Exposure 2 Powerpoint

Front 1

misrepresentation of an anatomic structure on an image receptor (size and shape) is known as

Back 1

distortion

Front 2

the sharpness of anatomic structures displayed on an image receptor is the

Back 2

recorded detail

Front 3

the overall blackness of the image is the

Back 3

density (mAs)

Front 4

the difference between adjacent densities on a radiograph is the

Back 4

contrast

Front 5

recorded detail (overall sharpness) depends on what 4 factors

Back 5

-oid

-sid

-fss

-screen speed

Front 6

distortion (misrepresentation) depends on what 3 factors

Back 6

-oid

-sid

-tube/part/film alignment

Front 7

mAsdn is an acronym for what rule

Back 7

mAs controls film density

Front 8

KCCL represents what rule

Back 8

Kvp

Controls

Contrast

quaLity

Front 9

T/F: a significant amount of mAs will compensate for a lack of kVp

Back 9

FALSE!! mAs controls the overall darkness; kVp will control the penetrability, therefore, mAs will not increase the energy of the beam

Front 10

high kV will carry long/short wavelengths

Back 10

short (more energy, which means higher frequency or more wavelengths in a sec)

Front 11

a high kV carries a long/short scale of contrast

Back 11

Long; many shades of gray

B///////////////////////////W

Front 12

a high kV has a wide/narrow latitude

Back 12

wide latitude

Front 13

what type of radiation exits the patient and carries the information to the film

Back 13

remnant radiation

Front 14

the invisible image on film after exposure/before processing is

Back 14

latent image

Front 15

visible image on film after processing is the

Back 15

manifest image

Front 16

what are the 2 components of recorded detail (aka resolving power)

Back 16

-contrast resolution

-spatial resolution (lp/mm)

Front 17

spatial resolution refers to

Back 17

how small an object can be imaged

Front 18

Very fast screens carry lp/mm of

Back 18

7

Front 19

direct exposure film has how many lp/mm

Back 19

50

Front 20

as intensification factor increases, spatial resolution will

Back 20

decrease

Front 21

on which end of the tube is penumbra greatest

Back 21

cathode end; place thickest part under the cathode end (known as Heel Effect or FATCAT)

Front 22

Better detail occurs under which end of the tube

Back 22

Anode; place area of interest under anode to see better detail

Front 23

3 Factors of unsharpness (mgm)

Back 23

-motion

-geometry (measurable)

-materials (measurable)

Front 24

4 methods to reduce exposure time

Back 24

-mA/time relationship

-kVp/mAs rule

-screen speed

-SID

Front 25

3 Factors of material unsharpness are

Back 25

-Film/screen contact (most intrisitic)

-Screen use

-Film used

Front 26

This evaluates a system's ability to record an extremely narrow beam slit of 10 microns wide

Back 26

Line Spread Function

Front 27

Ideal film screen contact includes this

Back 27

Absolute contact/complete contact

Front 28

Where is unsharpness evident on the film

Back 28

Only in the immediate area of the poor contact

Front 29

Inherent unsharpness with screens formula

Back 29

old sharpness X pc^2

Front 30

Material Unsharpness of slow screens is

Back 30

0.25 mm

Front 31

material unsharpness of par screens is

Back 31

0.35 mm

Front 32

material unsharpness of high screens is

Back 32

0.45 mm

Front 33

material unsharpness of rare earth screens is

Back 33

0.55 mm

Front 34

more/less xray photons needed for adequate density w/ screens

Back 34

less

Front 35

more/less radiographic technique needed w/ screens

Back 35

less

Front 36

more/less dose to the patient w/ screens

Back 36

less

Front 37

worse/better resolution w/ screens

Back 37

worse

Front 38

more/less contrast w/ screens

Back 38

more

Front 39

wide/narrow exposure latitude (gray tones) w/ screen

Back 39

narrow (fewer gray tones/increased contrast)

Front 40

any material that emits light in response to some outside stimulation is called

Back 40

luminescence or a phosphor (screen characteristic)

Front 41

Luminescence involves ______ of outer shell electrons' energy levels

Back 41

excitation

Front 42

2 types of luminescence are

Back 42

-fluoro (light emitted within 10^-8 sec)

-Phosphor (light emitted beyond) aka screen lag or afterglow ADDS DENSITY

Front 43

Speed screens range from _____ to _____

Back 43

50 to 1200, w/ par being 100

Front 44

As speed increases, detail will

Back 44

decrease

Front 45

Intensification factor will _____ as kVp rises

Back 45

increase

Front 46

As phosphor size and layer thickness increases, detail and dose will

Back 46

decrease

Front 47

As phosphor size and layer thickness increases, film density will

Back 47

increase

Front 48

If the anode bevel angle is less than 45 degrees, the EFSS is ____ than the actual FSS

Back 48

smaller (line focus principle)

Front 49

This is a problem which may arise from increasing mA applied to the tube; loss of image resolution; very little significance, but occurs in angography

Back 49

Blooming of Focus

Front 50

absorption of the xrays or a reduction in the amount as they pass through matter is known as

Back 50

attenuation

Front 51

what 2 factors determine attenuation

Back 51

-z number

-tissue density

Front 52

atomic number of bone is

Back 52

13

Front 53

atomic number of soft tissue is

Back 53

about 6

Front 54

A high Z number, such as bone, will appear

Back 54

radiopaque (white)

Front 55

secondary and scattered radiation produces ____ on the radiograph

Back 55

fog

Front 56

when kV is increased, the wavelength will increase/decrease allowing more radiation to go through the body

Back 56

decrease

Front 57

short scale contrast has ___ grays, ____ contrast, produced w/ ____ kV, and w/ ____wavelengths

Back 57

-few grays (narrow latitude)

-high

-low kV

-increasing wavelengths

Front 58

exposure or intensity is controlled by

Back 58

mAs