摘要:
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.
摘要:
A system that determines an invariant magnetic-resonance (MR) signature of a biological sample is disclosed. During operation, the system determines a magnetic-resonance (MR) model of voxels in a biological sample based on differences between MR signals associated with the voxels in multiple scans and simulated MR signals. The MR signals are measured or captured by an MR scanner in the system during multiple MR scans, and based on scanning instructions, and the simulated MR signals for the biological sample are generated using the MR model and the scanning instructions. Moreover, the system iteratively modifies the scanning instructions (including a magnetic-field strength and/or a pulse sequence) in the MR scans based on the differences until a convergence criterion is achieved. Then, the system stores, in memory, an identifier of the biological sample and a magnetic-field-strength-invariant MR signature of the biological sample that is associated with the MR model.
摘要:
Systems and methods are described for inducing tissue vibration for magnetic resonance elastography is described. The system includes a hydraulic drive component that is mechanically linked to a pneumatic drive component. The pneumatic drive component is pneumatically linked to a passive pneumatic actuator component that is positionable on a patient proximate to a target tissue. Alternating linear movement of an actuator piston within the passive actuator component induces vibration of the target tissue. The frequency of the alternating linear movement of the actuator piston within the passive pneumatic actuator component is controlled by adjusting how fluid is pumped in the hydraulic drive component.
摘要:
A coil pad according to one embodiment is a coil pad that is placed between a receiving coil and a subject. The receiving coil is mounted on the subject and receives a magnetic resonance signal emitted from the subject. The coil pad includes a pad opening and a vibrating portion. The pad opening is aligned with a coil opening included in the receiving coil and forms a through-hole between the coil opening and the subject. The vibrating portion vibrates with a medium that transmits vibration being filled therein.
摘要:
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.
摘要:
A method for magnetic resonance elastography (“MRE”) is described, in which an MRE inversion that accounts for waves propagating in a finite, bounded media is employed. A vibratory motion is induced in a subject and MRE is performed to measure one or more components of the resulting displacement produced in the subject. This displacement data is subsequently filtered to provide a more accurate and computationally efficient method of inversion. Wave equations based on the geometry of the bounded media are then utilized to calculate the material properties of the subject. Such a method allows for the performance of MRE on tissues such as the heart, eye, bladder, and prostate with more accurate results.
摘要:
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.
摘要:
In a methods for elastography in a defined region of an examined person, a radio-frequency pulse is radiated to manipulate a transverse magnetization in the defined region and at least one additional radio-frequency pulse with a spatial selectivity of the amplitude is radiated to generate shear waves in the defined region. A magnetic resonance signal from the defined region is detected and a determination of a value describing the tissue elasticity in the defined region is made based on the magnetic resonance signal.
摘要:
The invention provides for a medical instrument (200, 400, 500) comprising a magnetic resonance imaging system (202), a transducer (222) for mechanically vibrating at least a portion of the subject within the imaging zone. Instructions cause a processor (236) controlling the medical instrument to: control (100) the transducer to vibrate; control (102) the magnetic resonance imaging system to repeatedly acquire the magnetic resonance data (252) using a first spatially encoding pulse sequence (250); control (104) the magnetic resonance imaging system to acquire navigator data (256) using a second spatially encoding pulse sequence (254); construct (106) a set of navigator profiles (258, 804, 904, 1004, 1108, 1208, 1308) using the navigator data; determine (108) at least one parameter (260) descriptive of transducer vibrations using the set of navigator profiles; and reconstruct (110) at least one magnetic resonance rheology image (262) from the magnetic resonance data.
摘要:
A system for determining parameters of porous media or material, which in an embodiment is biological tissue, includes an actuator and a displacement monitor. The actuator is adapted to apply a displacement to tissue at a particular frequency selected from a range of frequencies, and the force monitor adapted to monitor a mechanical response of tissue. The system also has a processor coupled to drive the actuator and to read the mechanical response, the processor coupled to execute from memory a poroelastic model of mechanical properties of the material, and a convergence procedure for determining parameters for the poroelastic model such that the model predicts mechanical response of the tissue to within limits.