Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Bilateral patchy opacities overlie the hila and lung bases , which may represent pulmonary edema or infiltrate . The costophrenic angles are blunted bilaterally , compatible with small effusions . The heart appears of normal size . There is calcification of the aortic knob . No radiopaque foreign body . Osseous structures are unremarkable .
    OUTPUT:
    
Bilateral perihilar and basilar opacities , compatible with pulmonary edema or bilateral pneumonia in the correct clinical setting . Followup after treatment suggested .