Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of the chest provided . There is left basal opacity most compatible with atelectasis though an early pneumonia difficult to exclude in the correct clinical setting . Otherwise the lungs are clear . No effusion or pneumothorax . No congestion or edema . The cardiomediastinal silhouette is normal . Imaged osseous structures are intact . There has been interval vertebroplasty at 2 levels of the mid thoracic spine . No free air below the right hemidiaphragm is seen .
    OUTPUT:
    
Left basal opacity most compatible with atelectasis though difficult to exclude an early pneumonia .