Interpretation Principles

Question 1

What are the five opacities of radiography?

Answer 1

Air
Fat
Water
Bone
Metal

In order from darkest to lightest

Question 2

Of the five opacities, soft tissue is that same as ________

Answer 2

water

Question 3

What provides contrast in abdominal images?

Answer 3

fat

Question 4

What problems can occur due to x rays being 2d images of 3d objects?

Answer 4

Magnification/distortion
Loss of depth perception
Superimposition and summation shadows

Question 5

When patients are farther away from the flat plate - how will the image appear?

Answer 5

Magnified and blurry

*better images are taken when the patient is as close as possible to the plate

Question 6

______ is a special case of uneven magnification

Answer 6

Distortion

Question 7

What is super imposition?

Answer 7

A structure appears in an unexpected location and is misinterpreted as a lesion

(example from class - tick on the side of a dog appearing to be a lesion in the lung on lateral thorax rad)

Question 8

What is summation?

Answer 8

A special case of superimposition where overlapping structures create a summation opacity that is not really present in the patient

Question 9

What is silhouette sign?

Answer 9

The effacement or loss of visualization of the border of two structures of the same radiographic opacity that are in contact

(example from class - not being able to see the coronary band on the heart since they are of the same opacity and in contact)

Question 10

What way should the patients head always be facing when interpreting radiographs?

Answer 10

Head to the left (on lateral views - this is the case for all rads - even stifles etc)

Head at the top of the screen on VD - DV

Question 11

At what point on the distal limbs, does the orientation become dorsal - palmer/plantar?

Answer 11

At the level of the carpus or tarsus and below

Question 12

When interpreting limb radiographs, how should they be oriented?

Answer 12

Proximal at the top of the screen

Distal at the bottom of the screen

Question 13

T/F: When looking at a VD view - the patient’s right side should be on your right side

Answer 13

FALSE

The patients left side will be on the viewers right

Question 14

If you’re taking a right lateral radiograph of a dogs thorax - in what recumbency should the patient be?

Answer 14

Right

Question 15

What are the six roentgen signs that should be used to evaluate x rays?

Answer 15

Size
shape
number
location
margination
opacity