Abstract: An implantable medical device includes an electrode having a thermal switch. The thermal switch is configured to electrically decouple components of the implantable medical device when in contact with tissue at temperatures above normal body temperature.

Abstract: A system and method for predicting and avoiding a seizure in a patient. The system and method includes use of an implanted surface acoustic wave probe and coupled RF antenna to monitor temperature of the patient's brain, critical changes in the temperature characteristic of a precursor to the seizure. The system can activate an implanted cooling unit which can avoid or minimize a seizure in the patient.

Abstract: 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.

Abstract: In a method for automatically selecting a region of interest covering a heated area, in the context of high intensity focused ultrasonic technology during acquisition of magnetic resonance data, phase data of a scanned area are acquired, and a heated area is identified in the scanned area according to the phase data acquired. An image is reconstructed and displayed, and in the displayed image a region of interest covering the heated area is automatically demarcated according to a predetermined size of said region of interest that covers and is larger than the heated area. The method causes the heated area to be automatically and completely included in the region of interest; and eliminates the instability of a manual selection of the region of interest.

Abstract: The present embodiments relate to methods and devices for measuring a spatial temperature and/or SAR distribution in an examination subject in a magnetic resonance tomography device. Microwave thermosensors are provided for measuring the temperature with the aid of microwaves.

Abstract: State information of a user is detected via a biometric information sensor and is stored, in a nonvolatile memory, in association with a content identifier of content that is being reproduced for the user when the state information is detected. An information request, including the state information of another user at another terminal apparatus, is generated and transmitted. Provided information transmitted in response to the information request is received and provided to the user. When an information request is received by the user, information is extracted from the nonvolatile memory based on the state information of another user. Provided information that is based on the extracted information is transmitted to another user.

Abstract: Provided are methods, systems and computer program products evaluating magnetic resonance (MR) signals from a sample. The methods and systems can be used to evaluate MR signals from various constituents (e.g., metabolites, macromolecules) of the sample.

Abstract: An apparatus and method for correcting magnetic resonance temperature measurements is disclosed. In one aspect, the method identifies monitoring regions of interest outside a therapeutic region of interest. Next, a pulse sequence sensitive to changes in T1 and proton density is used to measure the temperature changes in these regions. Next, the PRFS is measured in these same regions. The PRFS in these regions will be caused both by the desired shift from temperature change, and the undesired shift from background magnetic field changes. Using the measured temperature changes from the T1-method, the component of the PRFS due to actual temperature changes is subtracted from the PRFS method, leaving only the component caused by the unwanted magnetic field changes. This analysis is performed separately for each region. At the end of this step, one has measured the change in background magnetic field within each region.

Abstract: A method and apparatus for determining a temperature differential at a portion of a patient's body utilizing temperature sensitive MRI measurements. A diagnostic fluid bolus is administered into a blood vessel of the patient, wherein the diagnostic fluid bolus has a diagnostic fluid bolus temperature waveform. MRI measurements are used to determine the thermodiluted temperature waveform of the diagnostic fluid bolus at a target site in the body spaced away from the administration site. The temperature differential may be used to determine a cardiovascular parameter.

Abstract: In a method and magnetic resonance (MR) system to create an MR magnitude image data set and a phase image data set of an examination subject, first echo signals in a first raw MR data set are detected after a first echo time TE1 and at least second echo signals in at least one second raw MR data set are detected after a second echo time TE2 that is longer than TE1, a magnitude image data set is generated on the basis of the first raw MR data set and the at least one second raw MR data set with averaging of the first and the at least one second raw MR data set, and the phase image data set is generated based on the phase information contained in the at least two raw MR data sets, with averaging of the respective phase information contained in the at least two raw MR data sets.

Abstract: Systems and methods are provided for detecting and responding to excessive heating of implantable medical device leads, such as leads used with pacemakers or implantable cardioverter-defibrillators (ICDs), during a magnetic resonance imaging (MRI) procedure. In one example, a critical temperature is determined for the lead that is representative, e.g., of the temperature at which tissue damage might occur or pacing/sensing might be significantly impaired. A temperature threshold is then set based on the critical temperature by subtracting a predetermined safety margin. Lead temperatures are then sensed during the MRI procedure. The lead temperatures are compared against the threshold and suitable warnings are transmitted to an external monitoring system if lead temperatures exceed their thresholds so that the attending personnel can take corrective action.

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.

Abstract: A thermal management system for cooling a heat generating component of a Magnetic Resonance Imaging (MRI) apparatus includes at least one heat pipe having a portion disposed proximate the heat generating component, such as a gradient coil and/or RF coil. When heat is removed from the component, a working fluid in a relatively hotter end of the heat pipe vaporizes and travels toward a relatively colder end of the heat pipe. The colder end may be operatively coupled to a heat sink for removing the heat from the colder end and increase the overall efficiency of the system. The heat pipe may be disposed along a horizontal, a vertical direction and/or along a diagonal of the heat generating component.

Abstract: A tear-away sheath is provided for use in an invasive procedure for insertion of a conductive device into a patient while the insertion is guided using Magnetic Resonance Imaging and has a peripheral wall surrounding a hollow interior through which a conductive device can be inserted. At least one and preferably two lines of weakness are formed along the length of the peripheral wall at which the sheath can be torn longitudinally so allow the peripheral wall to be opened to release engagement with a conductive device inserted therethrough. A temperature sensing device is embedded in the peripheral wall at or adjacent the distal end with an optical fiber extending longitudinally of the peripheral wall from the distal end to a position exposed form the patient for communicating the sensed temperature to a display device.

Abstract: The in vivo measurement of tissue temperature is performed during a medical procedure using an MRI system. Fat and Water images are acquired at each temperature measurement time and corresponding phase images are produced. A temperature map is produced by subtracting the phase at each Fat image pixel from the corresponding pixel in the Water phase image to improve measurement accuracy in tissues with fat/water mixtures.

Abstract: A medical device includes a sensor for sensing for an MRI gradient magnetic field and a microprocessor for responding to the detected gradient magnetic field by switching from a first electrical signal processing mode to a second electrical signal processing mode, such that electrical signals induced by the gradient magnetic field and an associated RF burst are not counted as cardiac events.

Abstract: A magnetic resonance imaging apparatus includes an RF coil unit which generates RF pulses toward a subject, and which receives an MR signal from the subject. Gradient magnetic field coils generate a gradient magnetic field for slice selection, a gradient magnetic field for phase encoding and a gradient magnetic field for frequency encoding, respectively. An arithmetic unit generates image data on the basis of the MR signal, and a sequence controller controls phase encoding gradient magnetic field coils in order to generate flow pulses for dephasing or rephasing the MR spin of blood flow within the subject, in the same direction as that of the phase encoding gradient magnetic field.

Abstract: An apparatus and method for correcting magnetic resonance temperature measurements is disclosed. In one aspect, the method identifies monitoring regions of interest outside a therapeutic region of interest. Next, a pulse sequence sensitive to changes in T1 and proton density is used to measure the temperature changes in these regions. Next, the PRFS is measured in these same regions. The PRFS in these regions will be caused both by the desired shift from temperature change, and the undesired shift from background magnetic field changes. Using the measured temperature changes from the T1-method, the component of the PRFS due to actual temperature changes is subtracted from the PRFS method, leaving only the component caused by the unwanted magnetic field changes. This analysis is performed separately for each region. At the end of this step, one has measured the change in background magnetic field within each region.

Abstract: A method for determining a metabolic rate of a portion of a body of a patient. The method includes obtaining magnetic resonance information from the portion of the body after introduction of a fluid and determining a magnetic resonance parameter using the magnetic resonance information. The method further includes using the magnetic resonance parameter to determine a temperature differential in the portion of the body and using the temperature differential to determine a metabolic rate of the portion of the body.

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.

Abstract: The apparatus 1 according to the invention comprises a computing unit 4, which is arranged to access phase images computed from the image data and representative of the target medium and the reference medium and carry out computing steps to yield temperature difference map according to the method of the invention. The operation of the computing means is preferably controlled by the computer program according to the invention, whereby the suitable computing steps are programmed as instructions to a suitable processor. The apparatus 1 further comprises a storage unit 8 arranged to store suitable image data which are accessed by the computer program during the computations. The storage unit 8 preferably stores system parameters of the magnetic resonance apparatus, like the strength of the main field B0, gyromagnetic ratio ?, and suitable parameters of the target medium, like screen constant ? in a file 3. The apparatus 1 further comprises a working memory 6, typically based on RAM.

Abstract: In one aspect, in general, a method is provided for detecting temperature and protein denaturation of a tissue during thermal therapy. The method includes generating a plurality of MR pulse sequences that include a first group of pulse sequences and a second group of pulse sequences, and receiving a plurality of response signals that include a first and second group of response signals in response to the first and second groups of pulse sequences, respectively. A first information associated with a degree of protein denaturation of the tissue is determined based on the first and second groups of response signals. A second information associated with a temperature of the tissue is determined based on at least some of the plurality of response signals.

Abstract: A device for locating a venous structure of a patient includes a frame having a bottom surface and a top surface, an adhesive disposed on the bottom surface of the frame to allow the frame to be removably attached to skin or a patient, and one or more sections removably attached to the top surface of the frame. The sections are formed of a liquid crystal material that is sensitive to human skin temperature ranges.

Abstract: PRF shift MRI data is acquired. The PRF shift MRI data may include signals affected by both a desired PRF shift and an undesired PRF shift. Thus, example systems and methods describe manipulating the PRF shift MR! data to make it substantially free of the effects of the undesired PRF shift, which facilitates displaying certain MRI images based on the desired PRF shift.

Abstract: The present invention discloses a novel active insulation device and method for thermally shielding an external body from temperature fluctuations of a contained body. The method comprising providing an active thermal insulation envelope between the contained body and the external body; regulating the heat transfer from the active thermal insulation envelope to the external body; and regulating the heat transfer from the contained body to the active thermal insulation envelope, thus maintaining the temperature of the external body at a constant temperature or within a narrow temperature range.

Abstract: The present invention provides a method of MR investigation of a sample, said method comprising: (i) nuclear spin polarizing a high T1 MR imaging agent which contains in its molecular structure at least two hyperpolarisable nuclei within the same molecule, the frequency difference between the two resonance lines from said nuclei, ??, being dependent upon either the temperature or the pH of said sample; (ii) administering the nuclear spin polarized MR imaging agent to said sample; (iii) exposing said sample to a radiation at a frequency selected to excite nuclear spin transitions in said MR imaging agent; and (iv) detecting and manipulating magnetic resonance signals from said sample using a single-shot RARE acquisition sequence with shifted data acquisition.

Abstract: This invention utilizes the nuclear magnetic resonance imaging and spectroscopy to experimentally measure thermal diffusivity, thermal conductivity, specific heat, specific absorption rate, thermal power, heat transfer coefficient, heat of reaction and the membrane permeability in substances and systems.

Abstract: The systems, methods and apparatus of the present invention comprise noninvasive methods of measuring temperature changes and rates of temperature change in selected body tissues and fluids as a result of absorption and/or dissipation of externally applied heat for the purpose of detecting and monitoring disease or dysfunction, and for preparing diagnostic images of the tissues and related areas from such measurements. Some embodiments of the present invention monitor temperatures of heated tissues directly while other embodiments may measure temperatures of tissues which are heated through flow of heated fluid therethrough.

Abstract: A thermal control system having an initial bore condition and a thermal boundary condition for an MRI includes a thermal controller adapted to set at least one dynamic limit on power input into an MRI gradient coil. The dynamic limit is determined for a first commanded prescription as a function of the initial bore condition and the thermal boundary condition.

Abstract: In a magnetic resonance system and operating method, antenna elements in an antenna array are disposed around an examination volume, and each antenna element has a separate transmission channel and reception channel associated therewith. The magnetic resonance apparatus is operated to obtain magnetic resonance signals, from which amplitude and phase information are derived for the individual antenna elements, and this information is used to subsequently operate the antenna elements in the array to emit RF energy with a predetermined phase and amplitude so as to generate focused RF energy for hyperthermic treatment. The magnetic resonance apparatus can also be used to obtain magnetic resonance signals in intervals which during which the hyperthermic treatment is interrupted, from which the temperature of the region being treated can be ascertained.

Abstract: In a magnetic resonance system and operating method, antenna elements in an antenna array are disposed around an examination volume, and each antenna element has a separate transmission channel and reception channel associated therewith. The magnetic resonance apparatus is operated to obtain magnetic resonance signals, from which amplitude and phase information are derived for the individual antenna elements, and this information is used to subsequently operate the antenna elements in the array to emit RF energy with a predetermined phase and amplitude so as to generate focused RF energy for hyperthermic treatment. The magnetic resonance apparatus can also be used to obtain magnetic resonance signals in intervals which during which the hyperthermic treatment is interrupted, from which the temperature of the region being treated can be ascertained.

Abstract: An electromagnetic shield has a first patterned or apertured layer having non-conductive materials and conductive material and a second patterned or apertured layer having non-conductive materials and conductive material. The conductive material may be a metal, a carbon composite, or a polymer composite. The non-conductive materials in the first patterned or apertured layer may be randomly located or located in a predetermined segmented pattern such that the non-conductive materials in the first patterned or apertured layer are located in a predetermined segmented pattern with respect to locations of the non-conductive materials in the second patterned or apertured layer.

Abstract: The invention concerns an assembly for heat treatment of a region of a biological tissue (410) comprising energy-generating means (100) to supply energy to the region; means (200) for measuring and recording spatial temperature distribution in said region; a control unit (300) comprising means for point-to-point digital processing of the temperature distribution in the region. The invention is characterised in that the energy-generating means comprise means(110) for spatial and temporal distribution of the power available to them on said region, the control unit (300) comprising means (330, 350), based on the temperature distribution, for controlling the amount and distribution of energy supplied by the generating means (100).

Abstract: A method of forming a magnetic resonance image involves separate measurement of the position of a measuring site. The magnetic resonance image is corrected on the basis of the measured position of the measuring site.

Abstract: A method of defining a three-dimensional imaging section which comprises displaying a plurality of localizer images of the structure of interest, acquiring operator inputs that designate regions on the plurality of localizer images and that correspond to regions within the structure of interest, and determining a volume based on the regions designated by the operator inputs. The volume defines the three-dimensional imaging section, which is a three-dimensional section of a structure of interest.

Abstract: The present invention relates to devices and method for melting solid polarised sample while retaining a high level of polarisation. In an embodiment of the present invention a sample is polarised in a sample-retaining cup (9) in a strong magnetic field in a polarising means (3a, 3b, 3c) in a cryostat (2) and then melted inside the cryostat (2) by melting means such as a laser (8) connected by an optical fibre (4) to the interior of the cryostat.

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.

Abstract: The invention is directed to imaging methods for performing real-time or near real-time assessment and monitoring. Embodiments of these methods are useful in a plurality of settings including surgery, clinical procedures, tissue assessment, diagnostic procedures, forensic, health monitoring and medical evaluations.

Abstract: A method for magnetic resonance imaging includes applying a first two echo gradient echo sequence to a tissue region, the first two echo sequence generating a first echo and a subsequent second echo. A second two echo gradient echo sequence is applied after heating the tissue region, the second two echo sequence generating a third echo and a subsequent fourth echo. A magnitude difference between the third echo and the first echo is measured and correlated to a temperature shift for fat tissue, and a phase difference between the fourth echo and the second echo is measured and correlated to a temperature shift for water-based tissue. A thermal image is generated of the tissue region based upon the temperature shift for both fat and water-based tissue.

Abstract: An MRI apparatus and method in which image data is produced using NMR signals obtained in plural measurements performed at different times respectively. Data is calculated indicating temperature distribution within the object for image data of each measurement time and spatial discontinuity of the calculated temperature distribution data is corrected. Temperature change distribution within the object between different measurement times is calculated by subtracting the corrected temperature distribution data of each measurement time, and the calculated temperature change distribution is transformed to indicative data for supply to a display for display.

Abstract: A magnetic resonance imaging (MRI) system is provided with an interventional instrument with an indicator element which influences, for example locally disturbs, the magnetic resonance image. The position of the interventional instrument within the patient to be examined is derived from the local disturbances in the image as caused by the interventional instrument. The degree of influencing of the magnetic resonance image is adjustable notably by rotation of the interventional instrument with the indicator element relative to the direction of the steady magnetic field of the magnetic resonance imaging system. For example, the indicator element is a paramagnetic strip which may include several segments of different magnetic susceptibility.

Abstract: An MRI guided surgical apparatus includes a heat source formed by a laser and an optical fiber carrying the heat energy into a part to be coagulated by hyperthermia with an end reflector to direct the energy in a beam to one side of the fiber end. The fiber includes a reinforcing sleeve along its length to prevent bending and twisting. The sleeve is mounted in a shielded, Piezo-electric motor which causes movement of the fiber longitudinally of its axis to move the end within the part and rotation of the fiber about its axis to cause the beam to rotate about the axis. A rigid elongate cannula is arranged for insertion to a position at the part of the patient having a bore for receiving a portion of the fiber adjacent the outlet end in sliding engagement therein such that the end can pass through the cannula into engagement with the part of the patient. A part of the sleeve projecting beyond the cannula is rigid and a further part connecting to the motor is stiff but less rigid.

Abstract: NMR images indicative of thermal changes in tissues undergoing therapy are produced using a gradient-recalled echo pulse sequence. Prior to therapy a contrast agent which shortens spin T1 relaxation time is injected into the patient and a reference phase image indicative of proton chemical shift is acquired. Temperature maps are produced in real-time as the therapy is subsequently performed by repeatedly acquiring NMR data, reconstructing measurement phase images and subtracting the reference phase image. The temporal rate at which the temperature maps are produced is increased by segmenting k-space and acquiring less than all the segments during each repetition.

Abstract: An ultrasonic therapeutic apparatus consisting of a therapeutic ultrasonic wave generating source driven by a driver circuit to generate therapeutic ultrasonic waves, an in vivo imaging probe so as to obtain a tissue tomographic image in the vicinity of the focus of the therapeutic ultrasonic waves. The imaging probe is used to receive echoes of the ultrasonic pulses emitted from therapeutic ultrasonic wave generating source. The driving conditions for the therapeutic ultrasonic wave generating source is adjusted on the basis of a received echo signal. The received echo signal contains information about actual intensity of the therapeutic ultrasonic waves within a living body, thus improving the safety and reliability of therapy.

Abstract: In a method for spatially resolved temperature monitoring in an examination subject, a suspension of ferromagnetic microparticles is intracorporeally introduced into the body Curie temperature of which substance corresponds to a desired temperature limit value. By means of an MR measurement, a spatially resolved representation of the body is obtained with artifacts that are caused by the substance being in the ferromagnetic state being employed as a criterion for determining that the temperature limit value has not yet been reached.

Abstract: An MRI system acquires NMR tracking data from a tracking coil imbedded in an ablation device which is guided by a physician using real time anatomic images produced from image data acquired by the MRI system. The same tracking coil is energized by an RF power source to deliver energy which ablates tissue after the device is guided into proper position.

Abstract: An absolute temperature measuring pulse sequence is executed and, subsequently, a relative temperature measuring pulse sequence is repeatedly executed. Since while a relative temperature can be measured from phase information, an absolute temperature requires frequency information, a time required in the relative temperature measuring pulse can be made shorter than that required in the absolute temperature measuring pulse sequence. Since the relative temperature reveals a temperature variation, if an absolute temperature at a given time is known, an absolute temperature at a subsequent time can be calculated from the relative temperature. Thus, a local internal temperature of the subject can be measured, with a shorter temporal resolution, with the use of the absolute temperature and relative temperature.

Abstract: A method and an apparatus for local heating and global monitoring of a tissue disposed in an imaging device, monitored by the imaging device and substantially simultaneously heated by focused ultrasound from an appropriate source. The ultrasound is generated outside the imaging device and is guided to the tissue through the use of a waveguide. In particular, the imaging device is a magnetic resonance scanner.

Abstract: In a magnetic resonance imaging apparatus being medical diagnostic equipment for understanding the internal structure of a human body, a radio frequency coil for a magnetic resonance imaging apparatus is provided for transmitting and receiving a magnetic resonance signal for forming a magnetic resonance image of a portion of a human body. The coil has an opening formed by splitting a portion of one turn of the coil into two. Thereby, a radio frequency coil for a vertical magnetic field provides a maximum open area. Therefore, a simple operation or an observation can be made through the opening simultaneously with taking a magnetic resonance image of the affected part. Also, a patient can feel less claustrophobic because they can see out through the opening.

Abstract: An inversion pulse is applied to the subject in a static magnetic field. An excitation pulse is applied after a delay time depending on the time constant of the longitudinal relaxation of the spins of proton contained in fat molecule from this inversion pulse. As a result, the spins of proton contained in the fat molecule can be suppressed at high precision. On the basis of the MR signal collected after this suppression, the resonance frequency data of the spins of proton contained in water molecule which is not suppressed or the data corresponding to this resonance frequency, or the magnetic field distribution data of the static magnetic field or the data corresponding to this magnetic field distribution can be determined at high precision.