Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lungs are hyperexpanded with lucent areas consistent with bullae corresponding to findings on CT , unchanged . No pneumonia , pulmonary edema , or pneumothorax . Mediastinal contours , hila , and cardiac borders are stable . Persistent elevation of the left hemidiaphragm with subdiaphragmatic coils and healed left rib fractures are unchanged . Sutures in the right apex and right mid lung are consistent with prior surgery .
    OUTPUT:
    
Severe COPD . No acute cardiopulmonary process .