Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP chest radiograph is taken with the patient in the upright position . Heart size can not be accurately assessed from the AP technique . Cardiomediastinal contours are unremarkable except for prominence of right paramedian stripe , possibly representing an azygos fissure . Small area of opacity projecting over the left base is compatible with atelectasis or consolidation . The lungs are otherwise clear . Small left pleural effusion . No pneumothorax .
    OUTPUT:
    
Small area of opacity in the left lower lobe is consistent with a small pleural effusion and superimposed atelectasis , but consolidation can not be excluded .