Cardiovascular Radiology Flashcards
How do you tell thoracic rads are good positioning
Vertebrae
Spinous processes (tear drop shaped)
centered on heart
image take at inspiration
What are the radiographic limitations
-Insensitive to heart chamber changes
-Nonspecific for diagnosis
-Mild enlargement debatable
-Phase of cardiac cycle can effect
-Rotation and degree of inspiration affects interpretation
Echocardiogram is the method of choice for evaluating and assessing anatomy, pathology, and function - includes individual chambers and part of vascularization
What are the benefits of radiology over Echo
Provides evaluation of pulmonary circulation as an indicator of cardiac function
-evaluates pulmonary vessels
-Evaluates pulmonary parenchyma
-Treatment Response (ex: cats with HCM)
What are you evaluating with the heart
-Size
-Chambers/vessels
-Apex location
-vessels (pulmonary)
-Lung prenchyma/ pleural space
How large is the normal dog’s heart?
2.5-3.5 intercostal spaces wide on lateral
breed variation
VD/DV: Half to 2/3 width of thorax or less
extensive breed variation
How large is the normal cat’s heart
2-2.5 ICS on lateral on lateral
VD/DV: approx 50% width of thorax on VD
Normal Dog’s heart on lateral is
2.5-3.5 intercostal spaces wide
extensive breed variation
Normal dog’s heart on VD/DV is
1/2 - 2/3 width of thorax
extensive breed variation
How do you take a vertebral heart sum in dogs
Draw your lines in short and long axis
take each line and measure parallel to the thoracic spine beginning at T4 veterbral body
Count the number of number of veterbrae caudally
Sum the number of vertebrae caudally
dogs normal 8.5-10.5
What is a dog’s normal VHS
8.5-10.5 vertebral bodies
What is a normal cat VHS
7.5 +/- 0.3 vertebrae
How should the cardiac apex be normally positioned
VD: apex positioned slightly to the left on midline
Lateral: apex adjacent to caudal sternum with adjacent fat outlines
what is the normal trachea relationship
deviates ventrally from the spine along course to heart base
*pushed dorsally by heart enlargement
On VD/DV, what is located at 11-1
aortic arch- primarily closer to 1:00
what cardiac chamber is located at midline
left atrium
On lateral, what is located in the cranial dorsal cardiac silhouette
Right atrium
aorta
main pulmonary artery
*Must use VD/DV to to distinguish further
On lateral, what is located in the caudal dorsal cardiac silhouette?
Left Atrium
sometimes have tracheobronchial lymph nodes there (tell apart from trachea being displaced dorsally with LA enlargement)
What are the radiographic findings of generalized cardiomegaly in the dog
1) Greater than 2/3 width of thoracic cavity (VD/DV)
2) Greater than 2.5 (cat) or 3.5 (dog) intercostal space on lateral view
3) Round shape to the heart +/-
4) Increased VHS (>10.5 dog)
What are the radiographic signs of left atrial enlargement
1) Straightening or rounding of caudo-dorsal heart margin / caudal waist (backpack sign)
2) Splitting of the mainstem bronchi (may compress- bowlegged cowboy)
3) Round opacity superimposed over caudal aspect of heart on VD (double opacity- apex)
summation of enlarged LA w rest of heart
4) Lateral: Left auricular bulge at 2-3oclock
Left Auricular bulges can be seen with left atrial enlargement, where is this seen
about 2-3 oclock on VD/DV
On lateral: what do you see that is enlarged with left atrial enlargement
Straightening or rounding of caudo-dorsal heart margin / caudal waist (backpack sign)
Where is the double opacity of left atrial enlargement seen
caudal aspect of heart on VD
-summation of enlarged LA with the rest of the heart
You will see bulge or round at 3-6:00 with_______
Left ventricular enlargement
What makes the heart taller on lateral
left ventricular enlargement (dorsal displaced trachea)
What are the radiographic findings of left ventricular enlargement
1) Lateral: heart taller (dorsally displaces the trachea)
2) Bulge/Rounding at 3-6 oclock
What are the clinical signs of right atrial enlargement
1) Lateral: Bulge in cranial-dorsal heart margin at the cranial waste
2) VD: Bulge at 9:00-11:00
What might cause right atrial enlargement in an older dog
Hemangiosarcoma
Tricuspid disease
On VD, what does a 9:00-11:00 bulge mean
right atrial enlargement
On VD, what does a 6:00-9:00 bulge mean
right ventricular enlargement
On lateral, where will the bulge with right atrial enlargement be
cranio-dorsal heart margin at the cranial waste
What are the radiographic findings of right ventricular enlargement
Lateral: Bulge at cranial ventral heart regions
Increased sternal contact
Elevated apex off sternum
VD: 6:00-9:00
What are the radiographic signs of aortic arch enlargement
Lateral: bulge at the cranial dorsal heart
VD/DV: bulge at 11:00-1:00 (close to mediastinum, noticed best on right side)
On lateral: where is the bulge with aortic arch enlargement
cranial dorsal heart
What does a bulge at 11-1:00 on VD tell you
aortic arch enlargement
-close to mediastinum, noticed best on the right side
On lateral: where will you see the bulge with MPA enlargement
cranial dorsal
What will you see with 1:00-2:00 bulge on VD
Main Pulmonary Artery enlargement
On lateral view, cranial lobe vessels should be ________________________
no larger than proximal 4th rib