Patent ID: 11885863
Assignee: ASELSAN ELEKTRONIK SANAYI VE TICARET ANONIM SIRKETI
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. A method for reconstructing images of a magnetic resonance imaging (MRI) system comprising the steps of;
acquiring with the MRI system, multiple images under an influence of different contrast mechanisms, wherein the different contrast mechanisms belong to a same anatomy,
solving an optimization problem with an optimization algorithm using both joint and individual objective functions simultaneously for each of multiple image contrasts or a subset of the multiple image contrasts, to reconstruct the multiple images from acquired data,
wherein the optimization problem solved with analysis based methods is as follows;, 
        
          
            
              A
              i
            
            ·
            
              
                x
                ^
              
              i
            
          
          -
          
            γ
            i
          
        
        
      
      2
      2
    
    <
    ϵ
  

  
    
      
        min
        
          x
          ^
        
      
      ⁢
      
        α
        ⁢
        
          
        
        ⁢
        
          CTV
          ⁡
          
            (
            
              
              
                x
                ^
              
              
            
            )
          
        
      
    
    +
    
      β
      ⁢
      
        
      
      ⁢
      
        GSp
        ⁡
        
          (
          
            
            
              x
              ^
            
            
          
          )
        
      
    
    +
    
      
        ∑
        i
      
      ⁢
      
        γ
        ⁢
        
          
        
        ⁢
        
          TV
          ⁡
          
            (
            
              
              
                
                  x
                  ^
                
                i
              
              
            
            )
          
        
      
    
    +
    
      
        ∑
        i
      
      ⁢
      
        θ
        ⁢
        
          
        
        ⁢
        
          Sp
          ⁡
          
            (
            
              
              
                
                  x
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                i
              
              
            
            )
          
        
      
    
  

where Ai denotes a transformation matrix, wherein the transformation matrix maps samples of an image to the samples in a data domain, and the data domain comprises a Fourier domain, {circumflex over (x)}i denotes a reconstructed image, and ŷi denotes associated acquired data for each of the multiple image contrasts; CTV, GSp, TV, and Sp denote a Color Total Variation, a Group Sparsity (12-1-norm), an individual Total Variation and an individual Sparsity (11-norm), respectively, and the Color Total Variation, the Group Sparsity, the individual Total Variation and the individual Sparsity are defined as:

CTV(|x|)=√{square root over (ΣnΣki=1k((∇1|x(i)[n]|)2+(∇2|x(i)[n]|)2),)}

∥x∥2,1=Σn√{square root over (Σi=1k|x(i)[n]|2)},

TV(|x(i)∥)=Σn√{square root over ((∇1|x(i)[n]|)2+(∇2|x(i)[n]|)2)},

∥x(i)∥1=Σn|x(i)[n]|, 

wherein functions CTV and GSp are applied jointly on all the multiple image contrasts, or the subset of the multiple image contrasts, TV and Sp functions are applied on each of the multiple image contrasts individually.