Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Comparison with prior studies is complicated due to magnifying effect of AP view on the heart . Allowing for those limitations , there lung volumes are low , but there is no definite focal opacity . The left lower lung field can not be assessed in the frontal view due to obliteration by magnified heart shadow , but the lateral view does not demonstrate focal opacities or pleual effusion at this level . There is no pleural effusion or pneumothorax .
    OUTPUT:
    
No definite evidence of acute intrathoracic process . Unchanged compared with ___ allowing for difference in techniques .