TABLE I.

Glossary of common abnormalities in pulmonary CT scans.

Lung disease	Notes
Bronchocele	A Y- or V-shaped branching structure. For bronchial atresia, the surrounding lung parenchyma may be of decreased CT attenuation.
Crazy-paving pattern	Thickened intralobular lines superimposed on ground-glass opacity.
Consolidation	Homogenous increase in attenuation in lung parenchyma, obscuring the margins of airways and walls.
Ground-glass opacity (GGO)	Hazy lung opacity. Margins of vessels may be indistinct. GGO is less opaque than consolidation.
Halo-sign	GGO surrounding a nodule or a mass.
Honeycomb	Closely approximated textured ring shadows that resemble honeycomb.
Micronodules	Discrete small, round focal opacity. The term is often limited to nodules with less than 3 mm in diameter.
Mycetoma	Sponge-like pattern and a foci of calcification.
Beaded septum	Irregular and nodular thickening of inter-lobular septa that appears like a row of beads.
Perilymplatic distribution	Abnormalities along or adjacent to lymphatic vessels in the lung.
Bleb	Small air-containing space within the visceral pleura (not larger than 1 cm in diameter).
Bulla	Visceral pleura (not less than 1 cm in diameter).
Cavity	Air-filled space within pulmonary consolidation, mass, or nodule.
Pulmonary infarction	Triangular or dome-shaped with base containing pleura and apex directed toward hilum.
Pleural plaque	Areas of pleural thickening often with calcification.
Pleural effusion	Excess of fluid that accumulates between the two pleural layers.