FILM FACTORS Flashcards

1
Q

• The study of the relationship between the intensity of exposure of the
film and the blackness after processing is called

A

sensitometry

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

6 types of FILM FACTORS

A

SPEED, PROCESSING TIME, PROCESSING TEMPERATURE, LATITUDE, DENSITY, CONTRAST

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

The two principal measurements involved in sensitometry are the
____ and ______
the processed film.

A

exposure to the film and the percentage of light transmitted through

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

The two principal measurements involved in sensitometry are the
____ and ______
the processed film.

A

exposure to the film and the percentage of light transmitted through

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

It describe the relationship between OD and radiation exposure.

A

H & D curve
Hurter and Driffield

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

– low radiation exposure level

A

Toe

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

– intermediate radiation exposure level
– the region in which a properly exposed
radiograph appears

A

Straight line portion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

– high radiation exposure level

A

Shoulder

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Apparatus that are needed to construct a characteristic curve:

A
  1. Optical step wedge / sensitometer
  2. Densitometer - a device that measures OD
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Apparatus that are needed to construct a characteristic curve:

A
  1. Optical step wedge / sensitometer
  2. Densitometer - a device that measures OD
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

The degree of blackening on the radiograph.
• It is a logarithmic function.
• Has a precise numeric value that can be calculated if the level of
light incident on a processed film (Io) and the level of light
transmitted through that film (It
) are measured.

A

OPTICAL DENSITY

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

is attributable to the composition of the base and the tint
added to the base to make the radiograph more pleasing to the eye.

A

Base density

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Base density has a value of approximately .

A

0.1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

results from inadvertent exposure of film during storage,
undesirable chemical contamination, improper processing, and a
number of other influences.

A

Fog density

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Fog density on a processed radiograph should not exceed .

A

0.1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

The useful range of OD is approximately

A

0.25 to 2.5.

17
Q

Base plus fog OD has a range of approximately

A

0.1 to 0.3.

18
Q

The ____ states that the OD on a radiograph is proportional
only to the total energy imparted to the radiographic film and
independent of the time of exposure.

A

reciprocity law

19
Q

Whether a radiograph is made with short exposure time or long
exposure time, the reciprocity law states that the

A

OD will be the same
if the mAs value is constant.

20
Q

The difference in optical density.

A

High Contrast
Low Contrast

21
Q
  • radiograph that has marked differences in OD
A

high contrast

22
Q
  • the OD differences are small and are not distinct
A

low contrast

23
Q

is the product of image receptor contrast and
subject contrast.

A

Radiographic contrast

24
Q

is inherent in the screen-film combination and
is influenced somewhat by processing of the film.

A

Image receptor contrast

25
Q

is determined by the size, shape, and x-ray
attenuating characteristics of the anatomy that is being examined and
the energy (kVp) of the x-ray beam.

A

Subject contrast

26
Q

The average gradient is the slope of a straight line drawn between two
points on the characteristic curve at ODs __ and __ above base and
fog densities. This is the approximate useful range of OD on most
radiographs.

A

0.25 and 2.0

27
Q

Most radiographic image receptors
have an average gradient in the
range of

A

2.5 to 3.5.

28
Q

is probably more
important than average gradient for
general radiography because many
clinical ODs appear in the toe region of
the characteristic curve.

A

Toe gradient

29
Q

is
more important for mammography.

A

Midgradient or shoulder gradient

30
Q

• Fast/high speed IR
• Par speed
• Slow/low/detail IR

• Slow speed → less noise → more patient dose
• Fast speed → more noise → less patient dose

A
  • more than 100
  • 100
  • less than 100
31
Q

→ long gray scale → low contrast

A

Wide latitude

32
Q

→ short gray scale → high contrast

A

Narrow latitude

33
Q

is required for optimal image receptor
contrast because the degree of development has a
pronounced effect on the level of fog density and on the ODs
resulting from a given exposure at a given image receptor
speed.

A

Proper film processing

34
Q

FACTORS THAT MAY AFFECT THE FINISHED RADIOGRAPH

A

-CONCENTRATION OF PROCESSING CHEMICALS
-DEGREE OF CHEMISTRY
AGITATION DURING
DEVELOPMENT
-DEVELOPMENT TIME
-DEVELOPMENT TEMPERATURE