Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Recently reported right upper lobe abnormality on CTA has rapidly cleared radiographically . Residual patchy and linear opacities within the right middle lobe and both lower lobes with associated volume loss appear relatively similar to the prior CT study . Small right pleural effusion is also noted .
    OUTPUT:
    
1 . Rapid resolution of right upper lobe opacities , which were most likely due to aspiration given the rapid clearance . 2 . Residual right middle and bilateral lower lobe opacities with volume loss are likely due to atelectasis , but coexistent infection is not excluded .