Patent EP0259998A2 successfully refreshed from Google Patents.
EP0259998A2
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EP
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Methods of imaging solids by NMR techniques
Assignee: BTG International Ltd
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Filing: 1987-08-20
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Granted: —
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Expires: 2007-08-20
Abstract
Abstract A sequence of a pair of r.f. pulses (90 x ° and 90 y °) is applied to a solid being imaged with a time interval (τ) after each pulse. A static magnetic field is maintained and a magnetic gradient field is superimposed in the said time intervals, the time integrals of the gradient magnitudes of the gradient fields being equal. A free induction solid echo signal is detected at the end of the second time interval. The sequence is repeated for different values of the time integral are to obtain a set of signals and Fourier transformations with respect to the said time integral are then carried out on the set to obtain one-dimensional information. Two-dimensional information can be obtained from a plurality of sets of signals, each set being obtained in the presence of an additional orthogonal gradient field of differing value for each set.
Inventors
- 👤 Peter John Mcdonald
- 👤 John Joseph Attard
- 👤 David Graham Taylor
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 06:18
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/44; G01R33/48; G01R33/4816
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
111 words
A method of providing NMR imaging information of solids comprising the steps of applying in the presence of a static magnetic field two successive resonant r. f. pulses, said pulses being each followed by time intervals in which a gradient magnetic field is superimposed on said static magnetic field and the time integrals of the gradient magnitudes of said gradient fields being equal, detecting the resultant free induction solid echo signal after said second time interval, repeating said steps with different values of said time integral to obtain a set of signals and then carrying out Fourier transformations with respect to the said time integral on the said set of signals.
Claim 2
Independent Claim
111 words
A method of providing NMR imaging information of solids comprising the steps of applying in the presence of a static magnetic field two successive resonant r. f. pulses, said pulses being each followed by time intervals in which a gradient magnetic field is superimposed on said static magnetic field and the time integrals of the gradient magnitudes of said gradient fields being equal, detecting the resultant free induction solid echo signal after said second time interval, repeating said steps with different values of said time integral to obtain a set of signals and then carrying out Fourier transformations with respect to the said time integral on the said set of signals.
Claim 3
Dependent Claim
21 words
The method as claimed in Claim 1 in which at least the first of said r.f. pulses is a 90° pulse.
Claim 4
Dependent Claim
40 words
The method as claimed in Claim 1 or Claim 2 in which both pulses of a pair are 90° pulses of relative phase quadrature and the respective gradient magnetic fields after each pulse have their gradients in the same direction.
Claim 5
Dependent Claim
62 words
The method as claimed in Claim 1 or Claim 2 in which the first of said r.f. pulses is a 90° pulse and the second of said rf pulses is a 180° pulse and the gradient magnetic field applied during the second time interval has its gradient in the opposite direction to the gradient magnetic field applied during the first time interval.
Claim 6
Independent Claim
26 words
The method as claimed in any one of the preceding claims in which the gradient magnetic fields have the same amplitude during both said time intervals.
Claim 7
Dependent Claim
35 words
The method as claimed in Claim 3 and Claim 5 in which the gradient magnetic field is maintained at the same amplitude and direction during both said time intervals and while said pulses are applied.
Claim 8
Independent Claim
22 words
The method as claimed in any one of the preceding claims in which the gradient magnetic fields are each of constant value.
Claim 9
Independent Claim
25 words
The method as claimed in any one of Claims 1 to 5 in which the magnetic gradient fields are substantially sinusoidal with respect to time,
Claim 10
Independent Claim
23 words
The method as claimed in any one of the preceding claims in which a preliminary 180° pulse is applied without a gradient field.
Claim 11
Independent Claim
68 words
The method as claimed in any one of the preceding claims in which a plurality of sets of signals are obtained, each set being obtained with the application of an additional magnetic gradient field which is orthogonal to the aforesaid gradient magnetic fields and is applied simultaneously therewith, the time integral of the gradient of the said additional field having a different value for each set of signals.
References Cited (Backward Citations)
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