Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral chest radiographs again demonstrate plate atelectasis in the right middle and left lower lobes . Additionally , there is a subtle slightly increased retrocardiac opacity and in a proper clinical setting could represent pneumonia . There is no pleural effusion or pneumothorax . The cardiomediastinal silhouette is normal .
    OUTPUT:
    
Linear retrocardiac opacity potentially atelectasis however possibly pneumonia in proper clinical setting .