EP0152069A2
Expired / Lapsed
EP
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Magnetic resonance imaging system
Assignee: Toshiba Corp
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Filing: 1985-02-07
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Granted: —
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Expires: 2005-02-07
Abstract
Abstract In a magnetic resonance imaging system, a reference sample (S1 or S2) made of material including predetermined atomic nuclei to be tomographed is disposed on the side of an object under inspection in a tomographing field (an area to be tomographed) of an MR image. In collecting projection data by detecting the MR signal, the magnitude of the projection data on the reference sample (S1 or S2) is detected. A substantial gain of an MR signal amplifying section is adjusted according to the detected magnitude.
Inventors
- 👤 Masatoshi C/O Patent Division Hanawa
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-24 11:48
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/28; G01R33/32; G01R33/36; G01R33/3621; G01R33/44; G01R33/48; G01R33/58
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
240 words
A magnetic resonance imaging system comprising: coil means (1, 3, 9) disposed around an imaging area in which an object (P) under inspection is placed; signal detecting means (2, 4, 6, 7, 8, 10) which cooperates with said coil means (1, 3, 9) to cause a magnetic resonance phenomenon in specific atomic nuclei in said imaging area and to detect magnetic resonance (MR) signals from a predetermined cross section in said imaging area; signal processing means for obtaining said projection data by applying a predetermined process to the MR signal detected by said signal detecting means (2, 4, 6, 7, 8, 10); image reconstructing means for obtaining image data based on the MR data on said cross section by applying an image reconstructing process to the projection data obtained by said signal processing means; a reference sample (Sl or S2) made of material including said specific atomic nuclei and disposed contiguous to said object and in said imaging area; detecting means for obtaining a value of the projection data on said reference sample from the output of said signal processing means; and gain adjust means for controlling one of said detecting means, said signal processing means and said image reconstructing means according to the value obtained by said detecting means, thereby to control a substantial gain in a processing system including said signal detecting means (2, 4, 6, 7, 8, 10), said signal processing means and said image reconstructing means.
Claim 2
Dependent Claim
240 words
A magnetic resonance imaging system comprising: coil means (1, 3, 9) disposed around an imaging area in which an object (P) under inspection is placed; signal detecting means (2, 4, 6, 7, 8, 10) which cooperates with said coil means (1, 3, 9) to cause a magnetic resonance phenomenon in specific atomic nuclei in said imaging area and to detect magnetic resonance (MR) signals from a predetermined cross section in said imaging area; signal processing means for obtaining said projection data by applying a predetermined process to the MR signal detected by said signal detecting means (2, 4, 6, 7, 8, 10); image reconstructing means for obtaining image data based on the MR data on said cross section by applying an image reconstructing process to the projection data obtained by said signal processing means; a reference sample (Sl or S2) made of material including said specific atomic nuclei and disposed contiguous to said object and in said imaging area; detecting means for obtaining a value of the projection data on said reference sample from the output of said signal processing means; and gain adjust means for controlling one of said detecting means, said signal processing means and said image reconstructing means according to the value obtained by said detecting means, thereby to control a substantial gain in a processing system including said signal detecting means (2, 4, 6, 7, 8, 10), said signal processing means and said image reconstructing means.
Claim 3
Dependent Claim
109 words
The apparatus according to claim 1, characterized in that said coil means includes a static magnetic field coil means (1) for generating a uniform static magnetic field, a first inclined magnetic field coil (3) means for generating a magnetic field inclination to specify a cross section to be tomographed, a second inclined magnetic field coil means (5) for generating a magnetic field inclination to specify a projecting direction, and a transmitting/receiving coil means (9) for applying a rotating magnetic field corresponding to the resonance frequency of said specific atomic nuclei in said imaging area and for receiving an MR signal caused by the application of the rotating magnetic field.
Claim 4
Dependent Claim
27 words
The apparatus according to claim 1, characterized in that said signal processing means includes Fourier transforming means for obtaining the projection data from said received MR signal.
Claim 5
Dependent Claim
36 words
The apparatus according to claim 1, characterized by further comprising a table (3) for supporting said object at the time of tomographing, said reference sanple being provided on a table board (14) of said table (13).
Claim 6
Dependent Claim
35 words
The apparatus according to claim 1, characterized by further comprising a head rest (15) for supporting the head of said object at the time of tomographing, said reference sample being provided to said headrest (15).
Claim 7
Dependent Claim
39 words
The apparatus according to claim 1, characterized in that said gain adjust means changes the substantial gain of said processing system by controlling the weighting on a plurality of pieces of the projection data in said image reconstructing means.
Claim 8
Dependent Claim
38 words
The apparatus according to claim 1, characterized in that said gain adjust means changes the substantial gain of a receiving processing system by controlling the detected gain by said signal detecting means (2, 4, 6, 7, 8, 10).
Claim 9
Dependent Claim
53 words
The apparatus according to claim 7, characterized in that said detecting means includes an amplifier for amplifying a received signal, and said gain adjusting means controls an amplifying gain on the detected signal in said amplifier to change the substantial detected gain of said signal detecting means (2, 4, 6, 7, 8, 10).
Claim 10
Dependent Claim
55 words
The apparatus according to claim 7, characterized in that said detecting means includes a detector circuit for detecting a received signal, and said gain adjust means controls a detecting gain on the detected signal in said detecting circuit, thereby to change the substantial detecting gain of said detecting means (2, 4, 6, 7, 8, 10).
Claim 11
Dependent Claim
30 words
The apparatus according to claim 1, characterized in that said gain adjust means changes the substantial gain of said receiving system by controlling a gain of said signal processing means.
Claim 12
Dependent Claim
75 words
The apparatus according to claim 10, characterized in that said signal processing means includes an A/D (analog to digital) converting means (lla) for A/D converting the detected signal, and a DFT (discrete Fourier transform) means (llb) for discrete Fourier transforming the A/D converted signal, and said gain adjust means controls a converting gain of said A/D converting means (lla) to change the substantial gain of said signal processing means (2, 4, 6, 7, 8, 10).
References Cited (Backward Citations)
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