Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: 2 views of the chest demonstrates a right chest wall pacemaker generator with right atrial and ventricular leads , unchanged in position since the prior study . Posterior fixation rods and pedicle screws in the thoracic spine are unchanged since the prior study . Heart size is top normal . Hilar and mediastinal contours are within normal limits . The lung volumes are decreased since the prior study . Right lung base atelectasis is noted . No pleural effusion or pneumothorax .
    OUTPUT:
    
Interval decrease in lung volume and right lung base atelectasis .