摘要:
An RF probe including: two coils for detecting MR signals which are arranged at positions which face each other at a predetermined distance; an apparatus for changing a distance between those coils; and an apparatus for reducing a high frequency coupling between the two coils which is caused due to a change in distance between the coils, in accordance with the distance between the coils.
摘要:
An RF probe for an MRI device including a plurality of hollow cylindrical resonators arranged in series such that the respective axes of the resonators align substantially in a z-axis direction of a three dimensional orthogonal coordinate system, radio frequency power signal supply/reception pickup coils to/from the respective resonators; and loop coils situated riding on two adjacent resonators in x- and y-axis directions, and an electromagnetic shield which surrounds the hollow cylindrical resonators, pickup coils and loop coils and grounded with respect to radio frequency.
摘要:
A probe for an MRI apparatus in a vertical magnetic field system including: an array coil which is formed by arranging a plurality of unit coils, which can be driven independently of one another, in a direction perpendicularly intersecting a direction of a static magnetic field; and a compensating coil which forms a magnetic field in a direction perpendicularly intersecting both a direction of a magnetic field formed by the array coil and the direction of the magnetic field, a signal detected by the array coil and a signal detected by the compensating coil being composed so as to be in phase with each other, thereby to be outputted.
摘要:
A probe for an MRI apparatus in a vertical magnetic field system including: an array coil which is formed by arranging a plurality of unit coils, which can be driven independently of one another, in a direction perpendicularly intersecting a direction of a static magnetic field; and a compensating coil which forms a magnetic field in a direction perpendicularly intersecting both a direction of a magnetic field formed by the array coil and the direction of the magnetic field, a signal detected by the array coil and a signal detected by the compensating coil being composed so as to be in phase with each other, thereby to be outputted.
摘要:
A nuclear magnetic resonance apparatus receives nuclear magnetic resonance signals from an object under test with an RF probe which is an array of coils, implements down-frequency conversion with frequency converters for the received signals in multiple channels such that the frequency bands of the converted signals do not virtually overlap, filters the converted signals with band pass filters each operating to cut off frequency bands of other channels, hybridizes the filtered signals of multiple channels to form a hybridized signal, and produces an image from the hybridized signal.
摘要:
In a bird cage resonator, the axial length of rungs is changed between orthogonal elements. By doing this, the real view fields of orthogonal ports A and B in the sagittal direction are changed and the sensitivity difference between both view fields is reduced. For an object with an elliptical section to be inspected such as the human body, a remarkable difference in detection sensitivity between each orthogonal ports is eliminated and the receiving sensitivity of MRI apparatus employing the QD method is improved.
摘要:
In an RF probe comprising a resonator and a pickup coil, the pickup coil is an 8-shaped coil, and a center portion of this pickup coil is constituted in such a manner that crossing coils become parallel to each other at the portion. The center portion where the coils of the pickup coil are parallel to each other is so disposed as to extend along, and in the vicinity of, a part of a conductor loop of the resonator.
摘要:
RF receiving coil device used in a magnetic resonance imaging apparatus capable of acquiring a tomographic image of an object under examination positioned in a static magnetic field along a predetermined direction including quadrature detection coils for detecting an MR signal component along a direction perpendicular to a body axis direction of the object under examination and also perpendicular to a direction of the static magnetic field, and for detecting another MR-signal component along the body axis direction.
摘要:
An MRI RF coil including first and second ring elements having a plurality of peripheral segments connected in ring shape which are apart from each other along a common vertical axial line. The RF coil also includes a plurality of axial conductive segments for connecting the first and second ring elements electrically to each other at the contacts of the plurality of peripheral segments with a plurality of current loops being formed by neighboring axial conductive segments and two peripheral segments connected thereby. Further, at least one control signal feeding point is positioned at any one of the peripheral segments of the first or second ring elements.
摘要:
An RF probe for MRI, in which a plurality of unit coils including conductive loops having resonance capacitors and inductors connected with the conductive loops in series are arranged so as to be distant from each other with a predetermined distance, electromagnetic coupling being produced between at least two inductors to remove electromagnetic coupling between the unit coils.