SAEVA Congress 2018 Proceedings | 12-15 February 2018 | ATKV Goudini Spa
Bulging ventral lung tip with fluid bronchograms
A gelatinous-appearing lung occurs with parenchymal necrosis; the affected lung is
usually sonolucent and bulging, although collapse of this area may follow. These
necrotic areas then both cavitate and form an abscess or rupture into the pleural space
creating a bronchial-pleural fistula. Pulmonary infarcts should be suspected when a
clearly demarcated hypoechoic to echoic area of lung is imaged. The infarcted area
often appears more echoic than the adjacent consolidated lung and has a segmental
appearance. Color flow and power Doppler ultrasound and superb microvascular
imaging can be used to evaluate pulmonary blood flow in suspected areas of infarction.
Bronchial pleural fistula/abscess
A bronchial-pleural fistula is diagnosed ultrasonographically when the visceral pleural
edge of the lung is no longer present, a cavitation is imaged involving the visceral edge
of the lung and hyperechoic air echoes, and sonolucent fluid echoes can be imaged in
real time moving from the gelatinous area of pulmonary necrosis into the pleural space.
This results in a pneumothorax, as a bronchus communicates with the pleural space.
The pneumothorax may occur with or without a concomitant pleural effusion. Horses
with bronchial-pleural fistulas, if they survive, usually develop a large bronchial-pleural
abscess surrounding the site of the bronchial-pleural fistula.
Pulmonary abscess
Abscesses are identified ultrasonographically in the lung by their cavitated appearance
and the absence of any normal pulmonary structures (vessels or bronchi) detected
within. An anechoic area lacking air or fluid bronchograms with acoustic enhancement
of the wall or lung deep to the sonolucent area is the initial sonographic appearance of
an abscess. Abscesses may be encapsulated with an echogenic fibrous capsule, but
are more frequently imaged without any ultrasonographic evidence of encapsulation.
The material contained within the abscess may vary from anechoic to hyperechoic,
depending upon the type of exudate present. Loculations or compartmentalization of
the abscess may be present. Most abscesses are more sonolucent than the
surrounding pulmonary parenchyma, but may appear more echogenic if thick purulent
or caseous exudate is present.
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