Idiopathic pulmonary fibrosis (IPF) is a progressive disease characterized by fibrosis and remodeling of the lung parenchyma. The median survival of patients with the disease is about three years after diagnosis or five years after the onset of symptoms. The pathological findings are those of usual interstitial pneumonia.¹ In many instances, the diagnosis can be made when typical clinical and radiologic features are present.²–⁵ The classic radiologic features are a patchy pattern of peripheral “honeycombing” that is more prominent in the bases of the lungs, traction bronchiectasis, and the absence of prominent ground-glass opacity. When these findings are not . . .