53960
In this procedure , holes are drilled in the skull , and air pumped through the holes in to the ventricle s , to facilitate clearer imaging on X-ray s. It has been replaced by more effective and less invasive imaging techniques .
 None
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: location, person, organization 
Text: {0} 
 Entities:  
Answer:
 None