Radiographic Distortion

Question 1

Radiographic Distortion

The ___ from true ___ or ___ of an object.

Answer 1

Radiographic Distortion

The deviation from true size or shape of an object.

Question 2

What are two categories of radiographic distortion?

1. ___ distortion (___)
2. ___ distortion (___ distortion)

Answer 2

What are two categories of radiographic distortion?

1. Size distortion (Magnification)
2. Shape distortion (True distortion)

Question 3

Size Distortion

___ of actual size of the object.

• Magnification = ___ the true size
• Minification= ___ than true size

Answer 3

Size Distortion

Misrepresentation of actual size of the object.

• Magnification = enlarges the true size
• Minification= smaller than true size

Question 4

What 2 things is size influenced by?

Answer 4

• SID
• OID

Question 5

Size Influenced by SID (also influences your detail)

SID – ___” SID true to size due to the use of the ___ rays of the beam.

• Longer the SID = ___ to size
• Shorter the SID = ___ of the size

Answer 5

Size Influenced by SID (also influences your detail)

SID – 72” SID true to size due to the use of the parallel rays of the beam.

• Longer the SID = true to size
• Shorter the SID = magnification of the size

Question 6

Size Influenced by OID

OID = You want the area of ___ as ___ to the image receptor as possible.

• Increase OID = ___
• Decrease OID = less ___

Answer 6

Size Influenced by OID

OID = You want the area of interest as close to the image receptor as possible.

• Increase OID = magnification
• Decrease OID = less magnification

Question 7

Patient Thickness

You will always have some degree of ___ on the radiographic image. Due
to:

___ (___ to ___ ___)
Since the body structures are not in the ___ ___, some structures will be ___ to the film than others.

• Increase patient size – object size ___
• Decrease patient size – object size ___

Answer 7

Patient Thickness

You will always have some degree of magnification on the radiographic image. Due
to:

SOD (source to object distance)
Since the body structures are not in the same plane, some structures will be closer to the film than others.

• Increase patient size – object size increases
• Decrease patient size – object size decreases

Question 8

Shape Distortion

Shape distortion is ___ distortion. The object is no longer “___” like itself.

Structures can appear:
1. ___ 2. ___ 3. ___ from ___ position

Answer 8

Shape Distortion

Shape distortion is true distortion. The object is no longer “shaped” like itself.

Structures can appear:
1. elongated 2. foreshortened 3. displaced from normal position

Question 9

To Minimize Shape Distortion

1. Part-IR Relationship – the plane of interest should be ___ to the plane of the IR.
2. CR Part-IR Alignment- the plane of interest should be ___ with the plane of the ___ and the ___ should be ___ to the plane of the IR.
3. CR Direction – CR ___ to the plane of the interest.

Answer 9

To Minimize Shape Distortion

1. Part-IR Relationship – the plane of interest should be parallel to the plane of the IR.
2. CR Part-IR Alignment- the plane of interest should be parallel with the plane of the IR and the CR should be perpendicular to the plane of the IR.
3. CR Direction – CR perpendicular to the plane of the interest.

Question 10

Do we use distortion to our advantage?

Yes, all the time!

• To avoid ___ structures.
• To better demonstrate ___ structures.

Answer 10

Do we use distortion to our advantage?

Yes, all the time!

• To avoid superimposed structures.
• To better demonstrate anatomical structures.