Named Radiologic Signs by Lung Region
| Lung Region | Named Radiologic Sign | Associated Condition / Meaning |
|---|---|---|
| Upper Lung | Luftsichel Sign | Collapse of the LUL, crescent of hyperlucency due to hyperexpanded superior segment of LLL |
| Golden S Sign | RUL collapse with central mass (e.g., bronchogenic carcinoma) causing reverse-S-shaped fissure | |
| Air Crescent Sign | Aspergilloma or cavitary retraction from healing infection (e.g., TB) | |
| Hollowed Cavity Sign | Cavitating lesion (often TB or fungal) in upper lobes | |
| Mid Lung | Hilum Overlay Sign | Distinguishes anterior or posterior mediastinal masses from hilar enlargement |
| Double Density Sign | Left atrial enlargement seen as double contour along right heart border | |
| Batwing Pattern | Alveolar edema due to CHF — bilateral perihilar opacities sparing the periphery | |
| Split Pleura Sign | Empyema — thickened, enhancing parietal and visceral pleura separated by fluid | |
| Sandwich Sign | Pericardial effusion seen between fat pads on lateral CXR | |
| Lower Lung | Deep Sulcus Sign | Pneumothorax on supine CXR — deepened costophrenic angle on affected side |
| Juxtaphrenic Peak Sign | Volume loss (esp. LUL collapse) causes peak at medial diaphragm insertion | |
| Shaggy Heart Border | Loss of clear heart border due to adjacent lower lobe infiltrates or ILD | |
| Meniscus Sign | Blunting of costophrenic angle due to pleural effusion (also called Ellis curve) | |
| Rounded Atelectasis Sign | Comet tail sign + mass-like pleural-based opacity often in posterior lower lobes (e.g., asbestos) |
Notes
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Some signs (e.g., air bronchogram, crazy paving) are diffuse and not zone-specific.
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Distribution here is based on typical presentations; pathology may vary.
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Signs such as the “finger-in-glove” (ABPA) or “tree-in-bud” (infection/bronchiolitis) appear peribronchially and often span multiple zones.