Cardiac Radiographs

Question 1

are cardiac chambers visible on radiographs

Answer 1

no - use knowledge of anatomy

Question 2

in lateral view - where is the right atrium and ventricle

Answer 2

RA: cranial and dorsal
RV: cranial and ventral

Question 3

in lateral view - where is the left atrium and ventricle

Answer 3

LA: caudal and dorsal
LV: caudal and ventral

Question 4

in DV view - where is the right atrium and ventricle

Answer 4

RA: right cranial
RV: right caudal

Question 5

in DV view - where is the left atrium and ventricle

Answer 5

LA: left caudal
LV: left caudal - pokes out from LA caudally

Question 6

in DV view - where are the great vessels

Answer 6

left cranial

Question 7

cardiac clock - DV

Answer 7

11 to 1: aorta
1 to 2: pulmonary trunk
2 to 3: left atrium
3 to 5: left ventricle
5 to 9: right ventricle
9 to 11: right atrium

Question 8

cardiac clock - lateral

Answer 8

12 to 3: left atrium
3 to 5: left ventricle
5 to 8: right ventricle
8 to 10: right atrium
10 to 12: great vessels

Question 9

is the left or right ventricular wall thicker

Answer 9

left

Question 10

how to ID pulmonary vessels on radiographs

Answer 10

located on either side of the bronchi

lateral: cranial pulmonary vessels

DV: caudal pulmonary vessels

Question 11

pulmonary veins vs arteries on radiographs

Answer 11

lateral:
- veins = ventral
- arteries = dorsal

DV:
- veins = medial
- arteries = lateral

Question 12

normal cardiac size in lateral

Answer 12

dogs: 2.5-3.5 intercostal spaces

cats: 2.5 intercostal spaces

Question 13

normal cardiac size in DV

Answer 13

heart occupies <2/3 thoracic width

Question 14

what causes normal variations in cardiac size

Answer 14

1. cardiac cycle (systole vs diastole)
2. respiratory cycle (inspiration makes heart appear smaller)
3. hydration status (dehydration decreases size)
4. body condition (obesity increases heart size)

Question 15

how does left atrial enlargement appear on radiographs

Answer 15

• bulge in LA area
• flattening of caudal aspect in lateral
• elevated trachea
• “bowlegged cowboy”

Question 16

ddx for enlarged LA on radiographs

Answer 16

1. mitral insufficiency
2. cardiomyopathies (DCM, HCM)
3. L to R shunts (PDA, VSD)

Question 17

is right or left atrial enlargement more common

Answer 17

left atrial enlargement

Question 18

how does right atrial enlargement appear on radiographs

Answer 18

• bulge in RA area
• widened cardiac silhouette on lateral (enlarged in cranial caudal direction)

Question 19

ddx for enlarged RA

Answer 19

1. tricuspid insufficiency
2. severe pulmonic stenosis
3. cardiomyopathies

Question 20

how does left ventricular enlargement appear on radiographs

Answer 20

• elongation of the heart
• elevated trachea
• prominent apex
• bulge in LV area

Question 21

ddx for left ventricular enlargement

Answer 21

1. sub aortic valve stenosis (dogs)
2. cardiomyopathies (HCM; cats)
3. mitral insufficiency

Question 22

how does right ventricular enlargement appear on radiographs

Answer 22

• “reverse D” shape
• widened cardiac silhouette on lateral
• cranio-ventral bulge
• elevation of apex from the sternum

Question 23

ddx for right ventricular enlargement

Answer 23

1. pulmonic stenosis
2. pulmonary hypertension
3. tricuspid insufficiency
4. cardiomyopathies

Question 24

what is the main cause of generalized/multi chamber enlargement in dogs

Answer 24

dilated cardiomyopathy or pericardial effusion

Question 25

DCM on radiographs

Answer 25

enlarged, normal shape and margins of auricles and apex

Question 26

pericardial effusion on radiographs

Answer 26

enlarged and rounded w/ sharp margins circular on DV

Question 27

what is the main cause of generalized/multi chamber enlargement in cats

Answer 27

hypertrophic cardiomyopathy or dilated cardiomyopathy

Question 28

HCM on radiographs

Answer 28

less marked enlargement than DCM large base with narrow apex (valentine's heart)

Question 29

peritoneal pericardial diaphragmatic hernia (PPDH)

Answer 29

herniation of the small intestines through an opening from the diaphragm into the pericardium

Question 30

caudal vena cava size on radiographs

Answer 30

<1.5x aorta aorta does not change size easily --> use as a marker for CVC size

Question 31

what does an enlarged CVC indicate

Answer 31

right heart failure OR volume overload

Question 32

how to evaluate pulmonary vessel size

Answer 32

arteries: should be smaller than the 9th rib on DV veins: should be same size as arteries

Question 33

what does enlarged pulmonary vessels indicate

Answer 33

arteries: bulge of pulmonary trunk veins: left sided congestive heart failure

Question 34

enlarged cardiac arteries/veins

Answer 34

1. fluid overload 2. left to right shunts

Question 35

causes of small cardiac arteries and veins

Answer 35

1. dehydration/hypovolemia 2. right to left shunts 3. severe pulmonic stenosis