homework review 3

Question 1

Working in conjunction with their partners in other agencies, the FDA intends to take action to
1. promote safe use of medical imaging devices.
2. support informed clinical decision.
3. increase patient awareness.

Answer 1

all of the options

Question 2

Which of the following statements is true?

a. Medical imaging personnel absolutely never receive equivalent doses that are close to the annual occupational effective dose limit.
b. Medical imaging personnel almost always receive equivalent doses that are close to the annual occupational effective dose limit.
c. Medical imaging personnel hardly ever receive equivalent doses that are close to the annual occupational effective dose limit.
d. Medical imaging personnel always receive equivalent doses that are close to the annual occupational effective dose limit.

Answer 2

Medical imaging personnel hardly ever receive equivalent doses that are close to the annual occupational effective dose limit.

Question 3

A radiation safety officer in a health care facility must have sufficient authority, organizational freedom, and management prerogative to

1. identify radiation safety problems.
2. initiate, recommend, or provide corrective action.
3. stop unsafe operations involving by-product material.
4. verify implementation of corrective actions.

Answer 3

all of the options

Question 4

Determine the cumulative effective dose (CumEfD) limit to the whole body of an occupationally exposed person who is 46 years old.

Answer 4

460 mSv

Question 5

Effective dose (EfD) limits may be specified for

whole-body exposure
partial-body exposure
exposure of individual organs
all of the options

Answer 5

all of the above

Question 6

The primary function of the Nuclear Regulatory Commission (NRC) is to

Answer 6

oversee the nuclear energy industry.

Question 7

Upper boundary safe radiation exposure limits for occupationally exposed persons are associated with risks that are similar to those encountered by employees in other industries that are generally considered to be reasonably safe. These industries include
1. manufacturing.
2. trade.
3. government.

Answer 7

all of the options

Question 8

the effective dose (EfD) limiting system is

Answer 8

the current method for controlling the risk of biologic damage to radiation workers and the general public from radiation exposure.

Question 9

The ALARA concept adopts an extremely conservative model concerning the relationship between

Answer 9

ionizing radiation and potential risk

Question 10

Which of the following are functions and/or responsibilities of the United States Occupational Safety and Health Administration (OSHA)?
1. Functions as a monitoring agency in places of employment, predominantly in industry
2. Regulates occupational exposure to radiation through Part 1910 of Title 29 of the U.S. Code of Federal Regulations (29 CFR 1910)
3. Responsible for regulations concerning an employee’s “right to know” with regard to hazards in the workplace

Answer 10

all of the options

Question 11

Digital radiography systems offer several advantages over computed radiography. Some of these include
1. lower dose.
2. ease of use.
3. immediate imaging results.
4. manipulation of the image.

Answer 11

all of the options

Question 12

During a fluoroscopic examination, a resettable cumulative timing device measures the x-ray beam-on time and sounds an audible alarm or in some cases temporarily interrupts the exposure after the fluoroscope has been activated for what length of time

Answer 12

5 minutes

Question 13

Fluoroscopic devices are capable of subjecting the patient, the equipment operator, and other personnel near the fluoroscopic equipment to substantial doses of ionizing radiation. These devices include
1. C-arm fluoroscopes.
2. fluoroscopes on stationary equipment with HLC mode used for interventional procedures.
3. biplane interventional fluoroscopic systems.

Answer 13

all of the options

Question 14

If the luminance of the collimator light source is sufficient, the localizing light beam will be able to satisfactorily outline the margins of the radiographic beam on the area of clinical interest on

Answer 14

patients of all skin pigmentations

Question 15

In standard image intensification fluoroscopy, an x-ray beam half-value-layer (HVL) of 3 to 4.5 mm aluminum is considered acceptable when kVp ranges from

Answer 15

80 to 100

Question 16

Luminance is determined by measuring the concentration of light

Answer 16

over a particular field of view.

Question 17

The control panel, where technical exposure factors are selected and visually displayed for the equipment operator, must be located

Answer 17

behind a suitable protective barrier that has a radiation-absorbent window that permits observation of the patient during any procedure.

Question 18

When using digital fluoroscopy systems, making use of the last image hold feature can

Answer 18

be an effective dose reduction technique.

Question 19

What is the purpose of radiographic beam filtration?

Answer 19

To reduce exposure to the patient’s skin and superficial tissues by absorbing most of the lower-energy photons from the heterogeneous beam

Question 20

Which of the following materials is commonly used in the tabletop of a radiographic examination table to make the tabletop as radiolucent as possible so that it will absorb only a minimal amount of radiation, thereby reducing the patient’s radiation dose?

Answer 20

carbon fiber material

Question 21

According to the American College of Radiology (ACR), abdominal radiologic examinations that have been requested after full consideration of the clinical status of a patient, including the possibility of pregnancy, need

Answer 21

not be postponed or selectively scheduled.

Question 22

According to the U.S. Public Health Service, the genetically significant dose (GSD) for the population of the United States is approximately

Answer 22

0.20 mSv

Question 23

Analysis of an imaging department’s repeat rate
1. provides valuable information for process improvement.
2. helps minimize patient exposure.
3. improves overall performance of the department.

Answer 23

all of the options

Question 24

Essentially all diagnostic medical procedures result in fetal exposures ______________, so that _______________________.

Answer 24

of less than 0.01 Gy; the risk of abnormality is very small

Question 25

Of the following radiologic procedures, which is (are) considered nonessential? 1. A chest x-ray examination automatically scheduled on admission to the hospital 2. Lumbar spine x-ray examination as part of a pre-employment physical 3. Whole-body computed tomography (CT) screening

Answer 25

all of the options

Question 26

Which of the following is frequently a problem in diagnostic pediatric radiography?

Answer 26

Patient motion

Question 27

________________________ are the sensing devices most often used to measure skin dose directly.

Answer 27

Thermoluminescent dosimeters

Question 28

Which of the following must always be the first step in protection of the reproductive organs?

Answer 28

Adequate and precise collimation of the radiographic beam to include only the anatomy of interest

Question 29

A miscentering of ________ can produce as much as __________% increase in patient dose.

Answer 29

2 cm; 25

Question 30

For routine head and body computed tomography examinations, effective doses fall into which of the following effective dose ranges?

Answer 30

1 to 10 mSv

Question 31

In CT because of higher effective energy of the x-ray beam, both ____________ and _______________ interactions contribute substantially to the image.

Answer 31

photoelectric, Compton

Question 32

In CT when a series of adjacent slices is obtained, some radiation will also scatter from the slice being made into the adjacent slices. What is this radiation called?

Answer 32

interslice scatter

Question 33

In the early 2000s various publications calculated individual and population risks of cancer from CT based upon risk estimates from studies of which of the following groups of people?

Answer 33

atomic bomb survivor

Question 34

The movement or advancement of the patient couch during a CT scan is known as

Answer 34

table increment

Question 35

To keep the patient’s radiation dose ALARA, for both initial and follow-up examinations, the image acquisition should

Answer 35

always be made in the same cardiac phase.

Question 36

With higher radiation exposure to the patient during a computed tomography examination, there is

Answer 36

an increased associated cancer risk.

Question 37

Which of the following is not typically used during a CT scan? a. Direct patient shielding b. Filtered back projection c. All of the options d. A tightly collimated x-ray beam

Answer 37

direct patient shielding

Question 38

Tube current modulation in CT scanning can

Answer 38

help to reduce patient dose

Question 39

the primary function of the NRC is to

Answer 39

oversee the nuclear energy industry

Question 40

which of the following terms involves a random effect of ionizing radiation? early tissue reactions reddening of the skin change in white blood cell count stochastic event

Answer 40

stochastic event

Question 41

Breast positioning for Digital Breast Tomography is ______________ for conventional digital mammography.

Answer 41

the same as is used

Question 42

what is the regulatory standard for total filtration for fixed x-ray units

Answer 42

2.5mm aluminum equivalent

Question 43

what is the regulatory standard for total filtration for fixed x-ray units: lead or aluminum?

Answer 43

aluminum

Question 44

during a screening mammography, __________________ between the breast and the support plate of the mammographic x-ray machine can noticeably reduce the degree of pain experienced by a sensitive patient.

Answer 44

some radiolucent cushioning

Question 45

Digital mammography units with the ability to enhance contrast with image gray-level manipulation offer

Answer 45

substantial improvement for patients with dense breasts.

Question 46

For rhodium x-ray tube targets, only _____________ filters are used.

Answer 46

rhodium

Question 47

Performing a 3D mammogram along with a standard mammogram can result in about _________ more breast cancer found for every ____________ women screened when compared with a standard mammogram alone.

Answer 47

one, 1,000

Question 48

The age recommendation for screening mammography is controversial because mammography is less accurate in the detection of breast cancer in younger women and is likely to result in _________________ readings, leading to unnecessary biopsies in that population.

Answer 48

many false-positive

Question 49

Which of the following procedures will lower the percentage of false-positive readings caused by very dense breasts and consequently permit a more effective x-ray screening of younger women?

Answer 49

Digital Tomosynthesis

Question 50

During mammography, axillary projections should be done only on request of the

Answer 50

radiologist

Question 51

In mammography maintaining and enhancing subject contrast is

Answer 51

of paramount importance for all patients.

Question 52

The x-ray spectrum used for tomosynthesis is generally similar to that employed in standard digital mammography, and the selected _____________ depends on the thickness and density of the compressed breast.

Answer 52

peak kVp

Question 53

a solid encapsulated radioactive source (can be/is never to be) touched directly with the hands

Answer 53

is never to be, instead long tongs which add distance should be used.

Question 54

Any radioactive material that is attached to or associated with dust particles or in liquid form and is found on various surfaces is referred to as

Answer 54

radioactive contamination

Question 55

Considering the design of the medical imaging suites listed below, which suite requires shielding for the highest energy photons?

Answer 55

PET-CT imaging suite

Question 56

During a radiation emergency, the dose limit for individuals engaging in lifesaving activities is

Answer 56

250 mSv per event

Question 57

Gamma rays differ from x-rays

Answer 57

only in the method of how they are produced

Question 58

Iodine-125 (125I53) has been used quite extensively since 2000 in the form of titanium-encapsulated cylindrical seeds to give a tumoricidal radiation equivalent dose to

Answer 58

cancers that are confined within the prostate gland

Question 59

Monoclonal antibodies (MAB) are antibodies that preferentially bind always to a specific

Answer 59

part of an antigen that is recognized by the antibody.

Question 60

the actual long-term health effects of a “dirty bomb” are likely to be

Answer 60

minimal

Question 61

While a patient receiving Iodine-131 (131I53) therapy is hospitalized, a large, _________, movable lead shield can be positioned between the patient and any attending personnel for protection.

Answer 61

up to 25-mm or 1-inch-thick

Question 62

The isotopes used in brachytherapy are characterized by

Answer 62

relatively long half-lives that are measured in terms of multiple days, months, or years and, except for a few of them, by relatively high energy emissions.

Question 63

A protective curtain, or sliding panel, with a minimum of 0.25-mm lead equivalent, should normally be positioned between the fluoroscopist and the patient to intercept what type of radiation?

Answer 63

scatter radiation above the tabletop

Question 64

For C-arm devices with similar fields of view, the dose rate to personnel located within a meter of the patient is ____________ the dose rate to personnel from ______________.

Answer 64

comparable to, routine fluoro

Question 65

For primary radiation, what is the term that represents a portion of beam-on time that the x-ray beam is directed at a primary barrier during the week?

Answer 65

use factor

Question 66

If the peak energy of the x-ray beam is 100 kVp, a protective lead apron must be the equivalent to at least which of the following measures?

Answer 66

0.25mm thickness of lead

Question 67

The annual effective dose limit for individual members of the general population not occupationally exposed is ___________ for continuous or frequent exposures from artificial sources other than medical irradiation and natural background and ____________ for infrequent annual exposure.

Answer 67

1 mSv, 5 mSv

Question 68

The maximum weekly permitted equivalent dose for a controlled area must not exceed

Answer 68

1 mSv

Question 69

most facilities room doors have attenuation for diagnostic energy x-ray equivalent to that provided by _______ mm of lead.

Answer 69

0.8

Question 70

While standing behind the control-booth barrier, a radiographer makes a radiographic exposure. The x-rays scattered from the patient’s body should ____________________

Answer 70

scatter a minimum of 2 times before reaching any area behind the control-booth barrier.

Question 71

Who should determine the exact shielding requirements for a particular imaging facility?

Answer 71

medical physicts