Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiomediastinal silhouette and pulmonary vasculature are unremarkable . Atherosclerotic calcifications are noted of the aortic arch . The lungs are mildly hyperexpanded but clear . There is no definite pleural effusion or pneumothorax , though evaluation is limited on this supine examination .
    OUTPUT:
    
No acute intrathoracic process .