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

Which approach is described as having overall concern for the patient, not just the injured part?

holistic approach

During diagnostic x-ray procedures, a ____ _____ to patient care is essential.

holistic approach

Holistic care begins with ______ ______.

effective communication

Effective communication is both ____ and _____; it reduces anxiety and emotional stress, enhances professional image, and makes the exam more likely to be successful.

verbal and non-verbal

For procedures that will cause pain or discomfort, when should you inform the patient?

before the exam

What are the two types of patient movement?

voluntary and involuntary

Which type of motion is controlled by will?

voluntary

Voluntary motion can be controlled through ______ and ______.

communication and immobilization

Which type of motion cannot be controlled by the patient?

involuntary

What two things can be used to minimize involuntary patient motion?

short exposure time and high speed IR

What things should be selectively shielded from the useful beam whenever possible?

lens of eye, breasts, and reproductive organs

What isthe first step in gonadal protection?

proper collimation

Female reproductive organs receive about ___ times more exposure during a procedure involving the pelvic region than males.

3

Flat contact shields over the reproductive organs can reduce exposure by ____ in females.

50%

Flat contact shields over the reproductive organs can reduce exposure by ____ in males.

90-95%

Which type of gonadal shielding device is placed directly over the patients reproductive organs?

flat contact shields

Which type of gonadal shileding device is cup shaped and designed specifically to protect the gonads of male patients?

shaped contact shields

What type of gonadal shielding device can be used with sterile fields?

shadow shields

What is another type of gonadal shielding device that uses a piece of plastic or glass lead?

clear lead

What must be adequate to ensure a diagnostic quality image with minimal patient exposure?

technique

______ IR systems must be processed correctly to enhance image quality and promote archival quality of film.

film-screen

What program ensures standardization of film-processing techniques and processing of digital images?

quality control program

The Quality Control progam ensures production of ___ ____ ____.

quality radiographic images

What can be used as an alternate to using a grid by removing scatter?

air gap technique

The air gap technique employs an increased ____.

OID

If magnification is a concern while using the air gap technique, what can be increased to compensate?

SID

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

Repeat image

What tracks the number of repeats and reasons for the repeat?

repeat analysis program

What are defined as exams that are performed in the absence of definite medical indications?

nonessential exams

What are the four ways to specify the amount of radiation received by a patient during a procedure?

entrance skin exposure, skin dose, gonadal dose, and bone marrow dose

What is the most common way to specify the amount o f radiation received by a patient during a procedure?

entrance skin exposure

The enterance sin exposure is measured by attaching ____ to the skin surface in the middle of the clinical area of internest and exposed during the procedure?

TLDs

What represents the absorbed dose to the most superficial layers of the skin?

skin dose

What may be converted to skin dose?

ESE

What are the differences in doses received by males and females due to protection by overlying tissues?

Gonadal dose

What is used to assess the impact of gonadal dose?

Genetically significant dose

What is also called "mean marrow dose"?

bone marrow dose

Bone marrow contains a large number of ___ ___.

stem cells

Radiation dose to bone marrow may be responsible for _______ ______.

radiation-induced leukemia

Bone Marrow Dose cannot be directly measured, only ____.

estimated

Technologists can determine the possibility of pregnancy through the use of what?

LMP form

Who will determine the absorbed EqD of irradiation during an unknown pregnancy?

RSO or medical physicist

___ is a frequently emplyed modality that is considered to be a relatively high radiation exposure exam.

CT

What are the two many concerns related to CT scanning?

skin dose and dose distribution

One of the main concerns with CT scanning is ____ ____ during the scanning procedure; this is due to the tube rotating around the patient rather than being stationary.

Dose distribution

_____ of the CT beam makes it possible to avoid exposing radiosensitive organs such as the eyes.

collimation

What type of patient protection is not typically used during CT?

shielding

What type of CT combines a continuous gantry rotation with continuous table movement to form a spiral path of scan data?

Spiral/Helical CT

When the ration of table movement and x-ray beam collimation (for CT) match ______, the dose to the patient is comparable to conventional CT.

1:1

If pitch is higher (2:1), dose is ______.

reduced

If the pitch is lower, patient dose _____.

increases

Small pixel sizes, thinner slices, and reduced noise for CT all _____ patient dose.

increase

To approximate the effective radiation dose to a patient after a CT study, the values of two _____ ______ _____ or quantities need to be determinefor each scan series.

CT-specific dose markers

What is the average absorbed dose within a scan volume for CT?

CTDIvol

What is the product of CTDIvol and the irradiated scan length?

dose length product

For children in general, risk is approximately ___ times that of an adult.

3

What includes dissemination of information on pediatric CT dose reduction to various medical specialties that refer patients for CT scans?

Image gently campaign

The Image Gently Campaign delivered the message that dose can be lowered by _____ _____ kVp and mA settings for peds and removing multiphase scans from pediatric protocols.

child sizing

Children are more vulnerable to ___ ____ ___ and genetic effects of radiation dose.

late somatic effects

Protecting the pregnant or potentially pregnant patient is the position of American College of Radiology on _____ _____ __ _____ ____.

radiologic examinations of female patients

The following is the official position of who? :

"Abdominal radiologic exams that have been requested after full consideration of the clinical status of a patient, including the possiblity of pregnancy, need not be postponed or selectively scheduled."

ACR

Persons who are much more vulnerable than adults to both the late somatic and genetic effects of ionizing radiation

children

a type of gonadal shield

shadow

that which is extremely important in pediatric studies

collimation

an air gap technique can be used as an alternative to the use of this device

grid

what is needed to eliminate or at least minimize patient motion

immobilization

type of mammography unit with the ability to enhance contrast with image gray level manipulation that offers improvement for dense breast patients

digital

dosimeters that are the sensing devices most often used to measure skin dose directly

thermoluminescent

when there is a lack of control, this type of motion results

voluntary

person who should perform the calculations necessary to determine fetal exposure, if a pregnant patient is inadvertently irradiated

physicist

the entrance exposure from a CT examination may be compared with the entrance exposure received during this routine type of examination

fluoroscopic

everyone within the imaging department should always behave as this type of professional

compassionate

every imaging department should establish this type of written protocol for each of its radiologic procedures

shielding

what the radiographic image will be if a patient moves during a radiographic exposure

blurred

what type of patient shielding not typically used in CT

direct

type of shilding used to protect male and female reproductive organs during a radiographic exposure

gonadal

during a diagnostic xray procedure, this is the type of approach that is essential to patient care

holistic

type of technique charts that should be available for each xray unit to help provide a uniform selection of technical exposure factors

standardized

radiation that scatters from the CT slice being scanned into adjacent slices

interslice

type of shilding that may be used to reduce or eliminate radiation exposure to radiosensitive body organs and tissues

protective

procedures that can result in the highest patient doses of all diagnostice procedures

cinefluorographiy

patients with this potential should be shielded during xray procedures whenever the diagnostic value of the examination is not compromised

reproductive

radiation-absorbent material used to make protective shielding

lead

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

repeat

type of motion that can be compensated for by shortening exposure time with an appropriate increase in mA and by using very high speed image receptors

involuntary

type of fluoroscopy that involves manual or automatic periodic activation of the fluoroscopic tube by the fluoroscopist rather than lengthy continuous activation

pulsed

Effective communication between the radiographer and the patient depends on what

verbal and nonverbal messages are congruent, so that they are understood as intended

the imaging procedure is explained in simple terms, and instructions are given clearly and concisely

the patient is given the opportunity to ask questions, which are answered truthfully within ethical limits

interslice scatter during a CT scanning procedure results in which of the following

increase in patient dose

because no localizing light field exists and the field of view is usually moving during a fluoroscopic study

a shadow shield is not suitalbe for use

because no localizing light field exists and the field of view is usually moving during a fluoroscopic study

a shadow shield is not suitable for use

Which of the following results in an increase in the patient dose

low kVp high mAs

in fluoroscopy, the amount of radiation that a patient receives is usually estimated by measuring the radiation exposure rate

at the tabletop and multipying this by the fluro time

An optimal-quality cross-table lateral projection of the cervical spine was obtained using appropriate technical exposure factors and an 8;1 ratio grid. 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 is what

about the same

the skkin and gonads of the patient recieve a "double dose" of x-radiation

whenever a repeat radiograph occurs as a consequence of human or mechanical error

the benefits of a repeat analysis program include

increased awareness among staff and student radiographers of the need to produce optimalquality recorded images

greater care in the production of radiographic images because radiographers are aware that the images are being reviewed

Initiation and continuation of inservice education programs for imaging personnel covering problems or concerns indentified through the program

The exposure of the fetus to radiation arising from diagnostic procedures

would rarely be cause, by itself for terminating a pregnancy

when an individual of childbearing age undergoes a diagnositc xray procedure, gonadal shielding should be used to protect the reproductive organs from exposure to the useful beam

when the reproductive organs are in or within approximately 5cm of a properly collimated xray beam

unless shielding will compromise the diagnostic value of the examination

which of the following are most often used to assess skin doses

thermoluminescent dosimeters

the image gently compaign advocates lowering patient dose by what

child-sizing the kV and mA

scanning only the indicated area

removing multiphase scans from pediatric protocols

in computed tomography, which of the following factors affect patient dose

changes in noise level

pixel size

slice thickness