Patent US4588948A successfully refreshed from Google Patents.
US4588948A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Nuclear magnetic resonance methods
Assignee: Individual
•
Filing: 1983-10-04
•
Granted: 1986-05-13
•
Expires: 2003-10-04
Abstract
Abstract A method of investigating a body by nuclear magnetic resonance comprising preferentially exciting resonance in a slice of the body, applying a magnetic field to the body having first and second gradients (Gx, Gy) in different directions in the slice with both the gradients being periodically reversed at regular intervals, detecting the free induction decay signals occurring when the gradients are applied and processing the detected signals to retrieve data. The method is an adaptation of the echo-planar technique suitable for obtaining chemical shift information.
Inventors
- 👤 Peter Mansfield
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 03:06
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/44; G01R33/48; G01R33/483; G01R33/485; G01R33/54; G01R33/56; G01R33/561; G01R33/5615; G01R33/5616
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
101 words
A method of investigating a body by NMR comprising the steps of: exciting resonance in a selected slice of the body; subsequently applying a magnetic field to said body having first and second gradients in different directions in said slice, both said gradients being periodically reversed at regular intervals with their periods of reversal being coordinated such that the period of reversal of one of said gradients is a multiple of the period of reversal of the other of said gradients; detecting the free induction decay signals occurring when said gradients are applied; and processing the detected signals to retrieve data.
Claim 2
Independent Claim
101 words
A method of investigating a body by NMR comprising the steps of: exciting resonance in a selected slice of the body; subsequently applying a magnetic field to said body having first and second gradients in different directions in said slice, both said gradients being periodically reversed at regular intervals with their periods of reversal being coordinated such that the period of reversal of one of said gradients is a multiple of the period of reversal of the other of said gradients; detecting the free induction decay signals occurring when said gradients are applied; and processing the detected signals to retrieve data.
Claim 3
Dependent Claim
41 words
A method of investigating a body by NMR according to claim 1 wherein said steps are executed a second time with one of the gradients starting with opposite polarity with respect to that obtaining in the first execution of said steps.
Claim 4
Dependent Claim
18 words
A method according to claim 1 wherein the respective directions of the two gradients are at right angles.
Claim 5
Dependent Claim
55 words
A method according to claim 1 wherein excitation of resonance in said slice is effected by application of a selective RF pulse in the presence of a first magnetic field gradient pulse followed by a nonselective 180° RF pulse and a further field gradient pulse of the same polarity as the first field gradient pulse.
Claim 6
Dependent Claim
42 words
A method of investigating a body by NMR according to claim 1 wherein said steps are carried out four times with a respective different combination of the starting polarities of said first and second gradients each time said steps are carried out.
References Cited (Backward Citations)
US4021726A
Cited
US4115730A
Cited
GB1580787A
Cited
GB1596160A
Cited
US4290019A
Cited
US4318043A
Cited
DE2920549A1
Cited
US4339716A
Cited
GB2057142A
Cited
US4361807A
Cited
EP0024640A1
Cited
GB2079463A
Cited
EP0076054A1
Cited
GB2107469A
Cited
US4509015A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-05-12 | 1989-11-11 | 1990-05-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-05-12 | 1993-11-11 | 1994-05-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-05-12 | 1997-11-11 | 1998-05-13 | $7700.00 | Window Closed / Lapsed |