Radiology2- Lung Diseases

• underexposure: if you can visualize the thoracic vertebrae well, it is appropriately exposed
• expiration rads: cranially displaced diaphragm and increased contact between cardiac silhouette and diaphragm means it was probably taken during exhalation

• Primary lung tumor
• Pulmonary metastases
• Granulomas (mycotic pneumonia)
• Thoracic wall lesion- not within lungs, take multiple views to eliminate this possibility
• Less common: traumatic bulla, hematoma, abscess, cyst, mucus in bronchus, lymphosarcoma (uncommon)

• non-cavitary (usually) unstructured interstitial pattern
• multiple, round nodules of various sizes
• usually in middle to peripheral aspects of lungs
• [more common than primary lung tumors]

• Disseminated structural interstitial pattern (milliary if nodules are very small)
• nodules are usually the same size
• frequently accompanied by tracheobronchial lymphadenopathy
• [Blasto, Histo, Coccidomycosis]

• structured interstitial pattern
• usually solitary mess lesion
• usually arise in the periphery
• may be cavitated if communicating with a bronchus
• [bronchogenic carcinomas most common]

• metastatic tumor
• pulmonary granuloma
• pulmonary abscess (esp if cavitated)
• traumatic cyst (area of lung full of blood- should have Hx of trauma)

• Paragonimiasis
• Abscess
• Bulla
• Less common: primary lung tumor, pulmonary mets, mycotic granuloma, cyst, bronchiectasis

• structured interstitial pattern, often cavitated
• focal, walled-off
• chronic- discrete mass, acute- irregularly margined

• cavitated structured interstitial pattern
• spherical, radiolucent area(s)
• smooth, thin-walled
• [congenital, traumatic, rarely infectious]

underexposure

• if you can see the blood vessels around each bronchus- UNSTRUCTURED INTERSTITIAL
• if you cannot see the blood vessels- ALVEOLAR

• blood (contusions, hemorrhage)
• pus (aspiration, bronchopneumonia, septic)
• water (cardiogenic or non-cardiogenic edema)
• absence of air (atelectesis- expiration or pleural dz)
• less commonly cells

as bacterial infection worsens, starts with unstructured interstitial pattern that progresses to alveolar pattern; as the lung lobe then recovers, it transitions from alveolar pattern to an unstructured interstitial pattern then back to normal

• old-age change
• mild fibrosis, severity depending on amount of pollutants inhaled throughout life, scarring from old lesions

• unstructured interstitial early, alveolar late/ severe
• secondary to left heart failure- signs of HF (enlarged left heart, rounded cardiac silhouette, enlarged pulmonary veins)
• hilar and perihilar location

• can look like anything, does not follow typical peri-hilar distribution
• very irregular distribution pattern
• mainly look for cardiac changes

• neurologic (head trauma, seizure, electric shock)
• severe allergic reaction
• advanced uremia
• pancreatitis
• irritating inhalants
• drowning
• radiation damage
• [overall, very uncommon]

• distribution is generalized (compared to cardiogenic edema), commonly more peripheral
• heart and pulmonary vein size is normal

• Partial lobe collapse
• Contusions
• Hemorrhage
• Pulmonary embolism (can also have completely normal looking rads- CT is better)
• Bronchial FB
• Disease in transition

• Bronchopneumonia
• Edema
• Hemorrhage
• Collapsed lobe (airway obstruction or pleural effusion)
• Primary lung tumor
• Pulmonary metastasis
• Pulmonary infarct
• [remember: exhalation is a type of atelectasis...this is why we take rads on full inspiration]

• Unstructured interstitial pattern most common (esp if only a little of the gas is removed from the lobe)
• Alveolar pattern also possible (esp if all or most of the air is removed)

• Incomplete aeration: film made during expiration, prolonged recumbency
• Airway obstruction: internal blockage (FB), external compression (tumor)
• Increased intrapleural pressure: pneumothorax, pleural effusion

• interstitial or alveolar
• look for other signs of trauma (as trauma is the most common cause....coagulopathy also possible)- rib fractures, pleural effusion, neumothorax, diaphragmatic hernia

• severe bronchopneumonia
• severe edema
• severe pulmonary contusions
• near-drowning
• smoke inhalation (as in house fire, not cigarette smoke)

• early- unstructured interstitial pattern, later- alveolar pattern [once you start treatment and it starts resolving, goes back to interstitial]
• bronchial pattern- if spread via airways, lobar sign
• hematogenous spread- patchy, multifocal distribution around vessels

• [cranioventral lung lobes]
• right cranial lung lobe
• right middle lung lobe (ESP WITH MEGAESOPHAGUS- most common location for aspiration pneumonia with megaesophagus)
• left cranial lung lobes

• unstructured interstitial pattern or alveolar pattern
• depends on the amount of fluid aspirated and the nature of the aspirated material

• patient position at time of aspiration
• passive aspiration--> right cranial and right middle lobes most common
• forceful aspiration--> right caudal most common

• bronchial mineralization
• allergic bronchitis
• chronic bronchitis
• peribronchial cuffing (esp with bronchopneumonia)

• feline asthma
• peribronchial infiltrate of eosinophils and mononuclear cells
• if severe, can get interstitial edema
• if chronic, can get permanent interstitial fibrosis

• Dogs- tracheobronchitis
• Cats- upper respiratory disease
• [not usually seen radiographically unless complicated by bacterial infection]

• loss of normal bronchial tapering
• changes in bronchial epithelium, mucus characteristics, ciliary function--> these lead to predisposition for chronic bacterial infections

chronic bacterial infections/ bronchopneumonia; changes in bronchial epithelium and mucociliary elevator.

• overexposure
• hypovolemia
• air trapping
• emphysema (usually accompanied by bronchial thickeing)
• overinflation (increased tidal volume, upper airway obstruction, iatrogenic)

• bronchial mineralization
• pulmonary osteomas
• granulomas
• histoplasmosis
• primary lung tumor
• aspirated barium sulfate

• hyperadrenocorticism (cushings)
• hyperparathyroidism
• chronic uremia
• idiopathic

usually 4

• usually bilateral
• ventral distribution most common
• interstitial or alveolar pattern
• abscesses/ granulomas more common than in small animals

Rhodococcus pneumonia

• Radiographic abnormalities only seen in advanced disease
• air trapping- you can see this by making inspiration and expiration projections (will look the same because gas is not leaving the lungs, hence "trapped")
• reticulated interstitial pattern
• +/- bronchiectasis

• pulmonary vessels very small
• lack of vascular markings
• microcardia