Microcode linker/loader that generates microcode sequences for MRI sequencer by modifying previously generated microcode sequences
First Claim
1. In a magnetic resonance imaging system of the type including a magnetic field generator, an RF field generator, an RF receiver, a data acquisition subsystem, and a control sequencer, said magnetic field generator and said RF field generator cooperating to stimulate nuclear magnetic resonance phenomena within an object to be imaged, said RF receiver receiving NMR signals produced by said nuclear magnetic resonance phenomena, said data acquisition subsystem acquiring digitized signals, said control sequencer controlling at least one of said magnetic field generator, said RF field generator and said data acquisition subsystem, said control sequencer having a control store for storing and accessing instructions for execution,a method of efficiently and rapidly generating instructions for execution by said control sequencer,said method comprising:
- (a) generating a sequencer control store memory image including sequencer instructions, said instructions including first parameters that define a first projection;
(b) loading said sequencer control store memory image, including said first projection parameters, into said sequencer control store;
(c) executing, with said sequencer, said sequencer control store memory image loaded into said sequencer control store by said loading step (b);
(d) controlling, with said sequencer, said magnetic field generator and/or said RF field generator in response to execution of said sequencer control store memory image by said executing step (c) so as to stimulate nuclear magnetic resonance phenomena within said object;
(e) acquiring, with said RF receiver and said data acquisition subsystem, first NMR signals emitted by said nuclear magnetic resonance phenomena stimulated by said controlling step (d);
(f) reusing said sequencer control store memory image by rapidly replacing said first projection parameters within said sequencer control store memory image with second projection parameters defining a second projection to create an altered sequence control store memory image, and loading said altered sequencer control store memory image, including said second projection parameters, into said sequencer control store;
(g) executing, with said control sequencer, said altered sequencer control store memory image loaded by said reusing step (f);
(h) controlling, with said sequencer, said magnetic field generator and/or said RF field generator in response to execution of said altered memory image by said executing step (g) so as to stimulate nuclear magnetic resonance phenomena within said object;
(i) acquiring, with said RF receiver and said data acquisition subsystem, second NMR signals emitted by said nuclear magnetic resonance phenomena stimulated by said controlling step (h); and
(j) generating an image of said object based at least in part on said first and second NMR signals acquired by said steps (e) and (i).
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Accused Products
Abstract
An extremely fast and efficient Linker for a Magnetic Resonance Imaging (MRI) system Nuclear Magnetic Resonance (NMR) pulse control sequencer efficiently derives subsequent blocks of microcode to be loaded by using the contents of a memory buffer containing previously loaded microcode as a template, Most of the template is reused "as is". Only the relatively few field values in the microinstructions which change from one signal generation process, or cycle, to the next are replaced with new values. Offsets are tabulated of instructions which have associated multi-entry cycle indexed program change table (PCT) values. When further code is to be linked and loaded, the linker accesses the PCTs based on the table and to inserts new values into the appropriate instruction fields. The microcode memory image may be continuously maintained in a host memory buffer and re-edited successive times. The Fast Linker provided by the present invention is capable of continually loading microcode into a sequencer writable control store, and is fast enough to run under a time shared operating system at the same time a higher priority data acquisition and display process is executing.
48 Citations
64 Claims
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1. In a magnetic resonance imaging system of the type including a magnetic field generator, an RF field generator, an RF receiver, a data acquisition subsystem, and a control sequencer, said magnetic field generator and said RF field generator cooperating to stimulate nuclear magnetic resonance phenomena within an object to be imaged, said RF receiver receiving NMR signals produced by said nuclear magnetic resonance phenomena, said data acquisition subsystem acquiring digitized signals, said control sequencer controlling at least one of said magnetic field generator, said RF field generator and said data acquisition subsystem, said control sequencer having a control store for storing and accessing instructions for execution,
a method of efficiently and rapidly generating instructions for execution by said control sequencer, said method comprising: -
(a) generating a sequencer control store memory image including sequencer instructions, said instructions including first parameters that define a first projection; (b) loading said sequencer control store memory image, including said first projection parameters, into said sequencer control store; (c) executing, with said sequencer, said sequencer control store memory image loaded into said sequencer control store by said loading step (b); (d) controlling, with said sequencer, said magnetic field generator and/or said RF field generator in response to execution of said sequencer control store memory image by said executing step (c) so as to stimulate nuclear magnetic resonance phenomena within said object; (e) acquiring, with said RF receiver and said data acquisition subsystem, first NMR signals emitted by said nuclear magnetic resonance phenomena stimulated by said controlling step (d); (f) reusing said sequencer control store memory image by rapidly replacing said first projection parameters within said sequencer control store memory image with second projection parameters defining a second projection to create an altered sequence control store memory image, and loading said altered sequencer control store memory image, including said second projection parameters, into said sequencer control store; (g) executing, with said control sequencer, said altered sequencer control store memory image loaded by said reusing step (f); (h) controlling, with said sequencer, said magnetic field generator and/or said RF field generator in response to execution of said altered memory image by said executing step (g) so as to stimulate nuclear magnetic resonance phenomena within said object; (i) acquiring, with said RF receiver and said data acquisition subsystem, second NMR signals emitted by said nuclear magnetic resonance phenomena stimulated by said controlling step (h); and (j) generating an image of said object based at least in part on said first and second NMR signals acquired by said steps (e) and (i). - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 61)
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24. A magnetic resonance imaging system for generating an image of an object, said system including:
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a magnetic field generator; an RF field generator cooperating with said magnetic field generator to stimulate nuclear magnetic resonance phenomena within said object; a data acquisition subsystem for acquiring digitized NMR signals; a control sequencer for controlling at least one of said magnetic field generator, said RF field generator and said data acquisition subsystem, said control sequencer having a control store for storing and accessing instructions for execution by said sequencer; a host computer including a computer memory, said host computer performing the following functions; (a) generating a first block of sequencer instructions including first parameters that define a first projection, (b) storing said first block of sequencer instructions within said computer memory, (c) loading said first block of sequencer instructions, including said first projection parameters, into said sequencer control store, (d) rapidly altering said first block of instructions stored within said computer memory by maintaining said first block but replacing said stored first projection parameters with second projection parameters defining a second projection, and (e) loading said altered first block of sequencer instructions, including said second projection parameters, into said control sequencer control store; said sequencer including a processor that executes said first block of sequencer instructions and said altered first block of sequencer instructions out of said sequencer control store, and controls said magnetic field generator and/or said RF field generator in response to said execution so as to stimulate nuclear magnetic resonance phenomena within said object, said stimulated phenomena generating NMR signals; a receiver and said data acquisition subsystem cooperating to receive and acquire at least first NMR signals corresponding to said first projection and second NMR signals corresponding to said second projection; and a display coupled to said data acquisition subsystem that generates an image of said object based on said acquired first and second NMR signals. - View Dependent Claims (25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44)
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45. In a magnetic resonance imaging system for imaging an object, said system including:
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(i) a magnetic field generator, (ii) an RF field generator, (iii) a data acquisition subsystem, (iv) a digital sequencer coupled to said magnetic field generator, said RF field generator, and said data acquisition subsystem, said sequencer including a sequencer memory for storing instructions, (v) an RF receiver, (vi) a display device, and (vii) a digital computing arrangement coupled to said sequencer, said digital computing arrangement including a buffer, a method of efficiently generating and supplying instructions to said sequencer memory comprising the following steps; (A) storing a set of sequencer instructions in said buffer; (B) generating a first set of projection-specific parameters corresponding to a first plurality of slices of said object; (C) writing said first set of projection-specific parameters into said buffer as parameters for at least some of said set of stored sequencer instructions; (D) copying said stored sequencer instructions including said first set of slice-specific parameters from said buffer to said sequencer memory; (E) executing said instructions including said first set of slice-specific parameters with said sequencer from said sequencer memory to control at least one of said magnetic field generator and said RF field generator; (F) receiving NMR signals corresponding to said first plurality of slices of said object with said RF receiver and digitizing them with said data acquisition subsystem; (G) generating a further set of slice-specific parameters corresponding to a further plurality of slices of said object; (H) reusing said set of said stored sequencer instructions by;
(h1) replacing said first set of stored projection specific values with said further set of projection specific values, and (h2) copying said set of sequencer instructions including said further set of projection specific parameters from said buffer to said sequencer memory;(I) executing said instructions copied by said reusing step (H) including said further set of projection specific parameters from said sequencer memory with said sequencer to control at least one of said magnetic field generator and said RF field generator; (J) receiving NMR signals corresponding to said further plurality of slices with said RF receiver and said data acquisition subsystem; and (K) generating, on said display device, an image based on said received NMR signals. - View Dependent Claims (46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60)
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62. In a magnetic resonance imaging system including:
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a magnetic field generator; an RF field generator cooperating with said magnetic field generator to stimulate nuclear magnetic resonance phenomena within an object to be imaged; a control sequencer for controlling in real time at least one of said magnetic field generator and said RF field generator, said control sequencer including a control store for storing and accessing instructions for execution by said sequencer; an RF receiver for receiving NMR signals; a data acquisition subsystem; and a display that displays an image based at least in part on said received NMR signals, a method of linking microcode for execution by said control sequencer, said method comprising; (1) creating a data structure having elements locating, within a first sequencer instruction block, at least one value dependent on an outer loop index; (2) creating a first sequencer control store memory image template by successively copying said first instruction block; (3) accessing said data structure elements; (4) rapidly locating and resolving outer loop index dependent values within said first template based at least in part on said accessed data structure elements; (5) creating a second sequencer control store memory image template by successively copying said first instruction block; (6) rapidly locating and resolving outer loop index dependent values within said second template based at least in part on said accessed data structure elements; (7) loading said first and second control store memory images into said sequencer control store; (8) executing said loaded first and second control store memory images with said sequencer; (9) controlling said magnetic and RF field generators based on said executing step to generate fields stimulating NMR phenomena within said object to be imaged; (10) receiving NMR signals with said RF receiver; (11) digitizing said received NMR signals with said data acquisition subsystems; and (12) generating at least one image on said display based on said digitized received NMR signals.
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63. A magnetic resonance imaging method comprising:
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(1) providing a data structure having elements locating, within a first instruction block, at least one value dependent on an outer loop index; (2) creating a first sequencer control store memory image template by replicating said first instruction block; (3) rapidly locating within said first template and resolving outer loop index dependent values based at least in part on said data structure elements; (4) creating a second sequencer control store memory image template by replicating said first instruction block; (5) rapidly locating within said second template and resolving outer loop index dependent values based at least in part on said data structure elements; (6) loading said first and second templates into a sequencer control store; (7) executing instructions within said loaded templates with a sequencer coupled to said control store; (8) controlling, in real time, generation of a magnetic field based on said sequencer execution; (9) controlling, in real time, generation of an RF field based on said sequencer execution; (10) receiving NMR signals generated in response to said magnetic and RF fields; (11) acquiring and digitizing said received NMR signals, and (12) displaying an image based at least in part on said digitized acquired NMR signals.
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64. Magnetic resonance imaging apparatus comprising:
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a main memory; a sequencer having a control store; means coupled to said main memory for generating a first block of sequencer instructions and for storing said first block within said main memory; data structure generating means coupled to said main memory for creating a data structure having elements locating, within said first instruction block, at least one value dependent on an outer loop index; replicating means coupled to said main memory for creating first and second sequencer control store memory image templates by replicating and storing, in said main memory, said first instruction block; linking means, coupled to said main memory and coupled to receive said data structure, for rapidly locating within said first and second templates and resolving outer loop index dependent values based at least in part on said data structure elements to produce first and second sequencer memory images; loading means coupled to said linking means for loading said first and second sequencer memory images into said sequencer control store, wherein said sequencer further includes; executing means coupled to said control store for executing instructions within said first and second sequencer memory images loaded into said sequencer control store, means coupled to said executing means for controlling generation of a magnetic field based on said sequencer execution, and means coupled to said executing means for controlling generation of an RF field based on said sequencer execution, wherein said apparatus further comprises; an RF receiver that receives NMR signals generated in response to said magnetic and RF fields; a data acquisition subsystem that digitizes and acquires said received NMR signals; and a display coupled to said data acquisition subsystem for displaying an image based at least in part on said received digitized and acquired NMR signals.
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Specification