Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There has been previous median sternotomy and coronary artery bypass surgery . Cardiomediastinal contours are stable in appearance . Worsening predominantly linear opacities in the mid and lower lungs bilaterally are present , but there are no confluent areas of consolidation . Apparent bronchial wall thickening is present in the lower lobes , best visualized on the lateral view . There is no pleural effusion or pneumothorax .
    OUTPUT:
    
1 . Multifocal linear opacities suggestive of atelectasis . 2 . Lower lobe predominant bronchial wall thickening , which could potentially represent bronchitis in the appropriate clinical setting .