3.15 Radiographs of Thorax

Question 1

x-rays:

Answer 1

-form of electromagnetic radiation
-composed of photon particles
-density of matter determines the amount of transmitted and absorbed photons

Question 2

Radiopacity:

Answer 2

-matter of higher density results in GREATER absorption of photons and a WHITER image

Question 3

Radiolucency:

Answer 3

-matter of lower density results in LESS absorption of photons and a DARKER image

Question 4

5 opacities:

Answer 4

-radiolucent: air
-fat
-soft tissue/fluid
-mineral
-radiopaque: metal

Question 5

Structures are only visible if:

Answer 5

-the adjacent structure has a DIFFERENT OPACITY
-thoracic structures are highly visible b/c most structures are surrounded by air

Question 6

Effacement:

Answer 6

-contacting structures of the same opacity CANNOT be distinguished from each other

Question 7

Projections and hanging protocol

Answer 7

-head of animal always displayed to left or top of screen
-for VD/DV, animal’s right is to the L. of the screen

Question 8

x-ray machine:

Answer 8

1. Generator
2. Collimator
3. X-ray photons
4. Detector

Question 9

Normal visible structures: extrathroacic

Answer 9

-musculoskeletal
>vertebrae
>ribs
>sternebrae
>thoracic limbs
>muscles
>soft tissues
-cranial abdomen

Question 10

Normal visible structures: respiratory

Answer 10

-lung parenchyma
-trachea
-bronchi

Question 11

Normal visible structure: cardiovascular

Answer 11

-cardiac silhouette
-aorta
-caudal vena cava
-pulmonary vessels

Question 12

Air:

Answer 12

-lung parenchyma
-airways (trachea and bronchi)

Question 13

Fat:

Answer 13

-mediastinal
-pericardial
-pleural
-subcutaneous
-falciform fat

Question 14

Soft tissue:

Answer 14

-cardiovascular structure
-mediastinum
-skin and muscle
-cranial abdominal organs

Question 15

Mineral:

Answer 15

-bones
-+/- gastric content

Question 16

Metal:

Answer 16

-microchip
-markers

Question 17

Anticlinal vertebrae:

Answer 17

-where orientation of dorsal spinous processes change
>more perpendicular and then angle a bit more caudally

Question 18

Ribs:

Answer 18

-head of rib
-body of rib
-costochondral junction
-costal cartilage

Question 19

Sternebrae:

Answer 19

-manubrium: first one (cranial)
-xiphoid: last one (caudal)
-intersternal cartilage

Question 20

Diaphragm: R. lateral projection

Answer 20

-vena cava going into R. curs directly
*R. crus will be more cranial

Question 21

Diaphragm: L. lateral projection

Answer 21

-caudal vena cava from R. crus
>see it ‘crossing over’ and going more caudally
*L crus is more cranial

Question 22

Diaphragm: VD

Answer 22

-more pressure on crus vs cupula
>more cranially

Question 23

Diaphragm: DV

Answer 23

-more pressure on cupula
>all you ‘see’

Question 24

Cardiac silhouette:

Answer 24

-heart
-pericardium
-pericardial spaces

Question 25

Clock face analogy of the canine cardiac silhouette:

Answer 25

-12: aortic arch
-1: MPA
-2-3: left auricle
-3-6: left ventricle
-6-9: right ventricle
-9-11: right atrium
-left atrium: middle caudal portion

Question 26

Pulmonary vessels:

Answer 26

-lateral view: artery more dorsally, vein more ventrally
-VD view: arteries more abaxial, veins more axially

Question 27

Veins:

Answer 27

-ventral and central

Question 28

Normal pulmonary artery and vein: lateral view

Answer 28

-less than proximal 4th rib
-approximately equal in size
*cranial lobar vessels are usually better seen on L. lateral projection than the right

Question 29

Normal pulmonary artery and vein: DV view

Answer 29

-no wider than 9th rib
-approximately equal in size
*caudal lobar vessels are usually better seen on DV than VD

Question 30

Why 2 lateral projections?

Answer 30

-use left lateral project to evaluate the right lungs
-use right lateral projection to evaluate the left lungs
*because of dependent atelectasis

Question 31

Independent:

Answer 31

-one that is normal

Question 32

Dependent:

Answer 32

-compressed one/side