Radiation imaging apparatus and nuclear medicine diagnosis apparatus using the same

Abstract

Disclosed herein is a radiation imaging apparatus and radiation-imaging-apparatus-based nuclear medicine diagnosis apparatus having a collimator in which a plurality of rectangular through-holes are arranged in a grid pattern and separated by septa is rotated through a predetermined angle as viewed from above in relation to the layout of a plurality of rectangular detectors that are arranged in a grid pattern. The predetermined angle ranges from 20 to 70 degree and more preferably from 30 deg to 60 deg. With this configuration, the influence of sensitivity variations (moire patterns) that are included in an image picked up due to interference with a collimator when pixel type detectors are used is eliminated.

1 . A radiation imaging apparatus comprising: 
 a plurality of rectangular detectors that are arranged in a grid pattern;    a radiation measurement circuit for reading detection signals of the detectors; and    a collimator in which a plurality of rectangular through-holes are arranged in a grid pattern and separated by septa;    wherein the collimator is rotated through a predetermined angle in relation to the layout of the detectors as viewed from above, and used to acquire radiation incidence position information from each of the detectors and image the acquired information.    
   
   
       2 . The radiation imaging apparatus according to  claim 1 , wherein the predetermined angle ranges from 20 deg to 70 deg.  
   
   
       3 . The radiation imaging apparatus according to  claim 2 , wherein the predetermined angle ranges from 30 deg to 60 deg.  
   
   
       4 . A nuclear medicine diagnosis apparatus that uses the radiation imaging apparatus according to  claim 1 .  
   
   
       5 . A radiation imaging apparatus comprising: 
 pixel type detectors that acquire the position information about radiation incident on image pixels that are arranged in a grid pattern;    a radiation measurement circuit for reading detection signal of the detector; and    a collimator in which a plurality of rectangular through-holes are arranged in a grid pattern and separated by septa;    wherein the collimator is rotated through a predetermined angle in relation to the layout of the detectors as viewed from above.    
   
   
       6 . The radiation imaging apparatus according to  claim 5 , wherein the predetermined angle ranges from 20 deg to 70 deg.  
   
   
       7 . The radiation imaging apparatus according to  claim 5 , wherein the predetermined angle ranges from 30 deg to 60 deg.  
   
   
       8 . A nuclear medicine diagnosis apparatus, comprising: 
 the radiation imaging apparatus according to  claim 5;     a gantry for supporting the radiation imaging apparatus;    a tomographic information creation device for acquiring detection signals from the detectors and generating image information; and    a display device for displaying the image information.    
   
   
       9 . The radiation imaging apparatus according to  claim 6 , wherein the intervals at which the collimator through-holes are positioned are √{square root over (2)} to 1.8 times the intervals at which the detectors' image pixels that are arranged in a grid pattern are positioned.  
   
   
       10 . The radiation imaging apparatus according to  claim 9 , wherein the detectors' image pixels that are arranged in a grid pattern are positioned at intervals of 1 mm or longer but shorter than 2 mm.  
   
   
       11 . The nuclear medicine diagnosis apparatus according to  claim 8 , wherein the tomographic information creation device performs a 3×3 matrix smoothing filter process.