The correlation of symptoms, pulmonary function tests and exercise testing with high-resolution computed tomography in patients with idiopathic interstitial pneumonia in a tertiary care hospital in South India

CONTEXT: For the follow-up of patients with idiopathic interstitial pneumonias (IIP), it is unclear which parameters of pulmonary function tests (PFT) and exercise testing would correlate best with high-resolution computed tomography (HRCT).. AIM: To find out the correlation of symptom scores, PFTs and exercise testing with HRCT scoring in patients diagnosed as idiopathic interstitial pneumonia. SETTINGS AND DESIGN: Cross-sectional study done in pulmonary medicine outpatients department of a tertiary care hospital in South India. MATERIALS AND METHODS: Consecutive patients who were diagnosed as IIP by a standard algorithm were included into the study. Cough and dyspnea were graded for severity and duration. Pulmonary function tests and exercise testing parameters were noted. HRCT was scored based on an alveolar score, an interstitial score and a total score. The HRCT was correlated with each of the clinical and physiologic parameters. Pearson's/Spearman's correlation coefficient was used for the correlation of symptoms and parameters of ABG, PFT and 6MWT with the HRCT scores. RESULTS: A total of 94 patients were included in the study. Cough and dyspnea severity (r = 0.336 and 0.299), FVC (r = −0.48), TLC (r = −0.439) and DLCO and distance saturation product (DSP) (r = −0.368) and lowest saturation (r = −0.324) had significant correlation with total HRCT score. Among these, DLCO, particularly DLCO corrected % of predicted, correlated best with HRCT score (r = −0.721).. CONCLUSION: Symptoms, PFT and exercise testing had good correlation with HRCT. DLCO corrected % of predicted correlated best with HRCT.