Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Since the prior exam , the extensive bilateral predominantly perihilar opacities have slightly improved , particularly on the right . There is no new opacity , pulmonary edema , pleural effusion , or pneumothorax . The mediastinal contours are normal . The heart size is at the upper limits of normal .
    OUTPUT:
    
Interval improvement in the bilateral perihilar opacities , consistent with infection , and possibly PCP ___ .