Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable AP chest radiograph demonstrates low lung volumes and pulmonary vascular congestion . There is also an opacity in the right upper lobe . The cardiomediastinal silhouette is normal . There is no pneumothorax . There is no large pleural effusion or pneumothorax .
    OUTPUT:
    
Mild pulmonary edema . Opacity in the right upper lobe may represent pneumonia .