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EP0390175A2 Expired / Lapsed EP ⏱️ 0.0 years remaining

Multi-echo NMR imaging method

Assignee: Hitachi Ltd
•
Filing: 1990-03-29
•
Granted: —
•
Expires: 2010-03-29
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Abstract

Abstract A multi-echo NMR imaging method of obtaining images separated from each other with respect to two kinds of chemical shifts, typically, a fat image and a water image, includes performing the measurement of an object to be examined through a multi-echo sequence (Fig. 1A-1F) in which phase differences of ϑ₁ ≠ nπ and ϑ₂ = 2nπ (n = ±1, ±2, ---) are respectively produced for first and second echoes between two kinds of spins to be separated from each other, deriving first and second complex images {equation (2)} from the first and second echoes, respectively, correcting the phase of the first image by converting a phase distribution of the second image into a distribution of phase error components contained in the first image which are caused by a static magnetic field inhomogeneity, and obtaining separative images for the two kinds of spins from real and imaginary parts of the first image corrected.

Inventors

  • 👤 Tatsuo Hitachi Daini Kyoshinryo Nozokido
  • 👤 Etsuji Yamamoto
  • 👤 Hideki Kohno

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-11-07 21:30
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/44; G01R33/48; G01R33/4828; G01R33/483; G01R33/485; G01R33/54; G01R33/56; G01R33/565; G01R33/56563

Claims Analysis

Total Claims: 5
Claim 1
Independent Claim 87 words
An NMR imaging method of measuring nuclear spin information of an object to be examined by generating a static magnetic field, field gradients and an RF magnetic field to detect a nuclear magnetic resonance signal from said object and performing an operation (102-107) on the detection signal (Fig. 1E), in which images separated from each other with respect to chemical shifts are obtained by use of only a detection signal acquired through only the measurement of one time for said object by a multi-echo sequence (Fig. 1A-1F).
Claim 2
Dependent Claim 87 words
An NMR imaging method of measuring nuclear spin information of an object to be examined by generating a static magnetic field, field gradients and an RF magnetic field to detect a nuclear magnetic resonance signal from said object and performing an operation (102-107) on the detection signal (Fig. 1E), in which images separated from each other with respect to chemical shifts are obtained by use of only a detection signal acquired through only the measurement of one time for said object by a multi-echo sequence (Fig. 1A-1F).
Claim 3
Dependent Claim 60 words
An NMR imaging method according to Claim 1, wherein the images {equations (3), (15)} separated from each other with respect to chemical shifts are obtained by use of detection signals acquired through the measure­ment (201) of one time for said object by the multi-echo sequence and the measurement (203) of one time for a homogeneous phantom by the same sequence.
Claim 4
Dependent Claim 48 words
An NMR imaging method according to Claim 1, wherein the separated images are obtained by use of only two reconstructed images {equation (3)} which are obtained from a first echo signal and a second echo signal in the measurement of one time by the multi-echo sequency (Fig. 1A-1F).
Claim 5
Dependent Claim 45 words
An NMR imaging method according to Claim 1, wherein in the measurement of one time by the multi-echo sequence a first echo signal and a second echo signal are detected at specified timings which are different from signal measurement timings in the conventional multi-echo sequence.

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