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In this study contrast-enhanced ultrasound (CEUS) of pulmonary lesions was carried out on n=55 patients with suspected pulmonary embolism (PE). In n=35 cases diagnosis was confirmed by CT or scintigraphy (group A). N=9 patients presented with deep vein thrombosis without confirmation of PE (group B). In n=11 patients pulmonary lesions were found by CEUS without confirmation of PE and without thrombosis (group C).
he aim of this study was to describe typical CEUS-patterns of pulmonary lesions based on a larger series of patients suffering from pulmonary embolism and to determine their clinical value. Therefore, several clinical aspects such as pleural effusion and “age” of the lesion (time elapsed between clinical symptoms and CEUS-investigation) were evaluated in retrospect based on the clinical records of each patient. Afterwards this data was correlated with the data from the CEUS-investigation and evaluated by means of descriptive and comparative statistics.
Pulmonary embolism often shows a CEUS-pattern consisting of a delayed time to contrast agent-enhancement indicating a lack of pulmonary arterial supply or a bronchial arterial supply, as well as a lack of enhancement or an inhomogeneous enhancement pattern in the pulmonary lesions. We found this CEUS-pattern in 73% (n=40) of our patients (80% in group A with confirmed pulmonary embolism, n=28).
Comparison of ‘typical’ and ‘atypical’ CEUS-patterns in patients with confirmed PE (group A)showed no significant differences concerning the investigated aspects (patient age, age and size of lesion, pleural effusion).
Pulmonary lesions >1cm showed vascularization in CEUS more often than smaller lesions. This can also be caused by better display of the lesion itself.
Pleural effusion was more often found in correlation with pulmonary arterial supply than with bronchial arterial supply (group A). Correlation between vascularization pattern and age of the lesion could not be confirmed.Depending on age and size of the lesion, different stages of pulmonary embolism can be
demonstrated by CEUS. CEUS can be of value to differentiate between pulmonary lesions of other cause e.g. pleuritis or peripheral malignant lesions.
Following studies with a larger series of patients and a prospective study design investigating a similar problem may provide different results.
In conclusion, CEUS is a fast, safe and low-cost diagnostic tool that can contribute to diagnostics of pulmonary embolism in specific cases and to investigate tissue vascularization in general.