Magnetic resonance imaging apparatus
First Claim
1. A magnetic resonance imaging apparatus for receiving radio frequency signals generated by an object to be imaged;
- said apparatus comprising;
a radio-frequency coil array formed of a plurality of radio-frequency coil assemblies arranged in at least one dimension, each radio-frequency coil assembly for receiving radio-frequency signals from two directions perpendicular to each other generated at a predetermined portion of the object and for generating two output signals in response thereto;
each radio-frequency coil assembly having an associated means for shifting a phase of one of the two output signals by about 90° and
for synthesizing the two output signals to obtain one synthesized signal;
means for substantially simultaneously operating at least two of said plurality of radio-frequency coil assemblies to generate substantially simultaneously at least two synthesized signals; and
means for reconstructing an image of the object on the basis of said at least two synthesized signals.
1 Assignment
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Accused Products
Abstract
Four QD surface coil assemblies each constituted by an 8-shaped coil and a rectangular coil are one-dimensionally arranged under the spine array of a patient in the direction of the body axis of the patient. Each 8-shaped coil senses an RF magnetic field in an x direction near the spine array of the patient, and each rectangular coil senses an RF magnetic field in a y direction. Outputs from the 8-shaped coils and the rectangular coils are input to 90° hybrid combiner circuits through pre-amplifiers, the phase of any one of the outputs is shifted by 90°, and then the outputs are added to each other. Outputs from the 90° hybrid combiner circuits are supplied as raw data, through receiver/data acquisition systems, to a data processing unit (computer). In the data processing unit, raw data are two-dimensionally Fourier-transformed to form image signals pi (x,y,z) (i=1 to 4). The signals p1 (x,y,z) are squared, the sum of pi (x,y,z) is calculated with respect to i, and finally, the square root of the sum is calculated to obtain an image.
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Citations
12 Claims
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1. A magnetic resonance imaging apparatus for receiving radio frequency signals generated by an object to be imaged;
- said apparatus comprising;
a radio-frequency coil array formed of a plurality of radio-frequency coil assemblies arranged in at least one dimension, each radio-frequency coil assembly for receiving radio-frequency signals from two directions perpendicular to each other generated at a predetermined portion of the object and for generating two output signals in response thereto; each radio-frequency coil assembly having an associated means for shifting a phase of one of the two output signals by about 90° and
for synthesizing the two output signals to obtain one synthesized signal;means for substantially simultaneously operating at least two of said plurality of radio-frequency coil assemblies to generate substantially simultaneously at least two synthesized signals; and means for reconstructing an image of the object on the basis of said at least two synthesized signals. - View Dependent Claims (2, 3, 4)
- said apparatus comprising;
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5. A magnetic resonance imaging apparatus for receiving radio-frequency signals generated by an object to be imaged, said apparatus comprising:
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a radio-frequency coil array formed of at least two pairs of radio-frequency coil assemblies arranged in at least one dimension, each pair of said radio-frequency coil assemblies is positioned with the object therebetween, and having a sensitivity for receiving two radio-frequency signals in two directions perpendicular to each other at a predetermined portion of the object, and for generating two output signals corresponding to the two radio-frequency signals received; each pair of radio-frequency coil assembly having an associated means for shifting a phase of one of the two output signals by about 90° and
for synthesizing the two output signals to obtain one synthesized signal;means for substantially simultaneously operating said at least two pairs of said radio-frequency coil assemblies to substantially simultaneously acquire a plurality of synthesized signals; and means for reconstructing an image of the object on the basis of the plurality of synthesized signals. - View Dependent Claims (6, 7)
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8. A magnetic resonance imaging apparatus for receiving radio-frequency signals generated by an object to be imaged;
- said apparatus comprising;
plural volume coil assemblies arranged in an axis of the object said assemblies positioned to surround the object and for receiving radio-frequency signals generated by the object and for producing plural output signals in response thereto; means for substantially simultaneously operating said plural volume coil assemblies to substantially simultaneously acquire said plural output signals from said plural volume coil assemblies; and means for reconstructing an image of the object on the basis of the plural output signals from said plural volume coil assemblies which are simultaneously acquired. - View Dependent Claims (9, 10)
- said apparatus comprising;
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11. A magnetic resonance imaging apparatus for receiving radio-frequency signals generated by an object to be imaged;
- said apparatus comprising;
a radio-frequency volume coil array formed of at least two radio-frequency volume coil assemblies arranged in a direction of a body axis of the object, each of the radio-frequency volume coil assemblies being formed of two radio-frequency coil assemblies sandwiching the object, and each of the volume radio-frequency coil assemblies having a sensitivity for receiving radio-frequency signals in two directions perpendicular to each other at a predetermined portion of the object and for producing two output signals corresponding to the two radio-frequency signals in response thereto; each volume coil assembly having an associated means for shifting a phase of one of two output signals by about 90° and
synthesizing the two output signals to obtain one synthesized signal;means for substantially simultaneously operating said at least two radio-frequency volume coil assemblies to substantially simultaneously acquire a plurality of synthesized signals; and means for reconstructing an image of the object on the basis of the plurality of synthesized signals which are simultaneously acquired.
- said apparatus comprising;
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12. A magnetic resonance imaging apparatus for receiving radio-frequency signals generated by an object to be imaged;
- said apparatus comprising;
a radio-frequency surface coil assembly formed of two radio-frequency surface coil assemblies, having a sensitivity for receiving radio-frequency signals in two directions perpendicular to each other at a predetermined portion of the object and for producing two surface output signals corresponding to the two radio-frequency signals received; a radio-frequency volume coil assembly formed of two radio-frequency coil assemblies surrounding the object, having a sensitivity for receiving radio-frequency signals in two directions perpendicular to each other at a predetermined portion of the object and for producing two volume output signals corresponding to the two radio-frequency signals received; first synthesizing means for shifting a phase of one of two surface output signals by about 90° and
for synthesizing the two surface output signal to obtain a first synthesized signal;second synthesizing means for shifting a phase of one of two volume output signals by about 90° and
for synthesizing the two volume output signals to obtain a second synthesized signal;means for substantially simultaneously operating said radio-frequency surface coil assembly and said radio-frequency volume coil assembly to substantially simultaneously acquire the first and second synthesized signals; and means for reconstructing an image of the object on the basis of the first and second synthesized signals which are simultaneously acquired.
- said apparatus comprising;
Specification