LRA 216 Ch 6 & 7: Quiz Review

Protective lead gloves must have a minimum lead equivalency of at least _____ mm lead.

0.25

Observation windows may be obtained in lead equivalencies from:

0.3 to 2 mm.

Lead aprons worn during a mobile exam must have a lead equivalency of at least _____ mm.

0.5

Factors that determine protective barrier thickness include: 1. Time of occupancy (T) 2. Workload (W) 3. Use (U)

1, 2 and 3

The cardinal rules of radiation protection include: 1. time 2. distance 3. shielding

1, 2 and 3

The average lead glass window of the shielded control booth consists of

1.5 mm Pb equivalent

Primary protective barriers must consist of _____ inch lead

1/16

The x-ray tube must be enclosed by a lead-lined metal covering, requiring _____ Pb.

1/16 inch

Applying the inverse square law, if we double our distance from the source, the intensity at our new distance is _____ as much as the original intensity.

1/4

Uncontrolled area design limits require barriers to reduce the exposure rate to less than _____ mrem/week.

10

Controlled area design limits require barriers to reduce the exposure rate to less than _____ mrem/wk.

100

Leakage radiation from the x-ray tube housing shall not exceed _____ mR/hr at a distance of 1 meter from the tube.

100

How tall must primary protective barriers be?

7 feet

The total filtration of fluoroscopic equipment must be at least _____ Al equivalent.

25

The exposure switch cord on a mobile unit must be long enough to allow the radiographer to stand back at least _____ feet during the exposure.

6

A computed radiography (CR) system includes the following: P. 183 1. Storage phosphor cassettes 2. A storage phosphor reader 3. Bar code scanner 4. Remote operator panel for entering patient data 5. A clinical workstation for reviewing and printing a. 1, 3, and 5 only b. 2 and 4 only c. 1 and 5 only d. 1, 2, 3, 4 and 5

ANS: D

An area occupied by radiation personnel is defined as a(n):

Controlled area

The fluoroscopic exposure switch is controlled by the radiologist by using either a foot pedal, or a hand switch located on the fluoro carriage. This switch is considered a

Deadman type switch

The lead glass observation windows of a control booth is typically_____ as thick as sheet lead for equivalent protection.

Four times

Radiation survey instruments, such as the _____, are used to detect and measure radiation.

Geiger-Muller counter and cutie pie meter

When wearing a lead apron, a pregnant radiographer is required to wear their fetal dosimeter

Inside the lead apron at the waist level

Increasing the distance between the individual and the source of radiation is an effective method of reducing exposure to radiation. Distance utilizes which of the following?

Inverse square law

The law that states the intensity of radiation at a given distance from a point source is inversely proportional to the square of the distance of the object from the source is the:

Inverse square law

Which of the following people should be asked to hold a patient who needs physical support during an exposure?

Male friend

When wearing a lead apron, a personnel dosimeter must be worn

Outside the lead apron at the collar level

The exposure cord for the control booth must be:

Short enough so that the exposure can occur only when the radiographer is behind the control booth barrier.

Patient dose decreases when: p.182 a. High-speed radiographic film is used in combination with high-speed intensifying screens b. Rare-earth intensifying screens are not used c. Low kVp techniques are used d. Non-screen film is used

a. High-speed radiographic film is used in combination with high-speed intensifying screens

Involuntary patient motion is best dealt with by:

Using a short exposure time with a high mA selection

To within what percent of the SID must the collimator light and actual irradiated area be accurate? p. 176 a. 2% b. 5% c. 10% d. 25%

a. 2%

Which of the following exposure techniques will provide the least amount of radiation exposure to the patient? P. 180-181 a. 50 mAs, 90 kVp b. 100 mAs, 90 kVp c. 200 mAs, 50 kVp d. 400 mAs, 50 kVp

a. 50 mAs, 90 kVp

An effective way of reducing patient dose is through p. 184 a. Accurate and effective positioning b. Using low kVp and high mAs c. Using low kVp and low mAs d. Using high kVp and high mAs

a. Accurate and effective positioning

Digital radiography (DR) utilizes a direct capture system of solid-state detector plates as the image receptor. These receptors are composed of: p. 184 a. Barium fluorohalide compounds b. Aluminum, tin, and copper c. Lithium fluoride d. Calcium fluoride

a. Barium fluorohalide compounds

Half-value layer (HVL) is defined as the thickness of a designated absorber required to: p. 178 a. Decrease the intensity of the primary beam by 50% of its initial value b. Decrease the intensity of the primary beam by 25% of its initial value c. Increase the intensity of the primary beam by 50% of its initial value d. Increase the intensity of the primary beam by 25% of its initial value

a. Decrease the intensity of the primary beam by 50% of its initial value

Which of the following combinations would reduce patient radiation dose during an x-ray exam? p. 173 a. higher kVp, lower mAs, increased filtration b. lower kVp, higher mAs, decreased filtration c. higher kVp, higher mAs, decreased filtration d. lower kVp, lower mAs, increased filtration

a. higher kVp, lower mAs, increased filtration

How much total filtration is required when using over 70 kVp? p. 178 a. 1.5 mm A b. 2.5 mm Al c. 3.0 mm Al d. 4.0 mm Al

b. 2.5 mm Al

When using fluoroscopy, federal law prohibits the useful beam at the image receptor from exceeding the visible image area by more than _____ of the source-to-image receptor distance (SID). p. 186 a. 1% b. 3% c. 5% d. 10%

b. 3%

The function of a filter is to remove which of the following from the x-ray beam? p. 177 a. Short wavelength radiation b. Long wavelength radiation c. Secondary radiation d. Scattered radiation

b. Long wavelength radiation

Which of the following are placed between the patient and the image receptor (IR) to absorb scatter radiation preferentially? p. 184 a. Lead shielding b. Radiographic grids c. Positioning aides d. Immobilization devices

b. Radiographic grids

Which of the following is the best type of gonadal shield to use during a sterile field procedure? p. 179 a. Flat contact b. Shadow shields c. Shaped contact d. Lead sheet

b. Shadow shields

Which of the following will best reduce radiation exposure to the patient? p. 182 a. Use non-screen film b. Use rare-earth screens c. Decrease kVp d. Increase mAs

b. Use rare-earth screens

The minimum source-to-tabletop distance permitted in mobile fluoroscopy is: p. 185 a. 4 inches b. 9 inches c. 12 inches d. 15 inches

c. 12 inches

The minimum source-to-tabletop distance permitted for fixed fluoroscopes is: p.186 a. 6 b. 12 c. 15 d. 20

c. 15

CR photostimulable phosphor cassettes use _____, which causes the screens to fluoresce upon exposure to ionizing radiation from the x-ray tube. p. 183 a. Thermoluminescent dosimeters b. Optically stimulated luminescent dosimeters c. Europium-activated barium fluorohalide crystals d. Lithium or calcium fluorohalide

c. Europium-activated barium fluorohalide crystals

Which of the following is not a type of beam limitation device? p. 174-175 a. Collimator b. Cone c. Filter d. Aperture diaphragm

c. Filter

The fundamental difference between computed radiography and conventional analog imaging is the replacement of film-screens with: P. 183 a. Thermoluminescent dosimeters b. Optically stimulated luminescent dosimeters c. Photostimulable phosphor plates d. Rare-earth stimulated plates

c. Photostimulable phosphor plates

Causes of repeat radiographs include the following: p. 185 1. Dirty screens 2. Incorrectly loaded cassettes 3. Light leaks 4. Chemical fog 5. Processor artifacts a. 1, 2, and 3 only b. 2, 3, and 4 only c. 1 and 5 only d. 1, 2, 3, 4 and 5

d. 1, 2, 3, 4 and 5

The tabletop exposure rate during fluoroscopy shall not exceed P. 186 a. 1 R/min b. 5 R/min c. 7 R/min d. 10 R/min

d. 10 R/min

The dynamic range of exposure for photostimulable phosphors is linear over a range of greater than _____, whereas, for analog radiographic images produced by screens, it is roughly 40 to 1. P. 183 a. 10 to 1 b. 100 to 1 c. 1,000 to 1 d. 10,000 to 1

d. 10,000 to 1

A fluoroscope must be equipped with a cumulative timing device that times the radiation exposure and sounds an audible alarm after the fluoroscope has been energized for p. 186 a. 1 minute b. 2 minutes c. 3 minutes d. 5 minutes

d. 5 minutes

Using CR, it is estimated that overexposures of up to _____ and underexposures up to _____ are recoverable, thus eliminating the need for retakes. p. 183 a. 50%, 10% b. 100%, 50% c. 80%, 500% d. 500%, 80%

d. 500%, 80%

In digital radiography (DR), a(n) _____ converts the analog image to a digital image. p. 184 a. Analog reader b. Digital reader c. Plate converter d. Analog to digital converter (ADC)

d. Analog to digital converter (ADC)

Which of the following is the most versatile type of x-ray beam limiting device? p. 174 a. Aperture diaphragm b. Cone c. Cylinder d. Collimator

d. Collimator

One way to ensure against irradiating a woman in the early stages of pregnancy is to institute _____ for nonemergency procedures. p. 184-185 a. Mandatory counseling b. Mandatory scheduling c. Institutional scheduling d. Elective scheduling

d. Elective scheduling

The number of repeat radiographs can be reduced by p. 172-173 a. Disregarding communication between patient and radiographer b. Eliminating voluntary patient motion using short exposure times c. Eliminating involuntary patient motion using immobilization devices d. Eliminating voluntary patient motion using immobilization devices

d. Eliminating voluntary patient motion using immobilization devices

Which of the following produces the greatest radiation exposure in diagnostic radiology? p. 185 a. Extremity radiographs b. Spine radiographs c. Skull radiographs d. Fluoroscopic procedures

d. Fluoroscopic procedures

The greatest beam limitation is accomplished when the cone/cylinder is _____, and the diameter opening is _____. p. 176 a. Shorter, bigger b. Shorter, smaller c. Longer, bigger d. Longer, smaller

d. Longer, smaller