EP0187389A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Apparatus for obtaining image information through use of a nuclear magnetic resonance signal
Assignee: Asahi Kasei Corp
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Filing: 1985-12-30
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Granted: —
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Expires: 2005-12-30
Abstract
Abstract A static magnetic field and a gradient magnetic field which is of the same direction as the former but the intensity of which is graded in three intersecting directions are applied to an examinee's body (47) so that space information therefrom can be discriminated. High-frequency pulses are applied by a solenoid coil (43) and/or a surface coil (49) to the examinee's body (47) and a nuclear magnetic resonance signal therefrom is received to obtain the spatial distribution of information contained in the received signal. A static field generating means (34a, 34b, 34c) is constructed so that the static magnetic field is directed horizontal and the examinee's body is brought into and out of the static magnetic field perpendicularly thereto from the horizontal direction. The axis of the solenoid coil (43) crosses the static magnetic field perpendicularly thereto and is held horizontal, and the examinee's body can be positioned in the solenoid coil. The surface coil whose RF direction is vertical is disposed in adjacent relation to a target region of the examinee's body so that the nuclear magnetic resonance signal can also be received by the surface coil.
Inventors
- 👤 Hidea Toyoshima
- 👤 Masaya Yamashita
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-25 19:39
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/28; G01R33/32; G01R33/34; G01R33/341; G01R33/38; G01R33/383; G01R33/387; G01R33/3873
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
207 words
Apparatus for obtaining image information through use of a nuclear magnetic resonance signal, comprising: static field generating means (32) for generating a static magnetic field which is horizontal and perpendicularly intersects the longitudinal axis of an examinee's body (47); gradient field generating means (39) for generating in the static magnetic field a gradient magnetic field the intensity of which is graded in three intersecting directions (X, Y, Z) and the direction of which is parallel to the static magnetic field; a solenoid coil (43) provided in the static magnetic field with its axis held perpendicular to the direction of the static magnetic field; a surface coil (49) provided in the static magnetic field with its RF direction held vertical so that it is disposed near a region of the examinee's body (47) to be examined; a transmitting means (13) for applying high-frequency pulses to at least one of the solenoid coil (43) and the surface coil (49); receiving means (16, 17) for amplifying and detecting the nuclear magnetic resonance (NMR) signal from the examinee's body (47) received by at least one of the solenoid coil (43) and the surface coil (49); and computer means (19) for obtaining spatial distribution of information contained in the detected NMR signal.
Claim 2
Dependent Claim
207 words
Apparatus for obtaining image information through use of a nuclear magnetic resonance signal, comprising: static field generating means (32) for generating a static magnetic field which is horizontal and perpendicularly intersects the longitudinal axis of an examinee's body (47); gradient field generating means (39) for generating in the static magnetic field a gradient magnetic field the intensity of which is graded in three intersecting directions (X, Y, Z) and the direction of which is parallel to the static magnetic field; a solenoid coil (43) provided in the static magnetic field with its axis held perpendicular to the direction of the static magnetic field; a surface coil (49) provided in the static magnetic field with its RF direction held vertical so that it is disposed near a region of the examinee's body (47) to be examined; a transmitting means (13) for applying high-frequency pulses to at least one of the solenoid coil (43) and the surface coil (49); receiving means (16, 17) for amplifying and detecting the nuclear magnetic resonance (NMR) signal from the examinee's body (47) received by at least one of the solenoid coil (43) and the surface coil (49); and computer means (19) for obtaining spatial distribution of information contained in the detected NMR signal.
Claim 3
Dependent Claim
48 words
Apparatus according to claim 1 wherein the static field generating means (32) comprises a plurality of magnet rings (34a, 34b, 34c), each composed of a plurality of permanent magnet blocks (33) arranged in the form of a ring, the magnet rings being arranged coaxially in the horizontal direction.
Claim 4
Dependent Claim
49 words
Apparatus according to claim 2 wherein a gradient magnetic field coil (39) is disposed, as a gradient field generating means, inside the magnet rings (34a, 34b, 34c) and the solenoid coil (43) is disposed inside the gradient magnetic field coil (39) coaxially with the magnet rings (34a, 34b, 34c).
Claim 5
Dependent Claim
35 words
Apparatus according to claim 3 wherein a bobbin . (38) is disposed inside the magnet rings (34a, 34b, 34c) substantially coaxially therewith and the gradient magnetic field coil (39) is wound on the bobbin (38).
Claim 6
Dependent Claim
41 words
Apparatus according to claim 4 wherein a rail (42) is fixedly mounted in the bobbin (38) and a carriage (46) for carrying the examinee (47) is slidably mounted on the rail (42) in parallel to the axis of the bobbin (38).
Claim 7
Dependent Claim
51 words
Apparatus according to claim 5 wherein a slot (42S) is formed in the rail (42) to extend from the farthest end to the center thereof and the solenoid coil (43) is disposed inside the bobbin (38) with a circumferential part of the solenoid coil (43) is inserted in the slot (42S).
Claim 8
Dependent Claim
29 words
Apparatus according to claim 6, comprising plural pairs of ring frames (37a, 37b, 37c) disposed around the respective magnet rings (34a, 34b, 34c) for fixedly supporting the magnet rings.
Claim 9
Dependent Claim
79 words
Apparatus according to claim 7 further comprising radial position adjustment means (75, 89) disposed between each pair of the ring frames (59, 61) and attached thereto for adjusting the position of the magnet block (33) of each magnet ring (34a, 34b, 34c) in the radial direction of the ring and tangential position adjustment means (87, 88) mounted on each pair of the ring frames (59, 61) for adjusting the position of each magnet block (33) in its tangential direction.
Claim 10
Dependent Claim
32 words
Apparatus according to claim 8 further comprising skew adjustment means for adjusting the skew of each magnet block of each magnet ring about an axis in the radial direction of the ring.
Claim 11
Dependent Claim
58 words
Apparatus according to claim 9 wherein the tangential position adjustment means (87, 88) is provided at on both outer sides of each pair of the ring frames .(59, 61) in opposing relation to each other angular position corresponding to each magnet block (33) and these tangential adjustment means perform the function of the skew adjustment means as well.
Claim 12
Dependent Claim
39 words
Apparatus according to claim 8 wherein the radial position adjustment means (75, 891 for the inner one of the magnet rings (34b) is higher in the precision of adjustment than those for the outer magnet rings (34a, 34c) .
Claim 13
Dependent Claim
26 words
Apparatus according to claim 11 wherein the radial position adjustment means (75, 89) for the inner magnet ring (34b) is formed by a wedge mechanism (87).
Claim 14
Dependent Claim
55 words
Apparatus according to claim 1, wherein both the solenoid coil (43) and the surface coil (49) are connected to the receiving means (17) via a coil selecting means (16) for selectively supplying the received NMR signal from at least one of the solenoid coil (43) and the surface coil (49) to the receiving means (17).
Claim 15
Dependent Claim
17 words
Apparatus according to claim 1, wherein the surface coil (49) is of a solenoid type (Fig. 2B).
Claim 16
Dependent Claim
17 words
Apparatus according to claim 1, wherein the surface coil (49) is of a cone-shaped spiral (Fig. 2C).
Claim 17
Dependent Claim
62 words
Apparatus according to claim 1, wherein a carriage (46) is slidably mounted on a rail (42) extending into the static magnetic field in a horizontal direction perpendicular to the direction of the static magnetic field so as to bring the examinee's body (47) into and out of the static magnetic field and the surface coil (49) is mounted on the carriage (46).
References Cited (Backward Citations)
No citation records indexed.
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