Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is left lower lobe atelectasis . No focal consolidation , pleural effusion or pneumothorax . The patient is status post CABG with mediastinal clips and sternal wires . An AICD is unchanged in position . Mild cardiomegaly is stable since ___ .
    OUTPUT:
    
No signs of pneumonia .