Carroll CH 39 TEST BANK

Which of the following represents a realistic, yet exemplary repeat rate for a radiographic

imaging department to strive for?

a. 1-2%

b. 3-5%

c. 8-10%

d. 12-13%

e. 20%

b. 3-5%

PP Q19

The use of repeat analysis in a radiographic imaging department provides pertinent direction for:

a. inservice topics

b. management decisions

c. cost-efficiency data

d. all of these

e. none of these

d. all of these

The validity of technique charts and technique guidelines is directly dependent upon proper:

a. positioning skills

b. calibration of equipment

c. methods of image storage

d. clinical patient care

b. calibration of equipment

The advent of digital imaging has reduced the percentage of all repeated exposures due to

improper brightness or density (too light or too dark) from approximately to .

a. 10%; 5%

b. 20%; 10%

c. 50%; 15%

d. 60%; 10%

e. 80%; 4%

d. 60%; 10%

In medical imaging departments with a quality control program in place, the great majority of

repeated exposures is due to improper:

a. radiographic technique

b. processing of the image

c. positioning

d. motion or poor patient cooperation

c. positioning

PP Q20

For most modern radiographers, the pursuit of continuing professional education is a matter

of:

a. continuing certification

b. professionalism

c. improved patient care

d. all of these

e. none of these

d. all of these

A line-pair group template test performed monthly on a particular x-ray unit suddenly shows a

decrease in the number of line-pairs resolved. This is most likely an indication of:

a. a burned out x-ray tube filament

b. blooming of the space charge in the x-ray tube

c. an anode warped from heat overload

d. any of the above

e. none of the above

c. an anode warped from heat overload

PP Q18

For a half-value layer test, the following exposures are measured by an ion chamber with

increasing amounts of aluminum absorber placed in the beam as indicated below; What is

the HVL for this x-ray beam?

0 mm Al: 160 mR

1 mm Al: 100 mR

2 mm Al: 60 mR

3 mm Al: 30 mR

a. 0.5 mm Al

b. 1.5 mm Al

c. 2.0 mm Al

d. 2.5 mm Al

e. 3.0 mm Al

b. 1.5 mm Al

The actual kVp of any x-ray beam should not deviate by more than of the read-out from the kVp meter:

a. 1

b. 2

c. 3

d. 5

e. 8

d. 5

PP Q17

An x-ray beam has a half-value layer of 2 mm Al. If 4 mm of aluminum filtration is added at

the collimator, the intensity of the beam will be reduced to:

a. 75%

b. 50%

c. 40%

d. 25%

e. 10%

d. 25%

PP Q16

The size of the projected light field must be within plus or minus of the actual size of the x-ray beam:

a. 1% of the SID

b. 2% of the SID

c. 5% of the SID

d. 10% of the SID

b. 2% of the SID

PP Q15

A beam verticality check shows the central ray to be precisely vertical. The field alignment

test on the same unit shows one side of the beam to be accurate, but the opposite side to

be off by 1 inch (2.5 cm). Taken together, these data most likely indicate:

a. slippage of one shutter in the collimator

b. misalignment of the light field mirror in the collimator

c. stripped locks on the x-ray tube head

d. a crooked ceiling crane holding the x-ray tube head

a. slippage of one shutter in the collimator

Government regulations and scientific recommendations require that each mA station be

linear to the two adjacent stations (the one above and the one below it) to within accuracy.

a. 2%

b. 5%

c. 10%

d. 20%

e. 50%

c. 10%

PP Q14

"Viewbox" illuminators used to examine hard copies of radiographs generally use

fluorescent light bulbs having __ watts:

a. 10

b. 12

c. 15

d. 20

e. 25

c. 15

By eliminating both peripheral and ambient lighting around any radiographic image

(electronic or hard copy), its apparent is enhanced:

a. contrast

b. sharpness

c. darkness

d. magnification

a. contrast

Which of the following equipment calibration checks should fall within plus or minus 5%:

1. exposure timer

2. mA linearity

3. mAs reproducibility

4. focal spot accuracy

5. x-ray beam alignment

a. 1 only

b. 1, 2 & 3 only

c. 1 & 3 only

d. 4 only

e. 2, 4 & 5 only

c. 1 & 3 only

PP Q13

And kVp calibration

All annually

Between all the different radiographic rooms within an imaging department, the automatic

exposure controls should be linear to within plus or minus:

a. 5%

b. 10%

c. 15%

d. 20%

e. 25%

a. 5%

PP Q12

Which of the following QC tests for digital imaging can be reasonably performed visually by

a radiographer:

a. field uniformity

b. erasure thoroughness or "ghosting"

c. intrinsic (dark) noise

d. uneven spatial resolution

e. all of the above

e. all of the above

A single CR phosphor plate is erased and then processed without exposing it to x-rays. This

describes an appropriate test for:

a. field uniformity

b. erasure thoroughness

c. lag or "ghosting"

d. intrinsic (dark) noise

d. intrinsic (dark) noise

PP Q11

For medical diagnosis, it is critical for every electronic image monitor within a(n) to be

set at precisely the same luminance and contrast:

a. hospital

b. imaging department

c. diagnostic workstation

d. display station

c. diagnostic workstation

Which of the following most closely describes a radiographic viewing area with class 2

monitors, where windowing and special post-processing operations can be performed on

images and saved, but where diagnostic findings are not dictated:

a. video display terminal (VDT)

b. any node in the PACS network

c. a technologist workstation

d. a display station

e. a radiologist workstation

c. a technologist workstation

For light emitted isotropically in all directions from a source, one candela generates one

lumen of light intensity per .

a. meter

b. square meter

c. steradian

d. radius

e. sphere

c. steradian

PP Q10

Which of the following emits by far the brightest light:

a. a CRT (cathode ray tube) monitor

b. an LCD (liquid crystal diode) monitor

c. an LED (light emitting diode) monitor

d. a conventional "viewbox" illuminator

d. a conventional "viewbox" illuminator

The device (provided by many manufacturers of display monitors) designed to directly

measure luminance, or the light intensity emitted from a display monitor, is the:

a. densitometer

b. photometer

c. lux inflector

d. SMPTE test device

e. the ammeter

b. photometer

PP Q9

For a small area on a hard-copy radiograph in which only one-thousandth of the light from an

illuminator can pass through, the measurement taken from a densitometer will be:

a. 1000

b. 0.001

c. 1.0

d. 2.0

e. 3.0

e. 3.0

Which of the following describes illuminance:

a. the intensity of light from other sources striking a surface

b. the intensity of light per area passing through space

c. the total intensity of light emitted in all directions from a source

d. the brightness of a particular portion of a radiographic image

e. the process by which radiography students come to understand the material taught

a. the intensity of light from other sources striking a surface

PP Q8

Which of the following units is best applied to a count of the number of light photons from a computer screen passing through one square centimeter at a distance of 12 inches from the screen, on their way to the human eye:

a. candela

b. lumens

c. lux

d. watts

e. roentgen

b. lumens

PP Q7

At 25 lux, the maximum ambient lighting in a radiologist's reading room while images are

being diagnosed should be less than of the typical lighting for offices in general:

a. 3/4

b. ½

c. 1/4

d. 1/10

c. 1/4

PP Q6

Compared to the cathode ray tube (CRT), the liquid crystal diode (LCD) has a very poor:

a. luminance response

b. luminance uniformity

c. luminance ratio

d. spatial resolution

e. diffuse reflectance

c. luminance ratio

On the SMPTE test pattern and other test patterns for electronic image display monitors,

there are sets of adjacent squares with "just noticeable differences" (JNDs) in density

between them. This type of pattern is designed to test:

a. luminance response

b. luminance ratio

c. maximum luminance

d. gray scale

e. spatial resolution

a. luminance response

The reflection of a light bulb that is behind the observer, from the surface of a display

monitor is classified as:

a. ambient lighting

b. inherent image noise

c. false images

d. specular reflectance

e. diffuse reflectance

d. specular reflectance

PP Q5

For electronic image display monitors, test patterns consisting of circles or squares of progressing just noticeable differences (JNDs) of density from a black background mask can be used not only for testing contrast, but also for testing:

a. noise

b. maximum luminance

c. luminance ratio

d. resolution

e. distortion

a. noise

PP Q4

On the SMPTE pattern or other test patterns for electronic display monitors, two series of narrow horizontal bars, one with high contrast alternating black and white and the other

with low contrast alternating dark gray and light gray, are designed to measure:

a. horizontal resolution

b. vertical resolution

c. contrast resolution

d. bandwidth

e. luminance ratio

b. vertical resolution

Which of the following deteriorates rapidly for CRTs, but very slowly for LCDs:

a. maximum luminance

b. resolution

c. pixel function

d. a & b

e. a, b & c

d. a & b

The minimum acceptable resolution for electronically displayed images, recommended by

physicist and radiological associations, is:

a. 2.5 LP/mm

b. 4 LP/mm

c. 6 LP/mm

d. 8 LP/mm

e. 10 LP/mm

a. 2.5 LP/mm

PP Q3

On an liquid crystal diode (LCD) monitor, a dead pixel is seen as:

a. a black spot against a white background, the size of a period in 12-point font

b. a white spot against a black background, the size of a period in 12-point font

c. a black spot against a white background, 1/18th the size of a period in 12-point font

d. a white spot against a black background, 1/18th the size of a period in 12-point font

b. a white spot against a black background, the size of a period in 12-point font

PP Q2

A class 1 LCD, used for diagnosis, must have ___ or fewer bad pixels across the entire area of the monitor screen:

a. 3

b. 8

c. 15

d. 25

e. 30

c. 15

PP Q1

Among image display monitors, which of the following problems occur only with cathode

ray tubes (CRTs):

a. pincushion distortion

b. barrel distortion

c. skew distortion

d. veiling glare

e. all of the above

e. all of the above

More expensive liquid crystal diode (LCD) monitors may have angled pixel segments in

order to reduce:

a. veiling glare

b. specular reflectance

c. diffuse reflectance

d. noise

e. viewing angle dependence

e. viewing angle dependence