Patent ID: 7542793
Filing Date: 2009-06-02
Classification: G01R

Abstract:
1. A method for monitoring the in vivo treatment of tissues with a magnetic resonance imaging (MRI) system, the steps comprising: a) performing a pulse sequence with the MRI system in which a spin-echo (SPE) NMR signal and a gradient-echo (GRE) NMR signal are acquired from the tissues being treated; b) repeating step a) to acquire a plurality of said SPE and said GRE NMR signals; c) reconstructing an SPE reference modulus image from the acquired plurality of SPE NMR signals, said SPE reference modulus image indicating the magnitude of the SPE NMR signal produced at locations in the tissues being treated; d) reconstructing a reference phase difference image from the acquired plurality of SPE and GRE NMR signals, said reference phase difference image indicating the difference in phase between the SPE and GRE NMR signals produced at locations in the tissues being treated; e) activating a treatment device aimed at the tissues to be treated to produce a change in temperature therein; f) repeating step a) to acquire a plurality of said SPE and said GRE NMR signals; g) reconstructing an SPE modulus image from the SPE NMR signals acquired in step f), said SPE modulus image indicating the magnitude of the SPE NMR signal produced at locations in the tissues being treated when step f) is performed; h) producing a modulus temperature map from the SPE reference modulus image and the SPE modulus image, said modulus temperature map indicating the temperature change at locations in the tissues being treated; i) reconstructing a phase difference image from the SPE and GRE NMR signals acquired in step f), said phase difference image indicating the difference in phase between the SPE and GRE NMR signals produced at locations in the tissues being treated when step f) is performed; j) producing a phase difference temperature map from the reference phase difference image and the phase difference image, said phase difference temperature map indicating the temperature change at locations in the tissues being treated; and k) displaying the modulus temperature map information and phase difference temperature map information.