Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP upright portable views of the chest were obtained . Per the radiology technologist , x-ray was repeated due to patient kyphosis . The patient 's chin overlies the lung apices . Again seen are increased interstitial markings , worse at the lung bases in this patient with history of known chronic interstitial pulmonary disease . Opacity at the right lung base appears increased compared to the prior study and superimposed infectious process is not excluded . No large pleural effusion or pneumothorax is seen . Cardiac and mediastinal silhouettes are unremarkable .
    OUTPUT:
    
Known chronic interstitial disease with increased interstitial markings seen at the lung bases . Interval increase in right base opacity raises concern for a superimposed infectious process .