Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The heart is at the upper limits of normal size . The aortic arch is partly calcified . The mediastinal and hilar contours appear unchanged . There is similar mild relative elevation of the right hemidiaphragm compared to the left . There is no pleural effusion or pneumothorax . There is a widespread predominantly central vague interstitial abnormality . Upper zone pulmonary vascularity does not appear distended and vessels are fairly distinct , however . Mild degenerative changes are similar along the mid to lower thoracic spine .
    OUTPUT:
    
Findings suggesting a mild interstitial abnormality . Considerations include atypical infection or possibly pulmonary congestion . Clinical correlation advised .