Techniques for temperature measurement and corrections in long-term magnetic resonance thermometry
First Claim
Patent Images
1. A method of performing proton resonance frequency (PRF) based magnetic resonance (MR) temperature measurement, the method comprising the steps of:
- using an MRI unit, acquiring a first phase image of an MR imaging area having a known temperature distribution, the MR imaging area comprising an area of interest;
using the MRI unit, acquiring a second phase image of the MR imaging area subsequent to the acquisition of the first phase image;
without modifying the first image, determining, from differences between the second phase image and the first phase image, one or more first corrections in one or more portions of the MR imaging area that have experienced a known or clinically insignificant change in temperature since the acquisition of the first phase image;
determining one or more second corrections in at least the area of interest by extrapolating the one or more first corrections;
assigning a first set of one or more absolute temperatures to the area of interest based at least in part on (i) the known temperature distribution and (ii) the one or more second corrections,detecting a movement and/or deformation of the area of interest;
determining a new temperature distribution of at least the area of interest by registering the known temperature distribution to the new temperature distribution based at least in part on the detected movement and/or deformation;
acquiring a third phase image of the MR imaging area subsequent to the detected movement and/or deformation;
acquiring a fourth phase image of the MR imaging area subsequent to the acquisition of the third phase image; and
assigning a second set of one or more absolute temperatures to the area of interest based at least in part on (i) the new temperature distribution and (ii) a difference between the fourth phase image and the third phase image.
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Abstract
Techniques for temperature measurement and correction in long-term MR thermometry utilize a known temperature distribution in an MR imaging area as a baseline for absolute temperature measurement. Phase shifts that arise from magnetic field drifts are detected in one or more portions of the MR imaging area, facilitating correction of temperature measurements in an area of interest.
205 Citations
24 Claims
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1. A method of performing proton resonance frequency (PRF) based magnetic resonance (MR) temperature measurement, the method comprising the steps of:
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using an MRI unit, acquiring a first phase image of an MR imaging area having a known temperature distribution, the MR imaging area comprising an area of interest; using the MRI unit, acquiring a second phase image of the MR imaging area subsequent to the acquisition of the first phase image; without modifying the first image, determining, from differences between the second phase image and the first phase image, one or more first corrections in one or more portions of the MR imaging area that have experienced a known or clinically insignificant change in temperature since the acquisition of the first phase image; determining one or more second corrections in at least the area of interest by extrapolating the one or more first corrections; assigning a first set of one or more absolute temperatures to the area of interest based at least in part on (i) the known temperature distribution and (ii) the one or more second corrections, detecting a movement and/or deformation of the area of interest; determining a new temperature distribution of at least the area of interest by registering the known temperature distribution to the new temperature distribution based at least in part on the detected movement and/or deformation; acquiring a third phase image of the MR imaging area subsequent to the detected movement and/or deformation; acquiring a fourth phase image of the MR imaging area subsequent to the acquisition of the third phase image; and assigning a second set of one or more absolute temperatures to the area of interest based at least in part on (i) the new temperature distribution and (ii) a difference between the fourth phase image and the third phase image. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A system for performing proton resonance frequency (PRF) based magnetic resonance (MR) temperature measurement, the system comprising:
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an MRI unit; a controlling means for communicating with the MRI unit, and causing the MRI unit to; acquire a first phase image of an MR imaging area having a known temperature distribution, the MR imaging area comprising an area of interest, and acquire a second phase image of the MR imaging area subsequent to the acquisition of the first phase image; and a processing means for accessing to image data acquired by the MRI unit, and; determining, from differences between the second phase image and the first phase image without modifying the first image, one or more first corrections in one or more portions of the MR imaging area that have experienced a known or clinically insignificant change in temperature since the acquisition of the first phase image, determining one or more second corrections in at least the area of interest by extrapolating the one or more first corrections, assigning a first set of one or more absolute temperatures to the area of interest based at least in part on (i) the known temperature distribution and (ii) the one or more second corrections, detecting a movement and/or deformation of the area of interest; determining a new temperature distribution of at least the area of interest by registering the known temperature distribution to the new temperature distribution based at least in part on the detected movement and/or deformation; acquiring a third phase image of the MR imaging area subsequent to the detected movement and/or deformation; acquiring a fourth phase image of the MR imaging area subsequent to the acquisition of the third phase image; and assigning a second set of one or more absolute temperatures to the area of interest based at least in part on (i) the new temperature distribution and (ii) a difference between the fourth phase image and the third phase image. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20)
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21. A non-transitory computer-readable medium storing computer-executable codes for causing at least one processor to correct proton resonance frequency (PRF) based magnetic resonance (MR) temperature measurement, the computer-readable medium comprising:
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computer-executable code adapted to acquire a first phase image of an MR imaging area having a known temperature distribution, the MR imaging area comprising an area of interest; computer-executable code adapted to acquire a second phase image of the MR imaging area subsequent to the acquisition of the first phase image; computer-executable code adapted to determine, from differences between the second phase image and the first phase image without modifying the first image, one or more first corrections in one or more portions of the MR imaging area that have experienced a known or clinically insignificant change in temperature since the acquisition of the first phase image; computer-executable code adapted to determine one or more second corrections in at least the area of interest by extrapolating the one or more first corrections; computer-executable code adapted to assign a first set of one or more absolute temperatures to the area of interest based at least in part on (i) the known temperature distribution and (ii) the one or more second corrections, computer-executable code adapted to detect a movement and/or deformation of the area of interest; computer-executable code adapted to determine a new temperature distribution of at least the area of interest by registering the known temperature distribution to the new temperature distribution based at least in part on the detected movement and/or deformation; computer-executable code adapted to acquire a third phase image of the MR imaging area subsequent to the detected movement and/or deformation; computer-executable code adapted to acquire a fourth phase image of the MR imaging area subsequent to the acquisition of the third phase image; and computer-executable code adapted to assign a second set of one or more absolute temperatures to the area of interest based at least in part on (i) the new temperature distribution and (ii) a difference between the fourth phase image and the third phase image. - View Dependent Claims (22, 23, 24)
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Specification