Indications for use of CT  
 
 
 
 

These are identical images displayed in different windows. The image on the left is in soft tissue windows and that on the right in lung windows. Both images show the tumor mass in the medial right lung. Note that the tumor extension into the mediastinum, adjacent to the aorta and trachea is only appreciated on the soft tissue windows. This is not well seen on the lung windows and was not visible on the patient's chest radiograph. Click here to view the accompanying chest radiograph.