Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable AP upright chest radiograph demonstrates no focal opacity convincing for pneumonia . Streaky peribronchiolar opacities at the bases may reflect atelectasis or alternatively possibly atypical pneumonia . Cardiomediastinal and hilar contours are within normal limits . There is no pleural effusion or pneumothorax . No evidence of pulmonary edema . Left hemidiaphragm is mildly elevated .
    OUTPUT:
    
No acute intrathoracic abnormality . Streaky peribronchiolar opacities at the bases may reflect atelectasis or alternatively possibly an atypical pneumonia . Short - term followup radiographs may be helpful in this regard if warranted clinically .