Ch 10 Radiographic Quality II

Question 1

What is film speed affected by?

Answer 1

• Immersion time
• Temperature
• Chemical activity

Question 2

The longer the film stays in the chemical bath, the _______ the line becomes.

Answer 2

Straighter

Question 3

If you increase your speed, what happens to your mAs?

Answer 3

It goes down

Question 4

Speed and mAs are _______ proportional.

Answer 4

Inversely

Question 5

A wide latitude, would have ____ shades of gray.

Answer 5

Many

Question 6

A narrow latitude, would have a ______ scale of contrast

Answer 6

Short

Question 7

Latitude and contrast are _______ proportional.

Answer 7

Inversely

Question 8

What is Latitude?

Answer 8

Range of exposures that will produce densities within the diagnostic range

Question 9

What is the formula for Latitude?

Answer 9

Latitude= E h - E I

Question 10

E h=

Answer 10

High exposure point OD 2.50

Question 11

E l=

Answer 11

Low exposure point OD 0.25

Question 12

A narrow latitude film requires ______ exposure accuracy and produces short gray scales.

Answer 12

Greater

Question 13

The _______ amount of magnification should be maintained.

Answer 13

Smallest

Question 14

What is the ratio of image size to object size?

Answer 14

Magnification

Question 15

Some magnification will _____ exist.
40”-?
72”-?

Answer 15

Always
40”- 1.1
72”- 1.05

Question 16

What is SOD?

Answer 16

Source to object distance

Question 17

What is OID?

Answer 17

Object to image distance

Question 18

What is the acceptable magnification range?

Answer 18

?

Question 19

How many cm are in an inch?

Answer 19

2.5

Question 20

What are the (2) factors that effect image magnification?

Answer 20

1. SID

2. OID

Question 21

What is distortion?

Answer 21

Unequal magnification of different portions of the same object

Question 22

Distortion is dependent on…

Answer 22

• Thickness of object/ part
• Position
• Shape of the object

Question 23

The thicker the object the _____ distortion present on the final radiograph.

Answer 23

More

Question 24

We must compensate for object unsharpness with factors we can control, such as:

Answer 24

• Focal spot size
• SID
• OID

Question 25

Fine detail=

Answer 25

Small focal spot

Question 26

Smaller x-ray beam width will produce a _____ image.

Answer 26

Sharper

Question 27

General radiology uses _____ focal spot

Answer 27

Large

Question 28

The larger the focal spot the more ____ you get.

Answer 28

Penumbra

Question 29

What is Penumbra?

Answer 29

Fuzzy border that appears outside the image

Question 30

The greater the distance between tube and the cassette, the greater the image...

Answer 30

Sharpness

Question 31

To reduce penumbra, use the _____ amount of SID.

Answer 31

Maximum

Question 32

The closer the object to the film, the _____ the detail.

Answer 32

Sharper

Question 33

When OID goes down, penumbra goes down and sharpness goes ____.

Answer 33

Up

Question 34

When OID goes up, penumbra goes up and sharpness goes ____.

Answer 34

Down

Question 35

Penumbra and Sharpness are _______ relational.

Answer 35

Inversely

Question 36

Objects not on the central axis appear ______.

Answer 36

Distorted

Question 37

If the object plane and the image plane are not parallel, image _______ will appear.

Answer 37

Distortion

Question 38

What is Foreshortening?

Answer 38

Image size is reduced as the angle on inclination along the central axis increases

Question 39

What is elongation?

Answer 39

The image size is lengthened as the inclination is increased

Question 40

What is shape distortion?

Answer 40

The misrepresentation by unequal magnification of the actual shape of the structure being examined

Question 41

The farther away the part of interest is from the CR of the image receptor, the greater the ______.

Answer 41

Distortion

Question 42

What is focal spot blur?

Answer 42

Focal spot is not a point, but rather a rectangular source (0.1- 1.5mm)

Question 43

What is the most important factor in determining resolution?

Answer 43

Focal spot blur

Question 44

What is focal spot blur caused by?

Answer 44

- Large effective focal spot - Short SID - Long OID

Question 45

What side of the tube is focal spot blur the greatest?

Answer 45

The cathode side

Question 46

How do you minimize focal spot blur?

Answer 46

- Use small focal spots - Decrease OID - Increase SID

Question 47

The difference between SID and OID =

Answer 47

SOD

Question 48

Can you control subject factors?

Answer 48

No