Cardio - Thoracic Rads Flashcards
What are the 5 steps to assessing thoracic rads?
- Film quality
- Extra-cardiac structures
- Cardiac sihouette
- Intrathoracic vessels
- Pulmonary parenchyma and airways
What are the components of film quality?
TPR:
Technique, Positioning, Respiratory Phase
What is kVP?
What is mAs?
kVp = energy/heat
mAs = time
What is the technique quality in A?
Underexposed;
kVP is too low or mAs is too short
What is the technique quality in B?
Just right
What are the optimal thoracic settings?
high kVp and low mAs
What is the technique quality in C?
overexposed
kVp is too high or mAs is too long
How can you tell that an xray was taken during inspiration?
Cranial lung lobe is extended pretty far cranially;
Diaphragm is not overlapping the cardiac silhouette;
Crust to pizza slice ratio is appropriate
What measurement can be used to evaluate for enlargement?
vertebral heart scores
What is a vertebral heart score?
Sum of width and length of heart (S and L) in terms of # of vertebrae
What is the normal VHS for dogs?
Cats?
Dogs = 8.5-10.5
Cats = ~7.5
How “tall” and “wide” should a normal heart be in a dog?
Tall = 2/3 height of chest cavity
Wide = 2/3 width of chest cavity (but this is breed-dependent)
How “tall” and wide should the heart be in a normal cat?
Tall = 2/3 height of chest cavity
Wide = 1/2 width of chest cavity
What is different about the apex-diaphragm relationship between cats and dogs?
Apex DOES NOT touch the diaphragm in cats
What can too wide of a heart indicate?
RV enlargement
What can too tall of a heart indicate?
LV enlargement > RV enlargement
What is the tracheal elevation pattern in LV enlargement?
trachea is consistently elevated
What is the tracheal elevation pattern in RV enlargement?
Sharp upward deviation of trachea just cranial to the corina
What is used to ID specific chamber/vessel dilation?
the clock face
What structure lies at 12:00 - 2:00 on a lateral view?
LA
What structure lies at 2:00 - 5:00 on a lateral view?
LV
What structure lies at 5:00 - 9:00 on a lateral view?
RV
What structure lies at 9:00 - 10:00 on a lateral view?
MPA, R auricle
What structure lies at 10:00 - 11:00 on a lateral view?
Aortic arch
What structure lies at 11:00 - 1:00 on a VD view?
Aortic arch
What structure lies at 1:00 - 2:00 on a VD view?
MPA
What structure lies at 2:00 - 3:00 on a VD view?
L auricle
What structure lies at 3:00 - 5:00 on a VD view?
LV
What structure lies at 5:00 - 9:00 on a VD view?
RV
What structure lies at 9:00 - 11:00 on a VD view?
RA
What does a “reverse D” appearance indicate?
R heart pressure overload disease
What 4 changes are seen in the reverse D?
- Main PA dilation
- RA enlargement
- RV enlargement
- Apex pushed to the L
What are possible radiographic findings in R heart enlargement?
RA/Raur dilation, wide cardiac silhouette (RVE), elevated trachea cranial to carina, MPA dilation, apex shifted to L on DV/VD (dogs only), reverse D shape on DV/VD
What are possible radiographic findings for L heart enlargement?
LA/Laur dilation, loss of cd waist, tall cardiac silhouette (LVE), elevated trachea cranial and caudal to carina, Ao dilation, rounded apex
What are the 3 radiographic features of L-CHF?
- Mod to severe LA dilation
- Pulm venous dilation
- Interstitial to alveolar pulmonary pattern
What are the 4 features of R-CHF?
- Mod to severe R heart enlargement
- Dilated caudal vena cava
- Fluid accumulation (ascites, pleural effusion, small vol pericardial effusion)
- Pulm vasculature size varies dep on type of R heart diz
What can you compare the caudal vena cava to when you are concerned about R-CHF?
the aorta - should be the same size normally;
can also see “rainbow” shape to CdVC
