Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Cardiac , mediastinal and hilar contours are unchanged with the heart size within normal limits . Lung volumes are reduced compared to the previous exam . Diffuse increased interstitial markings are again noted , compatible with known chronic interstitial lung disease , not substantially changed from prior accounting for differences in lung inflation . More focal patchy opacities within the lung bases may reflect atelectasis though infection can not be completely excluded . Low lung volumes results in crowding of the bronchovascular structures , although an element of mild pulmonary vascular congestion may be present . There are no pleural effusions or pneumothoraces . No acute osseous abnormalities present .
    OUTPUT:
    
Low lung volumes . Patchy opacities in the lung bases may reflect atelectasis though infection is not excluded . Chronic interstitial lung disease previously characterized on HRCT from ___ as NSIP . Possible mild pulmonary vascular congestion .