Deck 25: Fluoroscopy

Question 1

Fluoroscopy was developed so that radiologists could view _____ images.

A) static
B) dynamic
C) magnified
D) darkened

Answer 1

dynamic

Question 2

Electrons hit the _____ after exiting the anode.

A) output phosphor
B) tube housing
C) photocathode
D) focusing lenses

Answer 2

output phosphor

Question 3

The number of light photons emitted within the image intensifier is _____ to the amount of x-ray photons exiting the patient.

A) equal
B) unrelated
C) inversely proportional
D) directly proportional

Answer 3

directly proportional

Question 4

What is the milliamperage used during fluoroscopy?

A) £100 mA
B) £50 mA
C) £5 mA
D) £1 mA

Question 5

The output phosphor of the image intensifier is composed of _____.

A) cesium iodide
B) antimony
C) zinc cadmium sulfide
D) graphite

Question 6

The kinetic energy of photoelectrons in the image intensifier is greatly increased by the _____.

A) mAs of the exposure
B) potential difference across the tube
C) cesium iodide at the input phosphor
D) zinc cadmium sulfide at the output phosphor

Question 7

The input phosphor converts _____ to _____.

A) x-rays, electrons
B) light, electrons
C) electrons, light
D) x-rays, light

Question 8

The ability of the eye to detect differences in brightness levels is termed _____.

A) visual acuity
B) scotopic vision
C) photopic vision
D) contrast perception

Question 9

The capability of an image intensifier to increase the illumination level of the image is called its _____.

A) flux gain
B) conversion factor
C) brightness gain
D) veiling glare

Question 10

Visual acuity in the eye is greatest at the _____,where _____ are concentrated.

A) retinal periphery, cones
B) fovea centralis, cones
C) retinal periphery, rods
D) fovea centralis, rods

Question 11

Light produced at the output phosphor of the image intensifier has been increased _____ times in intensity.

A) 5-10
B) 20-35
C) 50-75
D) 100-300

Question 12

The _____ is the product of the minification gain and the flux gain.

A) horizontal resolution
B) brightness gain
C) contrast resolution
D) flux gain

Question 13

The _____ in the retina are stimulated by _____ light; the _____ are stimulated by _____ light.

A) rods, bright; cones, low
B) rods, low; cones, low
C) rods, low; cones, bright
D) rods, bright; cones, bright

Question 14

X-rays that exit the patient and enter the image intensifier first interact with the _____.

A) output phosphor
B) input phosphor
C) photocathode
D) anode

Question 15

With image intensification the light level is raised to _____ vision.

A) photopic
B) scotopic
C) night
D) twilight

Question 16

The image intensifier improved fluoroscopy by increasing image _____.

A) brightness
B) resolution
C) magnification
D) contrast

Question 17

The _____ in the image intensifier emits electrons when it is stimulated by light photons.

A) input phosphor
B) output phosphor
C) photocathode
D) electron gun

Question 18

Image intensified fluoroscopy is performed at illumination levels similar to _____.

A) star gazing
B) darkened theaters
C) night driving
D) radiograph viewing

Question 19

The ratio of x-rays incident on the input phosphor to light photons exiting the output phosphor is called _____ gain.

A) magnification
B) minification
C) brightness
D) flux

Question 20

An image intensifier tube is identified by the diameter of its _____.

A) input phosphor
B) glass housing
C) output phosphor
D) focusing lenses

Question 21

Fluoroscopy for an air contrast barium enema is generally done at _____ kVp.

A) 65-75
B) 70-80
C) 80-90
D) 100-110

Question 22

Brightness gain is typically in the range of _____.

A) 50-75
B) 100-1,000
C) 3,000-4,000
D) 5,000-30,000

Question 23

Automatic brightness control (ABC)maintains the brightness of the image by varying _____.

A) monitor settings
B) kVp and mA
C) monitor bandwidth
D) all of the above

Question 24

Television monitoring allows _____ to be controlled electronically.

A) brightness
B) contrast
C) bandwidth
D) both A and B

Question 25

Viewing the fluoroscopic image in magnification mode increases _____.

A) contrast resolution
B) spatial resolution
C) patient dose
D) all of the above