Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of the chest provided . Midline sternotomy wires are again seen . Lung volumes are somewhat low though allowing for this , the lungs are clear . Subtle linear peripheral opacities in the left upper lung are unchanged and could reflect subtle areas of perifissural scarring . No effusion or pneumothorax . Cardiomediastinal silhouette appears stable . Imaged bony structures are intact .
    OUTPUT:
    
No acute intrathoracic process .