40 results about "Magnetic resonance thermometry" patented technology

Techniques for correcting temperature measurement in MR thermometry are disclosed. In particular, phase shifts that arise from factors other than temperature changes are detected, facilitating correction of temperature measurements.

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.

During the thermal treatment of an anatomical zone of interest, tissue temperature within the zone may be determined with a computational model whose parameters are adjusted using spectroscopy-based temperature measurements at interfaces of fat and non-fat tissues.

Disclosed is a method and system for steady state free precession based magnetic resonance thermometry that measures changes in temperature on a pixel by pixel basis. The method comprises generating an RF pulse sequence used to find the proton resonance frequency shift, which is proportional to temperature change, processing the resultant MRI data to measure the proton frequency shift, and converting the measured proton frequency shift into change in temperature data. Further disclosed is a method for identifying and compensating for temperature drifts due to core heating of the gradient magnet.

The phase background of a proton resonance frequency shift treatment image may be estimated by fitting a combination of baseline images to the treatment image.

Proton resonance frequency shift thermometry may be improved by combining multibaseline and referenceless thermometry.

Techniques for correcting measurement artifacts in MR thermometry predict or anticipate movements of objects in or near an MR imaging region that may potentially affect a phase background and then acquire a library of reference phase images corresponding to different phase backgrounds that result from the predicted movements. For each phase image subsequently acquired, one reference phase image is selected from the library of reference phase images to serve as the baseline image for temperature measurement purposes. To avoid measurement artifacts that arise from phase wrapping, the phase shift associated with each phase image is calculated incrementally, that is, by accumulating phase increments from each pair of consecutively scanned phase images.

The phase background of a proton resonance frequency shift treatment image may be estimated by fitting a combination of baseline images to the treatment image.

A method for photomagnetic imaging of tissue includes the steps of heating the tissue using light; measuring a change in temperature of the tissue with magnetic resonance thermometry; and creating an optical property map from the measured change in temperature. An apparatus for performing photomagnetic imaging of tissue which includes a light source to heat the tissue, a magnetic resonance imaging system to measure a change in temperature of the tissue, and a data processor to generate an optical property map from the measured change in temperature. An optical property map of tissue photomagnetic imaging of tissue produced by: heating the tissue using light; measuring a change in temperature of the tissue with magnetic resonance thermometry; and creating an optical property map from the measured change in temperature.

The invention relates to a method for monitoring temperatures of tissues around an active implantation object. The method is based on magnetic resonance temperature measurement technologies and adopts a magnetic resonance imaging system, wherein the magnetic resonance imaging system is used to generate at least one sequence 2 which is applied to clinical inspection or scientific researches or other purposes, as well as a sequence 3 applied to temperature distribution measurement. The method comprises the steps that (S11) the sequence 2 is used for scanning, and scanning of the temperature measurement sequence 3 is conducted alternately in the sequence 2; and (S12), safety evaluation is conducted according to a scanning result of the temperature measurement sequence 3. The method has the advantages that radio frequency temperature rise during MRI scanning of a patient carrying an implanted medical appliance can be monitored effectively; and hidden safety risks can be eliminated.

A method for reducing errors in the measurement of temperature by magnetic resonance, for use in magnetic resonance imaging-guided HIFU equipment, includes acquiring an MR phase image, as a reference image, before heating an area to be heated with the HIFU equipment; acquiring another MR phase image, as a heated image, during or after the heating by the HIFU equipment; and calculating the temperature change in the heated area according to said heated image and said reference image; and making compensation to said temperature change according to the change in the magnetic field caused by the position change of an ultrasonic transducer in said HIFU equipment. The method can reduce significantly the temperature errors resulting from the position changes of the ultrasonic transducer.

Disclosed is a method and system for steady state free precession based magnetic resonance thermometry that measures changes in temperature on a pixel by pixel basis. The method comprises generating an RF pulse sequence used to find the proton resonance frequency shift, which is proportional to temperature change, processing the resultant MRI data to measure the proton frequency shift, and converting the measured proton frequency shift into change in temperature data. Further disclosed is a method for identifying and compensating for temperature drifts due to core heating of the gradient magnet.

The invention provides for a therapeutic apparatus comprising a tissue heating system (302, 480, 482). The therapeutic apparatus further comprises a magnetic resonance imaging system (300) for acquiring magnetic resonance thermometry data (366) from nuclei of a subject (318) located within an imaging volume (330). The therapeutic apparatus further comprises a radiation therapy system (304, 592) for irradiating an irradiation volume (316, 516) of the subject, wherein the irradiation volume is within the imaging volume. The therapeutic apparatus further comprises a controller (354) for controlling the therapeutic apparatus. The controller is adapted for acquiring (100, 210) magnetic resonance thermometry data repeatedly using the magnetic resonance imaging system. The controller is adapted for heating (102, 208) at least the irradiation volume using the tissue heating system. The heating is controlled using the magnetic resonance thermometry data. The controller is adapted for irradiating (104, 208) the irradiation volume.

A medical apparatus (300, 400, 500, 600) comprising a magnetic resonance imaging system (302). The medical apparatus further comprises a memory (332) storing machine readable instructions (352, 354, 356, 358, 470, 472, 474) for execution by a processor (326). Execution of the instructions causes the processor to acquire (100, 202) spectroscopic magnetic resonance data (334). Execution of the instructions further cause the processor to calculate (102, 204) a calibration thermal map (336) using the spectroscopic magnetic resonance data. Execution of the instructions further causes the processor to acquire (104, 206) baseline magnetic resonance thermometry data (338). Execution of the instructions further causes the processor to repeatedly acquire (106, 212) magnetic resonance thermometry data (340). Execution of the instructions further cause the processor to calculate (108, 214) a temperature map (351) using the magnetic resonance thermometry data, the calibration thermal map, and the baseline magnetic resonance thermometry data.

A therapeutic apparatus comprising a high intensity focused ultrasound system (302) for sonicating a sonication volume (324) of a subject (320). The therapeutic apparatus further comprises a magnetic resonance imaging system (300) for acquiring magnetic resonance thermometry data (350) within an imaging volume (316). The sonication volume is within the imaging volume. The therapeutic apparatus further comprises a controller (304) for controlling the therapeutic apparatus. The treatment plan comprises instructions for controlling the operation of the high intensity focused ultrasound system. The controller is adapted for sonicating (100) the target volume using the high intensity focused ultrasound system. The controller is adapted for repeatedly acquiring (102) magnetic resonance thermometry data using the magnetic resonance imaging system during execution of the treatment plan. The controller is adapted for modifying (104) the treatment plan during execution of the treatment plan using the magnetic resonance thermometry data.

Aspects of the present disclosure relate to magnetic resonance thermometry. In one embodiment, a method includes acquiring undersampled magnetic resonance data associated with an area of interest of a subject receiving focused ultrasound treatment, and reconstructing images corresponding to the area of interest based on the acquired magnetic resonance data, where the reconstructing uses Kalman filtering.

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.

The invention provides for a medical apparatus (400, 500, 600, 700, 800) comprising a magnetic resonance imaging system (402) for acquiring magnetic resonance thermometry data (442) from a subject (418). The magnetic resonance imaging system comprises a magnet (404) with an imaging zone (408). The medical apparatus further comprises a memory (432) for storing machine executable instructions (460, 462, 464, 466, 10, 660). The medical apparatus further comprises a processor (426) for controlling the medical apparatus, wherein execution of the machine executable instructions causes the processor to: acquire (100, 200, 300) the magnetic resonance thermometry data from multiple slices (421, 421', 421'') within the imaging zone by controlling the magnetic resonance imaging system; and interpolate (102, 202, 204, 302, 304) a three dimensional thermal dose estimate (444) in accordance with the magnetic resonance thermometry data.

A method for reducing errors in the measurement of temperature by magnetic resonance, for use in magnetic resonance imaging-guided HIFU equipment, includes acquiring an MR phase image, as a reference image, before heating an area to be heated with the HIFU equipment; acquiring another MR phase image, as a heated image, during or after the heating by the HIFU equipment; and calculating the temperature change in the heated area according to said heated image and said reference image; and making compensation to said temperature change according to the change in the magnetic field caused by the position change of an ultrasonic transducer in said HIFU equipment. The method can reduce significantly the temperature errors resulting from the position changes of the ultrasonic transducer.

Systems and methods provide accelerated MR thermometry utilizing prior knowledge about the images to be reconstructed from incomplete k-space data, thereby facilitating accurate reconstruction. In various embodiments, missing data is computationally estimated using a machine learning algorithm such as a neural network, and an image is generated based on iteratively updated estimated missing information.

A therapeutic apparatus comprising a high intensity focused ultrasound system (302) for sonicating a sonication volume (324) of a subject (320). The therapeutic apparatus further comprises a magnetic resonance imaging system (300) for acquiring magnetic resonance thermometry data (350) within an imaging volume (316). The sonication volume is within the imaging volume. The therapeutic apparatus further comprises a controller (304) for controlling the therapeutic apparatus. The treatment plan comprises instructions for controlling the operation of the high intensity focused ultrasound system. The controller is adapted for sonicating (100) the target volume using the high intensity focused ultrasound system. The controller is adapted for repeatedly acquiring (102) magnetic resonance thermometry data using the magnetic resonance imaging system during execution of the treatment plan. The controller is adapted for modifying (104) the treatment plan during execution of the treatment plan using the magnetic resonance thermometry data.

A medical apparatus (300, 400, 500, 600) comprising a magnetic resonance imaging system (302). The medical apparatus further comprises a memory (332) storing machine readable instructions (352, 354, 356, 358, 470, 472, 474) for execution by a processor (326). Execution of the instructions causes the processor to acquire (100, 202) spectroscopic magnetic resonance data (334). Execution of the instructions further cause the processor to calculate (102, 204) a calibration thermal map (336) using the spectroscopic magnetic resonance data. Execution of the instructions further causes the processor to acquire (104, 206) baseline magnetic resonance thermometry data (338). Execution of the instructions further causes the processor to repeatedly acquire (106, 212) magnetic resonance thermometry data (340). Execution of the instructions further cause the processor to calculate (108, 214) a temperature map (351) using the magnetic resonance thermometry data, the calibration thermal map, and the baseline magnetic resonance thermometry data.

The invention discloses a magnetic nanoparticle temperature measurement method based on electron paramagnetic resonance, which belongs to the technical field of nano material testing. Electron paramagnetic resonance equipment is used for measuring the temperature by measuring the change of the g factor of the resonance spectrum of the magnetic nanoparticles; specifically, the magnetic nanoparticles have superparamagnetism, and the electron paramagnetic resonance spectrum shape of the magnetic nanoparticles is related to the particle size, temperature and concentration of the particles. Under the condition that the particle size of the particles is known, the central resonance magnetic field of the electron paramagnetic resonance spectrum, namely the change of the g factor is only related to the temperature and is not obviously related to the concentration. By means of the characteristic, the temperature in living organs, tissues and even cells can be rapidly and accurately detected, the magnetic nano temperature measurement application scene is greatly broadened, and compared with magnetic resonance temperature measurement, the temperature measurement precision is effectively improved.

Thermography of an ablation site is carried out by navigating a probe into contact with target tissue in the heart, obtaining a first position of a position sensor in the probe and acquiring a first magnetic resonance thermometry image of the target tissue. The method is further carried out during ablation by iteratively reading the position sensor to obtain second positions, and acquiring a new magnetic resonance thermometry image of the target tissue when the distance between the first position and one of the second positions is less than a predetermined distance. The images are analyzed to determine the temperature of the target tissue.

The invention discloses a one-stop vertebral tumor microwave ablation operation simulation method and device, and relates to the technical field of medical instruments and simulation, and the method comprises the following steps: obtaining a magnetic resonance image of a patient before an operation, carrying out the image segmentation of the magnetic resonance image, and building an individual model of the patient based on the segmented image; collecting magnetic resonance temperature measurement data when the phantom is heated, calculating distribution of heat source items according to the magnetic resonance temperature measurement data, and establishing a microwave probe model based on the distribution of the heat source items; conducting temperature simulation on different needle inserting positions, located in the individual model, of the microwave probe model, conducting thermal damage evaluation on temperature simulation results to determine the optimal needle inserting position and heating duration, and an operation simulation scheme of the to-be-ablated area is generated. The method can be used to assist doctors in quickly and accurately determining proper needle inserting positions and microwave heating parameters, and high dependence on experience of the doctors is effectively reduced.

In a method and magnetic resonance apparatus for determining at least one datum providing a measure for the effect of at least one medical device that is to be connected to, or is connected to, an examination subject in the scope of a magnetic resonance examination that is to be executed, or has been executed, on the image data that are to be obtained, or have been obtained, in the scope of a magnetic resonance examination that is to be executed, or has been executed, and / or on the examination subject that is to be examined, or has been examined, in the scope of the magnetic resonance examination that is to be executed, or has been executed, the at least one datum is determined by at least one magnetic resonance thermometric measurement.

The invention provides for a medical apparatus (400, 500, 600, 700, 800) comprising a magnetic resonance imaging system (402) for acquiring magnetic resonance thermometry data (442) from a subject (418). The magnetic resonance imaging system comprises a magnet (404) with an imaging zone (408). The medical apparatus further comprises a memory (432) for storing machine executable instructions (460, 462, 464, 466, 10, 660). The medical apparatus further comprises a processor (426) for controlling the medical apparatus, wherein execution of the machine executable instructions causes the processor to: acquire (100, 200, 300) the magnetic resonance thermometry data from multiple slices (421, 421′, 421″) within the imaging zone by controlling the magnetic resonance imaging system; and interpolate (102, 202, 204, 302, 304) a three dimensional thermal dose estimate (444) in accordance with the magnetic resonance thermometry data.

Some aspects of the present disclosure relate to systems and methods for magnetic resonance thermometry. In one embodiment, a preliminary balanced steady state free precession (bSSFP) magnetic resonance imaging pulse sequence is applied to an area of interest of a subject. Based on bSSFP image phases, a relationship between frequency and image phase associated with the area of interest can be determined and a bSSFP magnetic resonance imaging pulse sequence applied for temperature change measurement during and / or after focused energy is applied to the subject. Based on image phase change associated with temperature change and using the determined relationship between frequency and image phase, a change in the resonance frequency associated with the target area due to the application of the focused energy can be determined, and the temperature change can be determined based on the determined change in the resonance frequency.