Rads 3033 Chapter 8 Image Production

Front 1

how does image production work

Back 1

photons pass through tissue and interact with the image receptor

Front 2

what is an image receptor

Back 2

a device that receives the radiation leaving the patient

Front 3

what affects the primary x-ray beam interaction with the various tissues that make up the anatomic part

Back 3

quantity and quality of the beam

Front 4

___________ of the anatomic tissues affects the beam interaction

Back 4

composition

Front 5

composition of anatomic tissues

Back 5

thickness, atomic number, tissue density

Front 6

what determines absorption characteristics of anatomic parts

Back 6

its composition

Front 7

how is the late image formed

Back 7

radiation exits the patient and is composed of varying energies and interacts with the IR

Front 8

as the primary beam passes through anatomic tissue, it loses some of its energy. This reduction in the energy or number of photons in the primary x-ray beam is known as what

Back 8

beam attenuation

Front 9

beam attenuation occurs as a result of what

Back 9

the photon interactions with the atomic structures that compose the tissue

Front 10

when does complete absorption of the incoming x-ray photon occur

Back 10

when it has enough energy to eject an inner-shell electron

Front 11

what is the name of the electron that is ejected from the inner-shell during complete absorption

Back 11

photoelectron

Front 12

quickly loses energy by interacting with nearby tissue

Back 12

photoelectron

Front 13

what is ionization

Back 13

the ability to eject electrons

Front 14

in the diagnostic range the ability to eject electrons is known as

Back 14

the photoelectric effect

Front 15

with the _____________ ______ the ionized atom has a vacancy or electron hole in its inner shell. An election from an _____-_____ drops down to fill the vacancy

Back 15

photoelectric effect

outer-shell

Front 16

for photoelectric events to occur,

Back 16

the incident x-ray energy must be equal or greater than the orbital shells binding energy

the incident x-ray photon interacts with the inner-shell electron of a tissue atom and remove it from orbit

Front 17

in this process the incident x-ray photon expends all of its energy and it totally absorbed

Back 17

photoelectric effect

Front 18

when incoming photons are not absorbed,but instead lose energy during interaction with the atoms composing the tissue its called __________ and is a result of _______ ______

Back 18

scattering

compton effect

Front 19

results from the diagnostic x-ray interaction known as the compton effect

Back 19

scatter

Front 20

the loss of some energy of the incoming photon occurs when it ejects an outer-shell electron from a tissue atom. The ejected electron is called a

Back 20

compton electron or secondary electron

Front 21

in the compton effect the remaining low energy photon changes direction and may do what

Back 21

leave the anatomic part to interact with the IR

Front 22

does scatter contribute to useful information to the image, why or why not

Back 22

no, it only results in image fog

Front 23

why is it desired to minimize compton scatter

Back 23

because most scattered photons are still directed towards the IR and fog the image

Front 24

why are compton interactions important in radiography

Back 24

because they can occur within all diagnostic x-ray energies

Front 25

the probability of a commton interaction occurring depends on what

Back 25

the energy of the incoming photon

Front 26

does common interaction depend on anatomic tissue

Back 26

no

Front 27

incoming photon has sufficient energy to eject an inner-shell electron and be completely absorbed

Back 27

photoelectric effect

Front 28

incoming photon loses energy when it ejects an outer-shell electron and changes direction

Back 28

compton effect

Front 29

an electron from an outer-shell fill the electron hole or vacancy in

Back 29

the photoelectric effect

Front 30

the scattered photon may be absorbed within the patients tissues, leave the anatomic part, interact with the image receptor, or expose anyone nearby in

Back 30

the compton effect

Front 31

a secondary photon is credited because of the difference in binding energies in

Back 31

the photoelectric effect

Front 32

scattered photon strike the IR and provide no useful information in

Back 32

the compton effect

Front 33

the probability of the photoelectric effect depends on what

Back 33

the energy of the incoming x-ray photon and the composition of the anatomic tissue

Front 34

fewer photon interactions happen at _____ kVp settings, but of those interaction, a smaller percentage are _____________ ____________

Back 34

higher

photoelectric interactions

Front 35

when does coherent scattering

Back 35

with low-energy x-rays, typically below the diagnostic range

Front 36

what happens in coherent scattering

Back 36

the incoming photon interacts with the atom, causing it to become excited. The x-ray does not lose energy but changes direction

Front 37

is coherent scatter considered an important interaction in radiography

Back 37

no

Front 38

what is it called if the incoming x-ray photon passes through the anatomic structures without the anatomic structures, it is called

Back 38

transmission

Front 39

the combination of __________ and____________ of the x-ray beam provides an image that structurally represents the anatomic part

Back 39

absorption and tranmission

Front 40

what factors affect beam attenuation

Back 40

tissue thickness, type of tissue, and x-ray beam quality

Front 41

x-ray are attenuated ___________ and generally reduced by __% for every _-_ cm of tissue thickness

Back 41

exponentially

50%

4-5

Front 42

the _______ the anatomic tissue the more x-ray are needed

Back 42

thicker

Front 43

tissue with a higher ______ ______ attenuates the -ray beam more than tissues with lower ______ _______

Back 43

atomic number

atomic numbers

Front 44

what does higher atomic number of tissue indicate

Back 44

there are more atomic particles to absorb or scatter the x-ray photon

Front 45

absorption is not likely to occur in tissues with a higher atomic number

tor f

Back 45

false

Front 46

tissues that absorb more x-rays demonstrate what on film and what in digital

Back 46

light areas on film

greater brightness in digital

Front 47

tissues with more transmission demonstrate what on film and what in digital

Back 47

darker on film

less brightness in digital

Front 48

how does tissue density affect beam attenuation

Back 48

the more dense the more attenuation

Front 49

during x-ray production what determines the energy or penetrability of the x-ray photon and its attenuation in anatomic tissue

Back 49

kVp

Front 50

what energy x-ray beam decreases beam attenuation and what increases it

Back 50

higher energy x-ray beam

lower energy x-ray bean

Front 51

higher penetrating x-ray are more likely to

Back 51

be transmitted though anatomic tissue without interacting with the tissues' anatomic structures

Front 52

higher penetrating x-rays are _____ in wavelength and _____ in frequency

Back 52

shorter

higher

Front 53

lower penetrating x-rays are more likely to

Back 53

interact with the anatomic structures and either be absorbed or scattered

Front 54

lower penetrating x-rays are ______ in wavelength and _____ in frequency

Back 54

longer

lower

Front 55

what percentage of the x-ray beam interacting with the anatomic part reaches the IR how much is used to create the radiographic image

Back 55

less than 5% reaches the IR and an even less percentage of that creates the image

Front 56

what creates the latent image

Back 56

the exit or remnant radiation leaving the patient interacts with an IR to create the latent image

Front 57

how do you produce the manifest image

Back 57

by processing the film

Front 58

how many types of IR are there and what kind of image do they produce

Back 58

two types: film/screen and digital and they both produce static images of the area of interest

Front 59

what type of IR uses a cassette for the film and the film is placed between two intensifying screens within the cassette

Back 59

film/screen

Front 60

what is a cassette

Back 60

light-tight container

Front 61

when exit radiation interacts with the intensifying screens in film/screen what is it converted too

Back 61

light

Front 62

the visual light emitted by the intensifying screen is proportional to what

Back 62

the radiation exiting the patient

Front 63

why can less radiation be used when using film/screen

Back 63

because of the intensifying screens

Front 64

do intensifying screens reduce patient exposure

Back 64

yes

Front 65

what type of imaging can be accomplished by using a specialized IR that acquires the latent image and then the computers processes the manifest image for monitor display

Back 65

digital imaging

Front 66

there is only one type of IR used for digital imaging

t or f

Back 66

no there are several

Front 67

film acquires, process, and displays image

Back 67

film/screen

Front 68

IR acquires, computer processes, monitor displays

Back 68

digital

Front 69

reguardless of the type of digital IR the image is composed of digital data and can be manipulated

t or f

Back 69

true

Front 70

how does fluoroscopy differ for static imaging

Back 70

it uses a continuous beam of x-rays to create images go moving internal structures that can be viewed on a monitor

Front 71

internal structures, such as vascular or gastrointestinal systems, can be visualized in their normal state of motion with the aid of ________ _____ that are ________ or ________

Back 71

contrast media

injected or ingested

Front 72

in fluro internal images can be best visualized when the images are brighter, which is accomplished with _____ _______________

Back 72

image intensification

Front 73

what is image intensification

Back 73

the process in which radiation from the anatomic area of interest interacts with a light-emitting material (input phosphor) for conversion to visible light

Front 74

in image intensification the light intensities (________) are equal to the intensity of the ____ _________ and are converted to _________ by a ____________

Back 74

energies

exit radiation

electron

photocathode

Front 75

in image intensification the electrons are focused by _____________ ________ ______ and the accelerated toward an _____ to strike the output phosphor and create a ________ _____ (__________ ____)

Back 75

electrostatic focusing lenses

anode

brighter image

brightness gain

Front 76

accelerating the electrons increases the light intensities at the output phosphor is what

Back 76

flux gain

Front 77

the reduction in the size of the output phosphor image as compared with input phosphor also increases the light intensifies is what

Back 77

minification gain

Front 78

what is brightness gain

Back 78

the product of flux gain and magnification gain and results in brighter image on the output phosphor

Front 79

In what are the image light intensities from the output phosphor are converted to an electronic video signal to display for monitor viewing

Back 79

dynamic IR: Fluoroscopy

Front 80

what additional filming devices can be attached to the fluoroscopic system to create permanent radiographic images of specific areas of interest

Back 80

spot film or cine