cardiac radiology Flashcards
what does left atrial enlargement look like on lateral x-ray
dog
- straight caudodorsal margin (loss of caudal waist)
- bulging of the cardiac contour at 12-2 o’clock
- increased height
- dorsal elevation +/- compression of the caudal mainstem bronchi
what does left atrial enlargement look like on DV/VD
dog
- double density superimposed on cardiac silhouette (bulge between 2-3 o’clock: left auricular enlargement
- widened angle between the caudal mainstem bronchi
what does left atrial enlargement look like on lateral x-ray
cat
- more difficult to identify
- widening of the heart base
- slight buldging or rounding of caudal contour
what does left atrial enlargement look like on DV/VD
cat
- left atrial bulge: 2-3 o’clock, but may extend further cranial
- “valentine heart” shape: severe left OR left and right atrial enlargement
what does left ventricular enlargement look like on lateral
- tall cardiac silhouette
- dorsal tracheal displacement
what does left ventricular englargement look like -DV/VD
- elongaeted cardiac silhouette
- rounded left heart
what does right atrial enlargement look like -lateral and VD
- rounded contour: 9-11 o’clock on both lateral and VD
- not as common
what does right ventricular enlargement look like - lateral
- rounded cranial heart: 5-9 o’clock
- right heart > 2/3 of the cardiac silhouette: wide heart
- increased cardiosternal contrast: may be seen in some normal dogs (barrel chested)
- caudodorsal tipping of apex
what does right ventricular enlargement look like -VD
- rounding of right heart: 5-9 o’clock
- reverse D shape
- may displace the apex to the left (false impression of left-sided cardiomegaly)
what does microcardia look like
small heart
- narrow, pointed heart
- apexx may lose contac with sternum
- pulmonary arteries and veins may be small
what are 3 differential diagnoses of microcardia
- hypovolemia (shock)
- hypoadrenocortism (addison’s disease)
- constrictive pericarditis (rare)
pulmonary artery and vein diameter
- approx. equal in size (artery ~ vein)
- < width of the proximal 1/3 of the 4th rib (lateral)
- ~ width of the 9th rib where it crosses (VD)
caudal vena cava diameter
- variable (respiration, cardiac cycle)
- < 1.5x diameter of the aorta (~1x)
- < length of T5
what are the differential diagnoses of an enlarged heart
- cats: age-related (aortic arch)
- patent ductus ateriosus
- post-stenotic dilation: subaortic stenosis
- aortic aneurysm (very rare)
what are the differential diagnoses for an enlarged caudal vena cava
- right heart failure
- obstruction of caudal vena cava or right atrium (caval syndrom - dirofilariasis, blood clot, mass)
- normal variation (respiration, cardiac cycle, evaluate on all views)
what are the differential diagnoses of enlarged main pulmonary artery
- post-stenotic dilation (pulmonic stenosis)
- pulmonary hypertension
- dirofilariasis or angiostrongylosis
- left to right shunt (PDA, ASD, VSD)
- fake out (VD proj, rotated proj, cardiac cycle - systole)
what are the differential diagnosis of enlarged pulmonary arteries
- dirofilariasis (pulmonary arteries often also tortuous and blunted)
- pulmonary hypertension
- pulmonary thromboembolism (PTE)
what are the differential diagnoses of enlarged pulmonary veins
- left heart failure (may not be enlarged if the patient received diruetics)
- fluid/volume overload (relative vs absolute)
- left atrial obstuction
what are the differential diagnosis for enlarged pulmonary arteries and veins
- left to right shunts
- pulmonary congestion (fluid volume overload, left heart failure - cats)
what are the differential diagnosis for small pulmonary arteries and veins
pulmonary hypoperfusion
- hypovolemia
- right to left shunts
- pulmonic stenosis
- pulmonary thromboembolism
- decreased cardiac output (pericardial effusion with tamponade, restrictive pericarditis, right heart failure)
what are radiographic signs of left heart failure
- enlarged left heart
- pulmonary venous congestion (enlarged pulmonary veins; cats - +/- enlarged pulmonary arteries)
- pulmonary edema
- interstitial to alveolar pulmonary pattern
- dogs: perihilar, caudodorsal (more severe in right caudal lobe than left, DCM: ocassionally ventral peripheral alveolar pattern)
- cats: patchy distribution
- cats: +/- pleural effusion
what does left heart failure look like
dog
- enlarged left atrium and ventricle
- enlarged pulmonary veins
- caudodorsal alveolar pattern (R>L)
what does left heart failure look lik
cat
- left sided cardiomegdally
- round margins
- tall
- buldge in LA (lateral
- VD - widening at LA & RA
- “valentine heart”
- pulmonary pattern too severe to see vasculature
- pulmonary edema w/ patchy distribution
what does pleural effusion look like with left sided heart failure
cats
- retraction of lung lobes from the body wall
- pleural fissure lines
- dont see pleural effusion with dogs
what does right heart failure look like
- enlarged right heart
- enlarged caudal vena cava
- hepatomegaly (congestion)
- adcites
- pleural effusion
what is degenerative valve disease (valvular endocardiosis)
- older small breed dogs
- valvular degeneration (regugitation -> volume overload)
- mitral valve disease (LA enlargement, LV enlargement, LH failure)
- tricuspid valve disease (RA enlargement, RV enlargement, RH failure)
what does degenerative mitral valve disease look like
- enlarged left atrium & ventricle
- left heart failure (enlarged pulmonary veins, caudodorsal alveolar pattern, R>L)
cardiomyopathy in dogs
large breed dogs
dilated cardiomyopathy
- generalized cardiomegaly
- left atrial enlargemlent
- +/- heart failure
- left-sided failure more common
what does dilated cardiomyopthy look like
dogs
- left atrial (+/- ventricular) enlargement
- diffuse interstitial pattern, ventral alveolar regions
cardiomyopathy in cats
hypertrophic cardiomyopathy
- also restrictive, dilated, unclassified
- LA & LV enlargement
- “valentine” shape
- +/- heart failure - right-sided cardiomegaly and heart failure less common
what does cardiomyopathy look like in cats
- left atrial & ventricular enlargement
- left heart failure - patchy alveolar pattern
heartworm (dirofilariasis) progression of dx
- pulmonary artieries are enlarged, tortous and blunted (R caudal lobar artery affected first)
- enlarged main pulmonary artery
- R sided cardiomegaly (cor pulmonale - 2nd to pulmonary hypertension)
- enlarged caudal vena cava (caval syndrom)
- R heart failure
- bronchial pulmonary pattern, multifocal alveolar pulmonary pattern (pneumonitis, thromboembolism)
what does heartworm look like
- enlarged, tortuous, blunted pulmonary arteries
- enlarged main pulmonary artery
- right ventriculomegaly
- diffuse bronchial pattern, patchy interstitial to alveolar pattern
what does patent ductus arteriosis (PDA) look like
enlarged:
- aortic arch
- left atrium/auricle (+ventricle)
- main pulmonary artery
- pulmonary artereies and veins (vascular pattern)
triad (triple bump) seen on VD
what are causes of pericardial effusion in dogs
- neoplasia (hemangiosarcoma, heart base tumor, mesothelioma)
- idiopathic
- congestive heart failure (right sided)
- left atrial rupture
what are causes of pericardial effusion in cats
- congestive heart failure (left or right sided)
- feline infectious peritonitis
- lymphoma
what does pericardial effusion look like
- large round (globoid) cardiac silhouette (on BOTH lateral and VD)
- sharp outline of the cardiac silhouette (no motion artifact from heart beating)
- cardiac tamponade (small pulmonary vasculature, r sided heart failure)
