Interface sign (HRCT chest)
Dendriform
pulmonary ossification in a case of usual interstitial pneumonia. Chest CT image shows bilateral subpleural reticulation and right subpleural areas of honeycombing and focal left subpleural area of honeycombing. Fine irregularities of pleural surfaces suggesting "interface sign" are also seen (arrows).
The interface sign is a feature seen on HRCT chest imaging and refers to the presence of irregular interfaces at the margins of pulmonary parenchymal structures or the pleural surface of the lung. It suggests interstitial thickening.