Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of the chest were obtained . Lungs are clear , though hyperinflated without focal consolidation , effusion , or pneumothorax . Linear left lower lung density is stable and likely represents an area of scarring . Cardiomediastinal silhouette is stable . Atherosclerotic calcification along the aortic knob noted . A density projecting over the left mid lung likely reflects an old rib fracture and has been seen dating back to multiple prior studies from ___ .
    OUTPUT:
    
No acute intrathoracic process .