G01R33/56358

SYSTEM AND METHOD FOR MAGNETIC RESONANCE ELASTOGRAPHY
20190104963 · 2019-04-11 · ·

An apparatus for use in a magnetic resonance (MR) system for capturing an MR Elastography measurement of a biological lifeform may include a platform; a gel pad on a surface of the platform; and a sensor array. In some embodiments, the sensor array includes at least one ultrasound transducer, and at least one radiofrequency (RF) transmitter and receiver coil. The sensor array is at least partially embedded within the gel pad, and the gel pad is configured to provide mechanical impedance matching between the at least one ultrasound transducer and the biological lifeform. In some embodiments, a system includes the apparatus and an MR system, the MR system including an ultrasonic wave generator, an interface circuit, and a computing device. In some such embodiments, the ultrasonic wave generator is configured to generate one or more shear waves in the biological lifeform.

Reverberant shear wave field estimation of body properties
12029525 · 2024-07-09 · ·

A reverberant shear wave field in an object such as a patient's body or organ causes deformations in one or more selected directions measured with an imaging modality such as ultrasound or MR equipment or other imaging equipment, to estimate displacements in one or more selected directions over time increments and then viscoelastic properties such as stiffness or other parameters of the ROI.

Tensor field mapping

During operation, a system may apply an external magnetic field and an RF pulse sequence to a sample. Then, the system may measure at least a component of a magnetization associated with the sample, such as MR signals of one or more types of nuclei in the sample. Moreover, the system may calculate at least a predicted component of the magnetization for voxels associated with the sample based on the measured component of the magnetization, a forward model, the external magnetic field and the RF pulse sequence. Next, the system may solve an inverse problem by iteratively modifying the parameters associated with the voxels in the forward model until a difference between the predicted component of the magnetization and the measured component of the magnetization is less than a predefined value. Note that the calculations may be performed concurrently with the measurements and may not involve performing a Fourier transform.

ELASTOGRAPHY IMAGING WITH MAGNETIC RESONANCE IMAGING GUIDED FOCUSED ULTRASOUND

A technology is described for multipoint tissue elastic property measurement. An example method (700) 700 includes generating a treatment map (710) of an anatomical region that shows focal points within the anatomical region to be exposed to Focused Ultrasound (FUS) pulses; acquiring a reference MR-ARFI image (720) of the anatomical region containing the focal points using the treatment map; acquiring an active MR-ARFI image (730) for each of the focal points in the anatomical region during exposure of the focal points to the FUS pulses using the treatment map; interleaving the reference MR-ARFI image and active MR-ARFI images (740) to create a combined image of the anatomical region and the focal points; and calculating a tissue displacement measurement (750) for the focal points exposed to the simultaneous and/or rapidly interleaved FUS pulses using the combined image of the anatomical region and the focal points exposed to the simultaneous FUS pulses.

Handheld oscillation applicator for use in a magnetic resonance rheology imaging system

A handheld oscillation applicator (40) for use in a magnetic resonance rheology imaging system (10), for applying mechanical oscillations to at least a portion of a subject of interest (20), the handheld oscillation applicator (40) comprising a housing (54), at least one transducer unit (48) configured to output mechanical energy, a piston (68) that is mechanically linked to the at least one transducer unit (48), the piston (68) including a first end (70), a second end (72), and an opening (74) that extends between the first end (70) and the second end (72), wherein the housing (54) comprises at least one opening (60), and the at least one opening (60) of the housing (54) and the opening (74) of the piston (68) at least partially overlap with regard to a housing opening direction (66) defined by an opening center (62) of the opening (60) of the housing (54) at a first surface (56) and an opening center (64) of the opening (60) of the housing (54) at a second surface (58); and an oscillation applicator system (38), including: a handheld oscillation applicator (40), a transducer driving unit (42) for energizing the at least one transducer unit (48), a sensing unit (50) configured to determine a physical quantity that is representative of an amplitude of mechanical oscillations being applied to at least the portion of the subject of interest (20), and to provide an output signal representing the determined physical quantity, at least one closed-loop control circuit for maintaining a mechanical displacement amplitude of the transducer unit (48) at a selected level, wherein the closed-loop control circuit is configured to provide an output signal for controlling the transducer driving unit (42), based on the output signal received from the sensing unit (50).

METHODS FOR QUANTIFYING TRABECULAR RESERVE USING MAGNETIC RESONANCE ELASTOGRAPHY
20190011522 · 2019-01-10 ·

Described here are systems and methods for evaluating the extent of brain-skull tethering, which may also be referred to as loss of trabecular reserve, in subjects using magnetic resonance elastography (MRE). The present disclosure describes a method for assessing progressive damage to arachnoid space (SAS) trabeculae. The method generally includes measuring the relative movement between the brain and the skull using MRE. As one example, an MRE-based method named slip interface imaging (SII) can be implemented. By measuring trabecular reserve in subjects who have a history of prior head trauma, the susceptibility of a given subject to future injury can be assessed.

System and method for simultaneous magnetic resonance elastography and water-fat imaging

Systems and methods for simultaneous water-fat magnetic resonance imaging (MRI) and magnetic resonance elastography (MRE) using an integrated data acquisition and reconstruction scheme are described. This integrated acquisition and reconstruction technique can mitigate motion misregistration and provide improved image SNR relative to existing multiparametric acquisition techniques that require multiple separate acquisitions.

Systems and methods for a magnetic resonance elastography phantom

A phantom for magnetic resonance elastography (MRE) is provided. In particular, systems and methods for a phantom that is capable of generating a wave-like pattern in MRE images where a wavelength of the generated wave-like pattern is controlled by the phantom geometry. The geometrically controlled wavelength enables the phantom to calibrate MRE image acquisition and mechanical property calculation.

MECHANICAL ACTUATOR AND A METHOD FOR MAGNETIC RESONANCE ELASTOGRAPHY USING CENTRIFUGAL FORCE

A mechanical actuator for Magnetic Resonance Elastography (MRE) and a method for inducing shear waves for MRE as well as respective system and method for MRE using the principle of centrifugal force for wave induction is disclosed. The mechanical actuator comprises a passive driver including a rotational turbine vibrator having an eccentric weight, the turbine vibrator being powered by a fluid (e.g. compresses air or water), and an active driver configured to control the pressure of the fluid powering the turbine vibrator.

MAGNETIC RESONANCE APPARATUS WITH STANDARDIZED RADIO COUPLING WITH AN EXTERNAL DEVICE

A magnetic resonance system that is designed to carry out an examination of an examination object, and has an RF controller, a gradient controller and an image sequence controller, which are designed to acquire MR data of a volume portion of the examination object. An arithmetic unit of the magnetic resonance system is designed to reconstruct MR images from the acquired MR data. A standardized REST-based HTTP radio interface of the magnetic resonance system is designed to establish a standardized wireless connection to at least one external device.