Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lungs are well expanded and clear with linear right basal scarring as on the previous examination , perhaps from prior chest tube placement . No pleural effusion or pneumothorax is seen . The heart is normal in size with valvular prosthesis , coronary stent , CABG clips and median sternotomy wires unchanged .
    OUTPUT:
    
No acute intrathoracic process .