Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The upright portable chest radiograph is obtained . Low lung volumes limit evaluation . Probable bronchovascular crowding accounts for opacity at the right medial lung base . No definite signs of pneumonia , aspiration , effusion , or pneumothorax . No signs of pulmonary vascular congestion . Cardiomediastinal silhouette is normal . Bony structures are intact .
    OUTPUT:
    
Limited study given the low lung volumes , without acute intrathoracic process .