Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes are lower compared to the previous study . This accentuates the size of the cardiac silhouette which appears moderately enlarged . Superior mediastinal widening is likely attributable to lower lung volumes . The aortic knob remains distinct . Hilar contours are normal . Pulmonary vasculature is normal . Minimal atelectasis is seen in the retrocardiac region . No focal consolidation , pleural effusion or pneumothorax is present . There are mild degenerative changes noted within the thoracic spine .
    OUTPUT:
    
Lower lung volumes account for accentuation of the cardiac silhouette now appearing moderately enlarged . Minimal retrocardiac atelectasis without focal consolidation .