Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Since ___ , there is a new focal opacity in the left retrocardiac region better appreciated in the infrahilar region on lateral view concerning for left lower lobe pneumonia . Lung volumes are normal . Right lung is grossly clear . No pneumothorax . No pleural effusion . Cardiomediastinal borders and hilar structures are normal
    OUTPUT:
    
Probable left lower lobe pneumonia , new since ___ .