What is the difference between a fan beam helical CT and a c
     What is the difference between a fan beam helical CT and a cone beam helical CT? What are the advantage of cone beam helical CT over fan beam helical CT  Calculate the CT number of blood with the following given data  Absorption coefficients of a body slice are given in the form of the following matrix. Perform the back project and calculated the background (bg) and the normalized number (n).  CT number of liver id  Find the  CT number of another tissue whose contrast with liver is 2  A matrix representing a wide body slice is given by the matrix below  Find the matrix corresponding to the filtered back projection using the following filter or mask. 
  
  Solution
CT number for spleen is between the range 14.9-58.3 exact
The exact CT number of spleen is 58 and the contrast is 2 as liver has ct number=60

