Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiomediastinal and hilar contours are stable , with mild cardiomegaly . Heterogeneous opacification in the retrocardiac left lower lobe appears slightly worse since the prior study . A small left pleural effusion is unchanged . Intraperitoneal free air , relates to the recent lumbar spine surgery .
    OUTPUT:
    
1 . Minimal worsening of the retrocardiac left lower lobe consolidation , with a stable small left effusion . 2 . Small pneumoperitoneum , likely relates to the patient 's recent lumbar spine surgery .