Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes remain low . There is slight interval improvement in pulmonary edema , now mild . There is unchanged atelectasis at the right lung base . The cardiomediastinal silhouette remains enlarged . There is a small left pleural effusion . No pneumothorax is seen . Lines and support devices are in unchanged positions . The course of the nasogastric to can not be fully assessed due to extensive scatter radiation .
    OUTPUT:
    
Slight interval improvement in bilateral pulmonary edema , although this may also be due to upright position on the current chest x-ray .