Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Pacemaker is again seen overlying the left anterior chest with pacer leads in appropriate position . Patient is status post CABG . There are low lung volumes . Mild chronic pulmonary vascular congestion is again seen , slightly improved from prior exam . No consolidation or mass is seen . There is mild cardiomegaly . There is no pneumothorax or pleural effusion . Visualized osseous structures are unremarkable .
    OUTPUT:
    
Mild chronic pulmonary vascular congestion , slightly improved from prior exam . No evidence of pneumonia or aspiration .