Deck 7: Quality Control of Fluoroscopic Equipment

Question 1

At any combination of tube potential and current, fluoroscopic equipment with an automatic brightness control should not produce an entrance skin exposure exceeding ____ R/min.

A) 2.5
B) 5
C) 10
D) 20

Answer 1

C
The intensity of the x-ray beam at tabletop should not exceed 10 R/min (2.6 mC kg^-1min^-1) for units equipped with ABC.

Question 2

A photocathode is a device that emits

A) light photons.
B) x-ray photons.
C) electrons.
D) All of the answer options are correct.

Answer 2

C
The light photons release electrons from the photocathode through the process of photoemission.

Question 3

Which type of distortion that can occur with tube-type fluoroscopic image intensifiers is most often caused by the presence of strong magnetic fields?

A) Veiling glare
B) S distortion
C) Pincushion distortion
D) Vignetting

Answer 3

B
An S distortion artifact is a warping of the image along an S-shaped axis and is the result of strong magnetic fields changing the trajectory of the electrons moving across the image intensifier tube.

Question 4

The input phosphor of an image intensifier tube converts a(n) _____ image into a(n) _____ image.

A) x-ray; light
B) light; electron
C) electron; light
D) x-ray; electron

Question 5

The television camera most commonly used to capture the fluoroscopic image from a tube type image intensifier is the:

A) image orthicon.
B) plumbicon.
C) vidicon.
D) charge-coupled device.

Question 6

A reduction in brightness at the periphery of the image captured with an image intensifier tube is referred to as

A) pincushion distortion.
B) vignetting.
C) barrel distortion.
D) quantum mottle.

Question 7

Performance testing of fluoroscopic systems must include all the following except

A) x-ray tube housing.
B) automatic film processor.
C) total filtration.
D) automatic brightness control.

Question 8

Quality control tests of fluoroscopic systems should be performed

A) daily.
B) weekly.
C) semiannually.
D) annually.

Question 9

Which type of test tool may be used to demonstrate pincushion distortion?

A) Dosimeter
B) Wire mesh tool
C) Ion chamber
D) Homogenous phantom

Question 10

In standard broadcast television, one image frame consists of

A) one television field.
B) two television fields.
C) 262.5 scan lines.
D) 17 ms.