Fluoroscopy/ Tomography

Question 1

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

Answer 1

Fluoroscopy

Question 2

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

Answer 2

Fluorescence

Question 3

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

Answer 3

Thomas Edison; motion

Question 4

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

Answer 4

X-ray tube, table and fluoroscopic screen

Question 5

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

Answer 5

Dark adapt; red goggles

Question 6

The two types of receptors in the retina are

Answer 6

Rods and cones

Question 7

Cones densely concentrated in the posterior portion of the retina

Answer 7

Fovea centralis

Question 8

Function most efficiently in bright light

Answer 8

Cones

Question 9

Daylight vision is also known as

Answer 9

Photopic vision

Question 10

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

Answer 10

Peripheral vision

Question 11

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

Answer 11

Rods

Question 12

Night vision is also known as

Answer 12

Peripheral or scotopic vision

Question 13

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

Answer 13

Blue-green

Question 14

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

Answer 14

Image intensifier

Question 15

5 Basic elements of the image intensifier

Answer 15

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

Question 16

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

Answer 16

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

Question 17

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

Answer 17

Proportional

Question 18

Photoemissive metal; responds to light from IP and emits electrons

Answer 18

Photocathode (PC)

Question 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

Answer 19

Curved; distance

Question 20

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

Answer 20

Electrostatic focusing lens

Question 21

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

Answer 21

Inverting and reversing

Question 22

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

Answer 22

Accelerating anode

Question 23

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

Answer 23

Zinc Cadmium Sulfide (ZnCdS)

Question 24

Contains the image of the IP in minified form

Answer 24

Output phosphor (OP)

Question 25

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

Answer 25

50 times

Question 26

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

Answer 26

Brightness gain

Question 27

Brightness gain is dependent on these two completely unrelated sources

Answer 27

Minification gain and flux gain

Question 28

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

Answer 28

Minification gain

Question 29

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

Answer 29

``` IP = 4" to 20" OP = 1" ```

Question 30

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

Answer 30

Brightness or intensity

Question 31

``` Flux gain = # of light photons at the _____ / # of light photons at the ____ ```

Answer 31

OP; IP

Question 32

Routine sizes of the input phosphor

Answer 32

4.5", 6", 9", 12" (16", 20")

Question 33

Two most common video cameras used in fluoroscopy

Answer 33

Vidicon and plumbicon

Question 34

Body section radiography

Answer 34

Tomography

Question 35

Tomography is a special x-ray technique that ____ out the ____ of superimposed structures to show more clearly to principle structures being examined

Answer 35

Blurs; shadows

Question 36

In tomography the object being examined is not focused in the normal sense but rather its _________ is enhanced by the blurring of the adjacent structures

Answer 36

Radiographic contrast

Question 37

Three other names for tomography

Answer 37

Planigraphy, stratigraphy and laminography

Question 38

Consists of an x-ray tube, movable bucky, and rigid connecting rod which rotates about a fixed fulcrum

Answer 38

Linear tomography

Question 39

The imaginary pivot point about which the tube and film move. It lies within the object or focal plane

Answer 39

Fulcrum

Question 40

Fulcrum is stationary; table and patient is raised or lowered

Answer 40

Grossman principle

Question 41

Adjustable fulcrum system where the fulcrum is raised or lowered and the patient/table remains stationary

Answer 41

Plaingraphic principle

Question 42

Determines the thickness of the tomographic cut

Answer 42

Tomographic angle

Question 43

Large angle = _____ thickness | Small angle = ______ thickness

Answer 43

Small; large

Question 44

Name the six types of tube motion

Answer 44

``` Linear Circular Elliptical Figure 8 Hypocycloidal Spiral/tri-spiral ```

Question 45

How do you determine the level of the tomo scout?

Answer 45

1. Measure the patient 2. Divide the measurement by 2 3. Subtract 2 from that number