PURPOSE:The value of high resolution computed tomography (HR-CT) in the recognition of pathologic changes of the lung parenchyma, especially in the diagnosis of sarcoidosis, is well established. The importance of these findings in regard to the inflammatory activity is not sufficiently documented, also because a direct histologic correlation is seldom possible.

METHOD:In a prospective study twenty-one patients with suspected or known sarcoidosis were evaluated. The diagnostic work up comprised the clinical examination, lung function tests, the radiological evaluation, including GH-CT, and bronchoscopy for bronchoalveolar lavage (BAL) and transbronchial biopsy.

RESULTS:The comparison of the HR-CT findings, like pathologic appearance of the bronchovascular bundle and intraparenchymal nodules, with serologic and BAL-parameters yielded high correlation coefficients with the total cell count in BAL and sIL-2R, and moderate correlations with the lavage lymphocyte count and the activity markers, like T4/T8 ratio, IL-2R and HLA-DR expression.

CONCLUSION:As a non invasive method, HR-CT depicts pathologic findings of the lung parenchyma which are associated with the inflammatory activity of sarcoidosis.