Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable supine radiograph is presented for review , which limits assessment of small pneumothoraces . Lungs are low in volume with dense retrocardiac opacity , which may represent extensive left lower lobar collapse versus consolidation accompanied by moderate pleural effusion . Pacemaker and epicardial pacer are difficult to assess . Cardiomegaly is unchanged .
    OUTPUT:
    
No evidence of large pneumothorax with persistent left lower lung opacity