Radiographic Findings

A preoperative plain film shows small lung volumes, especially on the left.

Where are the reticular opacities most prominent? Answer

Why do the heart and mediastinum look "shaggy"? Answer

What is the radiographic appearance of honeycombing? Answer

Considered together, what diagnosis do the findings suggest? Answer

Note the left lower lobe consolidation. Also, there is no evident pulmonary arterial enlargement.

A prone CT image (2/2/98) shows that the left lower lobe consolidative appearance (shown above) is due to dense honeycombing. Note the diffuse, somewhat thick-walled, regular cysts of 2-5 mm size: this small size makes the cysts difficult to see on the radiograph. The asymmetry of disease (worse on left) accounts for the greater volume loss in the left lung.

On the right, there are extensive reticular densities in the subpleural regions without clear honeycombing. Also, focal consolidation is seen in the RUL. Note that there is only mild ground-glass opacity associated with the reticular change and almost none seen in the more normal-appearing lung. Traction bronchiectasis is nicely demonstrated posteriorly in the RLL (upper white arrow). The traction bronchiectasis and the irregularly distorted outlines of many of the vessels and other lung markings such as interlobar fissures correspond to the architectural distortion seen histologically.

HRCT Changes in 46 Patients with Idiopathic Pulmonary Fibrosis [1]

Small cystic spaces with thick walls that begin subpleurally (see left lung)

Irregular thickening of bronchovascular bundles in regions of fibrosis (lower arrow, right lung)

Air bronchiolograms (traction bronchiolectasis) embedded in areas of increased attenuation (arrow, left lung)

Traction bronchiectasis and bronchiolectasis (upper arrow, right lung)

Irregular, reticular-appearing increased subpleural attenuation (both lungs)

Minor component of ground-glass attenuation, usually associated with regions of fibrosis


1. Nishimura K, Kitaichi M, Izumi T, Nagai S, Kanaoka M, Itoh H. Usual interstitial pneumonia: histologic correlation with high-resolution CT. Radiology 1992; 182:337-342.

Clinical summary Image 1

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Answer: At the periphery of the lower lobes, especially the RLL. The left lower lobe consolidation obscures any reticular change.































Answer: The peripheral reticular lung opacities at the mediastinal and cardiac margins give this appearance.































Answer: Typically, numerous circular densities with central lucencies, usually ranging from 3 mm to 1 to 2 cm in size are located peripherally at the lung bases. This chest film shows no frank honeycombing.






























Answer: Reticular densities are usually due to interstitial lung disease. When found at the lung bases, idiopathic pulmonary fibrosis is suggested. These reticular densities differ from the thickened interlobular septa--also known as Kerley B lines--seen in congestive heart failure and lymphangitic tumor. Kerley B lines are crisp, stacked, horizontal lines seen at the periphery of the lower lung zones. Reticular densities have a criss-cross appearance.