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.

Disclosed herein are example embodiments of devices, systems, and methods for mechanical fractionation of biological tissue using magnetic resonance imaging (MRI) feedback control. The examples may involve displaying an image representing first MRI data corresponding to biological tissue, and receiving input identifying one or more target regions of the biological tissue to be mechanically fractionated via exposure to first ultrasound waves. The examples may further involve applying the first ultrasound waves and, contemporaneous to or after applying the first ultrasound waves, acquiring second MRI data corresponding to the biological tissue. The examples may also involve determining, based on the second MRI data, one or more second parameters for applying second ultrasound waves to the biological tissue, and applying the second ultrasound waves to the biological tissue according to the one or more second parameters.

A device to estimate mechanical properties of brain and abdomen organs undergoing magnetic resonance elastography (MRE) includes electromagnetic actuators, mechanical wave generation mechanisms, and a control unit to generate oscillatory motion signals in synchronization with the MR scanner. Preserving only the shear wave component, a local fitting algorithm is used to estimate the viscoelastic properties of soft tissues. The device is portable and easy to implement in clinical diagnostics, and can be modified to measure other soft materials.

An information processing apparatus according to an embodiment includes a processing circuit. The processing circuit acquires a measurement field corresponding to a spatial distribution of a predetermined physical quantity in a subject of measurement. The processing circuit calculates an unknown quantity in the subject of measurement based on a first equation between the measurement field and the unknown quantity having spatial dependence, and on the acquired measurement field. The first equation is one that is acquired based on a second equation expressing a dual field divergence of which can be expressed using the measurement field, by using the measurement field and the unknown quantity, and on the Helmholtz decomposition of the dual field.

A method for quantitatively measuring a physical characteristic of a material includes performing one or more interrogations of a material sample, each interrogation using a push focal configuration. The method further includes taking measurements of displacement over time of a material sample caused by the one or more interrogations. Each measurement uses an interrogation focal configuration. The method further includes determining a physical characteristic of the material sample based on the measurements of displacement over time of the material sample. According to the method, at least one of the following is true: a tracking focal configuration used for one of the measurements is different from a tracking focal configuration used for another of the measurements; and a push focal configuration used for one of the interrogations is different from a push focal configuration used for another of the interrogations.

The invention relates to a magnetic resonance system (100) configured for acquiring magnetic resonance data from a GC subject (118). Execution of the machine executable instructions (140) stored in a memory (134) causes a processor (130) to control the magnetic resonance system (100) using a set of waveform and pulse sequence commands (142, 152) to prepare a first state of vibration (211) of the one or more hardware elements and/or the subject (118). The preparing comprises generating the vibration matching gradient (200) inducing the first vibrations (210) of the one or more hardware elements and/or the subject (118), while the net magnetization vector of the subject (118) is aligned along the longitudinal axis of the main magnetic field. The magnetic resonance system (100) is further controlled to acquire the magnetic resonance data (144, 154) according to a magnetic resonance protocol. The acquiring comprises generating in sequence at least two spin manipulating gradients (202, 204) for manipulating phases of nuclear spins within the subject (118), while the net magnetization vector of the subject (118) comprises a non-vanishing component in a transverse plane perpendicular to the longitudinal axis of the main magnetic field. A first one of the at least two spin manipulating gradients (202) is generated during the first state of vibration (211) and a second one of the at least two spin manipulating gradients (204) is generated during a second state of vibration (213) of the one or more hardware elements and/or the subject (118). The vibration matching gradient (200) is used for matching with the first state of vibration (211) the second state of vibration (213).

Provided is an evaluation method including evaluating accuracy of a model containing a hydrogel with respect to an organism based on organism shape information representing an organism shape obtained by capturing an image of the organism by MRI and model shape information representing a model shape obtained by capturing an image of the model by MRI.

The present disclosure relates to a system and method for non-invasively determining NAFLD activity scores (NAS) in patients using mechanical properties determined through magnetic resonance elastography (MRE) imaging. The non-invasively determined NAS score is then used to diagnose NFALD and NASH patients.

A method and system for performing three-dimensional, 3D, magnetic resonance elastography, MRE, using a multi-slice gradient echo, GRE, imaging sequence. Four scans typically required to be performed during MRE, and during four breath-holds, are combined into a single measurement that can be performed during a single breath-hold.

The present disclosure is directed to techniques for synchronizing a rotational eccentric mass of a gravitational transducer used for a magnetic resonance elastography acquisition with a corresponding magnetic resonance elastography scan carried out by a magnetic resonance imaging system, wherein the rotation of the eccentric mass is driven by a shaft. The method includes starting the rotation of the eccentric mass at a set vibration frequency and the magnetic resonance elastography scan at a set acquisition frequency; determining the rotational position of the shaft; defining the rotational position as first reference position; calculating further reference positions. At the start time of each subsequent acquisition period, determining the current rotational position of the shaft; comparing the determined current rotational position with the theoretically expected reference position and decreasing or increasing the rotational speed of the rotational eccentric mass based on the comparison.