EP0567794A2
Expired / Lapsed
EP
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Nuclear magnetic resonance imaging with high speed and interactive pulse sequence control
Assignee: Toshiba Corp
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Filing: 1993-03-31
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Granted: —
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Expires: 2013-03-31
Abstract
Abstract A nuclear magnetic resonance imaging capable of controlling a generation of a desired pulse sequence to be used interactively, realizing the adjustment of the pulse sequence easily and accurately, and realizing the high speed pulse sequence execution. The pulse sequence is automatically generated from a basic pulse sequence form and a parameter block storing the imaging parameters affected by the imaging conditions specified interavtively. The pulse sequence is then automatically adjusted to an optimum setting by simulating an execution of the pulse sequence by using simulated RF pulses, gradient magnetic fields, static magnetic field, and nuclear spin density distribution, according to the characteristic parameters measured in advance. In the actual execution of the pulse sequence, the event codes stored in the event memory of the sequence controller are decoded by a plurality of decoders in parallel, and the rewriting of the event memory is realized by using a rewriting table having entries specifying a manner of rewriting each slot of each entry in the event memory, and flags in the event memory indicating an appropriate rewriting table entry for each slot.
Inventors
- 👤 Shoichi Kanayama
- 👤 Yoshimoro Kassai
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 21:36
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/44; G01R33/48; G01R33/54; G01R33/56; G01R33/543; G01R33/546
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
106 words
A method for pulse sequence control in a nuclear magnetic resonance imaging, comprising the steps of: storing basic pulse sequence forms specifying pulse sequence parameters unaffected by imaging conditions for a plurality of pulse sequence types; selecting one of the basic pulse sequence forms corresponding to a desired pulse sequence type; storing parameter block containing pulse sequence parameters affected the imaging conditions; specifying desired imaging conditions to update the pulse sequence parameters in the parameter block; and automatically generating a desired pulse sequence from said one of the basic pulse sequence forms selected at the selecting step and the parameter block updated at the specifying step.
Claim 2
Dependent Claim
20 words
The method of claim 1, wherein at the specifying step, the desired imaging conditions are specified by an operator interactively.
Claim 3
Independent Claim
80 words
A method for pulse sequence control in a nuclear magnetic resonance imaging, comprising the steps of: measuring characteristic parameters affecting a pulse sequence; simulating an execution of the pulse sequence by using simulated RF pulses, simulated gradient magnetic fields, simulated static magnetic field, and simulated nuclear spin density distribution, according to the characteristic parameters measured at the measuring step; and automatically adjusting the pulse sequence to an optimum setting according to a result of a simulation at the simulating step.
Claim 4
Dependent Claim
42 words
The method of claim 3, wherein at the measuring step, the characteristic parameters includes system characteristic parameters related to an apparatus for the nuclear magnetic resonance imaging, and target characteristic parameters related to a target object of the nuclear magnetic resonance imaging.
Claim 5
Dependent Claim
48 words
The method of claim 3, wherein at the simulating step, the result of the simulation is obtained as a spin motion and an echo signal resulting from the simulated RF pulses, the simulated gradient magnetic fields, the simulated static magnetic field, and the simulated nuclear spin density distribution.
Claim 6
Dependent Claim
73 words
The method of claim 3, further comprising the steps of: storing event codes indicating events for realizing the execution of the pulse sequence; decoding a plurality of the event codes stored at the storing step by a plurality of decoder means in parallel; and controlling an apparatus for the nuclear magnetic resonance imaging by a sequence controller to carry out the events indicated the event codes decoded by said plurality of decoder means.
Claim 7
Dependent Claim
27 words
The method of claim 6, wherein at the decoding step, said plurality of decoder means pre-read a plurality of the event codes stored in the event memory.
Claim 8
Dependent Claim
21 words
The method of claim 6, wherein at the storing step, the event codes are stored in a plurality of event memories.
Claim 9
Dependent Claim
148 words
The method of claim 3, further comprising the steps of: storing event codes indicating events for realizing the execution of the pulse sequence in an event memory, each entry of the event memory having a time slot, an event code slot, and an argument slot; providing a rewriting table storing rewriting table entries specifying a manner of rewriting each one of the time slot, the event code slot, and the argument slot of each entry in the event memory; indicating an appropriate one of the rewriting table entries in the rewriting table for each one of the time slot, the event code slot, and the argument slot, in conjunction with the event memory; and rewriting any one of the time slot, the event code slot, and the argument slot of each entry in the event memory according to the corresponding rewriting table entry indicated at the indicating step.
Claim 10
Dependent Claim
68 words
The method of claim 9, wherein at the specifying step, the appropriate one of the rewriting table entries in the rewriting table for each one of the time slot, the event code slot, and the argument slot, is indicated in a form of a flag provided in the event memory in correspondence to said each one of the time slot, the event code slot, and the argument slot.
Claim 11
Independent Claim
122 words
An apparatus for pulse sequence control in a nuclear magnetic resonance imaging, comprising: basic pulse sequence form table means for storing basic pulse sequence forms specifying pulse sequence parameters unaffected by imaging conditions, for a plurality of pulse sequence types; parameter block means for storing pulse sequence parameters affected the imaging conditions; input means for selecting one of the basic pulse sequence forms corresponding to a desired pulse sequence type and specifying desired imaging conditions to update the pulse sequence parameters in the parameter block means; and pulse sequence generation means for automatically generating a desired pulse sequence from said one of the basic pulse sequence forms selected by the input means and the parameter block means updated by the input means.
Claim 12
Dependent Claim
19 words
The apparatus of claim 11, wherein the input means allows an operator to specify the desired imaging conditions interactively.
Claim 13
Independent Claim
89 words
An apparatus for pulse sequence control in a nuclear magnetic resonance imaging, comprising: measurement means for measuring characteristic parameters affecting a pulse sequence; simulator means for simulating an execution of the pulse sequence by using simulated RF pulses, simulated gradient magnetic fields, simulated static magnetic field, and simulated nuclear spin density distribution, according to the characteristic parameters measured by the measurement means; and pulse sequence adjustment means for automatically adjusting the pulse sequence to an optimum setting according to a result of a simulation obtained by the simulator means.
Claim 14
Dependent Claim
41 words
The apparatus of claim 13, wherein the measurementmeans measures the characteristic parameters including system characteristic parameters related to an apparatus for the nuclear magnetic resonance imaging, and target characteristic parameters related to a target object of the nuclear magnetic resonance imaging.
Claim 15
Dependent Claim
46 words
The apparatus of claim 13, wherein the simulator means obtains the result of the simulation as a spin motion and an echo signal resulting from the simulated RF pulses, the simulated gradient magnetic fields, the simulated static magnetic field, and the simulated nuclear spin density distribution.
Claim 16
Dependent Claim
79 words
The apparatus of claim 13, further comprising: event memory means for storing event codes indicating events for realizing the execution of the pulse sequence; a plurality of decoder means for decoding a plurality of the event codes stored in the event memory means in parallel; and sequence controller means for controlling an apparatus for the nuclear magnetic resonance imaging by a sequence controller to carry out the events indicated the event codes decoded by said plurality of decoder means.
Claim 17
Dependent Claim
24 words
The apparatus of claim 16, wherein said plurality of decoder means pre-read a plurality of the event codes stored in the event memory means.
Claim 18
Dependent Claim
48 words
The apparatus of claim 16, wherein the event memory means contains a plurality of event memories, such that the event codes for the pulse sequence as a whole is divided into a plurality of parts and each part is stored in one of said plurality of event memories.
Claim 19
Dependent Claim
153 words
The apparatus of claim 13, further comprising: event memory means for storing event codes indicating events for realizing the execution of the pulse sequence, each entry of the event memory means having a time slot, an event code slot, and an argument slot; rewriting table means for storing rewriting table entries specifying a manner of rewriting each one of the time slot, the event code slot, and the argument slot of each entry in the event memory means; indicator means for indicating an appropriate one of the rewriting table entries in the rewriting table for each one of the time slot, the event code slot, and the argument slot, in conjunction with the event memory; and means for rewriting any one of the time slot, the event code slot, and the argument slot of each entry in the event memory means according to the corresponding rewriting table entry indicated by the indicator means.
Claim 20
Dependent Claim
70 words
The apparatus of claim 19, wherein the indicator means for indicating the appropriate one of the rewriting table entries in the rewriting table for each one of the time slot, the event code slot, and the argument slot, is formed in a form of a flag provided in the event memory means in correspondence to said each one of the time slot, the event code slot, and the argument slot.
References Cited (Backward Citations)
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