Fluoroscopy/ Tomography Flashcards Preview

Physics > Fluoroscopy/ Tomography > Flashcards

Flashcards in Fluoroscopy/ Tomography Deck (45)
Loading flashcards...
1

A dynamic radiographic examination which make possible the visualization of internal organs in motion

Fluoroscopy

2

X-rays were initially discovered by Dr. Roentgen because of their ability to cause ________

Fluorescence

3

The Fluoroscope was invented by _____ in 1896 which was used to visualize the _____ of internal structures and fluids

Thomas Edison; motion

4

First generation fluoroscopes consisted of an ______, ______, and ________.

X-ray tube, table and fluoroscopic screen

5

Radiologists had to "________" their eyes for 20-30 minutes or use __________.

Dark adapt; red goggles

6

The two types of receptors in the retina are

Rods and cones

7

Cones densely concentrated in the posterior portion of the retina

Fovea centralis

8

Function most efficiently in bright light

Cones

9

Daylight vision is also known as

Photopic vision

10

Cones sparsely scattered over the rest of the retina are used for _________ during daylight

Peripheral vision

11

Located around the periphery of the retina and function best with low levels of illumination

Rods

12

Night vision is also known as

Peripheral or scotopic vision

13

Rod are most sensitive to _______ wavelengths of light; which is why radiologist use red goggles to filter it out

Blue-green

14

An electronic vacuum tube that converts the pattern of the x-ray beam to a bright light image

Image intensifier

15

5 Basic elements of the image intensifier

1. Input phosphor (IP)
2. Photocathode
3. Electrostatic focusing lens
4. Accelerating anode
5. Output phosphor (OP)

16

Newer IPs are made of ________ while older IPs are made of ________

Cesium Iodide (CsI); Zinc Cadmium Sulfide (ZnCdS)

17

The intensity of the light produced by the IP is ________ to the number of x-rays incident on it

Proportional

18

Photoemissive metal; responds to light from IP and emits electrons

Photocathode (PC)

19

Both IP and PC are ______ for undistorted focusing of the e- beam; this causes all the e- to travel the same _______ to the OP

Curved; distance

20

Functions in the same manner as the focusing cup by directing the e- to the OP

Electrostatic focusing lens

21

All e- converge/ meet at the focal point resulting in ______ and _______ of the image

Inverting and reversing

22

Located at the neck of the tube which functions to accelerate e- toward the OP

Accelerating anode

23

The OP is made of ________ ranging in size from 1/2" to 1" in diameter.

Zinc Cadmium Sulfide (ZnCdS)

24

Contains the image of the IP in minified form

Output phosphor (OP)

25

The OP produces _____ more light than the IP due to the high KE of the e- beam

50 times

26

The ability of the image intensifier to increase the illumination level of the image

Brightness gain

27

Brightness gain is dependent on these two completely unrelated sources

Minification gain and flux gain

28

Occurs due to the same number of light photons produced on IP being compressed to the small area of the OP

Minification gain

29

Input phosphor diameter can be from ___ to ___ and the output phosphor diameter is usually ____

IP = 4" to 20"
OP = 1"

30

M.G. is simply to increase _______ or _____, not to improve the quality or number of light photons of the image

Brightness or intensity