A quantitative analysis of long-term follow-up computed tomography of idiopathic pulmonary fibrosis: the correlation with the progression and prognosis

Background Quantitative analyses of computed tomography (CT) images using computer-aided detection (CAD) are correlated with visual assessments and pulmonary function test findings and might be useful for predicting the prognosis of patients with idiopathic pulmonary fibrosis (IPF). Purpose To evaluate the association between the quantitative analysis of long-term follow-up CT of IPF and the progression and prognosis. Material and Methods A total of 48 patients with IPF who received over one year of follow-up CT were included in this study. The results of quantitative analyses (emphysema, ground-glass attenuation [GGA], consolidation, reticulation, and honeycombing) using a CAD software program of initial and follow-up CT findings were evaluated, and the association with the progression of the total lesion of IPF and prognosis using Spearman's rank correlation and Cox regression analyses was considered. Results Results of quantitative analyses of consolidation, reticulation, honeycombing, and the total lesion on initial CT were correlated with progressive changes in the total lesion of IPF per year (r = 0.4375, 0.4128, 0.4649, and 0.4095, respectively). The results of quantitative analyses of honeycombing (hazard ratio [HR] = 1.40, 95% confidence interval [CI] = 1.03−1.89, P = 0.0314) and GGA (HR = 0.85, 95% CI = 0.72−0.99, P = 0.0384) at initial CT were prognostic factors according to a multivariate Cox regression analysis. Conclusion The quantitative analysis of honeycombing using a CAD software program of CT findings may be useful for predicting the progression and prognosis of patients with IPF.