Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is an opacity at the left lower lobe compatible with pneumonia . Background lung parenchyma demonstrates diffuse dilated and thickened bronchi compatible with chronic changes of cystic fibrosis . The cardiomediastinal silhouette and hilar contours are stable . There is a small left pleural effusion . No pneumothorax is identified . Visualized upper abdomen is unremarkable .
    OUTPUT:
    
Left lower lobe pneumonia with a small effusion against background of chronic parenchymal changes of cystic fibrosis .