Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heart is mildly enlarged and note is made of pulmonary vascular congestion and persistent distension of the azygos vein . Multifocal poorly defined opacities in both lungs show interval improvement , and no new areas of abnormal lung opacification are identified . There are no pleural effusions .
    OUTPUT:
    
Rapidly improving multifocal lung opacities , which may be due to multifocal aspiration or asymmetrical edema given the time course .