Principles of Radiographic Imaging Final Review | Quizlet

Which type of AEC converts light into an electrical signal that is sent to the timer?

Phototimer

Which type of AEC is considered an entrance type?

A) ionization chambers

B) back up timer

C) phototimers

D) minimal response time

Ionization Chambers

A high contrast image will have what type of grayscale?

Short Gray Scale

Which type of AEC is found between patient and image receptor?

A) ionization chamber

B) photodiode

C) phototimer

D) back up timer

Ionization Chamber

An increase in kVp will cause a(n) ______ in the exposure time and inadvertently the mAs.

A) increase

B) decrease

C) no change

Decrease

What shows us the amount of exposure to the IR on the control panel when utilizing AEC?

A) density controls

B) minimum response time

C) mAs readout

D) backup timer

mAs Readout

Which of the following is(are) a way for us to limit the amount of scatter reaching the IR?

1. grids

2. beam restriction

3. tube filtration

4. increasing kVp

All of them

What allows the collimator to automatically adjust the field size to match the IR?

A) mAs

B) aperture diaphragm

C) positive beam limiting

D) automatic exposure control

Positive Beam Limiting

Increasing SID will ______ the pneumbra in an image and ______ detail.

decrease;increase

increase;increase

decrease;decrease

increase;decrease

Decrease;Increase

X-ray intensity is ____ on the anode side and _____ on the cathode side of the beam.

A) greater;greater

B) greater;less

C) less;less

D) less;greater

Less;Greater

Increasing field size will _____ anode heel effect.

A) have no effect

B) increase

C) decrease

Increase

The amount of unsharpness in an image is termed:

A) penumbra

B) spatial resolution

C) focal spot

D) umbra

Penumbra

Decreasing SID will ____ spatial resolution.

A) have no effect

B) decrease

C) increase

Decrease

A decrease in OID will _____ size distortion and ____ detail.

A) decrease;decrease

B) increase;increase

C) increase;decrease

D) decrease;increase

Decrease;Increase

Increasing SID will _____ size distortion of an image.

A) decrease

B) have no effect on

C) increase

Decrease

What does the convergent point and line help determine in a focus grid?

1. grid radius

2. focal range

3. focal distance

A) 1 only

B) 3 only

C) 1 & 3

D) 1, 2, & 3

3 Only

What is the grid ratio with stripes measuring 6.0 mm high and separated by 1.0 mm?

A) 10:1

B) 5:1

C) 6:1

D) 12:1

6:1

The interspaces of a grid are comprised of ____.

A) lead

B) aluminum

C) tungsten

D) plastic

Aluminum

What type of grid allows for tube and grid angulation during exams?

A) criss-cross parallel

B) linear focused

C) criss-cross focused

D) linear parallel

Linear Parallel

Who developed the first grid?

A) Marie Curie

B) Wilhelm Roentgen

C) Gustave Bucky

D) Thomas Edison

Gustave Bucky

Grids help reduce the amount of scatter produced and reaching the IR.

A) True

B) False

False

What factor of grid construction tells us how many lead strips are within a certain distance inside a grid?

A) grid focus

B) grid pattern

C) grid ratio

D) grid frequency

Grid Frequency

Which of the following grids would be the most efficient?

12:1

Which of the following grids would be the most effective overall to use during an exam requiring its use?

A) 8:1

B) 5:1

C) 10:1

D) 16:1

16:1

Most fixed x-ray units utilize a stationary type focused grid.

A) True

B) False

False

The lower the grid ratio the ____ chance of grid cut off.

A) no

B) higher

C) lower

Lower

Which type of grid cut off will cause an overall loss of contrast in an image?

1. upside down

2. off-level

3. off-focus

4. lateral decentering

A) 2 & 4

B) 1 & 2

C) 1 only

D) 2 & 3

1 & 2

Which of the following grid ratio(s) are common in fixed x-ray systems?

1. 10:1

2. 6:1

3. 12:1

4. 16:1

A) 2 only

B) 3 & 4

C) 1 & 3

D) 1 only

1 & 3

An off-focus grid cutoff results from an incorrect:

A) upside down grid

B) CR centering

C) SID

D) tube or grid angulation

SID

Decreasing the grid ratio of a grid will require ____ mAs, which will ______ patient dose and _____ image contrast.

Less;Decrease;Decrease

Which of the following stationary grids does not secure to the IR?

A) grid cassette

B) grid cap

C) non-grid

D) wafer grid

Wafer Grid

Most mobile studies requiring a grid should use a lower ratio parallel type.

A) True

B) False

True

What is the grid conversion factor for a 5:1 grid?

A) 2

B) 3

C) 1

D) 6

2

Which of the following are ways to reduce scatter and secondary radiation?

1. use of optimum kVp

2. use of optimum mAs

3. collimation

4. air gap technique

5. grids

1, 3, 4, & 5

As scatter and secondary radiation increase, receptor exposure _______ and contrast _______.

Increase;Decrease

If SID increases then receptor exposure will _____ and image contrast will_____.

A) increase;decrease

B) decrease;not change

C) increase;not change

D) decrease;increase

Decrease;Not Change

If mAs increases then receptor exposure will ______ and image contrast will______.

Increase;Not Change

If beam restriction increases then receptor exposure will ______ and image contrast will ____.

A) increase;not change

B) decrease;decrease

C) decrease;increase

D) increase;decrease

Decrease;Increase

When imaging the T-spine, the _____ part of the anatomy needs to be positioned on the _____ side of tube.

A) thicker;cathode

B) thinner;cathode

C) thinner;anode

D) thicker;anode

Thicker;Cathode

As grid ratio increases, receptor exposure _____.

A) decrease

B) will not change

C) increase

Decrease

As angulation of tube or plate increase recorded detail/spatial resolution will ____, shape distortion will ____, and size distortion will ____.

A) decrease;increase;not change

B) decrease;decrease;not change

C) increase;decrease;decrease

D) decrease;increase;increase

Decrease;Increase;No Change

If SID increases then recorded detail (spatial resolution) will ____, shape distortion will ____, and size distortion will ____.

A) increase;decrease;not change

B) decrease;decrease;not change

C) increase;not change;decrease

D) decrease;decrease;increase

Increase;Not Change;Decrease

If kVp increases then receptor exposure will _____ and image contrast will ______.

A) decrease; not change

B) decrease; increase

C) increase; increase

D) increase; decrease

Increase;Decrease

What is the the formula for the Inverse Square Law? What is the Law used for? What do the variables stand for?

I1 / I2 = (D2^2) / (D1^2)

The Inverse Square Law is used to determine beam intensity when distance is changed.

I1= Intensity/Exposure/Dose/Kerma 1

I2= Intensity/Exposure/Dose/Kerma 2

D2= Distance 2

D1= Distance 1

An Increase in Grid Ratio will ____.

Increase Contrast.

Increase Patient Dose.

Increase required mAs.

What materials are used for grids?

Lead (Most Common)

Platinum

Tungsten

What is a Focus Grid? What do they account for? What is their weakness?

Focus Grids are built to match the divergence of the X-Ray Beam to increase scatter clean up.

If the tube is not put at the right distance or the grid is placed upside down, the exposure will have to be repeated.

What is a Moving Grid? What is an advantage of theirs?

Moving Grids are grids that move during the exposure.

Their movement can blur out grid lines that might otherwise be present on the finished Radiograph.

What is a Cross-Pattern Grid? What is its weakness?

Cross-Pattern Grids are built in a criss-crossing pattern.

They are significantly easier to miss-align.

What happens when you place a focus grid upside down? Why?

The image will be correctly exposed in the center but underexposed on the sides.

The X-rays will correctly pass through the center of the grid because there is no angulation there. They will be absorbed on the sides because of the incorrect angle of the lead strips.

What happens when you do not place the tube in the right position while using a focus grid? Why?

The image will be correctly exposed in the center but underexposed on the sides.

The X-Rays will pass through the center of the grid because the strips are not angled, they will be absorbed on the sides due to the misalignment of the tube and grid.

What is Grid Cutoff? What is the effect on the radiograph?

Grid Cutoff is caused by a misalignment of the tube and grid.

The result is an underexposure of the image receptor.

What is an off-level error? What is its effect on an image?

Which type of Radiography is more likely to cause grid errors?

Mobile Radiography

What is the purpose of an AEC?

To minimize patient exposure while still getting a diagnostic image.

What factor is controlled by the AEC?

Time (s)

What part of X-Ray system is the AEC wired to?

Exposure Timer

Define Hyposthenic. What portion of the population is classified under this body habitus?

What should be placed directly over the AECs in order to get the best exposure?

The anatomy of interest.

Why is it important not to cover an AEC with a lead shield?

Any X-Rays heading for the AEC would be absorbed, causing a massive increase in exposure time and patient dose.

What are density settings?

Density settings determine the exposure target. Increasing density will increase the exposure and decreasing density will decrease the exposure.

Density is the only way to change the overall exposure when using AECs.

When using AECs, will exposure time be affected if kVp is changed? If so, how?

Yes, kVp contributes to beam quantity, in addition to quality.

A decrease in kVp would cause an increase in exposure time. An increase in kVp would cause a decrease in exposure time.

When using AECs, how would you adjust exposure time?

By manipulating the mA accordingly.

Grids reduce scatter production.

A) True

B) False

False, grids prevent scatter from reaching the IR, not from being produced.

What will happen if a non-focused grid was placed upside down?

Nothing.

Which side of the tube has a higher beam intensity?

Cathode Side

Which side of the tube has a lower beam intensity?

Anode Side

The use of an x-ray tube with a large anode angle results in:

1 Increased focal spot size

2. Increased heat capacity

3. Increased heel effect

1 & 2

Which of the following exposure modifications will increase the anode heel effect?

A. Decreased kilovoltage peak (kVp)

B. Decreased exposure time (s)

C. Decreased milliamperage (mA)

D. Decreased source-to-image distance (SID)

Decreased source-to-image distance (SID)

Decreasing the SID increases the anode heel effect. Decreasing the SID requires the operator to use more of the extreme edges of the x-ray field where there is a very large difference in intensity. The anode side is less intense and the cathode side is more intense.

Which of the following collimation settings will demonstrate the most uniform beam intensity within the exposure field?

A. 6 x 6 inches

B. 8 x 10 inches

C. 10 x 12 inches

D. 17 x 17 inches

6 x 6 inches

Using a smaller field size results in an x-ray beam of more uniform intensity. The beam is NOT focused or concentrated, but increasing the collimation removes the extreme edges of the x-ray field where there are very large differences in intensity.