Diagnostics of pulmonary sarcoidosis by the method of computed tomographic densitovolumetry

Aim. To develop a new method for quantitative evaluation of digital data of chest CT images of patients with sarcoidosis, to evaluate the diagnostic significance of the obtained quantitative indicators in comparison with functional pulmonary tests.Materials and methods. Healthy individuals (n=21) and patients with pulmonary sarcoidosis (n=101), divided into 5 groups according to J.G.Scadding classification, were examined. The lung function was assessed according to the data of spirometry, body plethysmography and the study of the lung diffusion capacity. All examined patients underwent a two-stage computed tomography of the lungs in the inspiratory and expiratory phases with the measurement in 3 density ranges.Results. The values of the obtained quantitative indicators, determined by the new method of CT-densitovolumetry, differed from the control group both in the general group of patients with sarcoidosis and in individual groups according to the J.G.Scadding classification. Correlations were found between radiometric measurements and lung function parameters. In patients with sarcoidosis, a larger volume of poorly ventilated sections was determined in comparison with the healthy group.Conclusion. The new method of CT-densitovolumetry makes it possible to quantify the entire volume of lung tissue in the area of tomographic coverage, the obtained results can be used as a useful tool in predicting the course of the disease and the response to ongoing therapy.