Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lungs are well - expanded without evidence of pneumonia or pulmonary edema . Left lower lobe atelectasis is mild . Mediastinal contours , hila , and cardiac silhouette are normal . There is no pneumothorax or pleural effusion . Crescent - shaped lucency beneath the left hemidiaphragm .
    OUTPUT:
    
1 . Lucency beneath the left hemidiaphragm is somewhat atypical and could represent pneumoperitoneum . CT of the abdomen and pelvis is recommended for further evaluation . 2 . No evidence of pneumonia .