Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP and lateral views of the chest were performed with patient positioned upright . There is no definite evidence for pneumonia or CHF . Mild linear atelectasis in the left lower lung is noted . Cardiomediastinal silhouette is grossly unremarkable allowing for slight patient rotation as well as an unfolded thoracic aorta . Bony structures are intact .
    OUTPUT:
    
No evidence of pneumonia .