The relationship between high resolution computed tomography and pulmonary function tests in sarcoidosis

Abstract

Objectives: This study aims to assess the correlation between inspiration and expiration high resolution computed tomography (HRCT) findings and pulmonary function tests (PFTs) in patients with sarcoidosis.

Patients and methods: Forty-five patients with sarcoidosis (18 males, 27 females; mean age 42.1±11.6 years; range, 24 to 64 years) were included in this single-center, prospective, non-interventional study. Disease stage, presence and level of air trapping in expiratory and inspiratory HRCT patterns such as nodular, reticular, fibrotic and ground-glass patterns, and PFT results were recorded. The correlations between HRCT findings and PFTs were analyzed.

Results: Diagnoses of sarcoidosis were histopathologically (69% cases) or radiologically confirmed. According to X-ray findings, 3 (6.6%), 15 (33.3%), 24 (53.3%), and 3 (6.6%) patients were categorized as stage 0, I, II and III sarcoidosis, respectively. Air trapping was detected in HRCT in 33 (73.3%) patients. Although there was no association between air trapping and inspiratory imaging patterns and/or pulmonary function tests, they seemed more abundant in the lower/mid lung zones. Forced expiratory volume in one second (FEV1)/forced vital capacity (FVC) ratio and forced expiratory flow (FEF) 25-75 was significantly lower in patients with fibrosis. Significant negative correlations between the fibrotic pattern and FEV1/FVC (r= -0.354; p<0.005) and FEF_25-75 (r= -0.440; p<0.005) values were detected.

Conclusion: Although air trapping pattern in expiratory HRCT was not associated with pulmonary function tests, it may be a useful diagnostic parameter in assessing the level of parenchymal involvement of the lungs in sarcoidosis. Among the imaging patterns on HRCT, only fibrosis was associated with airway obstruction.

Cite this article as: Aykaç N. The relationship between high resolution computed tomography and pulmonary function tests in sarcoidosis. D J Med Sci 2020;6(2):53-61.

The author declared no conflicts of interest with respect to the authorship and/or publication of this article.

The author received no financial support for the research and/or authorship of this article.

We would like to thank Günay Can for the statistical analysis of the study and to Dr. Kemal Tahao¤lu, Tülin Sevim, Dr. Salih Güran and Dr. Güliz Ataç for their support in interpreting some of the data.