Ultrasound in the evaluation of interstitial pneumonia

The diagnostic value of thoracic ultrasonography (US) has recently increased. Skilled sonographers with experience in pulmonary medicine have demonstrated the existence of US signs of chest pathology.

To detect US findings associated with infectious interstitial pneumonia that can be used to supplement other diagnostic tools.

Over a period of 5 years (2001-2006), 55 patients were referred to our ultrasonography units for evaluation of probable viral or viral-like infections of the respiratory tract. Each patient was subjected to a work-up that included clinical examination, blood tests, pulmonary function tests, bronchoscopy, chest radiographs, high-resolution computed tomography (HRCT), and thoracic US, which was performed under blinded conditions.

Based on the findings that emerged from the work-up described above, all 55 patients were diagnosed with interstitial pneumonia. Evaluation of the US scans for the signs of interstitial lung disease described by Lichtenstein revealed "comet-tail" artifacts in the anterolateral lung fields in 31 (56.36%) patients and mixed patterns consisting in increased density associated with ring-down artifacts in 24 (46.64%). Pleural involvement was also observed in 34 cases (61.82%).

Thoracic US appears to be a useful adjunct to clinical, laboratory and radiological studies in patients suspected of having infectious interstitial pneumonia.