Patent EP0103397A2 successfully refreshed from Google Patents.
EP0103397A2
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EP
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Nuclear magnetic resonance imaging method
Assignee: BTG International Ltd
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Filing: 1983-08-08
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Granted: —
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Expires: 2003-08-08
Abstract
Abstract A method of deriving three dimensional image information from an object using nuclear magnetic resonance signals is described. The method comprises subjecting the object to a continuous, static magnetic field and carrying out the following set of sequential steps. 1. Exciting nuclear spins in a volume; 2. applying non-aligned first (G x (2) ), second (G y (2) ) and third (G z (2) ) gradients of the magnetic field; 3. causing the spins to rephase periodically in the presence of the first gradient (G x (3) ) ; 4. phase encoding the spins in the direction of the second gradient (G y (3) ) prior to every read-out of the rephased FIS from the object; and then successively repeating the above set of steps with different values of gradient of the third gradient (G z (2) ), there being a recovery interval between the repetition of successive sets of steps.
Inventors
- 👤 Glyn Johnson
- 👤 James Macdonald Strachan Hutchison
- 👤 Linda Mary Eastwood
- 👤 Thomas William Tennant Redpath
- 👤 John Rowland Mallard
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-25 07:11
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/44; G01R33/48; G01R33/4818; G01R33/482; G01R33/4822; G01R33/54; G01R33/56; G01R33/561; G01R33/5615; G01R33/5616
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
143 words
A method of deriving three dimensional image information from an object using nuclear magnetic resonance signals, the method comprising subjecting the object to a continuous, static magnetic field and carrying out a set of sequential steps which comprise: 1. exciting nuclear spins in a volume; 2. applying non-aligned first (G x ), second (G y ), and third (G z ) gradients of the magnetic field; 3. causing the spins to rephase periodically in the presence of the first gradient (G x ) ; 4. phase encoding the spins in the direction of the second gradient (G ) prior to every read-out of the rephased FIS from the object; and then successively repeating the above set of steps with different values of gradient of the third gradient (G z ), there being a recovery interval between the repetition of successive sets of steps.
Claim 2
Independent Claim
143 words
A method of deriving three dimensional image information from an object using nuclear magnetic resonance signals, the method comprising subjecting the object to a continuous, static magnetic field and carrying out a set of sequential steps which comprise: 1. exciting nuclear spins in a volume; 2. applying non-aligned first (G x ), second (G y ), and third (G z ) gradients of the magnetic field; 3. causing the spins to rephase periodically in the presence of the first gradient (G x ) ; 4. phase encoding the spins in the direction of the second gradient (G ) prior to every read-out of the rephased FIS from the object; and then successively repeating the above set of steps with different values of gradient of the third gradient (G z ), there being a recovery interval between the repetition of successive sets of steps.
Claim 3
Dependent Claim
25 words
A method according to claim 1, wherein the first (G x ), second (G y ), and third (G z ) gradients are mutually orthogonal.
Claim 4
Dependent Claim
36 words
A method according to claim 1 or claim 2, wherein the first (G x ), second (G y ), and third (G z ) gradients of the magnetic field are applied simultaneously in step number 2.
Claim 5
Independent Claim
44 words
A method according to any of the preceding claims, wherein step number 4 comprises encoding the spins in the direction of the second gradient (G ) prior to every alternate rephasing of the spins in the presence of the first gradient (G x ).
Claim 6
Independent Claim
54 words
A method according to any of claims 1 to 3, wherein step number 4 comprises encoding the spins in the direction of the second gradient (G ) prior to every rephasing of the spins in the presence of the first gradient (G x ), account being taken of the time reversal of successive echoes.
Claim 7
Independent Claim
26 words
A method according to any of the preceding claims, wherein step number 4 is carried out by successive applications of the second gradient (G y ).
Claim 8
Dependent Claim
26 words
A method according to claim 6, wherein the time integral of each application of the second gradient (G ) in step number 4 is the same.
Claim 9
Independent Claim
42 words
A method according to any of the preceding claims, wherein step number 1 comprises exciting nuclear spins in the presence of a selection of gradient (G y ) of the magnetic field which has a gradient direction perpendicular to a selected slab.
Claim 10
Dependent Claim
19 words
A method according to claim 8, further comprising reversing the direction of the selection gradient to rephase the spins.
Claim 11
Dependent Claim
27 words
A method according to claim 8 or claim 9, wherein step number 1 is achieved by applying a 90° pulse in the presence of the selection gradient.
References Cited (Backward Citations)
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