Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Ill - defined heterogeneous opacities in left lung base are new and concerning for infection or aspiration . Indistinctness of the left costophrenic angle suggests small pleural effusion . Lung volumes are low . No pneumothorax . Heart size is top normal . Mediastinal contours are stable . Azygos fissure is incidentally noted .
    OUTPUT:
    
Left base heterogeneous opacity concerning for infection or aspiration . Probable small left pleural effusion .