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

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 2

directly proportional

Question 3

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

Answer 3

flux

Question 4

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

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

Question 5

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 6

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

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

Question 7

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

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

Question 8

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 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

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 11

What is the milliamperage used during fluoroscopy?

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

Question 12

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 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

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 15

The image intensifier improved fluoroscopy by increasing image _________________.

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

Question 16

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 17

The input phosphor converts _________ to _________.

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

Question 18

Electrons hit the _______________ after exiting the anode.

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

Question 19

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 20

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

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

Question 21

Television monitoring allows ________________ to be controlled electronically.

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

Question 22

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 23

Brightness gain is typically in the range of ____________.

A) 50-75
B) 100-1,000
C) 3000-4000
D) 5000-30,000

Question 24

Viewing the fluoroscopic image in magnification mode increases _____________.

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

Question 25

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