Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lung volumes are slightly low , causing accentuation of the pulmonary vasculature and exaggeration of the heart size . Persistent right middle lobe heterogeneous opacity is concerning for chronic aspiration , although pneumonia could have a similar appearance . The lungs are otherwise clear . The cardiac and mediastinal contours are normal . There are no pleural abnormalities .
    OUTPUT:
    
Likely chronic aspiration involving the right middle lobe although pneumonia could have a similar appearance . Otherwise , no acute cardiac or pulmonary process .