Sonographic diagnosis and follow-up of pneumonia: a prospective study

Background: Although transthoracic ultrasound offers several important advantages as diagnostic imaging technique in pleural and pulmonary conditions, its significance for the diagnosis and monitoring of pneumonia has yet to be established.

Objectives: To identify sonographic features associated with pneumonia at admission and during the course of the disease under treatment.

Methods: Thirty patients (12 females, 18 males; median age 65.5 years) with X-ray-proven pneumonia underwent transthoracic sonography (TS) on day 0, between days 1 and 3, 4 and 7, 8 and 14, 15 and 21, and after day 21. TS was assessed according to: number, location, shape, echogenicity, echotexture, echostructure, breath-depending movement, size of pneumonic lesions, bronchoaerogram, fluid bronchogram, superficial fluid alveologram, necrotic areas, vascularity and incidence of local and/or basal pleural effusion.

Results: Thirty-three pneumonic infiltrates were eligible for analysis in 30 patients. In 57% (17/30), the likely pathogenic microorganism was identified. Pneumonia was recognized as a hypoechoic area of varying size (mean size between 33.7 x 9.38 and 91.2 x 45.3 mm) and shape, with irregular and blurred margins along with a nonhomogeneous echotexture. The most characteristic feature was a positive bronchoaerogram (32/33). Sixty-one percent (20/33) revealed basal and 9% (3/33) local effusion. During follow-up, lesions decreased in size or disappeared (30/33) or decreased in number (4/9). The bronchoaerogram became less pronounced (13/32), basal pleural effusion either diminished (7/20) or dissipated (7/20), as did localized effusion (3/3). In 30 cases, the course of pneumonia was comparable using X-ray and TS.

Conclusions: TS is a noninvasive technique for the diagnosis and follow-up of patients with pneumonia.