Intraoperative monitoring of temperature-induced tissue changes with a high-resolution digital X-ray system during thermotherapy

Abstract

A method of thermally inducing and monitoring changes to localized regions of tissue illuminating a volume of tissue with a first beam of X-rays, detecting the portions of the first beam of X-rays that passed through the volume of tissue, generating a first X-ray image signal from the portions of X 10 rays of the first beam detected, applying heat to at least a localized region of tissue within the volume of tissue after the illuminating and after the detecting, illuminating the volume of tissue with a second beam of X-rays, detecting portions of the second beam of X-rays that passed through the volume of tissue during the illuminating with the second beam of X-rays, generating a second X-ray image signal from the portions of X-rays of the second beam detected, and generating a difference image signal based upon a comparison of the first and second X-ray image signals. The difference image signal provides information of changes in X-ray attenuation by localized regions of tissue within the volume of tissue due to the application of heat.

1 . A method of monitoring thermal treatment of a tissue region of interest within a patient, said thermal treatment including heating of said tissue region of interest, comprising: 
 obtaining a first X-ray image of said tissue region of interest, said first X-ray image comprising X-ray image values corresponding with an array of spatial locations throughout said tissue region of interest;    acquiring at least a second X-ray image of said tissue region of interest after at least a portion of said thermal treatment, said second X-ray image comprising X-ray image values corresponding with said array of spatial locations throughout said tissue region of interest;    generating thermal information in relation to each of said spatial locations by employing said first X-ray image and said at least a second X-ray image, wherein said thermal information is indicative of relative magnitudes of temperature changes for each of said spatial locations throughout said tissue region of interest;    spatially displaying said thermal information for said array of spatial locations, wherein said relative magnitudes of temperature changes throughout said tissue region of interest are visually discernable.    
   
   
       2 . . A method according to  claim 1 , wherein said displaying step comprises: 
 representing a plurality of different ranges of relative magnitudes of temperature changes utilizing a corresponding plurality of different colors.    
   
   
       3 . A method according to  claim 1 , wherein said displaying step is accomplished in accordance with a predetermined transfer function.  
   
   
       4 . A method according to  claim 3 , wherein: 
 said predetermined transfer function is a linear function.    
   
   
       5 . A method according to  claim 3 , wherein said predetermined transfer function is utilized to amplify at least one portion of said thermal information of predetermined interest.  
   
   
       6 . A method according to  claim 5 , wherein said displaying step comprises: 
 utilizing different colors in predetermined relation to the amplification of said thermal information.    
   
   
       7 . A method according to  claim 5 , wherein said predetermined transfer function is selected from the group consisting of logarithmic and sinusoidal functions.  
   
   
       8 . A method according to  claim 1 , wherein said displaying step comprises: utilizing different colors to represent different relative magnitudes of temperature changes.  
   
   
       9 . A method according to  claim 1 , wherein said obtaining step is completed prior to said thermal treatment of said tissue region of interest, and wherein said acquiring step includes: 
 acquiring a plurality of X-ray images of said tissue region of interest; and,    wherein said generating step includes:    generating said thermal information employing said first x-ray image and different ones of said plurality of x-ray images.    
   
   
       10 . A method according to  claim 1 , wherein acquiring step includes: 
 acquiring a plurality of X-ray images of said tissue region of interest; and, wherein said generating step includes:    generating said thermal information employing different selected pairs of said plurality of X-ray images.