Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Mild cardiomegaly is persistent . There is calcification of the aortic knob . Otherwise , the hilar and mediastinal contours are unremarkable . Opacities in the mid to lower lungs have continued to improve and appear interstitial in character , suspected to represent persistent or resolving airway inflammation . Degenerative changes are seen throughout the spine . There is no large pleural effusion or pneumothorax .
    OUTPUT:
    
Continued improvement in areas of airway inflammation and possibly pneumonia .