EP0108421A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Nuclear magnetic resonance diagnostic apparatus
Assignee: Toshiba Corp
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Filing: 1983-11-08
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Granted: —
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Expires: 2003-11-08
Abstract
Abstract In an NMR diagnostic apparatus (100), a plurality of tomographic images in the diseased portion of the patient (P) are desirable to obtain diagnostic information thereof. To obtain a plurality of tomographic images, an auiliary coil (20) as a gradient field shifting coil is provided adjacent to the gradient field coils (19) in such a manner that combined magnetic field (GR; GS) generated by the auxilary coil (20) and the gradient field coils (19) serves to shift a magnetically-zero plane where the NMR phenomenon occurs under the influence of the static field (H0) and the RF pulse (H1).
Inventors
- 👤 Hiroshi Sugimoto
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 13:12
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/44; G01R33/48; G01R33/483; G01R33/4833; G01R33/4835; G01R33/28; G01R33/38; G01R33/385
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
424 words
An apparatus (100) for examining an object (P) by nuclear magnetic resonance characterized in that it comprises: magnet means (12; 13) for applying to the object (P) a static magnetic field ( HO ) along a longitudinal axis thereof; first coil means (19) which is arranged along the longitudinal axis, is selectively energized so as to apply to the object (P) a first gradient magnetic field (G X ; G Y ; G Z ) that in conjunction with the static magnetic field (H O ) gives a predetermined magnetic field in a slice (P 1 ; P 2 ; P 3 ) of the object (P), and also to apply to the slice (P 1 ; P 2 ; P 3 ) of the object (P) a second gradient magnetic field (G R ; G S ) for defining a projection angle of nuclear magnetic resonance signals; probe head coil means (14) for applying RF pulses (H 1 ) to the slice (P 1 ; P 2 ; P 3 ) of the object (P) so as to excite a nucleus therein to which is being applied the predetermined magnetic field superimposed by the static magnetic field (H O ) and the first gradient magnetic field (G X ; G Y ; G Z ), and for detecting the nuclear magnetic resonance signals derived from the slice (P 1 ; P 2 ; P 3 ) of the object (P); second coil means (20) which is arranged along the longitudinal axis and selectively energized so as to apply to the slice (P 1 ; P 2 ; P 3 ) of the object (P) a shifting magnetic field, the shifting magnetic field being superimposed to the first gradient magnetic field (G X ; G Y ; G Z ) so as to shift a magnetically-zero plane of the first gradient magnetic field (G X ; G Y ; G Z ) in a direction which is perpendicular to the magnetically-zero plane; and reconstruction means (16) which receives the nuclear magnetic resonance signals obtained from the slice (P 1 ; P 2 ; P 3 ) of the object (P) through the probe head coil means (14) with respect to a plurality of the projection angles of said first gradient magnetic field (G X ; Gy; G z ), and reconstructs a plurality of computerized tomography images for the nuclear density of the slice (P 1 ; P 2 ; P 3 ) of the object (P) based upon the nuclear magnetic resonance signals.
Claim 2
Independent Claim
424 words
An apparatus (100) for examining an object (P) by nuclear magnetic resonance characterized in that it comprises: magnet means (12; 13) for applying to the object (P) a static magnetic field ( HO ) along a longitudinal axis thereof; first coil means (19) which is arranged along the longitudinal axis, is selectively energized so as to apply to the object (P) a first gradient magnetic field (G X ; G Y ; G Z ) that in conjunction with the static magnetic field (H O ) gives a predetermined magnetic field in a slice (P 1 ; P 2 ; P 3 ) of the object (P), and also to apply to the slice (P 1 ; P 2 ; P 3 ) of the object (P) a second gradient magnetic field (G R ; G S ) for defining a projection angle of nuclear magnetic resonance signals; probe head coil means (14) for applying RF pulses (H 1 ) to the slice (P 1 ; P 2 ; P 3 ) of the object (P) so as to excite a nucleus therein to which is being applied the predetermined magnetic field superimposed by the static magnetic field (H O ) and the first gradient magnetic field (G X ; G Y ; G Z ), and for detecting the nuclear magnetic resonance signals derived from the slice (P 1 ; P 2 ; P 3 ) of the object (P); second coil means (20) which is arranged along the longitudinal axis and selectively energized so as to apply to the slice (P 1 ; P 2 ; P 3 ) of the object (P) a shifting magnetic field, the shifting magnetic field being superimposed to the first gradient magnetic field (G X ; G Y ; G Z ) so as to shift a magnetically-zero plane of the first gradient magnetic field (G X ; G Y ; G Z ) in a direction which is perpendicular to the magnetically-zero plane; and reconstruction means (16) which receives the nuclear magnetic resonance signals obtained from the slice (P 1 ; P 2 ; P 3 ) of the object (P) through the probe head coil means (14) with respect to a plurality of the projection angles of said first gradient magnetic field (G X ; Gy; G z ), and reconstructs a plurality of computerized tomography images for the nuclear density of the slice (P 1 ; P 2 ; P 3 ) of the object (P) based upon the nuclear magnetic resonance signals.
Claim 3
Dependent Claim
162 words
An apparatus (100) for examining an object (P) by nuclear magnetic resonance as claimed in Claim 1, characterized in that the first coil means (19) includes: a first gradient magnetic field coil (19X) which is arranged along the longitudinal axis of the object (P) and the field strength of which changes linearly in an opposite manner along a first axis (X) perpendicular to the longitudinal axis of the object (P); a second gradient magnetic field coil (19Y) which is arranged along the longitudinal axis of the object (P) and the field strength of which changes linearly in an opposite manner along a second axis (Y) perpendicular to the longitudinal axis as well as the first axis (X); and a third gradient magnetic field coil (19Z) which is arranged along the longitudinal axis of the object (P) and the field strength of which changes linearly in an opposite manner along a third axis (Z) parallel to the longitudinal axis of the object (P).
Claim 4
Dependent Claim
347 words
An apparatus (100) for examining an object (P) by nuclear magnetic resonance as claimed in Claim 2, characterized in that the first gradient magnetic field coil (19X) includes two units of electromagnetic coils as a pair combination (19X a ; l9X b ), each unit of which being constituted by two saddle-shaped coil halves as a pair combination (19X a-1 ; 19X a-2 ; 19X b-1 ; 19X b-2 ) which are symmetrically longitudinally disposed about the third axis (Z) and separated at a given distance, the second gradient magnetic field coil (19Y) includes two units of electromagnetic coils as a pair combination (19Y ; 19Y b ), each unit of which being constituted by two saddle-shaped coil halves as a pair combination (19Y a-1 ; 19X a-2 ; 19Y b-1 ; 19Y b-2 ) which are symmetrically longitudinally disposed about the third axis (Z) as well as perpendicular to the first gradient magnetic field coil (19X), and the third gradient magnetic field coil (19Z) includes a pair of electromagnetic coils, which pair being constituted by two solenoid coil halves (19Z a ; 19Z b ) which are symmetrically longitudinally disposed about the third axis (Z); and the second coil means (20) includes: a first shifting magnetic field coil (20X) constituted by two saddle-shaped electromagnetic coil halves (20X a ; 20X b ), each coil half being adjacent to one of the each saddle-shaped coil halves (19X a-1 ; 19X a-2 ; 19X b-1 ; 19X b-2 ) of the first gradient magnetic field coil (19X); a second shifting magnetic field coil (20Y) constituted by two saddle-shaped electromagnetic coil halves (20Y a : 20Y b ), each coil half being adjacent to one of the each saddle-shaped coil halves (19Y a-1 ; 19Y a-2 ; 19Y b-1 ; 19Y b-2 ) of the second gradient magnetic field coil (19Y); and a third shifting magnetic field coil (20Z) constituted by a solenoid coil, which coil being adjacent to one of the solenoid coil halves (19Z a ; 19Z b ) of the third gradient magnetic field coil (19Z).
Claim 5
Dependent Claim
44 words
An apparatus (100) for examining an object (P) by nuclear magnetic resonance as claimed in Claim 1, characterized in that the slice of the object (P) for the computerized tomography images is a cross-sectional slice of the object with respect to the longitudinal axis.
Claim 6
Dependent Claim
45 words
An apparatus (100) for examining an object (P) by nuclear magnetic resonance as claimed in Claim 1, characterized in that the slice of the object (P) for the computerized tomography images is a sagittal slice of the object (P) with respect to the longitudinal axis.
References Cited (Backward Citations)
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