Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes are low . The heart size is normal . The mediastinal and hilar contours are unchanged , with mild tortuosity of the thoracic aorta again noted . There is crowding of the bronchovascular structures , but no pulmonary edema is identified . Patchy bibasilar airspace opacities likely reflect atelectasis versus chronic interstitial abnormality , as seen on the prior study . No pleural effusion or pneumothorax is seen , with chronic blunting of the left costophrenic angle suggestive of pleural thickening . Degenerative changes are noted in both glenohumeral and acromioclavicular joints , as well as at multiple levels within the thoracic spine .
    OUTPUT:
    
Low lung volumes with patchy bibasilar airspace opacities , possibly reflecting atelectasis though a chronic interstitial abnormality is not excluded . Findings appear similar compared to the prior exam , and repeat radiographs can be obtained with improved inspiratory effort for clearer assessment of the lung bases .