Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes remain low . Focal airspace opacities noted at the left lung base appear to have increased from ___ , and appear similar to ___ . The left upper lung and right lung appear grossly clear . There is no pleural effusion , pneumothorax , or frank pulmonary edema . The cardiomediastinal silhouette is unchanged from the prior examination .
    OUTPUT:
    
Interval increased focal airspace opacity at the left lung base , which may represent recurrent infection or potentially aspiration .