Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lung volumes are slightly reduced . The heart size is normal . The aorta is mildly unfolded . The mediastinal and hilar contours are normal . Linear opacity within the right lung base is compatible with subsegmental atelectasis . No focal consolidation , pleural effusion or pneumothorax is visualized . Degenerative changes of the left glenohumeral joints are present . Mild degenerative changes are also seen within the thoracic spine .
    OUTPUT:
    
Subsegmental atelectasis in the right lung base . No radiographic evidence for pneumonia .