Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heart size is normal . The mediastinal and hilar contours are normal . The pulmonary vasculature is normal . There is a retrocardiac opacity which obscures the left hemidiaphragm concerning for pneumonia . There is no evidence of pneumothorax . Small left pleural effusion is noted . Large ___ .8 - cm ( craniocaudal ) left - sided pleural based lateral opacity may represent a loculated pleural effusion .
    OUTPUT:
    
Left lower lobe pneumonia with small left pleural effusion . Lateral left - sided pleural based lesion may represent a loculated pleural effusion . Recommend CT for further evaluation .