Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes are low compared to the previous study . Mild enlargement of the cardiac silhouette is re - demonstrated and exaggerated due to the presence of low lung volumes . Crowding of the bronchovascular structures is re - demonstrated without overt pulmonary edema . Atherosclerotic calcifications are noted throughout the aorta . The mediastinal contours are similar . Elevation of the right hemidiaphragm is chronic . Patchy opacities within the left lung base may reflect atelectasis but infection can not be completely excluded . No pleural effusion or pneumothorax is present . There are no acute osseous abnormalities .
    OUTPUT:
    
Low lung volumes with patchy opacity in the left lung base . This may reflect atelectasis but infection can not be completely excluded .