Patent ID: 11915420
Assignee: UNIVERSIDAD DE ZARAGOZA
Field: Computer technology (Electrical engineering)
Classification: CPC A  G | IPC G

Claim 10:
11. The method for obtaining an image biomarker that quantifies the quality of the trabecular structure of bones, according to claim 9, wherein extracting morphological and structural characteristic comprises:
calculating, from the binarized volume, BV/TV defined as the fraction or percentage between a number of voxels tagged as “1's” and a total number of voxels comprising the binarized volume;
calculating the TbTh defined as the average of the thickness of all the trabeculae present in the binarized volume based on:
detecting contours of the binarized volume;
performing a 2D skeletonization for each of the slices;
using a distance-transforming method applied to each point of the skeleton based on performing the 2D skeletonization for each of the slices, the minimum distance from each point to a contour being obtained and multiplied by two, in order to represent the thickness of the trabeculae at each point of the skeleton; and
adding all of the distances stored at each point of the skeleton and dividing by the number of points contained in the skeleton to obtain the TbTh,

calculating TbSp by repeating the previous two steps, but starting from an inverted binarized volume; and
calculating the TbN using the following equation:, TbN
        =
        
          
            B
            ⁢
            
              V
              /
              T
            
            ⁢
            V
          
          
            T
            ⁢
            b
            ⁢
            T
            ⁢
            h
          
        
      
    
    
      
        (
        
          equation
          ⁢
          
            
          
          ⁢
          1
        
        )
      
    
  

calculating the D2D, wherein calculating the D2D comprises:
obtaining the contour of the surface to be characterised;
applying an initial mesh to the surface to be characterised, where each plot contains contours;
reducing the size of each side of the plots by half;
repeating reduction of a matrix size iteratively until a pixel size is reached; and
solving a first equation:

log(N)=−D3D·log(λ)+k, where the first equation represents a ratio between a number of plots N corresponding to a size λ, the D2D and a proportionality constant; and
calculating the D3D, wherein calculating the D3D comprises:
obtaining the 3D volume to be characterised;
applying an initial mesh of cubes on the surface to be characterised;
reducing the size of the initial mesh of cubes iteratively until the size of the voxel is reached; and
solving a second equation:

log(N)=−D3D·log(λ)+k.