Radiology of cardiac heart dz in dog/cat Flashcards
What can affect what we qualify as normal radiographic appearance?
breed/conformation
recumbencycardiac cycle
respiratory cycle/degree of pulmonary distention
What are example of body shapes that influence the cardiac silhouette?
- brachy/puppies: rounded silhouette
- retrievers: square, broad
- dobermans: upright, straigh caudal border
- setters, afghans: tall, slim cardiac silhouette
Will disease change the cardiac silhouette?
cardiac silhouette changes MAY occur with dz
What can increase in cardiac silhouette size indicate?
can indicate :
cardiac dilatation
eccentric hypertrophy
pericardial effusion
How can we evaluate cardiac dimensions?
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
What should the cardiac silhouette be in number of intercostal spaces in a lateral projection for dogs and cats?
k9: 2.5-3.5
f9: 2-2.5
Where should the position of trachea/height of cardiac silhouette be for dogs?
70% of thoracic height
What should be the proportion of thoracic width occupied by the cardiac silhouette in dogs?
75% of width of thorax in DV
What should be the rib space length of height + width of the cardiac silhouette in dogs and cats?
k9: 8.7-10.7
f9: 6.9-8.1
What should we look for when looking at cardiac shape?
right sided cardiomegaly
left sided cardiomegaly
generalised cardiomegaly
focal changes in cardiac shape
What changes can we see on RL and DV view of LV?
RL: increase DV dimension
VD: elongated cardiac silhouette
What changes can we see on RL and DV view of LA?
RL: increase DV dimension, bulge on dorsocaudal aspect, dorsal displacement left caudal bronchus
DV: focal bulge on mid-left border
What changes can we see on RL and DV view of RV?
RL: increase Cr-Cd dimension, increase sternal contact
VD: more curved right border
What changes can we see on RL of DV view of RA?
RL: increase Cr-Cd dimension
DV: more curved right border without increase sternal contact
Where are the 4 chambers and aorta on a RL view?
LA: 12-2
LV: 2-5
RV: 5-8
RA: 8-10
Aorta: 10-12
Where are the 4 chamber, main pulmonary artery and aorta on a VD view?
Aorta: 12-1
MPA: 1-2
LA: 2-3
LV: 3-6
RV: 6-9
RA: 9-11
What are radiographic signs of Lsided CHF in k9?
pulmonary vascular (venous) congestion
pulmonary oedema
What are radiographic signs of Rsided CHF in k9?
hepatomegaly
peritoneal effusion
pleural effusion
What are radiographic signs of CHF in f9?
pleural effusion
What do we look at on Xrays to determine presence of CHF?
Artery-bronchus-vein formation
if vein is larger = significant enough to be picked up = CHF
What is the clinical use of radiography in cardiac dz?
can complement echocardiography
useful to detect signs of congestive heart failure
useful to monitor progression over time/response to therapy
What should we consider when looking at xrays in cases of cardiac dz?
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
What are the limitations of radiography with cardiac dz?
could be significant dz despite lack of xray alterations
- concentric changes
- early phase of dz process
- thromboembolic dz
- arrhythmias
