Occasionally, special radiological investigationsAfter a doctor has taken a history from a patient and carried a physical examination of appropriate body parts, he or sh... reveal that somebody has a narrowing of one of the main venous channels in the head, draining blood from the brain. If the specialists treating the patient believe that this narrowing is the cause of symptoms then a radiologist, skilled in the procedure, may be able to feed a stent into the affected vein, thereby opening-up the channel and improving the venous drainage.