Imaging of the Heart Flashcards
VD view
Ventrodorsal View
The dog is on its back
You can see both the right and left crus of the diaphragm and the cupula in the middle.
DV View
Dorsoventral view
Dog is laying sternally on stomach
You can see only one cura of the diaphragm and the cupula
Right lateral View
Look at the diaphragm. The right and left cura should be parallel with each other. The right curs is first. You will also see the caudal vena cava clearly going to the right crus. The cupula is at the bottom.
Left Lateral View
Look at the diaphragm. The right and left crus are not parallel, they crisscross. The dark lucent area in between is the stomach. The caudal vena cava is not as clear on the left lateral view since the left curs is on top of the right curs. The cupula is at the bottom.
Where will a lesion on the left lung be best seen?
On the right lateral view
the up lung will be better insufflated and provide better lesion contact
Which lung lobe has a middle lobe?
The right lung lobe
Mediastinum
Above the heart
What are the 3 types of intra-thoracic lymph nodes?
Sternal, cranial mediastinal, and tracheobronchial lymph nodes
What part of the heart is the right?
Cranial ventral part
What part of the heart is the left?
Caudal half
Describe the clock face analogy of the heart
11 - 1 = Ascending Aorta
1 - 2 = Main pulmonary artery
2 - 3 = Left auricle
3 - 5 = Left ventricle
5 - 9 = Right ventricle
9 - 11 = Right atrium
What is included in the right chambers of the heart?
What is included in the left chambers of the heart?
When does the right atrium and left auricle form an edge or margin?
On DV/VD
How does expiration affect the radiographic appearance of the heart?
Makes it look bigger because there is decreased overall volume of the thorax
What are some things to consider when deciding if a heart looks normal or not?
Obesity, breed conformation, inspiration and expiration, and positioning
How will the heart look on deep-chested breeds?
Narrow heart that looks compressed and upright. It will have minimal sternal contact.
How will the heart look on brachycephalic breeds?
Heart will appear wider and have increased sternal contact since they are deep chested
What does mediastinal fat look like on radiograph?
Increased opacity all around the heart with blurred margins
What can lift a heart from the sternum?
Fat or atelectasis
What are patterns of heart enlargement?
Left heart enlargement, right heart enlargement, generalized cardiomegaly, pulmonary trunk enlargement, and descending aorta enlargement
What is the most common heart enlargement pattern?
Left heart enlargement
What is the goal standard for mild cardiomegaly?
Echo
What will a left atrial heart enlargement look like on a lateral view?
Enlargement of dorsocaudal border (bulge) = left atrial, dorsal deviation (elevation) of entire trachea (parallel to spine), increased “verticality” of caudal margin of heart (tall heart), and caudal bronchi separation (left atrium bulges up between them)
What is the corina?
Where trachea bifurcates
What will left atrial enlargement look like on a VD/DV view?
Left atrium may produce increased opacity at base of the heart, with lateral deviation of caudal bronchi (bowlegged cowboy sign). Left auricle may bulge at 2-3 oclock as well as left atrial enlargement. Has to be a left atrial enlargement if we see a left auricle enlargement. LA doesn’t form margin, sits on top of the heart.
When do you typically see left ventricular enlargement?
Seen with left atrial enlargement
What are examples of left heart diseases?
Mitral valve disease, puppy PDA, SAS, VSD
What are examples of right heart diseases?
Tricuspid dysplasia, heartworm disease, Pulmonic stenosis, Teratology of Flow,
What is puppy PDA?
Patent Ductus arteriosus - ductus arteriosus fails to close and cause a huge volume overload on the left heart and get a very tall heart and big left atrium. You will see a bulge in descending aorta. Most of the most common heart defects in dogs.
What will right heart enlargement look like on a lateral view?
Increased width of heart, increased sternal contact, elevation of trachea if severe, corina & trachea will be going downhill (no LA enlargement), reversed D (left heart is straight but right side bulges out), decreased distance from right heart border to right chest wall, pulmonary trunk (MPA) can be enlarged (bulge at 1-2 oclock)
True or False: PA/PT enlargement is rarely seen in cats
True
What is not a common heart enlargement pattern?
Aortic enlargement (descending aorta). Not usually visible on lateral view, bulging of descending aorta on DV/VD view
Generalized cardiomegaly
Basketball heart (uniform), globoid, “pumpkin” shaped heart (if the pericardial effusion is severe)
What are the causes of generalized cardiomegaly?
Pericardial effusion (most common)
Right and left heart enlargement
Pericardial-peritoneal diaphragmatic hernia (congenital defect)
What is pericardial effusion?
Fluid between heart and pericardial
What is a pericardial-peritoneal diaphragmatic hernia?
Intestines in the heart
Are feline or dog heart enlargement patterns more subtle?
Feline
Describe left heart enlargement in the feline on lateral view
Increased length of heart (tall heart)
Slight bulging or bending of cardiac silhouette
Mainly due to left atrial enlargement
Left ventricle thickened at the expense of lumen
Trachea elevated dorsally
Describe left heart enlargement in feline on VD/DV view
LV hypertrophy: maintains normal apex
Widening of the cranial heart base due to mainly LA and LAaur enlargement
“Valentine shaped heart”
What is the Vertebral Heart Score (VHS) and how do you use it?
Used to measure if heart is too big or too small
How to measure:
1) Long axis of heart is measured from ventral border of left stem bronchus to most ventral portion of cardiac apex.
2) Maximum short axis of heart measured perpendicular to long axis
3) Lengths are compared to thoracic vertebrae starting at cranial T4 and extending caudally (going backwards)
4) Count the # of vertebral bodies from both lines and add the lines together to get the VHS on lateral radiograph
What is the normal VHS score of dogs?
9.7 +/- 0.5 vertebral body lengths
What is the normal VHS score of cats?
7.5 +/- 0.3 vertebral body lengths
What are the flaws of VHS?
Varies with breed (in dog)
Doesn’t specify which chamber enlarged
Considerable overlap between normal and abnormal dogs
