Bonus Material-32_ACCP 2025 Shah Part II

Pdf Summary

This lecture by Dr. Rakesh Shah, Chief of Thoracic Radiology at Northwell Health, provides a comprehensive overview of thoracic radiology focusing on the interpretation of pulmonary patterns and altered lung attenuation on imaging.<br /><br />Key components of the lecture include review of pulmonary anatomy, specifically the secondary pulmonary lobule and interstitium, followed by detailed discussion of patterns seen in thoracic imaging: linear and reticular opacities, nodules, and altered attenuation types—namely increased, decreased, and mosaic attenuation.<br /><br />Increased pulmonary attenuation features two main patterns: ground glass opacity (GGO) and consolidation. GGO is described as hazy lung attenuation with preserved vascular markings caused by partial alveolar filling, seen in conditions like pulmonary hemorrhage, COVID-19 infection, alveolar proteinosis, and bacterial pneumonia. Consolidation denotes complete alveolar replacement by fluid or cells, with differential including legionella pneumonia and chronic eosinophilic pneumonia. The "crazy-paving" pattern (GGO plus interlobular septal thickening) and the "reverse halo" or atoll sign are specific imaging findings associated with diseases such as organizing pneumonia, pulmonary infarct, and granulomatous conditions.<br /><br />Decreased pulmonary attenuation corresponds to air-filled spaces such as emphysema (centrilobular and panlobular types), honeycomb cysts, lung cysts, bronchiectasis, and cavitary nodules. Bronchiectasis is highlighted as irreversible bronchial dilatation identifiable best on CT, with etiologies including asthma-related ABPA, infections, and systemic diseases. Syndromes like cystic fibrosis, Kartagener’s, and infections like MAC are also discussed in this context.<br /><br />Mosaic attenuation involves patchy alternating areas of increased and decreased lung density. It arises from small airway diseases (reversible like asthma, or fixed obliterative bronchiolitis) or vascular diseases (pulmonary hypertension, chronic thromboembolic disease). Evaluation with paired inspiratory-expiratory images helps distinguish causes, with ancillary findings aiding diagnosis.<br /><br />Multiple illustrative cases emphasize various diseases such as pulmonary hemorrhage, COVID infection, adenocarcinoma, lymphangioleiomyomatosis, and pulmonary hypertension. The lecture concludes by reinforcing systematic evaluation of pulmonary patterns on imaging to narrow differential diagnoses and provide accurate interpretation in thoracic radiology.

Meta Tag

Concept Secondary Pulmonary Lobule

Concept Ground-Glass Opacity

Concept Consolidation

Concept Lung Imaging Pattern

Concept Mosaic Attenuation

Keywords

thoracic radiology

pulmonary attenuation

ground glass opacity

consolidation

crazy-paving pattern

reverse halo sign

bronchiectasis

mosaic attenuation

emphysema

pulmonary hemorrhage

Secondary Pulmonary Lobule

Ground-Glass Opacity

Consolidation

Lung Imaging Pattern

Mosaic Attenuation