Serial evaluation of high-resolution computed tomography findings in patients with idiopathic pulmonary fibrosis in usual interstitial pneumonia

BACKGROUND: The development of well-matured fibrosis in usual interstitial pneumonia (UIP) is strongly associated with an unfavorable outcome of patients with idiopathic pulmonary fibrosis (IPF). However, differences in the rates of development are likely to result in variable clinical courses in IPF patients. OBJECTIVE: We tried to evaluate the progression of honeycombing and ground-glass opacity on CT using a scoring system, and to examine those serial changes in the clinical course of disease. METHODS: A hospital-based, retrospective cohort study. Twenty-three patients with IPF diagnosed as UIP by surgical lung biopsy were analyzed during the initial examination by scoring the presence of honeycombing (HC: range, 0-24) and ground-glass opacity (GG: range, 0-24) on CT scan. We also compared the serial changes observed in the CT scores (interval: 2-42 months, 2-6 examinations). RESULTS: (1) The serial change in the HC score in treated patients (n = 10) was similar to that in untreated patients (n = 16); (2) the HC score at the time of the initial examination and the rate of HC progression were both higher in the non-surviving patients (HC 12.3 +/- 3.7, mean +/- SD; deltaHC 4.2 +/- 1.3 per year) than in the surviving patients (HC 5.8 +/- 2.7; deltaHC 1.2 +/- 0.7 per year) (p < 0.05); (3) the GG score did not correlate with the HC score at any of the examinations; (4) the HC score was higher in the lower lung field than in the upper and middle lung fields. CONCLUSIONS: Scoring of the honeycombing and its serial changes using the high-resolution computed tomography scoring method was useful for predicting the prognosis in patients with IPF/UIP. Corticosteroid treatment did not prevent the progression of HC.