Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Cardiomediastinal silhouettes are stable . The bilateral hila are unremarkable . New since prior are subtle opacities at the medial lung bases bilaterally . Elsewhere there is no focal consolidation , pulmonary edema , or pulmonary vascular congestion . There is no pneumothorax or pleural effusion .
    OUTPUT:
    
New subtle opacities at the lung bases bilaterally which could , in the correct clinical setting , represent sequelae of aspiration or pneumonia .