Nodular opacification is one of the broad patterns of pulmonary opacification that can be described on a chest radiograph or chest CT. The others, linear opacification and airway opacification are discussed separately.
Nodular opacification in the lung may be a
- pulmonary nodule
- airspace nodule
- part of an underlying reticulonodular pattern.
Pulmonary nodules are situated in the pulmonary interstitium, not within the airways. They are small, soft tissue density masses that are round or oval in shape and have smooth margins. They are homogeneous and contain no air bronchograms and well-defined with normal surrounding aerated lung. On the other hand, airspace nodules tend to have a diameter of 8 mm and irregular margins (often surrounded by areas of ground glass change).