High kVp, low mA. Taken in inspiration
Thoracic radiographs: technique and phase of respiration
1) Pleural effusion. 2) Pulmonary consolidation (alveolar pattern in caudal lung lobes). 3) Diaphragmatic hernia.
When is diaphragm not seen?
1) Cranial ventral mass – thymus, lymph node, tumor, abscess. 2) Heart enlargement/heart base tumor. 3) Positioning (head bent ventral)
What can dorsally displace the trachea?
Megaesophagus most common. Dorsal mediastinal mass.
Ventral displacement of trachea
Cranial mediastinal mass, pulmonary mass, mediastinal shift, positioning.
Lateral displacement of trachea
Cranial mediastinal mass.
Caudal displacement of trachea
On expiration.
Thoracic tracheal collapsed seen on when?
Increased radiolucency in mediastinum, tracheal stripe sign.
Signs of Pneumomediastinum
Pneumothorax, pneumoretroperitoneum, mediatstinitis.
Complications of a pneumomediastinum
Right (and left) heart failure, low colloidial osmotic pressure, increased capillary permeability due to neoplasia, trauma or infection, diaphragmatic hernia with incarceration of liver.
Causes of pleural effusion
1) Leafing of lung lobes. 2) Silhouette with cardiac shadow. 3) interlobar fissures. 4) retraction of lobes from body wall. 5) Rounding or costophrenic angles. 6) Widening of medistinum.
Signs of pleural effusion
Most common right middle and cranial left lung lobes. Non-inflated lungs, +/- air bronchograms. Large breed, deep chested dogs.
Lung lobe torsion
Heart appears dorsally displaced, retraction of lung lobes, lung lobes appear denser than normal, lack of vascular markings in periphery of lung field, flattened diaphragm.
Pneumothorax Signs
DV view, on expiration.
What view and respiration is a pneumothorax seen better?
Acquired: heartworm disease, tricuspid insufficiency. Congenital: Pulmonic stenosis, Tertology of Fallot, VSD.
Cardiac diseases associated with primary right-sided heart enlargement
Acquired: Mitral insufficiency. Congenital: Aortic stenosis.
Cardiac diseases associated with primarily left-sided heart enlargement
Acquired: cardiomyopathy, mitral and tricuspid insufficiency, pericardial effusion, neoplasia, peritoneal-pericardial hernia. Congenital: PDA
Cardiac diseases associated with both left and right-sided heart enlargement
Hepatomegaly, ascites, pericardial effusion, enlargement of pre or post cava, pleural effusion
Signs of RHF
Dilated dense pulmonary veins, interstitial or pulmonary edema (starts in hilar region), pleurall effusion (cats)
Signs of LHF
Lateral: RV enlargement (mild); loss of cranial waist; enlarged arteries; arteries distorted, tortuous, and end abruptly (pruning); areas of increased patchy radiolucency in lung parenchyma; normal left side of heart. DV: rounding of RV (reverse D); pulmonary a bulge; pulmonary vascular changes and pulmonary parenchymal changes.
Radiographic signs of Heartworm disease
Lateral: LA enlargement; LV enlargement; elevation of tracheal bifurcation; dorsal displacement and compression of bronchus; check for signs of concurrent LHF. DV: enlargement of left auricular appendage; LV enlargement; splitting of mainstem bronchi.
Radiographic signs of Mitral Insufficiency
Increased size of cardiac silhouette; heart becomes globoid.
Radiographic signs of pericardial effusion
Bilateral heart enlargement; signs of RHF or LHF.
Radiographic signs of cardiomyopathy – dog
Bilateral heart enlargement. LA enlarged. Valentine shape on DV. Commonly see pulmonary edema or pleural effusion.
Radiographic signs of cariomyopathy – cat
LH markedly enlarged, RH moderately enlarged. Enlargement of pulmonary segment. Enlargement of pulmonary vessels at the hilus. See edema of lungs posterior to tracheal bifurcation.
Radiographic signs of PDA
Edema, Pneumonia, Hemorrhage, atelectasis, tumor.
Differential Diagnoses of Alveolar Lung Pattern
Fibrosis, tumor, pneumonia, edema, allergy, granuloma, hemorrhage.
Differential Diagnoses of Interstitial Lung Pattern
Bronchitis, bronchiectasis.
Differential Diagnoses of bronchial lung pattern
Hyperperfusion, hypoperfusion, passive congestion, vascular dilation, vascular occlusion.
Differential Diagnoses of vascular lung pattern
Pulmonary infiltrate with eosinophils, feline asthma.
Differential Diagnoses of mixed lung pattern
Bilateral, symmetrical perhilar alveolar pattern – often spares periphery. Enlarged heart.
Alveolar Pulmonary edema due to LHF (cardiogenic)
Alveolar pattern: patchy, asymmetrical, contusions, DIC.
Alveolar Hemorrhage
Alveolar pattern: asymmetrical, patchy distribution (appears hilar if lymphadenopathy), cranioventral, peribronchial/peribronchial infiltrates common.
Bronchopneumonia
Alveolar pattern: cardiac shift, middle lung lobes, weeping willow effect
Atelectasis
Alveolar pattern: caudal lung lobes, not labile, may have pulmonary metastatic disease.
Neoplasia in Lung
Common w/ megaespoagus or vomiting in dogs with laryngeal hemiplegia. May happen after anesthesia. Mixed pattern, generalized or restricted to dependent lobes.
Aspiration pneumonia
