Thoracic Radiology of the Dog
Dr. LeeAnn Pack
Dipl. ACVR
http://people.upei.ca/lpack/vetrad/
Thoracic Radiology of the Dog
• Indications
• Technical factors
• Normal radiographic
anatomy
• Pulmonary vasculature
• Alveolar lung pattern
• ABC’s
• Bronchial Lung Ds
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• Cardiology
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PDA
Pulmonic stenosis
Aortic stenosis
Mitral insufficiency
DCM
Heartworm Disease
Pleural Effusion
Primary Lung Tumors
Pulmonary Nodules
Megaesophagus
Indications
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Coughing
Dyspnea
Cardiovascular disease
Thoracic trauma
Assessment of primary or secondary
neoplasia
• Regurgitation of food
• Other abnormalities detected on PE
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Technical Factors
• Potential for movement
– Low mAs
• High inherent contrast
– Low kVp
• INSPIRATION
• Collimation/centering
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Inspiration vs. Expiration
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Normal Radiographic Anatomy
• Heart
– 2 ½ to 3 ½ intercostal
spaces wide on lateral
view
– < 65% of the width of the
thorax on the VD view
– “clock face”
– Lung lobes
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Chamber Location
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Pulmonary Vasculature
• Cranial pulmonary vessels
– Lateral view
– Artery = dorsal, vein = ventral
– Diameter of vessels at the 4th ICS should
not exceed the diameter of the proximal
portion of the 3rd rib
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Cranial Pulmonary Vessels
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Pulmonary Vasculature
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Caudal pulmonary vessels
DV view
Artery = lateral, Vein = medial
Vessels should not exceed the diameter
of the 9th rib where they cross it
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Alveolar Lung Pattern
• Hallmark = air bronchograms
– Consolidation = alveoli filled with fluid/cells
• Retains shape
– Atelectasis = collapse of alveolar lung
space
• Lobe size decreased, mediastinal shift possible
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Air Bronchogram
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Alveolar Lung Pattern
• Lobar sign
• Summation – superimposed over
cardiac silhouette
• May not see pulmonary vessels in area
of pattern due to soft tissue opacity
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Nice Air Bronchograms 
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The ABC’s
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A
• Atelectasis
– General anx
– Recumbent animals
– Dependent lung lobes
affected
• Aspiration pneumonia
– Cranial,cranioventral lung
lobes affected
– Megaesophagus
– Post anesthesia
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B
• Bronchopneumonia
– Cranioventral,
ventral
• Bacterial pneumonia
– Cranioventral,
ventral
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C
• Contusion
– History of trauma
– Rib fractures
– Distribution varies
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D
• Dirofilariasis
– Most common cause
of thromboembolic
disease
– Increased lung
opacity
– Mixed interstitial –
alveolar
– Caudodorsal
distribution
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E
• Edema
• CARDIOGENIC
– Left heart failure
– Perihilar, symmetrical
• NON-CARDIOGENIC
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Electrocution
Salt water drowning
Seizures
caudodorsal
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Cardiogenic Edema
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Non Cardiogenic Edema Lateral
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Non Cardiogenic Edema VD’s
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F
• Foreign Body
– Located in bronchus
– Affected area
depends on affected
bronchus
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G
• Granulomatous
• Fungal
– Eosinophilic
• Variable distribution
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H
• Hemorrhage
– Distribution variable
depending on the
cause
– Trauma
• Rib fractures
– Coagulopathy
• Patchy, generalized
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Bronchial Lung Disease
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Bronchial – RR Tracks
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Bronchial
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Donuts
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Bronchial Lung Disease
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Bronchial Lung Disease
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Feline Asthma
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Feline Asthma
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Cardiology
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Congenital
Acquired
Small breeds
Large breeds
Younger
Older
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Patent Ductus Arteriosis
• Enlargement of the descending aorta
• Enlargement also of the:
– Main pulmonary artery
– Left atrium
– Left auricle
• Vessels enlarged, lungs over-circulated
• Poodle, pom, collie, GSD, sheltie
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PDA
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PDA
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Pulmonic Stenosis
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Malformation of the pulmonic valve
Enlargement of the main pulmonic aa
Right ventricular enlargement
Vessels normal to small
Beagle, English Bulldog, Samoyed,
mastiff, boxer
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PS
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Aortic Stenosis
• Narrowing of the subvalvular region of
the left ventricle
• Aortic arch enlarged
• Left ventricle enlarged
• Vessels normal
• GSD, Newfoundland, Boxer, golden
retriever, rott
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AS
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Mitral Insufficiency
• Primary degeneration of the mitral valve
leaflets
• Regurg through the valve  left atrial
enlargement
• Pulmonary veins enlarged
• Pulmonary edema due to left heart
failure
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Mitral Insufficiency
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Severe Left Atrial Enlargement
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Splitting of the MSB
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Compression at Carina
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Dilated Cardiomyopathy
• Cardiac chamber enlargement +
systolic ventricular dysfunction ~
impaired cardiac contractility
• Generalized cardiomegaly
• Vessels may be enlarged
• Pleural effusion due to right heart failure
• Dobe, Great Dane, Newfoundland, Irish
Wolfhound
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DCM
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DCM
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Pericardial Effusion
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Heartworm Disease
• Dilated, tortuous
pulmonary arteries
• Right sided heart
enlargement
• Reverse D shape
• DV radiograph to
see caudal vessels
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Pleural Effusion
• Fluid in the pleural space
• Exudate, transudate or modified
transudate
• Appearance is sam regardless of the type
• Usually bilateral
• Fissure lines, retraction of lungs,
silhouetting of heart and diaphragm
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Pleural Effusion – VD vs. DV
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Where Is the Heart?
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Pleural Effusion – CMM Present?
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Primary Lung Tumors
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Usually large solitary
Caudal lung lobes usually
Adenocarcinoma
Bronchogenic carcinoma
Squamous cell carcinoma
Malignant histiocytosis
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Pulmonary Nodules
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Megaesophagus
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Congenital
Acquired
Segmental
Generalized
Radiographic signs
Aspiration pneumonia
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Generalized Megaesophagus
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Segmental ME - Surveys
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Segmental ME - Contrast
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What Do You See?
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Chest Rads – Same Dog
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Thoracic Radiology in the Dog
Questions????
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