cryptogenic organizing pneumonia (COP)

Extensive subpleural ground-glass and consolidative airspace opacity with polygonal margins  involving the right lower lobe (predominantly anterior, lateral basal segments) demonstrating internal reticular changes (crazy paving pattern) with reverse halo sign – suggestive of cryptogenic organizing pneumonia (COP)

 Differential considerations also include:- acute viral pneumonia

 Small streaky subpleural atelectasis in right middle lobe, lingula.

 Small right pleural effusion