Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The heart size is normal . The mediastinal contours are unchanged . There is no pulmonary vascular congestion . Coarse interstitial and alveolar opacities are demonstrated , primarily within both lung bases , left greater than right , findings which have progressed when compared to the prior study . There are emphysematous changes again seen , most pronounced at the lung apices . No pleural effusion is identified and there is no pneumothorax . There are no acute osseous abnormalities .
    OUTPUT:
    
Coarse interstitial markings and alveolar opacities most pronounced at the lung bases and progressed when compared to the prior chest radiograph from ___ . Findings are highly concerning for a multifocal infectious process .