Method and apparatus for estimating temperature in a body

Abstract

The invention relates a method and an apparatus of predicting or planning a temperature distribution ( 52 ) in a body. The method comprises the steps of : a) obtaining a model of the body ( 50 ) related to a temperature transport mechanism or temperature distribution ( 52 ) in the body; b) simulating an application of heat to at least a part of the body such as targeted tissue; c) determining and/or predicting the temperature ( 52 ) or heat distribution in at least a part of the body using the model of the body ( 50 ).

1 . Method of predicting or planning a temperature distribution in a body comprising the steps of:
 a) obtaining a model of the body related to a temperature transport mechanism or temperature distribution in the body;   b) simulating an application of heat to at least a part of the body such as targeted tissue;   c) determining and/or predicting the temperature or heat distribution in at least a part of the body using the model of the body.   
     
     
         2 . Method according to  claim 1 , wherein determining and/or predicting the temperature or heat distribution in at least a part of the body comprises:
 performing thermodynamic simulations to simulate the heat propagation and/or distribution in the body; and/or   using optionally a series of one or more images or imaging sequences of the body without or under the application of heat such as an electromagnetic field or any other heat transport carrier from a heat source and adding the series of images or imaging sequences to the model of the body.   
     
     
         3 . Method of controlling or monitoring a temperature distribution in a body comprising the steps of:
 d) obtaining or providing a model of the body related to a temperature transport mechanism or temperature distribution in the body;   e) applying heat to at least a part of the body such as targeted tissue;   f) determining and/or predicting the temperature or heat distribution in the body using the model of the body.   
     
     
         4 . Method according to  claim 1 , further comprising:
 feeding into the body a dose of contrast agent or tracer such as Gadolinium.   
     
     
         5 . Method according to  claim 1 , wherein obtaining a model of the body comprises:
 obtaining a series of one or more images or imaging sequences of the body preferably enabling the calculation of perfusion and/or diffusion properties of the body; and/or   obtaining a perfusion model of the body achieved by magnetic resonance imaging and/or computer tomography; and/or   obtaining a model based on diffusion coefficients or proton-frequency-shift alterations, both being achieved with magnetic resonance imaging.   
     
     
         6 . Method according to  claim 1 , further comprising:
 obtaining from a database a reference model directed to a transport mechanism or temperature distribution mechanism in a reference body; and/or   obtaining from the images of the body under consideration a set of tissue parameters describing the body or parts of the body, such as the permeability surface area product of the endothelium and/or fractional size of the extravascular extracellular space; and/or   obtaining from the reference model and the tissue parameters an individualized model directed to a temperature transport mechanism or temperature distribution mechanism in the body under consideration.   
     
     
         7 . Method according to  claim 1 , wherein obtaining the temperature model from a model of the body, when using a perfusion model as the model of the body, refers to:
 obtaining a perfusion distribution of the body or of the model from a signal distribution of the images;   using a tabular dependency of a temperature or a temperature gradient or a time dependent change of the temperature at a point in space and time from the blood perfusion at that point in space and time; and/or   using a bioheat equation such as the Pennes equation.   
     
     
         8 . Method according to  claim 1 , further comprising:
 determining an initial perfusion distribution of the body before applying heat to the body;   calculating a temperature distribution in the body based on the initial perfusion distribution and a heat power input upon commencement of the heat application;   iteratively adjusting the perfusion distribution of the body based on the calculated temperature distribution and recalculating the temperature distribution based on the adjusted perfusion distribution and the heat power.   
     
     
         9 . Method according to  claim 1 , further comprising:
 determining a volume of necrosis in the targeted tissue based on the time and temperature relationship therein;   adjusting the perfusion distribution of the body based on the determined volume of necrosis.   
     
     
         10 . Method according to  claim 1 , wherein the images or imaging sequences are obtained with magnetic resonance T1-weighted gradient-echo sequences, or with magnetic resonance proton-frequency-shift alterations or with x ray tomography. 
     
     
         11 . Method according to  claim 1 , further comprising:
 obtaining absolute temperature values of the body by relating one or more reference temperature values obtained from measurements or from the database to corresponding one or more temperature values of the temperature model of the body.   
     
     
         12 . Method according to  claim 1 , further comprising:
 displaying and/or monitoring the calculated and/or forecasted temperature distribution within the body, especially in the targeted tissue.   
     
     
         13 . Computer program which, when loaded or running on a computer, performs or supports the method of  claim 1 . 
     
     
         14 . Program storage medium or computer program product comprising the program of  claim 13 . 
     
     
         15 . System for predicting or planning a temperature distribution in a body using a model of the body, said system comprising:
 a imaging equipment suitable to obtain images of at least a part of the body,   a database connected to the imaging equipment suitable to store images of the body and to retrieve the stored information,   a data processing unit connected to the imaging equipment and/or to the database, the data processing unit being capable to obtain a model directed to a temperature transport mechanism or temperature distribution in the body, and/or   a device suitable to perform or support the method of  claim 1 .   
     
     
         16 . System according to  claim 15 , wherein
 the data processing unit is suitable to simulate an application of heat to at least a part of the body.   
     
     
         17 . System according to  claim 15 , wherein
 the system comprises a heat source such as a source of an electromagnetic field or any other heat transport carrier, for example focal ultrasound, laser beam, catheter, x-ray, infrared, microwaves, gamma radiation, or any other radiation with a wave length suitable to apply thermal energy to tissue, nano particles, colloids, or liposome.   
     
     
         18 . System according to  claim 15 , wherein
 the data processing unit is suitable to determine and/or predict the temperature or heat distribution in at least a part of the body using the model of the body, and/or   the imaging equipment is suitable to obtain images or imaging sequences with magnetic resonance T1-weighted gradient-echo sequences or with magnetic resonance proton-frequency-shift alterations or with magnetic resonance tomography or with x-ray tomography.   
     
     
         19 . System according to  claim 15 , wherein
 the model of the body is a perfusion model of the body obtained with nuclear magnetic resonance or computer tomography, and/or   the model of the body is a model based on diffusion coefficients or proton frequency-shift alterations, both being obtained with nuclear magnetic resonance, and/or   the database is suitable to store tissue parameters of the body and/or a reference perfusion model of a reference body and/or a reference temperature model of a reference body.