Endoluminal chest sonography

Abstract

The anatomical limitations of chest sonography can be circumvented by endoluminal ultrasound application. There are several promising ways of ultrasound access to the thorax: the esophagus, the bronchial tree and the vasculature. The space between aorta and the pulmonary entry, a region difficult to evaluate by computed tomography, can reliably be investigated by transoesophacal ultrasound. Intravascular ultrasound may have a high diagnostic yield in the evaluation of local resectability in same cases. For ultrasound inspection from the bronchial tree, miniaturised ultrasound transducers (7.5–20 MHz) are available, which are applicable by fiberoptic bronchoscopy containing a large suction channel. The use of high frequency ultrasound enables the exact differention of bronchial walls and tumourous lesions in central airways. Tumour margins, submucousal neoplastic tissue and peribronchial structures are visualized reliably. Moreover, mediastinal vessels, peripheral pulmonary lesions, i.e. lung infarction, lung cnacer or lung metastases can be examined if the catheter has access by the bronchial lumen. Thus, endoluminal chest sonography may increase the sensitivity and specifity of bronchoscopy in the diagnosis of small central and peripheral pulmonary pathological lesions. Endoluminal chest sonography has the potential to further improve imaging diagnostics in chest disease. This potential advantage has to be confirmed in further prospective controlled studies.