Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes are slightly low . Streaky opacity over the left costophrenic angle is most compatible with atelectasis . No convincing evidence for pneumonia . No pleural effusion , edema , or pneumothorax . The heart size is normal . Mediastinum is not widened .
    OUTPUT:
    
1 . Left basal atelectasis . 2 . Normal heart size .