The present disclosure provides a system for MRI. The system may obtain a plurality of echo signals relating to a subject that are excited by an MRI pulse sequence applied to the subject. The system may perform a quantitative measurement on the subject based on the plurality of echo signals. The MRI pulse sequence may include a CEST module configured to selectively excite exchangeable protons or exchangeable molecules in the subject, an RF excitation pulse applied after the CEST module configured to excite a plurality of gradient echoes, and one or more refocusing pulses applied after the RF excitation pulse. Each of the refocusing pulses may be configured to excite one or more spin echoes. The one or more spin echoes excited by at least one of the one or more refocusing pulses may include a symmetric spin echo and one or more asymmetric spin echoes.

A method for magnetic resonance imaging (MRI)-guided interstitial thermal therapy includes receiving MRI data for tissue of a patient, generating an apparent diffusion coefficient (ADC) map from the MM data, identifying a target site for thermal therapy based on the ADC map, wherein the target site is identified based on an area on the ADC map with a lowest ADC value, planning the thermal therapy for the target site including identifying localized areas of the target site to be ablated first during delivery of the thermal therapy, activating a laser to deliver the thermal therapy using a laser fiber, and monitoring progress of the thermal therapy using MR thermometry.

In Magnetic Resonance Acoustic Radiation Force Imaging (MR-ARFI), an MR imaging device (10) performs gradient echo imaging including successive MR dynamics with opposite encoding of displacement to generate MR-ARFI data of a subject comprising successive image frames with opposite displacement encoding. An ultrasound device (12) applies sonication to the subject during the gradient echo imaging. An electronic processor (22) performs MR-ARFI data processing applied to image elements at image frames of the MR-ARFI data. A displacement is computed (30) for the image element at the image frame as proportional to a phase difference between the image element in the image frame and the image element in a succeeding or preceding image frame with opposite displacement encoding. The computed displacement is corrected (32) for a temperature change between the image frame and the succeeding or preceding image frame. The temperature change is determined using the MR-ARFI data.

A method for providing at least one measurement by a magnetic resonance imaging (MRI) system of a tissue property or underlying tissue property in a region sufficiently close to a metal object, so that the metal object induces artifacts is provided. At least one magnetic resonance imaging signal from the region is acquired through the MRI system. The acquired at least one MRI signal is processed to correct for artifacts induced by the metal object. At least one tissue property or underlying tissue property measurement is extracted from the processed at least one MRI signal.

During operation, a system may apply a polarizing field and an excitation sequence to a sample. Then, the system may measure a signal associated with the sample for a time duration that is less than a magnitude of a relaxation time associated with the sample. Next, the system may calculate the relaxation time based on a difference between the measured signal and a predicted signal of the sample, where the predicted signal is based on a forward model, the polarizing field and the excitation sequence. After modifying at least one of the polarizing field and the excitation sequence, the aforementioned operations may be repeated until a magnitude of the difference is less than a convergence criterion. Note that the calculations may be performed concurrently with the measurements and may not involve performing a Fourier transform on the measured signal.

A method for producing an image of a subject using a magnetic resonance imaging (MRI) system includes acquiring a series of echo signals by sampling k-space along radial lines that each pass through the center of k-space. Each projection of the radial lines is divided into multiple echoes and successive projections are spaced by a predetermined angular distance. The series of echo signals are reconstructed into a plurality of images, wherein each image corresponds to a distinct echo signal.

A system (100) includes an imaging system (130), and a therapy control device (122). The imaging system (130) generates temperature maps (140) and strain maps (142) of localized tissues of a patient. The therapy control device (122) includes one or more computer processors configured to detect at least one failure mode (300, 302, 304, 400) of generated mild hyperthermia in the localized tissues of the patient according to at least one of the temperature maps, the strain maps, or a signal indicative of detected inertial cavitation. In some embodiments, the therapy control device either halts therapy or issues a warning.

A local shimming system for magnetic resonance imaging and the method thereof, wherein the shimming method comprises the following steps: collecting B0 field map information using two-dimensional gradient echo (301); calculating and evaluating the homogeneity of B0 (302); optimizing the current of each channel shim coil (303); determining whether the minimum standard deviation value of f is obtained (304); outputting an optimal current combination values and setting an optimum current value corresponding to each channel of the shim coil on the current control software (305); and testing and evaluating the homogeneity of B0 to achieve the shimming goal (306).

The present disclosure describes methods and systems, including computer-implemented methods, computer program products, and computer systems, for measuring wettability of a rock sample. One method includes: at each temperature of a plurality of temperatures, obtaining a first Nuclear Magnetic Resonance (NMR) surface relaxation time for a rock sample having a saturation level; determining a first temperature sensitivity based on the first NMR surface relaxation times and corresponding temperatures; at each temperature of the plurality of temperatures, obtaining a second NMR surface relaxation time for the rock sample that is saturated with oil; determining a second temperature sensitivity based on the second NMR surface relaxation times and corresponding temperature; and determining a wettability of the rock sample based on the first temperature sensitivity and the second temperature sensitivity.

The invention relates a method and an apparatus of predicting or planning a temperature distribution (52) in a body. The method comprises the steps of: a) obtaining a model of the body (50) related to a temperature transport mechanism or temperature distribution (52) in the body; b) simulating an application of heat to at least a part of the body such as targeted tissue; c) determining and/or predicting the temperature (52) or heat distribution in at least a part of the body using the model of the body (50).