EP0143602A2
Expired / Lapsed
EP
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Nuclear magnetic resonance methods and apparatus
Assignee: Philips Design Ltd
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Filing: 1984-11-21
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Granted: —
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Expires: 2004-11-21
Abstract
Abstract (57) A method and apparatus for NMR imaging a selected elongated region of a body wherein different portions of the elongated region respectively defined by the intersection of a number of discrete first slices perpendicular to the region with a second slice containing the whole region are imaged in turn. Each portion is imaged by exciting spins in one of the first slices (B1 (90), Giz, -Giz) and then rotating through 180° any spins in the second slice (B2 (90), B3 (90), -Gy, Gy), the resulting spin echo of spins in the region of intersection of the first and second slices being then suitably encoded (Gx, G 2Z ) and detected. The method and apparatus find particular application for imaging the spine of a patient.
Inventors
- 👤 Ian Robert Young
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-28 23:59
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/44; G01R33/48; G01R33/483; G01R33/4833; G01R33/4835
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
166 words
A method for investigating the distribution of a quantity in a selected elongated region of a body using NMR techniques characterised by the steps of: (1) exciting nuclear magnetic spins preferentially in first selected slice of the body extending generally perpendicular to the length of said region ard containing a portion of the length of said region (B1, Giz, -Giz); (2) rotating through 180° the nuclear magnetic spins in a second selected slice of the body containing substantially the whole length of said region and intersecting said first slice (B2, B3, -Gy, Gy); (3) encoding the spins occurring in the portion of said first slice intersected by said second slice (Gx, G z) and detecting and processing to retrieve data signals representative of said encoded spins; and (4) repeating steps (1), (2) and (3) a plurality of times, the selected first slice for each step (1) being for a different slice of the body and hence containing a different portion of the length of said region.
Claim 2
Independent Claim
166 words
A method for investigating the distribution of a quantity in a selected elongated region of a body using NMR techniques characterised by the steps of: (1) exciting nuclear magnetic spins preferentially in first selected slice of the body extending generally perpendicular to the length of said region ard containing a portion of the length of said region (B1, Giz, -Giz); (2) rotating through 180° the nuclear magnetic spins in a second selected slice of the body containing substantially the whole length of said region and intersecting said first slice (B2, B3, -Gy, Gy); (3) encoding the spins occurring in the portion of said first slice intersected by said second slice (Gx, G z) and detecting and processing to retrieve data signals representative of said encoded spins; and (4) repeating steps (1), (2) and (3) a plurality of times, the selected first slice for each step (1) being for a different slice of the body and hence containing a different portion of the length of said region.
Claim 3
Dependent Claim
63 words
A method according to Claim 1 wherein said rotation through 180° is effected by applying two 90 0 RF pulses (B2, B3) in succession together with respective gradients (-Gy, Gy) on a magnetic field (Bo) defining an equilibrium axis of magnetic alignment in the body being investigated, said gradients (-Gy, Gy) being respectively directed in opposite directions perpendicular to said second selected slice.
Claim 4
Dependent Claim
41 words
A method according to Claim 1 or Claim 2 wherein for each said first selected slice steps (1), (2) and (3) are carried out a plurality of times with a different encoding magnetic field gradient (Gx) applied during each step (3).
Claim 5
Independent Claim
188 words
An apparatus for investigating the distribution of a quantity in a selected region of a body using NMR techniques characterised by means (1,7,9,11,17,19, 21,25,27,29) arranged to excite nuclear magnetic spins preferentially in any selected one of a plurality of substantially discrete first slices of the body extending generally perpendicular to the length of said region and containing a portion of the length of said region; means (1,3 or 5,7,9,11,13 or 15,19,21,23,27, 29) arranged to rotate through 180° the nuclear magnetic spins in a second selected slice of the body containing substantially the whole length of said region and intersecting said first slices; means (3 or 5,7,13 or 15,17,23,25,29) arranged to encode the spins occurring in the portion of any said selected first slice intersected by said second slice; a plurality of detector means (10) each positioned adjacent a different one of said first slices to produce signals representative of the spins therein; processing means (35,37,29) arranged to retrieve data from signals produced by said detector means; and switching means (43) operable to supply to said processing means the signals detected by any selected one of said detector means.
Claim 6
Independent Claim
188 words
An apparatus for investigating the distribution of a quantity in a selected region of a body using NMR techniques characterised by means (1,7,9,11,17,19, 21,25,27,29) arranged to excite nuclear magnetic spins preferentially in any selected one of a plurality of substantially discrete first slices of the body extending generally perpendicular to the length of said region and containing a portion of the length of said region; means (1,3 or 5,7,9,11,13 or 15,19,21,23,27, 29) arranged to rotate through 180° the nuclear magnetic spins in a second selected slice of the body containing substantially the whole length of said region and intersecting said first slices; means (3 or 5,7,13 or 15,17,23,25,29) arranged to encode the spins occurring in the portion of any said selected first slice intersected by said second slice; a plurality of detector means (10) each positioned adjacent a different one of said first slices to produce signals representative of the spins therein; processing means (35,37,29) arranged to retrieve data from signals produced by said detector means; and switching means (43) operable to supply to said processing means the signals detected by any selected one of said detector means.
Claim 7
Dependent Claim
63 words
An apparatus according to Claim 4 wherein said means arranged to rotate through 180° comprises means arranged to apply two 90° RF pulses (B2, B3) in succession together with respective gradients (-Gy, Gy) on a magnetic field defining an equilibrium axis of magnetic alignment in the body being investigated, said gradients being respectively directed in opposite directions perpendicular to said second selected slice.
Claim 8
Dependent Claim
19 words
An apparatus according to Claim 4 or Claim 5 wherein each said detector means comprises a respective coil (10).
References Cited (Backward Citations)
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