposure

two types of patient motion:

-voluntary (pt. can control)

-involuntary (pt. cannot control)

inability to exercise voluntary motion may be attributed to:

-patient's age

-breathing problems

-increased anxiety

-physical discomfort

-fear of examination

-fear of prognosis

-mental instability

what must the radiographer do to eliminate voluntary motion during the exam

-gain the patient's cooperation

-immobilize the individual during exam

some involuntary motions that cannot be controlled include:

-chills

-tremors (Parkinson's disease)

-muscle spasms

-pain

-active withdrawal

what can the radiographer do to compensate for involuntary motion

decrease exposure time (while increasing mA)

types of immobilization devices used for babies

swaddle, pigg-o-stat

the potential for radiation exposure to radiosensitive body organs or tissues of a patient require the use of what

intelligent patient positioning and/or personal shielding

which areas of the body should be shielded whenever possible

-lens of eye

-breasts

-reproductive organs

-thyroid gland

does a pa or an ap projection reduce patient dose to breasts

pa projection

what kind of shielding should be discontinued during diagnostic imaging procedures as routine practice

gonadal shielding

what is the first step in gonadal protection

proper collimation

what committee was created to educate the profession regarding the AAPM gonadal shielding position

CARES committee

appropriate selection of what is essential to ensure a diagnostic image with minimal patient dose

technical exposure factors

a high quality image has a good balance of

-sufficient brightness

-an appropriate level of subject contrast

-max. amount of spatial resolution

-min. amount of distortion

each x ray unit should have a standardized technique chart to ensure uniform selection of technical factors when what is not used

AEC

the radiographer is responsible for consulting the technique chart before making each radiographic exposure to ensure

a diagnostic image with minimal patient dose

when selecting technical factors, what must be considered

a patient's specific condition and history

what exposure factors reduce patient dose

high kVp, low mAs

what is essential to produce high quality diagnostic images

postprocessing

unwanted areas of brightness in the image that are not a part of the patient's anatomy

artifact

failure to eliminate these artifacts can result in

repeat exam, which increases patient dose

this includes regular monitoring and maintenance of processing and imaging display equipment

quality control program

quality control programs can prevent errors by

mandated full acceptance of new equipment, regular calibration and performance evaluation of existing equipment, and proactive and consistent image review

what is an alternative procedure to use in place of a radiographic grid for reducing scattered radiation

air gap technique

air gap technique is achieved by

increasing OID

repeats resulting from what must be eliminated

carelessness or poor judgement on the radiographer's part

is a repeat image permissible if the radiologist requests more diagnostic information?

yes

a repeat image can cause a double dose to

patient's skin and possibly the gonads

repeats have increased by how much

5% and up as high as 17%

digital imaging changed the cause of repeated images from exposure technique errors to

positioning errors

what has the unexpected increase in repeat rates been attributed to

the ease of repeating an image

is repeating an exposure to improve an acceptable image necessary?

no

what will determine the number of repeats and the reasons for producing unacceptable radiographic images, existing problems and conditions in an imaging department

repeat analysis program

reasons for unacceptable images

-patient mispositioning

-incorrect centering of beam

-patient motion during exposure

-incorrect collimation

-presence of external foreign bodies

-postprocessing artifacts

the responsibility for ordering a radiologic exam lies with

the referring physician

the physician must determine what concerning the risk of absorbed radiation from the procedure

benefit vs. risk

what is an exam performed in the absence of definite medical indications

nonessential radiologic examinations

if there is no useful information gained by the exam, is it beneficial for the patient?

no

three ways that the amount of radiation received by a patient from diagnostic imaging procedures may be presented

-entrance skin exposure (ESE)

-bone marrow dose

-gonadal dose

what is dose to the epidermis

entrance skin dose

-may be converted to patient skin dose

what are used most often to measure ESE

thermoluminescent dosimeters (TLDs)

what is the sensing material in TLDs and what does it do?

-lithium fluoride

-it responds similarly to human tissue when exposed to ionizing radiation

what is dose to the reproductive organs

gonadal dose

what is used to assess the impact of gonadal dose

genetically significant dose (GSD)

this is equivalent to 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

genetically significant dose

what is the estimated GSD for the U.S. population

.20 mSv

the average radiation dose to the entire active bone marrow

bone marrow dose

bone marrow dose cannot be measured accurately by a direct method, it can only be

estimated

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

fluoroscopic guided positioning (FGP)

does the ASRT condone FGP?

no

what provides the patient with the lowest dose

blind positioning; positioning using the radiographer's skill and the anatomic landmarks of the pt. without a repeat exposure

using FGP is considered

unacceptable and unethical

who holds this position for female patients"abdominal radiologic examinations that have been requested after full consideration of the clinical status of a patient, including the possibility of pregnancy, need not be postponed or selectively scheduled"

american college of radiology (ACR)

what should the radiographer ask a patient of childbearing age

-possibility of pregnancy

-date of last menstrual period

if there is a possibility of pregnancy, the physician may order a pregnancy test and obtain results before

the pelvis is irratiated

if you irradiate during an unknown pregnancy, what is the first step you should take

list the specifics of the x ray examination in as much detail as possible

info. needed to develop the request for pt. radiation dose form:

-x ray unit used

-projections taken

-number of images taken

-technical factors

-SID

-pt.'s AP or lateral dimensions

-for fluoro, kVp, mAs, and duration

NCRP states that the risk with regard to termination of pregnancy is considered to be negligible at a fetal absorbed dose of

5 cGy or less

NCRP states that the chance of malformation is significantly increased above control levels only at doses beyond

15 cGy

to determine the absorbed EqD to the patient's embryo fetus, you should collect necessary details on a summary form for

RSO or medical physicist

if the physician feels it is in the best interest of a pregnant or potentially pregnant patient to undergo a radiologic exam, the exam should be perfomed

without delay

you should make a special effort to minimize the dose of radiation to

her lower abdomen and pelvic region

minimizing the dose to a pregnant patient's abdomen or pelvic region can be accomplished by

-select exposure factors that will produce smallest exposure needed for a diagnostically useful image

-collimate the beam to area of interest

what effects are children more vulnerable to

late somatic effects and genetic effects of radiation

do children require smaller radiation dose than adults?

yes

what can you do to reduce patient motion?

-use very short exposure time (select higher mA)

-use effective immobilization

specially designed rooms for pediatric exams contain

entertainment devices and distraction devices

decreasing field size by collimation has what effect on the pt. and the image

-reduces pt. dose

-enhances the quality of the image by decreasing scatter

what is an initiative of the Alliance for Radiation Safety in Pediatric Imaging

Image Gently Campaign and Image Wisely Campaign

what is the Image Gently Campaign's goal

raise awareness about methods for lowering radiation dose during pediatric medical imaging

what is the objective of the Image Wisely Campaign

lowering the amount of radiation used in medically necessary procedures

what is a non invasive x ray procedure that can quantitatively predict the risk of bone fractures

dual energy x ray absorptiometry (DEXA)

a DEXA scan results in

less radiation exposure for the patient