Ch. 29 Distortion (Exp II)

Question 1

Distortion is a misrepresentation of…

Answer 1

Size and shape

Question 2

Size distortion in radiography can be ____ only.

Answer 2

Magnification

Question 3

Size distortion is controlled by…

Answer 3

• SID
• OID
• Radiographic distances

Question 4

As size distortion decreases, the resolution of recorded detail….

Answer 4

Increases

Question 5

The ____ the SID, the ____ the magnification.

Answer 5

Greater; smaller

Question 6

Examinations of body parts with a large inherent OID warrant a ____ whenever possible.

Answer 6

Large SID

Question 7

Which examination does not exhibit an inherently large OID?

a. AP lumbar spine
b. Lateral c-spine
c. Lateral chest
d. AP facial bones

Answer 7

a. AP lumbar spine

Question 8

As OID increases and SID remains constant, entrance skin exposure (ESE)…

Answer 8

Increases

Question 9

Large patients receive a greater exposure than small patients because their….

Answer 9

• SOD is decreased
• OID is increased
• Entrance skin surface is closer to the source

Question 10

The magnification factor for a radiographic procedure is calculated at 1.25. It may be assumed that there is a ____ magnification of the object.

Answer 10

125%

Question 11

What occurs when the tube or the image receptor is not properly aligned?

Answer 11

Elongation

Question 12

What occurs when the part is not properly aligned?

Answer 12

Foreshortening

Question 13

Proper alignment is achieved when the central ray is ____ to the part and ____ to the image receptor.

Answer 13

Perpendicular; perpendicular

Question 14

When the position of the patient is reversed, the direction of the tube angle must be ____ to maintain the relationship.

Answer 14

Reversed

Question 15

Because the x-ray beam is divergent,

Answer 15

Minification is impossible.

Question 16

x-ray tube angulations inherently…

Answer 16

• Change SID

- Introduce magnification to some degree

Question 17

In order to achieve a true SID of 40’’ with an x-ray tube angle of 30 degrees, the overhead scale should read

Answer 17

34.6’’

Question 18

Performing a routine chest radiograph in the AP projection will…

Answer 18

Produce improved resolution of the thoracic spine

Question 19

A renal calculus that measures 0.2 mm in size…

Answer 19

Cannot be visualized with an effective focal spot of 0.5 mm focal spot due to penumbral overlap

Question 20

Opening up the intervertebral joints of the cervical spine would best be accomplished with…

Answer 20

The patient in an AP projection with a 40” SID.