Safety - Equipment & Exposure - Semester 1

Question 1

What are 3 advantages of fixed fluoroscopic imaging systems over mobile fluoroscopic units?

Answer 1

1. Reduced radiation exposure 2. Lack of susceptibility to overheating and subsequent shutdown 3. Increased image quality

Question 2

What is the function of the xray tube?

Answer 2

The xray tube converts electrical energy from the generator into an xray beam

Question 3

What are the most common devices used in IR to visualize vessels?

Answer 3

Digital image receptors

Question 4

T/F Stochastic radiation effects are considered acute effects.

Answer 4

False.

Question 5

Define stochastic radiation effects.

Answer 5

Randomly occurring effects of radiation; the probability of such effects is proportional to the dose (increased dose equals increased probability, not severity, of effects)

Question 6

What is the disadvantage of pulsed fluoroscopy?

Answer 6

Increased motion artifact

Question 7

Define pulsed fluoro

Answer 7

The x-ray beam is pulsed to keep patient dose and heat units at a minimum.

Question 8

List 3 examples of deterministic effects.

Answer 8

1. Desquamation 2. Damage to blood vessels 3. Damage to glands.

Question 9

What are deterministic effects?

Answer 9

Effects of radiation that become more severe at high levels of radiation exposure and do not occur below a certain threshold dose.

Question 10

What is different about fluoroscopy generators when compared with standard radiography generation?

Answer 10

They have additional circuitry to allow for low continuous tube current or rapid pulsed exposure.

Question 11

How does pulsed fluoroscopy work?

Answer 11

An image is not generated between pulses and the monitor displays the previously stored image until the next pulse generates a new image.

Question 12

What are the 4 functions of the automatic exposure control (AEC) system?

Answer 12

1. Maintains consistent image brightness 2. Alters xray exposure to the image receptor 3. Designed to reduce patient radiation dose 4. Designed to reduce occupational exposure

Question 13

What is the AEC?

Answer 13

An ionization chamber that provides consistency of radiographic quality; placed between the patient and the image receptor

Question 14

List 3 examples of dynamic imaging.

Answer 14

1. Arteriography 2. UGI 3. VCUG

Question 15

The fluoroscopic beam must be collimated so that an unexposed border is visible on the image monitor when the input phosphor of the image intensifier is ___ cm above the tabletop and the collimators are fully open.

Answer 15

35 cm

Question 16

Label

Answer 16

a. Monitor
b. Video camera
c. Cine camera
d. Optical coupling
e. Image intensifier
f. Grid
g. Collimator/filter
h. xray tube
i. xray generator
j. photospot camera