Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiomediastinal silhouette and pulmonary vasculature are unremarkable . Scarring is seen at the lung apices . There is no pleural effusion or pneumothorax . At the left lung base , there is vague opacity , which likely represents atelectasis .
    OUTPUT:
    
No acute intrathoracic abnormality .