Fig. 4From: Clinical and radiological features of idiopathic interstitial pneumonias (IIPs): a pictorial reviewHoneycombing appearance on HRCT images. The cystic spaces reproduced on HRCT images (A and C); a real honeycomb (B, removed from apartment window of one of the authors). The honeycombing appearance consists of a cluster of cystic air spaces, usually with a diameter of 3–10 mm, although they may reach 2.5 cm in size [19, 20]Back to article page