STEEPLECHASE RADIO - CARDIAC + THORACIC Flashcards
1
Q
Thoracic radiography indications
A
- Coughing - pul disease, R-sided CHF, parasitic disease, neoplasia, inhaled FB
- Dyspnoea - airway obstruction, pul disorders, pleural disorders
- CVS disease - murmurs, CHF, arrhythmia - heart size
- Thoracic trauma - pneumothorax, haemothorax, rib Fx, diaphragmatic rupture
- Neoplasia - 1y, metastatic disease
- Regurg - megaoesophagus, FB, congenital disorders, differentiate between GI disease
- Thoracic wall lesions - neoplasia, thoracic deformity
2
Q
Considerations (thoracic)
A
- Exposure - high kV, low mAs, minimise effect of movement blur
- Inspiratory view - full inspiration, when animal breathes in
- Don’t GA dyspnoeic animal - risk of lung collapse
3
Q
Minimum orthogonal views (thoracic)
A
- Cardiac conditions = RL + DV (heart near x-ray plate)
- Lung path - RL+ VD (lungs flop to side + expand for visualisation)
- Pul metastases - RL, LL, VD
4
Q
Dorsoventral pos (thoracic)
A
5
Q
Ventrodorsal pos (thoracic)
A
6
Q
Lateral recum pos (thoracic)
A
7
Q
Included in thoracic radiograph
A
- Surrounding ST
- Cranial abdo + diaphragm
- Neck
- Bones + ribs
- Pleural space
- Mediastinum
- Trachea + carina
- Bronchi
- Cardiac silhouette
- Great vessels + pul vasculature
- Lungs
8
Q
Mediastinum
A
- Space between L + R pleural cavities
- Extends from thoracic inlet to diaphragm
- VD/DV size = dog = < twice width of vertebral column; cat = no wider than width superimposed thoracic spine
- Present but not visible = azygos vein, main pul a., vagus n.
9
Q
Cranial mediastinum
A
- Trachea
- Oesophagus
- Cranial VC
- Cranial mediastinal + sternal LNs
10
Q
Middle mediastinum
A
- Heart
- Oesophagus
11
Q
Caudal mediastinum
A
- Aorta
- Caudal VC
- Oesophagus
12
Q
Medistinal shift
A
- Movement of the mediastinum or structures within away from the mid line (indicates a change in volume of one hemithorax)
- DV or VD projection
- Causes: unilateral lung collapse; pleural disease; unilateral pleural effusion or pneumothorax; large single or multiple pulmonary masses; unilateral diaphragmatic rupture
13
Q
A
14
Q
A
15
Q
Cardiac sizing - dog
A
- On lateral view, cardiac length (base to apex) should be 70% of dorsal to ventral distance of thoracic cavity
- On lateral view, cardiac width should be 2.5 - 3.5 intercostal spaces
- On DV/VD view cardiac width is approx. 60 – 65 % of thoracic width
- Aorta - diameter approx. the height of the adjacent vertebra
- Vena cava diameter varies with intrathoracic pressure, disease, hypovolaemia
16
Q
Cardiac sizing - cat
A
- On lateral view, cardiac width should be 2 - 2.5 intercostal spaces
- VD - approx 2/3 of width of thorax
17
Q
How to take vertebral heart score
A
From a lateral thoracic radiograph:
- 1). Measure the long axis of the heart from the ventral border of the left main stem bronchus to the most distal ventral contour of the cardiac apex.
- 2). Transfer this measurement to the thoracic vertebrae - starting at the cranial margin of the 4th
thoracic vertebral body and progressing caudally - count the number of vertebrae to the nearest 0.1
- 3). Measure the short axis of the heart at the widest part of the cardiac silhouette, making a line perpendicular to the long axis
- 4). Transfer this measurement in the same way as for the long axis.
- 5). Add the two measurements to give the dog’s vertebral heart size.
18
Q
VHS breed variations
A
19
Q
A
Lateral thorax canine
20
Q
A
Lateral thorax feline
21
Q
A
VD thorax canine
22
Q
A
VD thorax feline
23
Q
A
VD thorax greyhound
24
Q
A
Lateral thorax greyhound
25
Q
A
VD thorax bulldog
26
Q
A
Lateral thorax bulldog
27
Q
How do you calculate the vertebral left atrial size?
A
- Draw line from centre of most ventral aspect of carina to caudal aspect of left atria (1)
- Second line equal length from cranial aspect of T4 (2)
- Count no. vertebrae
- > 2.3 LA enlargement
28
Q
Abnormalities?
A
- Small cardiac silhouette - reduced in all dimensions
- Apex lifted from sternum
- Heart more triangular in shape
- Hypolucency of (dark) lung fields
- Cranial lobar artery/vein small in diameter (compare diameter at 4th i/costal space with diameter of prox 4th rib)
- Dx: Small cardiac silhouette + pulmonary vasculatur -> hypovolaemia associated with dehydration (Hypovolaemic shock, Addisonian crisis)
29
Q
What abnormalities?
A
- Cardiac silhouette - globoid in shape
- Occupies > 70% of d/v thorax + > 3.5 intercostal spaces
- Trachea elevated
- Causes - generalised cardiomegaly (eccentric hypertrophy); pericardial effusion
- Differentiation: Ultrasound exam would differentiate
30
Q
Trachea
A
- Lateral view - head in neutral pos so no artefacts
- Pos - angle w/ thoracic spine, parallel to spine in lateral, superimposed on spine in DV
- Size - should not change during resp cycle, narrowing in tracheal collapse - hard to Dx
31
Q
Oesophagus
A
- Thoracic + cervical radiographs needed
- Dorsal mediastinum
- Can be air-filled in normal animal
- Tracheal strip = luminal air, seen w/ megaoesophagus
32
Q
Lung views
A
- DV/VD first
- Lateral will cause atelectasis (collapse) of dependent lobe
36
Q
Alveolar lung patterns
A
- Always clinically sig
- Alveoli filled w/ oedema (cardiogenic oedema from heart disease or strangulation/electrocution), exudate, blood (trauma), neoplastic cells
- Inc lung opacity - patchy or homogenous, focal, multifocal, diffuse
- Border effacement - alveolar filling
- Air bronchograms - branching radiolucent lines over consolidated lungs
- Inc visibility of borders of individual lung loves - lobar sign - when alveolar pattern extends to periphery of lobar margin + lies adjacent to some aerated lungs
37
Q
A
Alveolar lung patterns
(Air bronchogram = a pattern of air-filled bronchi on a background of airless lung)
40
Q
Alveolar lung patterns - lobar
A
Lung lobe torsion
43
Q
Interstitial lung patterns - nodular
A
- Nodular ST opacities in lung - granulomas common in fungal disease
- Cannonball - neoplastic, ST w/ radiolucent centre
- Miliary pattern - small multiple coalescing nodules - neoplastic, ST opacities, CT more useful, can only see if 3 - 5 mm in diameter
- Solitary (nodular) - neoplasia, abscess, granular
44
Q
Interstitial lung patterns - unstructured/reticular
A
- Diffuse swelling of interstitial space
- Common in WHWH w/ interstitial pul fibrosis
- Connective tissue - things look more opaque
- Oedema, H+, fibrosis, neoplasia, infection
45
Q
Bronchial lung patterns
A
- 1). Tram lines
- 2). Donuts
- Thickening of bronchial walls
- Peribronchial changes from cellular infiltrate in interstitium - older animals w/ chronic bronchitis
- Can be seen in inflammatory conditions such as those from parasites, allergy or infectious agents e.g. feline lower airway disease e.g. asthma - concurrent hyperinflation + lungs inflated towards last rib
46
Q
A
47
Q
A
48
Q
Lungs - pulmonary vessels
A
- Veins = ventral + central, drift away from bronchial wall towards lung periphery
- Arteries - close to a bronchus
- At same level, aa + vv should be same size
49
Q
Lung patterns - vascular pathology
A
- Enlargement of pul vv = congestive HF
- Enlargement of pul aa = angiostrongylus, pul hypertension (R to L cardiac shunt / pul thromboembolism)
- Narrowing of vv = hypovolaemia (shock/haemorrhage)
50
Q
Pleural space
A
- Not normally seen as potential space
- Due to pleural effusion = fluid in pleural space (inc radiopacity = (H+, exudate, transudate, chyle), masses or air (inc radiolucency)
- Most bilateral
- DV most sensitive for small effusions
- Retraction lung lobes from thoracic wall
- Widening of interlobar fissures
- Scalloped lung lobe borders
- Silhouette sign – heart partially or fully obscured
52
Q
A
Pneumothorax - apex of heart lifted from sternum - radiolucency (air) outlining lungs
53
Q
A
Lung interstitial pattern, diffuse = metastatic neoplasia
54
Q
A
- Lung interstitial pattern = nodular, solitary lesion
- Neoplasia, abscess, granuloma
55
Q
A
56
Q
A
R lateral thorax of normal dog
57
Q
A
58
Q
A
- Unstructured interstitial lung pattern in a 3 m/o w/ mycoplasma pneumoniae
- Inc hazy appearance over caudodorsal lung fields
- Pulmonary vessels are visible but have fuzzy margins, giving the appearance of “trees in a fog”, that is an interstitial pattern
59
Q
A
- Miliary metastasis from melanoma in a dog
- Extensive variably sized nodules coalesce to obscure resp + caridac detail
60
Q
A
- Pleural plaques in dog
- Small, mineralised opacities too small to be pulmonary nodules
61
Q
A
- Hypovascular lung pattern in hypovolaemic dog
- Small heart + small pulmonary vv as they cross fourth rib (red arrow)
62
Q
A
- Cat - severe bronchopneumonia w/ alveolar pattern in cranial lung lobe
- Lobar sign + bronchograms (red arrows)
- Severe diffuse broncho-interstitial lung pattern in caudodorsal lung fields (green arrows)
63
Q
A
- Cardiogenic oedema in cat
- Diffuse fluffy alveolar pattern - esp in caudodorsal lung lobes (red oval)
- Border effacement (sign of alveolar disease) obscures in cardiac outline (red arrow)
64
Q
A
- Hyperlucent pattern in cat w/ severe lower airway disease + dyspnoea
- Flattened, caudal displacement of diaphragm (red arrow)
- Straightened ribs (green arrows)
- Bronchial tramlines + donuts (red oval)
65
Q
A
- Cardiac silhouette appears enlarged (vertebral heart score = 13.5; normal 8.5 – 10.7) with a prominent bulge at the level of the left atrium particularly visible in the lateral view.
- Trachea is parallel with the thoracic spine, suggesting elevation, and is slightly compressed.
- Caudal vena cava is also angling upwards.
- The pulmonary vasculature is quite prominent.
- Evidence of pulmonary venous congestion and an interstitial pattern consistent with pulmonary oedema
- Respiratory system: peribronchial pattern throughout the caudodorsal and mid lung fields that could also be related to pulmonary oedema
- ATRIAL FIBRILLATION
