Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There has been slight progression of the bilateral airspace opacities in a predominately perihilar distribution but affecting large areas of the lung parenchyma . Mild cardiomegaly is unchanged . No pleural effusion or pneumothorax seen .
    OUTPUT:
    
Progression of the bilateral airspace opacities likely reflecting pulmonary edema although infection can not be excluded .