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US5241271A Expired / Lapsed US ⏱️ 0.0 years remaining

Ultra-fast imaging method and apparatus

Assignee: Hitachi Ltd
•
Filing: 1991-08-29
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Granted: 1993-08-31
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Expires: 2011-08-29
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Abstract

Abstract A magnetic resonance imaging apparatus selects a partial region of a slice in a subject with a radio frequency magnetic field and generates echo signals only from the partial region. The echo signals are collected from the subject by using an ultra-high speed data acquisition technique. An image of a partial region is reconstructed from the echo signals.

Inventors

  • 👤 Jun'ichi Taguchi
  • 👤 Koichi Sano
  • 👤 Tetsuo Yokoyama

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-08 17:35
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/44; G01R33/48; G01R33/54; G01R33/56; G01R33/561

Claims Analysis

Total Claims: 14
Claim 1
Independent Claim 159 words
An imaging method for imaging a partial region of a slice in a subject at an ultra-high speed by utilizing magnetic resonance, comprising the steps of: generating an electrostatic magnetic field; generating a first gradient magnetic field; generating a second gradient magnetic field in a direction substantially perpendicular to said first gradient magnetic field; generating a third gradient magnetic field in a direction substantially perpendicular to said first and second gradient magnetic fields; generating a radio frequency magnetic field; selecting the partial region of the slice in the subject by exciting and rotating spins in the subject with the radio frequency magnetic field and at least one of the gradient magnetic fields to re-phase the excited spins in the partial region of the slice and generate echo signals only from the partial region; collecting the echo signals from said subject by using an ultra-high speed data acquisition; and reconstructing the image of the partial region from the echo signals.
Claim 2
Dependent Claim 159 words
An imaging method for imaging a partial region of a slice in a subject at an ultra-high speed by utilizing magnetic resonance, comprising the steps of: generating an electrostatic magnetic field; generating a first gradient magnetic field; generating a second gradient magnetic field in a direction substantially perpendicular to said first gradient magnetic field; generating a third gradient magnetic field in a direction substantially perpendicular to said first and second gradient magnetic fields; generating a radio frequency magnetic field; selecting the partial region of the slice in the subject by exciting and rotating spins in the subject with the radio frequency magnetic field and at least one of the gradient magnetic fields to re-phase the excited spins in the partial region of the slice and generate echo signals only from the partial region; collecting the echo signals from said subject by using an ultra-high speed data acquisition; and reconstructing the image of the partial region from the echo signals.
Claim 3
Dependent Claim 45 words
An imaging method according to claim 1, wherein the size of the partial region to be imaged is varied in accordance with the resolution of said image, the intensity of said gradient magnetic field and a sequence for generating echo signals at an ultra-high speed.
Claim 4
Dependent Claim 25 words
An imaging method according to claim 1, wherein said echo signals are caused by the vibration of at least one of said gradient magnetic fields.
Claim 5
Dependent Claim 26 words
An imaging method according to claim 3, wherein said echo signals are encoded by generating at least one of said gradient magnetic fields in pulse form.
Claim 6
Dependent Claim 55 words
An imaging method according to claim 1, wherein selection of said partial region to be imaged is accomplished by generating a 90° radio frequency magnetic field simultaneously with the generation of said first gradient magnetic field and subsequently generating a 180° radio frequency magnetic field simultaneously with the generation of said second gradient magnetic field.
Claim 7
Dependent Claim 27 words
An imaging method according to claim 1, which further comprises the step of: executing each of said steps repeatedly while changing said partial region to be imaged.
Claim 8
Dependent Claim 14 words
An imaging method according to claim 6, wherein said partial regions are spatially continuous.
Claim 9
Dependent Claim 21 words
An imaging method according to claim 7, wherein the images of said partial regions which are continuous spatially are displayed simultaneously.
Claim 10
Dependent Claim 12 words
An imaging method according to claim 7, wherein said partial regions overlap.
Claim 11
Dependent Claim 51 words
An imaging method according to claim 1, which further comprises at least one of the following steps of: exchanging the direction of each of said gradient magnetic fields; changing the polarity of at least one of the gradient magnetic fields; and applying rotation to the directions of said gradient magnetic fields.
Claim 12
Dependent Claim 171 words
An imaging apparatus for imaging a partial region of a slice in a subject at an ultra-high speed by utilizing magnetic resonance, comprising: means for generating an electrostatic magnetic field; means for generating a first gradient magnetic field; means for generating a second gradient magnetic field in a direction substantially perpendicular to said first gradient magnetic field; means for generating a third gradient magnetic field in a direction substantially perpendicular to said first and second gradient magnetic fields; means for generating a radio frequency magnetic field; means for selecting the partial region of the slice in a subject by exciting and rotating spins in the subject with the radio frequency magnetic field and at least one of the gradient magnetic fields to re-phase the excited spins in the partial region of the slide and generate echo signals only from the partial region; means for collecting the echo from said subject by using an ultra-high speed data acquisition; and means for reconstructing the image of the partial region from the echo signals.
Claim 13
Dependent Claim 171 words
An imaging apparatus for imaging a partial region of a slice in a subject at an ultra-high speed by utilizing magnetic resonance, comprising: means for generating an electrostatic magnetic field; means for generating a first gradient magnetic field; means for generating a second gradient magnetic field in a direction substantially perpendicular to said first gradient magnetic field; means for generating a third gradient magnetic field in a direction substantially perpendicular to said first and second gradient magnetic fields; means for generating a radio frequency magnetic field; means for selecting the partial region of the slice in a subject by exciting and rotating spins in the subject with the radio frequency magnetic field and at least one of the gradient magnetic fields to re-phase the excited spins in the partial region of the slide and generate echo signals only from the partial region; means for collecting the echo from said subject by using an ultra-high speed data acquisition; and means for reconstructing the image of the partial region from the echo signals.
Claim 14
Dependent Claim 21 words
An imaging apparatus according to claim 11, wherein at least one of the three of said gradient magnetic fields is vibrating.

References Cited (Backward Citations)

US4859946A Cited
US4999581A Cited
US4916395A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1996-08-30 1997-03-01 1997-08-31 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2000-08-30 2001-03-01 2001-08-31 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2004-08-30 2005-03-01 2005-08-31 $7700.00 Window Closed / Lapsed

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