Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Again noted is subtle pectus excavatum causing apparent increased density at the right lung base . This is unchanged since the prior examination . Lung volumes are slightly lower than on prior examination . No definite new consolidation is identified . The thoracic aorta is tortuous . There is no pleural effusion or pneumothorax .
    OUTPUT:
    
No acute intrathoracic abnormality .