Kontrastunterstützte Sonographie bei Pneumonie: Charakteristische Darstellungsmuster und prognostische Bedeutung. Eine retrospektive Studie bei n=50 Patienten

In this study contrast-enhanced sonography (CES) of pulmonary lesions was carried out on n=50 patients with radiological diagnosed alveolar pneumonia. The aim was to describe a typical CES-pattern of pulmonary lesions based on a larger series of patients suffering from pneumonia, and to determine which clinical value would constitute an atypical CES-pattern. Therefore, several clinical aspects such as days of hospitalization, comorbidity and rate of complications were evaluated in retrospect based on the clinical records of each patient. Afterwards this data was correlated with the data from the CES-investigation and evaluated by means of descriptive and comparative statistics. Summarizing the results, pneumonia shows a typical CES-pattern consisting of a short time to a contrast agent enhancement indicating a pulmonary arterial supply, an isoechoic extent of enhancement compared to the spleen and a homogeneous enhancement of the contrast agent in the pulmonary lesions. We found this typical CES-pattern in 60% of our patients. Whereas 92% of n=50 pneumonias showed a pulmonary arterial supply, 76% showed an isoechoic extent of enhancement, and 78% a homogeneous enhancement. The typical CES-pattern found in pulmonary lesions caused by pneumonia resulting from this study consists of a short time to enhancement (1-6 seconds) indicating pulmonary arterial supply, an isoechoic extent of enhancement in comparison to the spleen and an homogeneous enhancement of the contrast agent within the pulmonary lesions. A deviation from this pattern can supply valuable information. A delayed time to enhancement indicating bronchial arterial supply and a hypoechoic extent of enhancement may possibly be a sign for pulmonary abscess or carnification. Responsible for the hypoechoic extent of enhancement could be the well-known hypoxic vasoconstriction in the pulmonary circulation. An inhomogeneous enhancement could also be a sign for liquefaction or pulmonary abscess formation. In this study, a clinical relevance regarding the prognostic value of CES in pneumonia could not be shown. However, we did find a tendency, which showed that atypical CES-patterns in pneumonia could lead to the assumption that complication in terms of abscess or carnification may occur. Following studies with a larger series of patients and a prospective study design investigating a similar problem may produce different results.