Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lungs are hypoinflated . In comparison to the prior examination , the cardiomediastinal silhouette appears stable . The pulmonary vasculature is mildly indistinct , though not significantly changed since prior examination . No definite pneumothorax or pleural effusion is noted .
    OUTPUT:
    
No acute intrathoracic process .