Patent ID: 11954768
Assignee: DELTA ELECTRONICS, INC.
Field: Measurement (Instruments)
Classification: CPC A  G | IPC A  G

Claim 0:
1. A method for gating in tomographic imaging system, comprising steps of:
(a) performing a tomographic imaging on an object for acquiring a plurality of projection images at different angles, wherein a target of the object in the projection images moves periodically along a first axis;
(b) obtaining a plurality of projected curves by projecting the plurality of projection images along the first axis, wherein the projected curve is obtained according to following equation:, C
    
     θ
     ⁢
     ts
    
   
   =
   
    
     ∑
     
      t
      =
      1
     
     T
    
    
     P
     
      θ
      ⁢
      ts
     
    
   
  
  ,
 

where Cθts is the projected curve, T is a number of pixels in the direction of a second axis perpendicular to the first axis in the projection image, and Pθts is the projection image;
(c) determining a position by calculating a largest variation among the projected curves;
(d) determining a target zone centering the position along the first axis on the projection images;
(e) calculating a parameter value of all pixel values in the target zone on each of the projection images, and obtaining a curve of a moving cycle of the target according to the parameter values of the projection images; and
(f) selecting the projection images under the same state in the moving cycle for image reconstruction according to the curve of the moving cycle of the target.