Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lungs are hypoinflated . The right lung is clear , while the left lung demonstrates an ill - defined opacity that is obscuring a portion of the margin of the left hemidiaphragm , which is confirmed in the lateral view where the left hemidiaphragm is not clearly identified . Cardiomediastinal and hilar contours are unremarkable . There is no pleural effusion or pneumothorax .
    OUTPUT:
    
Ill - defined opacity in the left lower lung base might represent atelectasis , although an infectious / inflammatory process can not be excluded .