Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: On the lateral view of the chest , there is a triangular - shaped artifact along the anterior chest wall , which is likely projectional and related to patient positioning , but it is difficult to exclude a sternal fracture in this region . No other osseous abnormality is detected . The lungs are clear without airspace opacification , pleural effusion or pneumothorax . The pulmonary vasculature is not engorged . The cardiac silhouette is normal in size . The mediastinal and hilar contours are within normal limits . The trachea is midline . The visualized upper abdomen shows no free air beneath the right hemidiaphragm on this upright view .
    OUTPUT:
    
Possible artifact projecting over the sternum seen only on the lateral view . A repeat lateral radiograph or CT could be considered for further evaluation if there is high clinical concern for sternal fracture .