History of Human Vision

Question 1

X-rays were initially discovered due to their ability to cause…

Answer 1

Fluorescence

Question 2

Who is given credit with inventing the fluoroscope?

Answer 2

Thomas Edison

Question 3

What did first generation fluoroscopes consist of?

Answer 3

Tube, Table, Screen

Question 4

The time it takes for the human eye to adjust to low light levels is called…

Answer 4

Adaption time

Question 5

The types of receptors which are densely concentrated in the posterior portion of the eye are the…

Answer 5

Cones

Question 6

Daylight vision is also known as ____ vision.

Answer 6

Photopic

Question 7

The receptors in the eye which are most sensitive to blue green light, and which are highly sensitive to low levels of illumination are the…

Answer 7

Rods

Question 8

Night vision is also known as…

Answer 8

Scotopic

Question 9

The cones, which are sparsely scattered over the curvature of the retina are used for ___ vision during daylight.

Answer 9

Peripheral

Question 10

In what month and year were x-rays discovered?

Answer 10

Nov 1895

Question 11

What part of the eye is capable of perceiving color?

Answer 11

Cones

Question 12

Prior to the development of the Image Intensifier, in order to enhance the brightness of the image during fluoroscopy, what steps had to be taken?

Answer 12

Increase the technique

Question 13

The first incidence of fluoroscopy was noted by…

Answer 13

Roentgen

Question 14

Rods are ______ to low levels of light.

Answer 14

Sensitive

Question 15

In the early days of fluoroscopy, what was used to view the fluoroscopic images emanating from the screen?

Answer 15

The rods in the periphery of the retina

Question 16

What conversion occurs in the image at the output phosphor of an image intensifier tube?

Answer 16

Electrons are converted to light

Question 17

What conversion occurs in the image at the input phosphor of an image intensifier tube?

Answer 17

X-rays to light

Question 18

What conversion occurs in the image at the photocathode of an image intensifier tube?

Answer 18

Light to electrons

Question 19

The input phosphor of modern image intensifiers is made of…

Answer 19

Cesium Iodide

Question 20

How is the appearance of “ghost images” on the monitor during fluoroscopy prevented?

Answer 20

Curving the tube of IP and PC

Question 21

Output phosphor:

Answer 21

Electrons to light

Question 22

Anode:

Answer 22

Aids in speeding up electrons

Question 23

Input Phosphor:

Answer 23

X-rays to light

Question 24

Photocathode:

Answer 24

Light to electrons

Question 25

Electrostatic Lens:

Answer 25

Keeps electrons in a narrow beam

Question 26

What is the order of the components that make up the Image intensifier?

Answer 26

1. Input phosphor
2. Photocathode
3. Electrostatic Focusing Lens
4. Accelerating Anode
5. Output Phosphor

Question 27

The input phosphor of modern image intensifiers are made up of what material?

Answer 27

Cesium Iodide

Question 28

What happens to the image when the electron beam passes through the focal point inside the image intensifier?

Answer 28

The image is inverted and reversed

Question 29

The image that is produced at the Output Phosphor, in the form of light photons, is the same image that was carried to the input phosphor via the…

Answer 29

Remnant x-ray beam

Question 30

What is the brightness gain for an image intensifier tube having a 4” diameter input phosphor and a flux gain of 50?

Answer 30

800

Question 31

An image intensifier has a brightness gain of 18,000 and a flux gain of 125. The output phosphor diameter is 1”. What is the diameter of the input phosphor?

Answer 31

12”