Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lung volumes are low . Hazy opacification at the left base and in the retrocardiac space is likely atelectasis , given the low lung volumes , though an early pneumonia is difficult to exclude . There is no pulmonary edema , pleural effusion , or pneumothorax . The cardiomediastinal silhouette is normal .
    OUTPUT:
    
Left basilar hazy opacity is likely atelectasis given the low lung volumes , though an early pneumonia is difficult to exclude .