Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Single semi upright AP portable radiograph demonstrates low lung volumes . A small left pneumothorax as identified on prior study is unchanged in extent . Bilateral lower lung zone streaky opacities is felt likely to reflect atelectasis . No large pleural through fusion is seen . Heart size is within normal limits . Low lung volumes likely results in bronchovascular crowding .
    OUTPUT:
    
The lung volumes . Previously seen pneumothorax in the left apex is unchanged . Streaky basilar opacities is thought most likely to reflect atelectasis .