Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: As compared to the previous radiograph , the pre-existing large left parenchymal opacity has completely cleared . The left lung base continues to show elevation of the left hemidiaphragm as well as a minimal pleural scarring limited to the location of the left costophrenic sinus . The postoperative right apical changes are constant in appearance . The lung volumes have increased , presumingly as a consequence of improved ventilation .
    OUTPUT:
    
Complete resolution of a pre-existing left lower lobe pneumonia . Reduction in extent of a pre-existing left pleural effusion .