Patient Radiation Dose Management

Patient dose from diagnostic x-rays can be reported by all of the following except for?

Eurythmic coefficient

What dose is most often reported because it is easy to measure?

Entrance skin exposure

True or false: bone marrow is believed to be the target organ responsible for radiation-induced leukemia

True

The _______ is the gonad dose that, if received by every member of the population would product the total genetic effect on the population as the sum of the individual doses actually received

Genetically significant dose

What are 2 ways to reduce unnecessary patient dose?

Minimize repeat exams, and use proper beam restriction

True or false: an increase in added filtration will increase patient dose

False

The most likely biological response to a high dose of radiation to the fetus during the first two weeks of pregnancy is?

Spontaneous abortion

True or false: all radiography of the abdomen or pelvis should be performed 10 days prior to the onset of menstruation

False

True or false: the first trimester during pregnancy is the most radiosensitive period

True

Entrance Skin Exposure

These are reported most often because they are easy to measure and result in reasonable accurate estimates

Mean Marrow Dose

Is the average radiation dose to the entire active bone marrow

Gonadal Dose

These measurements and estimates are of importance due to the suspected potential genetic effects of ionizing radiation

GSD

• Is the genetic dose of radiation born by each member of the reproductive population

• Is the gonad dose that, if received by every member of the population, would produce the total genetic effect on the population as the sum of the individual doses actually received

Nomogram

Is the absence of patient measurements, these area a family of curves used for estimating output x-ray intensity and approximate ESE values

True or false: Grid use not only reduces patient dose but also improves the quality of your image

False

What reduces patient dose and also improves the quality of your image?

• Beam restriction/collimation

• Use of a compression band

Which reduces patient dose to the lens of the eye-posterior pole?

PA skull

Which reduces patient dose to the thyroid?

RAO/LAO oblique C-spine

Which reduces patient dose to the gonads?

PA abdomen

Which reduces patient dose to the kidneys?

AP abdomen

What is the approximate half-value layer (HVL) of x-rays in soft tissue?

4 cm

Bone marrow is the target organ believed to be responsible for the stochastic response of radiation induced ______

Leukemia

True or false: It should never be necessary to repeat a digital radiographic exam

True

What affect does increasing the kVp only have on patient dose?

Increase

What affect does increasing the kVp with an associated mAs reduction have on patient dose?

Decrease

What affect does digital imaging systems have on patient dose?

Decrease

What affect does increase in the mAs only have on patient dose?

Increase

True or false: focal spot size has absolutely no effect on patient dose

True

When increasing collimation, does it reduce the volume of tissue directly irradiated?

Yes

When increasing collimation, does it increase the amount of scatter radiation produced?

No

When increasing collimation, does it increase patient dose?

No

What is the primary function of tube filtration?

To reduce patient skin dose (ESE)

AEC eliminates the need for the radiographer to set an ________

Exposure time

Which of the following is located beneath the cassette or IR?

Phototimer

Gestation

The length of time from conception to birth

Congenital

Refers to a condition present at birth

Neonatal

Relates to the time immediately after birth, typically the 1st month of life

Teratogenic Effects

These effects include radiation exposure to developing embryo or fetus, after conception

Mutagenic Effects

These effects include radiation exposure to human gametes (sperm and/or egg), prior to conception

True or false: When gonadal shields are in use, we do no need to be concerned with beam restriction/collimation

False

True or false: According to some sources, properly placed gonadal shielding significantly reduces patient exposure, approximately 50% in females and up to 90% in males

True

True or false: Gonadal shielding should be considered for all patients, except for children and those who are potentially reproductive

False

True or false: improperly placed gonadal shielding can double a patients dose due to an unnecessary repeat exposure

True

An _______ is an unanticipated finding not related to a suspected abnormality

Incidentaloma

What are the three types of gonadal shielding?

• Flat contact

• Shadow contact

• Shaped contact (contour)

Which specific types of gonadal shielding is best for surgery or to avoid contact during the use of a sterile field?

Shadow contact

Which specific types of gonadal shielding is more efficient for exams in which the patient must obtain oblique, lateral, or erect positions?

Shaped contact (contour)

True or false: the threshold dose for fetal damage is approximately 0.1 Gyt (100 mGyt) and most routine diagnostic procedures never reach this level

True

Effects in Utero are _____ after diagnostic levels of exposure

Rare

This period of gestation is the least hazardous time, referred to as “all-of-northing”, and if no spontaneous abortion occurs, the fetus is carried to term with no ill effects

0-2 weeks gestation

At 250 mGyt (100 mGyt or higher), which type of effects in utero are typically seen during the latter portion of major organogenesis?

Neurologic anomalies/deformities/defects of CNS or mental retardation

List at least three high risk exams during pregnancy:

Pelvis, hip, femur, l-spine, custograms/urograms, upper and lower GI, CT ab. pelvis

List four methods utilized to help prevent the unnecessary radiation exposure in early pregnancy:

• 10 day rule

• elective booking

• patient questionnaire, consent form

• radiation pregnancy caution sign

Tue or false: Although the rule is somewhat antiquated, according to the 10-day rule, it would be an acceptable practice to radiograph a pregnancy patient within day 8 or 9 of her menstrual cycle?

True

In accordance with the 10-day rule, it would be acceptable to preform an exam during pregnancy on day 11 or 12?

No

True or false: we meet out legal responsibility to the pregnant patient by posting pregnancy cautionary warning signs in the waiting room areas

True

These are evidence-based guidelines to assist referring physicians in making the most appropriate imaging decisions for a specific clinical condition or indication

ACR- appropriateness criteria

Imaging modalities according to to relative radiation levels (RRLs), why do ultrasound and MRI have a RRL level of zero?

They are not sources of ionization radiation