International Journal of Biomedical Imaging

Research Article

A Framework of Vertebra Segmentation Using the Active Shape Model-Based Approach

Algorithm 1

Determine the sequence of the vertebra corners.
Input:
  (i)  𝑙 1 : the upper anterior corner of the first vertebra
  (ii)   𝑙 2 𝑁 : the lower anterior corner of the last vertebra
  (iii)  𝐿 : the set of all the detected points
Data:
  (i)  𝑆 𝑖 : a sequence of 𝑖 points
  (ii) 𝑉 : a set of sequences composed by 2 𝑁 points
Result:
  (i)  𝑆 ⋆ : the sequence of 2 𝑁 points minimizing the path between 𝑙 1 and 𝑙 2 𝑁
begin
   𝑆 0 = ∅ ;
   𝑆 1 = 𝑆 0 ∪ 𝑙 1 ;
   𝑉 = ∅ ;
  RecursiveFunction ( 𝑆 1 ) ;
  min = distance between 𝑙 1 and 𝑙 2 𝑁 in 𝑉 ( 1 ) ;
   𝑖 𝑛 𝑑 𝑒 𝑥 𝑀 𝑖 𝑛 = 1
  for 𝑖 = 2 → 𝑠 𝑖 𝑧 𝑒 ( 𝑉 )   do
     dist = distance between 𝑙 1 and 𝑙 2 𝑁 in 𝑉 ( 𝑖 ) ;
     if 𝑑 𝑖 𝑠 𝑡 ≤ 𝑚 𝑖 𝑛   then
      𝑚 𝑖 𝑛 = 𝑑 ;
      𝑖 𝑛 𝑑 𝑒 𝑥 𝑀 𝑖 𝑛 = 𝑖 ;
   𝑆 ⋆ = 𝑉 ( 𝑖 𝑛 𝑑 𝑒 𝑥 𝑀 𝑖 𝑛 ) ;