Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Evaluation of the left mid to upper lung is limited given positioning of the patient 's head , with the chin superimposed over this region . Of note , the radiology technologist attempted to reposition the patient but was not able to clear the chin from obscuring lung parenchyma . A right - sided pacemaker and right ventricular lead are redemonstrated . There are multiple midline sternotomy wires and evidence of prior CABG . A single surgical clip is noted in the left upper abdominal quadrant . A vascular stent is again seen in the left axilla . A moderate left pleural effusion is substantially increased compared to the prior study from ___ . Left retrocardiac dense opacification is likely compressive atelectasis , although infection in this region is not excluded . The right lung is clear . There is marked rightward curvature of the thoracic spine that is at least partially attributable to patient positioning . There is no right pneumothorax . Evaluation for left pneumothorax is limited given obscuration of the left lung apex , previously discussed .
    OUTPUT:
    
Limited study due to patient positioning . Increased moderate left pleural effusion and degree of dense retrocardiac opacification that likely reflects compressive atelectasis .