108 results about "Magnetization transfer" patented technology

An RF coil assembly for an MRI system includes a resonator formed by a cylindrical shield and pairs of opposing conductive legs disposed symmetrically around a central axis and extending the axial length of the shield. One set of conductive leg pairs is tuned to operate at the Larmor frequency of 13C and another set is tuned to operate at the Larmor frequency of 1H. Drive circuitry operates the RF coil assembly to produce 1H spin magnetization which is transferred to 13C magnetization by the nuclear overhauser effect and to acquire MR data from the 13C spins. Multinuclear measurements can be made simultaneously at different Larmor frequencies.

A magnetic element includes a channel layer, a first magnetic electrode which is in contact with the channel layer, a second magnetic electrode which is in contact with the channel layer and is insulated from the first magnetic electrode, a first intermediate layer which is provided adjacent to the first magnetic electrode and has a first insulating layer, a first magnetic layer which is provided in contact with a surface of the first intermediate layer on an opposite side to a surface contacting the first magnetic electrode to transfer magnetization to the first magnetic electrode, a first electrode which is connected to the first magnetic electrode, and a second electrode which is connected to the second magnetic electrode, at least one of the first electrode and the second electrode outputting a first signal which changes depending on a magnetic arrangement of the first magnetic electrode and the second magnetic electrode.

Apparatus and methods for quantification of transverse relaxation times (T2) using steady-state free precession sequences (generally known as fast imaging sequences) and their sensitivity to a quadratic increase of the RF pulse phase, also known as RF spoiling. Using at least two image acquisitions with different partial RF spoiling increments, T2 can be assessed with high precision and with short acquisition times in the limit of large excitation angles being independent on the longitudinal relaxation time (T1) and magnetization transfer effects as compared to other SSFP based quantitative T2 methods. This invention is not restricted to any kind of target and may be applied in 3D as well as in 2D.

A method and system for magnetic resonance imaging comprises applying at least one radiofrequency magnetization transfer (MT) pulse to a coronary venous region of a subject positioned within a magnetic field, and acquiring magnetic resonance imaging data from the coronary venous region to produce an image of a coronary venous structure. This technique can be utilized as part of a 3D free-breathing, ECG-triggered gradient-echo Cartesian acquisition of the coronary region. One or more magnetization transfer (MT) preparation pulses are used to enhance the contrast between venous blood and myocardium. The MT preparation results in myocardial signal suppression without any significant signal loss in the arterial or venous blood so as to maintain venous blood signal-to-noise ratio while improving contrast between myocardium and veins. The image of a coronary venous structure can be acquired in connection with an interventional cardiovascular procedure, such as a cardiac resynchronization therapy.

A magnetic recording head used for microwave-assisted magnetic recording includes: a main pole; a spin torque oscillator provided on the main pole, including a high-speed rotating magnetization layer in which the magnetization is rapidly rotated by a spin torque; a trailing shield provided on the spin torque oscillator; and a sub pole magnetically coupled to the trailing shield provided in a medium-facing surface, extending in a vertical direction to the medium-facing surface. Then, a non-magnetic electrode is provided on the outside of a trailing gap in which the spin torque oscillator is provided with respect to a magnetic material of the main pole, the trailing shield, or the sub pole, to prevent the line resistance variation due to the AMR effect or the eddy current. Thus, the variation of the current flowing to the spin torque oscillator can be controlled to achieve stable oscillation.

The present invention is directed, in general, to contrast agents (CA), and methods and systems of using such agents for producing image contrast based on a magnetization transfer (MT) mechanism. The CA comprises a tetraazacyclododecane ligand having pendent arms R, R′, R″ and R′″ that are amides having a general formula: —CR1H—CO—NH—CH2—R2. R1 includes organic substituents and R2 is not hydrogen. A paramagnetic metal ion (M) is coordinated to the ligand. The method, comprises subjecting a CA, in a sample, to a radio frequency pulse. The CA has pendent arms R, R′, R″ and R′″ comprising organic substituents and the ligand further includes a M and a water molecule. A signal is obtained by applying a radio frequency pulse at a resonance frequency of the water molecule. The magnetic resonance system, comprises a magnetic resonance apparatus and the CA, the agent containing a ligand having the above described general formula.

An MRAM has: a memory cell including a first magnetoresistance element; and a reference cell including a second magnetoresistance element. The first magnetoresistance element has a first magnetization fixed layer, a first magnetization free layer, a first nonmagnetic layer sandwiched between the first magnetization fixed layer and the first magnetization free layer, a second magnetization fixed layer, a second magnetization free layer and a second nonmagnetic layer sandwiched between the second magnetization fixed layer and the second magnetization free layer. The first magnetization fixed layer and the first magnetization free layer have perpendicular magnetic anisotropy, and the second magnetization fixed layer and the second magnetization free layer have in-plane magnetic anisotropy. The first magnetization free layer and the second magnetization free layer are magnetically coupled to each other. Center of the second magnetization free layer is displaced in a first direction from center of the first magnetization free layer in a plane parallel to each layer. Whereas, the second magnetoresistance element has: a third magnetization free layer whose magnetization easy axis is parallel to a second direction; a third magnetization fixed layer whose magnetization direction is fixed in a third direction perpendicular to the second direction; and a third nonmagnetic layer sandwiched between the third magnetization fixed layer and the third magnetization free layer. The third magnetization fixed layer and the third magnetization free layer have in-plane magnetic anisotropy.

Apparatus and methods of generating magnetization transfer contrast images in which signal to noise ratios are improved and / or in which image acquisition times are reduced. In certain embodiments, apparatus and methods which utilize sensitivity and / or non-sensitivity to magnetization transfer effects to improve the contrast of images which are generated. In certain additional embodiments, apparatus and methods for generating magnetization transfer contrast images which exhibit sensitivity to longitudinal and transverse relaxation times of bound and free proton pools, respectively.