Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is consolidation in the retrocardiac region corresponding to the left lower lobe on the lateral radiograph with air bronchograms , which may represent atelectasis or pneumonia . There is a trace left pleural effusion on the lateral view . No focal consolidation concerning for pneumonia is seen . The right lung is grossly clear . There is no pneumothorax . No pulmonary vascular congestion or edema is seen . The cardiomediastinal and hilar contours are within normal limits . No acute osseous abnormality is detected . Degenerative changes at the acromioclavicular joints , greater on the right than the left are noted .
    OUTPUT:
    
Left lower lobe atelectasis or pneumonia and small left pleural effusion . Clinical correlation is needed .