Radiology of cardiac heart dz in dog/cat

Question 1

What can affect what we qualify as normal radiographic appearance?

Answer 1

breed/conformation
recumbencycardiac cycle
respiratory cycle/degree of pulmonary distention

Question 2

What are example of body shapes that influence the cardiac silhouette?

Answer 2

• brachy/puppies: rounded silhouette
• retrievers: square, broad
• dobermans: upright, straigh caudal border
• setters, afghans: tall, slim cardiac silhouette

Question 3

Will disease change the cardiac silhouette?

Answer 3

cardiac silhouette changes MAY occur with dz

Question 4

What can increase in cardiac silhouette size indicate?

Answer 4

can indicate :
cardiac dilatation
eccentric hypertrophy
pericardial effusion

Question 5

How can we evaluate cardiac dimensions?

Answer 5

1: Using number of intercostal spaced occupied by cardiac silhouette in a lateral projection
2: position of trachea/height of cardiac silhouette and distance between cardiac silhouette with diaphragm
3: proportion of thoracic width occupied by cardiac silhouette
4: VHS - intercostal space equivalent of height + width of cardiac silhouette

Question 6

What should the cardiac silhouette be in number of intercostal spaces in a lateral projection for dogs and cats?

Answer 6

k9: 2.5-3.5
f9: 2-2.5

Question 7

Where should the position of trachea/height of cardiac silhouette be for dogs?

Answer 7

70% of thoracic height

Question 8

What should be the proportion of thoracic width occupied by the cardiac silhouette in dogs?

Answer 8

75% of width of thorax in DV

Question 9

What should be the rib space length of height + width of the cardiac silhouette in dogs and cats?

Answer 9

k9: 8.7-10.7
f9: 6.9-8.1

Question 10

What should we look for when looking at cardiac shape?

Answer 10

right sided cardiomegaly
left sided cardiomegaly
generalised cardiomegaly
focal changes in cardiac shape

Question 11

What changes can we see on RL and DV view of LV?

Answer 11

RL: increase DV dimension
VD: elongated cardiac silhouette

Question 12

What changes can we see on RL and DV view of LA?

Answer 12

RL: increase DV dimension, bulge on dorsocaudal aspect, dorsal displacement left caudal bronchus
DV: focal bulge on mid-left border

Question 13

What changes can we see on RL and DV view of RV?

Answer 13

RL: increase Cr-Cd dimension, increase sternal contact
VD: more curved right border

Question 14

What changes can we see on RL of DV view of RA?

Answer 14

RL: increase Cr-Cd dimension
DV: more curved right border without increase sternal contact

Question 15

Where are the 4 chambers and aorta on a RL view?

Answer 15

LA: 12-2
LV: 2-5
RV: 5-8
RA: 8-10
Aorta: 10-12

Question 16

Where are the 4 chamber, main pulmonary artery and aorta on a VD view?

Answer 16

Aorta: 12-1
MPA: 1-2
LA: 2-3
LV: 3-6
RV: 6-9
RA: 9-11

Question 17

What are radiographic signs of Lsided CHF in k9?

Answer 17

pulmonary vascular (venous) congestion
pulmonary oedema

Question 18

What are radiographic signs of Rsided CHF in k9?

Answer 18

hepatomegaly
peritoneal effusion
pleural effusion

Question 19

What are radiographic signs of CHF in f9?

Answer 19

pleural effusion

Question 20

What do we look at on Xrays to determine presence of CHF?

Answer 20

Artery-bronchus-vein formation
if vein is larger = significant enough to be picked up = CHF

Question 21

What is the clinical use of radiography in cardiac dz?

Answer 21

can complement echocardiography
useful to detect signs of congestive heart failure
useful to monitor progression over time/response to therapy

Question 22

What should we consider when looking at xrays in cases of cardiac dz?

Answer 22

consider signalment and clinical presentation: congenital vs acquired, acute/chronic/acute on chronic

differentiate mainly cardiac vs mainly respiratory dz
differentiate rsided, lsided or global cardiomegaly

Question 23

What are the limitations of radiography with cardiac dz?

Answer 23

could be significant dz despite lack of xray alterations
- concentric changes
- early phase of dz process
- thromboembolic dz
- arrhythmias