EP0117725A2
Expired / Lapsed
EP
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Nuclear magnetic resonance diagnostic apparatus
Assignee: Toshiba Corp
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Filing: 1984-02-23
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Granted: —
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Expires: 2004-02-23
Abstract
Abstract @ Nuclear magnetic resonance diagnostic apparatus which forms an image of a slice of an object is described. The apparatus includes a circuit for detecting NMR signals induced from an object, having a resonance circuit formed by a receiving coil (31) which surrounds the object and a capacitor (32), peak-hold means (39) for receiving the NMR signals generated from the resonance circuit (31, 32) to retain the maximum value of the NMR signals in an excitation cycle of the sprins of the excited nuclei, and a synchronism device (42) for controlling the selection of the NMR signals in response to the value held by the peak-hold means being with a predetermined range of levels. The variation of the NMR signal level in accordance with the variation of floating capacitance of the resonance circuit, which alters according to the motion of the object, is thus used to detect the state of the objects movement and the NMR signals selected in a predetermined state of motion.
Inventors
- 👤 Tatsuhiko Kabushiki Kaisha Toshiba Kawachi
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 16:09
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/44; G01R33/48; G01R33/54; G01R33/56; G01R33/567; G01R33/5673
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
232 words
A nuclear magnetic resonance diagnostic apparatus for examining an object, comprising: means (31, 32, 33) for detecting nuclear magnetic resonance signal from nuclear magnetic resonance phenomena which are induced in the object by magnetically exciting the spins of specific atomic nuclei, under gradient magnetic fields in a variety of directons in a slice of the object, including a resonant circuit (31, 32) having a receiving coil (31) about the object and a capacitor (32); means (36) for Fourier transforming the nuclear magnetic resonance signals to obtain projection data of the spin density distribution of the specific atomic nuclei in the various directions, whereby an image of the spin density distribution of said specific atomic nuclei in the slice can be formed from said projection data; peak hold means (36, 39) for receiving the nuclear magnetic resonant signals from the resonant circuit, the level of which will vary with the floating capacitance of the resonant ciruit and which the capacitance alters with movement of the object, and retaining a maximum value of the nuclear magnetic resonance signals received during an excitation cycle of said spins; and means (36, 42) for controlling selection of the nuclear magnetic resonance .signals in response to the value retained by the peak-hold means (36, 39) being within a predetermined range of levels, whereby the selected nuclear magnetic resonance signals correspond to a predetermined state of the object's motion.
Claim 2
Dependent Claim
232 words
A nuclear magnetic resonance diagnostic apparatus for examining an object, comprising: means (31, 32, 33) for detecting nuclear magnetic resonance signal from nuclear magnetic resonance phenomena which are induced in the object by magnetically exciting the spins of specific atomic nuclei, under gradient magnetic fields in a variety of directons in a slice of the object, including a resonant circuit (31, 32) having a receiving coil (31) about the object and a capacitor (32); means (36) for Fourier transforming the nuclear magnetic resonance signals to obtain projection data of the spin density distribution of the specific atomic nuclei in the various directions, whereby an image of the spin density distribution of said specific atomic nuclei in the slice can be formed from said projection data; peak hold means (36, 39) for receiving the nuclear magnetic resonant signals from the resonant circuit, the level of which will vary with the floating capacitance of the resonant ciruit and which the capacitance alters with movement of the object, and retaining a maximum value of the nuclear magnetic resonance signals received during an excitation cycle of said spins; and means (36, 42) for controlling selection of the nuclear magnetic resonance .signals in response to the value retained by the peak-hold means (36, 39) being within a predetermined range of levels, whereby the selected nuclear magnetic resonance signals correspond to a predetermined state of the object's motion.
Claim 3
Dependent Claim
80 words
A nuclear magnetic resonance diagnostic apparatus as claimed in claim 1 wherein the means for controlling selection of the nuclear magnetic resonance signals has synchronism means (42) for receiving an output rom the peak-hold means, and for issuing a control signal when the value of output from the peak-hold means is within the predetermined range of levels, and means (36) for picking up the detected nuclear magnetic resonance signals in response to the control signal from the synchronism means (42).
Claim 4
Dependent Claim
59 words
A nuclear magnetic resonance diagnustic apparatus as claimed in claim 1 or 2, wherein the means (42) is for controlling selection arranged to receive an electrocardiographic signal (91.g), and the selection of the nuclear magnetic resonance signal takes place in response to the value of the detected nuclear magnetic resonance signal and a selected one of the electrocardiographic signals.
Claim 5
Dependent Claim
63 words
A nuclear magnetic resonance diagnostic apparatus as claimed in claim 1, wherein the means for Fourier transforming (36), the peak-hold means (36), and the means (36) for controlling selection of the nuclear magnetic resonance singlas, are constituted by data processing means (36) which oprate to receive the detected nuclear magnetic resonance signals and to store the selected nuclear magnetic resonance signals for processing.
Claim 6
Dependent Claim
34 words
A nuclear magnetic resonance diagnostic apparatus as claimed in any oen of claims 1 to 4 wherein the range of predetemined levels are selected in relation to the resiratory motion of a living animal.
References Cited (Backward Citations)
No citation records indexed.
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