Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Cardiomediastinal silhouette and hilar contours are normal . Atelectasis is present at the left lung base . Lungs are otherwise clear . There is no pleural effusion or pneumothorax .
    OUTPUT:
    
Left basal atelectasis . No evidence of intrathoracic amiodarone toxicity .