Deck 5: Quality Control of X-Ray Generators and Ancillary Radiographic Equipment

Question 1

What is the NEMA allowance parameter for an x-ray tube that has a stated focal spot size of 1.5 mm?

A) 50%
B) 40%
C) 30%
D) 20%

Answer 1

40%

Question 2

Conventional tomographic systems should produce images of tissue that lie within ____ mm of the indicated tomographic plane.

A) 5
B) 10
C) 15
D) 20

Answer 2

A
The level of the tomographic section (fulcrum level) that is indicated on the equipment and the actual level of the tomographic section that is imaged above the tabletop should be the same or within 5 mm.

Question 3

During AEC evaluation with varying kVp, the AEC system should maintain a constant film density to within ____ optical density units.

A) $\pm$ 0.05
B) $\pm$ 0.1
C) $\pm$ 0.2
D) $\pm$ 0.3

Answer 3

$\pm$ 0.3

Question 4

Which of the following devices can be used as the sensor in AEC units?

A) Ion chamber
B) Photocell
C) Solid-state detector
D) All of the answer options are correct.

Question 5

A synchronous spinning top is used on a three-phase unit with a time of 17 ms. Approximately how large of an arc should appear if the timer circuit is accurate?

A) 3 degrees
B) 6 degrees
C) 17 degrees
D) 36 degrees

Question 6

The x-ray tube must be mounted inside its housing so that the central ray exits the housing to within ____ degree(s) of perpendicular.

A) 1
B) 2
C) 3
D) 4

Question 7

Path closure in pluridirectional tomographic units should be within ____ of the path length.

A) 2%
B) 5%
C) 10%
D) 15%

Question 8

Two common quality control tests that should be performed on grids are grid _____ and grid _____ tests.

A) ratio; frequency
B) alignment; uniformity
C) ratio; alignment
D) uniformity; ratio

Question 9

X-ray system mAs reciprocity has an acceptance parameter of

A) $\pm$ 5%
B) $\pm$ 10%
C) $\pm$ 15%
D) $\pm$ 20%

Question 10

What is the acceptance criterion for a timer circuit with an exposure time shorter than 10 ms?

A) 5%
B) 10%
C) 15%
D) 20%

Question 11

Collimation systems equipped with positive beam limitation must be accurate to within ____ of the SID.

A) $\pm$ 5%
B) $\pm$ 4%
C) $\pm$ 3%
D) $\pm$ 2%

Question 12

The maximum variation coefficient for reproducibility of x-ray generators is

A) 0.05.
B) 0.07.
C) 0.10.
D) 0.20.

Question 13

An exposure of 600 mA and 16 ms yields an exposure output of 240 mR. What is the mR/mAs?

A) 2.5
B) 25
C) 250
D) 2500

Question 14

During testing for grid uniformity, films should be uniform within an optical density of

A) $\pm$ 0.4.
B) $\pm$ 0.3.
C) $\pm$ 0.2.
D) $\pm$ 0.1.

Question 15

The light field and radiation field of a radiographic unit must be congruent to within ____ of the SID.

A) $\pm$ 1%
B) $\pm$ 2%
C) $\pm$ 3%
D) $\pm$ 5%

Question 16

What is the accepted half-value layer (HVL) for an x-ray unit operating at 80 kVp?

A) 2.1 mm Al
B) 2.3 mm Al
C) 2.5 mm Al
D) 2.7 mm Al

Question 17

The minimum filtration required for general-purpose radiographic systems is _____ mm Al.

A) 2.0
B) 2.1
C) 2.5
D) 3.0

Question 18

The kilovolts peak (kVp) must be accurate to

A) ±2%.
B) ±5%.
C) ±10%.
D) ±15%.

Question 19

The tomographic exposure angle indicated on the equipment and the actual tomographic angle must coincide within ____ degrees for units operating at angles greater than 30 degrees.

A) 2
B) 5
C) 10
D) 20

Question 20

Which of the following tests can be used to determine focal spot size?

A) Safelight test
B) Wire mesh test
C) Wisconsin test cassette
D) Star pattern test