Pulmonary Disease

Question 1

Radiographing the thorax

Answer 1

Lung is mostly air with tissue strands throughout
Need low contrast images so as not to overexpose the lung and lesions
-lots of grey, few blacks, few whites
-low mAs, high kVp for film
-low contrast algorithm for digital

Question 2

Abnormal lung

Answer 2

increased opacity
These non-disease entities increase lung opacity and erroneous diagnosis:
-expiratory phase (air out- air provides contrast/radioleucency)
-atelectasis (as from recumbency)- lungs always look worse in lateral views
-over conditioning

Question 3

Effect of recumbency

Answer 3

In lateral recumbency the dependent lung collapses quickly
happens to less extent in VD and minimally in DV
Collapse of down lung is why L and R lateral thoracic views mandatory

Question 4

Effect of body habitus

Answer 4

fat = more opaque

Question 5

Thoracic radiography

Answer 5

Standard exam should comprise 3 views
VD (or DV)
left lat and R lateral
L and R lateral needed bc in a lateral view one is looking mainly at the non dependent up lung

Question 6

Lung patterns

Answer 6

increased lung opacity can fall into a particular pattern
-alveolar, bronchial, intersitital
Certain patterns associated with certain diseases
Distribution of pattern also important
Lung patterns assist in deciding what disease may be possible but do not make the diagnosis

Question 7

Alveolar pattern

Answer 7

something of soft tissue opacity replaces the air in the alveoli (usually fluid)
Blood- hemorrhage
Pus- exudate
water-edema (cardiogenic or non cardiogenic)
Rarely cells
The air in the bronchi are NOT replaced
Material in alveoli results in increased lung opacity
Bronchi remain radiolucent
Radiographs- air bronchogram, lobar sign, increased opacity that is intense but has no border (no air bronchogram, no lobar sign)

Question 8

Air bronchogram

Answer 8

An air bronchogram is a gas filled bronchus (dark) made visible by surrounding alveoli that contain something of soft tissue opacity (white)
Abnormal lung provides contrast to enable bronchus to be seem
Bronchi are bordered by an artery and vein pair; one on each side
bronchial lumen must contain air, surrounding lung must not

Question 9

Lobar sign

Answer 9

Not IN lobe- is EDGE of lobe
Occurs when lung disease (opacity) extends to periphery of lung lobe, and stops abruptly, leaving a dramatic transition between opacified lobe border and adjacent normal radiolucent lobe
Dz lobe against normal lobe - sharp demarcation
Least specific sign

Question 10

Only two things create intense lung disease

Answer 10

Alveolar disease will have indistinct margin

Lung mass will have distinct margin

Question 11

Diagnosing the cause of an alveolar pattern

Answer 11

All alveolar patterns look similar
Use other facts
-signalment, history, distribution of the pattern

Question 12

Bacterial pneumonia

Answer 12

Should improve radiographically in 5-7 days if the correct antibiotic is used

Question 13

Principal bronchus attenuation

Answer 13

Will cause coughing
misinterpreted clinically as heart failure
From tracheal collapse syndrome, chonromalacia
LA dilated- not statis because dog has mitral insufficiency so every heart contract = blood to atrium and auses dilation

Question 14

Cardiogenic edema

Answer 14

Should respond quickly to Lasix

Question 15

Non cardiogenic pulmonary edema

Answer 15

a specific form of pulmonary edema resulting from increased capillary permeability
two main causes- systemic inflammatory response syndrome
severe neurologic stimulation

Question 16

Systemic inflammatory response syndrome

Answer 16

Overabundance of cytokines and other mediators of inflammation
Results in altered capillary permeability leading to pulmonary edema (alveolar)- also called adult respiratory distress syndrome
distribution of pulmonary disease is highly variable
not very common

Question 17

Severre neurologic stimulation

Answer 17

Probably massive central stimulation
masses catecholamine release
-pulmonary and peripheral vasoconstriction
-pulmonary and systemic hypertension
-leads to pulmonary edema: LA hypertension, Blast theory from pulmonary hypertension, altered capillary permeability
in this form- the pulmonary edema is almost always dorsocaudal
hypoxia- choking, near drowning
severe seizure
head trauma
electrocution

Question 18

Bronchial pattern

Answer 18

something soft tissue opacity is present immediately adjacent to bronchi or in bronchial walls
cells- exudate- common; tumor cells- rare
water- edema- heart failure- not common
the air in the bronchus is not replaced
alveolar air is not replaced
material adjacent to or within bronchial walls creates ring and tram opacities

Question 19

Right middle lobe collapse

Answer 19

Due to bronchial plugging

Question 20

Interstitial pattern

Answer 20

something of soft tissue opacity is present in or proliferating in the pulmonary interstitium
water-edema
cells-inflammatory
cells-neoplastic
normal tissue-connective tissue, vasculature
the air in the bronchi is not replaced
alveolar is not replaced
due to increased substance, the opacity of the interstitium is increased
two basic manifestations:
unstructured, structured

Question 21

The interstitium

Answer 21

supporting tissue of the lung

the space between alveoli, vessels, and airways

Question 22

Unstructured interstitial pattern

Answer 22

generalized increased interstitial tissue without form 
artifact-most common
fibrosis
mycotic infection
tumor-LSA
idiopathic pneumonia
vascular proliferation
not very common
most difficult lung pattern
radiologists argue over this

Question 23

Structured interstitial pattern

Answer 23

nodules and masses
tumor- primary large mass
metastasis- multiple masses/nodules
granuloma- blastomycosis