Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Patient is status post median sternotomy . There relatively low lung volumes . Bilateral perihilar opacities suggest pulmonary vascular engorgement . Additional right upper to mid lung airspace opacity are worrisome for pneumonia . No large pleural effusion is seen although trace pleural effusion be difficult to exclude . No pneumothorax is seen . The cardiac and mediastinal silhouettes are stable .
    OUTPUT:
    
Right upper to mid lung airspace opacity is worrisome for pneumonia . Likely superimposed central pulmonary vascular engorgement / congestion . No large pleural effusion .