Review Questions

Which of the following are the prime factors of exposure in radiography?

Milliamperage, exposure time, kilovoltage, and source–image receptor distance (SID)

Which of the following, if increased, will result in increased radiographic density?

1. Increased mA

2. Increased exposure time

3. Increased kVp

All 3

When an image demonstrates great differences between the densities, the image is described as:

High contrast

When an image demonstrates only a few densities, and there is a great difference between the densities, the image is described as having:

A short scale of contrast

A low kVp setting produces an image with:

A short scale of contrast

Higher kVp settings produce images with:

Long-scale contrast

The principal means of controlling involuntary motion is to:

Decrease in exposure time (seconds)

Quantum mottle occurs when the:

mAs or kVp is set too low

Which of the following minimize shape distortion?

1. Position plane of subject parallel to plane of IR.

2. Position plane of subject perpendicular to plane of IR.

3. Position the CR perpendicular to IR and subject.

1 and 3 only

Which of the following will increase spatial resolution?

1. Increase in SID

2. Increase in OID

3. Decrease in focal spot size

1 and 3 only

What is the first step to reduce patient motion?

Communicate with the patient about the procedure and what the patient needs to do to help

What is the effect of magnification on spatial resolution?

Magnification decreases resolution

When an image demonstrates little or low difference between the densities, the image is described as:

Low contrast

When an image demonstrates many densities, and there is little difference between the densities, the image is described as having:

Long-scale contrast

The factors that affect x-ray quality are

1. Kilovoltage

2. Filtration

3. mAs

1 and 2 only

Contrast is directly influenced by

1. SID

2. Fog

3. Collimation

2 and 3 only

Shape distortion is the result of:

Unequal magnification of the actual shape of the structure

The geometric factors that affect the formation of the image are

1. SID

2. OID

3. Focal spot

All 3

Which of the following would be considered involuntary motion by the patient?

1. Tremors

2. Peristalsis

3. Breathing

1 and 2 only

The purpose of the photostimulable phosphor plate is to:

Store the image of the body part until processed

The front of the imaging plate is made of:

A radiolucent material that does not absorb x-rays

One of the main advantages of using CR and DR digital systems is

Ability to process images very fast

Barium fluorohalide with europium is used:

As the phosphor that absorbs the x-ray energy in the imaging plate

Which of the following must be used with digital-based x-ray processors to ensure that the ALARA concept is practiced?

An exposure technique chart

Quantum mottle occurs in digital images if:

There are not enough photons reaching the IR

Which of the following should be used when imaging body parts that have extreme differences in tissue thickness?

Compensating filter

Which of the following is a true statement regarding the centering of the body part when using digital systems?

The part must be placed in the center of the plate or detector

The storage phosphors in the CR plate are hypersensitive to:

Small levels of scatter radiation exposure

Which of the following is important to use when using digital systems for mobile radiography?

Grid

Which of the following artifacts appear along the length of travel on the image due to dust on the light guide?

White line

Which of the following matrix sizes will produce the best spatial resolution?

3200 × 2400 matrix

A matrix of 1200 × 1800 will show how many pixels on the viewing monitor?

2,160,000

Which of the following should never be placed on the radiographic image using electronic means (computer software)?

R and L markers

One of the most important aspects of setting the exposure factors when using digital systems is to ensure that the:

kVp is set correctly

Which of the following tells the operator that the correct exposure has been received by the phosphors in the imaging plate?

Exposure indicator number

The universally accepted standard for exchanging radiographic images inside and outside the institution, and among all manufacturers, is which of the following?

DICOM

Which radiographic examination would require “image stitching” of several separate images?

Full spine for scoliosis

Which of the following artifacts can appear in the radiographic image if the CR imaging plate is not erased properly?

Phantom or ghost images

Which of the following artifacts can occur if the CR imaging plate receives too much background or scatter radiation?

Fogging

Which of the following should be checked regularly on the viewing monitor?

1. Viewing surface and air flow

2. Image quality using a test pattern

3. Resolution

All 3

Which of the following takes the stored charge in the flat-panel detector and converts it into a digital value?

Analog-to-digital converter (ADC)

Which of the following will be seen in the x-ray image if either the kVp or the mA is set too low for the projection?

Quantum mottle

Which of the following contains a file of stored images for each projection, which are then referenced during processing of the digital image?

Look-up table (LUT)