MR-guided breast tumor ablation and temperature imaging system
First Claim
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.
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Abstract
An MRI system is employed to aim an ultrasonic transducer at tissues to be treated and to produce images which enable the treatment of the tissues to be monitored. A pulse sequence is used which produces both a spin-echo NMR signal and a gradient-echo NMR signal and changes in phase between these two signals is measured and used to produce a temperature map. Changes in amplitude of the spin-echo NMR signal from a reference spin-echo NMR signal is used to produce images which indicate temperature changes in both fat and water. These temperature maps may be used to aim the heat treatment device.
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Citations
19 Claims
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1. A method for monitoring the in vivo treatment of tissues with a magnetic resonance imaging (MRI) system, the steps comprising:
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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. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A method for producing a temperature map of tissues being treated with a magnetic resonance imaging (MRI) system, the steps comprising:
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a) performing a pulse sequence with the MRI system in which a spin-echo (SPE) NMR signal and a gradient-echo NMR signal are acquired from a subject;
b) repeating step a) a sufficient number of times to acquire k-space data sets from which images may be reconstructed;
c) reconstructing an SPE phase image from the k-space data set for the acquired SPE NMR signals;
d) reconstructing a GRE phase image from the k-space data set for the acquired GRE NMR signals; and
e) producing a phase difference temperature map by calculating the difference in phase values at corresponding locations in the SPE phase image and the GRE phase image. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19)
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Specification