Thorax & Heart Radiology Pt 1

Front 1

What kind of technique do you want to use when performing a thoracic radiograph?

Back 1

High kilovoltage peak (kVp)
-Chest has inherent contrast
-Goal is to spread out the grayscale
Low mAs
-Highest mA possible
-Shortest s possible (1/30 s)

Front 2

True or false. It is a good idea to anesthetize the patient when performing a thoracic radiograph.

Back 2

False! sedate the patient and avoid chest radiographs under anesthesia

Front 3

How can you prevent atelectasis when taking a radiograph of an anesthetized patient?

Back 3

Inflate the lungs several times before taking the radiograph

Front 4

What are 2 ways to maximize non-manual restraint when performing a thoracic radiograph?

Back 4

1) Use sandbands
2) Tape feet

Front 5

What 2 projections should be used when performing thoracic radiographs?

Back 5

2 orthogonal views
-L or R lateral
-Vd or DV

Front 6

Do you take thoracic radiographs at peak inspiration or expiration?

Back 6

Peak inspiration

Front 7

What 2 views are best for outlining the lung vessels?

Back 7

Left lateral
DV

Front 8

When should 3 thoracic views definitely be taken?

Back 8

If metastasis, mass, nodule, infiltrate or pneumonia is suspected,
-If in doubt take 3 views

Front 9

Where should you center the beam when taking a lateral thoracic radiograph? What are the anatomical boundaries a thoracic radiograph?

Back 9

On heart or caudal edge of scapula
-Include thoracic inlet to last rib

Front 10

How should you position a dog when taking a lateral thoracic radiograph?

Back 10

Pull legs forward
-The rib heads should be superimposed

Front 11

How should you position an animal for a VD or DV thoracic radiograph? Where should the beam be centered? What are the anatomical boundaries?

Back 11

-Legs pulled forward
-Center of beam on heart
-Thoracic inlet to last rib

Front 12

How can you tell if an animal was correctly positioned when viewing a VD or DV thoracic radiograph?

Back 12

Spine superimposed on sternum
-Teardrop-shaped dorsal spinous processes

Front 13

What views should be taken when taking a thoracic radiograph of large animals?

Back 13

2 lateral views-animal is standing
-Structures close to the film are well visualized and have sharp margins
-Structures further away will be magnified and less distinct

Front 14

What view do you take to evaluate rib or chest wall lesions?

Back 14

Oblique views

Front 15

What view do you take to evaluate fluid filled structures or pleural fluid?

Back 15

Horizontal beam

Front 16

What are 2 reasons to always take thoracic radiographs at peak inspiration?

Back 16

1) Maximize lung contrast
2) Reduced one variable

Front 17

On an inspiratory lateral thoracic view, where is the caudo-dorsal aspect of the lung located?

Back 17

Caudal to T12

Front 18

Taking a lateral thoracic radiograph upon inspiration cause increased aeration of the ______ lung lobe.

Back 18

Accessory

Front 19

Taking a lateral thoracic radiograph on inspiration is important for separation the _______ and_______.

Back 19

Heart silhouette & diaphragm

Front 20

Where is the diaphragmatic cupula normally located on an inspiratory VD or DV view?

Back 20

Caudal to mid T8

Front 21

Where are the lung tips normally located on an inspiratory VD or DV view?

Back 21

Caudal to T10

Front 22

How can you tell if a thoracic radiograph is dark enough?

Back 22

Should be able to see individual vessels

Front 23

How can you tell if a thoracic radiograph is too dark?

Back 23

Should be able to see peripheral pulmonary vessels with naked eye

Front 24

How do you correct minor bad exposure on a thoracic radiograph?

Back 24

Change kVp +/- 10% (usually 5-8 kVp)

Front 25

How do you correct major bad exposure on a thoracic radiograph?

Back 25

Double or half mAs

Front 26

What are 5 reasons to retake thoracic radiographs?

Back 26

1) Under- or overexposed
2) Not at peak inspiration
3) Poor positioning
4) Part of the thorax is omitted
5) Motion

Front 27

The likelihood of a diagnosis via a thoracic radiograph is strongly dependent on _____.

Back 27

Quality-even if you send them to a radiologist

Front 28

How is the heart usually shaped on a right lateral radiograph?

Back 28

Oval or egg shaped

Front 29

How are the diaphragmatic crura arranged on a right lateral projection?

Back 29

Crura are parallel

Front 30

True or false. There may be air in the fundus of the stomach on a left lateral projection.

Back 30

False, that's on a right lateral projection

Front 31

What lateral projection is better to visualize the right and left cranial pulmonary veins and arteries?

Back 31

Left lateral, in a right lateral projection they overlap

Front 32

How is the diaphragmatic crura position in a left lateral recumbency?

Back 32

Left diaphragmatic crus is more cranial
-See a V shape in diaphragm

Front 33

What view do you want to take to evaluate the caudal vena cava?

Back 33

Left lateral projection

Front 34

Do you want a right or left lateral radiograph to evaluate the apex of the heart?

Back 34

Right lateral because apex of heart tends to be displaced from the sternum

Front 35

What shape is the heart on a left lateral projection?

Back 35

Heart tends to be more circular in shape

Front 36

Which lateral projection allows better evaluation of relative vessel size?

Back 36

Left lateral projection

Front 37

What view do you want to visualize changes in the aorta and greater vessels?

Back 37

Dorsal recumbency

Front 38

What view do you want to take to visualize the accessory lung lobe?

Back 38

Dorsal recumbency
-Less aerated due to the cranial displacement of diaphgram in DV

Front 39

What shape is the heart in sternal recumbency? How is it positioned

Back 39

Tends to be more oval as it is in a more upright position
-Often displaced to the right due to the cranial position of the diaphragm

Front 40

What view do you want to visualize the caudal pulmonary vessels and bronchi?

Back 40

Sternal recumbency as they are magnified and more perpendicular to the x-ray beam

Front 41

What are the 4 structures (groups) to be evaluated on a thoracic radiograph?

Back 41

1) Heart & great vessels (middle mediastinum)
2) Cranial & caudal mediastinum
3) Lungs including pulmonary vessels & pleura
4) Extrathoracic structures

Front 42

What are 5 locations you can exam for abnormalities on a thoracic radiograph?

Back 42

1) Heart & great vessels
2) Mediastinum
3) Lungs & upper airways
4) Pleural cavity
5) Diaphragm & thoracic wall

Front 43

What are 4 ways that a thoracic radiograph can be used to evaluate the heart (what can be diagnosed)?

Back 43

1) Diagnosing heart enlargement
2) Diagnosing heart failure
3) Differentiating heart failure from lung disease
4) Diagnosing specific heart diseases

Front 44

The cardiac silhouette delineates the margins of the ______.

Back 44

Heart/pericardium

Front 45

True or false. You can determine wall thickness or chamber size of the heart on a thoracic radiograph

Back 45

False

Front 46

Is the canine or feline cardiac silhouette more consistent?

Back 46

Feline cardiac silhouette, canine cardiac silhouette varies widely
-Breed
-Size
-Body type

Front 47

True or false. Cardiac disease in equine patients is usually diagnosed radiographically.

Back 47

False, ultrasound is the technique of choice
-Hypoperfusion
-Hyperperfusion

Front 48

What is different about the heart in a boston terrier and sheltie?

Back 48

Increased sternal contact

Front 49

What forms the three knuckles on the heart in a VD projection?

Back 49

From right (of patient) to left:
Right auricle
Aortic outflow tract
Pulmonary outflow tract

Front 50

What 3 structures are located on the dorsal 1/3 of the cranial border of the heart?

Back 50

1) Right auricle
2) Ascending aorta
3) Main pulmonary artery

Front 51

What 2 structures are located on the ventral 2/3 of the cranial border of the heart?

Back 51

1) Wall of RV
2) Pulmonary outflow tract

Front 52

What is located on the dorsal 1/3 of the caudal border of the heart?

Back 52

Left atrium

Front 53

What is located on the ventral 2/3 of the caudal border of the heart?

Back 53

Left ventricle

Front 54

What is located at 11:00-1:00 according to the clock face analogy?

Back 54

Aortic arch

Front 55

What is located at 1:00-2:00 according to the clock-face analogy?

Back 55

Main pulmonary artery

Front 56

What is located at 2:30-3:00 according to the clock-face analogy?

Back 56

Left auricle

Front 57

What is located at 2:00-5:00 according to the clock face analogy?

Back 57

Left ventricle

Front 58

What is located at 5:00-9:00 according to the clock face analogy?

Back 58

Right ventricle

Front 59

What is located at 9:00-11:00?

Back 59

Right atrium

Front 60

Where is the tracheal bifurcation located on a DV/VD view?

Back 60

Left atrium

Front 61

What is a normal vertebral heart score in the dog? Cat?

Back 61

Dog 9.7 +/- 0.5
Cat 7.7 +/- 0.3

Front 62

How do you calculate a vertebral heart score?

Back 62

Ventral aspect of trachea to tip of heart, not including pericardial fat, then maximum width of heart at about 90 degree to other axis, then add lengths in vertebraes

Front 63

How large is a normal feline heart on a lateral projection? DV?

Back 63

2-2.5 IC spaces wide
2/3 DV thoracic height

Front 64

How do old cat hearts appear on radiographs?

Back 64

As cats age, they can develop "lazy heart" where the heart has increased sternal contact, a tortuous aorta, and an aortic bulge seen in VD/DV projections

Front 65

Where is the apex of the heart normally located on a DV/VD projection of a cat?

Back 65

Left side

Front 66

The heart is more elongated on a VD or DV projection of a cat?

Back 66

VD

Front 67

the normal width of the heart takes up how much of the chest on a DV/VD projection?

Back 67

1/2 to 2/3 width of chest

Front 68

How is the heart oriented in deep-chested dogs such as dobermans, collies and irish setters on a lateral projection and DV/VD projection?

Back 68

Lateral: upright orientation of heart, perpendicular to the spine
DV/VD: Circular to ovoid heart

Front 69

How wide should a heart normally be in a deep-chested dog such as dobermans, collies and irish setters? Height in DV?

Back 69

2.5 IC spaces wide
2/3 DV height

Front 70

Where should the apex of the heart be in a DV/VD projection of a deep-chested dog?

Back 70

Median to slightly left of midline

Front 71

How is the shape of the heart different in a DV/VD projection of a dog with intermediate conformation such as a German shepherd or Labrador retriever?

Back 71

More elongated

Front 72

Where is the apex of the heart normally located in a VD/DV projection of a dog with an intermediate conformation?

Back 72

To the left of midline

Front 73

How is the heart shaped in a dog with a shallow-chested conformation such as a Boston terrier or bulldog on a lateral projection? How wide? Height on DV?

Back 73

Heart is shorter, more round
3-3.5 IC spaces wide
2/3 or less DV heigh

Front 74

In which chest conformation of canines does the heart have the most sternal contact?

Back 74

Shallow-chested conformation

Front 75

How is the heart shaped in a shallow-chested dog on a DV/VD projection? Where is the apex located?

Back 75

Heart round to elongated
Apex shifted to the left
-Short distance from thoracic inlet to cupola of diaphragm

Front 76

What's an example of the fact that normal heart size does not mean normal function?

Back 76

Dilated cardiomyopathy and heart failure can be a normal sized heart

Front 77

What is the definition of microcardia?

Back 77

Cardiac silhouette < 2 1/2 intercostal spaces wide

Front 78

What are 2 supporting Roentgen signs of microcardia?

Back 78

1) Pulmonary hypoperfusion
2) Consistently small caudal vena cava
-May see heart elevated from sternum

Front 79

What are 3 differentials diagnoses for microcardia?

Back 79

1) Dehydration
2) Shock
3) Hypoadrenocorticism

Front 80

Normally the caudal vena cava is approximately the same as ______.

Back 80

Aorta

Front 81

The caudal vena cava is variable with ______ and ________.

Back 81

Cardiac cycle and respiration

Front 82

What are 2 differential diagnoses for a small caudal vena cava?

Back 82

1) Hypovolemia
2) Shock

Front 83

What is a differential diagnosis for an enlarged caudal vena cava?

Back 83

Congestive right sided heart failure

Front 84

Where is the aortic arch located?

Back 84

11:00-1:00 (VD/DV)

Front 85

What are 2 locations/causes for segmental enlargement of the aorta?

Back 85

1) Proximal descending aorta
-Ductus arteriosus
2) Aortic outflow tract stenosis/PDA

Front 86

According to the clock analogy where is the main pulmonary artery segment located?

Back 86

1:00-2:00 region (DV,VD)

Front 87

What are 2 causes of enlargement of the main pulmonary artery segment (1-2 o'clock)?

Back 87

1) Pulmonary hypertension
-Heartworm disease
2) Pulmonary outflow tract stenosis

Front 88

How are the pulmonary vessels arranged on a lateral view? How big should they be?

Back 88

Pulmonary artery is dorsal
Pulmonary vein is ventral
-Bronchus in b/w
-Veins are ventral & central
-Should be 0.5 to 1.0 width of 4th rib

Front 89

How are the pulmonary vessels arranged on a VD/DV? How big should they be?

Back 89

Pulmonary artery is lateral
Pulmonary vein is medial
0.5 to 1.0 width of 9th rib

Front 90

What does it mean if you see global enlargement of the heart?

Back 90

Pericardial effusion
-Always has rounded caudodorsal border
-Ovoid shape

Front 91

Is it a better prognosis to be able to detect global enlargement of the heart or left atrial enlargement?

Back 91

Global enlargement is NOT good

Front 92

True or false. The ability to evaluate MILD general heart enlargement on radiographs is important.

Back 92

False, not important, not reliable, diagnosis of the presence of heart disease is made by clinical methods, NOT radiography

Front 93

Radiography is used to help diagnose _________.

Back 93

Failure

Front 94

Do you take thoracic radiographs of a congenital disease for diagnosis or prognosis?

Back 94

Prognosis
-Larger the heart and more changes of vessels=worse prognosis

Front 95

What are 2 differential diagnoses for severe generalized cardiomegaly/globoid heart?

Back 95

1) Pericardial effusion
2) Dilated cardiomyopathy
-Medium to large size dogs
3) PPDH

Front 96

What are 2 differential diagnoses for mild/moderate generalized cardiomegaly?

Back 96

1) Mitral/tricuspic valve endocardiosis (small breed dogs)
2) Dilated cardiomyopathy (large breed dogs)

Front 97

What is a differential for left atrial enlargement in a dog ?

Back 97

Mitral endocardiosis (small breeds)

Front 98

What are 2 differential diagnoses for right heart enlargement in a dog?

Back 98

1) Tricuspid endocardiosis
2) Heart worm disease

Front 99

What are 2 differential diagnoses for cardiomegaly in a cat?

Back 99

1) Hypertrophic cardiomyopathy
2) Dilated cardiomyopathy (rare)

Front 100

What heart condition in a cat can still have a normal sized heart?

Back 100

Hypertrophic cardiomyopathy-radiographs are insensitive for HCM

Front 101

What should you do if you detect a heart murmur in a young animal?

Back 101

Should refer the animal and send the radiographs with the referral

Front 102

What are 3 changes in the shape of the heart should you look for?

Back 102

1) Left atrial enlargement
2) Reverse-D for cor pulmonale (heartworms)
3) Post-stenotic dilations in congenital disease

Front 103

What is the most common acquired cardiac disease?

Back 103

Mitral regurgitation

Front 104

What dogs have the highest prevalence of mitral regurgitation?

Back 104

Middle aged and old small-medium sized breeds
-Not a disease of young dogs

Front 105

What causes mitral regurgitation?

Back 105

Thickened mitral valve

Front 106

What are 3 signs of a mitral regurgitation on a lateral projection?

Back 106

1) Dorsal displacement of trachea
2) Increase in proportion of the DV diameter of the thorax
3) Straightening of the caudal border of the heart

Front 107

What are 3 typical signs of mitral regurgitation on a VD/DV?

Back 107

1) Double opacity sign
2) Separation of the main stem bronchi
-"Bow-legged cowboy"
3) Left auricular enlargement

Front 108

True or false. You can rule out divergence of the mainstem bronchi if you do not see the "bow legged cowboy".

Back 108

False, doesn't always cause divergence of main stem bronchi

Front 109

What 2 structures can be involved in the bow-legged cowboy?

Back 109

1) Tracheal bifurcation (carina)
2) Main bronchi

Front 110

What is located between the main stem bronchi?

Back 110

Left atrium

Front 111

What is a sign of left atrial enlargement on a lateral projection?

Back 111

Straightening of the caudal border of the heart and main stem bronchi is pushed dorsally (can lead to compression of main stem bronchi if severe

Front 112

What are 3 typical signs of mitral regurgitation on a VD/DV?

Back 112

1) Double opacity sign
2) Separation of the main stem bronchi
-"Bow-legged cowboy"
3) Left auricular enlargement

Front 113

True or false. You can rule out divergence of the mainstem bronchi if you do not see the "bow legged cowboy".

Back 113

False, doesn't always cause divergence of main stem bronchi

Front 114

What 2 structures can be involved in the bow-legged cowboy?

Back 114

1) Tracheal bifurcation (carina)
2) Main bronchi

Front 115

What is located between the main stem bronchi?

Back 115

Left atrium

Front 116

What is a sign of left atrial enlargement on a lateral projection?

Back 116

Straightening of the caudal border of the heart and main stem bronchi is pushed dorsally (can lead to compression of main stem bronchi if severe