An apparatus and a method for spatial encoding in magnetic resonance tomography using a radio frequency signal are provided. A first set of parameters from a first frequency and from a first amplitude, and from a second frequency and a second amplitude is determined by the magnetic resonance tomograph, and corresponding signals are generated by a radio frequency device and transmitted by an antenna apparatus. A first gradient above the Larmor frequency of the nuclear spins is generated by the Bloch-Siegert effect. The same thing ensues with a second set of parameters that differs from the first set of parameters at least in one frequency or amplitude and therefore generates a second, different gradient.

In a case where a subject parameter distribution is obtained using MRI, a magnetization transfer effect is suppressed such that the calculation accuracy of T1 and T2 of brain parenchyma can be improved and a variation in the T1 value of blood caused by the effect of blood flow can be reduced. In imaging for parameter estimation, a magnetization transfer effect is suppressed by using a high frequency magnetic field pulse having a narrow frequency band as an excitation pulse. In a case where the frequency band is narrow, the high frequency magnetic field pulse has a shape in which the excitation profile is similar to a Gaussian function. A rising portion of the shape is arranged in a field of view where the head is an imaging target.

A method for correcting a B0 inhomogeneity in a magnetic resonance scan with a magnetic resonance tomograph is provided. The magnetic resonance tomograph includes a controller, a radio frequency unit, and a transmitting antenna. In the method, the controller determines a transmission signal that is suitable for correcting an effect of an inhomogeneity of a static B0 magnetic field in an examination volume by the Bloch-Siegert effect. The transmission signal is emitted into the examination volume.

A system for performing magnetic resonance imaging (MRI) of a subject has a pulse sequence system that generates a pulse sequence and has a gradient system, a plurality of gradient coils, a radio-frequency system, and a plurality of RF coils. The pulse sequence system causes the subject to emit MR signals which are captured as k-space data. The system also has a k-space ordering processor that collects first k-space data and second k-space data, an MR signal modeler that generates a signal variation model, and a compensation module that applies the signal variation model to the second k-space data collected to produce compensated k-space data. A display processor reconstructs the compensated k-space data into an image of the subject. The compensated data accounts for variation in magnetization during the pulse sequence and k-space data collection to reduce artifacts in the images.

Methods, computer-readable storage devices, and systems are described for reducing movement of a patient undergoing a magnetic resonance imaging (MRI) scan by aligning MRI data, the method implemented on a Framewise Integrated Real-time MRI Monitoring (FIRMM) computing device including at least one processor in communication with at least one memory device. Aspects of the method comprise receiving a data frame from the MRI system, aligning the received data frame to a preceding data frame, calculating motion of a body part between the received data frame and the preceding data frame, calculating total frame displacement, and excluding data frames with a cutoff above a pre-identified threshold of the total frame displacement.

Described here are systems and methods for obtaining measurements of both tissue perfusion and permeability with a magnetic resonance imaging (MRI) system after the administration of a single dose of contrast agent. To this end, the MRI system is directed to acquire T2*-weighted data, during which the acquired signal values are monitored for a trigger event. When the trigger event occurs, the MRI system is directed to switch from acquiring the T2*-weighted data to acquiring T1-weighted data. The systems and methods of the present invention can thus be used for a fully automated, single acquisition of perfusion and permeability measurements using only a single dose of contrast agent.

A system and method is provided using a nuclear magnetic resonance (NMR) system. The method includes applying an off-resonance radio frequency (RF) pulse using a radio-frequency coil that is spatially inhomogeneous to induce a B1-dependent resonant frequency shift in spins in a subject and, in the presence of the off-resonance RF pulse, applying a frequency-modulated, frequency-selective RF excitation pulse to spatially encode the spins in the subject. The method also includes acquiring NMR data from the subject that is spatially encoded and reconstructing the NMR data to produce a report of internal materials forming the subject.

In a magnetic resonance tomography (MRT) apparatus and operating method, a field of view for imaging a target object is acquired. A relative position of this field of view in relation to a receiving space of the MRT scanner, in which the target object is received, is then automatically determined. A radio-frequency (RF) pulse to be used by the MRT scanner for imaging the target object is then automatically adjusted depending on this relative position. An excitation angle produced in the field of view by the RF pulse is changed compared to the use of the corresponding unadjusted RF pulse.

In one embodiment, an MRI apparatus includes: a scanner equipped with at least a static magnetic field magnet, a gradient coil, and an RF coil configured to apply RF pulses to an object and receive magnetic resonance signals from the object; and processing circuitry configured to set a pulse sequence in which refocusing pulses are sequentially applied subsequent to application of one excitation pulse and a predetermined number of magnetic resonance signals are acquired in each period between adjacent two refocusing pulses by using a water/fat separation method, such that the magnetic resonance signals are different in echo time TE for each of the plurality of refocusing pulses, cause the scanner to acquire the magnetic resonance signals under the pulse sequence, and generate a computed image from the magnetic resonance signals, the computed image being a magnetic resonance image of the object obtained by computation.

A magnetic-resonance imaging apparatus of an embodiment includes a gradient coil, a transmitter coil, and a processing circuitry. The gradient coil applies a gradient magnetic field to an imaging space in which a subject is placed. The transmitter coil applies a RF (radio frequency) pulse to the imaging space. The processing circuitry calculates a target temperature of the gradient coil throughout multiple protocols to be executed in an examination of the subject, and controls a temperature of the gradient coil to approach the target temperature when a data used to set a center frequency of the RF pulse is measured.