Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lung volumes are low . Pulmonary edema is mildly improved . Left lung base subsegmental atelectasis is unchanged . There is no pneumothorax . Generalized osteopenia and left shoulder degenerative changes are noted .
    OUTPUT:
    
Improving pulmonary edema . Stable left lung base subsegmental atelectasis .