C.P• Cough & expectoration of purulent sputum.• Constitutional symptoms.
Radiological findings of abscess• Rounded cavity with air fluid level & surrounding consolidation.• Appear rounded in frontal & lateral projections (DD with empyema).• All margins can be equally seen (DD with empyema).
CT• Cavitary lesion with or without air fluid level.• Thick irregular wall (acute).• Thin smooth wall (chronic).• Surrounding consolidation.• Truncation of the bronchi & vessels at the wall of the abscess.
DD of lung abscessCavitary Hiatal Empyema lesion hernia
Cavitary lesions Contents Air fluid level Air only Intracavitary soft tissue density Surface of Wall thickness the fluid level Fungal ball (most common) Rupture hydatid cystStraight Wavy Thick Thin Breakdown in a tumour Acute ruptured Blood clotAbscess hydatid cyst Irregular Site Tumor breakdown Central in the lung Peripheral subpleural Regular emphysematous Pneumatocele Chronic abscess bulla
Cavitary lesions by location Upper Lower lung zones lung zones TB Aspiration Lung abscess AmoebicHistoplasmosis Lung abscess (Rt) Pulmonary infarction Sequestrated lung segment (Lt)